Bone conduction speaker and magnetic circuit assembly thereof

Abstract

The present application mainly relates to a bone conduction speaker and a magnetic circuit assembly thereof, wherein the magnetic circuit assembly generates a first total magnetic field, and the magnetic circuit assembly comprises: a first magnetic element; a first magnetic conductive element, wherein the lower surface of the first magnetic conductive element is connected to the upper surface of the first magnetic element; a third magnetic element, wherein the third magnetic element surrounds the first magnetic element and forms a magnetic gap with the first magnetic element, wherein the magnetic gap is used to accommodate the voice coil of the bone conduction speaker; wherein, in the spacing direction between the upper surface and the lower surface of the first magnetic element, the lower surface of the third magnetic element is between the upper surface and the lower surface of the first magnetic element, and the upper surface of the third magnetic element is located on the side of the upper surface of the first magnetic conductive element away from the lower surface, and the angle between the magnetization direction of the third magnetic element and the magnetization direction of the first magnetic element is between 45 degrees and 135 degrees. The magnetic circuit assembly provided by the present application can increase the magnetic field strength of the first total magnetic field at the magnetic gap.

Description

[0001] This application is a divisional application of the Chinese patent application filed with the China Patent Office on September 11, 2018, with application number 201811056052.5 and invention name “A bone conduction speaker”.

[0002] The parent application claims priority to Chinese application No. 201810015581.4 filed on January 8, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to a bone conduction speaker, and in particular to a magnetic circuit component in the bone conduction speaker. Background Art

[0004] Bone conduction speakers can convert electrical signals into mechanical vibration signals, and transmit the vibration signals into the cochlea through human tissue and bones, so that the user can hear the sound. Compared with air conduction speakers that use the diaphragm to drive the air to vibrate to produce sound, bone conduction vibration speakers need to drive the user's soft tissue and bones to vibrate, so the mechanical power required is higher. Improving the sensitivity of bone conduction speakers can make the conversion of electrical energy into mechanical energy more efficient, thereby outputting greater mechanical power. Improving sensitivity is even more important for bone conduction speakers with higher power requirements. Summary of the invention

[0005] An embodiment of the present application provides a magnetic circuit component of a bone conduction speaker, the magnetic circuit component generates a first total magnetic field, and the magnetic circuit component includes: a first magnetic element; a first magnetic conductive element, the lower surface of the first magnetic conductive element is connected to the upper surface of the first magnetic element; a third magnetic element, the third magnetic element surrounds the first magnetic element and forms a magnetic gap with the first magnetic element, and the magnetic gap is used to accommodate the voice coil of the bone conduction speaker; wherein, in the spacing direction of the upper surface and the lower surface of the first magnetic element, the lower surface of the third magnetic element is between the upper surface and the lower surface of the first magnetic element, and the upper surface of the third magnetic element is located on the side of the upper surface of the first magnetic conductive element away from the lower surface, and the angle between the magnetization direction of the third magnetic element and the magnetization direction of the first magnetic element is between 45 degrees and 135 degrees.

[0006] The present application also provides a bone conduction speaker, which includes: a vibration component, the vibration component includes a voice coil and at least one vibration plate; and the magnetic circuit component described in the above embodiment.

[0007] The beneficial effect of the present application is that the magnetic circuit assembly provided by the present application can increase the magnetic field strength of the first full magnetic field at the magnetic gap.

[0008] Some additional features of the present application may be described in the following description. Some additional features of the present application will be apparent to those skilled in the art by inspection of the following description and the corresponding drawings or by understanding the production or operation of the embodiments. The features disclosed in the present application may be realized and achieved by practice or use of various methods, means and combinations of the specific embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The exemplary embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation of the present application. In each figure, the same reference numeral represents the same component.

[0010] Figure 1 is a structural module diagram of a bone conduction speaker according to some embodiments of the present application;

[0011] Figure 2 is a schematic longitudinal section diagram of a bone conduction speaker according to some embodiments of the present application;

[0012] Figure 3A is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0013] Figure 3B is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0014] Figure 3C is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0015] Figure 3D is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0016] Figure 3E is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0017] Figure 3F is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0018] Figure 3G is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0019] Figure 4A is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0020] Figure 4Bis a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0021] Figure 4C is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0022] Figure 4D is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0023] Figure 4E is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0024] Figure 4F is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0025] Figure 4G is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0026] Figure 4H is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0027] Fig. 4I is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0028] Figure 5A is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0029] Figure 5B is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0030] Figure 5C is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0031] Figure 5D is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0032] Figure 5E is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0033] Fig. 5F is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0034] Fig. 6A is a schematic cross-sectional view of a magnetic element according to some embodiments of the present application;

[0035] Figure 6B is a schematic diagram of a magnetic element according to some embodiments of the present application;

[0036] Figure 6C is a schematic diagram of the magnetization direction of a magnetic element in a magnetic circuit assembly according to some embodiments of the present application;

[0037] Fig.6D is a magnetic induction line distribution diagram of a magnetic element in a magnetic assembly according to some embodiments of the present application;

[0038] Fig. 7A is a structural schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0039] Figure 7B-7E The driving force coefficient at the voice coil shown in some embodiments of the present application is Fig. 7A The relationship curve of magnetic circuit component parameters shown;

[0040] Fig. 8A is a structural schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0041] Figures 8B-8E The driving force coefficient at the voice coil shown in some embodiments of the present application is Fig. 8A The relationship curve of magnetic circuit component parameters shown;

[0042] Fig.9A is a schematic diagram of magnetic flux distribution of a magnetic circuit component according to some embodiments of the present application;

[0043] Fig. 9B The magnetic induction intensity at the voice coil and the Fig.9A The relationship curve of the thickness of each component in the magnetic circuit assembly shown;

[0044] Fig. 10A is a schematic diagram of magnetic flux distribution of a magnetic circuit component according to some embodiments of the present application;

[0045] Fig. 10B The magnetic induction intensity at the voice coil and the Fig. 10A The relationship curve of the thickness of each component in the magnetic circuit assembly shown;

[0046] Fig.11A is a schematic diagram of magnetic flux distribution of a magnetic circuit component according to some embodiments of the present application;

[0047] Fig. 11B According to some embodiments of the present application Fig.9A , Fig. 10A and Fig.11A The relationship curve between the magnetic induction intensity of the middle magnetic circuit component and the thickness of the magnetic element;

[0048] Fig. 11C The magnetic induction intensity at the voice coil and the Fig.11A The relationship curve of the thickness of each component in the magnetic circuit assembly shown;

[0049] Fig. 12A is a structural schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0050] Fig. 12B The inductance and reactance of the voice coil shown in some embodiments of the present application are Fig. 12A The relationship curve of the conductive elements in the magnetic circuit assembly shown;

[0051] Fig.13A is a structural schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0052] Fig. 13B The inductance and reactance of the voice coil shown in some embodiments of the present application are Fig.13A The relationship curve of the conductive elements in the magnetic circuit assembly shown;

[0053] Fig.14A is a structural schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0054] Fig. 14B The inductance and reactance of the voice coil shown in some embodiments of the present application are Fig.14A The relationship curve of the number of conductive elements in the magnetic circuit assembly shown;

[0055] Fig.15A is a structural schematic diagram of a magnetic circuit assembly according to some embodiments of the present application;

[0056] Fig. 15B The Ampere force on the voice coil and the Fig.15A The relationship curve of the thickness of each component in the magnetic circuit assembly shown;

[0057] Fig.16 is a structural schematic diagram of a bone conduction speaker according to some embodiments of the present application;

[0058] Fig.17 is a structural schematic diagram of a bone conduction speaker according to some embodiments of the present application;

[0059] Fig.18 is a schematic structural diagram of a bone conduction speaker according to some embodiments of the present application; and

[0060] Fig.19 It is a schematic diagram of the structure of a bone conduction speaker according to some embodiments of the present application. DETAILED DESCRIPTION

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without paying creative work. It should be understood that these exemplary embodiments are given only to enable technicians in related fields to better understand and implement the present invention, and do not limit the scope of the present invention in any way. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0062] As shown in the present application and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not specifically refer to the singular and may also include the plural, unless the context clearly indicates an exception. Generally speaking, the terms "include" and "comprise" only indicate that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment". The relevant definitions of other terms will be given in the following description. Below, without loss of generality, when describing the bone conduction related technology in the present invention, the description of "bone conduction speaker" or "bone conduction earphone" will be used. This description is only a form of bone conduction application. For ordinary technicians in this field, "speaker" or "earphone" can also be replaced by other similar words, such as "player", "hearing aid", etc. In fact, the various implementations of the present invention can be easily applied to other non-speaker hearing devices. For example, for professionals in this field, after understanding the basic principle of bone conduction speakers, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing bone conduction speakers without deviating from this principle. In particular, the functions of picking up and processing ambient sound are added to the bone conduction speakers to enable the speakers to realize the functions of hearing aids. For example, microphones and other sound sources can pick up the sounds of the user / wearer's surrounding environment, and under a certain algorithm, the processed sounds (or the generated electrical signals) are transmitted to the bone conduction speaker part. That is, the bone conduction speaker can be modified to add the function of picking up ambient sound, and after certain signal processing, the sound is transmitted to the user / wearer through the bone conduction speaker part, thereby realizing the functions of bone conduction hearing aids. As an example, the algorithms mentioned here can include one or more combinations of noise elimination, automatic gain control, acoustic feedback suppression, wide dynamic range compression, active environmental recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, etc.

[0063] The present application provides a high-sensitivity bone conduction speaker. In some embodiments, the bone conduction speaker may include a magnetic circuit assembly. The magnetic circuit assembly may generate a first total magnetic field. The magnetic circuit assembly may include a first magnetic element, a first magnetic conductive element, a second magnetic conductive element, and one or more second magnetic elements. The first magnetic element may generate a second magnetic field, and the one or more second magnetic elements surround the first magnetic element and form a magnetic gap with the first magnetic element, and the magnetic field strength of the first total magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. The arrangement of multiple second magnetic elements in the magnetic circuit assembly surrounding the first magnetic element can reduce the volume and weight of the magnetic circuit assembly, improve the efficiency of the bone conduction speaker, and increase the service life of the bone conduction speaker while increasing the magnetic field strength of the magnetic gap and the sensitivity of the bone conduction speaker.

[0064] The bone conduction speaker has the characteristics of small size, light weight, high efficiency, high sensitivity and long service life, which makes it easy to combine the bone conduction speaker with wearable smart devices, so as to realize the multifunctionality of a single device and improve and optimize the user experience. The wearable smart devices include but are not limited to smart headphones, smart glasses, smart headbands, smart helmets, smart watches, smart gloves, smart shoes, smart cameras, smart video cameras, etc. The bone conduction speaker can be further combined with smart materials to integrate the bone conduction speaker into the manufacturing materials of the user's clothes, gloves, hats, shoes, etc. The bone conduction speaker can also be further implanted in the human body to cooperate with the human body implanted chip or external processor to realize more personalized functions.

[0065] Figure 1 1 is a structural module diagram of a bone conduction speaker 100 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 100 may include a magnetic circuit component 102, a vibration component 104, a support component 106 and a storage component 108.

[0066] The magnetic circuit component 102 can provide a magnetic field. The magnetic field can be used to convert a signal containing sound information into a vibration signal. In some embodiments, the sound information may include a video or audio file in a specific data format or data or files that can be converted into sound through a specific path. The signal containing sound information may come from the storage component 108 of the bone conduction speaker 100 itself, or from an information generation, storage or transmission system outside the bone conduction speaker 100. The signal containing sound information may include a combination of one or more electrical signals, optical signals, magnetic signals, mechanical signals, etc. The signal containing sound information may come from one signal source or multiple signal sources. The multiple signal sources may be related or unrelated. In some embodiments, the bone conduction speaker 100 may obtain the signal containing sound information in a variety of different ways, and the acquisition of the signal may be wired or wireless, and may be real-time or delayed. For example, the bone conduction speaker 100 may receive an electrical signal containing sound information in a wired or wireless manner, or may directly obtain data from a storage medium (e.g., the storage component 108) to generate a sound signal. For another example, a bone conduction hearing aid may include a component with a sound collection function, which converts the mechanical vibration of the sound into an electrical signal by picking up the sound in the environment, and obtains the electrical signal that meets specific requirements after being processed by an amplifier. In some embodiments, the wired connection may include a metal cable, an optical cable, or a hybrid cable of metal and optical, such as a coaxial cable, a communication cable, a flexible cable, a spiral cable, a non-metallic sheathed cable, a metal sheathed cable, a multi-core cable, a twisted pair cable, a ribbon cable, a shielded cable, a telecommunication cable, a two-strand cable, a parallel two-core conductor, a twisted pair, or a combination of one or more thereof. The examples described above are for convenience of explanation only, and the medium of the wired connection may also be other types, such as a transmission carrier of other electrical signals or optical signals.

[0067] Wireless connection may include radio communication, free space optical communication, acoustic communication, and electromagnetic induction, etc. Radio communication may include IEEE1002.11 series standards, IEEE1002.15 series standards (such as Bluetooth technology and ZigBee technology, etc.), first generation mobile communication technology, second generation mobile communication technology (such as FDMA, TDMA, SDMA, CDMA, and SSMA, etc.), general packet radio service technology, third generation mobile communication technology (such as CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth generation mobile communication technology (such as TD-LTE and FDD-LTE, etc.), satellite communication (such as GPS technology, etc.), near field communication (NFC) and other technologies running in ISM frequency bands (such as 2.4GHz, etc.); free space optical communication may include visible light, infrared signals, etc.; acoustic communication may include sound waves, ultrasonic signals, etc.; electromagnetic induction may include near field communication technology, etc. The examples described above are only for the convenience of explanation, and the medium of wireless connection may also be other types, such as Z-wave technology, other paid civil radio frequency bands and military radio frequency bands, etc. For example, as some application scenarios of the present technology, the bone conduction speaker 100 can obtain signals containing sound information from other devices through Bluetooth technology.

[0068] The vibration component 104 can generate mechanical vibration. The generation of the vibration is accompanied by energy conversion. The bone conduction speaker 100 can use a specific magnetic circuit component 102 and a vibration component 104 to realize the conversion of a signal containing sound information into mechanical vibration. The conversion process may include the coexistence and conversion of multiple different types of energy. For example, an electrical signal can be directly converted into mechanical vibration through a transducer to generate sound. For another example, sound information can be contained in an optical signal, and a specific transducer can realize the process of converting an optical signal into a vibration signal. Other types of energy that can coexist and convert during the operation of the transducer include thermal energy, magnetic field energy, etc. The energy conversion method of the transducer may include moving coil, electrostatic, piezoelectric, moving iron, pneumatic, electromagnetic, etc. The frequency response range and sound quality of the bone conduction speaker 100 will be affected by the vibration component 104. For example, in a dynamic coil transducer device, the vibration component 104 includes a wound cylindrical coil and a vibrating body (for example, a vibrating plate). The cylindrical coil driven by the signal current drives the vibrating body to vibrate and produce sound in the magnetic field. The extension and contraction of the vibrating body material, the deformation, size, shape and fixing method of the folds, the magnetic density of the permanent magnet, etc., will have a great impact on the sound quality of the bone conduction speaker 100. The vibrating body in the vibration component 104 can be a mirror-symmetrical structure, a centrally symmetrical structure or an asymmetrical structure; the vibrating body can be provided with an intermittent hole-shaped structure to make the vibrating body produce a larger displacement, so that the bone conduction speaker can achieve higher sensitivity and improve the output power of vibration and sound; the vibrating body can be a torus structure, and a plurality of support rods radiating to the center are provided in the torus, and the number of the support rods can be two or more.

[0069] The support assembly 106 can support the magnetic circuit assembly 102, the vibration assembly 104 and / or the storage assembly 108. The support assembly 106 can include one or more shells and one or more connectors. The one or more shells can form a storage space for accommodating the magnetic circuit assembly 102, the vibration assembly 104 and / or the storage assembly 108. The one or more connectors can connect the shell with the magnetic circuit assembly 102, the vibration assembly 104 and / or the storage assembly 108.

[0070] The storage component 108 can store signals containing sound information. In some embodiments, the storage component 108 may include one or more storage devices. The storage device may include storage devices on storage systems such as direct attached storage, network attached storage, and storage area network. The storage device may include various types of storage devices such as solid-state storage devices (solid-state hard disks, solid-state hybrid hard disks, etc.), mechanical hard disks, USB flash drives, memory sticks, memory cards (such as CF, SD, etc.), other drives (such as CD, DVD, HDDVD, Blu-ray, etc.), random access memory (RAM) and read-only memory (ROM). RAM may include decimal counters, select tubes, delay line memory, Williams tubes, dynamic random access memory (DRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), and zero capacitance random access memory (Z-RAM), etc.; ROM may include bubble memory, magnetic button line memory, thin film memory, magnetic plated line memory, magnetic core memory, magnetic drum memory, optical drive, hard disk, magnetic tape, early NVRAM (non-volatile memory), phase change memory, magnetoresistive random access memory, ferroelectric random access memory, non-volatile SRAM, flash memory, electronically erasable rewritable read-only memory, erasable programmable read-only memory, programmable read-only memory, shielded stack read memory, floating connection gate random access memory, nano random access memory, racetrack memory, variable resistance memory, and programmable metallization unit, etc. The above-mentioned storage devices / storage units are some examples, and the storage devices that can be used by the storage devices / storage units are not limited to these.

[0071] The above description of the structure of the bone conduction speaker is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone conduction speaker, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the bone conduction speaker without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 100 may include one or more processors, and the processor may execute one or more sound signal processing algorithms. The sound signal processing algorithm may modify or enhance the sound signal. For example, the sound signal is subjected to noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, or other similar or any combination of the above processing, and these modifications and changes are still within the scope of protection of the claims of the present invention. For another example, the bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a speed sensor, a displacement sensor, etc. The sensor may collect user information or environmental information.

[0072] Figure 2 FIG. 2 is a schematic longitudinal section diagram of a bone conduction speaker 200 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 200 may include a first magnetic element 202, a first magnetic conductive element 204, a second magnetic conductive element 206, a first vibration plate 208, a voice coil 210, a second vibration plate 212 and a vibration panel 214.

