Loudspeaker

Abstract

The embodiment of the invention provides a loudspeaker, which comprises a plurality of sound production units arranged at intervals along a first direction, and the plurality of sound production units vibrate along the first direction; the shell is configured to accommodate and support the plurality of sound production units, a plurality of sound outlet holes are formed in the shell, a plurality of acoustic cavities are defined by the shell and the plurality of sound production units, each acoustic cavity is acoustically coupled with at least one sound outlet hole in the shell, and each sound production unit comprises a vibrating diaphragm and a driving structure arranged on the vibrating diaphragm.

Description

Technical Field

[0001] The present invention relates to the field of acoustic technology, and in particular to a loudspeaker. Background Art

[0002] Audio devices, including open headphones, wireless headphones, audio glasses, etc., have gradually increased their requirements for acoustic performance in the low-frequency range. Existing electromagnetic speakers require a large movement range to ensure sufficient sound pressure level at low frequencies, resulting in a larger thickness of the device.

[0003] Therefore, it is necessary to provide a loudspeaker with a small design size and capable of providing sufficient low-frequency output. Summary of the invention

[0004] Some embodiments of the present application provide a loudspeaker, comprising: a plurality of sound-emitting units arranged at intervals along a first direction, the plurality of sound-emitting units vibrating along the first direction; a shell configured to accommodate and support the plurality of sound-emitting units, the shell being provided with a plurality of sound outlets, the shell and the plurality of sound-emitting units forming a plurality of acoustic cavities, each acoustic cavity being acoustically coupled to at least one sound outlet on the shell, wherein the plurality of sound-emitting units each comprises a diaphragm and a driving structure arranged on the diaphragm. The loudspeaker is optimized by providing a plurality of sound-emitting units arranged at intervals along the first direction, so that the acoustic output, especially the low-frequency output, of the loudspeaker is improved under the premise of a certain volume.

[0005] In some embodiments, the driving structure includes a piezoelectric driving structure, the shell includes a plurality of fixing rings, each fixing ring fixing a diaphragm of a sound-emitting unit; the piezoelectric driving structure is connected to the fixing ring via an elastic structure, and the elastic structure is symmetrical with respect to the major axis or minor axis of the piezoelectric driving structure. The setting of the elastic structure can avoid the connection between the driving structure and the fixing ring limiting the vibration of the diaphragm. Furthermore, the symmetrically arranged elastic structure can prevent the sound-emitting unit from having an inverted vibration mode.

[0006] In some embodiments, the driving structure includes a planar coil; the speaker also includes a magnet disposed in the shell; the magnet is disposed on the side of the diaphragm away from the planar coil; or, in the first direction, the magnets are respectively disposed on both sides of the diaphragm, and the planar coil is located between the two magnets; or, the magnet includes a separate magnet, and the separate magnet at least partially overlaps with the projection area of ​​the planar coil in the first direction. The magnet can act with the planar coil to generate a driving force to vibrate the diaphragm. The magnets are disposed on both opposite sides of the diaphragm in the first direction, which can increase the magnetic field strength in the area where the planar coil is located, so as to increase the driving force applied to the diaphragm and increase the vibration amplitude of the diaphragm. The provision of the separate magnet allows the overlapping portion of the planar coil with the separate magnet to be separately magnetized according to demand, so as to achieve separate regulation of the magnetic pole direction and magnetic field strength of the overlapping portion of the planar coil.

[0007] In some embodiments, the housing includes a plurality of fixing rings, each fixing ring fixing a sound-emitting unit, and each fixing ring is provided with two sound outlet holes on its circumference, and the two sound outlet holes are respectively coupled with the acoustic cavities on opposite sides of the sound-emitting unit. The sound-emitting unit can generate sound waves, and the sound waves can be transmitted outwardly through the acoustic cavity where the sound-emitting unit is located and the sound outlet holes acoustically coupled with the acoustic cavity.

[0008] In some embodiments, the shell includes a front shell and a rear shell, a first acoustic cavity is formed between the front shell and an adjacent sound-emitting unit, a second acoustic cavity is formed between the rear shell and another adjacent sound-emitting unit, a third acoustic cavity is formed between two adjacent sound-emitting units, and the thickness of the first acoustic cavity and / or the second acoustic cavity along the first direction is less than the thickness of the third acoustic cavity along the first direction. Since the first acoustic cavity and the second acoustic cavity are respectively formed by a sound-emitting unit and the front shell and the rear shell, and the third acoustic cavity is formed based on two adjacent sound-emitting units, and since fixing rings are evenly distributed on both sides of the sound-emitting unit, the thickness of the third acoustic cavity along the first direction is greater than the thickness of the first acoustic cavity and / or the second acoustic cavity along the first direction.

[0009] In some embodiments, the height of the first acoustic cavity and the second acoustic cavity in the first direction is greater than or equal to 150um, the height of the third acoustic cavity in the first direction is greater than or equal to 300um, the height of the sound holes corresponding to the first acoustic cavity and the second acoustic cavity in the first direction is greater than or equal to 50um, and the height of the sound holes corresponding to the third acoustic cavity in the first direction is greater than or equal to 100um. Through the above settings, when the height of the acoustic cavity and the sound hole coupled to the acoustic cavity is constant, while ensuring that the structural strength of the speaker is not affected, the sound hole can have a larger width in the direction perpendicular to the first direction, that is, the area of ​​the sound hole is larger, its acoustic resistance is smaller, and the output sound pressure level is larger.

[0010] In some embodiments, the piezoelectric drive structure includes a sintered piezoelectric ceramic, and the neutral layer of the sound-generating unit is located in the piezoelectric drive structure; the piezoelectric drive structure includes a first piezoelectric layer, a second piezoelectric layer, a first electrode layer, a second electrode layer and a third electrode layer, and in the first direction, the first electrode layer, the first piezoelectric layer, the second electrode layer, the second piezoelectric layer and the third electrode layer are arranged in sequence; the polarization direction of the first piezoelectric layer and the second piezoelectric layer are the same, and the first voltage of the first electrode layer and the third voltage of the third electrode layer are both greater than or less than the second voltage of the second electrode layer; or, the polarization directions of the first piezoelectric layer and the second piezoelectric layer are opposite, and the first voltage of the first electrode layer, the second voltage of the second electrode layer and the third voltage of the third electrode layer decrease or increase in sequence. Through the above arrangement, the deformation directions of the materials on both sides of the neutral layer along the first direction can be opposite, so as to ensure that the piezoelectric drive structure can have a larger displacement in the first direction, so that the amplitude of the diaphragm is larger.

[0011] In some embodiments, the piezoelectric drive structure includes a MEMS piezoelectric ceramic, and the neutral layer of the sound-generating unit is located outside the piezoelectric drive structure; the piezoelectric drive structure includes a first piezoelectric layer, a second piezoelectric layer, a first electrode layer, a second electrode layer and a third electrode layer, and in the first direction, the first electrode layer, the first piezoelectric layer, the second electrode layer, the second piezoelectric layer and the third electrode layer are arranged in sequence; the polarization directions of the first piezoelectric layer and the second piezoelectric layer are opposite, and the first voltage of the first electrode layer and the third voltage of the third electrode layer are both greater than or less than the second voltage of the second electrode layer; or, the polarization directions of the first piezoelectric layer and the second piezoelectric layer are the same, and the first voltage of the first electrode layer, the second voltage of the second electrode layer and the third voltage of the third electrode layer decrease or increase in sequence. Through the above arrangement, the deformation directions of the materials of the piezoelectric drive structure located on one side of the neutral layer along the first direction can be the same, and the deformation directions of the materials located on both sides of the neutral layer along the first direction are opposite, so as to ensure that the piezoelectric drive structure can have a larger displacement in the first direction, so that the amplitude of the diaphragm is larger.

[0012] In some embodiments, the first driving voltage of the first piezoelectric layer is the difference between the first voltage and the second voltage, the second driving voltage of the second piezoelectric layer is the difference between the second voltage and the third voltage, and the absolute value of the first driving voltage and the absolute value of the second driving voltage are both not higher than 5 V. This is in line with the battery power supply capacity and power consumption of common consumer electronic products such as headphones and audio glasses.

[0013] In some embodiments, the diaphragm includes a piezoelectric covering area and a non-piezoelectric covering area, and the ratio of the first area of ​​the piezoelectric covering area to the suspended area of ​​the sound unit is greater than or equal to 0.4, so that the area of ​​the piezoelectric covering area is larger, more piezoelectric materials participate in the driving, the volume of the pushed air is increased, and the output sound pressure level is increased.

[0014] In some embodiments, the diaphragm includes a piezoelectric covering area and a non-piezoelectric covering area, and the ratio of the second area of ​​the non-piezoelectric covering area to the suspended area of ​​the sound unit is less than 0.65, so as to make the non-piezoelectric covering area smaller, reduce the compliance of the non-piezoelectric covering area, increase the resonant frequency, and increase the output sound pressure level in the frequency band after the resonant frequency.

[0015] In some embodiments, the diaphragm or the driving structure has a long axis direction and a short axis direction, and the sound-emitting unit further includes a mass block arranged along the long axis direction or the short axis direction, and the size of the mass block in the long axis direction or the short axis direction is smaller than the size of the piezoelectric driving structure. The mass block is used to adjust the mass and stiffness of the diaphragm so that the output sound pressure level of the speaker is improved.

[0016] Some embodiments of the present application provide an acoustic output device, characterized in that it includes: a low-frequency unit and a high-frequency unit, wherein the low-frequency unit includes the speaker as described above, wherein the intersection of the frequency response curves of the low-frequency unit and the high-frequency unit is in the range of 300Hz-1000Hz; and the high-frequency unit works at least in the frequency range with the intersection as the lower boundary. The setting of the low-frequency unit and the high-frequency unit can improve the output sound pressure level of the acoustic output device at low frequency. The high-frequency unit works at least in the high-frequency band with the intersection as the lower boundary to achieve better sound pressure level output in the high-frequency band. The high-frequency unit can also work in the high-frequency band and the low-frequency band with the intersection as the boundary at the same time to further improve the low-frequency effect.

[0017] In some embodiments, the acoustic output device includes at least one of a back-hook earphone, an ear-hook earphone, an in-ear earphone, and glasses. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0019] Figure 1A is a schematic diagram of the structure of a speaker according to some embodiments of this specification;

[0020] Figure 1B yes Figure 1A A cross-sectional view of the loudspeaker shown;

[0021] Figure 1C yes Figure 1B A first view of a cross section of the loudspeaker is shown;

[0022] Figure 2A is a simplified structural diagram of a cross section of a loudspeaker according to some embodiments of this specification;

[0023] Figure 2B is a simplified structural diagram of a cross section of a loudspeaker when the diaphragm vibrates according to some embodiments of this specification;

[0024] Figure 3A is a schematic diagram of the structure of a fixing ring and an electrode according to some embodiments of this specification;

[0025] Figure 3B yes Figure 3A Cross-section at AA in the middle;

[0026] Figure 4A is a schematic diagram of the structure of a sound-emitting unit according to some embodiments of this specification;

[0027] Figure 4Bis a schematic structural diagram of a speaker with a sound unit according to some embodiments of this specification;

[0028] Figure 5 for Figure 4B A top view of the loudspeaker shown;

[0029] Figure 6 is a schematic diagram of the structure of a sound-emitting unit according to some embodiments of this specification;

[0030] Figure 7 is a schematic diagram of the structure of a sound-emitting unit according to other embodiments of this specification;

[0031] Figure 8 is a schematic diagram of the structure of a sound-emitting unit according to some other embodiments of the present specification;

[0032] Fig. 9 is a schematic diagram of the structure of a sound-emitting unit according to some other embodiments of the present specification;

[0033] Fig.10 is a cross-sectional view of a piezoelectric drive structure according to some embodiments of the present specification;

[0034] Fig.11A is a schematic diagram of the structure of the piezoelectric drive structure before deformation according to some embodiments of this specification;

[0035] Fig. 11B is a schematic diagram of a structure after a piezoelectric drive structure is deformed according to some embodiments of this specification;

[0036] Fig. 12A is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification;

[0037] Fig. 12B is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification;

[0038] Fig.13A is a schematic diagram of the structure of the piezoelectric drive structure before deformation according to some embodiments of this specification;

[0039] Fig. 13B is a schematic diagram of a structure after a piezoelectric drive structure is deformed according to some embodiments of this specification;

[0040] Fig.14A is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification;

[0041] Fig. 14B is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification;

[0042] Fig. 14C is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification;

[0043] Fig.14D is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification;

[0044] Fig.15 It is a frequency response curve diagram of a loudspeaker corresponding to different values ​​of β according to some embodiments of this specification;

[0045] Fig.16 is a schematic diagram of a quarter structure of a piezoelectric drive structure according to some embodiments of this specification;

[0046] Fig.17 It is a frequency response curve diagram of a loudspeaker corresponding to different values ​​of α according to some embodiments of this specification;

[0047] Fig.18 is a schematic diagram of the arrangement of mass blocks shown in some embodiments of the specification;

[0048] Fig.19A Deformation contour of the diaphragm for a massless setup;

[0049] Fig.19B The deformation cloud diagram of the diaphragm with the mass block set;

[0050] Fig. 20 is a schematic diagram of the arrangement of mass blocks shown in some embodiments of the specification;

[0051] Fig.21A Deformation contour of the diaphragm for a massless setup;

[0052] Fig. 21B The deformation cloud diagram of the diaphragm with the mass block set;

[0053] Fig. 22 is a schematic diagram of the arrangement of mass blocks shown in some embodiments of the specification;

[0054] Fig.23A Deformation contour of the diaphragm for a massless setup;

[0055] Fig. 23B The deformation cloud diagram of the diaphragm with the mass block set;

[0056] Fig.24A is a schematic diagram of the structure of a laminated (10-layer) speaker according to some embodiments of this specification;

[0057] Fig. 24Bis a frequency response curve diagram of a laminated speaker and a single-layer speaker according to some embodiments of this specification;

[0058] Fig.25 is an exemplary schematic diagram of an acoustic output device according to some embodiments of this specification;

[0059] Fig.26A is an exemplary schematic diagram 1 of an acoustic output device according to other embodiments of this specification;

[0060] Fig.26B is a second exemplary schematic diagram of an acoustic output device according to some embodiments of this specification;

[0061] Fig. 27 is an exemplary schematic diagram of an acoustic output device according to some other embodiments of the present specification;

[0062] Fig.28 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification.

