Micro-speaker and wearable device

Abstract

The utility model discloses a kind of miniature loudspeaker and wearable device, it is related to loudspeaker technical field, miniature loudspeaker includes positioning column, magnetic circuit structure, voice coil, positioning support and diaphragm, positioning column is hollow annular structure, magnetic circuit structure is located at the outer periphery of positioning column and is formed with annular gap, positioning support is connected in magnetic circuit structure, the inner and outer ends of diaphragm radial are connected with positioning column and positioning support respectively, voice coil is connected in diaphragm, and one end portion of voice coil back to diaphragm is inserted into annular gap.

Description

Technical Field

[0001] This utility model relates to the field of loudspeaker technology, and in particular to a miniature loudspeaker and a wearable device. Background Technology

[0002] A loudspeaker is an electroacoustic transducer that converts electrical signals into sound waves, and it is the core sound-generating unit in wearable electronic devices such as headphones. It converts the alternating current signal output by the electronic device into air vibrations that can be perceived by the human ear. As electronic devices become increasingly thinner and smaller, loudspeakers used in these devices naturally require miniaturized designs.

[0003] The magnetic gap width of miniature loudspeakers is only 0.2-0.3mm, making it difficult to dissipate the heat generated when the voice coil is working. When the input power is ≥10mW and the operation is continuous for 30 minutes, the temperature inside the magnetic gap can rise to over 55℃ (ambient temperature 25℃), which can easily cause the neodymium iron boron magnet to demagnetize, increase the voice coil resistance, and cause sound distortion. Utility Model Content

[0004] The main purpose of this invention is to propose a miniature speaker and wearable device, which aims to improve the heat dissipation effect of the miniature speaker.

[0005] To achieve the above objectives, the present invention proposes a miniature loudspeaker comprising a positioning post, a magnetic circuit structure, a voice coil, a positioning bracket, and a diaphragm. The positioning post has a hollow annular structure. The magnetic circuit structure is disposed on the outer periphery of the positioning post and forms an annular gap. The positioning bracket is connected to the magnetic circuit structure. The inner and outer ends of the diaphragm are respectively connected to the positioning post and the positioning bracket. The voice coil is connected to the diaphragm, and the end of the voice coil facing away from the diaphragm extends into the annular gap. Attached Figure Description

[0006] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0007] Figure 1 A schematic diagram of the structure of an embodiment of the miniature loudspeaker provided by this utility model;

[0008] Figure 2 for Figure 1 A structural schematic diagram of a miniature loudspeaker from another perspective;

[0009] Figure 3 for Figure 1A cross-sectional view of a miniature loudspeaker;

[0010] Figure 4 for Figure 1 A schematic diagram of the internal structure of a miniature loudspeaker.

[0011] Explanation of icon numbers:

[0012] 100. Miniature loudspeaker; 1. Positioning post; 11. Post; 12. Limiting part; 2. Magnetic circuit structure; 21. Magnetic guide plate; 21a. Through hole; 22. Inner ring magnet; 23. Outer ring magnet; 24. Washer; 3. Voice coil; 4. Positioning bracket; 41. Connecting ring; 42. Positioning part; 5. Diaphragm; 51. Inner ring part; 52. First annular protrusion; 53. Connecting part; 54. Second annular protrusion; 55. Outer ring part.

[0013] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0015] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0016] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0017] A loudspeaker is an electroacoustic transducer that converts electrical signals into sound waves, and it is the core sound-generating unit in wearable electronic devices such as headphones. It converts the alternating current signal output by the electronic device into air vibrations that can be perceived by the human ear. As electronic devices become increasingly thinner and smaller, loudspeakers used in these devices naturally require miniaturized designs.

[0018] The magnetic gap width of miniature loudspeakers is only 0.2-0.3mm, making it difficult to dissipate the heat generated when the voice coil is working. When the input power is ≥10mW and the operation is continuous for 30 minutes, the temperature inside the magnetic gap can rise to over 55℃ (ambient temperature 25℃), which can easily cause the neodymium iron boron magnet to demagnetize, increase the voice coil resistance, and cause sound distortion.