[0073] The magnetic element described in the present application refers to an element that can generate a magnetic field, such as a magnet. The magnetic element may have a magnetization direction, and the magnetization direction refers to the direction of the magnetic field inside the magnetic element. The first magnetic element 202 may include one or more magnets. In some embodiments, the magnet may include a metal alloy magnet, a ferrite, and the like. Among them, the metal alloy magnet may include neodymium iron boron, samarium cobalt, aluminum nickel cobalt, iron chromium cobalt, aluminum iron boron, iron carbon aluminum, or the like, or a combination of multiple thereof. The ferrite may include barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or a combination of multiple thereof.

[0074] The lower surface of the first magnetic conductive element 204 can be connected to the upper surface of the first magnetic element 202. The second magnetic conductive element 206 can be connected to the first magnetic element 202. It should be noted that the magnetic conductive body mentioned here can also be called a magnetic field concentrator or an iron core. The magnetic conductive body can adjust the distribution of the magnetic field (for example, the magnetic field generated by the first magnetic element 202). The magnetic conductive body may include an element processed from a soft magnetic material. In some embodiments, the soft magnetic material may include a metal material, a metal alloy, a metal oxide material, an amorphous metal material, etc., such as iron, an iron-silicon alloy, an iron-aluminum alloy, a nickel-iron alloy, an iron-cobalt alloy, a low-carbon steel, a silicon steel sheet, a silicon steel sheet, a ferrite, etc. In some embodiments, the magnetic conductive body may be processed by one or more combinations of casting, plastic processing, cutting processing, powder metallurgy, etc. Casting may include sand casting, investment casting, pressure casting, centrifugal casting, etc.; plastic processing may include one or more combinations of rolling, casting, forging, stamping, extrusion, drawing, etc.; cutting processing may include turning, milling, planing, grinding, etc. In some embodiments, the processing method of the magnetic conductor may include 3D printing, CNC machine tools, etc. The connection method between the first magnetic conductive element 204, the second magnetic conductive element 206 and the first magnetic element 202 may include one or more combinations of bonding, clamping, welding, riveting, bolting, etc. In some embodiments, the first magnetic element 202, the first magnetic conductive element 204 and the second magnetic conductive element 206 may be set as an axisymmetric structure. The axisymmetric structure may be an annular structure, a columnar structure or other axisymmetric structures.

[0075] In some embodiments, a magnetic gap may be formed between the first magnetic element 202 and the second magnetic conductive element 206. A voice coil 210 may be disposed in the magnetic gap. The voice coil 210 may be connected to the first vibration plate 208. The first vibration plate 208 may be connected to the second vibration plate 212, and the second vibration plate 212 may be connected to the vibration panel 214. When current is passed through the voice coil 210, the voice coil 210 is located in the magnetic field formed by the first magnetic element 202, the first magnetic conductive element 214, and the second magnetic conductive element 206, and is subjected to the Ampere force, which drives the voice coil 210 to vibrate, and the vibration of the voice coil 210 drives the vibration of the first vibration plate 208, the second vibration plate 212, and the vibration panel 214. The vibration panel 214 transmits the vibration to the auditory nerve through tissues and bones, so that people can hear the sound. The vibration panel 214 may be in direct contact with human skin, or may be in contact with the skin through a vibration transmission layer composed of a specific material.

[0076] In some embodiments, for a bone conduction speaker with a single magnetic element, the magnetic flux lines passing through the voice coil are not uniform but divergent. At the same time, magnetic leakage may be formed in the magnetic circuit, that is, more magnetic flux lines leak out of the magnetic gap and fail to pass through the voice coil, thereby reducing the magnetic induction intensity (or magnetic field intensity) at the voice coil position, affecting the sensitivity of the bone conduction speaker. Therefore, the bone conduction speaker 200 may further include at least one second magnetic element and / or at least one third magnetic conductive element (not shown). The at least one second magnetic element and / or at least one third magnetic conductive element can suppress the leakage of magnetic flux lines, constrain the shape of magnetic flux lines passing through the voice coil, so that more magnetic flux lines pass through the voice coil as horizontally and densely as possible, and enhance the magnetic induction intensity (or magnetic field intensity) at the voice coil position, thereby improving the sensitivity of the bone conduction speaker 200, and further improving the mechanical conversion efficiency of the bone conduction speaker 200 (that is, the efficiency of converting the electrical energy input to the bone conduction speaker 200 into the mechanical energy of the voice coil vibration). For more description of the at least one second magnetic element, please refer to Figures 3A-3G , 4A-4I and / or 5A-5F.

[0077] The above description of the structure of the bone conduction speaker 200 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone conduction speaker, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the bone conduction speaker without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 200 may include a housing, a connector, etc. The connector may connect the vibration panel 214 to the housing. For another example, the bone conduction speaker 200 may include a second magnetic element, which may be connected to the first magnetic conductive element 204. For another example, the bone conduction speaker 200 may further include one or more annular magnetic elements, which may be connected to the second magnetic conductive element 206.

[0078] Figure 3A is a schematic longitudinal section diagram of a magnetic circuit assembly 3100 according to some embodiments of the present application. Figure 3AAs shown, the magnetic circuit assembly 3100 may include a first magnetic element 302, a first magnetic conductive element 304, a second magnetic conductive element 306, and a second magnetic element 308. In some embodiments, the first magnetic element 302 and / or the second magnetic element 308 may include any one or more magnets described in the present application. In some embodiments, the first magnetic element 302 may include a first magnet, and the second magnetic element 308 may include a second magnet, and the first magnet and the second magnet may be the same or different. The first magnetic conductive element 304 and / or the second magnetic conductive element 306 may include any one or more magnetic conductive materials described in the present application. The processing method of the first magnetic conductive element 304 and / or the second magnetic conductive element 306 may include any one or more processing methods described in the present application. In some embodiments, the first magnetic element 302 and / or the first magnetic conductive element 304 may be set as an axisymmetric structure. For example, the first magnetic element 302 and / or the first magnetic conductive element 304 may be a cylinder, a cuboid, or a hollow ring (for example, a cross section in the shape of a runway). In some embodiments, the first magnetic element 302 and the first magnetic conductive element 304 may be coaxial cylinders having the same or different diameters. In some embodiments, the second magnetic conductive element 306 may be a groove-shaped structure. The groove-shaped structure may include a U-shaped cross-section (e.g., Figure 3A As shown). The groove-shaped second magnetic conductive element 306 may include a bottom plate and a side wall. In some embodiments, the bottom plate and the side wall may be integrally formed, for example, the side wall may be formed by extending the bottom plate in a direction perpendicular to the bottom plate. In some embodiments, the bottom plate may be connected to the side wall by any one or more connection methods described in this application. The second magnetic element 308 may be set to be annular or sheet-shaped. For the shape of the second magnetic element 308, reference may be made to the description elsewhere in the specification (for example, Figure 5A and 5B In some embodiments, the second magnetic element 308 can be coaxial with the first magnetic element 302 and / or the first magnetically conductive element 304.

[0079] The upper surface of the first magnetic element 302 can be connected to the lower surface of the first magnetic conductive element 304. The lower surface of the first magnetic element 302 can be connected to the bottom plate of the second magnetic conductive element 306. The lower surface of the second magnetic element 308 is connected to the side wall of the second magnetic conductive element 306. The connection between the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306 and / or the second magnetic element 308 can include one or more combinations of bonding, clamping, welding, riveting, bolting, etc.

[0080] A magnetic gap is formed between the first magnetic element 302 and / or the first magnetic conductive element 304 and the inner ring of the second magnetic element 308. The voice coil 328 can be disposed in the magnetic gap. In some embodiments, the second magnetic element 308 and the voice coil 328 are at the same height relative to the bottom plate of the second magnetic conductive element 306. In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306 and the second magnetic element 308 can form a magnetic loop. In some embodiments, the magnetic circuit assembly 3100 can generate a first total magnetic field (also referred to as "the total magnetic field of the magnetic circuit assembly"), and the first magnetic element 302 can generate a second magnetic field. The first total magnetic field is formed by the magnetic fields generated by all components in the magnetic circuit assembly 3100 (for example, the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306 and the second magnetic element 308). The magnetic field strength (also referred to as magnetic induction strength or magnetic flux density) of the first total magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the second magnetic element 308 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the first full magnetic field at the magnetic gap. Here, the third magnetic field increases the magnetic field strength of the first full magnetic field, which means that when the third magnetic field exists (that is, the second magnetic element 308 exists), the magnetic field strength of the first full magnetic field at the magnetic gap is greater than that of the first full magnetic field when the third magnetic field exists (that is, the second magnetic element 308 does not exist). In other embodiments in this specification, unless otherwise specified, the magnetic circuit assembly represents a structure including all magnetic elements and magnetic conductive elements, the first full magnetic field represents the magnetic field generated by the magnetic circuit assembly as a whole, and the second magnetic field, the third magnetic field, ..., and the Nth magnetic field respectively represent the magnetic fields generated by the corresponding magnetic elements. In different embodiments, the magnetic elements that generate the second magnetic field (or the third magnetic field, ..., the Nth magnetic field) can be the same or different.

[0081] In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the second magnetic element 308 is between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the second magnetic element 308 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the second magnetic element 308 is equal to or greater than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is perpendicular to the lower surface or the upper surface of the first magnetic element 302 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the second magnetic element 308 is from the inner ring of the second magnetic element 308 to the outer ring (as shown in the direction b in the figure, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected 90 degrees in the clockwise direction).

[0082] In some embodiments, at the position of the second magnetic element 308, the angle between the direction of the first total magnetic field and the magnetization direction of the second magnetic element 308 is not greater than 90 degrees. In some embodiments, at the position of the second magnetic element 308, the angle between the direction of the magnetic field generated by the first magnetic element 302 and the magnetization direction of the second magnetic element 308 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees.

[0083] Compared with a magnetic circuit assembly with a single magnetic element, the second magnetic element 308 can increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 3100, thereby increasing the magnetic induction intensity in the magnetic gap. In addition, under the action of the second magnetic element 308, the originally divergent magnetic flux lines will converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0084] The above description of the structure of the magnetic circuit assembly 3100 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3100 without deviating from this principle, but these corrections and changes are still within the scope described above. For example, the second magnetic conductive element 306 can be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3100 can further include a magnetic conductive cover, which can surround the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306 and the second magnetic element 308.

[0085] Figure 3B FIG. 3 is a schematic longitudinal section diagram of a magnetic circuit assembly 3200 according to some embodiments of the present application. Figure 3B As shown, different from the magnetic circuit assembly 3100 , the magnetic circuit assembly 3200 may further include a third magnetic element 310 .

[0086] The upper surface of the third magnetic element 310 is connected to the second magnetic element 308, and the lower surface is connected to the side wall of the second magnetic conductive element 306. A magnetic gap may be formed between the first magnetic element 302, the first magnetic conductive element 304, the second magnetic element 308 and / or the third magnetic element 310. The voice coil 328 may be disposed in the magnetic gap. In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306, the second magnetic element 308 and the third magnetic element 310 may form a magnetic circuit. In some embodiments, the magnetization direction of the second magnetic element 308 may refer to the present application. Figure 3A Detailed description.

[0087] In some embodiments, the magnetic circuit assembly 3200 can generate a first full magnetic field, and the first magnetic element 302 can generate a second magnetic field, wherein the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the third magnetic element 310 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0088] In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the third magnetic element 310 is between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the third magnetic element 310 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the third magnetic element 310 is equal to or greater than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is perpendicular to the lower surface or the upper surface of the first magnetic element 302 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the third magnetic element 310 is from the upper surface of the third magnetic element 310 to the lower surface (as shown in the direction c in the figure, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected 180 degrees in the clockwise direction).

[0089] In some embodiments, at the position of the third magnetic element 310, the angle between the direction of the first total magnetic field and the magnetization direction of the third magnetic element 310 is not greater than 90 degrees. In some embodiments, at the position of the third magnetic element 310, the angle between the direction of the magnetic field generated by the first magnetic element 302 and the magnetization direction of the third magnetic element 310 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees.

[0090] Compared with the magnetic circuit assembly 3100, the magnetic circuit assembly 3200 further adds a third magnetic element 310. The third magnetic element 310 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 3200, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the third magnetic element 310, the magnetic flux lines will further converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0091] The above description of the structure of the magnetic circuit assembly 3200 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3200 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the second magnetic conductive element 306 can be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3200 may not include the second magnetic conductive element 306. For another example, the magnetic circuit assembly 3200 can further add at least one magnetic element. In some embodiments, the lower surface of the further added magnetic element can be connected to the upper surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is opposite to the magnetization direction of the third magnetic element 312. In some embodiments, the further added magnetic element can be connected to the side wall of the first magnetic element 302 and the second magnetic conductive element 306. The magnetization direction of the further added magnetic element is opposite to the magnetization direction of the second magnetic element 308.

[0092] Figure 3C is a schematic longitudinal section diagram of a magnetic circuit assembly 3300 according to some embodiments of the present application. Figure 3C As shown, different from the magnetic circuit assembly 3100 , the magnetic circuit assembly 3300 may further include a fourth magnetic element 312 .

[0093] The fourth magnetic element 312 can be connected to the side wall of the first magnetic element 302 and the second magnetic conductive element 306 by one or more combinations of bonding, clamping, welding, riveting, bolting, etc. In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306, the second magnetic element 308 and the fourth magnetic element 312 can form a magnetic gap. In some embodiments, the magnetization direction of the second magnetic element 308 can refer to the present application Figure 3A Detailed description.

[0094] In some embodiments, the magnetic circuit assembly 3300 can generate a first full magnetic field, the first magnetic element 302 can generate a second magnetic field, and the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the fourth magnetic element 312 can generate a fourth magnetic field, and the fourth magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0095] In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the fourth magnetic element 312 is between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the fourth magnetic element 312 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the fourth magnetic element 312 is not higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is perpendicular to the lower surface or the upper surface of the first magnetic element 302 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the fourth magnetic element 312 is from the outer ring of the fourth magnetic element 312 to the inner ring (as shown in the direction d in the figure, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected 270 degrees in the clockwise direction).

[0096] In some embodiments, at the location of the fourth magnetic element 312, the angle between the direction of the first total magnetic field and the magnetization direction of the fourth magnetic element 312 is no greater than 90 degrees. In some embodiments, at the location of the fourth magnetic element 312, the angle between the direction of the magnetic field generated by the first magnetic element 302 and the magnetization direction of the fourth magnetic element 312 can be 0 degrees, 10 degrees, 20 degrees, or the like, which is less than or equal to 90 degrees.

[0097] Compared with the magnetic circuit assembly 3100, the magnetic circuit assembly 3300 further adds a fourth magnetic element 312. The fourth magnetic element 312 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 3300, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the fourth magnetic element 312, the magnetic flux lines will further converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0098] The above description of the structure of the magnetic circuit assembly 3300 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3300 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the second magnetic conductive element 306 can be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3300 may not include the second magnetic element 308. For another example, the magnetic circuit assembly 3300 can further add at least one magnetic element. In some embodiments, the lower surface of the further added magnetic element can be connected to the upper surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is the same as the magnetization direction of the first magnetic element 302. In some embodiments, the upper surface of the further added magnetic element can be connected to the lower surface of the second magnetic element 308. The magnetization direction of the magnetic element is opposite to the magnetization direction of the first magnetic element 302.

[0099] Figure 3D FIG. 3 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 3400 according to some embodiments of the present application. Figure 3D As shown, unlike the magnetic circuit assembly 3100, the magnetic circuit assembly 3400 may further include a fifth magnetic element 314. The fifth magnetic element 314 may include any one of the magnetic materials described in the present application. In some embodiments, the fifth magnetic element 314 may be configured as an axisymmetric structure. For example, the fifth magnetic element 314 may be a cylinder, a cuboid, or a hollow ring (for example, a cross-section having a shape of a runway). In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, and / or the fifth magnetic element 314 may be coaxial cylinders having the same or different diameters. The thickness of the fifth magnetic element 314 may be the same as or different from that of the first magnetic element 302. The fifth magnetic element 314 may be connected to the first magnetic conductive element 304.

[0100] In some embodiments, the angle between the magnetization direction of the fifth magnetic element 314 and the magnetization direction of the first magnetic element 302 is between 90 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the fifth magnetic element 314 and the magnetization direction of the first magnetic element 302 is between 150 degrees and 180 degrees. In some embodiments, the magnetization direction of the fifth magnetic element 314 is opposite to the magnetization direction of the first magnetic element 302 (as shown in the figure, direction a and direction e).

[0101] Compared with the magnetic circuit assembly 3100, the magnetic circuit assembly 3400 further adds a fifth magnetic element 314. The fifth magnetic element 314 can suppress the magnetic leakage of the first magnetic element 302 in the magnetic circuit assembly 3400 in the magnetization direction, so that the magnetic field generated by the first magnetic element 302 can be more compressed into the magnetic gap, thereby increasing the magnetic induction intensity in the magnetic gap.

[0102] The above description of the structure of the magnetic circuit assembly 3400 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3400 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the second magnetic conductive element 306 can be a ring structure or a sheet structure. For another example, the magnetic circuit assembly 3400 may not include the second magnetic element 308. For another example, the magnetic circuit assembly 3400 can further add at least one magnetic element. In some embodiments, the lower surface of the further added magnetic element can be connected to the upper surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is the same as the magnetization direction of the first magnetic element 302. In some embodiments, the upper surface of the further added magnetic element can be connected to the lower surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is opposite to the magnetization direction of the first magnetic element 302. In some embodiments, the further added magnetic element may connect the first magnetic element 302 and the second magnetic conductive element 306 , and the magnetization direction of the further added magnetic element is opposite to the magnetization direction of the second magnetic element 308 .

