A piezoelectric vibrator, a piezoelectric motor and a camera module

Abstract

The application discloses a piezoelectric vibrator, a piezoelectric motor and a camera module, and belongs to the technical field of camera modules. The piezoelectric vibrator comprises: a piezoelectric ceramic configured as a long strip and provided with two sub-zones symmetrically arranged along a width direction; a first elastic body arranged on one side of the piezoelectric ceramic and at least partially covering the two sub-zones, and a friction head arranged on the first elastic body; and a second elastic body arranged on the other side of the piezoelectric ceramic and at least partially covering the two sub-zones, and a positioning limiting structure adapted to a pre-pressing module of the piezoelectric motor arranged on the second elastic body. The piezoelectric vibrator, the piezoelectric motor and the camera module provided by the application have better positioning and displacement precision.

Description

Technical Field

[0001] This application belongs to the field of camera module technology, and particularly relates to a piezoelectric vibrator, a piezoelectric motor, and a camera module. Background Technology

[0002] In camera modules, a focusing motor is typically used to drive the lens along a set trajectory for focusing. Focusing motors generally include various drive mechanisms based on principles such as DC motors, linear motors, and piezoelectric motors. A piezoelectric motor is a drive device that directly converts electrical energy into mechanical motion using the inverse piezoelectric effect of piezoelectric materials. Compared to traditional electromagnetic motors, it has advantages such as compact structure, fast response, high precision, no electromagnetic interference, and quiet operation, and is widely used in precision instruments, optical focusing, medical devices, robotics, and other fields.

[0003] A piezoelectric vibrator is a key component of a piezoelectric motor. It utilizes the inverse piezoelectric effect of piezoelectric materials to convert electrical energy into mechanical vibration. Under alternating voltage, it undergoes periodic deformation (expansion / contraction), thus providing power for lens movement. In existing technologies, the piezoelectric vibrator needs to be precisely installed in a pre-pressurized module and engage with friction components to ensure the accuracy and stability of the drive stroke. However, because the piezoelectric vibrator requires a certain degree of deformation, the relative positional stability between it and its mating mover and stator is not ideal, making it prone to misalignment, which affects drive accuracy and image quality. Summary of the Invention

[0004] This application provides a piezoelectric vibrator, a piezoelectric motor, and a camera module, aiming to at least partially solve the technical problem of unsatisfactory reliability and stability in the positioning of the piezoelectric vibrator and its mating structure. Therefore, One aspect of this application provides a piezoelectric oscillator, comprising: The piezoelectric ceramic is configured as a long strip and has two partitions arranged symmetrically along the width direction; A first elastic body is disposed on one side of the piezoelectric ceramic and at least partially covers the two partitions, and a friction head is disposed on the first elastic body; A second elastic body is disposed on the other side of the piezoelectric ceramic and at least partially covers the two partitions, and the second elastic body is provided with a positioning and limiting structure adapted to the preload module of the piezoelectric motor.

[0005] In some embodiments, the positioning and limiting structure includes a positioning recess formed on the second elastic body.

[0006] In some embodiments, the second elastic body has a first hole, and a plurality of positioning recesses are symmetrically arranged on both sides of the first hole.

[0007] In some embodiments, the positioning recess includes a second hole, and the axes of the first hole and the second hole are located within the boundary plane of the two partitions.

[0008] In some embodiments, the ends of the first elastomer along the length direction are respectively provided with notches along the thickness direction, and the two notches are symmetrically arranged about the friction head, and the notches are symmetrical about the boundary plane of the two partitions.

[0009] In some embodiments, the first elastomer and the second elastomer are metallic elastic material parts and are formed by a stamping process.

[0010] Another aspect of this application embodiment also provides a piezoelectric motor, including a preload module, a friction element, and the piezoelectric vibrator, wherein the piezoelectric vibrator is mounted on the preload module through the positioning and limiting structure, and the friction head abuts against the friction element.

[0011] Another aspect of this application embodiment also provides a camera module, including: Base; A movable support is movably mounted on the base; The lens assembly is mounted on the movable support. The piezoelectric motor is connected to the base and the movable bracket to drive the movable bracket and the lens assembly to move along the optical axis of the lens assembly.

[0012] In some embodiments, the movable support includes a first movable base and a second movable base, the first movable base being movably disposed on the base, the second movable base being movably disposed on the first movable base, and the piezoelectric motor being connected to the first movable base and the base respectively; The camera module further includes a first lens and a driving mechanism. The first lens is disposed on the base, and the driving mechanism is connected to the second movable seat and the base respectively to drive the second movable seat to move relative to the first movable seat and the base. The lens assembly includes a second lens and a third lens. The second lens is mounted on the first movable base, and the third lens is mounted on the second movable base. The optical axes of the second lens, the third lens, and the first lens coincide. The first movable base and the second movable base are positioned along the optical axis of the first lens.

