Loudspeaker and electronic equipment

Abstract

The invention relates to the technical field of acoustic-electric conversion, and discloses a loudspeaker and electronic equipment, the loudspeaker comprises a vibrating diaphragm structure, the vibrating diaphragm structure comprises a first vibrating diaphragm and a second vibrating diaphragm, the first vibrating diaphragm is used for pushing air to vibrate so as to emit an initial sound wave, and a signal of the initial sound wave is modulated based on a signal of an audible sound frequency band; the cover plate structure, the cover plate structure and the vibrating diaphragm structure define a sounding cavity, the cover plate structure is internally provided with a sound outlet hole, the sounding cavity is communicated with the outside through the sound outlet hole, initial sound waves in the sounding cavity are transmitted to the outside from the sound outlet hole to form sound signals, and the second vibrating diaphragm and the cover plate structure form sound environment impedance. The acoustic environment impedance is used to modulate the initial sound wave to change the sound pressure of the sound signal. According to the loudspeaker and the electronic equipment provided by the invention, the sound signal covering the audible sound frequency band can be modulated and output based on the sound environment impedance.

Description

Technical Field

[0001] The present invention relates to the technical field of acoustic-electric conversion, and in particular to a loudspeaker and an electronic device. Background Art

[0002] Micro speakers are an important electroacoustic device that is widely used in consumer electronic devices. Micro speakers can be divided into dynamic micro speakers, balanced armature micro speakers and micro-electro-mechanical system (MEMS) speakers according to their technology types.

[0003] At present, both dynamic coil micro speakers and balanced iron micro speakers use electromagnetic force to drive the vibration structure to stimulate sound. Both dynamic coil micro speakers and balanced iron micro speakers will be affected by external magnetic field interference during operation, which will affect their performance, and their size is difficult to further miniaturize. MEMS speakers do not have the above problems and have many advantages such as low power consumption, low cost, small size, and high consistency.

[0004] However, the performance of MEMS speakers in outputting sound signals covering the audible sound frequency band needs to be improved. Summary of the invention

[0005] In view of the above problems, the main object of the present invention is to provide a speaker that can output a sound signal covering the audible sound frequency band based on acoustic environment impedance modulation.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention provides a loudspeaker, including: a diaphragm structure, the diaphragm structure includes a first diaphragm and a second diaphragm, the first diaphragm is used to drive air to vibrate to emit an initial sound wave, and the signal of the initial sound wave is based on signal modulation in the audible sound frequency band; a cover structure, the cover structure and the diaphragm structure form a sound cavity, the cover structure has a sound outlet hole, the sound outlet hole connects the sound cavity with the outside, the initial sound wave in the sound cavity is transmitted from the sound outlet hole to the outside to form a sound signal, the second diaphragm and the cover structure constitute an acoustic environment impedance, and the acoustic environment impedance is 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 arranged opposite to the first diaphragm; and the cover structure at least shields the second diaphragm.

[0011] Preferably, the sound cavity also has an intermediate layer, which is located between the diaphragm structure and the cover structure. The intermediate layer has a via hole that penetrates the thickness of the intermediate layer. The via hole is arranged opposite to the first diaphragm, and the via hole is staggered with the sound outlet hole. The intermediate layer at least blocks the second diaphragm to form an acoustic environment impedance with the second diaphragm and the cover structure.

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

[0013] Preferably, the shape of the first diaphragm includes circular, square, hexagonal or annular; the shape of the second diaphragm includes circular, square, hexagonal or annular.

[0014] Preferably, it also includes: a shielding element, which is located on a side of the cover structure away from the sound cavity, and the shielding element at least shields a portion of the sound outlet.

[0015] The technical solution of the present invention further provides an electronic device, comprising the speaker as in the above embodiment.

[0016] The beneficial effects of the present invention are that the diaphragm structure and the cover structure form a sound-emitting cavity, wherein the diaphragm structure includes a first diaphragm and a second diaphragm, the first diaphragm is used to push the air to vibrate to emit an initial sound wave, the second diaphragm and the cover structure constitute an acoustic environment impedance, and the acoustic environment impedance is used to modulate the initial sound wave so that the sound signal emitted by the sound outlet hole on the cover structure is a sound signal in the audible sound frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 work, among which:

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

[0019] FIG2( a ) is a spectrum diagram corresponding to a sound pressure signal of a sound source provided by an embodiment of the present invention;

[0020] FIG2( b ) is a spectrum diagram corresponding to an acoustic environment impedance provided by an embodiment of the present invention;

[0021] FIG2(c) is a frequency spectrum diagram corresponding to a sound pressure signal of an output sound signal provided by an embodiment of the present invention;

[0022] Figure 3A schematic diagram of the structure of a first speaker provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of the structure of a second speaker provided by an embodiment of the present invention;

[0024] Figure 5 A schematic diagram of the structure of a third loudspeaker provided in an embodiment of the present invention;

[0025] Figure 6 A schematic structural diagram of a fourth speaker provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present invention, many technical details are provided to enable readers to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present invention can be implemented.