[0103] Figure 3E FIG. 3 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 3500 according to some embodiments of the present application. Figure 3EAs shown, unlike the magnetic circuit assembly 3400, the magnetic circuit assembly 3500 may further include a third magnetic conductive element 316. In some embodiments, the third magnetic conductive element 316 may include any one or more magnetic conductive materials described in the present application. The magnetic conductive materials included in the first magnetic conductive element 304, the second magnetic conductive element 306 and / or the third magnetic conductive element 316 may be the same or different. In some embodiments, the third magnetic conductive element 316 may be arranged in a symmetrical structure. For example, the third magnetic conductive element 316 may be a cylinder. In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, the fifth magnetic element 314 and / or the third magnetic conductive element 316 may be coaxial cylinders having the same or different diameters. The third magnetic conductive element 316 may be connected to the fifth magnetic element 314. In some embodiments, the third magnetic conductive element 316 may be connected to the fifth magnetic element 314 and the second magnetic element 308. The third magnetic conductive element 316 , the second magnetic conductive element 306 , and the second magnetic element 308 may form a cavity, and the cavity may include the first magnetic element 302 , the fifth magnetic element 314 , and the first magnetic conductive element 304 .

[0104] Compared with the magnetic circuit assembly 3400, the magnetic circuit assembly 3500 further adds a third magnetic conductive element 316. The third magnetic conductive element 316 can suppress the leakage of the fifth magnetic element 314 in the magnetic circuit assembly 3500 in the magnetization direction, so that the magnetic field generated by the fifth magnetic element 314 can be more compressed into the magnetic gap, thereby improving the magnetic induction intensity in the magnetic gap.

[0105] The above description of the structure of the magnetic circuit assembly 3500 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3500 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the second magnetic conductive element 306 can be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3500 may not include the second magnetic element 308. For another example, the magnetic circuit assembly 3500 can further add at least one magnetic element. In some embodiments, the lower surface of the further added magnetic element can be connected to the upper surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is the same as the magnetization direction of the first magnetic element 302. In some embodiments, the upper surface of the further added magnetic element can be connected to the lower surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is opposite to the magnetization direction of the first magnetic element 302. In some embodiments, the further added magnetic element may connect the first magnetic element 302 and the second magnetic conductive element 306 , and the magnetization direction of the further added magnetic element is opposite to the magnetization direction of the second magnetic element 308 .

[0106] Figure 3F FIG. 3 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 3600 according to some embodiments of the present application. Figure 3F As shown, different from the magnetic circuit assembly 3100, the magnetic circuit assembly 3600 may further include one or more conductive elements (eg, a first conductive element 318, a second conductive element 320, and a third conductive element 322).

[0107] The conductive element may include a metal material, a metal alloy material, an inorganic non-metal material or other conductive material. The metal material may include gold, silver, copper, aluminum, etc.; the metal alloy material may include an iron-based alloy, an aluminum-based alloy material, a copper-based alloy, a zinc-based alloy, etc.; the inorganic non-metal material may include graphite, etc. The conductive element may be in the form of a sheet, a ring, a mesh, etc. The first conductive element 318 may be disposed on the upper surface of the first magnetic conductive element 304. The second conductive element 320 may connect the first magnetic element 302 and the second magnetic conductive element 306. The third conductive element 322 may connect the side wall of the first magnetic element 302. In some embodiments, the first magnetic conductive element 304 may protrude from the first magnetic element 302 to form a first recess, and the third conductive element 322 may be disposed in the first recess. In some embodiments, the first conductive element 318, the second conductive element 320, and the third conductive element 322 may include the same or different conductive materials. The first conductive element 318 , the second conductive element 320 , and the third conductive element 322 may be respectively connected to the first magnetic conductive element 304 , the second magnetic conductive element 306 , and / or the first magnetic element 302 by any one or more connection methods described in the present application.

[0108] A magnetic gap is formed between the first magnetic element 302, the first magnetic conductive element 304 and the inner ring of the second magnetic element 308. The voice coil 328 can be arranged in the magnetic gap. The first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306 and the second magnetic element 308 can form a magnetic loop. In some embodiments, the conductive element can reduce the inductive reactance of the voice coil 328. For example, if the voice coil 328 is supplied with a first alternating current, a first alternating induced magnetic field will be generated near the voice coil 328. Under the action of the magnetic field in the magnetic loop, the first alternating induced magnetic field will cause the voice coil 328 to generate inductive reactance, thereby hindering the movement of the voice coil 328. When a conductive element (for example, the first conductive element 318, the second conductive element 320 and the third conductive element 322) is arranged near the voice coil 328, the conductive element can induce a second alternating current under the action of the first alternating induced magnetic field. The third alternating current in the conductive element can generate a second alternating induced magnetic field in the vicinity thereof. The second alternating induced magnetic field is opposite in direction to the first alternating induced magnetic field, and can weaken the first alternating induced magnetic field, thereby reducing the inductive reactance of the voice coil 328, increasing the current in the voice coil, and improving the sensitivity of the bone conduction speaker.

[0109] The above description of the structure of the magnetic circuit assembly 3600 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3600 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the second magnetic conductive element 306 can be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3600 may not include the second magnetic element 308. For another example, the magnetic circuit assembly 3500 may further add at least one magnetic element. In some embodiments, the lower surface of the further added magnetic element may be connected to the upper surface of the second magnetic element 308. The magnetization direction of the further added magnetic element is the same as the magnetization direction of the first magnetic element 302.

[0110] Figure 3G FIG. 3 is a schematic longitudinal section diagram of a magnetic circuit assembly 3900 according to some embodiments of the present application. Figure 3G As shown, different from the magnetic circuit assembly 3500, the magnetic circuit assembly 3900 may further include a third magnetic element 310, a fourth magnetic element 312, a fifth magnetic element 314, a third magnetic conductive element 316, a sixth magnetic element 324, and a seventh magnetic element 326. The third magnetic element 310, the fourth magnetic element 312, the fifth magnetic element 314, the third magnetic conductive element 316, and / or the sixth magnetic element 324 and the seventh magnetic element 326 may be arranged as a coaxial annular cylinder.

[0111] In some embodiments, the upper surface of the second magnetic element 308 is connected to the seventh magnetic element 326, and the lower surface of the second magnetic element 308 can be connected to the third magnetic element 310. The third magnetic element 310 can be connected to the second magnetic conductive element 306. The upper surface of the seventh magnetic element 326 can be connected to the third magnetic conductive element 316. The fourth magnetic element 312 can connect the second magnetic conductive element 306 and the first magnetic element 302. The sixth magnetic element 324 can connect the fifth magnetic element 314, the third magnetic conductive element 316, and the seventh magnetic element 326. In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306, the second magnetic element 308, the third magnetic element 310, the fourth magnetic element 312, the fifth magnetic element 314, the third magnetic conductive element 316, the sixth magnetic element 324, and the seventh magnetic element 326 can form a magnetic loop and a magnetic gap.

[0112] In some embodiments, the magnetization direction of the second magnetic element 308 can refer to the present application. Figure 3A The magnetization direction of the third magnetic element 310 can be referred to in the detailed description of this application. Figure 3BFor a detailed description of the magnetization direction of the fourth magnetic element 312, please refer to the present application Figure 3C Detailed description in .

[0113] In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the sixth magnetic element 324 can be between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the sixth magnetic element 324 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the sixth magnetic element 324 is not higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is perpendicular to the lower surface or the upper surface of the first magnetic element 302 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the sixth magnetic element 324 is from the outer ring of the sixth magnetic element 324 to the inner ring (as shown in the direction g in the figure, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected 270 degrees in the clockwise direction). In some embodiments, in the same vertical direction, the magnetization direction of the sixth magnetic element 324 can be the same as the magnetization direction of the fourth magnetic element 312.

[0114] In some embodiments, at the location of the sixth magnetic element 324, the angle between the direction of the magnetic field generated by the magnetic circuit assembly 3900 and the magnetization direction of the sixth magnetic element 324 is not greater than 90 degrees. In some embodiments, at the location of the sixth magnetic element 324, the angle between the direction of the magnetic field generated by the first magnetic element 302 and the magnetization direction of the sixth magnetic element 324 can be 0 degrees, 10 degrees, 20 degrees, or the like, which is less than or equal to 90 degrees.

[0115] In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the seventh magnetic element 326 can be between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the seventh magnetic element 326 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 302 and the magnetization direction of the seventh magnetic element 326 is not higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is perpendicular to the lower surface or the upper surface of the first magnetic element 302 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the seventh magnetic element 326 is from the lower surface of the seventh magnetic element 326 to the upper surface (as shown in the direction f in the figure, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected 360 degrees in the clockwise direction). In some embodiments, the magnetization direction of the seventh magnetic element 326 can be opposite to the magnetization direction of the third magnetic element 310.

[0116] In some embodiments, at the seventh magnetic element 326, the angle between the direction of the magnetic field generated by the magnetic circuit assembly 3900 and the magnetization direction of the seventh magnetic element 326 is not greater than 90 degrees. In some embodiments, at the position of the seventh magnetic element 326, the angle between the direction of the magnetic field generated by the first magnetic element 302 and the magnetization direction of the seventh magnetic element 326 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees.

[0117] In the magnetic circuit assembly 3900, the third magnetic conductive element 316 can close the magnetic circuit generated by the magnetic circuit assembly 3900, so that more magnetic flux lines are concentrated in the magnetic gap, thereby achieving the effect of suppressing magnetic leakage, increasing the magnetic induction intensity at the magnetic gap, and improving the sensitivity of the bone conduction speaker. The above description of the structure of the magnetic circuit assembly 3900 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 3900 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the second magnetic conductive element 306 can be a ring structure or a sheet structure. For another example, the magnetic circuit assembly 3900 may not include the second magnetic element 308. For another example, the magnetic circuit assembly 3900 may further include at least one conductive element, which may connect the first magnetic element 302, the fifth magnetic element 314, the first magnetic conductive element 304, the second magnetic conductive element 306, and / or the third magnetic conductive element 316. In some embodiments, the magnetic circuit assembly 3900 may further add at least one conductive element, which may connect at least one of the second magnetic element 308, the third magnetic element 310, the fourth magnetic element 312, the sixth magnetic element 324, and the seventh magnetic element 326.

[0118] Figure 4A FIG. 4 is a schematic longitudinal section diagram of a magnetic circuit assembly 4100 according to some embodiments of the present application. Figure 4AAs shown, the magnetic circuit assembly 4100 may include a first magnetic element 402, a first magnetic conductive element 404, a first total magnetic field changing element 406, and a second magnetic element 408. In some embodiments, the first magnetic element 402 and / or the second magnetic element 408 may include any one or more magnets described in the present application. The first magnetic element 402 may include a first magnet, and the second magnetic element 408 may include a second magnet, and the first magnet and the second magnet may be the same or different. The first magnetic conductive element 404 may include any one or more magnetic conductive materials described in the present application, such as low carbon steel, silicon steel sheet, silicon steel sheet, ferrite, etc. In some embodiments, the first magnetic element 402 and / or the first magnetic conductive element 404 may be arranged as an axisymmetric structure. The first magnetic element 402 and / or the first magnetic conductive element 404 may be a cylinder. In some embodiments, the first magnetic element 402 and the first magnetic conductive element 404 may be coaxial cylinders with the same or different diameters. In some embodiments, the first total magnetic field changing element 406 may be any one of a magnetic element or a magnetic conductive element. The first full magnetic field changing element 406 and / or the second magnetic element 408 may be configured to be ring-shaped or sheet-shaped. For the description of the first full magnetic field changing element 406 and the second magnetic element 408, reference may be made to the description elsewhere in the specification (e.g., Figure 5A and 5B and its related description). In some embodiments, the second magnetic element 408 can be a coaxial annular cylinder with the first magnetic element 402, the first magnetic conductive element 404 and / or the first total magnetic field changing element 406, and contains inner rings and / or outer rings with the same or different diameters. The processing method of the first magnetic conductive element 404 and / or the first total magnetic field changing element 406 can include any one or more processing methods described in this application.

[0119] The upper surface of the first magnetic element 402 can be connected to the lower surface of the first magnetic conductive element 404, and the second magnetic element 408 can be connected to the first magnetic element 402 and the first total magnetic field changing element 406. The connection method between the first magnetic element 402, the first magnetic conductive element 404, the first total magnetic field changing element 406 and / or the second magnetic element 408 can be based on any one or more connection methods described in this application. In some embodiments, the first magnetic element 402, the first magnetic conductive element 404, the first total magnetic field changing element 406 and / or the second magnetic element 408 can form a magnetic circuit and a magnetic gap.

[0120] In some embodiments, the magnetic circuit assembly 4100 can generate a first full magnetic field, and the first magnetic element 402 can generate a second magnetic field, wherein the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the second magnetic element 408 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0121] In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the second magnetic element 408 may be between 0 and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the second magnetic element 408 is between 45 and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the second magnetic element 408 may be no greater than 90 degrees.

[0122] In some embodiments, at the position of the second magnetic element 408, the angle between the direction of the first total magnetic field and the magnetization direction of the second magnetic element 408 is not higher than 90 degrees. In some embodiments, at the position of the second magnetic element 408, the angle between the direction of the magnetic field generated by the first magnetic element 402 and the magnetization direction of the second magnetic element 408 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees. For another example, the magnetization direction of the first magnetic element 402 is perpendicular to the lower surface or the upper surface of the first magnetic element 402 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the second magnetic element 408 is from the outer ring of the second magnetic element 408 to the inner ring (as shown in the direction c in the figure, on the right side of the first magnetic element 402, the magnetization direction of the first magnetic element 402 is deflected 270 degrees in the clockwise direction).

[0123] Compared with a magnetic circuit assembly with a single magnetic element, the first full magnetic field changing element 406 in the magnetic circuit assembly 4100 can increase the total magnetic flux in the magnetic gap, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the first full magnetic field changing element 406, the originally divergent magnetic flux lines will converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0124] The above description of the structure of the magnetic circuit assembly 4100 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4100 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the magnetic circuit assembly 4100 may further include a magnetic conductive cover, and the magnetic conductive cover may include a first magnetic element 402, a first magnetic conductive element 404, a first full magnetic field changing element 406, and a second magnetic element 408.

[0125] Figure 4B 4 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 4200 according to some embodiments of the present application. Figure 4B As shown, different from the magnetic circuit assembly 4100 , the magnetic circuit assembly 4200 may further include a third magnetic element 410 .

[0126] The lower surface of the third magnetic element 410 can be connected to the first total magnetic field changing element 406. The connection method between the third magnetic element 410 and the first total magnetic field changing element 406 can be based on any one or more connection methods described in this application. In some embodiments, a magnetic gap can be formed between the first magnetic element 402, the first magnetic conductive element 404, the first total magnetic field changing element 406, the second magnetic element 408 and / or the third magnetic element 410. In some embodiments, the magnetic circuit assembly 4200 can generate a first total magnetic field, and the first magnetic element 402 can generate a second magnetic field, and the magnetic field strength of the first total magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the third magnetic element 410 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0127] In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the third magnetic element 410 may be between 0 and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the third magnetic element 410 is between 45 and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the third magnetic element 410 may be equal to or greater than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 402 is perpendicular to the lower surface or the upper surface of the first magnetic element 402 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the third magnetic element 410 is directed from the inner ring of the third magnetic element 410 to the outer ring (as shown in the direction b in the figure, on the right side of the first magnetic element 402, the magnetization direction of the first magnetic element 402 is deflected 90 degrees in the clockwise direction).

[0128] In some embodiments, at the location of the third magnetic element 410, the angle between the direction of the first total magnetic field and the magnetization direction of the second magnetic element 408 is no greater than 90 degrees. In some embodiments, at the location of the third magnetic element 410, the angle between the direction of the magnetic field generated by the first magnetic element 402 and the magnetization direction of the third magnetic element 410 can be 0 degrees, 10 degrees, 20 degrees, or the like, which is less than or equal to 90 degrees.

[0129] Compared with the magnetic circuit assembly 4100, the magnetic circuit assembly 4200 further adds a third magnetic element 410. The third magnetic element 410 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 4200, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the third magnetic element 410, the magnetic flux lines will further converge to the location of the magnetic gap, thereby increasing the magnetic induction intensity in the magnetic gap.

[0130] The above description of the structure of the magnetic circuit assembly 4200 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4200 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the magnetic circuit assembly 4200 may further include a magnetic conductive cover, and the magnetic conductive cover may include a first magnetic element 402, a first magnetic conductive element 404, a first full magnetic field changing element 406, a second magnetic element 408, and a third magnetic element 410.

[0131] Figure 4C 4 is a schematic diagram of a magnetic circuit assembly 4300 according to some embodiments of the present application. Figure 4C As shown, different from the magnetic circuit assembly 4200 , the magnetic circuit assembly 4300 may further include a fourth magnetic element 412 .

[0132] The lower surface of the fourth magnetic element 412 can be connected to the upper surface of the first total magnetic field changing element 406, and the upper surface of the fourth magnetic element 412 can be connected to the lower surface of the second magnetic element 408. The connection method between the fourth magnetic element 412 and the first total magnetic field changing element 406 and the second magnetic element 408 can be based on any one or more connection methods described in this application. In some embodiments, a magnetic gap can be formed between the first magnetic element 402, the first magnetic conductive element 404, the first total magnetic field changing element 406, the second magnetic element 408, the third magnetic element 410 and / or the fourth magnetic element 412. The magnetization directions of the second magnetic element 408 and the third magnetic element 410 can refer to the detailed description in 4A and / or 4B of this application, respectively.

[0133] In some embodiments, the magnetic circuit assembly 4300 can generate a first full magnetic field, the first magnetic element 402 can generate a second magnetic field, and the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the fourth magnetic element 412 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0134] In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the fourth magnetic element 412 may be between 0 and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the fourth magnetic element 412 is between 45 and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the fourth magnetic element 412 may be equal to or greater than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 402 is perpendicular to the lower surface or the upper surface of the first magnetic element 402 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the fourth magnetic element 412 is from the upper surface of the fourth magnetic element 412 to the lower surface (as shown in the direction d in the figure, on the right side of the first magnetic element 402, the magnetization direction of the first magnetic element 402 is deflected 180 degrees in the clockwise direction).

[0135] In some embodiments, at the location of the fourth magnetic element 412, the angle between the direction of the first total magnetic field and the magnetization direction of the fourth magnetic element 412 is no greater than 90 degrees. In some embodiments, at the location of the fourth magnetic element 412, the angle between the direction of the magnetic field generated by the first magnetic element 402 and the magnetization direction of the fourth magnetic element 412 can be 0 degrees, 10 degrees, 20 degrees, or the like, which is less than or equal to 90 degrees.

