CN106954152B - bone conduction speaker - Google Patents

Abstract

The invention discloses a bone conduction speaker, comprising an earphone holder/earphone strap and a vibration unit. During use, the earphone holder/earphone strap provides a clamping force between the vibration unit and the user, and the clamping force is 0.2 Between N‑4N. The invention can improve the sound quality of the bone conduction speaker and is comfortable to wear.

Description

bone conduction speaker

technical field

The invention relates to the technical field of bone conduction, in particular to a bone conduction speaker.

Background technique

In general, people can hear sound because the air transmits vibrations to the eardrum through the external ear canal, and the vibration formed by the eardrum drives the human auditory nerve, thereby perceiving the vibration of the sound. When the bone conduction speaker is working, it can usually be transmitted to the human auditory nerve through the human skin, subcutaneous tissue and bones, so that the human can hear the sound.

SUMMARY OF THE INVENTION

The present invention provides a bone conduction speaker, including an earphone holder/earphone strap and a vibration unit. During use, the earphone holder/earphone strap provides a clamping force between the vibration unit and the user, and the clamping force is 0.2N. between -4N. The invention can improve the sound quality of the bone conduction speaker and is comfortable to wear.

Description of drawings

Figure 1 shows the process by which bone conduction speakers cause the human ear to hear.

FIG. 2-A is an outline view of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 2-B is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 2-C is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 3-A is an equivalent vibration model of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 3-B is a vibration response curve of a bone conduction speaker to which the embodiment of the present invention is applied.

4 is a schematic diagram of a bone conduction speaker system for transmitting sound vibrations according to an embodiment of the present invention.

5-A and 5-B are respectively a top view and a side view of a bonding method of a bone conduction speaker panel according to an embodiment of the present invention.

FIG. 6 is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 7 is a vibration response curve of a bone conduction speaker to which the embodiment of the present invention is applied.

FIG. 8 is a vibration response curve of a bone conduction speaker to which the embodiment of the present invention is applied.

FIG. 9 is a structural diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 10 is a frequency response curve of a bone conduction speaker according to an embodiment of the present invention.

FIG. 11 is an equivalent model of a bone conduction speaker vibration generation and transmission system in an embodiment of the present invention.

FIG. 12 is a structural diagram of a bone conduction speaker according to an embodiment of the present invention.

13-A and 13-B are vibration response curves of a bone conduction speaker to which the embodiment of the present invention is applied.

14-A and 14-B are a method for measuring the clamping force of a bone conduction speaker provided in an embodiment of the present invention.

FIG. 14-C is a vibration response curve of a bone conduction speaker to which the embodiment of the present invention is applied.

FIG. 15 is a way of adjusting the clamping force in the embodiment of the present invention.

16-A is a schematic diagram of a contact surface of a vibration unit of a bone conduction speaker according to an embodiment of the present invention.

FIG. 16-B is a vibration response curve of a bone conduction speaker to which the embodiment of the present invention is applied.

FIG. 17 is a schematic diagram of the contact surface of the vibration unit of the bone conduction speaker according to the embodiment of the present invention.

18-A and FIG. 18-B are structural diagrams of a bone conduction speaker and a composite vibration device thereof according to an embodiment of the present invention.

FIG. 19 is a frequency response curve of a bone conduction speaker to which the embodiment of the present invention is applied.

FIG. 20 is a structural diagram of a bone conduction speaker and a composite vibration device thereof according to an embodiment of the present invention.

FIG. 21-A is an equivalent model diagram of a vibration generating part of a bone conduction speaker according to an embodiment of the present invention.

FIG. 21-B is a vibration response curve of a bone conduction speaker applied in a specific embodiment.

FIG. 21-C is a vibration response curve of a bone conduction speaker applied in a specific embodiment.

FIG. 22-A is a structural diagram of a vibration generating part of a bone conduction speaker in a specific embodiment.

FIG. 22-B is a vibration response curve of a vibration generating part of a bone conduction speaker in a specific embodiment.

FIG. 22-C is a sound leakage curve of a bone conduction speaker in a specific embodiment.

FIG. 23 is a structural diagram of a vibration generating part of a bone conduction speaker in a specific embodiment.

FIG. 24-A is an application scenario of a bone conduction speaker in a specific embodiment.

FIG. 24-B is a vibration response curve of the vibration generating part of the bone conduction speaker in a specific embodiment.

FIG. 25 is a structural diagram of a vibration generating portion of a bone conduction speaker in a specific embodiment.

FIG. 26 is a schematic structural diagram of a bone conduction speaker panel in a specific embodiment.

FIG. 27 shows the gradient structure outside the contact surface of the bone conduction speaker in the specific embodiment.

Figures 28-A and 28-B are vibration response curves in specific embodiments.

FIG. 29 shows the gradient structure on the inner side of the contact surface of the bone conduction speaker in the specific embodiment.

Fig. 30 is a structural diagram of a vibration generating part of a bone conduction speaker in a specific embodiment.

Detailed ways

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, not The scope of application of the present invention is limited. For those of ordinary skill in the art, the present invention can be applied to other similar scenarios according to these drawings without creative effort.

As shown in this specification and claims, unless the context clearly dictates otherwise, the words "a", "an", "an" and/or "the" are not intended to be specific in the singular and may include the plural. Generally speaking, the terms "comprising" and "comprising" only imply that the clearly identified steps and elements are included, and these steps and elements do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. The term "based on" is "based at least in part on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions of other terms will be given in the description below.

Hereinafter, without loss of generality, the description of "bone conduction speaker" or "bone conduction earphone" will be used when describing the bone conduction related technology in the present invention. This description is only a form of bone conduction application, and for those of ordinary skill in the art, "speaker" or "earphone" can also be replaced by other similar words, such as "player", "hearing aid" and so on. In fact, the various implementations of the present invention can be easily applied to other non-speaker hearing devices. For example, for those skilled in the art, after understanding the basic principle of bone conduction speakers, it is possible to carry out various forms and details on the specific ways and steps of implementing bone conduction speakers without departing from this principle. Modifications and changes, in particular, adding ambient sound pickup and processing functions to the bone conduction speaker, enabling the speaker to function as a hearing aid. For example, a microphone such as a microphone can pick up the sound of the surrounding environment of the user/wearer, and under a certain algorithm, the sound is processed (or the generated electrical signal) and transmitted to the bone conduction speaker part. That is, the bone conduction speaker can be modified to add the function of picking up the ambient sound, and after a certain signal processing, the sound can be transmitted to the user/wearer through the bone conduction speaker part, so as to realize the function of the bone conduction hearing aid. As an example, the algorithms mentioned here may include noise cancellation, automatic gain control, acoustic feedback suppression, wide dynamic range compression, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active whistling One or more combinations of suppression, volume control, etc.

Bone conduction speakers transmit sound through the bones to the hearing system, creating hearing. Fig. 1 shows the process of hearing the bone conduction speaker, which mainly includes the following steps: in step 101, the bone conduction speaker obtains or generates a signal containing sound information; in step 102, the bone conduction speaker generates vibration according to the signal; in step 103, The vibration is transmitted to the sensing terminal 104 through the transmission system. In a working scenario, bone conduction speakers pick up or generate signals containing sound information, convert the sound information into sound vibrations through a transducer device, and transmit the sound to the sensory organs through a transmission system, and finally hear the sound. Without loss of generality, the subject of the hearing system, sensory organs, etc. described above may be a human being or an animal having a hearing system. It should be noted that the following description of the use of bone conduction speakers by humans does not constitute a limitation on the use scenarios of bone conduction speakers, and similar descriptions can also be applied to other animals.

The above description of the general flow of the bone conduction speaker is only a specific example, and should not be regarded as the only feasible implementation. Obviously, for those skilled in the art, after understanding the basic principle of bone conduction speakers, it is possible to carry out various forms and details on the specific ways and steps of implementing bone conduction speakers without departing from this principle. Modifications and changes, but such modifications and changes are still within the scope of the above description. For example, between the acquisition of the signal containing sound information in step 101 and the generation of vibration in step 102, an additional signal correction or enhancement step may be added, which may enhance or correct the signal acquired in 101 according to a specific algorithm or parameter. Further, between the vibration generating step 102 and the vibration transmitting step 103 , a vibration strengthening or correction step may be additionally added. In this step, the vibration generated in 102 can be enhanced or corrected by using the sound signal of 101 or according to environmental parameters. Similarly, the vibration enhancement or correction step can be completed between steps 103 and 104, such as noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active environment recognition, active anti-noise, directional processing, Tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, or other similar processing, or any combination of the above processing, these modifications and changes are still within the scope of protection of the present invention. The methods and steps described herein may be implemented in any suitable order, where appropriate, or concurrently. Additionally, individual steps may be deleted from any one method without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

Specifically, in step 101, the bone conduction speaker may acquire or generate a signal containing sound information according to different methods. Sound information can refer to video and audio files with a specific data format, or it can also refer to data or files that can carry data or files that can be finally converted into sound through a specific way in a general sense. The signal containing sound information can come from the storage unit of the bone conduction speaker itself, or it can come from an information generation, storage or transmission system other than the bone conduction speaker. The sound signals discussed here are not limited to electrical signals, and may also include other forms other than electrical signals, such as optical signals, magnetic signals, mechanical signals, and the like. In principle, as long as the signal contains sound information that the loudspeaker can use to generate vibrations, it can be processed as a sound signal. The sound signal is also not limited to one source, and can come from multiple sources. These multiple signal sources may or may not be related to each other. The way of transmitting or generating the sound signal can be wired or wireless, real-time or delayed. For example, bone conduction speakers can receive electrical signals containing sound information in a wired or wireless manner, and can also directly obtain data from storage media to generate sound signals; bone conduction hearing aids can be added with sound acquisition components. In the sound, the mechanical vibration of the sound is converted into an electrical signal, and the electrical signal that meets the specific requirements is obtained after processing by the amplifier. Wherein, the wired connection includes but is not limited to the use of metal cables, optical cables or hybrid cables of metal and optics, such as: coaxial cables, communication cables, flexible cables, spiral cables, non-metal sheathed cables, metal sheathed cables, multiple Core Cable, Twisted Pair Cable, Ribbon Cable, Shielded Cable, Telecom Cable, Twisted Cable, Parallel Twin Conductor, and Twisted Pair.

The examples described above are only used for convenience of illustration, and the medium of the wired connection may also be other types, for example, other transmission carriers of electrical signals or optical signals. Wireless connections include, but are not limited to, radio communications, free space optical communications, acoustic communications, and electromagnetic induction, among others. Radio communications include, but are not limited to, IEEE802.11 series standards, IEEE802.15 series standards (such as Bluetooth technology and Zigbee technology, etc.), first-generation mobile communication technologies, and second-generation mobile communication technologies (such as FDMA, TDMA, SDMA, etc.) , CDMA, and SSMA, etc.), general packet radio service technology, third-generation mobile communication technologies (such as CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth-generation mobile communication technologies (such as TD-LTE and FDD-LTE) etc.), satellite communication (such as GPS technology, etc.), near field communication (NFC) and other technologies operating in the ISM frequency band (such as 2.4GHz, etc.); free space optical communication includes but is not limited to visible light, infrared signals, etc.; acoustic communication includes But not limited to sound waves, ultrasonic signals, etc.; electromagnetic induction includes but is not limited to near field communication technology, etc. The examples described above are only for convenience of illustration, and the medium of wireless connection may also be other types, for example, Z-wave technology, other chargeable civil radio frequency bands and military radio frequency bands, and the like. For example, as some application scenarios of this technology, the bone conduction speaker can obtain signals containing sound information from other devices through Bluetooth technology, or directly obtain data from the storage unit built in the bone conduction speaker, and then generate sound signals.

The storage device/storage unit mentioned here includes storage devices on storage systems such as Direct Attached Storage, Network Attached Storage, and Storage Area Network. Storage devices include but are not limited to common types of storage devices such as solid-state storage devices (solid-state drives, solid-state hybrid drives, etc.), mechanical hard drives, USB flash memory, memory sticks, memory cards (such as CF, SD, etc.), other drives (such as CDs, etc.) , DVD, HD DVD, Blu-ray, etc.), random access memory (RAM), and read only memory (ROM). Among them, RAM includes but is not limited to: decimal counter tube, selection tube, delay line memory, Williams tube, dynamic random access memory (DRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), and zero Capacitive random access memory (Z-RAM), etc.; ROM has but is not limited to: magnetic bubble memory, magnetic button wire memory, thin film memory, magnetic plating wire memory, magnetic core memory, magnetic drum memory, optical disk drive, hard disk, magnetic tape, early NVRAM (non-volatile memory), phase change memory, magnetoresistive random access memory, ferroelectric random access memory, non-volatile SRAM, flash memory, electronically erasable rewritable read-only memory, erasable programmable read-only memory Memory, programmable read only memory, shielded heap read memory, floating connection gate random access memory, nano random access memory, racetrack memory, variable resistance memory, and programmable metallization cells, etc. The storage devices/storage units mentioned above are just some examples, and the storage devices that can be used by the storage devices/storage units are not limited thereto.

At 102, the bone conduction speaker can convert the signal containing the acoustic information into vibration and produce sound. The generation of vibration is accompanied by the conversion of energy, and bone conduction speakers can use specific transducer devices to convert signals into mechanical vibrations. The conversion process may involve the coexistence and conversion of many different types of energy. For example, electrical signals can be directly converted into mechanical vibrations through transducer devices, producing sound. For another example, the sound information is contained in the optical signal, and a specific transducer device can realize the process of converting the optical signal into a vibration signal. Other types of energy that can coexist and transform during the operation of the transducer device include thermal energy, magnetic field energy, and the like. The energy conversion method of the transducer device includes, but is not limited to, a moving coil type, an electrostatic type, a piezoelectric type, a moving iron type, a pneumatic type, an electromagnetic type, and the like. The frequency response range and sound quality of bone conduction speakers are affected by the different transduction methods and the performance of the various physical components in the transducing device. For example, in a moving-coil transducer device, the wound cylindrical coil is connected to the vibrating plate, and the coil driven by the signal current drives the vibrating plate to vibrate and sound in the magnetic field. As well as the fixing method, the magnetic density of the permanent magnet, etc., will have a great impact on the final sound quality of the bone conduction speaker. For another example, the vibration plate can be a mirror-symmetric structure, a center-symmetric structure or an asymmetric structure; the vibration plate can be provided with an intermittent hole-like structure, so that the vibration plate can have a greater displacement, so that the bone conduction speaker can achieve better performance. High sensitivity improves the output power of vibration and sound; for another example, the vibration plate is a torus structure, and a plurality of struts converging toward the center are arranged in the torus body, and the number of struts can be two or more.

Obviously, for those skilled in the art, after understanding the basic principle that the transduction method and specific device can affect the sound quality of bone conduction speakers, it is possible to carry out the above-mentioned influencing factors without departing from this principle. Appropriate trade-offs, combinations, corrections or changes to obtain the desired sound quality. For example, the use of permanent magnets with high magnetic density, more ideal vibration plate material and design, can achieve better sound quality.

The term "audio quality" used here can be understood to reflect the quality of the sound, and refers to the fidelity of the audio after processing, transmission and other processes. Sound quality is mainly described by three elements: loudness, pitch and timbre. Loudness is the human ear's subjective perception of sound intensity, which is proportional to the logarithm of the sound intensity. The greater the sound intensity, the louder it sounds. And it is related to the frequency and waveform of the sound. Pitch, also known as pitch, refers to the human ear's subjective perception of the frequency of sound vibration. The pitch mainly depends on the fundamental frequency of the sound. The higher the fundamental frequency, the higher the pitch, and it is also related to the intensity of the sound. Timbre refers to the human ear's subjective perception of the characteristics of a sound. Timbre mainly depends on the spectral structure of the sound, and is also related to factors such as the loudness, duration, establishment process and decay process of the sound. The spectral structure of sound is described by fundamental frequency, number of harmonics, distribution of harmonics, amplitude and phase relationship. Different spectral structures have different timbres. Even if the fundamental frequency and loudness are the same, the timbre will be different if the harmonic structure is different.

There are many ways to realize the vibration of the bone conduction speaker. FIG. 2-A and FIG. 2-B are structural diagrams of the vibration generating part of the bone conduction speaker in a specific embodiment, including the casing 210 , the panel 220 , the transducer device 230 and the connecting piece 240 .