[0019] To solve the above problems, please refer to... Figures 1 to 4 This utility model proposes a miniature loudspeaker 100, including a positioning post 1, a magnetic circuit structure 2, a voice coil 3, a positioning bracket 4, and a diaphragm 5. The positioning post 1 has a hollow annular structure. The magnetic circuit structure 2 is located on the outer periphery of the positioning post 1 and forms an annular gap. The positioning bracket 4 is connected to the magnetic circuit structure 2. The inner and outer ends of the diaphragm 5 are respectively connected to the positioning post 1 and the positioning bracket 4. The voice coil 3 is connected to the diaphragm 5, and the end of the voice coil 3 facing away from the diaphragm 5 extends into the annular gap.

[0020] This utility model proposes a miniature speaker 100, primarily for use in portable electronic devices such as smartwatches and Bluetooth headsets, where size and acoustic performance are critical. Its core function is to convert electrical signals into sound waves to play sound. The miniature speaker 100 includes a positioning post 1, a magnetic circuit structure 2, a voice coil 3, a positioning bracket 4, and a diaphragm 5. These components form a complete acoustic system through specific assembly relationships. The positioning post 1 adopts a hollow annular structure design, typically made of aluminum alloy or other metal materials, ensuring structural rigidity while reducing overall weight. The hollow structure not only saves materials but also facilitates airflow along the axial direction of the miniature speaker 100, thereby improving heat dissipation and preventing sound distortion caused by rapid temperature increases during continuous operation. Furthermore, the hollow structure provides a sound wave conduction channel within the miniature speaker 100 and facilitates the arrangement of internal wires. The hollow structural design reduces the weight of the miniature speaker 100, meeting the lightweight design requirements of headphones and particularly contributing to improved user comfort when wearing in-ear headphones. Furthermore, the hollow, interconnected design of the miniature speaker 100 creates air convection channels at both ends of the axial direction, helping to maintain a balance between the pressure inside the middle ear cavity and the external atmospheric pressure when the user wears in-ear headphones. This ensures relative balance between the inner and outer ear pressures, preventing discomfort and improving the user experience. The magnetic circuit structure 2 is installed on the outer periphery of the positioning post 1, forming an annular gap through precision assembly. This gap is the area where magnetic field energy is concentrated, and its width and roundness directly affect the uniformity of the magnetic field. The voice coil 3 is made of enameled copper wire and is cylindrical. One end is fixed to the diaphragm 5 by glue or welding, and the other end is inserted into the annular gap. The insertion depth is precisely calculated to ensure it is in the area with the strongest magnetic field. The positioning bracket 4 is made of a rigid material, such as ABS plastic, and is connected to the magnetic circuit structure 2 by clips or screws, serving to fix the overall structure and support the edge of the diaphragm 5. The diaphragm 5 is made of a lightweight, highly elastic material, such as polyimide film or composite fiber material. Its inner edge is connected to the positioning post 1, its outer edge is fixed to the positioning bracket 4, and its middle area is connected to the voice coil 3. When an electrical signal is applied to the voice coil 3, the voice coil 3 experiences an axial vibration due to the Ampere force within the magnetic field of the annular gap. This vibration, in turn, causes the diaphragm 5 to vibrate synchronously. The vibration of the diaphragm 5 pushes the surrounding air to form compression and rarefaction waves, which are ultimately converted into audible sound waves. This achieves miniaturization of the loudspeaker while ensuring the sensitivity and sound quality performance of the miniature loudspeaker 100.

[0021] Furthermore, in one embodiment, the magnetic circuit structure 2 includes a magnetic guide plate 21, an inner ring magnet 22, an outer ring magnet 23, and a washer 24. The inner ring magnet 22 and the outer ring magnet 23 are connected to the side of the magnetic guide plate 21 facing the diaphragm 5. The outer ring magnet 23 is spaced apart outside the inner ring magnet 22. The washer 24 is connected to the side of the inner ring magnet 22 and the outer ring magnet 23 facing away from the magnetic guide plate 21.

