Piezoelectric loudspeaker

Abstract

The embodiment of the invention discloses a piezoelectric loudspeaker. The piezoelectric loudspeaker comprises a vibrating diaphragm and a reinforcing structure, the vibrating diaphragm comprises a substrate and a piezoelectric layer, and the piezoelectric layer is located on the surface of one side of the substrate. The reinforcing structure is located on one side of the substrate and at least makes contact with the piezoelectric layer. By adopting the technical scheme, the overall rigidity of the vibrating diaphragm is improved, so that the segmentation vibration of the vibrating diaphragm is inhibited, the frequency response stability of the piezoelectric loudspeaker is improved, and the performance of the piezoelectric loudspeaker is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of loudspeaker devices, and particularly to a piezoelectric loudspeaker. Background Art

[0002] With the improvement of the performance and the increase of functions of mobile devices such as mobile phones and TWS earphones, the internal space is continuously compressed, so there are higher requirements for the size and volume of components.

[0003] Piezoelectric loudspeakers have become the focus of attention in the loudspeaker field due to their small size and excellent high-frequency performance. Most piezoelectric loudspeakers have a fixed diaphragm or cantilever beam structure. When the piezoelectric loudspeaker operates in the high-frequency band, the higher-order modes of the two diaphragms or the splitting vibration caused by the poor uniformity of the thin film will lead to excessive local displacement, resulting in serious nonlinearity. Even the vibration displacements in different regions may be opposite, which will seriously affect the sound pressure level output of the loudspeaker. Summary of the Invention

[0004] An embodiment of the present invention provides a piezoelectric loudspeaker, which can suppress splitting vibration, improve the stability of the frequency response of the loudspeaker, and enhance the performance of the loudspeaker.

[0005] An embodiment of the present invention provides a piezoelectric loudspeaker, including: a diaphragm and a strengthening structure;

[0006] The diaphragm includes a substrate and a piezoelectric layer, and the piezoelectric layer is located on one side surface of the substrate;

[0007] The strengthening structure is located on one side of the substrate and is at least in contact with the piezoelectric layer.

[0008] Optionally, the strengthening structure includes at least two first strengthening structures;

[0009] Along the thickness direction of the diaphragm, the heights of the two first strengthening structures are different.

[0010] Optionally, the diaphragm at least includes a first diaphragm sub-structure and a second diaphragm sub-structure, and a slit is provided between the first diaphragm sub-structure and the second diaphragm sub-structure;

[0011] The strengthening structure includes at least one second strengthening structure, and the second strengthening structure connects the first diaphragm sub-structure and the second diaphragm sub-structure; and along the thickness direction of the diaphragm, the second strengthening structure overlaps with the slit.

[0012] Optionally, the diaphragm further includes at least one groove, and the groove is at least located in the piezoelectric layer;

[0013] The strengthening structure includes at least one third strengthening structure, and the third strengthening structure is embedded in the groove.

[0014] Optionally, the groove includes a first groove portion located in the piezoelectric layer and a second groove portion located in the substrate;

[0015] Part of the third reinforcing structure is located in the first groove portion, and the remaining part of the structure is located in the second groove portion.

[0016] Optionally, the reinforcing structure includes a plurality of sub-reinforcing structures, and the extending directions of two of the sub-reinforcing structures intersect;

[0017] And / or, there is a sub-reinforcing structure that is a ring structure.

[0018] Optionally, the sub-reinforcing structure includes at least one first sub-reinforcing structure;

[0019] The first sub-reinforcing structure includes a first end and a second end that are oppositely arranged; wherein, both the first end and the second end are located on the surface of the piezoelectric layer away from the substrate.

[0020] Optionally, the sub-reinforcing structure includes at least one second sub-reinforcing structure;

[0021] The second sub-reinforcing structure includes a third end and a fourth end that are oppositely arranged; wherein, the third end is located on the surface of the piezoelectric layer away from the substrate, and the fourth end is located on the surface of the substrate close to the piezoelectric layer.

[0022] Optionally, the sub-reinforcing structure includes at least one first sub-reinforcing structure and at least one second sub-reinforcing structure;

[0023] The first sub-reinforcing structure includes a first end and a second end that are oppositely arranged; wherein, both the first end and the second end are located on the surface of the piezoelectric layer away from the substrate;

[0024] The second sub-reinforcing structure includes a third end and a fourth end that are oppositely arranged; wherein, the third end is located on the surface of the piezoelectric layer away from the substrate, and the fourth end is located on the surface of the substrate close to the piezoelectric layer;

[0025] The first sub-reinforcing structure intersects and / or abuts against the second sub-reinforcing structure.

[0026] Optionally, the Young's modulus of the material of the reinforcing structure is greater than the Young's modulus of the material of the diaphragm.

