CN218570470U

CN218570470U - Piezoelectric loudspeaker and electronic device using same

Info

Publication number: CN218570470U
Application number: CN202222242807.9U
Authority: CN
Inventors: 陈家熠; 丁玉江; 潘春娇; 陶婧雅
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-08-24
Filing date: 2022-08-24
Publication date: 2023-03-03
Anticipated expiration: 2032-08-24

Abstract

A piezoelectric loudspeaker comprises a piezoelectric sheet, a diaphragm membrane and at least one elastic sheet. The diaphragm membrane is arranged on the piezoelectric sheet in a laminating mode and fixedly connected with the piezoelectric sheet. Each spring piece comprises a main body part and end parts connected with two opposite ends of the main body part. The shell fragment sets up in the piezoelectric patches one side that deviates from the vibrating diaphragm, and the relative piezoelectric patches of main part arches, tip and piezoelectric patches fixed connection. Or, the shell fragment setting is in the one side that the vibrating diaphragm deviates from the piezoelectric plate, and the relative vibrating diaphragm of main part arches, tip and vibrating diaphragm fixed connection. The elastic sheet provides support and compliance for the piezoelectric speaker. The main functions of the elastic sheet comprise: the vibration displacement of the piezoelectric plate is improved, and the sound pressure level is improved; the high-frequency peak valley in the frequency response curve of the piezoelectric loudspeaker is improved, so that the frequency response curve is flatter. The application also provides an electronic device comprising the piezoelectric loudspeaker.

Description

Piezoelectric loudspeaker and electronic device using same

Technical Field

The present application relates to a piezoelectric speaker and an electronic device using the same.

Background

A moving coil speaker is a conventional speaker, and includes an electromagnet, a coil, a diaphragm, etc., which generates a changing magnetic field by passing a changing current through the coil, and the changing magnetic field interacts (attracts or repels) with a magnetic field generated by the electromagnet to vibrate the coil. The coil is connected with the vibrating diaphragm together, so that the vibrating diaphragm is driven to vibrate together according to a preset frequency to produce sound. However, due to the arrangement of the magnet, the coil, and the like, the moving coil speaker generally has a certain thickness; when the moving coil speaker is disposed in an electronic product, the moving coil speaker occupies a relatively large volume and space, which is not favorable for miniaturization and thinning of the current electronic product.

SUMMERY OF THE UTILITY MODEL

A first aspect of an embodiment of the present application provides a piezoelectric speaker, including:

a piezoelectric sheet;

the vibrating diaphragm membrane is arranged on the piezoelectric sheet in a stacked mode and fixedly connected with the piezoelectric sheet;

each elastic sheet comprises a main body part and end parts connected with two opposite ends of the main body part;

each elastic sheet is arranged on one side of the piezoelectric sheet, which is far away from the diaphragm membrane, the main body part is arched relative to the piezoelectric sheet, and the end part is fixedly connected with the piezoelectric sheet; or

Each elastic sheet is arranged on one side, away from the piezoelectric sheet, of the vibrating diaphragm membrane, the main body portion is arched relative to the vibrating diaphragm membrane, and the end portion is fixedly connected with the vibrating diaphragm membrane.

The elastic sheet provides support and compliance for the piezoelectric speaker and increases the reliability of the piezoelectric speaker. The main functions of the elastic sheet comprise: the vibration displacement of the piezoelectric sheet is improved, and the sound pressure level is improved; the peak valley of the high frequency in the frequency response curve of the piezoelectric loudspeaker is improved, so that the frequency response curve is flatter.

In the embodiment of the application, when the elastic sheet is arranged on one side of the piezoelectric sheet, which is far away from the diaphragm membrane, the end part is fixedly connected to the surface of the piezoelectric sheet, which is far away from the diaphragm membrane; when the elastic sheet is arranged on one side, away from the piezoelectric sheet, of the diaphragm membrane, the end portion is fixedly connected to the surface, away from the piezoelectric sheet, of the diaphragm membrane.

In the embodiment of the application, when the elastic sheet is arranged on one side of the piezoelectric sheet, which is far away from the diaphragm membrane, the piezoelectric sheet comprises a first surface, a second surface and a side surface, wherein the first surface is far away from the diaphragm membrane, the second surface is connected with the diaphragm membrane, and the side surface is connected between the first surface and the second surface; the end portion is connected with the main body portion in a bent mode, and the end portion is fixedly connected with the side face of the piezoelectric sheet.