The vibration of the panel 220 is transmitted to the auditory nerve through the tissues and bones, so that the human can hear the sound. The panel 220 may be in direct contact with the human skin, or may be in contact with the skin through a vibration transmission layer (which will be described in detail below) composed of a specific material. The specific materials mentioned here can be selected from low-density materials, such as plastics (such as but not limited to high molecular polyethylene, blow-molded nylon, engineering plastics, etc.), rubber, or other single or composite material. For the type of rubber, such as but not limited to general-purpose rubber and special-purpose rubber. General-purpose rubbers include, but are not limited to, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, neoprene and the like. Special rubber includes but is not limited to nitrile rubber, silicone rubber, fluorine rubber, polysulfide rubber, polyurethane rubber, chlorohydrin rubber, acrylate rubber, propylene oxide rubber, etc. Among them, styrene-butadiene rubber includes but is not limited to emulsion-polymerized styrene-butadiene rubber and solution-polymerized styrene-butadiene rubber. For composite materials, reinforcements such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, fibers, graphene fibers, silicon carbide fibers, or aramid fibers. It can also be a composite of other organic and/or inorganic materials, such as various glass fiber reinforced plastics composed of glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. Other materials that can be used to make the vibration transmission layer also include a combination of one or more of silicone, polyurethane (Poly Urethane), and polycarbonate (Poly Carbonate). The transducer device 230 is a component that realizes the conversion of electrical signals to mechanical vibrations based on certain principles. The panel 220 is connected to the transducer device 230 and vibrates under the drive of the transducer device 230 . A connector 240 connects the panel 220 and the housing 210 for positioning the transducing device 230 in the housing. When the transducer device 230 transmits the vibration to the panel 220, the vibration will be simultaneously transmitted to the casing through the connecting member 240, causing the casing 210 to vibrate, and correspondingly changing the vibration mode of the panel 220, thereby affecting the vibration transmitted by the panel 220 to the human skin.

It should be noted that the way of fixing the transducer device and the panel in the housing is not limited to the connection way described in FIG. 2-B. Obviously, for those skilled in the art, whether to use the connecting piece 240, or to use different materials The formed connecting piece 240, the adjustment method of the transducer device 230 or the connection of the panel 220 to the housing 210, etc., will show different mechanical impedance characteristics, resulting in different vibration transmission effects, thereby affecting the overall vibration efficiency of the vibration system, resulting in different sound quality.

For example, if the connector is not used, the panel can be directly pasted on the casing by glue, or can be connected to the casing by clipping or welding. If the connector is used, the connector with moderate elastic force has the effect of shock absorption in the process of transmitting vibration, which can reduce the vibration energy transmitted to the casing, thereby effectively suppressing the leakage of the bone conduction speaker to the outside caused by the vibration of the casing. It can help to avoid the occurrence of abnormal sound caused by possible abnormal resonance, and achieve the effect of improving the sound quality. Connectors located at different positions in/on the housing also have different effects on the transmission efficiency of vibration. Preferably, the connectors can make the transducer device in different states such as suspension or support.

FIG. 2-B shows an example of a connection method, and the connection member 240 can be connected with the top end of the housing 210 . 2-C is an example of another connection method, the panel 220 protrudes from the opening of the housing 210 , the panel 220 and the transducer device 230 are connected through the connecting part 250 , and are connected with the housing 210 through the connecting piece 240 .

In other embodiments, the transducer device can also be fixed inside the housing in other connection manners, for example, the transducer device can be fixed on the inner bottom surface of the casing through a connecting piece, or the bottom of the transducer device (replacement The side where the energy device is connected to the panel is the top, and the opposite side is the bottom) is suspended and fixed inside the housing by a spring, or the top of the energy converter device can be connected to the shell, or the energy converter device and the shell can pass through A plurality of connectors located at different positions are connected, or any combination of the above connection methods.

In some specific embodiments, the connector has a certain elasticity. The elasticity of the connector is determined by the material, thickness and structure of the connector. For the material of the connector, for example, but 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, blow molding nylon, engineering plastics, etc.), it can also be other single or composite materials that can achieve the same performance. For composite materials, reinforcements such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, or aramid fibers. The material constituting the connector can also be a composite of other organic and/or inorganic materials, such as various types of glass fiber reinforced plastics composed of glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. The thickness of the connecting piece is not less than 0.005mm, preferably, the thickness is 0.005mm-3mm, more preferably, the thickness is 0.01mm-2mm, further preferably, the thickness is 0.01mm-1mm, and further preferably, the thickness is 0.02mm -0.5mm.

The structure of the connecting piece can be set in a ring shape, preferably, it includes at least one ring, preferably at least two rings, which can be concentric rings or non-concentric rings, and at least two rings pass between the rings. The struts are connected, and the struts radiate from the outer ring to the center of the inner ring, further preferably, at least one elliptical ring is included, further preferably, at least two elliptical rings are included, and different elliptical rings have different radii of curvature. The rings are connected by struts, and more preferably, at least one square ring is included. The structure of the connecting piece can also be set in a sheet shape, preferably, a hollow pattern is arranged on the sheet shape, more preferably, the area of the hollow pattern is not smaller than the area of the non-hollow part of the connecting piece. It is worth noting that the materials, thicknesses and structures of the connecting elements in the above description can be combined into different connecting elements in any manner. For example, the annular connector may have different thickness distributions, preferably, the thickness of the strut is equal to the thickness of the ring, more preferably, the thickness of the strut is greater than that of the ring, and further preferably, the thickness of the inner ring is greater than that of the outer ring.

Those of ordinary skill in the art can determine the material, position and connection method of the connector according to different practical applications, or modify, improve or combine the properties of the above-mentioned different connectors, but these modifications and improvements are still described above. within the range. For example, the connector described above is not necessarily necessary, and the panel can be directly mounted on the casing, or can be bonded to the casing by glue. It should be noted that the shape, size, proportion, etc. of the vibration-generating part of the bone conduction speaker in practical applications are not limited to those described in Figure 2-A, Figure 2-B or Figure 2-C. Other factors that may affect the sound quality of the bone conduction speaker, such as the degree of sound leakage of the bone conduction speaker, the generated octave sound, and the way of wearing, etc., can be changed to a certain extent by those skilled in the art according to the content described in the figure.

Careful design and tuning of transducers and panels can solve many of the problems often faced by bone conduction speakers. For example, bone conduction speakers are prone to sound leakage. The sound leakage mentioned here means that during the operation of the bone conduction speaker, the vibration of the speaker will generate sound transmitted to the surrounding environment. In addition to the wearer of the speaker, other people in the environment can also hear the sound from the speaker. . There are many reasons for the sound leakage phenomenon, including the vibration of the transducer device and the panel transmitted to the casing through the connector, causing the vibration of the casing, or the vibration of the transducer device causing the air in the casing to vibrate, and the air vibration is transmitted to the casing to cause the casing to vibrate. resulting in sound leakage. As shown in Figure 3-A, an equivalent vibration model of the vibration generating part of a bone conduction speaker includes a fixed end 301, a casing 311 and a panel 321, and the connection between the fixed end 301 and the casing 311 is equivalent to the elastic body 331 and the damping The housing 311 and the panel 321 are equivalently connected through the elastic body 341 . The fixed end 301 may be a relatively fixed point or a relatively fixed area of the bone conduction speaker during the vibration process (which will be described in detail below). The elastic body 331 and the damping 332 are determined by the connection method between the headphone holder/headphone strap and the shell, and the influencing factors include the stiffness, shape, composition material, etc. of the headphone frame/headphone strap, and the connection between the headphone frame/headphone strap and the shell The material properties of the part. The earphone stand/headphone strap mentioned here provides the contact pressure between the bone conduction speaker and the user. The elastic body 341 is determined by the connection method between the panel 321 (or the system composed of the panel and the transducer device) and the housing 311 , and the influencing factors include the connection member 240 mentioned above. Then the vibration equation can be expressed as:

mx ₂ ″+Rx ₂ ′-k ₁ (x ₁ -x ₂ )+k ₂ x ₂ =0 (1)

Among them, m is the mass of the housing 311, x ₁ is the displacement of the panel 321, x ₂ is the displacement of the housing 311, R is the vibration damping, k ₁ is the stiffness coefficient of the elastic body 341, and k ₂ is the stiffness of the elastic body 331 coefficient. In the case of stable vibration (without considering the transient response), the ratio of the vibration of the enclosure to the vibration of the panel, x ₂ /x ₁ , can be derived:

The ratio of shell vibration to panel vibration x ₂ /x ₁ mentioned here can reflect the sound leakage of bone conduction speakers. In general, the larger the value of x ₂ /x ₁ , the greater the vibration of the housing compared to the effective vibration transmitted to the hearing system, and the greater the sound leakage at the same volume; the greater the value of x ₂ /x ₁ The smaller the value, the smaller the vibration of the housing compared to the effective vibration transmitted to the hearing system, and the smaller the sound leakage at the same volume. It can be seen that the factors affecting the sound leakage of the bone conduction speaker include the connection method between the panel 321 (or the system composed of the panel and the transducer device) and the shell 311 (the stiffness coefficient k ₁ of the elastic body 341 ), the earphone Rack/headphone strap and housing system (k ₂ , R, m), etc. In one embodiment, the stiffness coefficient k ₁ of the elastic body 331 , the housing mass m and the damping R are related to the shape and wearing style of the speaker, and after k ₁ , m, R are determined, x ₂ /x ₁ and the elastic body 341 The relationship between the stiffness coefficient k ₁ is shown in Figure 3-B. As can be seen from the figure, different stiffness coefficients k ₁ will affect the ratio of the vibration amplitude of the casing to the vibration amplitude of the panel, namely x ₂ /x ₁ . When the frequency f is greater than 200Hz, the vibration of the casing is smaller than that of the panel (x ₂ /x ₁ <1), and as the frequency increases, the vibration of the casing gradually becomes smaller. In particular, as shown in Figure 3-B, for different values of k ₁ (from left to right, the stiffness coefficient is set to be 5 times, 10 times, 20 times, 40 times, 80 times and 160 times of k ₂ in turn ), when the frequency is greater than 400Hz, the casing vibration is already less than 1/10 of the panel vibration (x ₂ /x ₁ <0.1). In a specific embodiment, reducing the value of the stiffness coefficient k ₁ (for example, selecting the connecting piece 240 with a small stiffness coefficient) can effectively reduce the vibration of the casing, thereby reducing sound leakage.

In specific embodiments, the use of specific materials and connections for the connectors can reduce sound leakage. For example, connecting the panel, the transducer device and the shell with a certain elastic connector can reduce the vibration amplitude of the shell and reduce sound leakage when the panel vibrates with a relatively large amplitude. There are many materials that can be used to make the connector, including, but not limited to, stainless steel, beryllium copper, plastic (eg, polycarbonate), and the like. The shape of the connector can be set in a variety of ways. For example, the connecting piece can be a ring body, in which at least two struts converge toward the center, the thickness of the ring body is not less than 0.005mm, preferably, the thickness is 0.005mm-3mm, more preferably, The thickness is 0.01mm-2mm, more preferably, the thickness is 0.01mm-1mm, and further preferably, the thickness is 0.02mm-0.5mm. In another example, the connecting member may be a circular ring piece, and the circular ring piece may be further provided with a plurality of rings of discontinuous ring holes, and intermittent intervals are formed between each ring of ring holes. For another example, a certain number of sound-inducing holes that meet certain conditions can be opened on the shell or the panel (or the vibration transmission layer outside the panel, which will be described in detail below), so that the sound wave in the shell can be vibrated during the vibration of the transducer device. It guides and propagates to the outside of the shell, and interacts with the leakage sound waves formed by the vibration of the shell to achieve the effect of suppressing the sound leakage of bone conduction speakers. For another example, a shell made of sound-absorbing material may be selected, or a sound-absorbing material may be used on at least a part of the shell. The sound absorbing material can be applied to one or more of the inner/outer surfaces on the shell, or it can be a portion of an area of one of the inner/outer surfaces of the shell. A sound absorbing material refers to a material that can absorb incident sound energy by means of one or more mechanisms of the material's own physical properties (such as but not limited to porosity), film action, and resonance action. In particular, the sound absorbing material may be a porous material or a material with a porous structure, including but not limited to organic fiber materials (such as, but not limited to, natural plant fibers, organic synthetic fibers, etc.), inorganic fiber materials (such as, but not limited to, glass cotton, slag wool, aluminum silicate wool and rock wool, etc.), metal sound-absorbing materials (such as, but not limited to, metal fiber sound-absorbing panels, foamed metal materials, etc.), rubber sound-absorbing materials, foamed plastic sound-absorbing materials (such as but not limited to not limited to, polyurethane foam, polyvinyl chloride foam, polyacrylate polystyrene foam, phenolic resin foam, etc.), etc.; it can also be a flexible material that absorbs sound through resonance, including but not limited to closed-cell foam; film Materials, including but not limited to plastic film, cloth, canvas, linoleum or artificial leather; board materials, including but not limited to, such as hardboard, gypsum board, plastic board, metal board) or perforated board (such as hole made). The sound absorbing material can be a combination of one or more, or a composite material. The sound absorbing material can be arranged on the shell, or can be respectively arranged on the vibration transmission layer or the shell of the vibration shell.

The shell, the vibration transmission layer and the panel attached to the vibration transmission layer mentioned here together constitute the vibration unit of the bone conduction speaker. The transducer device is located in the vibration unit and transmits the vibration to the vibration unit through the connection to the panel and the housing. Preferably, at least more than 1% of the vibration unit is sound absorbing material, more preferably, at least more than 5% of the vibration unit is sound absorbing material, further preferably, the vibration unit has at least more than 10% sound absorbing material. Preferably, at least more than 5% of the shell is sound absorbing material, more preferably, at least more than 10% of the shell is sound absorbing material, further preferably, more than 40% of the shell is sound absorbing material, still more preferably , at least more than 80% of the shell is sound absorbing material. In a further embodiment, a compensation circuit may be introduced to actively control the sound leakage according to the nature of the sound leakage, so as to generate a reverse signal with an opposite phase to the sound leakage, thereby suppressing the sound leakage. It should be noted that the above-described ways of changing the sound quality of the bone conduction speaker can be selected or used in combination to obtain various embodiments, which are still within the protection scope of the present invention.

The above description of the structure of the vibration generating part of the bone conduction speaker is only a specific example, and should not be regarded as the only feasible implementation. Obviously, for those skilled in the art, after understanding the basic principle, various corrections and changes may be made to the specific structure and connection method for implementing vibration without departing from this principle, but these corrections and changes are still within the scope described above. For example, the connecting part 250 in FIGS. 2-B and 2-C can be a part of the panel 220, which is bonded to the transducer device 230 by glue; it can also be a part of the transducer device 230 (for example, the The protruding part) is bonded to the panel 220 by glue; it can also be an independent component, which is bonded to the panel 220 and the transducer device 230 at the same time by glue. Of course, the connection method between the connection portion 250 and the panel 220 or the transducer device 230 is not limited to bonding, and other connection methods known to those skilled in the art are also applicable to the present invention. Way. Preferably, the panel 220 and the housing 210 can be directly bonded by glue, more preferably, they can be connected by a component similar to the elastic member 240, and further preferably, a vibration transmission layer ( It is connected to the housing 210 in a manner that will be described in detail below. It should be noted that the connection portion 250 is a schematic diagram describing the connection between different components, and those skilled in the art can substitute components with similar functions and different shapes, and these substitutions and changes still fall within the protection scope of the above description.

At step 103, the sound is delivered to the hearing system through the delivery system. The transmission system can directly transmit the sound vibration to the hearing system through a medium, or it can also be transmitted to the hearing system after certain processing during the sound transmission process.

4 is a specific embodiment of a sound transmission system. When the bone conduction speaker in this embodiment is working, the speaker 401 is in contact with parts such as the back of the ear, the cheek or the forehead, etc., and the sound vibration is transmitted to the skin 402 through the subcutaneous tissue 403. , bone 404 is transmitted to the cochlea 405, and finally transmitted to the brain by the cochlear auditory nerve. The sound quality perceived by the human body is affected by the transmission medium and other factors that affect the physical properties of the transmission medium. For example, the density and thickness of the skin and subcutaneous tissue, the shape and density of the bones, and other tissues in the human body that the vibration may pass through during the transmission process will all have an impact on the final sound quality. Further, in the process of vibration transmission, the part of the bone conduction speaker in contact with the human body and the vibration transmission efficiency of human tissue will also affect the final sound effect.