[0027] In this embodiment, a reinforcing structure is provided on one side of the diaphragm substrate, and the reinforcing structure is in contact with at least the piezoelectric layer of the diaphragm, improving the overall rigidity of the diaphragm, thereby suppressing the splitting vibration caused by high-order vibration modes and film non-uniformity of the diaphragm, improving the stability of the frequency response of the piezoelectric speaker, and improving the performance of the piezoelectric speaker.

[0028] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 is a schematic structural diagram of a piezoelectric speaker provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0033] Figure 4 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0034] Figure 5 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0035] Figure 6 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0036] Figure 7 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0037] Figure 8 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0038] Figure 9 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0039] Figure 10It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0040] Figure 11 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0041] Figure 12 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0042] Figure 13 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0043] Figure 14 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0044] Figure 15 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0045] Figure 16 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention;

[0046] Figure 17 It is a schematic structural diagram of yet another piezoelectric speaker provided by an embodiment of the present invention. Detailed implementation manners

[0047] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily need to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0049] A piezoelectric speaker is a device that uses the piezoelectric effect to convert electrical energy into sound energy. Its core is piezoelectric material. When the audio signal is transmitted to the piezoelectric element through the circuit, the piezoelectric material will undergo elastic deformation toward or away from the direction perpendicular to the surface of the speaker, forming sound waves and thus producing sound. On the one hand, since the diaphragm of the piezoelectric speaker will vibrate according to a certain vibration mode when stimulated by an electrical signal, in addition to the basic global vibration mode, when the size, shape and driving frequency of the diaphragm satisfy a specific relationship, high-order vibration modes may be excited. The existence of high-order vibration modes will lead to inconsistent vibration amplitudes and phases in different areas of the diaphragm. In some areas, the vibration amplitude may be large, while in other areas it is small, or even the vibration direction may be opposite. This vibration unevenness will destroy the uniformity of sound propagation, causing differences in the propagation effects of sound in different directions, thereby producing a split vibration phenomenon; on the other hand, the material used to manufacture the diaphragm may have unevenness in density, elastic modulus, etc. The unevenness of the film will cause the stiffness of the diaphragm at different positions to be different. When the area with greater stiffness is stimulated by the same electrical signal, the vibration amplitude will be relatively small, while the area with less stiffness will produce a larger vibration amplitude. This stiffness difference will also lead to uneven vibration of the diaphragm, forming a split vibration phenomenon. It can be seen that the split vibration caused by high-order modes or poor film uniformity will lead to excessive local displacement and serious nonlinearity, and even cause opposite vibration displacements in different areas, thereby distorting the sound signal and seriously affecting the sound quality and performance of the piezoelectric speaker.

[0050] Based on the above problems, Figure 1 is a schematic diagram of the structure of a piezoelectric speaker provided by an embodiment of the present invention, such as Figure 1 As shown, a piezoelectric speaker provided by an embodiment of the present invention includes: a diaphragm 1 and a reinforcement structure 2; the diaphragm 1 includes a substrate 11 and a piezoelectric layer 12, and the piezoelectric layer 12 is located on one side surface of the substrate 11; the reinforcement structure 2 is located on one side of the substrate 11 and is in contact with at least the piezoelectric layer 12.

[0051] Specifically, the piezoelectric speaker includes a diaphragm 1, which is a device for radiating sound in the piezoelectric speaker, and can convert the mechanical vibration of the piezoelectric layer due to the piezoelectric effect into sound waves, thereby realizing the conversion of electrical signals into sound signals, and includes a substrate 11 and a piezoelectric layer 12. The substrate 11, as the basic supporting part of the diaphragm 1, is usually made of a material with a certain strength and toughness, and plays a role in supporting and protecting the piezoelectric layer 12. When the diaphragm 1 vibrates, the substrate 11 moves with the piezoelectric layer 12, but due to its own strength and stability, the overall stability of the diaphragm 1 during the vibration process is guaranteed. The piezoelectric layer 12 is a functional layer that uses the piezoelectric effect to realize the mutual conversion between electrical energy and mechanical energy. In a piezoelectric speaker, the piezoelectric layer 12 is located on one side surface of the substrate 11, plays a core driving role, and is a key component for generating sound. When an audio electrical signal is applied to the piezoelectric layer 12, the charge distribution in the crystal structure inside the piezoelectric layer 12 changes according to the positive and negative polarity changes of the signal, resulting in distortion of the unit cell. Macroscopically, the piezoelectric layer 12 produces a corresponding elongation or contraction deformation. This deformation responds quickly with the change of the electric field, and can convert the electrical signal into a mechanical vibration signal, driving the diaphragm 1 to move, thereby forming a sparse and dense wave in the air around the diaphragm 1, thereby realizing the vibration and sound generation of the diaphragm 1.

