Piezoelectric drivers, piezoelectric motors, camera modules and electronic equipment

Abstract

The present application relates to a piezoelectric driver, a piezoelectric motor, a camera module and an electronic device, wherein the piezoelectric driver comprises: an elastic base; a piezoelectric layer disposed on at least two orthogonal sides of the elastic base, wherein a plurality of first electrodes are disposed on the surface of the piezoelectric layer on each side away from the elastic base; and a friction head disposed on one side of the elastic base or on the first electrode. By regulating the different driving voltages applied to the first electrode, the piezoelectric driver can be stimulated to generate different vibration modes with orthogonal directions, so that the friction head supports the generation of displacement components along two orthogonal directions on different preset planes, so as to drive the contacting sliding parts to move along different directions of the target plane. Therefore, the structure of the piezoelectric driver of this embodiment is simple, and a single piezoelectric driver can drive the sliding part to realize dual-degree-of-freedom motion, which is conducive to miniaturization and high-precision displacement control.

Description

Technical Field

[0001] The present application relates to the technical field of piezoelectric motors, and in particular to a piezoelectric driver, a piezoelectric motor, a camera module and an electronic device. Background Art

[0002] With the continuous development of high-precision and micro-nano technology, piezoelectric motors that can achieve dual-degree-of-freedom displacement control have been increasingly widely studied.

[0003] However, the piezoelectric motors that can currently achieve dual-degree-of-freedom drive are mainly combined with a double-layer guide rail design, using two piezoelectric drivers that can drive a single degree of freedom to achieve a dual-degree-of-freedom displacement-driven piezoelectric motor. This type of motor has the disadvantages of being large in overall size and complex in structure, which is not conducive to miniaturization. Summary of the invention

[0004] The embodiments of the present application provide a piezoelectric driver, a piezoelectric motor, a camera module and an electronic device, which can achieve dual degrees of freedom on the basis of miniaturization.

[0005] The first aspect of the present application provides a piezoelectric driver, comprising:

[0006] Elastic base;

[0007] A piezoelectric layer is disposed on at least two orthogonal side surfaces of the elastic base, and a surface of the piezoelectric layer on each side surface away from the elastic base is provided with a plurality of first electrodes;

[0008] A friction head, disposed on the elastic base or on one side of the first electrode;

[0009] Among them, under the action of different driving voltages, each of the first electrodes excites the piezoelectric driver to produce different vibration modes with orthogonal directions, so that the friction head supports the generation of displacement components along two orthogonal directions on different preset planes, so as to drive the contacting sliding parts to move in different directions along the target plane, and the target plane is perpendicular to the different preset planes.

[0010] A second aspect of the present application provides a piezoelectric motor, comprising:

[0011] A piezoelectric actuator and a sliding member as described above;

[0012] Wherein, when the friction head contacts the sliding component and generates displacement components along two orthogonal directions on different preset planes, the sliding component is driven to move on the target plane.

[0013] A third aspect of the present application provides an electronic device, including:

[0014] A piezoelectric motor as described above.

[0015] A camera module comprises the piezoelectric motor as described above.

[0016] An electronic device comprises the camera module as described above.

[0017] The above-mentioned piezoelectric driver, piezoelectric motor, camera module and electronic equipment, wherein the piezoelectric driver comprises: an elastic base; a piezoelectric layer disposed on at least two orthogonal sides of the elastic base, wherein a plurality of first electrodes are disposed on the surface of the piezoelectric layer on each side away from the elastic base; and a friction head disposed on one side of the elastic base. By regulating the different driving voltages applied to the first electrodes, the piezoelectric driver can be stimulated to generate different vibration modes with orthogonal directions, so that the friction head supports the generation of displacement components along two orthogonal directions on different preset planes, so as to drive the contacting sliding parts to move along different directions of the target plane. Therefore, the structure of the piezoelectric driver of this embodiment is simple, and a single piezoelectric driver can drive the sliding parts to realize dual-degree-of-freedom motion, which is conducive to miniaturization and high-precision displacement control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is one of the structural block diagrams of a piezoelectric driver according to an embodiment.

[0020] Figure 2 This is one of the working modes and working principles of a piezoelectric driver according to an embodiment.

[0021] Figure 3 This is the second structural block diagram of a piezoelectric driver according to an embodiment.

[0022] Figure 4 This is the third structural block diagram of a piezoelectric driver according to an embodiment.

[0023] Figure 5 This is the fourth structural block diagram of a piezoelectric driver according to an embodiment.

[0024] FIG. 6( a ) is a diagram showing one of the voltage driving modes of a piezoelectric driver according to an embodiment of the present invention to drive a sliding component to move along the X-axis.

[0025] FIG. 6( b ) shows a second voltage driving method for a piezoelectric driver according to an embodiment to drive a sliding component to move along the X-axis.

[0026] FIG. 6( c ) is a third voltage driving method for driving the sliding component to move along the X-axis according to an embodiment of the present invention.

[0027] Figure 7 This is a voltage driving method in which a piezoelectric driver according to an embodiment drives a sliding component to move along the Y-axis.

[0028] Figure 8 This is the second working mode and working principle of the piezoelectric driver in one embodiment.

[0029] Fig. 9 This is one of the structural block diagrams of a piezoelectric motor according to an embodiment.

[0030] Fig.10 This is the second structural block diagram of a piezoelectric motor according to an embodiment.

[0031] Fig.11 FIG. 1 is a schematic diagram of the structure of an electronic device in an embodiment.

[0032] Fig.12 Schematic diagram of the structure of the camera module in some embodiments.

[0033] Fig.13 for Fig.12 An exploded schematic diagram of the camera module is shown.

[0034] Fig.14 for Fig.12 A schematic structural diagram of the camera module shown in another angle.

[0035] Fig.15 for Fig.14 The cross-sectional schematic diagram of the camera module shown is along the AA direction.

[0036] Fig.16 Schematic diagram of an explosion of some components of a camera module in some embodiments.

[0037] Fig.17 Schematic diagram of the structure in which a piezoelectric driver is arranged in an elastic preload structure in some embodiments.

[0038] Fig.18 Schematic diagram of the structure of the sliding component in some embodiments.

[0039] Fig.19 for Fig.18 A schematic structural diagram of the sliding component from another angle is shown.

[0040] Fig. 20 It is a schematic diagram of the structure in which the rolling element is arranged on the bracket in some embodiments.

[0041] Fig.21 Schematic diagram of an explosion of another part of the components of the camera module in some embodiments. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0043] It is understood that the terms "first", "second", etc. used in this application can be used to describe various elements in this article, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on another element or there can also be a centered element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there may be a centered element at the same time.

[0044] Piezoelectric motor is a kind of piezoelectric device that generates stress and strain through the inverse piezoelectric effect under the stimulation of an alternating electric field, causing the piezoelectric material (piezoelectric stator) to produce a slight vibration within a certain frequency, and then converts the slight vibration of the piezoelectric stator into a macroscopic linear or rotational motion of the mover (slider, lens, etc.) through the action of friction. Compared with traditional electromagnetic motors, piezoelectric motors have the advantages of fast response speed, low noise, small size, power-off self-locking, and no electromagnetic interference. Therefore, they have received widespread attention in recent decades. Piezoelectric motors can be widely used in aerospace, precision positioning systems, automatic zoom lenses, biotechnology and medicine, micro / nano electromechanical systems (MEMS / NEMS) and other fields. In addition, compared with electromagnetic motors (VCM) (in centimeters and below), the output power density of piezoelectric motors is almost independent of size changes, so piezoelectric motors are expected to achieve miniaturization and high thrust at the same time.

[0045] At present, the piezoelectric motors that can achieve dual-degree-of-freedom drive are mainly combined with a double-layer guide rail design, using two piezoelectric drivers that can drive a single degree of freedom to achieve dual-degree-of-freedom displacement drive. However, this type of piezoelectric motor requires two piezoelectric drivers to control the displacement of the X-axis and Y-axis respectively, which has the disadvantages of large overall size, complex structure, high assembly requirements, and short stroke, which is not conducive to miniaturization.

[0046] Based on this, the present application provides a piezoelectric driver, a piezoelectric motor and an electronic device, which can achieve high-precision dual-degree-of-freedom displacement on the basis of miniaturization.

