CN108184196B

CN108184196B - Bone conduction loudspeaker

Info

Publication number: CN108184196B
Application number: CN201810015517.6A
Authority: CN
Inventors: 张磊; 廖风云; 齐心
Original assignee: Shenzhen Voxtech Co Ltd
Current assignee: Shenzhen Voxtech Co Ltd
Priority date: 2018-01-08
Filing date: 2018-01-08
Publication date: 2024-04-09
Anticipated expiration: 2038-01-08
Also published as: CN108184196A

Abstract

The application relates to a magnetic circuit assembly of a bone conduction speaker, which comprises a first magnetic element and a second magnetic conduction element. The first magnetic element generates a first magnetic field. The magnetic circuit assembly further comprises at least one second magnetic element. The at least one second magnetic element surrounds the first magnetic element and forms a magnetic gap with the first magnetic element. The second magnetic element generates a second magnetic field that increases a magnetic field strength of the first magnetic field at the magnetic gap.

Description

Bone conduction loudspeaker

Technical Field

The present application relates to bone conduction speakers, and more particularly to magnetic circuit assemblies in bone conduction speakers.

Background

The bone conduction speaker can convert the electric signal into a mechanical vibration signal and conduct the vibration signal into the cochlea through human tissues and bones, so that the user can hear the sound. Compared with an air conduction loudspeaker, the air conduction loudspeaker drives air to vibrate through the vibrating diaphragm to generate sound, and the bone conduction vibration loudspeaker needs to drive soft tissues and bones of a user to vibrate, so that the required mechanical power is high. Increasing the sensitivity of bone conduction speakers can result in higher efficiency in the conversion of electrical energy to mechanical energy and thus greater mechanical power output. Increasing sensitivity is 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 for a bone conduction speaker. The magnetic circuit assembly includes 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.

According to some embodiments of the present application, an angle between the magnetization direction of the at least one second magnetic element and the 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 a second magnetically permeable element; and at least one third magnetic element. 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 a magnetic field strength of the first magnetic field at the magnetic gap.

According to some embodiments of the present application, 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.

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 conductive element, the at least one fourth magnetic element generating a fourth magnetic field that increases a magnetic field strength of the first magnetic field at the magnetic gap.

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

According to some embodiments of the present 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 at least one fifth magnetic element has a magnetization direction that is between 150 degrees and 180 degrees from the magnetization direction of the first magnetic element.

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

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

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

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

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

According to some embodiments of the present application, the magnetic circuit assembly further comprises at least one electrically conductive element, wherein the electrically conductive element connects 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 part of this application will be readily apparent to those skilled in the art from a review of the following description and the corresponding drawings, or from a study of the manufacture or operation of the embodiments. The features disclosed in this application may be implemented and realized in the practice or use of the 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 embodiments of the application and together with the description serve to explain the application and do not 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 section 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 schematic cross-sectional 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;

FIG. 4C is a schematic illustration 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 induction profile of 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 that are used in the description of the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some examples or embodiments of the present application, and it is obvious to those skilled in the art that the present application may be applied to other similar situations according to the drawings without inventive effort. It should be understood that these exemplary embodiments are presented merely to enable those skilled in the relevant art to better understand and practice the invention and are not intended to limit the scope of the invention in any way. Unless otherwise apparent from the context of the language or otherwise specified, like reference numerals in the figures refer to like structures or operations.

As used in this application and in the claims, the terms "a," "an," "the," and/or "the" are not specific to the singular, but may include the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus. 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". Related definitions of other terms will be given in the description below. 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 earphone" will be employed. The description is only one form of bone conduction application, and it will be appreciated by those of ordinary skill in the art that the "speaker" or "earpiece" may be replaced by other similar terms, such as "player", "hearing aid", etc. Indeed, various implementations of the invention may be readily applied to other non-speaker-like hearing devices. For example, it will be apparent to those skilled in the art that various modifications and changes in form and details of the specific manner and procedure of implementing the bone conduction speaker, and in particular the addition of ambient sound pick-up and processing functions to the bone conduction speaker, may be made without departing from the basic principles of the bone conduction speaker, thereby enabling the speaker to function as a hearing aid. For example, a microphone such as a microphone may pick up sound from the user/wearer's surroundings and, under certain algorithms, transmit the sound processed (or generated electrical signals) to the bone conduction speaker portion. That is, the bone conduction speaker can be modified to have a function of picking up environmental sound, and transmit the sound to the user/wearer through the bone conduction speaker portion after a certain signal processing, thereby realizing 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 noise immunity, 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 second magnetic elements in the magnetic circuit assembly encircle the first magnetic elements, so that the volume and the weight of the magnetic circuit assembly are reduced, the efficiency of the bone conduction speaker is improved, and the service life of the bone conduction speaker is prolonged under the conditions of improving the magnetic field strength of a magnetic gap and improving the sensitivity of the bone conduction speaker.