[0013] In some embodiments, the drive mechanism includes a voice coil motor, which is connected to the second movable base and the base respectively.

[0014] The embodiments of this application have at least the following beneficial effects: The piezoelectric vibrator, piezoelectric motor, and camera module provided in this application include a piezoelectric ceramic, a first elastomer, and a second elastomer. The piezoelectric ceramic is configured as a long strip and has two symmetrically arranged partitions along its width. The first elastomer is disposed on one side of the piezoelectric ceramic and at least partially covers the two partitions, and a friction head is provided on the first elastomer. The second elastomer is disposed on the other side of the piezoelectric ceramic and at least partially covers the two partitions, and a positioning and limiting structure adapted to the pre-pressure module of the piezoelectric motor is provided on the second elastomer. It is worth noting that by providing a positioning and limiting structure on the second elastomer, the piezoelectric vibrator can be precisely installed onto the pre-pressure module, and its position can be kept stable when the piezoelectric vibrator deforms. This significantly improves the positional reliability and stability of the piezoelectric vibrator during installation and operation, contributing to improved accuracy and imaging quality of focusing operations based on the piezoelectric motor. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of the piezoelectric vibrator in an embodiment of this application is shown; Figure 2 It shows Figure 1 Another structural diagram of the piezoelectric vibrator in the image; Figure 3 It shows Figure 1 A schematic diagram of the structure of the first elastic body of the piezoelectric oscillator in the image; Figure 4 It shows Figure 1 Schematic diagram of two modes of a piezoelectric oscillator; Figure 5 A schematic diagram of the structure of the piezoelectric motor provided in an embodiment of this application is shown; Figure 6 It shows Figure 5 A cross-sectional view of the piezoelectric motor in the image; Figure 7 A schematic diagram of the camera module provided in an embodiment of this application is shown; Figure 8 It shows Figure 7 Another structural diagram of the camera module in the image; Figure 9 It shows Figure 7A schematic diagram of the assembly status of the camera module.

[0017] Figure label: a-Piezoelectric motor, b-Prism; 1-Piezoelectric vibrator, 1a-Longitudinal stretching vibration mode, 1b-Bending vibration mode; 11-Piezoelectric ceramic, 111-A phase region, 112-B phase region, 113-Boundary plane; 12-First elastic body, 121-Friction head, 122-Notch; 13-Third elastic body, 131-Positioning and limiting structure, 131a-Positioning recess, 131a1-Second hole, 132-First hole; 2-Friction components; 3-Preload module, 31-Preload base, 32-Elastic element, 321-Helical spring, 33-Preload bracket, 331-Positioning boss, 332-Groove, 34-First guide rod, 35-Extension arm, 351-Guide hole, 36-Second guide rod; 4-Base; 5-Modible support, 51-First movable seat, 52-Second movable seat; 6-Lens assembly, 61-Second lens, 62-Third lens; 7-First shot; 8-Drive mechanism, 81-Drive magnet, 82-Drive coil; 91-First guide rail, 92-Second guide rail. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0020] This application is described below with reference to the accompanying drawings and specific embodiments: In some camera modules, especially those with long-stroke continuous zoom, piezoelectric motors are typically used as the focusing drive structure to meet the requirements of focusing accuracy and large adjustment range. The piezoelectric motor relies on the vibration and deformation of a piezoelectric vibrator to displace the vibrator relative to the contact friction element. Therefore, the installation accuracy of the piezoelectric vibrator and its positional reliability and stability during operation directly affect the driving accuracy and reliability of the piezoelectric motor. However, the piezoelectric vibrator is usually bonded to the pre-pressing module using adhesive materials, resulting in unreliable positioning accuracy and less than ideal position retention.

[0021] This application provides a piezoelectric vibrator, a piezoelectric motor, and a camera module, which aims to at least partially solve the technical problem of unsatisfactory reliability and stability of the positioning of the piezoelectric vibrator and its mating structure.

[0022] Combination Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 A piezoelectric motor (a) is a drive structure that converts electrical energy into mechanical energy using piezoelectric materials. It mainly includes a piezoelectric vibrator 1, a friction element 2, and a preload module 3. The piezoelectric vibrator 1 is mounted on the preload module 3, and the friction element 2 is disposed on one side of the piezoelectric vibrator 1. The piezoelectric vibrator 1 is stably pressed against the friction element 2 by the push of the preload module 3. When a drive signal is applied to the piezoelectric vibrator 1, the piezoelectric vibrator 1 can achieve a certain amplitude of stable deformation mode change (such as bending, torsion, extension, etc.), thereby causing the piezoelectric vibrator 1 to shift relative to the friction element 2 by a certain amplitude, thus achieving external drive.