[0047] Figure 1 FIG. 1 is a block diagram of a piezoelectric driver 10 according to an embodiment of the present invention. Figure 1 In this embodiment, the piezoelectric driver 10 includes an elastic base 100 , a piezoelectric layer 200 and a friction head 300 .

[0048] An elastic base 100; a piezoelectric layer 200, which is arranged on at least two orthogonal side surfaces of the elastic base 100 (as illustrated in the figure, the piezoelectric layer 200 is arranged on two orthogonal side surfaces), and a plurality of first electrodes (the first electrodes are not shown in the figure) are arranged on a surface of each side of the piezoelectric layer 200 away from the elastic base 100; a friction head 300, which is arranged on a side surface of the elastic base 100, or on the first electrode of the piezoelectric layer 200; wherein, each first electrode, under the action of different driving voltages, excites the piezoelectric driver 10 to generate different vibration modes with orthogonal directions, so that the friction head 300 supports the generation of displacement components along two orthogonal directions on different preset planes, so as to drive the contacting sliding parts to move along different directions of the target plane, and the target plane is perpendicular to the different preset planes.

[0049] The piezoelectric layer 200 is disposed on at least two orthogonal sides of the elastic base 100, and a plurality of first electrodes are disposed on a surface of the piezoelectric layer 200 on each side away from the elastic base 100, each first electrode is used to apply a driving voltage, and the driving voltages applied by different first electrodes may be the same or different. Optionally, the driving circuit may apply a driving voltage to each first electrode according to the configured driving parameters.

[0050] It can be understood that the several first electrodes in this embodiment include one or more. Optionally, the surface of one side of the piezoelectric layer 200 away from the elastic base 100 can be divided into several first electrode partitions according to needs, and each first electrode partition is provided with a first electrode. Each first electrode can be used to achieve polarization and can be used as a working electrode when a voltage is applied. When the driving voltage is applied to the piezoelectric layer 200 via the first electrode, the piezoelectric material will deform, for example, stretch and bend, thereby driving the friction head 300 to form a displacement component. Optionally, the first electrode on the surface of each piezoelectric layer 200 can be prepared by magnetron sputtering or screen printing. Optionally, several first electrodes on the piezoelectric layer 200 are completely covered on the surface of the piezoelectric layer 200, so that the piezoelectric layer 200 can be completely polarized, and the polarization method has a high overall utilization rate for the piezoelectric material, which is conducive to enhancing the deformation effect of the piezoelectric material and further enhancing the thrust of the friction head 300.

[0051] Optionally, the piezoelectric layer 200 can be prepared by piezoelectric ceramics, piezoelectric single crystals or textured ceramics. In order to reduce the driving voltage, multilayer co-fired ceramics can also be prepared by tape casting technology. Further optionally, piezoelectric ceramics and textured ceramics can be made of lead zirconate titanate (PZT)-based, lead magnesium niobate-lead titanate (PMN-PT)-based, lead indium niobate-lead magnesium niobate-lead titanate (PIN-PMN-PT)-based and other lead-containing components, and can also be made of barium titanate (BT)-based, sodium bismuth titanate (BNT)-based, potassium sodium niobate (KNN)-based, barium calcium zirconate titanate (BCZT)-based and other lead-free components. Further optionally, the piezoelectric single crystal can be selected from lead-containing components such as lead zinc niobate-lead titanate (PZN-PT) based, lead magnesium niobate-lead titanate (PMN-PT) based, lead indium niobate-lead zinc niobate-lead titanate (PIN-PZN-PT) based, lead indium niobate-lead magnesium niobate-lead titanate (PIN-PMN-PT) based, and can also be selected from lead-free components such as sodium bismuth titanate (BNT) based, sodium bismuth titanate-potassium bismuth titanate (BNT-BKT) based, sodium potassium titanate (KNN) based.

[0052] The elastic base 100 can be used to support each piezoelectric layer 200. Specifically, the piezoelectric layer 200 is provided on at least two intersecting sides of the elastic base 100. When the piezoelectric layer 200 generates a vibration mode, the elastic base 100 can be elastically deformed due to its elasticity. When a voltage is applied to each first electrode, the elastic base 100 can lead out a second electrode, and the second electrode is electrically connected to the surface of each piezoelectric layer 200 close to the elastic base 100 for grounding.

[0053] Optionally, the elastic base 100 can be made of non-conductive materials such as plastic and glass, or can be made of conductive materials such as metal and metal oxide. When the elastic base 100 is made of conductive materials, the elastic base 100 can be directly used as the second electrode and connected to the ground; when the elastic base 100 is made of non-conductive materials, the second electrode can be set on the end surface of the elastic base 100, or the center of the elastic base 100 can adopt a partial hollow structure to set the second electrode in the hollow structure. The shape of the hollow can be cylindrical, rectangular, cube, etc., so as to facilitate modal excitation or second electrode extraction.

[0054] Optionally, the projection of the elastic base 100 on the preset plane completely covers the projection of the piezoelectric layer 200 on the preset plane, that is, the length dimension and the width dimension of the side surface of the elastic base 100 are respectively greater than or equal to the length dimension and the width dimension of the side surface of the piezoelectric layer 200. Optionally, the elastic base 100 can be designed in a square structure, such as a rectangular parallelepiped structure, and the elastic base 100 can have two end surfaces opposite to each other along the length direction, and any end surface is respectively parallel to its width direction and its thickness direction; two side surfaces opposite to each other along the width direction, and any side surface is respectively parallel to its length direction and its thickness direction; two side surfaces opposite to each other along the thickness direction, and any side surface is respectively parallel to its length direction and its width direction.

[0055] The friction head 300 is disposed on one side of the elastic base 100. Optionally, it can be disposed on the first electrode of the piezoelectric layer 200 on one side of the elastic base 100, or it can be directly disposed on one side of the elastic base 100 (i.e., a position on the elastic base 100 where the piezoelectric layer 200 is not disposed). The friction head 300 can be used to generate displacement components along two orthogonal directions of a preset plane, i.e., micro-vibration, when the piezoelectric driver 10 simultaneously generates vibration modes with mutually orthogonal displacement directions, thereby generating an elliptical trajectory moving along the preset plane. When different driving voltages and driving modes are adjusted, the friction head 300 can generate displacement components along two orthogonal directions on different preset planes, and generate macroscopic linear motion or rotational motion on the preset plane through the action of friction force, so as to drive the contacting sliding parts to move along different directions of the target plane, and the target plane is perpendicular to different preset planes. The sliding component is, for example, a sliding component of a piezoelectric motor. By regulating the driving voltage, the piezoelectric driver 10 can generate vibration modes in different orthogonal directions, so that the friction head 300 can generate an elliptical trajectory moving along different preset planes to drive the contacting sliding components to output displacements with different degrees of freedom.

[0056] Optionally, the shape of the friction head 300 can be designed in regular shapes such as square, cylindrical, semi-cylindrical, spherical, triangular cone, etc., or can be designed in some other irregular shapes. The material of the friction head 300 can be selected from alumina (Al2O3), silicon oxide (SiO2), zirconium oxide (ZrO2) or carbon fiber, polyester fiber, aluminum, iron, copper, stainless steel and other wear-resistant materials to prevent wear under long-term work and maintain matching accuracy.

[0057] The piezoelectric driver 10 provided in this embodiment includes: an elastic base 100; a piezoelectric layer 200 disposed on at least two orthogonal sides of the elastic base 100, and a plurality of first electrodes are disposed on the surface of the piezoelectric layer 200 on each side away from the elastic base 100; and a friction head 300 disposed on the first electrode of the piezoelectric layer 200 on one side of the elastic base 100. By regulating different driving voltages applied to the first electrode, the piezoelectric driver 10 can be stimulated to generate different vibration modes with orthogonal directions, so that the friction head 300 supports the generation of displacement components along two orthogonal directions on different preset planes to drive the contacting sliding parts to move along different directions of the target plane. Therefore, the structure of the piezoelectric driver 10 in this embodiment is simple, and a single piezoelectric driver 10 can drive the sliding parts to realize dual-degree-of-freedom motion, which can simplify the design structure of the two-degree-of-freedom piezoelectric motor, reduce the overall thickness of the piezoelectric motor, reduce the volume of the piezoelectric motor, and facilitate miniaturization, while improving the problem of limited motion stroke. In addition, through vibration drive, it can have nanometer-level displacement accuracy and realize high-precision displacement control.