[0136] Compared with the magnetic circuit assembly 4200, the magnetic circuit assembly 4300 further adds a fourth magnetic element 412. The fourth magnetic element 412 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 4300, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the fourth magnetic element 412, the magnetic flux lines will further converge to the location of the magnetic gap, thereby increasing the magnetic induction intensity in the magnetic gap.

[0137] The above description of the structure of the magnetic circuit assembly 4300 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4300 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the magnetic circuit assembly 4200 may further include one or more conductive elements, and the one or more conductive elements may connect at least one of the first magnetic element 402, the first magnetic conductive element 404, the second magnetic element 408, the third magnetic element 410 and the fourth magnetic element 412.

[0138] Figure 4D FIG. 4 is a schematic longitudinal section diagram of a magnetic circuit assembly 4400 according to some embodiments of the present application. Figure 4D As shown, unlike the magnetic circuit assembly 4300 , the magnetic circuit assembly 4400 may further include a magnetic conductive cover 414 .

[0139] The magnetic shield 414 may include any one or more magnetic conductive materials described in the present application, for example, low carbon steel, silicon steel sheet, silicon steel sheet, ferrite, etc. The magnetic shield 414 may be connected to the first total magnetic field changing element 406, the second magnetic element 408, the third magnetic element 410, and the fourth magnetic element 412 by any one or more connection methods described in the present application. The processing method of the magnetic shield 414 may include any one of the processing methods described in the present application, for example, one or more combinations of casting, plastic processing, cutting, powder metallurgy, etc. In some embodiments, the magnetic shield 414 may include a bottom plate and a side wall, and the side wall is an annular structure. In some embodiments, the bottom plate and the side wall may be integrally formed. In some embodiments, the bottom plate may be connected to the side wall by any one or more connection methods described in the present application.

[0140] Compared with magnetic circuit assembly 4300, magnetic circuit assembly 4400 further includes magnetic conductive cover 414. Magnetic conductive cover 414 can suppress magnetic leakage of magnetic circuit assembly 4300, effectively reduce magnetic circuit length and magnetic resistance, so that more magnetic flux lines can pass through the magnetic gap, and improve the magnetic induction intensity in the magnetic gap.

[0141] The above description of the structure of the magnetic circuit assembly 4400 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4400 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the magnetic circuit assembly 4400 may further include one or more conductive elements, and the one or more conductive elements may be connected to at least one of the first magnetic element 402, the first magnetic conductive element 404, the second magnetic element 408, the third magnetic element 410 and the fourth magnetic element 412. For another example, the magnetic circuit assembly 4200 may further include a fifth magnetic element, the lower surface of the fifth magnetic element is connected to the upper surface of the first magnetic conductive element 404, and the magnetization direction of the fifth magnetic element is opposite to the magnetization direction of the first magnetic element 402.

[0142] Figure 4E FIG. 4 is a schematic longitudinal section diagram of a magnetic circuit assembly 4500 according to some embodiments of the present application. Figure 4E As shown, unlike the magnetic circuit assembly 4200 , the connection surface between the first full magnetic field changing element 406 and the second magnetic element 408 of the magnetic circuit assembly 4500 can be a wedge-shaped cross-section.

[0143] Compared with the magnetic circuit assembly 4100, the connection surface between the first full magnetic field changing element 406 and the second magnetic element 408 of the magnetic circuit assembly 4500 is configured as a wedge-shaped cross section, which can make the magnetic flux lines turn smoothly. At the same time, the wedge-shaped cross section can facilitate the assembly of the first full magnetic field changing element 406 and the second magnetic element 408 and can reduce the number of assembly components and reduce the weight of the bone conduction speaker.

[0144] The above description of the structure of the magnetic circuit assembly 4500 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4500 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the magnetic circuit assembly 4500 may further include one or more conductive elements, and the conductive elements may be connected to at least one of the first magnetic element 402, the first magnetic conductive element 404, the second magnetic element 408, and the third magnetic element 410. For another example, the magnetic circuit assembly 4500 may further include a fifth magnetic element, the lower surface of the fifth magnetic element is connected to the upper surface of the first magnetic conductive element 404, and the magnetization direction of the fifth magnetic element is opposite to the magnetization direction of the first magnetic element 402. In some embodiments, the magnetic circuit assembly 4500 may further include a magnetically conductive cover, which may include a first magnetic element 402 , a first magnetically conductive element 404 , a first total magnetic field changing element 406 , a second magnetic element 408 , and a third magnetic element 410 .

[0145] Figure 4F FIG. 4 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 4600 according to some embodiments of the present application. Figure 4FAs shown, unlike the magnetic circuit assembly 4100, the magnetic circuit assembly 4600 may further include a fifth magnetic element 416. In some embodiments, the fifth magnetic element 416 may include one or more magnets. The magnet may include any one or more magnetic materials described in the present application. In some embodiments, the fifth magnetic element 416 may include a first magnet, and the first magnetic element 402 may include a second magnet, and the magnetic materials included in the first magnet and the second magnet may be the same or different. In some embodiments, the fifth magnetic element 416, the first magnetic element 402, and the first magnetic conductive element 404 may be arranged as an axially symmetrical structure, for example, the fifth magnetic element 416, the first magnetic element 402, and the first magnetic conductive element 404 may be cylinders. In some embodiments, in some embodiments, the fifth magnetic element 416, the first magnetic element 402, and the first magnetic conductive element 404 may be coaxial cylinders with the same or different diameters. For example, the diameter of the first magnetic element 404 may be greater than the first magnetic element 402 and / or the fifth magnetic element 416, and the sidewalls of the first magnetic element 402 and / or the fifth magnetic element 416 may form a first recess and / or a second recess. In some embodiments, the ratio of the thickness of the fifth magnetic element 416 to the sum of the thicknesses of the first magnetic element 402, the fifth magnetic element 416, and the first magnetic element 404 is in the range of 0.4-0.6. The ratio of the first magnetic element 404 to the sum of the thicknesses of the first magnetic element 402, the fifth magnetic element 416, and the first magnetic element 404 is in the range of 0.5-1.5.

[0146] In some embodiments, the angle between the magnetization direction of the fifth magnetic element 416 and the magnetization direction of the first magnetic element 402 is between 150 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the fifth magnetic element 416 and the magnetization direction of the first magnetic element 402 is between 90 degrees and 180 degrees. For example, the magnetization direction of the fifth magnetic element 416 is opposite to the magnetization direction of the first magnetic element 402 (as shown in the figure, direction a and direction e).

[0147] Compared with magnetic circuit assembly 4100, magnetic circuit assembly 4600 further adds fifth magnetic element 416. Fifth magnetic element 426 can suppress the magnetic leakage of first magnetic element 402 in magnetic circuit assembly 4600 in the magnetization direction, so that the magnetic field generated by first magnetic element 402 can be more compressed into the magnetic gap, thereby improving the magnetic induction intensity in the magnetic gap.

[0148] The above description of the structure of the magnetic circuit assembly 4600 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4600 without deviating from this principle, but these corrections and changes are still within the scope described above. In some embodiments, the magnetic circuit assembly 4600 may further include one or more conductive elements, and the one or more conductive elements may be connected to at least one of the first magnetic element 402, the first magnetic conductive element 404, the second magnetic element 408, and the fifth magnetic element 416. For example, the one or more conductive elements may be arranged in the first recess and / or the second recess. In some embodiments, the magnetic circuit assembly 4600 may further add at least one magnetic element, and the further added magnetic element may be connected to the first full magnetic field changing element 406. In some embodiments, the magnetic circuit assembly 4600 may further include a magnetically conductive cover, which includes a first magnetic element 402 , a first magnetically conductive element 404 , a first total magnetic field changing element 406 , a second magnetic element 408 and a fifth magnetic element 416 .

[0149] Figure 4G 4 is a schematic longitudinal section diagram of a magnetic circuit assembly 4900 according to some embodiments of the present application. The magnetic circuit assembly 4900 may include a first magnetic element 402, a first magnetic conductive element 404, a first full magnetic field changing element 406, a second magnetic element 408, a third magnetic element 410, a fourth magnetic element 412, a fifth magnetic element 416, a sixth magnetic element 418, a seventh magnetic element 420, and a second annular element 422. The first magnetic element 402, the first magnetic conductive element 404, the first full magnetic field changing element 406, the second magnetic element 408, the third magnetic element 410, the fourth magnetic element 412, and the fifth magnetic element 416 may be referred to in the present application. Figure 4A , 4B , 4C, 4D, 4E and / or 4F. In some embodiments, the first full magnetic field changing element 406 and / or the second annular element 422 may include an annular magnetic element or an annular magnetic conductive element. The annular magnetic element may include any one or more magnetic materials described in this application, and the annular magnetic conductive element may include any one or more magnetic conductive materials described in this application.

[0150] In some embodiments, the sixth magnetic element 418 can be connected to the fifth magnetic element 416 and the second annular element 422, and the seventh magnetic element 420 can be connected to the third magnetic element 410 and the second annular element 422. In some embodiments, the first magnetic element 402, the fifth magnetic element 416, the second magnetic element 408, the third magnetic element 410, the fourth magnetic element 412, the sixth magnetic element 418 and / or the seventh magnetic element 420, the first magnetic conductive element 404, the first total magnetic field changing element 406 and the second annular element 422 can form a magnetic loop.

[0151] The magnetization direction of the second magnetic element 408 can refer to the present application Figure 4A The magnetization directions of the third magnetic element 410, the fourth magnetic element 412 and the fifth magnetic element 416 can refer to the detailed description of the present application. Figure 4B , 4C And a detailed description of 4F.

[0152] In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the sixth magnetic element 418 can be between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the sixth magnetic element 418 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the sixth magnetic element 418 is not higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 402 is perpendicular to the lower surface or the upper surface of the first magnetic element 402 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the sixth magnetic element 418 is from the outer ring of the sixth magnetic element 418 to the inner ring (as shown in the direction f in the figure, on the right side of the first magnetic element 402, the magnetization direction of the first magnetic element 402 is deflected 270 degrees in the clockwise direction). In some embodiments, in the same vertical direction, the magnetization direction of the sixth magnetic element 418 can be the same as the magnetization direction of the second magnetic element 408. In some embodiments, the magnetization direction of the first magnetic element 402 is perpendicular to the lower surface or the upper surface of the first magnetic element 402 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the seventh magnetic element 420 is from the lower surface of the seventh magnetic element 420 to the upper surface (as shown in the direction e in the figure, on the right side of the first magnetic element 402, the magnetization direction of the first magnetic element 402 is deflected 360 degrees in the clockwise direction). In some embodiments, the magnetization direction of the seventh magnetic element 420 can be the same as the magnetization direction of the third magnetic element 412.

[0153] In some embodiments, at the location of the sixth magnetic element 418, the angle between the direction of the magnetic field generated by the magnetic circuit assembly 4900 and the magnetization direction of the sixth magnetic element 418 is not greater than 90 degrees. In some embodiments, at the location of the sixth magnetic element 418, the angle between the direction of the magnetic field generated by the first magnetic element 402 and the magnetization direction of the sixth magnetic element 418 can be 0 degrees, 10 degrees, 20 degrees, or the like, which is less than or equal to 90 degrees.

[0154] In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the seventh magnetic element 420 may be between 0 and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the seventh magnetic element 420 is between 45 and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 402 and the magnetization direction of the seventh magnetic element 420 is not greater than 90 degrees.

[0155] In some embodiments, at the position of the seventh magnetic element 420, the angle between the direction of the magnetic field generated by the magnetic circuit assembly 4900 and the magnetization direction of the seventh magnetic element 420 is not greater than 90 degrees. In some embodiments, at the position of the seventh magnetic element 420, the angle between the direction of the magnetic field generated by the first magnetic element 402 and the magnetization direction of the seventh magnetic element 420 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees.

[0156] In some embodiments, the first full magnetic field changing element 406 may be an annular magnetic element. In this case, the magnetization direction of the first full magnetic field changing element 406 may be the same as the magnetization direction of the second magnetic element 408 or the fourth magnetic element 412. For example, on the right side of the first magnetic element 402, the magnetization direction of the first full magnetic field changing element 406 may be directed from the outer ring of the first full magnetic field changing element 406 to the inner ring. In some embodiments, the second annular element 422 may be an annular magnetic element. In this case, the magnetization direction of the second annular element 422 may be the same as the magnetization direction of the sixth magnetic element 418 or the seventh magnetic element 420. For example, on the right side of the first magnetic element 402, the magnetization direction of the second annular element 422 may be directed from the outer ring of the second annular element 422 to the inner ring.

[0157] In the magnetic circuit assembly 4900, multiple magnetic elements can increase the total magnetic flux. The interaction between different magnetic elements can suppress the leakage of magnetic flux lines, increase the magnetic induction intensity at the magnetic gap, and improve the sensitivity of the bone conduction speaker.

[0158] The above description of the structure of the magnetic circuit assembly 4900 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 4900 without deviating from this principle, but these corrections and changes are still within the scope of the above description. In some embodiments, the magnetic circuit assembly 4900 may further include one or more conductive elements, and the one or more conductive elements may connect at least one of the first magnetic element 402, the first magnetic conductive element 404, the second magnetic element 408, the third magnetic element 410, the fourth magnetic element 412, the fifth magnetic element 416, the sixth magnetic element 418 and the seventh magnetic element 420.

[0159] Figure 4H 4 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 41000 according to some embodiments of the present application. Figure 4H As shown, unlike the magnetic circuit assembly 4900 , the magnetic circuit assembly 41000 may further include a magnetic conductive cover 414 .

[0160] The magnetic shield 414 may include any one or more magnetic conductive materials described in the present application, such as low carbon steel, silicon steel sheet, silicon steel sheet, ferrite, etc. The magnetic shield 414 may be connected to the first magnetic element 402, the first full magnetic field changing element 406, the second magnetic element 408, the third magnetic element 410, the fourth magnetic element 412, the fifth magnetic element 416, the sixth magnetic element 418, the seventh magnetic element 420 and the second annular element 422 by any one or more connection methods described in the present application. The processing method of the magnetic shield 414 may include any one of the processing methods described in the present application, such as casting, plastic processing, cutting processing, powder metallurgy, etc. One or more combinations thereof. In some embodiments, the magnetic shield may include at least one bottom plate and a side wall, and the side wall is an annular structure. In some embodiments, the bottom plate and the side wall may be integrally formed. In some embodiments, the bottom plate may be connected to the side wall by any one or more connection methods described in the present application. For example, the magnetic cover 414 may include a first bottom plate, a second bottom plate and a side wall. The first bottom plate and the side wall may be integrally formed, and the second bottom plate may be connected to the side wall by any one or more connection methods described in this application.

[0161] In the magnetic circuit assembly 41000, the magnetic conductive cover 414 can close the magnetic circuit generated by the magnetic circuit assembly 41000, so that more magnetic flux lines are concentrated in the magnetic gap in the magnetic circuit assembly 41000, thereby achieving the effect of suppressing leakage flux, increasing the magnetic induction intensity at the magnetic gap, and improving the sensitivity of the bone conduction speaker.

[0162] The above description of the structure of the magnetic circuit assembly 41000 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 41000 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the magnetic circuit assembly 41000 may further include one or more conductive elements, and the one or more conductive elements may connect at least one of the first magnetic element 402, the first magnetic conductive element 404, the second magnetic element 408, the third magnetic element 410, the fourth magnetic element 412, the fifth magnetic element 416, the sixth magnetic element 418 and the seventh magnetic element 420.

[0163] Fig. 4I FIG. 4 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 41100 according to some embodiments of the present application. Fig. 4I As shown, different from the magnetic circuit assembly 4100, the magnetic circuit assembly 41100 may further include one or more conductive elements (eg, a first conductive element 424, a second conductive element 426, and a third conductive element 428).

[0164] The description of the conductive element is similar to that of conductive element 318 , conductive element 320 , and conductive element 322 , and the related descriptions thereof are not repeated here.

[0165] The above description of the structure of the magnetic circuit assembly 41100 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 41100 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the magnetic circuit assembly 41100 may further include at least one magnetic element and / or a magnetic conductive element.

[0166] Figure 5A is a schematic longitudinal section diagram of a magnetic circuit assembly 5100 according to some embodiments of the present application. Figure 5A As shown, the magnetic circuit assembly 5100 may include a first magnetic element 502 , a first magnetic conductive element 504 , a second magnetic conductive element 506 , and a second magnetic element 508 .

[0167] In some embodiments, the first magnetic element 502 and / or the second magnetic element 508 may include any one or more magnets described in the present application. In some embodiments, the first magnetic element 502 may include a first magnet, and the second magnetic element 508 may include a second magnet, and the first magnet and the second magnet may be the same or different. The first magnetic conductive element 504 and / or the second magnetic conductive element 506 may include any one or more magnetic conductive materials described in the present application. The processing method of the first magnetic conductive element 504 and / or the second magnetic conductive element 506 may include any one or more processing methods described in the present application. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504 and / or the second magnetic conductive element 508 may be set as an axisymmetric structure. For example, the first magnetic element 502, the first magnetic conductive element 504 and / or the second magnetic element 508 may be a cylinder. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504 and / or the second magnetic element 508 may be coaxial cylinders with the same or different diameters. The thickness of the first magnetic element 502 may be greater than or equal to the thickness of the second magnetic element 508. In some embodiments, the second magnetic conductive element 506 may be a groove-shaped structure. The groove-shaped structure may include a U-shaped cross-section (eg Figure 5A As shown). The groove-shaped second magnetic conductive element 506 may include a bottom plate and a side wall. In some embodiments, the bottom plate and the side wall may be integrally formed, for example, the side wall may be formed by extending the bottom plate in a direction perpendicular to the bottom plate. In some embodiments, the bottom plate may be connected to the side wall by any one or more connection methods described in this application. The second magnetic element 508 may be set to be annular or sheet-shaped. For the shape of the second magnetic element 508, reference may be made to the description elsewhere in the specification (for example, Fig. 6A and 6B In some embodiments, the second magnetic element 508 can be coaxial with the first magnetic element 502 and / or the first magnetic conductive element 504.

