Housing and audio terminal

Abstract

The present disclosure relates to a housing and an audio terminal, and belongs to the field of electronic equipment. The housing is used in conjunction with the audio terminal, and the housing is configured to be detachably connected to the audio terminal. The housing includes: a shell, a film speaker; the interior of the shell has a receiving cavity and a sound cavity that are connected, the film speaker is located in the receiving cavity, and the film speaker receives a driving signal emitted by the audio terminal. When the speaker driving circuit in the audio terminal is operating, it can drive the film speaker in the housing to emit sound, giving the housing a speaker function, which is beneficial to improving the sound quality of the audio terminal. Since the housing can be detachably connected to the audio terminal, the disassembly and assembly of the housing is easier and more labor-saving. Once the film speaker is damaged, it can be replaced by a new housing on the audio terminal without affecting the normal use of the audio terminal.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic equipment, and in particular to a housing and an audio terminal. Background Art

[0002] As part of an audio terminal, a speaker converts electronic signals into audio signals, enabling the terminal to produce sound. Currently, audio terminals such as mobile phones are becoming increasingly thinner and lighter, but the requirements for sound quality in mobile phones are becoming increasingly higher.

[0003] In the related art, in order to obtain better sound quality within a limited volume, a piezoelectric ceramic sheet is usually attached to the inner surface of the back shell of the mobile phone to drive the back shell of the mobile phone to vibrate and make sound, so that the back shell of the mobile phone has a speaker function.

[0004] In the process of implementing the present disclosure, the inventors discovered that there are at least the following problems in the related art:

[0005] Piezoelectric ceramic pieces are prone to breakage and failure when subjected to external impact, and the back cover of a mobile phone is difficult or even impossible to disassemble. Once the piezoelectric ceramic piece breaks and fails, it not only affects the use of the audio terminal, but also makes the replacement of the piezoelectric ceramic piece very inconvenient and difficult. Summary of the Invention

[0006] In order to overcome the problems existing in the related art, the present disclosure provides a housing and an audio terminal.

[0007] Specifically, the following technical solutions are included:

[0008] According to a first aspect of an embodiment of the present disclosure, there is provided a housing, which is used in conjunction with an audio terminal, and is configured to be detachably connected to the audio terminal;

[0009] The housing comprises: a shell and a film speaker;

[0010] The interior of the shell has a communicating accommodation cavity and a sound cavity. The film speaker is located in the accommodation cavity and receives a driving signal sent by the audio terminal.

[0011] In some possible implementations, the housing includes: a face wall and a side wall;

[0012] The accommodating cavity and the sound cavity are both located inside the face wall, the side wall is located at the periphery of the face wall, and the face wall and the side wall enclose and form a mounting cavity;

[0013] The installation cavity is used to accommodate the audio terminal.

[0014] In some possible implementations, the front wall and / or the side wall has an attachment made of an elastic material;

[0015] When the shell is assembled with the audio terminal, the attachment is tightly fitted with the shell of the audio terminal.

[0016] In some possible implementations, the shell is made of elastic polymer material.

[0017] In some possible implementations, the thin film speaker is a single-layer membrane structure, and the thin film speaker is obtained by weaving a filamentous piezoelectric conductive composite material into a membrane;

[0018] The piezoelectric conductive composite material includes: a core layer, an intermediate layer and an outer layer sequentially coated from the inside to the outside, the core layer and the outer layer are both made of conductive materials, and the intermediate layer is made of PVDF piezoelectric material and / or P (VDF-TrFE) piezoelectric material.

[0019] In some possible implementations, the filamentous piezoelectric conductive composite material is obtained by spinning using a three-layer coaxial spinning head.

[0020] In some possible implementations, the film speaker is a multi-layer film structure, and the film speaker includes: a piezoelectric film, a first conductive film, a second conductive film, a first insulating film, and a second insulating film;

[0021] The first conductive film is located on the first surface of the piezoelectric film;

[0022] The second conductive film is located on the second surface of the piezoelectric film;

[0023] The first insulating film is located on the first conductive film;

[0024] The second insulating film is located on the second conductive film;

[0025] The first surface and the second surface are opposite to each other, and the second surface faces the sound cavity.

[0026] In some possible implementations, the film speaker is divided into at least two areas, the first area is a first type of film speaker, and the second area is a second type of film speaker;

[0027] The first type of thin film loudspeaker is a single-layer membrane structure, and the first type of thin film loudspeaker is obtained by weaving a filamentous piezoelectric conductive composite material into a membrane;

[0028] The piezoelectric conductive composite material comprises: a core layer, an intermediate layer and an outer layer sequentially coated from the inside to the outside, the core layer and the outer layer are both made of conductive materials, and the intermediate layer is made of polymer piezoelectric material;

[0029] The second type of film speaker includes: a first conductive film, a piezoelectric film and a second conductive film stacked in sequence.

[0030] In some possible implementations, the driving signal is transmitted via wireless transmission;

[0031] The housing further includes a communication module, which is used to transmit the driving signal after establishing a connection with the audio terminal.

[0032] For example, the communication module includes: a receiving coil, the receiving coil is located in the accommodating cavity, and the receiving coil is connected to the film speaker;

[0033] The audio terminal has a built-in speaker driving circuit and a transmitting coil connected thereto, and the transmitting coil communicates wirelessly with the wireless charging receiving coil.

[0034] In some possible implementations, the driving signal is transmitted via a wired transmission method;

[0035] The housing further comprises: a connecting member connected to the film speaker;

[0036] The connecting member is also used to connect to the speaker driving circuit built into the audio terminal.

[0037] According to a second aspect of an embodiment of the present disclosure, an audio terminal is provided, on which the above-mentioned housing is detachably mounted.

[0038] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0039] The housing provided in the embodiments of the present disclosure can be used in conjunction with an audio terminal. When the housing is assembled on the audio terminal, the thin film speaker in the housing can be driven by the speaker driving circuit in the audio terminal. Thus, when the speaker driving circuit in the audio terminal is operating, the thin film speaker receives the driving signal emitted by the audio terminal, which can drive the thin film speaker in the housing to produce sound, giving the housing a speaker function, thereby improving the sound quality of the audio terminal. Because the housing can be detachably connected to the audio terminal, the housing can be easily and labor-savingly disassembled and assembled. Thus, if the thin film speaker is damaged, it can be replaced by a new housing on the audio terminal without affecting the normal use of the audio terminal.