[0058] In one embodiment, please refer to Figure 2 Under the action of different driving voltages, the piezoelectric driver 10 supports the first-order stretching vibration mode, the first-order bending vibration mode and the second-order bending vibration mode; wherein the first-order stretching vibration mode is coupled with the first-order bending vibration mode, so that the friction head 300 generates an elliptical trajectory moving along the first preset plane; the first-order bending vibration mode is coupled with the second-order bending vibration mode, so that the friction head 300 generates an elliptical trajectory moving along the second preset plane; the first preset plane is perpendicular to the second preset plane.

[0059] By adjusting different driving voltages and driving modes, the piezoelectric driver 10 can support the first-order stretching vibration mode, the first-order bending vibration mode, and the second-order bending vibration mode. Figure 2 As shown, the first-order stretching vibration mode can be understood as the stretching vibration mode along the X-axis direction (L in the figure). 1，X The first and second order bending vibration modes can be understood as bending vibration modes along the Z axis direction (B 2，Z The second-order bending vibration mode can be understood as the bending vibration mode along the Y-axis direction (B 2，Y vibration mode). Figure 2 As shown, L 1，X Vibration Mode and B 2，Z Vibration mode coupling causes the friction head 300 to generate an elliptical trajectory moving along the first plane (such as the XOZ plane in the figure), so that the sliding component can be derived; B 2，Y Vibration Mode and B 2，ZThe vibration mode coupling causes the friction head 300 to generate an elliptical trajectory moving along the second plane (such as the YOZ plane in the figure).

[0060] When there are two friction heads 300, the two friction heads 300 will contact the sliding part alternately in one vibration cycle, thereby alternately driving the sliding part to move along the target direction through friction. 1，X Vibration Mode and B 2，Z The vibration mode coupling makes the friction head 300 generate an elliptical trajectory moving along the XOZ plane, and the two friction heads 300 will alternately contact the sliding part in one vibration cycle, and drive the sliding part to move along the X-axis direction through the friction force; when B 2，Y Vibration Mode and B 2，Z The vibration mode coupling causes the friction head 300 to generate an elliptical trajectory moving along the YOZ plane, and the two friction heads 300 will alternately contact the sliding component within one vibration cycle, and drive the sliding component to move along the Y-axis direction through the friction force.

[0061] Among them, optionally, the resonant frequency of the first-order stretching vibration mode is equal to the resonant frequency of the first-order second-order bending vibration mode and the second-order bending vibration mode, respectively. It can be understood that the equality of this embodiment is not completely equal in a strict sense. Within an acceptable range, when the resonant frequency of the first-order stretching vibration mode is infinitely close to the resonant frequency of the first-order second-order bending vibration mode and the second-order bending vibration mode, respectively, this embodiment is also considered to be within the equal range. When the resonant frequency of the first-order stretching vibration mode is different from the resonant frequency of the first-order second-order bending vibration mode and the second-order bending vibration mode due to limitations of factors such as material and preparation process, as long as the corresponding vibration mode can realize the elliptical motion of the friction head in the corresponding plane to realize the corresponding driving function, it can be considered that the difference in resonant frequency is within an acceptable range, which can also be considered to belong to the equal scope of this application. Thus, when the resonance frequencies are close to being equal, by applying different driving voltages to different electrodes, the piezoelectric driver 10 can simultaneously excite mutually orthogonal first-order stretching vibration mode and second-order bending vibration mode, or mutually orthogonal first-order bending vibration mode and second-order bending vibration mode. Optionally, the size of the piezoelectric driver 10 can be optimized by finite element simulation so that the vibration frequencies of its first-order stretching vibration mode and second-order bending vibration mode are infinitely close.

[0062] It can be understood that in terms of modal excitation, the coupling between the first-order stretching vibration mode and the second-order bending vibration mode is adopted in this embodiment. In actual operation, it is not necessary to strictly select these two modes. As long as the elliptical motion of the friction head 300 can be excited, any combination of two or more modes is acceptable.

[0063] In one embodiment, the polarization direction of each piezoelectric layer 200 is parallel to the thickness direction of each piezoelectric layer 200 , and the polarization directions of two piezoelectric layers 200 on two orthogonal sides are orthogonal.

[0064] Among them, each piezoelectric layer 200 of this embodiment adopts a polarization method in the thickness direction, and the piezoelectric material of each piezoelectric layer 200 is polarized in a thickness direction parallel to each layer, so that the polarization directions of the two piezoelectric layers 200 on the two orthogonal sides are orthogonal, so that when the driving voltage is applied to the different piezoelectric layers 200 through the first electrode, they can be excited to produce different vibration modes with orthogonal directions. Optionally, the polarization directions of the two piezoelectric layers 200 on the two parallel sides can be the same or opposite, and this embodiment does not specifically limit this.

[0065] It should be noted that the polarization direction of each piezoelectric layer 200 is not limited to the thickness direction. In other embodiments, the polarization direction of each piezoelectric layer 200 may also be parallel to the width direction of each piezoelectric layer 200. It can be understood that based on the different polarization directions, the directions of the first vibration mode and the second vibration mode generated by the piezoelectric driver 10 are also different.

[0066] In one embodiment, if Figure 3 As shown, the elastic base 100 has four side surfaces, any two adjacent side surfaces are orthogonal, a piezoelectric layer 200 is provided on each side surface, and each piezoelectric layer 200 is provided with a plurality of first electrodes ( Figure 3 Take the example that each side surface corresponds to two first electrodes, the specific first electrodes are not shown, and only the gap is used to represent the existence interval of the first electrodes). The piezoelectric layer 200 on each side surface can generate a vibration mode through the driving voltage applied to the first electrode. On the one hand, more first electrodes can be used to excite more identical or different vibration modes to achieve the output of macroscopic motion; on the other hand, the overall vibration mode of the piezoelectric driver 10 can be made more uniform, and the overall driving ability of the piezoelectric driver 10 can be enhanced. Therefore, the piezoelectric driver 10 can achieve high thrust drive on the basis of miniaturization and high precision.

[0067] Optionally, the shapes and sizes of the piezoelectric layers 200 on the parallel sides may correspond to each other, so as to achieve a symmetrical arrangement between the parallel piezoelectric layers 200; the shapes and sizes of the first electrodes of the piezoelectric layers 200 on the parallel sides may correspond to each other, so as to achieve a symmetrical arrangement of the first electrodes between the parallel piezoelectric layers 200. It can be understood that the shapes and sizes of the piezoelectric layers 200 on the orthogonal sides may correspond to each other, and the shapes and sizes of the first electrodes of the piezoelectric layers 200 on the orthogonal sides may correspond to each other, and this embodiment does not further limit this. It can be understood that the number of first electrodes on the piezoelectric layer 200 on each side is not limited. In order to further improve the uniformity of the vibration mode, an even number of first electrodes on the piezoelectric layer 200 on each side may be set.

[0068] In one of the embodiments, please continue to refer to Figure 3 , there are two friction heads 300, which are respectively arranged on different first electrodes on the same side, and the two friction heads 300 contact the sliding part alternately in one vibration cycle. Therefore, the two friction heads 300 can alternately drive the sliding part to move in one vibration cycle, which is beneficial to reduce power consumption and improve the ability of the piezoelectric driver 10 to drive the sliding part. Optionally, the phases of the vibration trajectories of the two friction heads 300 differ by 180°, and the two friction heads 300 are alternately driven twice in the same direction in one vibration cycle, which is beneficial to further realize the high driving speed, high driving force and high power density of the piezoelectric driver 10.

[0069] In one of the embodiments, please continue to refer to Figure 3 The extending direction of each side surface is perpendicular to the thickness direction of the elastic base 100; the two friction heads 300 are arranged along the extending direction. Thus, the friction head 300 is arranged on one side of the length of the piezoelectric driver 10, so the thickness of the piezoelectric driver 10 is greatly reduced, miniaturization integration can be achieved, and device space can be saved.

