Loudspeaker and electronic device

Abstract

The present invention relates to the technical field of acoustic-electric conversion. Disclosed are a loudspeaker and an electronic device. The loudspeaker comprises: a diaphragm structure, the diaphragm structure comprising a first diaphragm and a second diaphragm, the first diaphragm being used for driving air to vibrate so as to emit an initial sound wave, and the signal of the initial sound wave being modulated on the basis of a signal of an audible sound frequency band; and a cover plate structure, wherein the cover plate structure and the diaphragm structure defines a sound production cavity, sound outlet holes are formed in the cover plate structure, the sound outlet holes communicate the sound production cavity with the outside, the initial sound wave in the sound production cavity is transmitted to the outside through the sound outlet holes to form a sound signal, the second diaphragm and the cover plate structure form an acoustic environment impedance, and the acoustic environment impedance is used for modulating the initial sound wave to change the sound pressure of the sound signal. The loudspeaker and the electronic device provided by the present invention can perform modulation on the basis of acoustic environment impedance, so as to output a sound signal covering an audible sound frequency band.

Description

Speakers and electronic devices Technical Field

[0001] This invention relates to the field of sound-to-electricity conversion technology, and in particular to a loudspeaker and an electronic device. Background Technology

[0002] Miniature loudspeakers, as an important electroacoustic device, are widely used in consumer electronics. Based on their technology, miniature loudspeakers can be classified into moving-coil microspeakers, balanced-iron microspeakers, and micro-electro-mechanical system (MEMS) loudspeakers.

[0003] Currently, both moving-coil and moving-iron microspeakers generate sound by driving a vibrating structure with electromagnetic force. Both types of microspeakers are susceptible to interference from external magnetic fields, affecting their performance, and their size is difficult to further miniaturize. MEMS speakers, however, do not suffer from these problems and offer numerous advantages such as low power consumption, low cost, small size, and high consistency.

[0004] However, the performance of MEMS loudspeakers in outputting sound signals covering the audible audio range still needs improvement. Summary of the Invention

[0005] To address the aforementioned problems, the main objective of this invention is to provide a loudspeaker that can output a sound signal covering the audible audio frequency range based on acoustic environment impedance modulation.

[0006] To achieve the above objectives, the present invention provides a loudspeaker, comprising: a diaphragm structure, the diaphragm structure including a first diaphragm and a second diaphragm, the first diaphragm being used to drive air vibration to emit an initial sound wave, the signal of the initial sound wave being modulated based on a signal of an audible audio frequency band; a cover plate structure, the cover plate structure and the diaphragm structure forming a sound-emitting cavity, the cover plate structure having a sound outlet hole, the sound outlet hole communicating the sound-emitting cavity with the outside, the initial sound wave in the sound-emitting cavity being transmitted to the outside through the sound outlet hole to form a sound signal, the second diaphragm and the cover plate structure constituting an acoustic environmental impedance, the acoustic environmental impedance being used to modulate the initial sound wave to change the sound pressure of the sound signal.

[0007] Preferably, the frequency of the initial sound wave is a preset frequency, and the second diaphragm is used to vibrate at the preset frequency.

[0008] Preferably, the first diaphragm is disposed around the second diaphragm.

[0009] Preferably, the second diaphragm is disposed around the first diaphragm.

[0010] Preferably, the sound outlet is positioned directly opposite the first diaphragm; the cover plate structure at least covers the second diaphragm.

[0011] Preferably, the sound-generating cavity also has an intermediate layer, which is located between the diaphragm structure and the cover plate structure. The intermediate layer has a through hole that penetrates the thickness of the intermediate layer. The through hole is directly opposite to the first diaphragm and is misaligned with the sound outlet. The intermediate layer at least blocks the second diaphragm so as to form an acoustic environment impedance with the second diaphragm and the cover plate structure.

