Loudspeaker

Abstract

An embodiment of the present specification provides a loudspeaker, comprising: a plurality of sounding units arranged at intervals in a first direction, the plurality of sounding units vibrating in the first direction; the shell is configured to contain and support the plurality of sound production units, a plurality of sound outlet holes are formed in the shell, the shell and the plurality of sound production units define a plurality of acoustic cavities, each acoustic cavity is acoustically coupled with at least one sound outlet hole in the shell, and under the excitation signal, the sound outlet holes are formed in the shell. And two adjacent sound production units in the plurality of sound production units, which share at least one acoustic cavity in the plurality of acoustic cavities, vibrate towards opposite directions in at least part of low-frequency bands.

Description

Technical Field

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

[0002] Current consumer electronic products, including open binaural headphones, audio glasses, TWS headphones, etc., have gradually increased their requirements for low-frequency output sound pressure levels. If existing air-conducted electromagnetic speakers need to have sufficient low-frequency output sound pressure levels, they require a large movement range and a large thickness, which poses a great challenge to product size. Therefore, it is necessary to provide a speaker with a reasonable size that can be adjusted based on actual needs and has a sufficiently high low-frequency output sound pressure level. Summary of the invention

[0003] 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 of the acoustic cavities being acoustically coupled with at least one sound outlet on the shell, wherein under an excitation signal, two adjacent sound-emitting units in the plurality of sound-emitting units and sharing at least one acoustic cavity in the plurality of acoustic cavities vibrate in opposite directions in at least a portion of a low-frequency band. This is to enhance the output sound pressure level of the loudspeaker, and to improve the output sound pressure level of the acoustic output device of the loudspeaker (e.g., the acoustic output device) in at least a portion of a low-frequency band, so as to meet the requirements of the current acoustic output device for gradually increasing the output sound pressure level in the low-frequency band.

[0004] 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 cavity on opposite sides of the sound-emitting unit. The sound outlet holes are used to radiate the sound generated by the sound-emitting unit to the outside.

[0005] 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.

[0006] 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.

[0007] In some embodiments, the at least part of the low frequency band includes a part of the frequency band less than 500 Hz. The speaker has a relatively high output sound pressure level in this frequency band, meeting the requirements of current acoustic output devices for gradually increasing output sound pressure levels in low frequency bands.

[0008] In some embodiments, the sound unit includes a first piezoelectric layer and a second piezoelectric layer arranged along the first direction, and the neutral layer of the sound unit is located between the first piezoelectric layer and the second piezoelectric layer; the sound unit also 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 deformation of the first piezoelectric layer is opposite to that of the second piezoelectric layer, so as to increase the deformation of the sound unit, thereby improving the sound pressure level radiated by the sound unit.

[0009] 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 5 V. This allows the speaker to better meet the battery power supply capacity and power consumption of common consumer electronic products such as headphones and audio glasses, making the speaker more practical.

[0010] In some embodiments, the sound-emitting unit includes an electrode-covered area and a non-electrode-covered area; the non-electrode-covered area is located at the center of the sound-emitting unit, and the ratio of the first area of ​​the electrode-covered area to the suspended area of ​​the sound-emitting unit is between 0.28-0.84, or the non-electrode-covered area is a ring surrounding the center of the sound-emitting unit, and the ratio of the second area of ​​the non-electrode-covered area to the suspended area of ​​the sound-emitting unit is less than or equal to 0.27. Through the above arrangement, the speaker can have a larger output sound pressure level. 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 enhance the low-frequency effect.

[0011] 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, 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; the high-frequency unit works at least within the frequency range with the intersection as the lower boundary.