The bone conduction speaker has the characteristics of small size, light weight, high efficiency, high sensitivity, long service life and the like, and is convenient to combine with the wearable intelligent device, so that the multifunctionalization of single device is realized, and the user experience is improved and optimized. 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, and the like. The bone conduction speaker may further be combined with smart materials, integrating bone conduction speakers 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 implanted chip or an external processor.

Fig. 1 is a block diagram of a bone conduction speaker 100 according to some embodiments of the present application. As illustrated, 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, audio files having a particular data format, or data or files that may be converted to sound by a particular means. The signal containing the audio information may be from the memory component 108 of the bone conduction speaker 100 itself, or from a system other than the bone conduction speaker 100 for generating, storing, or transmitting information. The signal containing the acoustic information may include one or more combinations of electrical signals, optical signals, magnetic signals, mechanical signals, and the like. The signal containing the sound information may come from one signal source or a plurality of signal sources. The plurality of signal sources may or may not be correlated. In some embodiments, bone conduction speaker 100 may acquire the signal containing the acoustic information in a number of different ways, either wired or wireless, and may be real-time or delayed. For example, bone conduction speaker 100 may receive electrical signals containing audio information via wired or wireless means, or may obtain data directly from a storage medium (e.g., storage component 108) to generate an audio signal. As another example, a bone conduction hearing aid may include components with sound collection capabilities that convert mechanical vibrations of sound into electrical signals by picking up the sound in the environment, and then processing the signals with an amplifier to obtain electrical signals that meet specific requirements. In some embodiments, the wired connection may include a metallic cable, an optical cable, or a hybrid metallic and optical cable, such as, for example, a coaxial cable, a communications cable, a flex cable, a spiral cable, a nonmetallic sheath cable, a metallic sheath cable, a multi-core cable, a twisted pair cable, a ribbon cable, a shielded cable, a telecommunications cable, a twinax cable, parallel twinax wires, twisted pair wires, or the like. The above described examples are for convenience of illustration only, and the medium of the wired connection may be of other types, such as other transmission carriers of electrical or optical signals, etc.

The wireless connection may include radio communication, free space optical communication, acoustic communication, electromagnetic induction, and the like. Wherein the radio communication may include IEEE802.11 series standards, IEEE802.15 series standards (e.g., bluetooth technology, zigbee technology, etc.), first generation mobile communication technologies, second generation mobile communication technologies (e.g., FDMA, TDMA, SDMA, CDMA, SSMA, etc.), general packet radio service technologies, third generation mobile communication technologies (e.g., CDMA2000, WCDMA, TD-SCDMA, wiMAX, etc.), fourth generation mobile communication technologies (e.g., TD-LTE, FDD-LTE, etc.), satellite communication (e.g., GPS technology, etc.), near Field Communication (NFC), and other technologies operating in the ISM band (e.g., 2.4GHz, etc.); free space optical communications 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 described examples are for convenience of illustration only and the medium of the wireless connection may also be of other types, e.g. Z-wave technology, other charged civilian and military radio bands, etc. For example, as some application scenarios of the present technology, bone conduction speaker 100 may obtain signals containing sound information from other devices through bluetooth technology.

