A bone conduction speaker

Abstract

The present application mainly relates to a bone conduction speaker, which includes an earphone fixing assembly, a shell connected to the earphone fixing assembly, and a magnetic circuit assembly and a vibration assembly arranged in the shell. The earphone fixing assembly is used to maintain stable contact between the bone conduction speaker and the human body. The shell has a shell panel facing the human body and a shell back opposite to the shell panel, and a shell side surface located between the shell panel and the shell back. The magnetic circuit assembly is used to provide a magnetic field. The vibration assembly includes a coil and a vibration transmission plate. At least a portion of the coil is located in the magnetic field and moves in the magnetic field under the drive of an electrical signal. One end of the vibration transmission plate is connected to the magnetic circuit assembly, and the other end is connected to the shell. The frequency response curve of the bone conduction speaker produces two low-frequency resonance peaks in a frequency range less than 500 Hz, and the two low-frequency resonance peaks are jointly generated by the vibration transmission plate and the earphone fixing assembly.

Description

[0001] This application is a divisional application of the Chinese patent application filed with the China Patent Office on January 5, 2019, with application number 201980039998.7 and invention name “A bone conduction speaker and its testing method”.

[0002] The parent application claims priority to Chinese application No. 201810624043.5 filed on June 15, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of bone conduction headphones, and in particular to a bone conduction speaker. Background Art

[0004] Bone conduction speakers convert electrical signals into mechanical vibration signals, which are then transmitted through human tissue and bone to the auditory nerves, allowing the wearer to hear sound. Because bone conduction speakers transmit sound through mechanical vibrations, their operation causes vibrations in the surrounding air, leading to sound leakage. This application provides a simple, compact bone conduction speaker that significantly reduces sound leakage from bone conduction headphones and improves their sound quality. Summary of the Invention

[0005] The present application provides a bone conduction speaker, which includes an earphone fixing assembly, a shell connected to the earphone fixing assembly, and a magnetic circuit assembly and a vibration assembly arranged in the shell. The earphone fixing assembly is used to maintain stable contact between the bone conduction speaker and the human body. The shell has a shell panel facing the human body, a shell back opposite to the shell panel, and a shell side surface located between the shell panel and the shell back. The magnetic circuit assembly is used to provide a magnetic field. The vibration assembly includes a coil and a vibration transmission plate. At least a portion of the coil is located in the magnetic field and moves in the magnetic field under the drive of an electrical signal. One end of the vibration transmission plate is connected to the magnetic circuit assembly, and the other end is connected to the shell. The frequency response curve of the bone conduction speaker produces two low-frequency resonance peaks in a frequency range less than 500 Hz, and the two low-frequency resonance peaks are jointly generated by the vibration transmission plate and the earphone fixing assembly.

[0006] Optionally, the two low-frequency resonance peaks correspond to the earphone fixing component and the vibration transmission piece respectively.

[0007] Optionally, the difference between the peak values ​​of the two low-frequency resonance peaks is no more than 150 Hz.

[0008] Optionally, the thickness of the vibration transmission sheet is 0.005mm-3mm.

[0009] Optionally, the frequency response curve of the bone conduction speaker generates a first high-frequency peak and a second high-frequency peak in a frequency range greater than 2000 Hz, the first high-frequency peak is generated by the side of the shell, and the second high-frequency peak is generated by the shell panel.

[0010] Optionally, the frequency response curve of the bone conduction speaker has a first high-frequency valley generated by the side surface of the housing in a frequency range greater than 4000 Hz.

[0011] Optionally, the peak frequency of the first high-frequency valley is lower than the peak frequency of the first high-frequency peak.

[0012] Optionally, the Young's modulus of the material of the shell is greater than 2000 MPa.

[0013] Optionally, the stiffness of the housing panel and the back of the housing is such that the effective frequency band of the frequency response curve of the bone conduction speaker covers at least 500Hz-6000Hz, there is no frequency width in the effective frequency band exceeding 1 / 8 octave, and the peak / valley value exceeds the peak / valley value of 10dB from the average vibration intensity.

[0014] Optionally, the weight of the shell is less than or equal to 8 grams. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present application will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent similar structures, wherein:

[0016] Figure 1 is a structural module diagram of a bone conduction headset according to some embodiments of the present application;

[0017] Figure 2 is a schematic longitudinal cross-sectional view of a bone conduction headset according to some embodiments of the present application;

[0018] Figure 3 1 is a partial frequency response curve of a bone conduction headphone according to some embodiments of the present application;

[0019] Figure 4 Partial frequency response curves of a bone conduction earphone when the shell of the bone conduction earphone is made of materials with different Young's moduli according to some embodiments of the present application;

[0020] Figure 5 1. The graph of some frequency response curves of a bone conduction earphone when the vibration transducer of the bone conduction earphone has different stiffnesses according to some embodiments of the present application.

[0021] Figure 61. The present invention provides a partial frequency response curve of a bone conduction earphone when the earphone fixing assembly of the bone conduction earphone has different stiffnesses according to some embodiments of the present application.

[0022] Figure 7A is a schematic diagram of the shell structure of a bone conduction headset according to some embodiments of the present application;

[0023] Figure 7B is a schematic diagram of the relationship between the frequency of generating high-order modes and the volume of the shell and the Young's modulus of the material according to some embodiments of the present application;

[0024] Figure 7C Schematic diagram of the relationship between the volume and housing volume of a bone conduction speaker according to some embodiments of the present application;

[0025] Figure 8 is a schematic diagram showing the principle of reducing sound leakage of a housing according to some embodiments of the present application;

[0026] Figure 9 1. This is a partial frequency response curve of a bone conduction earphone when the shell weight of the bone conduction earphone is different according to some embodiments of the present application;

[0027] Figure 10A is a schematic structural diagram of a shell of a bone conduction headset according to some embodiments of the present application;

[0028] Figure 10B is a schematic structural diagram of a shell of a bone conduction headset according to some embodiments of the present application;

[0029] Figure 10C is a schematic structural diagram of a shell of a bone conduction headset according to some embodiments of the present application;

[0030] Figure 11 This is a comparison chart of sound leakage effects between a traditional bone conduction headset and a bone conduction headset according to some embodiments of the present application;

[0031] Figure 12 It is the frequency response curve produced by the shell panel of the bone conduction earphone;

[0032] Figure 13 is a schematic structural diagram of a housing panel according to some embodiments of the present application;

[0033] Figure 14A It is the frequency response curve produced by the back of the shell of the bone conduction earphone;

[0034] Figure 14B It is the frequency response curve produced by the side of the shell of the bone conduction earphone;

[0035] Figure 15 It is the frequency response curve of the bone conduction earphones produced by the shell bracket of the bone conduction earphones;

[0036] Figure 16A is a structural schematic diagram of a bone conduction earphone with an earphone fixing assembly according to some embodiments of the present application;

[0037] Figure 16B is a schematic structural diagram of another bone conduction earphone with an earphone fixing assembly according to some embodiments of the present application;

[0038] Figure 17 is a schematic diagram of the shell structure of a bone conduction headset according to some embodiments of the present application;

[0039] Figure 18A 1 is a schematic structural diagram of a vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0040] Figure 18B is a schematic structural diagram of another vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0041] Figure 18C is a schematic structural diagram of another vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0042] Figure 18D is a schematic structural diagram of another vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0043] Figure 19 1 is a schematic structural diagram of a bone conduction headset with a stereo vibration transmission piece according to some embodiments of the present application;

[0044] Figure 20A is a schematic structural diagram of a bone conduction headset according to some embodiments of the present application;

[0045] Figure 20B is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

[0046] Figure 20C is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

[0047] Figure 20D is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

[0048] Figure 21 1 is a schematic structural diagram of a bone conduction earphone with a sound guide hole according to some embodiments of the present application;

[0049] Figures 22A-22C is a schematic structural diagram of a bone conduction headset according to some embodiments of the present application;

[0050] Figures 23A-23C is a schematic structural diagram of a bone conduction earphone with an earphone fixing assembly according to some embodiments of the present application;

[0051] Figure 24 This is an exemplary method for measuring vibration of a bone conduction earphone housing according to some embodiments of the present application;

[0052] Figure 25 is in accordance with Figure 24 An exemplary result measured in the manner shown;

[0053] Figure 26 This is an exemplary method for measuring vibration of a bone conduction earphone housing according to some embodiments of the present application;

[0054] Figure 27 is in accordance with Figure 26 An exemplary result measured in the manner shown;

[0055] Figure 28 is an exemplary method for measuring vibration of a bone conduction earphone housing according to some embodiments of the present application; and

[0056] Figure 29 This is an exemplary method for measuring the vibration of a bone conduction earphone shell according to some embodiments of the present application. DETAILED DESCRIPTION

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For those of ordinary skill in the art, the present application can also be applied to other similar scenarios based on these drawings without paying any creative work. It should be understood that these exemplary embodiments are provided only to enable those skilled in the relevant fields to better understand and implement the present invention, and are not intended to limit the scope of the present invention in any way. Unless otherwise apparent from the language context or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0058] As used in this application and the claims, unless the context clearly indicates an exception, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural, unless the context clearly indicates otherwise. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the specifically identified steps and elements, and these steps and elements do not constitute an exclusive list; the method or apparatus may also include other steps or elements. The term "based on" means "based, at least in part, on." The term "one embodiment" means "at least one embodiment," and the term "another embodiment" means "at least one additional embodiment." Definitions of other terms are provided below. Without loss of generality, the bone conduction-related technology of the present invention will be described using the terms "bone conduction speaker" or "bone conduction earphone." This description is merely one form of bone conduction application. For those skilled in the art, "speaker" or "earphone" can be replaced by other similar terms, such as "player" or "hearing aid." In fact, the various implementations of the present invention can be readily applied to other hearing devices other than speakers. For example, after understanding the basic principles of bone conduction headphones, professionals in this field may be able to make various modifications and changes in form and detail to the specific methods and steps of implementing bone conduction headphones without deviating from these principles. In particular, they may incorporate ambient sound pickup and processing capabilities into bone conduction headphones, allowing them to function as hearing aids. For example, a microphone or other sound source can pick up sounds from the user's / wearer's surroundings and, using a specific algorithm, transmit the processed sounds (or the generated electrical signals) to a bone conduction speaker. In other words, a bone conduction headphone can be modified to incorporate ambient sound pickup capabilities, which, after certain signal processing, are transmitted to the user / wearer via the bone conduction speaker, thereby functioning as a bone conduction hearing aid. For example, the algorithms mentioned here may include one or more combinations of noise cancellation, automatic gain control, acoustic feedback suppression, wide dynamic range compression, active environmental recognition, active noise cancellation, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, and volume control.

[0059] Figure 1 FIG. 1 is a structural module diagram of a bone conduction speaker 100 according to some embodiments of the present application. Figure 1 As shown, the bone conduction speaker 100 may include a magnetic circuit component 102 , a vibration component 104 , a housing 106 , and a connection component 108 .

[0060] The magnetic circuit assembly 102 can provide a magnetic field. This magnetic field can be used to convert a signal containing sound information into a vibration signal. In some embodiments, the sound information can include a video or audio file in a specific data format, or data or files that can be converted into sound through a specific method. The signal containing sound information can originate from a storage component within the bone conduction speaker 100 itself, or from an information generation, storage, or transmission system external to the bone conduction speaker 100. The signal containing sound information can include one or more combinations of electrical signals, optical signals, magnetic signals, mechanical signals, and the like. The signal containing sound information can originate from a single signal source or from multiple signal sources. The multiple signal sources can be related or unrelated. In some embodiments, the bone conduction speaker 100 can obtain the signal containing sound information through a variety of different methods, including wired or wireless, and in real time or with a delay. For example, the bone conduction speaker 100 can receive an electrical signal containing sound information through a wired or wireless method, or directly obtain data from a storage medium to generate a sound signal. For another example, a bone conduction hearing aid can include a component with a sound acquisition function that picks up sound from the environment, converts the mechanical vibrations of the sound into an electrical signal, and then processes the signal through an amplifier to obtain an electrical signal that meets 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 a coaxial cable, a communication cable, a flexible cable, a spiral cable, a non-metallic sheathed cable, a metallic sheathed cable, a multi-core cable, a twisted-pair cable, a ribbon cable, a shielded cable, a telecommunications cable, a two-strand cable, parallel two-core conductors, a twisted pair, or a combination thereof. The examples described above are for illustrative purposes only, and the medium of the wired connection may also be other types, such as other transmission carriers for electrical signals or optical signals.

[0061] Wireless connections may include radio communication, free-space optical communication, acoustic communication, and electromagnetic induction. Radio communication may include IEEE 802.11 standards, IEEE 802.15 standards (e.g., Bluetooth and cellular), first-generation mobile communication technologies, second-generation mobile communication technologies (e.g., FDMA, TDMA, SDMA, CDMA, and SSMA), general packet radio service (GPRS), third-generation mobile communication technologies (e.g., CDMA2000, WCDMA, TD-SCDMA, and WiMAX), fourth-generation mobile communication technologies (e.g., TD-LTE and FDD-LTE), satellite communication (e.g., GPS), near-field communication (NFC), and other technologies operating in the ISM band (e.g., 2.4 GHz). Free-space optical communication may include visible light and infrared signals; acoustic communication may include sound waves and ultrasonic signals; and electromagnetic induction may include near-field communication. The examples described above are for illustrative purposes only; other types of wireless connection media may also be used, such as Z-wave technology, other paid civilian radio bands, and military radio bands. For example, as some application scenarios of this technology, the bone conduction speaker 100 can obtain signals containing sound information from other devices through Bluetooth technology.