[0012] 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

[0013] 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:

[0014] Figure 1A is a schematic diagram of the structure of a speaker according to some embodiments of this specification;

[0015] Figure 1B is a schematic diagram of the structure of a speaker according to other embodiments of this specification;

[0016] Figure 1C is a schematic diagram of the structure of a speaker according to some embodiments of the present specification;

[0017] Figure 2A is a simplified structural diagram of a loudspeaker when the sound-emitting unit is not vibrating according to some embodiments of this specification;

[0018] Figure 2B is a simplified structural diagram of a loudspeaker when a sound-emitting unit vibrates according to some embodiments of this specification;

[0019] Figure 3Ais a schematic diagram of the structure of a fixing ring and an electrode according to some embodiments of this specification;

[0020] Figure 3B yes Figure 3A Sectional view at AA in the middle;

[0021] Figure 4A is a schematic diagram of the structure of a fixing ring and a sound generating unit according to some embodiments of this specification;

[0022] Figure 4B is a schematic diagram of the structure of a fixing ring, a sound generating unit and a mass block according to some embodiments of this specification;

[0023] Figure 4C is a schematic diagram of the structure of a fixing ring, a sound generating unit and a mass block according to other embodiments of this specification;

[0024] Figure 4D is a schematic diagram of the structure of a single-layer speaker according to some embodiments of this specification;

[0025] Figure 4E is a schematic diagram of the structure of a single-layer speaker according to other embodiments of this specification;

[0026] Figure 4F is a schematic diagram of the structure of a single-layer speaker according to some embodiments of this specification;

[0027] Figure 5 is a schematic diagram of the structure of a sound-emitting unit according to some embodiments of this specification;

[0028] Figure 6 is a sound principle diagram of a sound generating unit according to some embodiments of this specification;

[0029] Fig. 7A is an exemplary schematic diagram of polarization and voltage scheme 1 according to some embodiments of this specification;

[0030] Figure 7B is an exemplary schematic diagram of polarization and voltage scheme 2 according to some embodiments of this specification;

[0031] Figure 7C is an exemplary schematic diagram of polarization and voltage scheme three according to some embodiments of this specification;

[0032] Fig.7D is an exemplary schematic diagram of polarization and voltage scheme 4 according to some embodiments of this specification;

[0033] Fig. 8A is an exemplary schematic diagram of a sound-emitting unit fully covering an electrode according to some embodiments of this specification;

[0034] Figure 8B is a deformation diagram of a sound unit fully covering an electrode according to some embodiments of this specification;

[0035] Fig.9A is an exemplary schematic diagram of a sound-emitting unit partially covering an electrode according to some embodiments of this specification;

[0036] Fig. 9B is a deformation diagram of a sound-emitting unit partially covering an electrode according to some embodiments of this specification;

[0037] Fig. 10A is a frequency response curve diagram corresponding to different α shown in some embodiments of this specification;

[0038] Fig. 10B It is a local deformation cloud diagram of the sound-emitting unit corresponding to different α shown in some embodiments of this specification;

[0039] Fig.11A This is an exemplary embodiment of a sound unit partially covering a dual-region electrode according to some embodiments of this specification. intention;

[0040] Fig. 11B is a deformation diagram of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of this specification;

[0041] Fig.12 is a frequency response curve diagram corresponding to different β shown in some embodiments of this specification;

[0042] Fig.13A is a schematic diagram of the structure of a laminated (10-layer) speaker according to some embodiments of this specification;

[0043] Fig. 13B is a frequency response curve diagram of a laminated speaker and a single-layer speaker according to some embodiments of this specification;

[0044] Fig.14 is an exemplary schematic diagram of an acoustic output device according to some embodiments of this specification;

[0045] Fig.15A is an exemplary schematic diagram 1 of an acoustic output device according to other embodiments of this specification;

[0046] Fig. 15B is a second exemplary schematic diagram of an acoustic output device according to some embodiments of this specification;

[0047] Fig.16 is an exemplary schematic diagram of an acoustic output device according to some other embodiments of the present specification;

[0048] Fig.17 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification.

