Bone conduction speaker and bone conduction earphone

Abstract

The present application mainly relates to a bone conduction speaker, which includes: a magnetic circuit component for providing a magnetic field; a vibration component, at least a part of which is located in the magnetic field and converts an electrical signal input to the vibration component into a mechanical vibration signal; and a shell, which includes 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 shell accommodating the vibration component, the vibration component causing the shell panel and the shell back to vibrate, the vibration of the shell panel has a first phase, and the vibration of the shell back has a second phase, wherein, when the vibration frequency of the shell panel and the vibration frequency of the shell back are between 1000 Hz and 2000 Hz, the absolute value of the difference between the first phase and the second phase is less than 60 degrees.

Description

[0001] This application is a divisional application of the Chinese patent application submitted to 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 can convert electrical signals into mechanical vibration signals, and transmit the mechanical vibration signals to the human auditory nerve through human tissue and bones, so that the wearer can hear the sound. Since bone conduction speakers transmit sound through mechanical vibration, when the bone conduction speakers are working, they will cause the surrounding air to vibrate, resulting in sound leakage. The present application provides a bone conduction speaker with a simple structure and a compact size, which can not only significantly reduce the sound leakage of bone conduction headphones, but also improve the sound quality of bone conduction headphones. Summary of the invention

[0005] An embodiment of the present application provides a bone conduction speaker, comprising: a magnetic circuit component for providing a magnetic field; a vibration component, at least a portion of which is located in the magnetic field and converts an electrical signal input to the vibration component into a mechanical vibration signal; a shell, the shell accommodating the vibration component and the magnetic circuit component; and an earphone fixing component, the earphone fixing component being fixedly connected to the shell and used to maintain contact between the shell and the human body; wherein the shell has a shell panel facing the human body and a shell back side opposite to the shell panel, and a shell side surface located between the shell panel and the shell back side, the vibration component causes the shell to vibrate, the vibration of the shell panel has a first phase, and the vibration of the shell back has a second phase, and the overall stiffness of the shell is set so that when the vibration frequency is 1000 Hz to 2000 Hz or 2000 Hz to 3000 Hz, the absolute value of the difference between the first phase and the second phase is less than 60 degrees.

[0006] Optionally, the shell panel contacts the skin of a person's face so that the skin around the shell panel protrudes outward.

[0007] Optionally, the stiffness of the shell panel, the shell back and the shell sides and / or the connection method of the shell panel, the shell back and the shell sides are set so that when the vibration frequency is 1000Hz to 2000Hz or 2000Hz to 3000Hz, the absolute value of the difference between the first phase and the second phase is less than 60 degrees.

[0008] Optionally, the vibration of the housing panel has a first amplitude, the vibration of the housing back has a second amplitude, and within the frequency range of 1000 Hz to 2000 Hz or 2000 Hz to 3000 Hz, the ratio of the first amplitude to the second amplitude is within the range of 0.5 to 1.5.

[0009] Optionally, the vibration of the shell panel generates a first sound leakage wave, and the vibration of the back side of the shell generates a second sound leakage wave, and the first sound leakage wave and the second sound leakage wave are superimposed on each other, and the superposition reduces the amplitude of the first sound leakage wave.

[0010] Optionally, the overall stiffness of the housing is set so that when the vibration frequency is 1000 Hz to 2000 Hz or 2000 Hz to 3000 Hz, the absolute value of the difference between the first phase and the second phase is less than 45 degrees.

[0011] Optionally, the effective frequency band of the frequency response curve of the bone conduction speaker covers at least 1000Hz~2000Hz, 500Hz-4000Hz or 500Hz~6000Hz, there is no frequency width range exceeding 1 / 8 octave in the effective frequency band, and the peak / valley value exceeds the peak / valley of the average vibration intensity by 10db.

[0012] Optionally, the bone conduction speaker also includes a vibration transmitter, one end of which is connected to the magnetic circuit assembly, and the other end is connected to the shell, and the stiffness of the vibration transmitter and the earphone fixing assembly is set so that the frequency response curve of the bone conduction speaker has two low-frequency resonance peaks less than 150 Hz.

[0013] Optionally, the minimum frequency of the high-order mode appearing on the housing panel is not less than 4000 Hz or 6000 Hz.

[0014] Optionally, the volume of the housing is 400mm 3 -1000mm 3 and / or,

[0015] The Young's modulus of the material of the shell is between 2 GPa and 3 GPa; and / or,

[0016] The weight of the shell is less than or equal to 8 grams or 4 grams or 2 grams.

[0017] Optionally, the shell is a cylinder, the shell panel and the shell back are the upper end face and the lower end face of the cylinder respectively, the shell side is the side edge of the cylinder, the shell panel and the shell back have the same projected area on the cross section of the cylinder perpendicular to the axis, or the area difference between the shell panel and the shell back does not exceed 30% or 15% or 5% of the area of ​​the shell panel.

[0018] Optionally, the vibration assembly includes a coil, and both the housing panel and the housing back are caused to vibrate by the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present application will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents a similar structure, wherein:

[0020] Figure 1 is a structural module diagram of a bone conduction headset according to some embodiments of the present application;

[0021] Figure 2 is a schematic longitudinal section diagram of a bone conduction headset according to some embodiments of the present application;

[0022] Figure 3 is a partial frequency response curve of a bone conduction headset according to some embodiments of the present application;

[0023] Figure 4 It is a partial frequency response curve of a bone conduction earphone when the shell of the bone conduction earphone is made of materials with different Young's modulus according to some embodiments of the present application;

[0024] Figure 5 It is a partial frequency response curve of a bone conduction earphone when the vibration transmission piece of the bone conduction earphone is at different stiffnesses according to some embodiments of the present application;

[0025] Figure 6 It is a partial frequency response curve of a bone conduction earphone when an earphone fixing component of a bone conduction earphone has different stiffnesses according to some embodiments of the present application;

[0026] Fig. 7A is a schematic diagram of a shell structure of a bone conduction headset according to some embodiments of the present application;

[0027] 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;

[0028] Figure 7C is a schematic diagram of the relationship between the volume and the housing volume of a bone conduction speaker according to some embodiments of the present application;

[0029] Figure 8 is a schematic diagram of the principle of reducing sound leakage of a housing according to some embodiments of the present application;

[0030] Fig. 9 It 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;

[0031] Fig. 10Ais a schematic structural diagram of a shell of a bone conduction headset according to some embodiments of the present application;

[0032] Fig. 10B is a schematic structural diagram of a shell of a bone conduction headset according to some embodiments of the present application;

[0033] Fig. 10C is a schematic structural diagram of a shell of a bone conduction headset according to some embodiments of the present application;

[0034] Fig.11 is a comparison diagram of sound leakage effects between a traditional bone conduction earphone and a bone conduction earphone according to some embodiments of the present application;

[0035] Fig.12 It is the frequency response curve produced by the shell panel of the bone conduction earphone;

[0036] Fig.13 is a schematic structural diagram of a housing panel according to some embodiments of the present application;

[0037] Fig.14A It is the frequency response curve produced by the back of the shell of the bone conduction earphone;

[0038] Fig. 14B It is the frequency response curve produced by the side of the shell of the bone conduction earphone;

[0039] Fig.15 It is the frequency response curve of the bone conduction earphone produced by the shell bracket of the bone conduction earphone;

[0040] Fig.16A is a structural schematic diagram of a bone conduction earphone with an earphone fixing assembly according to some embodiments of the present application;

[0041] Fig. 16B is a schematic structural diagram of another bone conduction earphone with an earphone fixing assembly according to some embodiments of the present application;

[0042] Fig.17 is a schematic diagram of a shell structure of a bone conduction headset according to some embodiments of the present application;

[0043] Fig.18A is a schematic structural diagram of a vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0044] Fig.18B is a schematic structural diagram of another vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0045] Fig.18Cis a schematic structural diagram of another vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0046] Fig.18D is a schematic structural diagram of another vibration transmission piece of a bone conduction headset according to some embodiments of the present application;

[0047] Fig.19 is a schematic structural diagram of a bone conduction headset with a stereo vibration transmission piece according to some embodiments of the present application;

[0048] Fig. 20A is a structural schematic diagram of a bone conduction headset according to some embodiments of the present application;

[0049] Fig. 20B is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

[0050] Fig. 20C is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

[0051] Fig.20D is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

[0052] Fig.21 is a structural schematic diagram of a bone conduction earphone with a sound guide hole according to some embodiments of the present application;

[0053] Figures 22A-22C is a schematic diagram of the structure of a bone conduction headset according to some embodiments of the present application;

[0054] 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;

[0055] Fig.24 An exemplary method for measuring the vibration of a bone conduction earphone housing according to some embodiments of the present application;

[0056] Fig.25 is in accordance with Fig.24 An exemplary result measured in the manner shown;

[0057] Fig.26 An exemplary method for measuring the vibration of a bone conduction earphone housing according to some embodiments of the present application;

[0058] Fig. 27 is in accordance with Fig.26 An exemplary result measured in the manner shown;

[0059] Fig.28An exemplary method for measuring vibration of a bone conduction earphone housing according to some embodiments of the present application; and

[0060] Fig.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

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

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

[0063] Figure 1 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 .

