HK1257083A1

HK1257083A1 - Bone conduction speaker

Info

Publication number: HK1257083A1
Application number: HK18116258.3A
Authority: HK
Inventors: Lei Zhang; Fengyun LIAO; Xin Qi
Original assignee: 深圳市韶音科技有限公司
Priority date: 2018-12-19
Filing date: 2018-12-19
Publication date: 2019-10-11

Description

Bone conduction loudspeaker

Technical Field

The present invention relates to a bone conduction speaker, and more particularly, to a magnetic circuit assembly in a bone conduction speaker.

Background

The bone conduction speaker can convert the electric signal into a mechanical vibration signal, and the vibration signal is transmitted into a cochlea through human tissues and bones, so that a user can hear the sound. For the air conduction speaker, the vibrating diaphragm drives the air to vibrate to generate sound, and the bone conduction vibration speaker needs to drive the soft tissue and bone of the user to vibrate, so that the required mechanical power is high. Increasing the sensitivity of the bone conduction speaker enables a higher efficiency of converting electrical energy into mechanical energy, thereby outputting a greater mechanical power. Increasing the sensitivity is even more important for bone conduction speakers with higher power requirements.

Brief description of the drawings

One aspect of the present application relates to a magnetic circuit assembly of a bone conduction speaker. The magnetic circuit assembly comprises a first magnetic element that generates a first magnetic field; a first magnetic conductive element; and at least one second magnetic element surrounding the first magnetic element and forming a magnetic gap with the first magnetic element, the second magnetic element generating a second magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

According to some embodiments of the present application, an angle between a magnetization direction of the at least one second magnetic element and a magnetization direction of the first magnetic element is not less than 90 degrees.

According to some embodiments of the application, the magnetic circuit assembly further comprises a second magnetically permeable element; and at least one third magnetic element. The at least one third magnetic element connects the second magnetic permeable element and the at least one second magnetic element, the at least one third magnetic element generates a third magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

According to some embodiments of the present application, an angle between a magnetization direction of the at least one third magnetic element and a magnetization direction of the first magnetic element is not less than 90 degrees.

According to some embodiments of the present application, the magnetic circuit assembly further comprises at least one fourth magnetic element, wherein the at least one fourth magnetic element is disposed below the magnetic gap and connects the first magnetic element and the second magnetic permeable element, the at least one fourth magnetic element generating a fourth magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

According to some embodiments of the present application, between the magnetization direction of the at least one fourth magnetic element and the magnetization direction of the first magnetic element is between 45 degrees and 135 degrees.

According to some embodiments of the application, the magnetic circuit assembly further comprises at least one fifth magnetic element, wherein the at least one fifth magnetic element is connected to the upper surface of the first magnetically permeable element, the at least one fifth magnetic element generating a fifth magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

According to some embodiments of the present application, the magnetization direction of the at least one fifth magnetic element is at an angle between 150 degrees and 180 degrees to the magnetization direction of the first magnetic element.

According to some embodiments of the present application, a ratio of a thickness of the first magnetic element to a sum of thicknesses of the first magnetic element, the at least one fifth magnetic element, and the first magnetic conductive element ranges from 0.4 to 0.6.

According to some embodiments of the present application, a thickness of the at least one fifth magnetic element is equal to a thickness of the first magnetic element.

According to some embodiments of the present application, a thickness of the at least one fifth magnetic element is less than a thickness of the first magnetic element.

According to some embodiments of the application, the magnetic circuit assembly further comprises a third magnetic conductive element, wherein the third magnetic conductive element is connected to an upper surface of the fifth magnetic element, and the third magnetic conductive element is configured to suppress leakage of field strengths of the first magnetic field and the second magnetic field.

According to some embodiments of the present application, the first magnetic conductive element is connected to an upper surface of the first magnetic element, the second magnetic conductive element includes a bottom plate and a sidewall, and the first magnetic element is connected to the bottom plate of the second magnetic conductive element.

According to some embodiments of the application, the magnetic circuit assembly further comprises at least one electrically conductive element, wherein the electrically conductive element is connected to at least one of the first magnetic element, the first magnetically permeable element, or the second magnetically permeable element.

Additional features of the present application will be set forth in part in the description which follows. Additional features of some aspects of the present application will be apparent to those of ordinary skill in the art in view of the following description and accompanying drawings or may be learned by the manufacture or operation of the embodiments. The features disclosed in this application may be realized and attained by practice or use of various methods, instrumentalities and combinations of the specific embodiments described below.

Description of the drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. Like reference symbols in the various drawings indicate like elements.

FIG. 1 is a block diagram of a bone conduction speaker according to some embodiments of the present application;

fig. 2 is a schematic longitudinal cross-sectional view of a bone conduction speaker according to some embodiments of the present application;

fig. 3A is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

fig. 3B is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

fig. 3C is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

fig. 3D is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

fig. 3E is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

fig. 3F is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

fig. 3G is a schematic longitudinal cross-sectional view of a magnetic circuit assembly according to some embodiments of the present application;

FIG. 4A is a cross-sectional schematic view of a magnetic element according to some embodiments of the present application;

FIG. 4B is a schematic diagram of a magnetic element according to some embodiments of the present application;

figure 4C is a schematic view of the magnetization direction of a magnetic element in a magnetic circuit assembly according to some embodiments of the present application;

fig. 4D is a magnetic flux density profile for a magnetic element in a magnetic assembly according to some embodiments of the present application.

DETAILED DESCRIPTIONS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. It is understood that these exemplary embodiments are given solely to enable those skilled in the relevant art to better understand and implement the present invention, and are not intended to limit the scope of the invention in any way. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description. Hereinafter, without loss of generality, in describing the bone conduction related art in the present invention, a description of "bone conduction speaker" or "bone conduction headset" will be employed. The description is merely one form of bone conduction application and it will be apparent to one of ordinary skill in the art that the "speaker" or "earpiece" may be replaced by other words of the same kind, such as "player", "hearing aid", etc. Indeed, various implementations of the invention may be readily applied to other non-speaker-type hearing devices. For example, it will be apparent to those skilled in the art that, having the benefit of the basic principles of a bone conduction speaker, various modifications and changes in form and detail may be made to the specific manner and procedure of implementing a bone conduction speaker, and in particular, the incorporation of ambient sound pickup and processing functionality into a bone conduction speaker to enable the speaker to function as a hearing aid, without departing from such principles. For example, a microphone, such as a microphone, may pick up sounds from the user/wearer's surroundings and, under certain algorithms, transmit the sound processed (or resulting electrical signal) to a bone conduction speaker portion. That is, the bone conduction speaker may be modified to incorporate a function of picking up ambient sound, and after a certain signal processing, transmit the sound to the user/wearer through the bone conduction speaker portion, thereby implementing the function of the bone conduction hearing aid. By way of example, the algorithms described herein may include one or more combinations of noise cancellation, automatic gain control, acoustic feedback suppression, wide dynamic range compression, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, and the like.