[0070] In one embodiment, if Figure 4As shown, a plurality of stacked piezoelectric layers 200 are provided on each side of at least two sides, and a plurality of first electrodes (the first electrodes are not shown in the figure) are provided on the surface of each piezoelectric layer 200 away from the elastic base 100. Thus, the piezoelectric layers 200 with more layers can be driven via their respective first electrodes. By regulating the driving voltages of more piezoelectric layers 200, higher precision regulation can be further achieved, more vibration modes can be matched, and greater thrust can be achieved. Optionally, the internal electrodes of each piezoelectric layer can be divided into multiple areas by a forked electrode design, and a plurality of first electrodes can be provided on the surface of the side away from the elastic base corresponding to the piezoelectric layer segmentation area. It can be understood that the piezoelectric layers 200 with multiple layers of stacking are still relatively smaller than the stacking design of the dual piezoelectric driver 10 with a double-layer guide rail, so that the characteristics of miniaturization can still be achieved; it can be understood that the number of stacked layers can be adjusted according to the actual driving requirements and the overall size requirements, and this embodiment is not further limited to this. It can be understood that when there are multiple first electrodes on the same piezoelectric layer 200, the multiple first electrodes are spaced apart. At this time, when forming the first electrode, the piezoelectric layer 200 can directly form multiple first electrodes by electroplating, or after forming one electrode, multiple first electrodes can be formed by cutting; the interval positions between the corresponding first electrodes of the piezoelectric layer 200 can be flush with other positions, or grooves can be formed.

[0071] In one embodiment, a plurality of first electrodes are divided into at least two groups, each group includes at least two first electrodes, each first electrode in the same group is connected to the same AC voltage, and each first electrode in different groups is connected to an AC voltage with a phase difference of 90° or 270°; wherein the second electrode for grounding of the piezoelectric layer 200 is led out through the elastic base 100.

[0072] Among them, the multiple first electrodes are divided into at least two groups, which means that all the first electrodes of the entire piezoelectric driver 10 can be divided into at least two driving groups to apply different driving voltages. Each group includes at least two first electrodes, and the at least two first electrodes can come from the piezoelectric layer 200 on the same side, or from different piezoelectric layers 200. The second electrode for grounding of the piezoelectric layer 200 is led out through the elastic base 100, which may include: the second electrode is directly arranged on the end face of the elastic base 100, that is, it serves as the grounding electrode of the piezoelectric layer 200, and also as the lead-out electrode of the grounding electrode, and the second electrode is at least partially in contact with the piezoelectric layer 200; or the second electrode is arranged between the elastic base 100 and the piezoelectric layer 200, and then the second electrode is led out to the ground through the lead-out electrode arranged on the end face of the elastic base 100. The first electrode, the second electrode, the lead-out electrode, etc. can be metal sheets, or conductive layers such as conductive silver paste. The side of the piezoelectric layer 200 close to the elastic base 100 is connected to the ground voltage, and the polarization direction of each piezoelectric layer 200 points from the side of the piezoelectric layer 200 close to the elastic base 100 to the other side away from the elastic base 100, forming a voltage difference on different sides of each piezoelectric layer 200.

[0073] Each piezoelectric layer 200 is excited to generate a vibration mode by an AC voltage with a phase difference of 90°, 180° or 270° connected via different groups of first electrodes. The piezoelectric material of the piezoelectric layer 200 produces a displacement along the polarization direction due to the inverse piezoelectric effect of the piezoelectric mode, so that the vibration modes of the piezoelectric layer 200 with orthogonal directions are simultaneously excited under the action of the electric field. Due to the phase difference of the applied voltage, the displacement components perpendicular to each other along the preset plane generated in the friction head 300 will couple to form a microscopic elliptical motion.

[0074] The above embodiment is further explained below with specific examples:

[0075] In this embodiment, the elastic base 100 includes four side surfaces (the upper side surface, the lower side surface, the left side surface and the right side surface) and two end surfaces, each side surface is provided with a piezoelectric layer 200, each piezoelectric layer 200 is provided with two first electrodes, each end surface leads to a second electrode, and the number of friction heads 300 is two, and the two friction heads 300 are provided on the two first electrodes of the piezoelectric layer 200 on the upper side surface. The piezoelectric layers 200 on each side surface have the same shape and size, and the size is the same as that of the side surface; the shape and size of each first electrode are respectively the same.

[0076] like Figure 5As shown, the first electrodes on each piezoelectric layer 200 are named 11A1, 11A2, 11B1, 11B2 (located on the same piezoelectric layer 200 as 11B1), 11C1, 11C2, 11D1, 11D2. The lead-out electrode on the elastic base for leading out the second electrode of the piezoelectric layer 200 is named 11E1. Each piezoelectric layer 200 is polarized in a partitioned manner along the thickness direction, and the polarization directions of the piezoelectric layers 200 on opposite sides are the same.

[0077] In this embodiment, the voltage driving method of the piezoelectric driver 10 to drive the sliding component to move along the X-axis can be as follows:

[0078] As shown in FIG6(a), when a voltage Vsin(2πft) is applied to electrodes 11A1, 11B1, 11B2, and 11C1, a voltage Vsin(2πft+π / 2) is applied to electrodes 11A2 and 11C2, a voltage Vsin(2πft+π) is applied to electrodes 11D1 and 11D2, and electrode 11E is grounded (where f is close to L 1,X , B 2,Z Resonance frequency (vibration frequency), L 1,X , B 2,Z The vibration modes will be excited simultaneously (refer to Figure 8 ), due to the phase difference of the applied voltage, the mutually perpendicular displacement components along the X-axis and the Z-axis at the friction head 300 will couple to form a microscopic elliptical motion, and within one vibration cycle, the two friction heads 300 alternately contact the sliding part, pushing the sliding part to perform macroscopic linear motion along the X-axis.

[0079] As shown in FIG6(b), when a voltage Vsin(2πft) is applied to electrodes 11A1, 11B1, and 11C1, a voltage Vsin(2πft+π / 2) is applied to electrodes 11A2, 11B2, and 11C2, a voltage Vsin(2πft+π) is applied to electrode 11D1, a voltage Vsin(2πft+3π / 2) is applied to electrode 11D2, and electrode 11E is grounded; or as shown in FIG6(c), when a voltage Vsin(2πft) is applied to electrodes 11A1 and 11C1, and electrodes 11B1, 11B2, 11D1, 11D2, and 11E are grounded, L can also be excited simultaneously. 1,X , B 2,Z The vibration mode drives the sliding part to perform macroscopic linear motion along the X-axis.

[0080] In this embodiment, the voltage driving method of the piezoelectric driver 10 to drive the sliding component to move along the Y axis can be as follows:

[0081] like Figure 7 and Figure 8As shown, when a voltage Vsin(2πft) is applied to electrodes 11A1, 11B1, 11C1, 11D1, a voltage Vsin(2πft+π / 2) is applied to electrodes 11A2, 11B2, 11C2, 11D2, and electrode 11E is grounded (where f is close to B 2,Y , B 2,Z Resonance frequency (vibration frequency), B 2,Y , B 2,Z The vibration modes will be excited at the same time. Due to the phase difference of the applied voltage, the mutually perpendicular displacement components along the Y-axis and the Z-axis at the friction head 300 will couple to form a microscopic elliptical motion. In one vibration cycle, the two friction heads 300 alternately contact the sliding part, pushing the sliding part to perform macroscopic linear motion along the Y-axis.

[0082] Thus, the piezoelectric driver 10 of this embodiment can drive the sliding component to move arbitrarily in the XOY plane or at least move freely on the X-axis and the Y-axis. Figure 6(a)-Figure 6(c) When the driving voltage is as shown, the friction head 300 is in contact with and separated from the sliding output component, and the sliding output component can be pushed to move linearly along the X axis. Figure 7 When the driving voltage is 0.1V, the friction head 300 of the piezoelectric driver 10 is in contact and separated from the sliding output component, and the sliding output component can be pushed to move linearly along the Y axis. By changing the way of applying voltage, the piezoelectric motor can achieve two-degree-of-freedom motion along the X axis and the Y axis. Therefore, the piezoelectric driver 10 provided in this embodiment has the characteristics of miniaturization, high precision, large thrust, no electromagnetic interference, etc., and can simultaneously achieve displacement drive with two degrees of freedom.

[0083] The present application also provides a piezoelectric motor, such as Fig. 9 As shown, it includes the piezoelectric driver 10 and the sliding component 20 of the above embodiment; wherein, when the friction head 300 generates displacement components along two orthogonal directions on different preset planes, the sliding component 20 is driven to move in at least one direction on the target plane. The piezoelectric motor has a simple structure and is easy to integrate. It has the characteristics of miniaturization, high precision, large thrust, no electromagnetic interference, etc., and can simultaneously realize displacement drive with two degrees of freedom.