[0064] The magnetic circuit component 102 can provide a magnetic field. The magnetic field can be used to convert a signal containing sound information into a vibration signal. In some embodiments, the sound information may include a video or audio file with a specific data format or data or files that can be converted into sound through a specific path. The signal containing sound information may come from the storage component of the bone conduction speaker 100 itself, or from an information generation, storage or transmission system outside the bone conduction speaker 100. The signal containing sound information may include a combination of one or more electrical signals, optical signals, magnetic signals, mechanical signals, etc. The signal containing sound information may come from one signal source or multiple signal sources. The multiple signal sources may be related or unrelated. In some embodiments, the bone conduction speaker 100 may obtain the signal containing sound information in a variety of different ways, and the acquisition of the signal may be wired or wireless, and may be real-time or delayed. For example, the bone conduction speaker 100 may receive an electrical signal containing sound information in a wired or wireless manner, or may directly obtain data from a storage medium to generate a sound signal. For another example, a bone conduction hearing aid may include a component with a sound collection function, which converts the mechanical vibration of the sound into an electrical signal by picking up the sound in the environment, and obtains an electrical signal that meets specific requirements after being processed by an amplifier. In some embodiments, the wired connection may include a metal cable, an optical cable, or a hybrid cable of metal and optical, for example, a coaxial cable, a communication cable, a flexible cable, a spiral cable, a non-metallic sheathed cable, a metal sheathed cable, a multi-core cable, a twisted pair cable, a ribbon cable, a shielded cable, a telecommunication cable, a two-strand cable, a parallel two-core conductor, a twisted pair, etc. The examples described above are only for convenience of explanation, and the medium of the wired connection may also be other types, for example, a transmission carrier of other electrical signals or optical signals.

[0065] Wireless connection may include radio communication, free space optical communication, acoustic communication, and electromagnetic induction, etc. Radio communication may include IEEE802.11 series standards, IEEE802.15 series standards (such as Bluetooth technology and cellular technology, etc.), first generation mobile communication technology, second generation mobile communication technology (such as FDMA, TDMA, SDMA, CDMA, and SSMA, etc.), general packet radio service technology, third generation mobile communication technology (such as CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth generation mobile communication technology (such as TD-LTE and FDD-LTE, etc.), satellite communication (such as GPS technology, etc.), near field communication (NFC) and other technologies running in ISM frequency bands (such as 2.4GHz, etc.); free space optical communication may include visible light, infrared signals, etc.; acoustic communication may include sound waves, ultrasonic signals, etc.; electromagnetic induction may include near field communication technology, etc. The examples described above are only for the convenience of explanation, and the medium of wireless connection may also be other types, such as Z-wave technology, other paid civil radio frequency bands and military radio frequency bands, etc. For example, as some application scenarios of the present technology, the bone conduction speaker 100 can obtain signals containing sound information from other devices through Bluetooth technology.

[0066] The vibration component 104 can generate mechanical vibration. The generation of the vibration is accompanied by energy conversion. The bone conduction speaker 100 can use the magnetic circuit component 102 and the vibration component 104 to realize the conversion of a signal containing sound information into mechanical vibration. The conversion process may include the coexistence and conversion of multiple different types of energy. For example, an electrical signal can be directly converted into mechanical vibration through a transducer to generate sound. For another example, sound information can be contained in an optical signal, and a specific transducer can realize the process of converting an optical signal into a vibration signal. Other types of energy that can coexist and convert during the operation of the transducer include thermal energy, magnetic field energy, etc. The energy conversion method of the transducer may include dynamic, electrostatic, piezoelectric, moving iron, pneumatic, electromagnetic, etc. The frequency response range and sound quality of the bone conduction headset 100 will be affected by the vibration component 104. For example, in a dynamic coil transducer device, the vibration component 104 includes a wound cylindrical coil and a vibrating body (for example, a vibrating plate). The cylindrical coil driven by the signal current drives the vibrating body to vibrate and make sound in the magnetic field. The extension and contraction of the vibrating body material, the deformation, size, shape and fixing method of the folds, the magnetic density of the permanent magnet, etc., will affect the sound quality of the bone conduction speaker 100. The vibrating body in the vibration component 104 can be a mirror-symmetrical structure, a centrally symmetrical structure or an asymmetrical structure; the vibrating body can be provided with an intermittent hole-shaped structure, so that the vibrating body produces a larger displacement under the same input energy, so that the bone conduction speaker can achieve higher sensitivity and improve the output power of vibration and sound; the vibrating body can be a torus or a torus-like structure, and a plurality of support rods radiating to the center are provided in the torus, and the number of the support rods can be two or more. In some embodiments, the vibration component 104 can include a coil, a vibration plate, a vibration transmission plate, etc.

[0067] The housing 106 can transmit mechanical vibration to the human body so that the human body can hear the sound. The housing 106 can constitute a closed or non-closed accommodation space, and the magnetic circuit component 102 and the vibration component 104 can be arranged inside the housing 106. The housing 106 can include a housing panel. The housing panel can be directly or indirectly connected to the vibration component 104, and the mechanical vibration of the vibration component 104 is transmitted to the auditory nerve via the bones, so that the human body can hear the sound.

[0068] The connection assembly 108 can play a connecting and supporting role 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 with one or more structures in the magnetic circuit assembly 102 and / or the vibration assembly 104.

[0069] The above description of the structure of the bone conduction speaker is only a specific example and should not be regarded as the only feasible implementation scheme. Obviously, for professionals in this field, after understanding the basic principle of the bone conduction speaker, it is possible to make various modifications and changes in form and details to the specific methods and steps of implementing the bone conduction speaker without deviating from this principle, but these modifications and changes are still within the scope of the above description. For example, the bone conduction speaker 100 may include one or more processors, and the processor may execute one or more sound signal processing algorithms. The sound signal processing algorithm may modify or enhance the sound signal. For example, the sound signal is subjected to noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, or other similar or any combination of the above processing, and these modifications and changes are still within the scope of protection of the claims of the present invention. For another example, the bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a speed sensor, a displacement sensor, etc. The sensor may collect user information or environmental information.

[0070] Figure 2 2 is a schematic diagram of a bone conduction headset 200 according to some embodiments of the present application. Figure 2 As shown, the bone conduction earphone 200 may include a magnetic circuit component 210 , a coil 212 , a vibration transmitting piece 214 , a connector 216 , and a housing 220 .

[0071] 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 the present application refers to an element that can generate a magnetic field, such as a magnet. The magnetic element may have a magnetization direction, and the magnetization direction refers to the direction of the magnetic field inside the magnetic element. The first magnetic element 202 may include one or more magnets. In some embodiments, the magnet may include a metal alloy magnet, a ferrite, and the like. Among them, the metal alloy magnet may include neodymium iron boron, samarium cobalt, aluminum nickel cobalt, iron chromium cobalt, aluminum iron boron, iron carbon aluminum, or the like, or a combination of multiple thereof. The ferrite may include barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or a combination of multiple thereof.

[0072] 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 a side wall. 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 wall can surround the first magnetic element 202 and form a magnetic gap with the first magnetic element 202. It should be noted that the magnetic conductive body mentioned here can also be called a magnetic field concentrator or an iron core. The magnetic conductive body can adjust the distribution of the magnetic field (for example, the magnetic field generated by the first magnetic element 202). The magnetic conductive body may include an element processed from a soft magnetic material. In some embodiments, the soft magnetic material may include a metal material, a metal alloy, a metal oxide material, an amorphous metal material, etc., such as iron, an iron-silicon alloy, an iron-aluminum alloy, a nickel-iron alloy, an iron-cobalt alloy, a low-carbon steel, a silicon steel sheet, a silicon steel sheet, a ferrite, etc. In some embodiments, the magnetic conductive body can be processed by one or more combined methods such as casting, plastic processing, cutting processing, powder metallurgy, etc. Casting may include sand casting, investment casting, pressure casting, centrifugal casting, etc.; plastic processing may include rolling, casting, forging, stamping, extrusion, drawing, etc.; cutting processing may include turning, milling, planing, grinding, etc. In some embodiments, the processing method of the magnetic conductor may include 3D printing, CNC machine tools, etc. The connection method between the first magnetic conductive element 204, the second magnetic conductive element 206 and the first magnetic element 202 may include one or more combinations of bonding, clamping, welding, riveting, bolting, etc.

[0073] The coil 212 may be disposed in the magnetic gap between the first magnetic element 202 and the second magnetic conductive element 206. In some embodiments, a signal current may be passed through the coil 212, and the coil 212 is in the magnetic field formed by the magnetic circuit assembly 210, and is acted upon by the Ampere force, driving the coil 212 to generate mechanical vibration. At the same time, the magnetic circuit assembly 210 is acted upon by a reaction force opposite to the coil.

