Piezoelectric drive module and electronic device

Abstract

The application relates to a piezoelectric driver, a piezoelectric driving module and electronic equipment. The piezoelectric driver comprises a piezoelectric body and a friction layer. At least part of the piezoelectric body can be deformed by applying a voltage. The friction layer is arranged on the piezoelectric body and used to contact a driven part. The surface friction coefficient of the friction layer is greater than that of the piezoelectric body, and the hardness of the friction layer is greater than that of the piezoelectric body. The piezoelectric driver meets the requirements of friction driving and wear resistance, is beneficial to the compression of the volume of the piezoelectric driver, and is beneficial to the miniaturization design of the piezoelectric driver.

Description

Technical Field

[0001] This application relates to the field of piezoelectric drive technology, and in particular to a piezoelectric drive module and electronic device. Background Technology

[0002] A piezoelectric motor is a piezoelectric device that utilizes the inverse piezoelectric effect (the inverse piezoelectric effect refers to the mechanical deformation of a piezoelectric material when an electric field is applied along its polarization direction, and the deformation disappears when the electric field is removed) to excite a piezoelectric actuator (i.e., the stator) to vibrate at a specific frequency. Through friction, this vibration is converted into macroscopic linear or rotational motion of the mover. Traditional piezoelectric motors, in order to ensure that the micro-vibrations generated by the actuator act on the mover, typically require a larger space for the actuator, hindering miniaturization design. Summary of the Invention

[0003] This application provides a piezoelectric actuator, a piezoelectric drive module, and an electronic device to reduce the space occupied by the piezoelectric actuator.

[0004] A piezoelectric actuator, comprising:

[0005] A piezoelectric body, at least a portion of which can be subjected to a voltage to produce deformation motion; and,

[0006] A friction layer is disposed on the piezoelectric body and is used to contact the driven component. The surface friction coefficient of the friction layer is greater than that of the piezoelectric body, and the hardness of the friction layer is greater than that of the piezoelectric body.

[0007] A piezoelectric drive module includes a carrier, a driven component, and a piezoelectric actuator as described above. The piezoelectric actuator is disposed on the carrier, and the side of the friction layer of the piezoelectric actuator facing away from the piezoelectric body contacts the driven component.

[0008] In one embodiment, the piezoelectric drive module is a piezoelectric motor, the driven component is a mover, and the driven component is movably connected to the carrier.

[0009] In one embodiment, the piezoelectric drive module is a camera module, the driven component is a lens or image sensor, and the driven component is disposed on the carrier.

[0010] An electronic device includes a piezoelectric drive module as described in any of the above embodiments.

[0011] The aforementioned piezoelectric actuator has a friction layer on the piezoelectric body that contacts the driven component. When the piezoelectric body is subjected to voltage and deforms, the friction between the friction layer and the driven component drives the component to move. The surface friction coefficient of the friction layer is greater than that of the piezoelectric body, and the hardness of the friction layer is greater than that of the piezoelectric body, thus meeting the requirements for friction-driven operation and wear resistance. Furthermore, by utilizing the layered structure on the piezoelectric body for friction-driven operation, the piezoelectric actuator eliminates the need for protruding structures such as friction heads, which helps reduce the size of the actuator and facilitates miniaturization. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of a piezoelectric actuator provided in some embodiments of this application.

[0014] Figure 2 for Figure 1 An exploded view of the piezoelectric actuator shown.

[0015] Figure 3 This is a schematic diagram of a piezoelectric body provided in some embodiments of this application.

[0016] Figure 4 for Figure 3 The diagram shows a polarization mode of a piezoelectric body.

[0017] Figure 5 for Figure 3 A schematic diagram of another polarization mode of the piezoelectric body shown.

[0018] Figure 6 for Figure 3 A schematic diagram of another polarization mode of the piezoelectric body shown.

[0019] Figure 7 for Figure 3 A schematic diagram of another polarization mode of the piezoelectric body shown.

[0020] Figure 8 This is an exploded view of the piezoelectric body layer stack provided in some embodiments of this application.

[0021] Figure 9 This is a schematic diagram of the structure of the first grounding layer provided for some embodiments of this application.

[0022] Figure 10 This is a schematic diagram of the structure of the second grounding layer provided in some embodiments of this application.

[0023] Figure 11 This is a diagram showing the relative positions of the first external electrode, the second external electrode, and the third external electrode provided in some embodiments of this application.

[0024] Figure 12 Another relative positional relationship diagram of the first external electrode, the second external electrode, and the third external electrode provided for some embodiments of this application.

[0025] Figure 13 This is a schematic diagram of a piezoelectric body provided for other embodiments of this application.

[0026] Figure 14 This is a schematic diagram of a piezoelectric body provided for some embodiments of this application.

[0027] Figure 15 This is a schematic diagram of a piezoelectric body provided for some embodiments of this application.

[0028] Figure 16 for Figure 15 A simplified schematic diagram illustrating the polarization mode.

[0029] Figure 17 This is a schematic diagram of a piezoelectric body provided for some embodiments of this application.

[0030] Figure 18 for Figure 17 A simplified schematic diagram illustrating the polarization mode.

[0031] Figure 19 This is a schematic diagram of a piezoelectric body provided in another embodiment of this application.

[0032] Figure 20 for Figure 19 A simplified schematic diagram illustrating the polarization mode.

[0033] Figure 21 This is a schematic diagram of a piezoelectric body provided in another embodiment of this application.

[0034] Figure 22 for Figure 21 A simplified schematic diagram illustrating the polarization mode.

[0035] Figure 23 This is a schematic diagram of a piezoelectric drive module provided in an embodiment of this application.

[0036] Figure 24 This is a schematic diagram of a piezoelectric drive module provided for other embodiments of this application.

[0037] Figure 25 for Figure 23 A schematic diagram of the piezoelectric drive module from another angle.

[0038] Figure 26 for Figure 24 An exploded view of the piezoelectric drive module shown.

[0039] Figure 27 for Figure 24 The diagram shows a cross-sectional view of the piezoelectric drive module.

[0040] Figure 28 A schematic diagram of a piezoelectric drive module provided in some embodiments of this application.

[0041] Figure 29 This is a schematic diagram of a piezoelectric drive module provided in some embodiments of this application.

[0042] Figure 30 This is a schematic diagram of a piezoelectric drive module provided in some embodiments of this application.

[0043] Figure 31 A schematic diagram of an electronic device provided for some embodiments of this application. Detailed Implementation

[0044] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0045] As used herein, "electronic device" refers to, but is not limited to, a device capable of receiving and / or transmitting communication signals connected via any one or more of the following connection methods:

[0046] (1) Via wired connection, such as via Public Switched Telephone Networks (PSTN), Digital Subscriber Line (DSL), digital cable, or direct cable connection;

[0047] (2) Via wireless interface, such as cellular network, wireless local area network (WLAN), digital television network such as DVB-H network, satellite network, AM-FM broadcast transmitter.

[0048] An electronic device configured to communicate via a wireless interface can be referred to as a "mobile terminal". Examples of mobile terminals include, but are not limited to, the following electronic devices:

[0049] (1) Satellite phone or cellular phone;

[0050] (2) A Personal Communications System (PCS) terminal that can combine cellular radio telephone with data processing, fax and data communication capabilities;

[0051] (3) Radio telephone, pager, Internet / intranet access, web browser, notepad, calendar, personal digital assistant (PDA) equipped with a Global Positioning System (GPS) receiver;

[0052] (4) Conventional above-knee and / or palm-sized receivers;

[0053] (5) Conventional knee-mounted and / or handheld wireless telephone transceivers, etc.

[0054] Please refer to Figure 1 This application provides a piezoelectric actuator 100, which can also be referred to as a stacked piezoelectric actuator, piezoelectric actuator, stator, etc. The piezoelectric actuator 100 is used to generate high-frequency micro-amplitude vibrations to convert its own microscopic motion into the macroscopic motion of the driven component 202. The motion type of the piezoelectric actuator 100 can be, but is not limited to, elliptical motion, oblique motion, etc. In this application, the motion type of the piezoelectric actuator 100 is collectively referred to as deformation motion, and elliptical motion will be used as an example in the following description.