[0084] In one embodiment, the number of friction heads 300 is two. When the friction heads 300 generate an elliptical trajectory moving along a first preset plane, the two friction heads 300 contact the sliding component 20 alternately within one vibration cycle to drive the sliding component 20 to move at least along a first direction on the target plane by friction force; when each friction head 300 generates an elliptical trajectory moving along a second preset plane, the two friction heads 300 contact the sliding component 20 alternately within one vibration cycle to drive the sliding component 20 to move at least along a second direction on the target plane by friction force; the second direction is orthogonal to the first direction. Thus, by changing the applied voltage, the piezoelectric motor can achieve arbitrary movement within the target plane or free movement at least along the first direction and the second direction.

[0085] In one embodiment, a friction plate is provided on a side of the sliding component 20 that contacts the friction head 300, and the friction plate drives the sliding component 20 in the first direction and / or the second direction under the drive of the friction head 300. Thus, the relative friction movement between the friction head 300 and the friction plate can drive the movement of the sliding component 20.

[0086] Optionally, the friction plate can form a surface, line or point contact with the friction head 300 to drive the sliding component 20 to move under the drive of the friction head 300. Optionally, the friction plate can be made of a wear-resistant material, and the wear-resistant material includes at least one of aluminum oxide, zirconium oxide, silicon carbide, carbon fiber, and a polymer composite material. It can be understood that a specific wear-resistant material is selected according to different friction drive requirements, and this embodiment does not make further limitations on this.

[0087] In one embodiment, the number of piezoelectric drivers 10 is multiple, and the multiple piezoelectric drivers 10 drive the movement of the sliding component 20 at the same target plane at the same time, thereby greatly increasing the thrust of driving the sliding component 20. Further, the multiple piezoelectric drivers 10 can drive the sliding component 20 to move in the same direction; further, the multiple piezoelectric drivers 10 can also drive the sliding component 20 in different directions, so as to adjust the sliding component 20 to move in different directions, and even make the sliding component 20 rotate.

[0088] It can be understood that the multiple piezoelectric drivers 10 of this embodiment are not set as double-layer guide rails as in the related art, but can be understood as the design of the same layer and the same guide rail or the same layer and multiple guide rails. Therefore, the piezoelectric motor of this embodiment does not have an additional increase in thickness, which is still conducive to the miniaturization design of the piezoelectric motor.

[0089] like Fig.10 As shown, in one embodiment, the piezoelectric motor further includes: a fixed base 30 and an elastic pre-tightening structure 40 .

[0090] The piezoelectric driver 10 is installed on the fixed base 30 via the elastic pre-tightening structure 40 , and under the action of the pre-tightening force provided by the elastic pre-tightening structure 40 , the friction head 300 of the piezoelectric driver 10 is in elastic contact with the sliding component 20 .

[0091] Among them, the elastic preload structure 40 can give the piezoelectric driver 10 enough space to move, so as to ensure that the piezoelectric driver 10 can normally excite the coupling mode. At the same time, the piezoelectric driver 10 can have elastic force, so as to ensure that the friction head 300 on the piezoelectric driver 10 can alternately elastically contact the sliding part 20 or continuously contact the sliding part 20 as required. Optionally, the elastic preload structure 40 can be designed using springs, springs, and clamping parts. The purpose of the clamping part is to ensure that the bonding is firm while giving the piezoelectric driver 10 enough space to move, so as to ensure that the piezoelectric driver 10 can normally excite the coupling mode. The fixed base 30 is used to fix the piezoelectric motor to achieve stable driving of the piezoelectric motor.

[0092] This embodiment is based on the simple and compact structure of the piezoelectric driver 10, which is beneficial to the miniaturized design of the piezoelectric motor and can be used in the optical image stabilization of the lens shift and sensor shift in the mobile phone camera module (compact camera module); at the same time, based on the voltage regulation, high precision, large thrust, and no electromagnetic interference of the piezoelectric driver 10, the movement range of the piezoelectric motor is not limited, and it has the characteristics of self-locking when power is off, no electromagnetic interference, and micrometer-level or even nanometer-level displacement accuracy.

[0093] The present application also provides an electronic device, including: a piezoelectric motor as in the above embodiment, based on the above-mentioned piezoelectric motor and piezoelectric driver 10, which has greater application advantages in aerospace, precision positioning systems, automatic zoom lenses, biotechnology and medicine, micro / nano electromechanical systems (MEMS / NEMS) and other fields.

[0094] In some embodiments, each piezoelectric layer 200 in the piezoelectric driver 10 is arranged on the elastic base 100 by bonding. In other embodiments, when the piezoelectric layer 200 includes a multilayer piezoelectric sheet, the piezoelectric layer 200 can be prepared by an integrated sintering molding process, and multiple piezoelectric layers 200 can also be formed into an integrated structure by an integrated sintering molding process, and then bonded to the elastic base 100. Alternatively, each piezoelectric layer 200 is prepared by integrated sintering molding and then bonded to the elastic base 100, which is beneficial to simplifying the preparation process of the piezoelectric driver 10 and improving the feasibility of mass production.

[0095] See also Fig.11 , Fig.12 and Fig.13As shown, based on the piezoelectric driver 10 and the piezoelectric motor described in any of the above embodiments, examples of electronic devices 50 in some embodiments are given below. The electronic devices 50 provided in this embodiment include but are not limited to smart phones, tablet computers, e-readers, etc., and smart phones are used as examples below. In some embodiments, the electronic device 50 includes a housing 51 and a camera module 60. The housing 51 is provided with a light inlet 511. The camera module 60 is arranged in the housing 51 and can collect ambient light through the light inlet 511 to achieve a camera function.

[0096] Combination Fig.14 and Fig.15 As shown, in some embodiments, the camera module 60 includes a lens assembly 61 and an image sensor 62. The lens assembly 61 is opposite to the light inlet 511. The lens assembly 61 may include a lens barrel and one or more lenses with optical power arranged in the lens barrel. The image sensor 62 includes but is not limited to a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS). The lens assembly 61 can collect light through the light inlet 511, adjust the light through the lens, and then transmit the light to the photosensitive surface of the image sensor 62 for imaging.

[0097] Furthermore, combined with Fig.15 and Fig.16 As shown, in some embodiments, the camera module 60 further includes a bracket 63 and a piezoelectric motor as described in any of the above embodiments, the sliding component 20 of the piezoelectric motor is slidably disposed on the bracket 63, and the image sensor 62 is relatively fixed to the sliding component 20, for example, the image sensor 62 is directly fixed to the sliding component 20, or is indirectly fixed to the sliding component 20 through other elements. The piezoelectric driver 10 contacts the sliding component 20 and is used to drive the sliding component 20 to slide relative to the bracket 63, so that the sliding component 20 drives the image sensor 62 to move relative to the bracket 63 to achieve the optical image stabilization function of the camera module 60. It can be understood that the piezoelectric motor described in any of the above embodiments is used in the camera module 60 to achieve the optical image stabilization function. The piezoelectric motor has the characteristics of small size, no stroke limit, power-off self-locking, no electromagnetic interference, high displacement accuracy, etc., which is conducive to compressing the size of the camera module 60 and improving the accuracy of optical image stabilization, thereby facilitating the improvement of the imaging quality of the camera module 60. For example, when the piezoelectric driver 10 has two friction heads 300, the two friction heads 300 are arranged in a direction parallel to the photosensitive surface of the image sensor 62, for example, in the X-axis direction. While realizing the optical image stabilization function, it is also beneficial to compress the size of the piezoelectric driver 10 in the thickness direction (Z-axis direction) of the camera module 60, thereby facilitating the miniaturization design of the camera module 60.

[0098] In some embodiments, the friction head 300 of the piezoelectric driver 10 contacts the sliding component 20 and is used to generate displacement components along two orthogonal directions on the first preset plane or the second preset plane, thereby driving the sliding component 20 to drive the image sensor 62 to move on the target plane. Among them, the first preset plane and the second preset plane are perpendicular to each other and are both perpendicular to the photosensitive surface of the image sensor 62, and the target plane is parallel to the photosensitive surface of the image sensor 62. For example, the first preset plane is the XOZ plane in the figure, the second preset plane is the YOZ in the figure, and the target plane is the XOY plane in the figure. In other words, the piezoelectric driver 10 can drive the sliding component 20 to drive the image sensor 62 to move in any direction parallel to the X-axis direction and the Y-axis direction of the photosensitive surface, which can meet the requirements of optical image stabilization. At the same time, an unlimited travel X, Y dual-degree-of-freedom optical image stabilization can be achieved through a piezoelectric driver 10, without the need to set a dual-track structure, which is conducive to simplifying the structure of the camera module 60 and compressing the space occupied by the camera module 60.