The invention provides a bone conduction speaker with high sensitivity. In some embodiments, the bone conduction speaker may include a magnetic circuit assembly. The magnetic circuit assembly may include a first magnetic element, a first magnetically permeable element, and one or more second magnetic elements. The first magnetic element may generate a first 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. The one or more second magnetic elements generate a second magnetic field, and the second magnetic field increases a magnetic field strength of the first magnetic field within the magnetic gap. The plurality of second magnetic elements in the magnetic circuit assembly surround the first magnetic element, so that the volume and the weight of the magnetic circuit assembly can be reduced, the efficiency of the bone conduction loudspeaker can be improved, and the service life of the bone conduction loudspeaker can be prolonged under the conditions of improving the magnetic field intensity of the magnetic gap and improving the sensitivity of the bone conduction loudspeaker.

Bone conduction speaker has characteristics such as small, light in weight, efficient, sensitivity height and long service life, be convenient for with bone conduction speaker combines together with wearing formula smart machine to realize the multi-functionalization of single equipment, improve and optimize user experience. The wearable smart devices include, but are not limited to, smart headsets, smart glasses, smart headbands, smart helmets, smart watches, smart gloves, smart shoes, smart cameras, smart video cameras, and the like. The bone conduction speaker may further be integrated with smart materials, integrating the bone conduction speaker in the manufacturing materials of the user's clothing, gloves, hats, shoes, etc. The bone conduction speaker can be further implanted into a human body, and can realize more personalized functions in cooperation with a human body implantation chip or an external processor.

Fig. 1 is a block diagram illustrating a structure of a bone conduction speaker 100 according to some embodiments of the present application. As shown, the bone conduction speaker 100 may include a magnetic circuit assembly 102, a vibration assembly 104, a support assembly 106, and a storage assembly 108.

The magnetic circuit assembly 102 may provide a magnetic field. The magnetic field may be used to convert a signal containing acoustic information into a vibration signal. In some embodiments, the sound information may include video having a particular data format, an audio file, or data or files that may be converted to sound by a particular means. The signal containing the sound information may come from the memory component 108 of the bone conduction speaker 100 itself, or may come from an information generation, storage, or transmission system other than the bone conduction speaker 100. The signal containing acoustic information may include one or a combination of electrical, optical, magnetic, mechanical signals, and the like. The signal containing the sound information may be from one signal source or multiple signal sources. The multiple signal sources may or may not be correlated. In some embodiments, the bone conduction speaker 100 may acquire the signal containing the sound information in a number of different ways, 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 voice 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 voice signal. For another example, a bone conduction hearing aid may include a component having a sound collection function, which picks up sound in the environment, converts mechanical vibration of the sound into an electrical signal, and obtains the electrical signal meeting specific requirements after processing by an amplifier. In some embodiments, the wired connection may include a metal cable, an optical cable, or a hybrid of metal and optical cables, such as a coaxial cable, a communications cable, a flex cable, a spiral cable, a non-metal sheathed cable, a multi-core cable, a twisted-pair cable, a ribbon cable, a shielded cable, a telecommunications cable, a twinax cable, a parallel twin-core wire, a twisted pair cable, or a combination of one or more thereof. The above-described examples are merely for convenience of illustration, and the medium for wired connection may be other types of transmission medium, such as other transmission medium of electrical or optical signals.

Wireless connections may include radio communications, free space optical communications, acoustic communications, electromagnetic induction, and the like. Wherein the radio communications may include the IEEE802.11 family of standards, the IEEE802.15 family of standards (e.g., Bluetooth and ZigBee technologies, etc.), first generation mobile communication technologies, second generation mobile communication technologies (e.g., FDMA, TDMA, SDMA, CDMA, and SSMA, etc.), general packet radio service technologies, third generation mobile communication technologies (e.g., CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth generation mobile communication technologies (e.g., TD-LTE, FDD-LTE, etc.), satellite communications (e.g., GPS technologies, etc.), Near Field Communications (NFC), and other technologies operating in the ISM band (e.g., 2.4GHz, etc.); free space optical communication may include visible light, infrared signals, and the like; the acoustic communication may include acoustic waves, ultrasonic signals, etc.; electromagnetic induction may include near field communication techniques and the like. The above examples are for convenience of illustration only, and the medium for the wireless connection may be of other types, such as Z-wave technology, other premium civilian radio bands, and military radio bands, among others. For example, as some application scenarios of the present technology, the bone conduction speaker 100 may acquire signals containing sound information from other devices through bluetooth technology.

The vibration assembly 104 may generate mechanical vibrations. The generation of the vibration is accompanied by the conversion of energy, and the bone conduction speaker 100 can convert a signal containing sound information into mechanical vibration by using the specific magnetic circuit component 102 and the vibration component 104. The conversion process may involve the coexistence and conversion of multiple different types of energy. For example, the electrical signal may be directly converted to mechanical vibrations by a transducer device, producing sound. For another example, sound information may be included in the light signal, and a particular transducing device may effect the conversion of the light signal into a vibration signal. Other types of energy that may be co-present and converted during operation of the transducer device include thermal energy, magnetic field energy, and the like. The energy conversion mode of the energy conversion device can comprise moving coil type, electrostatic type, piezoelectric type, moving iron type, pneumatic type, electromagnetic type and the like. The frequency response range and sound quality of the bone conduction speaker 100 may be affected by the vibration component 104. For example, in the moving coil transducer device, the vibrating element 104 includes a wound cylindrical coil and a vibrating body (e.g., a vibrating reed), the cylindrical coil driven by a signal current drives the vibrating body to vibrate and generate sound in a magnetic field, and the expansion and contraction of the vibrating body material, the deformation, size, shape, and fixing manner of the folds, the magnetic density of the permanent magnet, and the like all have great influence on the sound effect quality of the bone conduction speaker 100. The vibrating body in the vibrating assembly 104 may be a mirror symmetric structure, a center symmetric structure, or an asymmetric structure; the vibrating body can be provided with a discontinuous hole-shaped structure, so that the vibrating body generates larger displacement, the bone conduction loudspeaker realizes higher sensitivity, and the output power of vibration and sound is improved; the vibrating body can be of a ring body structure, a plurality of supporting rods which converge towards the center are arranged in the ring body, and the number of the supporting rods can be two or more.