The vibration assembly 104 may generate mechanical vibrations. The generation of the vibrations is accompanied by energy conversion, and bone conduction speaker 100 may use specific magnetic circuit assembly 102 and vibration assembly 104 to effect conversion of signals containing acoustic information into mechanical vibrations. The process of conversion may involve the coexistence and conversion of a variety of different types of energy. For example, the electrical signal may be directly converted into mechanical vibrations by a transducer means, producing sound. For another example, sound information may be included in the optical signal and a particular transducer device may perform the conversion from the optical signal to a vibration signal. Other types of energy that may coexist and be converted during operation of the transducer include thermal energy, magnetic field energy, and the like. The energy conversion modes 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 bone conduction speaker 100 may be affected by vibration assembly 104. For example, in the moving coil transducer device, the vibration assembly 104 includes a wound columnar coil and a vibrator (e.g., a vibrating reed), and the columnar coil driven by the signal current drives the vibrator to vibrate in the magnetic field to generate sound, so that the stretching and shrinking of the material of the vibrator, the deformation, the size, the shape and the fixing manner of the wrinkles, the magnetic density of the permanent magnet, etc. have a great influence on the sound quality of the bone conduction speaker 100. The vibrating body in the vibrating assembly 104 may be a mirror symmetrical structure, a center symmetrical structure, or an asymmetrical structure; the vibration body can be provided with a discontinuous hole-shaped structure, so that the vibration body generates larger displacement, the bone conduction loudspeaker realizes higher sensitivity, and the output power of vibration and sound is improved; the vibrator may be a ring body structure, and a plurality of struts which are converged toward the center are arranged in the ring body, and the number of struts may 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 an accommodation space for accommodating 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 can store signals containing audio information. In some embodiments, the storage component 108 may include one or more storage devices. The storage devices may include storage devices on storage systems such as direct attached storage (Direct Attached Storage), network attached storage (Network Attached Storage), and storage area networks (Storage Area Network). The storage devices may include various types of storage devices such as solid state storage devices (solid state drives, solid state hybrid drives, etc.), mechanical hard drives, USB flash memory, memory sticks, memory cards (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 RAM may include a decimal counter, a selector, 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; ROM may include bubble memory, button wire memory, thin film memory plating line memory, magnetic core memory, magnetic drum memory, optical disk drive, hard disk magnetic tape, early NVRAM (nonvolatile memory), phase change memory, magnetoresistive RAM, ferroelectric RAM, nonvolatile SRAM flash memory, EEPROM, PROM, shielded heap read memory, floating gate RAM, nanometer RAM, racetrack memory, variable resistance memory, programmable metallization cell, etc. The above-mentioned storage devices/storage units are examples, and storage devices that can be used for the storage devices/storage units are not limited thereto.

The above description of bone conduction speaker structures is merely a specific example and should not be considered as the only viable embodiment. It will be apparent to those skilled in the art that various modifications and changes in form and detail of the specific manner and steps of implementing the bone conduction speaker may be made without departing from this principle, but remain within the scope of the above description. For example, 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 noise immunity, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, or the like, or any combination thereof, while remaining within the scope of the claimed invention. As another example, bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a speed sensor, a displacement sensor, and the like. The sensor may collect user information or environmental information.

Fig. 2 is a schematic longitudinal section of a bone conduction speaker 200 according to some embodiments of the present application. As shown, bone conduction speaker 200 may include a first magnetic element 202, a first magnetically permeable element 204, a second magnetically permeable element 206, a first diaphragm 208, a voice coil 210, a second diaphragm 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 magnets may include metal alloy magnets, ferrites, and the like. The metal alloy magnets may include neodymium iron boron, samarium cobalt, alnico, iron chromium cobalt, alfeb, iron carbon aluminum, or the like, or combinations thereof. The ferrite may include barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or various combinations thereof.

The lower surface of the first magnetically permeable element 204 may be coupled to the upper surface of the first magnetic element 202. The second magnetically permeable element 206 may be coupled 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 core. The magnetizer can adjust the distribution of a magnetic field (e.g., the magnetic field generated by the first magnetic element 202). The magnetic conductor may comprise an element machined 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, or the like, such as iron, a ferrosilicon-based alloy, a ferroaluminum-based alloy, a nickel-iron-based alloy, a ferrocobalt-based alloy, a low carbon steel, a silicon steel sheet, ferrite, or the like. In some embodiments, the magnetic conductor may be machined by one or more combination of casting, plastic working, cutting, powder metallurgy, and the like. Casting may include sand casting, investment casting, pressure casting, centrifugal casting, and the like; plastic working may include one or more combinations of rolling, casting, forging, stamping, extruding, drawing, etc.; the cutting process may include turning, milling, planing, grinding, and the like. In some embodiments, the method of machining the magnetizer may include 3D printing, numerically controlled machine tools, and the like. The connection between the first magnetically permeable element 204, the second magnetically permeable element 206, and the first magnetic element 202 may include one or more 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 disposed in an axisymmetric configuration. The axisymmetric structure may be a ring structure, a column structure, or other structures having axisymmetry.

In some embodiments, a magnetic gap may be formed between the first magnetic element 202 and the second magnetic conductive element 206. Voice coil 210 may be disposed in the magnetic gap. The voice coil 210 may be connected to the first diaphragm 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 a current is applied to the voice coil 210, the voice coil 210 is positioned in a 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 an ampere force, and the ampere force drives the voice coil 210 to vibrate, so that 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 vibrations through tissue and bone to the auditory nerve, thereby allowing the person to hear the sound. The vibration panel 214 may be in direct contact with the skin of the human body or may be in contact with the skin through a vibration transmission layer composed of a specific material.

