Piezoelectric motor and camera module thereof

Abstract

The invention provides a piezoelectric motor which is characterized by comprising a fixed assembly, a movable carrier, a piezoelectric actuator and a guide mechanism. The fixed assembly comprises a base, a shell and the like, the movable carrier is arranged above the base, the guide mechanism maintains the parallelism of the piezoelectric vibrator and the movable carrier, the piezoelectric actuator comprises a piezoelectric vibrator, an elastic piece and the like, one surface of the elastic piece is arranged on one surface of the piezoelectric vibrator, and the other surface of the elastic piece is arranged on the other surface of the piezoelectric vibrator. The other surface of the elastic sheet is connected to the shell; the elastic sheet is abutted against the piezoelectric vibrator, and the elastic sheet is in contact with two rectangular short edges of the piezoelectric vibrator; wherein the rectangular long edge of the elastic sheet is perpendicular to the rectangular long edge of the piezoelectric vibrator.

Description

Piezoelectric motor and camera module Technical Field

[0001] The present invention relates to the technical field of camera modules, and in particular to a camera module having a piezoelectric motor structure. Background Art

[0002] At present, the camera module in the mobile phone terminal generally includes: optical elements, actuators, filter elements and image sensors. Optical elements often include optical lenses, optical lens barrels, etc. Generally, in the camera module, when the sensor detects movement, the actuator works to make the optical element perform translational movement, thereby compensating the imaging light beam, that is, compensating for the displacement (linear displacement and / or angular displacement) caused by the movement. In order to meet the development trend of lightweight and thin portable electronic devices, the industry has tried to apply actuators that are widely used in medical, industrial, microscope, camera and other fields to small-sized camera modules. However, compared with the small-sized camera modules configured in portable electronic devices, the existing actuators have complex structures and larger volumes, resulting in the application of existing actuators to small-sized camera modules that can be mass-produced. There are still great challenges.

[0003] In recent years, with the rapid development and improvement of various functions of portable electronic devices, camera modules, as one of the important components of portable electronic devices, have also made great progress in design and application. Users have increasingly higher requirements for the size of camera modules. Users expect camera modules with high pixels, small size, and both zoom and anti-shake capabilities. But generally speaking, the higher the pixel of a camera module, the more optical elements there will be, and the total track length (TTL) of the optical elements will also be larger. Larger optical elements require the corresponding motor to bear a higher load, and the motor size is also increasing. There are voice coil spring motors in the prior art, but due to the problem of spring bearing capacity, the spring cannot well hold large and heavy optical elements. There are also ball motors in the prior art, but because the ball motor has a complex structure and no mechanical reset element, it is easy to cause abnormal noise, etc. Therefore, the use of piezoelectric motors in the field of camera modules can solve most problems. However, as a contact actuator solution, the piezoelectric motor and the driven part need to be frictionally connected with each other before the piezoelectric motor can drive the driven part to move. The contact design needs to pay special attention to the yield rate during assembly, reliability during use, product performance, and miniaturization. Therefore, the piezoelectric motor solution needs to be designed to achieve better performance.

[0004] In response to the above problems, the present invention provides a camera module with a piezoelectric motor. By adopting a piezoelectric actuator, a high-precision zoom effect is achieved, and the size of the overall motor is avoided from being further enlarged, the size of the camera module is reduced, the reliability of the piezoelectric motor is improved, and the installation yield of the piezoelectric motor is optimized through structural improvements. Therefore, at least one of the above problems can be solved.

[0005] Summary of the Invention

[0006] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and accompanying drawings.

[0007] One object of the present invention is to provide a piezoelectric motor that overcomes the shortcomings of the prior art and designs the piezoelectric motor to achieve at least one of the following effects: easy assembly, compact size, and excellent mechanical reliability.

[0008] According to one aspect of the present invention, the present invention provides a piezoelectric motor comprising:

[0009] A fixing assembly, the fixing assembly comprising a base and a shell, wherein the shell is located above the base;

[0010] a movable carrier, the movable carrier being arranged above the base;

[0011] A piezoelectric actuator includes a piezoelectric vibrator and a spring, wherein one side of the spring is arranged on a surface of the piezoelectric vibrator and the other side of the spring is connected to the housing; the spring abuts against the piezoelectric vibrator and contacts the two short sides of the rectangle of the piezoelectric vibrator; wherein the long side of the rectangle of the spring is perpendicular to the long side of the rectangle of the piezoelectric vibrator.

[0012] A guide mechanism maintains parallelism between the piezoelectric vibrator and the movable carrier.

[0013] According to an embodiment of the present invention, the piezoelectric actuator further comprises a piezoelectric friction head, and the piezoelectric friction head is disposed at a central position of a surface of the piezoelectric vibrator.