[0055] To facilitate subsequent explanations and understanding of the accompanying drawings, Figure 1 The viewpoint shown defines an XYZ Cartesian coordinate system. The X-axis is parallel to the length direction of the piezoelectric actuator 100, the Y-axis is parallel to the width direction of the piezoelectric actuator 100, and the Z-axis is parallel to the height direction of the piezoelectric actuator 100. Please refer to this location for a further description of the XYZ coordinate system.

[0056] The piezoelectric actuator 100 includes a stacked piezoelectric element 20 and a friction layer 24 disposed on the stacked piezoelectric element 20. At least a portion of the stacked piezoelectric element 20 can be subjected to a voltage to generate deformation motion. The function of the stacked piezoelectric element 20 is to generate high-frequency micro-amplitude vibrations, thereby driving the friction layer 24 to deform. The friction layer 24 is used to interact with the driven element 202 (shown in...). Figure 23 The friction layer 24 is used to directly or indirectly drive the driven component 202 through friction, either by contact with the friction structure on the driven component 202 or by contact with the friction structure on the driven component 202, so as to convert the micro motion of the stacked piezoelectric component 20 into the macro motion of the driven component 202 and ensure reliability.

[0057] Please refer to Figure 1 and Figure 2 In some embodiments, the stacked piezoelectric element 20 is a stacked structure, comprising a piezoelectric body 23, a first protective layer 21, and a second protective layer 22. The materials of the first protective layer 21 and the second protective layer 22 may be, but are not limited to, piezoelectric materials. The first protective layer 21 and the second protective layer 22 are respectively disposed on opposite sides of the piezoelectric body 23 along a first preset direction (Z-axis direction), that is, the first protective layer 21, the piezoelectric body 23, and the second protective layer 22 are stacked together in sequence. At least a portion of the piezoelectric body 23 can be subjected to voltage to generate deformation movement, thereby driving the first protective layer 21, the second protective layer 22, and the friction layer 24 to deform and move. The first protective layer 21 and the second protective layer 22 can protect the circuit in the piezoelectric body 23 and isolate signals, so that the piezoelectric body 23 can work normally.

[0058] It should be noted that when the laminated piezoelectric component 20 is provided with a first protective layer 21 and a second protective layer 22, the friction layer 24 can be formed on or provided on the side of the first protective layer 21 facing away from the piezoelectric body 23, or it can be connected to the piezoelectric body 23. The first protective layer 21 and the second protective layer 22 in the laminated piezoelectric component 20 can also be omitted, in which case the friction layer 24 is connected to the piezoelectric body 23, which is not limited here.

[0059] The surface friction coefficient of the friction layer 24 is greater than that of the piezoelectric body 23, and the hardness of the friction layer 24 is greater than that of the piezoelectric body 23.

[0060] The piezoelectric actuator 100 described above has a friction layer 24 on the piezoelectric body 23 that contacts the driven component 202. When the piezoelectric body 23 is subjected to voltage and deforms, the friction between the friction layer 24 and the driven component 202 drives the driven component 202 to move. The surface friction coefficient of the friction layer 24 is greater than that of the piezoelectric body 23, and the hardness of the friction layer 24 is greater than that of the piezoelectric body 23, which meets the requirements for friction-driven operation and wear resistance. Furthermore, by using the layer structure on the piezoelectric body 23 to drive the driven component 202 through friction, the piezoelectric actuator 100 does not need to have protruding structures such as a friction head. The dimension of the friction layer 24 in the thickness direction (Z-axis direction) is much smaller than that of protruding structures such as a friction head, which helps to reduce the volume of the piezoelectric actuator 100 and thus facilitates its miniaturization design.

[0061] In some embodiments, the friction layer 24 is formed by a hardening process. For example, the friction layer 24 is formed by hardening the outermost layer of the piezoelectric body 23, or the friction layer 24 is formed by hardening the layer of the first protective layer 21 away from the piezoelectric body 23. This is equivalent to hardening a portion of the layer structure of the laminated piezoelectric element 20 to form the friction layer 24, ensuring that the friction layer 24 does not increase the thickness of the laminated piezoelectric element 20. In other words, the overall thickness of the laminated piezoelectric element 20 and the friction layer 24 is comparable to the thickness of the laminated piezoelectric element in a conventional piezoelectric actuator with a friction head, eliminating the space occupied by the friction head in the thickness direction. This effectively reduces the overall thickness of the piezoelectric actuator 100 while providing the friction layer 24. The hardening processes involved in this application include, but are not limited to, carburizing, nitriding, or metallizing, as long as the friction layer 24 formed by the hardening process meets the requirements for surface friction coefficient and hardness, and can convert deformation motion into motion of the driven element 202 through friction.

[0062] In other embodiments, the friction layer 24 is a surface coating disposed on the stacked piezoelectric element 20, such as a surface coating disposed on the piezoelectric body 23, or a surface coating disposed on the side of the first protective layer 21 facing away from the piezoelectric body 23. Exemplarily, the friction layer 24 includes, but is not limited to, a metal film layer, a ceramic film layer, or a polymer material layer (polytetrafluoroethylene, hard rubber, etc.). Specifically, the friction layer 24 can be a metal film layer prepared by processes such as physical vapor deposition (PVD), chemical vapor deposition (CVD), electroplating, electroless plating, screen printing, etc.; or a ceramic film layer prepared by processes such as sol-gel method, CVD, atomic layer deposition (ALD), plasma spraying, etc.; or a polymer material layer prepared by processes such as spin coating, spraying, CVD, hot pressing, etc. It can be seen that when the friction layer 24 is a surface coating, the thickness of the friction layer 24 is much smaller than the thickness of traditional friction heads and other structures, which also helps to reduce the overall volume of the piezoelectric actuator 100.

[0063] In some embodiments, the friction layer 24 is laid flat on one surface of the piezoelectric body 23, that is, the projection of the friction layer 24 onto the piezoelectric body 23 covers one surface of the piezoelectric body 23 in the Z-axis direction. The friction layer 24 can be laid flat on the piezoelectric body 23 directly or indirectly. For example, when the stacked piezoelectric element 20 is provided with a first protective layer 21 and a second protective layer 22, the friction layer 24 can be provided on the first protective layer 21, that is, indirectly laid flat on the piezoelectric body 23. When the stacked piezoelectric element 20 is not provided with a first protective layer 21, the friction layer 24 can also be directly provided on the piezoelectric body 23.

[0064] The shape of the friction layer 24 is not limited. When the friction layer 24 is laid flat on the piezoelectric body 23, the piezoelectric body 23 can be roughly rectangular, and the friction layer 24 can be a square extending along the XY plane. Of course, the projection of the friction layer 24 on the piezoelectric body 23 can also only cover a part of a surface of the piezoelectric body 23 in the Z-axis direction. In this case, the cross-section of the friction layer 24 can be any applicable shape, including but not limited to a circle or a square.

[0065] refer to Figure 1 and Figure 2 As shown, in some embodiments, the friction layer 24 has a periodically arranged texture or a non-periodic texture 241 on the side facing away from the piezoelectric body 23. The texture or texture 241 can cover the entire surface of the friction layer 24 on the side facing away from the piezoelectric body 23. The texture on the friction layer 24 includes, but is not limited to, columnar structures, corrugated structures, mesh structures, or spiral structures. The texture 241 on the friction layer 24 includes, but is not limited to, random granular structures, irregular grooves, random textures 241, or protrusions of different shapes. The texture or texture 241 on the friction layer 24 comes into contact with the driven member 202, which helps to increase the contact area between the friction layer 24 and the driven member 202, enhances the friction performance between the friction layer 24 and the driven member 202, and thus helps to improve the driving performance of the piezoelectric actuator 100 on the driven member 202.

[0066] In some embodiments, in addition to meeting the requirements of surface friction coefficient and hardness, the surface of the friction layer 24 facing away from the piezoelectric body 23 can also be lubricated, for example, by providing a medium such as a lubricant on the friction layer 24 to reduce the noise and debris generated during the friction between the friction layer 24 and the driven component 202. The texture and pattern 241 also help to capture and retain the medium such as the lubricant, thus extending the service life of the piezoelectric actuator 100.