[0074] One end of the vibration transmission piece 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 transmission piece 214 is an elastic member. The elasticity is determined by the material, thickness, structure and other aspects of the vibration transmission piece 214. The material of the vibration transmission piece 214 includes, but is not limited to, steel (such as but not limited to stainless steel, carbon steel, etc.), light 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 other organic and / or inorganic material composites, such as various types of glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. In some embodiments, the thickness of the vibration transmission piece 214 is not less than 0.005 mm, preferably, the thickness is 0.005 mm-3 mm, more preferably, the thickness is 0.01 mm-2 mm, more preferably, the thickness is 0.01 mm-1 mm, and further preferably, the thickness is 0.02 mm-0.5 mm. In some embodiments, the vibration transmission piece 214 can be an elastic structure, which means that the structure itself is an elastic structure. Even if the material is relatively hard, the vibration transmission piece 214 itself is elastic because the structure itself is elastic. For example, the vibration transmission piece 214 can be made into an elastic structure similar to a spring. In some embodiments, the structure of the vibration transmission sheet 214 can be set to an annular or quasi-annular structure, preferably, including at least one ring, preferably, including at least two rings, which can be concentric rings or non-concentric rings, and the rings are connected by at least two struts, and the struts radiate from the outer ring to the center of the inner ring. It is further preferred that at least one elliptical ring is included, and it is further preferred that at least two elliptical rings are included, and different elliptical rings have different radii of curvature, and the rings are connected by struts. It is further preferred that the vibration transmission sheet 214 includes at least one square ring. The structure of the vibration transmission sheet 214 can also be set to a sheet, preferably, a hollow pattern is set on it, and the area of ​​the hollow pattern is not less than the area without hollowing. The materials, thicknesses, and structures described above can be combined into different vibration transmission sheets. For example, the annular vibration transmission sheet has different thickness distributions, preferably, the thickness of the strut is equal to the thickness of the ring, and it is further preferred that the thickness of the strut is greater than the thickness of the ring, and it is further preferred that the thickness of the inner ring is greater than the thickness of the outer ring. In some embodiments, part of the vibration transmission piece 214 is connected to the magnetic circuit assembly 210, and part of the vibration transmission piece 214 is connected to the housing 220. Preferably, the vibration transmission piece 214 is connected to the first magnetic conductive element 204. In some embodiments, the vibration transmission 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.

[0075] In some embodiments, the vibration transmission piece 214 can be connected to the magnetic circuit assembly 210 through 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 to 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.

[0076] The shell 220 has a shell panel 222, a shell back 224 and a shell side 226. The shell back 224 is located on a side opposite to the shell panel 222 and is respectively arranged on both end surfaces of the shell side 226. The shell panel 222, the shell back 224 and the shell side 226 form an integral structure with a certain accommodation space. In some embodiments, the magnetic circuit component 210, the coil 212 and the vibration transmission piece 214 are fixed inside the shell 220. In some embodiments, the bone conduction headset 200 may further include a shell bracket 228, and the vibration transmission piece 214 may be connected to the shell 220 through the shell bracket 228. In some embodiments, the coil 212 may be fixed on the shell bracket 228 and drive the shell 220 to vibrate through the shell bracket 228. Among them, the shell bracket 228 may be a part of the shell 220, or it may be a separate component, directly or indirectly connected to the inside of the shell 220. In some embodiments, the shell bracket 228 is fixed on the inner surface of the shell 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.

[0077] In some embodiments, the bone conduction speaker 100 further includes an earphone fixing assembly (in Figure 2 The earphone fixing assembly is fixedly connected to the shell 220, and maintains the bone conduction speaker 100 in stable contact with human tissue or bone, avoids the 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 respectively connected to both ends of the earphone fixing assembly to keep the shells 220 at both ends in contact with 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.

[0078] 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, in the frequency response range from 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 its components, the material properties, etc. may all affect the frequency response curve. Generally, low frequency refers to sounds less than 500Hz, mid-frequency refers to sounds in the range of 500Hz-4000Hz, and high frequency refers to sounds greater than 4000Hz. Figure 3 As shown, the frequency response curve of the bone conduction speaker 200 may have two resonance peaks (310 and 320) in the low frequency region, and a first high frequency valley 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 may be generated by the vibration transmission plate 214 and the earphone fixing component. The first high frequency valley 330 and the first high frequency peak 340 may be generated by the deformation of the housing side 226 at high frequency, and the second high frequency peak 350 may be generated by the deformation of the housing panel 222 at high frequency.

[0079] The positions of the different resonance peaks and high-frequency peaks / valleys are related to the stiffness of the corresponding components. The stiffness is the ability of a material or structure to resist elastic deformation when it is subjected to stress. Stiffness is related to the Young's modulus of the material itself and the structural dimensions. The greater the stiffness, the smaller the deformation of the structure when it is subjected to stress. As mentioned above, the frequency response from 500Hz to 6000Hz is particularly critical for bone conduction speakers. In this frequency range, very sharp peaks and valleys are not desired. 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 zone can be adjusted to a higher-frequency area by adjusting the stiffness of the housing panel 222 and the back of the housing 224. In some embodiments, the housing bracket 228 can also affect the peaks and valleys in the high-frequency zone. By adjusting the stiffness of the housing bracket 228, the peaks and valleys in the high-frequency zone can be adjusted to a higher-frequency area. In some embodiments, the effective frequency band of the frequency response curve of the bone conduction speaker can cover at least 500Hz to 1000Hz, or 1000Hz to 2000Hz. More preferably, 500 Hz to 2000 Hz, more preferably, 500 Hz to 4000 Hz, more preferably, 500 Hz to 6000 Hz, more preferably, 100 Hz to 6000 Hz, more preferably, 100 Hz to 10000 Hz. The effective frequency band referred to here refers to the one set according to the common standards in the industry, such as IEC and JIS. In some embodiments, there is no peak / valley with a frequency width exceeding 1 / 8 octave in the effective frequency band, and the peak / valley value exceeds the average vibration intensity by 10 dB.

[0080] 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, among other factors. 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 they can be made of 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 may be made of the same material as the housing panel 222, the housing back 224 and the housing side 226, so that the influence 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 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.

[0081] 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 made not less than 1000 Hz, preferably, the high-frequency peak frequency can be made not less than 2000 Hz, preferably, the high-frequency peak frequency can be made not less than 4000 Hz, preferably, the high-frequency peak frequency can be made not less than 6000 Hz, more preferably, the high-frequency peak frequency can be made not less than 8000 Hz, more preferably, the high-frequency peak frequency can be made not less than 10000 Hz, more preferably, the high-frequency peak frequency can be made not less than 12000 Hz, further preferably, the high-frequency peak frequency can be made not less than 14000 Hz, further preferably, the high-frequency peak frequency can be made not less than 16000 Hz, further preferably, the high-frequency peak frequency can be made not less than 18000 Hz, further preferably, the high-frequency peak frequency can be made not 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 made to be outside the hearing range of the human ear. In some embodiments, by adjusting the stiffness of the housing 220, the high-frequency peak frequency in the frequency response curve of the earphone can be placed within the hearing range of the human ear. In some embodiments, when there are multiple high-frequency peaks / troughs, by adjusting the stiffness of the housing 220, one or more high-frequency peak / trough frequencies in the frequency response curve of the bone conduction earphone can be placed outside the hearing range of the human ear, and the remaining one or more high-frequency peak / trough frequencies can be placed within the hearing range of the human ear. For example, the second high-frequency peak 350 can be placed outside the hearing range of the human ear, and the first high-frequency trough 330 and the first high-frequency peak 340 can be placed within the hearing range of the human ear.

[0082] In some embodiments, the shell 220 can be ensured to have greater rigidity by designing the connection mode of the shell panel 222, the shell back 224 and the shell side 226. In some embodiments, the shell panel 222, the shell back 224 and the shell side 226 can be integrally formed. In some embodiments, the shell back 224 and the shell side 226 can be integrally formed structures. The shell panel 222 and the shell side 226 can be directly pasted and fixed by glue, or fixed by clamping, welding or threaded connection. The glue can be a glue with strong viscosity and high hardness. In some embodiments, the shell panel 222 and the shell side 226 can be an integrally formed structure, and the shell back 224 and the shell side 226 can be directly pasted and fixed by glue, or fixed by clamping, welding or threaded connection. In some embodiments, the shell panel 222, the shell back 224 and the shell side 226 are all independent components, and the three can be fixedly connected by one or any combination of glue, clamping, welding or threaded connection. 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 clamping, welding or threading. Or 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 clamping, welding or threading.