[0014] According to an embodiment of the present invention, the piezoelectric actuator further includes a piezoelectric friction plate, wherein the piezoelectric friction plate abuts against the piezoelectric friction head.

[0015] According to an embodiment of the present invention, the piezoelectric friction plate is arranged parallel to one surface of the piezoelectric vibrator, and the piezoelectric friction head is located at the center of the piezoelectric friction plate.

[0016] According to an embodiment of the present invention, the spring has a spring frame, a middle area of ​​the spring frame is a rectangular hollow structure, and a size of the spring frame is larger than an area size of the surface of the piezoelectric vibrator.

[0017] According to an embodiment of the present invention, the spring frame of the spring provides pre-pressure on at least two short sides of the rectangle of the piezoelectric vibrator.

[0018] According to an embodiment of the present invention, the pre-pressed edge where the spring and the piezoelectric vibrator are in contact is parallel to the driving direction of the piezoelectric vibrator.

[0019] According to an embodiment of the present invention, the elastic sheet further includes at least one elastic sheet extension arm, the elastic sheet extension arm has a groove structure, and the elastic sheet extension arm is embedded in the housing and maintains a certain gap with the housing.

[0020] According to one embodiment of the present invention, the spring piece further has at least one spring piece positioning hole, through which the spring piece is fixed to the piezoelectric vibrator, and the spring piece positioning hole is located at the position where the amplitude of the piezoelectric vibrator in the longitudinal direction of the rectangle is the smallest.

[0021] According to an embodiment of the present invention, the fixing assembly further includes an FPC soft board, the FPC soft board is disposed in the groove structure of the elastic sheet extension arm, and the FPC soft board is attached to the elastic sheet.

[0022] According to another aspect of the present invention, the present invention provides a piezoelectric actuator comprising:

[0023] A piezoelectric vibrator, wherein the piezoelectric vibrator has electrodes and is in the shape of a rectangular parallelepiped;

[0024] A piezoelectric friction head, the piezoelectric friction head being arranged on a surface of the piezoelectric vibrator;

[0025] a piezoelectric friction plate, the piezoelectric friction plate abutting against the piezoelectric friction head;

[0026] a spring piece, the spring piece being arranged on the other surface of the piezoelectric vibrator;

[0027] The plane formed by the short sides of the rectangle of the piezoelectric vibrator is divided into four regions, and the regions that are diagonally opposite to each other are connected by electrodes.

[0028] According to an embodiment of the present invention, the four regions of the piezoelectric vibrator are, in clockwise order, a first region, a second region, a third region, and a fourth region.

[0029] According to an embodiment of the present invention, each of the four regions of the piezoelectric vibrator has electrodes at upper and lower ends.

[0030] According to one embodiment of the present invention, the upper electrode of the first region of the piezoelectric vibrator is connected to the lower electrode of the third region, and the upper electrode of the second region of the piezoelectric vibrator is connected to the lower electrode of the fourth region, that is, the electrodes of the two diagonal regions are connected.

[0031] According to one embodiment of the present invention, the spring sheet further has at least one spring sheet positioning hole, through which the spring sheet is fixed to the piezoelectric vibrator, and the resonance frequency of the piezoelectric vibrator in the direction of the long side of the rectangle is the same as that in the direction of the short side of the rectangle.

[0032] According to one embodiment of the present invention, the piezoelectric vibrator further includes a first phase electrode, a second phase electrode, a third phase electrode, and a fourth phase electrode. The first region of the piezoelectric vibrator has the first phase electrode and the second phase electrode, the second region of the piezoelectric vibrator has the second phase electrode and the third phase electrode, the third region of the piezoelectric vibrator has the first phase electrode and the fourth phase electrode, and the fourth region of the piezoelectric vibrator has the third phase electrode and the fourth phase electrode.

[0033] According to an embodiment of the present invention, the first phase electrode, the second phase electrode, the third phase electrode and the fourth phase electrode of the piezoelectric vibrator are stacked on each other in the direction of the long side of the rectangle.

[0034] According to one embodiment of the present invention, the second phase electrode of the piezoelectric vibrator is connected to the first region and the second region of the piezoelectric vibrator as a common potential electrode, and the fourth phase electrode of the piezoelectric vibrator is connected to the third region and the fourth region of the piezoelectric vibrator as a common potential electrode.

[0035] According to an embodiment of the present invention, the piezoelectric vibrator further comprises at least one substrate, which is disposed on a surface of the piezoelectric vibrator in the direction of a short side of a rectangle, and the substrate is connected to an electrode layer of the piezoelectric vibrator.

[0036] According to one embodiment of the present invention, the substrate includes a first substrate and a second substrate, the first substrate is connected to the first phase electrode of the first region and the first phase electrode of the third region of the piezoelectric vibrator, and the second substrate is connected to the third phase electrode of the second region and the third phase electrode of the fourth region of the piezoelectric vibrator.