[0067] The specific configuration of the piezoelectric body 23 is not limited, as long as it can generate deformation movement so that the friction layer 24 can drive the driven member 202 to move by means of the friction between the driven members 202. Please refer to... Figure 3 and Figure 4 In some embodiments, the piezoelectric body 23 includes: a first external electrode 231, a second external electrode 232, a third external electrode 233, a first ground layer 234, a second ground layer 235, a signal layer 236, and a plurality of piezoelectric layers 237. Here, the "first external electrode 231, second external electrode 232, and third external electrode 233" are defined as external electrodes, and the "first ground layer 234, second ground layer 235, and signal layer 236" are defined as internal electrodes. Subsequent descriptions involving internal and external electrodes will refer to this document.

[0068] Multiple piezoelectric layers 237 (the number of piezoelectric layers 237 is greater than or equal to 2) are arranged sequentially at intervals along the Z-axis. Each piezoelectric layer 237 has two opposing first surfaces 2371 and a bend connected to the first surfaces 2371 (see...). Figure 4 The second surface 2372 (see) Figure 3 The relative directions of the two first surfaces 2371 are parallel to the Z-axis direction.

[0069] The piezoelectric layer 237 is a piezoelectric material. The material of the piezoelectric layer 237 can be lead zirconate titanate (PZT) based piezoelectric ceramics, potassium sodium niobate (KNN) based piezoelectric ceramics, barium titanate (BT) based piezoelectric ceramics, lead magnesium niobate-lead indium niobate (PMN-PT) based piezoelectric single crystals, textured ceramics, etc.

[0070] Piezoelectric materials have no polarization direction in their initial state; polarization only occurs under specific conditions. When pressure or an electric field is applied, the positive and negative charges in the piezoelectric material rearrange themselves, resulting in different polarities at the top and bottom ends of the material. This process is called the polarization of the piezoelectric material.

[0071] The piezoelectric layer 237 can be a rectangular sheet, meaning that the projection shape of the piezoelectric layer 237 onto the XY plane can be rectangular. In other embodiments, the projection shape of the piezoelectric layer 237 onto the XY plane can also be circular, elliptical, irregular, etc. This application only uses a rectangle as an example.

[0072] The number of the first ground layer 234, the second ground layer 235, and the signal layer 236 in the Z-axis direction is greater than or equal to one, and the first ground layer 234, the second ground layer 235, and the signal layer 236 are arranged at intervals in the Z-axis direction. The first ground layer 234, the second ground layer 235, and the signal layer 236 are respectively connected to different first surfaces 2371, so that the electrodes on opposite sides of the same piezoelectric layer 237 are the signal layer 236 and the first ground layer 234, or the electrodes on opposite sides of the same piezoelectric layer 237 are the signal layer 236 and the second ground layer 235.

[0073] The signal layer 236 is mainly used to load AC drive signals during the operation of the piezoelectric actuator 100. The first ground layer 234 and the second ground layer 235 are used for grounding and loading AC drive signals during the operation of the piezoelectric actuator 100. The drive signal can be a square wave, sine wave, sawtooth wave, or other waveforms. The three internal electrodes—the first ground layer 234, the second ground layer 235, and the signal layer 236—can be made of conductive metal or a thin metal layer. The internal electrodes can be tightly bonded to the piezoelectric layer 237 by printing, plating, or other methods. For example, the signal layer 236 can be formed on the first surface 2371 by screen printing conductive silver paste or conductive adhesive.

[0074] If the electrodes on opposite sides of the piezoelectric layer 237 are a signal layer 236 and a first ground layer 234, respectively, the signal layer 236 and the first ground layer 234 are used to form a first electric field. That is, the signal layer 236 and the first ground layer 234 determine the distribution of the first electric field in the piezoelectric layer 237 located between them. The first electric field is used to polarize the piezoelectric layer 237 or drive the piezoelectric layer 237 to vibrate. If the electrodes on opposite sides of the piezoelectric layer 237 are a signal layer 236 and a second ground layer 235, respectively, the signal layer 236 and the second ground layer 235 are used to form a second electric field. That is, the signal layer 236 and the second ground layer 235 determine the distribution of the second electric field in the piezoelectric layer 237 located between them. The second electric field is used to polarize the piezoelectric layer 237 or drive the piezoelectric layer 237 to vibrate.

[0075] For ease of subsequent description, the “signal layer 236 and the first ground layer 234” will be collectively referred to as the “first polarization combination”, and the “piezoelectric layer 237 between the signal layer 236 and the first ground layer 234” will be referred to as the “first piezoelectric layer”; the “signal layer 236 and the second ground layer 235” will be collectively referred to as the “second polarization combination”, and the “piezoelectric layer 237 between the signal layer 236 and the second ground layer 235” will be referred to as the “second piezoelectric layer”. For subsequent descriptions involving the first polarization combination, the second polarization combination, the first piezoelectric layer, and the second piezoelectric layer, please refer to this document.

[0076] The first external electrode 231, the second external electrode 232, and the third external electrode 233 are all connected to the second surface 2372, and are spaced apart from each other to avoid electrical contact. The three external electrodes 231, 232, and 233 can be made of conductive metal or a thin metal layer.

[0077] The first external electrode 231 is electrically connected to the first ground layer 234. When there are multiple first ground layers 234, the first external electrode 231 is electrically connected to all the first ground layers 234 so that the various first ground layers 234 are connected in parallel.

[0078] The second external electrode 232 is electrically connected to the second ground layer 235. When there are multiple second ground layers 235, the second external electrode 232 is electrically connected to all the second ground layers 235 so that the various second ground layers 235 are connected in parallel.

[0079] The third external electrode 233 is electrically connected to the signal layer 236. When there are multiple signal layers 236, the third external electrode 233 is electrically connected to all signal layers 236 so that the signal layers 236 are connected in parallel.

[0080] The main function of each of the external electrodes is to form a connection with the corresponding internal electrode so that the driving signal is applied to the internal electrode. The first polarization combination and the second polarization combination can generate a suitable electric field to polarize the piezoelectric layer 237 or drive the piezoelectric layer 237 to vibrate.

[0081] In the piezoelectric actuator 100 provided in this application, by applying a suitable AC driving signal to the external electrode, each piezoelectric layer 237 can be excited to generate a corresponding vibration mode. Under the coordinated vibration of multiple piezoelectric layers 237, the entire piezoelectric actuator 100 can exhibit a corresponding motion pattern. The piezoelectric actuator 100 can estimate the frequency of the driving signal that can generate microscopic elliptical motion through size optimization and modal analysis. Elliptical motion can be achieved by a single mode, such as the B2 mode (second-order bending mode), or by superimposing multiple modes, such as the L1B2 mode (first-order elongation mode + second-order bending mode) or the B1B2 mode (first-order bending mode + second-order bending mode).

[0082] The piezoelectric actuator 100 provided in this application needs to be polarized to acquire piezoelectric properties and obtain the desired motion form. The polarization of the piezoelectric actuator 100 is achieved through an electric field formed by a first polarization combination and a second polarization combination. It should be noted that the polarization direction of the piezoelectric material after polarization is the same as the direction of the electric field applied when polarizing the piezoelectric material.

[0083] In this application, since the first ground layer 234 is connected to the first external electrode 231 and the second ground layer 235 is connected to the second external electrode 232, the first ground layer 234 and the second ground layer 235 are independent of each other. Because the first ground layer 234 and the second ground layer 235 are independent, the potential of the first ground layer 234 and the potential of the second ground layer 235 can be the same or different. Consequently, the direction of the electric field formed by the first polarization combination (hereinafter referred to as the first electric field) and the direction of the electric field formed by the second polarization combination (hereinafter referred to as the second electric field) can be the same or different. Therefore, the polarization direction of the first piezoelectric layer disposed between the first polarization combinations (hereinafter referred to as the first polarization direction) and the polarization direction of the second piezoelectric layer disposed between the second polarization combinations (hereinafter referred to as the second polarization direction) can be the same or different.

[0084] Therefore, for the piezoelectric actuator 100 provided in this application, its polarization scheme can adopt the following four types (e.g. Figures 4 to 7 As shown in the accompanying drawings of this application, the direction indicated by the hollow arrow represents the polarization direction.