[0052] Furthermore, the piezoelectric speaker also includes a reinforcement structure 2. The presence of the reinforcement structure 2 increases the overall rigidity of the diaphragm 1, so that the response of the diaphragm 1 to local excitation becomes consistent, and the entire diaphragm 1 is more inclined to vibrate as a whole, thereby reducing the split vibration caused by the uneven local stress of the diaphragm 1 due to high-order modes or poor film uniformity. During the operation of the piezoelectric speaker, the diaphragm 1 needs to vibrate quickly and frequently to produce sound along with the vibration generated by the piezoelectric layer 12 after being excited by an electrical signal. When the diaphragm 1 is provided with a reinforcement structure 2 on one side of the substrate 11 and the reinforcement structure 2 is at least in contact with the piezoelectric layer 12, its overall bending stiffness is improved, and it can effectively resist the local deformation caused by high-frequency signals; at the same time, the structure can constrain the irregular vibration of the diaphragm 1, reduce the excitation of high-order modes, and enable the diaphragm 1 to maintain overall synchronous vibration in a wider frequency range, thereby reducing the sound wave interference and frequency response distortion caused by split vibration, improving the stability of the frequency response of the piezoelectric speaker, and improving the performance of the piezoelectric speaker.

[0053] This embodiment improves the overall rigidity of the diaphragm by providing a reinforcement structure on one side of the diaphragm substrate, and the reinforcement structure is in contact with at least the piezoelectric layer of the diaphragm, thereby suppressing the split vibration of the diaphragm caused by high-order vibration modes and film unevenness, improving the stability of the frequency response of the piezoelectric speaker, and improving the performance of the piezoelectric speaker.

[0054] Based on the above embodiments, Figure 2 is a schematic diagram of the structure of another piezoelectric speaker provided by an embodiment of the present invention. Figure 2As shown, the reinforcement structure 2 includes at least two first reinforcement structures 21 ; along the thickness direction X of the diaphragm 1 , there are two first reinforcement structures 21 with different heights.

[0055] Specifically, when the reinforcement structure 2 is composed of at least two first reinforcement structures 21, it can provide additional support and reinforcement in different areas of the diaphragm 1, and improve the resonance frequency of the diaphragm 1 to move to a higher frequency range, which means that in the low frequency band, the vibration amplitude of the diaphragm 1 is relatively reduced, while in the high frequency band, the diaphragm 1 can better transmit high-frequency signals, so that the frequency response curve of the piezoelectric speaker is extended at the high frequency end, and the overall frequency response is more stable. When the diaphragm 1 is excited by the audio signal during the vibration process, multiple reinforcement structures help to further disperse the stress of the diaphragm 1, avoiding damage to the diaphragm 1 or split vibration caused by excessive local stress; at the same time, multiple first reinforcement structures 21 can be arranged along the extension direction of the diaphragm 1. A single reinforcement structure 2 may cause the vibration of the diaphragm 1 in the reinforcement structure 2 and non-reinforcement structure areas to be inconsistent, while multiple first reinforcement structures 21 can reduce this inconsistency and make the vibration of the entire diaphragm 1 in the thickness direction X more uniform.

[0056] Furthermore, along the thickness direction X of the diaphragm 1, there are two first reinforcement structures 21 with different heights, which can adapt to the vibration characteristics at different frequencies. When the diaphragm 1 vibrates at a low frequency, the deformation is relatively large and more integrated. A relatively high first reinforcement structure 21 can be set to limit the overall deformation of the diaphragm 1 in a larger range and prevent split vibration caused by excessive overall deformation; when the diaphragm 1 vibrates at a high frequency, the local vibration is more obvious. The lower first reinforcement structure 21 can stabilize the local vibration and suppress excessive vibration in the local area, thereby effectively reducing the occurrence of split vibration in the entire frequency band. This first reinforcement structure 21 with different heights can provide appropriate constraints on the diaphragm 1 for vibrations of different frequencies, so that the diaphragm 1 can maintain a better vibration state within a wider frequency range, reduce the split vibration phenomenon at different frequencies, improve the performance of the piezoelectric speaker, and improve the applicability of the piezoelectric speaker.