[0037] These and other objects, features and advantages of the present invention will be more fully understood from the following detailed description, accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG1 shows a schematic diagram of the overall structure of the camera module in this application.

[0039] FIG2 shows a cross-sectional schematic diagram of the camera module in this application.

[0040] FIG3 shows a schematic cross-sectional view of a piezoelectric motor in the present application.

[0041] FIG4 shows an exploded schematic diagram of the piezoelectric motor in the present application.

[0042] FIG5 shows an exploded schematic diagram of the piezoelectric motor in the present application from another angle.

[0043] FIG6 shows a schematic cross-sectional view of a first end surface of a piezoelectric vibrator in the present application.

[0044] FIG7 shows a schematic diagram of the electrical signal waveform of the piezoelectric vibrator in the present application.

[0045] FIG8 shows a schematic diagram of the electrode structure of the piezoelectric vibrator in this application.

[0046] FIG9 shows a schematic diagram of the side structure of the piezoelectric vibrator in the present application.

[0047] The above and other objects, features, and advantages of the present invention will become more apparent through a more detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are provided to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and are not intended to limit the present invention. In the drawings, the same reference numerals generally represent the same components or steps. DETAILED DESCRIPTION

[0048] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0049] In the description of the present invention, it should be noted that, for directional words, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present invention.

[0050] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0051] The terms "comprises" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, product or apparatus.

[0052] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct, contact, or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0053] As shown in FIG1 , a camera module 10 according to an embodiment of the present application is illustrated, which includes a lens assembly 20, a photosensitive assembly 30, and a piezoelectric motor 40. In the embodiment of the present application, the piezoelectric motor 40 surrounds the outside of the lens assembly 20, the photosensitive assembly 30 is located below the lens assembly 20, and the lens assembly 20 is held on the light-sensing path of the photosensitive assembly 30. The lens assembly 20 is used to collect imaging light from the subject and transmit the imaging light to the photosensitive assembly 30. The photosensitive assembly 30 is used to receive the light passing through the lens assembly 20 to form the captured image.

[0054] In the embodiment of the present application, referring to FIG2 , the lens assembly 20 includes a lens barrel 21 and one or more optical lenses 22 disposed therein. The lens assembly 20 is disposed above the photosensitive component 30, wherein at least one optical lens 22 is disposed inside the lens barrel 21, and the lens barrel 21 surrounds the outer side of the optical lens 22, and the lens barrel plays a certain supporting role for the optical lens 22.

[0055] In the embodiment of the present application, with continued reference to FIG2 , the photosensitive component 30 includes at least one circuit board 31, at least one photosensitive chip 32, and a filter element 33. The photosensitive chip 32 is the photosensitive portion of the photosensitive component 30, and is used to receive imaging light from the outside world and perform imaging. The photosensitive chip 32 is disposed at the bottom of the camera module 10, above the circuit board 31, and is mounted and electrically connected to the circuit board 31. The filter element 33 is maintained on the light-sensing path of the photosensitive chip 32, so that light entering the filter element 33 passes through the filter element 33 and reaches the photosensitive chip 32 of the photosensitive component 30, thereby achieving imaging.

[0056] The circuit board 31 can serve as the substrate of the photosensitive component 30 and is used to carry other parts of the photosensitive component 30. The circuit board 31 can have an inner surface 311 and an outer surface 312 opposite to the inner surface 311, wherein the inner surface 311 faces the object side and the outer surface 312 faces away from the object side. The circuit board 31 includes a circuit board body, a connecting belt and a connector part (wherein the connecting belt and the connector part are not shown in the figure). The connecting belt part is connected between the circuit board body and the connector part to achieve electrical conduction between the circuit board body and the connector part, and the connector is used to connect to an external device.

[0057] The photosensitive chip 32 may be a photosensitive coupled device (CCD) or a complementary metal oxide semiconductor device (CMOS), and the photosensitive chip 32 may include a photosensitive area located in the center and a non-photosensitive area surrounding the photosensitive area. The photosensitive area of ​​the photosensitive chip 32 may receive light passing through the lens assembly 20 and has a photosensitive path corresponding to the photosensitive area. The photosensitive chip 32 may be arranged on the inner surface 311 of the circuit board 31. Specifically, the photosensitive chip 32 may be mounted on the central area of ​​the inner surface 311 of the circuit board 31. The specific implementation method of electrically connecting the photosensitive chip 32 to the circuit board 31 is not limited to the present application. For example, the photosensitive chip 32 may be electrically connected to the circuit board body of the circuit board 31 by wire bonding (gold wire), welding, flip-chip (FC), redistribution layer (RDL), etc. Exemplarily, the electrical connection may be implemented as wire bonding. After the photosensitive chip 32 is mounted on the circuit board 31, one end of the gold wire is connected to the photosensitive chip 32 and the other end is connected to the circuit board 31 through the gold wire punching process. The connecting wire can also be of other types, such as silver wire, copper wire, etc. In some embodiments, the circuit board 31 has a mounting groove for accommodating the photosensitive chip 32, and the shape of the mounting groove corresponds to the shape of the photosensitive chip 32. Exemplarily, the depth of the mounting groove can be equal to the thickness of the circuit board 31. The filter element 33 is maintained on the photosensitive path of the photosensitive chip 32 and is used to filter the imaging light entering the photosensitive chip 32.

