Loudspeaker

Abstract

A loudspeaker (100) comprises: a plurality of sound production units (110) arranged at intervals along a first direction, the plurality of sound production units (110) vibrating along the first direction; the shell (120) is configured to accommodate and support the plurality of sound production units (110), the shell (120) is provided with a plurality of sound outlet holes (121), the shell (120) and the plurality of sound production units (110) enclose a plurality of acoustic cavities (122), each acoustic cavity (122) is acoustically coupled with at least one sound outlet hole (121) in the shell (120), and under an excitation signal, the sound production units (110) are driven by the sound outlet holes (121) to produce sound. Two adjacent sound production units (110) of the plurality of sound production units (110), which share at least one acoustic cavity (122) of the plurality of acoustic cavities (122), vibrate in opposite directions in at least part of the low frequency band.

Description

A speaker Technical Field

[0001] This specification relates to the field of acoustic technology, and in particular to a loudspeaker. Background Art

[0002] Current consumer electronics, including open-ear headphones, audio glasses, and TWS earphones, are increasingly demanding low-frequency output sound pressure levels. However, existing air-conduction electromagnetic speakers require a large travel range and thickness to achieve sufficient low-frequency sound pressure levels, posing significant challenges to product size. Therefore, it is necessary to provide a speaker with reasonable size, adjustable based on actual needs, and sufficient low-frequency output sound pressure levels.

[0003] Summary of the Invention

[0004] An embodiment of the present specification provides a loudspeaker, comprising: a plurality of sound-emitting units arranged at intervals along a first direction, the plurality of sound-emitting units all 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 of the acoustic cavities being acoustically coupled to at least one sound outlet hole on the shell, wherein, under an excitation signal, two adjacent sound-emitting units among the plurality of sound-emitting units and sharing at least one acoustic cavity among the plurality of acoustic cavities vibrate in opposite directions in at least part of a low-frequency band.

[0005] In some embodiments, the shell includes multiple fixing rings, each fixing ring fixes a sound unit, and each fixing ring has two sound holes opened on its circumference, and the two sound holes are respectively coupled with the acoustic cavity on opposite sides of the sound unit.

[0006] 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, and 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.

[0007] 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.

[0008] In some embodiments, the shell includes a front shell and a rear shell, each of the fixing rings is provided with at least two electrodes, and the at least two electrodes on each of the fixing rings are respectively connected to the front shell or the rear shell through corresponding conductive electrodes.

[0009] In some embodiments, the at least part of the low frequency band includes a part of the frequency band less than 500 Hz.

[0010] In some embodiments, the sound-generating unit includes a flexible piezoelectric material, and the Young's modulus of the flexible piezoelectric material is 1.5 GPa-9 GPa.

[0011] In some embodiments, the sound-emitting unit includes a first piezoelectric layer and a second piezoelectric layer arranged along the first direction, and the neutral layer of the sound-emitting unit is located between the first piezoelectric layer and the second piezoelectric layer.

[0012] In some embodiments, the sound-emitting unit further includes a first electrode layer, a second electrode layer, and a third electrode layer. 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 are configured as follows: the deformation of the first piezoelectric layer and the second piezoelectric layer are opposite.

[0013] In some embodiments, the first driving voltage of the first piezoelectric layer is the difference between the first voltage of the first electrode layer and the second voltage of the second electrode layer, the second driving voltage of the second piezoelectric layer is the difference between the second voltage and the third voltage of the third electrode layer, and the absolute value of the first driving voltage and the absolute value of the second driving voltage are both no higher than 5V.

[0014] In some embodiments, one or more mass blocks are provided on the sound-generating unit.

[0015] In some embodiments, the sound-emitting unit includes an electrode-covered area and an electrode-non-covered area.

[0016] In some embodiments, the non-electrode covering area is located at the center of the sound unit, and the ratio of the first area of ​​the electrode covering area to the suspended area of ​​the sound unit is between 0.28-0.84.

[0017] In some embodiments, the non-electrode covering area is a ring surrounding the center of the sound unit, and the ratio of the second area of ​​the non-electrode covering area to the suspended area of ​​the sound unit is less than or equal to 0.27.

[0018] An embodiment of this specification also provides an acoustic output device, comprising: a low-frequency unit and a high-frequency unit, wherein the low-frequency unit comprises the loudspeaker according to any one of claims 1 to 14, 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 to 1000 Hz.

[0019] In some embodiments, the high frequency unit includes an air conduction speaker and / or a bone conduction speaker.

[0020] In some embodiments, the high-frequency unit operates at least within a frequency range with the intersection point as a lower boundary.

[0021] In some embodiments, the acoustic output device has a height direction parallel to the first direction and a thickness direction perpendicular to the first direction, wherein the low-frequency unit and the high-frequency unit are arranged 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 parallel in the thickness direction, and the high-frequency unit is arranged on the side of the acoustic output device close to the user.

[0022] In some embodiments, the high-frequency unit is acoustically coupled to a first sound outlet provided in the acoustic output device, and the low-frequency unit is acoustically coupled to a second sound outlet provided in the acoustic output device, and the first sound outlet and the second sound outlet are both arranged toward the user, wherein the first sound outlet and the second sound outlet are the same hole or different holes.

[0023] In some embodiments, the acoustic output device includes at least one of a back-hook headset, an ear-hook headset, an in-ear headset, and glasses. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0025] FIG1A is a schematic structural diagram of a speaker according to some embodiments of this specification;

[0026] FIG1B is a schematic structural diagram of a speaker according to other embodiments of this specification;

[0027] FIG1C is a schematic structural diagram of a speaker according to yet other embodiments of this specification;

[0028] FIG2A is a simplified structural diagram of a loudspeaker when a sound-emitting unit is not vibrating according to some embodiments of this specification;

[0029] FIG2B is a simplified structural diagram of a loudspeaker when a sound-emitting unit vibrates according to some embodiments of this specification;

[0030] FIG3A is a schematic diagram of the structure of a fixing ring and electrodes according to some embodiments of this specification;

[0031] FIG3B is a cross-sectional view taken along line AA in FIG3A ;

[0032] FIG4A is a schematic structural diagram of a fixing ring and a sound-emitting unit according to some embodiments of this specification;

[0033] FIG4B is a schematic structural diagram of a fixing ring, a sound generating unit, and a mass block according to some embodiments of this specification;

[0034] FIG4C is a schematic structural diagram of a fixing ring, a sound generating unit, and a mass block according to other embodiments of this specification;

[0035] FIG4D is a schematic structural diagram of a single-layer speaker according to some embodiments of this specification;

[0036] FIG4E is a schematic structural diagram of a single-layer speaker according to other embodiments of this specification;

[0037] FIG4F is a schematic structural diagram of a single-layer speaker according to some embodiments of this specification;

[0038] FIG5 is a schematic structural diagram of a sound-emitting unit according to some embodiments of this specification;

[0039] FIG6 is a diagram showing a sound generating principle of a sound generating unit according to some embodiments of this specification;

[0040] FIG7A is an exemplary schematic diagram of a first polarization and voltage scheme according to some embodiments of the present specification;

[0041] FIG7B is an exemplary schematic diagram of a second polarization and voltage scheme according to some embodiments of this specification;

[0042] FIG7C is an exemplary schematic diagram of a third polarization and voltage scheme according to some embodiments of this specification;

[0043] FIG7D is an exemplary schematic diagram of a fourth polarization and voltage scheme according to some embodiments of this specification;

[0044] FIG8A is an exemplary schematic diagram of a sound-emitting unit fully covering an electrode according to some embodiments of this specification;