The arched elastic sheet is fixedly bonded with the piezoelectric sheet or the diaphragm membrane, so that the piezoelectric sheet or the diaphragm membrane is restrained, the medium-high frequency mode is improved, and the medium-high frequency peak valley is smoothed.

In an embodiment of the present application, an adhesive is disposed on a surface of the main body portion facing away from the piezoelectric sheet.

The adhesive glue is used for connecting a component/frame of an end product (such as an electronic device), so that the elastic sheet is connected with the piezoelectric sheet/diaphragm membrane and the component/frame of the end product (such as the electronic device), and the elastic sheet has certain elasticity similar to a spring, so that the dropping reliability is better when the piezoelectric sheet/diaphragm membrane falls. The arched elastic sheet is connected with a component/frame of a terminal product (such as an electronic device), so that the piezoelectric material can be lifted to vibrate up and down integrally when deformation occurs, vibration displacement is improved, and low-frequency sensitivity is improved.

In the embodiment of the present application, the main body portion includes a flat plate region located in the middle and a bending region connected to opposite ends of the flat plate region, and the bending region is connected to the flat plate region and obliquely connected between the end portions.

In the embodiment of the application, the flat plate area is provided with bonding glue.

The flat plate area is provided with adhesive for connecting a component/frame of an end product (such as an electronic device), so that the elastic sheet is connected with the piezoelectric sheet/diaphragm membrane and the component/frame of the end product (such as the electronic device), and the elastic sheet has certain elasticity similar to a spring, so that the drop reliability is better when the drop occurs. The arched elastic sheet is connected with a component/frame of a terminal product (such as an electronic device), so that the piezoelectric material can be lifted to vibrate up and down integrally when deformation occurs, vibration displacement is improved, and low-frequency sensitivity is improved.

In an embodiment of the present application, the piezoelectric speaker further includes a frame surrounding and connecting the periphery of the diaphragm membrane.

The frame provides stability to the overall structure of the piezoelectric speaker.

In the embodiment of the present application, the diaphragm membrane is a flat plate structure.

In the embodiment of the present application, the diaphragm membrane includes a main body region and a peripheral region surrounding and connected to the main body region, the main body region is flat, and the peripheral region is an arch structure that is arched along the thickness direction of the diaphragm membrane.

The arch structure is also arranged to improve the compliance of the diaphragm membrane so as to facilitate the back-and-forth vibration of the diaphragm membrane.

In the embodiment of the application, a bonding adhesive is arranged between the diaphragm membrane and the piezoelectric sheet.

And adhesive glue is arranged between the diaphragm membrane and the piezoelectric sheet, so that the diaphragm membrane and the piezoelectric sheet are fixedly connected.

In an embodiment of the present application, the piezoelectric speaker includes two or more of the elastic pieces, and the two or more of the elastic pieces are disposed to intersect with each other.

In an embodiment of the application, the piezoelectric speaker includes one elastic sheet, the main body portion includes at least one longitudinal portion and at least one transverse portion cross-connected to the at least one longitudinal portion, two ends of each longitudinal portion are respectively connected to one of the end portions, and two ends of each transverse portion are respectively connected to one of the end portions.

The elastic sheet of the piezoelectric loudspeaker is of an integrally formed structure.

In an embodiment of the application, the piezoelectric speaker includes two or more elastic sheets, the two or more elastic sheets are non-crossed and arranged at intervals, the main body portion of each elastic sheet is provided with adhesive, and the adhesive is located in the middle of the main body portion.

A second aspect of the embodiments of the present application provides an electronic device, including a housing and a speaker disposed in the housing, wherein the speaker separates the interior of the housing into two isolated cavities, and the speaker is a piezoelectric speaker according to the first aspect of the embodiments of the present application.

The thickness of piezoelectric speaker is thinner, and it is less to occupy the inside space of casing, and piezoelectric speaker excellent performance, sound effect is good.

In the embodiment of the application, the casing is provided with the sound outlet hole, the position where the loudspeaker is arranged is right opposite to the sound outlet hole, and the sound outlet hole is communicated with one of the two cavities.

In the embodiment of the application, the bonding glue arranged on the main body part of the elastic sheet is fixedly connected with the shell.

In the embodiment of the application, a structural part is arranged in the shell, and the bonding glue arranged on the main body part of the elastic sheet is fixedly connected with the structural part.