[0063] Description of the accompanying drawings: 100, speaker; 110, sound unit; 1101, first sound unit; 1102, second sound unit; 1103, third sound unit; 1104, fourth sound unit; 110n, nth sound unit; 111, diaphragm; 112, driving structure; 1121, planar coil; 1122, magnet; 11221, first magnet; 11222, second magnet; 1123, magnetic plate; 1124, magnetic ring; 1125, piezoelectric driving structure; 1125a, piezoelectric covering area; 1125b, non-piezoelectric covering area; 11251, first electrode layer; 11252, first piezoelectric layer; 11253, second electrode layer; 11254, second piezoelectric layer; 11255, The third electrode layer; 11256, the neutral layer; 113, the elastic structure; 114, the lead; 120, the shell; 1201, the front shell; 1202, the rear shell; 121, the sound outlet hole; 1211, the first sound outlet hole; 1212, the second sound outlet hole; 121i, the i-th sound outlet hole; 121(n+1), the n+1-th sound outlet hole; 1212-1, 1212-2, 1213-1, the sub-sound outlet hole; 122, the acoustic cavity; 1221, the first acoustic cavity; 1222, the second acoustic cavity; 1223, the third acoustic cavity; 123, the fixing ring; 130, the mass block; 140, the damping / dust-proof mesh; 200, the acoustic output device; 201, the first hole portion; 202, the second hole portion; 203, the third hole portion. DETAILED DESCRIPTION

[0064] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0065] It should be understood that the "system", "device", "unit" and / or "module" used herein is a method for distinguishing different components, elements, parts, parts or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions. As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not specifically refer to the singular and may also include the plural. In general, the terms "comprises" and "includes" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

[0066] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0067] The embodiment of the present specification provides a loudspeaker, which includes a housing and a plurality of sound-emitting units. Among them, the plurality of sound-emitting units are arranged at intervals along a first direction and all vibrate along a first direction. The housing is configured to accommodate and support the plurality of sound-emitting units. The housing is provided with a plurality of sound outlets. The housing and the plurality of sound-emitting units enclose a plurality of acoustic cavities, and each acoustic cavity is acoustically coupled with at least one sound outlet hole on the housing. The sound-emitting unit can generate sound waves, and the sound waves can be transmitted outward through the acoustic cavity in which the sound-emitting unit is located and the sound outlet hole acoustically coupled with the acoustic cavity. In some embodiments, the plurality of sound-emitting units each include a diaphragm and a driving structure arranged on the diaphragm. The driving structure drives the diaphragm to vibrate, and the diaphragm in a vibrating state pushes the air in the acoustic cavity to generate sound waves. The embodiment of the present specification optimizes the loudspeaker by setting a plurality of sound-emitting units arranged at intervals along a first direction, so that the loudspeaker can improve the acoustic output, especially the low-frequency output, under the premise of certain restrictions on the volume. And the size of the speaker in the thickness direction can be adjusted by adjusting the number of sound-emitting units in the first direction, so that the speaker can flexibly adapt to the usage scenario.

[0068] Figure 1AIt is a schematic diagram of the structure of a speaker according to some embodiments of this specification. Figure 1B yes Figure 1A A cross-sectional view of the loudspeaker is shown. Figure 1C yes Figure 1B A first view of a loudspeaker in cross section is shown.

[0069] See also Figures 1A-1C The speaker 100 includes a housing 120 and a plurality of sound generating units 110 arranged at intervals along a first direction.

[0070] The first direction described in the embodiment of this specification refers to the thickness direction of the speaker 100. Figure 1A The z direction shown in . The arrangement plane where the sound unit 110 is located is perpendicular to the thickness direction of the speaker 100 (i.e., the first direction). It should be noted that the description of directions involved in this description is not limited to absolute directions, but may also be approximate directions. For example, a plurality of sound units 110 arranged at intervals along a first direction may also be arranged approximately at intervals along the first direction. For another example, the arrangement plane where the sound unit 110 is located is perpendicular to the first direction, or may be approximately perpendicular. The approximate direction here refers to a direction that forms a certain angle with the absolute direction (e.g., the first direction), and the angle may range from -30° to 30°.

[0071] The housing 120 is a regular or irregular three-dimensional structure having an internal accommodating cavity. For example, the housing 120 may be a hollow frame structure, including but not limited to regular shapes such as a rectangular frame, a circular frame, a regular polygonal frame, and any irregular shape. The housing 120 is used to accommodate the sound unit 110. In some embodiments, see Figures 1A-1C , the housing 120 may be a rectangular frame structure. For ease of description, this specification takes the housing 120 as an example of a rectangular frame structure. In some embodiments, the housing 120 may be made of metal (e.g., stainless steel, copper, aluminum alloy, etc.), plastic (e.g., polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and acrylonitrile-butadiene-styrene copolymer (ABS), etc.), composite materials (e.g., metal-based composite materials or non-metal-based composite materials), epoxy resin, phenolic, ceramic, polyimide, glass fiber (e.g., FR4-glass fiber), semiconductor materials (e.g., silicon, silicon dioxide, silicon nitride, silicon carbide, etc.), etc., or any combination thereof.

[0072] The sound unit 110 is a device for generating sound waves. The sound unit 110 is located in the accommodating cavity of the housing 120. In some embodiments, the sound unit 110 includes a diaphragm and a driving structure.

[0073] The driving structure is used to convert an audio signal (e.g., an electrical signal containing audio information) into mechanical vibration. In some embodiments, the driving structure includes a piezoelectric layer. The piezoelectric layer can convert an audio signal into mechanical vibration. Due to the inverse piezoelectric effect of the piezoelectric layer, when the electrical signal (audio signal) acts on the piezoelectric layer, the piezoelectric layer will generate mechanical vibration. In some embodiments, the piezoelectric layer can be made of piezoelectric material, and exemplary piezoelectric materials can include piezoelectric ceramics, piezoelectric crystals, piezoelectric polymers (e.g., polyvinylidene fluoride), etc., or any combination thereof. In some embodiments, the driving structure can be of any shape, such as a sheet, block, columnar, annular structure, etc., or any combination thereof.

[0074] The diaphragm is a component that converts mechanical vibrations from a driving structure into sound waves. In some embodiments, the diaphragm can generate vibrations along a first direction in response to the vibrations of the driving structure, thereby generating sound waves (sound signals). In some embodiments, the driving structure is disposed on the diaphragm. The diaphragm directly responds to the deformation or displacement of the driving structure to generate vibrations, and can drive the air around the diaphragm to vibrate with a larger proportion of the vibration driving force, thereby generating sound waves. In some embodiments, the diaphragm can be a thin film structure with elasticity. For a detailed description of the sound unit 110, please refer to Figure 4A , Figure 6-Figure 9 and its related description.

[0075] When a single sound unit 110 is arranged in the housing cavity of the shell 120 of the speaker 100, the thickness dimension of the speaker 100 is relatively small. By arranging a plurality of sound units 110 in the housing cavity of the shell 120 and arranged at intervals along the first direction, the dimension of the thickness direction of the speaker 100 can be flexibly adjusted, and the speaker 100 can obtain a larger low-frequency output while meeting the smaller design dimension. In some embodiments, the number of sound units 110 arranged at intervals in the first direction can be determined according to actual needs. For example, the number of sound units 110 arranged at intervals in the first direction is determined according to the requirements for the thickness dimension of the speaker 100. For another example, the number of sound units 110 arranged at intervals in the first direction is determined according to the requirements for the output sound pressure level.

[0076] In some embodiments, a plurality of sound generating units 110 arranged at intervals along the first direction divide the housing 120 accommodating cavity into a plurality of acoustic cavities 122 distributed along the first direction. A plurality of sound outlet holes are correspondingly arranged on the housing 120, and each acoustic cavity 122 is acoustically coupled with at least one sound outlet hole on the housing 120, so that each acoustic cavity 122 can communicate with the outside of the speaker 100 to transmit the sound waves generated by the sound generating unit 110 to the outside. Figure 1B and Figure 1CAs shown, n sound units 110 are arranged at intervals along the first direction, and the n sound units 110 include a first sound unit 1101, a second sound unit 1102...the nth sound unit 110n. The housing cavity of the shell 120 is divided to form n+1 acoustic cavities 122 distributed along the first direction, and n+1 sound holes are correspondingly arranged on the shell 120, and the n+1 sound holes 121 include a first sound hole 1211, a second sound hole 1212...the n+1th sound hole 121(n+1). Each acoustic cavity 122 is acoustically coupled with a sound hole 121. In some embodiments, the sound hole 121 is a hole that passes through the shell 120, connecting the acoustic cavity 122 with the outside of the shell 120. In some embodiments, the sound hole 121 can be a hole of regular shape or irregular shape such as a circle, rectangle, triangle, etc., and is not limited to the following. Figures 1A-1C The long strip-shaped holes shown.

[0077] In some embodiments, the housing 120 includes a front housing 1201 and a rear housing 1202. Figure 1B , the front shell 1201 is a part of the shell 120 close to the top of the shell 120 along the first direction, and the rear shell 1202 is a part of the shell 120 close to the bottom of the shell 120 along the first direction. A first acoustic cavity 1221 is formed between the front shell 1201 and the adjacent sound unit 110, a second acoustic cavity 1222 is formed between the rear shell 1202 and another adjacent sound unit 110, a third acoustic cavity 1223 is formed between two adjacent sound units 110, and the structure enclosing the third acoustic cavity 1223 also includes a part of the shell 120 between two adjacent sound units 110. Since the diaphragm can generate vibrations upward and downward along the first direction in response to the vibration of the driving structure, the sound unit 110 can generate sound waves in the acoustic cavities 122 above and below it, and the sound waves are transmitted outwardly through the sound outlet holes 121 acoustically coupled with the corresponding acoustic cavities 122. Therefore, the sound unit 110 adjacent to the front housing 1201 exclusively uses the first acoustic cavity 1221, the sound unit 110 adjacent to the rear housing 1202 exclusively uses the second acoustic cavity 1222, and two adjacent sound units 110 (including the sound unit 110 adjacent to the front housing 1201 and the sound unit 110 adjacent to the rear housing 1202) share the third acoustic cavity 1223 therebetween. Figure 1B and Figure 1CThe first sound unit 1101 exclusively uses the first acoustic cavity 1221, and the first sound unit 1101 and the second sound unit 1102 share the third acoustic cavity 1223 between the first sound unit 1101 and the second sound unit 1102. The sound waves output by the first sound unit 1101 are transmitted outward via the first acoustic cavity 1221 and the third acoustic cavity 1223 between the first sound unit 1101 and the second sound unit 1102.