[0023] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 8 and Figure 9 In some embodiments, the piezoelectric vibrator 1 includes a piezoelectric ceramic 11, a first elastic body 12, and a second elastic body 13. The first elastic body 12 and the second elastic body 13 are disposed on both sides of the piezoelectric ceramic 11, acting as resonators to resonate with the piezoelectric ceramic 11. This amplifies the micro-amplitude vibration of the piezoelectric ceramic 11, cooperating with the friction element 2 to achieve a larger mechanical movement, thereby driving the piezoelectric vibrator 1 to shift relative to the friction element 2, thus driving the two main bodies to move relative to each other. The first elastic body 12 is provided with a friction head 121, which abuts against the friction element 2 and moves relative to it.

[0024] To meet the requirements of long-stroke focusing linear drive, the piezoelectric ceramic 11 can be configured as a long strip and symmetrically planned into two partitions along the width direction X of the piezoelectric ceramic 11, namely A phase region 111 and B phase region 112, and both A phase region 111 and B phase region 112 are connected to the first elastic body 12 and the second elastic body 13.

[0025] During operation, AC voltage signals with a 90-degree phase difference are applied to the A-phase region 111 and the B-phase region 112 respectively, superimposing the vibrations of the two regions to synthesize a traveling wave along the length Y of the piezoelectric ceramic 11. This causes the friction head 121 on the piezoelectric vibrator 1 to exhibit an approximately elliptical moving trajectory, and the major axis of the elliptical moving trajectory is approximately consistent with the length Y of the piezoelectric ceramic 11.

[0026] Specifically, the A phase region 111 mainly excites the oscillator in longitudinal stretching vibration mode 1a along the length direction Y, and the B phase region 112 mainly excites the oscillator in bending vibration mode 1b along the thickness direction Z of the piezoelectric ceramic 11 (the direction of the line connecting the first elastic body 12 and the second elastic body 13); these two modes (longitudinal stretching vibration and thickness bending vibration mode) are orthogonal in space, that is, the vibration directions are perpendicular to each other.

[0027] Applying AC voltage signals with a 90-degree phase difference to the A-phase region 111 and the B-phase region 112 respectively can excite two standing waves with a 90-degree spatiotemporal phase difference in the first elastic body 12 and the second elastic body 13, namely a longitudinal standing wave and a flexural standing wave. The positions of the antinodes and nodes are fixed, but their spatial distribution is offset by a quarter wavelength.

[0028] According to vibration theory, when two standing waves with the same frequency, equal amplitude, 90-degree time phase difference, and a quarter-wavelength offset in spatial position are superimposed, they can synthesize a traveling wave that propagates in a single direction. This causes the elliptical motion trajectory of the particles on the surface of the oscillator (i.e., the location of the friction head 121) to form a continuous and directional propagation in space, that is, to synthesize a surface traveling wave that propagates along the length direction Y.

[0029] Because the energy of the standing wave oscillates between antinodes and nodes, the particles only reciprocate near their equilibrium positions. The traveling wave energy is continuously transmitted along the direction of wave propagation, causing the friction head 121 to exhibit an elliptical motion trajectory, with its major axis pointing in the direction of the traveling wave propagation, i.e., the length direction Y of the piezoelectric ceramic 11. Within one cycle of the elliptical motion, the friction head 121 exhibits both motion perpendicular to the contact surface of the friction element 2 (providing normal force) and tangential motion parallel to the contact surface (providing driving force); this directional elliptical motion can continuously drive the piezoelectric vibrator 1 to move in the opposite direction of the traveling wave propagation through friction, thereby achieving focusing drive.

[0030] Considering the large deformation range of the piezoelectric vibrator 1, a positioning and limiting structure 131 can be set on the second elastic body 13 to cooperate with the positioning and limiting part on the pre-compression module 3 to achieve precise positioning and installation of the piezoelectric vibrator 1, and maintain the relative position stability of the piezoelectric vibrator 1 during operation, thereby ensuring focus shift accuracy and imaging quality.

[0031] It is worth noting that the first elastic body 12 and the second elastic body 13 are fixedly connected to both sides of the piezoelectric ceramic 11, which can provide preload to the piezoelectric ceramic 11 and adjust the system stiffness.

