Bone conduction speaker device and bone conduction earphone

Abstract

This application discloses a bone conduction speaker device and bone conduction headphones, belonging to the field of speaker technology. Existing bone conduction speakers use cantilever springs as elastic supports, which have drawbacks such as easy oscillation of the vibrator causing frictional noise, stress concentration leading to fatigue cracking, and assembly sensitivity. This application includes a housing, a magnetic vibrator, and a coil. The magnetic vibrator is housed within the housing, and the coil is fixed to the housing to drive the magnetic vibrator to vibrate. It also includes a wave spring assembly and a washer. The wave spring assembly consists of a first wave spring and a second wave spring respectively disposed on both sides of the axial direction of the magnetic vibrator. Each wave spring elastically supports the magnetic vibrator between the magnetic vibrator and the housing and is in a compressed state, providing symmetrical axial restoring force on both sides of the magnetic vibrator. Two washers are respectively fixed to both ends of the magnetic vibrator's axial direction, and a limiting gap exists between the washer and the housing to limit the axial travel of the magnetic vibrator and prevent the wave springs from exceeding their elastic limits and deforming. This application can reduce vibrator oscillation and frictional noise, and improve impact resistance.

Description

Technical Field

[0001] This application relates to the field of loudspeaker technology, and more particularly to the field of bone conduction sound technology, specifically to a bone conduction loudspeaker device and bone conduction headphones. Background Technology

[0002] Bone conduction loudspeakers convert electrical signals into mechanical vibrations, which are then transmitted through the vibrating surface of the transducer to the temporal or zygomatic bone of the human body to produce sound. Common electromagnetic bone conduction loudspeakers typically include a housing, a magnetic circuit assembly, a coil assembly, and a vibrating mass assembly. To ensure that the vibrating mass assembly performs approximately one-dimensional reciprocating motion along the desired vibration axis and to maintain the working air gap between the magnetic circuit and the vibrating body, a spring suspension structure is used as an elastic connection element between the vibrating mass assembly and the housing. Specific forms of this spring suspension structure include metal cantilever springs, bridge-type multi-arm springs, and racetrack-shaped ring springs with elastic arms. The outer ring of the spring is fixed to the housing, and the inner ring connects to the vibrating mass assembly, which is elastically suspended within the housing by the spring. The vibrations generated by the transducer are output through the spring and reset through the elastic deformation of the spring. The performance of the spring directly affects the sound quality of the bone conduction loudspeaker.

[0003] However, the aforementioned spring suspension structure still has the following shortcomings under large displacement operation and long-term cyclic conditions. First, to obtain the required low equivalent stiffness, the spring often needs to be designed as a thinner or longer cantilever arm, which increases the axial space occupied. Furthermore, the cantilever arm is more prone to out-of-plane torsion or tilting during vibration, causing the vibrating mass component to wobble, leading to unexpected friction or impact with the shell, generating abnormal noise and worsening mechanical distortion and auditory perception. Second, the transition zone at the root of the cantilever is prone to high stress concentration under alternating large deflection conditions. Combined with the influence of factors such as forming fillet radius, assembly prestress, and assembly deviation, the stiffness constant of the spring will become discrete, resulting in inconsistent unit frequency response and even the risk of fatigue cracking. Third, springs are mostly supported by a few connection points, making them sensitive to installation parallelism and initial deflection. Improper assembly can easily introduce static eccentric force, causing uneven working air gap and affecting transducer linearity and harmonic distortion. In addition, the stiffness of the spring is quite sensitive to processing errors. When multiple springs are used as elastic components, each spring must maintain a high degree of consistency. Otherwise, it is easy to cause deviation in the stiffness coefficient, which will cause the vibration component to deviate from the axis. Summary of the Invention

[0004] This application aims to provide a bone conduction speaker device and bone conduction headphones, which can provide a more uniform axial restoring force and better self-centering ability through an elastic support scheme. By replacing the traditional spring with a corrugated spring, the elastic constraint of the vibrating mass component is more axisymmetric and the load distribution is more uniform. This allows for controllable stiffness and stroke within a limited Z-axis height, and improves problems such as swaying, eccentric wear, sensitivity to assembly and adjustment deviations, and impact overload.

[0005] In a first aspect, this application provides a bone conduction loudspeaker device, including a housing, a magnetic vibrator and a coil, wherein the housing encloses a receiving cavity, the magnetic vibrator is disposed in the receiving cavity and can reciprocate along the axial direction, and the coil is fixed to the housing for driving the magnetic vibrator to vibrate; Also includes: The corrugated spring assembly includes a first corrugated spring and a second corrugated spring respectively disposed on both sides of the axial direction of the magnet oscillator. Each corrugated spring is elastically supported between the magnet oscillator and the housing and is in a compressed state to provide symmetrical axial restoring force on both sides of the magnet oscillator. Two washers are provided, which are fixed at both ends of the magnetic oscillator. There is a limiting gap between the washers and the housing to limit the axial travel of the magnetic oscillator and prevent the corrugated spring assembly from deforming beyond its elastic limit.

[0006] Preferably, both the first and second corrugated springs are multi-wave-shaped cross-section annular elastic elements, which are formed by stacking or nesting at least two single-layer wave washers along the axial direction.

[0007] Preferably, the cross-section of a single single-layer waveform washer is a continuous wave shape, with wave crests and troughs alternately distributed along the circumference, and the radii of curvature of the wave crests and the troughs change continuously along the circumference.

[0008] Preferably, the outer periphery of the magnetic oscillator is provided with an annular flange, and the inner edges of the first and second corrugated springs respectively abut against the upper and lower end faces of the annular flange.

[0009] Preferably, the washer is a rigid metal gasket with an outer diameter larger than that of the magnetic oscillator; when the magnetic oscillator vibrates to its limit stroke, the outer edge of the washer abuts against the inner wall or inner step surface of the housing.

[0010] Preferably, the washer is made of a magnetically conductive metal material and is used to participate in magnetic circuit conduction.

[0011] Preferably, the coil is fitted outside the magnetic oscillator, and a working air gap is left between the inner wall of the coil and the outer wall of the magnetic oscillator.