[0078] In some embodiments, the sound outlet holes 121 corresponding to the first acoustic cavity 1221 are opened upward along the first direction. In some embodiments, the sound outlet holes 121 corresponding to the second acoustic cavity 1222 are opened downward along the first direction. In some embodiments, the sound outlet holes 121 corresponding to the first acoustic cavity 1221, the second acoustic cavity 1222 and the third acoustic cavity 1223 can be opened laterally perpendicular to the first direction. In some embodiments, the laterally opened sound outlet holes 121 can be located on one side along the long side of the speaker 100, or on one side along the short side of the speaker 100. In some embodiments, in order to avoid the sound waves output by the sound outlet holes 121 corresponding to the adjacent acoustic cavities 122 from affecting each other and causing interference, the sound outlet holes 121 corresponding to the adjacent acoustic cavities 122 can be staggered. In some embodiments, the sound outlet holes 121 corresponding to the adjacent acoustic cavities 122 are respectively located on opposite sides of the housing 120. For example, the sound outlet holes 121 corresponding to the adjacent acoustic cavities 122 are respectively located on opposite sides of the housing 120 along the long side. In another embodiment, the sound outlet holes 121 corresponding to adjacent acoustic cavities 122 are respectively located on two adjacent sides of the shell 120. For example, the sound outlet holes 121 corresponding to one acoustic cavity 122 in the adjacent acoustic cavities 122 are located on one side of the shell 120 along the long side, and the sound outlet holes 121 corresponding to another acoustic cavity 122 in the adjacent acoustic cavity 122 are located on one side of the shell 120 along the short side. In yet another embodiment, the sound outlet holes 121 corresponding to adjacent acoustic cavities 122 are located on the same side of the shell 120, and the sound outlet holes 121 corresponding to the adjacent acoustic cavities 122 are respectively arranged close to two adjacent side surfaces of the shell 120, and the two side surfaces of the shell 120 are relatively distributed. For example, the sound outlet holes 121 corresponding to adjacent acoustic cavities 122 are located on the same side of the shell 120 along the long side, and the sound outlet holes 121 corresponding to the adjacent acoustic cavities 122 are respectively arranged close to two opposite sides of the shell 120 along the short side.

[0079] In some embodiments, the housing 120 includes a plurality of fixing rings 123, and the fixing rings 123 are used to fix the sound unit 110. In some embodiments, the plurality of fixing rings 123 are overlapped along the first direction, and the plurality of fixing rings 123 are spliced ​​up and down to form the housing 120 portion between the front housing 1201 and the rear housing 1202, and the sound outlet 121 is provided on the fixing rings 123. The fixing rings 123 close to the front housing 1201 are connected to the front housing 1201, and the fixing rings 123 close to the rear housing 1202 are connected to the rear housing 1202.

[0080] Figure 2A It is a simplified structural diagram of a loudspeaker cross section according to some embodiments of this specification. Figure 2B 1 is a simplified structural diagram of a loudspeaker cross section when the diaphragm vibrates according to some embodiments of this specification. For ease of explanation, Figure 2A and Figure 2B Four sound generating units 110 are shown as an example.

[0081] In some embodiments, Figure 2A-2B As shown, in the first direction, the sound unit 110 is disposed in the fixing ring 123. In some embodiments, in the first direction, the sound unit 110 is disposed in the middle of the fixing ring 123, that is, the fixing ring 123 is evenly distributed on both sides of the sound unit 110.

[0082] In some embodiments, a first acoustic cavity 1221 may be formed between the front shell 1201 and the first sound unit 1101, a second acoustic cavity 1222 may be formed between the rear shell 1202 and the fourth sound unit 1104, and a third acoustic cavity 1223 may be formed between the first sound unit 1101 and the second sound unit 1102, between the second sound unit 1102 and the third sound unit 1103, and between the third sound unit 1103.

[0083] In some embodiments, the thickness of the first acoustic cavity 1221 and / or the second acoustic cavity 1222 along the first direction is less than the thickness of the third acoustic cavity 1223 along the first direction. Figure 2A-2B As shown, since the first acoustic cavity 1221 and the second acoustic cavity 1222 are respectively formed by a sound unit 110 and the front shell 1201 and the rear shell 1202, and the third acoustic cavity 1223 is based on two adjacent sound units 110, and since fixing rings 123 are evenly distributed on both sides of the sound unit 110, the thickness of the third acoustic cavity 1223 along the first direction is greater than the thickness of the first acoustic cavity 1221 and / or the second acoustic cavity 1222 along the first direction.

[0084] In some embodiments, the vibration of the plurality of sound-emitting units 110 along the first direction may include at least one of the plurality of sound-emitting units 110 vibrating in a vertically upward direction and / or at least one of the plurality of sound-emitting units 110 vibrating in a vertically downward direction. Further, the vibration of the plurality of sound-emitting units 110 along the first direction may include two adjacent sound-emitting units 110 in the plurality of sound-emitting units 110 that share at least one of the plurality of acoustic cavities 122 vibrating in opposite directions. Figure 2A-2B As shown, the first sound unit 1101 vibrates in a vertically downward direction, and the second sound unit 1102 vibrates in a vertically upward direction; the third sound unit 1103 vibrates in a vertically downward direction, and the fourth sound unit 1104 vibrates in a vertically upward direction. It should be noted that, under the excitation signal, two sound units 110 that are adjacent to each other and share at least one acoustic cavity 122 among the multiple acoustic cavities 122 can vibrate in opposite directions in the full frequency band to enhance the output sound pressure level of the loudspeaker 100 in the full frequency band. In some embodiments, under the excitation signal, two sound units 110 that are adjacent to each other and share at least one acoustic cavity 122 among the multiple acoustic cavities 122 vibrate in opposite directions in at least part of the low frequency band to enhance the output sound pressure level of the acoustic output device (e.g., the acoustic output device 200) including the loudspeaker 100 in at least part of the low frequency band, meeting the current acoustic output device's requirement for gradually increasing the output sound pressure level of the low frequency band.

[0085] In some embodiments, by controlling the excitation voltage of the plurality of sound-emitting units 110, the phase difference of the excitation voltage on the two sound-emitting units 110 of at least one acoustic cavity 122 is 180°, so that two sound-emitting units 110 that are adjacent to each other and share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 can be made to vibrate in opposite directions in at least part of the low-frequency band. Based on the fact that two sound-emitting units 110 that are adjacent to each other and share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 vibrate in opposite directions in at least part of the low-frequency band, combined with the design of the sound outlet 121 shown in some embodiments of the present specification, the sound pressure level output by the speaker 100 (laminated speaker) having n sound-emitting units 110 can be increased by 20×log compared to the sound pressure level output by the speaker 100 (single-layer speaker) having only one sound-emitting unit 110. 10 (n) times.

[0086] In some embodiments, at least part of the low frequency band may include a part of the frequency band less than 500 Hz. In some embodiments, at least part of the low frequency band may include a part of the frequency band less than 300 Hz. For example, the part of the frequency band may be 50 Hz-100 Hz; for example, the part of the frequency band may be 100 Hz-150 Hz; for another example, the part of the frequency band may be 150 Hz-280 Hz, etc.

[0087] In some embodiments, two sound outlet holes 121 are provided on the circumference of each fixing ring 123, and the two sound outlet holes 121 are respectively coupled to the acoustic cavity 122 on opposite sides of the sound-emitting unit 110. The circumference of the fixing ring 123 can be understood as the four sides of the fixing ring 123. For example, when the speaker 100 is designed as a rectangular parallelepiped structure, the circumference of the fixing ring 123 can include a pair of long sides and a pair of short sides.

[0088] In some embodiments, the sound outlet holes 121 can be relatively arranged on two sides of the fixing ring 123 (e.g., opposite long sides or opposite short sides) or adjacently arranged on two sides of the fixing ring 123 (e.g., adjacent long sides and short sides) to couple with two different acoustic cavities 122 respectively.

[0089] like Figure 2A As shown, the dotted line represents the connection surface of two adjacent fixing rings 123. The first fixing ring 1231 has two sound holes on its circumference, namely the first sound hole 1211 and the sub-sound hole 1212-1. The second fixing ring 1232 has two sound holes on its circumference, namely the sub-sound hole 1212-2 and the sub-sound hole 1213-1. Among them, the sub-sound hole 1212-1 is connected to the sub-sound hole 1212-2, and can form a complete second sound hole 1212 coupled to the acoustic cavity 122. In some embodiments, the multiple fixing rings 123 can also be integrally formed. In this case, the housing 120 can be regarded as including only one fixing ring 123, and the multiple sound-emitting units 110 are all arranged in one fixing ring 123.

[0090] In some embodiments, in the first direction, the size of the sound outlet hole 121 corresponding to the first acoustic cavity 1221 and / or the second acoustic cavity 1222 is smaller than the size of the sound outlet hole 121 corresponding to the third acoustic cavity 1223. The size of the sound outlet hole 121 may include but is not limited to the height of the sound outlet hole 121 along the first direction.

[0091] In some embodiments of the present specification, based on the fact that two adjacent sound units 110 among a plurality of sound units 110 and sharing at least one acoustic cavity 122 among a plurality of acoustic cavities 122 vibrate in opposite directions in at least part of the low-frequency band, combined with the design of the sound outlet 121 shown in some embodiments of the present specification, the sound pressure level output by a loudspeaker 100 (laminated loudspeaker) having n sound units 110 can be improved compared to the sound pressure level output by a loudspeaker 100 (single-layer loudspeaker) having only one sound unit 110, thereby utilizing the advantage of the small thickness of the single-layer sound unit 110 to realize a loudspeaker 100 with a smaller thickness and a large low-frequency output sound pressure level.

[0092] Figure 3A is a schematic diagram of the structure of a fixing ring and an electrode according to some embodiments of this specification; Figure 3B yes Figure 3A Cross-section view at AA in the middle.

[0093] In some embodiments, the shell 120 may include a front shell 1201 and a rear shell 1202 , each fixing ring 123 is provided with at least two electrodes, and the at least two electrodes on each fixing ring 123 are respectively connected to the front shell 1201 or the rear shell 1202 through corresponding conductive electrodes.

[0094] In some embodiments, the number of electrodes on each fixing ring 123 includes but is not limited to two. For example, based on actual needs, the number of electrodes on each fixing ring 123 may also be three. Figure 3A-3B As shown, the fixing ring 123 may include two electrodes, namely, electrode E1 and electrode E2.

[0095] In some embodiments, based on at least two electrodes (eg, electrode E1 and electrode E2 ) on each fixing ring 123 , an excitation signal (eg, excitation voltage) may be provided to the sound generating unit 110 fixed on the fixing ring 123 .

[0096] The conducting electrode refers to an electrode structure that connects the corresponding electrodes on each fixing ring 123. Figure 3B As shown, the first conductive electrode D1 can connect the electrode E1 on each fixing ring 123 to the front shell 1201 or the rear shell 1202 , and the second conductive electrode D2 can connect the electrode E2 on each fixing ring 123 to the front shell 1201 or the rear shell 1202 .

[0097] In some embodiments, the fixing ring 123 is a part of the housing 120, and the material of the fixing ring 123 can be consistent with the material of the housing 120. In some embodiments, the fixing ring 123 can include one or more of FR4, FPC, and plastic. The fixing ring 123 is provided with at least two conducting holes extending along the first direction, and at least two electrodes are respectively provided in the corresponding conducting holes. The electrodes corresponding to any two adjacent fixing rings 123 can be mutually conductive to form conductive electrodes. Mutual conductive means that the electrodes are electrically connected to each other.

[0098] For example, when the fixing ring 123 is made of FR4 or FPC, the conduction between the two end faces of the fixing ring 123 can be achieved directly through the conducting hole, and then at least two electrodes on each fixing ring 123 can be conducted to form corresponding conducting electrodes by coating with conductive silver paste, conductive glue, patch, etc. For another example, when the fixing ring 123 is made of resin polymer material such as plastic, a metal electrode can be arranged in the conducting hole to achieve mutual conduction between the electrodes corresponding to any two connected fixing rings 123 to form conducting electrodes.

[0099] Figure 4A It is a schematic diagram of the structure of the sound unit shown in some embodiments of this specification. Figure 4A The sound-emitting unit 110 shown may be the sound-emitting unit 110 included in the speaker 100 in any embodiment of the present specification.