[0040] Since the volume of the shell is not limited by the development of lightweight audio terminals, the volume of the shell can be as large as possible. At the same time, since only one device, a thin film speaker, is set in the shell, the size of the thin film speaker can also be as large as possible. Any of the above factors is conducive to obtaining richer low-frequency sound waves, thereby achieving the purpose of improving sound quality.

[0041] In addition, the housing provided in the embodiment of the present disclosure can not only be used as an external speaker, but also can be used as a protective shell for the audio terminal.

[0042] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0044] Figure 1 The figure is a schematic diagram showing the assembly relationship between a housing and an audio terminal according to an exemplary embodiment.

[0045] Figure 2 is a schematic diagram of a cross-sectional structure of a housing according to an exemplary embodiment, wherein: Figure 2 The arrangement of the housing from an empty state to an assembled state is shown, and connecting elements in the form of electrical interfaces are used as an example.

[0046] Figure 3 The figure is a combined schematic diagram of a front structure and a back structure of a housing according to an exemplary embodiment.

[0047] Figure 4 is a cross-sectional view of a piezoelectric conductive composite material according to an exemplary embodiment.

[0048] Figure 5 is a cross-sectional view of a thin film speaker having a multi-layer membrane structure according to an exemplary embodiment.

[0049] Figure 6 is a cross-sectional view of another thin film loudspeaker having a multi-layer membrane structure according to an exemplary embodiment.

[0050] Figure 7 is a cross-sectional view of a thin film speaker having a multilayer piezoelectric film according to an exemplary embodiment.

[0051] Figure 8 FIG. 1 is a schematic diagram showing a case having multiple film speakers according to an exemplary embodiment.

[0052] Figure 9 The present invention is a block diagram showing the wireless transmission relationship between a thin film speaker in a housing and a speaker driving circuit in an audio terminal according to an exemplary embodiment.

[0053] Figure 10The present invention is a block diagram showing the Bluetooth transmission relationship between a thin film speaker in a housing and a speaker driving circuit in an audio terminal according to an exemplary embodiment.

[0054] Figure 11 The present invention is a block diagram showing the Bluetooth transmission relationship between a thin film speaker in a housing and a mainboard in an audio terminal according to an exemplary embodiment.

[0055] Figure 12 The present invention is a block diagram showing the wired transmission relationship between a thin film speaker in a housing and a speaker driving circuit in an audio terminal according to an exemplary embodiment.

[0056] in, Figure 1-Figure 3 In the examples, a mobile phone is used as an audio terminal.

[0057] The reference numerals represent:

[0058] 100-housing,

[0059] 1- Shell,

[0060] 101-accommodation cavity, 102-sound cavity,

[0061] 11-face wall, 12-side wall, 13-installation cavity, 14-card strip,

[0062] 2-film speaker, 201-first type of film speaker, 202-second type of film speaker,

[0063] 21-piezoelectric conductive composite material, 211-core layer, 212-middle layer, 213-outer layer,

[0064] 22-piezoelectric film, 23-first conductive film, 24-second conductive film,

[0065] 25-first insulating film, 26-second insulating film,

[0066] 3a-communication module, 3b-connector,

[0067] 31- Wireless charging receiving coil,

[0068] 32-first Bluetooth receiver, 33-power amplifier circuit, 34-battery,

[0069] 35-first electrical interface,

[0070] 200-Audio Terminal,

[0071] 2001-Speaker driver circuit,

[0072] 2002-Motherboard,

[0073] 2003-Wireless charging transmitting coil,

[0074] 2004-Second Bluetooth Receiver,

[0075] 2005-Second electrical interface. DETAILED DESCRIPTION

[0076] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0077] An audio terminal is a device that produces sound through a speaker. It has internal audio circuitry, including a microphone and speaker. The microphone collects sound waves from the user and the environment, converting them into electrical signals that are fed into a processor for processing or into a radio frequency circuit for voice communication. The speaker converts the electrical signals from the processor or radio frequency circuit into sound waves, or audio signals.

[0078] As users' demands for audio quality in audio terminals gradually increase, larger audio terminals, such as stereos, typically achieve better sound quality by improving the structure of their internal speakers, for example, by increasing the speaker size. However, for smaller audio terminals, such as mobile phones, tablets, and smartwatches, the trend toward thinner and lighter audio terminals makes improving speakers within these limited sizes increasingly difficult.

[0079] To achieve superior sound quality within the limited footprint of increasingly lightweight audio terminals, piezoelectric ceramic chips are typically attached to the inner surface of the rear housing to drive the rear housing to vibrate and generate sound, thus providing a speaker function. However, piezoelectric ceramic chips are susceptible to shattering and failure when subjected to external forces. Furthermore, disassembling the rear housing of an audio terminal can be difficult, if not impossible. Once a piezoelectric ceramic chip shatters and fails, it not only affects the use of the audio terminal but also makes replacement extremely inconvenient and difficult.

[0080] Figure 1 1 is a schematic diagram showing an assembly relationship between a housing 100 and an audio terminal 200 according to an exemplary embodiment. The embodiment of the present disclosure provides a housing 100, as shown in FIG. Figure 1 As shown, the housing 100 is used in conjunction with the audio terminal 200 , that is, the housing 100 is assembled on the audio terminal 200 during use, and the housing 100 is configured to be detachably connected to the audio terminal 200 .

[0081] Figure 2 is a schematic cross-sectional structure diagram of a housing 100 according to an exemplary embodiment, wherein: Figure 2 The connector 3 in the form of an electrical interface is used as an example, as shown in the attached Figure 2 As shown, the housing 100 includes: a shell 1 and a film speaker 2; the interior of the shell 1 has a connected accommodating cavity 101 and a sound cavity 102, the film speaker 2 is located in the accommodating cavity 101, and the film speaker 2 receives a driving signal emitted by the audio terminal 200.