[0012] Preferably, the driving method of the first diaphragm includes electrostatic driving, piezoelectric driving, or electromagnetic driving; the driving method of the second diaphragm includes electrostatic driving, piezoelectric driving, or electromagnetic driving.

[0013] Preferably, the shape of the first diaphragm includes a circle, a square, a hexagon, or a ring; the shape of the second diaphragm includes a circle, a square, a hexagon, or a ring.

[0014] Preferably, it further includes: a blocking element, the blocking element being located on the side of the cover structure away from the sound-emitting cavity, the blocking element blocking at least part of the sound outlet.

[0015] The present invention also provides an electronic device, including a speaker as described in the above embodiments.

[0016] The beneficial effects of the present invention are as follows: the diaphragm structure and the cover plate structure form a sound cavity, wherein the diaphragm structure includes a first diaphragm and a second diaphragm. The first diaphragm is used to drive the air to generate vibration to emit an initial sound wave. The second diaphragm and the cover plate structure constitute an acoustic environment impedance. The acoustic environment impedance is used to modulate the initial sound wave so that the sound signal emitted by the sound outlet on the cover plate structure is a sound signal in an audible audio frequency range. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0018] Figure 1 is a schematic diagram of the equivalent circuit modeling structure of a loudspeaker provided in an embodiment of the present invention;

[0019] Figure 2(a) is a spectrum diagram of a sound pressure signal from a sound source provided in an embodiment of the present invention;

[0020] Figure 2(b) is a spectrum diagram corresponding to the acoustic environment impedance provided in an embodiment of the present invention;

[0021] Figure 2(c) is a spectrum diagram of the sound pressure signal corresponding to an output sound signal provided in an embodiment of the present invention;

[0022] Figure 3 is a schematic diagram of the structure of the first type of loudspeaker provided in an embodiment of the present invention;

[0023] Figure 4 is a structural schematic diagram of the second type of loudspeaker provided in an embodiment of the present invention;

[0024] Figure 5 is a structural schematic diagram of the third type of loudspeaker provided in an embodiment of the present invention;

[0025] Figure 6 is a structural schematic diagram of the fourth type of loudspeaker provided in an embodiment of the present invention. Embodiments of the present invention

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the various embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this invention to facilitate a better understanding of the invention. However, the technical solutions claimed in this invention can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0027] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments of the present invention, technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0030] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0031] In the accompanying drawings corresponding to the embodiments of the present invention, the thickness and area of ​​the layers are enlarged for better understanding and ease of description.

[0032] In the description of the embodiments of the present invention, when a component “includes” another component, other components are not excluded unless otherwise stated, and other components may be further included.

[0033] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0034] Figure 1 is a schematic diagram of the equivalent circuit modeling structure of a loudspeaker provided in an embodiment of the present invention.

[0035] In a loudspeaker, a diaphragm typically vibrates to generate sound signals that propagate in all directions. During sound wave propagation, the environment, propagation path, and load all contribute to sound wave loss, thus affecting the sound pressure level of the signal received by the load. Referring to Figure 1, the sound source generated by the diaphragm is equivalent to a constant current source I. The sound wave loss caused by environmental factors is equivalent to the ambient impedance Z1, such as losses due to walls, skin, sound absorbers, or other environmental structures. The sound wave loss caused by obstacles in the propagation path is equivalent to the path impedance Z2, such as losses due to obstructions in front of the sound outlet. The sound wave loss caused by the load itself is equivalent to the load impedance Zload, such as the loss from the human ear or the microphone itself. The ambient impedance Z1 is equivalent to the sum of the path impedance Z2 and the load impedance Zload connected in parallel, serving as the total impedance of the constant current source I.

[0036] Taking an ultrasonic sound wave with frequency f0 generated by a diaphragm pushing air as an example, the constant current source I is represented by the product of the diaphragm area and the amplitude velocity. The sound source is subjected to an audible sound frequency f. a Modulation, f a For any value between 20Hz and 20kHz, the constant current source I satisfies the following relationship (1):

[0037]

[0038] Where I0 is a constant and t is time.