[0168] The upper surface of the first magnetic element 502 can be connected to the lower surface of the first magnetic conductive element 504. The lower surface of the first magnetic element 502 can be connected to the bottom plate of the second magnetic conductive element 506. The lower surface of the second magnetic element 508 is connected to the upper surface of the first magnetic conductive element 504. The connection method between the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506 and / or the second magnetic element 508 can include one or more combinations of bonding, clamping, welding, riveting, bolting, etc.

[0169] A magnetic gap is formed between the first magnetic element 502, the first magnetic conductive element 504 and / or the second magnetic element 508 and the side wall of the second magnetic conductive element 506. The voice coil 520 can be disposed in the magnetic gap. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506 and the second magnetic element 508 can form a magnetic circuit. In some embodiments, the magnetic circuit assembly 5100 can generate a first full magnetic field, and the first magnetic element 502 can generate a second magnetic field. The first full magnetic field is formed by the magnetic fields generated by all components in the magnetic circuit assembly 5100 (for example, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506 and the second magnetic element 508). The magnetic field strength (also referred to as magnetic induction strength or magnetic flux density) of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the second magnetic element 508 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0170] In some embodiments, the angle between the magnetization direction of the second magnetic element 508 and the magnetization direction of the first magnetic element 502 is between 90 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the second magnetic element 508 and the magnetization direction of the first magnetic element 502 is between 150 degrees and 180 degrees. In some embodiments, the magnetization direction of the second magnetic element 508 is opposite to the magnetization direction of the first magnetic element 502 (as shown in the figure, direction a and direction b).

[0171] Compared with a magnetic circuit assembly with a single magnetic element, the magnetic circuit assembly 5100 has an additional second magnetic element 508. The magnetization direction of the second magnetic element 508 is opposite to that of the first magnetic element 502, which can suppress the leakage of the first magnetic element 502 in the magnetization direction, so that the magnetic field generated by the first magnetic element 502 can be more compressed into the magnetic gap, thereby increasing the magnetic induction intensity in the magnetic gap.

[0172] The above description of the structure of the magnetic circuit assembly 5100 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone magnetic circuit assembly, it is possible to make various corrections and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 5100 without deviating from this principle, but these corrections and changes are still within the scope of the above description. For example, the second magnetic conductive element 506 can be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 5100 can further include a conductive element, which can connect the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506 and the second magnetic element 508.

[0173] Figure 5B FIG. 5 is a schematic longitudinal section diagram of a magnetic circuit assembly 5200 according to some embodiments of the present application. Figure 5B As shown, different from the magnetic circuit assembly 5100 , the magnetic circuit assembly 5200 may further include a third magnetic element 510 .

[0174] The lower surface of the third magnetic element 510 is connected to the side wall of the second magnetic conductive element 506. A magnetic gap may be formed between the first magnetic element 502, the first magnetic conductive element 504, the second magnetic element 508 and / or the third magnetic element 510. The voice coil 520 may be disposed in the magnetic gap. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506, the second magnetic element 508 and the third magnetic element 510 may form a magnetic circuit. In some embodiments, the magnetization direction of the second magnetic element 508 may refer to the present application. Figure 3A Detailed description.

[0175] In some embodiments, the magnetic circuit assembly 5200 can generate a first full magnetic field, and the first magnetic element 502 can generate a second magnetic field, wherein the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the third magnetic element 510 can generate a third magnetic field, and the third magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0176] In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the third magnetic element 510 is between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the third magnetic element 510 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the third magnetic element 510 is equal to or greater than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 502 is perpendicular to the lower surface or the upper surface of the first magnetic element 502 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the third magnetic element 510 is from the inner ring of the third magnetic element 510 to the outer ring (as shown in the direction c in the figure, on the right side of the first magnetic element 502, the magnetization direction of the first magnetic element 502 is deflected 90 degrees in the clockwise direction).

[0177] In some embodiments, at the position of the third magnetic element 510, the angle between the direction of the first total magnetic field and the magnetization direction of the third magnetic element 510 is not greater than 90 degrees. In some embodiments, at the position of the third magnetic element 510, the angle between the direction of the magnetic field generated by the first magnetic element 502 and the magnetization direction of the third magnetic element 510 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees.

[0178] Compared with the magnetic circuit assembly 5100, the magnetic circuit assembly 5200 further adds a third magnetic element 510. The third magnetic element 510 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 5200, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the third magnetic element 510, the magnetic flux lines will further converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0179] Figure 5C FIG. 5 is a longitudinal cross-sectional schematic diagram of a magnetic circuit assembly 5300 according to some embodiments of the present application. Figure 5C As shown, different from the magnetic circuit assembly 5100 , the magnetic circuit assembly 5300 may further include a fourth magnetic element 512 .

[0180] The fourth magnetic element 512 can be connected to the side wall of the first magnetic element 502 and the second magnetic conductive element 506 by one or more combinations of bonding, clamping, welding, riveting, bolting, etc. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506, the second magnetic element 508 and the fourth magnetic element 512 can form a magnetic gap. In some embodiments, the magnetization direction of the second magnetic element 508 can refer to the present application Figure 5A Detailed description.

[0181] In some embodiments, the magnetic circuit assembly 5200 can generate a first full magnetic field, the first magnetic element 502 can generate a second magnetic field, and the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the fourth magnetic element 512 can generate a fourth magnetic field, and the fourth magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0182] In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the fourth magnetic element 512 is between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the fourth magnetic element 512 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the fourth magnetic element 512 is not higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 502 is perpendicular to the lower surface or the upper surface of the first magnetic element 502 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the fourth magnetic element 512 is from the outer ring of the fourth magnetic element 512 to the inner ring (as shown in the direction e in the figure, on the right side of the first magnetic element 502, the magnetization direction of the first magnetic element 502 is deflected 270 degrees in the clockwise direction).

[0183] In some embodiments, at the location of the fourth magnetic element 512, the angle between the direction of the first total magnetic field and the magnetization direction of the fourth magnetic element 512 is no greater than 90 degrees. In some embodiments, at the location of the fourth magnetic element 512, the angle between the direction of the magnetic field generated by the first magnetic element 502 and the magnetization direction of the fourth magnetic element 512 can be 0 degrees, 10 degrees, 20 degrees, or the like, which is less than or equal to 90 degrees.

[0184] Compared with the magnetic circuit assembly 5200, the magnetic circuit assembly 5300 further adds a fourth magnetic element 512. The fourth magnetic element 512 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 5300, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the fourth magnetic element 512, the magnetic flux lines will further converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0185] Figure 5D FIG. 5 is a schematic longitudinal section diagram of a magnetic circuit assembly 5400 according to some embodiments of the present application. Figure 5D As shown, different from the magnetic circuit assembly 5200 , the magnetic circuit assembly 5400 may further include a fifth magnetic element 514 .

[0186] The lower surface of the third magnetic element 510 is connected to the fifth magnetic element 514, and the lower surface of the fifth magnetic element 514 is connected to the side wall of the second magnetic conductive element 506. A magnetic gap may be formed between the first magnetic element 502, the first magnetic conductive element 504, the second magnetic element 508 and / or the third magnetic element 510. The voice coil 520 may be disposed in the magnetic gap. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506, the second magnetic element 508, the third magnetic element 510 and the fifth magnetic element 514 may form a magnetic circuit. In some embodiments, the magnetization direction of the second magnetic element 508 and the third magnetic element 510 may refer to the present application. Figure 5A and a detailed description of 5B.

[0187] In some embodiments, the magnetic circuit assembly 5400 can generate a first full magnetic field, the first magnetic element 502 can generate a second magnetic field, and the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the fifth magnetic element 514 can generate a fifth magnetic field, and the fifth magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0188] In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the fifth magnetic element 514 is between 0 and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the fifth magnetic element 514 is between 45 and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the fifth magnetic element 514 is equal to or greater than 90 degrees.

[0189] In some embodiments, at the position of the fifth magnetic element 514, the angle between the direction of the first total magnetic field and the magnetization direction of the fifth magnetic element 514 is not higher than 90 degrees. In some embodiments, at the position of the fifth magnetic element 514, the angle between the direction of the magnetic field generated by the first magnetic element 502 and the magnetization direction of the fifth magnetic element 514 can be 0 degrees, 10 degrees, 20 degrees, etc., which is less than or equal to 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 502 is perpendicular to the lower surface or upper surface of the first magnetic element 502 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the fifth magnetic element 514 is from the upper surface of the fifth magnetic element 514 to the lower surface (as shown in the direction d in the figure, on the right side of the first magnetic element 502, the magnetization direction of the first magnetic element 502 is deflected 180 degrees in the clockwise direction).

[0190] Compared with the magnetic circuit assembly 5200, the magnetic circuit assembly 5400 further adds a fifth magnetic element 514. The fifth magnetic element 514 can further increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 5400, thereby increasing the magnetic induction intensity in the magnetic gap. Moreover, under the action of the fourth magnetic element 514, the magnetic flux lines will further converge to the location of the magnetic gap, further increasing the magnetic induction intensity in the magnetic gap.

[0191] Figure 5E FIG. 5 is a schematic longitudinal section diagram of a magnetic circuit assembly 5500 according to some embodiments of the present application. Figure 5E As shown, different from the magnetic circuit assembly 5300 , the magnetic circuit assembly 5500 may further include a sixth magnetic element 516 .

[0192] The sixth magnetic element 516 can be connected to the side wall of the second magnetic element 508 and the second magnetic conductive element 506 by one or more combinations of bonding, clamping, welding, riveting, bolting, etc. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic conductive element 506, the second magnetic element 508, the fourth magnetic element 512 and the sixth magnetic element 516 can form a magnetic gap. In some embodiments, the magnetization directions of the second magnetic element 508 and the fourth magnetic element 512 can refer to the present application. Figure 5A and 5C Detailed description.

[0193] In some embodiments, the magnetic circuit assembly 5500 can generate a first full magnetic field, the first magnetic element 502 can generate a second magnetic field, and the magnetic field strength of the first full magnetic field in the magnetic gap is greater than the magnetic field strength of the second magnetic field in the magnetic gap. In some embodiments, the sixth magnetic element 516 can generate a sixth magnetic field, and the sixth magnetic field can increase the magnetic field strength of the second magnetic field at the magnetic gap.

[0194] In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the sixth magnetic element 516 is between 0 degrees and 180 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the sixth magnetic element 516 is between 45 degrees and 135 degrees. In some embodiments, the angle between the magnetization direction of the first magnetic element 502 and the magnetization direction of the sixth magnetic element 516 is not higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 502 is perpendicular to the lower surface or the upper surface of the first magnetic element 502 and is vertically upward (as shown in the direction a in the figure), and the magnetization direction of the sixth magnetic element 516 is from the outer ring of the sixth magnetic element 516 to the inner ring (as shown in the direction f in the figure, on the right side of the first magnetic element 502, the magnetization direction of the first magnetic element 502 is deflected 270 degrees in the clockwise direction).

[0195] In some embodiments, at the location of the sixth magnetic element 516, the angle between the direction of the first total magnetic field and the magnetization direction of the sixth magnetic element 516 is no greater than 90 degrees. In some embodiments, at the location of the sixth magnetic element 516, the angle between the direction of the magnetic field generated by the first magnetic element 502 and the magnetization direction of the sixth magnetic element 516 can be 90 degrees, 110 degrees, 120 degrees, or an angle greater than 90 degrees.

[0196] Compared with the magnetic circuit assembly 5100, the magnetic circuit assembly 5500 further adds a fourth magnetic element 512 and a sixth magnetic element 516. The fourth magnetic element 512 and the sixth magnetic element 516 can increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 5500, increase the magnetic induction intensity at the magnetic gap, and thus improve the sensitivity of the bone conduction speaker.

[0197] Fig. 5F FIG. 5 is a schematic longitudinal section diagram of a magnetic circuit assembly 5600 according to some embodiments of the present application. Fig. 5F As shown, unlike the magnetic circuit assembly 5100 , the magnetic circuit assembly 5600 may further include a third magnetic conductive element 518 .

[0198] In some embodiments, the third magnetic conductive element 518 may include any one or more magnetic conductive materials described in the present application. The magnetic conductive materials included in the first magnetic conductive element 504, the second magnetic conductive element 506 and / or the third magnetic conductive element 518 may be the same or different. In some embodiments, the third magnetic conductive element 5186 may be arranged as a symmetrical structure. For example, the third magnetic conductive element 518 may be a cylinder. In some embodiments, the first magnetic element 502, the first magnetic conductive element 504, the second magnetic element 508 and / or the third magnetic conductive element 518 may be coaxial cylinders having the same or different diameters. The third magnetic conductive element 518 may be connected to the second magnetic element 508. In some embodiments, the third magnetic conductive element 518 may be connected to the second magnetic element 5084 and the second magnetic conductive element 506 so that the third magnetic conductive element 518 and the second magnetic conductive element 506 form a cavity, and the cavity may contain the first magnetic element 502, the second magnetic element 508 and the first magnetic conductive element 504.

[0199] Compared with the magnetic circuit assembly 5100, the magnetic circuit assembly 5600 further adds a third magnetic conductive element 518. The third magnetic conductive element 518 can suppress the leakage of the second magnetic element 508 in the magnetic circuit assembly 5600 in the magnetization direction, so that the magnetic field generated by the second magnetic element 508 can be more compressed into the magnetic gap, thereby improving the magnetic induction intensity in the magnetic gap.

[0200] Fig. 6A600 is a cross-sectional schematic diagram of a magnetic element structure according to some embodiments of the present application. The magnetic element 600 can be applied to any magnetic circuit component in the present application (for example, Figures 3A-3G , Figures 4A-4I or Figures 5A-5F As shown in the figure, the magnetic element 600 can be annular. The magnetic element 600 can include an inner ring 602 and an outer ring 604. In some embodiments, the shape of the inner ring 602 and / or the outer ring 604 can be circular, elliptical, triangular, quadrilateral or other arbitrary polygons.

[0201] Figure 6B is a schematic diagram of a magnetic element structure according to some embodiments of the present application. The magnetic element can be used in any magnetic circuit component in the present application (for example, Figures 3A-3G , Figures 4A-4I or Figures 5A-5F Magnetic circuit assembly shown). As shown in the figure, the magnetic element can be composed of a plurality of magnets arranged. The two ends of any one of the magnets can be connected to the two ends of the adjacent magnet or there is a certain distance. The spacing between the multiple magnets can be the same or different. In some embodiments, the magnetic element can be composed of 2 or 3 sheet-like magnets (for example, magnets 608-2, 608-4, and 608-6) arranged equidistantly. The shape of the sheet-like magnet can be a fan-shaped, quadrilateral, etc.

[0202] Figure 6C Schematic diagram of the magnetization direction of magnetic elements in a magnetic circuit assembly according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly may include a first magnetic element 601, a second magnetic element 603 and a third magnetic element 605. The magnetization direction of the first magnetic element 601 may be from the lower surface of the first magnetic element 601 to the upper surface (i.e., perpendicular to the direction outward from the paper). The second magnetic element 603 may be arranged around the first magnetic element 601. A magnetic gap may be formed between the inner ring of the second magnetic element 503 and the inner ring of the first magnetic element 601. The magnetization direction of the second magnetic element 603 may be from the inner ring of the second magnetic element 603 to the outer ring. The inner ring of the third magnetic element 605 may be connected to the outer ring of the first magnetic element 601, and the outer ring of the third magnetic element 605 may be connected to the inner ring of the second magnetic element 603. The magnetization direction of the third magnetic element 605 may be from the outer ring of the third magnetic element 603 to the inner ring.

[0203] Fig.6D FIG. 6 is a schematic diagram of magnetic induction lines of a magnetic element in a magnetic circuit assembly according to some embodiments of the present application. As shown in the figure, a magnetic circuit assembly 600 (for example, Figures 3A-3G , 4A-4I or Figures 5A-5FThe magnetic circuit assembly shown in FIG. 600 may include a first magnetic element 602 and a second magnetic element 604. The magnetization direction of the first magnetic element 602 may be from the lower surface of the first magnetic element 602 to the upper surface (as shown by arrow a). The first magnetic element 602 may generate a second magnetic field, which may be represented by magnetic induction lines (the solid line in the figure represents the distribution of the second magnetic field in the absence of the second magnetic element 604), and the magnetic field direction of the second magnetic field at a certain point is the tangent direction of the point on the magnetic induction line. The magnetization direction of the second magnetic element 604 may be from the inner ring of the second magnetic element 604 to the outer ring (as shown by arrow b). The second magnetic element 604 may generate a third magnetic field. The third magnetic field may also be represented by magnetic induction lines (the dotted line in the figure represents the distribution of the third magnetic field in the absence of the first magnetic element 602), and the magnetic field direction of the third magnetic field at a certain point is the tangent direction of the point on the third magnetic induction line. Under the interaction of the second magnetic field and the third magnetic field, the magnetic circuit assembly 600 may generate a first full magnetic field. The magnetic field strength of the first full magnetic field at the voice coil 606 is greater than the magnetic field strength of the second magnetic field or the third magnetic field at the voice coil 606. As shown in the figure, the angle between the magnetic field direction of the second magnetic field at the voice coil 606 and the magnetization direction of the second magnetic element 604 is less than or equal to 90 degrees.

[0204] Fig. 7A 7000 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 7000 may include a first magnetic element 702, a first magnetic conductive element 704, a first annular magnetic element 706, and a second annular magnetic element 708. The first annular magnetic element 706 may also be referred to as a first full magnetic field changing element (e.g., Figure 4A The first magnetic element 702, the first magnetic conductive element 704, the first annular magnetic element 706, and the second annular magnetic element 708 can refer to the present application. Figure 4A , 4B , 4C, 4D, 4E, 4F, 4G, 4H and / or 4I. For example, the first annular magnetic element 706 can be integrally formed of a magnetic material, or can be formed by splicing and combining a plurality of magnetic elements. The second annular magnetic element 708 can be integrally formed of a magnetic material, or can be formed by splicing and combining a plurality of magnetic elements. For another example, the second annular magnetic element 708 can connect the first magnetic element 702 and the first annular magnetic element 706. Furthermore, the first annular magnetic element 706 is connected to the upper surface of the second annular magnetic element 708, and the inner wall of the second annular magnetic element 708 is connected to the outer wall of the first magnetic element 702.