[0082] Among them, as attached Figure 2 As shown, the interior of the shell 1 has a cavity, which is divided into two parts. The first part is the accommodating cavity 101, which is used to accommodate the film speaker 2. The second part is the sound cavity 102, which is used to provide an operating space for the film speaker 2 to facilitate vibration and sound production.

[0083] In some examples, the accommodating cavity 101 and the sound cavity 102 are parallel to each other and connected, and both extend along the surface of the audio terminal 200, where the surface of the audio terminal 200 refers to its front or back, not its side wall. For example, the audio terminal 200 is a mobile phone, and the surface of the mobile phone refers to the front where the display screen is located or the back where the back shell is located.

[0084] In some possible examples, the sound cavity 102 is an air cavity, that is, it contains only air and no other components. In the disclosed embodiment, the sound cavity 102 can be closer to the audio terminal 200 relative to the accommodating cavity 101. The thickness of the sound cavity 102 can be 0.05mm-0.2mm, for example, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, etc.

[0085] The housing 100 provided in the embodiment of the present disclosure can be used in conjunction with an audio terminal 200. When the housing 100 is assembled on the audio terminal 200, the thin film speaker 2 in the housing 100 can receive a driving signal from the speaker driving circuit 2001 in the audio terminal 200. Thus, when the speaker driving circuit 2001 in the audio terminal 200 is in operation, it can drive the thin film speaker 2 in the housing 100 to produce sound, giving the housing 100 a speaker function, thereby improving the sound quality of the audio terminal 200. Because the housing 100 can be detachably connected to the audio terminal 200, the housing 100 can be easily and labor-savingly assembled and disassembled. Thus, if the thin film speaker 2 is damaged, it can be replaced by a new housing 100 on the audio terminal 200 without affecting the normal use of the audio terminal 200.

[0086] Since the volume of the housing 100 is not limited by the lightweight development of the audio terminal 200, the volume of the housing 100 can be as large as possible. At the same time, since only one device, the film speaker 2, is provided in the housing 100, the size of the film speaker 2 can also be as large as possible. Any of the above factors is conducive to obtaining more powerful low-frequency sound waves, thereby achieving the purpose of improving sound quality.

[0087] In addition, the housing 100 provided in the embodiment of the present disclosure can not only be used as an external speaker, but also can be used as a protective shell for the audio terminal 200 .

[0088] In the disclosed embodiment, the detachable connection methods between the housing 1 and the audio terminal 200 include, but are not limited to, snap-on connection, plug-in connection, snap-on connection, threaded connection, magnetic connection, etc. The specific connection method between the housing 1 and the audio terminal 200 can be determined based on the specific type of the audio terminal 200, the assembly position of the housing 1 on the audio terminal 200, the material of the housing 1, etc.

[0089] The snap-fitting structure required by the snap-fitting method is simple and easy to implement. In the embodiment of the present disclosure, the snap-fitting method can be used to detachably connect the housing 1 and the audio terminal 200.

[0090] The structure of the housing 1 can be adaptively designed according to the structure of the audio terminal 200 to be used. For example, when the audio terminal 200 is a mobile phone, the housing 1 can be designed as a rectangular shell that matches the structure of the mobile phone.

[0091] Figure 3 FIG1 is a schematic diagram showing the front and back structural combination of a mobile phone housing 100 according to an exemplary embodiment. Figure 3 As shown, in some possible implementations, the shell 1 includes: a face wall 11 and a side wall 12, wherein the accommodating cavity 101 and the sound cavity 102 are both located inside the face wall 11, and the side wall 12 is located at the periphery of the face wall 11, and the face wall 11 and the side wall 12 are arranged to form an installation cavity 13.

[0092] The front wall 11 of the housing 1 is a wall parallel to and opposite to the surface of the audio terminal 200, and the side wall 12 of the housing 1 is a wall parallel to and opposite to the side of the audio terminal 200. The side wall 12 surrounds the front wall 11, and the side wall 12 and the side wall 12 cooperate to form a mounting cavity 13 for accommodating the audio terminal 200.

[0093] For example, when the audio terminal 200 is a mobile phone, the shell 1 includes: a rectangular face wall 11 and four side walls 12. The four side walls 12 are connected in sequence to form a cavity with openings at both ends, and the same end of the four side walls 12 is simultaneously connected to the face wall 11. In this way, the face wall 11 blocks the opening at one end of the cavity to form a rectangular installation cavity 13 that is compatible with the outer contour structure of the mobile phone.

[0094] After the housing 100 is assembled on the audio terminal 200, the side walls 12 of the housing 1 cover the sides of the audio terminal 200, and the front wall 11 of the housing 1 covers the back of the audio terminal 200. The front side of the audio terminal 200, opposite the back side, is exposed outside the housing 100 as a user operation area, facilitating user operation of the audio terminal 200. Thus, the housing 100 provided in the embodiment of the present disclosure can not only be used as an external speaker, but also serve as a protective shell for the audio terminal 200, providing protection for the audio terminal 200.

[0095] In the embodiment of the present disclosure, the installation cavity 13 is used to accommodate the audio terminal 200, and the audio terminal 200 can be detachably installed in the installation cavity 13. The detachable connection methods between the audio terminal 200 and the shell 1 include but are not limited to the following: snap connection, plug-in connection, buckle connection, threaded connection, magnetic connection, etc.

[0096] Take the card connection method as an example, Figure 1 As shown, a clip 14 can be provided at the end of the side wall 12 away from the face wall 11. An angle is formed between the clip 14 and the side wall 12, for example, an angle of 80°-90°. The clip 14 is the same length as the side wall 12 of the housing 100, and the clip 14 is wide enough to reach the connection between the surface and the side of the audio terminal 200. In this way, the clip 14 can be adaptively clipped to the connection between the surface and the side of the audio terminal 200. Because a small groove is generally formed at the connection between the surface and the side of the audio terminal 200, utilizing this groove as a clipping groove for the clip 14 not only achieves effective and stable clipping but also helps simplify the structure of the housing 100.