[0085] The first polarization scheme: the polarization direction of the first piezoelectric layer is from the first ground layer 234 toward the signal layer 236, and the polarization direction of the second piezoelectric layer is from the second ground layer 235 toward the signal layer 236, such as... Figure 4 As shown;

[0086] The second polarization scheme: the polarization direction of the first piezoelectric layer is from the signal layer 236 toward the first ground layer 234, and the polarization direction of the second piezoelectric layer is from the signal layer 236 toward the second ground layer 235, such as... Figure 5 As shown;

[0087] The third polarization scheme: the polarization direction of the first piezoelectric layer is from the first ground layer 234 toward the signal layer 236, and the polarization direction of the second piezoelectric layer is from the signal layer 236 toward the second ground layer 235, such as... Figure 6 As shown;

[0088] The fourth polarization scheme: the polarization direction of the first piezoelectric layer is from the signal layer 236 toward the first ground layer 234, and the polarization direction of the second piezoelectric layer is from the second ground layer 235 toward the signal layer 236, such as... Figure 7 As shown.

[0089] exist Figure 4 Since the polarization direction of the first piezoelectric layer and the polarization direction of the second piezoelectric layer are both "the direction from the ground layer to the signal layer 236", the polarization direction of the first piezoelectric layer and the polarization direction of the second piezoelectric layer are considered to be the same, that is, the polarization direction of this type of piezoelectric actuator 100 is a single direction.

[0090] exist Figure 5 Since the polarization direction of the first piezoelectric layer and the polarization direction of the second piezoelectric layer are both "signal layer 236 toward ground layer", the polarization direction of the first piezoelectric layer and the polarization direction of the second piezoelectric layer are considered to be the same, that is, the polarization direction of this type of piezoelectric actuator 100 is a single direction.

[0091] exist Figure 6 In this context, since the polarization direction of the first piezoelectric layer is "from the ground layer toward the signal layer 236", and the polarization direction of the second piezoelectric layer is "from the signal layer 236 toward the ground layer", the polarization directions of the first piezoelectric layer and the second piezoelectric layer are considered to be opposite. That is, the polarization direction of this type of piezoelectric actuator 100 is two directions.

[0092] exist Figure 7 In this context, since the polarization direction of the first piezoelectric layer is "signal layer 236 toward ground layer" and the polarization direction of the second piezoelectric layer is "ground layer toward signal layer 236", the polarization directions of the first and second piezoelectric layers are considered to be opposite. That is, the polarization direction of this type of piezoelectric actuator 100 is two directions.

[0093] Compared to a piezoelectric actuator 100 with a single polarization direction, a piezoelectric actuator 100 with two polarization directions can excite modes with larger vibration amplitudes, i.e., larger vibration amplitudes, and thus greater driving force and driving speed.

[0094] In related technologies, the first ground layer and the second ground layer of the piezoelectric actuator 100 are connected to the same external electrode, so there is no difference between the first ground layer and the second ground layer. Therefore, for the piezoelectric actuator 100, its polarization direction must be a single direction, that is, the polarization direction of the piezoelectric actuator 100 is "the direction from the signal layer to the ground layer", or the polarization direction is "the direction from the ground layer to the signal layer".

[0095] Therefore, compared with related technologies, the polarization direction of the piezoelectric actuator 100 provided in this application can be not only a single direction, but also two directions. When two polarization directions are adopted, the piezoelectric actuator 100 provided in this application has a greater driving force and driving speed than the piezoelectric actuator 100 provided in related technologies, that is, it can output a greater energy density. Moreover, under the same output energy density, the volume of the piezoelectric actuator 100 provided in this application can be made smaller.

[0096] In summary, in the piezoelectric actuator 100 provided in this application, a suitable driving signal can be applied to the first ground layer 234, the second ground layer 235, and the signal layer 236 through the first external electrode 231, the second external electrode 232, and the third external electrode 233, thereby exciting each piezoelectric layer 237 to generate corresponding vibrations. Under the coordinated vibration of multiple piezoelectric layers 237, the entire piezoelectric actuator 100 can exhibit a corresponding motion pattern. Furthermore, since the first ground layer 234 is connected to the first external electrode 231 and the second ground layer 235 is connected to the second external electrode 232, the first ground layer 234 and the second ground layer 235 are independent of each other. Therefore, the direction of the electric field (hereinafter referred to as the first electric field) formed by the first ground layer 234 and the signal layer 236 can be the same as or different from the direction of the electric field (hereinafter referred to as the first electric field) formed by the second ground layer 235 and the signal layer 236. Therefore, the polarization direction of the piezoelectric layer 237 located between the first ground layer 234 and the signal layer 236 (referred to as the first polarization direction) can be the same as or different from the polarization direction of the piezoelectric layer 237 located between the second ground layer 235 and the signal layer 236 (referred to as the second polarization direction). Specifically, the piezoelectric actuator 100 needs to be polarized to have piezoelectric properties. When the direction of the first electric field used to polarize the piezoelectric layer 237 is the same as the direction of the second electric field, the first polarization direction and the second polarization direction are the same. That is, the first polarization direction is "the direction from the first ground layer 234 to the signal layer 236" and the second polarization direction is "the direction from the second ground layer 235 to the signal layer 236", or the first polarization direction is "the direction from the signal layer 236 to the first ground layer 234" and the second polarization direction is "the direction from the signal layer 236 to the second ground layer 235". For the piezoelectric actuator 100 with the same first polarization direction and second polarization direction, its polarization direction is a single direction. When the direction of the first electric field used to polarize the piezoelectric layer 237 is different from the direction of the second electric field, the first polarization direction and the second polarization direction are different. That is, the first polarization direction is "the direction from the first ground layer 234 to the signal layer 236" and the second polarization direction is "the direction from the signal layer 236 to the second ground layer 235", or the first polarization direction is "the direction from the signal layer 236 to the first ground layer 234" and the second polarization direction is "the direction from the second ground layer 235 to the signal layer 236". For a piezoelectric actuator 100 with different first and second polarization directions, its polarization direction is two directions. Compared with related technologies, when the piezoelectric actuator 100 provided in this application adopts a two-polarization-direction scheme, it has a greater driving force and driving speed, that is, it can output a greater energy density. Moreover, under the same output energy density, the volume of the piezoelectric actuator 100 provided in this application can be made smaller.Furthermore, the polarization direction of the piezoelectric actuator 100 can be a single direction or two directions, indicating that the polarization mode of the piezoelectric actuator 100 is diversified, and the design flexibility is higher, so it can be adapted to more driving scenarios.

[0097] Please refer to Figure 3 and Figure 4 Each signal layer 236 includes multiple signal electrodes X236, which are arranged at intervals. That is, signal electrodes X236 located in the same layer are not connected to each other. It should be noted that "multiple signal electrodes X236" corresponds to "one signal layer 236", not "the entire piezoelectric actuator 100". For example, if one signal layer 236 contains N signal electrodes X236, and if one piezoelectric actuator 100 contains M signal layers 236, then one piezoelectric actuator 100 contains N*M signal electrodes X236.

[0098] Furthermore, the third external electrode 233 includes multiple sub-electrodes X233. The number of sub-electrodes X233 is the same as the number of signal electrodes X236 contained in one signal layer 236, specifically 2, 3, 4, 5, 6, etc. This application only uses 2 as an example. Different sub-electrodes X233 are electrically connected to different signal electrodes X236, that is, the sub-electrodes X233 and signal electrodes X236 are electrically connected in a one-to-one correspondence.

[0099] In this embodiment, since different sub-electrodes X233 are electrically connected to different signal electrodes X236, the different signal electrodes X236 are independent of each other, so that the polarization direction of the piezoelectric layer 237 portion corresponding to different signal electrodes X236 can be the same or different, thereby making the polarization mode of the piezoelectric actuator 100 more diverse, and the design flexibility is higher, so that it can be adapted to more driving scenarios.

[0100] Please refer to Figure 8 and Figure 9 The first ground layer 234 includes a first body portion 2341 and a first lead-out portion 2342. The first lead-out portion 2342 and the first body portion 2341 can be an integral structure or a separate structure. The first body portion 2341 is disposed opposite to the signal layer 236, meaning that the orthographic projection of the first body portion 2341 onto the signal layer 236 at least partially falls within the area of ​​the signal layer 236. The first body portion 2341 is spaced at the periphery of the first surface 2371 of the piezoelectric layer 237 to prevent the first body portion 2341 from directly contacting the external electrode. One end of the first lead-out portion 2342 is connected to the first body portion 2341, and the other end of the first lead-out portion 2342 is connected to the first external electrode 231, so that the first body portion 2341 is electrically connected to the first external electrode 231 through the first lead-out portion 2342.