[0012] Preferably, the housing includes a bottom shell, an outer shell, and a top cover, wherein the bottom shell and the top cover are respectively provided with support steps for supporting the outer edges of the first corrugated spring and the second corrugated spring.

[0013] Preferably, the first and second corrugated springs bear loads continuously in the circumferential direction, so that the elastic restoring force on the magnetic oscillator is uniformly distributed in the circumferential direction.

[0014] Preferably, the housing includes a bottom shell, an outer shell, and a top cover, wherein the bottom shell and the top cover are press-fitted together to lock the compressed state of the corrugated spring assembly.

[0015] Preferably, the bottom shell and the top cover are pressed and fixed together by ultrasonic welding, snap-fitting, or bonding.

[0016] Preferably, under normal operating conditions, the vibration stroke of the magnetic oscillator is less than the limiting gap, and the washer remains in a non-contact state with the housing.

[0017] Secondly, this application provides a bone conduction headphone, including the bone conduction speaker device as described in any of the preceding technical solutions.

[0018] Compared with the prior art, this application has at least the following beneficial effects: This application uses corrugated springs instead of traditional cantilever springs as elastic support elements, converting the bending stress of the cantilever beam into the axial compressive stress of the corrugated springs. The corrugated springs bear load continuously in the circumferential direction, making the elastic restoring force on the magnet oscillator more uniform along the circumference. This significantly reduces out-of-plane sway and eccentric friction of the vibrating mass assembly, reduces mechanical modulation distortion and abnormal impact noise, and improves the listening experience. Double corrugated springs are respectively set on both sides of the magnet oscillator axially, forming a symmetrical elastic support structure. The springs on both sides together provide a balanced axial restoring force to the magnet oscillator. At the same axial height, the required low axial stiffness can be achieved, and the coupling between the spring mode and the vibration signal is avoided, reducing resonance noise.

[0019] Furthermore, the annular inner / outer edge connection method transforms the traditional point connection cantilever of the spring sheet into a connection closer to the surface / ring, which has a higher tolerance for installation parallelism and assembly deviation, better consistency of working air gap, and reduces the difficulty of assembly and adjustment and manufacturing cost; at the same time, it has a higher tolerance for processing errors of elastic elements, and the non-consistency of the corrugated springs used will not cause non-axial movement of the magnetic oscillator, and prevent the oscillator from swaying and impacting.

[0020] Furthermore, a hard limiting structure is formed by a preset limiting gap between the washer and the housing. When the vibrator moves to its limit stroke under conditions such as large signal drive, impact, or drop, the outer edge of the washer abuts against the inner wall or inner step surface of the housing, bearing the impact load and limiting the compression deformation of the corrugated spring within the elastic limit range. This prevents the corrugated spring from undergoing plastic damage or fatigue failure due to excessive deformation, thus improving the impact resistance and long-term reliability of the bone conduction speaker device. The washer also participates in magnetic circuit conduction as a magnetic guiding element. Its dual-purpose design makes the magnet vibrator structure more compact, eliminating the need for additional limiting parts and facilitating the miniaturization of bone conduction speakers. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a side sectional view of the bone conduction loudspeaker device of this application.

[0023] Figure 2 This is an exploded view of the bone conduction loudspeaker device of this application.

[0024] Figure 3 This is a cross-sectional view of the corrugated spring, magnetic oscillator, and washer used in the bone conduction loudspeaker device of this application.

[0025] Figure 4 This is a perspective view of the corrugated spring, magnetic vibrator, washer, bottom shell, and top cover used in the bone conduction loudspeaker device of this application.

[0026] Figure 5 This is a cross-sectional view of the washer, magnetic oscillator, corrugated spring, coil, bottom shell, and top cover used in the bone conduction loudspeaker device of this application.

[0027] Figure 6 This is a schematic diagram of the corrugated spring assembly of this application.

[0028] Among them, 10 is the bottom shell; 20 is the outer shell; 30 is the top cover; 40 is the magnetic oscillator; 41 is the annular flange; 50 is the coil; 60 is the corrugated spring assembly; 61 is the first corrugated spring; 62 is the second corrugated spring; and 70 is the washer. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort should fall within the scope of protection of the present application.

[0030] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that the reference numerals in the drawings are used to indicate corresponding components, such as the bottom shell 10, the outer shell 20, the top cover 30, the magnetic oscillator 40, the coil 50, the first corrugated spring 61, the second corrugated spring 62, the washer 70, the annular flange 41, etc. The connection relationships, positional relationships, and mating relationships between the components will be described one by one below.

[0031] It should be noted that in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," "outer," "axial," and "radial," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this application, unless otherwise expressly specified and limited, the terms "installed," "connected," "joined," "fixed," and "set," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] In this application, "shell" refers to the peripheral structural components of the bone conduction speaker device, used to enclose and form a receiving cavity and provide a mounting base and support for the internal components. In some embodiments of this application, the shell may include three independent components: a bottom shell 10, an outer shell 20, and a top cover 30, which are assembled to form a complete shell structure; in other embodiments, the shell may also be composed of two components (such as a front shell and a rear shell), or it may adopt an integrally molded structure. "Magnetic vibrator 40" refers to a component in the bone conduction speaker that acts as a vibrating mass component. It is magnetic and can interact with the alternating magnetic field generated by the coil 50 after it is energized, thereby being driven by a driving force and generating reciprocating vibration along the axial direction. The mechanical vibration generated by the magnetic vibrator 40 is transmitted through the shell to the vibration transmission surface of the bone conduction headphones, and then acts on the temporal bone or cheekbone area of ​​the human body to realize bone conduction sound generation. "Wave spring" refers to a ring-shaped elastic element with a wave-shaped cross section. Its axial cross section has a continuously undulating wave shape with alternating peaks and troughs distributed along the circumference. It provides axial force through the elastic deformation of the wave structure. Unlike traditional cantilever springs, wave springs bear load continuously in the circumferential direction, which can provide a more uniform distribution of elastic restoring force.