The support assembly 106 may support the magnetic circuit assembly 102, the vibration assembly 104, and/or the storage assembly 108. The support assembly 106 may include one or more housings, one or more connectors. The one or more housings may form a receiving space for receiving the magnetic circuit assembly 102, the vibration assembly 104, and/or the storage assembly 108. The one or more connectors may connect the housing with the magnetic circuit assembly 102, the vibration assembly 104, and/or the storage assembly 108.

The storage component 108 may store signals containing sound information. In some embodiments, storage component 108 may include one or more storage devices. The Storage device may include a Storage device on a Storage system such as Direct Attached Storage (Direct Attached Storage), Network Attached Storage (Network Attached Storage), and Storage area Network (Storage area Network). The storage device may include various types of storage devices such as solid-state storage devices (solid-state disk, solid-state hybrid disk, etc.), mechanical hard disk, USB flash memory, memory stick, memory card (e.g., CF, SD, etc.), other drives (e.g., CD, DVD, HD DVD, Blu-ray, etc.), Random Access Memory (RAM), and Read Only Memory (ROM). Wherein the RAM can comprise a decimal count tube, a number selection tube, a delay line memory, a Williams tube, a Dynamic Random Access Memory (DRAM), a Static Random Access Memory (SRAM), a thyristor random access memory (T-RAM), a zero-capacitance random access memory (Z-RAM) and the like; the ROM may include bubble memory, magnetic button wire memory, thin film memory, magnetic wire memory, magnetic core memory, magnetic drum memory, optical disk drives, hard disks, magnetic tape, early NVRAM (non-volatile memory), phase change memory, magnetoresistive random access memory, ferroelectric random access memory, non-volatile SRAM, flash memory, EEPROM, erasable programmable read only memory, shielded read-heap memory, floating gate random access memory, nano-RAM, racetrack memory, variable resistive memory, and programmable metallization cells, among others. The above-mentioned storage device/storage unit is just to exemplify some examples, and the storage device that can be used by the storage device/storage unit is not limited thereto.

The above description of the bone conduction speaker configuration is merely a specific example and should not be considered the only possible embodiment. It will be obvious to those having skill in the art that, having the benefit of the teachings of the present bone conduction speaker, it is possible to embody the bone conduction speaker in the specific manner and procedure with various modifications and changes in form and detail without departing from such teachings, but such modifications and changes are intended to be within the purview of the foregoing description. For example, the bone conduction speaker 100 may include one or more processors that may execute one or more sound signal processing algorithms. The sound signal processing algorithm may modify or enhance the sound signal. Such as 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 the like, or any combination thereof, of the acoustic signal, and such modifications and variations are intended to be within the scope of the claims appended hereto. For another example, the bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a velocity sensor, a displacement sensor, and the like. The sensor may collect user information or environmental information.

Fig. 2 is a schematic longitudinal cross-sectional view of a bone conduction speaker 200 according to some embodiments of the present application. As shown, 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.

The magnetic element described in the present application refers to an element that can generate a magnetic field, such as a magnet or the like. The magnetic element may have a magnetization direction, which refers to a direction of a magnetic field inside the magnetic element. The first magnetic element 202 may include one or more magnets. In some embodiments, the magnet may comprise a metal alloy magnet, ferrite, or the like. Wherein the metal alloy magnet may comprise neodymium iron boron, samarium cobalt, alnico, iron chromium cobalt, aluminum iron boron, iron carbon aluminum, or the like, or combinations thereof. The ferrite may comprise barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or various combinations thereof.

The lower surface of the first magnetic conductive element 204 may be connected to the upper surface of the first magnetic element 202. The second magnetic permeable element 206 may be connected to the first magnetic element 202. It should be noted that the magnetizer referred to herein may also be referred to as a magnetic field concentrator or an iron core. The magnetizer may adjust a distribution of a magnetic field (e.g., the magnetic field generated by the first magnetic element 202). The magnetizer may include a member 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, and the like, such as iron, an iron-silicon based alloy, an iron-aluminum based alloy, a nickel-iron based alloy, an iron-cobalt based alloy, a low carbon steel, a silicon steel sheet, a ferrite, and the like. In some embodiments, the magnetizer may be processed by one or more combined methods of casting, plastic working, cutting working, powder metallurgy, and the like. The casting may include sand casting, investment casting, pressure casting, centrifugal casting, etc.; the plastic working may include one or more combinations of rolling, casting, forging, stamping, extruding, drawing, and the like; the cutting process may include turning, milling, planing, grinding, and the like. In some embodiments, the processing method of the magnetizer may include 3D printing, numerical control machine tool, and the like. The first magnetic conductive element 204, the second magnetic conductive element 206 and the first magnetic element 202 may be connected by one or more combinations of bonding, clamping, welding, riveting, bolting, etc. In some embodiments, the first magnetic element 202, the first magnetic permeable element 204, and the second magnetic permeable element 206 may be arranged in an axisymmetric configuration. The axisymmetrical structure can be a ring structure, a column structure or other axisymmetrical structures.

In some embodiments, a magnetic gap may be formed between the first magnetic element 202 and the second magnetic permeable 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. After the current is applied to 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 will be subjected to an ampere force, the ampere force drives the voice coil 210 to vibrate, and the vibration of the voice coil 210 drives the first vibration plate 208, the second vibration plate 212, and the vibration panel 214 to vibrate. The vibration panel 214 transmits the vibration to the auditory nerve through the tissue and bone, thereby making the human hear the sound. The vibration panel 214 may be in direct contact with the skin of a human body, or may be in contact with the skin through a vibration transmission layer composed of a specific material.

