CN116782107A

CN116782107A - Loudspeaker

Info

Publication number: CN116782107A
Application number: CN202311061687.5A
Authority: CN
Inventors: 侯杰; 王勇臻; 李恩晓; 刘守勇; 张帆
Original assignee: Gettop Acoustic Co Ltd
Current assignee: Gettop Acoustic Co Ltd
Priority date: 2023-08-23
Filing date: 2023-08-23
Publication date: 2023-09-19

Abstract

The application provides a loudspeaker, which comprises a bracket, a high-pitch unit and a low-pitch unit, wherein the high-pitch unit and the low-pitch unit are coaxially arranged on the bracket, and the low-pitch unit comprises a vibration component; the high-pitch unit comprises a piezoelectric film, a connecting pin and a rear cavity; the connecting pin is used for conducting the piezoelectric film and a power supply; the piezoelectric film is fixed on the outer surface of the vibration component, and the rear cavity is formed between the piezoelectric film and the outer surface of the vibration component. The loudspeaker provided by the application has the advantages of small volume, wide audio frequency, no phase difference and the like, can realize and enhance low-frequency diving and high-frequency extension, and improves the comprehensive sound production effect.

Description

Loudspeaker

Technical Field

The application relates to the technical field of sound production devices, in particular to a loudspeaker.

Background

The sound-emitting electronic products such as the Bluetooth earphone, the intelligent glasses and the small-sized sound equipment present gradually to the development of light and small-sized structures, and more functions and better tone quality experience are required to be obtained in a smaller space. The speaker is therefore required to have a surge bass, full midrange and a clear treble.

Most of the conventional speakers focus on the sound effect of the mid-bass section, because the human voice is mainly distributed at the mid-low frequency, which can meet the daily needs of most users. However, the high-frequency sound attenuation of the loudspeaker is very serious, and when the high-frequency sound is played, the loudness is small, the sound is unclear and is not transparent, and the sound characteristics of the high-frequency range, such as the high-frequency sound of a flute, a saxophone, a metal percussion instrument and the like, cannot be completely displayed.

The requirements of the design of the high and low tones are two mutually contradictory directions in various types of loudspeakers. Therefore, in the present, the speaker in the home sound box or in the portable product is only capable of using the multi-unit sound module to give consideration to the sounds of the low, medium and high frequency bands, that is, the sound module has more than two sound units, the medium and low sound speaker gives out bass and medium sound, the high sound speaker gives out high sound, and the two sound units are respectively responsible for the sound of the respective frequency bands so as to realize the best tone enjoyment. For example, there is a coaxial speaker in which a plurality of sound emitting units are combined in a stacked manner in an axial direction, a high pitch unit of the coaxial speaker occupies a high space of a magnetic circuit assembly of a part of a low pitch unit, and a through hole is added in the middle of a magnetic circuit of the low pitch unit in order to leave a vent hole for the high pitch unit, thereby balancing the air pressure of the high pitch unit. Not only is this design bulky, it reduces the magnetic field strength of the bass unit, resulting in a weak loudness of the bass unit. Meanwhile, the high-pitch unit and the low-pitch unit are designed in a coplanar mode, and the high-pitch unit occupies a part of effective radiation area of the low-pitch unit, so that the loudness of the low-pitch unit is weakened. It can be seen that the coaxial speaker, although comprehensively designed with respect to the sound emission effects of the high and low tones, causes deterioration of the sound emission effects of the low tone unit.

Disclosure of Invention

Based on the above, the application provides a loudspeaker to solve the problems of large volume and non-ideal comprehensive sound production effect of the loudspeaker in the prior art.

In order to achieve the above object, the technical solution of the embodiment of the present application is as follows:

the embodiment of the application provides a loudspeaker, which comprises a bracket, a high-pitched unit and a low-pitched unit, wherein the high-pitched unit and the low-pitched unit are coaxially arranged on the bracket, and the low-pitched unit comprises a vibration component; the high-pitch unit comprises a piezoelectric film, a connecting pin and a rear cavity; the connecting pin is used for conducting the piezoelectric film and a power supply; the piezoelectric film is fixed on the outer surface of the vibration component, and the rear cavity is formed between the piezoelectric film and the outer surface of the vibration component.

In one embodiment, the piezoelectric film is provided with a plurality of fixing areas, and the fixing areas are used for being fixedly connected with the vibration assembly, or the fixing areas are used for being provided with reinforcing ribs so that the piezoelectric film forms a plurality of piezoelectric film units.

In one embodiment, the piezoelectric film unit is disposed to protrude outward with respect to the fixing area.

In one embodiment, the piezoelectric film units are symmetrically distributed relative to the center of the piezoelectric film.

In one embodiment, the loudspeaker is a cone-type loudspeaker, the vibration assembly comprises a voice coil, a cone, a folding ring and a dust cap, the voice coil is fixedly connected with the cone, and the folding ring and the dust cap are respectively fixedly connected with the cone; the piezoelectric film is fixed on the outer side face of the dustproof cap, and the rear cavity is formed between the piezoelectric film and the dustproof cap.