[0049] Description of the accompanying drawings: 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 shell, 1201 is a front shell, 1202 is a rear shell, 121 is a sound outlet (including 1211, 1212, 1212-1, 1212-2, 1213-1…121i…121(n+1)), 122 is an acoustic cavity, 1221 is a first acoustic cavity, 1222 is a second acoustic cavity, 1223 is a third acoustic cavity, 123 is a fixing ring, 1231 is a first fixing ring, 1232 is a second fixing ring, 130 is a mass block, 140 is a dustproof / damping net, 1401 is a front cavity dustproof / damping net, 1402 is a rear cavity dustproof / damping net, 200 is an acoustic output device, 201 is a first sound outlet, 202 is a second sound outlet, and 203 is a third sound outlet. DETAILED DESCRIPTION

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Current consumer electronic products, including open binaural headphones, audio glasses, TWS headphones, etc., have gradually increased requirements for output sound pressure levels in the low-frequency band. If the existing air-conducted electromagnetic speakers need to output sufficient sound pressure levels at low frequencies, they require a large movement stroke and a large thickness, which poses a great challenge to the product size. Piezoelectric speakers have the advantage of being thin. Some embodiments of this specification provide a speaker that uses a plurality of piezoelectric sound-generating units to stack and superimpose to form a laminated speaker, and the number of sound-generating units in the laminated speaker (i.e., the number of layers) can be set according to the actual product size at different locations and different usage scenarios. The sound pressure level output effect required, so that a larger low-frequency output can be obtained while meeting the requirements of a smaller size.

[0054] Figure 1A is a schematic diagram of the structure of a speaker according to some embodiments of this specification; Figure 1B is a schematic diagram of the structure of a speaker according to other embodiments of this specification; Figure 1C is a schematic diagram of the structure of a speaker according to some embodiments of the present specification; Figure 2A is a simplified structural diagram of a loudspeaker when the sound-emitting unit is not vibrating according to some embodiments of this specification; Figure 2B It is a simplified structural diagram of a loudspeaker when a sound-emitting unit vibrates according to some embodiments of this specification.

[0055] like Figure 1A-Figure 1C As shown, some embodiments of the present specification provide a speaker 100 including a plurality of sound-emitting units 110 spaced apart along a first direction and a housing 120 .

[0056] The first direction refers to the direction in which the plurality of sound generating units 110 of the speaker 100 are stacked. 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 generating unit 110.

[0057] In some embodiments, the housing 120 may be used to accommodate and support multiple sound generating units 110. In some embodiments, the housing 120 may be an integrally formed structure or a split structure. For example, the housing 120 may be based on multiple structural parts, combined by bonding, snap-fit ​​connection, etc.

[0058] In some embodiments, a plurality of sound outlet holes 121 are provided on the shell 120 , and the shell 120 and the plurality of sound emitting units 110 may enclose a plurality of acoustic cavities 122 , and each acoustic cavity 122 is acoustically coupled with at least one sound outlet hole 121 on the shell 120 .

[0059] The acoustic cavity 122 refers to the cavity structure in the speaker 100. In some embodiments, the housing 120 and the sound unit 110 and / or the space between two adjacent sound units 110 may enclose the acoustic cavity 122. Figure 1C As shown, when the number of the sound generating units 110 is n, the number of the acoustic cavities 122 may be n+1. For more information about the acoustic cavity, please refer to Figure 2A-2B and its related description.

[0060] The sound outlet hole 121 refers to a structure in the speaker 100 for radiating sound. In some embodiments, the sound outlet hole 121 may be arranged corresponding to the acoustic cavity 122, that is, one acoustic cavity 122 corresponds to at least one sound outlet hole 121. In some embodiments, the number of sound outlet holes 121 may be the same as the number of acoustic cavities 122. Figure 1C As shown, when the number of the sound generating units 110 is n, the number of the acoustic cavities 122 is n+1, and the number of the sound outlet holes 121 can also be n+1. For more information about the sound outlet holes, please refer to Figure 2A-2B and its related description.

[0061] The sound unit 110 refers to a component in the speaker 100 that vibrates to generate sound. In some embodiments, the specific number of the sound unit 110 is not limited, and it can be set based on actual needs. For example, it can be selected based on the demand for the sound pressure level of the speaker 100; for another example, it can be selected based on the thickness of the speaker 100. Figure 1B As shown, the sound emitting unit 110 may include a first sound emitting unit 1101 , a second sound emitting unit 1102 . . . an nth sound emitting unit 110n .