[0022] The magnetic guide plate 21 is made of a soft magnetic material with high permeability, such as cold-rolled steel plate. Its shape matches the overall size of the miniature speaker 100. As the bottom magnetic guiding element of the magnetic circuit, the magnetic guide plate 21 can effectively concentrate the magnetic field and reduce magnetic leakage. The inner ring magnet 22 and the outer ring magnet 23 are both permanent magnets, preferably high-performance neodymium iron boron magnets, and are glued to the surface of the magnetic guide plate 21 facing the diaphragm 5. The outer ring magnet 23 is coaxially arranged with the inner ring magnet 22, and the two maintain a fixed distance to form an annular magnetic field gap. The washer 24 is also made of soft magnetic material, and its shape matches the magnets. It covers the ends of the inner ring magnet 22 and the outer ring magnet 23 away from the magnetic guide plate 21, and is fixed to the magnets with glue. The arrangement of the washer 24 can further enhance the magnetic field strength, especially in the annular gap area, making the magnetic field distribution more uniform. The magnetic guide plate 21, inner ring magnet 22, outer ring magnet 23, and washer 24 together form a closed magnetic circuit. The magnetic field starts from the inner ring magnet 22, passes through the washer 24, the annular gap, and the outer ring magnet 23, and returns to the magnetic guide plate 21, forming a complete magnetic loop. This structural design can efficiently concentrate magnetic energy within the annular gap where the voice coil 3 moves, improving the magnetic field utilization rate, thereby enhancing the driving force on the voice coil 3 and improving the electroacoustic conversion efficiency of the loudspeaker.

[0023] In one embodiment, the inner ring magnet 22 and the outer ring magnet 23 are magnetized axially, with opposite magnetic poles at the same end. Axial magnetization means that the magnetization direction is parallel to the central axis of the magnet, achieved through a dedicated magnetization device to ensure that the magnetic field direction inside the magnet is consistent. Specifically, if the end of the inner ring magnet 22 facing the washer 24 is the N pole, then the end of the outer ring magnet 23 facing the washer 24 is the S pole, and vice versa. In practical applications, the inner ring magnet 22 can have either the N pole facing the washer 24 or the S pole facing the washer 24, both ensuring the normal operation of the magnetic circuit structure 2. It is only necessary to ensure that the axial magnetic pole directions of the inner ring magnet 22 and the outer ring magnet 23 are opposite, which can be selected according to actual needs. This magnetic pole configuration creates a radially distributed magnetic field in the annular gap, i.e., the magnetic field direction radiates from the inner ring to the outer ring or from the outer ring to the inner ring. When an alternating current flows through the voice coil 3, according to the left-hand rule, the direction of the current in the voice coil 3 is perpendicular to the direction of the magnetic field in the annular gap, thereby generating an axial driving force. Because the inner ring magnet 22 and the outer ring magnet 23 have opposite poles, the consistency of the magnetic field direction within the annular gap is ensured, making the force on the voice coil 3 uniform and stable throughout its entire vibration stroke, avoiding fluctuations in driving force caused by changes in the magnetic field direction. This design effectively reduces harmonic distortion in the loudspeaker, improves the smoothness of the frequency response curve, and enhances sound fidelity.

[0024] In one embodiment, please refer to Figure 3The positioning post 1 includes a post body 11 and a limiting part 12. The limiting part 12 extends outward along the end of the post body 11. The magnetic plate 21 is connected to the end of the limiting part 12. The inner ring magnet 22 is sleeved on the post body 11 and abuts against the limiting part 12 for limiting.

[0025] The positioning post 1 consists of a post body 11 and a limiting part 12, which can be integrally formed using a metal stamping process to ensure the integrity of the structure and dimensional accuracy. The post body 11 is a hollow cylindrical structure, and its outer diameter matches the inner diameter of the inner ring magnet 22, providing radial positioning for the inner ring magnet 22. The limiting part 12 extends outward along one end edge of the post body 11 to form an annular flange structure, the radial dimension of which is larger than the outer diameter of the post body 11. The center of the magnetic guide plate 21 has a mounting hole that matches the post body 11. During assembly, the post body 11 passes through the mounting hole, and the surface of the magnetic guide plate 21 is attached to the end of the limiting part 12 and fixed by glue or welding to achieve axial positioning of the magnetic guide plate 21. The inner ring magnet 22 is sleeved on the outer periphery of the post body 11, and one end of it abuts against the other side surface of the limiting part 12, thereby limiting the axial displacement of the inner ring magnet 22. This structural design allows the positioning post 1 to simultaneously position both the inner ring magnet 22 and the magnetic guide plate 21, reducing the need for independent positioning parts 42 and simplifying the assembly process. Simultaneously, the rigid support of the limiting part 12 ensures the stability of the relative position between the inner ring magnet 22 and the magnetic guide plate 21, preventing displacement under vibration or impact conditions, thereby guaranteeing the stability of the magnetic circuit structure 2 and the consistency of the magnetic field distribution. Furthermore, please refer to... Figure 2 A through hole 21a is provided on the magnetic conductive plate 21. The through hole 21a penetrates the thickness direction of the magnetic conductive plate 21, connecting the outside world and the inner cavity of the miniature speaker 100. This serves two purposes: firstly, to balance the air pressure inside and outside the miniature speaker 100, facilitating the vibration of the diaphragm 5; and secondly, to facilitate gas exchange inside and outside the miniature speaker 100, improving its heat dissipation. In this embodiment, the through hole 21a is an arc-shaped hole symmetrically arranged radially along the magnetic conductive plate 21. In other embodiments, the shape and number of through holes 21a can be selected according to actual needs.