[0039] The acoustic environmental impedance Z1 is based on the ultrasonic frequency f0 modulation of the sound source, and the acoustic environmental impedance Z1 satisfies the following relationship (2):

[0040]

[0041] Where Z0 is a constant.

[0042] Combining equations (1) and (2), the sound pressure Pload on the load can be obtained:

[0043]

[0044] When the obstruction along the propagation path of the sound wave remains constant, the sound path impedance Z2 is a constant; when the load is fixed, the load impedance Zload is a constant.

[0045] Therefore, when Z0 < Z2 + Zload, the sound pressure Pload transmitted to the load after modulation by the acoustic environment impedance Z1 can be obtained:

[0046]

[0047] Finally, at the audible sound frequency f a Sound pressure Pa:

[0048]

[0049] In this way, the loudspeaker can modulate the output sound signal covering the audible audio range based on the acoustic environment impedance Z1.

[0050] Figure 2(a) is a spectrum diagram of a sound source sound pressure signal provided in an embodiment of the present invention; Figure 2(b) is a spectrum diagram of an acoustic environment impedance provided in an embodiment of the present invention; Figure 2(c) is a spectrum diagram of an output sound signal sound pressure signal provided in an embodiment of the present invention.

[0051] Referring to Figure 2(a), after modulating the sound pressure signal of the sound source according to the above relationship (1), the sound pressure signal of the sound source can output f0-f a ~f0+f a Sound waves in the frequency band; referring to Figure 2(b), the acoustic environment impedance is modulated based on the ultrasonic frequency f0 of the sound source; referring to Figure 2(c), based on the above principle, the acoustic pressure signal of the sound source can be modulated by the acoustic environment impedance to generate an audible sound frequency band f a The sound signal.

[0052] Figure 3 is a schematic diagram of the structure of the first type of loudspeaker provided in an embodiment of the present invention.

[0053] Referring to Figure 3, the first loudspeaker provided by the technical solution of the present invention, the loudspeaker is modulated based on the above principle, including: a diaphragm structure 101 and a cover plate structure 102. The diaphragm structure 101 includes a first diaphragm 111 and a second diaphragm 121, the second diaphragm 121 is disposed around the first diaphragm 111, the first diaphragm 111 is used to drive air vibration to emit an initial sound wave B0, the signal of the initial sound wave B0 is modulated based on the signal of the audible audio frequency band, the specific modulation method can be referred to the above relation (1). The cover plate structure 102 and the diaphragm structure 101 form a sound cavity 103, the cover plate structure 102 has a sound outlet 104, the sound outlet 104 communicates the sound cavity 103 with the outside, the initial sound wave B0 in the sound cavity 103 is transmitted to the outside through the sound outlet 104 to form a sound signal B1. The sound outlet 104 is positioned opposite the first diaphragm 111, and the cover plate structure 102 at least blocks the second diaphragm 121. Thus, the second diaphragm 121 and the cover plate structure 102 constitute an acoustic environment impedance. The acoustic environment impedance is used to modulate the initial sound wave B0 to change the sound pressure of the sound signal. The specific modulation method of the acoustic environment impedance can be referred to the above relationship (2).

[0054] The first diaphragm 111 can be manufactured using MEMS (microelectromechanical systems) manufacturing processes that utilize SOI (silicon on insulator) or POI (polysilicon on insulator) wafers.

[0055] The second diaphragm 121 can be manufactured using MEMS (microelectromechanical systems) fabrication processes that utilize SOI (silicon on insulator) or POI (polysilicon on insulator) wafers.

[0056] In some embodiments, the structure of the first diaphragm 111 may be the same as the structure of the second diaphragm 121; or, the structure of the first diaphragm 111 may be different from the structure of the second diaphragm 121.

[0057] The driving methods of the first diaphragm 111 include electrostatic driving, piezoelectric driving, or electromagnetic driving.