[0032] Wherein, any two of the length direction Y, the width direction X, and the thickness direction Z are orthogonal.

[0033] In some embodiments, the friction head 121 may be disposed at the center of the piezoelectric vibrator 1, thereby enabling high-sensitivity tracking of the modal changes of the piezoelectric vibrator 1.

[0034] In other words, the distances from the friction head 121 to both ends of the piezoelectric vibrator 1 in the length direction are equal, and the distances to both ends of the piezoelectric vibrator 1 in the width direction are also equal.

[0035] In some embodiments, the first elastomer 12 and the second elastomer 13 may be firmly bonded to the piezoelectric ceramic 11 using a high-strength structural adhesive such as high-performance epoxy resin, acrylate adhesive or special ceramic adhesive.

[0036] Generally, the first elastomer 12 and the second elastomer 13 should be stably bonded at least in the vibration node or anti-node region and need to withstand high-frequency vibration. Therefore, the adhesive material layer needs to reduce the damping interference of vibration, the adhesive layer should be as thin as possible, and it also needs to have high strength, toughness and fatigue resistance.

[0037] In some embodiments, considering that the deformation direction of the piezoelectric vibrator 1 includes the length direction Y, the width direction X, and the thickness direction Z of the piezoelectric vibrator 1, in order to accurately position and stably limit the position, the positioning and limiting structure 131 may include a positioning recess 131a for cooperating with the positioning boss 331 nested on the pre-pressing module 3, so that the piezoelectric vibrator 1 can be accurately positioned and installed on the pre-pressing module 3, and can adapt to the displacement of the length direction Y, the width direction X, and the thickness direction Z, and maintain a relatively stable position.

[0038] In some embodiments, the positioning recess 131a may be provided in multiple ways, such as two. The two positioning recesses 131a are respectively provided at the vibration node of the piezoelectric vibrator 1 to balance the force and reduce the risk of interference vibration modes.

[0039] Generally, the vibration node is located at one-quarter of the length Y of the second elastic body 13, that is, the distance from the vibration node to the end of the second elastic body 13 in the length Y direction is about one-quarter of the length of the second elastic body 13.

[0040] In some embodiments, a first hole 132 may be formed on the second elastomer 13. The first hole 132 can reduce the mass of the second elastomer 13 to a certain extent, so that the vibration response on the corresponding side is more agile.

[0041] The first hole 132 can also reduce air resistance to a certain extent during high-frequency vibration.

[0042] The first hole 132 can also enhance heat dissipation and reduce the thermal expansion interference caused by vibration and heat generation of the second elastomer 13.

[0043] In some embodiments, the first hole 132 may be disposed between the two positioning recesses 131a, i.e. between the two vibration nodes, and the two positioning recesses 131a are symmetrical about the first hole 132, so that the mass distribution of the second elastic body 13 is uniform, reducing the risk of uneven stress distribution, thereby maintaining the deformation uniformity of the second elastic body 13.

[0044] In some embodiments, considering the difference in vibration modes between phase A region 111 and phase B region 112, in order to balance the forces, the position of the first hole 132 can be matched with the boundary plane 113 between phase A region 111 and phase B region 112, such that the axis of the first hole 132 is located within the boundary plane 113, thereby the boundary plane 113 bisects the first hole 132 axially.

[0045] In other words, the first hole 132 is divided into two parts, located in the A phase region 111 and the B phase region 112 respectively, and is symmetrical about the interface 113.

[0046] In some embodiments, the first hole 132 may be configured as a square hole, which can further reduce the mass of the second elastomer 13 and maintain the stability of the structural morphology and the uniformity of deformation.

[0047] In some embodiments, the positioning recess 131a can also be configured as a hole-type structure, that is, the positioning recess 131a can be configured as a second hole 131a1, which can also reduce the mass of the second elastic body 13 to a certain extent, making the vibration response on the corresponding side more agile.

[0048] On the other hand, the axis of the second hole 131a1 is also located within the dividing plane 113, so the dividing plane 113 bisects the second hole 131a1 along the axial direction; that is, the second hole 131a1 is divided into two parts, located in the A phase region 111 and the B phase region 112 respectively, and is symmetrical about the dividing plane 113, thereby balancing the forces on the A phase region 111 and the B phase region 112 and reducing the risk of uneven force distribution affecting the vibration mode.

[0049] In some embodiments, the second hole 131a1 can be configured as a circular hole to obtain good positioning adaptability and facilitate nesting positioning; it can also adapt to the torsional displacement generated when the second elastic body 13 is deformed, reducing the resistance to the deformation of the second elastic body 13.