[0045] FIG8B is a deformation diagram of a sound unit fully covering an electrode according to some embodiments of this specification;

[0046] FIG9A is an exemplary schematic diagram of a sound-emitting unit partially covering an electrode according to some embodiments of the present specification;

[0047] FIG9B is a deformation diagram showing a sound-emitting unit partially covering an electrode according to some embodiments of this specification;

[0048] FIG10A is a frequency response curve diagram corresponding to different α values ​​according to some embodiments of this specification;

[0049] FIG10B is a cloud diagram of local deformation of a sound unit corresponding to different α values ​​according to some embodiments of this specification;

[0050] FIG11A is an exemplary schematic diagram of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of the present specification;

[0051] FIG11B is a diagram showing a deformation of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of this specification;

[0052] FIG12 is a frequency response curve diagram corresponding to different β values ​​shown in some embodiments of this specification;

[0053] FIG13A is a schematic structural diagram of a laminated (10-layer) loudspeaker according to some embodiments of this specification;

[0054] FIG13B is a frequency response curve diagram of a stacked speaker and a single-layer speaker according to some embodiments of the present specification;

[0055] FIG14 is an exemplary schematic diagram of an acoustic output device according to some embodiments of the present specification;

[0056] FIG15A is an exemplary schematic diagram 1 of an acoustic output device according to some other embodiments of this specification;

[0057] FIG15B is a second exemplary schematic diagram of an acoustic output device according to some embodiments of this specification;

[0058] FIG16 is an exemplary schematic diagram of an acoustic output device according to yet other embodiments of the present specification;

[0059] FIG. 17 is a frequency response curve diagram of an acoustic output device according to some embodiments of the present specification.

[0060] Explanation of reference numerals: 100 is a speaker, 110 is a sound unit, 1101 is a first sound unit, 1102 is a second sound unit, 1103 is a third sound unit, 1104 is a fourth sound unit, 110n is an nth sound unit, 111 is a piezoelectric layer, 1111 is a first piezoelectric layer, 1112 is a second piezoelectric layer, 112 is a neutral layer, 113 is an electrode layer, 1131 is a first electrode layer, 1132 is a second electrode layer, 1133 is a third electrode layer, 120 is a housing, 1201 is a front housing, 1202 is a rear housing, 121 is a sound outlet (including 1211, 1212, 1212-1, 1212-2, 1213-1…121i…121(n+1)), 122 is the acoustic cavity, 1221 is the first acoustic cavity, 1222 is the second acoustic cavity, 1223 is the third acoustic cavity, 123 is the fixing ring, 1231 is the first fixing ring, 1232 is the second fixing ring, 130 is the mass block, 140 is the dustproof / damping net, 1401 is the front cavity dustproof / damping net, 1402 is the rear cavity dustproof / damping net, 200 is the acoustic output device, 201 is the first sound outlet, 202 is the second sound outlet, and 203 is the third sound outlet. DETAILED DESCRIPTION

[0061] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0062] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0063] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0064] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0065] Current consumer electronic products, including open-ear headphones, audio glasses, and TWS headphones, have increasingly higher requirements for low-frequency output sound pressure levels. However, existing air-conducted electromagnetic speakers require a large range of motion and thickness to achieve sufficient low-frequency sound pressure levels, posing a significant challenge to product size. Piezoelectric speakers have the advantage of being thin. Some embodiments of this specification provide a speaker that utilizes multiple piezoelectric sound-generating units stacked and superimposed to form a laminated speaker. Furthermore, the number of sound-generating units (i.e., the number of layers) in the laminated speaker can be adjusted based on the actual product size, the sound pressure level output required at different locations, and in different usage scenarios. This allows for a larger low-frequency output while still meeting the requirements for a smaller size.

[0066] Figure 1A is a structural diagram of a speaker according to some embodiments of the present specification; Figure 1B is a structural diagram of a speaker according to other embodiments of the present specification; Figure 1C is a structural diagram of a speaker according to still other embodiments of the present specification; Figure 2A is a structural diagram of a speaker when the sound-emitting unit is not vibrating according to some embodiments of the present specification; Figure 2B is a structural diagram of a speaker when the sound-emitting unit is vibrating according to some embodiments of the present specification.

[0067] As shown in FIG. 1A to FIG. 1C , some embodiments of the present specification provide a speaker 100 , comprising a plurality of sound-emitting units 110 spaced apart along a first direction and a housing 120 .

[0068] The first direction refers to the stacking direction of the plurality of sound units 110 of the speaker 100. For example, the first direction may be a vertically upward direction or a vertically downward direction. In some embodiments, the first direction may be a thickness direction of the sound unit 110.

[0069] In some embodiments, the housing 120 can be used to accommodate and support multiple sound units 110. In some embodiments, the housing 120 can be a one-piece structure or a split structure. For example, the housing 120 can be composed of multiple structural parts assembled using bonding, snap-fit ​​connections, etc.

[0070] In some embodiments, a plurality of sound holes 121 are provided on the shell 120 . The shell 120 and the plurality of sound emitting units 110 may form a plurality of acoustic cavities 122 . Each acoustic cavity 122 is acoustically coupled with at least one sound hole 121 on the shell 120 .

[0071] The acoustic cavity 122 refers to the cavity structure within the speaker 100. In some embodiments, the acoustic cavity 122 may be formed between the housing 120 and the sound unit 110, and / or between two adjacent sound units 110. As shown in FIG1C , when the number of sound units 110 is n, the number of acoustic cavities 122 may be n+1. For more information on the acoustic cavity, please refer to FIG2A-2B and the related description.

[0072] The sound outlet 121 refers to a structure in the speaker 100 for radiating sound to the outside. In some embodiments, the sound outlet 121 can be arranged corresponding to the acoustic cavity 122, that is, one acoustic cavity 122 corresponds to at least one sound outlet 121. In some embodiments, the number of sound outlets 121 can be the same as the number of acoustic cavities 122. As shown in Figure 1C, when the number of sound units 110 is n, the number of acoustic cavities 122 is n+1, and the number of sound outlets 121 can also be n+1. For more information about the sound outlet, please refer to Figures 2A-2B and their related descriptions.

[0073] The sound-generating unit 110 refers to the component in the speaker 100 that vibrates to produce sound. In some embodiments, the specific number of sound-generating units 110 is not limited and can be set based on actual needs. For example, the number can be selected based on the required sound pressure level of the speaker 100; for another example, the number can be selected based on the thickness of the speaker 100. As shown in Figure 1B, the sound-generating unit 110 may include a first sound-generating unit 1101, a second sound-generating unit 1102, and so on. The nth sound-generating unit 110n.

[0074] In some embodiments, the plurality of sound-emitting units 110 may be spaced apart along a first direction within the housing 120, and the plurality of sound-emitting units 110 may all vibrate along the first direction. In some embodiments, under an excitation signal, two adjacent sound-emitting units 110 among the plurality of sound-emitting units 110 that share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 vibrate in opposite directions, as shown in FIG2B . It should be noted that under an excitation signal, the two adjacent sound-emitting units 110 among the plurality of sound-emitting units 110 that share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 may vibrate in opposite directions across the entire frequency band to enhance the output sound pressure level of the speaker 100 across the entire frequency band. In some embodiments, under an excitation signal, 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, so as to enhance the output sound pressure level of an acoustic output device including the speaker 100 (e.g., the acoustic output device 200) in at least part of the low-frequency band, thereby meeting the current requirement of acoustic output devices for gradually increasing the output sound pressure level in the low-frequency band.