[0062] The vibration component 104 can generate mechanical vibrations. The generation of such vibrations is accompanied by energy conversion. The bone conduction speaker 100 can use the magnetic circuit component 102 and the vibration component 104 to convert a signal containing sound information into mechanical vibrations. The conversion process may involve the coexistence and conversion of multiple different types of energy. For example, an electrical signal can be directly converted into mechanical vibrations through a transducer to generate sound. For another example, sound information can be contained in an optical signal, and a specific transducer can realize the process of converting the optical signal into a vibration signal. Other types of energy that can coexist and convert during the operation of the transducer include thermal energy, magnetic field energy, etc. The energy conversion method of the transducer may include dynamic, electrostatic, piezoelectric, moving iron, pneumatic, electromagnetic, etc. The frequency response range and sound quality of the bone conduction earphone 100 will be affected by the vibration component 104. For example, in a dynamic coil transducer device, the vibration assembly 104 includes a wound cylindrical coil and a vibrating body (e.g., a vibrating plate). Driven by a signal current, the cylindrical coil causes the vibrating body to vibrate and produce sound in a magnetic field. The expansion and contraction of the vibrating body's material, the deformation of its wrinkles, its size, shape, and mounting method, and the magnetic density of the permanent magnet all affect the sound quality of the bone conduction speaker 100. The vibrating body in the vibration assembly 104 can have a mirror-symmetrical structure, a centrally symmetrical structure, or an asymmetrical structure. The vibrating body can be provided with intermittent holes to generate greater displacement for the same input energy, thereby achieving higher sensitivity and improving the vibration and sound output of the bone conduction speaker. The vibrating body can be a torus or a torus-like structure, with multiple rods radiating toward the center disposed within the torus. The number of rods can be two or more. In some embodiments, the vibration assembly 104 can include a coil, a vibrating plate, a transducer plate, and the like.

[0063] The housing 106 can transmit mechanical vibrations to the human body, enabling the human body to hear sounds. The housing 106 can constitute a sealed or non-sealed housing space, and the magnetic circuit assembly 102 and the vibration assembly 104 can be disposed within the housing 106. The housing 106 can include a housing panel. The housing panel can be directly or indirectly connected to the vibration assembly 104, transmitting the mechanical vibrations of the vibration assembly 104 to the auditory nerve via the bones, enabling the human body to hear sounds.

[0064] The connection assembly 108 can provide a connection and support function for the magnetic circuit assembly 102, the vibration assembly 104, and / or the housing 106. The connection assembly 108 can include one or more connectors. The one or more connectors can connect the housing 106 to one or more structures in the magnetic circuit assembly 102 and / or the vibration assembly 104.

[0065] The above description of the bone conduction speaker structure is merely a specific example and should not be considered the only viable implementation. Clearly, those skilled in the art, after understanding the basic principles of bone conduction speakers, may make various modifications and alterations in form and detail to the specific methods and steps for implementing bone conduction speakers without departing from these principles. However, such modifications and alterations remain within the scope of the above description. For example, the bone conduction speaker 100 may include one or more processors that may execute one or more sound signal processing algorithms. These sound signal processing algorithms may modify or enhance the sound signal. For example, these algorithms may perform noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active environmental recognition, active noise cancellation, directional processing, tinnitus treatment, multi-channel wide dynamic range compression, active howling suppression, volume control, or other similar processing, or any combination thereof. These modifications and alterations remain within the scope of the claims of the present invention. For another example, the bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a velocity sensor, a displacement sensor, etc. These sensors may collect user or environmental information.

[0066] Figure 2 FIG. 2 is a structural diagram of a bone conduction earphone 200 according to some embodiments of the present application. Figure 2 As shown, the bone conduction earphone 200 may include a magnetic circuit assembly 210 , a coil 212 , a vibration transmitting piece 214 , a connector 216 , and a housing 220 .

[0067] The magnetic circuit assembly 210 may include a first magnetic element 202, a first magnetic conductive element 204, and a second magnetic conductive element 206. The magnetic element described in this application refers to an element that can generate a magnetic field, such as a magnet. The magnetic element may have a magnetization direction, and the magnetization direction refers to the direction of the magnetic field inside the magnetic element. The first magnetic element 202 may include one or more magnets. In some embodiments, the magnet may include a metal alloy magnet, a ferrite, or the like. The metal alloy magnet may include neodymium iron boron, samarium cobalt, aluminum nickel cobalt, iron chromium cobalt, aluminum iron boron, iron carbon aluminum, or the like, or a combination of multiple thereof. The ferrite may include barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or a combination of multiple thereof.

[0068] The lower surface of the first magnetic conductive element 204 can be connected to the upper surface of the first magnetic element 202. The second magnetic conductive element 206 can be a concave structure, including a bottom wall and side walls. The inner side of the bottom wall of the second magnetic conductive element 206 can be connected to the first magnetic element 202, and the side walls can surround the first magnetic element 202 and form a magnetic gap between the first magnetic element 202. It should be noted that the magnetic conductive body mentioned here can also be called a magnetic field concentrator or an iron core. The magnetic conductive body can adjust the distribution of the magnetic field (for example, the magnetic field generated by the first magnetic element 202). The magnetic conductive body may include an element processed from a soft magnetic material. In some embodiments, the soft magnetic material may include a metal material, a metal alloy, a metal oxide material, an amorphous metal material, etc., such as iron, iron-silicon alloy, iron-aluminum alloy, nickel-iron alloy, iron-cobalt alloy, low-carbon steel, silicon steel sheet, silicon steel sheet, ferrite, etc. In some embodiments, the magnetic conductive body can be processed by one or more combinations of methods such as casting, plastic processing, cutting, powder metallurgy, etc. Casting can include sand casting, investment casting, pressure casting, centrifugal casting, etc.; plastic processing can include rolling, casting, forging, stamping, extrusion, drawing, etc.; cutting processing can include turning, milling, planing, grinding, etc. In some embodiments, the processing method of the magnetic conductor can include 3D printing, CNC machine tools, etc. The connection method between the first magnetic conductive element 204, the second magnetic conductive element 206 and the first magnetic element 202 can include one or more combinations of bonding, clamping, welding, riveting, bolting, etc.

[0069] Coil 212 can be disposed in the magnetic gap between first magnetic element 202 and second magnetically conductive element 206. In some embodiments, a signal current can be supplied to coil 212. Coil 212 is exposed to the magnetic field formed by magnetic circuit assembly 210 and is subjected to the Ampere force, which drives coil 212 to generate mechanical vibrations. Simultaneously, magnetic circuit assembly 210 is subjected to a reaction force opposing the coil.

[0070] One end of the vibration transmitting plate 214 can be connected to the magnetic circuit assembly 210, and the other end can be connected to the housing 220. In some embodiments, the vibration transmitting plate 214 is an elastic component. The elasticity is determined by many aspects such as the material, thickness, and structure of the vibration transmitting plate 214. The material of the vibration transmitting plate 214 includes, but is not limited to, steel (such as but not limited to stainless steel, carbon steel, etc.), lightweight alloy (such as but not limited to aluminum alloy, beryllium copper, magnesium alloy, titanium alloy, etc.), plastic (such as but not limited to high molecular polyethylene, blown nylon, engineering plastics, etc.), and can also be other single or composite materials that can achieve the same performance. Composite materials can include, for example, but not limited to reinforcing materials such as glass fiber, carbon fiber, boron fiber, graphite fiber, graphene fiber, silicon carbide fiber or aramid fiber, or composites of other organic and / or inorganic materials, such as various types of glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. In some embodiments, the thickness of the vibration transmitting plate 214 is no less than 0.005 mm. Preferably, the thickness is between 0.005 mm and 3 mm, more preferably, the thickness is between 0.01 mm and 2 mm, even more preferably, the thickness is between 0.01 mm and 1 mm, and even more preferably, the thickness is between 0.02 mm and 0.5 mm. In some embodiments, the vibration transmitting plate 214 may be an elastic structure. An elastic structure refers to a structure that is inherently elastic. Even if the material is relatively hard, the inherent elasticity of the structure makes the vibration transmitting plate 214 inherently elastic. For example, the vibration transmitting plate 214 may be made into an elastic structure similar to a spring. In some embodiments, the vibration transmitting plate 214 can be configured as an annular or quasi-annular structure. Preferably, it comprises at least one ring, preferably at least two rings, which can be concentric or non-concentric, connected by at least two struts radiating from the outer ring to the inner ring's center. More preferably, it comprises at least one elliptical ring, more preferably at least two elliptical rings, each with a different radius of curvature, connected by struts. Even more preferably, the vibration transmitting plate 214 comprises at least one square ring. The vibration transmitting plate 214 can also be configured as a sheet, preferably with a hollow pattern, where the area of ​​the hollow pattern is no less than the area without the hollow pattern. The materials, thicknesses, and structures described above can be combined to create different vibration transmitting plates. For example, an annular vibration transmitting plate can have different thickness distributions. Preferably, the strut thickness is equal to the ring thickness, more preferably, the strut thickness is greater than the ring thickness, and even more preferably, the inner ring thickness is greater than the outer ring thickness. In some embodiments, the vibration transmitting piece 214 is partially connected to the magnetic circuit assembly 210 and partially connected to the housing 220. Preferably, the vibration transmitting piece 214 is connected to the first magnetic conductive element 204. In some embodiments, the vibration transmitting piece 214 can be connected to the magnetic circuit assembly 210 and the housing 220 by glue.In some embodiments, the vibration transmission plate 214 can be fixed to the shell 220 by welding, clamping, riveting, threaded connection (screws, screws, bolts, etc.), interference connection, clamp connection, pin connection, wedge key connection, and molded connection.

[0071] In some embodiments, the vibration transmission piece 214 can be connected to the magnetic circuit assembly 210 via a connector 216. In some embodiments, the bottom end of the connector 216 can be fixed to the magnetic circuit assembly 210, for example, the connector can be fixed to the upper surface of the first magnetic conductive element. In some embodiments, the connector 216 has a top end opposite the bottom surface, and the top end can be fixedly connected to the vibration transmission piece 214. In some embodiments, the top end of the connector 216 can be glued to the vibration transmission piece 214.

[0072] The housing 220 includes a housing panel 222, a housing back 224, and housing sides 226. The housing back 224 is located opposite the housing panel 222 and is disposed on both ends of the housing side 226. The housing panel 222, the housing back 224, and the housing side 226 form a monolithic structure with a certain amount of accommodation space. In some embodiments, the magnetic circuit assembly 210, the coil 212, and the transducer 214 are fixed within the housing 220. In some embodiments, the bone conduction headset 200 may further include a housing bracket 228, through which the transducer 214 is connected to the housing 220. In some embodiments, the coil 212 may be fixed to the housing bracket 228 and, through the housing bracket 228, drive the housing 220 to vibrate. The housing bracket 228 may be a part of the housing 220 or a separate component, directly or indirectly connected to the interior of the housing 220. In some embodiments, the housing bracket 228 is fixed to the inner surface of the housing side 226. In some embodiments, the housing bracket 228 can be adhered to the housing 220 by glue, or fixed to the housing 220 by stamping, injection molding, clamping, riveting, threading or welding.

[0073] In some embodiments, the bone conduction speaker 100 further includes an earphone fixing assembly (in Figure 2 Not shown in the figure). The earphone fixing assembly is fixedly connected to the shell 220, and maintains stable contact between the bone conduction speaker 100 and human tissue or bone, avoids shaking of the bone conduction speaker 100, and ensures that the earphone can stably transmit sound. In some embodiments, the earphone fixing assembly can be an arc-shaped elastic component that can form a force that rebounds toward the middle of the arc. A shell 220 is connected to each end of the earphone fixing assembly to maintain contact between the shells 220 and human tissue or bone. For a more detailed description of the earphone fixing assembly, please refer to the description elsewhere in this application, for example, Figure 16 and related descriptions.

[0074] Figure 3 It is a frequency response curve of a bone conduction speaker shown in some embodiments of the present application. The horizontal axis is the vibration frequency, and the vertical axis is the vibration intensity of the bone conduction speaker 200. The vibration intensity mentioned here can be expressed as the vibration acceleration of the bone conduction speaker 200. In some embodiments, within the frequency response range of 1000Hz to 10000Hz, the flatter the frequency response curve is, the better the sound quality of the bone conduction speaker 200 is considered to be. The structure of the bone conduction speaker 200, the design of the components, the material properties, etc. may all have an impact on the frequency response curve. Generally, low frequency refers to sound less than 500Hz, mid-frequency refers to sound in the range of 500Hz-4000Hz, and high frequency refers to sound greater than 4000Hz. As Figure 3 As shown, the frequency response curve of the bone conduction speaker 200 can have two resonance peaks (310 and 320) in the low-frequency region, and a first high-frequency trough 330, a first high-frequency peak 340, and a second high-frequency peak 350 in the high-frequency region. The two resonance peaks (310 and 320) in the low-frequency region can be generated by the interaction of the vibration transmission plate 214 and the earphone fixing assembly. The first high-frequency trough 330 and the first high-frequency peak 340 can be generated by deformation of the housing side 226 at high frequencies, and the second high-frequency peak 350 can be generated by deformation of the housing panel 222 at high frequencies.