Drawings

Fig. 1 is a perspective view schematically showing a piezoelectric speaker according to a first embodiment of the present application.

Fig. 2 is an exploded schematic view of the piezoelectric speaker of fig. 1.

Fig. 3 is a perspective view schematically showing a piezoelectric speaker according to a second embodiment of the present application.

Fig. 4 is a perspective view schematically showing a piezoelectric speaker according to a third embodiment of the present application.

Fig. 5 is a perspective view schematically showing a piezoelectric speaker according to a fourth embodiment of the present application.

Fig. 6 is a schematic perspective view of a diaphragm membrane of a piezoelectric speaker according to an embodiment of the present application.

Fig. 7 is a schematic cross-sectional view of a diaphragm membrane of a piezoelectric speaker according to another embodiment of the present application.

Fig. 8 is a schematic view illustrating a displacement magnification principle of the resilient sheet.

Fig. 9 is a frequency response curve of the piezoelectric speaker of the present application and a conventional piezoelectric speaker.

Fig. 10 is a perspective view schematically showing a piezoelectric speaker according to a fifth embodiment of the present application.

Fig. 11 is a schematic diagram of an electronic device according to an embodiment of the present application.

Fig. 12 is a schematic view of an electronic device according to another embodiment of the present application.

Description of the main elements

Piezoelectric speaker

100, 400

Piezoelectric patch 10

Diaphragm membrane 20

Spring sheet 30

Main body 31

End 33

Body region 21

Peripheral region 23

First surface 11

Second surface 13

Side 12

Adhesive glue 50

Longitudinal portion 312

Transverse part 314

Plate region 311

Inflection region 313

Frame 40

Electronic device

200, 300

Case 210

Front chamber 201

Rear cavity 203

Sound outlet 211

Sound outlet hole connecting piece 213

Display screen 220

Middle frame 310

Detailed Description

The embodiments of the present application are described below with reference to the drawings.

The piezoelectric loudspeaker drives the vibrating diaphragm or the body thereof to generate bending deformation through the bending deformation of the piezoelectric material sheet, so as to push the air to produce sound. Since the piezoelectric material sheet itself is the driving structure, no additional driving device is required, and thus the overall thickness of the piezoelectric speaker can be made very thin. However, the vibration unit of the piezoelectric speaker is bent and deformed, and the vibration area is small, resulting in insufficient low-frequency performance. Piezoelectric speakers often require a large lateral area to boost low frequency performance.

The application provides a piezoelectric speaker, through the setting of arched shell fragment, effectively promotes piezoelectric speaker's low frequency performance, and piezoelectric speaker's area is less.

Referring to fig. 1 and fig. 2, a piezoelectric speaker 100 includes a piezoelectric sheet 10, a diaphragm membrane 20, and at least one elastic sheet 30 (only one elastic sheet 30 is shown in fig. 1). The diaphragm membrane 20 and the piezoelectric sheet 10 are stacked, and the diaphragm membrane 20 is fixedly connected to the piezoelectric sheet 10. The elastic sheet 30 is disposed on a side of the piezoelectric sheet 10 away from the diaphragm membrane 20. The diaphragm membrane 20 and the elastic sheet 30 are respectively located on two opposite surfaces of the piezoelectric sheet 10.

Each spring plate 30 is disposed across the piezoelectric plate 10. Each spring 30 comprises a main body 31 and an end 33 connected to the main body 31. The resilient piece 30 shown in fig. 1 includes two end portions 33 respectively connected to two opposite ends of the main body portion 31. The body portion 31 is arched with respect to the piezoelectric patch 10, and the end portion 33 is fixedly connected to the piezoelectric patch 10. The end portion 33 is bent and connected to the main body portion 31. In this embodiment, each elastic sheet 30 is an integrally formed structure, and the main body 31 of each elastic sheet 30 is substantially rectangular. In this embodiment, the at least one elastic sheet 30 partially covers the first surface 11 of the piezoelectric sheet 10 away from the diaphragm membrane 20. In other embodiments, the at least one elastic sheet 30 may also completely cover the first surface 11 of the piezoelectric sheet 10 facing away from the diaphragm membrane 20. The spring sheet 30 provides support and compliance for the piezoelectric speaker 100. The main functions of the elastic sheet 30 include: the vibration displacement of the piezoelectric patch 10 is improved, and the sound pressure level is improved; the peak valley of the high frequency in the frequency response curve of the piezoelectric loudspeaker is improved, so that the frequency response curve is flatter. The end portion 33 and the piezoelectric sheet 10 may be fixedly connected by means of an adhesive, which is not shown and is disposed between the end portion 33 and the piezoelectric sheet 10. The material of the elastic sheet 30 is not limited, and may be metal, alloy, carbon fiber or polymer material. Compliance represents the degree of deformation of the spring sheet 30 when subjected to a force, and the greater the degree of deformation, the greater the compliance.