In some embodiments, for bone conduction speakers with a single magnetic element, the magnetic induction lines through the voice coil are not uniform, diverging. Meanwhile, magnetic leakage can be formed in the magnetic circuit, namely more magnetic induction wires leak out of the magnetic gap and cannot 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 loudspeaker is affected. Accordingly, 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 element may inhibit leakage of the magnetic induction lines, restrict the form of the magnetic induction lines passing through the voice coil, so that more magnetic induction lines pass through the voice coil as horizontally and densely as possible, and enhance magnetic induction (or magnetic field strength) at the position of the voice coil, 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 into the bone conduction speaker 200 into mechanical energy of vibration of the voice coil). For a further description of the at least one second magnetic element, see fig. 3A-3G.

The above description of the structure of bone conduction speaker 200 is merely a specific example and should not be considered as the only viable embodiment. It will be apparent to those skilled in the art that various modifications and changes in form and detail of the specific manner and steps of implementing the bone conduction speaker may be made without departing from this principle, but remain within the scope of the above description. For example, 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, bone conduction speaker 200 may include a second magnetic element that may be coupled to first magnetically permeable element 204. For another example, bone conduction speaker 200 may further include one or more annular magnetic elements that may be coupled to second magnetically permeable element 206.

Fig. 3A is a schematic longitudinal cross-sectional view of a magnetic circuit assembly 3100, according to some embodiments of the present application. As shown in fig. 3A, magnetic circuit assembly 3100 may include a first magnetic element 302, a first magnetically permeable element 304, a second magnetically permeable 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 include a first magnet and the second magnetic element 308 may include a second magnet, which may be the same or different from the first magnet. The first magnetically permeable element 304 and/or the second magnetically permeable element 306 may comprise any one or more of the magnetically permeable materials described herein. The method of machining the first magnetically permeable element 304 and/or the second magnetically permeable element 306 may include any one or more of the methods described herein. In some embodiments, the first magnetic element 302 and/or the first magnetically permeable element 304 may be disposed in an axisymmetric configuration. For example, the first magnetic element 302 and/or the first magnetically permeable element 304 may be a cylinder, a cuboid, or a hollow ring (e.g., racetrack shaped in cross-section). In some embodiments, the first magnetic element 302 and the first magnetically permeable element 304 may be coaxial cylinders, containing the same or different diameters. In some embodiments, the second magnetically permeable element 306 may be a groove-type structure. The groove-type structure may comprise a U-shaped cross-section (as shown in fig. 3A). The second magnetically permeable element 306 may include a bottom plate and a side wall. In some embodiments, the base plate and the side walls may be integrally formed, for example, the side walls may be formed from the base plate extending in a direction perpendicular to the base 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 or a sheet. In some embodiments, the second magnetic element 308 may be coaxial with the first magnetic element 302 and/or the first magnetically permeable element 304.

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

A magnetic gap is formed between the first magnetic element 302 and/or the first magnetically permeable element 304 and the inner ring of the second magnetic element 308. A 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 element 306. In some embodiments, the first magnetic element 302, the first magnetically permeable element 304, the second magnetically permeable element 306, and the second magnetic element 308 may form a magnetic circuit. In some embodiments, 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 first magnetic element 302 may generate a second magnetic field. The first full magnetic field is formed by magnetic fields generated by all components (e.g., first magnetic element 302, first magnetic element 304, second magnetic element 306, and second magnetic element 308) in 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 referred to herein means that the first full magnetic field is greater in the magnetic gap when the third magnetic field is present (i.e., the second magnetic element 308 is present) than when the third magnetic field is absent (i.e., the second magnetic element 308 is absent). In other embodiments in this specification, unless otherwise specified, the magnetic circuit assembly represents a structure including all magnetic elements and magnetically conductive elements, the first full magnetic field represents the magnetic field generated by the magnetic circuit assembly as a whole, and the second, third, … …, and nth magnetic fields represent the magnetic fields generated by the respective magnetic elements, respectively. In different embodiments, the magnetic elements that generate the second magnetic field (or 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 (as shown in the a direction) perpendicular to the lower or 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 (as shown in the b direction, 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).

In some embodiments, the angle between the direction of the first full magnetic field and the magnetization direction of the second magnetic element 308 is no more than 90 degrees at the location of the second magnetic element 308. In some embodiments, the angle between the direction of the magnetic field generated by the first magnetic element 302 and the direction of magnetization of the second magnetic element 308 may be less than or equal to 90 degrees, such as 0 degrees, 10 degrees, 20 degrees, etc., at the location of the second magnetic element 308.