[0075] The locations of the different resonance peaks and high-frequency peaks / valleys are related to the stiffness of the corresponding components. Stiffness is the ability of a material or structure to resist elastic deformation when subjected to stress. Stiffness is related to the Young's modulus of the material itself and the structural dimensions. The greater the stiffness, the less the structure deforms when subjected to stress. As mentioned above, the frequency response from 500Hz to 6000Hz is particularly critical for bone conduction speakers. Within this frequency range, sharp peaks and valleys are undesirable. The flatter the frequency response curve, the better the sound quality of the headphones. In some embodiments, the peaks and valleys in the high-frequency region can be adjusted to a higher frequency region by adjusting the stiffness of the housing panel 222 and the housing back 224. In some embodiments, the housing bracket 228 can also affect the peaks and valleys in the high-frequency region. By adjusting the stiffness of the housing bracket 228, the peaks and valleys in the high-frequency region can be adjusted to a higher frequency region. In some embodiments, the effective frequency band of the frequency response curve of the bone conduction speaker can be made to cover at least 500Hz to 1000Hz, or 1000Hz to 2000Hz. More preferably, the effective frequency range is 500Hz to 2000Hz, more preferably, 500Hz to 4000Hz, more preferably, 500Hz to 6000Hz, more preferably, 100Hz to 6000Hz, and more preferably, 100Hz to 10000Hz. The effective frequency band referred to herein is defined in accordance with commonly used industry standards, such as IEC and JIS. In some embodiments, the effective frequency band does not have a frequency width exceeding 1 / 8 octave, and the peak / valley value does not exceed 10dB of the average vibration intensity.

[0076] In some embodiments, the stiffness of different components (eg, housing 220 and housing bracket 228 ) is related to the Young's modulus of their materials, thickness, size, and volume. Figure 4 This is a frequency response curve of a bone conduction speaker when the shell of a bone conduction speaker shown in some embodiments of the present application is made of materials with different Young's modulus. It should be noted that, as mentioned above, the shell 220 may include a shell panel 222, a shell back 224 and a shell side 226. The shell panel 222, the shell back 224 and the shell side 226 can be made of the same material or different materials. For example, the shell back 224 and the shell panel 222 can be made of the same material, and the shell side 226 can be made of other materials. Figure 4 In the embodiment, the housing 220 can be made of the same material for the housing panel 222, the housing back 224 and the housing side 226, so that the effect of the change of the Young's modulus of the housing material on the frequency response curve of the bone conduction earphone can be clearly explained. Figure 4 In the figure, by comparing the frequency response curves of the shell 220 of the same size made of three different materials with Young's modulus of 18000MPa, 6000MPa and 2000MPa, it can be found that: under the condition of unchanged size, the greater the Young's modulus of the shell 220 material, the greater the stiffness of the shell 220, and the higher the frequency of the high-frequency peak in the frequency response curve. The stiffness of the shell mentioned here can be characterized as the elastic modulus of the shell, that is, the change in shape of the shell when it is subjected to force. When the structure and size of the shell are constant, the stiffness of the shell increases with the increase of the Young's modulus of the shell material. In some embodiments, the frequency response curve can be adjusted to a higher frequency at the high-frequency peak by adjusting the Young's modulus of the shell 220 material. In some embodiments, the Young's modulus of the shell 220 material may be greater than 2000 MPa. Preferably, the Young's modulus of the shell 220 material may be greater than 4000 MPa. Preferably, the Young's modulus of the shell 220 material is greater than 6000 MPa. Preferably, the Young's modulus of the shell 220 material is greater than 8000 MPa. Preferably, the Young's modulus of the shell 220 material is greater than 12000 MPa. More preferably, the Young's modulus of the shell 220 material is greater than 15000 MPa. Further preferably, the Young's modulus of the shell 220 material is greater than 18000 MPa.

[0077] In some embodiments, by adjusting the stiffness of the housing 220, the high-frequency peak frequency in the frequency response curve of the bone conduction earphone can be set to no less than 1000 Hz, preferably no less than 2000 Hz, preferably no less than 4000 Hz, preferably no less than 6000 Hz, more preferably no less than 8000 Hz, more preferably no less than 10000 Hz, more preferably no less than 12000 Hz, further preferably no less than 14000 Hz, further preferably no less than 16000 Hz, further preferably no less than 18000 Hz, further preferably no less than 20000 Hz. In some embodiments, by adjusting the stiffness of the housing 220, the high-frequency peak frequency in the frequency response curve of the bone conduction earphone can be set outside the human hearing range. In some embodiments, by adjusting the stiffness of the housing 220, the high-frequency peaks in the headphone's frequency response curve can be positioned within the human hearing range. In some embodiments, when there are multiple high-frequency peaks / valleys, by adjusting the stiffness of the housing 220, one or more of the high-frequency peaks / valleys in the bone conduction headphone's frequency response curve can be positioned outside the human hearing range, while the remaining one or more high-frequency peaks / valleys can be positioned within the human hearing range. For example, the second high-frequency peak 350 can be positioned outside the human hearing range, while the first high-frequency valley 330 and the first high-frequency peak 340 can be positioned within the human hearing range.

[0078] In some embodiments, the housing 220 can be designed to have greater rigidity by designing the connection method between the housing panel 222, the housing back 224, and the housing side 226. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 can be integrally formed. In some embodiments, the housing back 224 and the housing side 226 can be integrally formed. The housing panel 222 and the housing side 226 can be directly affixed with glue, or secured by snap-fitting, welding, or threading. The glue can be a highly viscous and hard glue. In some embodiments, the housing panel 222 and the housing side 226 can be integrally formed, and the housing back 224 and the housing side 226 can be directly affixed with glue, or secured by snap-fitting, welding, or threading. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 are independent components, and can be fixedly connected by one or a combination of gluing, snap-fitting, welding, or threading. For example, the housing panel 222 and the housing side 226 are connected by glue, and the housing back 224 and the housing side 226 are connected by snapping, welding, or screwing. Alternatively, the housing back 224 and the housing side 226 are connected by glue, and the housing panel 222 and the housing side 226 are connected by snapping, welding, or screwing.

[0079] In some embodiments, the overall rigidity of the housing 220 can be improved by selecting materials with the same or different Young's moduli. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 can all be made of the same material. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 can be made of different materials, and the different materials can have the same Young's modulus or different Young's moduli. In some embodiments, the housing panel 222 and the housing back 224 are made of the same material, and the housing side 226 is made of another material. The Young's modulus of the two materials can be the same or different. For example, the Young's modulus of the material of the housing side 226 can be greater than the Young's modulus of the material of the housing panel 222 and the housing back 224, or the Young's modulus of the material of the housing side 226 can be less than the Young's modulus of the material of the housing panel 222 and the housing back 224. In some embodiments, the housing panel 222 and the housing side 226 are made of the same material, and the housing back 224 is made of another material. The Young's modulus of the two materials can be the same or different. For example, the Young's modulus of the material of the housing back 224 can be greater than the Young's modulus of the material of the housing panel 222 and the housing side 226, or the Young's modulus of the material of the housing back 224 can be less than the Young's modulus of the material of the housing panel 222 and the housing side 226. In some embodiments, the housing back 224 and the housing side 226 are made of the same material, and the housing panel 222 is made of a different material. The Young's modulus of the two materials can be the same or different. For example, the Young's modulus of the material of the housing panel 222 can be greater than the Young's modulus of the material of the housing back 224 and the housing side 226, or the Young's modulus of the material of the housing panel 222 can be less than the Young's modulus of the material of the housing back 224 and the housing side 226. In some embodiments, the materials of the housing panel 222, the housing back 224, and the housing side 226 are different. The Young's modulus of the three materials can be the same or different, and the Young's modulus of the three materials can all be greater than 2000 MPa.

[0080] Figure 5 This is a frequency response curve of a bone conduction headset when the vibration transducer of the bone conduction headset has different stiffnesses according to some embodiments of the present application. Figure 6 The frequency response curve of a bone conduction earphone when the earphone fixing assembly of the bone conduction earphone has different stiffness according to some embodiments of the present application. Figure 5 and Figure 6It can be seen that the two resonance peaks in the low-frequency region are related to the vibration transmission plate and the earphone fixing assembly. The smaller the stiffness of the vibration transmission plate 214 and the earphone fixing assembly, the more obvious the resonance peak response at low frequencies. When the stiffness of the vibration transmission plate 214 and the earphone fixing assembly is greater, the resonance peak will change toward the mid-frequency or high-frequency direction, resulting in a decrease in sound quality. Therefore, when the stiffness of the vibration transmission plate 214 and the earphone fixing assembly is smaller, the better the elasticity of the structure itself, the better the sound quality of the earphone. In some embodiments, by adjusting the stiffness of the vibration transmission plate 214 and the earphone fixing assembly, the two resonance peak frequencies in the low-frequency region of the bone conduction earphone can be made less than 2000Hz. Preferably, the two resonance peak frequencies in the low-frequency region of the bone conduction earphone can be made less than 1000Hz. More preferably, the two resonance peak frequencies in the low-frequency region of the bone conduction earphone can be made less than 500Hz. In some embodiments, the peak value difference between the two resonance peaks in the low-frequency region of the bone conduction earphones is no more than 150 Hz. Preferably, the peak value difference between the two resonance peaks in the low-frequency region of the bone conduction earphones is no more than 100 Hz. More preferably, the peak value difference between the two resonance peaks in the low-frequency region of the bone conduction earphones is no more than 50 Hz.

[0081] As described above, the present application can adjust the stiffness of each component of the bone conduction speaker (for example, the shell, the housing bracket, the vibration transmission plate or the earphone fixing component) to adjust the peak / valley of the high-frequency zone to a higher frequency and the low-frequency resonance peak to a low frequency, thereby ensuring a frequency response curve platform within the range of 500Hz to 6000Hz and improving the sound quality of the bone conduction earphones.

[0082] On the other hand, bone conduction speakers can generate sound leakage during vibration transmission. This leakage occurs when the vibration of the internal components of the bone conduction speaker 200 or the vibration of the housing causes the volume of the surrounding air to change, creating compressed or rarefied areas in the surrounding air that propagate in all directions, transmitting sound to the surrounding environment and allowing people other than the wearer of the bone conduction headphones to hear the sound from the headphones. This application can provide a solution to reduce sound leakage in bone conduction headphones by modifying the housing structure and rigidity, among other aspects.

[0083] Figure 7AFIG7 is a schematic diagram of the housing structure of a bone conduction earphone according to some embodiments of the present application. As shown in FIG7 , the housing 700 may include a housing panel 710, a housing back 720, and a housing side 730. The housing panel 710 contacts the human body, transmitting the vibration of the bone conduction earphone to the human auditory nerve. In some embodiments, when the overall stiffness of the housing 700 is relatively high, within a certain frequency range, the vibration amplitude and phase of the housing panel 710 and the housing back 720 remain the same or substantially the same (the housing side 730 does not compress air and therefore does not generate sound leakage), allowing the first sound leakage signal generated by the housing panel 710 and the second sound leakage signal generated by the housing back 720 to superimpose on each other. This superposition can reduce the amplitude of the first or second sound leakage sound waves, thereby reducing sound leakage from the housing 700. In some embodiments, the certain frequency range includes at least a portion with a frequency greater than 500 Hz. Preferably, the certain frequency range includes at least a portion with a frequency greater than 600 Hz. Preferably, the certain frequency range includes at least a portion with a frequency greater than 800 Hz. Preferably, the certain frequency range includes at least a portion with a frequency greater than 1000 Hz. Preferably, the certain frequency range includes at least a portion with a frequency greater than 2000 Hz. More preferably, the certain frequency range includes at least a portion with a frequency greater than 5000 Hz. More preferably, the certain frequency range includes at least a portion with a frequency greater than 8000 Hz. Further preferably, the certain frequency range includes at least a portion with a frequency greater than 10000 Hz. For more descriptions of the shell structure of the bone conduction earphone, please refer to the description elsewhere in this application (for example, Figures 22A-22C , and its related descriptions).