[0057] For example, continue to refer to Figure 2The diaphragm 1 includes a substrate 11 and a piezoelectric layer 12. The first reinforcement structures 21 of different heights can be manufactured by deposition or step-by-step etching. The three first reinforcement structures 21 are arranged in contact with each other along the extension direction Y of the diaphragm 1 on the side surface of the piezoelectric layer 12 away from the substrate 11. Along the thickness direction X of the diaphragm 1, the thickness of the first first reinforcement structure 21 is less than the thickness of the second first reinforcement structure 21, and the thickness of the second first reinforcement structure 21 is less than the thickness of the third first reinforcement structure 21. The first reinforcement structure 21 can suppress excessive vibration in a local area of ​​the diaphragm 1, and the third first reinforcement structure 21 can limit the overall deformation of the diaphragm 1 in a larger range. The three first reinforcement structures cooperate with each other to improve the suppression effect of the split vibration of the diaphragm 1 at each frequency. It should be noted that at least two first reinforcing structures 21 may be arranged in contact with each other on the side surface of the piezoelectric layer 12 away from the substrate 11, or may be arranged at a predetermined distance on the side surface of the piezoelectric layer 12 away from the substrate 11; a plurality of first reinforcing structures 21 with different heights may be increased in sequence at a fixed value, or the heights of the first reinforcing structures 21 at different positions may be set separately according to actual needs. Figure 2 The configuration of the first reinforcement structure 21 is merely shown for illustrative purposes and is not intended to be a specific limitation on this embodiment.

[0058] In this embodiment, the reinforcement structure includes at least two first reinforcement structures to provide support and reinforcement in different areas of the diaphragm, uniformly improving the overall rigidity of the diaphragm, making the vibration of the entire diaphragm in the thickness direction more uniform, and avoiding the uncoordinated vibration of the diaphragm caused by the reinforcement structure. Along the thickness direction of the diaphragm, there are two first reinforcement structures with different heights, which can provide appropriate constraints for the diaphragm in a targeted manner, improve the performance of the piezoelectric speaker, and improve the applicability of the piezoelectric speaker.

[0059] Based on the above embodiments, Figure 3 is a schematic diagram of the structure of another piezoelectric speaker provided by an embodiment of the present invention. Figure 3 As shown, the diaphragm 1 includes at least a first diaphragm substructure 3 and a second diaphragm substructure 4, and a slit 5 is arranged between the first diaphragm substructure 3 and the second diaphragm substructure 4; the reinforcement structure 2 includes at least one second reinforcement structure 22, and the second reinforcement structure 22 connects the first diaphragm substructure 3 and the second diaphragm substructure 4; and along the thickness direction X of the diaphragm 1, the second reinforcement structure 22 overlaps with the slit 5.

[0060] Specifically, the diaphragm 1 includes a first diaphragm sub-structure 3 and a second diaphragm sub-structure 4, and there is a slit 5 between the two diaphragm sub-structures. Therefore, the first diaphragm sub-structure 3 and the second diaphragm sub-structure 4 can vibrate independently to a certain extent. Within the frequency range of the audio signal, signals of the same frequency may cause differential vibrations on the first diaphragm sub-structure 3 and the second diaphragm sub-structure 4, resulting in a splitting vibration phenomenon of the diaphragm 1, and the diaphragm 1 generates non-linear distortion, thereby reducing the sound quality of the piezoelectric speaker. To solve the above problems, at least one second strengthening structure 22 can be provided in the piezoelectric speaker. The second strengthening structure 22 straddles the slit 5 and overlaps with the slit 5 in the thickness direction X of the diaphragm 1, forming a rigid connection between the first diaphragm sub-structure 3 and the second diaphragm sub-structure 4, eliminating the vibration isolation between the first diaphragm sub-structure 3 and the second diaphragm sub-structure 4 caused by the slit 5, enabling the two sub-structures to maintain phase consistency during vibration, restricting the relative displacement on both sides of the slit 5, preventing the vibration energy from diffusing through the slit 5 to adjacent sub-structures, forcing the vibration energy to concentrate on the low-order overall mode rather than the high-order splitting mode, reducing the multi-region out-of-phase vibration, and avoiding local differential deformations caused by the separation of the slit 5. On the other hand, the second strengthening structure 22 overlaps with the slit 5 in the thickness direction X, which is equivalent to forming a structure similar to a "bridge" in the slit 5 region. Among them, the "bridge" structure can be prepared by adding a sacrificial layer under the second strengthening structure 22. The second strengthening structure 22 with the "bridge" structure significantly increases the sectional moment of inertia of the slit 5 region, improves the bending stiffness of the first diaphragm sub-structure 3 and the second diaphragm sub-structure 3 at the edge of the slit 5, reduces the local bending deformation of the sub-structures during high-frequency vibration, suppresses the out-of-phase vibration of the first diaphragm sub-structure 3 and the second diaphragm sub-structure 4 under high-frequency signals (such as the vibration directions of the central region and the edge are opposite), suppresses the splitting motion through the second strengthening structure 22, thereby reducing the frequency response peaks and valleys in the high-frequency band, making the sound pressure level curve smoother, reducing the distortion rate, and improving the performance of the piezoelectric speaker.