[0100] like Figure 4A As shown, the sound unit 110 includes a diaphragm 111 and a driving structure 112, and the driving structure 112 is arranged on the diaphragm 111. The driving structure 112 includes a piezoelectric driving structure (for example Fig.10 The piezoelectric drive structure 1125 shown in the figure, due to the piezoelectric inverse piezoelectric effect, when an electrical signal (audio signal) acts on the piezoelectric drive structure, the piezoelectric drive structure will generate mechanical vibration. The peripheral side of the diaphragm 111 is connected to the inner wall of the fixed ring 123 located in the acoustic cavity 122, and covers the internal area of ​​the fixed ring 123 to separate the internal area of ​​the fixed ring 123 into two adjacent acoustic cavities 122 located on opposite sides of the diaphragm 111, namely the front cavity and the rear cavity. The diaphragm 111 receives the vibration of the piezoelectric drive structure and generates vibration. At this time, the diaphragm 111 can push the air in the front cavity and the rear cavity respectively to generate sound waves. Due to the non-redundant structural design between the diaphragm 111 and the driving structure 112, the diaphragm 111 directly responds to the driving structure 112 to generate vibrations. Compared with an additional vibration transfer unit provided between the driving structure 112 and the diaphragm 111, the speaker 100 involved in this specification can use a larger proportion of the vibration driving force to generate sound signals, thereby improving the output sound pressure level and significantly reducing the overall thickness of the speaker 100.

[0101] In some embodiments, the circumference of the diaphragm 111 is embedded with the inner wall of the fixing ring 123 to achieve the connection between the diaphragm 111 and the fixing ring 123. As an example only, a groove is provided on the inner wall of the fixing ring 123 along its circumferential direction, and the circumference of the diaphragm 111 is embedded in the groove to achieve fixation with the fixing ring 123.

[0102] In some embodiments, the driving structure 112 may be a plate-like structure. In some embodiments, the driving structure 112 may be a plate-like structure of regular or irregular shapes such as a circle, an ellipse, a square, a pentagon, a hexagon, an octagon, or other polygons. In some embodiments, the driving structure 112 may also be a sheet-like or rod-like structure. For ease of description, this specification takes the driving structure 112 as a square plate-like structure as an example. In some embodiments, Figure 4A As shown, the driving structure 112 is arranged on the side of the diaphragm 111 located in the front cavity, and the side of the diaphragm 111 located in the front cavity is connected to the side of the driving structure 112 close to the rear cavity. In other embodiments, the driving structure 112 is arranged on the side of the diaphragm 111 located in the rear cavity, and the side of the diaphragm 111 located in the rear cavity is connected to the side of the driving structure 112 close to the front cavity. In some other embodiments, the sound unit 110 may include two diaphragms 111, and the two diaphragms 111 are respectively arranged on both sides of the driving structure 112 along the first direction. One of the diaphragms 111 is located in the front cavity and is connected to the side of the driving structure 112 close to the front cavity; the other diaphragm 111 is located in the rear cavity and is connected to the side of the driving structure 112 close to the rear cavity. In some embodiments, in order to make the driving structure 112 drive the diaphragm 111 more uniformly so that the diaphragm 111 can push the air with a larger vibration amplitude, the driving structure 112 is arranged in the middle area of ​​the diaphragm 111. In some embodiments, while the driving structure 112 is connected to the diaphragm 111, the driving structure 112 is also connected to the fixing ring 123 to prevent the mass of the driving structure 112 from affecting the vibration state of the diaphragm 111. In some embodiments, in order to prevent the connection between the driving structure 112 and the fixing ring 123 from limiting the vibration of the diaphragm 111, thereby making it impossible for the driving structure 112 to drive the diaphragm 111 to vibrate, the driving structure 112 is connected to the fixing ring 123 via the elastic structure 113. Specifically, the first end of the elastic structure 113 is connected to the peripheral side of the driving structure 112, and the second end of the elastic structure 113 is connected to the inner wall of the fixing ring 123. In some embodiments, the second end of the elastic structure 113 is embedded with the inner wall of the fixing ring 123 to achieve the connection between the elastic structure 113 and the fixing ring 123.

[0103] In some embodiments, the speaker 100 may have one sound generating unit 110 . Figure 4B is a schematic diagram of a structure of a speaker with a sound unit according to some embodiments of this specification. Figure 4BAs shown, the speaker 100 may include a housing 120 and a sound unit 110. The sound unit 110 is disposed in a receiving cavity of the housing 120 perpendicular to a first direction. The housing 120 includes a fixing ring 123, which is a cylindrical structure extending along the first direction and is used to support and fix the sound unit 110. For a detailed description of the sound unit 110 and the connection between the sound unit 110 and the fixing ring 123, please refer to Figure 4A and its related description.

[0104] In some embodiments, the housing 120 further includes a front housing 1201, which is connected to the upper end surface of the fixing ring 123 along the first direction. In some embodiments, the front housing 1201 is formed as a plate-like structure having a hole. The hole is a sound outlet hole 121. In some embodiments, the housing 120 further includes a rear housing (not shown in the figure), which is connected to the lower end surface of the fixing ring 123 along the first direction. In some embodiments, the rear housing 1202 is formed as a plate-like structure having a hole. The hole is another sound outlet hole 121. The sound unit 110 includes a diaphragm 111 and a driving structure 112, and the diaphragm 111 divides the accommodating cavity into a front cavity (i.e., a first acoustic cavity 1221) and a rear cavity (i.e., a second acoustic cavity 1222) located on opposite sides of the diaphragm 111. The diaphragm 111 vibrates in response to the deformation or displacement of the driving structure 112. The vibration of the diaphragm 111 drives the air in the front cavity or the rear cavity to produce fluctuations, that is, sound waves (sound signals). The sound waves can be transmitted to the outside through the sound outlet 121 set on the front shell 1201 or the rear shell 1202.

[0105] In some embodiments, Figure 4B As shown, the diaphragm 111 is located at one side of the front cavity and connected to the side of the driving structure 112 close to the rear cavity. At this time, the diaphragm 111 can push the air in the rear cavity to generate sound waves, and the sound waves are transmitted to the outside through the sound outlet holes 121 provided on the rear shell 1202. In other embodiments, the diaphragm 111 is located at one side of the rear cavity and connected to the side of the driving structure 112 close to the front cavity. At this time, the diaphragm 111 can push the air in the front cavity to generate sound waves, and the sound waves are transmitted to the outside through the sound outlet holes 121 provided on the front shell 1201.

[0106] In some embodiments, the sound outlet 121 on the front housing 1201 or the rear housing 1202 is dustproof by encapsulation. In some embodiments, the sound outlet 121 can be dustproof encapsulated by a damping / dustproof mesh 140. Figure 4B As shown, a single sound unit 110 that implements dustproof packaging can be used as a speaker. Figure 1AAs shown, in a speaker 100 including a plurality of sound generating units 110 spaced apart along a first direction, a damping / dustproof mesh 140 may be provided at the sound outlets 121 corresponding to each of the plurality of acoustic cavities 122 to achieve dustproof packaging. Figure 1A In the loudspeaker 100 shown in FIG. 1 , dustproof packaging may not be performed between two adjacent sound units 110, so that the front cavity and the rear cavity between the two adjacent sound units 110 are not separated, and an acoustic cavity 122 may be formed. Figure 1A In the loudspeaker 100 shown, dust-proof packaging can also be performed between two adjacent sound-emitting units 110 (for example, a damping / dust-proof mesh 140 is provided between two adjacent sound-emitting units 110, not shown in the figure), so as to adjust the output sound pressure level of the loudspeaker 100 and the Q value of the output frequency response.

[0107] Figure 5 for Figure 4B The top view of the loudspeaker is shown in FIG. Figure 5 As shown, the two opposite sides of the driving structure 112 are connected to the fixing ring 123 through the elastic structure 113, and the elastic structures 113 on both sides are relative to the long axis of the driving structure 112 (see Figure 5 The symmetrically arranged elastic structure 113 can prevent the sound unit 110 from having a flipping vibration mode. In some embodiments, the elastic structures 113 on both sides are symmetrical with respect to the short axis (see FIG. Figure 5 The long axis is the center line of the driving structure 112 along the long axis direction, and the short axis is the center line of the driving structure 112 along the short axis direction.

[0108] In some embodiments, the elastic structure 113 is in a bent shape, which can increase the effective length of the elastic structure 113 within the effective space and reduce the stiffness of the elastic structure 113, thereby reducing the impact on the overall stiffness of the diaphragm 111, which is beneficial to increasing the vibration amplitude of the diaphragm 111 and improving the acoustic output of the speaker 100.

[0109] Figure 6 It is a schematic diagram of the structure of the sound unit 110 according to some embodiments of this specification. Figure 6 The sound unit 110 shown is Figure 4A The sound unit 110 shown is similar, with the main difference being that a lead 114 (i.e., electrode) is provided on the diaphragm 111, the sound unit 110 does not include the elastic structure 113, and the opposite sides of the driving structure 112 are connected to the diaphragm 111 through the lead 114. In some embodiments, the lead 114 is directly prepared on the diaphragm 111.

[0110] The driving structure 112 in this embodiment is not connected to the fixing ring 123 , which can avoid the connection between the driving structure 112 and the fixing ring 123 increasing the rigidity of the diaphragm 111 , thereby avoiding reducing the vibration amplitude of the diaphragm 111 .

[0111] The following will be combined Figure 7-Figure 9 The sound unit 110 is described when the driving structure 112 is an electromagnetic driving structure 112. The sound unit 110 may be the sound unit 110 included in the speaker 100 in any embodiment of the present specification.

[0112] Figure 7 It is a schematic diagram of the structure of the sound unit shown in other embodiments of this specification.

[0113] like Figure 7 As shown, the sound unit 110 includes a diaphragm 111 and a driving structure 112. The circumference of the diaphragm 111 is connected to the inner wall of the fixing ring 123, see Figure 4A And related descriptions. The driving structure 112 includes a planar coil 1121 and a magnetic circuit assembly. The planar coil 1121 is arranged on the diaphragm 111. The magnetic circuit assembly includes a magnet 1122, a magnetic conductive plate 1123 and a magnetic conductive ring 1124. Among them, the magnetic conductive ring 1124 is arranged around the planar coil 1121 in a plane perpendicular to the first direction, the magnet 1122 is arranged on the side of the diaphragm 111 away from the planar coil 1121, the magnet 1122 is spaced apart from the diaphragm 111 in the first direction, and the magnetic conductive plate 1123 is supported and connected to the lower surface of the magnet 1122 along the first direction. When the audio signal acts on the planar coil 1121, the planar coil 1121 generates electromagnetic waves, which cut with the electromagnetic field of the magnetic circuit assembly, thereby generating a driving force, and the driving force drives the diaphragm 111 to vibrate.

[0114] In some embodiments, the outer wall of the magnetic conductive ring 1124 extending along the first direction is connected and fixed to the inner wall of the fixed ring 123. In some embodiments, the peripheral side of the magnetic conductive plate 1123 is connected and fixed to the inner wall of the fixed ring 123. The "connection" described in this specification can be understood as the connection between different parts of the same structure, or after preparing different parts or structures respectively, each independent part or structure is fixedly connected by welding, riveting, clamping, bolting, adhesive bonding, etc., or during the preparation process, the first part or structure is deposited on the second part or structure by physical deposition (for example, physical vapor deposition) or chemical deposition (for example, chemical vapor deposition). The diaphragm 111 separates the cavity inside the fixed ring 123, and the diaphragm 111 forms a front cavity (i.e., the first acoustic cavity 1221) above the first direction, and a rear cavity (i.e., the second acoustic cavity 1222) is formed between the diaphragm 111 and the magnetic conductive plate 1123. When the diaphragm 111 vibrates, it pushes the air in the front cavity and the rear cavity to generate sound waves. In some embodiments, the magnetic plate 1123 is provided with a sound outlet 121 for transmitting the sound waves generated in the rear cavity to the outside. In some embodiments, the driving structure 112 may not include the magnetic plate 1123, and a circle of magnetic conductive material is provided around the magnet 1122 to form a magnetic conductive ring. The magnet 1122 is connected and fixed to the inner wall of the fixing ring 123 through the magnetic conductive ring, which can reduce the thickness of the sound unit 110, thereby reducing the thickness of the speaker 100.

[0115] In some embodiments, in order to make the magnet 1122 and the planar coil 1121 interact more strongly and generate a larger driving force to drive the diaphragm 111, the magnet 1122 and the planar coil 1121 are arranged in parallel or approximately in parallel, that is, the diaphragm 111, the magnet 1122 and the planar coil 1121 are arranged in parallel or approximately in parallel. In some embodiments, in order to make the magnet 1122 and the planar coil 1121 drive the diaphragm 111 more uniformly so that the diaphragm 111 can push the air with a larger vibration amplitude, the planar coil 1121 is arranged in the middle area of ​​the diaphragm 111, and the magnet 1122 is arranged close to the middle area of ​​the diaphragm 111 in a plane perpendicular to the first direction.

[0116] In some embodiments, the material of the planar coil 1121 may include materials such as copper, gold, aluminum, titanium, platinum, or a composite material thereof. In some embodiments, the magnet 1122 may include a permanent magnet (e.g., aluminum iron boron) and / or an electromagnet. In some embodiments, the material of the magnetic ring 1124 or the magnetic plate 1123 may be a magnetic material. Exemplary magnetic materials may include, but are not limited to, silicon steel, manganese zinc ferrite, nickel zinc ferrite, iron, etc. In some embodiments, the material of the fixing ring 123 may be a semiconductor material.