For example, the panel of a bone conduction speaker transmits vibrations through human tissue to the body's hearing system. Changing the panel's material, contact area, shape and/or size, as well as the interaction force between the panel and the skin, can affect how sound passes through the medium. transfer efficiency, thereby affecting sound quality. For example, under the same drive, the vibrations transmitted by panels of different sizes have different distributions on the wearer's fit surface, which in turn will lead to differences in volume and sound quality. Preferably, the area of the panel is not less than 0.15 cm ² , more preferably, the area is not less than 0.5 cm ² , and further preferably, the area is not less than 2 cm ² . For another example, the panel is driven by the transducer device to vibrate, and the bonding point between the panel and the transducer device is at the center of panel vibration. Preferably, the mass distribution of the panel around the vibration center is uniform (that is, the vibration center is the physical center), and more preferably, the mass in the vibration is unevenly distributed around the panel (ie the vibration center is offset from the physical center of the panel). For another example, a vibrating plate can be connected to multiple panels, the shapes and materials between multiple panels can be the same or different from each other, multiple panels can be connected or not connected, and multiple panels use multiple channels to transmit sound and vibration. , the vibration transmission modes between different paths are different from each other, and the positions transmitted to the panels are also different. The vibration signals between different panels can complement each other and generate a relatively flat frequency response. For another example, dividing a large-area vibrating plate into two or more smaller-area vibrating plates can effectively improve the uneven vibration caused by panel deformation at high frequencies, making the frequency response more ideal.

It is worth noting that the physical properties of the panel, such as mass, size, shape, stiffness, vibration damping, etc., can affect the efficiency of panel vibration. Those skilled in the art can select panels made of appropriate materials according to actual needs, or use different molds to inject the panels into different shapes. The shape of the panel can be a figure obtained by cutting the edge of a rectangle, a circle or an ellipse (for example, but not limited to, symmetrically cutting a circle to obtain an oval-like shape, etc.), and further preferably, the panel can be set as hollow of. The panel materials mentioned here include but are not limited to Acrylonitrile butadiene styrene (ABS), Polystyrene (PS), High impact polystyrene (HIPS) , polypropylene (Polypropylene, PP), polyethylene terephthalate (Polyethylene terephthalate, PET), polyester (Polyester, PES), polycarbonate (Polycarbonate, PC), polyamide (Polyamides, PA), poly Polyvinyl chloride (PVC), Polyurethanes (PU), Polyvinylidene chloride (Polyvinylidene chloride), Polyethylene (PE), Polymethyl methacrylate (PMMA), Polyetheretherketone (Polyetheretherketone, PEEK), phenolic resin (Phenolics, PF), urea-formaldehyde (Urea-formaldehyde, UF), melamine-formaldehyde (Melamine formaldehyde, MF) and some metals, alloys (such as aluminum alloys, chromium molybdenum steel, scandium alloys, magnesium alloys, titanium alloys, magnesium-lithium alloys, nickel alloys, etc.) or composite materials. Relevant parameters include the relative density of the material, tensile strength, elastic modulus, Rockwell hardness, etc. Preferably, the relative density of the panel material is 1.02-1.50, more preferably, the relative density is 1.14-1.45, and further preferably, the relative density is 1.15-1.20. The tensile strength of the panel is not less than 30MPa, more preferably, the tensile strength is 33MPa-52MPa, and further preferably, the tensile strength is not less than 60MPa. The elastic modulus of the panel material may be within 1.0GPa-5.0GPa, more preferably, the elastic modulus is within 1.4GPa-3.0GPa, further preferably, the elastic modulus is within 1.8GPa-2.5GPa. Similarly, the hardness (Rockwell hardness) of the panel material may be 60-150, more preferably, the hardness may be 80-120, and further preferably, the hardness may be 90-100. In particular, considering both the panel material and the tensile strength, the relative density can be 1.02-1.1 and the tensile strength is 33MPa-52MPa, more preferably, the relative density of the panel material is 1.20-1.45, and the tensile strength is 56-66MPa .

In some other embodiments, the outer side of the panel of the bone conduction speaker is wrapped with a vibration transmission layer, the vibration transmission layer is in contact with the skin, and the vibration system composed of the panel and the vibration transmission layer transmits the generated sound vibration to human tissue. Preferably, the outer side of the panel is wrapped with a layer of vibration transmission layer, more preferably, the outer side of the panel is wrapped with multiple layers of vibration transmission layer; the vibration transmission layer can be made of one or more materials, and the material composition of different vibration transmission layers can be the same, It can also be different; the multi-layer vibration transmission layers can be superimposed on each other in the vertical direction of the panel, or they can be spread out and arranged in the horizontal direction of the panel, or a combination of the above two arrangements. The area of the vibration transmission layer can be set to different sizes, preferably, the area of the vibration transmission layer is not less than 1 cm ² , more preferably, the area of the vibration transmission layer is not less than 2 cm ² , and further preferably, the area of the vibration transmission layer is not less than 2 cm 2 . less than 6cm ² .

The vibration transmission layer can be composed of materials with certain adsorption, flexibility, and chemical properties, such as plastics (such as but not limited to high molecular polyethylene, blow-molded nylon, engineering plastics, etc.), rubber, or can achieve the same performance. Other single or composite materials. For the type of rubber, such as but not limited to general-purpose rubber and special-purpose rubber. General-purpose rubbers include, but are not limited to, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, neoprene and the like. Special rubber includes but is not limited to nitrile rubber, silicone rubber, fluorine rubber, polysulfide rubber, polyurethane rubber, chlorohydrin rubber, acrylate rubber, propylene oxide rubber, etc. Among them, styrene-butadiene rubber includes but is not limited to emulsion-polymerized styrene-butadiene rubber and solution-polymerized styrene-butadiene rubber. For composite materials, reinforcements such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, fibers, graphene fibers, silicon carbide fibers, or aramid fibers. It can also be a composite of other organic and/or inorganic materials, such as various glass fiber reinforced plastics composed of glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. Other materials that can be used to make the vibration transmission layer also include a combination of one or more of silicone, polyurethane (Poly Urethane), and polycarbonate (Poly Carbonate).

The existence of the vibration transmission layer can affect the frequency response of the system, change the sound quality of the bone conduction speaker, and also protect the components in the shell. For example, the vibration transfer layer can change the way the panel vibrates, making the overall frequency response of the system smoother. The vibration mode of the panel is affected by the properties of the panel itself, the connection method between the panel and the vibration plate, the connection method between the panel and the vibration transmission layer, and the vibration frequency. The properties of the panel itself include, but are not limited to, the mass, size, shape, stiffness, vibration damping, etc. of the panel. Preferably, panels of non-uniform thickness may be employed (eg, but not limited to, the center of the panel being thicker than the edges). The connection method between the panel and the vibration plate includes but is not limited to glue bonding, clamping or welding, etc.; the connection between the panel and the vibration transmission layer includes but is not limited to glue connection; different vibration frequencies will correspond to different vibration modes of the panel, including the overall panel. The choice of panels with specific vibration patterns in specific frequency ranges can change the sound quality of bone conduction speakers. Preferably, the specific frequency range mentioned here may be 20Hz-20000Hz, more preferably, the frequency range may be 400Hz-10000Hz, further preferably, the frequency range may be 500Hz-2000Hz, still further preferably, the frequency range may be 800Hz-1500Hz.

Preferably, the vibration transmission layer described above is wrapped on the outside of the panel and constitutes one side surface of the vibration unit. Different regions on the vibration transmission layer have different transmission effects on vibration. For example, there are a first contact surface area and a second contact surface area on the vibration transmission layer. Preferably, the first contact surface area is not attached to the panel, and the second contact surface area is attached to the panel; more preferably, the vibration transmission layer When in direct or indirect contact with the user, the clamping force on the first contact surface area is smaller than the clamping force on the second contact surface area (the clamping force here refers to the contact surface between the vibration unit and the user). more preferably, the first contact surface area is not in direct contact with the user, and the second contact surface area is in direct contact with the user and transmits vibration. The area size of the first contact surface area is not equal to the area size of the second contact surface area. Preferably, the area of the first contact surface area is smaller than the area of the second contact surface area. holes to further reduce the area of the first contact area; the outer surface of the vibration transmission layer (that is, the surface facing the user) may be flat or uneven, preferably, the first contact surface area and the second contact surface The regions are not on the same plane; more preferably, the second contact surface region is higher than the first contact surface region; further preferably, the second contact surface region and the first contact surface region form a stepped structure; further preferably, the second contact surface region The face area is in contact with the user, and the first contact face area is not in contact with the user. The constituent materials of the first contact surface region and the second contact surface region may be the same or different, and may be a combination of one or more of the materials of the vibration transmission layer described above. The above description of the clamping force on the contact surface is only a manifestation of the present invention. Those skilled in the art can modify the above-described structures and methods according to actual needs, and these modifications are still within the protection scope of the present invention. Inside. For example, the vibration transmission layer may not be necessary, the panel may be in direct contact with the user, and different contact surface areas may be provided on the panel, and the different contact surface areas have the first contact surface area and the second contact surface area described above. nature. For another example, a third contact surface area may be provided on the contact surface, and structures different from the first contact surface area and the second contact surface area may be provided on the third contact surface area, and these structures can reduce housing vibration and suppress leakage. Sound, improve the frequency response curve of the vibration unit and other aspects to obtain a certain effect.

As a specific embodiment, FIGS. 5-A and 5-B are a front view and a side view of the panel and the vibration transmission layer being connected, respectively. The panel 501 and the vibration transmission layer 503 are bonded by glue 502 , and the glue bonding is located at both ends of the panel 501 . Preferably, the projection of the panel 501 on the vibration transmission layer 503 is the second contact surface area, and the area around the second contact surface area is the first contact surface area.

The panel and the vibration transmission layer can be completely pasted with glue, which equivalently changes the quality, size, shape, stiffness, vibration damping, vibration mode and other properties of the panel, and also makes the vibration transmission more efficient; the panel and the transmission layer are It is also possible to only use glue to partially bond, then there is gas conduction in the non-stick area between the panel and the transfer layer, which can enhance the transmission of low-frequency vibration and improve the effect of low-frequency sound. Preferably, the glue area accounts for 1% of the panel area- 98%, more preferably, the glue area accounts for 5%-90% of the panel area, still preferably, the glue area accounts for 10%-60% of the panel area, even more preferably, the glue area accounts for 20%-40% of the panel area %; the panel and the transmission layer can also be bonded without glue, then the vibration transmission efficiency of the panel and the transmission layer is different from the case of using glue to bond, and the sound quality of the bone conduction speaker will also be changed. In a specific embodiment, changing the sticking mode of the glue can change the vibration mode of the corresponding components in the bone conduction speaker, thereby changing the sound generation and transmission effect. Further, the properties of the glue will also affect the sound quality of the bone conduction speaker, such as the hardness, shear strength, tensile strength and ductility of the glue. For example, preferably, the tensile strength of the glue is not less than 1MPa, more preferably, the tensile strength is not less than 2MPa, further preferably, the tensile strength is not less than 5MPa; preferably, the elongation at break of the glue is 100%-500 %, more preferably, the elongation at break is 200%-400%; preferably, the shear strength of the glue is not less than 2MPa, more preferably, the shear strength is not less than 3MPa; 25-30, more preferably 30-50 Shore hardness. One type of glue can be used, or a combination of glues with different properties can be used. The bonding strength between the glue and the panel and between the glue and the plastic can also be set within a certain range, for example, but not limited to, within 8MPa-14MPa. It should be noted that the material of the vibration transmission layer in the embodiment is not limited to silica gel, and plastic, biological material or other materials with certain adsorption, flexibility and chemical properties may also be used. Those skilled in the art can also decide the type and properties of the glue, as well as the panel material and vibration transmission layer material bonded with the glue according to actual needs, to determine the sound quality of the bone conduction speaker to a certain extent.

FIG. 6 is a specific embodiment of the connection mode of each component in the vibration generating part of the bone conduction speaker. The transducer device 610 is connected to the casing 620, the panel 630 and the vibration transmission layer 640 are bonded by glue 650, and the edge of the vibration transmission layer 640 is connected to the casing 620. In different embodiments, the frequency response of the bone conduction speaker can be changed by changing the distribution, hardness or quantity of the glue 650, or changing the hardness of the transmission layer 640, etc., thereby changing the sound quality. Preferably, glue may not be applied between the panel and the vibration transmission layer, more preferably, glue may be applied between the panel and the vibration transmission layer, further preferably, glue is applied to a part of the area between the panel and the vibration transmission layer, still further preferably, the panel The area where the glue is applied between the vibration transmission layer and the vibration transmission layer should not be larger than the area of the panel.

Those skilled in the art can decide the quantity of glue selected according to actual needs, so as to achieve the effect of adjusting the sound quality of the speaker. As shown in FIG. 7 , in one embodiment, the effects of different glue connection methods on the frequency response of the bone conduction speaker are reflected. The three curves correspond to the frequency responses of no vibration transmission layer and glue, no glue applied between the vibration transmission layer and the panel, and full glue between the vibration transmission layer and the panel. It can be seen that when a small amount of glue or no glue is applied between the vibration transmission layer and the panel, the resonant frequency of the bone conduction speaker will shift to low frequencies compared to the case of full glue. The bonding between the vibration transmission layer and the panel through glue can reflect the influence of the vibration transmission layer on the vibration system. Therefore, changing the bonding method of the glue can significantly change the frequency response curve of the bone conduction speaker.

Personnel in the field can adjust and improve the bonding method and quantity of glue according to the actual frequency response requirements, thereby improving the sound quality of the system. Similarly, in another embodiment, FIG. 8 reflects the effect of the stiffness of different vibration transmission layers on the vibration response curve. The solid line is the vibration response curve corresponding to the bone conduction speaker using a harder transmission layer, and the dotted line is the vibration response curve corresponding to the bone conduction speaker using a softer transmission layer. It can be seen that the use of vibration transmission layers with different hardness can make the bone conduction speaker obtain different frequency responses. The greater the hardness of the vibration transmission layer, the stronger the ability to transmit high frequency vibration; the smaller the hardness of the vibration transmission layer, the stronger the ability to transmit low frequency vibration. Different sound quality can be obtained by selecting the vibration transmission layer of different materials (not limited to silica gel, plastic, etc.). For example, a vibration transmission layer made of 45-degree silicone on bone conduction speakers can achieve better bass effects, and a vibration transmission layer made of 75-degree silicone can achieve better treble effects. The low frequency mentioned here refers to the sound less than 500Hz, the intermediate frequency refers to the sound in the range of 500Hz-4000Hz, and the high frequency refers to the sound greater than 4000Hz.

Of course, the above description of the glue and the vibration transmission layer is only an example that can affect the sound quality of the bone conduction speaker, and should not be regarded as the only feasible implementation. Obviously, for professionals in the field, after understanding the basic principles that affect the sound quality of bone conduction speakers, it is possible to adjust and adjust the various components and connection methods in the vibration generating part of the bone conduction speakers without departing from this principle. changes, but these adjustments and changes are still within the scope of protection described above. For example, the material of the vibration transmission layer can be arbitrary, and can also be customized according to the user's usage habits. The use of glues with different hardness after curing between the vibration transmission layer and the panel may also have an impact on the sound quality of bone conduction speakers. In addition, increasing the thickness of the vibration transmission layer can be equivalent to increasing the mass in the composed vibration system, and can also achieve the effect of decreasing the resonance frequency of the system. Preferably, the thickness of the transfer layer is 0.1mm-10mm, more preferably, the thickness is 0.3mm-5mm, further preferably, the thickness is 0.5mm-3mm, and further preferably, the thickness is 1mm-2mm. The tensile strength, viscosity, hardness, tear strength, elongation, etc. of the transfer layer will also affect the sound quality of the system. The tensile strength of the transmission layer material refers to the force required in a unit range when the transmission layer sample is torn, preferably, the tensile strength is 3.0MPa-13MPa, more preferably, the tensile strength is 4.0MPa-12.5MPa, Further preferably, the tensile strength is 8.7MPa-12MPa. Preferably, the shore hardness of the transfer layer is 5-90, more preferably, the shore hardness is 10-80, and further preferably, the shore hardness is 20-60. The elongation of the transmission layer refers to the percentage that the transmission layer increases relative to the original length when it breaks, preferably, the elongation is between 90% and 1200%, and more preferably, the elongation is between 160% and 700%. , and further preferably, the elongation is between 300% and 900%. The tear strength of the transmission layer refers to the resistance to the expansion of the incision or score when a force is applied to the notched transmission layer, preferably, the tear strength is between 7kN/m-70kN/m, more preferably, tearing The strength is between 11kN/m-55kN/m, further preferably, the tear strength is between 17kN/m-47kN/m.

In the vibration system composed of the panel and the vibration transmission layer described above, in addition to changing the physical properties of the panel and the transmission layer, as well as the bonding method between the panel and the vibration transmission layer, the performance of the bone conduction speaker can also be changed from other aspects.