[0058] In some embodiments, the photosensitive component 30 further includes a bracket 34 for supporting and holding the filter element 33. The filter element 33 is mounted on the bracket 34 and corresponds to at least part of the photosensitive area of ​​the photosensitive chip 32 so as to be maintained on the photosensitive path of the photosensitive chip 32. The manner in which the bracket 34 is combined with the circuit board 31 is not limited by the present application. The bracket 34 may be molded separately to form a structure independent of the circuit board 31, and the bracket 34 of the filter element 33 is attached to the circuit board 31 by an adhesive and can be used to support other components. In other embodiments, the bracket 34 of the filter element 33 and the circuit board 31 are integrally formed at a preset position of the circuit board 31 body through a molding process.

[0059] The photosensitive assembly 30 further includes at least one electronic component 35, which is disposed on the circuit board 31 and electrically connected to the circuit board 31. The electronic component 35 can be disposed on the inner surface 311 of the circuit board 31 and spaced apart from the photosensitive chip 32. Specifically, the electronic component 35 can be mounted on the edge area of ​​the inner surface 311 of the circuit board 31 and spaced a certain distance from the photosensitive chip 32. The electronic component 35 can be implemented as a capacitor, a resistor, a driver, etc., for example.

[0060] In the embodiment of the present application, as shown in FIG. 3 and FIG. 4 , the piezoelectric motor 40 includes a fixing assembly 41 , a movable carrier 42 , a piezoelectric actuator 43 and a guide mechanism 44 .

[0061] The fixing assembly 41 further includes a base 411 and a housing 412. The base 411 is located at the bottom of the piezoelectric motor 40 and can be supported by the lens assembly 20. The base 411 has a through hole 4111. The through hole 4111 is a circular through hole with a profile slightly larger than or the same as that of the lens assembly 20. The through hole 4111 of the base 411 does not affect the high transmittance of the lens assembly 20 to visible light. The centerline of the through hole 4111 is coaxial with the optical lens 22, allowing the base 411 to surround the lens assembly 20.

[0062] The housing 412 is located above the base 411 and has a hollow cavity 4121. The hollow cavity 4121 is a circular through hole 4111 with a profile slightly larger than or the same as that of the lens assembly 20. The hollow cavity 4121 of the housing 412 does not affect the high visible light transmittance of the optical lens 22. The bottom of the housing 412 is connected to the base 411. The housing 412 encloses the piezoelectric actuator 43, movable carrier 42, and other components within it, protecting the internal components of the camera module 10. The housing 412 also has at least one housing ball groove 4122.

[0063] The movable carrier 42 is located above the base 411 and can be supported by the lens assembly 20. The movable carrier 42 has an accommodating cavity 421, which is a circular through-hole 4111 with a contour slightly larger than or the same as that of the lens assembly 20. The accommodating cavity 421 of the movable carrier 42 does not affect the high transmittance of the optical lens 22 to visible light. The movable carrier 42 can surround the lens assembly 20. The outer wall of the movable carrier 42 also has at least one carrier ball groove 422, which corresponds to the position of the outer shell ball groove 4122.

[0064] 3 , 4 and 5 , the piezoelectric actuator 43 includes a piezoelectric vibrator 431 , a piezoelectric friction head 432 , a piezoelectric friction plate 433 and a spring 434 .

[0065] The piezoelectric vibrator 431 is rectangular and strip-shaped, with the long side of the rectangle parallel to an outer side of the base 411 and perpendicular to the optical axis. The piezoelectric vibrator 431 is disposed outside the movable carrier 42. The side of the piezoelectric vibrator 431 facing the lens assembly 20 is an inner side surface 4311 of the piezoelectric vibrator 431, and the side of the piezoelectric vibrator 431 facing away from the lens assembly 20 is an outer side surface 4312 of the piezoelectric vibrator 431. The inner side surface 4311 and the outer side surface 4312 are disposed opposite each other.