In some embodiments, for a bone conduction speaker with a single magnetic element, the lines of magnetic induction through the voice coil are not uniform and diverge. Meanwhile, magnetic leakage may be formed in the magnetic circuit, that is, more magnetic induction lines leak out of the magnetic gap and fail to pass through the voice coil, so that the magnetic induction intensity (or magnetic field intensity) at the position of the voice coil is reduced, and the sensitivity of the bone conduction speaker is affected. Accordingly, 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 the at least one third magnetic conductive element may inhibit leakage of magnetic induction lines, and constrain a magnetic induction line state passing through the voice coil, so that more magnetic induction lines may horizontally and densely pass through the voice coil as much as possible, and magnetic induction intensity (or magnetic field intensity) at the position of the voice coil may be enhanced, thereby improving sensitivity of the bone conduction speaker 200, and further improving mechanical conversion efficiency of the bone conduction speaker 200 (i.e., efficiency of converting electric energy input to the bone conduction speaker 200 into mechanical energy of vibration of the voice coil). For more description of the at least one second magnetic element, reference may be made to fig. 3A-3G.

The above description of the structure of the bone conduction speaker 200 is merely a specific example and should not be considered as the only possible embodiment. It will be obvious to those having skill in the art that, having the benefit of the teachings of the present bone conduction speaker, it is possible to embody the bone conduction speaker in the specific manner and procedure with various modifications and changes in form and detail without departing from such teachings, but such modifications and changes are intended to be within the purview of the foregoing description. For example, the bone conduction speaker 200 may include a housing, a connector, and the like. The connector may connect the vibration panel 214 with the housing. For another example, the bone conduction speaker 200 may include a second magnetic element, which may be coupled to the first magnetic conductive element 204. Also for example, the bone conduction speaker 200 may further include one or more ring-shaped magnetic elements, which may be coupled to the second magnetic conductive element 206.

Fig. 3A is a longitudinal cross-sectional schematic view of a magnetic circuit assembly 3100, according to some embodiments of the present application. As shown in fig. 3A, 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 of the magnets described herein. In some embodiments, the first magnetic element 302 may comprise a first magnet and the second magnetic element 308 may comprise a second magnet, which may be the same or different. The first and/or second magnetic conductive elements 304, 306 may comprise any one or more of the magnetic conductive materials described herein. The method of processing the first magnetic conductive element 304 and/or the second magnetic conductive element 306 may include any one or more of the processing methods described herein. In some embodiments, the first magnetic element 302 and/or the first magnetic permeable element 304 may be arranged in an axisymmetric configuration. For example, the first magnetic element 302 and/or the first magnetically permeable element 304 may be cylindrical, rectangular parallelepiped, or hollow toroidal (e.g., racetrack shaped in cross-section). In some embodiments, the first magnetic element 302 and the first magnetic permeable element 304 may be coaxial cylinders, containing the same or different diameters. In some embodiments, the second magnetic permeable element 306 may be a groove-type structure. The channel-type structure may comprise a U-shaped cross-section (as shown in fig. 3A). The groove-type second magnetic permeable element 306 may include a bottom plate and a sidewall. In some embodiments, the bottom plate and the side walls may be integrally formed, for example, the side walls may be formed by the bottom plate extending in a direction perpendicular to the bottom plate. In some embodiments, the bottom panel may be connected to the side walls by any one or more of the connections described herein. The second magnetic element 308 may be configured in a ring shape or a sheet shape. In some embodiments, the second magnetic element 308 may be coaxial with the first magnetic element 302 and/or the first magnetic permeable element 304.

The upper surface of the first magnetic element 302 may be connected to the lower surface of the first magnetic permeable element 304. The lower surface of the first magnetic element 302 may 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 sidewall 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 may include one or more of bonding, snapping, welding, riveting, bolting, and the like.

The first magnetic element 302 and/or the first magnetic permeable element 304 forms a magnetic gap with the inner ring of the second magnetic element 308. Voice coil 328 may 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 permeable 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 may form a magnetic circuit. In some embodiments, the magnetic circuit assembly 3100 may generate a first full magnetic field (which may also be referred to as a "total magnetic field of the magnetic circuit assembly"), and the first magnetic element 302 may generate a second magnetic field. The first full magnetic field is formed collectively by the magnetic fields generated by all of the components (e.g., the first magnetic element 302, the first magnetic conductive element 304, the second magnetic conductive element 306, and the second magnetic element 308) in the magnetic circuit assembly 3100. The magnetic field strength (which may also be referred to as magnetic induction or magnetic flux density) of the first full magnetic field within the magnetic gap is greater than the magnetic field strength of the second magnetic field within the magnetic gap. In some embodiments, the second magnetic element 308 may generate a third magnetic field that may increase the magnetic field strength of the first full magnetic field at the magnetic gap. The third magnetic field increasing the magnetic field strength of the first full magnetic field as used herein means that the magnetic field strength of the first full magnetic field in the presence of the third magnetic field (i.e., in the presence of the second magnetic element 308) is greater than the magnetic field strength of the first full magnetic field in the absence of the third magnetic field (i.e., in the absence of the second magnetic element 308). In other embodiments in this specification, unless otherwise specified, the magnetic circuit assembly indicates a structure including all the magnetic elements and the magnetic conductive element, the first full magnetic field indicates a 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 each indicate a magnetic field generated by the corresponding magnetic element. In different embodiments, the magnetic elements that generate the second magnetic field (or the third magnetic field, … …, nth magnetic field) may be the same or different.

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 vertically upward (a direction shown in the figure) perpendicular to the lower surface or the upper surface of the first magnetic element 302, and the magnetization direction of the second magnetic element 308 is directed from the inner ring to the outer ring of the second magnetic element 308 (the magnetization direction of the first magnetic element 302 is shifted 90 degrees in the clockwise direction on the right side of the first magnetic element 302 as shown in the b direction in the figure).

In some embodiments, at the location of the second magnetic element 308, the angle between the direction of the first full magnetic field and the magnetization direction of the second magnetic element 308 is no higher than 90 degrees. In some embodiments, 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 at the location of the second magnetic element 308 may be an angle of less than or equal to 90 degrees, such as 0 degrees, 10 degrees, 20 degrees, and the like.

The second magnetic element 308 may increase the total magnetic flux in the magnetic gap in the magnetic circuit assembly 3100, thereby increasing the magnetic induction in the magnetic gap, as compared to a magnetic circuit assembly with a single magnetic element. Moreover, under the action of the second magnetic element 308, the originally divergent magnetic induction lines converge toward the position of the magnetic gap, and further increase the magnetic induction intensity in the magnetic gap.