A well-designed vibration-generating part containing a vibration-transmitting layer can further effectively reduce the sound leakage of bone conduction speakers. Preferably, perforating the surface of the vibration transmission layer can reduce sound leakage. An example is shown in FIG. 9 , the vibration transmission layer 940 is bonded to the panel 930 through glue 950, and the bonding area on the vibration transmission layer with the panel is more convex than the non-bonded area on the vibration transmission layer 940. Below the area is a cavity. The non-adhesive area on the vibration transmission layer 940 and the surface of the casing 920 are respectively provided with sound-inducing holes 960 . Preferably, the non-adhesive area where part of the sound-inducing hole is opened is not in contact with the user. On the one hand, the sound hole 960 can effectively reduce the area of the non-bonded area on the vibration transmission layer 940, which can make the air inside and outside the vibration transmission layer transparent, reduce the difference in air pressure inside and outside, thereby reducing the vibration of the non-bonded area; In one aspect, the sound-inducing holes 960 can lead the sound waves formed by the vibration of the air inside the casing 920 to the outside of the casing 920, and cancel the sound leakage sound waves formed by the vibration of the casing 920 pushing the air outside the casing, so as to reduce the amplitude of the sound leakage sound waves. Specifically, the sound leakage of a bone conduction speaker at any point in space is proportional to the sound pressure P at that point,

in,

P=P ₀ +P ₁ +P ₂ (3)

P ₀ is the sound pressure generated by the casing (including the part of the vibration transmission layer that does not contact the skin) at the above point, P ₁ is the sound pressure at the above point of the sound transmitted by the sound holes on the side of the casing, and P ₂ is the vibration The sound pressure of the sound transmitted by the sound introduction holes on the transmission layer at the above points, P ₀ , P ₁ , and P ₂ are respectively:

Among them, k is the wave vector, ρ ₀ is the air density, ω is the angular frequency of vibration, R(x', y') is the distance from a point on the sound source to a point in space, and S ₀ is the shell that is not in contact with the face Area, S ₁ is the opening area of the sound introduction hole on the side of the shell, S ₂ is the opening area of the sound introduction hole on the vibration transmission layer, W(x, y) represents the sound source intensity per unit area, It represents the phase difference of the sound pressure generated by different sound sources at a point in space. It is worth noting that there are some areas on the vibration transmission layer that are not in contact with the skin (for example, in FIG. 9 , the edge area where the sound introduction holes 960 on the vibration transmission layer 940 are located), which are affected by the vibration of the panel and the casing In order to generate vibration and radiate sound to the outside world, the above-mentioned outer shell area should include the part of the vibration transmission layer that is not in contact with the skin. The sound pressure at any point in space (when the angular frequency is ω) can be expressed as:

Our goal is to reduce the value of P as much as possible, so as to achieve the effect of reducing sound leakage. In actual use, the coefficients A1 and A2 can be adjusted by adjusting the size and number of the sound holes, and the phase can be adjusted by adjusting the position of the sound holes. value of . After understanding the principle that the vibration system composed of the panel, the transducer device, the vibration transmission layer and the shell will affect the sound quality of the bone conduction speaker, those skilled in the art can adjust the shape, opening position, number and size of the sound introduction hole according to the actual needs. And the damping on the hole, etc., so as to achieve the purpose of suppressing sound leakage. For example, there may be one or more sound introduction holes, preferably more than one. For the sound introduction holes arranged annularly on the side of the housing, the number of sound introduction holes in each layout area may be one or more, for example, 4-8. The shape of the sound introduction hole can be circular, oval, rectangular or elongated. The sound introduction holes on a bone conduction speaker can be sound introduction holes with the same shape, or a combination of sound introduction holes with different shapes. For example, different shapes and numbers of sound-inducing holes are arranged on the vibration transmission layer and the side of the casing, and the number density of the sound-inducing holes on the vibration-transmitting layer is greater than the number density of the sound-inducing holes on the side of the casing. For another example, arranging a plurality of small holes on the vibration transmission layer can effectively reduce the area of the part of the vibration transmission layer that is not in contact with the skin, thereby reducing the sound leakage generated by this part. For another example, adding damping material or sound absorbing material to the sound-inducing hole on the side of the vibration transmission layer/shell can further strengthen the purpose of suppressing sound leakage. Further, the sound-inducing holes can be expanded into other materials or structures that facilitate the conduction of air vibrations in the housing out of the housing. For example, using phase adjustment material (such as but not limited to sound absorbing material) as part of the material of the housing, so that the phase of the air vibration it conducts is in the range of 90° to 270° with the vibration phase of other parts of the housing, so as to play a role in the sound phase. elimination effect. The description about the arrangement of the sound-inducing holes in the shell appears in the Chinese patent application No. 201410005804.0 filed on January 6, 2014, entitled "A method for suppressing sound leakage of a bone conduction speaker and a bone conduction speaker", the full text of the patent document Cited here as a reference. Further, by adjusting the connection mode between the transducer device and the casing, the phase of the vibration of other parts of the casing can be changed, and the phase difference between the sound and the sound conducted by the sound-inducing hole can be within the range of 90° to 270°, So as to play the role of sound cancellation. For example, an elastic connector is used between the transducer device and the housing, and the material of the connector, such as but 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, etc.) copper, magnesium alloy, titanium alloy, etc.), plastics (such as but not limited to high molecular polyethylene, blow-molded nylon, engineering plastics, etc.), or other single or composite materials that can achieve the same performance. For composite materials, reinforcements such as, but not limited to, glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, or aramid fibers. The material constituting the connector can also be a composite of other organic and/or inorganic materials, such as various types of glass fiber reinforced plastics composed of glass fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix. The thickness of the connecting piece is not less than 0.005mm, preferably, the thickness is 0.005mm-3mm, more preferably, the thickness is 0.01mm-2mm, further preferably, the thickness is 0.01mm-1mm, and further preferably, the thickness is 0.02mm -0.5mm. The structure of the connecting piece can be set in a ring shape, preferably, it includes at least one ring, preferably at least two rings, which can be concentric rings or non-concentric rings, and at least two rings pass between the rings. The struts are connected, and the struts radiate from the outer ring to the center of the inner ring, further preferably, at least one elliptical ring is included, further preferably, at least two elliptical rings are included, and different elliptical rings have different radii of curvature. The rings are connected by struts, and more preferably, at least one square ring is included. The structure of the connecting piece can also be set in a sheet shape, preferably, a hollow pattern is arranged on the sheet shape, more preferably, the area of the hollow pattern is not smaller than the area of the non-hollow part of the connecting piece. It is worth noting that the materials, thicknesses and structures of the connecting elements in the above description can be combined into different connecting elements in any manner. For example, the annular connector may have different thickness distributions, preferably, the thickness of the strut is equal to the thickness of the ring, more preferably, the thickness of the strut is greater than that of the ring, and further preferably, the thickness of the inner ring is greater than that of the outer ring.

The above description of the sound absorption hole is an embodiment of the present invention, and does not constitute a limitation on improving sound quality and suppressing sound leakage of bone conduction speakers. Corrections and improvements, which remain within the scope of the protection described above. For example, preferably, the sound-inducing holes are only opened on the vibration transmission layer, more preferably, the sound-inducing holes only start in the area where the vibration transmission layer does not overlap with the panel, and further preferably, the sound-inducing holes are opened so as not to be in contact with the user Preferably, the sound-inducing hole is opened in a cavity inside the vibration unit. For another example, the sound-inducing holes can also be opened on the bottom wall of the casing, and the number of sound-inducing holes opened in the bottom wall can be one, arranged in the center of the bottom wall, or more than one, arranged in a ring-shaped circumference around the center of the bottom wall. to a uniform distribution. For another example, the sound-inducing holes may be opened on the side wall of the casing, and the number of sound-inducing holes opened on the side wall of the casing may be one or more, which are evenly distributed in the circumferential direction.

The above description of the vibration transfer of bone conduction speakers is only a specific example and should not be considered as the only possible implementation. Obviously, for professionals in the field, after understanding the basic principle of bone conduction speakers, it is possible to make various corrections and changes in the form and details of the vibration description of bone conduction speakers without departing from this principle. , but these modifications and changes are still within the scope of the above description. For example, the use of implantable bone conduction hearing aids can be directly attached to the bones of the human body, and the sound vibration can be directly transmitted to the bones without going through the skin or subcutaneous tissue, which can avoid the vibration transmission process by the skin or subcutaneous tissue to a certain extent. Attenuation and change in frequency response. For another example, in some applications, the conduction part can be teeth, that is, the bone conduction device can be fitted on the teeth, and the sound vibration can be transmitted to the bones and surrounding tissues through the teeth, and it can also reduce the impact of the skin on the vibration process to a certain extent. The effect of frequency response. The introduction of bone conduction application scenarios above is only for descriptive purposes. After understanding the basic principles of bone conduction, those skilled in the art can apply bone conduction technology in different scenarios. Partial variations of the delivery routes described above are still within the scope of protection described above.

In step 104, the sound quality perceived by the human body is also related to the human body's hearing system, and different groups of people may have different degrees of sensitivity to sounds in different frequency ranges. In some embodiments, the sensitivity of the human body to sounds of different frequencies can be reflected by an equal loudness curve. Some people are not sensitive to the sound in a specific frequency range in the sound signal, so the response strength of the corresponding frequency on the equal-loudness curve is lower than the response strength of other frequencies. For example, some people are not sensitive to high-frequency sound signals, that is, on the equal-loudness curve, the intensity response of the corresponding high-frequency signal is lower than that of other frequencies; On the equal-loudness curve, the intensity response of the corresponding mid-low frequency signal is lower than that at other frequencies. The low frequency mentioned here refers to the sound less than 500Hz, the intermediate frequency refers to the sound in the range of 500Hz-4000Hz, and the high frequency refers to the sound greater than 4000Hz.

Of course, the low frequency and high frequency of the sound can be relative. According to the different responses of the hearing system of some special people to the sound in different frequency ranges, the intensity of the sound produced by the bone conduction speaker can be selectively changed or adjusted in the corresponding frequency range. Distribution can enable corresponding groups of people to obtain different sound experiences. It is worth noting that the high frequency, medium frequency or low frequency part of the sound signal discussed above can be a description of the corresponding part within the hearing range of a normal human ear, or a description of the corresponding part within the natural sound range to be expressed by the speaker. .

In one embodiment, the equal loudness curve of the hearing system of some groups of people is shown as curve 3 in FIG. 10 , a peak appears near the frequency of point A, indicating that the group is more sensitive to the sound of the frequency near point A than other frequency points (point B in the figure). When designing bone conduction loudspeakers, it is possible to compensate for insensitive frequency parts in the human hearing system. Curve 4 in the figure is a bone conduction speaker frequency response curve correspondingly compensated for hearing curve 3, and there is a resonance peak near the frequency of point B. Combined with the equal loudness curve 3 when the human ear receives the sound and the frequency response curve 4 generated by the bone conduction speaker, the final sound heard by the human body is more ideal and the sound experience is broader. As a specific example, the frequency of point A can be selected to be about 500 Hz, and the frequency of point B can be selected to be about 2000 Hz. It should be noted that the above examples of corresponding frequency compensation for bone conduction speakers should not be regarded as the only feasible implementation. Those skilled in the art can set appropriate peak values for practical application scenarios after understanding the principle. value and compensation method.

Obviously, for those skilled in the art, after understanding the relevant basic principles, various modifications and changes in form and details may be made to the specific manner and selection of implementing bone conduction speakers without departing from this principle. , but these modifications and changes are still within the scope of the above description. For example, bone conduction hearing aids are also applicable to the above method of frequency response compensation for bone conduction speakers, that is, the frequency response characteristics of one or more hearing aids can be designed according to the hearing response curve of hearing-impaired people to compensate for its possible performance. The resulting insensitivity to a specific frequency range, in practical applications, bone conduction hearing aids can be intelligently selected or the frequency response can be adjusted according to the user's input information. For example, the system automatically obtains or the user inputs its own equal loudness curve, and adjusts the frequency response of the bone conduction speaker according to the curve to compensate for the sound of a specific frequency. In one embodiment, for a point with relatively low loudness on the equal-loudness curve (for example, a minimum point on the curve), the frequency response amplitude of the bone conduction speaker near the frequency corresponding to the point can be increased, thereby obtaining an ideal sound quality. Similarly, for a point with relatively high loudness on the equal-loudness curve (for example, a maximum point on the curve), the frequency response amplitude of the bone conduction speaker near the frequency corresponding to the point can be reduced. Further, there may be multiple maximum points or minimum points on the frequency response curve described above or the equal-loudness curve of the human ear, and the corresponding compensation curve (frequency response curve) may also correspond to multiple maximum values or extreme points. small value. For those skilled in the art, in the above description of the sensitivity of human hearing, "equal loudness curve" can be replaced by similar words, for example, "equal loudness curve", "hearing response curve" and so on. In fact, the human body's sensitivity to hearing can also be regarded as a frequency response of sound. In the description of various embodiments of the present invention, the human body's sensitivity to sound and the frequency response of bone conduction speakers are combined to finally reflect the bone Conductive speaker sound quality.

Under normal circumstances, the sound quality of bone conduction speakers is affected by the physical properties of the components of the speaker itself, the vibration transmission relationship between the components, the vibration transmission relationship between the speaker and the outside world, and the efficiency of the vibration transmission system in transmitting vibration. factor. The components of the bone conduction speaker itself include components that generate vibration (such as but not limited to transducer devices), components that fix the speaker (such as but not limited to earphone racks/headphone straps), and components that transmit vibration (such as but not limited to panels). , vibration transmission layer, etc.). The vibration transmission relationship between the components and the vibration transmission relationship between the speaker and the outside world are determined by the contact method between the speaker and the user (such as but not limited to clamping force, contact area, contact shape, etc.). As shown in FIG. 11, an equivalent schematic diagram of a vibration generation and transmission system of a bone conduction speaker, including an equivalent system of a bone conduction speaker including a fixed end 1101, a sensing terminal 1102, a vibration unit 1103, and a transducer device 1104. The fixed end 1101 is connected to the vibration unit 1103 through the transmission relationship K1 (k ₄ in FIG. 11 ), the sensing terminal 1102 is connected to the vibration unit 1103 through the transmission relationship K2 (R ₃ , k ₃ in FIG. 11 ), and the vibration unit 1103 passes through The transfer relationship K3 (R ₄ , k ₅ in FIG. 11 ) is connected to the transducer device 1104 .

The vibrating unit mentioned here is a vibrating body composed of a panel and a transducer device, and the transfer relationships K1, K2 and K3 are descriptions of the action relationship between the corresponding parts in the equivalent system of the bone conduction speaker (will be described in detail below). The vibration equation of the equivalent system can be expressed as:

m ₃ x″ ₃ +R ₃ x′ ₃ -R ₄ x′ ₄ +(k ₃ +k ₄ )x ₃ +k ₅ (x ₃ -x ₄ )=f ₃ (8)

m ₄ x″ ₄ +R ₄ x″ ₄ -k ₅ (x ₃ -x ₄ )=f ₄ (9)

where m ₃ is the equivalent mass of the vibration unit 1103 , m ₄ is the equivalent mass of the transducer device 1104 , x ₃ is the equivalent displacement of the vibration unit 1103 , x ₄ is the equivalent displacement of the transducer device 1104 , and k ₃ is the equivalent elastic coefficient between the sensing terminal 1102 and the vibration unit 1103, k ₄ is the equivalent elastic coefficient between the fixed end 1101 and the vibration unit 1103, k ₅ is the equivalent elastic coefficient between the transducer device 1104 and the vibration unit 1103, etc. effective elastic coefficient, _R3 is the equivalent damping between the sensing terminal 1102 and the vibration unit 1103, R4 is the equivalent damping between the transducer device ₁₁₀₄ and the vibration unit 1103, _f3 and _f4 are the vibration unit 1103, respectively and the interaction force between the transducer device 1104. The equivalent amplitude A3 _of the vibrating element in the system is:

Among them, f ₀ represents the unit driving force, and ω represents the vibration frequency. It can be seen that the factors affecting the frequency response of the bone conduction speaker include the vibration generating parts (such as but not limited to the vibration unit, the transducer device, the casing and the interconnection method, such as m ₃ , m ₄ , k ₅ in formula (10), R ₄ , etc.), vibration transmission part (for example, but not limited to, the way of contact with the skin, the properties of the earphone stand/headphone strap, such as k ₃ , k ₄ , R ₃ in formula (10), etc.). Change the structure of each part of the bone conduction speaker and the parameters of the connection between the components, for example, changing the magnitude of the clamping force is equivalent to changing the size of k ₄ , changing the bonding method of the glue is equivalent to changing the size of R ₄ and k ₅ , Changing the hardness, elasticity, damping, etc. of the relevant materials is equivalent to changing the size of _k3 and _R3 , which can change the frequency response and sound quality of bone conduction speakers.