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

The above description of the structure of magnetic circuit assembly 3100 is merely a specific example and should not be considered the only viable embodiment. It will be apparent to those skilled in the art, after having appreciated the basic principles of the bone magnetic circuit assembly, that various modifications and changes in form and detail of the specific manner and steps of implementing the magnetic circuit assembly 3100 may be made without departing from such principles, but such modifications and changes remain within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like structure. For another example, magnetic circuit assembly 3100 may further include a magnetically permeable cover that may surround first magnetic element 302, first magnetically permeable element 304, second magnetically permeable element 306, and 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 disclosure. As shown in fig. 3B, unlike magnetic circuit assembly 3100, magnetic circuit assembly 3200 may further include a third magnetic element 310.

The third magnetic element 310 has an upper surface connected to the second magnetic element 308 and a lower surface connected to a sidewall of the second magnetic element 306. A magnetic gap may be formed between the first magnetic element 302, the first magnetically permeable element 304, the second magnetic element 308, and/or the third magnetic element 310. A 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 be as described in detail with reference to fig. 3A of the present application.

In some embodiments, magnetic circuit assembly 3200 may generate a first full magnetic field and 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 fig. a) perpendicular to the lower or upper surface of the first magnetic element 302, and the magnetization direction of the third magnetic element 310 is directed from the upper surface of the third magnetic element 310 to the lower surface (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 deflected 180 degrees in a 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 more 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 direction of magnetization of the third magnetic element 310 may be less than or equal to 90 degrees, 0 degrees, 10 degrees, 20 degrees, etc.

Magnetic circuit assembly 3200 further adds third magnetic element 310 as compared to magnetic circuit assembly 3100. Third magnetic element 310 may further increase the total magnetic flux within the magnetic gap in magnetic circuit assembly 3200, thereby increasing the magnetic induction in the magnetic gap. Under the action of the third magnetic element 310, the magnetic induction line further converges toward the position of the magnetic gap, and the magnetic induction intensity in the magnetic gap is further increased.

The above description of the structure of magnetic circuit assembly 3200 is merely a specific example and should not be considered as the only viable embodiment. It will be apparent to those skilled in the art, having the benefit of the basic principles of the magnetic circuit assembly, that various modifications and changes in form and detail of the specific manner and steps of implementing magnetic circuit assembly 3200 may be made without departing from such principles, but such modifications and changes remain within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like structure. For another example, magnetic circuit assembly 3200 may not include second magnetically permeable element 306. For another example, magnetic circuit assembly 3200 may further incorporate 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 added magnetic element may connect the sidewalls of the first magnetic element 302 and the second magnetically 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 schematic longitudinal cross-sectional view of a magnetic circuit assembly 3300, according to some embodiments of the present application. As shown in fig. 3C, unlike magnetic circuit assembly 3100, magnetic circuit assembly 3300 can further include 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 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 may form a magnetic gap. In some embodiments, the magnetization direction of the second magnetic element 308 may be as described in detail with reference to fig. 3A of the present application.

In some embodiments, magnetic circuit assembly 3300 may generate a first full magnetic field and 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 included 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 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 fig. a) perpendicular to the lower or upper surface of the first magnetic element 302, and the magnetization direction of the fourth magnetic element 312 is directed from the outer ring of the fourth magnetic element 312 to the inner ring (as shown in the direction 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, the angle between the direction of the first full magnetic field and the magnetization direction of the fourth magnetic element 312 is no more than 90 degrees at the location of the fourth magnetic element 312. 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 may be less than or equal to 90 degrees, such as 0 degrees, 10 degrees, 20 degrees, etc.

The magnetic circuit assembly 3300 further adds fourth magnetic element 312 as compared to magnetic circuit assembly 3100. Fourth magnetic element 312 may further increase the total magnetic flux within the magnetic gap in magnetic circuit assembly 3300, thereby increasing the magnetic induction in the magnetic gap. Under the action of the fourth magnetic element 312, the magnetic induction line further converges toward the position of the magnetic gap, and the magnetic induction intensity in the magnetic gap is further increased.

The above description of the structure of the magnetic circuit assembly 3300 is merely a specific example and should not be considered the only viable embodiment. It will be apparent to those skilled in the art, after having appreciated the basic principles of the bone magnetic circuit assembly, that 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 remain within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like structure. For another example, magnetic circuit assembly 3300 may not include second magnetic element 308. For another example, magnetic circuit assembly 3300 may further incorporate 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 added magnetic element may be connected to the lower surface of the second magnetic element 308. The magnetization direction of the magnetic elements is opposite to the magnetization direction of the first magnetic element 302.