The above description of the structure of the magnetic circuit assembly 3100 is merely a specific example and should not be considered the only possible embodiment. It is clear that, after having understood the basic principle of the bone magnetic circuit assembly, it is possible for a person skilled in the art to carry out various modifications and variations in form and detail of the specific way and the steps of implementing the magnetic circuit assembly 3100 without departing from this principle, but these modifications and variations are still within the scope of what has been described above. For example, the second magnetic permeable element 306 may be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3100 may further include a magnetic shield that may surround the first magnetic element 302, the first magnetic element 304, the second magnetic element 306, and the second magnetic element 308.

Fig. 3B is a schematic longitudinal cross-sectional view of a magnetic circuit assembly 3200 according to some embodiments of the present application. As shown in fig. 3B, unlike the magnetic circuit assembly 3100, the magnetic circuit assembly 3200 may further include a third magnetic element 310.

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 sidewall of the second magnetic conductive element 306. The first magnetic element 302, the first magnetic conductive element 304, the second magnetic element 308, and/or the third magnetic element 310 may form a magnetic gap therebetween. 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 can be as described in detail with reference to FIG. 3A herein.

In some embodiments, the magnetic circuit assembly 3200 may generate a first full magnetic field and the first magnetic element 302 may generate a second magnetic field, the first full magnetic field having a magnetic field strength within the magnetic gap that is greater than a magnetic field strength of the second magnetic field within the magnetic gap. In some embodiments, the third magnetic element 310 may generate a third magnetic field that may increase the magnetic field strength of the second magnetic field at the magnetic gap.

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 vertically upward (as shown in the direction of a) perpendicular to the lower surface or the upper surface of the first magnetic element 302, and the magnetization direction of the third magnetic element 310 is directed from the upper surface to the lower surface of the third magnetic element 310 (as shown in the direction of c, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is shifted by 180 degrees in the clockwise direction).

In some embodiments, at the location of the third magnetic element 310, the angle between the direction of the first full magnetic field and the magnetization direction of the third magnetic element 310 is no higher than 90 degrees. In some embodiments, at the location 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 may be an angle of 0 degrees, 10 degrees, 20 degrees, etc., that is less than or equal to 90 degrees.

The magnetic circuit assembly 3200 further adds a third magnetic element 310 as compared to the magnetic circuit assembly 3100. The third magnetic element 310 may further increase the total magnetic flux within the magnetic gap in the magnetic circuit assembly 3200, thereby increasing the magnetic induction in the magnetic gap. Further, the third magnetic element 310 causes the magnetic induction lines to further converge toward the position of the magnetic gap, thereby further increasing the magnetic induction intensity in the magnetic gap.

The above description of the structure of the magnetic circuit assembly 3200 is merely a specific example and should not be considered the only possible embodiment. It will be clear to those skilled in the art, having the understanding of the basic principles of the magnetic circuit assembly, that various modifications and changes in form and detail of the specific manner and procedure of implementing the magnetic circuit assembly 3200 may be made without departing from such principles, but such modifications and changes are within the scope of the above description. For example, the second magnetic permeable element 306 may be an annular structure or a sheet structure. As another example, the magnetic circuit assembly 3200 may not include the second magnetic conductive element 306. As another example, the magnetic circuit assembly 3200 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 opposite to the magnetization direction of the third magnetic element 312. In some embodiments, the further magnetic element may be connected to the sidewalls of the first magnetic element 302 and the second magnetic permeable element 306. The magnetization direction of the further added magnetic element is opposite to the magnetization direction of the second magnetic element 308.

Fig. 3C is a longitudinal cross-sectional schematic view of a magnetic circuit assembly 3300 according to some embodiments of the present application. As shown in fig. 3C, unlike the magnetic circuit assembly 3100, the magnetic circuit assembly 3300 can further include a fourth magnetic element 312.

The fourth magnetic element 312 may be attached to the sidewalls of the first magnetic element 302 and the second magnetic element 306 by one or more of bonding, snapping, 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 may form a magnetic gap. In some embodiments, the magnetization direction of the second magnetic element 308 can be as described in detail with reference to FIG. 3A herein.

In some embodiments, the magnetic circuit assembly 3300 may generate a first full magnetic field and the first magnetic element 302 may generate a second magnetic field, the first full magnetic field having a magnetic field strength within the magnetic gap that is greater than a magnetic field strength of the second magnetic field within the magnetic gap. In some embodiments, the fourth magnetic element 312 may generate a fourth magnetic field that may increase the magnetic field strength of the second magnetic field at the magnetic gap.

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 no higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is vertically upward (as shown in the direction of a) perpendicular to the lower surface or the upper surface of the first magnetic element 302, and the magnetization direction of the fourth magnetic element 312 is directed from the outer ring to the inner ring of the fourth magnetic element 312 (as shown in the direction of d, 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, at the position of the fourth magnetic element 312, the angle between the direction of the first full magnetic field and the magnetization direction of the fourth magnetic element 312 is not higher than 90 degrees. In some embodiments, at the position 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 may be an angle of 0 degrees, 10 degrees, 20 degrees, etc., that is less than or equal to 90 degrees.

The magnetic circuit assembly 3300 further adds the fourth magnetic element 312 as compared to the magnetic circuit assembly 3100. The fourth magnetic element 312 may further increase the total magnetic flux within the magnetic gap in the magnetic circuit assembly 3300, thereby increasing the magnetic induction in the magnetic gap. Further, the fourth magnetic element 312 causes the magnetic induction lines to further converge toward the position of the magnetic gap, thereby further increasing the magnetic induction intensity in the magnetic gap.

The above description of the structure of the magnetic circuit assembly 3300 is merely a specific example and should not be considered the only possible embodiment. It will be apparent to those skilled in the art that, having the benefit of the teachings of the bone magnetic circuit assembly, various modifications and changes in form and detail of the specific manner and steps of implementing the magnetic circuit assembly 3300 may be made without departing from such principles, but such modifications and changes are intended to be within the purview of the foregoing description. For example, the second magnetic permeable element 306 may be an annular structure or a sheet structure. As another example, the magnetic circuit assembly 3300 may not include the second magnetic element 308. As another example, the magnetic circuit assembly 3300 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. In some embodiments, the upper surface of the further magnetic element may 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.