[0075] In some embodiments, at least part of the low frequency band may include a frequency band less than 500 Hz. In some embodiments, at least part of the low frequency band may include a frequency band less than 300 Hz. For example, the frequency band may be 50 Hz-100 Hz, 100 Hz-150 Hz, or 150 Hz-280 Hz.

[0076] In some embodiments, the vibration of the plurality of sound-emitting units 110 along the first direction may include at least one sound-emitting unit 110 among the plurality of sound-emitting units 110 vibrating in a vertically upward direction and / or at least one sound-emitting unit 110 vibrating in a vertically downward direction. Furthermore, the vibration of the plurality of sound-emitting units 110 along the first direction may include two adjacent sound-emitting units 110 among the plurality of sound-emitting units 110 that share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 vibrating in opposite directions in at least a portion of the low-frequency band. As shown in Figures 2A and 2B, the first sound-emitting unit 1101 vibrates in a vertically downward direction, the second sound-emitting unit 1102 vibrates in a vertically upward direction; the third sound-emitting unit 1103 vibrates in a vertically downward direction, and the fourth sound-emitting unit 1104 vibrates in a vertically upward direction.

[0077] In some embodiments, by controlling the excitation voltages of the plurality of sound-emitting units 110, the phase difference between the excitation voltages of the two sound-emitting units 110 of at least one acoustic cavity 122 is 180°, thereby enabling two adjacent sound-emitting units 110 among the plurality of sound-emitting units 110 that share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 to vibrate in opposite directions in at least a portion of the low-frequency band. Based on the fact that the two adjacent sound-emitting units 110 among the plurality of sound-emitting units 110 that share at least one acoustic cavity 122 among the plurality of acoustic cavities 122 vibrate in opposite directions in at least a portion of the low-frequency band, combined with the design of the sound outlet 121 shown in some embodiments of this specification, the sound pressure level output by a loudspeaker 100 (stacked loudspeaker) having n sound-emitting units 110 can be increased by 20×log compared to the sound pressure level output by a loudspeaker 100 (single-layer loudspeaker) having only one sound-emitting unit 110. 10 (n) times.

[0078] For more information about the sound-emitting unit, please refer to Figures 2A-2B, Figures 4A-13B and their related descriptions.

[0079] In some embodiments of this specification, due to the relatively thin thickness of a piezoelectric speaker, multiple piezoelectric sound generating units are spaced apart in a first direction (thickness direction), thereby achieving a high low-frequency output while maintaining a compact speaker design. Furthermore, the flexible adjustment of the number of sound generating units in the first direction based on actual needs allows the speaker to be adapted to a wider range of usage scenarios, providing it with broad applicability and practicality.

[0080] As shown in FIG. 1B and FIG. 2A-FIG . 2B , the housing 120 may include a plurality of fixing rings 123 .

[0081] The fixing ring 123 is a structure for fixing the sound unit 110. In some embodiments, in the first direction, the sound unit 110 is disposed within 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 rings 123 are evenly distributed on both sides of the sound unit 110.

[0082] In some embodiments, each fixing ring 123 fixes a sound unit 110 , and two sound holes 121 are opened on the circumference of each fixing ring 123 . The two sound holes 121 are respectively coupled to the acoustic cavities 122 on opposite sides of the sound unit 110 .

[0083] 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. In some embodiments, the sound outlet holes 121 can be arranged on two opposite sides of the fixing ring 123 (e.g., opposite long sides or opposite short sides) or adjacent to each other 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.

[0084] As shown in Figure 2A, 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 sound hole 1211 and sound hole 1212-1. The second fixing ring 1232 has two sound holes on its circumference, namely sound hole 1212-2 and sound hole 1213-1. Among them, the sound hole 1212-1 is connected to the sound hole 1212-2 to form a complete 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 shell 120 can be regarded as including only one fixing ring 123, and the multiple sound units 110 are all arranged in one fixing ring 123.

[0085] In some embodiments, the shell 120 may include a front shell 1201 and a rear shell 1202, wherein 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, and a third acoustic cavity 1223 is formed between the two adjacent sound units 110.

[0086] As shown in Figures 2A and 2B, a first acoustic cavity 1221 can be formed between the front shell 1201 and the first sound unit 1101, a second acoustic cavity 1222 can be formed between the rear shell 1202 and the fourth sound unit 1104, and a third acoustic cavity 1223 can 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.

[0087] 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. It is understandable that, as shown in Figures 2A and 2B, 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, while the third acoustic cavity 1223 is formed based on two adjacent sound units 110, and since the 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.

[0088] Furthermore, in some embodiments, in the first direction, the size of the sound outlet 121 corresponding to the first acoustic cavity 1221 and / or the second acoustic cavity 1222 is smaller than the size of the sound outlet 121 corresponding to the third acoustic cavity 1223. The size of the sound outlet 121 may include, but is not limited to, the height of the sound outlet 121 along the first direction.

[0089] In some embodiments of the present specification, two adjacent sound-emitting units among multiple sound-emitting units and sharing at least one acoustic cavity among multiple acoustic cavities vibrate in opposite directions in at least part of the low-frequency band. In combination with the design of the sound outlet holes shown in some embodiments of the present specification, the sound pressure level output by a loudspeaker (laminated loudspeaker) having n sound-emitting units can be improved compared to the sound pressure level output by a loudspeaker (single-layer loudspeaker) having only one sound-emitting unit. Furthermore, by taking advantage of the small thickness of a single-layer sound-emitting unit, a loudspeaker with a smaller thickness and a large low-frequency output sound pressure level can be realized.

[0090] FIG3A is a schematic structural diagram of a fixing ring and an electrode according to some embodiments of the present disclosure; FIG3B is a cross-sectional view taken along line AA in FIG3A .

[0091] 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.

[0092] 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 may also be three. As shown in Figures 3A-3B, the fixing ring 123 may include two electrodes, namely, electrode E1 and electrode E2.

[0093] 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) can be provided to the sound unit 110 fixed on the fixing ring 123 .

[0094] Conductive electrodes refer to electrode structures that connect corresponding electrodes on each fixing ring 123. As shown in Figure 3B, a 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 a second conductive electrode D2 can connect the electrode E2 on each fixing ring 123 to the front shell 1201 or the rear shell 1202.

[0095] In some embodiments, the fixing ring 123 may comprise one or more of FR4, FPC, and plastic. The fixing ring 123 is provided with at least two conductive holes extending along a first direction, and at least two electrodes are respectively disposed in corresponding conductive holes. The electrodes corresponding to any two adjacent fixing rings 123 can be electrically connected to each other to form conductive electrodes. Mutual electrical connection refers to electrical connection between the electrodes.

[0096] For example, when the fixing ring 123 is made of FR4 or FPC, the two end faces of the fixing ring 123 can be directly connected through the conductive holes. Then, by applying conductive silver paste, conductive adhesive, or patching, at least two electrodes on each fixing ring 123 can be connected to each other to form corresponding conductive electrodes. For another example, when the fixing ring 123 is made of a resin polymer material such as plastic, metal electrodes can be placed in the conductive holes to achieve mutual conductive connection between the corresponding electrodes of any two connected fixing rings 123 to form conductive electrodes.

[0097] Figure 4A is a schematic diagram of the structure of a fixing ring and a sound-emitting unit according to some embodiments of this specification; Figure 4B is a schematic diagram of the structure of a fixing ring, a sound-emitting unit and a mass block according to some embodiments of this specification; Figure 4C is a schematic diagram of the structure of a fixing ring, a sound-emitting unit and a mass block according to other embodiments of this specification.