[0033] In this application, a corrugated spring replaces the suspension structures commonly used in traditional bone conduction loudspeakers, such as multi-arm cantilever springs, bridge-type multi-arm springs, and racetrack-shaped annular elastic bands. Its stress distribution is transformed from the bending stress of the cantilever beam to the axial compressive stress of the corrugated spring, fundamentally changing the force distribution mode of the elastic element. "Washer 70" refers to the rigid pads disposed at both axial ends of the magnet oscillator 40. In this application, it has a dual function: on the one hand, it can act as a magnetically conductive element in the magnetic circuit to participate in the magnetic field distribution; on the other hand, it can act as a hard limiting structure to restrict the extreme stroke of the magnet oscillator 40. The washer 70 can be made of magnetically conductive metal materials (such as iron, low-carbon steel, etc.). "Limiting gap" refers to the axial distance reserved between the washer 70 and the housing. This distance is less than the limit compression stroke of the bellows spring. During normal operation, the vibration amplitude of the magnet oscillator 40 is less than this limiting gap, and the washer 70 remains in a non-contact state with the housing. When the magnet oscillator 40 moves to its limit stroke under abnormal conditions such as large signal drive, impact, or drop, the washer 70 comes into contact with the housing, thereby limiting the deformation of the bellows spring within the elastic limit range. "Compression state" refers to the working state of the bellows spring after it undergoes elastic compression deformation under axial preload during assembly. The two bellows springs are respectively set on both sides of the axial direction of the magnet oscillator 40, both in a compressed state, thereby forming axial preload forces in opposite directions and in balance on both sides of the magnet oscillator 40, providing a stable initial reset force for the magnet oscillator 40.

[0034] like Figure 1As shown, this application provides a bone conduction loudspeaker device employing a corrugated spring, including a housing, a magnetic resonator 40, and a coil 50. The housing encloses and forms a receiving cavity. In some embodiments of this application, such as Figure 1 and Figure 2 As shown, the housing includes a bottom shell 10, an outer shell 20, and a top cover 30, which together enclose a receiving cavity. The bottom shell 10 and the top cover 30 are respectively located at the axial ends of the outer shell 20, and the three can be fixedly connected by ultrasonic welding, snap-fit ​​connection, adhesive bonding, or threaded connection to form a closed receiving space. A magnetic oscillator 40 is disposed within the receiving cavity and can reciprocate along the axial direction. As a vibrating mass component, the magnetic oscillator 40 is located in the middle of the receiving cavity and can reciprocate along the axial direction under the drive of the alternating magnetic field generated after the coil 50 is energized. After the magnetic oscillator 40 vibrates, the vibration is transmitted to the vibration transmission surface of the bone conduction headphones through at least one of the housings (such as the bottom shell 10, the outer shell 20, or the top cover 30), and then acts on the temporal bone or cheekbone area of ​​the human body to achieve bone conduction sound generation. The coil 50 is fixed to the housing and is used to drive the magnetic oscillator 40 to vibrate. Figure 1 and Figure 5 As shown, coil 50 is fixedly mounted on the bottom shell 10 or the top cover 30. In some embodiments of this application, coil 50 is fixed on the bottom shell 10. In other embodiments of this application, coil 50 is fixed on the top cover 30. Coil 50 is electrically connected to an external audio signal source. When an audio current is applied to coil 50, coil 50 generates an alternating magnetic field. This alternating magnetic field interacts with the magnetic field of the magnetic oscillator 40, generating an axial driving force, thereby causing the magnetic oscillator 40 to reciprocate along the axial direction in accordance with the audio signal. This application adopts the above-described housing, magnetic oscillator 40, and coil 50 cooperation structure. By energizing coil 50 to generate an alternating magnetic field, the magnetic oscillator 40 is driven to reciprocate along the axial direction, realizing the conversion of electrical signals into mechanical vibration, providing a basic driving scheme for bone conduction sound generation. Compared to the relative arrangement of the magnet oscillator 40 and the coil 50 in traditional bone conduction loudspeakers, this application allows the coil 50 to be fixed on the bottom shell 10 or the top cover 30 according to actual design needs, providing flexible installation options for different types of magnetic circuit structures and facilitating optimized design based on the overall spatial layout.

[0035] This application also includes a corrugated spring assembly 60, which includes a first corrugated spring 61 and a second corrugated spring 62 respectively disposed on both axial sides of the magnetic oscillator 40. Figure 1 and Figure 3As shown, the first corrugated spring 61 is disposed on one axial side of the magnet oscillator 40 (as shown below), and the second corrugated spring 62 is disposed on the other axial side of the magnet oscillator 40 (as shown above). Each corrugated spring is elastically supported between the magnet oscillator 40 and the housing. Specifically, the first corrugated spring 61 is disposed between the bottom shell 10 and the magnet oscillator 40, and the second corrugated spring 62 is disposed between the top cover 30 and the magnet oscillator 40. Each corrugated spring is in a compressed state. In this application, the bottom shell 10 and the top cover 30 are fixedly connected by pressing during assembly. During the pressing process, the first corrugated spring 61 and the second corrugated spring 62 are subjected to axial pressure and undergo compression deformation. This pre-compression amount can be set according to the target resonant frequency, maximum amplitude, and overall height. In the compressed state, the two corrugated springs apply axial elastic forces of opposite directions and appropriate magnitudes to the upper and lower sides of the magnet oscillator 40, respectively, forming a mutually balanced pre-tightened state. With the arrangement of the double corrugated springs described above, each corrugated spring provides symmetrical axial restoring force on both sides of the magnet oscillator 40. When the magnet oscillator 40 deviates axially from the equilibrium position, the corrugated spring on one side is further compressed, generating an increased thrust, while the corrugated spring on the other side releases part of its compression, generating a decreased thrust. The resultant force of the two springs always points towards the equilibrium position, thereby enabling the magnet oscillator 40 to obtain a stable axial restoring capability.