[0026] In another embodiment, please refer to Figure 1 and Figure 3 The diaphragm 5 is provided with an inner ring portion 51, a first annular protrusion 52, a connecting portion 53, a second annular protrusion 54 and an outer ring portion 55 in a radial direction from the inside to the outside. The inner ring portion 51 is connected to the positioning post 1, the outer ring portion 55 is connected to the positioning bracket 4, and the connecting portion 53 is connected to the voice coil 3. The first annular protrusion 52 corresponds to the inner ring magnet 22, and the second annular protrusion 54 corresponds to the outer ring magnet 23.

[0027] The diaphragm 5 is arranged radially from the inside to the outside as follows: an inner ring portion 51, a first annular protrusion 52, a connecting portion 53, a second annular protrusion 54, and an outer ring portion 55. These structures can be manufactured using an integral molding process, such as thermoforming or injection molding, to ensure the overall structural integrity and mechanical properties of the diaphragm 5. The inner ring portion 51 is an annular structure, and its inner diameter matches the inner diameter of the positioning post 1. It is fixedly connected to the end of the positioning post 1 with glue, forming the inner fixed boundary of the diaphragm 5. The outer ring portion 55 is also an annular structure, which mates with the connecting portion 53 of the positioning bracket 4 and is fixed by glue or snap-fit, forming the outer fixed boundary of the diaphragm 5. The connecting portion 53 is located in the middle area of ​​the diaphragm 5, and its surface is connected to the end of the voice coil 3 with glue, transmitting the vibration of the voice coil 3 to the entire diaphragm 5. The first annular protrusion 52 is located between the inner ring portion 51 and the connecting portion 53, corresponding to the inner ring magnet 22; the second annular protrusion 54 is located between the connecting portion 53 and the outer ring portion 55, corresponding to the outer ring magnet 23. The annular protrusion structure increases the rigidity of the diaphragm 5 while providing a certain amount of elastic deformation space, allowing the diaphragm 5 to generate a larger amplitude during vibration. The positional design corresponding to the magnet optimizes the vibration modes of the diaphragm 5 during vibration, reducing the generation of segmented vibrations. This structural design effectively expands the frequency response range of the miniature speaker 100, especially in the low-frequency range, producing richer sound details and improving overall sound quality.

[0028] In one embodiment, the first annular protrusion 52 and the second annular protrusion 54 are dome structures that protrude outward from the magnetic circuit structure 2.

[0029] The first annular protrusion 52 and the second annular protrusion 54 adopt a dome structure design that protrudes outward from the magnetic circuit structure 2, meaning the protrusion direction faces away from the magnetic circuit structure 2. The radius of curvature of the dome structure is optimized through acoustic simulation and is usually determined based on the material properties and dimensions of the diaphragm 5 to ensure optimal vibration performance. The dome structure can maintain the consistency of overall motion during vibration, reducing acoustic distortion caused by inconsistent local vibration. The design of the protrusion facing away from the magnetic circuit structure 2 increases the spatial distance between the diaphragm 5 and the magnetic circuit structure 2, providing ample space for the diaphragm 5 to vibrate and avoiding collisions with the magnet during large-amplitude vibrations. At the same time, the dome structure can change the equivalent stiffness of the diaphragm 5, enabling the diaphragm 5 to have a faster response speed in the high-frequency range and generate a larger amplitude in the low-frequency range, thereby achieving a wider frequency response range. This is beneficial for improving the sensitivity of the miniature loudspeaker 100 in the high-frequency region, making the sound clearer and more natural.