[0061] In this embodiment, the first diaphragm sub-structure and the second diaphragm sub-structure are connected by the second strengthening structure, so that the first diaphragm sub-structure and the second diaphragm sub-structure are integrated into a cooperative motion unit. And along the thickness direction of the diaphragm, the second strengthening structure overlaps with the slit, ensuring the vibration consistency of the two, strengthening the local rigidity of the first diaphragm sub-structure and the second diaphragm sub-structure near the slit, suppressing the splitting motion of the diaphragm, and improving the stability of the frequency response of the piezoelectric speaker.

[0062] Based on the above embodiment, Figure 4 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention. As Figure 4 shown, the diaphragm 1 further includes at least one groove 13, and the groove 13 is at least located in the piezoelectric layer 12; the strengthening structure 2 includes at least one third strengthening structure 23, and the third strengthening structure 23 is embedded in the groove 13.

[0063] Specifically, the diaphragm 1 is subjected to alternating stress during the vibration process. At least one groove 13 is provided in the piezoelectric layer 12. The groove 13 can be used as a buffer area. When the diaphragm 1 is subjected to different degrees of stress in different areas, the groove 13 can allow the diaphragm 1 to have a certain deformation space locally, thereby avoiding excessive stress concentration in a specific area and causing damage to the diaphragm 1, thereby extending the service life of the diaphragm 1. The presence of the groove 13 will change the mass distribution and stiffness distribution of the diaphragm 1, thereby affecting the vibration mode of the diaphragm 1. Therefore, the third reinforcement structure is embedded in the groove 13, and the vibration of the diaphragm 1 can be finely adjusted. The combination of the two allows the diaphragm 1 to maintain a certain flexibility to adapt to the change of vibration when it is subjected to a large vibration amplitude, and to resist excessive deformation with the help of the rigidity of the third reinforcement structure 23, suppress unnecessary vibration, and make the vibration of the diaphragm 1 more concentrated in the effective sound frequency range, thereby improving the quality and clarity of the sound. The material density of the third reinforcement structure 23 can be different from that of the piezoelectric layer 12. By adjusting its embedding position and volume ratio, the equivalent mass and stiffness ratio of the diaphragm 1 can be precisely controlled to prevent high-frequency splitting vibrations caused by the diaphragm 1 having too low mass and / or rigidity. The internal splitting vibrations of the piezoelectric layer 12 can be accurately suppressed to avoid high-frequency distortion and improve the performance of the piezoelectric speaker.

[0064] Furthermore, compared with providing an additional reinforcement structure on the surface of the piezoelectric layer 12 away from the substrate 11 to suppress the split vibration, the third reinforcement structure 23 is embedded in the groove 13 of the diaphragm 1, which not only suppresses the split vibration of the diaphragm 1, but also effectively saves the overall space occupation of the device, meets the demand for miniaturization of the piezoelectric speaker, and facilitates the internal layout and assembly of the piezoelectric speaker.

[0065] In this embodiment, at least one groove is provided in the diaphragm, and the groove is located at least in the piezoelectric layer. A third reinforcement structure is provided inside the groove to achieve an integrated design of the third reinforcement structure and the diaphragm, thereby reducing the overall space occupation of the device and meeting the demand for miniaturization of the piezoelectric speaker. In addition, the groove improves the deformation resistance of the diaphragm, and the third reinforcement structure filled inside can accurately control the equivalent mass and stiffness ratio of the diaphragm, accurately suppress the internal split vibration of the diaphragm, avoid high-frequency distortion, and improve the performance of the piezoelectric speaker.

[0066] Optional, Figure 5 is a schematic diagram of the structure of another piezoelectric speaker provided by an embodiment of the present invention. Figure 5 As shown, the groove 13 includes a first groove section 131 located in the piezoelectric layer 12 and a second groove section 132 located in the substrate 11 ; part of the structure in the third reinforcement structure 23 is located in the first groove section 131 , and the rest of the structure is located in the second groove section 132 .

[0067] Specifically, the materials of the piezoelectric layer 12 and the substrate 11 usually have different physical and mechanical properties. The groove 13 may include a first groove portion 131 located in the piezoelectric layer 12 and a second groove portion 132 located in the substrate 11. This layered design enables the groove 13 to play a buffering role at different levels of the diaphragm 1. When the diaphragm 1 vibrates, the stresses borne by the piezoelectric layer 12 and the substrate 11 are different. The layered groove 13 can relieve the stress characteristics of the piezoelectric layer 12 and the substrate 11 respectively, precisely reducing the stress concentration in each layer. The presence of the first groove portion 131 and the second groove portion 132 can make the vibration mode of the diaphragm 1 more complex and diverse. By reasonably designing the size, shape, and position of the two groove portions and cooperating with the corresponding third reinforcing structure 23 filled therein, the equivalent mass-to-stiffness ratio of the piezoelectric layer 12 and the equivalent mass-to-stiffness ratio of the substrate 11 are respectively and precisely regulated, accurately suppressing the splitting vibration of the piezoelectric layer 12 and the substrate 11, improving the overall vibration stability of the diaphragm 1, enabling it to better match sound signals of different frequencies, thereby improving the quality and clarity of sound and enhancing the performance of the piezoelectric loudspeaker.