[0036] This application employs a technical solution where two corrugated springs are respectively positioned on both sides of the magnetic vibrator 40 along its axial direction. Compared to the traditional bone conduction speaker structure with a single-sided spring suspension, the two corrugated springs form symmetrical elastic supports on both sides of the magnetic vibrator 40, ensuring a uniform distribution of elastic force on both sides of the magnetic vibrator 40 along its axial direction, thus avoiding the swaying problem easily caused by single-sided support. The corrugated springs bear continuous load in the circumferential direction, resulting in a more uniform distribution of elastic restoring force compared to the point connection load method of the cantilever spring, effectively reducing out-of-plane sway and eccentric friction of the vibrating mass component. At the same axial height, the required low axial stiffness can be achieved by selecting corrugated springs with appropriate waveform parameters, which is beneficial for improving the low-frequency response of the bone conduction speaker. Since the elastic force of the corrugated springs originates from the axial compression deformation of the wave-shaped structure rather than the bending deformation of the cantilever beam, its stress distribution is more uniform, avoiding the problem of stress concentration at the root of the cantilever spring, which is beneficial for improving the fatigue life of the elastic element.

[0037] This application also includes a washer 70, of which two wereher 70s are respectively fixed to both ends of the axial direction of the magnetic oscillator 40. Figure 1 and Figure 3As shown, two washers 70 are fixedly installed on the upper and lower end faces of the magnet oscillator 40, respectively. The washers 70 and the magnet oscillator 40 can be fixedly connected by means of bonding, welding, or integral molding. There is a limiting gap between the washers 70 and the housing to limit the axial travel of the magnet oscillator 40 and prevent the bellows assembly 60 from exceeding its elastic limit deformation. In this application, the limiting gap refers to the axial distance reserved between the outer edge of the washers 70 and the corresponding limiting surface of the housing (such as the inner wall of the outer shell 20, the inner stepped surface of the bottom shell 10, or the inner stepped surface of the top cover 30). The value of this limiting gap is less than the limit compression stroke of the bellows assembly 60. Under normal operating conditions, the magnet oscillator 40 performs small-amplitude reciprocating vibrations driven by an audio signal. Its vibration amplitude is less than the limiting gap, so the washers 70 do not contact the housing, and the magnet oscillator 40 vibrates freely relying on the elastic restoring force provided by the bellows assembly 60. When the bone conduction speaker is subjected to external impact, drop, or abnormally large amplitude signal, the displacement of the magnet oscillator 40 increases to its limit stroke. At this point, the outer edge of the washer 70 abuts against the limiting surface of the housing, preventing the magnet oscillator 40 from continuing to displace through rigid contact, thereby limiting the compression deformation of the corrugated spring assembly 60 within the elastic limit range. The washer 70 also prevents the magnet oscillator 40 from colliding with the housing.

[0038] This application presents a technical solution that utilizes a pre-set limiting gap between the washer 70 and the housing to form a rigid limiting structure. Compared to traditional bone conduction loudspeakers that rely solely on the spring itself to limit the travel, the washer 70, as a rigid metal component, can withstand greater impact loads through its rigid contact with the housing. This allows the impact energy to be directly borne by the limiting surface rather than by the corrugated spring, effectively preventing plastic deformation or fatigue damage to the corrugated spring due to excessive compression. The washer 70 also serves as a magnetic guiding element in the magnetic circuit; its dual-purpose design eliminates the need for additional limiting components, facilitating miniaturization and structural simplification of the bone conduction loudspeaker. The preset value of the limiting gap can be precisely controlled according to design requirements, ensuring free vibration of the oscillator under normal operating conditions while providing reliable overload protection under abnormal conditions, thus improving the impact resistance and long-term reliability of the bone conduction loudspeaker device. The limiting gap is smaller than the limit compression travel of the corrugated spring assembly from its free state to its compressed state.

[0039] In some embodiments of this application, such as Figure 1 , Figure 2 and Figure 4As shown, the housing includes a bottom shell 10, an outer shell 20, and a top cover 30, which together form a receiving cavity. The bottom shell 10 serves as the bottom support structure of the entire device, supporting the lower part of the coil 50, the first corrugated spring 61, and the magnetic oscillator 40. The upper surface of the bottom shell 10 is provided with a positioning structure for mounting the coil 50 and a support step for supporting the outer edge of the first corrugated spring 61. The top cover 30 serves as the top closed structure of the entire device, cooperating with the bottom shell 10 and the outer shell 20 to form a closed receiving space. The lower surface of the top cover 30 is provided with a support step for supporting the outer edge of the second corrugated spring 62. The outer shell 20 is disposed between the bottom shell 10 and the top cover 30, and the three can be pressed and fixed together by ultrasonic welding, snap-fitting, or adhesive bonding. During assembly, the bottom shell 10 is first positioned and fitted with the outer shell 20. After the internal components are sequentially installed, the top cover 30 is pressed against the outer shell 20 or the bottom shell 10. This pressing assembly causes the first corrugated spring 61 and the second corrugated spring 62 to undergo predetermined compression deformation, thereby locking the corrugated spring assembly 60 into a compressed state. In some embodiments of this application, the bottom shell 10 and the top cover 30 are pressed and fixed by ultrasonic welding. This method provides reliable connection, good sealing, and is suitable for mass production. In other embodiments of this application, the bottom shell 10 and the top cover 30 are pressed and fixed by snap-fit. This method is simple to assemble and allows for disassembly, facilitating maintenance and replacement of internal components. In still other embodiments of this application, the bottom shell 10 and the top cover 30 are pressed and fixed by adhesive bonding. This method provides a stable connection and has lower tolerance requirements for components.

[0040] In some embodiments of this application, such as Figure 6As shown, both the first corrugated spring 61 and the second corrugated spring 62 are annular elastic elements with multi-wave cross-sections. They are formed by stacking or nesting at least two single-layer corrugated washers axially. The first corrugated spring 61 and the second corrugated spring 62 have mounting surfaces on both the top and bottom. The cross-section of each single-layer corrugated washer is continuously wavy, with alternating crests and troughs distributed circumferentially. The radii of curvature of the crests and troughs change continuously circumferentially. This continuous wavy structure allows the corrugated spring to undergo elastic deformation simultaneously at each crest and trough when subjected to axial compressive force, distributing the axial load across the entire circumference. The design of continuously varying radii of curvature of the crests and troughs circumferentially avoids stress abrupt changes or stress concentrations in the transition area between crests and troughs, ensuring uniform stress distribution circumferentially and thus improving the fatigue life of the corrugated spring. The first corrugated spring 61 and the second corrugated spring 62 provide axial restoring force through the synergistic elastic deformation of the multi-layer corrugated washers. In some embodiments of this application, the number of single-layer corrugated washers can be selected and adjusted according to the required stiffness. The more layers, the greater the elastic force provided under the same amount of deformation, and the higher the equivalent stiffness. By adjusting the number of stacked layers and the waveform parameters (such as wave height, wave pitch, thickness, etc.) of the single-layer corrugated washers, the elastic stiffness can be flexibly adjusted without changing the axial installation space. In some embodiments of this application, the first corrugated spring 61 and the second corrugated spring 62 can also adopt a single-layer corrugated washer structure, as long as it can provide sufficient axial elastic restoring force.