[0101] Please refer to Figure 8 and Figure 10 The second grounding layer 235 includes a second body portion 2351 and a second lead-out portion 2352. The second lead-out portion 2352 and the second body portion 2351 can be an integral structure or a separate structure. The second body portion 2351 is disposed opposite to the signal layer 236, meaning that the orthographic projection of the second body portion 2351 onto the signal layer 236 at least partially falls within the area of ​​the signal layer 236. The second body portion 2351 is spaced at the periphery of the first surface 2371 of the piezoelectric layer 237 to prevent the second body portion 2351 from directly contacting the external electrode. One end of the second lead-out portion 2352 is connected to the second body portion 2351, and the other end of the second lead-out portion 2352 is connected to the second external electrode 232, so that the second body portion 2351 is electrically connected to the second external electrode 232 through the second lead-out portion 2352.

[0102] Furthermore, the projections of the first lead-out portion 2342 and the second lead-out portion 2352 onto the piezoelectric layer 237 do not overlap. This arrangement facilitates the connection of the first external electrode 231 to the first lead-out portion 2342 and the second external electrode 232 to the second lead-out portion 2352, while ensuring that the first external electrode 231 and the second external electrode 232 are spaced apart.

[0103] Please refer to Figure 8 and Figure 9 The first body portion 2341 has a first end D1 and a second end D2 that are far apart from each other. The first end D1 is closer to the second lead-out portion 2352 than the second end D2. The first lead-out portion 2342 is connected to the second end D2. In short, the first lead-out portion 2342 is connected to the end of the first body portion 2341 that is far apart from the second lead-out portion 2352.

[0104] Please refer to Figure 8 and Figure 10 The second body portion 2351 has a third end D3 and a fourth end D4 that are far apart from each other. The fourth end D4 is closer to the first lead-out portion 2342 than the third end D3. The second lead-out portion 2352 is connected to the third end D3. In short, the second lead-out portion 2352 is connected to the end of the second body portion 2351 that is far away from the first lead-out portion 2342.

[0105] With the above arrangement, the first lead-out portion 2342 and the second lead-out portion 2352 can be kept as far apart as possible, which can better avoid the problem of the first external electrode 231 and the second external electrode 232 coming into contact due to errors during the manufacturing process of the piezoelectric actuator 100.

[0106] At least one of the three ground layers 234, 235, and 236 has an edge flush with the second surface 2372.

[0107] Optionally, at least a portion of the edges of the signal layer 236 are flush with the second surface 2372, such as... Figure 3 As shown, this configuration allows the third external electrode 233 to be flatly connected to each signal layer 236, thereby enabling all signal layers 236 to be connected in parallel through the third external electrode 233.

[0108] Optionally, at least a portion of the edges of the first ground layer 234 are flush with the second surface 2372, such as... Figure 9 As shown, this configuration allows the first external electrode 231 to be flatly connected to the first ground layer 234 of each layer, thereby enabling all the first ground layers 234 to be connected in parallel through the first external electrode 231.

[0109] Optionally, at least a portion of the edges of the second ground layer 235 are flush with the second surface 2372, such as... Figure 10 As shown, this configuration allows the second external electrode 232 to be flatly connected to the second ground layer 235 of each layer, thereby enabling all the second ground layers 235 to be connected in parallel through the second external electrode 232.

[0110] Please refer to Figures 11 to 12 Furthermore, the second surface 2372 includes a first side surface 2372a, a second side surface 2372b, a third side surface 2372c, and a fourth side surface 2372d. Among them, the first side surface 2372a is opposite to the second side surface 2372b, and the third side surface 2372c and the fourth side surface 2372d are opposite to each other.

[0111] In one implementation, such as Figure 11 As shown, the third external electrode 233 is disposed on the first side 2372a, and the first external electrode 231 and the second external electrode 232 are disposed on the second side 2372b.

[0112] In another implementation, such as Figure 12 As shown, the third external electrode 233 is disposed on the first side 2372a, the first external electrode 231 is disposed on the fourth side 2372d, and the second external electrode 232 is disposed on the third side 2372c.

[0113] Of course, in addition to the two implementation methods mentioned above, the relative positional relationship of the first external electrode 231, the second external electrode 232, and the third external electrode 233 can also be in other forms, which will not be described in detail here.

[0114] Generally, under the same voltage conditions, the more piezoelectric layers 237 are stacked, the greater the output power of the piezoelectric actuator 100. Therefore, by stacking multiple piezoelectric layers 237, the piezoelectric actuator 100 can have a larger output power. Depending on the driving requirements, the number of piezoelectric layers 237 can be, but is not limited to, 2, 3, 4, 5, 6, 7, 8, or 9. Several examples of different numbers of piezoelectric layers 237 are given below.

[0115] Please refer to Figure 13 In one embodiment, there are two piezoelectric layers 237 in the Z-axis direction. In the illustrated piezoelectric actuator 100 structure, there is one signal layer 236, one first ground layer 234, and one second ground layer 235, and the signal layer 236 is disposed between the first ground layer 234 and the second ground layer 235.

[0116] Please refer to Figures 4 to 7 In another embodiment, the number of piezoelectric layers 237 in the Z-axis direction is three. In the illustrated piezoelectric actuator 100 structure, the number of signal layers 236 in the Z-axis direction is two, and the number of the first ground layer 234 and the second ground layer 235 is one each.

[0117] Please refer to Figure 14 In another embodiment, the number of piezoelectric layers 237 in the Z-axis direction is four. In the illustrated piezoelectric actuator 100 structure, the number of signal layers 236 in the Z-axis direction is two, the number of first ground layers 234 in the Z-axis direction is two, and the number of second ground layers 235 is one. It is understood that in... Figure 14 In this process, different arrangement structures can be formed by swapping the positions of any one of the first grounding layers 234 and the second grounding layer 235.

[0118] It should be noted that in the structure of the piezoelectric actuator 100, the number of the first ground layer 234 and the second ground layer 235 can be the same or different, and the number of the first ground layer 234 and the second ground layer 235 can be multiple or one. The following is an example of the case where there are multiple first ground layers 234 and multiple second ground layers 235.

[0119] Please refer to Figure 15 The piezoelectric body 23 is divided into a first region A1 and a second region A2 along the Z-axis. There are multiple first grounding layers 234, second grounding layers 235, and signal layers 236, which can be 2, 3, 4, 5, etc.

[0120] Multiple signal layers 236 are simultaneously disposed in the first region A1 and the second region A2, and all signal layers 236 are connected in parallel through the third external electrode 233.

[0121] Multiple first ground layers 234 are disposed in the first region A1, and the first ground layers 234 and signal layers 236 are disposed alternately. That is, in the first region A1, a signal layer 236 is disposed between two adjacent first ground layers 234, and a first ground layer 234 is disposed between two adjacent signal layers 236. Furthermore, all the first ground layers 234 are connected in parallel through the first external electrode 231.

[0122] Multiple second ground layers 235 are disposed in the second region A2, and the second ground layers 235 and signal layers 236 are disposed alternately. That is, in the second region A2, a signal layer 236 is disposed between two adjacent second ground layers 235, and a second ground layer 235 is disposed between two adjacent signal layers 236. Furthermore, all the second ground layers 235 are connected in parallel through the second external electrode 232.

[0123] In this embodiment, each external electrode is electrically connected to each internal electrode, forming a parallel structure of corresponding internal electrodes in different layers on the circuit. Assuming the number of piezoelectric layers 237 is n, applying a voltage U will enable the piezoelectric actuator 100 to achieve a driving effect of n*U voltage. Furthermore, a first ground layer 234 is disposed in the first region A1, and a second ground layer 235 is disposed in the second region A2. The polarization direction of the first region A1 and the polarization direction of the second region A2 can be the same or different. When the polarization directions of the first region A1 and the second region A2 are different, the piezoelectric actuator 100 has a larger vibration amplitude, thereby achieving a greater driving force and driving speed.

[0124] Below Figure 15 Based on the structure shown, the polarization scheme of the piezoelectric actuator 100 is further explained.