[0205] The first magnetic element 702, the first magnetic conductive element 704, the first annular magnetic element 706, and the second annular magnetic element 708 can form a magnetic circuit and a magnetic gap. The voice coil 720 can be placed in the magnetic gap. The voice coil 720 can be circular or non-circular. The non-circular shape can include an ellipse, a triangle, a quadrilateral, a pentagon, other polygons or other irregular shapes. When an alternating current passes through the voice coil 720, the voice coil 720 in the magnetic gap vibrates due to the Ampere force under the action of the magnetic field in the magnetic circuit, thereby converting the sound signal into a vibration signal, and the vibration signal is transmitted through other components in the bone conduction earphone (for example, Figure 1 The vibration component 104 shown in the figure is transmitted to the auditory nerve through human tissue and bones, so that people can hear the sound. The magnitude of the Ampere force on the voice coil can affect the vibration of the voice coil, thereby further affecting the sensitivity of the bone conduction earphone. The magnitude of the Ampere force on the voice coil is related to the magnetic induction intensity in the magnetic gap. Further, the magnetic induction intensity in the magnetic gap can be changed by adjusting the parameters of the magnetic circuit component.

[0206] The parameters of the magnetic circuit assembly 7000 may include the thickness H of the first magnetic element 702 (eg Fig. 7A , i.e., the height H of the first magnetic element 702), the thickness w of the first annular magnetic element 706, the height h of the second annular magnetic element 708, the magnetic circuit radius R, etc. In some embodiments, the magnetic circuit (i.e., magnetic loop) radius R may refer to the average half width of the magnetic circuit, i.e., equal to the central axis of the magnetic circuit component (e.g., Fig. 7AIn some embodiments, the parameters of the magnetic circuit assembly 7000 may also include a ratio of a magnetic circuit radius R to a thickness H of the first magnetic element 702 (which may be expressed as R / H), a ratio of a thickness w of the first magnetic element 706 to a magnetic circuit radius R (which may be expressed as w / R), a ratio of a height h of the second magnetic element 708 to a thickness H of the first magnetic element 702 (which may be expressed as h / H), etc. In some embodiments, a ratio R / H of a magnetic circuit radius R to a thickness H of the first magnetic element 702 ranges from 2.0 to 4.0. For example, a ratio R / H of a magnetic circuit radius R to a thickness H of the first magnetic element 702 may be 2.0, 2.4, 2.8, 3.2, 3.6, or 4.0. A ratio h / H of a height h of the second magnetic element 708 to a thickness H of the first magnetic element 702 may be no greater than 0.8, or no greater than 0.6, or no greater than 0.5, etc. For example, the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 may be equal to 0.4. The ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R may be in the range of 0.05-0.50, or 0.1-0.35, or 0.1-0.3, or 0.1-0.25, or 0.1-0.20, etc. For example, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R may be in the range of 0.16-0.18.

[0207] In some embodiments, the two parameters w / R and h / H can be optimized under the condition that the ratio of the thickness H of the first magnetic element 702 to the magnetic path radius R remains unchanged (i.e. R / H remains unchanged) so that the magnetic induction intensity at the magnetic gap and the Ampere force on the voice coil are maximized, i.e. the driving force coefficient BL value is maximized. For more descriptions on the relationship between the parameters w / R and h / H and the driving force coefficient BL, please refer to Figure 7B In some embodiments, by setting different R / H and adjusting the two parameters w / R and h / H, the magnetic induction intensity at the magnetic gap and the Ampere force on the coil can be maximized, that is, the driving force coefficient BL value is maximized. For more descriptions on the relationship between the parameters R / H, w / R, h / H and the driving force coefficient BL, please refer to Figure 7C-7E Detailed description in .

[0208] Figure 7B is the driving force coefficient at the voice coil 720 and Fig. 7A The relationship curve of magnetic circuit component parameters is shown. Figure 7BAs shown, when the ratio of the magnetic circuit radius R to the thickness H of the first magnetic element 702 remains unchanged (i.e., R / H remains unchanged), the driving force coefficient BL changes with the changes in the parameters w / R and h / H. In some embodiments, when the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic circuit radius R remains unchanged, the larger the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702, the larger the driving force coefficient BL. Furthermore, if the size of the magnetic circuit (i.e., the magnetic circuit radius R) remains unchanged, the larger the height h of the second annular magnetic element 708, the larger the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 can be, and the larger the driving force coefficient BL. However, as the height h of the second annular magnetic element 708 increases, the distance between the second annular magnetic element 708 and the voice coil 720 becomes smaller, and the voice coil 720 is prone to collide with the second annular magnetic element 708 during vibration, resulting in broken sound, thereby affecting the sound quality of the bone conduction earphones. As Figure 7B As shown, the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 may be no greater than 0.8, or no greater than 0.6, or no greater than 0.5, etc. For example, the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 may be equal to 0.4.

[0209] In some embodiments, when the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 remains unchanged, the driving force coefficient BL may first increase and then decrease as the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R increases. The ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R corresponding to the maximum driving force coefficient BL is within a certain range. For example, when the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 is 0.4, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R may be within the range of 0.08-0.25. When the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 is different, the range of the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R corresponding to the maximum driving force coefficient BL will change. For example, when the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 is 0.72, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R can be in the range of 0.04-0.20. For more description of the value range of the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R under the maximum driving force coefficient BL, please refer to Figure 7C-7E .

[0210] Figure 7C-7E is the driving force coefficient at the voice coil 720 and Fig. 7A The relationship curve of magnetic circuit component parameters is shown. Figure 7C-7E As shown, the driving force coefficient BL of the voice coil 720 in the magnetic circuit assembly 7000 changes with the parameters R / H, w / R and h / H of the magnetic circuit assembly 7000. Figure 7C As shown, when the ratio R / H of the magnetic path radius R to the thickness H of the first magnetic element 702 is 2.0 and 2.4, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R can be in the range of 0.05-0.20, or 0.05-0.15, or 0.05-0.25, or 0.1-0.25, or 0.1-0.18. Fig.7D As shown, when the ratio R / H of the magnetic path radius R to the thickness H of the first magnetic element 702 is 2.8 and 3.2, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic path radius R can be in the range of 0.05-0.25, or 0.1-0.20, or 0.05-0.30, or 0.10-0.25. Fig. 7E As shown, when the ratio R / H of the magnetic circuit radius R to the thickness H of the first magnetic element 702 is 3.6 and 4.0, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic circuit radius R can be in the range of 0.05-0.20, or 0.10-0.15, or 0.05-0.25, or 0.10-0.20.

[0211] Combination Figure 7C-7E When the ratio h / H of the height h of the second annular magnetic element 708 to the thickness H of the first magnetic element 702 is 0.4, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic circuit radius R can be in the range of 0.15-0.20, or 0.16-0.18.

[0212] Fig. 8A 8000 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 8000 may include a first magnetic element 802, a first magnetic conductive element 804, a first annular magnetic element 806, a second annular magnetic element 808, and a magnetic conductive cover 814. The first annular magnetic element 806 may also be referred to as a first full magnetic field changing element (e.g., Figure 4A The first magnetic element 802, the first magnetic conductive element 804, the first annular magnetic element 806, the second annular magnetic element 808, and the magnetic conductive cover 804 can refer to the present application. Figure 4A , 4B, 4C, 4D, 4E, 4F, 4G, 4H and / or 4I. For example, the first annular magnetic element 806 can be integrally formed of a magnetic material, or it can be formed by splicing and combining multiple magnetic elements. The second annular magnetic element 808 can be integrally formed of a magnetic material, or it can be formed by splicing and combining multiple magnetic elements. For another example, the magnetic shield 814 surrounds the first magnetic element 802, the first annular magnetic element 806 and the second annular magnetic element 808. In some embodiments, the magnetic shield 814 may include a bottom plate and a side wall, and the side wall is an annular structure. In some embodiments, the bottom plate and the side wall may be integrally formed. The first magnetic element 802, the first magnetic conductive element 804, the first annular magnetic element 806, and the second annular magnetic element 808 can form a magnetic circuit and a magnetic gap. The voice coil 820 can be placed in the magnetic gap. The voice coil 820 can be circular or non-circular. The non-circular shape can include an ellipse, a triangle, a quadrilateral, a pentagon, other polygons or other irregular shapes.

[0213] The parameters of the magnetic circuit assembly 8000 may include the thickness H of the first magnetic element 802 (eg Fig. 8A As shown in , that is, the height H of the first magnetic element 802), the thickness w of the first annular magnetic element 806, the height h of the second annular magnetic element 808, the magnetic circuit radius R, etc. In some embodiments, the magnetic circuit (i.e., magnetic circuit) radius R can be equal to the central axis of the magnetic circuit assembly 8000 (e.g. Fig. 8AIn some embodiments, the parameters of the magnetic circuit assembly 8000 may also include a ratio of a magnetic circuit radius R to a thickness H of the first magnetic element 802 (which may be expressed as R / H), a ratio of a thickness w of the first magnetic element 806 to a magnetic circuit radius R (which may be expressed as w / R), a ratio of a height h of the second magnetic element 808 to a thickness H of the first magnetic element 802 (which may be expressed as h / H), etc. In some embodiments, a ratio R / H of a magnetic circuit radius R to a thickness H of the first magnetic element 802 ranges from 2.0 to 4.0. For example, a ratio R / H of a magnetic circuit radius R to a thickness H of the first magnetic element 802 may be 2.0, 2.4, 2.8, 3.2, 3.6, or 4.0. A ratio h / H of a height h of the second magnetic element 808 to a thickness H of the first magnetic element 802 may be no greater than 0.8, or no greater than 0.6, or no greater than 0.5, etc. For example, the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 702 can be equal to 0.4. The ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R can be in the range of 0.02-0.50, or 0.05-0.35, or 0.05-0.25, or 0.1-0.25, or 0.1-0.20. For example, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R can be in the range of 0.16-0.18. In some embodiments, the two parameters w / R and h / H can be optimized while the thickness H of the first magnetic element 802 and the magnetic path radius R remain unchanged (that is, R / H remains unchanged), so that the magnetic induction intensity at the magnetic gap and the Ampere force exerted on the coil are maximized, that is, the driving force coefficient BL value is maximized. The relationship between the parameters w / R and h / H and the driving force coefficient BL can be referred to. Figure 8B In some embodiments, the two parameters w / R and h / H can be adjusted under the condition of changing R / H to maximize the magnetic induction intensity at the magnetic gap and the Ampere force on the coil, that is, the driving force coefficient BL value is maximized. For the relationship between the parameters R / H, w / R, h / H and the driving force coefficient BL, please refer to Figures 8C-8E Detailed description in .

[0214] Figure 8B is the driving force coefficient at the voice coil 820 and Fig. 8A The relationship curve of magnetic circuit component parameters is shown. Figure 8BAs shown, when the ratio of the magnetic circuit radius R to the thickness H of the first magnetic element 802 remains unchanged (i.e., R / H remains unchanged), the driving force coefficient BL changes with the change of the parameters w / R and h / H. In some embodiments, when the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic circuit radius R remains unchanged, the greater the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802, the greater the driving force coefficient BL. Furthermore, the greater the height h of the second annular magnetic element 808, the greater the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 702 can be, and the greater the driving force coefficient BL. As shown in FIG. Figure 8B As shown, the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 may be no greater than 0.8, or no greater than 0.6, or no greater than 0.5. For example, the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 may be equal to 0.4.

[0215] In some embodiments, when the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 remains unchanged, the driving force coefficient BL changes with the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R. For example, when the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 is 0.4, the driving force coefficient BL first increases and then decreases as the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R increases. When the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 is different, the range of the maximum driving force coefficient BL corresponding to the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R will change. For example, when the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 is 0.4, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R is in the range of 0.02-0.22. When the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 is 0.72, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R can be in the range of 0.02-0.16.

[0216] Combination Figure 7B As shown in FIG. 1 , when the parameters R / H, w / R, and h / H of the magnetic circuit components 8000 and 7000 are the same, the driving force coefficient BL of the voice coil in the magnetic circuit component 8000 with a magnetic shield is greater than the driving force coefficient BL in the magnetic circuit component 7000 without a magnetic shield, that is, the Ampere force received by the voice coil in the magnetic circuit component 8000 is greater than the Ampere force received by the voice coil in the magnetic circuit component 7000. For example, Figure 7B and 8B As shown, if w / R and h / H are about 0.21 and 0.4 respectively, the driving force coefficient BL of the voice coil in the magnetic circuit assembly 8000 is 2.817, and the driving force coefficient BL of the voice coil in the magnetic circuit assembly 7000 is 2.376.

[0217] Figures 8C-8E is the driving force coefficient at the voice coil 820 and Fig. 8A The relationship curve of magnetic circuit component parameters is shown. Figures 8C-8E As shown, the driving force coefficient BL of the voice coil 820 in the magnetic circuit assembly 8000 changes with the parameters R / H, w / R and h / H of the magnetic circuit assembly 8000. Figure 8C As shown, when the ratio R / H of the magnetic path radius R to the thickness H of the first magnetic element 802 is 2.0 and 2.4, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R can be in the range of 0.02-0.15, 0.05-0.15, or 0.02-0.20. Fig.8D As shown, when the ratio R / H of the magnetic circuit radius R to the thickness H of the first magnetic element 802 is 2.8 and 3.2, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic circuit radius R can be 0.01-0.20, or 0.05-0.15, or 0.02-0.25, or 0.10-0.15. Fig. 8E As shown, when the ratio R / H of the magnetic circuit radius R to the thickness H of the first magnetic element 802 is 3.6 and 4.0, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic circuit radius R can be in the range of 0.02-0.20, or 0.05-0.15, or 0.05-0.25, or 0.10-0.20.

[0218] Combination Figures 8C-8E , when the ratio h / H of the height h of the second annular magnetic element 808 to the thickness H of the first magnetic element 802 is 0.4, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic path radius R can be in the range of 0.05-0.20 or 0.16-0.18. Figure 7C and 8C , Fig.7D and 8D as well as Fig. 7E and 8E, when the ratio R / H of the magnetic circuit radius R to the thickness H of the first magnetic element 802 is the same, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic circuit radius R in the magnetic component 8000 with the magnetic conductive cover changes along a decreasing trend relative to the magnetic component 7000. For example, when the ratio R / H of the magnetic circuit radius R to the thickness H of the first magnetic element 802 (or 702) is 2.0, if the driving force coefficient BL is maximized, the ratio w / R of the thickness w of the first annular magnetic element 806 to the magnetic circuit radius R in the magnetic component 8000 with the magnetic conductive cover is in the range of 0.02-0.15. The ratio w / R of the thickness w of the first annular magnetic element 706 to the magnetic circuit radius R in the magnetic component 7000 without the magnetic conductive cover is in the range of 0.05-0.25.

[0219] Fig.9A 1 is a schematic diagram of magnetic flux distribution of a magnetic circuit assembly 900 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 900 may include a first magnetic element 902, a first magnetic conductive element 904, a second magnetic conductive element 906, and a second magnetic element 914. The first magnetic element 902, the first magnetic conductive element 904, the second magnetic conductive element 906, and the second magnetic element 914 may refer to the present application. Figure 3D Detailed description of the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306 and the second magnetic element 314 in FIG. The magnetization direction of the first magnetic element 902 is opposite to the magnetization direction of the second magnetic element 914. The magnetic flux lines generated by the first magnetic element 902 and the magnetic flux lines generated by the second magnetic element 914 interact with each other, so that the magnetic flux lines generated by the first magnetic element 902 and the magnetic flux lines generated by the second magnetic element 914 can pass through the voice coil 928 vertically more, reducing the leakage of magnetic flux lines of the first magnetic element 902 in the magnetization direction at the voice coil 928.

[0220] Fig. 9B The magnetic induction intensity at the voice coil and the Fig.9AThe relationship curve of the thickness of the components in the magnetic circuit component 900 shown in the figure. Wherein, the horizontal axis is the ratio of the thickness (h3) of the first magnetic element 902 to the sum of the thickness (h3) of the first magnetic element 902, the thickness (h2) of the first magnetic element 904, and the thickness (h5) of the second magnetic element 914 (h2+h3+h5), hereinafter referred to as the first thickness ratio. The vertical axis is the normalized magnetic induction intensity at the voice coil 928, and the normalized magnetic induction intensity can be the ratio of the actual magnetic induction intensity at the voice coil 928 to the maximum magnetic induction intensity under the magnetic circuit formed by the single magnetic magnetic circuit component. The single magnetic circuit component can refer to a magnetic circuit formed by the magnetic circuit component that includes only one magnetic element. For example, the single magnetic magnetic circuit component can include a first magnetic element, a first magnetic conductive element, and a second magnetic conductive element. The volume of the magnetic element in the single magnetic magnetic circuit component is equal to the sum of the volumes of the magnetic elements in the multi-magnetic circuit component corresponding to the single magnetic circuit component (for example, the first magnetic element 902 and the second magnetic element 914 in the magnetic circuit component 900). k is the ratio of the thickness (h2) of the first magnetic conductive element 904 to the sum of the thicknesses (h2+h3+h5) of the first magnetic element 902, the first magnetic conductive element 904 and the second magnetic element 914, hereinafter referred to as the second thickness ratio (indicated by "k" in the figure). As shown in the figure, as the first thickness ratio gradually increases, the magnetic induction intensity at the voice coil 928 gradually increases, and gradually decreases after reaching a certain value, that is, the magnetic induction intensity at the voice coil 928 has a maximum value, and the first thickness ratio corresponding to the maximum value is in the range of 0.4-0.6. The second thickness ratio corresponding to the maximum value is in the range of 0.26-0.34.