[0062] In some embodiments, the plurality of sound generating units 110 may be arranged in the housing 120 at intervals along the first direction, and the plurality of sound generating units 110 all vibrate along the first direction. In some embodiments, under the excitation signal, two adjacent sound generating units 110 among the plurality of sound generating units 110 and sharing at least one acoustic cavity 122 among the plurality of acoustic cavities 122 vibrate in opposite directions, such as Figure 2BAs shown. It should be noted that, under the excitation signal, two adjacent sound-emitting units 110 among the multiple sound-emitting units 110 and sharing 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 adjacent sound-emitting units 110 among the multiple sound-emitting units 110 and sharing 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., acoustic output device 200) including the loudspeaker 100 in at least part of the low frequency band, thereby meeting the current acoustic output device's requirement for gradually increasing the output sound pressure level of the low frequency band.

[0063] 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.

[0064] 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 in at least a portion of the low-frequency band. 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.

[0065] 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.

[0066] For more information about the sound unit, see Figure 2A-2B , Figures 4A-13B and its related description.

[0067] In some embodiments of the present specification, since the thickness of the piezoelectric speaker is relatively thin, a plurality of piezoelectric sound-emitting units are arranged at intervals in the first direction (thickness direction), so that a large low-frequency output can be obtained while satisfying the design size of the speaker. Moreover, based on actual needs, 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.

[0068] like Figure 1B , Figure 2A-2B As shown, the housing 120 may include a plurality of fixing rings 123 .

[0069] The fixing ring 123 refers to a structure for fixing the sound unit 110. In some embodiments, 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.

[0070] In some embodiments, each fixing ring 123 fixes a sound unit 110 , and two sound outlet holes 121 are opened on the circumference of each fixing ring 123 . The two sound outlet holes 121 are respectively coupled to the acoustic cavities 122 on opposite sides of the sound unit 110 .

[0071] 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 relatively arranged on both sides of the fixing ring 123 (e.g., opposite long sides or opposite short sides) or adjacently arranged on both sides of the fixing ring 123 (e.g., adjacent long sides and short sides) to couple with two different acoustic cavities 122 respectively.

[0072] 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, 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 with 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 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.

[0073] 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 an 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.

[0074] like Figure 2A-2B As shown, 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.

[0075] 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-2BAs 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.

[0076] Further, 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.

[0077] In some embodiments of the present specification, based on the fact that two adjacent sound units among multiple sound 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, combined with the design of the sound outlet holes shown in some embodiments of the present specification, the sound pressure level output by a speaker (laminated speaker) having n sound units can be improved compared to the sound pressure level output by a speaker (single-layer speaker) having only one sound unit. Furthermore, by taking advantage of the small thickness of the single-layer sound unit, a speaker with a smaller thickness and a large low-frequency output sound pressure level can be realized.

[0078] 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.

[0079] 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.

[0080] 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. Figure 3A-3B As shown, the fixing ring 123 may include two electrodes, namely, electrode E1 and electrode E2.

[0081] 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 .

[0082] 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 .

[0083] In some embodiments, the fixing ring 123 may include one or more of FR4, FPC, and plastic, and 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, and the electrodes corresponding to any two adjacent fixing rings 123 may be mutually conductive to form conductive electrodes. Mutual conductive means that the electrodes are electrically connected to each other.

[0084] 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.

[0085] Figure 4A is a schematic diagram of the structure of a fixing ring and a sound generating unit according to some embodiments of this specification; Figure 4B is a schematic diagram of the structure of a fixing ring, a sound generating unit and a mass block according to some embodiments of this specification; Figure 4C It is a schematic diagram of the structure of a fixing ring, a sound generating unit and a mass block according to other embodiments of this specification.

[0086] like Figure 4A As shown, 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 .

[0087] In some embodiments, one or more mass blocks 130 may be further provided on the sound generating unit 110. For example, the number of mass blocks 130 may be 1, 2, 3, etc.