The piezoelectric sheet 10 has a sheet structure. The piezoelectric sheet 10 is a vibration unit of the piezoelectric speaker 100, and provides a driving force to drive the diaphragm membrane 20 to vibrate and sound. The piezoelectric sheet 10 includes a piezoelectric material layer (e.g., a piezoelectric ceramic material layer, not shown) and electrodes (not shown) disposed on opposite surfaces of the piezoelectric material layer, wherein when different voltages are applied to the electrodes on the opposite surfaces of the piezoelectric material layer, the piezoelectric material layer deforms and vibrates, so as to drive the diaphragm membrane 20 to vibrate.

It is understood that the piezoelectric sheet 10 may have a single-layer piezoelectric material structure, or may have a stacked structure of two or more layers of piezoelectric materials. In the prior art, when the piezoelectric sheet 10 has a stacked structure of two or more layers of piezoelectric materials, the piezoelectric sheet 10 can be divided into single-crystal piezoelectric sheets or double-crystal piezoelectric sheets according to the polarization direction of the piezoelectric materials and the voltage direction formed by the electrodes on the upper and lower surfaces. Both of the single crystal piezoelectric sheet and the bimorph piezoelectric sheet can be used as the piezoelectric sheet of the present application.

The diaphragm membrane 20 is sheet-like. An adhesive 50 may be disposed on an interface where the diaphragm membrane 20 and the piezoelectric plate 10 are combined, that is, the adhesive 50 is disposed between the diaphragm membrane 20 and the piezoelectric plate 10, so that the diaphragm membrane 20 and the piezoelectric plate 10 are fixedly connected. In this embodiment, as shown in fig. 1, the area of the diaphragm membrane 20 is larger than the area of the piezoelectric sheet 10, but not limited thereto.

In one embodiment, as shown in fig. 6, the diaphragm membrane 20 may be a flat sheet.

In another embodiment, as shown in fig. 7, the diaphragm membrane 20 includes a main body region 21 and a peripheral region 23 surrounding and connecting the main body region 21, where the main body region 21 is flat plate-shaped, and the peripheral region 23 is a dome-shaped structure that is arched along the thickness direction of the diaphragm membrane 20. The provision of the peripheral region 23 of the dome-shaped structure also serves to improve the compliance of the diaphragm membrane 20, so that the diaphragm membrane 20 can vibrate back and forth.

The material of the diaphragm membrane 20 may be, but is not limited to, one of aluminum, aluminum alloy, steel, and carbon fiber. The material of the diaphragm membrane 20 includes, but is not limited to, polyetherimide (PEI), polyethylene terephthalate (PET), polyetheretherketone (PEEK), polyimide (PI), and the like.

As shown in fig. 1 and 2, the piezoelectric sheet 10 includes a first surface 11 facing away from the diaphragm membrane 20, a second surface 13 connecting the diaphragm membrane 20, and a side surface 12 connecting between the first surface 11 and the second surface 13. As shown in fig. 1, in an embodiment, each end portion 33 of the elastic sheet 30 is bent to connect with the main body portion 31, and the end portion 33 is fixedly connected with the side surface 12 of the piezoelectric sheet 10. At this time, the main body 31 spans the piezoelectric sheet 10, and the end 33 bent and extended from the main body 31 overlaps the side surface 12 of the piezoelectric sheet 10.

In another embodiment, as shown in fig. 3, two end portions 33 of each elastic sheet 30 are disposed and fixedly connected to a surface of the piezoelectric sheet 10 facing away from the diaphragm membrane 20. At this time, each end portion 33 is bent to connect the main body portion 31, and has a substantially flat structure, and the main body portion 31 and the two end portions 33 are fitted to span the piezoelectric sheet 10.