[0066] The inner side surface 4311 of the piezoelectric vibrator 431 is provided with a piezoelectric friction head 432, which is located at the center of the inner side surface 4311 of the piezoelectric vibrator 431. A piezoelectric friction plate 433 is provided on the other side of the piezoelectric friction head 432. The piezoelectric friction plate 433 is fixed to the movable carrier 42. The piezoelectric friction plate 433 is a rectangular sheet structure and is arranged parallel to the inner side surface 4311 of the piezoelectric vibrator 431. The piezoelectric friction head 432 abuts the center of the piezoelectric friction plate 433, making the force on the piezoelectric friction head 432 and the piezoelectric friction plate 433 more uniform. The piezoelectric friction head 432 is tightly fitted with the piezoelectric vibrator 431 and the piezoelectric friction plate 433, generating friction and thus driving the piezoelectric vibrator.

[0067] An elastic piece 434 is disposed on the outer side surface 4312 of the piezoelectric vibrator 431 . The elastic piece 434 further includes an elastic piece frame 4341 , an elastic piece extension arm 4342 , and an elastic piece positioning hole 4343 .

[0068] The spring piece 434 is a rectangular sheet-like structure, arranged parallel to the outer surface 4312 of the piezoelectric vibrator 431 and perpendicular to the upper surface of the base 411. The long side of the rectangle of the spring piece 434 is aligned with the piezoelectric vibrator 431. The middle area of ​​the spring piece 434 forms a spring frame 4341, which is a rectangular hollow structure. The size of the spring frame 4341 is larger than the area of ​​the outer surface 4312 of the piezoelectric vibrator 431. The hollow structure of the spring frame 4341 can prevent interference with the piezoelectric vibrator 431.

[0069] The spring piece 434 has a spring extension arm 4342 on the upper and lower sides in the optical axis direction. Preferably, the number of the spring extension arms 4342 is 2, and the spring extension arms 4342 include a first extension arm 43421 and a second extension arm 43422. The first extension arm 43421 is located at one end close to the base 411, and the first extension arm 43421 extends toward the base 411 in the optical axis direction. When the first extension arm 43421 is extended to the base 411, it is bent and extended toward the outside of the spring piece 434, and the bending angle is 90°. At this time, the bending surface is always in contact with the upper surface of the base 411. After extending to a certain length, it is bent and extended again in the optical axis direction. The bending angle is 90° and the extension direction is away from the base 411. At this time, the bending surface is always perpendicular to the upper surface of the base 411, so that the bent part of the first extension arm 43421 can form a groove structure. The second extension arm 43422 is located at an end away from the base 411. The second extension arm 43422 extends along the optical axis away from the base 411. After extending to a certain length, the second extension arm 43422 bends and extends toward the outside of the elastic piece 434 at a 90° angle. The bent surface is always parallel to the upper surface of the base 411. The bent portion of the elastic piece extension arm 4342 is embedded in the housing 412, leaving a certain gap between the housing and the housing 412 along the optical axis, thereby adjusting the position of the elastic piece 434 relative to the base 411.

[0070] A spring positioning hole 4343 is provided at the connection between the spring piece 434 and the piezoelectric vibrator 431. The spring positioning hole 4343 is a through-hole structure. The spring positioning hole 4343 is located at the center of the long side of the rectangle of the spring piece 434, so that the piezoelectric vibrator 431 is also located at the center of the spring piece 434, making the spring piece 434 easy to install, thereby making the structure of the camera module 10 more stable.

[0071] The spring clip 434 can fix and limit the piezoelectric vibrator 431 and provide a certain pre-pressure; on the one hand, the spring clip frame 4341 can prevent the piezoelectric vibrator 431 from interfering, and on the other hand, the spring clip frame 4341 can prevent the spring clip 434 from deforming, thereby affecting the pre-pressure provided by the spring clip 434 to the piezoelectric vibrator 431; the spring clip extension arm 4342 can provide supporting force to the housing 412 and other components; the spring clip 434 makes the piezoelectric vibrator 431 and the piezoelectric friction plate 433 contact with the movable carrier 42.

[0072] Continuing with reference to Figures 3, 4, and 5, the fixing assembly 41 further includes an FPC board 413 and at least one fixing member 414. The FPC board 413 is attached to the outside of the spring 434 and is located in the groove of the first extension arm 43421 of the spring 434. One end of the FPC board 413 is connected to the spring 434, and the other end extends and bends in the other direction of the spring 434 and extends parallel to the other outer edge of the base 411. The FPC board 413 is perpendicular to the base 411. A first fixing member 4141 is attached to the outside of the FPC 413. The length and width of the first fixing member 4141 are both greater than those of the FPC 413, allowing the FPC 413 to be completely attached to the first fixing member 4141. The first fixing member 4141 provides a certain degree of support and is also perpendicular to the base 411. A position sensor (not shown) is placed inside the first fixing member 4141 and the FPC 413. The position sensor is parallel to the optical axis and is located on one side of the piezoelectric vibrator 431. The position sensor can sense the position of the movable carrier 42. A second fixing member 4142 is provided on the other side of the unbent end of the FPC 413. The second fixing member 4142 is the same size as the first fixing member 4141. The second fixing member 4142 is parallel to the other outer side of the base 411 and is also perpendicular to the base 411. The first fixing member 4141 and the second fixing member 4142 are symmetrically distributed around the piezoelectric vibrator 431, making the overall structure more stable.