[0088] like Figure 4B As shown, a mass block 130 may be disposed 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.

[0089] In some embodiments of the present specification, a mass block is provided on the sound-emitting unit so as to adjust the resonant frequency F0 of the loudspeaker.

[0090] like Figure 4C As shown, two mass blocks 130 may be provided on the sound unit 110 fixed in the fixing ring 123. The structures and sizes 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.

[0091] In some embodiments of the present 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.

[0092] Figure 4D is a schematic diagram of the structure of a single-layer speaker according to some embodiments of this specification; Figure 4E is a schematic diagram of the structure of a single-layer speaker according to other embodiments of this specification; Figure 4F It is a schematic diagram of the structure of a single-layer speaker according to some embodiments of this specification.

[0093] 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.

[0094] like Figure 4D-4F As shown, the front shell 1201 and the rear shell 1202 are respectively connected to the two end surfaces of the fixing ring 123 along the first direction, and in the direction perpendicular to the first direction, a front cavity dustproof / damping net 1401 and a rear cavity dustproof / damping net 1402 are respectively arranged between the front shell 1201 and the rear shell 1202. Among them, the front shell 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 shell 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 Figure 1A As shown, 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 each of the sound outlets 121 corresponding to the plurality of acoustic cavities 122 to achieve dustproof packaging. Figure 1AIn 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, dustproof packaging can 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 loudspeaker 100 and the Q value of the output frequency response.

[0095] 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.

[0096] Figure 5 is a schematic diagram of the structure of a sound-emitting unit according to some embodiments of this specification; Figure 6 It is a sound-generating principle diagram of a sound-generating unit according to some embodiments of this specification.

[0097] In some embodiments, the sound unit 110 may include a flexible piezoelectric material. For example, the sound unit 110 includes but is not limited to polyvinylidene fluoride (PVDF), a copolymer of polyvinylidene fluoride (eg, a vinylidene fluoride-trifluoroethylene copolymer), and the like.

[0098] 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.

[0099] In some embodiments of the present specification, based on the use of flexible piezoelectric materials in the sound-emitting unit, the sound-emitting unit can realize a vibration function while also having a driving function.

[0100] like Figure 5-Figure 6 As shown, 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 .

[0101] 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 the 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 is opposite to that of the second piezoelectric layer 1112. That is, when the first piezoelectric layer 1111 is extended, the second piezoelectric layer 1112 is shortened; or, when the first piezoelectric layer 1111 is shortened, the second piezoelectric layer 1112 is extended. In combination with the setting that the neutral layer 112 of the sound unit 110 is located between the first piezoelectric layer 1111 and the second piezoelectric layer 1112, the deformation of the sound unit 110 can be increased.

[0102] 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 realizing the inverse piezoelectric effect; and the electrode layer 113 refers to a layered structure capable of realizing current conduction.

[0103] In some embodiments, when the speaker 100 produces sound, the sound unit 110 needs to deform along a 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.

[0104] In some embodiments, when the sound unit 110 is a flexible piezoelectric material (e.g., PVDF), the sound unit 110 has a d33 mode and a d31 mode. Further, 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 the first direction, the sound unit 110 is moved along the first direction ( Figure 6 ) and a direction perpendicular to the first direction ( Figure 6 1 direction shown in the figure) will produce telescopic deformation. If only the d33 mode in the first direction is used, the deformation of the sound unit 110 is extremely small. At this time, the sound pressure level output by the sound unit 110 cannot meet the actual needs, so it is necessary to use the d31 mode in a direction perpendicular to the first direction.

[0105] 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-emitting 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 to each other. For example, the first piezoelectric layer 1111 generates an expansion deformation in the first direction, and the second piezoelectric layer 1112 generates a contraction deformation in the first direction; or the first piezoelectric layer 1111 generates a contraction deformation in the first direction, and the second piezoelectric layer 1112 generates an expansion deformation in the first direction. Figure 6 As shown, 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 deform in opposite directions, so that the expansion and contraction deformation in a 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.