[0083] In some embodiments, the overall rigidity of the housing 220 can be improved by selecting materials with the same or different Young's modulus. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 can all be made of a single 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 modulus. 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 other materials, and 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 other materials, and 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 shell back 224 may be greater than the Young's modulus of the material of the shell panel 222 and the shell side 226, or the Young's modulus of the material of the shell back 224 may be less than the Young's modulus of the material of the shell panel 222 and the shell side 226. In some embodiments, the shell back 224 and the shell side 226 are made of the same material, and the shell panel 222 is made of other materials, and the Young's modulus of the two materials may be the same or different. For example, the Young's modulus of the material of the shell panel 222 may be greater than the Young's modulus of the material of the shell back 224 and the shell side 226, or the Young's modulus of the material of the shell panel 222 may be less than the Young's modulus of the material of the shell back 224 and the shell side 226. In some embodiments, the materials of the shell panel 222, the shell back 224, and the shell side 226 are all different, and the Young's modulus of the three materials may be all the same or all different, and the Young's modulus of the three materials are all greater than 2000 MPa.

[0084] 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 zone are related to the vibration plate and the earphone fixing assembly. The smaller the stiffness of the vibration plate 214 and the earphone fixing assembly, the more obvious the response of the resonance peak at the low frequency. When the stiffness of the vibration plate 214 and the earphone fixing assembly is greater, the resonance peak will change toward the medium frequency or high frequency direction, resulting in a decrease in sound quality. Therefore, when the stiffness of the vibration 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 plate 214 and the earphone fixing assembly, the two resonance peak frequencies in the low-frequency zone of the bone conduction earphone can be made less than 2000Hz. Preferably, the two resonance peak frequencies in the low-frequency zone of the bone conduction earphone can be made less than 1000Hz. More preferably, the two resonance peak frequencies in the low-frequency zone of the bone conduction earphone can be made less than 500Hz. In some embodiments, the peak values ​​of the two resonance peaks in the low-frequency region of the bone conduction earphone differ by no more than 150 Hz. Preferably, the peak values ​​of the two resonance peaks in the low-frequency region of the bone conduction earphone differ by no more than 100 Hz. More preferably, the peak values ​​of the two resonance peaks in the low-frequency region of the bone conduction earphone differ by no more than 50 Hz.

[0085] As described above, the present application can adjust the peak / valley in the high-frequency region toward a higher frequency and the low-frequency resonance peak toward a low frequency by adjusting the stiffness of the various components of the bone conduction speaker (for example, the shell, the housing bracket, the vibration transducer or the earphone fixing assembly), thereby ensuring a frequency response curve platform within the range of 500Hz to 6000Hz and improving the sound quality of the bone conduction earphone.

[0086] On the other hand, the bone conduction speaker will leak sound during the vibration transmission process. The sound leakage refers to the change in the volume of the surrounding air caused by the vibration of the internal components of the bone conduction speaker 200 or the vibration of the shell, which causes the surrounding air to form a compression area or a sparse area and spread in all directions, resulting in the transmission of sound to the surrounding environment, so that people other than the wearer of the bone conduction headset can hear the sound emitted by the headset. The present application can provide a solution to reduce the sound leakage of bone conduction headphones from the perspective of changing the shell structure, rigidity, etc.

[0087] Fig. 7A7 is a schematic diagram of the shell structure of a bone conduction headset according to some embodiments of the present application. As shown in FIG7 , the shell 700 may include a shell panel 710, a shell back 720 and a shell side 730. The shell panel 710 contacts the human body and transmits the vibration of the bone conduction headset to the auditory nerve of the human body. In some embodiments, when the overall stiffness of the shell 700 is large, within a certain frequency range, the vibration amplitude and phase of the shell panel 710 and the shell back 720 remain the same or substantially the same (the shell side 730 does not compress the air and thus does not generate sound leakage), so that the first sound leakage signal generated by the shell panel 710 and the second sound leakage signal generated by the shell back 720 can be superimposed on each other. The superposition can reduce the amplitude of the first sound leakage sound wave or the second sound leakage sound wave, thereby achieving the purpose of reducing the sound leakage of the shell 700. In some embodiments, the certain frequency range at least includes a part with a frequency greater than 500 Hz. Preferably, the certain frequency range at least includes a part with a frequency greater than 600 Hz. Preferably, the certain frequency range at least includes a part with a frequency greater than 800 Hz. Preferably, the certain frequency range at least includes a part 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 descriptions elsewhere in this application (e.g., Figures 22A-22C , and its related description).

[0088] When the frequency exceeds a certain threshold, a specific part of the housing 700 (e.g., the housing panel 710, the housing back 720, and the housing side 730) will generate a higher-order mode when vibrating (i.e., different points on the specific part will vibrate inconsistently). In some embodiments, the housing volume and material of the housing 700 can be designed so that the frequency of the higher-order mode is higher. 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 according to 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 is, the higher the frequency of the high-order mode generated by it is. For example, when the shell volume is 25000mm 3 When the shell 700 generates a high-order mode with a frequency of about 4000 Hz, the shell volume is 400 mm 3 , the frequency of the high-order mode generated by the shell 700 is above 32000 Hz. 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 5 GPa. 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 2 GPa. 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 2 GPa and 18 GPa. Preferably, the shell volume is 400 mm 3 -5000mm 3 In the range of 200 mm, the Young's modulus of the shell material is between 2 GPa and 10 GPa. More preferably, the shell volume is 400 mm. 3 -3500mm 3 In the range of 2GPa-6GPa, the Young's modulus of the shell material is between 400mm and 2GPa. 3 -3000mm 3 In the range of 200 mm, the Young's modulus of the shell material is between 2 GPa and 5.5 GPa. More preferably, the shell volume is 400 mm 3 -2800mm 3 The Young's modulus of the shell material is between 2 GPa and 5 GPa. More preferably, the shell volume is between 400 mm 3 -2000mm 3 In the range of , the Young's modulus of the shell material is between 2GPa-4GPa, and further preferably, the shell volume is 400mm 3 -1000mm 3 range, and the Young's modulus of the shell material is between 2GPa-3GPa.

[0089] It should be noted that when the shell volume is larger, the shell 700 can accommodate a larger magnetic circuit system, so that the bone conduction speaker has a higher sensitivity. In some embodiments, the sensitivity of the bone conduction speaker can be reflected by the volume generated by the bone conduction speaker under a certain input signal. When the same signal is input, the larger the volume generated by the bone conduction speaker, the higher the sensitivity of the bone conduction speaker. Figure 7C Schematic diagram of the relationship between the volume and the housing volume of a bone conduction speaker 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 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 shell is 400mm, the relative volume of the bone conduction speaker is 1. 3 When the volume of the bone conduction speaker is between 0.25 and 0.5, the relative volume of the bone conduction speaker is between 0.25 and 0.5. 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 .

[0090] Figure 8 700 is a schematic diagram showing the principle of reducing sound leakage. Figure 8As shown, when the bone conduction speaker is in working state, the shell panel 710 contacts the human body and vibrates mechanically. In some embodiments, the shell panel 710 can contact the skin of the human face, and produce a certain degree of compression on the contacted skin, so that the skin around the shell panel 710 protrudes outward and deforms. When the shell panel 710 vibrates, it moves toward the face of the person, squeezes the skin, and pushes the deformed skin around the shell panel 710 to protrude outward, compressing the air around the shell panel 710. When the shell panel moves away from the face of the person, a sparse area will be formed between the shell panel 710 and the skin of the face, and the air around the shell panel 710 will be absorbed. This compression and absorption of air leads to a continuous change in the volume of the air around the shell panel 710, so that the surrounding air continuously forms a compressed area or a sparse area and spreads around, transmitting sound to the surrounding environment, thereby causing sound leakage. If the rigidity of the housing 700 is large enough, so that the housing back 720 can vibrate together with the housing panel 710, and the vibration magnitude and direction are consistent, when the housing panel 710 moves toward the face of the person, the housing back 720 also moves toward the face of the person, and a sparse air area will be formed around the housing back 720, that is, when the air is compressed around the housing panel 710, the air will be absorbed around the housing back 720. When the housing panel 710 moves away from the face, the housing back 720 also moves away from the face, and a compressed air area is formed around the housing back 720, that is, when the air is absorbed around the housing panel 710, the air will be compressed around the housing back 720. The opposite effects of the housing back 720 and the housing panel 710 on the air can offset each other's effects on the surrounding air, that is, the external sound leakage can offset each other, achieving the effect of significantly reducing the sound leakage outside the housing 700. That is to say, the overall rigidity of the shell 700 can be improved to ensure that the back side 720 of the shell and the shell panel 710 vibrate in unison, while the side side 730 of the shell does not push the air and does not cause sound leakage. This can cancel out the sound leakage from the back side 720 of the shell and the shell panel 710, greatly reducing the sound leakage from the outside of the shell 700.