[0097] In some possible implementations, the front wall 11 and / or the side wall 12 has an attachment made of an elastic material; when the housing 100 and the audio terminal 200 are assembled, the attachment fits tightly against the housing of the audio terminal 200 .

[0098] For example, the attachment is located at the edge of the face wall 11 and / or the side wall 12. The attachment can be designed as a suction cup to increase the adsorption force between it and the audio terminal 200, thereby enabling the shell to form a sealed cavity with the audio terminal 200, which is beneficial to improving the sound effect.

[0099] In order to improve the snap-fitting strength of the housing 100 , the housing 1 can be made of an elastic material. Thus, the housing 1 itself also has a certain elasticity, and its own elastic force can further improve the snap-fitting strength between the housing 100 and the audio terminal 200 .

[0100] In some possible implementations, the shell 1 involved in the embodiment of the present disclosure is made of elastic polymer materials, such as elastic plastic, silicone, rubber, etc., in particular, it can be thermoplastic polyurethane elastomer rubber, which not only has a certain elasticity, but also has many advantages such as a wide hardness range (60HA-85HD), wear resistance, and oil resistance.

[0101] When housing 1 is made of an elastic polymer material, it can be formed in one piece using a mold, simplifying the manufacturing process of housing 1. Furthermore, the elastic polymer material has insulating properties, thus providing good insulation from thin film speaker 2, ensuring a safe operating environment for thin film speaker 2.

[0102] The above is an exemplary description of the structure and assembly and disassembly of the housing 1. The following is an exemplary description of the structure of the film speaker 2:

[0103] In some possible implementations, the film loudspeaker 2 provided by the embodiment of the present disclosure is a single-layer membrane structure, and the film loudspeaker 2 is obtained by weaving a filamentous piezoelectric conductive composite material 21 into a membrane.

[0104] Figure 4 FIG is a cross-sectional view of a piezoelectric conductive composite material 21 according to an exemplary embodiment. Figure 4 As shown, the piezoelectric conductive composite material 21 includes: a core layer 211, an intermediate layer 212 and an outer layer 213 sequentially coated from the inside to the outside, the core layer 211 and the outer layer 213 are both made of conductive materials, and the intermediate layer 212 is made of polymer piezoelectric materials, such as PVDF piezoelectric materials and / or P (VDF-TrFE) piezoelectric materials.

[0105] The single-layer membrane structure of the film loudspeaker 2 is always in a tensioned state (i.e., stretched state), providing a certain preload force to facilitate effective vibration when driven. For example, the connection between the film loudspeaker 2 and the housing 1 can be secured by bonding or hot melt adhesive to maintain the tensioned state.

[0106] In the embodiment of the present disclosure, the middle layer 212 is prepared by polymer piezoelectric materials, which are generally divided into the following types: one is a strong dielectric polymer piezoelectric material, such as polyvinylidene fluoride (PVDF for short), vinylidene fluoride-trifluoroethylene copolymer (P(VDF-TrFE) for short), etc.; another is a polarized polymer piezoelectric material, such as nylon polyvinyl fluoride, polyvinyl chloride, polyurea, etc.; and another is a polylactic acid-based polymer piezoelectric material.

[0107] Since PVDF and P(VDF-TrFE) have good piezoelectric properties, relatively low acoustic impedance (softness), good impact resistance, and easy film formation, the polymer piezoelectric material involved in the embodiments of the present disclosure may be PVDF and / or P(VDF-TrFE).

[0108] PVDF and P(VDF-TrFE), ferroelectric polymers, have excellent piezoelectricity. The piezoelectric constant d 31 The film formed from PVDF and P(VDF-TrFE) is stretched to orient the polymer chains in the stretching direction. Then, different charges are imparted to the front and back of the film through corona discharge or other methods. This generates an electric field perpendicular to the film surface, aligning the permanent dipoles containing fluorine located in the polymer chain side chains parallel to the direction of the electric field, thus imparting piezoelectricity.

[0109] In particular, PVDF has the highest piezoelectricity among the aforementioned polymer piezoelectric materials, and PVDF also has a good conversion efficiency from electricity to sound. Therefore, the embodiments of the present disclosure may use PVDF polymer piezoelectric material.

[0110] For example, the diameter of the filamentary piezoelectric conductive composite material 21 can be less than or equal to 150 μm, further, less than or equal to 100 microns, further, less than or equal to 80 microns, etc., wherein, for the core layer 211 and the outer layer 213 as the conductive layer, the diameter of the core layer 211 and the radial thickness of the outer layer 213 can be the same, and the thickness of the intermediate layer 212 as the piezoelectric layer is determined based on the actual piezoelectric performance. It is desirable to maximize the piezoelectric performance while ensuring conductivity. For example, the diameter of the core layer 211 and the radial thickness of the outer layer 213 can be, for example, 20 microns to 40 microns, and the radial thickness of the intermediate layer 212 serves as a margin.

[0111] A weaving process is used to weave the filamentary piezoelectric conductive composite material 21 to form a complete single-membrane structure of the film loudspeaker 2 (which can also be understood as a structure similar to cloth). Because the specific weaving method used in the weaving process may affect the piezoelectric performance of the film loudspeaker 2, the specific weaving method can be determined based on the actual piezoelectric performance. For example, weaving methods include but are not limited to: plain weave, twill weave, dense weave, mat-type twill weave, double-filament Dutch weave, five-harness weave, etc.

[0112] The weaving process of the filamentary piezoelectric conductive composite material 21 can be performed using a loom, for example, a circular loom or a flat loom.

[0113] The embodiment of the present disclosure obtains a thin film loudspeaker 2 by weaving a filamentous piezoelectric conductive composite material 21 into a membrane, which has at least the following advantages: (1) the woven membrane has stronger elasticity and is softer, which is conducive to increasing the vibration amplitude, thereby obtaining better sound quality and stronger volume; (2) the woven membrane has stronger strength, making it more impact-resistant and less prone to damage, which is conducive to increasing the service life of the thin film loudspeaker 2; (3) the woven membrane also has good dust and water resistance, which is further conducive to increasing the service life of the thin film loudspeaker 2 and maintaining a good sound effect.