[0125] Please refer to Figure 15 Each signal layer 236 includes a first signal electrode 2361 and a second signal electrode 2362, which are spaced apart. Figure 15 In this embodiment, the first signal electrode 2361 and the second signal electrode 2362 are arranged along the X-axis. In other embodiments, they may also be arranged along the Y-axis or in other directions inclined to the X-axis and Y-axis, which is not limited here.

[0126] Using the position between the first signal electrode 2361 and the second signal electrode 2362 as the boundary, the first region A1 is divided into a first sub-region A11 and a second sub-region A12, and the second region A2 is divided into a third sub-region A21 and a fourth sub-region A22. That is, after the region is divided, the first signal electrode 2361 is located within the first sub-region A11 and the third sub-region A21, and the second signal electrode 2362 is located within the second sub-region A12 and the fourth sub-region A22.

[0127] The third external electrode 233 includes a first sub-electrode 2331 and a second sub-electrode 2332. The first sub-electrode 2331 is electrically connected to all the first signal electrodes 2361 located in the first sub-region A11 and the third sub-region A21, so that the first signal electrodes 2361 of each layer are connected in parallel. The second sub-electrode 2332 is electrically connected to all the second signal electrodes 2362 located in the second sub-region A12 and the fourth sub-region A22, so that the second signal electrodes 2362 of each layer are connected in parallel.

[0128] In the first sub-region A11, since all the first signal electrodes 2361 are electrically connected to the first sub-electrode 2331 and all the first ground layers 234 are electrically connected to the first external electrode 231, all the piezoelectric layers 237 in the first sub-region A11 have the same polarization direction.

[0129] In the second sub-region A12, since all the second signal electrodes 2362 are electrically connected to the second sub-electrode 2332 and all the first ground layers 234 are electrically connected to the first external electrode 231, all the piezoelectric layers 237 in the second sub-region A12 have the same polarization direction.

[0130] In the third sub-region A21, since all the first signal electrodes 2361 are electrically connected to the first sub-electrode 2331 and all the second ground layers 235 are electrically connected to the second external electrode 232, all the piezoelectric layers 237 in the third sub-region A21 have the same polarization direction.

[0131] In the fourth sub-region A22, since all the second signal electrodes 2362 are electrically connected to the second sub-electrode 2332 and all the second ground layers 235 are electrically connected to the second external electrode 232, all the piezoelectric layers 237 in the fourth sub-region A22 have the same polarization direction.

[0132] It is understandable that, through the above configuration, the first sub-region A11, the second sub-region A12, the third sub-region A21, and the fourth sub-region A22 can be regarded as independent of each other. Therefore, the polarization directions of the four regions, the first sub-region A11, the second sub-region A12, the third sub-region A21, and the fourth sub-region A22, can be the same or different, so that the piezoelectric actuator 100 has multiple polarization forms.

[0133] The following is about Figure 15 Several possible polarization configurations of the piezoelectric actuator 100 are illustrated.

[0134] Please refer to Figure 15 and Figure 16The first polarization configuration of the piezoelectric actuator 100 is as follows: In the first sub-region A11, the polarization direction of the piezoelectric layer 237 is from the first ground layer 234 to the first signal electrode 2361. In the second sub-region A12, the polarization direction of the piezoelectric layer 237 is from the first ground layer 234 to the second signal electrode 2362. In the third sub-region A21, the polarization direction of the piezoelectric layer 237 is from the first signal electrode 2361 to the second ground layer 235. In the fourth sub-region A22, the polarization direction of the piezoelectric layer 237 is from the second signal electrode 2362 to the second ground layer 235.

[0135] Please refer to Figure 17 and Figure 18 The second polarization configuration of the piezoelectric actuator 100 is as follows: In the first sub-region A11, the polarization direction of the piezoelectric layer 237 is from the first ground layer 234 to the first signal electrode 2361. In the second sub-region A12, the polarization direction of the piezoelectric layer 237 is from the second signal electrode 2362 to the first ground layer 234. In the third sub-region A21, the polarization direction of the piezoelectric layer 237 is from the first signal electrode 2361 to the second ground layer 235. In the fourth sub-region A22, the polarization direction of the piezoelectric layer 237 is from the second ground layer 235 to the second signal electrode 2362.

[0136] Please refer to Figure 19 and Figure 20 The third polarization mode of the piezoelectric actuator 100 is as follows: In the first sub-region A11, the polarization direction of the piezoelectric layer 237 is from the first ground layer 234 to the first signal electrode 2361. In the second sub-region A12, the polarization direction of the piezoelectric layer 237 is from the second signal electrode 2362 to the first ground layer 234. In the third sub-region A21, the polarization direction of the piezoelectric layer 237 is from the second ground layer 235 to the first signal electrode 2361. In the fourth sub-region A22, the polarization direction of the piezoelectric layer 237 is from the second signal electrode 2362 to the second ground layer 235.

[0137] Please refer to Figure 21 and Figure 22 The fourth polarization configuration of the piezoelectric actuator 100 is as follows: In the first sub-region A11, the polarization direction of the piezoelectric layer 237 is the direction from the first signal electrode 2361 to the first ground layer 234. In the second sub-region A12, the polarization direction of the piezoelectric layer 237 is the direction from the first ground layer 234 to the second signal electrode 2362. In the third sub-region A21, the polarization direction of the piezoelectric layer 237 is the direction from the second ground layer 235 to the first signal electrode 2361. In the fourth sub-region A22, the polarization direction of the piezoelectric layer 237 is the direction from the second signal electrode 2362 to the second ground layer 235.

[0138] Please see Figure 23 and Figure 24 This application also provides a piezoelectric drive module 200, which includes a carrier 201, a driven member 202, and a piezoelectric actuator 100 as described in any of the above embodiments. The piezoelectric actuator 100 is disposed on the carrier 201, and the friction layer 24 of the piezoelectric actuator 100 is in contact with the driven member 202 on the side facing away from the piezoelectric body 23.

[0139] When a suitable AC drive signal is applied to the piezoelectric actuator 100, it can generate high-frequency micro-amplitude vibrations, which in turn convert the micro-motion of the piezoelectric actuator 100 into the macro-motion of the driven member 202 through the friction between the friction layer 24 and the driven member 202. The motion of the driven member 202 can be linear or rotational; here, only linear motion is illustrated.

[0140] refer to Figure 23 and Figure 25 As shown, in some embodiments, the piezoelectric drive module 200 further includes a preload member 205, which is connected to the carrier 201 and is used to apply a preload force to the piezoelectric drive 100 on the side of the piezoelectric drive 100 facing away from the driven member 202, so as to press the friction layer 24 of the piezoelectric drive 100 against the driven member 202, so that the friction between the friction layer 24 and the driven member 202 can convert the microscopic motion of the piezoelectric drive 100 itself into the macroscopic motion of the driven member 202.

[0141] The preload 205 includes, but is not limited to, an elastic structure such as a spring sheet, which can elastically press the piezoelectric actuator 100 against the driven member 202. The two ends of the preload 205 can be connected to the carrier 201, and the middle part of the preload 205 is pressed against the side of the piezoelectric actuator 100 facing away from the driven member 202.

[0142] In some embodiments, the piezoelectric drive module 200 further includes a buffer 206, which is disposed between the piezoelectric actuator 100 and the preload member 205 and is pressed against the piezoelectric actuator 100 by the preload member 205. The buffer 206 provides cushioning for the piezoelectric actuator 100, which helps reduce wear and noise during operation. The material of the buffer 206 includes, but is not limited to, any suitable cushioning material such as rubber, foam, silicone, or polymer.

[0143] In some embodiments, the opposing sides of the buffer member 206 are adhesive to bond the piezoelectric actuator 100 and the pretensioner 205. Thus, the buffer member 206 bonds the piezoelectric actuator 100 and the pretensioner 205 into a single structure, further reducing wear and noise during operation of the piezoelectric actuator 100 and improving the structural reliability of the piezoelectric drive module 200. Adhesive tape may be provided on the opposing sides of the buffer member 206 to provide adhesiveness, and the buffer member 206 may also employ a structure such as a buffer tape with cushioning effect and adhesiveness.