Figure 3D is a longitudinal cross-sectional schematic view of a magnetic circuit assembly 3400 according to some embodiments of the present application. As shown in fig. 3D, 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 comprise any of the magnet materials described herein. In some embodiments, the fifth magnetic element 314 may be disposed in an axisymmetric configuration. For example, the fifth magnetic element 314 may be a cylinder, a rectangular parallelepiped, or a hollow ring shape (e.g., a cross-section in the shape of a racetrack). In some embodiments, the first magnetic element 302, the first magnetic permeable element 304, and/or the fifth magnetic element 314 may be coaxial cylinders, containing the same or different diameters. The thickness of the fifth magnetic element 314 may be the same or different than the first magnetic element 302. The fifth magnetic element 314 may be coupled to the first magnetic permeable element 304. In some embodiments, the ratio of the thickness of the first magnetic element 302 to the sum of the thicknesses of the first magnetic element 302, the fifth magnetic element 314, and the first magnetic permeable element 304 is in the range of 0.4-0.6.

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, a-direction and e-direction).

The magnetic circuit assembly 3400 further adds the fifth magnetic element 314 as compared to the magnetic circuit assembly 3100. The fifth magnetic element 314 can suppress leakage of the magnetic flux in the magnetization direction of the first magnetic element 302 in the magnetic circuit assembly 3400, so that the magnetic field generated by the first magnetic element 302 can be compressed more into the magnetic gap, thereby improving the magnetic induction intensity in the magnetic gap.

The above description of the structure of the magnetic circuit assembly 3400 is merely a specific example and should not be considered as the only possible embodiment. It will be clear to a person skilled in the art, having the understanding of the basic principles of the magnetic circuit assembly, that various modifications and variations in form and detail of the specific modes and procedures for implementing the magnetic circuit assembly 3400 are possible without departing from such principles, but that such modifications and variations are within the scope of the above description. For example, the second magnetic permeable element 306 may be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3400 may not include the second magnetic element 308. As another example, the magnetic circuit assembly 3400 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. In some embodiments, the upper surface of the further magnetic element may 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 permeable element 306, the further added magnetic element having a magnetization direction opposite to the magnetization direction of the second magnetic element 308.

Fig. 3E is a longitudinal cross-sectional schematic view of a magnetic circuit assembly 3500 in accordance with some embodiments of the present application. As shown in fig. 3E, unlike the magnetic circuit assembly 3400, the magnetic circuit assembly 3500 may further include a third magnetically permeable element 316. In some embodiments, the third magnetically permeable element 316 may comprise any one or more of the magnetically permeable materials described herein. The first, second, and/or third magnetic permeable elements 304, 306, and 316 may comprise the same or different magnetic permeable materials. In some embodiments, the third magnetic permeable element 316 may be arranged in a symmetrical configuration. For example, the third magnetic permeable 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 can be coaxial cylinders, having the same or different diameters. The third magnetic permeable element 316 may be connected to the fifth magnetic element 314. In some embodiments, a third magnetic permeable 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.

The magnetic circuit assembly 3500 further adds a third magnetically permeable element 316 as compared to the magnetic circuit assembly 3400. The third magnetic permeable element 316 can suppress leakage of magnetic flux in the magnetization direction of the fifth magnetic element 314 in the magnetic circuit assembly 3500, so that the magnetic field generated by the fifth magnetic element 314 can be compressed into the magnetic gap to a large extent, thereby improving the magnetic induction intensity in the magnetic gap.

The above description of the structure of the magnetic circuit assembly 3500 is merely a specific example and should not be considered the only possible embodiment. It will be apparent to those skilled in the art that, having the benefit of the teachings of the magnetic circuit assembly, various modifications and changes in form and detail of the specific manner and process of implementing the magnetic circuit assembly 3500 may be made without departing from such principles, but such modifications and changes are intended to be within the purview of the foregoing description. For example, the second magnetic permeable element 306 may 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 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. In some embodiments, the upper surface of the further magnetic element may 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 permeable element 306, the further added magnetic element having a magnetization direction opposite to the magnetization direction of the second magnetic element 308.

Fig. 3F is a schematic longitudinal cross-sectional view of a magnetic circuit assembly 3600 according to some embodiments of the present application. As shown in fig. 3F, unlike the magnetic circuit assembly 3100, the magnetic circuit assembly 3600 may further include one or more conductive elements (e.g., the first conductive element 318, the second conductive element 320, and the third conductive element 322).

The conductive element may comprise a metallic material, a metal alloy material, an inorganic non-metallic material, or other conductive material. The metal material may include gold, silver, copper, aluminum, etc.; the metal alloy material can comprise iron-based alloy, aluminum-based alloy material, copper-based alloy, zinc-based alloy and the like; the inorganic non-metallic material may include graphite, etc. The conductive elements may be sheet-like, annular, mesh-like, and the like. The first conductive element 318 may be disposed on an upper surface of the first magnetic conductive element 304. The second conductive element 320 may be connected to the first magnetic element 302 and the second magnetic conductive element 306. The third conductive element 322 may be connected to a sidewall 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 is 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 comprise the same or different conductive materials. The first conductive element 318, the second conductive element 320, and the third conductive element 322 may be connected to the first magnetic conductive element 304, the second magnetic conductive element 306, and/or the first magnetic element 302, respectively, by any one or more of the connection methods described herein.

A magnetic gap is formed between the inner rings of the first magnetic element 302, the first magnetic permeable element 304, and the second magnetic element 308. Voice coil 328 may be disposed 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 may form a magnetic circuit. In some embodiments, the conductive element may reduce the inductive reactance of voice coil 328. For example, if a first alternating current is applied to voice coil 328, a first alternating induced magnetic field is generated near voice coil 328. The first alternating induced magnetic field, under the influence of the magnetic field in the magnetic circuit, causes an inductive reactance to be generated in voice coil 328, impeding the motion of voice coil 328. When conductive elements (e.g., first conductive element 318, second conductive element 320, and third conductive element 322) are disposed near voice coil 328, the conductive elements may induce a second alternating current under the first alternating induced magnetic field. The third alternating current in the conductive element may generate a second alternating induced magnetic field in a vicinity thereof, and the second alternating induced magnetic field may be opposite to the first alternating induced magnetic field, and may weaken the first alternating induced magnetic field, thereby reducing an inductive reactance of the voice coil 328, increasing a current in the voice coil, and improving a sensitivity of the bone conduction speaker.