[0091] In some embodiments, the rigidity of the housing 700 is relatively large, which can ensure that the housing panel 710 and the housing back 720 vibrate in unison, so that the sound leakage outside the housing 700 can offset each other, achieving the purpose of significantly reducing the sound leakage. In some embodiments, the rigidity of the housing 700 is relatively large, which can reduce the sound leakage of the housing panel 710 and the housing back 720 in the mid- and low-frequency range.

[0092] In one embodiment, the rigidity of the housing 700 can be improved by improving 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 the Young's modulus, size, weight and other parameters of the material. The larger 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 housing panel 710 material is greater than 2000Mpa, preferably, the Young's modulus of the housing panel 710 material is greater than 3000Mpa, the Young's modulus of the housing panel 710 material is greater than 4000Mpa, preferably, the Young's modulus of the housing panel 710 material is greater than 6000Mpa, preferably, the Young's modulus of the housing panel 710 material is greater than 8000Mpa, preferably, the Young's modulus of the housing panel 710 material is greater than 12000Mpa, more preferably, the Young's modulus of the housing panel 710 material is greater than 15000Mpa, and further preferably, the Young's modulus of the housing panel 710 material is greater than 18000Mpa. 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 (Polyvinylidene chloride), polyethylene (PE), polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), phenolic resin (PF), urea formaldehyde resin (UF), melamine formaldehyde resin (Melamine The material of the housing panel 710 is any material selected from the group consisting of ferrite, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc., glass fiber, and carbon fiber, or any combination of the above materials. In some embodiments, the material of the housing panel 710 is any combination of glass fiber, carbon fiber, polycarbonate (PC), polyamide (PA), and the like.In some embodiments, the material of the outer shell panel 710 may be a mixture of carbon fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the outer shell panel 710 may be a mixture of carbon fiber, glass fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the outer shell panel 710 may be a mixture of glass fiber and polycarbonate (PC) in a certain proportion, or glass fiber and polyamide (PA) may be mixed in a certain proportion. Adding different proportions of carbon fiber or glass fiber will result in different stiffness of the obtained material. For example, by adding 20% ​​to 50% of glass fiber, the Young's modulus of the material can reach 4000MPa to 8000MPa.

[0093] In some embodiments, the greater the thickness of the shell panel 710, the greater the rigidity of the shell panel 710. In some embodiments, the thickness of the shell panel 710 is not less than 0.3 mm, preferably, the thickness of the shell panel 710 is not less than 0.5 mm, more preferably, the thickness of the shell panel 710 is not less than 0.8 mm, and more preferably, the thickness of the shell panel 710 is not less than 1 mm. However, as the thickness increases, the weight of the shell 700 will also increase, thereby increasing the deadweight of the bone conduction earphone, resulting in the sensitivity of the earphone being affected. Therefore, the thickness of the shell panel 710 should not be too large. In some embodiments, the thickness of the shell panel 710 does not exceed 2.0 mm, preferably, the thickness of the shell panel 710 does not exceed 1.5 mm, preferably, the thickness of the shell panel 710 does not exceed 1.2 mm, more preferably, the thickness of the shell panel 710 does not exceed 1.0 mm, and more preferably, the thickness of the shell panel 710 does not exceed 0.8 mm.

[0094] In some embodiments, the housing panel 710 can be configured in different 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 in which the four corners of the rectangle are replaced with arcs), an ellipse, 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 6 cm 2 Preferably, the area of ​​the housing panel 710 is not greater than 5 cm 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 .

[0095] In some embodiments, the rigidity of the housing 700 can be achieved by adjusting the weight of the housing 700. The heavier the weight of the housing 700, the greater the rigidity of the housing 700. However, the heavier the weight of the housing 700, the greater the weight of the earphone, which affects the wearing comfort of the bone conduction earphone. In addition, the heavier the weight of the housing 700, the lower the overall sensitivity of the earphone. Fig. 9 This is a frequency response curve of a bone conduction headset when the housing weight of the bone conduction headset is different according to some embodiments of the present application. Fig. 9 As shown, when the weight of the shell is heavier, the frequency response curve of the high frequency changes toward the low frequency direction as a whole, so that the frequency response curve of the earphone has peaks / troughs in the mid-high frequency, and the sound quality deteriorates. In some embodiments, the weight of the shell 700 is less than or equal to 8 grams, preferably, the weight of the shell 700 is less than or equal to 6 grams, more preferably, the weight of the shell 700 is less than or equal to 4 grams, and further preferably, the weight of the shell 700 is less than or equal to 2 grams.

[0096] In some embodiments, the rigidity of the outer shell panel 710 can be improved by adjusting any combination of factors such as the Young's modulus, thickness, weight, and shape of the outer shell panel 710 at the same time. For example, the ideal rigidity can be obtained by adjusting the Young's modulus and thickness. Or the ideal rigidity can be obtained 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 2000MPa, and the thickness is not less than 1mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 4000MPa, and the thickness is not less than 0.9mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 6000MPa, and the thickness is not less than 0.7mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 8000MPa, and the thickness is not less than 0.6mm. In some embodiments, the Young's modulus of the material of the outer shell panel 710 is not less than 10000MPa, and the thickness is not less than 0.5mm. In some embodiments, the Young's modulus of the material of the housing panel 710 is not less than 18000 MPa and the thickness is not less than 0.4 mm.

[0097] In some embodiments, the housing can be any shape that can vibrate as a whole, not limited to the shape shown in FIG. 7. 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 Fig. 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 a shape similar to a hemisphere, such as Fig. 10B As shown, the housing panel 910 may be a plane or a curved surface, the housing side 920 may be a curved surface (e.g., a bowl-shaped curved surface), the plane parallel to the housing panel 910 is used as the projection surface, the housing back 930 may 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, Fig. 10C As shown, the shell panel 910 and the shell back 930 are relative curved surfaces, the shell side 920 is a curved surface transitioning 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, and the cross-section with the largest cross-sectional area is taken as the projection plane, and 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%. More preferably, the difference in area between the shell panel and the back of the shell does not exceed 12% 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 10% 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 8% 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 5% 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 3% 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 1% 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 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.

[0098] Fig.11 The figure is a comparison diagram 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 composed of a shell made of a material with a conventional Young's modulus. Fig.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 of the traditional speaker at low frequency is used as the benchmark to draw the sound leakage cancellation curve. 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 effect of sound leakage cancellation is the best, which can reduce the sound leakage 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, so as to measure the size of the sound leakage.

[0099] Depend on Fig.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 effect of reducing sound leakage is significantly better than that of traditional bone conduction headphones. However, when high-frequency vibration occurs, since it is difficult for the shell to remain 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 offset 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.

[0100] Fig.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 in 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 Fig.12As shown). In some embodiments, the Young's modulus, weight and / or size of the material of the housing panel 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 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. 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.

[0101] 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.

[0102] In some embodiments, the outer shell panel may be composed of one material. In some embodiments, the outer shell panel may be composed of two or more materials stacked in layers. In some embodiments, the outer shell panel may be composed of a layer of material with a larger Young's modulus and an additional layer of material with a smaller Young's modulus. This has the advantage of ensuring the rigidity requirements of the outer shell panel while also increasing the comfort of contact with the human body and improving the degree of fit 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), polyamide (PA), polyvinyl chloride (PVC), polyurethane (PU), polyvinylidene chloride (PE), polyethylene (PE), polymethyl methacrylate (PMMA), polymethyl methacrylate (PMMA), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene terephthalate (PET), polyester (PES), polycarbonate (PC), polyamide (PA), polyvinyl chloride (PVC), polyurethane (PU), polyvinylidene chloride (PE), polymethyl methacrylate (PMMA ... The outer shell panel 710 may be made of any material selected from polyimide (polymethacrylate, PMMA), polyetheretherketone (Polyetheretherketone, PEEK), phenolic resin (Phenolics, PF), urea formaldehyde resin (Urea-formaldehyde, UF), melamine-formaldehyde resin (Melamineformaldehyde, 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 outer shell panel 710 is any combination of glass fiber, carbon fiber and polycarbonate (Polycarbonate, PC), polyamide (Polyamides, PA) and other materials. In some embodiments, the material of the outer shell panel 710 may 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 may 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 may be a mixture of glass fiber and polycarbonate (Polycarbonate, PC) in a certain proportion.Adding different proportions of carbon fiber or glass fiber can result in different stiffness of the obtained material. For example, adding 20% ​​to 50% of glass fiber can result in a Young's modulus of 4000 MPa to 8000 MPa. In some embodiments, the material with a smaller Young's modulus can be silicone.

[0103] In some embodiments, the outer surface of the housing panel in contact with 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 Fig.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.