[0144] refer to Figure 24 , Figure 26 and Figure 27 As shown, in some embodiments, the piezoelectric drive module 200 further includes a first magnetic mating member 207 and a second magnetic mating member 208. The first magnetic mating member 207 is disposed on the carrier 201, and the second magnetic mating member 208 is disposed on the driven member 202. The first magnetic mating member 207 and the second magnetic mating member 208 are configured to attract each other through magnetic attraction. Thus, the piezoelectric drive module 200 can use the magnetic attraction between the first magnetic mating member 207 and the second magnetic mating member 208 to make the carrier 201 and the driven member 202 tend to move closer to each other, thereby applying a preload force to the piezoelectric actuator 100 directed towards the driven member 202. Similarly, it can press the friction layer 24 against the driven member 202 so that the driven member 202 can be driven to move by the friction between the friction layer 24 and the driven member 202. Meanwhile, the first magnetic mating member 207 and the second magnetic mating member 208 are respectively disposed on the carrier 201 and the driven member 202, for example, they can be at least partially embedded in or accommodated on the carrier 201 and the driven member 202, and the preload member 205 is omitted, which is beneficial to compressing the volume of the piezoelectric drive module 200. Furthermore, by applying a preload force to the piezoelectric actuator 100 through magnetic attraction, the first magnetic mating member 207 and the second magnetic mating member 208 do not need to contact the piezoelectric actuator 100, which is beneficial to reducing noise and wear during the operation of the piezoelectric actuator 100.

[0145] The specific configuration of the first magnetic mating component 207 and the second magnetic mating component 208 is not limited, as long as the magnetic attraction generated by the first magnetic mating component 207 and the second magnetic mating component 208 can press the friction layer 24 against the driven component 202 to meet the frictional force requirements. In the accompanying drawings of this application, the first magnetic mating component 207 is a magnet and the second magnetic mating component 208 is a steel sheet as an example. The materials of the first magnetic mating component 207 and the second magnetic mating component 208 can also be interchanged, or both the first magnetic mating component 207 and the second magnetic mating component 208 can be magnets.

[0146] In some embodiments, one of the first magnetic mating member 207 and the second magnetic mating member 208 is an electromagnetic structure, such as an electromagnet composed of a coil and an iron core. Thus, by adjusting the magnitude of the current applied to the electromagnetic structure, the magnitude of the preload between the piezoelectric actuator 100 and the driven member 202 can also be adjusted to meet different driving requirements.

[0147] In some embodiments, when the piezoelectric drive module 200 is provided with a first magnetic mating member 207 and a second magnetic mating member 208, the piezoelectric drive module 200 further includes a rolling member 209. The rolling member 209 is disposed between the carrier 201 and the driven member 202, and rolls with the carrier 201 and the driven member 202. The rolling member 209 provides a structural basis for the relative movement between the carrier 201 and the driven member 202, making the sliding of the driven member 202 relative to the carrier 201 under the drive of the piezoelectric actuator 100 smoother.

[0148] In some embodiments, at least one of the two opposing surfaces of the carrier 201 and the driven member 202 is provided with a rolling groove 204. The extending direction of the rolling groove 204 is parallel to the relative sliding direction of the carrier 201 and the driven member 202, and the rolling member 209 is rotatably disposed within the rolling groove 204. The rolling groove 204 can provide a limiting effect on the rolling member 209, thereby constraining the sliding direction of the driven member 202 relative to the carrier 201, and also preventing the rolling member 209 from coming off, which is beneficial to improving the structural reliability of the piezoelectric drive module 200.

[0149] Further, refer to Figure 26 and Figure 27 As shown, in some embodiments, at least one of the first magnetic mating member 207 and the second magnetic mating member 208 is located between the piezoelectric actuator 100 and the rolling member 209 in an extension direction perpendicular to the rolling groove 204 (i.e., perpendicular to the relative movement direction between the driven member 202 and the carrier 201). Figure 27 In the illustrated embodiment, the first magnetic mating member 207 is located between the piezoelectric actuator 100 and the rolling member 209, while the second magnetic mating member 208 also covers the rolling member 209 as an example. In other embodiments, both the first magnetic mating member 207 and the second magnetic mating member 208 may be located between the piezoelectric actuator 100 and the rolling member 209. With this arrangement, the piezoelectric actuator 100 and the rolling member 209 can provide support for the driven member 202 and the carrier 201 on the opposite sides of the first magnetic mating member 207, allowing the support to work well with the magnetic attraction, thus improving the stability of the relative movement between the driven member 202 and the carrier 201.

[0150] The number of rolling grooves 204 and the number of rolling elements 209 are not limited, and can be set according to the relative sliding requirements of the driven member 202 and the carrier 201. In the accompanying drawings of this application, two rolling grooves 204 are provided on the side of the carrier 201 facing the driven member 202, and three rolling elements 209 are arranged sequentially in each rolling groove 204 as an example. The rolling elements 209 include, but are not limited to, any applicable structure such as balls.

[0151] refer to Figure 27 As shown, in some embodiments, the piezoelectric drive module 200 further includes a friction element 210, which is disposed on the driven member 202 and contacts the friction layer 24. The friction element 210 increases the frictional force between the driven member 202 and the piezoelectric actuator 100, thereby making it easier to drive the driven member 202 to move through the frictional action between the friction layer 24 and the friction element 210. The friction element 210 can be a sheet-like structure disposed on the driven member 202, and the material of the friction element 210 includes, but is not limited to, any suitable material such as polytetrafluoroethylene, nylon, polyester, metal, and ceramic.

[0152] In some embodiments, the surface of the friction element 210 facing the friction layer 24 is provided with periodically arranged textures or non-periodic textures 241. The specific type of textures or textures 241 provided on the friction element 210 can be referred to the above description of the friction layer 24. Providing textures or textures 241 on the friction element 210 helps to increase the contact area between the friction element 210 and the friction layer 24, further improving the friction effect between the friction element 210 and the friction layer 24, thereby enhancing the driving effect of the piezoelectric actuator 100 on the driven element 202. At the same time, when a lubricating medium such as a lubricant is provided between the friction element 210 and the friction layer 24, the textures or textures 241 on the friction element 210 and the friction layer 24 can also capture and retain the medium, which helps to enhance the friction performance.

[0153] Please refer to Figure 28 In some embodiments, the piezoelectric drive module 200 is a piezoelectric motor, in which case the driven member 202 serves as the mover of the piezoelectric drive module 200, and the piezoelectric actuator 100 serves as the stator of the piezoelectric drive module 200. The carrier 201 can be a protective shell for storage and protection. The piezoelectric actuator 100 is connected to (e.g., by bonding or welding) the carrier 201; the specific connection method is related to the structural and modal design and is not limited here. The driven member 202 is movably connected to the carrier 201. The friction head 10 of the piezoelectric actuator 100 abuts against the driven member 202 to drive the driven member 202 to move along a second preset direction F2.

[0154] The piezoelectric drive module 200 may further include a rolling element 203, which may be a spherical ball or a cylindrical roller. The rolling element 203 is disposed between the driven member 202 and the carrier 201, so that the driven member 202 can move relative to the carrier 201. When the driven member 202 moves relative to the carrier 201 under the action of the piezoelectric actuator 100, the piezoelectric drive module 200 can output driving force through the driven member 202 to drive components other than the piezoelectric drive module 200 to move.

[0155] Please refer to Figure 29 and Figure 30 In some other embodiments, the piezoelectric drive module 200 may also be a camera module, in which case the piezoelectric drive module 200 may include a lens and an image sensor 211, and the driven member 202 may be either the lens or the image sensor 211. The driven member 202 is movably disposed on the carrier 201, and the piezoelectric actuator 100 is fixed on the carrier 201 with the friction layer 24 facing the driven member 202 and in contact with the driven member 202.

[0156] The lens is used to collect light from the subject and focus it onto the image sensor 211. The image sensor 211, also known as a photosensitive chip, photosensitive element, or sensor, receives light passing through the lens and converts the light signal into an electrical signal. The image sensor 211 can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device.

[0157] When the lens is used as the driven component 202, the piezoelectric actuator 100 can be directly or indirectly connected to the lens. The lens, as the driven component 202, drives the lens to move during the operation of the camera module, so as to realize the AF (autofocus) function and / or OIS (optical image stabilization) function of the camera module.

[0158] In one embodiment, the piezoelectric actuator 100 can drive the lens to move relative to the image sensor 211 along the extension direction of the optical axis G, thereby realizing the AF (autofocus) function of the camera module, such as... Figure 29 As shown.