Fig. 3D is a schematic longitudinal cross-sectional view of a magnetic circuit assembly 3400, according to some embodiments of the present application. As shown in fig. 3D, unlike magnetic circuit assembly 3100, magnetic circuit assembly 3400 may further include a fifth magnetic element 314. Fifth magnetic element 314 may comprise any of the magnet materials described herein. In some embodiments, fifth magnetic element 314 may be disposed in an axisymmetric configuration. For example, the fifth magnetic element 314 may be a cylinder, a cuboid, or a hollow ring (e.g., racetrack shaped in cross-section). 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 containing the same or different diameters. The thickness of the fifth magnetic element 314 may be the same as or different from the thickness of the first magnetic element 302. The fifth magnetic element 314 may be coupled to the first magnetically 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 magnetically permeable element 304 ranges from 0.4 to 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, the a-direction and the e-direction).

The magnetic circuit assembly 3400 further adds a fifth magnetic element 314 as compared to the magnetic circuit assembly 3100. The fifth magnetic element 314 can inhibit 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 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 viable embodiment. It will be apparent to those skilled in the art that various modifications and changes in form and detail of the specific manner and steps of implementing the magnetic circuit assembly 3400 may be made without departing from this principle, but such modifications and changes remain within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like 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 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 added 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 element 306, with the further added magnetic element having a magnetization direction opposite to the magnetization direction of the second magnetic element 308.

Fig. 3E is a schematic longitudinal cross-sectional view of a magnetic circuit assembly 3500 shown in accordance with some embodiments of the present application. As shown in fig. 3E, unlike magnetic circuit assembly 3400, magnetic circuit assembly 3500 may further include a third magnetically conductive element 316. In some embodiments, third magnetically permeable element 316 may comprise any one or more of the magnetically permeable materials described herein. The magnetically permeable materials included in the first magnetically permeable element 304, the second magnetically permeable element 306, and/or the third magnetically permeable element 316 may be the same or different. In some embodiments, the third magnetically permeable element 316 may be provided in a symmetrical configuration. For example, the third magnetically permeable element 316 may be a cylinder. In some embodiments, the first magnetic element 302, the first magnetic conductive element 304, the fifth magnetic conductive element 314, and/or the third magnetic conductive element 316 may be coaxial cylinders containing the same or different diameters. The third magnetically permeable element 316 may be coupled to the fifth magnetic element 314. In some embodiments, the third magnetically permeable element 316 may connect the fifth magnetic element 314 with the second magnetic element 308. The third magnetically permeable element 316, the second magnetically permeable element 306, and the second magnetic element 308 may form a cavity that may include the first magnetic element 302, the fifth magnetic element 314, and the first magnetically permeable element 304.

The magnetic circuit assembly 3500 further adds a third magnetic conductive element 316 as compared to the magnetic circuit assembly 3400. The third magnetic conductive element 316 can inhibit the magnetic 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.

The above description of the structure of magnetic circuit assembly 3500 is merely a specific example and should not be considered the only viable embodiment. It will be apparent to those skilled in the art that various modifications and changes in form and detail of the specific manner and steps of implementing the magnetic circuit assembly 3500 may be made without departing from this principle, while still remaining within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like structure. For another example, magnetic circuit assembly 3500 may not include second magnetic element 308. For another example, magnetic circuit assembly 3500 may further incorporate 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 added 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 element 306, with 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, shown in accordance with some embodiments of the present application. As shown in fig. 3F, unlike magnetic circuit assembly 3100, magnetic circuit assembly 3600 can further include one or more conductive elements (e.g., first conductive element 318, second conductive element 320, and third conductive element 322).

The conductive elements may comprise metallic materials, metallic alloy materials, inorganic nonmetallic materials, or other conductive materials. 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 nonmetallic material may include graphite or the like. The conductive elements may be sheet-like, ring-like, mesh-like, etc. The first conductive element 318 may be disposed on an upper surface of the first magnetically permeable element 304. The second conductive element 320 may connect the first magnetic element 302 and the second magnetically permeable 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 coupled to the first magnetically permeable element 304, the second magnetically permeable element 306, and/or the first magnetic element 302, respectively, by any one or more of the coupling means described herein.

A magnetic gap is formed between the first magnetic element 302, the first magnetically permeable element 304, and the inner ring of the second magnetic element 308. A 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 the voice coil 328. For example, if the voice coil 328 is energized with a first alternating current, a first alternating induced magnetic field is generated in the vicinity of the voice coil 328. The first alternating induction magnetic field causes the voice coil 328 to generate inductive reactance under the action of the magnetic field in the magnetic loop, and impedes the movement of the voice coil 328. When conductive elements (e.g., first conductive element 318, second conductive element 320, and third conductive element 322) are disposed adjacent to 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 the vicinity thereof, which is opposite to the first alternating induced magnetic field, and may weaken the first alternating induced magnetic field, thereby reducing the inductance of the voice coil 328, increasing the current in the voice coil, and improving the 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 viable embodiment. It will be apparent to those skilled in the art that various modifications and variations in form and detail of the specific manner and steps of implementing the magnetic circuit assembly 3600 are possible without departing from this principle, and yet remain within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like structure. For another example, the magnetic circuit assembly 3600 may not include the second magnetic element 308. For another example, magnetic circuit assembly 3500 may further incorporate 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, according to some embodiments of the present application. As shown in fig. 3G, unlike magnetic circuit assembly 3500, magnetic circuit assembly 3700 may further include third magnetic element 310, fourth magnetic element 312, fifth magnetic element 314, third magnetic conductive element 316, sixth magnetic element 324, and seventh magnetic element 326. The third, fourth, fifth, third and/or sixth magnetic elements 310, 312, 314, 316, 324, 326 may be provided as coaxial annular cylinders.