[0027] In the description of the embodiments of the present invention, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may 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", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., which indicate orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present invention.

[0030] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

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

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

[0033] The terms used in the description of the various described embodiments herein are used only to describe specific embodiments and are not intended to be limiting. As used in the description of the various described embodiments and the appended claims, "components" are also intended to include plural forms unless the context clearly indicates otherwise.

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

[0035] In a speaker, a diaphragm is usually used to push air to vibrate to emit a sound signal and propagate it in all directions. During the propagation of the sound wave, the environment, propagation path, and load of the sound wave will cause loss to the sound wave, thereby affecting the sound pressure of the sound signal obtained by the load. Figure 1 , the sound source generated by the diaphragm is equivalent to the constant current source I; the loss of the sound waves of the sound source caused by the environment is equivalent to the acoustic environment impedance Z1, for example, the loss of the sound waves caused by the environmental structures such as walls, skin, and sound absorbers; the loss of the sound waves of the sound source caused by the obstruction on the propagation path is equivalent to the acoustic path impedance Z2, for example, the loss of the sound waves caused by the obstruction in front of the sound outlet; the loss of the sound waves of the sound source caused by the load itself is equivalent to the load impedance Zload, for example, the load can be the loss of the human ear or the microphone itself. The acoustic environment impedance Z1 is equivalent to being connected in parallel with the sum of the acoustic path impedance Z2 and the load impedance Zload as the total impedance of the constant current source I.

[0036] The frequency of ultrasound generated by the sound source being the diaphragm pushing the air is f 0 Taking the sound wave as an example, the constant current source I is expressed as the product of the area of ​​the diaphragm and the amplitude speed. The sound source is the audible sound frequency f a Modulation, f aFor any value between 20 Hz and 20 kHz, the constant current source I satisfies the following relationship (1):

[0037] I=I 0 sin(2πf 0 t)sin(2πf a t)

[0038] Among them, I 0 is a constant; t is time.

[0039] The acoustic environment impedance Z1 is based on the ultrasonic frequency f of the sound source 0 Modulation, the acoustic environment impedance Z1 satisfies the following relationship (2):

[0040] I=I 0 sin(2πf 0 t)sin(2πf a t)

[0041] Among them, Z0 is a constant.

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

[0043]

[0044] When the obstacles on the propagation path of the sound wave remain unchanged, the sound path impedance Z2 is a constant value; when the load is determined, the load impedance Zload is a constant value.

[0045] Therefore, when Z0<Z2+Zload, the sound pressure Pload transmitted to the load after being modulated 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 speaker can modulate and output a sound signal covering the audible sound frequency band based on the acoustic environment impedance Z1.

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

[0051] Referring to FIG. 2( a ), after the sound pressure signal of the sound source is modulated according to the above relationship (1), the sound pressure signal of the sound source can be output as f0 -f a ~f 0 +f a frequency band; refer to Figure 2(b), the acoustic environment impedance is based on the ultrasonic frequency f of the sound source 0 Modulation; Referring to Figure 2 (c), based on the above principle, the acoustic environment impedance is used to modulate the sound source sound pressure signal to generate an audible sound frequency band f a sound signal.

[0052] Figure 3 A schematic structural diagram of a first speaker provided in an embodiment of the present invention.

[0053] refer to Figure 3 The first loudspeaker provided by the technical solution of the present invention is modulated based on the above principle, and includes: a diaphragm structure 101 and a cover structure 102. The diaphragm structure 101 includes a first diaphragm 111 and a second diaphragm 121. The second diaphragm 121 is arranged around the first diaphragm 111. The first diaphragm 111 is used to push the air to vibrate to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal in the audible sound frequency band. The specific modulation method can refer to the above relationship (1). The cover structure 102 and the diaphragm structure 101 form a sound cavity 103. The cover structure 102 has a sound outlet 104. The sound outlet 104 connects the sound cavity 103 with the outside. The initial sound wave B0 in the sound cavity 103 is transmitted from the sound outlet 104 to the outside to form a sound signal B1. The sound outlet 104 is arranged opposite to the first diaphragm 111, and the cover structure 102 at least blocks the second diaphragm 121. In this way, the second diaphragm 121 and the cover structure 102 constitute an acoustic environment impedance, which 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 refer to the above-mentioned relationship (2).