[0117] In some embodiments, the sound unit 110 can be prepared by a semiconductor process. For example, a diaphragm layer corresponding to the diaphragm 111 is prepared on a silicon wafer, and then a planar coil 1121 layer is formed by deposition, sputtering or evaporation on the diaphragm layer, and then the desired planar coil 1121 shape is formed by photolithography. At this time, the planar coil 1121 is located on the upper surface of the diaphragm 111. For another example, a planar coil 1121 layer is formed by deposition, sputtering or evaporation, photolithography and etching on a silicon wafer, and then spin coating, sputtering, and evaporation are used for preparation, and the desired diaphragm layer shape is formed by photolithography and etching. At this time, the planar coil 1121 is located on the lower surface of the diaphragm 111. For another example, the fixing ring 123 is made of silicon material and is obtained by back cavity etching of a silicon wafer. In some embodiments, the sound unit 110 can be prepared by a conventional process. For example, the diaphragm 111 can directly adopt a film of materials such as polyimide (PI) and polyetheretherketone (PEEK), or can adopt polyimide (PI), polyetheretherketone (PEEK) and other materials to form a film by spin coating and curing; and the planar coil 1121 can be prepared on the diaphragm 111 through a printing process.

[0118] In this embodiment, the thickness of the speaker 100 can be reduced by adopting the planar coil 1121 and other related structural designs.

[0119] Figure 8 It is a schematic diagram of the structure of the sound unit 110 shown in some other embodiments of this specification. Figure 8 The sound unit 110 shown is Figure 7 The sound unit 110 shown is similar, and the main difference is that the first magnet 11221 and the second magnet 11222 are respectively provided on opposite sides of the diaphragm 111 in the first direction. A front cavity (i.e., the first acoustic cavity 1221) is formed between the diaphragm 111 and the first magnet 11221, and a rear cavity (i.e., the second acoustic cavity 1222) is formed between the diaphragm 111 and the second magnet 11222. When the audio signal acts on the planar coil 1121, the planar coil 1121 generates electromagnetic waves, and the electromagnetic fields of the first magnet 11221 and the second magnet 11222 are cut, thereby generating a driving force, which drives the diaphragm 111 to vibrate. When the diaphragm 111 vibrates, it pushes the air in the front cavity and the rear cavity to fluctuate, thereby generating sound waves.

[0120] In some embodiments, a circle of magnetic conductive material is disposed around the first magnet 11221 and the second magnet 11222 to form a magnetic conductive circle, and the first magnet 11221 and the second magnet 11222 are connected and fixed to the inner wall of the fixing ring 123 through the magnetic conductive circle, which can reduce the thickness of the sound unit 110, thereby reducing the thickness of the speaker 100. In some embodiments, the first magnet 11221 and the second magnet 11222 are both provided with sound outlet holes 121 for transmitting the sound waves generated in the front cavity and the rear cavity to the outside.

[0121] In this embodiment, magnets 1122 are provided on opposite sides of the diaphragm 111 in the first direction, so that the magnetic field strength in the area where the planar coil 1121 is located can be increased, thereby increasing the driving force applied to the diaphragm 111 and improving the vibration amplitude of the diaphragm 111.

[0122] Fig. 9 It is a schematic diagram of the structure of the sound unit 110 shown in some other embodiments of this specification. Fig. 9 The sound unit 110 shown is Figure 8 The sound unit 110 shown is similar, and the main difference is that the first magnet 11221 and the second magnet 11222 are respectively arranged on the opposite sides of the diaphragm 111 in the first direction, wherein the first magnet 11221 and the second magnet 11222 are both separate magnets. The separate magnet is a magnet 1122 distributed in a certain shape, and the separate magnet has a hollow area and a magnet area. In some embodiments, the planar coil 1121 is distributed in a ring shape, and the distribution shape of the separate magnet corresponds to the distribution shape of the planar coil 1121. Among them, the projection of the magnet area of ​​the separate magnet 1122 along the first direction overlaps at least partially with the projection of the planar coil 1121 along the first direction. In this embodiment, by setting a separate magnet, a magnet area is set corresponding to each ring on the planar coil 1121, and each magnet area corresponding to each ring of the planar coil 1121 can be separately magnetized according to demand, so as to realize the separate regulation of the magnetic pole direction and magnetic field strength at each ring of the planar coil 1121. For example, the magnetic field intensity at the middle ring of the planar coil 1121 can be maximized through regulation to increase the vibration amplitude of the diaphragm 111 .

[0123] In some embodiments, see Figure 4A The drive structure 112 may include a piezoelectric drive structure (eg Fig.10 The piezoelectric drive structure 1125 shown in the figure includes a piezoelectric material. In some embodiments, the Young's modulus of the piezoelectric material is 30 GPa-100 GPa to ensure that the rigidity of the drive structure 112 does not excessively restrict the vibration of the diaphragm 111. Preferably, the Young's modulus of the piezoelectric material is 40 GPa-90 GPa. More preferably, the Young's modulus of the piezoelectric material is 50 GPa-80 GPa.

[0124] Fig.10 is a cross-sectional view of a piezoelectric drive structure according to some embodiments of the present specification.

[0125] like Fig.10As shown, the piezoelectric driving structure 1125 includes, from top to bottom along the first direction, a first electrode layer 11251, a first piezoelectric layer 11252, a second electrode layer 11253, a second piezoelectric layer 11254, and a third electrode layer 11255. In some embodiments, the first electrode layer 11251, the first piezoelectric layer 11252, the second electrode layer 11253, the second piezoelectric layer 11254, the third electrode layer 11255, and the diaphragm 111 are sequentially connected through their adjacent sides.

[0126] In some embodiments, the material of the piezoelectric layer (the first piezoelectric layer 11252 and the second piezoelectric layer 11254) may include, but is not limited to, lead zirconate titanate (PZT) or zinc oxide (ZnO) or aluminum nitride (AlN) and combinations thereof. In some embodiments, the material of the electrode layer (the first electrode layer 11251, the second electrode layer 11253 and the third electrode layer 11255) may include, but is not limited to, platinum (Pt), gold (Au) or titanium (Ti) and any combination thereof. In some embodiments, the material of the diaphragm 111 may be a flexible polymer material. Exemplary flexible polymer materials include, but are not limited to, one or more of polyimide (PI), polyethylene terephthalate (PET), polyethyleneimine (PEI), polyetheretherketone (PEEK), silicone, polycarbonate (PC), vinyl polymer (PVC), acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene (PE), polyparaxylene (PPX), etc., and may also be a multilayer composite material formed by the above materials. In some embodiments, the Young's modulus of the flexible polymer material is in the range of 1 GPa-9 GPa (e.g., 2 GPa-8 GPa, 3 GPa-7 GPa, or 4 GPa-6 GPa, etc.). In some embodiments, the material of the diaphragm 111 may be a semiconductor material. Exemplary semiconductor materials include, but are not limited to, silicon (Si), silicon dioxide (SiO 2 ), silicon nitride (Si x N y ), or a multilayer composite material formed by the above materials. In some embodiments, the Young's modulus of the semiconductor material ranges from 100 GPa to 200 GPa (e.g., 120 GPa to 190 GPa, 130 GPa to 180 GPa, or 140 GPa to 170 GPa, etc.).

[0127] In some embodiments, the thickness of the electrode layer may range from 80nm to 200nm (e.g., 100nm to 180nm, 120nm to 160nm, or 130nm to 150nm, etc.). In some embodiments, when the piezoelectric layer is prepared by a magnetron sputtering process or a sol-gel or other MEMS process, the thickness of the piezoelectric layer ranges from 1um to 3um (e.g., 1.5nm to 2.5nm, 1.6nm to 2.8nm, or 1.8nm to 2.6nm, etc.). When the piezoelectric layer is prepared by a sintering process, the thickness of the piezoelectric layer ranges from 20um to 100um (e.g., 20nm to 80nm, 30nm to 60nm, or 30nm to 50nm, etc.).

[0128] In some embodiments, the piezoelectric driving structure 1125 has a d33 mode and a d31 mode. In some embodiments, a voltage is applied along a first direction to each electrode layer, and the piezoelectric layer is moved along the first direction and along the second direction (see Fig.11A x direction) will produce expansion and contraction deformation (such as Fig. 11B If the piezoelectric drive structure 1125 is only deformed by the d33 mode in the first direction, the sound pressure level output by the sound unit 110 cannot meet the actual demand. In order to ensure that the piezoelectric drive structure 1125 can have a larger displacement in the first direction so that the amplitude of the diaphragm 111 is larger, the d31 mode in a direction perpendicular to the first direction can be used.

[0129] Fig.11A It is a schematic diagram of the structure of the piezoelectric drive structure before deformation according to some embodiments of this specification. Fig. 11B It is a schematic diagram of the structure after the piezoelectric driving structure is deformed according to some embodiments of this specification.

[0130] In some embodiments, the piezoelectric drive structure 1125 includes a sintered piezoelectric ceramic. The sintered piezoelectric ceramic is a piezoelectric ceramic layer (i.e., a piezoelectric layer) prepared by a sintering process. The thickness of the piezoelectric ceramic layer is limited by the process, and its thickness is greater than 15 um. Therefore, the thickness of the piezoelectric ceramic layer is preferably greater than the thickness of the diaphragm 111 (e.g., Fig.11A As shown), the neutral layer 11256 is located inside the piezoelectric drive structure 1125 (as shown Fig. 11B shown).

[0131] In some embodiments, when the neutral layer 11256 is located inside the piezoelectric driving structure 1125, in order to ensure that the piezoelectric driving structure 1125 can have a larger displacement in the first direction so that the amplitude of the diaphragm 111 is larger, it can be achieved by designing the polarization direction of each piezoelectric layer and the positive and negative applied voltage so that the deformation directions of the materials on both sides of the neutral layer 11256 along the first direction are opposite.

[0132] Fig. 12AIt is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification.

[0133] Taking two piezoelectric layers as an example, when the polarization directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are the same (for example, Fig. 12A In order to make the deformation of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 opposite, that is, one is tensilely deformed and the other is compressively deformed, the potential directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 can be opposite. In some embodiments, the first voltage of the first electrode layer 11251 and the third voltage of the third electrode layer 11255 can both be greater than the second voltage of the second electrode layer 11253, and the first voltage of the first electrode layer 11251 and the third voltage of the third electrode layer 11255 can both be less than the second voltage of the second electrode layer 11253. For example, the first voltage is equal to the third voltage, and the second voltage is 0V.

[0134] When both the first voltage and the third voltage are greater than the second voltage, the potential direction of the first piezoelectric layer 11252 is downward along the first direction, which is opposite to the polarization direction, and the first piezoelectric layer 11252 is compressed; the potential direction of the second piezoelectric layer 11254 is upward along the first direction, which is the same as the polarization direction, and the second piezoelectric layer 11254 is stretched. Since the neutral layer 11256 is located in the piezoelectric drive structure 1125, the piezoelectric drive structure 1125 is bent and deformed downward as a whole. At this time, the sound unit 110 is bent and deformed downward as a whole, and the diaphragm 111 is stretched. When both the first voltage and the third voltage are less than the second voltage, the potential direction of the first piezoelectric layer 11252 is upward along the first direction, which is the same as the polarization direction, and the first piezoelectric layer 11252 is stretched; the potential direction of the second piezoelectric layer 11254 is downward along the first direction, which is opposite to the polarization direction, and the second piezoelectric layer 11254 is compressed. Since the neutral layer 11256 is located in the piezoelectric driving structure 1125, the piezoelectric driving structure 1125 is bent and deformed upward as a whole. At this time, the sound unit 110 is bent and deformed upward as a whole, and the diaphragm 111 is compressed.

[0135] Fig. 12B It is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification.

[0136] Taking two piezoelectric layers as an example, when the polarization directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are opposite (for example, Fig. 12BAs shown, the polarization direction of the first piezoelectric layer 11252 is upward along the first direction, and the polarization direction of the second piezoelectric layer 11254 is downward along the first direction). In order to make the deformation of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 opposite, the electric potential directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 can be the same. In some embodiments, the first voltage, the second voltage, and the third voltage can decrease or increase in sequence.