[0084] When the frequency exceeds a certain threshold, specific locations on the housing 700 (e.g., the housing panel 710, the housing back 720, and the housing side 730) may generate higher-order modes when vibrating (i.e., different points on the specific locations may vibrate inconsistently). In some embodiments, the housing volume and material of the housing 700 may be designed to produce higher frequencies for these higher-order modes. Figure 7B It is a schematic diagram of the relationship between the frequency of generating high-order modes and the shell volume and the Young's modulus of the material shown in some embodiments of the present application. For the convenience of description, it is assumed here that different parts of the shell 700 (for example, the shell panel 710, the shell back 720 and the shell side 730) are made of materials with the same Young's modulus. It should be known that for those skilled in the art, when different parts of the shell 700 are made of materials with different Young's modulus (for example, as shown in the embodiments elsewhere in this application), similar results can still be obtained. Figure 7BAs shown, the dotted line 712 represents the relationship between the frequency of the high-order mode generated by the shell 700 and the shell volume when the Young's modulus of the material is 15 GPa. Specifically, when the Young's modulus of the shell material is 15 GPa, the smaller the shell volume of the shell 700, the higher the frequency of the high-order mode generated. For example, when the shell volume is 25000 mm 3 When the shell 700 generates a high-order mode with a frequency of about 4000 Hz, the shell volume is 400 mm 3 When the Young's modulus of the shell material is 5GPa, the frequency of the high-order mode generated by the shell 700 is above 32000Hz. Similarly, the dotted line 713 represents the relationship between the frequency of the high-order mode generated by the shell 700 and the shell volume when the Young's modulus of the shell material is 5GPa. The solid line 714 represents the relationship between the frequency of the high-order mode generated by the shell 700 and the shell volume when the Young's modulus of the shell material is 2GPa. It can be seen that when the shell volume is smaller and the Young's modulus of the shell material is larger, the frequency of the high-order mode generated by the shell 700 is higher. In some embodiments, the volume of the shell 700 can be made 400mm 3 -6000mm 3 The Young's modulus of the shell material is between 2GPa and 18GPa. Preferably, the shell volume is 400mm 3 -5000mm 3 The Young's modulus of the shell material is between 2GPa and 10GPa, and more preferably, the shell volume is 400mm 3 -3500mm 3 The Young's modulus of the shell material is between 2GPa-6GPa, and the shell volume is 400mm 3 -3000mm 3 The Young's modulus of the shell material is between 2GPa and 5.5GPa. More preferably, the shell volume is 400mm 3 -2800mm 3 The Young's modulus of the shell material is between 2GPa and 5GPa, and more preferably, the shell volume is 400mm 3 -2000mm 3 In the range of 2GPa-4GPa, the Young's modulus of the shell material is between 2GPa and 4GPa. More preferably, the shell volume is 400mm 3 -1000mm 3 range, and the Young's modulus of the shell material is between 2GPa-3GPa.

[0085] It's important to note that a larger housing volume allows for a larger magnetic circuit system within housing 700, resulting in a higher sensitivity for the bone conduction speaker. In some embodiments, the sensitivity of a bone conduction speaker can be reflected by the volume produced by the speaker under a given input signal. When the same input signal is used, a higher volume indicates a higher sensitivity. Figure 7C Schematic diagram of the relationship between the volume of a bone conduction speaker and the volume of the housing according to some embodiments of the present application. Figure 7C As shown in the figure, the horizontal axis represents the size of the shell volume, and the vertical axis represents the volume of the bone conduction speaker under the same input signal (expressed in terms of the size relative to the reference volume, i.e., relative volume). The volume of the bone conduction speaker increases as the shell volume increases. For example, when the shell volume is 3000mm 3 When the volume of the bone conduction speaker is 400mm, the relative volume of the bone conduction speaker is 1. 3 In some embodiments, in order to make the bone conduction speaker have a higher sensitivity (volume), the shell volume can be 2000mm 3 -6000mm 3 , preferably, the housing volume can be 2000mm 3 -5000mm 3 , preferably, the housing volume can be 2800mm 3 -5000mm 3 , preferably, the housing volume can be 3500mm 3 -5000mm 3 , preferably, the housing volume can be 1500mm 3 -3500mm 3 , preferably, the housing volume can be 1500mm 3 -2500mm 3 .

[0086] Figure 8 Schematic diagram of the principle of reducing sound leakage of housing 700. Figure 8As shown, when the bone conduction speaker is in operation, the outer shell panel 710 contacts the human body and mechanically vibrates. In some embodiments, the outer shell panel 710 can contact the skin of the human face, exerting a certain degree of compression on the skin in contact, causing the skin around the outer shell panel 710 to protrude outward and deform. When the outer shell panel 710 vibrates, it moves toward the face of the person, compressing the skin, pushing the deformed skin around the outer shell panel 710 outward, and compressing the air around the outer shell panel 710. When the outer shell panel moves away from the face of the person, a sparse area is formed between the outer shell panel 710 and the skin of the person's face, absorbing the air around the outer shell panel 710. This compression and absorption of air causes the volume of the air around the outer shell panel 710 to continuously change, causing the surrounding air to continuously form compressed or sparse areas and spread in all directions, transmitting sound to the surrounding environment, thereby causing sound leakage. If the rigidity of the housing 700 is sufficiently great so that the housing back 720 can vibrate together with the housing panel 710, with the same magnitude and direction of vibration, when the housing panel 710 moves toward the person's face, the housing back 720 also moves in that direction, forming a rarefaction zone of air around the housing back 720. That is, when the air around the housing panel 710 is compressed, the air around the housing back 720 is absorbed. Conversely, when the housing panel 710 moves away from the person's face, the housing back 720 also moves away from the person's face, forming a compression zone of air around the housing back 720. That is, when the air around the housing panel 710 is absorbed, the air around the housing back 720 is compressed. These opposing effects of the housing back 720 and the housing panel 710 on the air cancel each other out, meaning that external sound leakage can be offset, significantly reducing sound leakage outside the housing 700. That is to say, by improving the overall stiffness of the shell 700, it is possible to ensure that the back side 720 of the shell and the shell panel 710 vibrate in unison, and the side 720 of the shell does not push the air and does not cause sound leakage, so that the sound leakage from the back side 720 of the shell and the shell panel 710 can be canceled out, greatly reducing the sound leakage from the outside of the shell 700.

[0087] In some embodiments, the housing 700 has a high rigidity, which can ensure that the housing panel 710 and the housing back 720 vibrate in unison, thereby canceling out sound leakage from the outside of the housing 700, significantly reducing sound leakage. In some embodiments, the housing 700 has a high rigidity, which can reduce sound leakage from the housing panel 710 and the housing back 720 in the mid- and low-frequency range.

[0088] In one embodiment, the rigidity of the housing 700 can be increased by increasing the rigidity of the housing panel 710, the housing back 720, and the housing side 730. The rigidity of the housing panel 710 is related to parameters such as the Young's modulus of the material, size, and weight. The greater the Young's modulus of the material, the greater the rigidity of the housing panel 710. In some embodiments, the Young's modulus of the material of the housing panel 710 is greater than 2000 MPa, preferably, the Young's modulus of the material of the housing panel 710 is greater than 3000 MPa, the Young's modulus of the material of the housing panel 710 is greater than 4000 MPa, preferably, the Young's modulus of the material of the housing panel 710 is greater than 6000 MPa, preferably, the Young's modulus of the material of the housing panel 710 is greater than 8000 MPa, preferably, the Young's modulus of the material of the housing panel 710 is greater than 12000 MPa, more preferably, the Young's modulus of the material of the housing panel 710 is greater than 15000 MPa, and further preferably, the Young's modulus of the material of the housing panel 710 is greater than 18000 MPa. In some embodiments, the shell panel 710 material includes but is not limited to acrylonitrile butadiene styrene (ABS), polystyrene (PS), high impact polystyrene (HIPS), polypropylene (PP), polyethylene terephthalate (PET), polyester (PES), polycarbonate (PC), polyamides (PA), polyvinyl chloride (PVC), polyurethanes (PU), polyvinylidene chloride (Polyvinyl chloride), polyethylene (PE), polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), phenolic resin (PF), urea formaldehyde resin (UF), melamine formaldehyde resin (MEL ...yl chloride (Polyvinylidene chloride), polyethylene (PE), polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), polyvinyl chloride (PVC), polyvinyl chloride (PVC), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride), polyvinyl chloride (Polyvinyl chloride The material of the housing panel 710 is any material selected from the group consisting of aluminum, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc., glass fiber, and carbon fiber, or any combination thereof. In some embodiments, the housing panel 710 is any combination of glass fiber, carbon fiber, and materials such as polycarbonate (PC) and polyamides (PA).In some embodiments, the material of the outer shell panel 710 can be a mixture of carbon fiber and polycarbonate (Polycarbonate, PC) in a certain proportion. In some embodiments, the material of the outer shell panel 710 can be a mixture of carbon fiber, glass fiber and polycarbonate (Polycarbonate, PC) in a certain proportion. In some embodiments, the material of the outer shell panel 710 can be a mixture of glass fiber and polycarbonate (Polycarbonate, PC) in a certain proportion, or a mixture of glass fiber and polyamide (Polyamides, PA) in a certain proportion. Adding different proportions of carbon fiber or glass fiber will result in different stiffness of the resulting material. For example, by adding 20% ​​to 50% of glass fiber, the Young's modulus of the material can reach 4000MPa to 8000MPa.

[0089] In some embodiments, the greater the thickness of the housing panel 710, the greater the rigidity of the housing panel 710. In some embodiments, the thickness of the housing panel 710 is not less than 0.3 mm, preferably, the thickness of the housing panel 710 is not less than 0.5 mm, more preferably, the thickness of the housing panel 710 is not less than 0.8 mm, and more preferably, the thickness of the housing panel 710 is not less than 1 mm. However, as the thickness increases, the weight of the housing 700 also increases, thereby increasing the weight of the bone conduction earphones and affecting the sensitivity of the earphones. Therefore, the thickness of the housing panel 710 should not be too large. In some embodiments, the thickness of the housing panel 710 does not exceed 2.0 mm, preferably, the thickness of the housing panel 710 does not exceed 1.5 mm, preferably, the thickness of the housing panel 710 does not exceed 1.2 mm, more preferably, the thickness of the housing panel 710 does not exceed 1.0 mm, and more preferably, the thickness of the housing panel 710 does not exceed 0.8 mm.

[0090] In some embodiments, the housing panel 710 can be configured in various shapes. For example, the housing panel 710 can be configured in a rectangular shape, a substantially rectangular shape (i.e., a runway shape, or a structure where the four corners of the rectangle are replaced with arcs), an elliptical shape, or any other arbitrary shape. The smaller the area of ​​the housing panel 710, the greater the rigidity of the housing panel 710. In some embodiments, the area of ​​the housing panel 710 is not greater than 8 cm 2 Preferably, the area of ​​the housing panel 710 is not greater than 6cm 2 Preferably, the area of ​​the housing panel 710 is not greater than 5cm 2 More preferably, the area of ​​the housing panel 710 is no greater than 4 cm 2 More preferably, the area of ​​the housing panel 710 is no greater than 2 cm 2 .

[0091] In some embodiments, the rigidity of the housing 700 can be adjusted by adjusting the weight of the housing 700. The heavier the housing 700, the greater its rigidity. However, a heavier housing 700 also increases the weight of the earphones, affecting the wearing comfort of the bone conduction earphones. Furthermore, a heavier housing 700 can reduce the overall sensitivity of the earphones. Figure 9 This is a frequency response curve of a bone conduction earphone when the shell weight of the bone conduction earphone is different according to some embodiments of the present application. Figure 9 As shown, as the housing becomes heavier, the high-frequency frequency response curve shifts toward low frequencies overall, causing peaks / troughs in the mid- and high-frequency response curve of the earphones, resulting in poor sound quality. In some embodiments, the housing 700 weighs less than or equal to 8 grams, preferably less than or equal to 6 grams, more preferably less than or equal to 4 grams, and even more preferably less than or equal to 2 grams.

[0092] In some embodiments, the rigidity of the outer shell panel 710 can be increased by simultaneously adjusting any combination of factors such as the Young's modulus, thickness, weight, and shape of the outer shell panel 710. For example, the desired rigidity can be achieved by adjusting the Young's modulus and thickness. Alternatively, the desired rigidity can be achieved by adjusting the Young's modulus, thickness, and weight. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 2000 MPa and the thickness is not less than 1 mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 4000 MPa and the thickness is not less than 0.9 mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 6000 MPa and the thickness is not less than 0.7 mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 8000 MPa and the thickness is not less than 0.6 mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 10000 MPa and the thickness is not less than 0.5 mm. In some embodiments, the Young's modulus of the material of the housing panel 710 is not less than 18,000 MPa and the thickness is not less than 0.4 mm.