[0054] The first diaphragm 111 may be manufactured by a MEMS (Micro Electro Mechanical System) manufacturing process using a SOI (Silicon On Insulator / Si) or POI (Polycrystalline Silicon On Insulator / Polysilicon) wafer.

[0055] The second diaphragm 121 may be manufactured by a MEMS (Micro Electro Mechanical System) manufacturing process using a SOI (Silicon On Insulator / Si) or POI (Polycrystalline Silicon On Insulator / Polysilicon) wafer.

[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 first diaphragm 111 is driven by electrostatic drive, piezoelectric drive or electromagnetic drive.

[0058] The second diaphragm 121 may be driven by electrostatic driving, piezoelectric driving or electromagnetic driving.

[0059] In some embodiments, the driving mode of the first diaphragm 111 and the driving mode of the second diaphragm 121 may be the same; or, the driving mode of the first diaphragm 111 and the driving mode of the second diaphragm 121 may be different.

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

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

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

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

[0064] In some embodiments, the support column 115 may be a continuous structure disposed around the first diaphragm 111 ; or, there may be a plurality of support columns 115 , which are disposed around the first diaphragm 111 at intervals.

[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 hole 104 may be provided as a single hole or a plurality of holes, and the shape of the sound outlet hole 104 may be circular, elliptical, triangular, quadrilateral, hexagonal or arc-shaped.

[0067] Figure 4 A schematic structural diagram of a second speaker provided in an embodiment of the present invention.

[0068] refer to Figure 4The second loudspeaker provided by the technical solution of the present invention is modulated based on the above principle, and includes: a diaphragm structure 201 and a cover structure 202. The diaphragm structure 201 includes a first diaphragm 211 and a second diaphragm 221. The first diaphragm 211 is arranged around the second diaphragm 221. The first diaphragm 211 is used to push the air to vibrate to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal in the audible sound frequency band. The specific modulation method can refer to the above relationship (1). The cover structure 202 and the diaphragm structure 201 form a sound cavity 203. The cover structure 202 has a sound outlet 204. The sound outlet 204 connects the sound cavity 203 with the outside. The initial sound wave B0 in the sound cavity 203 is transmitted from the sound outlet 204 to the outside to form a sound signal B1. The sound outlet 204 is arranged opposite to the first diaphragm 211, and the cover structure 202 at least blocks the second diaphragm 221. In this way, the second diaphragm 221 and the cover structure 202 constitute an acoustic environment impedance, which 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 refer to the above-mentioned relationship (2).

[0069] The parts of the first diaphragm 211 and the second diaphragm 221 that are identical or corresponding to the first diaphragm 111 and the second diaphragm 121 in the first embodiment refer to the aforementioned embodiment and will not be described in detail here.

[0070] refer to Figure 4 The speaker also includes a supporting structure 205, which includes a supporting cylinder 225 and a supporting column 215. The supporting cylinder 225 is cylindrical, and the first diaphragm 211 is fixed to the inner wall of the supporting cylinder 125 on all sides, and the second diaphragm 221 is fixed to the first diaphragm 211 on all sides through the supporting column 215.

[0071] In some embodiments, the support column 215 may be a continuous structure disposed around the second diaphragm 221 ; or, there may be a plurality of support columns 215 , which are disposed around the second diaphragm 221 at intervals.

[0072] In some embodiments, the sound holes 204 may be arranged in an arc shape, a circle, an ellipse, a triangle, a quadrilateral or a hexagon, etc. The number of the sound holes 204 may be multiple, and the multiple sound holes 204 are arranged at intervals along the circumferential direction of the second diaphragm 221 .

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

[0074] refer to Figure 5The third loudspeaker provided by the technical solution of the present invention is modulated based on the above principle, and includes: a diaphragm structure 301, a cover 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 arranged around the first diaphragm 311. The first diaphragm 311 is used to push the air to vibrate to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal in the audible sound frequency band. The specific modulation method can refer to the above relationship (1). The cover structure 302 and the diaphragm structure 301 form a sound cavity 303. The cover structure 302 has a sound outlet 304. The sound outlet 304 connects the sound cavity 303 with the outside. The initial sound wave B0 in the sound cavity 303 is transmitted from the sound outlet 304 to the outside to form a sound signal B1. The intermediate layer 306 is arranged in the sound cavity 303, and the intermediate layer 306 is located between the diaphragm structure 301 and the cover 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 arranged opposite to the first diaphragm 311, and the through hole 316 is staggered with the sound outlet 304; the intermediate layer 306 at least blocks the second diaphragm 321 to form an acoustic environment impedance with the second diaphragm 321 and the cover 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 refer to the above-mentioned relationship (2).