[0106] In some embodiments, since the sound unit 110 is a flexible piezoelectric material, it has a polarization direction, and applying voltage at different positions along the polarization direction will produce 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 many ways to achieve the opposite deformation directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112.

[0107] Fig. 7A is an exemplary schematic diagram of polarization and voltage scheme 1 according to some embodiments of this specification; Figure 7B is an exemplary schematic diagram of polarization and voltage scheme 2 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; Fig.7D is an exemplary schematic diagram of polarization and voltage scheme four according to some embodiments of this specification.

[0108] like Figure 7A-7D As shown in the figure, the arrows inside the displaced first piezoelectric layer 1111 and the second piezoelectric layer 1112 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.

[0109] In some embodiments, the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are opposite. Fig. 7A and Figure 7BThe 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 may decrease or increase in sequence, that is, V1>V2>V3 or V1<V2<V3.

[0110] like Fig. 7A As shown, 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, which is opposite to the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 produces 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 stretching deformation, and the sound unit 110 as a whole is displaced 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 undergoes tensile deformation, and 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 undergoes shortening deformation, and the sound unit 110 as a whole undergoes an upward displacement in the first direction.

[0111] like Figure 7BAs shown, 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 downward, and the polarization direction of the second piezoelectric layer 1112 is 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, and the first piezoelectric layer 1111 produces a tensile deformation, and 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; 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 undergoes shortening deformation, and 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 undergoes tensile deformation, and the sound unit 110 as a whole moves downward in the first direction.

[0112] In some embodiments, the polarization directions of the first piezoelectric layer 1111 and the second piezoelectric layer 1112 are the same, and the first voltage V1 of the first electrode layer 1131 and the third voltage V3 of the third electrode layer 1133 may be both greater than or less than the second voltage V2 of the second electrode layer 1132, that is, V1>V2, V3>V2 or V1<V2, V3<V2. Further, V1 may be equal to V3, and V2 may be 0V.

[0113] like Figure 7CAs shown, the polarization direction of the first piezoelectric layer 1111 is the same as that of the second piezoelectric layer 1112, and the polarization direction of the first piezoelectric layer 1111 and the polarization direction of the second piezoelectric layer 1112 are both 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, which is opposite to the polarization direction of the first piezoelectric layer 1111, and the first piezoelectric layer 1111 is shortened and deformed, and 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 is stretched and deformed, and the sound unit 110 as a whole is displaced 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 smaller 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 undergoes tensile deformation, and 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 undergoes shortening deformation, and the sound unit 110 as a whole undergoes an upward displacement in the first direction.

[0114] like Fig.7D As shown, the polarization direction of the first piezoelectric layer 1111 is the same as that of the second piezoelectric layer 1112, and the polarization direction of the first piezoelectric layer 1111 and the polarization direction of the second piezoelectric layer 1112 are both 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 is stretched and deformed, and 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 is shortened and deformed, and the sound unit 110 as a whole is displaced 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 smaller 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 undergoes shortening deformation, and 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 undergoes tensile deformation, and the sound unit 110 as a whole moves downward in the first direction.

[0115] 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), 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.

[0116] In some embodiments of the present 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.

[0117] It should be noted that, since the electrode design of the sound unit 110 has a significant impact on the deformation form and degree of deformation of the sound unit itself, some embodiments of this specification will design the electrode so that the sound unit 110 can deform to a greater extent, push a larger volume of air to radiate sound pressure, and thus improve the output sound pressure level of the sound unit 110. The electrode design may include but is not limited to the design of the area of ​​the electrode coverage area, the shape of the electrode coverage area, etc.

[0118] Fig. 8A is an exemplary schematic diagram of a sound-emitting unit fully covering an electrode according to some embodiments of this specification; Figure 8B is a deformation diagram of a sound unit fully covering an electrode according to some embodiments of this specification; Fig.9A is an exemplary schematic diagram of a sound-emitting unit partially covering an electrode according to some embodiments of this specification; Fig. 9B is a deformation diagram of a sound-emitting unit partially covering an electrode according to some embodiments of this specification; Fig. 10A is a frequency response curve diagram corresponding to different α shown in some embodiments of this specification; Fig. 10B It is a local deformation cloud diagram of the sound unit corresponding to different α shown in some embodiments of this specification.