[0073] As shown in FIG4 , in some embodiments, the guide mechanism 44 includes at least one ball 441 disposed on the outer sidewall of the movable carrier 42. The movable carrier 42 has at least one carrier ball groove 422 capable of accommodating the ball 441. One end of the ball 441 is disposed within the carrier ball groove 422 of the movable carrier 42, and the other end of the ball 441 is disposed within the shell ball groove 4122 of the housing 412, such that the ball 441 is encompassed by both the carrier ball groove 422 of the movable carrier 42 and the shell ball groove 4122 of the housing 412. The balls 441 are vertically distributed along the optical axis, with at least one ball 441 disposed on opposite sides. The balls 441 can move with multiple degrees of freedom. When the carrier ball groove 422 has a direction, the movement trajectory of the balls 441 is limited within the carrier ball groove 422, thereby playing a guiding role during the movement of the lens assembly 20. Preferably, there are two carrier ball grooves 422, one on each opposite side of the movable carrier 42, so that the camera module 10 can remain stable. The number of balls 441 is six, wherein each carrier ball groove 422 is provided with three balls 441 therein, and the three balls 441 are stacked in a vertical direction (parallel to the optical axis). It should be noted that the balls 441 on the upper and lower sides of the carrier ball groove 422 are slightly larger than the balls 441 in the middle position to reduce the contact points between the middle balls 441 and the carrier ball groove 422, thereby preventing interference. At the same time, by setting the ball 441, the auxiliary effect of the ball 441 can reduce the friction during the movement, and the balls 441 are arranged relative to each other so that the camera module 10 can remain stable. The balls 441 are symmetrically arranged with the piezoelectric friction head 432 as the center. Since the piezoelectric vibrator 431 is extended and retracted during the movement stroke, the piezoelectric friction head 432 is tilted in the elliptical direction during the extension and retraction of the piezoelectric vibrator 431, thereby causing the piezoelectric friction head 432 to generate a tilting torque applied to the outer wall of the movable carrier 42 during the stroke trajectory. The balls 441 can disperse the tilting torque, thereby making the overall structure more stable. The balls 441 use rolling friction instead of sliding friction. The balls 441 and the carrier ball groove 422 and the shell ball groove 4122 serve as the guide mechanism 44 to provide greater support for the camera module 10, further maintaining the parallelism between the piezoelectric vibrator and the movable carrier.

[0074] Taking the piezoelectric actuator 43 as an example, the piezoelectric vibrator 431 is a substrate that has an inverse piezoelectric effect and contracts or expands according to the polarization direction and electric field direction. It can be used by polarizing the substrate in the thickness direction of single crystal, polycrystalline ceramics, polymers, etc. The inverse piezoelectric effect refers to the application of an electric field in the polarization direction of the dielectric, and the dielectric undergoes mechanical deformation when a potential difference is generated. The piezoelectric vibrator 431 has the effect of ultrasonic oscillation and can achieve elliptical motion on a specifically configured electrode layer. The piezoelectric vibrator 431 is composed of PZT material and is connected to the circuit board 31 to achieve circuit conduction, thereby providing power excitation.

[0075] The inner side surface 4311 and outer side surface 4312 of the piezoelectric vibrator 431 are parallel to the optical axis, and each surface has two rectangular long sides and two rectangular short sides. The two surfaces connected to and perpendicular to the rectangular short sides of the inner side surface 4311 and outer side surface 4312 of the piezoelectric vibrator 431 are the first end surface 4313 and the second end surface 4314 of the piezoelectric vibrator 431. The first end surface 4313 and the second end surface 4314 of the piezoelectric vibrator 431 are parallel to the optical axis, and each surface has four rectangular short sides. The surface closest to the bent end of the FPC board 413 is the first end surface 4313 of the piezoelectric vibrator 431, and the surface away from the bent end of the FPC board 413 is the second end surface 4314 of the piezoelectric vibrator 431.