[0050] In some embodiments, notches 122 are respectively provided at both ends of the first elastic body 12 along the length direction. The notches 122 penetrate the first elastic body 12 along the thickness direction Z, and the two notches 122 are symmetrical about the friction head 121 in the length direction Y.

[0051] The notch 122 reduces the local cross-sectional area and lowers the stiffness of the area, concentrating vibration energy near the notch 122 and enhancing the amplitude in a specific direction, such as enhancing bending vibration to achieve a greater displacement. Simultaneously, the notch 122 reduces the risk of fatigue fracture caused by excessive end stress in the first elastic body 12.

[0052] It is worth emphasizing that when the second elastic body 13 has the first hole 132, the notch 122 on the first elastic body 12 can increase the difference in vibration phase and amplitude between the first elastic body 12 and the second elastic body 13, that is, form obvious differential vibration, which helps the friction head 121 to form an elliptical motion trajectory and improve the linear drive efficiency.

[0053] In some embodiments, the notch 122 is symmetrical about the dividing plane 113, that is, the dividing plane 113 divides the notch 122 into two symmetrical parts about the dividing plane 113, thereby making the mass distribution and stress distribution of the A phase region 111 and the B phase region 112 approximately equal, which can reduce the influence of uneven stress on the vibration mode.

[0054] In some embodiments, the notch 122 can be configured as an arc shape, which can reduce defects such as stress concentration caused by sharp corners and slits to a certain extent, and reduce the risk of vibration tearing.

[0055] In some embodiments, the first elastomer 12 and the second elastomer 13 may be made of metal materials to obtain better structural strength, provide stable preload, and reduce the risk of the piezoelectric ceramic 11 falling off or breaking.

[0056] Generally, in order to reduce the risk of short circuits, an insulating material layer such as epoxy resin or polyimide film can be provided between the piezoelectric ceramic 11 and the first elastomer 12 and the second elastomer 13 for isolation.

[0057] Since the stiffness and mass of the metal material affect the resonant frequency, a material with good balance can be selected according to actual needs. For example, titanium alloys can be used, which have the characteristics of low density and high stiffness, making them particularly suitable for high-frequency vibration conditions; or stainless steel can be used to obtain high damping characteristics, which can suppress stray modes and help improve driving accuracy.

[0058] In some embodiments, the friction head 121, the notch 122, the first hole 132 and the second hole 131a1 can be directly formed by stamping, which is simple, efficient and has high forming accuracy.

[0059] That is, the friction head 121 can be configured as a hollow cylindrical cap-shaped part that is stamped out of the first elastic body 12.

[0060] In some embodiments, the surface of the friction head 121 is typically bonded or sintered with wear-resistant friction materials such as polyimide or special ceramic powder composites to increase friction and wear resistance, thereby helping to improve drive reliability, stability and service life.

[0061] See Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, a piezoelectric motor a is also provided, including the piezoelectric vibrator 1, the friction element 2, and the pre-pressure module 3. The piezoelectric vibrator 1 is matched and installed on the pre-pressure module 3 through the positioning and limiting structure 131 (i.e., the second hole 131a1). The friction head 121 is correspondingly abutted against the friction element 2, and the pre-pressure module 3 applies a stable pressing force to the piezoelectric vibrator 1 for a continuous period of time to maintain the stable contact between the friction head 121 and the friction element 2.

[0062] It is worth noting that during assembly and use, the pre-pressure module 3 and the friction element 2 can be installed on two relatively movable main bodies, such as the base and the mover in the camera module, thereby driving the two to move relative to each other.

[0063] In some embodiments, the pre-compression module 3 may include a pre-compression base 31, an elastic element 32, and a pre-compression bracket 33. The elastic element 32 is connected to the pre-compression base 31, and the pre-compression bracket 33 is connected to the elastic element 32. The elastic element 32 maintains a deformed state and can continuously apply pre-compression pressure to the piezoelectric vibrator 1 through the pre-compression bracket 33.

[0064] On the other hand, the pre-compression bracket 33 is provided with a positioning boss 331, which is matched and embedded in the second hole 131a1.

[0065] In some embodiments, the preload bracket 33 has a groove 332, the elastic element 32 is embedded in the groove 332, and the elastic element 32 is compressed between the preload base 31 and the bottom of the groove 332, thereby protecting the deformation reliability of the elastic element 32 and reducing external interference.

[0066] Generally, the elastic element 32 can be a component with stable linear deformation capability, such as a helical spring 321, to ensure stable elastic contact between the friction head 121 and the friction element 2.