[0119] In some embodiments, the sound unit 110 may be fully covered with electrodes. Figure 8A-B As shown, when the sound unit 110 is fully covered with electrodes, the sound unit 110 will produce full-area deformation after the excitation voltage is applied, and the deformation shape is a concave or convex deformation shape in the first-order mode and before.

[0120] In some embodiments, the sound unit 110 may be partially covered with electrodes.

[0121] 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 an area on the sound unit 110 covered with electrodes, and the electrode-uncovered area refers to an area on the sound unit 110 not covered with electrodes.

[0122] In some embodiments, the non-electrode covering area may be located at the center of the sound emitting unit 110 .

[0123] like Figures 8A-9B As shown, 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 overall 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

[0124] In some embodiments, when the sound unit 110 partially covers the electrode, the deformation form is a local concave or convex deformation form plus a local piston deformation form in the first-order mode and before. 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 improving the output sound pressure level of the sound unit 110.

[0125] 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 larger 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.

[0126] In some embodiments, by designing the first area S of the electrode coverage area d , the local concave or convex deformation form plus the local piston deformation form of the sound unit 110 can be effectively controlled. Based on this, some embodiments of this specification will be explained by parameter α.

[0127] 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.

[0128] In some embodiments, when α is small or large, the output sound pressure level is low. Figure 10A-10BAs shown in FIG. 1 , when α=0.92 and α=0.07, the output sound pressure level (SPL) is significantly reduced compared to when α=0.28-0.84, with a difference of more than 5 dB. This is because when α is small, that is, the first area S of the electrode coverage area is d When α is smaller, 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 6um. When α is larger, i.e., the first area S of the electrode coverage area is 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 the 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 value when α=0.07 and α=0.84, and there is a larger piston area, so the overall output sound pressure level is significantly larger; 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.

[0129] Fig.11A is an exemplary schematic diagram of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of this specification; Fig. 11B is a deformation diagram of a sound-emitting unit partially covering a dual-region electrode according to some embodiments of this specification; Fig.12 1 is a frequency response curve diagram corresponding to different β shown in some embodiments of this specification.

[0130] In some embodiments, the non-electrode covering area may be a ring-shaped area surrounding the center of the sound emitting unit 110 , that is, the sound emitting unit 110 may be partially covered by the dual-region electrode.

[0131] like Figure 11A-11B As shown, 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 overall area of ​​the sound unit minus the area in contact with the housing), and defines parameter β 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

[0132] In some embodiments, the design of the sound unit 110 partially covering the dual-region electrode 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, so as to adjust the deformation form of the sound unit 110, and further adjust the acoustic effect. In this case, the non-electrode covering area is a ring surrounding the center of the sound unit 110, and the two electrode covering areas are located inside and outside the ring respectively.

[0133] 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 second area S of the non-electrode-covered area of ​​the sound-emitting unit 110 is too large, 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 generating unit 110. Based on this, some embodiments of this specification will be described by using the parameter β.

[0134] 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.

[0135] 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 unit 110 involved in generating the deformation. Fig.12 As shown, 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, 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 parameter β can be less than or equal to 0.27. Further, the value range of parameter β can be less than or equal to 0.22.

[0136] Fig.13A is a schematic diagram of the structure of a laminated (10-layer) speaker according to some embodiments of this specification; Fig. 13B It is a frequency response curve diagram of a laminated speaker and a single-layer speaker according to some embodiments of this specification.

[0137] 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.13A 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 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 (such as 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 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 its adjacent nth sound-emitting 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.

[0138] like Fig. 13B As shown, SP10 represents a laminated (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 laminated 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 laminated 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 When 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.

[0139] 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, hq1≥150um, hq n+1 ≥150um, hk i ≥100um、hk1≥50um、hk n+1 ≥50um.