[0058] The driving methods for the second diaphragm 121 include electrostatic driving, piezoelectric driving, or electromagnetic driving.

[0059] In some embodiments, the driving method of the first diaphragm 111 may be the same as that of the second diaphragm 121; or, the driving method of the first diaphragm 111 may be different from that of the second diaphragm 121.

[0060] The shape of the first diaphragm 111 can be circular, square, hexagonal, or ring-shaped.

[0061] The shape of the second diaphragm 121 can be circular, square, hexagonal, or ring-shaped.

[0062] Referring to Figure 3, the loudspeaker also includes a support structure 105, which includes a support cylinder 125 and a support column 115. The support cylinder 125 is cylindrical, and the second diaphragm 121 is fixed to the inner wall of the support cylinder 125. The first diaphragm 111 is fixed to the second diaphragm 121 by the support column 115.

[0063] The cross-section of the support cylinder 125 can be set to a circular, elliptical, rectangular, or rounded rectangular shape.

[0064] In some embodiments, the support column 115 may be a continuous structure surrounding the first diaphragm 111; or, the number of support columns 115 may be multiple, with multiple support columns 115 spaced apart around the first diaphragm 111.

[0065] Preferably, the frequency of the initial sound wave B0 is a preset frequency, and the second diaphragm 121 is used to vibrate at the preset frequency, thereby achieving modulation of the acoustic environment impedance.

[0066] In some embodiments, the sound outlet 104 can be configured as one or more, and the shape of the sound outlet 104 can be circular, elliptical, triangular, quadrilateral, hexagonal or arc-shaped.

[0067] Figure 4 is a schematic diagram of the structure of the second type of loudspeaker provided in an embodiment of the present invention.

[0068] Referring to Figure 4, the second type of loudspeaker provided by the technical solution of the present invention, the loudspeaker is modulated based on the above principle, including: a diaphragm structure 201 and a cover plate structure 202. The diaphragm structure 201 includes a first diaphragm 211 and a second diaphragm 221. The first diaphragm 211 is disposed around the second diaphragm 221. The first diaphragm 211 is used to drive air vibration to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal of the audible audio frequency band. The specific modulation method can be referred to the above relation (1). The cover plate structure 202 and the diaphragm structure 201 form a sound cavity 203. The cover plate structure 202 has a sound outlet 204. The sound outlet 204 communicates the sound cavity 203 with the outside. The initial sound wave B0 in the sound cavity 203 is transmitted to the outside through the sound outlet 204 to form a sound signal B1. The sound outlet 204 is positioned opposite the first diaphragm 211, and the cover plate structure 202 at least blocks the second diaphragm 221. Thus, the second diaphragm 221 and the cover plate structure 202 constitute the acoustic environment impedance. The acoustic environment impedance is used to modulate the initial sound wave B0 to change the sound pressure of the sound signal. The specific modulation method of the acoustic environment impedance can be referred to the above relationship (2).

[0069] The parts of the first diaphragm 211 and the second diaphragm 221 that are the same as or correspond to the first diaphragm 111 and the second diaphragm 121 in the first embodiment are referred to in the foregoing embodiment, and will not be repeated here.

[0070] Referring to Figure 4, the loudspeaker also includes a support structure 205, which includes a support cylinder 225 and a support column 215. The support cylinder 225 is cylindrical, and the periphery of the first diaphragm 211 is fixed to the inner wall of the support cylinder 225. The periphery of the second diaphragm 221 is fixed to the first diaphragm 211 by the support column 215.

[0071] In some embodiments, the support column 215 may be a continuous structure surrounding the second diaphragm 221; or, the number of support columns 215 may be multiple, with multiple support columns 215 spaced apart around the second diaphragm 221.

[0072] In some embodiments, the sound outlet 204 can be configured as an arc shape, a circle, an ellipse, a triangle, a quadrilateral, or a hexagon, etc. The number of sound outlets 204 can be set to multiple, and the multiple sound outlets 204 are arranged at intervals along the circumferential direction of the second diaphragm 221.