[0068] Optionally, continuing to refer to Figure 4 , along the thickness direction X of the diaphragm 1, the thickness of the third reinforcing structure 23 is the same as the depth of the groove 13.

[0069] Specifically, the design in which the thickness of the third reinforcing structure 23 is the same as the depth of the groove 13 can ensure that after the groove 13 is formed in the diaphragm 1, the surface on one side of the diaphragm 1 including the opening of the groove 13 remains flattened. The reflection and scattering of sound on the surface of the diaphragm 1 will be more regular. Compared with the diaphragm 1 with an uneven surface, the flat diaphragm 1 can make the sound wave propagate forward more effectively, reduce the sound wave scattering caused by surface unevenness, and can better respond to sound signals of different frequencies during the vibration process, making the frequency response curve of the loudspeaker flatter and avoiding the loss and distortion of sound signals during the propagation process. At the same time, the flattening of the surface of the diaphragm 1 can reduce the situation of local stress concentration. When the surface of the diaphragm 1 is uneven, during the vibration process, the stress will concentrate at the uneven parts, and it is easy to cause fatigue damage to the diaphragm after long-term use. However, the flat surface of the diaphragm 1 can make the stress distribution more uniform, reducing the risk of damage caused by excessive local stress, thereby extending the service life of the diaphragm 1.

[0070] Based on the above embodiments, Figure 6 is a schematic structural diagram of another piezoelectric loudspeaker provided by an embodiment of the present invention; Figure 7 is a schematic structural diagram of another piezoelectric loudspeaker provided by an embodiment of the present invention. As Figures 6 to 7As shown, the reinforcing structure 2 includes a plurality of sub-reinforcing structures 24, and there are two sub-reinforcing structures 24 whose extending directions intersect; and / or, there is a sub-reinforcing structure 24 that is a ring structure.

[0071] Specifically, when the piezoelectric speaker is working, the diaphragm 1 will be subjected to forces from different directions, such as inertial forces generated by vibration, sound pressure, etc. When there are two sub-reinforcing structures 24 with intersecting extending directions in the reinforcing structure 2 on one side of the diaphragm 1, as Figure 6 shown, the intersecting sub-reinforcing structures 24 can transfer these forces along different directions, avoiding stress concentration in a local area, thereby reducing the risk of damage to the diaphragm 1 due to stress concentration; at the same time, the two sub-reinforcing structures 24 with intersecting extending directions will form a grid-like support structure, increasing the overall rigidity of the diaphragm 1. This improvement in rigidity can make the diaphragm 1 more stable during vibration, reduce unnecessary deformation, and thus suppress the splitting vibration of the diaphragm 1, improving the sound quality. When there is a sub-reinforcing structure 24 with a ring structure in the reinforcing structure 2 on one side of the diaphragm 1, as Figure 7 shown, since the ring structure has no obvious starting and ending points, the force can be continuously transmitted within the ring, and there will be no stress concentration at the endpoints, thereby making the stress distribution on the surface of the diaphragm 1 more uniform. This uniform stress distribution helps to improve the stability of the diaphragm 1 under different working conditions and reduce deformation or damage caused by excessive local stress; at the same time, the ring-shaped sub-reinforcing structure 24 provides a complete support ring for the diaphragm 1, enhancing the edge strength of the diaphragm 1. The edge of the diaphragm 1 is a part that is relatively easy to vibrate and deform. The ring-shaped sub-reinforcing structure 24 can effectively fix the edge of the diaphragm 1, increase the overall rigidity of the diaphragm 1, suppress the splitting vibration generated at the edge, improve the stability of the frequency response of the piezoelectric speaker, and enhance the performance of the piezoelectric speaker.

[0072] In this embodiment, by setting the reinforcing structure to include a plurality of sub-reinforcing structures, there are two sub-reinforcing structures whose extending directions intersect; and / or, there is a sub-reinforcing structure that is a ring structure, thereby avoiding stress concentration on the diaphragm in a local area, prolonging the service life of the diaphragm. At the same time, the overall rigidity of the diaphragm is improved by using a plurality of sub-reinforcing structures, the splitting vibration of the diaphragm is suppressed, the stability of the frequency response of the piezoelectric speaker is improved, and the performance of the piezoelectric speaker is improved.