[0221] Fig. 10A 1 is a schematic diagram of magnetic flux distribution of a magnetic assembly 1000 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 1000 may include a first magnetic element 1002, a first magnetic conductive element 1004, a second magnetic conductive element 1006, a second magnetic element 1014, and a third magnetic conductive element 1016. The first magnetic element 1002, the first magnetic conductive element 1004, the second magnetic conductive element 1006, the second magnetic element 1014, and the third magnetic conductive element 1016 may refer to the present application. Figure 3EDetailed description of the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306, the second magnetic element 308, the second magnetic element 314 and the third magnetic conductive element 316. Among them, the third magnetic conductive element 1016 is not connected to the second magnetic conductive element 1006. The magnetization direction of the first magnetic element 1002 is opposite to the magnetization direction of the second magnetic element 1014. The magnetic flux lines generated by the first magnetic element 1002 and the magnetic flux lines generated by the second magnetic element 1014 interact with each other, so that the magnetic flux lines generated by the first magnetic element 1002 and the magnetic flux lines generated by the second magnetic element 1014 can pass through the voice coil 1028 vertically more, reducing the leakage of the magnetic flux lines of the first magnetic element 1002 at the voice coil 1028. The third magnetic conductive plate 1016 further reduces the leakage of the magnetic flux lines of the first magnetic element 1002 at the voice coil 1028.

[0222] Fig. 10B is a curve showing the relationship between the magnetic induction intensity at the voice coil and the thickness of the components in the magnetic circuit assembly according to some embodiments of the present application. Fig.9A The magnetic circuit assembly 900 shown in FIG. 1 corresponds to curve b. Fig. 10A The magnetic circuit assembly 1000 shown in FIG. The horizontal axis is the first thickness ratio, and the vertical axis is the normalized magnetic flux density at the voice coil 928 or 1028. The first thickness ratio and the normalized magnetic flux density can be referred to in the attached document of this application. Fig. 9B Detailed description in. Curve a is a curve showing the relationship between the magnetic induction intensity of the voice coil 928 in the magnetic circuit assembly 900 and the first thickness ratio, and curve b is a curve showing the relationship between the magnetic induction intensity of the voice coil 1028 in the magnetic circuit assembly 1000 and the first thickness ratio. Fig. 10B As shown, in the magnetic circuit assembly 1000 provided with the third magnetic conductive element 1016, when the first thickness ratio is in the range of 0-0.55, the magnetic induction intensity at the voice coil 1028 is significantly stronger than the magnetic induction intensity at the voice coil 928 (for example, the magnetic induction intensity corresponding to curve b is higher than the magnetic induction intensity corresponding to curve a). When the first thickness ratio is in the range of 0.55-1, the magnetic induction intensity at the voice coil 1028 is significantly lower than the magnetic induction intensity at the voice coil 928 (for example, the magnetic induction intensity corresponding to curve b is lower than the magnetic induction intensity corresponding to curve a).

[0223] Fig.11A 1 is a schematic diagram of magnetic flux distribution of a magnetic circuit assembly 1100 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 1100 may include a first magnetic element 1102, a first magnetic conductive element 1104, a second magnetic conductive element 1106, a second magnetic element 1114, and a third magnetic conductive element 1116. The first magnetic element 1102, the first magnetic conductive element 1104, the second magnetic conductive element 1106, the second magnetic element 1114, and the third magnetic conductive element 1116 may refer to the present application. Figure 3E Detailed description of the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306, the second magnetic element 308, the fifth magnetic element 314 and the third magnetic conductive element 316 in FIG. The third magnetic conductive element 1116 is connected to the second magnetic conductive element 1106. The magnetization direction of the first magnetic element 1102 is opposite to the magnetization direction of the second magnetic element 1114. The magnetic field of the first magnetic element 1102 and the magnetic field of the second magnetic element 1114 repel each other at the junction of the first magnetic element 1102 and the second magnetic element 1114, so that the originally divergent magnetic field (for example, the magnetic field generated only by the first magnetic element 1102 or the magnetic field generated only by the second magnetic element 1114) can pass through the voice coil 1128 under the action of the mutually repelling magnetic field, thereby increasing the magnetic field strength at the voice coil 1128. The third magnetic conductive plate 1116 is connected to the second magnetic conductive element 1106 , so that the magnetic fields of the second magnetic element 1114 and the first magnetic element 1102 are bounded in the magnetic loop formed by the second magnetic conductive element 1106 and the third magnetic conductive element 1116 , further increasing the magnetic induction intensity at the voice coil 1128 .

[0224] Fig. 11B is a curve showing the relationship between the magnetic induction intensity and the thickness of each component in the magnetic circuit assembly according to some embodiments of the present application. Among them, curve a corresponds to Fig.9A The magnetic circuit assembly 900 shown in FIG. 1 corresponds to curve b. Fig. 10A The magnetic circuit assembly 1000 shown in FIG. 1 corresponds to curve c. Fig.11A The magnetic circuit assembly 1100 shown. The horizontal axis is the ratio of the thickness (h3) of the first magnetic element (902, 1002, 1102) to the sum of the thicknesses (h3+h5) of the first magnetic element (902, 1002, 1102) and the second magnetic element (914, 1014, 1114), hereinafter referred to as the third thickness ratio. The vertical axis is the normalized magnetic induction intensity at the voice coil (928, 1028, 1128), and the normalized magnetic induction intensity can be referred to in the present application. Fig. 9B Detailed description in. Curve a is a curve showing the relationship between the magnetic induction intensity of the voice coil 928 in the magnetic circuit assembly 900 and the first thickness ratio, curve b is a curve showing the relationship between the magnetic induction intensity of the voice coil 1028 in the magnetic circuit assembly 1000 and the first thickness ratio, and curve c is a curve showing the relationship between the magnetic induction intensity of the voice coil 1128 in the magnetic circuit assembly 1100 and the first thickness ratio. Fig. 11BAs shown, in the case where the first thickness ratio is less than 0.7, the magnetic flux density at the corresponding voice coil (e.g., voice coil 1028, voice coil 1128) of the magnetic circuit assembly 1000 and 1100 including the third magnetic conductive element (e.g., magnetic conductive element 1014, magnetic conductive element 1114) is stronger than the magnetic flux density at the voice coil 928 in the magnetic circuit assembly 900 not including the third magnetic conductive element (e.g., the magnetic flux density corresponding to curve b and curve c is higher than the magnetic flux density corresponding to curve a). When the third magnetic conductive element is connected to the second magnetic conductive element (e.g., the third magnetic conductive element 1116 and the second magnetic conductive element 1106 in the magnetic circuit assembly 1100 are connected to each other), the magnetic flux density at the voice coil 1128 is stronger than the magnetic flux density at the voice coil 1028 (e.g., the magnetic flux density corresponding to curve c is higher than the magnetic flux density corresponding to curve b).

[0225] Fig. 11C The magnetic induction intensity at the voice coil and the Fig.11A The relationship curve of the thickness of the components in the magnetic circuit assembly 1100 is shown. The horizontal axis is the second thickness ratio (indicated by "h2 / (h2+h3+h5)" in the figure), and the vertical axis is the normalized magnetic flux density at the voice coil 1128. The second thickness ratio and the normalized magnetic flux density can be referred to in the present application. Fig. 9B Detailed description in Fig. 11C As shown, as the second thickness ratio gradually increases, the magnetic induction intensity at the voice coil 1128 gradually increases to a maximum value and then decreases. The second thickness ratio corresponding to the maximum value of the magnetic induction intensity is in the range of 0.3-0.6.

[0226] Fig. 12A 1 is a schematic diagram of the structure of a magnetic circuit assembly 1200 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 1200 may include a first magnetic element 1202, a first magnetic conductive element 1204, a second magnetic conductive element 1206, and a first conductive element 1208. The first magnetic element 1202, the first magnetic conductive element 1204, the second magnetic conductive element 1206, and the first conductive element 1208 may refer to the relevant description in the present application. The first conductive element 1204 may protrude from the first magnetic element 1202 to form a first recess, and the first conductive element 1208 may be disposed in the first recess and connected to the first magnetic element 1202.

[0227] The first magnetic element 1202, the first magnetic conductive element 1204 and the second magnetic conductive element 1206 can form a magnetic gap. The voice coil 1210 can be placed in the magnetic gap. The cross-sectional shape of the voice coil 1210 can be circular or non-circular, such as an ellipse, a rectangle, a square, a pentagon, other polygons or other irregular shapes. In some embodiments, an alternating current can be passed through the voice coil 1210, and the direction of the alternating current is perpendicular to the paper surface and inward as shown in the figure. In the magnetic circuit formed by the first magnetic element 1202, the first magnetic conductive element 1204 and the second magnetic conductive element 1206, the voice coil 1210 can generate an alternating induced magnetic field A (also referred to as "first alternating induced magnetic field") under the action of the magnetic field in the magnetic circuit, and the direction of the induced magnetic field A is counterclockwise (as shown in A). The alternating induced magnetic field A will cause a reverse induced current to be generated in the voice coil 1210, thereby reducing the current in the voice coil 1210. The first conductive element 1208 can generate an alternating induced current under the action of the alternating induced magnetic field A, and the alternating induced current can generate an alternating induced magnetic field B (also referred to as a "second alternating induced magnetic field") under the action of the magnetic field in the magnetic circuit. The direction of the induced magnetic field B is counterclockwise (as shown by B). Since the directions of the induced magnetic field A and the induced magnetic field B are opposite, the reverse induced current in the voice coil 1210 is reduced, that is, the inductive reactance in the voice coil 1210 is reduced, and the current in the voice coil 1210 is increased.

[0228] The above description of the structure of the magnetic circuit assembly 1200 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone conduction speaker, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 1200 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the first conductive element 1208 can be arranged near the voice coil 1210, such as the inner wall, outer wall, upper surface and / or lower surface of the voice coil 1210.

[0229] Fig. 12B According to some embodiments of the present application Fig. 12A The influence curve of the conductive element in the magnetic circuit assembly 1200 on the inductive reactance in the voice coil is shown. Curve a corresponds to the magnetic circuit assembly 1200 without the first conductive element 1208, and curve b corresponds to the magnetic circuit assembly 1200 with the first conductive element 1208. The horizontal axis is the frequency of the alternating current in the voice coil 1210, and the vertical axis is the inductive reactance in the voice coil 1210. Fig. 12BAs shown, when the frequency of the alternating current increases to about 1200 Hz, the inductive reactance in the voice coil 1210 increases with the increase of the frequency of the alternating current. When the first conductive element 1208 is set, the inductive reactance in the voice coil is significantly lower than the inductive reactance in the voice coil when the first conductive element 1208 is not set (such as the inductive reactance corresponding to curve b is lower than the inductive reactance corresponding to curve a).

[0230] Fig.13A 1 is a schematic diagram of the structure of a magnetic circuit assembly 1300 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 1300 may include a first magnetic element 1302, a first magnetic conductive element 1304, a second magnetic conductive element 1306, and a first conductive element 1318. The first magnetic element 1302, the first magnetic conductive element 1304, the second magnetic conductive element 1306, and the first conductive element 1318 may refer to the relevant description in the present application. The first conductive element 1318 may be connected to the upper surface of the first magnetic conductive element 1304. The shape of the first conductive element 1318 may be sheet-shaped, ring-shaped, mesh-shaped, orifice-shaped, etc.

[0231] The first magnetic element 1302, the first magnetic conductive element 1304, and the second magnetic conductive element 1306 may form a magnetic gap. The voice coil 1328 may be placed in the magnetic gap. The cross-sectional shape of the voice coil 1328 may be circular or non-circular. The non-circular shape may include an ellipse, a triangle, a quadrilateral, a pentagon, other polygons, or other irregular shapes.

[0232] The above description of the structure of the magnetic circuit assembly 1300 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 1300 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the first conductive element 1318 can be arranged near the voice coil 1328, such as the inner wall, outer wall, upper surface and / or lower surface of the voice coil 1328.

[0233] Fig. 13B According to some embodiments of the present application Fig.13A The influence curve of the magnetic conductive element in the magnetic circuit assembly 1300 on the inductive reactance in the voice coil is shown. Curve a corresponds to the magnetic circuit assembly 1300 without the first conductive element 1318, and curve b corresponds to the magnetic circuit assembly 1300 with the first conductive element 1318. The horizontal axis is the frequency of the alternating current in the voice coil 1110, and the vertical axis is the inductive reactance in the voice coil 1110. Fig. 13BAs shown, when the frequency of the alternating current increases to about 1200 Hz, the inductive reactance in the voice coil 1110 increases with the increase of the frequency of the alternating current. When the first conductive element 1318 is set, the inductive reactance in the voice coil 1110 is significantly lower than the inductive reactance in the voice coil when the first conductive element 1318 is not set (such as the inductive reactance corresponding to curve b is lower than the inductive reactance corresponding to curve a).

[0234] Fig.14A 1 is a schematic diagram of the structure of a magnetic circuit assembly 1400 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 1400 may include a first magnetic element 1402, a first magnetic conductive element 1404, a second magnetic conductive element 1406, a first conductive element 1418, a second conductive element 1420, and a third conductive element 1422. The first magnetic element 1402, the first magnetic conductive element 1404, the second magnetic conductive element 1406, the first conductive element 1418, the second conductive element 1420, and the third conductive element 1422 may refer to the present application. Figure 3F The first magnetic element 1302, the first magnetic conductive element 1304, and the second magnetic conductive element 1306 may form a magnetic gap. The voice coil 1428 may be placed in the magnetic gap. The cross-sectional shape of the voice coil 1428 may be circular or non-circular. The non-circular shape may include an ellipse, a triangle, a quadrilateral, a pentagon, other polygons, or other irregular shapes.

[0235] The above description of the structure of the magnetic circuit assembly 1400 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 1400 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the first conductive element 1418 can be arranged near the voice coil 1428, such as the inner wall, outer wall, upper surface and / or lower surface of the voice coil 1428.

[0236] Fig. 14B According to some embodiments of the present application Fig.14A The curve m corresponds to a magnetic circuit component without a conductive element, and the curve n corresponds to a magnetic circuit component with a conductive element (such as Fig. 12A The magnetic circuit assembly 1200 shown in FIG. 1 ) corresponds to a magnetic circuit assembly having multiple conductive elements (such as Fig.14A The horizontal axis is the frequency of the alternating current in the voice coil, and the vertical axis is the inductive reactance in the voice coil. Fig. 14BAs shown in FIG. 1 , when the frequency of the alternating current increases to about 1200 Hz, the inductive reactance in the voice coil increases with the increase of the frequency of the alternating current. When one or more conductive elements are provided, the inductive reactance in the voice coil is significantly lower than the inductive reactance in the voice coil when no conductive element is provided (e.g., the inductive reactance corresponding to curves n and l is lower than the inductive reactance corresponding to curve m). When multiple conductive elements are provided, the inductive reactance in the voice coil is significantly lower than the inductive reactance in the voice coil when only one conductive element is provided (e.g., the inductive reactance corresponding to curve l is lower than the inductive reactance corresponding to curve n).

[0237] Fig.15A 1 is a schematic diagram of the structure of a magnetic circuit assembly 1500 according to some embodiments of the present application. As shown in the figure, the magnetic circuit assembly 1500 may include a first magnetic element 1502, a first magnetic conductive element 1504, a first annular element 1506, a first annular magnetic element 1508, a second annular magnetic element 1510, a third annular magnetic element 1512, a magnetic conductive cover 1514 and a second magnetic element 1516. The first magnetic element 1502, the first magnetic conductive element 1504, the first annular element 1506, the first annular magnetic element 1508, the second annular magnetic element 1510, the third annular magnetic element 1512, the magnetic conductive cover 1514 and the second magnetic element 1516 can refer to the present application. Figure 4A , 4B , 4C, 4D, 4E, 4F, 4G, 4H and / or 4I.

[0238] The first magnetic element 1502, the first magnetic conductive element 1504, the second magnetic element 1516, the second annular magnetic element 1510 and / or the third annular magnetic element 1512 may form a magnetic gap. The voice coil 1528 may be placed in the magnetic gap. The voice coil 1528 may be circular or non-circular. The non-circular shape may include an ellipse, a triangle, a quadrilateral, a pentagon, other polygons or other irregular shapes.

[0239] The above description of the structure of the magnetic circuit assembly 1500 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the magnetic circuit assembly 1500 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the magnetic circuit assembly 1500 may further include one or more conductive elements, which may be arranged near the voice coil 1528, such as the inner wall, outer wall, upper surface and / or lower surface of the voice coil 1528. In some embodiments, the conductive element may be connected to the first magnetic element 1502, the second magnetic element 1516, the first annular magnetic element 1508, the second annular magnetic element 1510 and / or the third annular magnetic element 1512. For another example, the magnetic circuit assembly 1500 may further include a third magnetic conductive element, which is connected to the second magnetic element 1516.

[0240] Fig. 15B The Ampere force on the voice coil and the Fig.15A The relationship curve of the thickness of the magnetic elements in the magnetic circuit component 1500 shown in the figure. Wherein, the horizontal axis is the first thickness ratio, and the vertical axis is the normalized Ampere force received by the voice coil. The normalized Ampere force may refer to the ratio of the actual Ampere force received by the voice coil to the maximum Ampere force received in the single magnetic magnetic circuit component. The single magnetic magnetic circuit component may include a magnetic element. For example, the single magnetic circuit component may include a first magnetic element, a first magnetic conductive element, and a second magnetic conductive element. The volume of the first magnetic element in the single magnetic magnetic circuit component is the same as the sum of the volumes of the first magnetic element 1502 and the second magnetic element 1516 in the magnetic circuit component 1500. The first thickness ratio and the second thickness ratio can be referred to in the appendix of this application. Fig. 9B Detailed description in Fig. 15B As shown, for any second thickness ratio k, the ordinate value is greater than 1, that is, in the magnetic circuit assembly 1500, the Ampere force on the voice coil 1528 is greater than the Ampere force on the voice coil in the single magnetic magnetic circuit assembly. When the second thickness ratio k remains unchanged, as the first thickness ratio increases, the Ampere force on the voice coil 1528 gradually decreases. When the first thickness ratio remains unchanged, as the second thickness ratio k decreases, the Ampere force on the voice coil 1528 gradually increases. When the first thickness ratio is in the range of 0.1-0.3 or the second thickness ratio k is in the range of 0.2-0.7, the Ampere force on the voice coil 1528 is increased by 50%-60% compared with the Ampere force on the voice coil in the single magnetic magnetic circuit assembly.