In one embodiment, the high-pitched unit further includes a circuit board, two connection pins and two first bonding pads are disposed on the circuit board, each first bonding pad is electrically connected with a corresponding connection pin, and the first bonding pads are used for being connected with a power supply; the circuit board is of a hollowed-out frame structure and comprises a connecting part, wherein the connecting part is fixedly connected with the piezoelectric film, so that a rear cavity is formed between the piezoelectric film and the dustproof cap.

In one embodiment, the speaker is a dome speaker, and the vibration component includes a diaphragm, a voice coil, and a dome; the vibrating diaphragm is of a hollow structure in the middle, and the inner periphery of the vibrating diaphragm is fixedly connected with the dome; the dome is fixedly connected with the voice coil; the dome is fixedly connected with the piezoelectric film, and the rear cavity is formed between the piezoelectric film and the dome.

In one embodiment, the diaphragm is provided with the connection pin and two first bonding pads, the first bonding pads are respectively and electrically connected with the corresponding connection pins, and the first bonding pads are used for being connected with a power supply.

In one embodiment, a convex rib is disposed on a surface of the piezoelectric film facing to one side of the dome, and is fixedly connected with the dome to form the rear cavity between the piezoelectric film and the dome, the thickness of the dome is defined as h1, the thickness of the convex rib is defined as h4, and h1/3 is equal to or less than h4 is equal to or less than 4h1

In one embodiment, the tweeter unit further includes a support frame disposed between the dome and the piezoelectric film such that the rear cavity is formed between the dome and the piezoelectric film; the thickness of the dome is defined as h1, the thickness of the supporting frame is defined as h5, and h1/3 is more than or equal to h5 and less than or equal to 4h1 is required.

In one embodiment, the dome is provided with a flange at a circumferential edge, the piezoelectric film being fixed to the flange such that the rear cavity is formed between the dome and the piezoelectric film; the thickness of the dome is defined as h1, the thickness of the flange is defined as h2, and h1/3 is less than or equal to h2 and less than or equal to 4h1 is required.

In one embodiment, the high-pitched unit further includes a circuit board, two connection pins and two first bonding pads are disposed on the circuit board, each first bonding pad is electrically connected with a corresponding connection pin, and the first bonding pads are used for being connected with a power supply; the circuit board is of a hollowed-out frame structure and comprises a connecting part, and the connecting part is fixedly connected with the piezoelectric film.

In one embodiment, a flange is arranged on the dome, and the flange is arranged corresponding to the connecting part and fixedly connected with the connecting part; the thickness of the dome is defined as h1, the thickness of the flange is defined as h2, the thickness of the connecting part is defined as h6, h2 is required to be more than or equal to 0 and less than or equal to 2h1, and h1/3 is required to be more than or equal to h6 and less than or equal to 2h1.

In one embodiment, the connecting portion is fixed on the dome, the thickness of the dome is defined as h1, the thickness of the connecting portion is defined as h6, and h 1/3.ltoreq.h6.ltoreq.4h1 is required.

The application has at least the following beneficial effects: the high-pitch unit of the loudspeaker is manufactured by adopting the piezoelectric film, the piezoelectric film is fixed on the vibration component of the low-pitch unit, the piezoelectric film has the advantage of small size, the size of the loudspeaker is reduced, meanwhile, the piezoelectric film is arranged on the vibration component, the magnetic circuit space of the low-pitch unit cannot be occupied, the piezoelectric film is also used as a part of the radiation area of the low-pitch unit, the defect that the multi-unit coaxial loudspeaker can sacrifice the frequency response intensity of part of the low-pitch unit is overcome, and the low-frequency diving and high-frequency extension can be realized and enhanced. The loudspeaker provided by the embodiment of the application has the advantages that the high-pitched unit comprises the rear cavity formed by the piezoelectric film and the vibration component, and the rear cavity can avoid the front-rear sound short circuit of the high-pitched unit, so that the sound quality is improved.

Drawings

Fig. 1 is an exploded view of a dome speaker according to an embodiment of the present application.

Fig. 2 is a schematic sectional view of a dome speaker according to an embodiment of the present application.

Fig. 3 is an exploded view of a part of the components of a dome speaker according to an embodiment of the present application.

Fig. 4 is a schematic diagram of various piezoelectric films of a dome speaker according to an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a diaphragm and a bracket (excluding a circuit board) of a dome speaker according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram of a circuit board and a bracket of a dome speaker according to an embodiment of the present application.

Fig. 7 is a schematic structural diagram of a side of a bracket of a dome speaker close to a magnetic circuit assembly according to an embodiment of the present application.

Fig. 8 is a schematic view of the piezoelectric films of fig. 4 in a mode at different stages.

Fig. 9 is a schematic sectional structure diagram (a piezoelectric film projection arrangement) of a dome speaker according to another embodiment of the present application.