[0114] In some possible implementations, the filamentary piezoelectric conductive composite material 21 involved in the embodiments of the present disclosure is prepared by a spinning process, in particular, by spinning using a three-layer coaxial spinning head.

[0115] The three-layer coaxial spinning head, also known as the three-layer coaxial spinning needle or the three-layer coaxial spinning nozzle, can use the three-axis coaxial injection technology to compound three materials together to form a concentric structure of micro-nano-scale filamentous composite materials.

[0116] Before spinning, the conductive material and the polymer piezoelectric material need to be melted first to form a core layer 211 melt, a middle layer 212 melt and an outer layer 213 melt. These three are placed in corresponding syringes respectively, and then these three syringes are respectively installed in three syringes, so that these three melts are connected to the coaxial spinning head. Spinning is carried out under the set spinning process conditions to prepare a filamentous piezoelectric conductive composite material 21.

[0117] Both the core layer 211 and the outer layer 213 are made of conductive materials. Metallic conductive materials with greater ductility are more suitable for spinning. For example, such conductive materials include, but are not limited to, silver, aluminum, iron, copper, and their alloys, or a combination thereof. These conductive materials not only generate an effective electric field but also have excellent sound transmission properties, eliminating sound obstruction and facilitating sound transmission.

[0118] In some examples, silver may be used because silver has better conductivity, which helps to obtain a more uniform electric field.

[0119] In some possible implementations, the film speaker 2 provided in the embodiment of the present disclosure is a multi-layer film structure. Figure 5 FIG is a cross-sectional view of a thin film loudspeaker 2 having a multi-layer membrane structure according to an exemplary embodiment. Figure 5As shown, the film speaker 2 includes a piezoelectric film 22, a first conductive film 23, and a second conductive film 24. The first conductive film 23 is located on the first surface of the piezoelectric film 22, that is, the first conductive film 23 covers the first surface of the piezoelectric film 22, for example, covering at least 80% of its area. The second conductive film 24 is located on the second surface of the piezoelectric film 22, that is, the second conductive film 24 covers the second surface of the piezoelectric film 22, for example, covering at least 80% of its area. The first surface and the second surface are opposite each other, and the second surface faces the sound cavity 102.

[0120] Similarly, the above-mentioned multi-layer membrane structure film loudspeaker 2, specifically the piezoelectric film 22 thereof is always in a tensioned state (ie stretched state), so that it has a certain pre-tightening force so that it can effectively vibrate when driven.

[0121] For example, the thickness of the piezoelectric film 22 is 20um-80um, for example, 20um, 30um, 40um, 50um, 60um, 70um, 80um, etc.;

[0122] The thickness of the first conductive film 23 and the second conductive film 24 are both in the nanometer range, for example, 80 nm to 120 nm, such as 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 111 nm, etc.

[0123] The piezoelectric film 22 is a film made of a piezoelectric material having piezoelectric properties. The piezoelectric materials used include but are not limited to: piezoelectric ceramics, polymer piezoelectric materials. For example, the polymer piezoelectric materials include but are not limited to the following: polyvinylidene fluoride (abbreviated as PVDF), vinylidene fluoride-trifluoroethylene copolymer (abbreviated as P(VDF-TrFE)), nylon 11, polyvinyl fluoride, polyvinyl chloride, polyurea, polylactic acid-based polymer piezoelectric materials, etc.

[0124] Since PVDF and P (VDF-TrFE) have good piezoelectric properties, relatively low acoustic impedance (softness), good impact resistance, and easy film formation, the embodiments of the present disclosure can use PVDF or P (VDF-TrFE) to prepare the piezoelectric film 22.

[0125] The first conductive film 23 and the second conductive film 24 are made of conductive materials. For example, the conductive film can be made of metal materials, such as one or a combination of copper (Cu), silver (Ag), iron (Fe), aluminum (Al), chromium (Cr), nickel (Ni), titanium (Ti), etc., or the conductive film can be made of metal oxide materials, such as one or a combination of titanium nitride (TiN), tin oxide (SnO2), indium oxide (In2O3), zinc oxide (ZnO), indium tin oxide (ITO), etc.

[0126] The first conductive film 23 and the second conductive film 24 can be formed on both surfaces of the piezoelectric film 22 by evaporation, sputtering, deposition, electroplating, chemical plating or coating, and the conductive films substantially cover most areas of the first and second surfaces of the piezoelectric film 22.

[0127] It is not excluded that the first conductive film 23 and the second conductive film 24 may also be fixed on the two surfaces of the piezoelectric film 22 by resin gluing.

[0128] When in use, the film speaker 2 is connected to the speaker driving circuit 2001 in the audio terminal 200 through the connector 3. Specifically, the connector 3 transmits the driving current from the speaker driving circuit 2001 to the first conductive film 23 and the second conductive film 24. The conductive film forms an electric field to cause the piezoelectric film 22 to vibrate and make it make sound, thereby giving the housing 100 the speaker function.

[0129] Figure 6 FIG is a cross-sectional view of another thin film loudspeaker 2 having a multi-layer membrane structure according to an exemplary embodiment. Figure 6 As shown, in some possible implementations, the film speaker 2 provided by the embodiment of the present disclosure further includes: a first insulating film 25 and a second insulating film 26 , the first insulating film 25 is located on the first conductive film 23 , and the second insulating film 26 is located on the second conductive film 24 .

[0130] For example, the first insulating film 25 covers the entire area of ​​the first conductive film 23. For example, the thickness of the first insulating film 25 is 8 micrometers to 15 micrometers, such as 10 micrometers, 11 micrometers, 12 micrometers, 13 micrometers, 14 micrometers, etc.

[0131] The first insulating film 25 is made of insulating material, such as rubber, plastic, etc. Furthermore, the first insulating film 25 can be made elastic, or have a porous structure, so that the first insulating film 25 has a certain buffering property to avoid hindering the vibration of the piezoelectric film 22.