[0099] In some embodiments, the piezoelectric motor is provided with two piezoelectric drivers 10, and both piezoelectric drivers 10 are in contact with the sliding part 20. It can be understood that when the two piezoelectric drivers 10 simultaneously drive the sliding part 20 to move in the same direction along the X-axis direction or the Y-axis direction, the superposition of the effects of the two piezoelectric drivers 10 can improve the accuracy, driving force and reliability of optical image stabilization. In some embodiments, the two piezoelectric drivers 10 can also generate motions along the first preset plane and the second preset plane respectively. For example, one of the piezoelectric drivers 10 drives the sliding part 20 to move along the X-axis direction, and the other piezoelectric driver 10 drives the sliding part 20 to move along the Y-axis direction, so that the cooperation of the two piezoelectric drivers 10 can drive the sliding part 20 to rotate around an axis perpendicular to the photosensitive surface of the image sensor 62, for example, around the Y-axis. Therefore, by setting two piezoelectric drivers 10, the translation, rotation and other movements of the image sensor 62 on the XOY plane can be realized, which effectively meets the requirements of optical image stabilization and improves the imaging quality of the camera module 60. In this embodiment, the two piezoelectric drivers 10 can respectively contact the two opposite edges of the sliding component 20 in the X-axis direction, or the two opposite edges in the Y-axis direction, so that the force on the sliding component 20 is more uniform, thereby improving the accuracy and reliability of optical image stabilization.

[0100] In some embodiments, the piezoelectric motor further includes an elastic pre-tightening structure 40. The elastic pre-tightening structure 40 can be designed using structures such as springs, springs, and clamping components. The elastic pre-tightening structure 40 is connected to the bracket 63 and elastically abuts against the side of the piezoelectric driver 10 that is away from the sliding component 20. It can be understood that in this embodiment, the bracket 63 plays the role of a fixed base of the piezoelectric motor. The elastic pre-tightening structure 40 is provided to elastically abut the piezoelectric driver 10 against the sliding component 20. The elastic pre-tightening structure 40 can give the piezoelectric driver 10 enough room for movement, so that the piezoelectric driver 10 can normally excite the coupling mode. At the same time, the elastic force of the elastic pre-tightening structure 40 is also conducive to the friction head 300 to alternately elastically contact or continuously contact the sliding component 20 according to needs to maintain the stability of the driving function.

[0101] Combination Fig.16 and Fig.17 As shown, in some embodiments, the elastic preload structure 40 includes a limiting portion 636 and an elastic connection portion 638, the limiting portion 636 is provided with a limiting groove 637 facing the sliding component 20, at least part of the piezoelectric driver 10 is fixedly disposed in the limiting groove 637, for example, fixed to the bottom surface of the limiting groove 637 by any suitable fixing method such as gluing, and the two ends of the elastic connection portion 638 are respectively connected to the bracket 63 and the limiting portion 636. When two piezoelectric drivers 10 are provided, two elastic preload structures 40 may also be provided, and the structural designs of the two elastic preload structures 40 may be the same, for example, they may be mirror-symmetrical about the XOZ plane.

[0102] Combination Fig.17 and Fig.18 As shown, in some embodiments, two opposite edges of the sliding component 20 are provided with matching grooves 633 on the side facing away from the base, and at least parts of the two piezoelectric drivers 10 are located in the matching grooves 633 and contact the bottom surface of the matching grooves 633. It can be understood that when the piezoelectric driver 10 drives the sliding component 20 to move in the X-axis direction and / or the Y-axis direction, the piezoelectric driver 10 will also synchronously move relative to the sliding component 20 in the matching groove 633. The dimensions of the matching groove 633 in the X-axis direction and the Y-axis direction are larger than the dimensions of the piezoelectric driver 10. The maximum travel of the piezoelectric driver 10 in the matching groove 633 in the X-axis direction and the Y-axis direction determines the anti-shake movement travel of the image sensor 62.

[0103] refer to Fig.16 , Fig.19 and Fig. 20As shown, in some embodiments, the piezoelectric motor further includes a rolling element 71, including but not limited to a ball, etc. The rolling element 71 is rotatably disposed on one of the sliding component 20 and the bracket 63, and rollingly cooperates with a slide groove 634 disposed on the other of the sliding component 20 and the bracket 63, so that the sliding component 20 can slide relative to the bracket 63 under the drive of the piezoelectric driver 10. For example, in Fig.19 and Fig. 20 In the illustrated embodiment, the rolling element 71 is rotatably disposed on the bracket 63. For example, the rolling element 71 may be partially embedded in the bracket 63 and rotatably connected to the bracket 63 through a rotating shaft or other structures. A sliding groove 634 is provided at a portion of the sliding component 20 that is opposite to the rolling element 71. The rolling element 71 is partially located in the sliding groove 634 and rolls with the bottom surface of the groove 634. It can be understood that when the sliding component 20 moves relative to the bracket 63 under the drive of the piezoelectric driver 10, the rolling element 71 will also roll synchronously in the sliding groove 634 and generate relative displacement with the sliding component 20. The dimensions of the sliding groove 634 in the X-axis direction and the Y-axis direction are greater than the dimensions of the rolling element 71. The maximum movement stroke of the rolling element 71 in the sliding groove 634 determines the anti-shake movement stroke of the image sensor 62.

[0104] In some embodiments, four rolling members 71 are provided, and the four rolling members 71 are rotatably provided at the four corners of the bracket 63 respectively. The sliding component 20 is provided with four sliding grooves 634. The four sliding grooves 634 roll in cooperation with the four rolling members 71 in a one-to-one correspondence. The stability of the relative movement between the sliding component 20 and the bracket 63 is improved through the four rolling members 71, thereby improving the accuracy and stability of the optical image stabilization function.

[0105] Please see again Fig.15 and Fig.16 As shown, in some embodiments, the camera module 60 further includes a hard circuit board 72 and a filter 73, the hard circuit board 72 includes but is not limited to a printed circuit board (PCB), etc., the image sensor 62 is arranged on the hard circuit board 72 and is electrically connected to the hard circuit board 72, the hard circuit board 72 is fixedly arranged on the sliding component 20 so that the image sensor 62 and the sliding component 20 are relatively fixed, and the filter 73 is fixedly arranged on the sliding component 20 and is located on the side of the image sensor 62 facing away from the hard circuit board 72. The filter 73 includes but is not limited to an infrared cutoff filter 73, and the filter 73 is arranged between the lens and the image sensor 62 along the Z-axis direction, and is used to filter out interference light, so as to prevent the interference light in the light emitted by the lens from being projected onto the image sensor 62 and affecting the imaging quality. It can be understood that when the piezoelectric driver 10 drives the sliding component 20 to move relative to the bracket 63 to achieve the optical image stabilization function, the sliding component 20, the image sensor 62, the filter 73 and the hard circuit board 72 will move synchronously relative to the bracket 63 to maintain the stability and reliability of the electrical connection performance during the movement.

[0106] Further, in some embodiments, the camera module 60 further includes a flexible circuit board 74, one end of which is electrically connected to the rigid circuit board 72, and the other end of which extends to the outside of the bracket 63 and is electrically connected to external components, such as the central processing unit of the electronic device 50, or a chip in the electronic device 50 specifically used for image processing, so as to realize power supply and control of the image sensor 62. In some embodiments, the portion of the flexible circuit board 74 located between the sliding component 20 and the bracket 63 has at least one corner, that is, the flexible circuit board 74 has two overlapping parts, for example, a portion of the flexible circuit board 74 is folded and overlapped to form a corner. Thus, when the rigid circuit board 72, the image sensor 62 and the sliding component 20 move synchronously relative to the bracket 63, the flexible circuit board 74 can adapt to the movement of the rigid circuit board 72 at the corner and deform, change the corner position and the overlapping area of ​​the overlapping part, and is not easy to interfere with the movement of the rigid circuit board 72 relative to the bracket 63, nor is it easy to be damaged due to deformation and pulling, which is conducive to improving the structural reliability of the camera module 60 and the stability of the optical image stabilization function.