Fig. 10 is a schematic perspective view of the dome speaker of fig. 9.

Fig. 11 is a schematic diagram of the magnetic field direction of the magnetic circuit assembly of the dome speaker according to the embodiment of the present application.

Fig. 12 is a schematic diagram showing a vibration pattern of a piezoelectric film of a tweeter unit of a dome speaker according to an embodiment of the present application.

Fig. 13 is a schematic sectional view of a cone-type speaker according to an embodiment of the present application.

Fig. 14 is a schematic structural diagram of a tweeter unit and a vibration assembly of a dome speaker according to an embodiment of the present application.

Fig. 15 is a schematic structural view of a tweeter unit and a vibration assembly of a dome speaker according to another embodiment of the present application.

Fig. 16 is a schematic structural view of a tweeter unit and a vibration assembly of a dome speaker according to still another embodiment of the present application.

Fig. 17 is a schematic structural view of a tweeter unit and a vibration assembly of a dome speaker according to still another embodiment of the present application.

Fig. 18 is a schematic structural view of a tweeter unit and a vibration assembly of a dome speaker according to still another embodiment of the present application.

The meaning of the various reference numerals in the drawings is as follows:

10. a dome speaker;

11. a treble unit; 111. a piezoelectric film; 1111. a piezoelectric film unit; 1112. a fixed zone; 1113. a rounded corner structure; 1114. convex ribs; 112. a circuit board; 1121. a connection pin; 1122. a first bonding pad; 1123. a connection part; 1124. a first rib; 12. a vibration assembly; 121. a vibrating diaphragm; 122. a dome; 1221. a flange; 1222. a second rib; 123. a voice coil; 124. a support frame; 13. a bracket; 131. a second bonding pad; 132. a treble unit contact; 133. a bass unit contact; 14. a magnetic circuit assembly; 141. a pole piece; 142. main magnetic steel; 143. auxiliary magnetic steel; 144. a magnetic shield; 145. a magnetic gap; 15. a rear cavity;

20. cone-basin type loudspeaker;

21. a basin stand; 22. a treble unit; 221. a piezoelectric film; 222. a circuit board; 23. a rear cavity; 24. a bass unit; 241. a vibration assembly; 2411. a folding ring; 2412. a cone basin; 2413. a dust cap; 2414. a skeleton; 2415. a flick wave; 2416. a voice coil; 242. a magnetic circuit assembly; 2421. washer; 2422. a magnet; 2423. a U-shaped cup; 2424. a magnetic gap.

Detailed Description

The technical scheme of the application is further elaborated below by referring to the drawings in the specification and the specific embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the implementations of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the description of the present application, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

The following description will take a dome speaker 10 and a cone speaker 20 as examples, respectively, for the speaker according to the embodiment of the present application.

Example 1: referring to fig. 1 and 2, a dome speaker 10 according to an embodiment of the present application includes a stand 13, and a bass unit and a treble unit 11 disposed on the stand 13.

The bass unit includes a magnetic circuit assembly 14 and a vibration assembly 12. The magnetic circuit assembly 14 includes a magnetic shield 144, a primary magnetic steel 142, a secondary magnetic steel 143, and a pole piece 141. For convenience of explanation, the directions will be described with reference to the directions shown in the drawings. The magnetic shield 144 is arranged at the bottommost part of the magnetic circuit assembly 14, the main magnetic steel 142 and the auxiliary magnetic steel 143 are fixedly adhered to the magnetic shield 144, the main magnetic steel 142 and the auxiliary magnetic steel 143 are arranged at intervals, a magnetic gap 145 is formed at the intervals, and the pole piece 141 is fixedly adhered to the upper surfaces of the main magnetic steel 142 and the auxiliary magnetic steel 143. The magnetic circuit assembly 14 is energized to form magnetic force for driving the vibration assembly 12 to vibrate, thereby producing sound. The vibration assembly 12 includes a voice coil 123, a dome 122, and a diaphragm 121. The lower part of voice coil 123 is located in magnetic gap 145, and the top and the ball top 122 fixed connection of voice coil 123, vibrating diaphragm 121 are middle part hollow out construction, and the outside edge fixed connection of vibrating diaphragm 121 and ball top 122 constitutes vibrating diaphragm subassembly jointly, and vibrating diaphragm 121's outside edge is fixed in on support 13, and support 13's top and vibrating diaphragm 121 fixed connection, bottom and magnet steel fixed connection.