[0098] As shown in FIG4A , in a speaker 100 (laminated speaker) having multiple (eg, n) sound units 110 , a single sound unit 110 is disposed in the middle of a fixing ring 123 , that is, the fixing ring 123 is evenly distributed on both sides of the sound unit 110 .

[0099] In some embodiments, the sound unit 110 may further be provided with one or more mass blocks 130. For example, the number of mass blocks 130 may be 1, 2, 3, or the like.

[0100] As shown in Figure 4B, a mass block 130 may be provided on the sound unit 110 fixed in the fixing ring 123. In some embodiments, the structure and size of the mass block 130 are not limited and may be configured based on actual needs.

[0101] In some embodiments of this specification, a mass block is provided on the sound-emitting unit to adjust the resonant frequency F0 of the loudspeaker.

[0102] As shown in Figure 4C, two mass blocks 130 may be provided on the sound unit 110 fixed in the fixing ring 123. The structure and size of the two mass blocks 130 are not limited and may be the same or different, and may also be provided based on actual needs.

[0103] In some embodiments of this specification, by further increasing the number of mass blocks 130 on the sound unit 110, the resonant frequency F0 of the speaker can be further adjusted so that the speaker can better meet the different needs of different users and different usage scenarios.

[0104] Figure 4D is a structural diagram of a single-layer speaker according to some embodiments of this specification; Figure 4E is a structural diagram of a single-layer speaker according to other embodiments of this specification; Figure 4F is a structural diagram of a single-layer speaker according to some embodiments of this specification.

[0105] In some embodiments, in a speaker 100 (single-layer speaker) with only one sound unit 110, it may not only include the sound unit 110 and the fixing ring 123, with the sound unit 110 being arranged in the middle position of the fixing ring 123, but also include a front shell 1201, a rear shell 1202 and a dust / damping net 140 connected to the front shell 1201 and the rear shell 1202.

[0106] As shown in Figures 4D-4F , the front housing 1201 and the rear housing 1202 are respectively connected to the two end surfaces of the fixing ring 123 along the first direction. In a direction perpendicular to the first direction, a front cavity dustproof / damping net 1401 and a rear cavity dustproof / damping net 1402 are respectively disposed between the front housing 1201 and the rear housing 1202. The front housing 1201, the front cavity dustproof / damping net 1401, the upper half of the fixing ring 123, and the upper side of the sound unit 110 together form the front cavity of the speaker 100; the rear housing 1202, the rear cavity dustproof / damping net 1402, the lower half of the fixing ring 123, and the lower side of the sound unit 110 together form the rear cavity of the speaker 100. In some embodiments, as shown in FIG1A , in a speaker 100 including a plurality of sound-emitting units 110 spaced apart along a first direction, a dustproof / damping net 140 may be provided at the sound outlets 121 corresponding to each of the plurality of acoustic cavities 122 to achieve dustproof packaging. In some embodiments, for the speaker 100 shown in FIG1A , dustproof packaging may not be performed between two adjacent sound-emitting units 110, so that the front cavity and the rear cavity between the two adjacent sound-emitting units 110 are not separated, and an acoustic cavity 122 may be formed. In some embodiments, for the speaker 100 shown in FIG1A , dustproof packaging may also be performed between two adjacent sound-emitting units 110 (for example, a dustproof / damping net 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 speaker 100 and the Q value of the output frequency response.

[0107] In some embodiments, in the front cavity of the speaker 100 , the sound unit 110 may be provided with a mass block 130 or may not be provided with a mass block 130 , which may be determined based on actual needs.

[0108] FIG5 is a schematic structural diagram of a sound-generating unit according to some embodiments of the present specification; FIG6 is a schematic diagram of a sound-generating principle of a sound-generating unit according to some embodiments of the present specification.

[0109] In some embodiments, the sound unit 110 may include a flexible piezoelectric material, such as, but not limited to, polyvinylidene fluoride (PVDF), a copolymer of polyvinylidene fluoride (eg, vinylidene fluoride-trifluoroethylene copolymer), and the like.

[0110] In some embodiments, the Young's modulus of the flexible piezoelectric material may be 1.5 GPa-9 GPa. For example, the Young's modulus of the flexible piezoelectric material is 1.5 GPa-5 GPa, 3 GPa-7 GPa, 5 GPa-9 GPa, or other intervals.

[0111] In some embodiments of this specification, based on the use of flexible piezoelectric materials in the sound-emitting unit, the sound-emitting unit can realize the vibration function while also having the driving function.

[0112] As shown in FIG. 5 and FIG. 6 , the sound unit 110 may include a first piezoelectric layer 1111 and a second piezoelectric layer 1112 arranged along a first direction, and the neutral layer 112 of the sound unit 110 is located between the first piezoelectric layer 1111 and the second piezoelectric layer 1112 .

[0113] In some embodiments, the sound unit 110 may further include a first electrode layer 1131, a second electrode layer 1132, and a third electrode layer 1133. In a first direction, the first electrode layer 1131, the first piezoelectric layer 1111, the second electrode layer 1132, the second piezoelectric layer 1112, and the third electrode layer 1133 are arranged in sequence. The first piezoelectric layer 1111 and the second piezoelectric layer 1112 are configured such that the deformation of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are opposite. That is, when the first piezoelectric layer 1111 extends, the second piezoelectric layer 1112 shortens; alternatively, when the first piezoelectric layer 1111 shortens, the second piezoelectric layer 1112 extends. Combined with the neutral layer 112 of the sound unit 110 being located between the first piezoelectric layer 1111 and the second piezoelectric layer 1112, the deformation of the sound unit 110 can be increased.

[0114] In some embodiments, the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are collectively referred to as the piezoelectric layer 111; the first electrode layer 1131, the second electrode layer 1132, and the third electrode layer 1133 are collectively referred to as the electrode layer 113. The piezoelectric layer 111 refers to a layered structure capable of achieving the inverse piezoelectric effect; the electrode layer 113 refers to a layered structure capable of conducting current.

[0115] In some embodiments, when the speaker 100 produces sound, the sound unit 110 needs to deform along the first direction and further displace in the first direction to push the air in the acoustic cavity 122 on the upper and lower sides of the sound unit 110 to radiate sound pressure, thereby producing sound.

[0116] In some embodiments, when the sound unit 110 is made of a flexible piezoelectric material (e.g., PVDF), the sound unit 110 has a d33 mode and a d31 mode. Furthermore, when voltages V1, V2, and V3 are applied to the first electrode layer 1131, the second electrode layer 1132, and the third electrode layer 1133, respectively, along a first direction, the sound unit 110 will experience expansion and contraction deformation along the first direction (direction 3 shown in FIG6 ) and in a direction perpendicular to the first direction (direction 1 shown in FIG6 ). If only the d33 mode in the first direction is used, the deformation of the sound unit 110 is extremely small, and the sound pressure level output by the sound unit 110 cannot meet actual requirements. Therefore, the d31 mode in a direction perpendicular to the first direction is required.