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

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

[0077] In some embodiments, the number of the via hole 316 may be single or multiple, and the via hole 316 may be arranged in an arc shape, a circle, an ellipse, a triangle, a quadrilateral, a hexagon, or the like.

[0078] The parts of the first diaphragm 311 and the second diaphragm 321 that are identical or corresponding to the first diaphragm 111 and the second diaphragm 121 in the first embodiment refer to the aforementioned embodiment and will not be described in detail here.

[0079] refer to Figure 5The speaker also includes a supporting structure 305, and the supporting structure 305 includes a supporting cylinder 325 and a supporting column 315. The supporting cylinder 325 is cylindrical, and the first diaphragm 311 is fixed to the inner wall of the supporting cylinder 325, and the middle layer 306 is fixed to the inner wall of the supporting cylinder 325. The first diaphragm 311 is fixed to the second diaphragm 321 by the supporting column 315.

[0080] In some embodiments, the support column 315 may be a continuous structure disposed around the first diaphragm 311 , or there may be a plurality of support columns 315 , which are disposed around the first diaphragm 311 at intervals.

[0081] In some embodiments, the sound holes 304 may be arranged in an arc shape, a circle, an ellipse, a triangle, a quadrilateral or a hexagon, etc. The number of the sound holes 304 may be multiple, and the multiple sound holes 304 are arranged at intervals along the circumferential direction of the first diaphragm 311 .

[0082] Figure 6 A schematic structural diagram of a fourth speaker provided in an embodiment of the present invention.

[0083] refer to Figure 6 The fourth loudspeaker provided by the technical solution of the present invention is modulated based on the above principle, and includes: a diaphragm structure 401, a cover 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 arranged around the second diaphragm 421. The first diaphragm 411 is used to push the air to vibrate to emit an initial sound wave B0. The signal of the initial sound wave B0 is modulated based on the signal in the audible sound frequency band. The specific modulation method can refer to the above relationship (1). The cover structure 402 and the diaphragm structure 401 form a sound cavity 403. The cover structure 402 has a sound outlet 404. The sound outlet 404 connects the sound cavity 403 with the outside. The initial sound wave B0 in the sound cavity 403 is transmitted from the sound outlet 404 to the outside to form a sound signal B1. The intermediate layer 406 is arranged in the sound cavity 403, and the intermediate layer 406 is located between the diaphragm structure 401 and the cover 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 arranged opposite to the first diaphragm 411, and the through hole 416 is staggered with the sound outlet 404; the intermediate layer 406 at least blocks the second diaphragm 421 to form an acoustic environment impedance with the second diaphragm 421 and the cover 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 refer to the above-mentioned relationship (2).

[0084] The acoustic environment impedance formed by the middle layer 406 , the second diaphragm 421 and the cover structure 402 includes a main acoustic environment impedance and a matching acoustic environment impedance. The main acoustic environment impedance is based on the second diaphragm 421 and the middle layer 406 , and the matching acoustic environment impedance is based on the middle layer 406 and the cover structure 402 .

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

[0086] In some embodiments, the via hole 416 may be arranged in an arc shape, a circle, an ellipse, a triangle, a quadrilateral or a hexagon, etc. There may be a plurality of via holes 416 , and the plurality of via holes 416 are arranged at intervals along the circumferential direction of the second diaphragm 421 .

[0087] The parts of the first diaphragm 411 and the second diaphragm 421 that are identical or corresponding to the first diaphragm 111 and the second diaphragm 121 in the first embodiment refer to the aforementioned embodiment and will not be described in detail here.

[0088] refer to Figure 6 The speaker also includes a supporting structure 405, and the supporting structure 405 includes a supporting cylinder 425 and a supporting column 415. The supporting cylinder 425 is cylindrical, and the second diaphragm 421 is fixed to the inner wall of the supporting cylinder 425 on all sides, and the intermediate layer 406 is fixed to the inner wall of the supporting cylinder 425 on all sides, and the first diaphragm 411 is fixed to the second diaphragm 421 on all sides through the supporting column 415.

[0089] In some embodiments, the support column 415 may be a continuous structure disposed around the second diaphragm 421 , or there may be a plurality of support columns 415 , which are disposed at intervals around the second diaphragm 421 .

[0090] In some embodiments, the sound outlet hole 404 may be provided as a single hole or a plurality of holes, and the shape of the sound outlet hole 404 may be circular, elliptical, triangular, quadrilateral, hexagonal or arc-shaped.