[0041] In some embodiments of this application, such as Figure 3 As shown, the outer periphery of the magnet oscillator 40 is provided with an annular flange 41. The annular flange 41 protrudes radially outward from the outer periphery of the magnet oscillator 40, forming an annular stepped surface for abutting against the inner edge of the corrugated spring. The inner edges of the first corrugated spring 61 and the second corrugated spring 62 abut against the upper and lower end faces of the annular flange 41, respectively. Specifically, the inner edge of the first corrugated spring 61 abuts against the lower end face of the annular flange 41, and the inner edge of the second corrugated spring 62 abuts against the upper end face of the annular flange 41. Through the above structure, the magnet oscillator 40 forms an abutting fit with the inner edges of the upper and lower corrugated springs through the annular flange 41, so that the magnet oscillator 40 is axially held in the middle by the two corrugated springs. When the magnet oscillator 40 deviates from the axial equilibrium position, the annular flange 41 pushes the corrugated spring on the corresponding side to form further compression deformation, thereby obtaining an elastic restoring force.

[0042] This application adopts a structure in which an annular flange 41 abuts against the inner edge of the corrugated spring: the annular flange 41 serves as a continuous annular structure on the outer periphery of the magnet oscillator 40, forming a continuous circumferential annular abutment with the inner edge of the corrugated spring. This results in a large contact area and uniform stress distribution, avoiding stress concentration and wear problems caused by point or partial connections between the spring and the oscillator in traditional applications. The abutment between the annular flange 41 and the inner edge of the corrugated spring does not require additional fasteners or adhesives, making assembly simple and enabling the transmission of larger axial forces. This structure allows for a certain positional tolerance in the radial direction between the magnet oscillator 40 and the corrugated spring, reducing the requirements for assembly accuracy.

[0043] In some embodiments of this application, such as Figure 1 and Figure 4 As shown, the washer 70 is a rigid metal gasket. The outer diameter of the washer 70 is larger than the outer diameter of the magnet oscillator 40, causing the outer edge of the washer 70 to protrude radially beyond the outer circumferential surface of the magnet oscillator 40. When the magnet oscillator 40 undergoes axial displacement, the washer 70 moves synchronously with it, its protruding outer edge acting as a limiting portion. When the magnet oscillator 40 vibrates to its limit stroke, the outer edge of the washer 70 abuts against the inner wall or inner stepped surface of the housing. In some embodiments of this application, such as... Figure 1 As shown, when the magnetic oscillator 40 moves upward to its limit stroke, the outer edge of the upper washer 70 abuts against the inner wall of the outer casing 20 or the inner stepped surface of the top cover 30. When the magnetic oscillator 40 moves downward to its limit stroke, the outer edge of the lower washer 70 abuts against the inner wall of the outer casing 20 or the inner stepped surface of the bottom shell 10. In some embodiments of this application, the washer 70 is made of a magnetically conductive metal material and is used to participate in the magnetic circuit conduction. Specifically, the washer 70 can be made of iron, low-carbon steel, or other magnetically conductive metal materials. The washer 70 serves as both a hard limiting structure and a magnetically conductive element in the magnetic circuit, enabling it to gather and guide magnetic field lines, improve the distribution of the magnetic field, increase the utilization efficiency of the magnetic field, thereby enhancing the vibration sensitivity of the vibration system and reducing distortion.

[0044] Specifically, such as Figure 1 and Figure 5 As shown, the coil 50 is fitted onto the outside of the magnet oscillator 40, and a working air gap is provided between the inner wall of the coil 50 and the outer wall of the magnet oscillator 40. This working air gap provides the space required for the axial vibration of the magnet oscillator 40, ensuring that the magnet oscillator 40 does not come into contact with or rub against the coil 50 during reciprocating vibration.

[0045] Furthermore, such as Figure 1 and Figure 4As shown, the outer edges of the first corrugated spring 61 and the second corrugated spring 62 are supported by support steps on the bottom shell 10 and the top cover 30, respectively. Specifically, the bottom shell 10 is provided with an annular support step for supporting the outer edge of the first corrugated spring 61, and the top cover 30 is provided with an annular support step for supporting the outer edge of the second corrugated spring 62. Through the above-mentioned support steps, the outer ring of the corrugated spring is fixed to the shell, and the inner ring is connected to the magnetic oscillator 40 through the annular flange 41, thereby realizing that the magnetic oscillator 40 is elastically suspended relative to the shell by the corrugated spring assembly 60.

[0046] Furthermore, the first corrugated spring 61 and the second corrugated spring 62 continuously bear load in the circumferential direction, ensuring that the elastic restoring force on the magnetic oscillator 40 is uniformly distributed circumferentially. That is, the annular wave structure of the corrugated springs is continuously distributed along its entire circumference without any local gaps or breaks. Under any axial displacement of the magnetic oscillator 40, the corrugated springs can provide continuous elastic support force throughout the entire circumference. This characteristic of continuous circumferential bearing is fundamentally different from the traditional multi-arm cantilever spring method, which provides support force only through a few discrete cantilever segments.

[0047] Under normal operating conditions, the vibration stroke of the magnet oscillator 40 is less than the limiting gap, and the washer 70 remains in non-contact with the housing. That is, when the bone conduction speaker is operating normally (audio signal amplitude is within the normal range, and no abnormal situations such as impact or drop occur), the magnet oscillator 40 undergoes small-amplitude reciprocating vibrations under the elastic constraint of the corrugated spring assembly 60, and its displacement range does not exceed the preset limiting gap. The outer edge of the washer 70 never contacts the housing during vibration. The hard limiting function of the washer 70 is only triggered when the displacement of the magnet oscillator 40 exceeds the normal operating range (i.e., reaches the limit stroke).