[0073] Figure 5 is a structural schematic diagram of the third type of loudspeaker provided in an embodiment of the present invention.

[0074] Referring to Figure 5, the third type of loudspeaker provided by the technical solution of the present invention is modulated based on the above principle, including: a diaphragm structure 301, a cover plate structure 302, and an intermediate layer 306. The diaphragm structure 301 includes a first diaphragm 311 and a second diaphragm 321. The second diaphragm 321 is disposed around the first diaphragm 311. The first diaphragm 311 is used to drive air vibration to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal of the audible audio frequency band. The specific modulation method can be referred to the above relation (1). The cover plate structure 302 and the diaphragm structure 301 form a sound cavity 303. The cover plate structure 302 has a sound outlet 304, which connects the sound cavity 303 to the outside. The initial sound wave B0 in the sound cavity 303 is transmitted to the outside through the sound outlet 304 to form a sound signal B1. The intermediate layer 306 is disposed in the sound-generating cavity 303. The intermediate layer 306 is located between the diaphragm structure 301 and the cover plate structure 302. The intermediate layer 306 has a through hole 316 that penetrates the thickness of the intermediate layer 306. The through hole 316 is directly opposite to the first diaphragm 311 and is misaligned with the sound outlet 304. The intermediate layer 306 at least blocks the second diaphragm 321 so as to form an acoustic environment impedance with the second diaphragm 321 and the cover plate structure 302. The acoustic environment impedance is used to modulate the initial sound wave B0 to change the sound pressure of the sound signal. The specific modulation method of the acoustic environment impedance can be referred to the above relationship (2).

[0075] The acoustic environment impedance formed by the intermediate layer 306, the second diaphragm 321, and the cover plate structure 302 includes the main acoustic environment impedance and the matching acoustic environment impedance. The main acoustic environment impedance is formed by the second diaphragm 321 and the intermediate layer 306, and the matching acoustic environment impedance is formed by the intermediate layer 306 and the cover plate structure 302.

[0076] In some embodiments, the intermediate layer 306 may be a stationary layer, i.e., it does not move or vibrate. In other embodiments, the intermediate layer 306 may be a moving layer, i.e., the intermediate layer 306 may vibrate or move to further modulate the initial sound wave B0.

[0077] In some embodiments, the number of vias 316 can be single or multiple, and the vias 316 can be configured as arc-shaped, circular, elliptical, triangular, quadrilateral or hexagonal, etc.

[0078] The parts of the first diaphragm 311 and the second diaphragm 321 that are the same as or correspond to the first diaphragm 111 and the second diaphragm 121 in the first embodiment are referred to in the foregoing embodiment, and will not be repeated here.

[0079] Referring to Figure 5, the loudspeaker also includes a support structure 305, which includes a support cylinder 325 and a support column 315. The support cylinder 325 is cylindrical, and the periphery of the first diaphragm 311 is fixed to the inner wall of the support cylinder 325. The periphery of the intermediate layer 306 is also fixed to the inner wall of the support cylinder 325. The periphery of the first diaphragm 311 and the second diaphragm 321 are fixed together by the support column 315.

[0080] In some embodiments, the support column 315 can be a continuous structure surrounding the first diaphragm 311, or the number of support columns 315 can be multiple, with multiple support columns 315 spaced apart around the first diaphragm 311.

[0081] In some embodiments, the sound outlet 304 can be configured as an arc shape, a circle, an ellipse, a triangle, a quadrilateral, or a hexagon, etc. The number of sound outlets 304 can be set to multiple, and the multiple sound outlets 304 are arranged at intervals along the circumferential direction of the first diaphragm 311.

[0082] Figure 6 is a structural schematic diagram of the fourth type of loudspeaker provided in an embodiment of the present invention.