[0030] In one embodiment, the annular gap is filled with a magnetic fluid, the volume of which accounts for 10% to 15% of the annular gap volume. The selected magnetic fluid is a colloidal solution of ferromagnetic nanoparticles dispersed in a carrier liquid, possessing good magnetic responsiveness and fluidity. Its saturation magnetization and viscosity are selected to meet the operating requirements of the miniature loudspeaker 100. The magnetic fluid is filled into the annular gap using a precision dispensing process. Under the influence of a magnetic field, the magnetic fluid is adsorbed within the annular gap, forming a stable liquid film. The filled magnetic fluid can generate viscous damping force when the voice coil 3 vibrates, suppressing the resonance peak of the voice coil 3 and reducing the distortion of the miniature loudspeaker 100. At the same time, the magnetic fluid has good thermal conductivity, which can transfer the heat generated by the voice coil 3 during operation to the magnetic circuit structure 2, and then dissipate it through the outer shell, effectively reducing the temperature of the voice coil 3 and improving the power handling capacity of the loudspeaker. When the volume of the magnetic fluid accounts for 10% to 15% of the annular gap volume, it can provide sufficient damping effect and heat dissipation capacity without increasing the movement resistance of the voice coil 3 due to excessive magnetic fluid, ensuring that the sensitivity of the loudspeaker is not affected. Suitable for high-power operating scenarios, it can improve the reliability and service life of the miniature speaker 100.

[0031] In one embodiment, a limiting step is formed at one end of the positioning bracket 4 near the diaphragm 5, and the outer ring portion 55 is engaged with the limiting step.

[0032] A limiting step is machined at one end of the positioning bracket 4 near the diaphragm 5. This limiting step consists of a horizontal platform and a vertical sidewall, the dimensions of which match the thickness and width of the outer ring 55 of the diaphragm 5. The outer ring 55 of the diaphragm 5 is fitted within the limiting step, meaning the lower surface of the outer ring 55 is in contact with the horizontal platform of the limiting step, and its side surface contacts the vertical sidewall. The connection is achieved by adhesive. The limiting step provides a precise axial and radial positioning reference for the diaphragm 5, ensuring consistent positioning during assembly and reducing performance differences caused by assembly errors. The horizontal platform evenly supports the outer ring 55 of the diaphragm 5, ensuring uniform force distribution at the edges and preventing localized deformation during vibration. The vertical sidewall restricts radial displacement of the diaphragm 5, preventing it from shifting during large-amplitude vibrations and avoiding interference with other components. This structural design improves the accuracy and stability of the diaphragm 5 assembly, ensuring the consistency and reliability of the miniature loudspeaker 100, while simplifying the assembly process and increasing production efficiency.

[0033] In one embodiment, please refer to Figure 3 and Figure 4 The positioning bracket 4 includes a connecting ring 41 and a positioning part 42. The positioning part 42 is connected to the inner peripheral wall of the connecting ring 41, and a limiting step is provided on the connecting ring 41.

[0034] The positioning bracket 4 consists of a connecting ring 41 and a positioning part 42, both manufactured using an integral injection molding process. The material is high-strength engineering plastic to ensure sufficient structural strength. The connecting ring 41 has a circular structure, with a limiting step located on the inner side of the end of the connecting ring 41 near the diaphragm 5, used to mount the outer ring 55 of the diaphragm 5. The positioning part 42 is a raised structure evenly distributed along the inner circumferential wall of the connecting ring 41. In this embodiment, there are two positioning parts 42, symmetrically arranged on opposite sides of the connecting ring 41. In other embodiments, the number of positioning parts 42 can be selected according to actual needs. The end face of the positioning part 42 is connected to the washer 24 in the magnetic circuit structure 2 with adhesive. The even distribution of the positioning parts 42 ensures a more balanced force on the magnetic circuit structure 2, preventing deformation of the positioning bracket 4 due to uneven force and ensuring the stability of the overall structure. The combined design of the connecting ring 41 and the positioning part 42 enables the positioning bracket 4 to simultaneously achieve the dual functions of fixing the diaphragm 5 and the magnetic circuit structure 2, simplifying the overall structure of the miniature speaker 100, reducing the number of parts, which is conducive to miniaturization design, and improving assembly efficiency and structural reliability.