In some embodiments, an upper surface of the second magnetic element 308 is coupled to the seventh magnetic element 326 and a lower 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 magnetically permeable element 306. An upper surface of seventh magnetic element 326 may be coupled to third magnetic element 316. The fourth magnetic element 312 may connect the second magnetic element 306 and the first magnetic element 302. The sixth magnetic element 324 may connect the fifth magnetic element 314, the third magnetic 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 may refer to the detailed description of fig. 3A of the present application, the magnetization direction of the third magnetic element 310 may refer to the detailed description of fig. 3B of the present application, and the magnetization direction of the fourth magnetic element 312 may refer to the detailed description of fig. 3C of the present application.

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 included 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 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 fig. a) perpendicular to the lower or upper surface of the first magnetic element 302, and the magnetization direction of the sixth magnetic element 324 is directed from the outer ring of the sixth magnetic element 324 to the inner ring (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 270 degrees in a clockwise direction). In some embodiments, the magnetization direction of the sixth magnetic element 324 may be the same as the magnetization direction of the fourth magnetic element 312 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 more 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 may be less than or equal to 90 degrees, such as 0 degrees, 10 degrees, 20 degrees, etc., at the location of the sixth magnetic element 324.

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 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 fig. 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 to the upper surface (as shown in the direction f, on the right side of the first magnetic element 302, the magnetization direction of the first magnetic element 302 is deflected 360 degrees in a clockwise direction). In some embodiments, the magnetization direction of seventh magnetic element 326 may be opposite to the magnetization direction of third magnetic element 310.

In some embodiments, at seventh magnetic element 326, the angle between the direction of the magnetic field generated by magnetic circuit assembly 3700 and the direction of magnetization of seventh magnetic element 326 is no more than 90 degrees. In some embodiments, at the location of seventh magnetic element 326, the angle between the direction of the magnetic field generated by first magnetic element 302 and the direction of magnetization of seventh magnetic element 326 may be less than or equal to 90 degrees, 0 degrees, 10 degrees, 20 degrees, etc.

In the magnetic circuit assembly 3700, the third magnetic conductive element 316 can seal 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 inhibiting magnetic leakage, increasing magnetic induction intensity at the magnetic gap, and improving 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 as the only viable embodiment. It will be apparent to those skilled in the art that various modifications and changes in form and detail of the specific manner and steps of implementing the magnetic circuit assembly 3700 may be made without departing from this principle, but remain within the scope of the foregoing description. For example, the second magnetically permeable element 306 may be a ring-shaped structure or a sheet-like structure. For another example, magnetic circuit assembly 3700 may not include second magnetic element 308. For another example, magnetic circuit assembly 3700 can further include at least one electrically conductive element that can connect first magnetic element 302, fifth magnetic element 314, first magnetically permeable element 304, second magnetically permeable element 306, and/or third magnetically permeable element 316. In some embodiments, magnetic circuit assembly 3700 may further add at least one conductive element, which may connect at least one of second magnetic element 308, third magnetic element 310, fourth magnetic element 312, sixth magnetic element 324, and seventh magnetic element 326.

Fig. 4A is a schematic cross-sectional view 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 of the present application (e.g., the magnetic circuit assemblies shown in fig. 3A-3G). As shown, the magnetic element 400 may be annular. 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.

Fig. 4B is a schematic diagram of a magnetic element structure, according to some embodiments of the present application. The magnetic element may be adapted for use in any of the magnetic circuit assemblies of the present application (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 may be connected to the two ends of the adjacent magnets or may 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 plate-like magnets (e.g., magnets 408-2, 408-4, and 408-6) arranged equidistantly. The shape of the sheet-like magnet may be a sector, a quadrangle, or the like.