[0083] Referring to Figure 6, the fourth type of loudspeaker provided by the technical solution of the present invention is modulated based on the above principle, including: a diaphragm structure 401, a cover plate structure 402, and an intermediate layer 406. The diaphragm structure 401 includes a first diaphragm 411 and a second diaphragm 421. The first diaphragm 411 is disposed around the second diaphragm 421. The first diaphragm 411 is used to drive air vibration to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal of the audible audio frequency band. The specific modulation method can be referred to the above relation (1). The cover plate structure 402 and the diaphragm structure 401 form a sound cavity 403. The cover plate structure 402 has a sound outlet 404, which connects the sound cavity 403 to the outside. The initial sound wave B0 in the sound cavity 403 is transmitted to the outside through the sound outlet 404 to form a sound signal B1. The intermediate layer 406 is disposed in the sound-generating cavity 403. The intermediate layer 406 is located between the diaphragm structure 401 and the cover plate structure 402. The intermediate layer 406 has a through hole 416 that penetrates the thickness of the intermediate layer 406. The through hole 416 is directly opposite to the first diaphragm 411 and is misaligned with the sound outlet 404. The intermediate layer 406 at least blocks the second diaphragm 421 so as to form an acoustic environment impedance with the second diaphragm 421 and the cover plate structure 402. The acoustic environment impedance is used to modulate the initial sound wave B0 to change the sound pressure of the sound signal. The specific modulation method of the acoustic environment impedance can be referred to the above relationship (2).

[0084] The intermediate layer 406, the second diaphragm 421, and the cover plate structure 402 constitute the acoustic environment impedance, including the main acoustic environment impedance and the matching acoustic environment impedance. The main acoustic environment impedance is based on the second diaphragm 421 and the intermediate layer 406, and the matching acoustic environment impedance is based on the intermediate layer 406 and the cover plate structure 402.

[0085] In some embodiments, the intermediate layer 406 may be a stationary layer, i.e., it does not move or vibrate. In other embodiments, the intermediate layer 406 may be a moving layer, i.e., the intermediate layer 406 may vibrate or move to further modulate the initial sound wave B0.

[0086] In some embodiments, the via 416 can be configured as an arc shape, a circle, an ellipse, a triangle, a quadrilateral, or a hexagon, etc. There can be multiple vias 416, which are spaced apart along the circumferential direction of the second diaphragm 421.

[0087] The parts of the first diaphragm 411 and the second diaphragm 421 that are the same as or correspond to the first diaphragm 111 and the second diaphragm 121 in the first embodiment are referred to in the foregoing embodiment, and will not be repeated here.

[0088] Referring to Figure 6, the loudspeaker also includes a support structure 405, which includes a support cylinder 425 and a support column 415. The support cylinder 425 is cylindrical, and the second diaphragm 421 is fixed to the inner wall of the support cylinder 425. The intermediate layer 406 is also fixed to the inner wall of the support cylinder 425. The first diaphragm 411 and the second diaphragm 421 are fixed together by the support column 415.

[0089] In some embodiments, the support column 415 may be a continuous structure surrounding the second diaphragm 421, or the number of support columns 415 may be multiple, with multiple support columns 415 spaced apart around the second diaphragm 421.

[0090] In some embodiments, the sound outlet 404 can be configured as one or more, and the shape of the sound outlet 404 can be circular, elliptical, triangular, quadrilateral, hexagonal or arc-shaped.

[0091] In some embodiments, the sound outlet 404 can be configured as one or more, and the shape of the sound outlet 104 can be circular, elliptical, triangular, quadrilateral, hexagonal or arc-shaped.

[0092] In any of the first to fourth embodiments described above, the loudspeaker may further include a shielding element (not shown in the figure), located on the side of the cover structure away from the sound-emitting cavity, the shielding element at least partially shielding the sound outlet. Thus, the shielding element can constitute the acoustic path impedance, and the initial sound wave is modulated based on the acoustic environment impedance and acoustic path impedance in the above embodiments, so that the loudspeaker outputs a sound signal covering the audible audio frequency range.