As shown in fig. 3, the high-pitched unit 11 of the present embodiment includes a piezoelectric film 111, connection pins 1121 and a rear cavity 15, wherein upper and lower surfaces of the piezoelectric film 111 are respectively plated with conductive layers, and the upper and lower surfaces thereof are positive and negative electrodes of the piezoelectric film 111, and the connection pins 1121 are respectively electrically connected with the positive and negative electrodes of the piezoelectric film 111. The piezoelectric film 111 serves as a sounding film of the tweeter unit 11, and by applying a voltage to the piezoelectric film 111 under an inverse piezoelectric effect by an alternating current, mechanical stress is generated to deform the piezoelectric film 111, thereby disturbing the piezoelectric film 111 and vibrating to sound. The piezoelectric film 111 has filtering effects of passing high frequency and blocking low frequency, and the capacitance of the piezoelectric film 111 can be changed by adjusting the thickness or the area of the piezoelectric film 111 according to design requirements, so that the frequency division points of the low-frequency unit and the high-frequency unit 11 are changed to optimize the performance, and the high-frequency unit 11 and the low-frequency unit are respectively connected into a circuit to achieve the effects of enhancing the low-frequency diving and the high-frequency extension.

As shown in fig. 4, the piezoelectric film 111 is provided with a plurality of fixing areas 1112, the fixing areas 1112 being used to fix the tweeter unit 11 to the outer surface of the vibration member 12, or the fixing areas 1112 being used to provide reinforcing ribs (not shown) so that the piezoelectric film forms a plurality of piezoelectric film units. The reinforcing ribs can be made of polymer materials such as PET, and the high-frequency segmentation vibration can be reduced by adding the reinforcing ribs. And the fixing region 1112 divides the piezoelectric film 111 into a plurality of piezoelectric film units 1111. The shape and the number of the piezoelectric film units 1111 are not limited, and may be various shapes such as triangle, square, circle, diamond, and the like. To make the weight of the vibration system more uniform, the piezoelectric film units 1111 may be grouped, and each group of piezoelectric film units has the same size and shape, that is, each group of piezoelectric film units 1111 is symmetrically distributed with respect to the center of the piezoelectric film 111. In order to avoid fatigue tearing at the joint of the fixed areas 1112 when the piezoelectric film unit 1111 vibrates, two adjacent fixed areas 1112 can be transited through a fillet structure 1113 to reduce stress concentration at the joint of the fixed areas 1112, and the radius of the fillet is required to be not less than 0.25mm, so that the stress at the included angle can be well dispersed, and fatigue tearing of the piezoelectric film 111 caused by long-time vibration can be prevented. Dome 122 is fixedly coupled to mounting region 1112.

The rear cavity 15 of the high-pitched unit 11 is formed between the inner side of the piezoelectric film 111 and the dome 122, and the rear cavity 15 is provided to avoid deterioration of sound quality caused by a front-rear sound short circuit of the high-pitched unit 11.

The piezoelectric film 111 may be provided with a connection pin 1121 through the circuit board 112 to be electrically connected to an external power source, or may be provided with a connection pin 1121 through the diaphragm 121 to be electrically connected to an external power source.

As shown in fig. 5, when the circuit board 112 is not provided, two connection pins 1121 are respectively provided on the upper surfaces of two adjacent corners on one side of the diaphragm 121, two first pads 1122 are respectively provided on the other surfaces of the two adjacent corners, and the first pads 1122 are respectively electrically connected to the corresponding connection pins 1121. At this time, as shown in fig. 17, a support frame 124 may be added between the edge of the piezoelectric film 111 and the edge of the dome 122 so that a rear cavity 15 is formed between the piezoelectric film 111 and the dome 122. The thickness of dome 122 is defined as h1, the thickness of support frame 124 is defined as h3, and h 1/3.ltoreq.h3.ltoreq.4h1 is required. The supporting frame 124 may be a PCB board, a light metal (such as aluminum), a polymer hard material, etc. Alternatively, as shown in fig. 15 and 16, a flange 1221 may be provided on the dome 122, and the edge of the piezoelectric film 111 may be fixedly connected to the flange 1221, so that a rear cavity 15 is formed between the piezoelectric film 111 and the dome 122, where the thickness of the dome 122 is defined as h1, and the thickness of the flange 1221 is defined as h2, where h1/3 is equal to or less than h2 and equal to or less than 4h1 is required. Alternatively, as shown in FIG. 16, both the flange 1221 and the support frame 124 are provided on the dome 122, defining the thickness h1 of the dome 122, the thickness h2 of the flange 1221, and the thickness h5 of the support frame 124, 0.ltoreq.h2.ltoreq.2h1, and h 1/3.ltoreq.h5.ltoreq.2h1. Alternatively, as shown in FIG. 18, the surface of the piezoelectric film 111 facing the dome 122 is provided with ribs 1114, the ribs 1114 are fixedly connected with the dome 122 to form a rear cavity between the piezoelectric film 111 and the dome 122, the thickness of the dome 122 is defined as h1, the thickness of the ribs 1114 is defined as h4, and h 1/3.ltoreq.h4.ltoreq.4h1 is required.