[0107] In some embodiments, the bracket 63 includes a bottom plate 631 and a side plate 632 arranged around the bottom plate 631. In the direction perpendicular to the photosensitive surface of the image sensor 62 (Z-axis direction), the bottom plate 631, the sliding component 20 and the piezoelectric driver 10 are arranged in sequence, the rolling member 71 is arranged between the bottom plate 631 and the sliding component 20, and the side plate 632 is arranged around the sliding component 20. Therefore, when assembling the camera module 60, the rolling member 71, the sliding component 20 and the piezoelectric driver 10 can be arranged on the bracket 63 in sequence, which is conducive to simplifying the assembly process and improving the structural reliability. Of course, in other embodiments, the piezoelectric driver 10 can also be arranged between the sliding component 20 and the bottom plate 631, and the layout of the rolling member 71 can be adjusted adaptively, as long as the sliding component 20 can drive the image sensor 62 to move relative to the bracket 63 to achieve the optical image stabilization function.

[0108] See also Fig.13 , Fig.15 and Fig.21As shown, in some embodiments, the camera module 60 further includes a housing 75, a lens assembly 61 is disposed on the sliding component 20 of the piezoelectric motor, a piezoelectric driver 10 of the piezoelectric motor is disposed on the housing 75, the friction head 300 faces the sliding component 20 and contacts the sliding component 20, and the piezoelectric driver 10 is used to drive the sliding component 20 to drive the lens assembly 61 to move along the axial direction (Z-axis direction) to achieve the optical focus function of the camera module 60. It can be understood that the piezoelectric motor described in any of the above embodiments is used in the camera module 60 to achieve the optical focus function. The piezoelectric motor has the characteristics of small size, no stroke limit, power-off self-locking, no electromagnetic interference, high displacement accuracy, etc., which is conducive to compressing the size of the camera module 60 and improving the accuracy of optical focus, thereby facilitating the improvement of the imaging quality of the camera module 60. For example, when the piezoelectric driver 10 has two friction heads 300, the two friction heads 300 are arranged in a direction perpendicular to the axis of the lens assembly 61, for example, in the X-axis direction, which is beneficial to compressing the size of the piezoelectric driver 10 in the thickness direction (Z-axis direction) of the camera module 60 while realizing the optical image stabilization function, thereby facilitating the miniaturization design of the camera module 60. It can be understood that in this embodiment, the housing 75 acts as a fixed base of the piezoelectric motor.

[0109] In some embodiments, the friction head 300 contacts the sliding member 20 and is used to move the lens assembly 61 in a predetermined plane (eg, Fig.21 Displacement components along two orthogonal directions are generated on the YOZ plane shown in the figure, wherein the direction of one displacement component is perpendicular to the axis of the lens assembly 61, and the direction of the other displacement component is parallel to the axis of the lens assembly 61, thereby driving the lens assembly 61 to move along the axial direction (Z-axis direction) to achieve the optical focusing function.

[0110] In some embodiments, the piezoelectric motor further comprises a rolling member 71, which is rotatably disposed on one of the housing 75 and the sliding component 20 and rolls with the other of the housing 75 and the sliding component 20, so that the housing 75 and the sliding component 20 can slide relative to each other, and the relative sliding direction of the housing 75 and the sliding component 20 is parallel to the axis of the lens assembly 61, that is, parallel to the Z-axis direction. For example, in the embodiment shown in the figure, the rolling member 71 is rotatably disposed on the housing 75, and the sliding component 20 is provided with a rolling groove 635 opposite to the rolling member 71, and the rolling member 71 is partially embedded in the rolling groove 635 and rolls with the bottom wall of the rolling groove 635, and the rolling groove 635 extends along the axis direction (Z-axis direction) of the lens assembly 61 to limit the relative sliding direction of the sliding component 20 and the housing 75.

[0111] The number of rolling elements 71 is not limited, as long as the relative sliding between the sliding component 20 and the housing 75 can be achieved. Fig.21In the embodiment shown in , there are two groups of rolling elements 71, two rolling grooves 635 are provided on the sliding component 20, and the two groups of rolling elements 71 are rollingly matched in the two rolling grooves 635 in a one-to-one correspondence in the sliding component 20, and each group of rolling elements 71 includes three rolling elements 71 arranged in sequence along the axis direction of the lens assembly 61. By providing two groups of multiple rolling elements 71, the stability and accuracy of the relative sliding between the sliding component 20 and the housing 75 can be improved.

[0112] In some embodiments, the piezoelectric motor further includes an elastic pre-tightening structure 40, which is disposed on the side of the housing 75 facing the sliding component 20, and the piezoelectric driver 10 is disposed on the side of the elastic pre-tightening structure 40 facing away from the housing 75 and in contact with the sliding component 20. The elastic pre-tightening structure 40 includes but is not limited to structures such as springs, and the provision of the elastic pre-tightening structure 40 can provide sufficient activity space for the piezoelectric driver 10 so that the piezoelectric driver 10 can normally excite the coupling mode. At the same time, the elastic force of the elastic pre-tightening structure 40 can also make the friction head 300 on the piezoelectric driver 10 alternately elastically contact the sliding component 20 or continuously contact the sliding component 20 according to needs, thereby improving the stability and reliability of the operation of the piezoelectric motor.

[0113] In some embodiments, the sliding component 20 is circumferentially arranged around the lens assembly 61, the housing 75 is circumferentially arranged around the sliding component 20, the piezoelectric driver 10 and the elastic preload structure 40 are located between the inner wall surface of the housing 75 and the outer wall surface of the sliding component 20, and the connection method between the piezoelectric driver 10, the elastic preload structure 40 and the housing 75 includes but is not limited to gluing, etc.

[0114] It should be noted that in Fig.15 In the illustrated embodiment, the camera module 60 is equivalent to being provided with two groups of piezoelectric motors, one of which is used to drive the image sensor 62 to move on a plane parallel to the photosensitive surface to achieve the optical image stabilization function of the camera module 60, and the other group of piezoelectric motors is used to drive the lens assembly 61 to move along the axis direction to achieve the optical focus function of the camera module 60. In other embodiments, the camera module 60 may also be provided with only one group of piezoelectric motors, which is used to drive one of the image sensor 62 or the lens assembly 61 to move to achieve one of the optical image stabilization and optical focus functions. When the piezoelectric motor used to drive the movement of the lens assembly 61 is omitted, the lens assembly 61 can be directly arranged on the housing 75, and when the piezoelectric motor used to drive the movement of the image sensor 62 is omitted, the image sensor 62 and the hard circuit board 72 can be directly arranged on the bracket 63. The various components of the camera module 60 can be adapted and adjusted according to the number and setting position of the piezoelectric motors, which will not be described in detail in this application.

[0115] Of course, in some embodiments, the piezoelectric motor is used to realize the setting of the optical image stabilization and / or optical focus function, and the position sensing device can also be used to monitor the position of the lens assembly 61 or the image sensor 62, so as to realize closed-loop control in cooperation with the piezoelectric motor, thereby improving the accuracy of the optical image stabilization and / or optical focus function. The specific setting of the position sensing device is not limited, including but not limited to the use of a grating scale, a capacitive scale, or a combination of a magnet and a Hall element.

[0116] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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.

[0117] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A piezoelectric actuator, characterized in that: include: Elastic base; A piezoelectric layer is disposed on at least two orthogonal side surfaces of the elastic base, and a surface of the piezoelectric layer on each side surface away from the elastic base is provided with a plurality of first electrodes; A friction head, disposed on the elastic base or on one side of the first electrode; Among them, under the action of different driving voltages, each of the first electrodes excites the piezoelectric driver to produce different vibration modes with orthogonal directions, so that the friction head supports the generation of displacement components along two orthogonal directions on different preset planes, so as to drive the contacting sliding parts to move in different directions along the target plane, and the target plane is perpendicular to the different preset planes.

2. The piezoelectric actuator according to claim 1, characterized in that: Under the action of different driving voltages, the piezoelectric driver supports the first-order stretching vibration mode, the first-order bending vibration mode and the second-order bending vibration mode; Among them, the first-order stretching vibration mode is coupled with the first-order second-order bending vibration mode, so that the friction head produces an elliptical trajectory moving along the first preset plane; the first-order second-order bending vibration mode is coupled with the second-order second-order bending vibration mode, so that the friction head produces an elliptical trajectory moving along the second preset plane; the first preset plane is perpendicular to the second preset plane.