[0104] Fig.14A It is the frequency response curve of the back of the shell of the bone conduction speaker. The back of the shell vibrates in the same way as the shell panel at medium and low frequencies, and at high frequencies, high-order modes appear on the back of the shell. The high-order modes on the back of the shell will pass through the side of the shell, affecting the movement speed and direction of the shell panel. At high frequencies, the deformation of the back of the shell can reinforce or offset the deformation of the shell panel, producing peaks and valleys at high frequencies. In some embodiments, the peak frequency that appears can be higher by adjusting the material and geometric dimensions of the back of the shell, so as to obtain a flatter frequency response curve over a larger range. Improve the sound quality of bone conduction headphones. And reduce the sensitivity of the human ear to high-frequency sound leakage, thereby reducing the sound leakage of the speaker. In some embodiments, the peak frequency that appears on the back of the shell can be adjusted by adjusting the Young's modulus, weight and / or size of the material of the back panel of the shell. In some embodiments, the Young's modulus of the material on the back of the shell may be greater than 2000Mpa, preferably, the Young's modulus of the material may be greater than 4000Mpa, preferably, the Young's modulus of the material is greater than 6000Mpa, preferably, the Young's modulus of the material is greater than 8000Mpa, preferably, the Young's modulus of the material is greater than 12000Mpa, more preferably, the Young's modulus of the material is greater than 15000Mpa, further preferably, the Young's modulus of the material is greater than 18000Mpa.

[0105] In some embodiments, by adjusting the stiffness of the back side of the shell, the peak frequency appearing on the back side 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 side of the shell can be made greater than 8000Hz, more preferably, the peak frequency of the back side of the shell can be made greater than 10000Hz, more preferably, the peak frequency of the back side of the shell can be made greater than 12000Hz, further preferably, the peak frequency of the back side of the shell can be made greater than 14000Hz, further preferably, the peak frequency of the back side of the shell can be made greater than 16000Hz, further preferably, the peak frequency of the back side of the shell can be made greater than 18000Hz, further preferably, the peak frequency of the back side of the shell can be made greater than 20000Hz.

[0106] In some embodiments, the back side of the housing can be made of one material. In some embodiments, the back side of the housing can be made of two or more materials stacked.

[0107] Fig. 14B It is the frequency response curve of the side of the shell of the bone conduction earphone. As mentioned before, the side of the shell itself will not cause sound leakage when it vibrates at low frequencies. But the side of the shell will also affect the sound leakage of the speaker at high frequencies. The reason is that at high frequencies, the side of the shell will deform, and 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. Fig. 14B As shown, the frequency response curve of the side of the shell will have peaks / valleys at high frequencies. In some embodiments, the frequency of the peaks and valleys can be higher by adjusting the material and geometric dimensions of the side of the shell, so as to obtain a flatter frequency response curve in a larger range. Improve the sound quality of the bone conduction speaker. And reduce 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 shell 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 shell can be greater than 2000Mpa, preferably, the Young's modulus of the material can be greater than 4000Mpa, preferably, the Young's modulus of the material is greater than 6000Mpa, preferably, the Young's modulus of the material is greater than 8000Mpa, preferably, the Young's modulus of the material is greater than 12000Mpa, more preferably, the Young's modulus of the material is greater than 15000Mpa, and further preferably, the Young's modulus of the material is greater than 18000Mpa.

[0108] 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.

[0109] In some embodiments, the housing side surface may be composed of one material. In some embodiments, the housing side surface may be composed of two or more materials stacked.

[0110] The stiffness of the housing bracket can also affect the frequency response of the earphone at high frequencies. Fig.15 This is the frequency response curve of the housing support of the bone conduction earphone. Fig.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 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 2000MPa, preferably, the Young's modulus of the material can be greater than 4000MPa, preferably, the Young's modulus of the material is greater than 6000MPa, preferably, the Young's modulus of the material is greater than 8000MPa, preferably, the Young's modulus of the material is greater than 12000MPa, more preferably, the Young's modulus of the material is greater than 15000MPa, and further preferably, the Young's modulus of the material is greater than 18000MPa.

[0111] In some embodiments, by adjusting the stiffness of the outer shell bracket, the peak frequency of the outer shell bracket can be made greater than 2000Hz, preferably, the peak frequency of the outer shell bracket can be made greater than 4000Hz, preferably, the peak frequency of the outer shell bracket can be made greater than 6000Hz, preferably, the peak frequency of the outer shell bracket can be made greater than 8000Hz, more preferably, the peak frequency of the outer shell bracket can be made greater than 10000Hz, more preferably, the peak frequency of the outer shell bracket can be made greater than 12000Hz, further preferably, the peak frequency of the outer shell bracket can be made greater than 14000Hz, further preferably, the peak frequency of the outer shell bracket can be made greater than 16000Hz, further preferably, the peak frequency of the outer shell bracket can be made greater than 18000Hz, further preferably, the peak frequency of the outer shell bracket can be made greater than 20000Hz.

[0112] In this application, the rigidity of the shell is increased by adjusting the Young's modulus and size of the shell material to ensure the consistency of the shell vibration, so that the sound leakage can be superimposed and canceled, thereby reducing the sound leakage. And the peak frequencies corresponding to different parts of the shell are adjusted to higher frequencies, which can reduce the sound leakage while improving the sound quality.

[0113] Fig.16A It is a structural schematic 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 the stable contact between the bone conduction earphone and the human tissue or bone, avoid the 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 (that is, the stiffness coefficient is smaller), the resonance peak is more obvious at low frequencies, 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 (that is, the stiffness coefficient is small), it is conducive to the vibration of the shell.

[0114] Fig. 16B The bone conduction speaker 1600 and the earphone fixing assembly 1620 are connected to the housing 1610 through a connecting component 1630. In some embodiments, the connecting component 1630 can be one of silica gel, sponge, and shrapnel, or any combination of the two.

[0115] In some embodiments, the earphone fixing component 1620 can be in the form of an ear hook, and the two ends of the earphone fixing component 1620 are respectively connected to a shell 1610, and the two shells are respectively fixed on the two sides of the skull in the form of ear hooks. In some embodiments, the earphone fixing component 1620 can be a single-ear ear clip. The earphone fixing component 1620 can be connected to a shell 1610 alone, and the shell 1610 is fixed to one side of the skull.

[0116] It should be noted that the above methods for connecting the earphone fixing assembly to the housing are only some examples or embodiments of the present application. A person skilled in the art can 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 the present application (for example, Figure 23A-23C , and its related description).

[0117] Embodiment 1

[0118] like Fig.17 As shown, the bone conduction speaker 1700 may include a magnetic circuit component 1710, a coil 1720, a connector 1730, a vibration transmission sheet 1740, a housing 1750 and a housing bracket 1760. In some embodiments, the bone conduction speaker 1700 further includes a first element and a second element. The coil 1720 is connected to the housing 1750 through the first element. The magnetic circuit component 1710 is connected to the housing 1750 through the second element. The elastic modulus of the first element is greater than the elastic modulus of the second element. In order to achieve a hard connection between the coil and the housing, and a soft connection between the magnetic circuit component and the housing. The purpose of adjusting the position of the low-frequency resonance peak and the high-frequency resonance peak and optimizing the frequency response curve is achieved. In some embodiments, the first element may be a housing bracket 1760, the housing bracket 1760 is fixedly connected to the inside of the housing 1750, and the coil 1720 is connected to the housing bracket 1760. The housing bracket 1760 is an annular bracket fixed to the inner wall of the 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 2000Mpa. In some embodiments, the second element can be a vibration transmission piece 1740. The magnetic circuit assembly 1710 is connected to the vibration transmission piece 1740, and the vibration transmission piece is an elastic component. The shell 1750 can vibrate mechanically under the drive of the vibration transmission piece 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 headset 1700 is working, the shell 1750 vibrates as a whole, that is, the shell panel, the shell side and the 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.

[0119] The 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 the first magnetic conductive element 1704 may be connected to the upper surface of the first magnetic element 1706. The upper surface of the second magnetic conductive element 1708 may be connected to the lower surface of the first magnetic element 1706. The lower surface of the second magnetic element 1702 may be connected to the upper surface of the first magnetic conductive element 1704. The magnetization directions of the first magnetic element 1706 and the second magnetic element 1702 are opposite. The second magnetic element 1702 may suppress the leakage magnetic flux on one side of the upper surface of the first magnetic element 1706, so that the magnetic field generated by the first magnetic element 1706 can be more compressed into the magnetic gap between the second magnetic conductive element 1708 and the first magnetic element 1706, thereby increasing the magnetic induction intensity in the magnetic gap, and further increasing the sensitivity of the bone conduction earphone 1700.

[0120] Similarly, a third magnetic element 1709 can be added to the lower surface of the second magnetic conductive element 1708. The third magnetic element 1709 has a magnetization direction opposite to that of the first magnetic element 1706, and is used to suppress leakage magnetic flux 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.

[0121] 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 element 1709 can be fixed by gluing. Holes can also be punched 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 element 1709 to fix them by screws.

[0122] Embodiment 2

[0123] Figures 18A-18D The following are schematic diagrams of several structures of the vibration transducer of the bone conduction earphone. Fig.18A 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 outer ring and the inner ring may be concentric circles. The connecting rods may be arc-shaped with a certain length. The number of connecting rods may be 3 or more. The inner ring of the vibration transmission plate may be fixedly connected to the connecting member.