[0132] Since the first conductive film 23 faces the inner wall of the shell 1, in order to prevent the two from scratching or rubbing each other, or to prevent the shell 100 from forming a leakage area on the first conductive film 23 when it is subjected to external impact, the first insulating film 25 is used to provide protection for the first conductive film 23.

[0133] For example, the thickness of the second insulating film 26 is 8 micrometers to 15 micrometers, for example, 10 micrometers, 11 micrometers, 12 micrometers, 13 micrometers, 14 micrometers, etc.

[0134] The composition and function of the second insulating film 26 refer to the first insulating film 25 . This configuration can further optimize the above-mentioned effect.

[0135] In some examples, the piezoelectric film 22 is provided as only one layer. Figure 7 FIG is a cross-sectional view of a thin film speaker 2 having a multilayer piezoelectric film 22 according to an exemplary embodiment. Figure 7 As shown, in other examples, the piezoelectric film 22 can be configured as multiple layers connected in series, for example, 2 to 10 layers, with a conductive film layer located between two adjacent layers of piezoelectric film 22, i.e., both layers share a common conductive film layer. For example, this conductive film can be the first conductive film 23 described above. When the piezoelectric film 22 is configured as multiple layers, the required driving voltage is lower than that of a single layer of piezoelectric film 22, while still achieving the same vibration effect.

[0136] In some possible implementations, such as the attached Figure 8 As shown, the film speaker 2 is divided into at least two areas, the first area is the first type of film speaker 201, and the second area is the second type of film speaker 202. For example, the first area is located in the middle position, and the second area is located at the periphery of the first area.

[0137] As attached Figure 4 As shown, the first type of thin film speaker 201 is a single-layer membrane structure. The first type of thin film speaker 201 is obtained by weaving a filamentous piezoelectric conductive composite material 21 into a membrane; the piezoelectric conductive composite material 21 includes: a core layer 211, an intermediate layer 212 and an outer layer 213 sequentially wrapped from the inside to the outside, the core layer 211 and the outer layer 213 are both made of conductive materials, and the intermediate layer 212 is made of polymer piezoelectric material.

[0138] That is to say, the first type of thin film loudspeaker 201 can refer to the thin film loudspeaker 2 with a single-layer membrane structure shown above.

[0139] As attached Figure 6As shown, the second type of film speaker 202 includes: a first conductive film 23, a piezoelectric film 22 and a second conductive film 24 stacked in sequence. Further, it can also include a first insulating film 25 and a second insulating film 26. The first insulating film 25 is located on the first conductive film 23, and the second insulating film 26 is located on the second conductive film 24.

[0140] That is to say, the second type of thin film speaker 202 can refer to the thin film speaker 2 with a multi-layer membrane structure shown above.

[0141] By arranging a plurality of film speakers 2 in the housing 100 and making the types of the plurality of film speakers 2 different, for example, the second type of film speakers 202 are located in a small area, and the first type of film speakers 201 are located in a large area, in this way, a plurality of types of film speakers 2 are combined to obtain different sound effects. For example, when a smaller sound is required, only the second type of film speakers 202 can be used, and when a larger sound is required, the first type of film speakers 201 and the second type of film speakers 202 can be used in combination.

[0142] In the embodiment of the present disclosure, the signal transmission between the film speaker 2 and the speaker driving circuit 2001 of the audio terminal 200 can be wireless transmission or wired transmission. The connection methods of the two are respectively described as follows:

[0143] In some possible implementations, such as the attached Figure 9 As shown, the driving signal is transmitted via wireless transmission; the housing 100 further includes: a communication module 3a, which is used to transmit the driving signal after establishing a connection with the audio terminal 200. This includes but is not limited to the following: (1) the communication module 3a and the speaker driving circuit 2001 use a wireless charging method to transmit the driving signal; (2) the communication module 3a and the speaker driving circuit 2001 use a Bluetooth transmission method to transmit the driving signal.

[0144] Figure 9 This is a block diagram showing a film speaker 2 in a housing 100 and a speaker driving circuit 2001 in an audio terminal 200 when wireless charging is used for transmission according to an exemplary embodiment. Figure 9 As shown, the communication module 3 a includes: a receiving coil 31 , which is located in the accommodating cavity 101 and connected to the film speaker 2 .

[0145] The audio terminal 200 has a built-in speaker driving circuit 2001 and a transmitting coil 2003 connected thereto. The transmitting coil 2003 communicates wirelessly with the receiving coil 31 .

[0146] For example, the receiving coil 31 is a wireless charging receiving coil, and the transmitting coil 2003 is a wireless charging transmitting coil adapted thereto.

[0147] The receiving coil 31 can be fixed on the inner wall of the shell 1, or fixed on the insulating film of the film speaker 2, or clamped between the inner wall of the shell 1 and the insulating film of the film speaker 2.

[0148] The receiving coil 31 has two connection ends, which are connected to the film speaker 2. For example, when the film speaker 2 is the above-mentioned woven single-layer membrane structure, the two connection ends are respectively connected to the conductive layers where the core layer 211 and the outer layer 213 are located; when the film speaker 2 is the above-mentioned multi-layer membrane structure, the two connection ends are respectively electrically connected to the first conductive film 23 and the second conductive film 24.

[0149] The built-in transmitting coil 2003 of the audio terminal 200 is common in the art and will not be described in detail in the present embodiment. Specifically, the transmitting coil 2003 in the audio terminal 200 and the receiving coil 31 in the housing 100 can perform wireless communication.

[0150] This wireless charging connection utilizes wireless communication between the transmitting coil 2003 and the receiving coil 31. Driven by the speaker driver circuit 2001 of the audio terminal 200, the transmitting coil 2003 converts the audio signal into an alternating magnetic field, which the receiving coil 31 then converts into an audio signal. The audio signal then drives the piezoelectric film 22 into bending vibrations, which in turn compresses the air and converts it into audible sound. This wireless charging connection utilizes a relatively small footprint for all components, facilitating a compact housing 100.