The above description of the structure of the magnetic circuit assembly 3600 is merely a specific example and should not be considered the only possible embodiment. It will be apparent to those skilled in the art that, having the benefit of the teachings of the magnetic circuit assembly, various modifications and changes in form and detail of the specific manner and procedure of implementing the magnetic circuit assembly 3600 are possible without departing from such principles, but such modifications and changes are within the scope of the above description. For example, the second magnetic permeable element 306 may be an annular structure or a sheet structure. As 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.

Fig. 3G is a schematic longitudinal cross-sectional view of a magnetic circuit assembly 3700, shown in accordance with some embodiments of the present application. As shown in fig. 3G, unlike the magnetic circuit assembly 3500, the magnetic circuit assembly 3700 may further include a third magnetic element 310, a fourth magnetic element 312, a fifth magnetic element 314, a third magnetic permeable 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 permeable element 316 and/or the sixth magnetic element 324 and the seventh magnetic element 326 may be provided as coaxial annular cylinders.

In some embodiments, the top surface of the second magnetic element 308 is coupled to the seventh magnetic element 326, and the bottom surface of the second magnetic element 308 may be coupled to the third magnetic element 310. The third magnetic element 310 may be coupled to the second magnetic permeable element 306. The upper surface of the seventh magnetic element 326 may be connected to the third magnetic permeable element 316. The fourth magnetic element 312 may connect the second magnetic permeable element 306 and the first magnetic element 302. The sixth magnetic element 324 may be coupled to the fifth magnetic element 314, the third magnetic permeable element 316, and the seventh magnetic element 326. In some embodiments, the first magnetic element 302, the first magnetic element 304, the second magnetic 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 element 316, the sixth magnetic element 324, and the seventh magnetic element 326 may form a magnetic circuit and a magnetic gap.

In some embodiments, the magnetization direction of the second magnetic element 308 can be described in detail with reference to FIG. 3A, the magnetization direction of the third magnetic element 310 can be described in detail with reference to FIG. 3B, and the magnetization direction of the fourth magnetic element 312 can be described in detail with reference to FIG. 3C.

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 may 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 no higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is vertically upward (as shown in the direction of a) perpendicular to the lower surface or the upper surface of the first magnetic element 302, and the magnetization direction of the sixth magnetic element 324 is directed from the outer ring to the inner ring of the sixth magnetic element 324 (as shown in the direction of g, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected by 270 degrees in the clockwise direction). In some embodiments, the magnetization direction of the sixth magnetic element 324 and the magnetization direction of the fourth magnetic element 312 may be the same in the same vertical direction.

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 3700 and the magnetization direction of the sixth magnetic element 324 is no higher than 90 degrees. In some embodiments, 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 at the location of the sixth magnetic element 324 may be an angle of 0 degrees, 10 degrees, 20 degrees, etc., that is less than or equal to 90 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 may 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 no higher than 90 degrees. In some embodiments, the magnetization direction of the first magnetic element 302 is vertically upward (as viewed in the direction of a) perpendicular to the lower or upper surface of the first magnetic element 302, and the magnetization direction of the seventh magnetic element 326 is directed from the lower surface of the seventh magnetic element 326 toward the upper surface (as viewed in the direction of f, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is shifted 360 degrees in the clockwise direction). In some embodiments, the magnetization direction of the seventh magnetic element 326 may be opposite to the magnetization direction of the third magnetic element 310.

In some embodiments, at the seventh magnetic element 326, the angle between the direction of the magnetic field generated by the magnetic circuit assembly 3700 and the magnetization direction of the seventh magnetic element 326 is no higher 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 may be an angle of 0 degrees, 10 degrees, 20 degrees, etc. that is less than or equal to 90 degrees.

In the magnetic circuit assembly 3700, the third magnetic conductive element 316 can close the magnetic circuit generated by the magnetic circuit assembly 3700, so that more magnetic induction lines are concentrated in the magnetic gap, thereby achieving the effects 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 3700 is merely a specific example and should not be considered the only possible embodiment. It is clear that, after understanding the basic principles of the magnetic circuit assembly, it is possible for a person skilled in the art to carry out various modifications and variations in form and detail of the specific manner and procedure of implementing the magnetic circuit assembly 3700, without departing from such principles, but within the scope of what has been described above. For example, the second magnetic permeable element 306 may be an annular structure or a sheet structure. For another example, the magnetic circuit assembly 3700 may not include the second magnetic element 308. Also for example, the magnetic circuit assembly 3700 may further include at least one electrically conductive element that may be coupled to 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 3700 may further add at least one electrically conductive element that 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.

Figure 4A is a cross-sectional schematic diagram of a magnetic element structure according to some embodiments of the present application. The magnetic element 400 may be adapted for use in any of the magnetic circuit assemblies described herein (e.g., the magnetic circuit assemblies shown in fig. 3A-3G). As shown, the magnetic element 400 may be ring-shaped. The magnetic element 400 may include an inner ring 402 and an outer ring 404. In some embodiments, the shape of the inner ring 402 and/or the outer ring 404 may be circular, elliptical, triangular, quadrilateral, or any other polygon.

Figure 4B is a schematic diagram of a magnetic element structure according to some embodiments of the present application. The magnetic element may be suitable for use in any of the magnetic circuit assemblies described herein (e.g., the magnetic circuit assemblies shown in fig. 3A-3G). As shown, the magnetic element may be comprised of a plurality of magnet arrangements. The two ends of any one of the magnets can be connected with the two ends of the adjacent magnet or have a certain distance. The spacing between the plurality of magnets may be the same or different. In some embodiments, the magnetic element may be comprised of 2 or 3 magnets (e.g., magnets 408-2, 408-4, and 408-6) in sheet form, arranged equidistantly. The shape of the sheet-shaped magnet may be a sector, a quadrangle, or the like.