[0137] When the first voltage, the second voltage, and the third voltage decrease in sequence, the electric potential direction of the first piezoelectric layer 11252 is downward along the first direction, which is opposite to the polarization direction, and the first piezoelectric layer 11252 is compressed; the electric potential direction of the second piezoelectric layer 11254 is downward along the first direction, which is the same as the polarization direction, and the second piezoelectric layer 11254 is stretched. Since the neutral layer 11256 is located in the piezoelectric drive structure 1125, the piezoelectric drive structure 1125 is bent and deformed downward as a whole. At this time, the sound unit 110 is bent and deformed downward as a whole, and the diaphragm 111 is stretched. When the first voltage, the second voltage, and the third voltage increase in sequence, the electric potential direction of the first piezoelectric layer 11252 is upward along the first direction, which is the same as the polarization direction, and the first piezoelectric layer 11252 is stretched; the electric potential direction of the second piezoelectric layer 11254 is upward along the first direction, which is opposite to the polarization direction, and the second piezoelectric layer 11254 is compressed. Since the neutral layer 11256 is located in the piezoelectric driving structure 1125, the piezoelectric driving structure 1125 is bent and deformed upward as a whole. At this time, the sound unit 110 is bent and deformed upward as a whole, and the diaphragm 111 is compressed.

[0138] Fig.13A It is a schematic diagram of the structure of the piezoelectric drive structure before deformation according to some embodiments of this specification. Fig. 13B It is a schematic diagram of the structure after the piezoelectric driving structure is deformed according to some embodiments of this specification.

[0139] In some embodiments, the piezoelectric drive structure 1125 includes a MEMS piezoelectric ceramic. The MEMS piezoelectric ceramic is a piezoelectric ceramic layer (i.e., a piezoelectric layer) prepared using a MEMS process. The thickness of the piezoelectric ceramic layer here is relatively small, so the thickness of the piezoelectric ceramic layer is preferably smaller than the thickness of the diaphragm 111, such as Fig.13A As shown, at this time, the neutral layer 11256 is located outside the piezoelectric driving structure 1125, that is, inside the diaphragm 111.

[0140] In some embodiments, when the neutral layer 11256 is located outside the piezoelectric drive structure 1125 and inside the diaphragm 111, in order to ensure that the piezoelectric drive structure 1125 can have a larger displacement in the first direction so that the amplitude of the diaphragm 111 is larger, it can be achieved by designing the polarization direction of each piezoelectric layer and the positive and negative applied voltage, so that the deformation directions of the materials of the piezoelectric drive structure 1125 located on one side of the neutral layer 11256 along the first direction are the same, and the deformation directions of the materials located on both sides of the neutral layer 11256 along the first direction are opposite.

[0141] Fig.14A It is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification. Fig. 14B It is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification.

[0142] Taking two piezoelectric layers as an example, when the polarization directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are opposite, Fig.14A As shown, the polarization direction of the first piezoelectric layer 11252 is upward along the first direction, and the polarization direction of the second piezoelectric layer 11254 is downward along the first direction; or, as shown Fig. 14B As shown, the polarization direction of the first piezoelectric layer 11252 is downward along the first direction, and the polarization direction of the second piezoelectric layer 11254 is upward along the second direction. In order to make the deformation of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 the same, the electric potential directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are opposite. In some embodiments, the first voltage of the first electrode layer 11251 and the third voltage of the third electrode layer 11255 can both be greater than the second voltage of the second electrode layer 11253, and the first voltage of the first electrode layer 11251 and the third voltage of the third electrode layer 11255 can both be less than the second voltage of the second electrode layer 11253.

[0143] Fig.14AIn the embodiment, when the first voltage and the third voltage are both greater than the second voltage, the electric potential direction of the first piezoelectric layer 11252 is downward along the first direction, which is opposite to the polarization direction, and the first piezoelectric layer 11252 is compressed; the electric potential direction of the second piezoelectric layer 11254 is upward along the first direction, which is opposite to the polarization direction, and the second piezoelectric layer 11254 is compressed. Since the neutral layer 11256 is located outside the piezoelectric drive structure 1125 and inside the diaphragm 111, the piezoelectric drive structure 1125 is compressed as a whole, the diaphragm 111 is stretched, and the sound unit 110 is bent and deformed downward as a whole. When the first voltage and the third voltage are both less than the second voltage, the electric potential direction of the first piezoelectric layer 11252 is upward along the first direction, which is the same as the polarization direction, and the first piezoelectric layer 11252 is stretched; the electric potential direction of the second piezoelectric layer 11254 is downward along the first direction, which is the same as the polarization direction, and the second piezoelectric layer 11254 is stretched. Since the neutral layer 11256 is located outside the piezoelectric driving structure 1125 and inside the diaphragm 111, the piezoelectric driving structure 1125 is stretched as a whole, the diaphragm 111 is compressed, and the sound unit 110 is bent and deformed upward as a whole.

[0144] Fig. 14B In the embodiment, when the first voltage and the third voltage are both greater than the second voltage, the electric potential direction of the first piezoelectric layer 11252 is downward along the first direction, which is the same as the polarization direction, and the first piezoelectric layer 11252 is stretched; the electric potential direction of the second piezoelectric layer 11254 is upward along the first direction, which is the same as the polarization direction, and the second piezoelectric layer 11254 is stretched. Since the neutral layer 11256 is located outside the piezoelectric drive structure 1125 and inside the diaphragm 111, the piezoelectric drive structure 1125 is stretched as a whole, the diaphragm 111 is compressed, and the sound unit 110 is bent and deformed upward as a whole. When the first voltage and the third voltage are both less than the second voltage, the electric potential direction of the first piezoelectric layer 11252 is upward along the first direction, which is opposite to the polarization direction, and the first piezoelectric layer 11252 is compressed; the electric potential direction of the second piezoelectric layer 11254 is downward along the first direction, which is opposite to the polarization direction, and the second piezoelectric layer 11254 is compressed. Since the neutral layer 11256 is located outside the piezoelectric driving structure 1125 and inside the diaphragm 111, the piezoelectric driving structure 1125 is compressed as a whole, the diaphragm 111 is stretched, and the sound unit 110 is bent and deformed downward as a whole.

[0145] Fig. 14C It is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification. Fig.14D It is a schematic diagram of the polarization direction of each piezoelectric layer of the piezoelectric driving structure shown in some embodiments of this specification.

[0146] Taking two piezoelectric layers as an example, when the polarization directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are the same, Fig. 14CAs shown, the polarization directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are both upward along the first direction; or, as shown Fig.14D As shown, the polarization directions of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 are both downward along the first direction. In order to make the deformation of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 the same, the electric potential direction of the first piezoelectric layer 11252 and the second piezoelectric layer 11254 is the same. In some embodiments, the first voltage, the second voltage, and the third voltage can decrease in sequence or increase in sequence.

[0147] Fig. 14C In the embodiment, when the first voltage, the second voltage, and the third voltage decrease in sequence, the electric potential direction of the first piezoelectric layer 11252 is downward along the first direction, which is opposite to the polarization direction, and the first piezoelectric layer 11252 is compressed; the electric potential direction of the second piezoelectric layer 11254 is downward along the first direction, which is opposite to the polarization direction, and the second piezoelectric layer 11254 is compressed. Since the neutral layer 11256 is located outside the piezoelectric drive structure 1125 and inside the diaphragm 111, the piezoelectric drive structure 1125 is compressed as a whole, the diaphragm 111 is stretched, and the sound unit 110 is bent and deformed downward as a whole. When the first voltage, the second voltage, and the third voltage increase in sequence, the electric potential direction of the first piezoelectric layer 11252 is upward along the first direction, which is the same as the polarization direction, and the first piezoelectric layer 11252 is stretched; the electric potential direction of the second piezoelectric layer 11254 is upward along the first direction, which is the same as the polarization direction, and the second piezoelectric layer 11254 is stretched. Since the neutral layer 11256 is located outside the piezoelectric driving structure 1125 and inside the diaphragm 111, the piezoelectric driving structure 1125 is stretched as a whole, the diaphragm 111 is compressed, and the sound unit 110 is bent and deformed upward as a whole.

[0148] Fig.14DIn the embodiment, when the first voltage, the second voltage, and the third voltage decrease in sequence, the electric potential direction of the first piezoelectric layer 11252 is downward along the first direction, which is the same as the polarization direction, and the first piezoelectric layer 11252 is stretched; the electric potential direction of the second piezoelectric layer 11254 is downward along the first direction, which is the same as the polarization direction, and the second piezoelectric layer 11254 is stretched. Since the neutral layer 11256 is located outside the piezoelectric drive structure 1125 and inside the diaphragm 111, the piezoelectric drive structure 1125 is stretched as a whole, the diaphragm 111 is compressed, and the sound unit 110 is bent and deformed upward as a whole. When the first voltage, the second voltage, and the third voltage increase in sequence, the electric potential direction of the first piezoelectric layer 11252 is upward along the first direction, which is opposite to the polarization direction, and the first piezoelectric layer 11252 is compressed; the electric potential direction of the second piezoelectric layer 11254 is upward along the first direction, which is opposite to the polarization direction, and the second piezoelectric layer 11254 is compressed. Since the neutral layer 11256 is located outside the piezoelectric driving structure 1125 and inside the diaphragm 111, the piezoelectric driving structure 1125 is compressed as a whole, the diaphragm 111 is stretched, and the sound unit 110 is bent and deformed downward as a whole.

[0149] In some embodiments, in order to meet the battery power supply capacity and power consumption of common consumer electronic products such as headphones and audio glasses, the absolute value of the first driving voltage and the absolute value of the second driving voltage are not higher than 5 V. The first driving voltage of the first piezoelectric layer 11252 is the difference between the first voltage and the second voltage, and the second driving voltage of the second piezoelectric layer 11254 is the difference between the second voltage and the third voltage.

[0150] The suspended area on the diaphragm 111 refers to the area where the diaphragm 111 is suspended in the acoustic cavity 122. The suspended area is the surface area of ​​the diaphragm 111 minus the area where the diaphragm 111 contacts the fixing ring 123. In some embodiments, the suspended area includes a piezoelectric covering area and a non-piezoelectric covering area. The piezoelectric covering area refers to the surface area of ​​the diaphragm 111 where the piezoelectric driving structure 1125 is projected onto the diaphragm 111 along the first direction. The non-piezoelectric covering area is the surface area of ​​the diaphragm 111 outside the piezoelectric covering area. The surface area of ​​the diaphragm 111 is the surface area of ​​the diaphragm 111 perpendicular to the first direction.

[0151] In some embodiments, since the thickness of the sintered piezoelectric ceramic diaphragm 111 is smaller than the thickness of the piezoelectric layer, the diaphragm 111 has little effect on the resonant frequency and output sound pressure level of the speaker 100 , and the output sound pressure level of the speaker 100 is mainly affected by the size of the piezoelectric driving structure 1125 .

[0152] The parameter β is defined as the ratio of the piezoelectric covering area Sq to the suspended area Sp of the diaphragm 111 , wherein the piezoelectric covering area is the area of ​​the piezoelectric covering area of ​​the diaphragm 111 , and the suspended area of ​​the diaphragm 111 is the area of ​​the suspended area of ​​the diaphragm 111 .

[0153] When β is larger, the piezoelectric coverage area is larger, and more piezoelectric materials participate in the drive, thereby pushing the air volume to increase and the output sound pressure level to increase. When β is smaller, the corresponding output sound pressure level decreases.

[0154] Fig.15 It is a frequency response curve diagram of a loudspeaker corresponding to different values ​​of β according to some embodiments of this specification.

[0155] like Fig.15 As shown, when β=0.2, the output sound pressure level of the speaker 100 is low; when β=0.4, the output sound pressure level is significantly improved compared to β=0.2; when β continues to increase, for example, α=0.5, 0.61 or 0.8, the output sound pressure level of the speaker 100 is further improved. Therefore, in some embodiments, the value range of β is β≥0.4. Preferably, the value range of β is β≥0.61.

[0156] Fig.16 It is a schematic diagram of a quarter structure of a piezoelectric drive structure according to some embodiments of this specification.

[0157] like Fig.16 As shown, the piezoelectric driving structure 1125 can be a multi-piece separated structure. The first piece of the piezoelectric driving structure 1125 is located in the central area of ​​the diaphragm 111, and the second piece of the piezoelectric driving structure 1125 is arranged around the first piece. Accordingly, the piezoelectric covering area 1125a on the diaphragm 111 can be divided into two parts: a second piezoelectric covering area located in the central area of ​​the diaphragm 111 and surrounding the first piezoelectric covering area, and the second piezoelectric covering area is annular. The remaining area of ​​the surface area of ​​the diaphragm 111 except the piezoelectric covering area 1125a is the non-piezoelectric covering area 1125b.