[0067] In some embodiments, considering that the pre-pressure bracket 33 may elastically shift relative to the pre-pressure base 31, in order to maintain the stability of the shift, the pre-pressure module 3 further includes a first guide rod 34, which is embedded in the cavity 332 to constrain the pre-pressure bracket 32 ​​to slide along the first guide rod 34, thereby maintaining the stability of the direction of the pressure applied by the pre-pressure bracket 32 ​​to the piezoelectric vibrator 1.

[0068] In some embodiments, considering that the pre-compression bracket 33 may elastically shift relative to the pre-compression base 31, in order to maintain the stability of the shift, an extension arm 35 may be connected to the pre-compression bracket 33, and a guide hole 351 is provided on the extension arm 35. A second guide rod 36 is connected to the pre-compression base 31, and the second guide rod 36 passes through the guide hole 351 on the extension arm 35. Thus, the swing and rotation amplitude of the pre-compression bracket 33 are constrained by the first guide rod 34 and the second guide rod 36, thereby ensuring the stability of the moving posture of the pre-compression bracket 33.

[0069] In some embodiments, a camera module is also provided, employing the aforementioned piezoelectric motor a, to obtain good focus adjustment capability.

[0070] The camera module includes a base 4, a movable bracket 5, a lens assembly 6, and the aforementioned piezoelectric motor a. The movable bracket 5 is movably mounted on the base 4, and the lens assembly 6 is movably mounted on the movable bracket 5. The piezoelectric motor a is connected to the movable bracket 5 and the base 4 respectively, and the moving direction of the movable bracket 5 is set along the optical axis of the lens assembly 6. Thus, the piezoelectric motor a can drive the movable bracket 5 to move the lens assembly 6 as a whole, thereby realizing a long-stroke focusing operation.

[0071] In some embodiments, in order to obtain zoom capability, the camera module further includes a first lens 7, which is disposed in the base 4 and the optical axes of the first lens 7 and the lens assembly 6 are coincident, so that the distance between the first lens 7 and the lens assembly 6 in the optical axis direction can be adjusted under the drive of the piezoelectric motor a to achieve zoom.

[0072] The piezoelectric motor a has a large drive stroke, which enables it to achieve a large zoom adjustment capability.

[0073] In some embodiments, in order to achieve continuous zoom and improve focusing capability and accuracy, the camera module further includes a drive mechanism 8; the movable support 5 includes a first movable base 51 and a second movable base 52, the first movable base 51 being movably disposed on the base 4, and the second movable base 52 being movably disposed on the first movable base 51; the lens assembly 6 includes a second lens 61 and a third lens 62.

[0074] The second lens 61 is mounted on the first movable base 51, the third lens 62 is mounted on the second movable base 52, the piezoelectric motor a is connected to the base 4 and the first movable base 51 respectively, and the drive mechanism 8 is connected to the base 4 and the second movable base 52.

[0075] The optical axes of the first lens 7, the second lens 61, and the third lens 62 coincide, and the moving directions of the first movable base 51 and the second movable base 52 are set along the optical axis direction of the first lens 7.

[0076] During continuous zoom, the piezoelectric motor a can drive the first moving base 51 to move closer to or further away from the first lens 7, thereby causing the first lens 7, the second lens 61, and the second moving base 52 to move closer to or further away from the first lens 7, achieving the first zoom operation. The drive mechanism 8 can also drive the second moving base 52 to move closer to or further away from the first lens 7, thereby causing the second lens 61 to move closer to or further away from the first lens 7, achieving the second zoom.

[0077] In other words, by coordinating the actions of the piezoelectric motor a and the drive mechanism 8, the second lens 61 and the distance between the second lens 61 and the first lens 7 are adjusted, achieving continuous zoom. The piezoelectric motor a has a large drive stroke, thus enabling a large zoom adjustment range; and the drive mechanism 8 can further zoom, thus providing an even larger adjustment range.

[0078] In some embodiments, the drive mechanism 8 may also employ a piezoelectric motor a, thereby further expanding the zoom range.

[0079] In some embodiments, considering that the piezoelectric motor a has a certain size, the zoom mechanism consisting of two piezoelectric motors requires a larger installation and operating space. Therefore, the drive mechanism 8 can employ a drive component based on the voice coil motor principle.

[0080] Specifically, the driving mechanism 8 includes a driving magnet 81 and a driving coil 82. The driving magnet 81 and the driving coil 82 are arranged opposite to each other and are respectively disposed on the second movable seat 52 and the base 4. The driving force can be adjusted by controlling the magnitude and direction of the current applied to the driving coil 82.

[0081] It is worth noting that the voice coil motor requires less installation space compared to the piezoelectric motor, thus helping to reduce the overall size of the camera module. Furthermore, the voice coil motor offers finer adjustment precision than the piezoelectric motor, which contributes to improved zoom accuracy.