[0117] In some embodiments, in order to convert the expansion and contraction deformation in a direction perpendicular to the first direction into the forward and backward displacement of the sound unit 110 in the first direction, it is necessary to make the deformation directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 opposite, for example, the first piezoelectric layer 1111 produces an expansion deformation in the first direction, and the second piezoelectric layer 1112 produces a shortening deformation in the first direction; or the first piezoelectric layer 1111 produces a shortening deformation in the first direction, and the second piezoelectric layer 1112 produces an expansion deformation in the first direction. At this time, as shown in Figure 6, a neutral layer 113 is provided between the first piezoelectric layer 1111 and the second piezoelectric layer 1112. The length of the neutral layer 113 remains unchanged during the deformation of the sound unit 110, and the piezoelectric layers 111 on the upper and lower sides of the neutral layer 113 have opposite deformation directions, so that the expansion and contraction deformation in the direction perpendicular to the first direction is converted into a large forward and backward displacement of the sound unit 110 in the first direction, thereby improving the sound pressure level radiated by the sound unit 110.

[0118] In some embodiments, because the sound unit 110 is made of a flexible piezoelectric material, it has a polarization direction, and applying voltage at different locations along the polarization direction produces different deformation effects. For example, when the potential direction is the same as the polarization direction, the piezoelectric layer 111 will produce a tensile deformation; when the potential direction is opposite to the polarization direction, the piezoelectric layer 111 will produce a shortening deformation. Based on this, there are various methods that can achieve opposite deformation directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112.

[0119] Figure 7A is an exemplary schematic diagram of polarization and voltage scheme one according to some embodiments of this specification; Figure 7B is an exemplary schematic diagram of polarization and voltage scheme two according to some embodiments of this specification; Figure 7C is an exemplary schematic diagram of polarization and voltage scheme three according to some embodiments of this specification; Figure 7D is an exemplary schematic diagram of polarization and voltage scheme four according to some embodiments of this specification.

[0120] As shown in FIG. 7A to FIG. 7D , the arrows inside the first piezoelectric layer 1111 and the second piezoelectric layer 1112 in the figure represent the polarization directions of the corresponding piezoelectric layers 111 , and the corresponding V1 , V2 , and V3 respectively represent the external excitation voltages applied when the speaker 100 is working.

[0121] In some embodiments, the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are opposite, as shown in Figures 7A and 7B. The first voltage V1 of the first electrode layer 1131, the second voltage V2 of the second electrode layer 1132, and the third voltage V3 of the third electrode layer 1133 can decrease or increase in sequence, that is, V1>V2>V3 or V1<V2<V3.

[0122] As shown in Figure 7A, the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are opposite: the polarization direction of the first piezoelectric layer 1111 is upward, and the polarization direction of the second piezoelectric layer 1112 is downward. When the first voltage V1 of the first electrode layer 1131, the second voltage V2 of the second electrode layer 1132, and the third voltage V3 of the third electrode layer 1133 decrease in sequence (i.e., V1>V2>V3), the electric potential direction of the first piezoelectric layer 1111 is downward, opposite to the polarization direction of the first piezoelectric layer 1111, causing the first piezoelectric layer 1111 to shorten and deform. The electric potential direction of the second piezoelectric layer 1112 is downward, the same as the polarization direction of the second piezoelectric layer 1112, causing the second piezoelectric layer 1112 to stretch and deform, causing the entire sound unit 110 to displace downward in the first direction. When the first voltage V1 of the first electrode layer 1131, the second voltage V2 of the second electrode layer 1132, and the third voltage V3 of the third electrode layer 1133 increase successively (i.e., V1<V2<V3), the electric potential direction of the first piezoelectric layer 1111 is upward, which is the same as the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 produces a tensile deformation. The electric potential direction of the second piezoelectric layer 1112 is upward, which is opposite to the polarization direction of the second piezoelectric layer 1112, and the second piezoelectric layer 1112 produces a shortening deformation, and the sound unit 110 as a whole is displaced upward in the first direction.

[0123] As shown in Figure 7B, the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are opposite, with the first piezoelectric layer 1111 being polarized downward and the second piezoelectric layer 1112 being polarized upward. When the first voltage V1 of the first electrode layer 1131, the second voltage V2 of the second electrode layer 1132, and the third voltage V3 of the third electrode layer 1133 decrease in sequence (i.e., V1>V2>V3), the electric potential direction of the first piezoelectric layer 1111 is downward, which is the same as the polarization direction of the first piezoelectric layer 1111, causing the first piezoelectric layer 1111 to undergo tensile deformation. The electric potential direction of the second piezoelectric layer 1112 is downward, which is opposite to the polarization direction of the second piezoelectric layer 1112, causing the second piezoelectric layer 1112 to undergo shortening deformation, causing the entire sound unit 110 to displace upward in the first direction. When the first voltage V1 of the first electrode layer 1131, the second voltage V2 of the second electrode layer 1132, and the third voltage V3 of the third electrode layer 1133 increase successively (i.e., V1<V2<V3), the electric potential direction of the first piezoelectric layer 1111 is upward, which is opposite to the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 produces a shortening deformation. The electric potential direction of the second piezoelectric layer 1112 is upward, which is the same as the polarization direction of the second piezoelectric layer 1112, and the second piezoelectric layer 1112 produces a tensile deformation, and the sound unit 110 as a whole is displaced downward in the first direction.

[0124] In some embodiments, the first piezoelectric layer 1111 and the second piezoelectric layer 1112 have the same polarization direction. The first voltage V1 of the first electrode layer 1131 and the third voltage V3 of the third electrode layer 1133 can both be greater than or less than the second voltage V2 of the second electrode layer 1132, i.e., V1>V2, V3>V2 or V1<V2, V3<V2. Furthermore, V1 can be equal to V3, and V2 can be 0V.

[0125] As shown in FIG7C , the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are the same, and both the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are upward. When the first voltage V1 of the first electrode layer 1131 and the third voltage V3 of the third electrode layer 1133 are both greater than the second voltage V2 of the second electrode layer 1132 (i.e., V1>V2, V3>V2), the electric potential direction of the first piezoelectric layer 1111 is downward, opposite to the polarization direction of the first piezoelectric layer 1111, causing the first piezoelectric layer 1111 to shorten and deform. The electric potential direction of the second piezoelectric layer 1112 is upward, the same as the polarization direction of the second piezoelectric layer 1112, causing the second piezoelectric layer 1112 to stretch and deform, causing the entire sound unit 110 to displace downward in the first direction. When the first voltage V1 of the first electrode layer 1131 and the third voltage V3 of the third electrode layer 1133 are both less than the second voltage V2 of the second electrode layer 1132 (i.e., V1 < V2, V3 < V2), the electric potential direction of the first piezoelectric layer 1111 is upward, which is the same as the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 produces a tensile deformation. The electric potential direction of the second piezoelectric layer 1112 is downward, which is opposite to the polarization direction of the second piezoelectric layer 1112, and the second piezoelectric layer 1112 produces a shortening deformation, and the sound unit 110 as a whole is displaced upward in the first direction.

[0126] As shown in FIG7D , the first piezoelectric layer 1111 and the second piezoelectric layer 1112 have the same polarization direction, and both the polarization direction of the first piezoelectric layer 1111 and the polarization direction of the second piezoelectric layer 1112 are downward. When the first voltage V1 of the first electrode layer 1131 and the third voltage V3 of the third electrode layer 1133 are both greater than the second voltage V2 of the second electrode layer 1132 (i.e., V1>V2, V3>V2), the electric potential direction of the first piezoelectric layer 1111 is downward, which is the same as the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 experiences tensile deformation. The electric potential direction of the second piezoelectric layer 1112 is upward, which is opposite to the polarization direction of the second piezoelectric layer 1112, and the second piezoelectric layer 1112 experiences shortening deformation, causing the entire sound unit 110 to displace upward in the first direction. When the first voltage V1 of the first electrode layer 1131 and the third voltage V3 of the third electrode layer 1133 are both less than the second voltage V2 of the second electrode layer 1132 (i.e., V1 < V2, V3 < V2), the electric potential direction of the first piezoelectric layer 1111 is upward, which is opposite to the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 produces a shortening deformation. The electric potential direction of the second piezoelectric layer 1112 is downward, which is the same as the polarization direction of the second piezoelectric layer 1112, and the second piezoelectric layer 1112 produces a tensile deformation, and the sound unit 110 as a whole is displaced downward in the first direction.