[0158] In some embodiments, since the thickness of the diaphragm 111 of the piezoelectric ceramic prepared by the MEMS process is greater than the thickness of the piezoelectric layer, the diaphragm 111 has a significant effect on the resonant frequency and output sound pressure level of the speaker 100. The compliance of the diaphragm 111 mainly comes from the non-piezoelectric covering area 1125b. When the area of ​​the non-piezoelectric covering area 1125b is small, the compliance of the non-piezoelectric covering area 1125b is too small, and the resonant frequency of the speaker 100 is high. When the area of ​​the non-piezoelectric covering area 1125b is large, the compliance of the non-piezoelectric covering area 1125b is too large, and local high-order modes are generated in a lower frequency range, affecting the output of the speaker 100.

[0159] The parameter α is defined as the ratio of the non-piezoelectric covering area Sd to the suspended area Sp of the diaphragm 111 . Fig.16 The area of ​​the non-piezoelectric covering region shown is the sum of the areas of the first piezoelectric covering region and the second piezoelectric covering region.

[0160] When α is large, the area of ​​the non-piezoelectric covering region is large, the compliance of the non-piezoelectric covering region is too large, and local high-order modes are generated at lower frequencies, resulting in reduced output of the speaker 100. When α is small, the area of ​​the non-piezoelectric covering region is small, the compliance of the non-piezoelectric covering region is reduced, the resonant frequency is increased, and the output sound pressure level in the frequency band after the resonant frequency will also increase.

[0161] Fig.17 It is a frequency response curve diagram of a speaker corresponding to different values ​​of α according to some embodiments of this specification.

[0162] like Fig.17 As shown, when α=0.75, the resonant frequency of the loudspeaker 100 is low, the output sound pressure level is low, and the frequency response peaks and valleys are obvious; when α=0.65, compared with α=0.75, the output sound pressure level is significantly improved, and the improvement exceeds 10dB; when α continues to decrease, for example, α=0.36, 0.24 or 0.15, the resonant frequency of the loudspeaker 100 increases, and the output sound pressure level of the frequency range after the resonant frequency is further improved. Therefore, in some embodiments, the value range of α is α≤0.65. Preferably, the value range of α is α≤0.36.

[0163] In some embodiments, in order to adjust the resonant frequency and vibration mode of the speaker 100 , the speaker 100 may further include a mass block 130 , and the mass block 130 is used to adjust the mass and stiffness of the diaphragm 111 , so that the output sound pressure level of the speaker 100 is improved.

[0164] The diaphragm 111 or the driving structure 112 has a long axis direction and a short axis direction, wherein the long axis direction refers to the direction along the long axis (see Figure 5 The short axis direction refers to the direction along the short axis (see Figure 5 The direction in which the y-axis (shown) extends.

[0165] In some embodiments, the mass block 130 may be arranged along the long axis direction, and in the long axis direction, the size of the mass block 130 is equal to or smaller than the size of the piezoelectric driving structure 1125. In some embodiments, the ratio of the size of the mass block 130 along the long axis direction (referred to as the long axis size) to the long axis size of the piezoelectric driving structure 1125 is less than or equal to 1. In some embodiments, the mass block 130 may be arranged along the short axis direction, and in the short axis direction, the size of the mass block 130 is equal to or smaller than the size of the piezoelectric driving structure 1125. In some embodiments, the ratio of the size of the mass block 130 along the short axis direction (referred to as the short axis size) to the short axis size of the piezoelectric driving structure 1125 is less than or equal to 1.

[0166] Fig.18 It is a schematic diagram of the arrangement of the mass block shown in some embodiments of the specification.

[0167] like Fig.18 As shown, the mass block 130 is disposed on the sound unit 110 and is disposed along the long axis direction. In some embodiments, the mass block 130 is disposed on the piezoelectric drive structure 1125. In some embodiments, the mass block 130 is located at or approximately at the short axis of the piezoelectric drive structure 1125.

[0168] Fig.19A The deformation contour of the diaphragm without mass block. Fig.19A As shown, the non-piezoelectric covering area of ​​the diaphragm 111 close to the shell 120 in the long axis direction will produce local concave deformation, which is opposite to the deformation direction of other areas of the diaphragm 111, thereby reducing the overall air volume pushed by the diaphragm 111 and further reducing the output sound pressure level of the speaker 100.

[0169] Fig.19B is the deformation cloud diagram of the diaphragm with the mass block set. Fig.19B As shown, by arranging the mass block 130 along the long axis direction, the non-piezoelectric covering area of ​​the diaphragm 111 close to the shell 120 in the long axis direction can be moved together and kept consistent with the deformation of other parts of the diaphragm 111.

[0170] Fig. 20 It is a schematic diagram of the arrangement of the mass block shown in some embodiments of the specification.

[0171] like Fig. 20 As shown, the mass block 130 is disposed on the sound unit 110 and is disposed along the short axis direction. In some embodiments, the mass block 130 is disposed on the piezoelectric drive structure 1125. In some embodiments, the mass block 130 is located at or approximately at the long axis of the piezoelectric drive structure 1125.

[0172] Fig.21A The deformation contour of the diaphragm without mass block. Fig.21A As shown, the non-piezoelectric covering area of ​​the diaphragm 111 close to the shell 120 in the long axis direction will produce local concave deformation, which is opposite to the deformation direction of other areas of the diaphragm 111, thereby reducing the overall air volume pushed by the diaphragm 111 and further reducing the output sound pressure level of the speaker 100.

[0173] Fig. 21B is the deformation cloud diagram of the diaphragm with the mass block set. Fig. 21BAs shown, by setting the mass block 130 along the short axis direction, although the depression of the non-piezoelectric covering area of ​​the diaphragm 111 close to the shell 120 in the long axis direction cannot be improved, the maximum displacement of the central part of the sound unit 110 of the speaker 100 is increased from an absolute value of 15um to 20um, and the absolute value of the displacement of the depression area of ​​the non-piezoelectric covering area in the opposite direction to the central part is reduced from 30um to 25um, which can reduce the amount of mutual cancellation of sound caused by the displacement in the opposite directions of the depression area of ​​the central part and the non-piezoelectric covering area, thereby effectively increasing the overall amount of air pushed, and thereby increasing the output sound pressure level.

[0174] Fig. 22 It is a schematic diagram of the arrangement of the mass block shown in some embodiments of the specification.

[0175] like Fig. 20 As shown, the mass block 130 is disposed on the sound unit 110, and the mass block 130 has a certain size in both the long axis direction and the short axis direction, so that the mass block 130 is disposed along the long axis and along the short axis direction. In some embodiments, the mass block 130 is disposed on the piezoelectric drive structure 1125. In some embodiments, the mass block 130 is located at or approximately located in the middle area of ​​the piezoelectric drive structure 1125. In some embodiments, the long axis size of the mass block 130 is equal to or smaller than the long axis size of the piezoelectric drive structure 1125, and the short axis size of the mass block 130 is equal to or smaller than the short axis size of the piezoelectric drive structure 1125.

[0176] Fig.23A The deformation contour of the diaphragm without mass block. Fig.23A As shown, the non-piezoelectric covering area of ​​the diaphragm 111 close to the shell 120 in the long axis direction will produce local concave deformation, which is opposite to the deformation direction of other areas of the diaphragm 111, thereby reducing the overall air volume pushed by the diaphragm 111 and further reducing the output sound pressure level of the speaker 100.

[0177] Fig. 23B is the deformation cloud diagram of the diaphragm with the mass block set. Fig. 23B As shown, by arranging the mass block 130 along the major axis and the minor axis, the non-piezoelectric covering area of ​​the diaphragm 111 close to the shell 120 in the major axis direction can be moved together and kept consistent with the deformation of other parts of the diaphragm 111. At the same time, the maximum displacement of the sound unit 110 of the speaker 100 is increased, which can effectively increase the overall pushed air volume, thereby increasing the output sound pressure level.

[0178] Fig.24A is a schematic diagram of the structure of a laminated (10-layer) speaker according to some embodiments of this specification; Fig. 24B It is a frequency response curve diagram of a laminated speaker and a single-layer speaker according to some embodiments of this specification.

[0179] In some embodiments of this specification, a laminated speaker composed of 10 (layers) of sound generating units 110 is used as an example to compare with a single-layer speaker under the same conditions (eg, the same material, the same structure size, etc.). Fig.24A As shown, the height of the first acoustic cavity 1221 formed between the front housing 1201 and the adjacent first sound unit 1101 in the first direction is represented by hq 1 , the height of the first sound outlet hole 1211 coupled to the first acoustic cavity 1221 in the first direction is represented by hk 1 The height of the third acoustic cavity 1223 formed between two adjacent sound-emitting units 110 (such as the i-1th sound-emitting unit 110 and the i-th sound-emitting unit 110) in the first direction is represented by hq i The height of the i-th sound outlet hole 121i coupled to the third acoustic cavity 1223 in the first direction is represented by hk i The height of the second acoustic cavity 1222 formed between the rear housing 1202 and the adjacent nth sound unit 110 in the first direction is represented by hq n+1 , and the height of the n+1th sound outlet 121(n+1) coupled to the second acoustic cavity 1222 in the first direction is represented by hk n+1 . Wherein, i is an integer greater than 1 and less than n.

[0180] like Fig. 24B As shown in the figure, SP10 represents the output sound pressure level of a stacked (10-layer) speaker; SP1 represents the output sound pressure level of a single-layer speaker. i =300um, hq 1 =hq n+1 =150um, hk i =100um, hk 1 =hk n+1 =50um, at the same frequency, the output sound pressure level of the laminated speaker ( Fig. 24B The SP10 shown in the figure is about 60dB, while the output sound pressure level of a single-layer speaker ( Fig. 24B The SP1 shown in FIG is about 40 dB, which shows that the output sound pressure level of the stacked speaker is about 20 dB higher than that of the single-layer speaker (20 dB = 20 × log 10 (10)). Further explanation: when hq i =300um, hq 1 =hq n+1 =150um, hk i =100um, hk 1 =hk n+1When φ = 50 um, the output sound pressure level of the laminated speaker is not reduced due to the small height of the acoustic cavity 122 and the sound outlet hole 121 coupled to the acoustic cavity 122.

[0181] It can be understood that when the height of the acoustic cavity 122 and the sound outlet hole 121 coupled to the acoustic cavity 122 is constant, under the condition that the structural strength of the loudspeaker 100 is not affected, the larger the width of the sound outlet hole 121 in the direction perpendicular to the first direction, that is, the larger the area of ​​the sound outlet hole 121, the smaller its acoustic resistance, and the greater the output sound pressure level. Therefore, the height of the acoustic cavity 122 and the sound outlet hole 121 coupled to the acoustic cavity 122 in the laminated loudspeaker in the first direction is preferably hq i ≥300um, hq 1 ≥150um, hq n+1 ≥150um, hk i ≥100um、hk 1 ≥50um、hk n+1 ≥50um.

[0182] Fig.25 is an exemplary schematic diagram of an acoustic output device according to some embodiments of this specification; Fig.26A is an exemplary schematic diagram 1 of an acoustic output device according to other embodiments of this specification; Fig.26B is a second exemplary schematic diagram of an acoustic output device according to some embodiments of this specification; Fig. 27 is an exemplary schematic diagram of an acoustic output device according to some other embodiments of the present specification; Fig.28 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification.

[0183] In some embodiments, this specification provides an acoustic output device, including: a low-frequency unit and a high-frequency unit, wherein the low-frequency unit includes Figure 1A-Figure 24B The speaker 100 described herein and its related contents.

[0184] In some embodiments, the acoustic output device 200 may include one or more of a back-hook headset, an ear-hook headset, an in-ear headset, and glasses.

[0185] In some embodiments, the acoustic output device 200 may include at least one low-frequency unit and at least one high-frequency unit. Fig.25 As shown, for open-ear headphones, a low-frequency unit and a high-frequency unit can be respectively provided on the two side headphones.

[0186] like Fig.26BAs shown, for open-ear audio glasses, two low-frequency units and one high-frequency unit can be set on each side of the temples to improve the output sound pressure level at low frequencies.

[0187] like Fig.28 As shown, SP d For low frequency unit, SP q For high frequency unit, SP h The acoustic output device 200 after frequency division and combination, the dotted line represents the frequency division line L (i.e., SP d With SP q In some embodiments, the intersection of the frequency response curves of the low frequency unit and the high frequency unit is within the range of 300 Hz-1000 Hz, that is, the frequency division line L is within the range of 300 Hz-1000 Hz.

[0188] The low frequency unit refers to a structural unit capable of achieving good sound pressure level output in the low frequency band in the acoustic output device 200. In some embodiments, the low frequency unit includes but is not limited to an air-conducting piezoelectric stacked speaker (eg, speaker 100).