As shown in fig. 6, when the circuit board 112 is provided, the circuit board 112 is preferably an FPC circuit board, and the circuit board 112 can transmit an input signal to the piezoelectric film 111 as a transmission path of an alternating current signal. The circuit board 112 in this embodiment is a hollow frame structure, and includes a connection portion 1123, and a first rib 1124 disposed in the connection portion 1123 and fixedly connected to the connection portion 1123; the connection portion 1123 and the first rib 1124 are disposed corresponding to the fixing area 1112, respectively, and the fixing area 1112 is fixedly connected to the corresponding connection portion 1123 and first rib 1124, respectively. The connection portion 1123 in the present embodiment is also a connection pin 1121, and the connection portion 1123 is for supporting the piezoelectric film 111, and at the same time, it may be electrically connected to the lower surface of the piezoelectric film 111 by providing a conductive layer, for example, may be thermally connected to the piezoelectric film 111 by conductive silver paste. On opposite sides of the connection portion 1123, one connection pin 1121 is symmetrically provided, respectively, and the connection pin 1121 is electrically connected to the upper surface of the piezoelectric film 111. As shown in fig. 1, the connection portion 1123 and the first rib 1124 of the circuit board 112 are configured corresponding to the structure of the dome 122, the dome 122 includes a flange 1221 and a second rib 1222, and the flange 1221 is configured corresponding to the connection portion 1123 and fixedly connected to the connection portion 1123; the second rib 1222 is disposed corresponding to the first rib 1124 and fixedly connected to the first rib 1124. The two first pads 1122 are electrically connected to the connection pins 1121, respectively. The width of the first rib 1124 is set to be more than 0.25mm, the circuit board 112 is attached to the dome 122, the dome 122 is provided with a second rib 1222 corresponding to the first rib 1124, the second rib 1222 provides support for the piezoelectric film 111, and can effectively reduce the high-level modal split vibration of the piezoelectric film 111, and a rear cavity 15 is formed among the dome 122, the piezoelectric film 111 and the circuit board 112. Defining the thickness of dome 122 as h1, the thickness of flange 1221 as h2, the thickness of connecting portion 1123 as h6, 0.ltoreq.h2.ltoreq.2h1, h 1/3.ltoreq.h6.ltoreq.2h1, this relationship requires that the tweeter unit has an independent rear cavity 15, while guaranteeing the rigidity of dome 122, while avoiding the overall height of the speaker being too high.

When the reinforcing ribs are provided on the fixing area 1112, the circuit board 112 does not need to be provided with the first rib 1124, and the dome 122 does not need to be provided with the second rib 1222. As shown in FIG. 14, dome 122 may be directly fixed to dome 122 without providing flange 1221, and connection portion 1123 of circuit board 112 is defined as having a thickness h1 of dome 122 and a thickness h6 of connection portion 1123, where h 1/3.ltoreq.h6.ltoreq.24h1.

As shown in fig. 7, the brackets 13 are provided with the high pitch unit contacts 132 at positions corresponding to the first pads 1122, and the brackets 13 are provided with the low pitch unit contacts 133 on the other side opposite to the high pitch unit contacts 132. The high pitch unit contact 132 is electrically connected to the first pad 1122, and the low pitch unit contact 133 is electrically connected to the positive and negative electrodes of the low pitch unit. As shown in fig. 6 and 7, the high pitch unit contact 132 and the low pitch unit contact 133 are respectively disposed on the surface of the bracket 13 on the side close to the magnetic circuit assembly 14, and the second pad 131 electrically connected to the high pitch contact may be disposed on the surface of the bracket 13 on the side away from the magnetic circuit assembly 14, and electrically connected to the first pad 1122 via the second pad 131. The signal contact points of the high-pitch unit 11 and the low-pitch unit are all designed on the bracket 13, so that the connection with the whole machine can be facilitated.

The outer edge of the circuit board 112 is fixed on the vibrating diaphragm 121 and is supported on the bracket 13 together with the vibrating diaphragm 121 to form a double suspension system, so that the stability of the vibrating assembly 12 is enhanced.

The piezoelectric film 111 may cover the entire dome 122 or may partially cover the dome 122, and is not limited, and preferably the area of the piezoelectric film 111 is not less than half the projected area of the dome 122, and more preferably the dome 122 is covered. To fully utilize the space of the bass cell dome 122, the high frequency response of the treble cell 11 is highest when the area of the piezoelectric film 111 is the same as the projected area of the bass cell dome 122.

When the piezoelectric film 111 covers the entire dome 122, the vibration mass of the piezoelectric film 111 and the circuit board 112 of the high-pitched unit 11 at this time is M2, which is about 1/15 of the vibration system mass M1 of the low-pitched unit (mainly the sum of the masses of the voice coil 123, the dome 122, and the diaphragm 121).

The sound pressure level (SPL, sound Pressure Level) is obtained by multiplying the ratio of the sound pressure p to be measured to the reference sound pressure p (ref) by 20. Calculating the sound pressure level change of the quality control area after the resonance frequency by a formula:

wherein Δspl represents a change in sound pressure level;

m2 represents the vibration mass of the treble unit, unit: g (g);

m1 represents the vibration mass of the bass unit, unit: gram (g).