[0127] In some embodiments, the first driving voltage ΔV1 of the first piezoelectric layer 1111 is the difference between the first voltage V1 and the second voltage V2 (i.e., ΔV1 = V1-V2), and the second driving voltage ΔV2 of the second piezoelectric layer 1112 is the difference between the second voltage V2 and the third voltage V3 (ΔV2 = V2-V3), and the absolute values ​​of the first driving voltage ΔV1 and the second driving voltage ΔV2 may not be higher than 5V.

[0128] In some embodiments of this specification, by limiting the driving voltage applied to the first piezoelectric layer and the second piezoelectric layer, the speaker can be made more compatible 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.

[0129] It should be noted that because the electrode design of the sound unit 110 has a significant impact on the deformation form and degree of the sound unit itself, some embodiments of this specification will design the electrodes to enable the sound unit 110 to deform to a greater extent, pushing a larger volume of air to radiate sound pressure, thereby increasing the output sound pressure level of the sound unit 110. The electrode design may include, but is not limited to, designing the area and shape of the electrode coverage area.

[0130] Figure 8A is an exemplary schematic diagram of a fully covered electrode of a sound-emitting unit according to some embodiments of the present specification; Figure 8B is a deformation diagram of a fully covered electrode of a sound-emitting unit according to some embodiments of the present specification; Figure 9A is an exemplary schematic diagram of a partially covered electrode of a sound-emitting unit according to some embodiments of the present specification; Figure 9B is a deformation diagram of a partially covered electrode of a sound-emitting unit according to some embodiments of the present specification; Figure 10A is a frequency response curve diagram corresponding to different α according to some embodiments of the present specification; Figure 10B is a local deformation cloud diagram of a sound-emitting unit corresponding to different α according to some embodiments of the present specification.

[0131] In some embodiments, the sound unit 110 may be fully covered with electrodes. As shown in Figures 8A-8B, when the sound unit 110 is fully covered with electrodes, the sound unit 110 will deform over the entire area after the excitation voltage is applied. The deformation is concave or convex in the first-order mode and before.

[0132] In some embodiments, the sound unit 110 may be partially covered with electrodes.

[0133] In some embodiments, the sound unit 110 may include an electrode-covered area and an electrode-uncovered area, wherein the electrode-covered area refers to the area on the sound unit 110 covered with electrodes, and the electrode-uncovered area refers to the area on the sound unit 110 not covered with electrodes.

[0134] In some embodiments, the non-electrode covering area may be located at the center of the sound emitting unit 110 .

[0135] As shown in Figures 8A-9B, S d represents the first area of ​​the electrode coverage area; S p represents the suspended area of ​​the sound unit 110 (i.e., the entire area of ​​the sound unit minus the area in contact with the housing), and defines parameter α as the first area S of the electrode coverage area. d The suspended area S of the sound unit 110 p Ratio, that is

[0136] In some embodiments, when the sound unit 110 partially covers the electrode, the deformation form in the first-order mode and before is a local concave or convex deformation form plus a local piston deformation form. By partially covering the electrode with the sound unit 110, the driving area can be deformed more. The superimposed displacement of the piston area can increase the overall volume of the pushed air, thereby increasing the output sound pressure level of the sound unit 110.

[0137] Specifically, since the non-electrode covering area located at the center of the sound unit 110 will not deform, under the same conditions (such as the same voltage, the same material, etc.), the deformation produced by the driving area of ​​the annular electrode covering area is greater than the area corresponding to the driving area of ​​the annular electrode covering area on the full electrode covering area. Combined with the setting of the piston area, the overall volume of the air pushed by the sound unit 110 can be increased, thereby improving the output sound pressure level of the sound unit 110.

[0138] In some embodiments, by designing the first area S of the electrode coverage area d , it is possible to effectively control the local concave or convex deformation of the sound unit 110 and the local piston deformation. Based on this, some embodiments of this specification will be described using the parameter α.

[0139] In some embodiments, the first area S of the electrode coverage region d The suspended area S of the sound unit 110 p The ratio α can be between 0.28 and 0.84.

[0140] In some embodiments, when α is small or large, the output sound pressure level is low. As shown in Figures 10A-10B, when α = 0.92 and α = 0.07, the output sound pressure level (SPL) is significantly lower than when α = 0.28-0.84, with a difference of more than 5dB. This is because when α is small, that is, the first area S of the electrode coverage area is d When α is small, the area of ​​the sound unit 110 involved in generating the driving force is small (i.e., the driving area is small). Even if the piston area is large, the overall displacement is small. For example, when α = 0.07, the local deformation cloud diagram of the sound unit 110 shows that its maximum absolute displacement is 6 μm. When α is large, that is, the first area S of the electrode coverage area is large. d When α is larger, the area of ​​the sound unit 11 involved in generating the driving force is large (i.e., the driving area is large), but the piston area is small. For example, when α = 0.84, the local deformation cloud diagram of the sound unit 110 shows that its maximum displacement absolute value is 7um. Although the maximum displacement is larger than when α = 0.07, the overall volume of air pushed is small. When α = 0.45, it can be seen from the local deformation cloud diagram of the sound unit 110 that its maximum displacement absolute value is 9um, which is significantly larger than the maximum displacement absolute values ​​when α = 0.07 and α = 0.84, and there is a larger piston area, so the overall output sound pressure level is significantly higher; when α = 0.28-0.84, the output sound pressure level is significantly higher than the output sound pressure level when α = 0.92 and α = 0.07 (more than 5dB difference). Therefore, the value range of parameter α can be between 0.28-0.84. Further, the value range of parameter α can be between 0.28-0.74.

[0141] Figure 11A is an exemplary schematic diagram of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of this specification; Figure 11B is a deformation diagram of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of this specification; Figure 12 is a frequency response curve diagram corresponding to different β shown in some embodiments of this specification.

[0142] In some embodiments, the non-electrode covering area may be a ring surrounding the center of the sound unit 110 , that is, the sound unit 110 may be partially covered by the dual-region electrode.

[0143] As shown in FIG11A-FIG11B, S k represents the second area of ​​the non-electrode covering area; S p represents the suspended area of ​​the sound unit 110 (i.e., the entire area of ​​the sound unit minus the area in contact with the housing), and parameter β is defined as the second area S of the non-electrode covering area. k The suspended area S of the sound unit 110 p Ratio, that is

[0144] In some embodiments, designing a dual-region electrode that partially covers the sound unit 110 can further increase the deformation of the sound unit 110 in the original piston area, compared to the method of partially covering the electrode of the sound unit 110, thereby adjusting the deformation shape of the sound unit 110 and further controlling the acoustic effect. In this case, the non-electrode-covered area is a ring surrounding the center of the sound unit 110, and the two electrode-covered areas are located inside and outside the ring respectively.