3. The piezoelectric actuator according to claim 2, characterized in that: The resonance frequency of the first-order stretching vibration mode is equal to the resonance frequency of the first-order second-order bending vibration mode and the second-order second-order bending vibration mode.

4. The piezoelectric actuator according to claim 1, characterized in that: The polarization direction of each piezoelectric layer is parallel to the thickness direction of each piezoelectric layer, and the polarization directions of the two piezoelectric layers on two orthogonal side surfaces are orthogonal to each other.

5. The piezoelectric actuator according to claim 1, characterized in that: The elastic base has four side surfaces, any two adjacent side surfaces are orthogonal, each side surface is provided with the piezoelectric layer, and each piezoelectric layer is provided with a plurality of first electrodes spaced apart from each other.

6. The piezoelectric actuator according to claim 5, characterized in that: There are two friction heads, which are respectively arranged on different first electrodes on the same side surface, and the two friction heads contact the sliding component alternately in one vibration cycle.

7. The piezoelectric actuator according to claim 6, characterized in that: The extending direction of each of the side surfaces is perpendicular to the thickness direction of the elastic base; and the two friction heads are arranged along the extending direction.

8. The piezoelectric actuator according to claim 1, characterized in that: A plurality of stacked piezoelectric layers are provided on each of the at least two side surfaces, and a plurality of the first electrodes are provided on a surface of each piezoelectric layer that is away from the elastic base.

9. The piezoelectric driver according to any one of claims 1 to 8, characterized in that: The plurality of first electrodes are divided into at least two groups, each group includes at least two first electrodes, the first electrodes in the same group are connected to the same AC voltage, and the first electrodes in different groups are connected to AC voltages with a phase difference of 90°, 180° or 270°; Wherein, the second electrode of the piezoelectric layer used for grounding is led out through the elastic base.

10. A piezoelectric motor, characterized in that: include: The piezoelectric actuator and sliding component as described in any one of claims 1 to 9; Wherein, when the friction head contacts the sliding component and generates displacement components along two orthogonal directions on different preset planes, the sliding component is driven to move on the target plane.

11. The piezoelectric motor according to claim 10, wherein: In the case where the friction head generates an elliptical trajectory moving along a first preset plane, the friction head drives the sliding component to move at least along a first direction on the target plane through friction force; In the case where the friction head generates an elliptical trajectory moving along a second preset plane, the friction head drives the sliding component to move at least along a second direction on the target plane through friction force; the second direction is orthogonal to the first direction.

12. The piezoelectric motor according to claim 11, characterized in that A friction plate is provided on a surface of the sliding component that contacts the friction head. The friction plate drives the sliding component in the first direction and / or the second direction under the drive of the friction head.

13. The piezoelectric motor according to claim 10, wherein: The number of the piezoelectric drivers is one or more. When the number of the piezoelectric drivers is plural, the multiple piezoelectric drivers drive the movement of the sliding component at the same target plane at the same time.

14. The piezoelectric motor according to claim 10, wherein: Also includes: Fixed base and elastic preload structure; Wherein, the piezoelectric driver is mounted on the fixed base via the elastic pre-tightening structure, and under the action of the pre-tightening force provided by the elastic pre-tightening structure, the friction head of the piezoelectric driver is in elastic contact with the sliding component.

15. An electronic device, characterized in that: include: A piezoelectric motor as claimed in any one of claims 10 to 14.

16. A camera module, characterized in that: Comprising a piezoelectric motor as described in any one of claims 10-14.

17. The camera module according to claim 16, characterized in that: The camera module also includes an image sensor and a bracket. The sliding component is slidably disposed on the bracket. The image sensor and the sliding component are relatively fixed. The piezoelectric driver is in contact with the sliding component and is used to drive the sliding component to slide relative to the bracket.

18. The camera module according to claim 17, characterized in that: The friction head is used to generate displacement components along two orthogonal directions on a first preset plane or a second preset plane, the first preset plane and the second preset plane are perpendicular to each other and both perpendicular to the photosensitive surface of the image sensor, and the target plane is parallel to the photosensitive surface of the image sensor.

19. The camera module according to claim 18, characterized in that: The piezoelectric motor is provided with two piezoelectric drivers, both of which are in contact with the sliding component, and the friction heads of the two piezoelectric drivers can respectively perform elliptical motion along the first preset plane and the second preset plane to drive the sliding component to rotate around an axis perpendicular to the photosensitive surface of the image sensor.

20. The camera module according to claim 17, characterized in that: The piezoelectric motor further comprises an elastic pre-tightening structure, which is connected to the bracket and elastically abuts against a side of the piezoelectric driver facing away from the sliding component.

21. The camera module according to claim 20, characterized in that: The elastic pre-tightening structure includes a limiting portion and an elastic connecting portion, the limiting portion is provided with a limiting groove facing the sliding component, at least a portion of the piezoelectric driver is fixedly disposed in the limiting groove, and both ends of the elastic connecting portion are respectively connected to the bracket and the limiting portion.

22. The camera module according to claim 17, characterized in that: The camera module also includes a hard circuit board and a filter. The hard circuit board is fixedly arranged on the sliding component. The image sensor is arranged on the hard circuit board. The filter is fixedly arranged on the sliding component and is located on the side of the image sensor facing away from the hard circuit board.

23. The camera module according to claim 22, characterized in that: The camera module also includes a flexible circuit board, one end of which is connected to the hard circuit board, and the other end of which extends outside the bracket, and the portion of the flexible circuit board located between the sliding component and the bracket has at least one corner.

24. The camera module according to claim 17, characterized in that: The piezoelectric motor further comprises a rolling element, which is rotatably disposed on one of the sliding component and the bracket and rollingly cooperates with a sliding groove on the other one of the sliding component and the bracket.

25. The camera module according to claim 24, characterized in that: The bracket includes a base plate and a side plate arranged around the base plate. In a direction perpendicular to the photosensitive surface of the image sensor, the base plate, the sliding component and the piezoelectric driver are arranged in sequence, the rolling member is arranged between the base plate and the sliding component, and the side plate is arranged around the sliding component.

26. The camera module according to claim 25, characterized in that: The two opposite edges of the sliding component are provided with matching grooves on the side facing away from the bottom plate, and at least parts of the two piezoelectric drivers are located in the matching grooves and contact with the bottom surfaces of the matching grooves.

27. The camera module according to claim 17, characterized in that: There are two friction heads, and the two friction heads are arranged in a direction parallel to the photosensitive surface of the image sensor.

28. The camera module according to claim 16, characterized in that: The camera module also includes a housing and a lens assembly, wherein the lens assembly is disposed on the sliding component, the piezoelectric driver is disposed on the housing, and the friction head faces the sliding component and contacts the sliding component.

29. The camera module according to claim 28, characterized in that: The friction head is in contact with the sliding component and is used to generate displacement components along two orthogonal directions on a preset plane parallel to the axis of the lens assembly, wherein the direction of one displacement component is perpendicular to the axis of the lens assembly, and the direction of the other displacement component is parallel to the axis of the lens assembly.

30. The camera module according to claim 28, characterized in that: The piezoelectric motor also includes a rolling member, which is rotatably disposed on one of the outer shell and the sliding component and rollingly cooperates with the other of the outer shell and the sliding component so that the outer shell and the sliding component can slide relative to each other, and the relative sliding direction of the outer shell and the sliding component is parallel to the axis of the lens assembly.

31. The camera module according to claim 28, characterized in that: The number of the friction heads is two, and the two friction heads are arranged in a direction perpendicular to the axis of the lens assembly.

32. The camera module according to claim 28, characterized in that: The piezoelectric motor further comprises an elastic pre-tightening structure, which is arranged on a side of the housing facing the sliding component, and the piezoelectric driver is arranged on a side of the elastic pre-tightening structure facing away from the housing and in contact with the sliding component.

33. The camera module according to claim 28, characterized in that: The sliding component is arranged around the lens assembly in a circumferential direction, the housing is arranged around the sliding component in a circumferential direction, and the piezoelectric driver is located between the inner wall surface of the housing and the outer wall surface of the sliding component.

34. An electronic device, characterized in that: Comprising a camera module as described in any one of claims 16-33.

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