[0082] In some embodiments, a rolling support or a sliding support may be provided between the first movable seat 51 and the base 4 to improve the smoothness of movement of the first movable seat 51.

[0083] Similarly, a rolling support or a sliding support can also be provided between the second movable seat 52 and the first movable seat 51 to improve the smoothness of movement of the second movable seat 52.

[0084] In some embodiments, the base 4 is provided with a first guide rail 91, and the first movable seat 51 slides against the first guide rail 91, so that the first movable seat 51 can slide relative to the base 4 along the first guide rail 91.

[0085] Generally, the guiding direction of the first guide rail 91 can be set along the optical axis of the first lens 7.

[0086] Similarly, the first movable seat 51 is provided with a second guide rail 92, and the second movable seat 52 slides against the second guide rail 92, so that the second movable seat 52 can slide relative to the first movable seat 51 along the second guide rail 92.

[0087] Generally, the guiding direction of the second guide rail 92 can be set along the optical axis of the first lens 7.

[0088] In some embodiments, the base 4 and the first movable seat 51 are respectively provided with grooves adapted to the first guide rail 91, and a portion of the rod of the first guide rail 91 is slidably embedded in the groove.

[0089] Similarly, the second movable seat 52 and the first movable seat 51 of the base are respectively provided with grooves that are adapted to the second guide slide rail 92, and a portion of the rod of the second guide slide rail 91 is slidably embedded in the groove.

[0090] In some embodiments, a first ball bearing rolls between the base 4 and the first base 51, thereby allowing the first movable seat 51 to slide stably relative to the base 4.

[0091] Similarly, a second ball bearing rolls between the second movable seat 52 and the first base 51, so that the second movable seat 52 can slide stably relative to the first base 51.

[0092] Generally, the base 4 and the first movable seat 51 are respectively provided with sliding grooves adapted to the first ball bearing, and a portion of the first ball bearing is respectively rolled and embedded in the sliding groove.

[0093] Similarly, the second movable seat 52 and the first movable seat 51 are respectively provided with a sliding groove adapted to the second ball, and a portion of the second ball is respectively rolled and embedded in the sliding groove.

[0094] The piezoelectric motor a includes a piezoelectric vibrator 1 as a drive source and a friction element 2 that frictionally engages with the piezoelectric vibrator 1. For focusing drive, the friction element 2 is fixedly connected to the base 4, or the friction element 2 is integrally formed with the base 4. The piezoelectric vibrator 1 is mounted on the first movable seat 51 via the pre-pressure module 3. Under the thrust of the pre-pressure module 3, the friction head 121 on the piezoelectric vibrator 1 is tightly pressed against the working surface of the friction element 2.

[0095] During operation, the electrical signal applied to the piezoelectric vibrator 1 causes it to vibrate at high frequency, thereby driving the friction head 121 to move along a predetermined trajectory. Since the friction element 2 is fixed to the base 4, the friction between the friction head 121 and the friction element 2 will drive the piezoelectric vibrator 1 and the first movable seat 51 it carries to move stably relative to the base 4 along the optical axis.

[0096] To achieve continuous zoom, this camera module employs a two-stage drive architecture. The first movable base 51 carries the second lens 61 and is driven by the piezoelectric motor a to move relative to the base 4 and the first lens 7 fixed thereon, achieving the first stage of coarse adjustment. The second movable base 52 carries the third lens 62 and is driven by an independent drive mechanism 8 to move relative to the first movable base 51, achieving the second stage of fine adjustment.

[0097] During continuous zoom, their interaction is as follows: First, when a large focal length adjustment is required, the piezoelectric motor a is activated. The driving force generated by the piezoelectric motor a directly acts on the first movable base 51, driving the first movable base 51, together with the second lens 61 and the entire second movable base 52, to move relative to the base 4 along the optical axis. This process changes the distance between the first lens 7 and the second lens 61, realizing a preliminary, large-stroke adjustment of the zoom range.

[0098] Subsequently, when more precise focus adjustment or compensation is required, the drive mechanism 8 is activated; the drive mechanism 8 (e.g., a voice coil motor) drives the second moving base 52 to move relative to the already positioned first moving base 51 along the optical axis. This process precisely adjusts the distance between the second lens 61 and the third lens 62, thereby achieving high-precision continuous zoom and focus adjustment.

[0099] Through the coordinated operation of the two-stage drive mechanism, namely, the piezoelectric motor a achieves large-stroke drive to expand the zoom range, and the drive mechanism 8 achieves high-precision fine-tuning to optimize image quality, this camera module can balance a wide range of continuous zoom capabilities with good focusing accuracy.