[0035] This utility model also proposes a wearable device, which includes a miniature speaker 100. The specific structure of the miniature speaker 100 is as described in the above embodiments. Since this wearable device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here. Wearable devices include smartwatches, Bluetooth headsets, smart bracelets, smart glasses, etc. These devices are characterized by small size and light weight, while needing to have good audio playback and call functions. The compact structure of the miniature speaker 100 can adapt to the limited internal space of the wearable device, and its lightweight design helps to reduce the overall weight of the device and improve the user's wearing experience. The wide frequency response characteristics of the miniature speaker 100 can meet the audio needs of the wearable device in different scenarios, such as music playback, voice calls, and voice assistant interaction, ensuring that the sound is clear and distinguishable. Its good heat dissipation performance and reliability ensure stable operation during long-term wear and use, adapting to different ambient temperatures and usage conditions. By integrating the miniature speaker 100, the wearable device can provide high-quality audio output, enhance the user's interactive experience, expand the functional application range of the device, and meet the diverse needs of consumers for wearable devices.

[0036] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A miniature loudspeaker, characterized in that, The miniature loudspeaker includes a positioning post, a magnetic circuit structure, a voice coil, a positioning bracket, and a diaphragm. The positioning post has a hollow annular structure. The magnetic circuit structure is located on the outer periphery of the positioning post and forms an annular gap. The positioning bracket is connected to the magnetic circuit structure. The inner and outer ends of the diaphragm are respectively connected to the positioning post and the positioning bracket. The voice coil is connected to the diaphragm, and the end of the voice coil facing away from the diaphragm extends into the annular gap.

2. The miniature loudspeaker as described in claim 1, characterized in that, The magnetic circuit structure includes a magnetic guide plate, an inner ring magnet, an outer ring magnet, and a washer. The inner ring magnet and the outer ring magnet are connected to the side of the magnetic guide plate facing the diaphragm. The outer ring magnet is spaced apart outside the inner ring magnet. The washer is connected to the side of the inner ring magnet and the outer ring magnet facing away from the magnetic guide plate.

3. The miniature loudspeaker as described in claim 2, characterized in that, The inner ring magnet and the outer ring magnet are magnetized along the axial direction, and the magnetic poles of the inner ring magnet and the outer ring magnet at the same end are opposite.

4. The miniature loudspeaker as described in claim 2, characterized in that, The positioning post includes a post body and a limiting part. The limiting part extends outward along the end of the post body. The magnetic plate is connected to the end of the limiting part. The inner ring magnet is sleeved on the post body and abuts against the limiting part for limiting.

5. The miniature loudspeaker as described in any one of claims 2 to 4, characterized in that, The diaphragm is provided with an inner ring portion, a first annular protrusion, a connecting portion, a second annular protrusion, and an outer ring portion in a radial direction from the inside to the outside. The inner ring portion is connected to the positioning post, the outer ring portion is connected to the positioning bracket, and the connecting portion is connected to the voice coil. The first annular protrusion corresponds to the inner ring magnet, and the second annular protrusion corresponds to the outer ring magnet.

6. The miniature loudspeaker as described in claim 5, characterized in that, The first annular protrusion and the second annular protrusion are dome structures that bulge outwards from the magnetic circuit structure.

7. The miniature loudspeaker as described in claim 5, characterized in that, The annular gap is filled with magnetic fluid, and the volume of the magnetic fluid accounts for 10% to 15% of the volume of the annular gap.

8. The miniature loudspeaker as described in claim 5, characterized in that, The positioning bracket has a limiting step at one end near the diaphragm, and the outer ring is engaged with the limiting step.

9. The miniature loudspeaker as described in claim 8, characterized in that, The positioning bracket includes a connecting ring and a positioning part, the positioning part being connected to the inner peripheral wall of the connecting ring, and the limiting step being provided on the connecting ring.

10. A wearable device, characterized in that, Includes a miniature loudspeaker as described in any one of claims 1 to 9.

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