[0076] Referring to Figure 6 , let the long side of the rectangle of the piezoelectric vibrator 431 be the X-axis, the short side of the rectangle of the piezoelectric vibrator 431 be the Y-axis, and the Z-axis be parallel to the optical axis and perpendicular to the X- and Y-axes. The YZ plane of the piezoelectric vibrator 431 is divided into four regions: the upper left portion is the first region 43131, the upper right portion is the second region 43132, the lower right portion is the third region 43133, and the lower left portion is the fourth region 43134. Due to the piezoelectric effect of d31, each pair of regions can be grouped together to perform telescopic motion in the X-axis direction. When the first region 43131 and the second region 43132 are grouped together, and the third region 43133 and the fourth region 43134 are grouped together, vibration in the Z-axis direction can be achieved. When the first region 43131 and the fourth region 43134 are grouped together, and the second region 43132 and the third region 43133 are grouped together, vibration in the Y-axis direction can be achieved. Assume that the electrode polarization of the first region 43131 and the second region 43132 is positive, and the electrode polarization of the third region 43133 and the fourth region 43134 is negative. Furthermore, a sin signal is input to the electrodes of the first region 43131 and the third region 43133, and a cos signal is input to the electrodes of the second region 43132 and the fourth region 43134. Therefore, from a waveform perspective, the piezoelectric vibrator 431 moves in a sin state in the first region 43131, a cos state in the second region 43132, a -sin state in the third region 43133, and a -cos state in the fourth region 43134. This will cause cyclic extension of the second region 43132, the first region 43131, the fourth region 43134, the third region 43133, the second region 43132, and so on. This will further cause the piezoelectric vibrator 431 to achieve periodic bending, and the friction head on the surface of the piezoelectric vibrator 431 will achieve elliptical motion, that is, the superposition of vibration in the Y-axis direction and vibration in the Z-axis direction to form an elliptical motion. From the perspective of the YZ plane of the piezoelectric vibrator 431 , in existing piezoelectric technologies, the height of the piezoelectric vibrator 431 in the Z-axis direction is often very long to ensure that the piezoelectric vibrator 431 has a sufficiently long stroke.

[0077] In the embodiment of the present application, to make the electrode wiring of the piezoelectric vibrator 431 more reasonable, the first end surface 4313 of the piezoelectric vibrator 431 is used as a front view for illustration. Continuing with FIG6 , the piezoelectric vibrator 431 is divided equally horizontally and vertically into four regions: the upper left portion is the first region 43131, the upper right portion is the second region 43132, the lower right portion is the third region 43133, and the lower left portion is the fourth region 43134. Assuming that two wires are drawn from each region, that is, each region has an electrode at its upper and lower ends, the first region 43131, the second region 43132, the third region 43133, and the fourth region 43134 each have electrodes at their upper and lower ends, for a total of eight electrodes. To reduce the number of electrodes, the lower electrodes of the first region 43131 and the second region 43132 and the upper electrodes of the third region 43133 and the fourth region 43134 (a total of four electrodes) are combined into a common ground terminal. During polarization, the signal wiring is as follows: the common ground electrode is grounded, the upper electrode of the first area 43131 and the upper electrode of the second area 43132 are connected to the positive electrode, and the lower electrode of the third area 43133 and the lower electrode of the fourth area 43134 are connected to the negative electrode; during driving, the common ground electrode is grounded, the upper electrode of the first area 43131 and the lower electrode of the third area 43133 input the sin signal, and the upper electrode of the second area 43132 and the lower electrode of the fourth area 43134 input the cos signal. The driving situation according to this electrode connection method is: assuming that the polarization of the upper electrode of the first region 43131 is +, the upper electrode of the second region 43132 is also +, and the lower electrode of the third region 43133 and the lower electrode of the fourth region 43134 are -; considering the working conditions after the polarization of the electrodes in each region, from the waveform perspective, as shown in Figure 7, the motion signal of the piezoelectric vibrator 431, that is, the upper electrode of the first region 43131 is sin, the upper electrode of the second region 43132 is cos, the lower electrode of the third region 43133 is -sin, and the lower electrode of the fourth region 43134 is -cos.

[0078] In the embodiment of the present application, the first region 43131 and the third region 43133 of the piezoelectric vibrator 431 are grouped together, and the second region 43132 and the fourth region 43134 are grouped together. The upper electrode of the first region 43131 of the piezoelectric vibrator 431 is connected to the lower electrode of the third region 43133, and the upper electrode of the second region 43132 of the piezoelectric vibrator 431 is connected to the lower electrode of the fourth region 43134, that is, the electrodes of the two diagonal regions are connected; Continuing to refer to FIG. 7, since the motion signal of the piezoelectric vibrator 431, that is, the upper electrode of the first region 43131 is sin, the The upper electrode of the second region 43132 is cos, the lower electrode of the third region 43133 is -sin, and the lower electrode of the fourth region 43134 is -cos. Then, there is a phase difference of 180° between the first region 43131 and the third region 43133, and there is a phase difference of 180° between the second region 43132 and the fourth region 43134, thereby making the piezoelectric vibrator 431 have a longer stroke when driven, and from the direction of the first end face 4313 of the piezoelectric vibrator 431, the height of the piezoelectric vibrator 431 is further shortened, which is in line with the miniaturized design of the camera module 10.