[0093] In some embodiments, the housing can be any shape that can vibrate as a whole, not limited to the shape shown in FIG7. In some embodiments, the housing can be any shape in which the projection area of ​​the housing panel and the back of the housing on the same plane is equal. In some embodiments, the housing 900 can be a cylinder, such as Figure 10AAs shown, the housing panel 910 and the housing back 930 are the upper end face and the lower end face of the cylinder, respectively, and the housing side 920 is the side of the cylinder. The projected areas of the housing panel 910 and the housing back 930 on the cross section of the cylinder perpendicular to the axis are equal. In some embodiments, the sum of the projected areas of the housing back and the housing side is equal to the projected area of ​​the housing panel. For example, the housing 900 can be in the shape of a hemisphere, such as Figure 10B As shown, the housing panel 910 can be a plane or a curved surface, the housing side 920 can be a curved surface (for example, a bowl-shaped curved surface), with the plane parallel to the housing panel 910 as the projection surface, the housing back 920 can be a plane or a curved surface whose projection area is smaller than the projection area of ​​the housing panel 910, and the sum of the projection areas of the housing side 920 and the housing back 930 is equal to the projection area of ​​the housing panel 910. In some embodiments, the projection area of ​​the side of the housing facing the human body is equal to the projection area of ​​the side of the housing facing away from the human body. For example, Figure 10C As shown, the shell panel 910 and the shell back 930 are opposite curved surfaces, and the shell side 920 is a curved surface that transitions from the shell panel 910 to the shell back. A portion of the shell side 920 is located on the same side as the shell panel 910, and another portion of the shell side 920 is located on the same side as the shell back 930. Taking the cross-section with the largest cross-sectional area as the projection plane, the sum of the projection areas of a portion of the shell side 920 and the shell panel 910 is equal to the sum of the projection areas of another portion of the shell side 920 and the shell back 930. In some embodiments, the difference in area between the shell panel and the back of the shell does not exceed 50% of the area of ​​the shell panel, preferably, the difference in area between the shell panel and the back of the shell does not exceed 40% of the area of ​​the shell panel, more preferably, the difference in area between the shell panel and the back of the shell does not exceed 30% of the area of ​​the shell panel, more preferably, the difference in area between the shell panel and the back of the shell does not exceed 25% of the area of ​​the shell panel, more preferably, the difference in area between the shell panel and the back of the shell does not exceed 20% of the area of ​​the shell panel, more preferably, the difference in area between the shell panel and the back of the shell does not exceed 15% of the area of ​​the shell panel, more preferably, the difference in area between the shell panel and the back of the shell does not exceed 15% of the area of ​​the shell panel, More preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 12% of the area of ​​the shell panel, more preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 10% of the area of ​​the shell panel, more preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 8% of the area of ​​the shell panel, more preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 5% of the area of ​​the shell panel, more preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 3% of the area of ​​the shell panel, more preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 1% of the area of ​​the shell panel, more preferably, the difference between the area of ​​the shell panel and the back of the shell does not exceed 0.5% of the area of ​​the shell panel, more preferably, the areas of the shell panel and the back of the shell are equal.

[0094] Figure 11 This is a comparison chart of the sound leakage cancellation effect of a traditional bone conduction speaker and a bone conduction speaker according to some embodiments of the present application. Among them, the traditional bone conduction speaker refers to a bone conduction speaker with a shell made of a material with a conventional Young's modulus. Figure 11 In the figure, the dotted line is the sound leakage curve of the traditional bone conduction speaker, and the solid line is the sound leakage curve of the bone conduction speaker of the present application. The sound leakage of the traditional speaker at low frequency is set to 0, that is, the sound leakage cancellation curve of the traditional speaker at low frequency is used as the benchmark. It can be seen that the sound leakage cancellation effect of the bone conduction speaker of the present application is significantly better than that of the traditional speaker. In the low-frequency part (for example, the part with a frequency less than 100Hz), the sound leakage cancellation effect is the best, and the sound leakage can be reduced by 40dB compared with the traditional bone conduction speaker. As the frequency increases, the degree of sound leakage cancellation gradually weakens. At 1000Hz, the sound leakage can be reduced by 20dB compared with the traditional bone conduction speaker, while at 4000Hz, the sound leakage can only be reduced by 5dB. In some embodiments, the above-mentioned comparative test results can be obtained by simulation. In some embodiments, the above-mentioned comparative test results can be obtained by physical testing. For example, the bone conduction speaker can be placed in a quiet environment, a signal current can be input into the bone conduction speaker, and a microphone can be arranged in the space around the bone conduction speaker to receive the sound signal, thereby measuring the size of the sound leakage.

[0095] Depend on Figure 11 It can be seen from the results in that at medium and low frequencies, the vibration consistency of the bone conduction speaker shell of the present application is good, which can offset most of the sound leakage, and its sound leakage reduction effect is significantly better than that of traditional bone conduction headphones. However, when high-frequency vibration occurs, since it is difficult for the shell to maintain a whole and vibrate together, there will still be relatively serious sound leakage. On the one hand, due to the high frequency, even if a material with a large Young's modulus is used, the shell will inevitably deform. When the outer shell panel and the back of the shell are deformed, and the deformation is inconsistent (for example, the outer shell panel and the back of the shell themselves will have high-order modes at high frequencies), the sound leakage generated by the two will not cancel each other, resulting in sound leakage. In addition, at high frequencies, the side of the shell will also be deformed, resulting in greater deformation of the outer shell panel and the back of the shell, and greater sound leakage.

[0096] Figure 12 This is the frequency response curve of the shell panel of the bone conduction speaker. At low and medium frequencies, the shell moves as a whole, and the shell panel and the back of the shell vibrate with the same magnitude, speed and direction. At high frequencies, the shell panel has high-order modes (that is, the vibration of points on the shell panel is inconsistent), and the shell will also have obvious peaks in the frequency response curve due to the existence of high-order modes (see Figure 12(As shown). In some embodiments, the Young's modulus, weight, and / or dimensions of the housing panel material can be adjusted to adjust the peak frequency. In some embodiments, the Young's modulus of the housing panel material can be greater than 2000 MPa, preferably, the Young's modulus of the material can be greater than 4000 MPa, preferably, the Young's modulus of the material can be greater than 6000 MPa, preferably, the Young's modulus of the material can be greater than 8000 MPa, preferably, the Young's modulus of the material can be greater than 12000 MPa, more preferably, the Young's modulus of the material can be greater than 15000 MPa, and further preferably, the Young's modulus of the material can be greater than 18000 MPa. In some embodiments, the minimum frequency of high-order modes appearing on the shell panel is not less than 4000 Hz, preferably, the minimum frequency of high-order modes appearing on the shell panel is not less than 6000 Hz, more preferably, the minimum frequency of high-order modes appearing on the shell panel is not less than 8000 Hz, more preferably, the minimum frequency of high-order modes appearing on the shell panel is not less than 10000 Hz, more preferably, the minimum frequency of high-order modes appearing on the shell panel is not less than 15000 Hz, more preferably, the minimum frequency of high-order modes appearing on the shell panel is not less than 20000 Hz.

[0097] In some embodiments, by adjusting the stiffness of the shell panel, the peak frequency in the frequency response curve of the shell panel can be made greater than 1000Hz, preferably, the peak frequency can be made greater than 2000Hz, preferably, the peak frequency can be made greater than 4000Hz, preferably, the peak frequency can be made greater than 6000Hz, more preferably, the peak frequency can be made greater than 8000Hz, more preferably, the peak frequency can be made greater than 10000Hz, more preferably, the peak frequency can be made greater than 12000Hz, further preferably, the peak frequency can be made greater than 14000Hz, further preferably, the peak frequency can be made greater than 16000Hz, further preferably, the peak frequency can be made greater than 18000Hz, further preferably, the peak frequency can be made greater than 20000Hz.

[0098] In some embodiments, the outer shell panel can be composed of a single material. In some embodiments, the outer shell panel can be formed by laminating two or more materials. In some embodiments, the outer shell panel can be composed of a layer of material with a higher Young's modulus and an outer layer of material with a lower Young's modulus. This has the advantage of ensuring the required rigidity of the outer shell panel while also increasing the comfort of contact with the human body and improving the compatibility between the outer shell panel and the human body. In some embodiments, the material with a larger Young's modulus can be acrylonitrile butadiene styrene (ABS), polystyrene (PS), high impact polystyrene (HIPS), polypropylene (PP), polyethylene terephthalate (PET), polyester (PES), polycarbonate (PC), polyamides (PA), polyvinyl chloride (PVC), polyurethanes (PU), polyvinylidene chloride (PE), polyethylene (PE), polymethyl methacrylate (PMMA), polymethyl methacrylate (PMMA), polybutylene ... methacrylate (PMMA), polyetheretherketone (PEEK), phenolic resin (PF), urea formaldehyde resin (Urea-formaldehyde, UF), melamine-formaldehyde resin (MF) and some metals, alloys (such as aluminum alloy, chrome-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc.), glass fiber or carbon fiber, or a combination of any of the above materials. In some embodiments, the material of the shell panel 710 is any combination of glass fiber, carbon fiber and polycarbonate (PC), polyamide (PA) and other materials. In some embodiments, the material of the shell panel 710 can be a mixture of carbon fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the shell panel 710 can be a mixture of carbon fiber, glass fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the shell panel 710 can be a mixture of glass fiber and polycarbonate (PC) in a certain proportion.Adding different proportions of carbon fiber or glass fiber can result in different stiffness of the resulting material. For example, adding 20% ​​to 50% glass fiber can increase the Young's modulus of the material to 4000 MPa to 8000 MPa. In some embodiments, the material with a lower Young's modulus can be silicone.

[0099] In some embodiments, the outer surface of the housing panel that contacts the human body can be a plane. In some embodiments, the outer surface of the housing panel can have some protrusions or pits, such as Figure 13 As shown, the upper surface of the housing panel 1300 may have a protrusion 1310. In some embodiments, the outer surface of the housing panel may be a curved surface with any contour.

[0100] Figure 14A This is the frequency response curve of the back of the housing of the bone conduction speaker. At medium and low frequencies, the back of the housing vibrates in unison with the housing panel. At high frequencies, higher-order modes appear on the back of the housing. The higher-order modes on the back of the housing will pass through the side of the housing, affecting the movement speed and direction of the housing panel. At high frequencies, the deformation of the back of the housing can reinforce or offset the deformation of the housing panel, producing peaks and valleys at high frequencies. In some embodiments, the material and geometric dimensions of the back of the housing can be adjusted to make the peak frequency higher, thereby obtaining a flatter frequency response curve over a larger range. This improves the sound quality of bone conduction headphones. It also reduces the human ear's sensitivity to high-frequency sound leakage, thereby reducing sound leakage from the speaker. In some embodiments, the peak frequency of the back of the housing can be adjusted by adjusting the Young's modulus, weight, and / or dimensions of the material of the housing back panel. In some embodiments, the Young's modulus of the material on the back of the shell may be greater than 2000 MPa, preferably, the Young's modulus of the material may be greater than 4000 MPa, preferably, the Young's modulus of the material is greater than 6000 MPa, preferably, the Young's modulus of the material is greater than 8000 MPa, preferably, the Young's modulus of the material is greater than 12000 MPa, more preferably, the Young's modulus of the material is greater than 15000 MPa, and further preferably, the Young's modulus of the material is greater than 18000 MPa.

[0101] In some embodiments, by adjusting the stiffness of the back of the shell, the peak frequency of the back of the shell can be made greater than 1000Hz, preferably, the peak frequency can be made greater than 2000Hz, preferably, the peak frequency can be made greater than 4000Hz, preferably, the peak frequency can be made greater than 6000Hz, more preferably, the peak frequency of the back of the shell can be made greater than 8000Hz, more preferably, the peak frequency of the back of the shell can be made greater than 10000Hz, more preferably, the peak frequency of the back of the shell can be made greater than 12000Hz, further preferably, the peak frequency of the back of the shell can be made greater than 14000Hz, further preferably, the peak frequency of the back of the shell can be made greater than 16000Hz, further preferably, the peak frequency of the back of the shell can be made greater than 18000Hz, further preferably, the peak frequency of the back of the shell can be made greater than 20000Hz.

[0102] In some embodiments, the back of the housing can be made of one material. In some embodiments, the back of the housing can be made of two or more materials stacked together.

[0103] Figure 14B It is the frequency response curve of the side of the shell of the bone conduction earphone. As mentioned above, the side of the shell itself will not cause sound leakage when it vibrates at low frequencies. However, the side of the shell will also affect the sound leakage of the speaker at high frequencies. The reason is that when the frequency is high, the side of the shell will be deformed. This deformation will cause the movement of the shell panel and the back of the shell to be inconsistent, so that the sound leakage of the shell panel and the back of the shell cannot offset each other, causing the overall sound leakage to increase. In addition, when the side of the shell is deformed, it will also cause changes in the sound quality of bone conduction. Figure 14B As shown, the frequency response curve of the side of the housing will have peaks / valleys at high frequencies. In some embodiments, the frequency of the peaks and valleys can be increased by adjusting the material and geometric dimensions of the side of the housing, thereby obtaining a flatter frequency response curve over a wider range. This improves the sound quality of the bone conduction speaker. It also reduces the sensitivity of the human ear to high-frequency sound leakage, thereby reducing the sound leakage of the speaker. In some embodiments, the Young's modulus, weight and / or size of the material on the side of the housing can be adjusted to adjust the frequency of the peaks / valleys. In some embodiments, the Young's modulus of the material on the side of the housing can be greater than 2000 MPa, preferably, the Young's modulus of the material can be greater than 4000 MPa, preferably, the Young's modulus of the material is greater than 6000 MPa, preferably, the Young's modulus of the material is greater than 8000 MPa, preferably, the Young's modulus of the material is greater than 12000 MPa, more preferably, the Young's modulus of the material is greater than 15000 MPa, and further preferably, the Young's modulus of the material is greater than 18000 MPa.