[0151] The variation of the induced electromotive force, that is, the magnitude of the magnetic field, can be represented by the following formula (1). By adjusting the number of turns of the coil, the magnitude of the magnetic field can be adjusted accordingly, thereby adjusting the vibration amplitude of the piezoelectric film 22.

[0152] e(t) = -n(dΦ) / (dt) (1);

[0153] Where e(t) is the change in induced electromotive force, n is the number of turns in the coil, dΦ is the change in magnetic flux, and dt is the time it takes for the change to occur.

[0154] Figure 10 This is a block diagram showing a film speaker 2 in a housing 100 and a speaker driving circuit 2001 in an audio terminal 200 for signal transmission via Bluetooth transmission according to an exemplary embodiment. Figure 10As shown, the communication module 3a includes: a Bluetooth receiver (referred to as the first Bluetooth receiver 32), a power amplifier circuit 33, and a battery 4, wherein the battery 4 is used to power the power amplifier circuit 33, and the battery 4 can be an ultra-thin flexible battery 4; the power amplifier circuit 33 is electrically connected to the first Bluetooth receiver 32 and the thin film speaker 2 at the same time, wherein, when the thin film speaker 2 is the above-mentioned woven single-layer membrane structure, the power amplifier circuit 33 is electrically connected to the conductive layer where the core layer 211 and the outer layer 213 are located; when the thin film speaker 2 is the above-mentioned multi-layer membrane structure, the power amplifier circuit 33 is electrically connected to the first conductive film 23 and the second conductive film 24.

[0155] Correspondingly, the audio terminal 200 has a Bluetooth receiver (referred to as the second Bluetooth receiver 2004) that is compatible with the first Bluetooth receiver 32 in the shell 100. The first Bluetooth receiver 32 and the second Bluetooth receiver 2004 can be paired, so that the speaker driving circuit 2001 on the audio terminal 200 and the film speaker 2 in the shell 100 can be connected through the Bluetooth protocol.

[0156] In the embodiment of the present disclosure, the second Bluetooth receiver 2004 in the audio terminal 200 can be connected to the speaker driving circuit 2001 therein, so that when the speaker in the audio terminal 200 is operating, the film speaker 2 in the housing 100 will perform corresponding sound operations.

[0157] Figure 11 1 is a block diagram showing a Bluetooth connection relationship between a film speaker 2 in a housing 100 and a mainboard 2002 in an audio terminal 200 according to an exemplary embodiment. Figure 11 As shown, the second Bluetooth receiver 2004 in the audio terminal 200 can also be connected to the control motherboard 2002 of the audio terminal 200. In this way, when the audio terminal 200 plays the audio data stored in itself, the film speaker 2 in the housing 100 will perform the corresponding sound operation.

[0158] In this example, the communication module 3 a can be fixed on the inner wall of the housing 1 , inside the accommodating cavity 101 , or on the insulating film of the film speaker 2 .

[0159] The above is an exemplary description of the wireless transmission mode of signal transmission between the communication module 3a and the speaker driving circuit 2001. The following is an exemplary description of the wired transmission mode of signal transmission between the connector 3 and the speaker driving circuit 2001.

[0160] Figure 12 FIG. 1 is a block diagram showing a wired connection relationship between a thin film speaker 2 in a housing 100 and a speaker driving circuit 2001 in an audio terminal 200 according to an exemplary embodiment. Figure 1 and attached Figure 12As shown, the housing 100 further includes: a connecting member 3b, which is connected to the film speaker 2; the connecting member 3b is also used to connect to the speaker driving circuit 2001 built into the audio terminal 200.

[0161] There is a wired connection between the connector 3b and the speaker driving circuit 2001. There are various types of wired connection methods. For example, the connector 3b is an electrical interface (referred to as the first electrical interface 35), and the first electrical interface 35 is electrically connected to the film speaker 2. When the film speaker 2 is the above-mentioned woven single-layer membrane structure, the first electrical interface 35 can be electrically connected to the conductive layer where the core layer 211 and the outer layer 213 are located through a wire; when the film speaker 2 is the above-mentioned multi-layer membrane structure, the electrical interface can be electrically connected to the first conductive film 23 and the second conductive film 24 through a wire.

[0162] Correspondingly, the audio terminal 200 has another electrical interface (hereinafter referred to as the second electrical interface 2005) that is compatible with the first electrical interface 35 and connected to the speaker driving circuit 2001. One of the first electrical interface 35 on the housing 100 and the second electrical interface 2005 on the audio terminal 200 is a male interface, and the other is a female interface, and the two can be adapted and plugged together.

[0163] When the connector 3 b is an electrical interface, the position of the connector 3 b in the housing 100 needs to be determined according to the position of the electrical interface on the audio terminal 200 , so that the connector 3 b can be adaptively inserted into the electrical interface on the audio terminal 200 .

[0164] For example, when the audio terminal 200 is a mobile phone, the electrical interface connected to the speaker driving circuit 2001 is generally located on the bottom wall of the audio terminal 200. Accordingly, the connecting member 3b is also located on the bottom of the housing 1 (i.e., on the side wall 12 at the bottom).

[0165] For example, connector 3b includes an electrical interface body and two terminals electrically connected to the electrical interface body, which are used to connect to film speaker 2. The terminals can be flexible circuit boards or cables. When film speaker 2 has the aforementioned woven single-layer membrane structure, the two terminals are electrically connected to the conductive layers of core layer 211 and outer layer 213, respectively. When film speaker 2 has the aforementioned multi-layer membrane structure, the two terminals are electrically connected to first conductive film 23 and second conductive film 24, respectively.

[0166] For example, the electrical interface includes but is not limited to: Type-A interface, Type-B interface, Type-C interface, etc. Since the Type-C interface has a much smaller volume than the Type-A interface and the Type-B interface, it is beneficial to the miniaturization of the shell 100, and accordingly, it is also beneficial to the miniaturization of the audio terminal 200. Therefore, the electrical interface used in the embodiment of the present disclosure can be a Type-C interface.

[0167] In a wired connection mode, the speaker driving circuit 2001 transmits the audio signal to the film speaker 2 through an electrical interface, for example, to the piezoelectric film 22 for bending vibration. The vibrating piezoelectric film 22 compresses the air and converts it into audible sound.