[0100] In some embodiments, the camera module is further configured with a prism b, which is disposed on the light-inlet side of the first lens 7. Light enters the first lens 7 after the light path is changed by the prism b, thereby enabling periscope shooting.

[0101] The embodiments of this application have at least the following beneficial effects: The piezoelectric vibrator, piezoelectric motor, and camera module provided in this application include a piezoelectric ceramic, a first elastomer, and a second elastomer. The piezoelectric ceramic is configured as a long strip and has two symmetrically arranged partitions along its width. The first elastomer is disposed on one side of the piezoelectric ceramic and at least partially covers the two partitions, and a friction head is provided on the first elastomer. The second elastomer is disposed on the other side of the piezoelectric ceramic and at least partially covers the two partitions, and a positioning and limiting structure adapted to the pre-pressure module of the piezoelectric motor is provided on the second elastomer. It is worth noting that by providing a positioning and limiting structure on the second elastomer, the piezoelectric vibrator can be precisely installed onto the pre-pressure module, and its position can be kept stable when the piezoelectric vibrator deforms. This significantly improves the positional reliability and stability of the piezoelectric vibrator during installation and operation, contributing to improved accuracy and imaging quality of focusing operations based on the piezoelectric motor.

[0102] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0103] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0104] It should be noted that all directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. In this application, unless otherwise explicitly specified and limited, the terms "connection" and "fixed" should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction relationship between two components, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances. In addition, the descriptions involving "first," "second," etc., in this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" or "second" may explicitly or implicitly include one or more of the aforementioned features. In the description of this application, "multiple" means two or more, unless otherwise explicitly and specifically limited.

[0105] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0106] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0107] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A piezoelectric oscillator, characterized in that, include: The piezoelectric ceramic is configured as a long strip and has two partitions arranged symmetrically along the width direction; A first elastic body is disposed on one side of the piezoelectric ceramic and at least partially covers the two partitions, and a friction head is disposed on the first elastic body; A second elastic body is disposed on the other side of the piezoelectric ceramic and at least partially covers the two partitions, and the second elastic body is provided with a positioning and limiting structure adapted to the preload module of the piezoelectric motor.

2. The piezoelectric vibrator as described in claim 1, characterized in that, The positioning and limiting structure includes a positioning recess formed on the second elastic body.

3. The piezoelectric vibrator as described in claim 2, characterized in that, The second elastic body has a first hole, and a plurality of positioning recesses are symmetrically arranged on both sides of the first hole.

4. The piezoelectric vibrator as described in claim 3, characterized in that, The positioning recess includes a second hole, and the axes of the first hole and the second hole are located within the boundary plane of the two partitions.

5. The piezoelectric vibrator according to any one of claims 1 to 4, characterized in that, The first elastic body has notches along its thickness at its ends along its length, and the two notches are symmetrically arranged about the friction head. The notches are also symmetrical about the boundary plane of the two partitions.

6. The piezoelectric vibrator as described in claim 5, characterized in that, The first elastomer and the second elastomer are made of metallic elastic material and are formed by stamping.

7. A piezoelectric motor, characterized in that, It includes a pre-compression module, a friction element, and a piezoelectric vibrator as described in any one of claims 1 to 6, wherein the piezoelectric vibrator is mounted on the pre-compression module via the positioning and limiting structure, and the friction head abuts against the friction element.

8. A camera module, characterized in that, include: Base; A movable support is movably mounted on the base; The lens assembly is mounted on the movable support. The piezoelectric motor as described in claim 7 is connected to the base and the movable bracket to drive the movable bracket and the lens assembly to move along the optical axis of the lens assembly.

9. The camera module as described in claim 8, characterized in that, The movable support includes a first movable base and a second movable base. The first movable base is movably disposed on the base, and the second movable base is movably disposed on the first movable base. The piezoelectric motor is connected to the first movable base and the base respectively. The camera module further includes a first lens and a driving mechanism. The first lens is disposed on the base, and the driving mechanism is connected to the second movable seat and the base respectively to drive the second movable seat to move relative to the first movable seat and the base. The lens assembly includes a second lens and a third lens. The second lens is mounted on the first movable base, and the third lens is mounted on the second movable base. The optical axes of the second lens, the third lens, and the first lens coincide. The first movable base and the second movable base are positioned along the optical axis of the first lens.

10. The camera module as described in claim 9, characterized in that, The drive mechanism includes a voice coil motor, which is connected to the second movable seat and the base respectively.

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