[0145] In some embodiments, for the method in which the sound unit 110 partially covers the dual-region electrode, the second area S of the non-electrode-covered area of ​​the sound unit 110 is k The design of the non-electrode covering area S is extremely important. Since the area of ​​this part is too small, the process difficulty will increase and higher process control accuracy will be required. However, the second area S of the non-electrode covering area k If the area S of the non-electrode-covered area of ​​the sound-emitting unit 110 is too large, the area of ​​the sound-emitting unit 110 that participates in the deformation will be significantly reduced, thereby reducing the output sound pressure level. k Control is performed to effectively ensure the output sound pressure level of the sound-emitting unit 110. Based on this, some embodiments of this specification will be described using the parameter β.

[0146] In some embodiments, the second area S of the non-electrode covered area k The suspended area S of the sound unit 110 p The ratio β can be less than or equal to 0.27.

[0147] In some embodiments, when β is large, the output sound pressure level is significantly reduced due to the reduction in the area of ​​the sound-emitting unit 110 involved in the deformation. As shown in Figure 12, when β = 0.33 and β = 0.27, the output sound pressure level is significantly reduced compared to β ≤ 0.22, and the difference exceeds 2dB before the corresponding resonant frequency F0 (for example, the resonant frequency F0' corresponding to β = 0.33, and the resonant frequency F0" ​​corresponding to β = 0.27); when β = 0.27, although the output sound pressure level is significantly reduced before the corresponding resonant frequency F0 (i.e., F0"), the output sound pressure level after the corresponding resonant frequency F0 (i.e., F0") is close to β ≤ 0.22. Therefore, the value range of the parameter β can be less than or equal to 0.27. Further, the value range of the parameter β can be less than or equal to 0.22.

[0148] FIG13A is a schematic structural diagram of a laminated (10-layer) loudspeaker according to some embodiments of the present specification; FIG13B is a frequency response graph of a laminated loudspeaker and a single-layer loudspeaker according to some embodiments of the present specification.

[0149] In some embodiments of this specification, a stacked speaker composed of 10 (layers) of sound units 110 is used as an example to compare with a single-layer speaker under the same conditions (e.g., the same materials, the same structural dimensions, etc.). As shown in FIG13A , the height of the first acoustic cavity 1221 formed between the front housing 1201 and the first adjacent sound unit 1101 in the first direction is represented as hq1, and the height of the sound outlet 1211 coupled to the first acoustic cavity 1221 in the first direction is represented as hk1; the height of the third acoustic cavity 1223 formed between two adjacent sound units 110 (e.g., the i-1th sound unit and the ith sound unit) in the first direction is represented as hq i The height of the sound outlet 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 its adjacent nth sound unit in the first direction is represented by hq n+1 , and the height of the sound outlet hole 121(n+1) coupled to the second acoustic cavity 1222 in the first direction is represented as hk n+1 . Wherein, i is an integer greater than 1 and less than n.

[0150] As shown in FIG13B, SP10 represents a stacked (10-layer) speaker; SP1 is a single-layer speaker. i =300um, hq1=hq n+1 =150um, hk i =100um、hk1=hk n+1= 50um, at the same frequency, the output sound pressure level (SPL) of the stacked speaker SP10 is about 60dB, while the output sound pressure level of the single-layer speaker SP1 is about 40dB. It can be seen that the output sound pressure level of the stacked speaker SP10 is about 20dB higher than that of the single-layer speaker SP1 (20dB = 20×log 10 (10)). Further explanation: when hq i =300um, hq1=hq n+1 =150um, hk i =100um、hk1=hk n+1 =50 μm, the output sound pressure level of the laminated loudspeaker 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.

[0151] It can be understood that when the height of the acoustic cavity 122 and the sound outlet 121 coupled to the acoustic cavity 122 is constant, while ensuring that the structural strength of the speaker 100 is not affected, the larger the width of the sound outlet 121 in the direction perpendicular to the first direction, that is, the larger the area of ​​the sound outlet 121, the smaller its acoustic resistance, and the higher the output sound pressure level. Therefore, the height of the acoustic cavity 122 and the sound outlet 121 coupled to the acoustic cavity 122 in the laminated speaker in the first direction is preferably hq i ≥300um、hq1≥150um、hq n+1 ≥150um, hk i ≥100um、hk1≥50um、hk n+1 ≥50um.

[0152] Figure 14 is an exemplary schematic diagram of an acoustic output device according to some embodiments of the present specification; Figure 15A is an exemplary schematic diagram 1 of an acoustic output device according to other embodiments of the present specification; Figure 15B is an exemplary schematic diagram 2 of an acoustic output device according to some embodiments of the present specification; Figure 16 is an exemplary schematic diagram of an acoustic output device according to still other embodiments of the present specification; Figure 17 is a frequency response curve diagram of an acoustic output device according to some embodiments of the present specification.

[0153] 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 the speaker 100 described in FIG. 1A to FIG. 13B and related contents.

[0154] 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.

[0155] In some embodiments, the acoustic output device 200 may include at least one low-frequency unit and at least one high-frequency unit. As shown in FIG14 , for open-ear headphones, a low-frequency unit and a high-frequency unit may be provided on each of the two headphones.

[0156] As shown in FIG15B , for open-ear audio glasses, two low-frequency units and one high-frequency unit may be provided on each side of the temples to enhance the output sound pressure level at low frequencies.

[0157] As shown in Figure 17, SP d is the frequency response curve of the low frequency unit, SP q is the frequency response curve of the high frequency unit, SP h The frequency response curve of the acoustic output device after the frequency division 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 crossover line L is within the range of 300 Hz-1000 Hz.

[0158] The low-frequency unit refers to a structural unit in the acoustic output device 200 that can achieve a good sound pressure level output in the low frequency band. In some embodiments, the low-frequency unit includes but is not limited to an air-conducting piezoelectric stack speaker.

[0159] In some embodiments, the low-frequency unit can operate within a first frequency range with the crossover 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 the range of 300 Hz-1500 Hz. In some embodiments, the first frequency range can be referred to as a low-frequency band.

[0160] In some embodiments, since the air-conducting piezoelectric stack loudspeaker can output a larger sound pressure level in the low frequency band, in order to better achieve a fuller low-frequency effect, the air-conducting piezoelectric stack loudspeaker can be used in the low frequency band.

[0161] The high frequency unit refers to a structural unit in the acoustic output device 200 that can achieve a good sound pressure level output in the high frequency band. In some embodiments, the high frequency unit may include an air conduction speaker and / or a bone conduction speaker.

[0162] In some embodiments, the high-frequency unit can operate within at least a second frequency range with the crossover line L as the lower boundary. In some embodiments, the second frequency range can be referred to as a high-frequency band. As shown in Figures 14-17, when the high-frequency unit is a bone conduction speaker, since the bone conduction speaker can output a higher sound pressure level in the high-frequency band but is slightly insufficient in the low-frequency band, in order to achieve a full-band sound effect, the acoustic output device 200 can use a method of combining a bone conduction speaker with an air-conducted piezoelectric stack speaker, so that the bone conduction speaker is responsible for the high-frequency band, while the air-conducted piezoelectric stack speaker is responsible for the low-frequency band. Of course, in some embodiments, in addition to operating in the high-frequency band, the bone conduction speaker can also operate in the low-frequency band to further enhance the low-frequency effect. In this case, in the low-frequency band, the output of the air-conducted piezoelectric stack speaker dominates.

[0163] As shown in Figures 14-16 , the high-frequency unit of the acoustic output device 200 can also be an air conduction speaker. In this case, the acoustic output device can adopt a frequency division design or not. That is, the air conduction speaker (high-frequency unit) can operate only in the high frequency band (the second frequency range) or simultaneously in the low and high frequency bands. In this case, the output of the air conduction speaker and the air-conducted piezoelectric stack speaker in the low frequency band is superimposed to further enhance the low-frequency effect.