[0168] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present disclosure, and will not be described in detail here.

[0169] Figure 1 is a schematic diagram showing an assembly relationship between a housing 100 and an audio terminal 200 according to an exemplary embodiment, referring to Figure 1 The embodiment of the present disclosure further provides an audio terminal 200 on which the housing 100 described above is detachably mounted.

[0170] When the housing 100 is assembled on the audio terminal 200, the film speaker 2 in the housing 100 is connected to the speaker driving circuit 2001 in the audio terminal 200 through the connector 3. In this way, when the speaker driving circuit 2001 in the audio terminal 200 is in operation, it can drive the film speaker 2 in the housing 100 to emit sound, giving the housing 100 a speaker function, thereby helping to improve the sound quality of the audio terminal 200. Since the housing 100 can be detachably connected to the audio terminal 200, the disassembly and assembly of the housing 100 is easier and more labor-saving. In this way, once the film speaker 2 is damaged, it can be replaced by a new housing 100 on the audio terminal 200, and the normal use of the audio terminal 200 will not be affected. In addition, the housing 100 provided in the embodiment of the present disclosure can be used not only as an external speaker, but also as a protective shell for the audio terminal 200.

[0171] For example, the audio terminal 200 involved in the embodiments of the present disclosure includes but is not limited to: mobile phones, tablet computers, phone watches, reading machines, MP3 players (Moving Picture Experts Group Audio Layer III, Moving Picture Experts Group Audio Layer 3), MP4 (Moving Picture Experts Group Audio Layer IV, Moving Picture Experts Group Audio Layer 4) players, laptop computers, etc.

[0172] In the embodiments of the present disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0173] The term "and / or" in the embodiments of the present disclosure is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0174] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0175] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A housing, characterized in that: The housing (100) is used in conjunction with an audio terminal (200), and the housing (100) is configured to be detachably connected to the audio terminal (200); The housing (100) comprises: a shell (1), a thin film speaker (2); The housing (1) has a communicating accommodation cavity (101) and a sound cavity (102) inside, the film speaker (2) is located in the accommodation cavity (101), the sound cavity (102) is used to provide an operating space for the film speaker (2), and the film speaker (2) receives a driving signal sent by an audio terminal (200); The film loudspeaker (2) is divided into at least two areas, the first area being a first-type film loudspeaker (201), and the second area being a second-type film loudspeaker (202); the first area is located in the middle, and the second area is located at the periphery of the first area; The first type of thin film loudspeaker (201) is a single-layer membrane structure, and the first type of thin film loudspeaker (201) is obtained by weaving a filamentary piezoelectric conductive composite material (21) into a membrane; the filamentary piezoelectric conductive composite material (21) is obtained by spinning using a three-layer coaxial spinning head; the piezoelectric conductive composite material (21) comprises: a core layer (211), an intermediate layer (212), and an outer layer (213) sequentially coated from the inside to the outside, the core layer (211) and the outer layer (213) both using conductive materials, and the intermediate layer (212) using PVDF piezoelectric material and / or P (VDF-TrFE) piezoelectric material; The second type of film loudspeaker (202) comprises: a first conductive film (23), a piezoelectric film (22), a second conductive film (24), a first insulating film (25), and a second insulating film (26) stacked in sequence; The first conductive film (23) is located on the first surface of the piezoelectric film (22); The second conductive film (24) is located on the second surface of the piezoelectric film (22); The first insulating film (25) is located on the first conductive film (23); The second insulating film (26) is located on the second conductive film (24); wherein the first surface and the second surface are opposite to each other, and the second surface faces the sound cavity (102); The driving signal is transmitted via wireless transmission; The housing (100) further comprises: a communication module (3a), the communication module (3a) being used to establish a connection with the audio terminal (200) and transmit the driving signal; The communication module (3a) comprises: a receiving coil (31), the receiving coil (31) is located in the accommodating cavity (101), and the receiving coil (31) is connected to the thin film speaker (2); The audio terminal (200) is built with a speaker driving circuit (2001) and a transmitting coil (2003) connected to each other. The transmitting coil (2003) communicates wirelessly with the receiving coil (31). The receiving coil (31) is a wireless charging receiving coil, and the transmitting coil (2003) is a wireless charging transmitting coil adapted thereto. Under the driving action of the speaker driving circuit (2001) of the audio terminal (200), the transmitting coil (2003) converts the audio signal into an alternating magnetic field, and the receiving coil (31) can convert the alternating magnetic field into an audio signal. The audio signal drives the piezoelectric film (22) to perform bending vibration, and the vibrating film compresses air and converts it into audible sound.

2. The housing according to claim 1, wherein The housing (1) comprises: a face wall (11) and a side wall (12); The accommodating cavity (101) and the sound cavity (102) are both located inside the face wall (11), the side wall (12) is located at the periphery of the face wall (11), and the face wall (11) and the side wall (12) are surrounded to form a mounting cavity (13); The installation cavity (13) is used to accommodate the audio terminal (200).

3. The housing according to claim 2, wherein: The face wall (11) and / or the side wall (12) are provided with attachments, and the attachments are made of elastic material; When the housing (100) and the audio terminal (200) are assembled, the attachment is tightly fitted to the housing of the audio terminal (200).

4. The housing according to claim 2, wherein: The shell (1) is made of elastic polymer material.

5. The housing according to any one of claims 1 to 4, characterized in that: The driving signal is transmitted via wireless transmission; The housing (100) further comprises: a communication module (3a), wherein the communication module (3a) is used to transmit the driving signal after establishing a connection with the audio terminal (200).

6. The housing according to any one of claims 1 to 4, characterized in that: The driving signal is transmitted via wired transmission; The housing (100) further comprises: a connecting member (3b), wherein the connecting member (3b) is connected to the thin film speaker (2); The connecting member (3b) is also used to connect to a speaker driving circuit (2001) built into the audio terminal (200).

7. An audio terminal, characterized in that: The housing (100) according to any one of claims 1 to 6 is detachably mounted on the audio terminal (200).

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