[0073] Optionally, Figure 8 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 9 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 10 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 11 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 12It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 13 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention. As Figure 1 , and Figures 8 to 13 shown, the sub-strengthening structure 24 includes at least one first sub-strengthening structure 241; the first sub-strengthening structure 241 includes a first end 2411 and a second end 2412 which are oppositely arranged; wherein, both the first end 2411 and the second end 2412 are located on the surface of the piezoelectric layer 12 away from the substrate 11.

[0074] Specifically, the sub-strengthening structure 24 may include at least one first sub-strengthening structure 241. The first sub-strengthening structure 241 includes a first end 2411 and a second end 2412 which are oppositely arranged, that is, the head end and the tail end of the first sub-strengthening structure 241. By arranging both the first end 2411 and the second end 2412 on the surface of the piezoelectric layer 12 away from the substrate 11, it can be ensured that the strengthening structure 2 is completely arranged on the upper surface of the piezoelectric layer 12, which is more simple and feasible in the production process of the piezoelectric speaker. This design enables the first sub-strengthening structure 241 to be attached to the piezoelectric layer through relatively simple surface processing, pasting or fixing processes after the piezoelectric layer 12 is manufactured, greatly improving the production efficiency and product consistency; at the same time, there is no need to perform complex internal structure processing or deep integration with the piezoelectric layer 12, which will not affect the original vibration properties of the diaphragm 1, simplifies the operation of enhancing the overall rigidity of the diaphragm 1, and reduces the technical difficulty of realizing the suppression of the splitting vibration of the diaphragm 1.

[0075] Optionally, Figure 14 It is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention. As Figure 14 shown, the sub-strengthening structure 24 includes at least one second sub-strengthening structure 242; the second sub-strengthening structure 242 includes a third end 2421 and a fourth end 2422 which are oppositely arranged; wherein, the third end 2421 is located on the surface of the piezoelectric layer 12 away from the substrate 11, and the fourth end 2422 is located on the surface of the substrate 11 close to the piezoelectric layer 12.

[0076] Specifically, the sub-reinforcement structure 24 may include at least one second sub-reinforcement structure 242. The second sub-reinforcement structure 242 includes a relatively arranged third end 2421 and a fourth end 2422, that is, the head end and the tail end of the second sub-reinforcement structure 242. The third end 2421 is disposed on the surface of the piezoelectric layer 12 away from the substrate 11, and the fourth end 2422 is located on the surface of the substrate 11 close to the piezoelectric layer 12. While increasing the overall rigidity of the diaphragm 1 and suppressing the splitting vibration of the diaphragm 1, the second sub-reinforcement structure 242 serves as a connection bridge between the substrate 11 and the piezoelectric layer 12. One end connected to the substrate 11 can provide a stable support foundation, and the other end connected to the piezoelectric layer 12 enables the vibration of the substrate 1 and the piezoelectric layer 12 to be coordinated. This synergistic effect makes the vibration of the diaphragm 1 more efficient, can respond in a timely manner to the vibration changes of the piezoelectric layer 12, and enhances the vibration sensitivity of the speaker.

[0077] Optionally, Figure 15 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 16 is a schematic structural diagram of another piezoelectric speaker provided by an embodiment of the present invention; Figure 17 is a schematic structural diagram of yet another piezoelectric speaker provided by an embodiment of the present invention. As Figures 15 to 17 shown, the sub-reinforcement structure 24 includes at least one first sub-reinforcement structure 241 and at least one second sub-reinforcement structure 242; the first sub-reinforcement structure 241 includes a relatively arranged first end 2411 and a second end 2412; wherein, both the first end 2411 and the second end 2412 are located on the surface of the piezoelectric layer 12 away from the substrate 11; the second sub-reinforcement structure 242 includes a relatively arranged third end 2421 and a fourth end 2412; wherein, the third end 2421 is located on the surface of the piezoelectric layer 12 away from the substrate 11, and the fourth end 2422 is located on the surface of the substrate 11 close to the piezoelectric layer 12; the first sub-reinforcement structure 241 intersects and / or abuts against the second sub-reinforcement structure 242.

[0078] Specifically, the first sub-reinforcement structure 241 intersects and / or abuts against the second sub-reinforcement structure 242. By directly enhancing the local stiffness inside the piezoelectric layer 12 through the first sub-reinforcement structure 241, the high-frequency splitting vibration is suppressed, and the phase distortion caused by the deformation of the piezoelectric material itself is reduced. Through the second sub-reinforcement structure 242, a rigid anchoring between the piezoelectric layer 12 and the substrate 11 is established, the overall structural stability is improved, the vibration stress is dispersed, and the risks of energy loss and interface delamination are avoided. The combination of the two improves the setting flexibility and adaptability of the reinforcement structure 2, broadens the applicable scenarios of the reinforcement structure 2, and the first sub-reinforcement structure 241 and the second sub-reinforcement structure 242 respectively achieve coordinated effects from two dimensions of internal constraint and boundary condition control, not only expanding the effective vibration suppression frequency band, but also enhancing the durability of the device, and can be applicable to miniaturized, high-power or wide-frequency acoustic scenarios, realizing a double breakthrough in the performance and reliability of the piezoelectric speaker.