[0048] The assembly process can be performed using the following steps: First, place the first corrugated spring 61 and coil 50 in their corresponding mounting positions on the bottom shell 10; then, place the magnet oscillator 40, with the washer 70 already fixed, into the receiving cavity, so that the inner edge of the first corrugated spring 61 abuts against the lower end face of the annular flange 41; subsequently, install the second corrugated spring 62, so that its inner edge abuts against the upper end face of the annular flange 41; finally, press the top cover 30 into the bottom shell 10 or the outer shell 20, during which the first corrugated spring 61 and the second corrugated spring 62 undergo pre-compression deformation. The pre-compression amount can be set according to the target resonant frequency, maximum amplitude, and overall height of the machine.

[0049] This application also provides a bone conduction headphone, which includes the bone conduction speaker device described in any of the above-mentioned technical solutions. The bone conduction speaker device is disposed within the housing of the bone conduction headphone, and its vibrations are transmitted to the vibration transmission surface of the bone conduction headphone via at least one of the bottom shell 10, the outer shell 20, or the top cover 30. The vibration transmission surface is used to contact the human head, transmitting mechanical vibrations through the temporal bone or zygomatic bone region to the inner ear, thereby achieving bone conduction hearing. The bone conduction headphone can be worn in any form, such as over-ear, ear-hook, or clip-on.

[0050] The bone conduction speaker device provided in this application can serve as the core sound-generating component of bone conduction headphones. When worn, the bone conduction headphones are attached to the user's ear area via a wearing structure (such as an ear hook or headband), ensuring close contact between the headphone's vibration transmission surface and the skin of the user's temporal or zygomatic bone area. During operation, the audio electrical signal output from an external audio source (such as a mobile phone, music player, etc.) is processed by the headphone's internal drive circuit and transmitted to the coil 50. When energized, the coil 50 experiences alternating Ampere forces in the magnetic field of the magnetic oscillator 40, generating an alternating driving force corresponding to the audio signal, driving the magnetic oscillator 40 to reciprocate axially. The vibration of the magnetic oscillator 40 is transmitted to the housing via two corrugated springs, then through the housing to the vibration transmission surface in contact with the human body, and finally through the bone conduction pathway to the inner ear, allowing the user to perceive sound. During the above operation, the vibration amplitude of the magnetic oscillator 40 is proportional to the amplitude of the audio signal. At normal volume, the vibration amplitude of the magnetic vibrator 40 is less than the limiting gap between the washer 70 and the housing. The washer 70 does not contact the housing, and the magnetic vibrator 40 vibrates freely under the elastic support of the double corrugated springs, providing a clear bone conduction sound experience. When the bone conduction headphones are subjected to accidental impact or drop during use, the magnetic vibrator 40 will generate a large displacement beyond its normal operating range due to inertia. When the displacement reaches its limit stroke, the outer edge of the washer 70 abuts against the housing, bearing the impact load through rigid contact and preventing excessive deformation of the corrugated springs. After the impact, the magnetic vibrator 40 returns to its equilibrium position under the elastic restoring force of the corrugated spring assembly 60, and the bone conduction speaker device resumes normal operation. In some embodiments of this application, the limiting gap is preferably 0.1mm to 0.5mm. This value range ensures that the magnetic vibrator 40 has sufficient vibration space to obtain good low-frequency response and sufficient output volume under normal operating conditions, and can also trigger the limiting protection in time when an abnormal impact occurs, controlling the deformation of the corrugated springs within the elastic limit. The specific values ​​can be determined comprehensively based on parameters such as the mass of the magnet oscillator 40, the stiffness coefficient of the corrugated spring assembly 60, and the target maximum output sound pressure level. In some embodiments of this application, the compression amount (i.e., the sum of the pre-compression amount and the working compression amount) of the first corrugated spring 61 and the second corrugated spring 62 is preferably 10% to 40% of the free height of the corrugated spring. Within this range, the corrugated spring can obtain good linear elastic characteristics and a long fatigue life.

[0051] As a specific embodiment, such as Figures 1 to 5 As shown, this application also provides a bone conduction loudspeaker device. The bone conduction loudspeaker device includes a base shell 10, an outer shell 20, a top cover 30, a magnetic vibrator 40, a coil 50, a corrugated spring assembly 60, and a washer 70. The base shell 10, outer shell 20, and top cover 30 are interconnected and together enclose a receiving cavity. The magnetic vibrator 40 is disposed within this receiving cavity and is capable of reciprocating vibration along the axial direction of the device. In this application, "axial direction" refers to the direction in which the magnetic vibrator 40 reciprocates relative to the base shell 10 and the top cover 30; "radial direction" refers to the direction perpendicular to the axial direction.

[0052] In some embodiments of this application, such as Figures 1 to 6 As shown, the corrugated spring assembly 60 includes a first corrugated spring 61 and a second corrugated spring 62 respectively disposed on both axial sides of the magnet oscillator 40. An annular flange 41 is provided on the outer periphery of the magnet oscillator 40. The inner edge of the first corrugated spring 61 abuts against the lower end face of the annular flange 41, and the inner edge of the second corrugated spring 62 abuts against the upper end face of the annular flange 41. The outer edge of the first corrugated spring 61 is supported by a support step on the bottom shell 10, and the outer edge of the second corrugated spring 62 is supported by a support step on the top cover 30. After the bottom shell 10, the outer shell 20, and the top cover 30 are assembled, both the first corrugated spring 61 and the second corrugated spring 62 are in a pre-compressed state, thereby forming axial elastic restoring forces in opposite directions and in mutual balance on both axial sides of the magnet oscillator 40. Since both the first corrugated spring 61 and the second corrugated spring 62 are annular corrugated elastic elements, and their inner ring edges form a continuous circumferential contact with the magnetic oscillator 40 through the annular flange 41, while their outer ring edges form continuous circumferential support through the support steps of the bottom shell 10 and the top cover 30, the elastic support force on the magnetic oscillator 40 can be more evenly distributed circumferentially and form a symmetrical constraint along the axial direction. This structure can reduce the problems of out-of-plane sway, uneven working air gap, friction noise, and stress concentration caused by discrete arm segment load, local stiffness differences, or assembly deviations in traditional cantilever springs.