[0091] In some embodiments, the sound outlet hole 404 may be provided as a single hole or a plurality of holes, and the shape of the sound outlet hole 104 may be circular, elliptical, triangular, quadrilateral, hexagonal or arc-shaped.

[0092] In any of the loudspeakers in the first to fourth embodiments, a shielding element (not shown in the figure) may be further included, the shielding element being located on a side of the cover structure away from the sound-emitting cavity, and the shielding element at least shielding a portion of the sound outlet. In this way, the shielding element may constitute an acoustic path impedance, and the initial sound wave is modulated based on the acoustic environment impedance and the acoustic path impedance in the above embodiment, so that the loudspeaker outputs a sound signal covering the audible sound frequency band.

[0093] In some embodiments, the shielding element can vibrate along the sound output direction of the sound hole to modulate the output sound signal; or, the shielding element can reciprocate and translate in a direction parallel to the cover structure to block or open the sound hole, thereby achieving modulation of 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 loudspeaker provided by the technical solution of the present invention forms a sound cavity through a diaphragm structure and a cover structure, wherein the diaphragm structure includes a first diaphragm and a second diaphragm, the first diaphragm is used to push air to vibrate to emit initial sound waves, the second diaphragm and the cover structure constitute an acoustic environment impedance, and the acoustic environment impedance is used to modulate the initial sound waves so that the sound signal emitted by the sound outlet hole on the cover structure is a sound signal in the audible sound frequency band.

[0096] Correspondingly, the technical solution of the present invention further provides an electronic device, comprising a speaker as in the above embodiment, which is configured to output a sound signal covering an audible sound frequency band based on acoustic environment impedance modulation.

[0097] In some embodiments, the electronic device may include a mobile phone, a tablet computer, a laptop computer, a personal digital assistant (PDA), a camera, a personal computer, a vehicle-mounted device, a wearable device, augmented reality (AR) glasses, AR helmets, virtual reality (VR) glasses, VR helmets, fixed-line handsets (pickups), medical auxiliary equipment (such as hearing aids), various headphones (such as wireless headphones or wired headphones), and other devices with speakers. The embodiments of the present invention do not impose any special restrictions on the specific forms of the above electronic devices.

[0098] Those skilled in the art will appreciate that the above-mentioned embodiments are specific embodiments for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A loudspeaker, characterized in that: include: A diaphragm structure, the diaphragm structure comprising a first diaphragm and a second diaphragm, the first diaphragm is used to push air to vibrate to emit an initial sound wave, the signal of the initial sound wave is modulated based on a signal in an audible sound frequency band; A cover plate structure, wherein the cover plate structure and the diaphragm structure form a sound cavity, the cover plate structure has a sound outlet hole, the sound outlet hole connects the sound cavity with the outside, the initial sound wave in the sound cavity is transmitted from the sound outlet hole to the outside to form a sound signal, the second diaphragm and the cover plate structure constitute an acoustic environment impedance, and the acoustic environment impedance is used to modulate the initial sound wave to change the sound pressure of the sound signal.

2. The loudspeaker according to claim 1, characterized in that 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 according to claim 1, characterized in that The first diaphragm is disposed around the second diaphragm.

4. The loudspeaker according to claim 1, characterized in that The second diaphragm is disposed around the first diaphragm.

5. The loudspeaker according to any one of claims 1 to 4, characterized in that: The sound outlet is arranged opposite to the first diaphragm; and the cover structure at least covers the second diaphragm.

6. The loudspeaker according to any one of claims 1 to 4, characterized in that: The sound cavity also has an intermediate layer, the intermediate layer is located between the diaphragm structure and the cover plate structure, the intermediate layer has a via hole penetrating the thickness of the intermediate layer, the via hole is arranged opposite to the first diaphragm, and the via hole is staggered with the sound outlet hole; The intermediate layer at least blocks the second diaphragm to form the acoustic environment impedance together with the second diaphragm and the cover structure.

7. The loudspeaker according to claim 1, characterized in that The driving mode of the first diaphragm includes electrostatic driving, piezoelectric driving or electromagnetic driving; the driving mode of the second diaphragm includes electrostatic driving, piezoelectric driving or electromagnetic driving.

8. The loudspeaker according to claim 1, characterized in that The shape of the first diaphragm includes circular, square, hexagonal or annular; the shape of the second diaphragm includes circular, square, hexagonal or annular.

9. The loudspeaker according to claim 1, characterized in that It also includes: a shielding element, which is located on a side of the cover structure away from the sound cavity, and the shielding element at least shields a portion of the sound outlet.

10. An electronic device, characterized in that: The invention comprises the loudspeaker according to any one of claims 1 to 9.

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