[0124] like Fig.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 the connecting rods may be 3 or more.

[0125] like Fig.18CAs shown, the vibration transmission plate may include an inner ring and a plurality of curved rods surrounding the inner ring and radially distributed outwards. The number of the curved rods may be 3 or more.

[0126] like Fig.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 the curved rods can be 3 or more.

[0127] Embodiment 3

[0128] Fig.19 19 is a schematic 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 transmission sheet 1930, a housing 1940 and a housing bracket 1950. Fig.17 , compared with the structure in Example 1, Fig.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 Fig.19 As shown, the vibration transmission sheet 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 transmission sheet can reduce the size of the bone conduction earphone 1900 in the thickness direction. Fig.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 connector can be eliminated to simplify the internal structure. On the other hand, when the shell of a stereoscopic transducer and the shell of a planar transducer are of the same size, the stereoscopic transducer can have a larger vibration amplitude than the planar transducer, thereby increasing the maximum volume that the bone conduction speaker can provide.

[0129] The projection shape of the three-dimensional vibration transmission sheet 1930 can be any one of the shapes in the second embodiment.

[0130] In some embodiments, the outer edge of the stereoscopic vibration sheet 1930 can be connected to the inner side of the housing bracket 1950. For example, when the stereoscopic vibration sheet 1930 is used as Fig.18AWhen the three-dimensional vibration transmission piece 1930 is configured as shown in FIG. 18B, its outer ring can be connected to the inner side of the housing bracket 1950 by gluing, clamping, welding or threading. Fig.18C When the vibration transmission piece is configured as shown in FIG. 18D, the curved rod surrounding the inner ring can be connected to the inner side of the outer shell bracket 1950 by glue, clamping, welding or threaded connection. In some embodiments, the outer shell bracket 1950 can be provided with a plurality of slots, and the outer edge of the three-dimensional vibration transmission piece 1930 can pass through the slots and be connected to the outer side of the outer shell bracket 1950. At the same time, the length of the vibration transmission piece can be increased, which is conducive to the change of the resonance peak to the low frequency direction, thereby improving the sound quality. The size of the slot can provide enough space for the vibration of the vibration transmission piece.

[0131] Embodiment 4

[0132] Figures 20A-20D Schematic diagram of the structure of several bone conduction speakers according to some embodiments of the present application. Fig. 20A As shown, unlike the structure in the first embodiment, there is no housing bracket in the speaker structure, and the first element is the connecting member 2030, through which the coil 2020 is connected to the housing 2050. The connecting member 2030 includes a columnar body, one end of which is connected to the housing 2050, and the other end of the columnar body is provided with a circular end with a larger cross-sectional area, and the circular end is fixedly connected to the coil 2020. The connecting member 2030 is a rigid member, and the connecting member is made of a material with a Young's modulus greater than 4000Mpa. A gasket may be connected between the coil 2020 and the connecting member 2030. The second element is a vibration transmission piece 2040, and the magnetic circuit assembly 2010 is connected to the vibration transmission piece 2040, and the vibration transmission piece 2040 is directly connected to the housing 2050. The vibration transmission piece 2040 is an elastic member. The vibration transmission piece 2040 may be located above the magnetic circuit assembly 2010, and the vibration transmission piece 2040 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 may be connected via a gasket.

[0133] like Fig. 20B As shown, Fig. 20A The structure is different from that of the embodiment of the present invention in 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.

[0134] like Fig. 20C As shown, the vibration transmission piece 2040 can also be disposed below the magnetic circuit assembly 2010 and connected to the lower surface of the second magnetic conductive element 2008 .

[0135] like Fig.20D As shown, the coil 2020 is fixedly connected to the back of the housing via a connector 2030 .

[0136] Embodiment 5

[0137] like Fig.21 As shown, the bone conduction speaker 2100 may include a magnetic circuit component 2110, a coil 2120, a connector 2130, a vibration transmission piece 2140, a housing 2150 and a housing bracket 2160. The housing 2150 may be mechanically vibrated under the drive of the vibration transmission piece 2140, and the vibration is transmitted to the tissue and bone, and then transmitted to the auditory nerve through the tissue and bone, so that the human body can hear the sound. The overall rigidity of the housing 2150 is relatively large, so that when the bone conduction earphone 2100 is working, the housing 2150 vibrates as a whole, and the sound leakage outside the housing 2150 can be offset, significantly reducing the external sound leakage. The housing 2150 may be provided with a plurality of sound guide holes 2151. The sound guide holes 2151 can transmit the sound leakage inside the earphone 2100 to the outside of the housing 2150, and offset the sound leakage outside the housing 2150, further reducing the sound leakage of the earphone. It should be understood that the vibration of the components inside the housing 2150 will also generate vibration of the internal air, thereby generating sound leakage. Furthermore, the vibration of the internal components and the vibration of the housing 2150 may 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.

[0138] Embodiment 6

[0139] In different application scenarios, the shell of the bone conduction headset 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 headset 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 by snapping, welding, or threading. Specifically, in order to better understand the assembly method of the shell of the bone conduction headset in this application, Figures 22A-22C Several examples of how the housing of a bone conduction headphone may be assembled are described.

[0140] like Fig.22AAs shown, the shell of the bone conduction earphone may include a shell panel 2222, a shell back 2224 and a shell side 2226. The shell side 2226 and the shell back 2224 are made by an integral molding method, and the shell panel 2222 is connected to one end of the shell side 2226 by a sub-assembly method. The sub-assembly method includes using glue to bond and fix, or fixing the shell panel 2222 to one end of the shell side 2226 by a clamping, welding or threading method. The shell panel 2222 and the shell side 2226 (or the shell back 2224) can 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, and 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 (PE), polyethylene (PE), polymethyl methacrylate (PMMA ... The outer shell panel 710 may be made of any material selected from the group consisting of polymethacrylate (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 outer 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 outer shell panel 2222 and / or the outer shell side 2226 may be a mixture of carbon fiber and polycarbonate (PC) in a certain proportion. In some embodiments, the material of the outer shell panel 2222 and / or the outer 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 shell panel 2222 and / or the shell 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.

[0141] like Fig.22AAs shown, the housing panel 2222, the housing back 2224 and the housing side 2226 form an integral structure with a certain accommodation space. In the integral structure, the vibration transmission piece 2214 is connected to the magnetic circuit assembly 2210 through a connector 2216. The two sides of the magnetic circuit assembly 2210 are respectively connected to the first magnetic conductive element 2204 and the second magnetic conductive element 2206. The vibration transmission piece 2214 is fixed to the inside of the integral structure through 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 alone. In this case, optionally, the housing side 2226 and the housing bracket 2228 can be integrally formed. In some embodiments, the housing bracket 2228 can be directly fixed to the housing panel 2222 (for example, by gluing, clamping, welding or threading). The fixed housing panel 2222 and the housing bracket 2228 are then fixed to the side of the housing (for example, by gluing, clamping, welding or threading). In this case, the housing bracket 2228 and the housing panel 2222 can be integrally formed.

[0142] like Fig. 22B As shown, Fig.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 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 split combination structure, and the housing panel 2252, the housing back 2254, the housing bracket 2258 and the housing side 2256 are fixedly connected by gluing, snapping, welding or threading.

[0143] like Fig. 22C As shown, Fig.22A and Fig. 22BThe difference is that the housing panel 2282 and the housing side 2286 are integrally formed. The housing back 2284 is fixed to the housing side 2286 on the side opposite to 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, optionally, the housing bracket 2288, the housing panel 2282 and the housing side 2286 are an integrally formed structure.

[0144] Embodiment 7

[0145] As described elsewhere in this application, the shell of the bone conduction headset can maintain stable contact with human tissue or bone through the headset fixing assembly. In different application scenarios, the headset fixing assembly and the shell can be connected in different ways. For example, the headset fixing assembly and the shell can be integrally formed, or a combination of the two. In the split combination, the headset 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 a shell panel, a back side of the shell, and / or a side of the shell. Specifically, in order to better understand the connection method between the headset 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.

[0146] like Fig.23A As shown, taking the ear hook as the headphone fixing component as an example, Fig.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 means of snap connection, welding or threaded connection. 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 rigidity (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.

[0147] like Fig. 23B As shown, in Fig. 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 side 2356 of the shell or the back 2354 of the shell by snapping, welding or threading. Fig.23A Similarly, the portion of the ear hook 2360 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.

[0148] like Fig.23C As shown, in Fig. 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 side 2386 of the shell or the back 2384 of the shell by snapping, welding or threading. Fig.23A Similarly, the portion of the ear hook 2390 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.