[0053] Two washers 70 are fixed to the axial ends of the magnetic oscillator 40 and move synchronously with it. The outer diameter of the washers 70 is larger than that of the magnetic oscillator 40, and a limiting gap is formed between the outer edge of the washers 70 and the corresponding limiting surface of the housing. The limiting surface is the inner wall of the outer shell 20, the inner stepped surface of the bottom shell 10, or the inner stepped surface of the top cover 30. Under normal operating conditions, the vibration stroke of the magnetic oscillator 40 is less than the limiting gap, the washers 70 remain in non-contact with the housing, and the magnetic oscillator 40 reciprocates axially by the elastic restoring force provided by the first corrugated spring 61 and the second corrugated spring 62. When the bone conduction speaker device is subjected to a drop, impact, or abnormally large signal drive, the magnetic oscillator 40 will generate a displacement in the axial direction that exceeds the normal operating range. When the magnetic oscillator 40 moves to its limit stroke, the outer edge of the washer 70 located at the corresponding axial end abuts against the limiting surface of the housing. The impact load is borne by the rigid contact between the washer 70 and the housing, and the magnetic oscillator 40 is prevented from continuing to move. This limits the deformation of the first corrugated spring 61 and the second corrugated spring 62 to the elastic limit range, and prevents the corrugated spring assembly 60 from plastic deformation, fatigue damage, or failure due to excessive compression.

[0054] In some embodiments of this application, the washer 70 is made of a magnetically conductive metal material. Thus, the washer 70 serves two purposes: firstly, as a magnetically conductive element at the axial end of the magnet oscillator 40, it participates in magnetic circuit conduction; secondly, as a limiting element, it abuts against the housing and bears impact loads during extreme strokes. By enabling the washer 70 to perform both magnetic conduction and limiting functions, there is no need for an additional independent limiting component within the housing cavity, which simplifies the internal structure and reduces the axial dimension of the bone conduction loudspeaker device.

[0055] The magnetic oscillator 40, as a vibrating mass component, is disposed in the center of the receiving cavity. The coil 50 is fixedly mounted on the bottom shell 10 or the top cover 30 and sleeved on the outer periphery of the magnetic oscillator 40, forming a working air gap between the inner wall of the coil 50 and the outer wall of the magnetic oscillator 40. When an audio current is passed through the coil 50, the coil 50 generates an alternating magnetic field. This alternating magnetic field interacts with the magnetic field of the magnetic oscillator 40, causing the magnetic oscillator 40 to reciprocate along the axial direction in accordance with the audio signal. This vibration is transmitted to the vibration transmission surface of the bone conduction headphones through at least one of the bottom shell 10, the outer shell 20, or the top cover 30, and then acts on the temporal bone or cheekbone region of the human body to achieve bone conduction sound generation.

[0056] In this supplementary embodiment, the corrugated spring assembly 60 includes a first corrugated spring 61 and a second corrugated spring 62. The first corrugated spring 61 is disposed between the bottom shell 10 and the magnetic oscillator 40, and the second corrugated spring 62 is disposed between the top cover 30 and the magnetic oscillator 40. An annular flange 41 is provided on the outer periphery of the magnetic oscillator 40. The inner edge of the first corrugated spring 61 abuts against the lower end face of the annular flange 41, and the inner edge of the second corrugated spring 62 abuts against the upper end face of the annular flange 41. The outer edges of the first corrugated spring 61 and the second corrugated spring 62 are respectively supported by support steps or limiting surfaces on the bottom shell 10 and the top cover 30, thereby allowing the magnetic oscillator 40 to be elastically suspended in the receiving cavity by the upper and lower corrugated springs.

[0057] Both the first corrugated spring 61 and the second corrugated spring 62 are annular corrugated elastic elements, with their cross-sections forming continuous crests and troughs along the circumference. Preferably, the first corrugated spring 61 and the second corrugated spring 62 are each formed by at least two single-layer corrugated washers stacked or nested axially, so as to provide the required axial elastic stiffness through the synergistic deformation of the multiple corrugated washers. Compared with the traditional multi-arm spring structure, the corrugated springs bear load continuously or nearly continuously in the circumferential direction, which can make the elastic restoring force on the magnet oscillator 40 more uniform, reducing swaying, rubbing, and abnormal noise caused by local stiffness differences.

[0058] During assembly, first place the first corrugated spring 61 and coil 50 in their corresponding mounting positions on the bottom shell 10, then place the magnet oscillator 40, with the washer 70 already fixed, into the receiving cavity. The first corrugated spring 61 abuts against the lower end face of the annular flange 41; subsequently, install the second corrugated spring 62, abutting against the upper end face of the annular flange 41; finally, press the top cover 30 into the bottom shell 10 or the outer shell 20. After the bottom shell 10 and the top cover 30 are pressed together, both the first corrugated spring 61 and the second corrugated spring 62 undergo pre-compression deformation, thereby forming axial mechanical restoring forces in opposite directions and balanced on the upper and lower sides of the magnet oscillator 40. This pre-compression amount can be set according to the target resonant frequency, maximum amplitude, and overall height.

[0059] Two washers 70 are provided, fixedly installed on the upper and lower sides of the magnetic oscillator 40 respectively. The washers 70 can be made of iron, low-carbon steel, or other magnetically conductive metal materials. They participate in magnetic circuit conduction and also serve as a rigid limiting structure for the magnetic oscillator 40. Specifically, the outer diameter of the washers 70 is larger than the outer diameter of the magnetic oscillator 40. When the magnetic oscillator 40 moves to its limit stroke under impact, drop, or large signal drive, the outer edge of the washers 70 can abut against the inner wall of the outer casing 20, the inner stepped surface of the bottom shell 10, or the inner stepped surface of the top cover 30 to limit the further displacement of the magnetic oscillator 40. This prevents the first corrugated spring 61 and the second corrugated spring 62 from entering an over-compressed or over-stretched state, reducing the risk of plastic deformation or fatigue damage to the corrugated springs.