The resonant frequency of the loudspeaker is calculated by a formula, and the specific calculation method is as follows:

；

wherein F is _s Representing the resonant frequency of the loudspeaker, unit: kilohertz (KHz);

M _ms representing the mass of the loudspeaker vibration system in units: g (g);

C _ms representing the force of the speaker in units of: millimeter/newton (mm/N).

；

Wherein DeltaF _s A change rate indicating a change in resonance frequency;

representing the resonant frequency of the original woofer in units of: kilohertz (KHz);

the resonance frequency of the piezoelectric coaxial speaker is expressed in units: kilohertz (KHz).

Calculated resonant frequency F _s The change was about 3%. From the above-mentioned deduction, the speaker equipped with the high-pitched unit 11 designed in this way has a very small mass change as compared with the speaker without the high-pitched unit 11, which is almost negligible. For the conventional bass unit, the high-frequency cut-off point is generally 4 KHz-6 KHz, the sound is not transparent and unclear when the high-frequency bass unit plays high-frequency tones, and the loudspeaker added with the high-frequency bass unit 11 can expand the bandwidth to more than 20KHz, and the influence on the low-frequency bass unit can be ignored, so that the loudspeaker can sound in a wide frequency range, has the expanded low-frequency tone, the full midrange and the transparent high-frequency tone, and has better tone quality effect.

The supporting rib structure (the connecting portion 1123, the first rib 1124, the flange 1221 and the second rib 1222) under the piezoelectric film 111 is bonded to the fixing area 1112 of the piezoelectric film 111, and the non-bonded portion (the piezoelectric film unit 1111) of the piezoelectric film 111 can vibrate freely, so that the supporting rib structure can support the piezoelectric film 111 as the main sounding position of the high-pitched unit 11, and can improve the stress and the high-order mode of the vibration of the piezoelectric film 111, and the supporting rib structure is required to be symmetrically arranged about the center of the piezoelectric film 111 so as to ensure the weight uniformity of the vibration system and the balance of the vibration.

The following analysis is now performed on the shape of the piezoelectric film unit 1111:

as shown in fig. 4, the structure of the piezoelectric film 111 is designed according to A, B, C, D in the drawing, and as shown in fig. 8, the first-order mode, the second-order mode, and the third-order mode corresponding to the structure of each piezoelectric film 111 in fig. 4 are shown. As can be seen from an analysis of the mode diagrams of the piezoelectric film 111 in the structures of fig. a, B and C, in this embodiment, the large-area piezoelectric film 111 is divided into a plurality of piezoelectric film units 1111 by a plurality of support structures, each piezoelectric film unit 1111 forms a small vibration area, so that the problem of unbalanced higher-order modes which easily occurs when the area of the piezoelectric film 111 is large is reduced, but the frequencies of the first-order modes and the multiple-order modes are related to the vibration area thereof, the same frequencies are similar, and the shape change of the piezoelectric film is not obvious to the higher-order modes of the piezoelectric film 111, so that the shape of the piezoelectric film 111 with a planar structure is not specified, and can be in various shapes such as square, round, triangle and the like.

As can be seen from an analysis of the modal patterns of the piezoelectric film 111 in fig. C and D, the piezoelectric film unit 1111 in fig. C and D has a similar shape and a different size. Both separate the large-area piezoelectric film 111 into a plurality of small vibration areas, both can disperse the resonance frequency of the whole piezoelectric film 111, so as to reduce the peak-valley size of high-order vibration, make the high-order frequency response curve smoother, and make the effect of the graph D structure with smaller area of the piezoelectric film unit 1111 better.

As shown in fig. 9 and 10, in some embodiments, the piezoelectric film unit 1111 may also be provided to protrude outward with respect to the fixing region 1112. For example, when the cross section of the piezoelectric film unit 1111 is circular, the piezoelectric film unit 1111 is hemispherical convex. The raised piezoelectric film unit 1111 can enhance the structural strength of the piezoelectric film 111, reduce the split vibration of the higher-order modes, make the higher-order frequency response smoother, make the high-tone radiation range emitted by the piezoelectric film 111 larger, make the high-tone audible region wider, and increase the radiation area of the piezoelectric film 111, thereby increasing the sound loudness.

As shown in fig. 11, the magnetic field direction of the magnetic circuit assembly 14 of the dome speaker 10 of the present embodiment is schematically shown, and as shown in fig. 12, the vibration pattern of the piezoelectric film 111 of the tweeter unit 11 of the dome speaker 10 of the present embodiment is schematically shown.

Example 2: as shown in fig. 13, the cone speaker 20 of the embodiment of the present application includes a frame 21 (cradle), a bass unit 24, and a treble unit 22.