[0189] In some embodiments, the low frequency unit can operate within a first frequency range with the frequency division line L as the upper boundary. That is, the upper boundary of the first frequency range is within the range of 300 Hz-1000 Hz. In some embodiments, the upper boundary of the first frequency range can also be within other suitable ranges. For example, the upper boundary of the first frequency range is within 300 Hz-1500 Hz, etc. In some embodiments, the first frequency range can be referred to as a low frequency band.

[0190] In some embodiments, since the piezoelectric stack loudspeaker (such as the loudspeaker 100 ) can output a larger sound pressure level in the low frequency band, in order to better achieve a fuller low-frequency effect, the piezoelectric stack loudspeaker (such as the loudspeaker 100 ) can be used in the low frequency band.

[0191] The high frequency unit refers to a structural unit that can achieve a good sound pressure level output in the high frequency band in the acoustic output device 200. In some embodiments, the high frequency unit may include an air conduction speaker and / or a bone conduction speaker.

[0192] In some embodiments, the high frequency unit can operate at least within a second frequency range with the frequency division line L as the lower boundary. In some embodiments, the second frequency range can be referred to as a high frequency band. Figure 25-28As shown, when the high-frequency unit is a bone conduction speaker, since the bone conduction speaker can output a larger sound pressure level in the high frequency band, but it is slightly insufficient in the low frequency band, in order to achieve a full sound effect in the full frequency band, the acoustic output device 200 can use a method of combining a bone conduction speaker with an air-conducted piezoelectric stack speaker (such as speaker 100) so that the bone conduction speaker is responsible for the high frequency band, and the air-conducted piezoelectric stack speaker (such as speaker 100) is responsible for the low frequency band. Of course, in some embodiments, in addition to working in the high frequency band, the bone conduction speaker can also work in the low frequency band to further enhance the low frequency effect. At this time, in the low frequency band, the output of the air-conducted piezoelectric stack speaker (such as speaker 100) is dominant.

[0193] like Figure 25-27 As shown, the high frequency unit of the acoustic output device 200 may also be an air conduction speaker. In this case, the acoustic output device may adopt a frequency division design or not, that is, the air conduction speaker (high frequency unit) may work only in the high frequency band (second frequency range) or in both the low frequency band and the high frequency band. In this case, the outputs of the air conduction speaker and the air conduction piezoelectric stack speaker (such as the speaker 100) are superimposed in the low frequency band to further enhance the low frequency effect.

[0194] In some embodiments, the acoustic output device 200 has a height direction parallel to the first direction and a thickness direction perpendicular to the first direction. The low-frequency unit and the high-frequency unit are arranged in parallel in the height direction, and the low-frequency unit is located below the high-frequency unit; or the low-frequency unit and the high-frequency unit are arranged in parallel in the thickness direction, and the high-frequency unit is arranged on the side of the acoustic output device 200 close to the user.

[0195] The height direction parallel to the first direction can be understood as a direction parallel to the front end surface of the acoustic output device 200 close to the user; the thickness direction perpendicular to the first direction can be understood as a direction perpendicular to the front end surface of the acoustic output device 200 close to the user.

[0196] In some embodiments of the present specification, by disposing the high-frequency unit on the side of the acoustic output device 200 close to the user, when the high-frequency unit adopts a bone conduction speaker 100, it can be more conducive to the transmission of sound to improve the user experience.

[0197] like Figure 25-27 As shown, the high frequency unit is acoustically coupled with the first hole portion 201 provided in the acoustic output device 200, and the low frequency unit is acoustically coupled with the second hole portion 202 provided in the acoustic output device 200, and both the first hole portion 201 and the second hole portion 202 are arranged toward the user so that the sound can be better output to the user. The first hole portion 201 and the second hole portion 202 are the same hole or different holes.

[0198] like Fig.25As shown, when the high frequency unit of the acoustic output device 200 adopts the bone conduction speaker 100SP g In this case, there is no need to provide the first hole portion 201 acoustically coupled to the high frequency unit.

[0199] In some embodiments, the first hole 201 and the second hole 202 are the same hole, which can be understood as the first hole 201 and the second hole 202 are the holes for sound emission shared by the high-frequency unit and the low-frequency unit; the first hole 201 and the second hole 202 are different holes, which can be understood as the first hole 201 and the second hole 202 are independently set holes for sound emission. By respectively setting the first hole 201 and the second hole 202 that are acoustically coupled with the high-frequency unit and the low-frequency unit, the cavity of the high-frequency unit and the low-frequency unit can be isolated, which is conducive to improving the sound transmission effect.

[0200] In some embodiments, the acoustic output device 200 may include a plurality of holes for emitting sound. For example, the acoustic output device 200 may include a first hole 201 acoustically coupled to the high frequency unit, and two second holes 202 acoustically coupled to the low frequency unit, or may include two first holes 201 acoustically coupled to the high frequency unit, and one second hole 202 acoustically coupled to the low frequency unit (e.g., Fig. 27 As shown); For another example, the acoustic output device 200 may include a first hole portion 201 and a second hole portion 202 that are independently arranged and acoustically coupled to the high-frequency unit and the low-frequency unit, respectively, and may also include a hole portion for sound output shared by the high-frequency unit and the low-frequency unit or the two low-frequency units, referred to as a third hole portion 203 (as shown Figure 26A-26B shown).

[0201] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: 1) Based on the fact that two adjacent sound-emitting units in a plurality of sound-emitting units and sharing at least one acoustic cavity in a plurality of acoustic cavities vibrate in opposite directions in at least part of the low-frequency band, combined with the design of the sound outlet holes shown in some embodiments of this specification, the sound pressure level output by a loudspeaker (laminated loudspeaker) having n sound-emitting units can be increased by 20×log compared to the sound pressure level output by a loudspeaker (single-layer loudspeaker) having only one sound-emitting unit. 10(n) times; 2) Since the thickness of the piezoelectric speaker is relatively thin, by arranging a plurality of piezoelectric sound units at intervals in the first direction (thickness direction), a larger low-frequency output can be obtained while meeting the smaller design size of the speaker; 3) By flexibly adjusting the number of sound units in the first direction, the speaker can be applied to more usage scenarios, making it widely applicable and practical; 4) By setting a mass block along the long axis or short axis direction of the sound unit on the sound unit, the mass and stiffness of the diaphragm can be adjusted, and the deformation of the diaphragm during vibration can be adjusted, thereby improving the output sound pressure level of the speaker; 5) By limiting the voltage applied to the first piezoelectric layer and the second piezoelectric layer, the speaker can be more in line with the battery power supply capacity and power consumption of common consumer electronic products such as headphones and audio glasses, making the speaker more practical.

[0202] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0203] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0204] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

[0205] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this specification, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0206] Similarly, it should be noted that in order to simplify the description disclosed in this specification and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this specification, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this specification are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0207] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0208] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A loudspeaker, characterized in that: include: A plurality of sound-emitting units are arranged at intervals along a first direction, and the plurality of sound-emitting units all vibrate along the first direction; The shell is configured to accommodate and support the multiple sound-emitting units, the shell is provided with multiple sound outlets, the shell and the multiple sound-emitting units form multiple acoustic cavities, each acoustic cavity is acoustically coupled with at least one sound outlet on the shell, wherein: The plurality of sound generating units each include a diaphragm and a driving structure arranged on the diaphragm.

2. The loudspeaker according to claim 1, characterized in that The driving structure includes a piezoelectric driving structure, and the housing includes a plurality of fixing rings, each fixing ring fixing a diaphragm of a sound-emitting unit; The piezoelectric driving structure is connected to the fixing ring via an elastic structure, and the elastic structure is symmetrical with respect to the major axis or the minor axis of the piezoelectric driving structure.

3. The loudspeaker according to claim 1, characterized in that The driving structure includes a planar coil; the speaker also includes a magnet disposed in the housing; The magnet is arranged on a side of the diaphragm away from the planar coil; Alternatively, in the first direction, the magnets are respectively disposed on both sides of the diaphragm, and the planar coil is located between the two magnets; Alternatively, the magnet includes a separate magnet, and the separate magnet at least partially overlaps with a projection area of ​​the planar coil in the first direction.

4. The loudspeaker according to claim 1, characterized in that The shell includes a plurality of fixing rings, each fixing ring fixes a sound-emitting unit, and two sound outlet holes are provided on the circumference of each fixing ring, and the two sound outlet holes are respectively coupled with the acoustic cavities on opposite sides of the sound-emitting unit.

5. The loudspeaker according to claim 4, characterized in that The shell includes a front shell and a rear shell, a first acoustic cavity is formed between the front shell and an adjacent sound-emitting unit, a second acoustic cavity is formed between the rear shell and another adjacent sound-emitting unit, and a third acoustic cavity is formed between two adjacent sound-emitting units, and a thickness of the first acoustic cavity and / or the second acoustic cavity along the first direction is less than a thickness of the third acoustic cavity along the first direction.

6. The loudspeaker according to claim 5, characterized in that The height of the first acoustic cavity and the second acoustic cavity in the first direction is greater than or equal to 150um, the height of the third acoustic cavity in the first direction is greater than or equal to 300um, the height of the sound holes corresponding to the first acoustic cavity and the second acoustic cavity in the first direction is greater than or equal to 50um, and the height of the sound holes corresponding to the third acoustic cavity in the first direction is greater than or equal to 100um.

7. The loudspeaker according to claim 2, characterized in that The piezoelectric drive structure includes a sintered piezoelectric ceramic, and the neutral layer of the sound-generating unit is located in the piezoelectric drive structure; the piezoelectric drive structure includes a first piezoelectric layer, a second piezoelectric layer, a first electrode layer, a second electrode layer and a third electrode layer, and in the first direction, the first electrode layer, the first piezoelectric layer, the second electrode layer, the second piezoelectric layer and the third electrode layer are arranged in sequence; The first piezoelectric layer and the second piezoelectric layer have the same polarization direction, and the first voltage of the first electrode layer and the third voltage of the third electrode layer are both greater than or less than the second voltage of the second electrode layer; Alternatively, the polarization directions of the first piezoelectric layer and the second piezoelectric layer are opposite, and the first voltage of the first electrode layer, the second voltage of the second electrode layer, and the third voltage of the third electrode layer decrease or increase in sequence.

8. The loudspeaker according to claim 2, characterized in that The piezoelectric drive structure includes a MEMS piezoelectric ceramic, and the neutral layer of the sound unit is located outside the piezoelectric drive structure; the piezoelectric drive structure includes a first piezoelectric layer, a second piezoelectric layer, a first electrode layer, a second electrode layer and a third electrode layer, and in the first direction, the first electrode layer, the first piezoelectric layer, the second electrode layer, the second piezoelectric layer and the third electrode layer are arranged in sequence; The polarization directions of the first piezoelectric layer and the second piezoelectric layer are opposite, and the first voltage of the first electrode layer and the third voltage of the third electrode layer are both greater than or less than the second voltage of the second electrode layer; Alternatively, the polarization directions of the first piezoelectric layer and the second piezoelectric layer are the same, and the first voltage of the first electrode layer, the second voltage of the second electrode layer, and the third voltage of the third electrode layer decrease or increase in sequence.

9. The loudspeaker according to claim 7 or 8, characterized in that: The first driving voltage of the first piezoelectric layer is the difference between the first voltage and the second voltage, the second driving voltage of the second piezoelectric layer is the difference between the second voltage and the third voltage, and the absolute value of the first driving voltage and the absolute value of the second driving voltage are both no higher than 5V.

10. The loudspeaker according to claim 7, characterized in that The diaphragm includes a piezoelectric covering area and a non-piezoelectric covering area, and a ratio of a first area of ​​the piezoelectric covering area to a suspended area of ​​the sound unit is greater than or equal to 0.

4.

11. The loudspeaker according to claim 8, characterized in that The diaphragm includes a piezoelectric covering area and a non-piezoelectric covering area, and the ratio of the second area of ​​the non-piezoelectric covering area to the suspended area of ​​the sound unit is less than 0.

65.

12. The loudspeaker according to claim 1, wherein: The diaphragm or the driving structure has a long axis direction and a short axis direction, and the sound unit also includes a mass block arranged along the long axis direction or the short axis direction. In the long axis direction or the short axis direction, the size of the mass block is smaller than the size of the piezoelectric driving structure.

13. An acoustic output device, characterized in that: include: A low frequency unit and a high frequency unit, wherein the low frequency unit comprises a loudspeaker as claimed in any one of claims 1 to 8, wherein: The intersection of the frequency response curves of the low-frequency unit and the high-frequency unit is within the range of 300 Hz-1000 Hz; The high-frequency unit operates at least within a frequency range with the intersection point as a lower boundary.

14. The acoustic output device according to claim 13, characterized in that: The acoustic output device includes at least one of a back-hook earphone, an ear-hook earphone, an in-ear earphone, and glasses.

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