[0093] In some embodiments, the blocking element can vibrate along the sound outlet direction to modulate the output sound signal; or, the blocking element can reciprocate along a direction parallel to the cover structure to block or open the sound outlet, thereby modulating the output sound signal.

[0094] In some embodiments, the shape of the shielding element can be designed according to the shape of the sound outlet.

[0095] The speaker provided by the technical solution of the present invention forms a sound cavity by means of a diaphragm structure and a cover plate structure. The diaphragm structure includes a first diaphragm and a second diaphragm. The first diaphragm is used to drive the air to generate vibration to emit an initial sound wave. The second diaphragm and the cover plate structure constitute an acoustic environment impedance. The acoustic environment impedance is used to modulate the initial sound wave so that the sound signal emitted by the sound outlet on the cover plate structure is a sound signal in an audible audio frequency range.

[0096] Accordingly, the present invention also provides an electronic device, including a speaker as described in the above embodiments, to output a sound signal covering the audible audio range based on acoustic ambient impedance modulation.

[0097] In some embodiments, electronic devices may include mobile phones, tablets, laptops, personal digital assistants (PDAs), cameras, personal computers, in-vehicle devices, wearable devices, augmented reality (AR) glasses, AR headsets, virtual reality (VR) glasses, VR headsets, landline handsets (pickups), medical assistive devices (such as hearing aids), and various headphones (such as wireless or wired headphones) with speakers. The embodiments of the present invention do not impose special limitations on the specific form of the above-described electronic devices.

[0098] Those skilled in the art will understand that the above embodiments are specific implementations of the present invention, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A loudspeaker, comprising: A diaphragm structure, comprising a first diaphragm and a second diaphragm, wherein the first diaphragm is used to drive air to vibrate in order to emit an initial sound wave, the signal of which is based on signal modulation of an audible audio frequency band; A cover plate structure and a diaphragm structure form a sound-generating cavity. The cover plate structure has a sound outlet hole that connects the sound-generating cavity to the outside. An initial sound wave in the sound-generating cavity is transmitted to the outside through the sound outlet hole to form a sound signal. The second diaphragm and the cover plate structure constitute an acoustic environment impedance. The acoustic environment impedance is used to modulate the initial sound wave to change the sound pressure of the sound signal.

2. The loudspeaker of claim 1, wherein, The frequency of the initial sound wave is a preset frequency, and the second diaphragm is used to vibrate at the preset frequency.

3. The loudspeaker of claim 1, wherein, The first diaphragm is disposed around the second diaphragm.

4. The loudspeaker of claim 1, wherein, The second diaphragm is disposed around the first diaphragm.

5. The loudspeaker of any one of claims 1-4, wherein, The sound outlet is positioned directly opposite the first diaphragm; the cover plate structure at least covers the second diaphragm.

6. The loudspeaker of any one of claims 1-4, wherein, The sound-generating cavity also has an intermediate layer, which is located between the diaphragm structure and the cover plate structure. The intermediate layer has a through hole that penetrates the thickness of the intermediate layer. The through hole is directly opposite to the first diaphragm and is misaligned with the sound outlet. The intermediate layer at least shields the second diaphragm to form the acoustic impedance together with the second diaphragm and the cover plate structure.

7. The loudspeaker of claim 1, wherein, The first diaphragm can be driven by electrostatic driving, piezoelectric driving, or electromagnetic driving; the second diaphragm can be driven by electrostatic driving, piezoelectric driving, or electromagnetic driving.

8. The loudspeaker of claim 1, wherein, The shape of the first diaphragm includes a circle, a square, a hexagon, or a ring; the shape of the second diaphragm includes a circle, a square, a hexagon, or a ring.

9. The loudspeaker of claim 1, wherein, It also includes: a blocking element located on the side of the cover structure away from the sound-emitting cavity, the blocking element at least partially blocking the sound outlet.

10. An electronic device comprising a speaker as claimed in any one of claims 1 to 9.

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