As shown in fig. 4, in an embodiment, the piezoelectric speaker 100 includes two or more elastic sheets 30, and the elastic sheets 30 are non-intersecting and spaced apart from each other, for example, parallel to each other. Or, the number of the elastic sheets 30 is two or more, and the elastic sheets 30 are arranged in a mutually crossed manner. The piezoelectric speaker shown in fig. 5 can be seen to include two spring plates 30 arranged in a crisscross.

It should be understood that the elastic sheet 30 shown in fig. 5 may also be an integrally formed elastic sheet, and the elastic sheet 30 is cross-shaped. The main body 31 of the elastic sheet 30 includes a longitudinal portion 312 and a lateral portion 314 intersecting the longitudinal portion 312, the longitudinal portion 312 spans the piezoelectric sheet 10, and both ends of the longitudinal portion 312 are respectively connected to one end 33 and fixedly connected to the piezoelectric sheet 10, and the lateral portion 314 spans the piezoelectric sheet 10, and both ends of the lateral portion are respectively connected to one end 33 and fixedly connected to the piezoelectric sheet 10.

It is understood that the shape of the integrally formed resilient plate 30 is not limited to the cross shape, and the number of the longitudinal portions and the transverse portions may be increased as needed as long as the main body 31 includes at least one longitudinal portion 312 and at least one transverse portion 314 connected to the at least one longitudinal portion 312 in a crossing manner. For example, the elastic sheet 30 is shaped like a Chinese character 'jing', and includes two longitudinal portions arranged in parallel and two lateral portions arranged in parallel.

As shown in fig. 1, the piezoelectric speaker 100 is provided with only one elastic sheet 30, the main body 31 of the elastic sheet 30 is provided with an adhesive 50, and the adhesive 50 is located on a surface of the main body 31 away from the piezoelectric sheet 10. The adhesive 50 is used to fixedly connect the resilient piece 30 to a component/frame of an end product (e.g., an electronic device). The adhesive 50 is located at the center of the body 31. In some embodiments, the central portion of the main body 31 may be configured as a flat plate structure to better securely connect with a component/frame of an end product (e.g., an electronic device). That is, as shown in fig. 8, the main body 31 includes a flat plate region 311 located in the middle, and a bending region 313 bent to connect opposite ends of the flat plate region 311, the flat plate region 311 is flat and spaced apart from the piezoelectric sheet 10, and the bending region 313 is connected between the flat plate region 311 and the end portion 33 in an inclined manner.

As shown in fig. 4, when the piezoelectric speaker 100 includes two or more elastic sheets 30 that are not crossed and are disposed at intervals, an adhesive 50 is disposed on a surface of the main body 31 of each elastic sheet 30 that faces away from the piezoelectric sheet 10, so as to fixedly connect the elastic sheet 30 with a component/frame of an end product (e.g., an electronic device). The adhesive 50 is located at the center of the body 31.

As shown in fig. 5, when the piezoelectric speaker 100 includes two or more elastic sheets 30 arranged in a crossed manner, an adhesive 50 is disposed on a surface of the main body 31 of the elastic sheet 30 stacked on the top of the piezoelectric sheet 10, the surface being away from the piezoelectric sheet 10, and the adhesive 50 is used for fixedly connecting the elastic sheet 30 with a component/frame of an end product (e.g., an electronic device).

The arched elastic sheet 30 is fixedly connected to the piezoelectric sheet 10 and a component/frame of an end product (e.g., an electronic device), and when the piezoelectric sheet 10 is driven by a voltage to deform, the arched elastic sheet 30 deforms.

The arched elastic sheet 30 is connected to a component/frame of a terminal product (e.g., an electronic device), so that the piezoelectric sheet 10 is lifted to vibrate up and down integrally when deformed, thereby improving vibration displacement and low-frequency sensitivity. The arched elastic sheet 30 is fixedly bonded with the side surface 12 of the piezoelectric sheet 10 or the surface deviating from the diaphragm membrane 20, so that the piezoelectric sheet 10 is restrained, the medium-high frequency mode is improved, and the medium-high frequency peak valley is smoothed. The dome-shaped spring sheet 30 connects the piezoelectric sheet 10 and the component/frame of the end product (e.g., electronic device), and has a certain elasticity like a spring, thereby having better drop reliability when dropped. The arched elastic sheet 30 improves the sensitivity of the piezoelectric sheet 10, and can achieve better performance in a smaller area of the piezoelectric sheet 10, thereby reducing the cost.