Fig. 4C is a schematic diagram illustrating the magnetization direction of a magnetic element in a magnetic circuit assembly according to some embodiments of the present application. As illustrated, 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., a direction out of the page perpendicular to the page). 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 may be connected to the outer ring of the first magnetic element 401 and the outer ring of the third magnetic element 405 may be connected to the inner ring of the second magnetic element 403. The magnetization direction of the third magnetic element 405 may be directed from the outer ring of the third magnetic element 403 to the inner ring.

Fig. 4D 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, a 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 is directed toward 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 (solid lines in the figure represent the distribution of the second magnetic field in the absence of the second magnetic element 404), the magnetic field direction of the second magnetic field at a point being 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 toward 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 dashed lines in the figure represent the distribution of the third magnetic field in the absence of the first magnetic element 402), the magnetic field direction of the third magnetic field at a point being the tangential direction of the point on the third lines of magnetic induction. The magnetic circuit assembly 400 may generate a first full magnetic field under the interaction of the second magnetic field and the third 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 direction of the magnetic field 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.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the above disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements, and adaptations of the present application may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within this application, and are therefore within the spirit and scope of the exemplary embodiments of this application.

Meanwhile, the present application uses specific words to describe embodiments of the present application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the present application. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the present application may be combined as suitable.

Furthermore, those skilled in the art will appreciate that the various aspects of the invention are illustrated and described in terms of several patentable categories or circumstances, including any novel and useful procedures, machines, products, or materials, or any novel and useful modifications thereof. Accordingly, aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, micro-code, etc.) or by a combination of hardware and software. The above hardware or software may be referred to as a "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the present application may take the form of a computer product, comprising computer-readable program code, embodied in one or more computer-readable media.

Furthermore, the order in which the elements and sequences are processed, the use of numerical letters, or other designations are used herein is not intended to limit the order in which the processes and methods of the present application are performed unless explicitly recited in the claims. While certain presently useful inventive embodiments have been discussed in the foregoing disclosure, by way of various examples, it is to be understood that such details are merely illustrative 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 included within the spirit and scope of the embodiments of the present application. For example, while the system components described above may be implemented by hardware devices, they may also be implemented solely by software solutions, such as installing the described system on an existing server or mobile device.

Likewise, it should be noted that in order to simplify the presentation disclosed herein and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure, however, is not intended to imply that more features than are presented in the claims are required for the subject application. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments, in some examples, are modified with the modifier "about," "approximately," or "substantially," etc. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical data used in the specification and claims is approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical data should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and data used in some embodiments of the present application to determine the breadth of their ranges are approximations, in particular embodiments, the settings of such numerical values are as precise as possible.

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 this application. Thus, by way of example, and not limitation, alternative configurations of embodiments of the present application may be considered in keeping with the teachings of the present application. Accordingly, embodiments of the present application are not limited to only the embodiments explicitly described and depicted herein.

Claims

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

a first magnetic element that generates a first magnetic field;

the first magnetic conduction element is connected with the upper surface of the first magnetic 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;

the second magnetic conduction element comprises a bottom plate and side walls, the first magnetic element is connected with the bottom plate of the second magnetic conduction element, and the lower surface of the second magnetic element is connected with the side walls of the second magnetic conduction element; and

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 conductive element, the at least one fourth magnetic element generating a fourth magnetic field that increases a magnetic field strength of the first magnetic field at the magnetic gap;

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;

the third magnetic conduction element is connected with the upper surface of the fifth magnetic element and the upper surface of the second magnetic element, and the third magnetic conduction element, the second magnetic conduction element and the second magnetic element can form a cavity, and the cavity comprises the first magnetic element, the fifth magnetic element, the first magnetic conduction element and the voice coil; the third magnetically permeable element is configured to inhibit field strength leakage of the first magnetic field and the second magnetic field.

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:

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 a magnetic field strength of the first magnetic field at the magnetic gap.

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

5. A magnetic circuit assembly according to claim 3, wherein the magnetization direction of the at least one fourth magnetic element is between 45 degrees and 135 degrees from the magnetization direction of the first magnetic element.

6. The magnetic circuit assembly of claim 1, wherein the at least one fifth magnetic element has a magnetization direction that is between 150 degrees and 180 degrees from the magnetization direction of the first magnetic element.

7. The magnetic circuit assembly of claim 1, 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 magnetically permeable element ranges from 0.4 to 0.6.

8. The magnetic circuit assembly of claim 1, wherein the thickness of the at least one fifth magnetic element is equal to the thickness of the first magnetic element.

9. The magnetic circuit assembly of claim 1, wherein the thickness of the at least one fifth magnetic element is less than the thickness of the first magnetic element.

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

at least one electrically conductive element, wherein the electrically conductive element connects at least one of the first magnetic element, the first magnetically permeable element, or the second magnetically permeable element.

11. 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 one of claims 1 to 10.