[0060] Under normal operating conditions, the vibration stroke of the magnetic oscillator 40 is less than the preset gap between the washer 70 and the adjacent limiting surface. The washer 70 does not participate in collision limiting. The magnetic oscillator 40 mainly relies on the first corrugated spring 61 and the second corrugated spring 62 for elastic support and reset. When subjected to external impact or abnormally large amplitude drive, the washer 70 contacts the limiting surface and bears the impact load, so that the impact energy is not directly concentrated on the corrugated spring assembly 60, thereby improving the impact resistance and long-term reliability of the bone conduction headphone speaker device.

[0061] In this supplementary embodiment, after the corrugated spring assembly 60 replaces the traditional cantilever spring, the elastic support of the magnetic oscillator 40 is borne by the circumferentially distributed corrugated structure. The elastic force is more uniform along the circumference, which can reduce the yaw and out-of-plane coupling of the magnetic oscillator 40 during vibration. At the same time, the corrugated spring can provide a longer effective elastic stroke within a small axial height, which is beneficial to reducing the equivalent stiffness of the vibration system and improving the low-frequency response. With the hard limiting structure of the washer 70, this supplementary embodiment can also improve the reliability of the vibration system under drop, impact, and large signal operating conditions.

[0062] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. For those skilled in the art, equivalent substitutions or modifications can be made to the specific shape, material, connection method, and relative position of the bottom shell 10, outer shell 20, top cover 30, magnetic oscillator 40, coil 50, corrugated spring assembly 60, and washer 70 without departing from the concept of this application, and such substitutions or modifications should all fall within the scope of protection of this application.

[0063] Compared to existing spring suspension systems (multi-arm cantilever / bridge-type springs, etc.), this supplementary embodiment has at least the following advantages: It converts the bending stress of the cantilever beam into the axial compressive stress of the corrugated spring, with the load borne by the axially distributed corrugated bending section. This results in a more axisymmetric elastic stroke, reducing out-of-plane swaying and eccentric friction of the vibrating mass component, and decreasing mechanical modulation distortion and abnormal impact noise. It achieves the required low axial stiffness at the same axial height and avoids coupling between the spring mode and vibration signal, reducing resonance noise. The annular inner and outer edge connection method transforms the point-connected cantilever into a connection closer to a surface or ring, resulting in higher assembly tolerance and better air gap consistency. Combined with the washer hard limiting structure, more impact and drop energy is borne by the limiting surface, reducing the risk of overload plastic deformation of the corrugated elastic component and improving long-term reliability. It has a higher tolerance for processing errors in the elastic element, and the inconsistency of the corrugated spring will not cause non-axial movement of the magnetic oscillator, preventing oscillation and impact.

[0064] The above content is only for illustrating the technical concept of this application and should not be used to limit the scope of protection of this application. Any modifications made to the technical solution based on the technical concept proposed in this application shall fall within the scope of protection of the claims of this application.

Claims

1. A bone conduction loudspeaker device, characterized in that, The device includes a housing, a magnetic oscillator (40), and a coil (50). The housing encloses and forms a receiving cavity. The magnetic oscillator (40) is disposed in the receiving cavity and can reciprocate along the axial direction. The coil (50) is fixed to the housing and is used to drive the magnetic oscillator (40) to vibrate. Also includes: The corrugated spring assembly (60) includes a first corrugated spring (61) and a second corrugated spring (62) respectively disposed on both sides of the axial direction of the magnet oscillator (40). Each corrugated spring is elastically supported between the magnet oscillator (40) and the housing and is in a compressed state to provide symmetrical axial restoring force on both sides of the magnet oscillator (40). Two washers (70) are provided and fixed at both ends of the axial direction of the magnet oscillator (40). There is a limiting gap between the washers (70) and the housing to limit the axial travel of the magnet oscillator (40) and prevent the corrugated spring assembly (60) from deforming beyond the elastic limit.

2. The bone conduction loudspeaker device according to claim 1, characterized in that: The first corrugated spring (61) and the second corrugated spring (62) are both multi-wave cross-section annular elastic elements, which are formed by stacking or nesting at least two single-layer wave washers along the axial direction.

3. The bone conduction loudspeaker device according to claim 2, characterized in that: The cross-section of a single single-layer waveform washer is a continuous wave shape, with wave crests and troughs distributed alternately along the circumference, and the radii of curvature of the wave crests and troughs change continuously along the circumference.

4. The bone conduction loudspeaker device according to claim 1, characterized in that: The outer periphery of the magnet oscillator (40) is provided with an annular flange (41), and the inner ring edges of the first corrugated spring (61) and the second corrugated spring (62) respectively abut against the upper and lower end faces of the annular flange (41).

5. The bone conduction loudspeaker device according to claim 1, characterized in that: The washer (70) is a rigid metal pad with an outer diameter larger than that of the magnetic oscillator (40); when the magnetic oscillator (40) vibrates to its limit stroke, the outer edge of the washer (70) abuts against the inner wall or inner step surface of the housing; or, The washer (70) is made of magnetically conductive metal material and is used to participate in magnetic circuit conduction.

6. The bone conduction loudspeaker device according to claim 1, characterized in that: The coil (50) is fitted outside the magnet oscillator (40), and there is a working air gap between the inner wall of the coil (50) and the outer wall of the magnet oscillator (40).

7. The bone conduction loudspeaker device according to claim 1, characterized in that: The first corrugated spring (61) and the second corrugated spring (62) bear continuous load in the circumferential direction, so that the elastic restoring force on the magnetic oscillator (40) is evenly distributed in the circumferential direction.

8. The bone conduction loudspeaker device according to claim 1, characterized in that: The housing includes a bottom shell (10), an outer shell (20), and a top cover (30). The bottom shell (10) and the top cover (30) are respectively provided with support steps for supporting the outer edges of the first corrugated spring (61) and the second corrugated spring (62). The bottom shell (10) and the top cover (30) are pressed together to lock the compressed state of the corrugated spring assembly (60).

9. The bone conduction loudspeaker device according to claim 1, characterized in that: Under normal operating conditions, the vibration stroke of the magnetic oscillator (40) is less than the limiting gap, and the washer (70) remains in a non-contact state with the housing.

10. A bone conduction headphone, characterized in that: Includes the bone conduction loudspeaker device as described in any one of claims 1 to 9.

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