[0140] Fig.14 is an exemplary schematic diagram of an acoustic output device according to some embodiments of this specification; Fig.15A is an exemplary schematic diagram 1 of an acoustic output device according to other embodiments of this specification; Fig. 15B is a second exemplary schematic diagram of an acoustic output device according to some embodiments of this specification; Fig.16 is an exemplary schematic diagram of an acoustic output device according to some other embodiments of the present specification; Fig.17 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification.

[0141] 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 13B The speaker 100 described herein and its related contents.

[0142] 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.

[0143] In some embodiments, the acoustic output device 200 may include at least one low-frequency unit and at least one high-frequency unit. Fig.14 As shown, for open-ear headphones, a low-frequency unit and a high-frequency unit can be respectively provided on the two side headphones.

[0144] like Fig. 15B As 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.

[0145] like Fig.17 As shown, 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 hThe 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 frequency division line L is within the range of 300 Hz-1000 Hz.

[0146] The low-frequency unit refers to a structural unit that can achieve 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 stack speaker, etc.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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 14-17 As 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, so that the bone conduction speaker is responsible for the high frequency band, and the air-conducted piezoelectric stack speaker 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 is dominant.

[0151] like Figure 14-16As 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 are superimposed in the low frequency band to further enhance the low frequency effect.

[0152] 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.

[0153] 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.

[0154] 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, it can be more conducive to the transmission of sound to improve the user experience.

[0155] like Figure 14-16 As shown, the high-frequency unit is acoustically coupled with a first sound outlet hole 201 provided in the acoustic output device 200, and the low-frequency unit is acoustically coupled with a second sound outlet hole 202 provided in the acoustic output device 200, and both the first sound outlet hole 201 and the second sound outlet hole 202 are arranged toward the user, wherein the first sound outlet hole 201 and the second sound outlet hole 202 are the same hole or different holes.

[0156] like Fig.14 As shown, when the high frequency unit of the acoustic output device 200 adopts a bone conduction speaker SP g At this time, there is no need to set the first acoustic hole 201 acoustically coupled to the high-frequency unit.

[0157] In some embodiments, the first sound outlet hole 201 and the second sound outlet hole 202 are the same hole, which can be understood as the first sound outlet hole 201 and the second sound outlet hole 202 are shared by the high-frequency unit and the low-frequency unit; the first sound outlet hole 201 and the second sound outlet hole 202 are different holes, which can be understood as the first sound outlet hole 201 and the second sound outlet hole 202 are independently set sound outlets. By respectively setting the first sound outlet hole 201 and the second sound outlet hole 202 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.

[0158] In some embodiments, the acoustic output device 200 may include a plurality of sound outlet holes. For example, the acoustic output device 200 may include a first sound outlet hole 201 acoustically coupled to the high frequency unit, and two second sound outlet holes 202 acoustically coupled to the low frequency unit, or may include two first sound outlet holes 201 acoustically coupled to the high frequency unit, and one second sound outlet hole 202 acoustically coupled to the low frequency unit (e.g., Fig.16 As shown); For another example, the acoustic output device 200 may include a first sound outlet 201 and a second sound outlet 202 that are independently arranged and acoustically coupled to the high-frequency unit and the low-frequency unit, respectively, and may also 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 Figure 15A-15B shown).

[0159] 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-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 in 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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 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, 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.

3. The loudspeaker according to claim 2, 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.

4. The loudspeaker according to claim 3, 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.

5. The loudspeaker according to claim 1, characterized in that The at least part of the low frequency band includes a part of the frequency band less than 500 Hz.

6. The loudspeaker according to claim 1, characterized in that The sound-generating unit comprises 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; 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.

7. The loudspeaker according to claim 6, characterized in that 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.

8. The loudspeaker according to claim 1, wherein: The sound-generating unit includes an electrode-covered area and an electrode-non-covered area; The non-electrode covered area is located at the center of the sound unit, and the ratio of the first area of ​​the electrode covered area to the suspended area of ​​the sound unit is between 0.28 and 0.84; Alternatively, 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.

9. 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.

10. The acoustic output device according to claim 9, 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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