[0241] Fig.161 is a schematic diagram of the structure of a bone conduction speaker 1600 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 1600 may include a first magnetic element 1602, a first magnetic conductive element 1604, a second magnetic conductive element 1606, a second magnetic element 1608, a voice coil 1610, a third magnetic conductive element 1612, a bracket 1614 and a connector 1616. The first magnetic element 1602, the first magnetic conductive element 1604, the second magnetic conductive element 1606, the second magnetic element 1608, the voice coil 1610 and / or the third magnetic conductive element 1612 may refer to the relevant description of other figures in the present application.

[0242] The upper surface of the first magnetic element 1602 may be connected to the lower surface of the first magnetic conductive element 1604. The lower surface of the second magnetic element 1608 may be connected to the upper surface of the first magnetic conductive element 1604. The second magnetic conductive element 1606 may include a first bottom plate and a first side wall. The lower surface of the first magnetic element 1602 may be connected to the upper surface of the first bottom plate. The side wall of the second magnetic conductive element 1606 forms a magnetic gap with the side walls of the first magnetic element 1602, the first magnetic conductive element 1604 and / or the second magnetic element 1608. The bracket 1614 may include a second bottom plate and a second side wall. After the bracket 1614 is connected to the voice coil 1610, the voice coil 1610 may be disposed in the magnetic gap. The voice coil 1610 may be connected to the second side wall. A side seam may be formed between the upper surface of the voice coil 1610 and the second bottom plate. When the voice coil 1610 is placed in the magnetic gap, the third magnetic conductive element 1612 can pass through the side seam to connect the upper surface of the second magnetic element 1608 and the first side wall of the second magnetic conductive element 1606, so that the third magnetic conductive element 1612 and the second magnetic conductive element 1606 form a closed cavity. The connection between the first magnetic element 1602, the first magnetic conductive element 1604, the second magnetic conductive element 1606, the second magnetic element 1608, the voice coil 1610 and / or the third magnetic conductive element 1612 can be any one or more connection methods described in the present application. In some embodiments, one or more hole-like structures (for example, pin holes, threaded holes, etc.) can be set on the first magnetic element 1602, the first magnetic conductive element 1604, the second magnetic conductive element 1606, the second magnetic element 1608, the third magnetic conductive element 1612 and / or the bracket 1614. The hole-like structure can be arranged at the center, periphery or other positions of the first magnetic element 1602, the first magnetic conductive element 1604, the second magnetic conductive element 1606, the second magnetic element 1608, the third magnetic conductive element 1612 and / or the bracket 1614. The connecting member 1616 can pass through the hole-like structure and connect the various elements. For example, the connecting member 1616 can be a pipe pin. The pipe pin 1616 can be punched and deformed by a punch head through the bracket 1614, thereby fixing the various components in the bone conduction speaker 1600.

[0243] The above description of the structure of the bone conduction speaker 1600 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the bone conduction speaker 1600 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 1600 may include one or more conductive elements, and the one or more conductive elements are arranged on the inner wall, outer wall, top and / or bottom of the voice coil 1610. For another example, the bone conduction speaker 1600 may further include one or more annular magnetic elements, and the one or more annular magnetic elements may be connected to the upper surface of the side wall of the second magnetic conductive element 1606 or fixed in the magnetic gap.

[0244] Fig.171 is a structural schematic diagram of a bone conduction speaker 1700 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 1700 may include a first magnetic element 1702, a first magnetic conductive element 1704, a second magnetic conductive element 1706, a second magnetic element 1708, a voice coil 1710, a third magnetic conductive element 1712, a bracket 1714, a connector 1716, a bracket connecting rod 1718 and a washer 1720. The upper surface of the first magnetic element 1702 may be connected to the lower surface of the first magnetic conductive element 1706. The lower surface of the second magnetic element 1708 may be connected to the upper surface of the first magnetic conductive element 1706. The second magnetic conductive element 1706 may include a first bottom plate and a first side wall, and the first side wall may be formed by the bottom plate extending in a direction perpendicular to the bottom plate. The lower surface of the first magnetic element 1702 may be connected to the upper surface of the bottom plate of the second magnetic conductive element 1706. The side wall of the second magnetic conductive element 1706 forms a magnetic gap with the side wall of the first magnetic element 1702, the first magnetic conductive element 1704 and / or the second magnetic element 1708. One or more rod-shaped structures may be arranged around the support connecting rod 1718. The voice coil 1710 may be connected to the support connecting rod 1718. After the support connecting rod 1718 is connected to the voice coil 1710, the voice coil 1710 may be arranged in the magnetic gap. The third magnetic conductive element 1712 may include a second bottom plate and a second side wall, the second side wall may be formed by extending the second bottom plate, the second side wall may be provided with one or more first hole-shaped structures, the first hole-shaped structures correspond to the rod-shaped structures of the support connecting rod 1718, and the rod-shaped structures of the support connecting rod 1718 may pass through the first hole-shaped structures of the third magnetic conductive element 1712. When the voice coil 1710 is placed in the magnetic gap, the second side wall of the third magnetic conductive element 1712 can be connected to the rod-shaped structure of the bracket connecting rod 1718 through the first hole-shaped structure, and the second bottom plate can be connected to the upper surface of the second magnetic element 1708. The connection between the first magnetic element 1702, the first magnetic conductive element 1704, the second magnetic conductive element 1706, the second magnetic element 1708, the voice coil 1710 and / or the third magnetic conductive element 1712 can be through any one or more connection methods described in this application. In some embodiments, the first magnetic element 1702, the first magnetic conductive element 1704, the second magnetic conductive element 1706, the second magnetic element 1708, the third magnetic conductive element 1712 and / or the bracket 1714 can be provided with a second hole-shaped structure at the center, around or other positions. The connector 1716 can pass through the hole-shaped structure and connect the various elements. For example, the connector 1716 can be a pipe pin. A punch head may be used to punch through the bracket 1714 to deform the tube pin 1716 , thereby fixing the first magnetic element 1702 , the first magnetic conductive element 1704 , the second magnetic conductive element 1706 , the second magnetic element 1708 and the third magnetic conductive element 1712 .The bracket 1914 can be connected to the bracket rail 1718, and the washer 1920 can be further connected to the second side wall of the third magnetic conductive element 1712 and the first side wall of the second magnetic conductive element 1706, so as to further fix the second magnetic conductive element 1706 and the third magnetic conductive element 1712. In some embodiments, the washer 1720 can be connected to the bracket 1714 through a vibration plate.

[0245] The above description of the structure of the bone conduction speaker 1700 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the bone conduction speaker 1700 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 1700 may include one or more conductive elements, and the one or more conductive elements are arranged on the inner wall, outer wall, top and / or bottom of the voice coil 1710. For another example, the bone conduction speaker 1700 may further include one or more annular magnetic elements, and the one or more annular magnetic elements may be connected to the upper surface of the side wall of the second magnetic conductive element 1706 or fixed in the magnetic gap.

[0246] Fig.181 is a schematic diagram of the structure of a bone conduction speaker 1800 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 1800 may include a first magnetic element 1802, a first magnetic conductive element 1804, a second magnetic conductive element 1806, a gasket 1808, a voice coil 1810, a first vibration plate 1812, a bracket 1814, a second vibration plate 1816 and a vibration panel 1818. The lower surface of the first magnetic element 1802 is connected to the inner wall of the second magnetic conductive element 1806. The upper surface of the first magnetic element 1802 is connected to the upper surface of the first magnetic conductive element 1804. A magnetic gap may be formed between the first magnetic element 1802, the first magnetic conductive element 1804 and the second magnetic conductive element 1806. The voice coil 1810 may be placed in the magnetic gap. In some embodiments, the voice coil 1810 may be a circular or non-circular structure, such as a triangle, rectangle, square, ellipse, pentagon or other irregular shapes. The voice coil 1810 is connected to the bracket 1814, the bracket 1814 is connected to the first vibration plate 1812, and the first vibration plate 1812 is connected to the second magnetic conductive element 1806 through the washer 1808. The lower surface of the second vibration plate 1816 is connected to the bracket 1814, and the upper surface of the second vibration plate 1816 is connected to the vibration panel 1818. In some embodiments, the first magnetic element 1802, the first magnetic conductive element 1804, the second magnetic conductive element 1806, the washer 1808, the voice coil 1810, the first vibration plate 1812, the bracket 1814, the second vibration plate 1816 and / or the vibration panel 1818 can be connected by any one or more of the connection methods described in the present application. For example, the first magnetic element 1802 can be connected to the first magnetic conductive element 1804 and / or the second magnetic conductive element 1806 by welding. For another example, the first magnetic element 1802, the first magnetic conductive element 1804 and / or the second magnetic conductive element 1806 may be provided with a hole-shaped structure, and the first magnetic element 1802, the first magnetic conductive element 1804 and / or the second magnetic conductive element 1806 may be connected by punching and deforming with a pipe pin. In some embodiments, the first vibration plate 1812 and / or the second vibration plate 1816 may be provided as one or more coaxial annular bodies, wherein the multiple annular bodies are provided with multiple support rods converging toward the center, and the converging center thereof is consistent with the center of the first vibration plate 1812 and / or the second vibration plate 1816. The multiple support rods are arranged in a staggered manner.

[0247] The above description of the structure of the bone conduction speaker 1800 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the bone conduction speaker 1800 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 1800 may include one or more conductive elements, and the one or more conductive elements are arranged on the inner wall, outer wall, top and / or bottom of the voice coil 1810. For another example, the bone conduction speaker 18000 may further include one or more annular magnetic elements, and the one or more annular magnetic elements may be connected to the upper surface of the side wall of the second magnetic conductive element 1806 or fixed in the magnetic gap. In some embodiments, the bone conduction speaker may further include a second magnetic element and / or a third magnetic conductive element.

[0248] Fig.19 1 is a structural schematic diagram of a bone conduction speaker 1900 according to some embodiments of the present application. As shown in the figure, the bone conduction speaker 1900 may include a first magnetic element 1902, a first magnetic conductive element 1910, a second magnetic element 1904, a third magnetic element 1906, a second magnetic conductive element 1908, a washer 1914, a voice coil 1912, a first vibration plate 1916, a bracket 1918, a second vibration plate 1920 and a vibration panel 1922. The lower surface of the first magnetic element 1902 is connected to the inner wall of the second magnetic conductive element 1908. The upper surface of the first magnetic element 1902 is connected to the lower surface of the first magnetic conductive element 1910. The outer wall of the second magnetic element 1904 is connected to the inner wall of the second magnetic conductive element 1908. The third magnetic element 1906 is below the second magnetic element 1904. At the same time, the outer wall of the third magnetic element 1906 is connected to the inner wall of the second magnetic conductive element 1908; the inner wall of the third magnetic element 1906 is connected to the outer wall of the first magnetic element 1902; the lower surface of the third magnetic element 1906 is connected to the inner wall of the second magnetic conductive element 1908; a magnetic gap can be formed between the first magnetic element 1902, the first magnetic conductive element 1910 and the second magnetic element 1904, the third magnetic element 1906. The voice coil 1912 can be placed in the magnetic gap. In some embodiments, the voice coil 1912 can be Fig.19The racetrack shape shown may also be other geometric shapes, such as triangle, rectangle, square, ellipse, pentagon or other irregular shapes. The voice coil 1912 is connected to the bracket 1918, the bracket 1918 is connected to the first vibration plate 1916, and the first vibration plate 1916 is connected to the second magnetic conductive element 1908 through the gasket 1914. The lower surface of the second vibration plate 1920 is connected to the bracket 1918, and the upper surface of the second vibration plate 1920 is connected to the vibration panel 1922. In some embodiments, the second magnetic element 1904 can be composed of multiple magnetic elements, such as Fig.19 As shown, it can be composed of four magnetic elements 19041, 19042, 19043, 19044. The shape surrounded by multiple magnetic elements can be Fig.19 The racetrack shape shown may also be other geometric shapes, such as triangle, rectangle, square, ellipse, pentagon or other irregular shapes. The third magnetic element 1906 may be composed of multiple magnetic elements, such as Fig.19 As shown, it can be composed of four magnetic elements 19061, 19062, 19063, 19064. The shape surrounded by multiple magnetic elements can be Fig.19 The racetrack shape shown may also be other geometric shapes, such as triangle, rectangle, square, ellipse, pentagon or other irregular shapes. As described in other embodiments of the present application, the second magnetic element 1904 or the third magnetic element 1906 may be replaced by a plurality of interconnected magnetic elements with different magnetization directions, and the plurality of interconnected magnetic elements with different magnetization directions may increase the magnetic field strength at the magnetic gap in the bone conduction speaker 1900, thereby increasing the sensitivity of the bone conduction speaker 1900.

[0249] In some embodiments, each of the first magnetic element 1902, the first magnetic conductive element 1910, the second magnetic element 1904, the third magnetic element 1906, the second magnetic conductive element 1908, the washer 1914, the voice coil 1912, the first vibration plate 1916, the bracket 1918, the second vibration plate 1920 and / or the vibration panel 1922 can be connected by any one or more of the connection methods described in the present application. For example, the first magnetic element 1902, the second magnetic element 1904, and the third magnetic element 1906 can be connected to the first magnetic conductive element 1910 and / or the second magnetic conductive element 1908 by bonding. For another example, the washer 1914 can be connected to the second magnetic conductive element 1908 by an undercut structure, and further, the washer 1914 can be connected to the second magnetic conductive element 1908 and / or the second magnetic element 1904 by an undercut structure plus bonding. In some embodiments, the first vibration plate 1916 and / or the second vibration plate 1920 can be configured as one or more coaxial ring bodies, wherein the plurality of ring bodies are provided with a plurality of support rods converging toward the center, and the center of convergence is consistent with the center of the first vibration plate 1916 and / or the second vibration plate 1920. The plurality of support rods are staggered. The plurality of support rods are straight rods or curved rods or partly straight rods and partly curved rods. Preferably, the plurality of support rods are curved rods. In some embodiments, the outer surface of the vibration panel 1922 can be a plane or a curved surface. For example, the outer surface of the vibration panel 1922 is Fig.19 The convex curved surface shown.

[0250] The above description of the structure of the bone conduction speaker 1900 is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the magnetic circuit assembly, various modifications and changes in form and details can be made to the specific methods and steps of implementing the bone conduction speaker 1900 without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 1900 may include one or more conductive elements, and the one or more conductive elements are arranged on the inner wall, outer wall, top and / or bottom of the voice coil 1912. For another example, the bone conduction speaker 1900 may further include one or more annular magnetic elements, and the one or more annular magnetic elements may connect the lower surface of the second magnetic element 1904 and the upper surface of the third magnetic element 1906. In some embodiments, the bone conduction speaker may further include a fifth magnetic element and / or a third magnetic conductive element as described in other embodiments of the present application.

[0251] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0252] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment" and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0253] In addition, it will be appreciated by those skilled in the art that various aspects of the present application may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances or any new and useful improvements thereto. Accordingly, various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, the product including computer-readable program code.

[0254] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters or other names, are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0255] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0256] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used to describe the embodiments are modified by modifiers such as "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical data used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical data should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and data used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0257] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in this application.

Claims

1. A magnetic circuit assembly of a bone conduction speaker, characterized in that: The magnetic circuit component generates a first full magnetic field, and the magnetic circuit component includes: a first magnetic element; A first magnetic conductive element, wherein a lower surface of the first magnetic conductive element is connected to an upper surface of the first magnetic element; a third magnetic element, the third magnetic element surrounding the first magnetic element and forming a magnetic gap with the first magnetic element, the magnetic gap being used to accommodate the voice coil of the bone conduction speaker; Wherein, in the spacing direction between the upper surface and the lower surface of the first magnetic element, the lower surface of the third magnetic element is between the upper surface and the lower surface of the first magnetic element, and the upper surface of the third magnetic element is located on the side of the upper surface of the first magnetic conductive element away from the lower surface, and in the spacing direction, the distance from the lower surface of the voice coil to the lower surface of the third magnetic element is smaller than the distance from the lower surface of the voice coil to the upper surface of the third magnetic element, and the angle between the magnetization direction of the third magnetic element and the magnetization direction of the first magnetic element is between 45 degrees and 135 degrees.

2. The magnetic circuit assembly according to claim 1, characterized in that: The magnetization direction of the first magnetic element is perpendicular to the lower surface or the upper surface of the first magnetic element and is vertically upward. The magnetization direction of the third magnetic element is from the inner ring to the outer ring of the third magnetic element.

3. The magnetic circuit assembly according to claim 1, characterized in that: The magnetic circuit assembly further includes a first total magnetic field changing element, which surrounds the first magnetic element, and a lower surface of the third magnetic element is connected to an upper surface of the first total magnetic field changing element.

4. The magnetic circuit assembly according to claim 3, characterized in that: The first total magnetic field changing element is a magnetic element or a magnetic conductive element.

5. The magnetic circuit assembly according to claim 3, characterized in that: The magnetic circuit assembly also includes a magnetic cover, which includes a bottom plate and a side wall. The side wall is an annular structure. The lower surface of the first magnetic element is connected to the bottom plate, and the first full magnetic field changing element and the third magnetic element are connected to the inner surface of the side wall.

6. The magnetic circuit assembly according to claim 3, characterized in that: The magnetic circuit assembly also includes a fourth magnetic element, the lower surface of the fourth magnetic element is connected to the upper surface of the first total magnetic field changing element, the upper surface of the fourth magnetic element is connected to the lower surface of the third magnetic element, and the angle between the magnetization direction of the fourth magnetic element and the magnetization direction of the first magnetic element is between 45 degrees and 135 degrees, or is 180 degrees.

7. The magnetic circuit assembly according to claim 1, characterized in that: The magnetic circuit assembly further includes a fifth magnetic element connected to an upper surface of the first magnetic conductive element.

8. The magnetic circuit assembly according to claim 7, characterized in that: An angle between a magnetization direction of the fifth magnetic element and a magnetization direction of the first magnetic element is between 150 degrees and 180 degrees.

9. The magnetic circuit assembly according to claim 7, characterized in that: The ratio of the thickness of the fifth magnetic element to the sum of the thicknesses of the first magnetic element, the fifth magnetic element and the first magnetic conductive element is in the range of 0.4-0.

6.

10. A bone conduction speaker, characterized in that: The bone conduction speaker comprises: a vibration assembly, the vibration assembly comprising a voice coil and at least one vibration plate; and The magnetic circuit component according to any one of claims 1 to 9.

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