In a specific embodiment, the fixed end 1101 may be a relatively fixed point or a relatively fixed area of the bone conduction speaker during the vibration process, and these points or areas may be regarded as the fixed end of the bone conduction speaker during the vibration process , the fixed end can be composed of specific components, or it can be a position determined according to the overall structure of the bone conduction speaker. For example, the bone conduction speaker can be suspended, bonded or adsorbed near the human ear through a specific device, and the structure and shape of the bone conduction speaker can also be designed so that the bone conduction part can stick to the human skin.

The sensing terminal 1102 is the hearing system for the human body to receive sound signals, and the vibration unit 1103 is the part of the bone conduction speaker used to protect, support, and connect the transducer device, including the vibration transmission layer or panel that transmits the vibration to the user and uses. Parts that are in direct or indirect contact with other vibration generators, as well as housings that protect and support other vibration-generating components. The transducer device 1104 is a sound vibration generating device, which can be one or a combination of the transducer devices discussed above.

The transmission relationship K1 connects the fixed end 1101 and the vibration unit 1103, and represents the vibration transmission relationship between the vibration generating part and the fixed end of the bone conduction speaker during operation, and K1 depends on the shape and structure of the bone conduction device. For example, the bone conduction speaker can be fixed on the human head in the form of a U-shaped headphone stand/headphone strap, or it can be installed on helmets, fire masks or other special-purpose masks, glasses and other equipment. The shape of different bone conduction speakers Both the structure and the structure will have an impact on the vibration transfer relationship K1. Further, the structure of the speaker also includes physical properties such as the constituent materials and quality of different parts of the bone conduction speaker. The transfer relationship K2 connects the sensing terminal 1102 and the vibration unit 1103 .

K2 depends on the composition of the transmission system, including but not limited to the transmission of sound vibrations through the user's tissue to the hearing system. For example, when sound is transmitted to the hearing system through skin, subcutaneous tissue, bone, etc., the physical properties and interconnection of different human tissues will affect K2. Further, the vibration unit 1103 is in contact with human tissue. In different embodiments, the contact surface on the vibration unit may be a vibration transmission layer or a side surface of the panel. The surface shape, size, and interaction between the contact surface and human tissue Force, etc. will affect the transfer coefficient K2.

The transmission relationship K3 between the vibration unit 1103 and the transducer device 1104 is determined by the connection properties inside the vibration generating device of the bone conduction speaker. The relative position between the two will change the transmission efficiency of the transducer device to transmit the vibration to the vibration unit, especially the panel, thereby affecting the transmission relationship K3.

During the use of bone conduction speakers, the generation and transmission of sound will affect the final sound quality experienced by the human body. For example, the above-mentioned fixed end, human sensory terminal, vibration unit, transducer device, and transmission relationships K1, K2, and K3, etc., may all have an impact on the sound quality of the bone conduction speaker. It should be noted that K1, K2, and K3 here are only a representation of the connection methods of different device parts or systems involved in the vibration transmission process, which may include but are not limited to physical connection methods, force transmission methods, and sound transmission efficiency. Wait.

The above description of the equivalent system of a bone conduction speaker is only a specific example and should not be considered as the only possible implementation. Obviously, for professionals in the field, after understanding the basic principle of bone conduction speakers, it is possible to carry out formal and detailed analysis of the specific methods and steps that affect the vibration transmission of bone conduction speakers without departing from this principle. Various modifications and changes, but still within the scope of the above description. For example, K1, K2, and K3 described above can be simple vibration or mechanical transmission methods, or can include complex nonlinear transmission systems. The transmission relationship can be formed by direct connection of various parts, or it can be carried out in a non-contact way. transfer.

In a specific embodiment, the structure of the bone conduction speaker is shown in FIG. 12 , including an earphone stand/earphone strap 1201 , a vibration unit 1202 and a transducer device 1203 . The vibration unit 1202 includes a contact surface 1202a, a housing 1202b, and the transducer device 1203 is located inside and connected to the vibration unit 1202. Preferably, the vibration unit 1202 includes the above-described panel and the vibration transmission layer, and the contact surface 1202a is the surface of the vibration unit 1202 in contact with the user, preferably, the outer surface of the vibration transmission layer.

During use, the headphone stand/headphone strap 1201 fixes the bone conduction speaker to a specific part of the user (eg, the head), providing a clamping force between the vibration unit 1202 and the user. The contact surface 1202a is connected to the transducer device 1203 and keeps in contact with the user, and transmits the sound to the user through vibration. The fixed end 1101 shown in FIG. 11 can be approximately selected as a relatively fixed point when the bone conduction speaker works. If the bone conduction speaker has a symmetrical structure, and it is assumed that the driving forces provided by the transducers on both sides are equal in magnitude and opposite in direction during the working process, the center point on the headphone stand/headphone strap can be selected as the equivalent fixed end, such as shown in 1204. Position; if the bone conduction speaker can provide stereo sound, that is, the instantaneous driving force provided by the two transducers is not equal, or the bone conduction speaker has asymmetry in structure, you can choose the headphone stand/headphone strap or the headphone Other points or areas other than the stand/headphone strap are used as equivalent fixed ends. The fixed end mentioned here can be regarded as the equivalent end of the bone conduction speaker whose position is relatively fixed in the process of generating vibration. The fixed end 1101 and the vibration unit 1202 are connected through the earphone stand/headphone hanging strap 1201, and the transmission relation K1 is related to the clamping force provided by the earphone holder/headphone hanging strap 1201 and the earphone holder/headphone hanging strap 1201, which depends on the The physical properties of the headphone strap 1201. Preferably, changing the physical quantities such as the clamping force provided by the headphone stand/headphone strap and the quality of the headphone frame/headphone strap can change the sound transmission efficiency of the bone conduction speaker and affect the frequency response of the system in a specific frequency range. For example, a headphone stand/headphone strap made of a stronger material will provide a different clamping force than a headphone holder/headphone strap made of a lower strength material, or the Structure, adding an auxiliary device that can provide elastic force to the headphone holder/headphone strap can also change the clamping force, thereby affecting the sound transmission efficiency; changes in the size of the headphone holder/headphone strap will also affect the clamping force. Size, the clamping force increases with the increase of the distance between the vibration units at both ends of the headphone stand/headphone strap.

In order to obtain the earphone stand/headphone strap that meets the specific clamping force conditions, those skilled in the art can select materials with different rigidity and different modulus to make the earphone stand/headphone strap or adjust the earphone stand/headphone according to the actual situation. The size and size of the lanyard. It should be noted that the clamping force of the headphone stand/headphone strap will not only affect the sound transmission efficiency, but also affect the user's sound experience in the bass frequency range. The clamping force mentioned here is the pressure between the contact surface and the user, preferably, the clamping force is between 0.1N-5N, more preferably, the clamping force is between 0.2N-4N, further preferably, The clamping force is between 0.2N-3N, more preferably, the clamping force is between 0.2N-1.5N, and still more preferably, the clamping force is between 0.3N-1.5N.

The material of the headphone holder/headphone strap can determine the amount of clamping force. Preferably, the material of the earphone stand/earphone strap can be selected from plastic with a certain hardness. For example but not limited to Acrylonitrile butadiene styrene (ABS), Polystyrene (PS), High impact polystyrene (HIPS), Polypropylene (Polypropylene, PP), Polyethylene terephthalate (PET), Polyester (PES), Polycarbonate (PC), Polyamide (Polyamides, PA), Polyvinyl chloride (Polyvinyl chloride, PVC), Polyurethanes (PU), Polyvinylidene chloride (Polyvinylidene chloride), Polyethylene (PE), Polymethyl methacrylate (PMMA), Polyetheretherketone (PEEK), Phenolics (PF), urea-formaldehyde (UF), melamine-formaldehyde (MF), etc. More preferably, the materials constituting the earphone stand/earphone strap may include some metals, alloys (such as aluminum alloys, chrome-molybdenum steels, scandium alloys, magnesium alloys, titanium alloys, magnesium-lithium alloys, nickel alloys, etc.) or composite materials, etc. . Further preferably, the material of the earphone stand/earphone strap can be selected from a material with memory function. Memory materials include but are not limited to memory alloy materials, polymer memory materials, inorganic non-memory materials, and the like. Memory alloys include but are not limited to titanium-nickel-copper memory alloys, titanium-nickel-iron memory alloys, titanium-nickel-chromium memory alloys, copper-nickel memory alloys, copper-aluminum memory alloys, copper-zinc memory alloys, iron memory alloys, and the like. Polymer memory materials include but are not limited to polynorbornene, trans-polyisoprene, styrene-butadiene copolymer, cross-linked polyethylene, polyurethane, polylactone, fluoropolymer, polyamide, Cross-linked polyolefins, polyesters, etc. Inorganic non-memory materials include, but are not limited to, memory ceramics, memory glass, garnet, mica, and the like. Further preferably, the memory material of the earphone stand/headphone strap has a selected memory temperature, preferably, the memory temperature can be selected to be not lower than 10°C, more preferably, the memory temperature is selected to be not lower than 40°C, further preferably Preferably, the memory temperature is selected to be not lower than 60°C, and further preferably, the memory temperature is selected to be not lower than 100°C. The proportion of the memory material in the earphone stand/earphone strap material is not less than 5%, preferably, the proportion is not less than 7%, more preferably, the proportion is not less than 15%, and further preferably, the proportion is not less than 30%, more preferably, the ratio is not less than 50%. The headphone stand/headphone hanging strap mentioned here refers to the rear hanging structure that generates the clamping force of the bone conduction speaker. The memory material is located at different positions of the headphone rack/headphone strap, preferably, the memory material is located at a stress concentration position on the headphone rack/headphone strap, such as but not limited to the connection part of the headphone rack/headphone strap and the vibration unit, the headphone rack / Near the symmetrical center of the headphone strap or the position where the lines in the headphone stand/headphone strap are densely distributed, etc. In one embodiment, a memory alloy is used to make an earphone stand/an earphone strap, which provides a small difference in the clamping force for user heads of different sizes, so that the wearing consistency is higher, and the sound quality affected by the clamping force is improved. Consistency is also higher. In another embodiment, the earphone holder/earphone hanger made of memory alloy has good elasticity, can normally return to the original shape after being subjected to large deformation, and can still be stably deformed after a long time. Maintain the size of the clamping force. In another embodiment, the earphone holder/rear hanging earphone made of memory alloy is light in weight and can provide deformation with a greater degree of freedom, so that it can better fit the user.

The clamping force provides pressure between the contact surface of the vibration generating portion of the bone conduction speaker and the user. 13-A and 13-B are vibration response curves of a bone conduction speaker under different pressures between the contact surface and the user in one embodiment. In the process of vibration transmission, it is not conducive to the transmission of medium frequency and high frequency vibration when the clamping force is lower than a certain threshold. As shown in (a), for the same vibration source (sound source), when the clamping force is 0.1N, the mid-frequency and high-frequency parts of the vibration (sound) received by the wearer are significantly less than the clamping force of 0.2N And the vibration (sound) received at 1.5N, that is, in terms of sound quality, when the clamping force is 0.1N, the performance of the intermediate frequency and high frequency parts is weaker than that when the clamping force is 0.2N-1.5N. At the same time, in this embodiment, the clamping force of 0.1N can just ensure that the bone conduction earphone is worn on the user without falling off. Similarly, in the process of vibration transmission, when the clamping force is greater than a certain threshold, it is not conducive to the transmission of low-frequency vibrations. As shown in (b), for the same vibration source (sound source), when the clamping force is 5.0N, the low-frequency part of the vibration (sound) received by the wearer is significantly less than when the clamping force is 0.2N and 1.5N The received vibration (sound), that is, in terms of sound quality, when the clamping force is 5.0N, the low-frequency part is weaker than that when the clamping force is 0.2N-1.5N. Meanwhile, in this embodiment, the clamping force of 5.0N makes the user feel obvious pain.

In a specific embodiment, the pressure between the contact surface and the user is maintained within an appropriate range by selecting appropriate earphone holder/headphone hanging strap materials and setting appropriate earphone holder/headphone hanging strap results. The pressure between the contact surface and the user is greater than a certain threshold, preferably, the threshold is 0.1N, more preferably, the threshold is 0.2N, further preferably, the threshold is 0.3N, and still preferably, the threshold is 0.5N. The pressure between the contact surface and the user is less than another threshold, preferably, the threshold is 5.0N, more preferably, the threshold is 4N, further preferably, the threshold is 3N, and still preferably, the threshold is 1.5N . After understanding the basic principle that the clamping force of the bone conduction speaker changes the frequency response of the bone conduction system, those skilled in the art can set the Clamping force range to meet different sound quality requirements, and these modifications and substitutions are still within the scope of this specification.

The clamping force of bone conduction speakers can be measured by specific equipment or methods. Figures 14-A and 14-B are a specific embodiment of measuring the clamping force of a bone conduction speaker. Point A and point B are two points on the earphone stand/earphone strap of the bone conduction speaker in this embodiment, which are close to the vibration unit. During the test, fix point A or point B, and connect the other point to the dynamometer. When the distance L between point A and point B is between 125mm and 155mm, the clamping force is measured. Figure 14-C is a frequency vibration response curve of a bone conduction speaker under different clamping force states. The clamping forces corresponding to the three curves are 0N, 0.61N and 1.05N respectively. Figure 14-C shows that with the increase of the clamping force of the bone conduction speaker, the load generated by the human face on the vibration unit of the bone conduction speaker (for example, the panel, the vibration transmission layer connected to the panel, etc.) will increase accordingly, and the vibration surface vibration will be attenuated. If the clamping force is too small or too large, the frequency response of the bone conduction speaker will be greatly uneven during the vibration process (such as the range of 500Hz-800Hz on the curve of the clamping force of 0N and 1.05N). If the clamping force is too large (such as the corresponding curve when the clamping force is 1.05N), the wearer will feel uncomfortable, and the vibration of the speaker will become weaker and the sound will become smaller; if the clamping force is too small (such as the clamping force The curve corresponding to 0N), the wearer will feel a more obvious vibration.

It should be noted that the above description of the method of changing the clamping force of the bone conduction speaker is only a specific example, and should not be regarded as the only feasible implementation. Obviously, for professionals in the field, after understanding the basic principle of bone conduction speakers, it is possible to change the clamping force of bone conduction speakers for different shapes and structures of bone conduction speakers without departing from this principle. changes in the manner described above, but these changes are still within the scope of the above description. For example, the bone conduction speaker stand can use materials with memory function (such as memory metal), which can adjust the opening arc according to the head shape of the person, and has good elasticity, which can maximize the wearing comfort and adjust the clamping. strength. Further, an elastic bandage 1501 for adjusting the clamping force can be installed on the bone conduction speaker frame, as shown in FIG. Provides additional resilience.

The transmission relationship K2 between the sensing terminal 1102 and the vibration unit 1103 also affects the frequency response of the bone conduction system. The sound heard by the human ear depends on the energy received by the cochlea, which is affected by different physical quantities during the transmission process, which can be expressed by the following formula:

P=∫∫ _S α·f(a,R)·L·ds (11)

Among them, P is proportional to the energy received by the cochlea, S is the contact area between the contact surface and the face, α is a dimensional transformation coefficient, f(a, R) represents the acceleration a of a point on the contact surface and the contact surface and the skin The influence of the tightness of contact R on energy transfer, L is the impedance of mechanical wave transmission at any contact point, that is, the transmission impedance per unit area.

It can be seen from (11) that the transmission of sound is affected by the transmission impedance L, the vibration transmission efficiency of the bone conduction system is related to L, and the frequency response curve of the bone conduction system is the superposition of the frequency response curves of each point on the contact surface. Without loss of generality, when describing the structure of the contact surface of the bone conduction system, the term "contact surface" can be the surface that is at least partially in direct or indirect contact with the user, or the surface that is at least partially in direct or indirect contact with the user. , with a "contact layer" of a certain thickness. Factors that change the impedance include the size, shape, roughness, force size or force distribution of the energy transfer area. For example, by changing the structure and shape of the vibration unit 1202, the transmission effect of sound can be changed, thereby changing the sound quality of the bone conduction speaker. Just as an example, changing the corresponding physical properties of the contact surface 1202a of the vibration unit 1202 can achieve the effect of changing the sound transmission.