[0149] Embodiment 8

[0150] As described elsewhere in this application, the rigidity of the shell of the bone conduction earphone affects the vibration amplitude and phase of different parts of the shell (e.g., the shell panel, the back of the shell and / or the side of the shell), thereby affecting the sound leakage of the bone conduction earphone. In some embodiments, when the shell of the bone conduction earphone has a relatively large rigidity, the shell panel and the back of the shell can maintain the same or substantially the same vibration amplitude and phase at a higher frequency, thereby significantly reducing the sound leakage of the bone conduction earphone.

[0151] The higher frequency mentioned here may include a frequency of not less than 1000 Hz, for example, a frequency between 1000 Hz-2000 Hz, a frequency between 1100 Hz-2000 Hz, a frequency between 1300 Hz-2000 Hz, a frequency between 1500 Hz-2000 Hz, a frequency between 1700 Hz-2000 Hz, a frequency between 1900 Hz-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-3000 Hz, a frequency between 2100 Hz-3000 Hz, a frequency between 2300 Hz-3000 Hz, a frequency between 2500 Hz-3000 Hz, a frequency between 2700 Hz-3000 Hz, or a frequency between 2900 Hz-3000 Hz. Preferably, the higher frequency mentioned here 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 here 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.

[0152] Here, the vibration amplitudes of the housing panel and the housing back side being the same or substantially the same means that the ratio of the vibration amplitudes of the housing panel and the housing back side is within a certain range. For example, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.3 and 3, preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.4 and 2.5, preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.5 and 1.5, more preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.6 and 1.4, more preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.7 and 1.2, more preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.75 and 1.15, more preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.8 and 1.1, more preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.85 and 1.1, and further preferably, the ratio of the vibration amplitude of the shell panel to the back of the shell is between 0.9 and 1.05. In some embodiments, the vibration of the shell panel and the back of the shell can be represented by other physical quantities that can characterize their vibration amplitudes. For example, the vibration amplitudes of the housing panel and the housing back can be characterized by the sound pressures generated by the housing panel and the housing back at a point in space, respectively.

[0153] 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°.

[0154] 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, Figure 24-26 Several examples of methods for measuring vibrations of a bone conduction earphone housing are described.

[0155] like Fig.24As shown, the signal generating device 2420 can provide a driving signal to the bone conduction earphone, so that the shell panel 2412 of the shell 2410 vibrates. 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, so as to obtain the phase difference (also called the first phase difference) between the two signals. Similarly, the rangefinder 2440 can measure the second electrical signal (also referred to as the 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 the second phase difference) between the periodic signal and the second electrical signal. According to 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.

[0156] In some embodiments, a microphone may be used instead of the rangefinder 2440. Specifically, the microphone may 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 may 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 may 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 relatively close to the housing panel 2412 and the back of the housing (for example, a vertical distance of 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.

[0157] Fig.25 is based on Fig.24 An exemplary result of the measurement. The horizontal axis represents time and the vertical axis represents the magnitude of the signal. In the figure, the solid line 2410 represents the periodic signal generated by the signal generating device 2420, and the dotted 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:

[0158] 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.

[0159] 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:

[0160] 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.

[0161] It should be noted that when testing the vibration of the housing panel and the back of the housing respectively, the state of the test system should be kept consistent as much as possible to avoid inaccurate phase difference calculated later. If the test system generates delay during measurement, it is necessary to compensate for the delay of each measurement result separately, or make the delay of the test system the same when measuring the housing panel and the back of the housing to offset the influence of the delay.

[0162] Fig.26 Another exemplary method of measuring vibration of a bone conduction earphone housing is described. Fig.24 The difference is that Fig.26 The present invention includes two rangefinders 2640 and 2640'. The two rangefinders can simultaneously measure the vibration of the housing panel and the back of the housing of the housing 2610 of the bone conduction earphone, and transmit the first electrical signal and the second electrical signal reflecting the vibration of the housing panel and the back of the housing to the signal testing device 2630 respectively. Similarly, the two rangefinders 2640 and 2640' can be replaced by two microphones respectively.

[0163] Fig. 27 is based on Fig.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:

[0164] 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.

[0165] Embodiment 9

[0166] Fig.28 and Fig.29 An example of a method for measuring vibrations of a bone conduction earphone shell in the presence of an earphone mounting assembly is described.

[0167] Fig.28 and Fig.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 on 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 accordingly.

[0168] Fig.29 and Fig.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 on 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 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 accordingly.

[0169] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0170] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment" and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0171] In addition, those skilled in the art will appreciate that various aspects of the present application may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances or any new and useful improvements thereto. Accordingly, various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0172] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters or other names, are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0173] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0174] In some embodiments, numbers are used to describe the number of components and attributes. It should be understood that such numbers used to describe the embodiments are modified by modifiers such as "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical data used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical data should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and data used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0175] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A bone conduction speaker, characterized in that: include: A magnetic circuit assembly, used for providing a magnetic field; a vibration component, at least a portion of which is located in the magnetic field and converts an electrical signal input to the vibration component into a mechanical vibration signal; a housing, the housing accommodating the vibration assembly and the magnetic circuit assembly; as well as An earphone fixing assembly, the earphone fixing assembly is fixedly connected to the shell and is used to keep the shell in contact with the human body; Wherein, the shell has a shell panel facing the human body, a shell back side opposite to the shell panel, and a shell side surface located between the shell panel and the shell back side, the vibration component causes the shell to vibrate, the vibration of the shell panel has a first phase, the vibration of the shell back side has a second phase, and the overall stiffness of the shell is set so that when the vibration frequency is 1000Hz to 2000Hz or 2000Hz to 3000Hz, the absolute value of the difference between the first phase and the second phase is less than 60 degrees.

2. The bone conduction speaker according to claim 1, characterized in that: The shell panel contacts the human facial skin so that the skin around the shell panel protrudes outward.

3. The bone conduction speaker according to claim 1 or 2, characterized in that: The stiffness of the shell panel, the shell back and the shell side and / or the connection method of the shell panel, the shell back and the shell side are configured so that when the vibration frequency is 1000 Hz to 2000 Hz or 2000 Hz to 3000 Hz, the absolute value of the difference between the first phase and the second phase is less than 60 degrees.

4. The bone conduction speaker according to claim 1 or 2, characterized in that: The vibration of the housing panel has a first amplitude, and the vibration of the back of the housing has a second amplitude. In the frequency range of 1000 Hz to 2000 Hz or 2000 Hz to 3000 Hz, the ratio of the first amplitude to the second amplitude is in the range of 0.5 to 1.

5.

5. The bone conduction speaker according to claim 1 or 2, characterized in that: The vibration of the shell panel generates a first sound leakage wave, and the vibration of the back side of the shell generates a second sound leakage wave. The first sound leakage wave and the second sound leakage wave are superimposed on each other, and the superposition reduces the amplitude of the first sound leakage wave.

6. The bone conduction speaker according to claim 1 or 2, characterized in that: The overall rigidity of the housing is set so that when the vibration frequency is 1000 Hz to 2000 Hz or 2000 Hz to 3000 Hz, the absolute value of the difference between the first phase and the second phase is less than 45 degrees.

7. The bone conduction speaker according to claim 1 or 2, characterized in that: The effective frequency band of the frequency response curve of the bone conduction speaker covers at least 1000Hz to 2000Hz, 500Hz-4000Hz or 500Hz to 6000Hz. In the effective frequency band, there is no peak / valley with a frequency width exceeding 1 / 8 octave, and the peak / valley value exceeds the average vibration intensity by 10db.

8. The bone conduction speaker according to claim 1 or 2, characterized in that: The bone conduction speaker also includes a vibration transmission plate, one end of which is connected to the magnetic circuit assembly, and the other end is connected to the shell. The stiffness of the vibration transmission plate and the headphone fixing assembly is set so that the frequency response curve of the bone conduction speaker has two low-frequency resonance peaks less than 150 Hz.

9. The bone conduction speaker according to claim 1 or 2, characterized in that: The minimum frequency of the high-order mode appearing on the shell panel is not less than 4000 Hz or 6000 Hz.

10. The bone conduction speaker according to claim 1 or 2, characterized in that: The volume of the housing is 400mm 3 -1000mm 3 and / or, The Young's modulus of the material of the shell is between 2 GPa and 3 GPa; and / or, The weight of the shell is less than or equal to 8 grams or 4 grams or 2 grams.

11. The bone conduction speaker according to claim 1 or 2, characterized in that: The shell is a cylinder, the shell panel and the shell back are the upper end face and the lower end face of the cylinder respectively, the shell side is the side of the cylinder, the shell panel and the shell back have the same projected area on the cross section of the cylinder perpendicular to the axis, or the area difference between the shell panel and the shell back does not exceed 30% or 15% or 5% of the area of ​​the shell panel.

12. The bone conduction speaker according to claim 1 or 2, characterized in that: The vibration assembly includes a coil, and both the housing panel and the housing back are caused to vibrate by the coil.

13. A bone conduction headset, characterized in that: Comprising a bone conduction speaker as described in any one of claims 1-12.

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