Taking the upward vibration of the piezoelectric speaker as an example, the working principle of the elastic sheet 30 is described as follows: as shown in fig. 8, wherein the dotted lines in fig. 8 represent the elastic sheet 30 and the diaphragm 20 after the vibration displacement, the piezoelectric sheet 10 contracts inward after being powered on, so as to drive the bending region 313 of the arched elastic sheet 30 to arch inward and deform, thereby integrally lifting the piezoelectric sheet 10 and the diaphragm 20; due to the bonding of the piezoelectric sheet 10 and the diaphragm membrane 20, and due to the constraint action of the diaphragm membrane 20, the whole body is bent upwards. Therefore, the displacement of the diaphragm membrane 20 is significantly increased after the elastic piece 30 is added.

As shown in fig. 1 to 5, the piezoelectric speaker 100 further includes a frame 40, and the frame 40 surrounds and connects the periphery of the diaphragm membrane 20. In this embodiment, the frame 40 is vertically connected to the diaphragm 20. In this embodiment, the frame 40 extends in a rectangular loop shape to match the rectangular diaphragm membrane 20. The frame 40 may be disposed on the side of the diaphragm 20 having the piezoelectric sheet 10, or may be disposed on the side of the diaphragm 20 not having the piezoelectric sheet 10. The frame 40 provides stability to the overall structure of the piezoelectric speaker 100.

The adhesive 50 of the present application provides bonding capability between each portion of the device, different components can use the same adhesive 50, and different adhesives 50 can be used, the adhesive 50 including but not limited to UV glue, hot melt glue, bi-component glue, structural back glue, silica gel, etc.

Referring to fig. 10, the present embodiment further provides another piezoelectric speaker 400, which has a structure substantially similar to that of the piezoelectric speaker 100, and also includes a piezoelectric sheet 10, a diaphragm membrane 20 stacked on the piezoelectric sheet 10 and fixedly connected to the piezoelectric sheet 10, and at least one elastic sheet 30. The piezoelectric speaker 400 is different from the piezoelectric speaker 100 in that the elastic piece 30 is disposed at a different position, and the elastic piece 30 of the piezoelectric speaker 400 is disposed on a side of the diaphragm membrane 20 away from the piezoelectric piece 10; the piezoelectric sheet 10 and the elastic sheet 30 are respectively located on two opposite surfaces of the diaphragm membrane 20.

The elastic sheet 30 is disposed across the diaphragm membrane 20. Each spring plate 30 comprises a main body portion 31 and an end portion 33 connected to the main body portion 31. The main body 31 is arched with respect to the diaphragm membrane 20, and the end 33 is fixedly connected to the diaphragm membrane 20.

In this embodiment, the end 33 of the elastic sheet 30 is disposed and fixedly connected to the surface of the diaphragm membrane 20 away from the piezoelectric sheet 10. The surface of the main body 31 facing away from the diaphragm membrane 20 is provided with an adhesive 50.

The shape and number of the elastic pieces 30, the adhesive 50 on the elastic pieces 30, and the like can be designed and laid out according to the piezoelectric speaker 100, and are not described in detail herein.

The arched elastic sheet 30 is arranged on the diaphragm membrane 20 and fixedly bonded with the surface of the diaphragm membrane 20, has a constraint effect on the piezoelectric sheet 10 and the diaphragm membrane 20, and can also improve medium-high frequency mode and smooth medium-high frequency peak valley. The dome-shaped spring sheet 30 connects the diaphragm membrane 20 and the component/frame of the end product (e.g., electronic device), and has a certain elasticity like a spring, thereby having better drop reliability when dropped.

The piezoelectric loudspeaker of this application improves low frequency sensitivity and intermediate frequency peak valley difference for traditional piezoelectric loudspeaker. Under the same design conditions, the frequency response curves of the piezoelectric speaker of the present application and the conventional piezoelectric speaker (different from the piezoelectric speaker of the present application in that no spring is provided) are tested, and the results are shown in fig. 9, where the solid line is the frequency response curve of the piezoelectric speaker of the present application, and the dotted line is the frequency response curve of the conventional piezoelectric speaker. The low-frequency characteristic evaluation frequency point of the piezoelectric loudspeaker is set to be 200Hz, and the low frequency of the loudspeaker scheme is improved by 2.5dB; the higher the low frequency sensitivity, the stronger the representation of the low frequency of the loudspeaker, and the better the hearing. The evaluation frequency point of the medium-frequency peak valley characteristic of the piezoelectric loudspeaker is set to be 3550Hz, the medium-frequency valley is optimized by 10dB by applying the loudspeaker scheme of the embodiment of the application, and the shallower the medium-frequency valley is, the better the hearing is.