A well-designed interface surface is provided with a gradient structure, which refers to regions of the interface surface where there is a high degree of variation. The gradient structure can be a convex/concave or stepped structure that exists on the outside of the contact surface (the side that fits the user), or it can be a convex/concave structure that exists on the inside of the contact surface (the side facing away from the user). Concave or stepped structures. An embodiment of the vibration unit of a bone conduction speaker is shown in FIG. 16-A, and the contact surface 1601 (outside of the contact surface) has a convex or concave (not shown in FIG. 16-A) portion. During the operation of the bone conduction speaker, the convex or concave part is in contact with the skin of the human face, changing the pressure when different positions on the contact surface 1601 are in contact with the human face. The convex part is in closer contact with the human face, and the skin and subcutaneous tissue in contact with it are subject to greater pressure than other parts; correspondingly, the skin and subcutaneous tissue in contact with the concave part are subject to less pressure than other parts. For example, there are three points A, B, and C on the contact surface 1601 in FIG. 16-A, which are respectively located on the non-convex part, the edge of the convex part and the convex part of the contact surface 1601. In the process of contacting with the skin, the magnitude of the clamping force on the skin at the three points A, B, and C is F _C > F _A > F _B . In some embodiments, the magnitude of the clamping force at point B is zero, that is, point B is not in contact with the skin. Human facial skin and subcutaneous tissue exhibit different impedances and responses to sound under different pressures. The high-pressure part has a small impedance ratio, which has a high-pass filtering characteristic for sound waves, and the low-pressure part has a large impedance ratio and a low-pass filtering characteristic. The impedance characteristic L of each part of the contact surface 1601 is different. According to formula (11), different parts have different responses to the frequency of sound transmission. The effect of sound transmission through the full contact surface is equivalent to the sum of the sound transmission of each part, and finally the sound is transmitted to the brain. A smooth frequency response curve is formed, avoiding the appearance of excessive resonance peaks at low frequencies or high frequencies, so as to obtain an ideal frequency response within the entire audio bandwidth. Similarly, the material and thickness of the contact surface 1601 will also affect the transmission of sound, thereby affecting the sound quality. For example, when the contact surface material is soft, the sound wave transmission effect in the low frequency range is better than that in the high frequency range. When the contact surface material is hard, the sound wave transmission effect in the high frequency range is better than that in the low frequency range.

Figure 16-B shows the frequency response of bone conduction speakers with different contact surfaces. The dashed line corresponds to the frequency response of the bone conduction speaker with raised structures on the contact surface, and the solid line corresponds to the frequency response of the bone conduction speaker without raised structures on the contact surface. In the mid-low frequency range, the vibration of the non-convex structure is significantly weakened compared with the vibration of the convex structure, and a "deep pit" is formed on the frequency response curve, which shows a less than ideal frequency response, thus affecting bone conduction. the sound quality of the speakers.

The above description of FIG. 16-B is only an explanation for a specific example. For those skilled in the art, after understanding the basic principles affecting the frequency response of the bone conduction speaker, the structure and components of the bone conduction speaker can be carried out in various ways. Corrections and changes to obtain different frequency response effects.

It should be noted that, for those skilled in the art, the shape and structure of the contact surface 1601 are not limited to the above description, and may also meet other specific requirements. For example, the convex or concave parts of the contact surface can be distributed on the edge of the contact surface, and can also be distributed in the middle part of the contact surface. The contact surface may contain one or more raised or recessed portions, and the raised and recessed portions may be distributed on the contact surface at the same time. The material of the convex or concave part of the contact surface can be different from the material of the contact surface, it can be flexible, rigid, or more suitable for producing a specific pressure gradient; it can be a memory material, or It is a non-memory material; it can be a single-property material or a composite material. The structure patterns of the convex or concave portion of the contact surface include, but are not limited to, axisymmetric patterns, centrosymmetric patterns, rotationally symmetric patterns, asymmetric patterns, and the like. The structure pattern of the convex or concave part of the contact surface can be one kind of pattern, or it can be a combination of two or more kinds of patterns. The contact surface includes, but is not limited to, having a certain degree of smoothness, roughness, waviness, and the like. The position distribution of the convex or concave portion of the contact surface includes, but is not limited to, axisymmetric, centrosymmetric, rotationally symmetrical, asymmetrical distribution, and the like. The convex or concave part of the contact surface can be at the edge of the contact surface, or can be distributed inside the contact surface.

1704-1711 in FIG. 17 are specific embodiments of the contact surface structure described above.

Among them, 1704 in the figure is an example in which the contact surface includes a plurality of protrusions with similar shapes and structures. The protrusions may be constructed of the same or similar material as the rest of the panel, or a different material than the rest of the panel. In particular, the protrusions may be composed of a memory material and a vibration transmission layer material, wherein the proportion of the memory material is not less than 10%, and preferably, the proportion of the memory material in the protrusions is not less than 50%. The area of a single protrusion accounts for 1%-80% of the total area, preferably, the proportion of the total area is 5%-70%, and more preferably, the proportion of the total area is 8%-40%. The total area of all protrusions accounts for 5%-80% of the total area, preferably, the ratio is 10%-60%. There may be at least one protrusion, preferably, there are one protrusion, more preferably, there are two protrusions, and further preferably, there are at least five protrusions. The shape of the bulge can be a circle, an ellipse, a triangle, a rectangle, a trapezoid, an irregular polygon, or other similar figures, wherein the structure of the bulge part can be symmetrical or asymmetrical, and the position distribution of the bulge part can also be Symmetrical or asymmetrical, the number of raised portions may be one or more, the heights of raised portions may be the same or different, and the height and distribution of raised portions may form a certain gradient.

Shown at 1705 in the figure is an example in which the structure of the raised portion of the contact surface is a combination of two or more patterns, wherein the number of projections of different patterns may be one or more. The two or more protruding shapes can be any two or a combination of two or more of circles, ovals, triangles, rectangles, trapezoids, irregular polygons, or other similar shapes. The material, number, area, symmetry, etc. of the protrusions are similar to 1704 in the figure.

1706 in the figure is an example in which the raised parts of the contact surface are distributed on the edge and inside of the contact surface, wherein the number of raised parts is not limited to what is shown in the figure. The number of protrusions located at the edge of the contact surface accounts for 1%-80% of the total number of protrusions, preferably, the ratio is 5%-70%, more preferably, the ratio is 10%-50%, further preferably, the The ratio is 30%-40%. The material, number, area, shape, symmetry, etc. of the protrusions are similar to 1704 in the figure.

1707 in the figure is a structure pattern of the concave part of the contact surface. The structure of the concave part can be symmetrical or asymmetrical, the position distribution of the concave part can also be symmetrical or asymmetrical, and the number of the concave part can be One or more, the shape of the concave portion may be the same or different, and the concave portion may be hollowed out. The area of a single depression accounts for 1%-80% of the total area, preferably, the proportion of the total area is 5%-70%, and more preferably, the proportion of the total area is 8%-40%. The total area of all depressions accounts for 5%-80% of the total area, preferably, the proportion is 10%-60%. There may be at least one depression, preferably, there are 1 depression, more preferably, there are 2 depressions, and further preferably, there are at least 5 depressions. The concave shape may be a circle, an ellipse, a triangle, a rectangle, a trapezoid, an irregular polygon, or other similar shapes.

1708 in the figure is an example in which the contact surface has both a convex part and a concave part, and the number of the convex part and the concave part is not limited to one or more. The ratio of the number of depressions to the number of protrusions is 0.1-100, preferably, the ratio is 1-80, more preferably, the ratio is 5-60, further preferably, the ratio is 10-20. The material, area, shape, symmetry, etc. of a single protrusion/recess is similar to 1704 in the figure.

1709 in the figure is an example where the contact surface has a certain waviness. The corrugations are arranged by two or more protrusions/concavities or a combination of two, preferably, the distances between adjacent protrusions/concavities are equal, and more preferably, the distances between the protrusions/concavities are equal. arrangement.

1710 in the figure is an example in which there is a larger area of protrusion on the contact surface. The raised area accounts for 30%-80% of the total contact surface area. Preferably, a portion of the edge of the protrusion and a portion of the edge of the contact surface are substantially in contact with each other.

1711 in the figure is a contact surface with a first protrusion with a larger area, and a second protrusion with a smaller area on the first protrusion. The larger-area protrusions account for 30%-80% of the total area of the contact surface, and the smaller-area protrusions account for 1%-30% of the total contact surface area, preferably, the ratio is 5%-20%. The smaller area occupies 5%-80% of the larger area, preferably, the proportion is 10%-30%.

The above description of the contact surface structure of the bone conduction speaker is only a specific example, and should not be regarded as the only feasible implementation. Obviously, for professionals in the field, after understanding the basic principle that the structure of the contact surface of the bone conduction speaker affects the sound quality of the bone conduction speaker, it is possible to implement the specific implementation of the contact surface of the bone conduction speaker without departing from this principle. Various modifications and changes in form and detail, but still within the scope of the above description. For example, the number of protrusions or depressions is not limited to that shown in FIG. 17 , and the above-described protrusions, depressions or surface patterns of the contact surface may be modified to some extent, and these modifications are still within the protection scope described above. . Moreover, the contact surfaces of at least one or more vibration units included in the bone conduction speaker can use the same or different shapes and materials as above, and the vibration effects transmitted on different contact surfaces will also vary with the properties of the contact surfaces. Get different sound effects.

It can be seen from FIG. 11 that the vibration mode of the transducer device 1104 in the bone conduction speaker vibration system and the way K3 connected to the vibration unit 1103 will also affect the sound effect of the system. Preferably, the transducer device includes a vibrating plate, a vibrating plate, a set of coils and a magnetic circuit system, and more preferably, the transducer device includes a composite vibration device composed of a plurality of vibrating plates and vibrating plates. The frequency response of the sound produced by the system is affected by the physical properties of the vibrating plate and the vibration transmission plate. Selecting the size, shape, material, thickness and vibration transmission method of the specific vibration plate and vibration transmission plate can produce sound effects that meet the actual requirements.

An example of a composite vibration device is shown in Figure 18-A and Figure 18-B, including: a composite vibration component composed of a vibration transmission sheet 1801 and a vibration plate 1802, the vibration transmission sheet 1801 is set as a first annular body 1813 , and three first support rods 1814 converge toward the center are arranged in the first annular body, and the center position of the convergent center is fixed with the center of the vibration plate 1802 . The center of the vibration plate 1802 is the groove 1820 that matches the center of the vergence and the first support rod. The vibrating plate 1802 is provided with a second annular body 1821 having a radius different from that of the vibration transmission sheet 1801, and three second struts 1822 having different thicknesses from the first struts 1814. The first support rod 1814 and the second support rod 1822 are staggered, and may be, but not limited to, at an angle of 60 degrees.

The above-mentioned first and second support rods can be straight rods or other shapes that meet specific requirements. aspect requirements. The vibration transmission sheet 1801 has a thin thickness and can increase the elastic force, and the vibration transmission sheet 1801 is stuck in the center of the groove 1820 of the vibration plate 1802 . A voice coil 1808 is provided on the lower side of the second annular body 1821 adhered to the vibration plate 1802 . The composite vibration device also includes a bottom plate 1812, on which a ring magnet 1810 is arranged, and an inner magnet 1811 is arranged concentrically in the ring magnet 1810; an inner magnetic conducting plate 1809 is arranged on the top surface of the inner magnet 1811, and at the same time An annular magnetic conducting plate 1807 is arranged on the annular magnet 1810 , a washer 1806 is fixed above the annular magnetic conducting plate 1807 , and the first annular body 1813 of the vibration transmission plate 1801 is fixedly connected to the washer 1806 . The entire composite vibration device is connected to the outside through a panel 1830 , the panel 1830 is fastened to the center of the vergence of the vibration-transmitting sheet 1801 , and fixed at the center of the vibration-transmitting sheet 1801 and the vibrating plate 1802 .

Using a composite vibration device composed of a vibrating plate and a vibrating plate, the frequency response shown in Figure 19 is obtained. Two resonance peaks are generated by the double composite vibration. By adjusting the parameters such as the size and material of the two components, the resonance is The peak moves, the resonance peak of low frequency moves to lower frequency, and the resonance peak of high frequency moves to higher frequency. Preferably, the stiffness coefficient of the vibration plate is greater than that of the vibration transmission sheet. Finally, it can be fitted to the dashed frequency response curve shown in Figure 19, that is, a flat frequency response in an ideal state. The range of these resonance peaks can be set within the frequency range of the sound audible to the human ear, or Not therein, preferably, neither of the two resonant peaks are in the frequency range of the audible sound; more preferably, one resonant peak is in the frequency range of the audible sound by the human ear, and the other resonant peak is in the outside the frequency range of the sound audible to the human ear; more preferably, both resonance peaks are within the frequency range of the sound audible to the human ear; and even more preferably, both resonance peaks are within the human ear audible frequency range Within the frequency range of the heard sound, and its peak frequency is between 80Hz-18000Hz; more preferably, the two resonance peaks are within the frequency range of the sound audible to the human ear, and its peak value is between 200Hz-15000Hz more preferably, the two resonance peaks are in the frequency range of the sound that can be heard by the human ear, and the peak value thereof is between 500Hz-12000Hz; even more preferably, the two resonance peaks are both within the human ear can reach. The frequency range of the sound, and its peak value is between 800Hz-11000Hz. Preferably, the frequencies of the peaks of the resonance peaks can have a certain difference. For example, the peaks of the two resonance peaks are different by at least 500 Hz; preferably, the peaks of the two resonance peaks are different by at least 1000 Hz; more preferably, the peaks of the two resonance peaks are different. At least 2000 Hz; even more preferably, the peaks of the two resonance peaks differ by at least 5000 Hz. In order to achieve a better effect, the two resonant peaks may both be within the audible range of the human ear, and the peak frequencies of the resonant peaks may differ by at least 500 Hz; preferably, the two resonant peaks may both be within the audible range of the human ear, The peaks of the two resonant peaks differ by at least 1000 Hz; further preferably, the two resonant peaks may both be within the audible range of the human ear, and the peaks of the two resonant peaks differ by at least 2000 Hz; and still further preferably, the two resonant peaks Both can be within the audible range of the human ear, and the difference between the peaks of the two resonance peaks is at least 3000 Hz; it is further preferable that the two resonance peaks can both be within the audible range of the human ear, and the peaks of the two resonance peaks are different from each other. At least 4000Hz. One of the two resonant peaks may be within the audible range of the human ear, and the other may be outside the audible range of the human ear, and the peak frequencies of the two resonant peaks differ by at least 500 Hz; preferably, one resonant peak is audible to the human ear Within the range, the other is outside the audible range of the human ear, and the peak frequencies of the two resonant peaks differ by at least 1000 Hz; more preferably, one resonant peak is within the audible range of the human ear, and the other is audible to the human ear. outside the range, and the peak frequencies of the two resonant peaks differ by at least 2000 Hz; further preferably, one resonant peak is within the audible range of the human ear, the other is outside the audible range of the human ear, and the peaks of the two resonant peaks The frequencies differ by at least 3000 Hz; further preferably, one resonant peak is within the audible range of the human ear and the other is outside the audible range of the human ear, and the peak frequencies of the two resonant peaks differ by at least 4000 Hz. The two resonant peaks can both be between the frequencies 5Hz-30000Hz, and the peak frequencies of the two resonant peaks differ by at least 400Hz; preferably, the two resonant peaks can both be between the frequencies 5Hz-30000Hz, and the peak values of the two resonant peaks The frequencies differ by at least 1000Hz; more preferably, the two resonance peaks can both be at frequencies of 5Hz-30000Hz, and the peak frequencies of the two resonance peaks can be different by at least 2000Hz; further preferably, both resonance peaks can be at frequencies of 5Hz-30000Hz and the peak frequencies of the two resonant peaks differ by at least 3000 Hz; further preferably, the two resonant peaks can both be in the frequency range of 5 Hz-30000 Hz, and the peak frequencies of the two resonant peaks differ by at least 4000 Hz. The two resonant peaks may both be in the frequency range of 20Hz-20000Hz, and the peak frequencies of the two resonant peaks may differ by at least 400Hz; The frequencies differ by at least 1000Hz; more preferably, the two resonance peaks may both be at frequencies of 20Hz-20000Hz, and the peak frequencies of the two resonance peaks may be different by at least 2000Hz; further preferably, both resonance peaks may be at frequencies of 20Hz-20000Hz and the peak frequencies of the two resonant peaks differ by at least 3000 Hz; further preferably, the two resonant peaks may both have frequencies between 20 Hz and 20000 Hz, and the peak frequencies of the two resonant peaks differ by at least 4000 Hz. The two resonant peaks may both be in the frequency range of 100Hz-18000Hz, and the peak frequencies of the two resonant peaks may differ by at least 400Hz; The frequencies differ by at least 1000Hz; more preferably, the two resonance peaks may both be at frequencies of 100Hz-18000Hz, and the peak frequencies of the two resonance peaks may be at least 2000Hz apart; further preferably, both resonance peaks may be at frequencies of 100Hz-18000Hz and the peak frequencies of the two resonant peaks differ by at least 3000 Hz; further preferably, the two resonant peaks may both be in the frequency range of 100 Hz-18000 Hz, and the peak frequencies of the two resonant peaks differ by at least 4000 Hz. The two resonant peaks may both be in the frequency range of 200Hz-12000Hz, and the peak frequencies of the two resonant peaks may differ by at least 400Hz; The frequencies differ by at least 1000Hz; more preferably, the two resonance peaks may both be at frequencies of 200Hz-12000Hz, and the peak frequencies of the two resonance peaks may be at least 2000Hz apart; further preferably, both resonance peaks may be at frequencies of 200Hz-12000Hz and the peak frequencies of the two resonant peaks differ by at least 3000 Hz; further preferably, the two resonant peaks may both have frequencies between 200 Hz and 12000 Hz, and the peak frequencies of the two resonant peaks differ by at least 4000 Hz. The two resonant peaks may both be in the frequency range of 500Hz-10000Hz, and the peak frequencies of the two resonant peaks may differ by at least 400Hz; The frequencies differ by at least 1000Hz; more preferably, the two resonance peaks may both be at frequencies of 500Hz-10000Hz, and the peak frequencies of the two resonance peaks may be different by at least 2000Hz; further preferably, both resonance peaks may be at frequencies of 500Hz-10000Hz and the peak frequencies of the two resonant peaks differ by at least 3000 Hz; further preferably, the two resonant peaks may both be in the frequency range of 500 Hz-10000 Hz, and the peak frequencies of the two resonant peaks differ by at least 4000 Hz. In this way, the resonant response range of the loudspeaker is widened, and the sound quality that meets the conditions is obtained. It is worth noting that in the actual use process, multiple vibration transmission sheets and vibration plates can be set to form a multi-layer vibration structure, corresponding to different frequency response ranges, to achieve full-range full-frequency response high-quality speaker vibration, or Make the frequency response curve meet the usage requirements in some specific frequency range. For example, in bone conduction hearing aids, in order to meet normal hearing requirements, a transducer device composed of one or more vibration plates and vibration transmission sheets with a resonance frequency in the range of 100Hz-10000Hz can be selected. The description of the composite vibration device composed of the vibration plate and the vibration transmission sheet appears in the patent application entitled "A Bone Conduction Speaker and Its Composite Vibration Device" disclosed in Chinese Patent Application No. 201110438083.9 filed on December 23, 2011 , the entirety of this patent document is incorporated herein by reference.