[0079] Optionally, as Figure 1 shown, the Young's modulus of the material of the reinforcing structure 2 is greater than that of the material of the diaphragm 1.

[0080] Specifically, the Young's modulus is a core parameter in material mechanics, which is used to quantify the anti-deformation ability of a material when it is stressed, that is, the stiffness of the material itself. The larger the Young's modulus, the more difficult it is to stretch or compress the material, and the stronger the rigidity. By locally embedding or connecting the reinforcing structure 2 with a Young's modulus higher than that of the main body of the diaphragm 1, the bending stiffness of the target area in the diaphragm 1 can be enhanced specifically, so that the high-frequency vibration energy is more evenly distributed throughout the diaphragm 1, reducing local deformation and phase difference caused by the soft material; at the same time, the high Young's modulus material can efficiently transmit vibration stress, so that the reinforcing structure 2 can suppress the relative displacement of different positions of the diaphragm 1 itself, maintain the overall modal consistency of the diaphragm 1, thereby reducing the acoustic interference distortion caused by split vibration and extending the service life of the device under high load. Exemplarily, the material of the reinforcing structure 2 can be at least one of alumina, silicon nitride or silicon carbide.

[0081] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A piezoelectric speaker, characterized in that, Comprising: A diaphragm and a strengthening structure; The diaphragm includes a substrate and a piezoelectric layer, and the piezoelectric layer is located on one side surface of the substrate; The strengthening structure is located on one side of the substrate and is in contact with at least the piezoelectric layer.

2. The piezoelectric speaker according to claim 1, wherein The strengthening structure includes at least two first strengthening structures; Along the thickness direction of the diaphragm, the heights of the two first strengthening structures are different.

3. The piezoelectric speaker according to claim 1, wherein The diaphragm at least includes a first diaphragm sub-structure and a second diaphragm sub-structure, and a slit is provided between the first diaphragm sub-structure and the second diaphragm sub-structure; The strengthening structure includes at least one second strengthening structure, and the second strengthening structure connects the first diaphragm sub-structure and the second diaphragm sub-structure; and along the thickness direction of the diaphragm, the second strengthening structure overlaps with the slit.

4. The piezoelectric loudspeaker according to claim 1, wherein, The diaphragm further includes at least one groove, and the groove is at least located in the piezoelectric layer; The strengthening structure includes at least one third strengthening structure, and the third strengthening structure is embedded in the groove.

5. The piezoelectric speaker according to claim 4, wherein, The groove includes a first groove portion located in the piezoelectric layer and a second groove portion located in the substrate; Part of the structure of the third strengthening structure is located in the first groove portion, and the remaining part of the structure is located in the second groove portion.

6. The piezoelectric speaker according to claim 1, wherein The strengthening structure includes a plurality of sub-strengthening structures, and the extending directions of two of the sub-strengthening structures intersect; And / or, there is a sub-strengthening structure that is an annular structure.

7. The piezoelectric speaker according to claim 6, characterized in that, The sub-strengthening structure includes at least one first sub-strengthening structure; The first sub-strengthening structure includes a first end and a second end that are oppositely arranged; wherein, both the first end and the second end are located on the side surface of the piezoelectric layer away from the substrate.

8. The piezoelectric speaker according to claim 6, characterized in that, The sub-strengthening structure includes at least one second sub-strengthening structure; The second sub-strengthening structure includes a third end and a fourth end that are oppositely arranged; wherein, the third end is located on the side surface of the piezoelectric layer away from the substrate, and the fourth end is located on the side surface of the substrate close to the piezoelectric layer.

9. The piezoelectric speaker according to claim 6, wherein The sub-strengthening structure includes at least one first sub-strengthening structure and at least one second sub-strengthening structure; The first sub-strengthening structure includes a first end and a second end that are oppositely arranged; wherein, both the first end and the second end are located on the side surface of the piezoelectric layer away from the substrate; The second sub-strengthening structure includes a third end and a fourth end that are oppositely arranged; wherein, the third end is located on the side surface of the piezoelectric layer away from the substrate, and the fourth end is located on the side surface of the substrate close to the piezoelectric layer; The first sub-strengthening structure intersects and / or is connected to the second sub-strengthening structure.

10. The piezoelectric speaker according to claim 1, characterized in that, The Young's modulus of the material of the strengthening structure is greater than the Young's modulus of the material of the diaphragm.

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