Compared with the traditional piezoelectric speaker, the piezoelectric speaker 100 of the present application adds the elastic sheet 30 as a support constraint structure, provides a buffer when falling, and improves the falling reliability. Compare in traditional piezoelectric speaker, the piezoelectric speaker of this application possess better low frequency performance, therefore under the same condition of required low frequency performance, the area of the piezoelectric speaker of this application is littleer, but reduce cost.

The application also provides an electronic device comprising the piezoelectric loudspeaker. Referring to fig. 11, the electronic device 200 includes a housing 210, and the piezoelectric speaker 100 is disposed in the housing 210, and the piezoelectric speaker divides the interior of the housing 210 into two isolated cavities (not connected to each other). The two cavities are named front cavity 201 and back cavity 203. The piezoelectric speaker 100 is disposed in the housing 210 in the following orientation: the thickness direction of the piezoelectric speaker 100 (the stacking direction of the piezoelectric sheet 10 and the diaphragm membrane 20) is the same as the thickness direction of the electronic device 200. The electronic device 200 may be a mobile phone, a tablet, a personal computer, or other terminal products, but not limited thereto. The thickness of the piezoelectric speaker 100 is thin, the occupied space inside the housing 210 is small, and the piezoelectric speaker 100 has excellent performance and good sound effect.

The housing 210 is formed with a sound outlet hole 211, the piezoelectric speaker 100 is correspondingly disposed at the position of the sound outlet hole 211, and the sound generated by the piezoelectric speaker 100 can be transmitted through the sound outlet hole 211. In this embodiment, the sound emitting hole 211 is disposed on a sidewall of the housing 210. A sound hole connector 213 is disposed in the housing 210 to surround the sound hole 211, and the piezoelectric speaker 100 is connected to the sound hole connector 213. The sound outlet hole connector 213 may be a rubber ring, a foam ring, or the like.

A display screen 220 is disposed on the front surface of the housing 210, and a portion of the housing 210 opposite to the display screen 220 is a rear shell of the housing 210. In this embodiment, the front cavity 201 is communicated with the sound outlet 211, the front cavity 201 is surrounded by the diaphragm membrane 20, the frame 40, the sound outlet connector 213, and a portion of the back shell of the housing 210, and the piezoelectric plate 10 and the elastic plate 30 are located in the front cavity 201. The other area inside the housing 210 is a back cavity 203, and the back cavity 203 is at least enclosed by the diaphragm membrane 20, the frame 40 and the display screen 220 of the piezoelectric speaker. In this embodiment, the elastic sheet 30 of the piezoelectric speaker 100 is connected to the housing 210 of the electronic device 200, and as mentioned above, the surface of the main body portion 31 of the elastic sheet 30, which is away from the piezoelectric sheet 10, is provided with the adhesive 50, and the elastic sheet 30 is fixedly connected to the rear shell of the housing 210 through the adhesive 50.

The present application also provides another electronic device including the piezoelectric speaker described above. Referring to fig. 12, the electronic device 300 is substantially the same as the electronic device 200 shown in fig. 11, and also includes a housing 210, the piezoelectric speaker 100 is also disposed in the housing 210, and the piezoelectric speaker 100 also divides the interior of the housing 210 into two isolated cavities. The two cavities are also named front cavity 201 and back cavity 203. The electronic device 300 is different from the electronic device 200 shown in fig. 11 in that: the piezoelectric speaker 100 is placed in the housing 210 in an inverted orientation.

The housing 210 is also provided with a sound outlet hole 211, and the piezoelectric speaker 100 is correspondingly disposed at the position of the sound outlet hole 211. In this embodiment, the front cavity 201 is also communicated with the sound outlet 211, and the front cavity 201 is similarly enclosed by the diaphragm membrane 20, the frame 40, the sound outlet connector 213, and a part of the rear shell of the housing 210 of the piezoelectric speaker 100, but the piezoelectric patch 10 and the elastic sheet 30 are not located in the front cavity 201. The other area inside the housing 210 is a back cavity 203, the back cavity 203 is at least enclosed by the diaphragm membrane 20, the frame 40 and the display screen 220 of the piezoelectric speaker, and the piezoelectric sheet 10 and the elastic sheet 30 are located in the back cavity 203. A structural member of the electronic device 300, such as a middle frame 310, is further disposed in the rear cavity 203, the middle frame 310 is disposed between the display screen 220 and the piezoelectric speaker 100, and the elastic sheet 30 of the piezoelectric speaker 100 is fixedly connected to the structural member (the middle frame 310). As mentioned above, the surface of the main body 31 of the elastic sheet 30 away from the piezoelectric sheet 10 is provided with the adhesive 50, and the elastic sheet 30 is fixedly connected to the structural member (middle frame) in the housing 210 through the adhesive 50.