As shown in FIG. 20, in another embodiment, the vibration system includes a vibration plate 2002, a first vibration transmission plate 2003 and a second vibration transmission plate 2001, and the first vibration transmission plate 2003 connects the vibration plate 2002 and the second vibration transmission plate 2001. The vibration plate 2001 is fixed on the housing 2019, and the composite vibration system composed of the vibration plate 2002, the first vibration transmission plate 2003 and the second vibration transmission plate 2001 can generate no less than two resonance peaks, which are generated within the audible range of the hearing system. Flatter frequency response curve to improve the sound quality of bone conduction speakers. The equivalent model of the vibration system is shown in Figure 21-A:

Among them, 2101 is the casing, 2102 is the panel, 2103 is the voice coil, 2104 is the magnetic circuit vibration, 2105 is the first vibration transmission plate, 2106 is the second vibration transmission plate, 2107 is the vibration plate, wherein the first vibration transmission plate, Both the second vibration transmission piece and the vibration plate are abstracted into elements with elasticity and damping, and the shell, the panel, the voice coil and the magnetic circuit system can all be abstracted into an equivalent mass block. The vibration equation of the system can be expressed as:

m ₆ x″ ₆ +R ₆ (x ₆ -x ₅ )′+k ₆ (x ₆ -x ₅ )=F (12)

m ₇ x″ ₇ +R ₇ (x ₇ -x ₅ )′+k ₇ (x ₇ -x ₅ )=-F (13)

m ₅ x″ ₅ -R ₆ (x ₆ -x ₅ )'-R ₇ (x ₇ -x ₅ )'+R ₈ x' ₅ +k ₈ x ₅ -k ₆ (x ₆ -x ₅ )-k ₇ (x ₇ -x ₅ ) = 0 (14)

where F is the driving force, k ₆ is the equivalent stiffness coefficient of the second vibration transmission sheet, k ₇ is the equivalent stiffness coefficient of the vibration plate, k ₈ is the equivalent stiffness coefficient of the first vibration transmission sheet, R ₆ is the equivalent damping of the second vibration transmission piece, _R7 is the equivalent damping of the vibration plate, _R8 is the equivalent damping of the first vibration transmission piece, _m5 is the mass of the panel, _m6 is the mass of the magnetic circuit system, m ₇ is the voice coil mass, x ₅ is the panel displacement, x ₆ is the magnetic circuit system displacement, and x ₇ is the voice coil displacement. Then it can be concluded that the amplitude of the panel 2102 is:

where ω is the angular frequency of vibration and f ₀ is the unit driving force.

The vibration system of the bone conduction speaker transmits the vibration to the user through the panel. According to formula (15), the vibration efficiency of the system is related to the stiffness coefficient and vibration damping of the vibration plate, the first vibration transmission sheet, and the second vibration transmission sheet. Preferably, the stiffness coefficient k ₇ of the vibration plate is greater than the second vibration coefficient k ₆ , and the stiffness coefficient k ₇ of the vibration plate is greater than the first vibration coefficient k ₈ . Wherein, the number of resonance peaks generated by the triple composite vibration system with the first vibration transmission plate is more than the resonance peak generated by the composite vibration system without the first vibration transmission plate, preferably, there are at least three resonance peaks; more preferably, at least A resonant peak is not within the audible range of the human ear; more preferably, the resonant peaks are all within the audible range of the human ear; further preferably, the resonant peaks are all within the audible range of the human ear , and its peak frequency is not higher than 18000Hz; further preferably, the resonance peaks are all within the frequency range of the sound audible to the human ear, and its peak value is between 100Hz-15000Hz; further preferably, the resonance peaks are all within The frequency range of the sound that can be heard by the human ear, and its peak value is between 200Hz-12000Hz; more preferably, the resonance peaks are all within the frequency range of the sound that can be heard by the human ear, and its peak value is between 500Hz-11000Hz . The frequencies of the peaks of the resonant peaks preferably have a certain difference, for example, there are at least two resonant peaks whose peaks differ by at least 200 Hz; preferably, there are at least two resonant peaks whose peaks differ by at least 500 Hz; more preferably, there are at least two The peaks of the resonant peaks differ by at least 1000 Hz; further preferably, there are at least two resonant peaks that differ by at least 2000 Hz; still further preferably, there are at least two resonant peaks that differ by at least 5000 Hz. In order to achieve a better effect, the resonant peaks can all be within the audible range of the human ear, and there are at least two resonant peaks whose peak frequencies differ by at least 500 Hz; preferably, the resonant peaks can all be within the audible range of the human ear, There are at least two resonance peaks whose peaks differ by at least 1000 Hz; more preferably, the resonance peaks can both be within the audible range of the human ear, and there are at least two resonance peaks whose peaks differ by at least 1000 Hz; further preferably, the resonance peaks can be both Within the audible range of the human ear, there are at least two resonant peaks whose peaks differ by at least 2000 Hz; and further preferably, the resonant peaks may all be within the human audible range, and there are at least two resonant peaks whose peaks differ by at least 2000 Hz. 3000 Hz; further preferably, the resonant peaks can all be within the audible range of the human ear, and there are at least two resonant peaks whose peaks differ by at least 4000 Hz. Two of the resonant peaks may be within the audible range of the human ear, and the other may be outside the audible range of the human ear, and there are at least two resonant peaks whose peak frequencies differ by at least 500 Hz; preferably, the two resonant peaks are within the human audible range. Within the audible range of the ear, another resonant peak is outside the audible range of the human ear, and there are at least two resonant peaks whose peak frequencies differ by at least 1000 Hz; more preferably, the two resonant peaks are within the audible range of the human ear , the other is outside the audible range of the human ear, and there are at least two resonance peaks whose peak frequencies differ by at least 2000 Hz; further preferably, the two resonance peaks are within the audible range of the human ear, and the other is within the audible range of the human ear. outside the range, and there are at least two resonance peaks whose peak frequencies differ by at least 3000 Hz; further preferably, the two resonance peaks are within the audible range of the human ear, and the other is outside the audible range of the human ear, and there are at least two resonance peaks The peak frequencies of the two resonant peaks differ by at least 4000 Hz. One of the resonant peaks may be within the audible range of the human ear, and the other two may be outside the audible range of the human ear, and there are at least two resonant peaks whose peak frequencies differ by at least 500 Hz; preferably, one resonant peak is within the human ear audible range. Within the audible range, the other two resonant peaks are outside the audible range of the human ear, and there are at least two resonant peaks whose peak frequencies differ by at least 1000 Hz; more preferably, one resonant peak is within the audible range of the human ear, The other two are outside the audible range of the human ear, and there are at least two resonant peaks whose peak frequencies differ by at least 2000 Hz; further preferably, one resonant peak is within the audible range of the human ear, and the other two are audible to the human ear. outside the range, and there are at least two resonance peaks whose peak frequencies differ by at least 3000 Hz; further preferably, one resonance peak is within the audible range of the human ear, and the other two are outside the audible range of the human ear, and at least there are The peak frequencies of the two resonant peaks differ by at least 4000 Hz. The resonant peaks can all be between the frequencies 5Hz-30000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 400Hz; preferably, the resonant peaks can both be between the frequencies 5Hz-30000Hz, and there are at least two resonant peaks. The frequencies differ by at least 1000Hz; more preferably, the resonant peaks can all be between the frequencies 5Hz-30000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 2000Hz; further preferably, the resonant peaks can both be between the frequencies 5Hz-30000Hz , and there are at least two resonant peaks whose peak frequencies differ by at least 3000 Hz; more preferably, the resonant peaks can both be between frequencies 5Hz-30000 Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 4000 Hz. The resonant peaks can all be between the frequencies of 20Hz-20000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 400Hz; preferably, the resonant peaks can both be between the frequencies of 20Hz-20000Hz, and there are at least two resonant peaks with peak frequencies The frequencies differ by at least 1000Hz; more preferably, the resonant peaks can all be between the frequencies 20Hz-20000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 2000Hz; further preferably, the resonant peaks can both be between the frequencies 20Hz-20000Hz , and there are at least two resonant peaks whose peak frequencies differ by at least 3000 Hz; more preferably, the resonant peaks can both be between 20 Hz and 20000 Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 4000 Hz. The resonance peaks may all be between frequencies of 100Hz-18000Hz, and there are at least two resonance peaks whose peak frequencies differ by at least 400Hz; preferably, the resonance peaks may both be between frequencies of 100Hz-18000Hz, and there are at least two resonance peaks with peak frequencies The frequencies differ by at least 1000Hz; more preferably, the resonant peaks can all be between the frequencies 100Hz-18000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 2000Hz; further preferably, the resonant peaks can both be between the frequencies 100Hz-18000Hz , and there are at least two resonance peaks whose peak frequencies differ by at least 3000 Hz; more preferably, the resonance peaks can both be between 100 Hz and 18000 Hz, and there are at least two resonance peaks whose peak frequencies are at least 4000 Hz different. The resonance peaks can all be between the frequencies of 200Hz-12000Hz, and there are at least two resonance peaks whose peak frequencies differ by at least 400Hz; preferably, the resonance peaks can all be between the frequencies of 200Hz-12000Hz, and there are at least two peaks of the resonance peaks The frequencies differ by at least 1000Hz; more preferably, the resonant peaks can all be between the frequencies 200Hz-12000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 2000Hz; further preferably, the resonant peaks can both be between the frequencies 200Hz-12000Hz , and there are at least two resonant peaks whose peak frequencies differ by at least 3000 Hz; more preferably, the resonant peaks can both be between 200 Hz and 12000 Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 4000 Hz. The resonant peaks can all be between the frequencies of 500Hz-10000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 400Hz; preferably, the resonant peaks can all be between the frequencies 500Hz-10000Hz, and there are at least two peaks of the resonant peaks The frequencies differ by at least 1000Hz; more preferably, the resonant peaks can all be between the frequencies 500Hz-10000Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 2000Hz; further preferably, the resonant peaks can both be between the frequencies 500Hz-10000Hz , and there are at least two resonant peaks whose peak frequencies differ by at least 3000 Hz; more preferably, the resonant peaks can both be between 500 Hz and 10000 Hz, and there are at least two resonant peaks whose peak frequencies differ by at least 4000 Hz. In order to further obtain a better effect, at least two resonance peaks can be within the audible range of human ears, and the resonance peaks generated by the first vibration transmission sheet are not higher than 20,000 Hz. Preferably, at least two resonance peaks can be within the human ear. Within the audible range of the ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 10000Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 10000Hz. The resonance peak is not higher than 5000Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 2000Hz, preferably, at least two resonance peaks can be Within the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 1000 Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet The generated resonance peak is not higher than 500Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 300Hz, preferably, at least two resonance peaks The peaks may be within the audible range of the human ear, and the resonance peaks generated by the first vibration transmission sheet are not higher than 200 Hz; The resonance peak generated by the vibrating plate is in the range of 20-20000Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance peak generated by the first vibration transmission plate is in the range of 20-10000Hz, preferably, At least two resonance peaks can be within the audible range of human ears, and the resonance peaks generated by the first vibration transmission sheet are within the range of 20-5000 Hz, preferably, at least two resonance peaks can be within the audible range of human ears, And the resonance peak generated by the first vibration transmission sheet is in the range of 20-2000 Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is in the range of 20-1000 Hz The range, preferably, at least two resonance peaks can be within the audible range of human ears, and the resonance peaks generated by the first vibration transmission sheet are in the range of 20-500 Hz, preferably, at least two resonance peaks can be within the human ear audible range. Within the listening range, and the resonance peaks generated by the first vibration transmission sheet are in the range of 20-300 Hz, preferably, at least two resonance peaks can be within the audible range of the human ear, and the resonance generated by the first vibration transmission sheet The peak is in the range of 20-200 Hz; more preferably, the energy-transducing device generates at least two resonance peaks in the audible range of the human ear, and the resonance peak generated by the first vibration-transmitting sheet is not higher than 20,000 Hz, more preferably, the energy-transducing device At least two resonance peaks are generated in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 10000 Hz, more preferably, the transducer device generates at least two resonance peaks in the audible range of the human ear, and The resonance peak generated by the first vibration transmission sheet is not higher than 5000Hz. More preferably, the transducer device generates at least two resonance peaks in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 2000Hz. , more preferably, the transducing device produces at least two The resonant peaks are in the audible range of human ears, and the resonant peaks generated by the first vibrating plate are not higher than 1000 Hz. The resonance peak generated by the vibration transmission sheet is not higher than 500Hz, more preferably, the transducer device generates at least two resonance peaks in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 300Hz, more preferably Preferably, the transducer device generates at least two resonance peaks in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is not higher than 200 Hz; more preferably, the transducer device generates at least two resonance peaks in the human ear. The audible range, and the resonant peaks generated by the first vibration transmission sheet are in the range of 20-20000 Hz, more preferably, the transducer device generates at least two resonance peaks in the audible range of the human ear, and the resonance peaks generated by the first vibration transmission sheet are in the range of 20-20000 Hz. The resonant peak is in the range of 20-10000Hz, more preferably, at least two resonant peaks generated by the transducer device are in the audible range of the human ear, and the resonant peak generated by the first vibration transmission sheet is in the range of 20-5000Hz, more preferably, change The energy device generates at least two resonance peaks in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is in the range of 20-2000 Hz. More preferably, the energy conversion device generates at least two resonance peaks in the human ear audible range. range, and the resonant peaks generated by the first vibration transmission sheet are in the range of 20-1000 Hz, more preferably, the transducer device generates at least two resonance peaks in the audible range of the human ear, and the resonance peaks generated by the first vibration transmission sheet In the range of 20-500 Hz, more preferably, the transducing device generates at least two resonance peaks in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is in the range of 20-300 Hz, more preferably, the transducing device At least two resonance peaks are generated in the audible range of the human ear, and the resonance peak generated by the first vibration transmission sheet is in the range of 20-200 Hz. In one embodiment, the frequency response shown in Figure 21-B can be obtained by using a triple composite vibration system composed of a vibration plate, a first vibration transmission sheet and a second vibration transmission sheet. The composite vibration system produces three distinct resonant peaks, resulting in a flatter frequency response and improved sound quality.