[0104] In some embodiments, by adjusting the stiffness of the side of the shell, the peak frequency of the side of the shell can be made greater than 2000Hz, preferably, the peak frequency of the side of the shell can be made greater than 4000Hz, preferably, the peak frequency of the side of the shell can be made greater than 6000Hz, preferably, the peak frequency of the side of the shell can be made greater than 8000Hz, more preferably, the peak frequency of the side of the shell can be made greater than 10000Hz, more preferably, the peak frequency of the side of the shell can be made greater than 12000Hz, further preferably, the peak frequency of the side of the shell can be made greater than 14000Hz, further preferably, the peak frequency of the side of the shell can be made greater than 16000Hz, further preferably, the peak frequency of the side of the shell can be made greater than 18000Hz, further preferably, the peak frequency of the side of the shell can be made greater than 20000Hz.

[0105] In some embodiments, the housing side surface can be made of one material. In some embodiments, the housing side surface can be made of two or more materials stacked together.

[0106] The stiffness of the housing brackets can also affect the frequency response of the earphones at high frequencies. Figure 15 This is the frequency response curve of the housing support of the bone conduction earphone. Figure 15 As shown, at high frequencies, the housing bracket will produce a resonance peak on the frequency response curve. Housing brackets with different stiffness have different resonance peak positions at high frequencies. In some embodiments, the frequency of the resonance peak can be made higher by adjusting the material and geometric dimensions of the housing bracket, so that the bone conduction speaker can obtain a flatter frequency response curve in a wider range at medium and low frequencies, thereby improving the sound quality of the bone conduction speaker. In some embodiments, the Young's modulus, weight and / or size of the material of the housing bracket can be adjusted to adjust the frequency of the resonance peak. In some embodiments, the Young's modulus of the housing bracket material can be greater than 2000 MPa, preferably, the Young's modulus of the material can be greater than 4000 MPa, preferably, the Young's modulus of the material is greater than 6000 MPa, preferably, the Young's modulus of the material is greater than 8000 MPa, preferably, the Young's modulus of the material is greater than 12000 MPa, more preferably, the Young's modulus of the material is greater than 15000 MPa, and further preferably, the Young's modulus of the material is greater than 18000 MPa.

[0107] In some embodiments, by adjusting the stiffness of the shell bracket, the peak frequency of the shell bracket can be made greater than 2000Hz, preferably, the peak frequency of the shell bracket can be made greater than 4000Hz, preferably, the peak frequency of the shell bracket can be made greater than 6000Hz, preferably, the peak frequency of the shell bracket can be made greater than 8000Hz, more preferably, the peak frequency of the shell bracket can be made greater than 10000Hz, more preferably, the peak frequency of the shell bracket can be made greater than 12000Hz, further preferably, the peak frequency of the shell bracket can be made greater than 14000Hz, further preferably, the peak frequency of the shell bracket can be made greater than 16000Hz, further preferably, the peak frequency of the shell bracket can be made greater than 18000Hz, further preferably, the peak frequency of the shell bracket can be made greater than 20000Hz.

[0108] In this application, by adjusting the Young's modulus and dimensions of the shell material to increase the rigidity of the shell and ensure consistent shell vibration, sound leakage can be superimposed and canceled, reducing sound leakage. Furthermore, by adjusting the peak frequencies corresponding to different parts of the shell toward higher frequencies, sound leakage can be reduced while improving sound quality.

[0109] Figure 16A 1 is a structural diagram of the connection between the fixing component and the shell of a bone conduction speaker 1600 shown in some embodiments of the present application. As shown in the figure, the earphone fixing component 1620 is connected to the shell 1610. The earphone fixing component 1620 can maintain stable contact between the bone conduction earphone and human tissue or bone, avoid shaking of the bone conduction earphone, and ensure that the earphone can stably transmit sound. As mentioned above, the earphone fixing component 1620 can be equivalent to an elastic structure. When the stiffness of the earphone fixing component 1620 is smaller (i.e., the stiffness coefficient is smaller), the more obvious the resonance peak is at low frequency, which is more conducive to improving the sound quality of the bone conduction earphone. On the other hand, if the stiffness of the earphone fixing component 1620 is small (i.e., the stiffness coefficient is small), it is conducive to the vibration of the shell.

[0110] Figure 16B The bone conduction speaker 1600 and the earphone fixing assembly 1620 are connected to the housing 1610 via a connecting member 1630. In some embodiments, the connecting member 1630 can be one of silicone, sponge, and shrapnel, or any combination thereof.

[0111] In some embodiments, the headphone fixing assembly 1620 can be in the form of an ear hook, with a housing 1610 connected to each end of the headphone fixing assembly 1620, and the two housings are fixed to the sides of the skull in an ear hook manner. In some embodiments, the headphone fixing assembly 1620 can be a single ear clip. The headphone fixing assembly 1620 can be connected to a single housing 1610 and fix the housing 1610 to one side of the skull.

[0112] It should be noted that the above methods for connecting the earphone fixing assembly to the housing are merely examples or embodiments of the present application. A person skilled in the art may also make appropriate adjustments to the above methods for connecting the earphone fixing assembly to the housing according to different application scenarios of the present application. For more descriptions on the connection between the earphone fixing assembly and the housing, please refer to the descriptions elsewhere in this application (for example, Figures 23A-23C , and its related descriptions).

[0113] Example 1

[0114] like Figure 17 As shown, bone conduction speaker 1700 may include a magnetic circuit assembly 1710, a coil 1720, a connector 1730, a vibration transmission plate 1740, a housing 1750, and a housing bracket 1760. In some embodiments, bone conduction speaker 1700 further includes a first element and a second element. Coil 1720 is connected to housing 1750 via the first element. Magnetic circuit assembly 1710 is connected to housing 1750 via the second element. The elastic modulus of the first element is greater than that of the second element. This allows for a rigid connection between the coil and the housing and a flexible connection between the magnetic circuit assembly and the housing. This allows for the adjustment of the positions of the low-frequency and high-frequency resonance peaks, optimizing the frequency response curve. In some embodiments, the first element may be housing bracket 1760, which is fixedly attached to the interior of housing 1750 and to which coil 1720 is connected. Housing bracket 1760 is an annular bracket fixed to the inner wall of housing 1750. The outer shell bracket 1760 is a rigid component, and the outer shell bracket 1760 is made of a material with a Young's modulus greater than 2000 MPa. In some embodiments, the second element can be a vibration transmitting plate 1740. The magnetic circuit assembly 1710 is connected to the vibration transmitting plate 1740, and the vibration transmitting plate is an elastic component. The shell 1750 can vibrate mechanically under the drive of the vibration transmitting plate 1740, transmit the vibration to the tissue and bone, and transmit it to the auditory nerve through the tissue and bone, so that the human body can hear the sound. The overall rigidity of the shell 1750 is relatively large, so that when the bone conduction earphone 1700 is working, the shell 1750 vibrates as a whole, that is, the shell panel, shell side and shell back on the shell 1750 can maintain basically the same vibration amplitude and phase, and can superimpose and cancel the sound leakage outside the shell 1750, significantly reducing external sound leakage.

[0115] Magnetic circuit assembly 1710 may include a first magnetic element 1706, a first magnetic conductive element 1704, a second magnetic element 1702, and a second magnetic conductive element 1708. The lower surface of first magnetic conductive element 1704 may be connected to the upper surface of first magnetic element 1706. The upper surface of second magnetic conductive element 1708 may be connected to the lower surface of first magnetic element 1706. The lower surface of second magnetic element 1708 may be connected to the upper surface of first magnetic conductive element 1704. The magnetization directions of first magnetic element 1706 and second magnetic element 1708 are opposite. Second magnetic element 1708 can suppress magnetic flux leakage from the upper surface of first magnetic element 1706, thereby compressing the magnetic field generated by first magnetic element 1706 into the magnetic gap between second magnetic conductive element 1708 and first magnetic element 1706. This increases the magnetic induction intensity within the magnetic gap and, in turn, improves the sensitivity of bone conduction earphone 1700.

[0116] Similarly, a third magnetic element 1709 can be added to the lower surface of the second magnetic conductive element 1708. The magnetization direction of the third magnetic element 1709 is opposite to that of the first magnetic element 1706, and is used to suppress the leakage magnetic field on one side of the lower surface of the first magnetic element 1706, and further compress the magnetic field generated by the first magnetic element 1706 into the magnetic gap, thereby improving the magnetic induction intensity in the magnetic gap and the sensitivity of the bone conduction speaker 1700.

[0117] The first magnetic element 1706, the first magnetic conductive element 1704, the second magnetic element 1702, the second magnetic conductive element 1708, and the third magnetic conductive element 1709 can be fixed by gluing. Alternatively, holes can be drilled in the first magnetic element 1706, the first magnetic conductive element 1704, the second magnetic element 1702, the second magnetic conductive element 1708, and the third magnetic conductive element 1709 so that they can be fixed by screws.

[0118] Example 2

[0119] Figures 18A-18D The following are schematic diagrams of several structures of the vibration plate of bone conduction headphones. Figure 18A As shown, the vibration transmission plate may include an outer ring and an inner ring, and a plurality of connecting rods disposed between the outer and inner rings. The outer and inner rings may be concentric circles. The connecting rods may be arc-shaped with a certain length. The number of connecting rods may be three or more. The inner ring of the vibration transmission plate may be fixedly connected to a connecting member.

[0120] like Figure 18B As shown, the vibration transmission plate may include an outer ring and an inner ring, and a plurality of connecting rods arranged between the outer ring and the inner ring. The connecting rods may be straight rods. The number of connecting rods may be 3 or more.

[0121] like Figure 18CAs shown, the vibration transmission plate may include an inner ring and a plurality of curved rods surrounding the inner ring and radiating outwards. The number of the curved rods may be 3 or more.

[0122] like Figure 18D As shown, the vibration transmission plate can be composed of a plurality of curved rods, one end of the curved rods is concentrated at the center point of the vibration transmission plate, and the other end of the curved rods surrounds the center point of the vibration transmission plate. The number of curved rods can be 3 or more.

[0123] Example 3

[0124] Figure 19 19 is a structural diagram of a bone conduction speaker according to some embodiments of the present application. The bone conduction speaker 1900 may include a magnetic circuit component 1910, a coil 1920, a vibration transmitting plate 1930, a housing 1940 and a housing bracket 1950. Figure 17 , compared with the structure in Example 1, Figure 17 The vibration transmission piece in the embodiment is a planar structure, and the vibration transmission piece is on a plane. The vibration transmission piece in this embodiment is a three-dimensional structure, such as Figure 19 As shown, the vibration plate 1930 has a three-dimensional structure in the thickness direction when it is in a natural state without any force. The use of a three-dimensional vibration plate can reduce the size of the bone conduction earphone 1900 in the thickness direction. Figure 17 When the vibration transmitter is a planar structure, in order to ensure that the vibration transmitter can vibrate in the vertical direction when working, a certain space needs to be reserved above and below the vibration transmitter. If the vibration transmitter itself has a thickness of 0.2mm, a size of 1mm needs to be reserved above the vibration transmitter, and a size of 1mm needs to be reserved below the vibration transmitter, then at least 2.2mm of space is required from the lower surface of the panel of the shell 1940 to the upper surface of the magnetic circuit assembly. After adopting a three-dimensional vibration transmitter, the vibration transmitter can vibrate in its own thickness space. The size of the three-dimensional vibration transmitter in the thickness direction can be 1.5mm. At this time, the distance from the lower surface of the panel of the shell 1940 to the upper surface of the magnetic circuit assembly 1910 is only 1.5mm, saving 0.7mm of space. The size of the earphone 1900 in the thickness direction is greatly reduced. And the connectors can be eliminated to simplify the internal structure. On the other hand, when the shell of the stereoscopic vibration transducer has the same size as the shell of the planar vibration transducer, the stereoscopic vibration transducer can have a larger vibration amplitude than the planar vibration transducer, thereby increasing the maximum volume that the bone conduction speaker can provide.

[0125] The projection shape of the three-dimensional vibration transmission sheet 1930 can be any one of the shapes in the second embodiment.

[0126] In some embodiments, the outer edge of the 3D vibration transmission piece 1930 can be connected to the inner side of the housing bracket 1950. For example, when the 3D vibration transmission piece 1930 is used as Figure 18AOr the vibration transmission piece configuration shown in FIG18B, its outer ring can be connected to the inner side of the housing bracket 1950 by glue, clamping, welding or threaded connection. Figure 18C When the transducer plate is configured as shown in FIG18D , the curved rods surrounding the inner ring can be connected to the inner side of the outer shell bracket 1950 by gluing, clamping, welding, or threading. In some embodiments, the outer shell bracket 1950 can be provided with a plurality of slots, through which the outer edge of the three-dimensional transducer plate 1930 can pass to connect to the outer side of the outer shell bracket 1950. This can also increase the length of the transducer plate, facilitating the shift of the resonance peak toward lower frequencies, thereby improving sound quality. The slots are sized to provide sufficient space for the transducer plate to vibrate.