[0159] In another embodiment, the piezoelectric actuator 100 can drive the lens to move relative to the image sensor 211 in a direction perpendicular to the optical axis G, thereby realizing the OIS (optical image stabilization) function of the camera module, such as... Figure 30 As shown.

[0160] In another embodiment, a plurality of piezoelectric actuators 100 are disposed in the camera module, wherein at least one piezoelectric actuator 100 is used to implement the AF (autofocus) function of the camera module, and at least one piezoelectric actuator 100 is used to implement the OIS (optical image stabilization) function of the camera module.

[0161] Of course, in other embodiments, the piezoelectric actuator 100 can also be used to drive the image sensor 211 to move relative to the lens to realize the AF (autofocus) function and / or OIS (optical image stabilization) function of the camera module.

[0162] Please refer to Figure 31 This application also provides an electronic device 300, which includes a device body 302 and a piezoelectric drive module 200 as described in any of the above embodiments, wherein the piezoelectric drive module 200 is mounted on the device body 302.

[0163] The electronic device 300 can be a mobile phone, tablet computer, laptop computer, wearable device (such as a smartwatch, bracelet, VR device, etc.), television set, in-vehicle device, e-reader, etc. It should be noted that this application embodiment only uses a mobile phone as an example for illustration.

[0164] The device body 302 refers to the main body of the electronic device 300. The main body includes functional components that realize the main functions of the electronic device 300 and mechanical structures that protect and support these functional components. Taking a mobile phone as an example, the device body 302 may include a display screen, a mid-frame, and a battery cover. The display screen and the battery cover are both connected to the mid-frame and are respectively located on opposite sides of the mid-frame.

[0165] When the piezoelectric drive module 200 is a camera module, it can be either a straight-through camera or a periscope camera. A periscope camera refers to a camera whose optical axis G is bent (e.g., bent at 90°), while a straight-through camera refers to a camera whose optical axis G is a straight line without bending. Depending on the actual needs, the light-transmitting window of the piezoelectric drive module 200 can be located anywhere on the electronic device 300. Taking a mobile phone as an example, the light-transmitting window of the piezoelectric drive module 200 can be located on the front, back, or side of the phone. The front refers to the side of the phone with the display screen; the back refers to the side of the phone with the battery cover; and the side refers to the circumference of the phone's frame. It is understood that the definitions of "front," "back," and "side" may differ depending on the type of electronic device 300; other types of electronic devices 300 will not be listed here.

[0166] In related technologies, camera modules use electromagnetic motors to drive lens movement to achieve AF (autofocus) and OIS (optical image stabilization) functions. However, the magnetic field generated by the electromagnetic motor will interfere with other electronic components within the electronic device 300. In this application, the piezoelectric drive module 200 uses a piezoelectric actuator 100, which does not generate a magnetic field during operation, thereby avoiding magnetic field interference problems.

[0167] In the piezoelectric drive module 200 and electronic device, the piezoelectric actuator 100 described in any of the above embodiments is used. The piezoelectric actuator 100 is in direct or indirect contact with the driven member 202 through the friction layer 24 of the layer structure. The driven member 202 is driven to move by the friction between the friction layer 24 and the driven member 202. Compared with traditional friction heads and other structures, the setting of the friction layer 24 is beneficial to reducing the thickness of the piezoelectric actuator 100, thereby reducing the space occupied by the piezoelectric actuator 100 in the piezoelectric drive module 200 and electronic device, which is beneficial to the miniaturization design of the piezoelectric drive module 200 and electronic device.

[0168] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0169] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A piezoelectric drive module, characterized in that, The device includes a carrier, a driven member, a piezoelectric actuator, a first magnetic mating member, and a second magnetic mating member. The piezoelectric actuator is disposed on the carrier and contacts the driven member, and is used to drive the driven member to move relative to the carrier. The first magnetic mating member is disposed on the carrier, and the second magnetic mating member is disposed on the driven member. The first magnetic mating member and the second magnetic mating member are configured to attract each other through magnetic attraction.

2. The piezoelectric drive module according to claim 1, characterized in that, The piezoelectric drive module further includes a rolling element, which is disposed between the carrier and the driven component and rolls in cooperation with the carrier and the driven component.

3. The piezoelectric drive module according to claim 2, characterized in that, At least one of the carrier and the driven member is provided with a rolling groove, and the rolling member is rotatably disposed in the rolling groove. In the extension direction perpendicular to the rolling groove, at least one of the first magnetic mating member and the second magnetic mating member is located between the piezoelectric actuator and the rolling member.

4. The piezoelectric drive module according to claim 2, characterized in that, The first magnetic mating member and the second magnetic mating member are at least partially opposite each other, one of the first magnetic mating member and the second magnetic mating member is located between the piezoelectric actuator and the rolling member, and the other is in contact with at least a portion of the rolling member.

5. The piezoelectric drive module according to claim 1, characterized in that, The piezoelectric drive module is a piezoelectric motor, the driven component is a mover, and the driven component is movably connected to the carrier.

6. The piezoelectric drive module according to claim 1, characterized in that, The piezoelectric drive module is a camera module, and the driven component is a lens or image sensor. The driven component is disposed on the carrier. Under the drive of the piezoelectric actuator, the driven component can move relative to the carrier in a direction parallel or perpendicular to the optical axis.

7. The piezoelectric drive module according to claim 1, characterized in that, At least one of the first magnetic mating component and the second magnetic mating component is an electromagnet.

8. The piezoelectric drive module according to claim 1, characterized in that, The piezoelectric drive module also includes a friction element, which is disposed on the driven component and in contact with the piezoelectric actuator. The surface of the friction element facing the piezoelectric actuator is provided with a periodically arranged texture or a non-periodic arrangement of patterns.

9. The piezoelectric drive module according to claim 1, characterized in that, The piezoelectric actuator includes a piezoelectric body and a friction layer. At least a portion of the piezoelectric body can be subjected to a voltage to generate deformation motion. The friction layer is disposed on the piezoelectric body and contacts the driven member.

10. The piezoelectric drive module according to claim 9, characterized in that, The piezoelectric body has two opposing surfaces, and the friction layer is laid flat on one of the surfaces of the piezoelectric body.

11. The piezoelectric drive module according to claim 9, characterized in that, The piezoelectric actuator further includes a first protective layer and a second protective layer, which are respectively disposed on opposite sides of the piezoelectric body, wherein: The friction layer is formed on the side of the first protective layer opposite to the piezoelectric body, or the friction layer is disposed on the side of the first protective layer opposite to the piezoelectric body.

12. The piezoelectric drive module according to claim 9, characterized in that, The friction layer is formed through a hardening process, or the friction layer is a surface coating applied to the piezoelectric body.

13. The piezoelectric drive module according to claim 12, characterized in that, When the friction layer is formed by a hardening process, the hardening process includes carburizing, nitriding or metal infiltration. When the friction layer is a surface coating on the piezoelectric body, the surface coating includes a metal film, a ceramic film, or a polymer film.

14. The piezoelectric drive module according to claim 9, characterized in that, The friction layer has a periodically arranged texture or a non-periodic arrangement of patterns on the side facing away from the piezoelectric body.

15. The piezoelectric drive module according to claim 9, characterized in that, The piezoelectric body includes a first external electrode, a second external electrode, a third external electrode, a first ground layer, a second ground layer, a signal layer, and multiple piezoelectric layers; the multiple piezoelectric layers are arranged sequentially at intervals along a first preset direction, and each piezoelectric layer has two first surfaces that are opposite to each other in the first preset direction and a second surface connected to the first surfaces; The first ground layer, the second ground layer, and the signal layer are respectively connected to different first surfaces, so that the electrodes on opposite sides of the same piezoelectric layer are the signal layer and the first ground layer, or the electrodes on opposite sides of the same piezoelectric layer are the signal layer and the second ground layer. The first external electrode, the second external electrode, and the third external electrode are all connected to the second surface, and the first external electrode is electrically connected to the first ground layer, the second external electrode is electrically connected to the second ground layer, and the third external electrode is electrically connected to the signal layer.

16. An electronic device, characterized in that, Includes the piezoelectric drive module as described in any one of claims 1-15.

Images