[0164] 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 parallel to each other in the height direction, with the low-frequency unit located below the high-frequency unit; or the low-frequency unit and the high-frequency unit are arranged parallel to each other in the thickness direction, with the high-frequency unit located on the side of the acoustic output device 200 closest to the user.

[0165] The height direction parallel to the first direction can be understood as the direction parallel to the front face of the acoustic output device 200 close to the user; the thickness direction perpendicular to the first direction can be understood as the direction perpendicular to the front face of the acoustic output device 200 close to the user.

[0166] In some embodiments of this 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, it can be more conducive to the transmission of sound, thereby improving the user experience.

[0167] As shown in Figures 14 to 16, the high-frequency unit is acoustically coupled to the first sound outlet 201 provided in the acoustic output device 200, and the low-frequency unit is acoustically coupled to the second sound outlet 202 provided in the acoustic output device 200. The first sound outlet 201 and the second sound outlet 202 are both set toward the user, wherein the first sound outlet 201 and the second sound outlet 202 are the same hole or different holes.

[0168] As shown in FIG14 , when the high frequency unit of the acoustic output device 200 adopts a bone conduction speaker SP g In this case, there is no need to set the first acoustic hole 201 acoustically coupled with the high frequency unit.

[0169] In some embodiments, if the first sound hole 201 and the second sound hole 202 are the same hole, it can be understood that the first sound hole 201 and the second sound hole 202 are shared by the high-frequency unit and the low-frequency unit; if the first sound hole 201 and the second sound hole 202 are different holes, it can be understood that the first sound hole 201 and the second sound hole 202 are independently provided. By providing the first sound hole 201 and the second sound hole 202 that are acoustically coupled to the high-frequency unit and the low-frequency unit respectively, the cavity of the high-frequency unit and the low-frequency unit can be isolated, which is conducive to improving sound transmission.

[0170] In some embodiments, the acoustic output device 200 may include multiple sound outlets. For example, the acoustic output device 200 may include a first sound outlet 201 acoustically coupled to the high-frequency unit and two second sound outlets 202 acoustically coupled to the low-frequency unit, or may include two first sound outlets 201 acoustically coupled to the high-frequency unit and one second sound outlet 202 acoustically coupled to the low-frequency unit (as shown in FIG16 ). For another example, the acoustic output device 200 may include independently arranged first sound outlets 201 and second sound outlets 202 acoustically coupled to the high-frequency unit and the low-frequency unit, respectively, or may include a sound outlet shared by the high-frequency unit and the low-frequency unit or the two low-frequency units, referred to as a third sound outlet 203 (as shown in FIG15A-FIG15B ).

[0171] 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 with n sound-emitting units (stacked loudspeaker) can be increased by 20×log compared to the sound pressure level output by a loudspeaker with only one sound-emitting unit (single-layer loudspeaker). 10(n) times; 2) Since the thickness of the piezoelectric speaker is relatively thin, by arranging multiple piezoelectric sound-emitting 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) The number of sound-emitting units can be flexibly adjusted in the first direction, so that the speaker can be applied to more usage scenarios, making it widely applicable and practical; 4) By setting at least one mass block on the sound-emitting unit, the resonant frequency F0 of the speaker can be adjusted so that the speaker can better meet the different needs of different users and different usage scenarios; 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.

[0172] 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 possible beneficial effects.

[0173] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0174] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0175] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended 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 spirit 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.

[0176] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0177] In some embodiments, numbers are used to describe the quantity of components and attributes. 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 stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics 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 settings of such numerical values ​​are as accurate as possible within the feasible range.

[0178] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not 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 described and illustrated in this specification.

Claims

1. A loudspeaker, comprising: 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 of the acoustic cavities is acoustically coupled with at least one sound outlet on the shell, wherein: Under the excitation signal, two adjacent sound-emitting units among the plurality of sound-emitting units and sharing at least one acoustic cavity among the plurality of acoustic cavities vibrate in opposite directions in at least a portion of the low-frequency band.

2. The loudspeaker according to claim 1, wherein 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.

3. The loudspeaker according to claim 2, wherein: 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.

4. The loudspeaker according to claim 3, wherein: 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.

5. The loudspeaker according to claim 2, wherein: The shell includes a front shell and a rear shell, each of the fixing rings is provided with at least two electrodes, and the at least two electrodes on each of the fixing rings are respectively connected to the front shell or the rear shell through corresponding conducting electrodes.

6. The loudspeaker according to claim 1, wherein The at least part of the low frequency band includes a part of the frequency band less than 500 Hz.

7. The loudspeaker according to claim 1, wherein: The sound generating unit comprises a flexible piezoelectric material, and the Young's modulus of the flexible piezoelectric material is 1.5 GPa-9 GPa.

8. The loudspeaker according to claim 1, wherein: The sound-generating unit includes a first piezoelectric layer and a second piezoelectric layer arranged along the first direction, and a neutral layer of the sound-generating unit is located between the first piezoelectric layer and the second piezoelectric layer.

9. The loudspeaker according to claim 8, wherein: The sound-generating unit further includes 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 are configured such that the first piezoelectric layer and the second piezoelectric layer have opposite deformations.

10. The loudspeaker according to claim 9, wherein The first driving voltage of the first piezoelectric layer is the difference between the first voltage of the first electrode layer and the second voltage of the second electrode layer, the second driving voltage of the second piezoelectric layer is the difference between the second voltage and the third voltage of the third electrode layer, and the absolute value of the first driving voltage and the absolute value of the second driving voltage are both no higher than 5V.

11. The loudspeaker according to claim 1, wherein The sound generating unit is provided with one or more mass blocks.

12. The loudspeaker according to claim 1, wherein The sound-generating unit includes an electrode-covered area and an electrode-non-covered area.

13. The loudspeaker according to claim 12, wherein: The non-electrode covering area is located at the center of the sound-emitting unit, and the ratio of the first area of ​​the electrode covering area to the suspended area of ​​the sound-emitting unit is between 0.28-0.

84.

14. The loudspeaker according to claim 12, wherein: The non-electrode covering area is a ring shape surrounding the center of the sound-emitting unit, and the ratio of the second area of ​​the non-electrode covering area to the suspended area of ​​the sound-emitting unit is less than or equal to 0.

27.

15. An acoustic output device, comprising: 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 14, 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.

16. The acoustic output device according to claim 15, wherein: The high frequency unit includes an air conduction speaker and / or a bone conduction speaker.

17. The acoustic output device according to claim 15, wherein: The high-frequency unit operates at least within a frequency range with the intersection point as a lower boundary.

18. The acoustic output device according to claim 15, wherein: The acoustic output device has a height direction parallel to the first direction and a thickness direction perpendicular to the first direction, wherein: The low-frequency unit and the high-frequency unit are arranged in parallel in the height direction, and the low-frequency unit is located at the lower side of the high-frequency unit; Alternatively, 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 a side of the acoustic output device close to the user.

19. The acoustic output device according to claim 18, wherein: The high-frequency unit is acoustically coupled to a first sound outlet hole provided in the acoustic output device, and the low-frequency unit is acoustically coupled to a second sound outlet hole provided in the acoustic output device, wherein both the first sound outlet hole and the second sound outlet hole are arranged toward the user, wherein: The first sound outlet hole and the second sound outlet hole are the same hole or different holes.

20. The acoustic output device according to any one of claims 15 to 19, wherein: 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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