[0127] Example 4

[0128] Figures 20A-20D Schematic diagram of the structure of several bone conduction speakers according to some embodiments of the present application. Figure 20A As shown, unlike the structure in Example 1, this speaker structure lacks a housing bracket. The first component is a connector 2030, through which the coil 2020 is connected to the housing 2050. Connector 2030 comprises a cylindrical body, one end of which is connected to the housing 2050. The other end of the cylindrical body is provided with a circular end having a larger cross-sectional area, which is fixedly connected to the coil 2020. Connector 2030 is a rigid component made of a material with a Young's modulus greater than 4000 MPa. A gasket may be connected between coil 2020 and connector 2030. The second component is a vibration transmission plate 2040, to which the magnetic circuit assembly 2010 is connected, and which is directly connected to the housing 2050. Vibration transmission plate 2040 is an elastic component. Vibration transmission plate 2040 may be located above the magnetic circuit assembly 2010 and may be connected to the upper end surface of the second magnetic conductive element 2008. The vibration transmission plate 2040 and the second magnetic conductive element 2008 can be connected via a gasket.

[0129] like Figure 20B As shown, Figure 20A The difference in structure is that the vibration transmission piece 2040 can be located between the second magnetic conductive element 2008 and the side wall of the shell 2050, and connected to the outer side of the second magnetic conductive element 2008.

[0130] like Figure 20C As shown, the vibration transmission piece 2040 can also be set below the magnetic circuit component 2010 and connected to the lower surface of the second magnetic conductive element 2008.

[0131] like Figure 20D As shown, the coil 2020 is fixedly connected to the back of the housing via a connector 2030 .

[0132] Example 5

[0133] like Figure 21 As shown, the bone conduction speaker 2100 may include a magnetic circuit assembly 2110, a coil 2120, a connector 2130, a transducer 2140, a housing 2150, and a housing support 2160. Driven by the transducer 2140, the housing 2150 mechanically vibrates, transmitting the vibrations to tissue and bone. These vibrations are then transmitted to the auditory nerve, enabling the human body to hear sound. The high overall rigidity of the housing 2150 allows the entire housing 2150 to vibrate together when the bone conduction earphone 2100 is in operation, canceling out sound leakage from the housing 2150 and significantly reducing external sound leakage. The housing 2150 may be provided with a number of sound-introducing holes 2151. These holes 2151 transmit sound leakage from within the earphone 2100 to the exterior of the housing 2150, thereby canceling out any sound leakage from the exterior of the housing 2150 and further reducing sound leakage. It should be understood that the vibration of components within the housing 2150 also causes vibrations in the air within it, resulting in sound leakage. Furthermore, the vibration of the internal components and the vibration of the housing 2150 can also be consistent, thereby generating sound leakage in the opposite direction of the housing 2150, which can offset the sound leakage of the housing 2150 and reduce the sound leakage. The internal sound leakage that needs to be drawn out can be adjusted by adjusting the position, size, and number of the sound-introducing holes 2151 to ensure that the internal and external sound leakage can cancel each other out and reduce the sound leakage. In some embodiments, a damping layer can be provided at the position of the sound-introducing holes 2151 on the housing 2150 to adjust the phase and amplitude of the sound when it is drawn out, thereby enhancing the effect of canceling the sound leakage.

[0134] Example 6

[0135] In different application scenarios, the shell of the bone conduction earphones described in this application can be made by different assembly methods. For example, as described elsewhere in this application, the shell of the bone conduction earphones can be formed in an integrated manner, or in a split combination manner, or in a combination of the two. In the split combination manner, the different parts can be fixed by gluing, or fixed by snap-on, welding or threaded connection. Specifically, in order to better understand the assembly method of the shell of the bone conduction earphones in this application, Figures 22A-22C Several examples of how to assemble the housing of a bone conduction headphone are described.

[0136] like Figure 22AAs shown, the housing of the bone conduction earphone may include a housing panel 2222, a housing back 2224, and a housing side 2226. The housing side 2226 and the housing back 2224 are integrally formed, and the housing panel 2222 is connected to one end of the housing side 2226 by a subassembly. The subassembly method includes gluing, or fixing the housing panel 2222 to one end of the housing side 2226 by snapping, welding, or threading. The housing panel 2222 and the housing side 2226 (or the housing back 2224) may be made of different, the same, or partially the same materials. In some embodiments, the shell panel 2222 and the shell side 2226 are made of the same material, and the Young's modulus of the same material is greater than 2000 MPa, more preferably, the Young's modulus of the same material is greater than 4000 MPa, more preferably, the Young's modulus of the same material is greater than 6000 MPa, more preferably, the Young's modulus of the shell 220 material is greater than 8000 MPa, more preferably, the Young's modulus of the same material is greater than 12000 MPa, more preferably, the Young's modulus of the same material is greater than 15000 MPa, and further preferably, the Young's modulus of the same material is greater than 18000 MPa. In some embodiments, the shell panel 2222 and the shell side 2226 are made of different materials, and the Young's modulus of the different materials is greater than 4000 MPa. More preferably, the Young's modulus of the different materials is greater than 6000 MPa. More preferably, the Young's modulus of the different materials is greater than 8000 MPa. More preferably, the Young's modulus of the different materials is greater than 12000 MPa. More preferably, the Young's modulus of the different materials is greater than 15000 MPa. Further preferably, the Young's modulus of the different materials is greater than 18000 MPa.In some embodiments, the material of the housing panel 2222 and / or the housing side 2226 includes, but is not limited to, acrylonitrile butadiene styrene (ABS), polystyrene (PS), high impact polystyrene (HIPS), polypropylene (PP), polyethylene terephthalate (PET), polyester (PES), polycarbonate (PC), polyamides (PA), polyvinyl chloride (PVC), polyurethanes (PU), polyvinylidene chloride (PVC), polyethylene (PE), polymethyl methacrylate (PMMA), polymethyl methacrylate (PMMA), polybutylene ... The shell panel 710 may be made of any material selected from polyurethane (such as methacrylate, PMMA), polyetheretherketone (PEEK), phenolic resin (PF), urea formaldehyde resin (UF), melamine formaldehyde resin (MF) and some metals, alloys (such as aluminum alloy, chrome-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc.), glass fiber or carbon fiber, or a combination of any of the above materials. In some embodiments, the material of the shell panel 710 is any combination of glass fiber, carbon fiber and polycarbonate (PC), polyamide (PA) and other materials. In some embodiments, the material of the shell panel 2222 and / or the shell side 2226 may be a mixture of carbon fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the shell panel 2222 and / or the shell side 2226 may be a mixture of carbon fiber, glass fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the housing panel 2222 and / or the housing side 2226 can be a mixture of glass fiber and polycarbonate (PC) in a certain proportion, or a mixture of glass fiber and polyamide (PA) in a certain proportion.

[0137] like Figure 22AAs shown, the housing panel 2222, the housing back 2224, and the housing side 2226 form an integral structure with a certain accommodation space. Within the integral structure, the vibration transmission plate 2214 is connected to the magnetic circuit assembly 2210 via a connector 2216. The first magnetic conductive element 2204 and the second magnetic conductive element 2206 are connected to the two sides of the magnetic circuit assembly 2210, respectively. The vibration transmission plate 2214 is fixed to the interior of the integral structure via a housing bracket 2228. In some embodiments, the housing side 2226 has a step structure for supporting the housing bracket 2228. After the housing bracket 2228 is fixed to the housing side 2226, the housing panel 2222 can be fixed to the housing bracket 2228 and the housing side 2226 at the same time, or fixed to the housing bracket 2228 or the housing side 2226 separately. In this case, optionally, the housing side 2226 and the housing bracket 2228 can be formed integrally. In some embodiments, the housing bracket 2228 can be directly fixed to the housing panel 2222 (for example, by gluing, snapping, welding, or threading). After the housing panel 2222 and the housing bracket 2228 are fixed, they are then fixed to the side of the housing (for example, by gluing, snapping, welding, or threading). In this case, the housing bracket 2228 and the housing panel 2222 can optionally be integrally formed.

[0138] like Figure 22B As shown, Figure 22A The difference is that the housing bracket 2258 and the housing side 2256 are integrally formed. The housing panel 2252 is fixed to one side of the housing side 2256 where it is connected to the housing bracket 2258 (for example, by gluing, snapping, welding, or threading), and the housing back 2254 is fixed to the other side of the housing side 2256 (for example, by gluing, snapping, welding, or threading). In this case, optionally, the housing bracket 2258 and the housing side 2256 are a separate assembly structure, and the housing panel 2252, the housing back 2254, the housing bracket 2258, and the housing side 2256 are all fixedly connected by gluing, snapping, welding, or threading.

[0139] like Figure 22C As shown, Figure 22A and Figure 22BThe difference is that the housing panel 2282 and the housing side 2286 are integrally formed. The housing back 2284 is fixed to the side of the housing side 2286 opposite the housing panel 2282 (for example, by gluing, snapping, welding, or threading). The housing bracket 2288 is fixed to the housing panel 2282 and / or the housing side 2286 by gluing, snapping, welding, or threading. In this case, the housing bracket 2288, the housing panel 2282, and the housing side 2286 are optionally integrally formed.

[0140] Example 7

[0141] As described elsewhere in this application, the shell of the bone conduction earphone can maintain stable contact with human tissue or bone through the earphone fixing assembly. In different application scenarios, the earphone fixing assembly and the shell can be connected in different ways. For example, the earphone fixing assembly and the shell can be integrally formed, or a separate combination, or a combination of the two. In the separate combination, the earphone fixing assembly can be glued, or fixedly connected to a specific part on the shell by snapping or welding. The specific part on the shell includes the shell panel, the back of the shell, and / or the side of the shell. Specifically, in order to better understand the connection method between the earphone fixing assembly and the shell in this application, Figures 23A-23C Several examples of how the housings of bone conduction headphones are connected are described.

[0142] like Figure 23A As shown, taking the ear hook as the headset fixing component as an example, Figure 22A On the basis of the ear hook 2330, the ear hook 2330 is fixedly connected to the shell. The fixed connection method includes using glue to bond and fix, or fixing the ear hook 2330 to the side 2326 of the shell or the back 2324 of the shell by snapping, welding or threading. The part of the ear hook 2330 connected to the shell can be made of the same, different, or partially the same material as the side 2326 of the shell or the back 2324 of the shell. In some embodiments, in order to make the ear hook 2330 have a smaller stiffness (i.e., a smaller stiffness coefficient), the ear hook 2330 can also include plastic, silicone and / or metal materials. For example, the ear hook 2330 can include an arc-shaped titanium wire. Optionally, the ear hook 2330 can be integrally formed with the side 2326 of the shell or the back 2324 of the shell.

[0143] like Figure 23B As shown, in Figure 22B On the basis of the ear hook 2360 is fixedly connected to the shell. The fixed connection method includes using glue to fix, or fixing the ear hook 2360 to the shell side 2356 or the shell back 2354 by snap connection, welding or thread connection. Figure 23A Similarly, the portion of the ear hook 2360 that is connected to the housing can be made of the same, different, or partially the same material as the housing side 2356 or the housing back 2354. Optionally, the ear hook 2360 can be integrally formed with the housing side 2356 or the housing back 2354.

[0144] like Figure 23C As shown, in Figure 22C On the basis of the ear hook 2390 is fixedly connected to the shell. The fixed connection method includes using glue to fix, or fixing the ear hook 2390 to the shell side 2386 or the shell back 2384 by snap connection, welding or thread connection. Figure 23A Similarly, the portion of the ear hook 2390 that is connected to the housing can be made of the same, different, or partially the same material as the housing side 2386 or the housing back 2384. Optionally, the ear hook 2390 can be integrally formed with the housing side 2386 or the housing back 2384.

[0145] Example 8

[0146] As described elsewhere in this application, the rigidity of a bone conduction earphone's housing affects the vibration amplitude and phase of different parts of the housing (e.g., the housing panel, the housing back, and / or the housing sides), thereby affecting sound leakage from the bone conduction earphone. In some embodiments, when the housing of a bone conduction earphone has relatively high rigidity, the housing panel and the housing back can maintain the same or substantially the same vibration amplitude and phase at higher frequencies, thereby significantly reducing sound leakage from the bone conduction earphone.