The bass unit 24 comprises a magnetic circuit assembly 242 and a vibration assembly 241, wherein the magnetic circuit assembly 242 comprises a U-shaped cup 2423, a magnet 2422 arranged in the U-shaped cup 2423 and a washer 2421 arranged above the magnet 2422, a magnetic gap 2424 is arranged between the magnet 2422 and the inner wall of the U-shaped cup 2423, and the basin stand 21 is fixed on the U-shaped cup 2423. The vibration assembly 241 includes a voice coil 2416, a backbone 2414, a spring 2415, a cone 2412, a collar 2411, and a dust cap 2413. The voice coil 2416 is disposed in the magnetic gap 2424, and the voice coil 2416 is fixedly connected with the frame 2414; one end of the elastic wave 2415 is fixed on the framework 2414, and the other end is fixedly connected with the basin stand 21; one end of the framework 2414 is fixedly connected with the voice coil 2416, the other end of the framework is fixedly connected with the cone basin 2412, the dustproof cap 2413 covers the inner hole of the cone basin 2412, the folding ring 2411 is sleeved outside the cone basin 2412, the inner side edge of the folding ring 2411 is fixedly connected with the cone basin 2412, and the outer side edge of the folding ring 2411 is fixedly connected with the basin frame 21.

The treble unit 22 includes a piezoelectric film 221 and a circuit board 222. The circuit board 222 of the present embodiment is an FPC circuit board. The circuit board 222 is provided with two connection pins and two first bonding pads, and each first bonding pad is electrically connected with a corresponding connection pin. The circuit board 222 is a hollow frame structure, and includes a connection portion, and a first rib disposed in the connection portion and fixedly connected to the connection portion. The piezoelectric film 221 is provided with a plurality of fixing areas, the positions of the fixing areas are correspondingly arranged with the positions of the connecting portions and the first ribs, and the fixing areas are fixedly connected with the corresponding connecting portions and the first ribs respectively. The circuit board 222 is disposed on the surface of the piezoelectric film 221 near the bass unit 24, the circuit board 222 is adhered and fixed on the dust cap 2413, and the rear cavity 23 of the treble unit 22 is formed between the piezoelectric film 221 and the dust cap 2413. Likewise, other forms of the construction of the tweeter 11 in the dome speaker 10 are also applicable to the cone speaker 20.

Similarly, in the cone-type speaker 20, the piezoelectric film 221 unit may be provided in a convex structure to improve the sound quality of the entire speaker.

The high-pitch unit in the embodiment can be used for a dome speaker and a cone-basin speaker, and can also be used for speakers with other structures to form a coaxial speaker so as to improve the sound quality effect of the speaker.

The high-pitch unit of the loudspeaker provided by the embodiment of the application uses a piezoelectric film material, such as a PVDF piezoelectric film, under the effect of inverse piezoelectric, the piezoelectric film vibrates to sound after being connected with alternating current, and meanwhile, the piezoelectric film has the characteristics of light weight, thinness, and the piezoelectric film is used as a sound emitting part of the high-pitch unit and is adhered to the spherical top of the low-pitch unit, so that the assembled loudspeaker with the multi-pitch unit maintains the advantage of small volume of the original single-pitch unit loudspeaker, and meanwhile, the audio frequency is wide and no phase difference exists. Meanwhile, the high-frequency sound can be emitted by the piezoelectric film as the high-frequency unit, and the defect that the coaxial loudspeaker of the multi-tone unit can sacrifice the frequency response intensity of part of the low-tone unit is overcome, so that the enhancement of low-frequency diving and high-frequency extension is truly realized.

The dome speaker of the embodiment of the application uses the piezoelectric film as the high-pitched unit, and is bonded and combined with the dome of the low-pitched unit, so that the characteristics of thinness and thinness of the piezoelectric film are exerted, the vibration quality and the overall thickness of the piezoelectric film are basically similar to those of a speaker only provided with the low-pitched unit, and the volume is hardly increased.

The piezoelectric film is adhered to the dome of the bass unit, so that the space of the magnetic circuit assembly of the bass unit is not occupied, and the loudness of the bass unit is not reduced due to the fact that part of magnetic field intensity is sacrificed.

The piezoelectric film is adhered to the dome of the bass unit, and becomes a part of the radiating area of the bass unit, so that the effective radiating area of the bass unit is not reduced to reduce the loudness of the bass unit. And the sounding positions of the high-pitch unit and the low-pitch unit are positioned on the same surface, so that the high-pitch unit and the low-pitch unit have no phase difference.

The cavity formed by the rib position structure of the ball top and the circuit board and the piezoelectric film is used as a rear cavity of the high-pitch unit, so that the influence on sound quality caused by the short circuit of front and rear sounds of the high-pitch unit is avoided.

The surface of the piezoelectric film is plated with a conductive layer (the partial surfaces or the whole surfaces of the two surfaces of the film are plated with the conductive layer, the conductive layer can be made of nickel or silver and other materials, the thickness can be 1 nm-5000 nm, preferably 100 nm-500 nm), the conductive layer is connected and conducted with a circuit board, and meanwhile, a corresponding bonding pad is arranged on a bracket and is welded with the bonding pad of the circuit board, so that signal contact points of a high-bass unit are all positioned on the bracket, and the effect of convenient connection with a complete machine is achieved.