Fig. 4C is a schematic view of the magnetization direction of a magnetic element in a magnetic circuit assembly according to some embodiments of the present application. As shown, the magnetic circuit assembly may include a first magnetic element 401, a second magnetic element 403, and a third magnetic element 405. The magnetization direction of the first magnetic element 401 may be directed from the lower surface of the first magnetic element 401 to the upper surface (i.e., the direction out of the paper). The second magnetic element 403 may be disposed around the first magnetic element 401. A magnetic gap may be formed between the inner ring of the second magnetic element 403 and the inner ring of the first magnetic element 401. The magnetization direction of the second magnetic element 403 may be directed from the inner ring to the outer ring of the second magnetic element 403. The inner ring of the third magnetic element 405 can be connected to the outer ring of the first magnetic element 401 and the outer ring of the third magnetic element 405 can be connected to the inner ring of the second magnetic element 403. The magnetization direction of the third magnetic element 405 can be directed from the outer ring to the inner ring of the third magnetic element 403.

Figure 4D is a magnetic flux line schematic of a magnetic element in a magnetic circuit assembly according to some embodiments of the present application. As shown, the magnetic circuit assembly 400 (e.g., as shown in fig. 3A-3G) may include a first magnetic element 402 and a second magnetic element 404. The magnetization direction of the first magnetic element 402 may be such that the lower surface of the first magnetic element 402 points towards the upper surface (as indicated by arrow a). The first magnetic element 402 may generate a second magnetic field, which may be represented by lines of magnetic induction (the solid line in the figure represents the distribution of the second magnetic field in the absence of the second magnetic element 404), and the magnetic field direction of the second magnetic field at a point is the tangential direction of the point on the lines of magnetic induction. The magnetization direction of the second magnetic element 404 may be such that the inner ring of the second magnetic element 404 points towards the outer ring (as indicated by arrow b). The second magnetic element 404 may generate a third magnetic field. The third magnetic field may also be represented by lines of magnetic induction (the dotted line in the figure represents the distribution of the third magnetic field in the absence of the first magnetic element 402), and the direction of the magnetic field of the third magnetic field at a certain point is the tangential direction of the point on the third lines of magnetic induction. Under the interaction of the second magnetic field and the third magnetic field, the magnetic circuit assembly 400 may generate a first full magnetic field. The magnetic field strength of the first full magnetic field at voice coil 406 is greater than the magnetic field strength of the second magnetic field or the third magnetic field at voice coil 406. As shown, the angle between the magnetic field direction of the second magnetic field at the voice coil 406 and the magnetization direction of the second magnetic element 404 is less than or equal to 90 degrees.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Further, those skilled in the art will appreciate that aspects of the present application may be illustrated and described in terms of several patentable species or situations, including any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Accordingly, various aspects of the present application may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media.

Additionally, the order in which elements and sequences of the processes are recited in the present application, the use of alphanumeric or other designations, is not intended to limit the order of the processes and methods in the present application, unless otherwise indicated in the claims. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially", etc. Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical data used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, numerical data should take into account the specified significant digits and employ a general digit preservation approach. Notwithstanding that the numerical ranges and data setting forth the broad scope of the range presented in some of the examples are approximations, in specific examples, such numerical values are set forth as precisely as possible within the practical range.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments of the present application. Other variations are also possible within the scope of the present application. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present application can be viewed as being consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to only those embodiments explicitly described and depicted herein.

Claims

1. A magnetic circuit assembly of a bone conduction speaker, the magnetic circuit assembly comprising:

a first magnetic element that generates a first magnetic field;

a first magnetic conductive element; and

at least one second magnetic element surrounding the first magnetic element and forming a magnetic gap with the first magnetic element, the second magnetic element generating a second magnetic field that increases a magnetic field strength of the first magnetic field at the magnetic gap.

2. The magnetic circuit assembly of claim 1, wherein an angle between a magnetization direction of the at least one second magnetic element and a magnetization direction of the first magnetic element is not less than 90 degrees.

3. The magnetic circuit assembly of claim 1, further comprising:

a second magnetic conductive element; and

at least one third magnetic element, wherein the at least one third magnetic element connects the second magnetically permeable element and the at least one second magnetic element, the at least one third magnetic element generating a third magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

4. The magnetic circuit assembly of claim 3, wherein an angle between the magnetization direction of the at least one third magnetic element and the magnetization direction of the first magnetic element is not less than 90 degrees.

5. The magnetic circuit assembly of claim 3, further comprising:

at least one fourth magnetic element, wherein the at least one fourth magnetic element is disposed below the magnetic gap and connects the first magnetic element and the second magnetic permeable element, and the at least one fourth magnetic element generates a fourth magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

6. The magnetic circuit assembly of claim 5, the magnetization direction of the at least one fourth magnetic element being between 45 degrees and 135 degrees from the magnetization direction of the first magnetic element.

7. The magnetic circuit assembly of claim 3, further comprising:

at least one fifth magnetic element, wherein the at least one fifth magnetic element is coupled to the upper surface of the first magnetic permeable element, the at least one fifth magnetic element generating a fifth magnetic field that increases the magnetic field strength of the first magnetic field at the magnetic gap.

8. The magnetic circuit assembly of claim 7, the magnetization direction of the at least one fifth magnetic element being at an angle between 150 degrees and 180 degrees to the magnetization direction of the first magnetic element.

9. The magnetic circuit assembly of claim 7, wherein a ratio of a thickness of the first magnetic element to a sum of thicknesses of the first magnetic element, the at least one fifth magnetic element, and the first magnetic permeable element ranges from 0.4 to 0.6.

10. The magnetic circuit assembly of claim 7, the at least one fifth magnetic element having a thickness equal to a thickness of the first magnetic element.

11. The magnetic circuit assembly of claim 7, the at least one fifth magnetic element having a thickness less than a thickness of the first magnetic element.

12. The magnetic circuit assembly of claim 7, further comprising:

a third magnetic conductive element, wherein the third magnetic conductive element is connected to an upper surface of the fifth magnetic element, and the third magnetic conductive element is configured to suppress leakage of field strengths of the first magnetic field and the second magnetic field.

13. The magnetic circuit assembly of claim 7, the first magnetic conductive element coupled to an upper surface of the first magnetic element, the second magnetic conductive element including a bottom plate and a sidewall, and the first magnetic element coupled to the bottom plate of the second magnetic conductive element.

14. The magnetic circuit assembly of claim 7, further comprising:

at least one conductive element, wherein the conductive element is connected to at least one of the first magnetic element, the first magnetically permeable element, or the second magnetically permeable element.

15. A bone conduction speaker, the bone conduction speaker comprising:

a vibration assembly including a voice coil and at least one vibration plate; and a magnetic circuit assembly as claimed in any of claims 1 to 14.