It is understood that, although not shown, the piezoelectric speaker 400 may be applied to an electronic device and disposed in a housing of the electronic device.

It should be noted that, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present application, and shall cover the protection scope of the present application; in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A piezoelectric speaker, comprising:

a piezoelectric sheet;

each elastic sheet comprises a main body part and an end part connected with the main body part;

2. The piezoelectric speaker according to claim 1, wherein when the resilient piece is disposed on a side of the piezoelectric piece away from the diaphragm membrane, the end portion is fixedly connected to a surface of the piezoelectric piece away from the diaphragm membrane;

when the elastic sheet is arranged on one side, away from the piezoelectric sheet, of the diaphragm membrane, the end portion is fixedly connected to the surface, away from the piezoelectric sheet, of the diaphragm membrane.

3. The piezoelectric speaker according to claim 1, wherein when the resilient tab is disposed on a side of the piezoelectric sheet facing away from the diaphragm membrane, the piezoelectric sheet includes a first surface facing away from the diaphragm membrane, a second surface connected to the diaphragm membrane, and a side surface connected between the first surface and the second surface; the end portion is connected with the main body portion in a bent mode, and the end portion is fixedly connected with the side face of the piezoelectric sheet.

4. The piezoelectric speaker according to claim 1, wherein a surface of the main body portion facing away from the piezoelectric sheet is provided with an adhesive.

5. The piezoelectric speaker of claim 1, wherein the body portion includes a plate region in the middle and a bending region connecting opposite ends of the plate region, the bending region being connected obliquely between the plate region and the end portions.

6. The piezoelectric speaker as claimed in claim 5, wherein the plate area is provided with an adhesive.

7. The piezoelectric speaker of claim 1, further comprising a frame surrounding and connecting the periphery of the diaphragm membrane.

8. The piezoelectric speaker of claim 1, wherein the diaphragm membrane is a flat plate structure.

9. The piezoelectric speaker of claim 1, wherein said diaphragm membrane includes a main body region and a peripheral region surrounding and connecting said main body region, said main body region being flat, said peripheral region being an arch-shaped structure that is arched in a thickness direction of said diaphragm membrane.

10. The piezoelectric speaker according to claim 1, wherein an adhesive is provided between the diaphragm membrane and the piezoelectric sheet.

11. The piezoelectric speaker according to claim 1, wherein the piezoelectric speaker comprises two or more spring pieces, and the two or more spring pieces are disposed to cross each other.

12. The piezoelectric speaker according to claim 1, wherein the piezoelectric speaker comprises one spring, the main body includes at least one longitudinal portion and at least one transverse portion connected to the at least one longitudinal portion in a crossing manner, two ends of each longitudinal portion are respectively connected to one of the end portions, and two ends of each transverse portion are respectively connected to one of the end portions.

13. The piezoelectric speaker according to claim 1, wherein the piezoelectric speaker comprises two or more spring plates, the two or more spring plates are non-crossed and spaced from each other, and the main body of each spring plate is provided with adhesive glue at a middle position of the main body.

14. An electronic device comprising a housing and a loudspeaker arranged in the housing, the loudspeaker separating the interior of the housing into two chambers isolated from each other, characterized in that the loudspeaker is a piezoelectric loudspeaker as claimed in any one of claims 1 to 13.

15. The electronic device of claim 14, wherein the housing defines a sound outlet, the speaker is disposed opposite to the sound outlet, and the sound outlet is connected to one of the two cavities.

16. The electronic device according to claim 14, wherein the adhesive disposed on the main body portion of the resilient piece is fixedly connected to the housing.

17. The electronic device according to claim 14, wherein a structural member is disposed in the housing, and the adhesive disposed on the main body portion of the spring plate is fixedly connected to the structural member.