By changing the parameters such as the size and material of the first vibration transmission plate, the resonance peak can be moved, and finally the frequency response in the ideal state can be obtained. For example, reducing the stiffness coefficient of the first vibration transmission sheet to the design value can move the resonance peak to the low frequency to the design position, which can greatly improve the sensitivity of the frequency response of the bone conduction speaker in the low frequency range, and it is easy to obtain better sound quality. As shown in Figure 21-C, when the stiffness coefficient of the first vibration transmission piece gradually decreases (that is, the first vibration transmission piece changes from hard to soft), the resonance peak moves to the low frequency direction, and the frequency response of the bone conduction speaker is at low frequency. Sensitivity in the range is significantly improved. Preferably, the first vibration transmission sheet is an elastic sheet. The elasticity is determined by the material, thickness, structure and other aspects of the first vibration transmission sheet. The material of the first vibration transmission plate, such as but 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, blow molded nylon, engineering plastics, etc.), or other single or composite materials that can achieve the same performance. For composite materials, such as but not limited to reinforcing materials such as glass fiber, carbon fiber, boron fiber, graphite fiber, graphene fiber, silicon carbide fiber or aramid fiber, it can also be a composite of other organic and/or inorganic materials, such as glass Fiber reinforced unsaturated polyester, epoxy resin or phenolic resin matrix composed of various types of glass fiber reinforced plastics. The thickness of the first vibration transmission sheet is not less than 0.005mm, preferably, the thickness is 0.005mm-3mm, more preferably, the thickness is 0.01mm-2mm, more preferably, the thickness is 0.01mm-1mm, further preferably, the thickness 0.02mm-0.5mm. The structure of the first vibration transmission sheet can be set to be annular, preferably, it includes at least one ring, preferably at least two rings, which can be concentric rings or non-concentric rings, and the rings pass through each other. At least two struts are connected, and the struts radiate from the outer ring to the center of the inner ring, further preferably, at least one elliptical ring is included, further preferably, at least two elliptical rings are included, and different elliptical rings have different curvatures Radius, the rings are connected by struts, and more preferably, the first vibration transmission sheet includes at least one square ring. The structure of the first vibration-transmitting sheet can also be set in a sheet shape, preferably, a hollow pattern is arranged on it, and the area of the hollow pattern is not less than the area without hollow. The materials, thicknesses and structures described above can be combined into different vibration transmission sheets. For example, the annular vibration-transmitting sheet has different thickness distributions, preferably, the thickness of the strut is equal to the thickness of the ring, more preferably, the thickness of the strut is greater than the thickness of the ring, and further preferably, the thickness of the inner ring is greater than the thickness of the outer ring .

specific embodiment

Example 1

A bone conduction speaker, comprising: a U-shaped earphone stand/earphone hanging strap, two sound vibration units, and a transducer device is fixedly connected to the sound vibration unit. The vibration unit includes a contact surface and a housing, the contact surface being the outer side of the silicone transfer layer. There is a gradient structure on the contact surface, the gradient structure including a raised structure. The clamping force of the contact surface provided by the earphone stand/headphone strap in contact with the skin, and the clamping force is not uniformly distributed on the contact surface. The gradient structure portion and the non-gradient structure portion have different sound transmission efficiencies.

Embodiment 2

The difference between this embodiment and the first embodiment is that the structure of the earphone rack/headphone strap includes an alloy with a memory function, and the earphone rack/headphone strap can fit the curves of the heads of different users. And has good elasticity, with better wearing comfort. After a certain period of deformation, the headphone stand/headphone strap can still return to its original shape. A certain period of time here may refer to ten minutes, thirty minutes, one hour, two hours, five hours, or one day, two days, ten days, one month, one year or longer. The clamping force provided by the headphone stand/headphone strap remains stable, and the clamping force will not gradually decrease as the wearing time becomes longer. The pressure of the bone conduction speaker in contact with the surface of the human body is within a certain appropriate range, so that the human body will not feel excessive pressure and cause pain or obvious vibration when wearing it. During use, the clamping force of the bone conduction speaker is in the range of 0.2N to 1.5N.

Embodiment 3

The difference between this embodiment and Embodiment 1 or Embodiment 2 is that the elastic coefficient of the earphone stand/headphone strap is kept within a specific range, so that the frequency response curve of the bone conduction speaker is at low frequencies (for example, below 500 Hz during use). ) are higher than values near high frequencies (eg, above 4000 Hz).

Embodiment 4

The difference between this embodiment and the first embodiment is that the bone conduction speaker is integrated on the spectacle frame or inside the special-purpose helmet and mask.

Embodiment 5

The difference between this embodiment and the first embodiment is that the vibration unit of the bone conduction speaker includes two or more panels, and different panels or the vibration transmission layer connected to the panels have different gradient structures on the contact surface of the user. For example, one of the contact surfaces is a raised structure and the other is a recessed structure; or the gradient structures on both contact surfaces are both raised or recessed structures, but the shape and number of the raised structures are both. There is at least one difference between them.

Embodiment 6

In a portable bone conduction hearing aid, a variety of frequency response curves can be selected, and the user or tester can select an appropriate hearing aid response curve for compensation according to the actual response curve of the hearing system. In addition, according to actual needs, the vibration device in the bone conduction hearing aid enables the hearing aid to generate an ideal frequency response within a specific frequency range, for example, the frequency range is 500Hz to 4000Hz.

Embodiment 7

The vibration generating part of a bone conduction speaker is shown in Figure 22-A. The transducer device includes a magnetic circuit system composed of a magnetic conducting plate 2210, a magnet 2211 and a magnet conducting body 2212, a vibrating plate 2214, a coil 2215, a first vibrating sheet 2216 and a second vibrating sheet 2217. The panel 2213 protrudes from the housing 2219 and is bonded with the vibrating sheet 2214 by glue. The first vibrating sheet 2216 connects and fixes the transducer device on the housing 2219 to form a suspension structure.

During the operation of the bone conduction speaker, the triple vibration system composed of the vibration plate 2214, the first vibration transmission plate 2216 and the second vibration transmission plate 2217 can generate a flatter frequency response curve, thereby improving the sound quality of the bone conduction speaker. The first vibration transmission sheet 2216 elastically connects the transducer device to the casing 2219, which can reduce the vibration transmitted by the transducer device to the casing, thereby effectively reducing the sound leakage caused by the casing vibration, and also reducing the impact of the casing vibration on the bones. The effect of conduction speaker sound quality. Figure 22-B shows the response curve of the vibration intensity of the casing and the panel vibration intensity with frequency of the vibration generating part. The thick line shows the frequency response of the vibration generating part after using the first vibration transmission sheet 2216, and the thin line shows the frequency response of the vibration generating part without using the first vibration transmission sheet 2216. It can be seen that the vibration of the speaker housing is greater than that of the device using the first vibration transmission plate 2216 in the frequency range above 500 Hz in the device without the first vibration transmission plate 2216 . FIG. 22-C shows a comparison of sound leakage in the case where the first vibration transmission sheet 2216 is used and the first vibration transmission sheet 2216 is not used in the vibration generating part. Wherein, the sound leakage of the device using the first vibration transmission sheet 2216 in the intermediate frequency (for example, about 1000 Hz) range is smaller than the sound leakage of the device without the first vibration transmission sheet 2216 in the corresponding frequency range. It can be seen from this that the use of the first vibration transmission sheet between the panel and the casing can effectively reduce the vibration of the casing, thereby reducing sound leakage.

The first vibration transmission sheet can be made of, for example, but not limited to, stainless steel, beryllium copper, plastic, polycarbonate and other materials, and its thickness is in the range of 0.01mm-1mm.

Embodiment 8

The difference between this embodiment and the seventh embodiment is that, as shown in FIG. 23 , a vibration transmission layer 2320 (such as but not limited to silica gel) is added on the panel 2313, and the vibration transmission layer 2320 can generate a certain deformation to adapt to the shape of the skin. The part of the vibration transmission layer 2320 that is in contact with the panel 2313 is higher than the part of the vibration transmission layer 2320 that is not in contact with the panel 2313, forming a stepped structure. One or more small holes 2321 are designed in the part of the vibration transmission layer 2320 which is not in contact with the panel 2313 (the part where the vibration transmission layer 2320 is not protruded in FIG. 23 ). Designing small holes in the vibration transmission layer can reduce sound leakage: the connection between the panel 2313 and the casing 2319 through the vibration transmission layer 2320 is weakened, and the vibration transmitted from the panel 2313 to the casing 2319 through the vibration transmission layer 2320 is reduced, thereby reducing the vibration of the casing 2319. The unprotruded part of the vibration transmission layer 2320 is provided with small holes 2321 and the area is reduced, the air that can be driven is reduced, and the sound leakage caused by air vibration is reduced; the unprotruded part of the vibration transmission layer 2320 is provided with small holes 2321 Afterwards, the sound waves in the casing formed by the air vibration in the casing are guided out of the casing, and cancel each other with the sound leakage sound waves formed by the air vibration caused by the casing 2319 to reduce the sound leakage.

Embodiment 9

The difference between this embodiment and the seventh embodiment is that because the panel protrudes from the speaker casing, and the first vibration transmission sheet is used to connect the panel to the speaker casing, the coupling degree between the panel and the outer casing is greatly reduced, and the first vibration transmission sheet can provide With a certain deformation, the panel has a higher degree of freedom when it is attached to the user, and can better adapt to the complex attaching surface (as shown in the right picture in Figure 24-A). The panel is inclined at a certain angle relative to the housing. Preferably, the angle of inclination does not exceed 5°.

Further, the vibration efficiency of the speaker differs depending on the fit state. A good fit has a higher vibration transmission efficiency. As shown in Figure 24-B, the thick line shows the vibration transmission efficiency in the state of good fit, and the thin line shows the vibration transmission efficiency in the state of poor fit. It can be seen that the vibration transmission in the better fit state higher efficiency.

Embodiment ten

The difference between this embodiment and the seventh embodiment is that a surrounding edge is added to the edge of the shell, and the surrounding edge can make the force distribution more uniform and increase the wearing comfort of the bone conduction speaker when the shell is in contact with the skin. As shown in FIG. 25 , there is a height difference d ₀ between the peripheral edge 2510 and the panel 2513 . The force of the skin acting on the panel 2513 reduces the distance d between the panel 2513 and the surrounding edge 2510. When the pressure between the bone conduction speaker and the user is greater than the force when the first vibration transfer sheet 2516 is deformed to d ₀ , the excess clamping force will be transmitted to the skin through the surrounding edge 2510 without affecting the clamping force of the vibrating part, so that the consistency of the clamping force is higher, thereby ensuring the sound quality.

Embodiment 11

The shape of the panel is shown in FIG. 26 , and the connecting part 2620 between the panel 2610 and the transducer device (not shown in FIG. 26 ) is shown in dotted lines. The transducer device transmits the vibration to the panel 2610 through the connection part 2620 , and the position of the connection part 2620 is the vibration center of the panel 2610 . The distances between the center O of the connecting member 2620 and the two sides of the panel 2610 are L ₁ and L ₂ , respectively. By changing the size of the panel 2610 and the position of the connecting member 2620 on the panel 2610, the fit performance of the panel to the skin and the transmission efficiency of vibration can be changed. Preferably, the ratio of L ₁ and L ₂ is set to be greater than 1, more preferably, the ratio of L ₁ and L ₂ is set to be greater than 1.61, and further preferably, the ratio of L ₁ and L ₂ is set to be greater than 2. For another example, a large panel, a middle panel and a small panel can be selected to act on the vibrating device. The large panel mentioned here refers to the panel described in FIG. 26 , the area of the panel 2610 is larger than that of the connecting part 2620 , the middle panel refers to the size of the panel 2610 and the connecting part 2620 is the same, and the small panel refers to the case that the area of the panel 2610 is smaller than that of the connecting part 2620 . The vibrations transmitted by the panels of different sizes and the positions of the connection parts 2620 have different distributions on the wearer's fitting surface, which in turn will bring about differences in volume and sound quality.

Embodiment 12

This embodiment involves various configurations of the gradient structure outside the contact surface of the vibration unit of the bone conduction speaker. As shown in FIG. 27 , the gradient structure has different numbers of protrusions, and the protrusions are located at different positions outside the contact surface. Option 1 has one protrusion, which is close to the edge of the contact surface; Option 2 has one protrusion, which is located at the center of the contact surface; Option 3 has two protrusions on the contact surface, which are close to the edge of the contact surface; There are three bumps in option 4; there are four bumps in option 5. The number and position of protrusions will have different effects on the vibration transmission efficiency of the contact surface. As shown in Figures 28-A and 28-B, the contact surface without raised structures exhibits a different frequency response curve than the contact surfaces with raised structures in Schemes 1-5. It can be seen that after the gradient structure (protrusion) is added to the fitting surface, the frequency response curve is significantly raised in the range of 300Hz-1100Hz, indicating that after the gradient structure is added, the middle and low frequency parts of the sound are significantly improved. improvement.

Embodiment thirteen

This embodiment involves various configurations of the gradient structure on the inner side of the vibration contact surface of the bone conduction speaker. As shown in Fig. 29, the gradient structure of the contact surface is located on the inner side of the contact surface, ie, the side facing away from the user. In scheme A, the inner side of the vibration transmission layer is attached to the panel, and the bonding surface has a certain inclination angle with the outer side of the vibration transmission layer; in scheme B, there is a stepped structure inside the vibration transmission layer, and the step is located at the edge of the vibration transmission layer; in scheme C, the vibration There is another stepped structure inside the transmission layer, and the stepped structure is located in the center of the vibration transmission layer; in scheme D, there are multiple stepped structures inside the vibration transmission layer. Due to the gradient structure on the inner side of the contact surface, different points of the contact surface and the panel have different vibration transmission efficiencies at different positions on the bonding surface of the panel, which can broaden the frequency response curve of vibration and make the frequency response more "flat" within a certain frequency range. , thereby improving the sound quality of bone conduction speakers.

Embodiment 14

The difference between this embodiment and the eighth embodiment is that, as shown in FIG. 30 , sound guide holes are designed on the vibration transmission layer 3020 and the casing 3019, and the sound waves in the casing formed by the air vibration in the casing are guided through the sound guide holes. When drawn out of the casing, it cancels out the sound leakage sound waves formed by the air vibration caused by the casing 3019 to reduce the sound leakage.

The above-mentioned embodiments only represent several specific embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that, for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, such as several methods of changing bone conduction sound transmission disclosed in this specification, Any combination and modification can be made, but these modifications and combinations are still within the protection scope of the claims of the present invention.

Claims (9)

1. a bone conduction loudspeaker, is characterized in that, comprises earphone rack/earphone strap and vibration unit, during use, described earphone rack/earphone strap provides clamping force between described vibration unit and user , the clamping force is between 0.2N-4N, the bone conduction speaker further includes a transducer device, the vibration unit at least includes a contact surface, the contact surface is connected with the transducer device, and at least partially Direct or indirect contact with the user to transmit sound to the user through vibration, the surface of the contact surface has areas of high variation so that the clamping force is not evenly distributed on the contact surface. 2 . The bone conduction speaker according to claim 1 , wherein the bone conduction speaker has a symmetrical structure, and the clamping force is that the two ends of the earphone frame/earphone strap are respectively close to the vibration unit. 3 . Clamping force measured when the distance between two points is 125-155mm. 3. The bone conduction speaker according to claim 1, wherein the clamping force is between 0.3N-1.5N. 4 . The bone conduction speaker according to claim 1 , wherein a convex, concave or stepped structure exists on the outer side or the inner side of the contact surface. 5 . 5 . The bone conduction speaker according to claim 1 , wherein a first protrusion with a larger area exists on the contact surface, and a second protrusion with a smaller area exists on the first protrusion. 6 . . 6 . The bone conduction speaker according to claim 5 , wherein the larger-area protrusions account for 30%-80% of the total area of the contact surface, and the smaller-area protrusions account for 30%-80% of the total area of the contact surface. 7 . 1%-30% of the total area of the contact surface. 7 . The bone conduction speaker according to claim 4 , wherein there is at least one protrusion on the contact surface, and the area of a single protrusion accounts for 1%-80% of the total area of the contact surface, and all protrusions The total area of the contact surface accounts for 5%-80% of the total area of the contact surface, or the contact surface has at least one depression, and the area of a single depression accounts for 1%-80% of the total area of the contact surface. , the total area of all depressions accounts for 5%-80% of the total area of the contact surface. 8 . The bone conduction speaker according to claim 4 , wherein the contact surface has corrugations formed by two or more protrusions/concavities or a combination of two, wherein adjacent protrusions/concavities are arranged. 9 . The distances between the lower ones are equal or equally arranged. 9 . The bone conduction speaker according to claim 1 , wherein the vibration unit comprises a panel and a vibration transmission layer, the inner side of the vibration transmission layer is attached to the panel, and the attached surface is attached to the vibration transmission layer. 10 . There is a certain inclination angle on the outside.