The loudspeaker provided by the embodiment of the application separates the large-area piezoelectric vibrating diaphragm into a plurality of small vibrating areas, the vibrating areas are symmetrically arranged about the center of the piezoelectric film, the resonant frequency of the piezoelectric film can be dispersed, the concentrated resonance of a high order is reduced, and the high-order frequency response curve is smoother.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A loudspeaker comprises a bracket, a high-pitch unit and a low-pitch unit, wherein the high-pitch unit and the low-pitch unit are coaxially arranged on the bracket, and the low-pitch unit comprises a vibration component; the method is characterized in that: the high-pitch unit comprises a piezoelectric film, a connecting pin and a rear cavity; the connecting pin is used for conducting the piezoelectric film and a power supply; the piezoelectric film is fixed on the outer surface of the vibration component, and the rear cavity is formed between the piezoelectric film and the outer surface of the vibration component.

2. A loudspeaker according to claim 1, wherein: the piezoelectric film is provided with a plurality of fixed areas, the fixed areas are used for being fixedly connected with the vibration component, or the fixed areas are used for being provided with reinforcing ribs so that the piezoelectric film forms a plurality of piezoelectric film units.

3. A loudspeaker according to claim 2, wherein: the piezoelectric film unit is arranged to protrude outwards relative to the fixed area.

4. A loudspeaker according to claim 1, wherein: the piezoelectric film units are symmetrically distributed relative to the center of the piezoelectric film.

5. A loudspeaker according to any one of claims 1 to 4, wherein: the loudspeaker is a cone-basin type loudspeaker, the vibration assembly comprises a voice coil, a cone basin, a folding ring and a dustproof cap, the voice coil is fixedly connected with the cone basin, and the folding ring and the dustproof cap are respectively and fixedly connected with the cone basin; the piezoelectric film is fixed on the outer side face of the dustproof cap, and the rear cavity is formed between the piezoelectric film and the dustproof cap.

6. A loudspeaker according to claim 5, wherein: the high-pitch unit further comprises a circuit board, wherein two connecting pins and two first bonding pads are arranged on the circuit board, each first bonding pad is electrically connected with the corresponding connecting pin, and the first bonding pad is used for being connected with a power supply; the circuit board is of a hollowed-out frame structure and comprises a connecting part, wherein the connecting part is fixedly connected with the piezoelectric film, so that a rear cavity is formed between the piezoelectric film and the dustproof cap.

7. A loudspeaker according to any one of claims 1 to 4, wherein: the loudspeaker is a dome loudspeaker, and the vibration component comprises a vibrating diaphragm, a voice coil and a dome; the vibrating diaphragm is of a hollow structure in the middle, and the inner periphery of the vibrating diaphragm is fixedly connected with the dome; the dome is fixedly connected with the voice coil; the dome is fixedly connected with the piezoelectric film, and the rear cavity is formed between the piezoelectric film and the dome.

8. A loudspeaker according to claim 7, wherein: the surface of the piezoelectric film facing one side of the dome is provided with convex ribs, the convex ribs are fixedly connected with the dome so as to form a rear cavity between the piezoelectric film and the dome, the thickness of the dome is defined as h1, the thickness of the convex ribs is h4, and h1/3 is required to be less than or equal to h4 and less than or equal to 4h1.

9. A loudspeaker according to claim 7, wherein: the high-pitched unit further comprises a supporting frame, wherein the supporting frame is arranged between the dome and the piezoelectric film, so that the rear cavity is formed between the dome and the piezoelectric film; the thickness of the dome is defined as h1, the thickness of the supporting frame is defined as h5, and h1/3 is more than or equal to h5 and less than or equal to 4h1 is required.

10. A loudspeaker according to claim 7, wherein: the ball top is provided with a flange at the circumferential edge, and the piezoelectric film is fixed on the flange, so that the rear cavity is formed between the ball top and the piezoelectric film; the thickness of the dome is defined as h1, the thickness of the flange is defined as h2, and h1/3 is less than or equal to h2 and less than or equal to 4h1 is required.

11. A loudspeaker according to claim 7, wherein: the high-pitch unit further comprises a circuit board, wherein two connecting pins and two first bonding pads are arranged on the circuit board, each first bonding pad is electrically connected with the corresponding connecting pin, and the first bonding pad is used for being connected with a power supply; the circuit board is of a hollowed-out frame structure and comprises a connecting part, and the connecting part is fixedly connected with the piezoelectric film.

12. A loudspeaker according to claim 11, wherein: the top of the ball is provided with a flange which is arranged corresponding to the connecting part and fixedly connected with the connecting part; the thickness of the dome is defined as h1, the thickness of the flange is defined as h2, the thickness of the connecting part is defined as h6, h2 is required to be more than or equal to 0 and less than or equal to 2h1, and h1/3 is required to be more than or equal to h6 and less than or equal to 2h1.

13. A loudspeaker according to claim 11, wherein: the connecting part is fixed on the dome, the thickness of the dome is defined as h1, the thickness of the connecting part is h6, and h1/3 is less than or equal to h6 and less than or equal to 4h1 is required.