[0147] The higher frequency mentioned here may include a frequency of not less than 1000 Hz, for example, a frequency between 1000 Hz and 2000 Hz, a frequency between 1100 Hz and 2000 Hz, a frequency between 1300 Hz and 2000 Hz, a frequency between 1500 Hz and 2000 Hz, a frequency between 1700 Hz and 2000 Hz, or a frequency between 1900 Hz and 2000 Hz. Preferably, the higher frequency mentioned here may include a frequency of not less than 2000 Hz, for example, a frequency between 2000 Hz and 3000 Hz, a frequency between 2100 Hz and 3000 Hz, a frequency between 2300 Hz and 3000 Hz, a frequency between 2500 Hz and 3000 Hz, a frequency between 2700 Hz and 3000 Hz, or a frequency between 2900 Hz and 3000 Hz. Preferably, the higher frequency mentioned herein may include a frequency of not less than 4000 Hz, for example, a frequency between 4000 Hz and 5000 Hz, a frequency between 4100 Hz and 5000 Hz, a frequency between 4300 Hz and 5000 Hz, a frequency between 4500 Hz and 5000 Hz, a frequency between 4700 Hz and 5000 Hz, or a frequency between 4900 Hz and 5000 Hz. More preferably, the higher frequency mentioned herein may include a frequency of not less than 6000 Hz, for example, a frequency between 6000 Hz and 8000 Hz, a frequency between 6100 Hz and 8000 Hz, a frequency between 6300 Hz and 8000 Hz, a frequency between 6500 Hz and 8000 Hz, a frequency between 7000 Hz and 8000 Hz, a frequency between 7500 Hz and 8000 Hz, or a frequency between 7900 Hz and 8000 Hz. Further preferably, the higher frequency mentioned here may include a frequency of not less than 8000 Hz, for example, a frequency between 8000 Hz and 12000 Hz, a frequency between 8100 Hz and 12000 Hz, a frequency between 8300 Hz and 12000 Hz, a frequency between 8500 Hz and 12000 Hz, a frequency between 9000 Hz and 12000 Hz, a frequency between 10000 Hz and 12000 Hz, or a frequency between 11000 Hz and 12000 Hz.

[0148] Here, the fact that the housing panel and the housing back maintain the same or substantially the same vibration amplitude means that the ratio of the vibration amplitudes of the housing panel and the housing back is within a certain range. For example, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.3 and 3, preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.4 and 2.5, preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.5 and 1.5, more preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.6 and 1.4, more preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.7 and 1.2, more preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.75 and 1.15, more preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.8 and 1.1, more preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.85 and 1.1, further preferably, the ratio of the vibration amplitude of the housing panel and the back of the housing is between 0.9 and 1.05. In some embodiments, the vibration of the housing panel and the back of the housing can be represented by other physical quantities that can characterize its vibration amplitude. For example, the vibration amplitudes of the housing panel and the housing back can be represented by the sound pressures generated by the housing panel and the housing back at a point in space, respectively.

[0149] Here, the shell panel and the back of the shell maintain the same or substantially the same vibration phase, which means that the difference in vibration phase between the shell panel and the back of the shell is within a certain range. For example, the difference in vibration phase between the shell panel and the back of the shell is between -90° and 90°, preferably, the difference in vibration phase between the shell panel and the back of the shell is between -80° and 80°, preferably, the difference in vibration phase between the shell panel and the back of the shell is between -60° and 60°, preferably, the difference in vibration phase between the shell panel and the back of the shell is between -45° and 45°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -30° and 30°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -20° and 20°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -15° and 15°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -12° and 12°, more preferably, the shell panel The difference in vibration phase between the shell panel and the back of the shell is between -10° and 10°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -8° and 8°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -6° and 6°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -5° and 5°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -4° and 4°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -3° and 3°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -2° and 2°, more preferably, the difference in vibration phase between the shell panel and the back of the shell is between -1° and 1°, and further preferably, the difference in vibration phase between the shell panel and the back of the shell is 0°.

[0150] Specifically, in order to better understand the relationship between the vibration amplitude and phase of the housing panel and the housing back in this application, Figures 24-26 Several examples of methods for measuring vibrations of a bone conduction earphone housing are described.

[0151] like Figure 24As shown, the signal generating device 2420 can provide a driving signal to the bone conduction earphones, causing the shell panel 2412 of the shell 2410 to vibrate. For the sake of simplicity, a periodic signal (for example, a sinusoidal signal) is used as the driving signal for description. The shell panel 2412 vibrates periodically under the drive of the periodic signal. The rangefinder 2440 transmits a test signal 2450 (for example, a laser) to the shell panel 2412, receives the signal reflected from the shell panel 2412, converts it into a first electrical signal, and then sends it to the signal testing device 2430. The first electrical signal (also called the first vibration signal) can reflect the vibration state of the shell panel 2412. The signal testing device 2430 can compare the periodic signal generated by the signal generating device 2420 and the first electrical signal measured by the rangefinder 2440 to obtain the phase difference between the two signals (also called the first phase difference). Similarly, the rangefinder 2440 can measure a second electrical signal (also referred to as a second vibration signal) generated by the vibration of the back of the housing, and the signal testing device 2430 can obtain the phase difference (also referred to as a second phase difference) between the periodic signal and the second electrical signal. Based on the first phase difference and the second phase difference, the phase difference between the housing panel 2412 and the back of the housing can be obtained. Similarly, by comparing the amplitudes of the first electrical signal and the second electrical signal, the relationship between the vibration amplitudes of the housing panel 2412 and the back of the housing can be determined.

[0152] In some embodiments, a microphone can be used instead of the rangefinder 2440. Specifically, the microphone can be placed near the housing panel 2412 and the back of the housing, respectively, and the sound pressure generated by the housing panel 2412 and the back of the housing can be measured respectively to obtain signals similar to the first electrical signal and the second electrical signal, and based on this, the relationship between the vibration amplitude and phase of the housing panel 2412 and the back of the housing can be determined. It should be noted that when measuring the magnitude and phase of the sound pressure generated by the housing panel 2412 and the back of the housing respectively, the microphone is preferably placed at a position closer to the housing panel 2412 and the back of the housing (for example, the vertical distance is less than 10 mm), and the distance between the microphone and the housing panel 2412 and the back of the housing is kept the same, similar, or close, and the corresponding positions of the microphone and the housing panel 2412 and the back of the housing are the same, etc.

[0153] Figure 25 is based on Figure 24 An exemplary result is obtained. The horizontal axis represents time, and the vertical axis represents signal magnitude. In the figure, solid line 2410 represents the periodic signal generated by signal generator 2420, and dashed line 2520 represents the first electrical signal measured by the rangefinder. The amplitude of the first electrical signal, i.e., V1 / 2, can reflect the vibration amplitude of the housing panel. The phase difference between the first electrical signal and the periodic signal can be expressed as:

[0154] Wherein, t1 represents the time interval between adjacent peaks of the periodic signal and the first electrical signal, and t2 represents the period of the periodic signal.

[0155] Similarly, the amplitude of the second electrical signal can be obtained. The ratio of the amplitude of the first electrical signal to the amplitude of the second electrical signal can represent the ratio of the vibration amplitude of the housing panel to the vibration amplitude of the back of the housing. In addition, considering that there may be a 180° phase difference between the first electrical signal and the second electrical signal during measurement (i.e., the measurement is performed by transmitting the test signal to the outer surface of the housing panel and the back of the housing respectively), the phase difference between the second electrical signal and the periodic signal can be expressed as:

[0156] Wherein, t1′ represents the time interval between adjacent peaks of the periodic signal and the second electrical signal, and t2′ represents the period of the periodic signal. The difference between and can reflect the phase difference between the housing panel 2412 and the back of the housing.

[0157] It's important to note that when measuring vibration on the front and back of the enclosure, the test system should maintain consistent operation to avoid inaccuracies in the subsequent phase difference calculation. If the test system experiences delay during measurement, it's necessary to compensate for this delay in each measurement, or ensure the same delay when measuring the front and back of the enclosure to offset the effect.

[0158] Figure 26 Another exemplary method for measuring vibration of a bone conduction earphone housing is described. Figure 24 The difference is that, Figure 26 The device includes two rangefinders 2640 and 2640'. These two rangefinders can simultaneously measure the vibrations of the housing front panel and the back of the housing 2610 of the bone conduction earphone, and transmit first and second electrical signals reflecting the vibrations of the housing front panel and the back of the housing, respectively, to the signal testing device 2630. Similarly, the two rangefinders 2640 and 2640' can each be replaced by two microphones.

[0159] Figure 27 is based on Figure 26 An exemplary result measured. In the figure, the solid line 2710 represents the first electrical signal reflecting the vibration of the shell panel, and the dotted line 2720 represents the second electrical signal reflecting the vibration of the back of the shell. The amplitude of the first electrical signal, i.e., V3 / 2, can reflect the vibration amplitude of the shell panel. The amplitude of the second electrical signal, i.e., V4 / 2, can reflect the vibration amplitude of the back of the shell. In this case, the ratio of the vibration amplitudes of the shell panel and the back of the shell is V3 / V4. The phase difference between the first electrical signal and the second, i.e., the vibration phase difference between the shell panel and the back of the shell, can be expressed as:

[0160] Wherein, t3′ represents the time interval between adjacent peaks of the first signal and the second electrical signal, and t4′ represents the period of the second signal.

[0161] Embodiment 9

[0162] Figure 28 and Figure 29 An example of a method for measuring vibrations of a bone conduction earphone housing in the presence of an earphone mounting assembly is described.

[0163] Figure 28 and Figure 24 The difference is that the shell 2810 of the bone conduction earphone is fixedly connected to the earphone fixing assembly 2860, for example, by any of the connection methods described elsewhere in this application. During the measurement process, the earphone fixing assembly 2860 is further fixed to the fixing device 2870. The fixing device 2870 can keep the part of the earphone fixing assembly 2860 connected to it in a stationary state. After the signal generating device 2820 provides a driving signal to the bone conduction earphone, the shell 2810 as a whole can vibrate relative to the vibration device 2870. Similarly, the signal testing device 2830 can respectively obtain a first electrical signal and a second electrical signal reflecting the vibration of the shell panel and the back of the shell, and determine the phase difference between the shell panel and the back of the shell based on this.

[0164] Figure 29 and Figure 26 The difference is that the shell 2910 of the bone conduction earphone is fixedly connected to the earphone fixing assembly 2960, for example, by any of the connection methods described elsewhere in this application. During the measurement process, the earphone fixing assembly 2960 is further fixed to the fixing device 2970. The fixing device 2970 can keep the part of the earphone fixing assembly 2960 connected to it in a stationary state. After the signal generating device 2920 provides a driving signal to the bone conduction earphone, the shell 2910 as a whole can vibrate relative to the fixing device 2970. Similarly, the signal testing device 2830 can simultaneously obtain the first electrical signal and the second electrical signal reflecting the vibration of the shell panel and the back of the shell, and determine the phase difference between the shell panel and the back of the shell based on this.

[0165] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0166] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0167] In addition, it will be understood by those skilled in the art that various aspects of the present application can be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances or any new and useful improvements thereto. Accordingly, various aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0168] In addition, unless expressly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters, or the use of other names, are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some embodiments of the invention that are currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0169] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0170] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by modifiers such as "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical data used in the description and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical data should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical fields and data used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0171] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other variations may also fall within the scope of this application. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this application may be considered consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly introduced and described in this application.

Claims

1. A bone conduction speaker, characterized in that: The bone conduction speaker includes an earphone fixing component, a shell connected to the earphone fixing component, and a magnetic circuit component and a vibration component arranged in the shell. The earphone fixing component is used to maintain stable contact between the bone conduction speaker and the human body. The shell has a shell panel facing the human body and a shell back opposite to the shell panel, and a shell side surface located between the shell panel and the shell back. The magnetic circuit component is used to provide a magnetic field. The vibration component includes a coil and a vibration transmitter. The coil is connected to the shell through a first element. At least a portion of the coil is located in the magnetic field and moves in the magnetic field under the drive of an electrical signal. One end of the vibration transmitter is connected to the magnetic circuit component, and the other end is connected to the shell. The frequency response curve of the bone conduction speaker produces two low-frequency resonance peaks in a frequency range less than 500 Hz, and the two low-frequency resonance peaks are jointly generated by the vibration transmitter and the earphone fixing component.

2. The bone conduction speaker according to claim 1, wherein The two low-frequency resonance peaks correspond to the earphone fixing component and the vibration transmission plate respectively.

3. The bone conduction speaker according to claim 1, wherein The difference between the peak values ​​of the two low-frequency resonance peaks is no more than 150 Hz.

4. The bone conduction speaker according to claim 1, wherein The thickness of the vibration transmission plate is 0.005mm-3mm.

5. The bone conduction speaker according to claim 1, wherein The rigidity of the shell is set so that the frequency response curve of the bone conduction speaker generates a first high-frequency peak and a second high-frequency peak in a frequency range greater than 2000 Hz, wherein the first high-frequency peak is generated by the side of the shell and the second high-frequency peak is generated by the shell panel.

6. The bone conduction speaker according to claim 5, characterized in that The frequency response curve of the bone conduction speaker has a first high-frequency valley generated by the side surface of the housing in a frequency range greater than 4000 Hz.

7. The bone conduction speaker according to claim 6, characterized in that The peak frequency of the first high-frequency valley is lower than the peak frequency of the first high-frequency peak.

8. The bone conduction speaker according to claim 5, wherein: The Young's modulus of the material of the shell is greater than 2000 MPa.

9. The bone conduction speaker according to claim 1, wherein The stiffness of the housing panel and the back of the housing is set so that the effective frequency band of the frequency response curve of the bone conduction speaker can cover at least 500Hz-6000Hz, and there is no frequency width range exceeding 1 / 8 octave in the effective frequency band, and the peak / valley value exceeds the average vibration intensity by 10dB.

10. The bone conduction speaker according to claim 1, wherein The weight of the shell is less than or equal to 8 grams.

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