[0079] When the piezoelectric actuator 43 is powered, the piezoelectric vibrator 431 undergoes different surface changes in the Y-axis or Z-axis states, thereby driving the piezoelectric friction head 432 to produce elliptical motion. Due to the frictional contact between the piezoelectric friction head 432 and the piezoelectric friction plate 433, the piezoelectric friction plate 433 moves, thereby driving the movable carrier 42 to move. Specifically, when the piezoelectric actuator 43 is powered, the piezoelectric vibrator 431 produces a telescopic motion along the Y-axis and a tensile motion along the optical axis (Z-axis). Driven by the piezoelectric vibrator 431, the piezoelectric friction head 432 produces elliptical motion in the YZ-axis plane, thereby driving the piezoelectric friction plate 433 to move up and down in the Z-axis direction. The four areas of the piezoelectric vibrator 431 vibrate in turn, that is, the four areas protrude in sequence, and the phase difference of each area is 90°. Under the condition that the wave has a certain length, the electrodes of the diagonal areas of the piezoelectric vibrator 431 are connected to satisfy the phase difference of the diagonal areas of 180°, that is, an "upside-down" form. This connection method enables the piezoelectric vibrator 431 to have the advantages of large stroke, large thrust, high frequency, and small size.

[0080] Therefore, the piezoelectric actuator 43 has a degree of freedom in the Z-axis direction and can drive the movable carrier 42 to move in the Z-axis direction to adjust the relative position between the lens assembly 20 and the photosensitive assembly 30 to achieve AF zoom. The movable carrier 42 also plays a certain supporting role, which can improve the stability of the piezoelectric actuator 43 during the optical zoom process and enhance image quality.

[0081] When the piezoelectric vibrator 431 moves after being energized, it has a certain amplitude within the stroke of power excitation, wherein the amplitude of the middle part of the main body of the piezoelectric vibrator 431 is larger, and the amplitude of the two side parts is smaller. Therefore, the spring frame 4341 can prevent the piezoelectric vibrator 431 from interfering; and the movement of the piezoelectric vibrator 431 after being energized will also cause the piezoelectric vibrator 431 itself to undergo a certain deformation. The spring 434 can provide a certain inward potential energy, so that the spring 434 and the piezoelectric vibrator 431 are pressed tighter, thereby reducing the degree of deformation of the piezoelectric vibrator 431, so that the piezoelectric vibrator 431 can still return to its original position after vibration and implement the next vibration.

[0082] From an electrode perspective, as shown in Figures 8 and 9 , the four regions of the piezoelectric vibrator 431 can be further divided into a first phase electrode 43135, a second phase electrode 43136, a third phase electrode 43137, and a fourth phase electrode 43138. Specifically, the first region 43131 of the piezoelectric vibrator 431 has the first phase electrode 43135 and the second phase electrode 43136, the second region 43132 of the piezoelectric vibrator 431 has the second phase electrode 43136 and the third phase electrode 43137, the third region 43133 of the piezoelectric vibrator 431 has the first phase electrode 43135 and the fourth phase electrode 43138, and the fourth region 43134 of the piezoelectric vibrator 431 has the third phase electrode 43137 and the fourth phase electrode 43138. It should be noted that the first phase electrode 43135, the second phase electrode 43136, the third phase electrode 43137 and the fourth phase electrode 43138 are stacked on each other in the direction of the long side of the rectangle, wherein the second phase electrode 43136 is connected to the first region 43131 and the second region 43132 of the piezoelectric vibrator 431, and the second phase electrode 43136 is a common potential electrode arranged in the direction of the long side of the rectangle; the fourth phase electrode 43138 is connected to the third region 43133 and the fourth region 43134 of the piezoelectric vibrator 431, and the fourth phase electrode 43138 is a common potential electrode arranged in the direction of the long side of the rectangle. This design can reduce the number of stacked electrode layers, thereby reducing the electrode size. In addition, the piezoelectric vibrator 431 also has at least one substrate 4315, which is arranged on the inner side 4311 and the outer side 4312 of the piezoelectric vibrator 431 in the direction of the short side of the rectangle, thereby connecting the entire electrode layer of the piezoelectric vibrator 431, and the substrate 4315 is arranged on the side of the piezoelectric vibrator 431 to further reduce the electrode size and reasonably utilize the space. The substrate 4315 further includes a first substrate 43151 and a second substrate 43152. The first substrate 43151 is connected to the first phase electrode 43135 of the first area 43131 and the first phase electrode 43135 of the third area 43133. The second substrate 43152 is connected to the third phase electrode 43137 of the second area 43132 and the third phase electrode 43137 of the fourth area 43134, so as to ensure that the electrodes of the two diagonal areas of the piezoelectric vibrator 431 are connected to each other, thereby reducing the size of the piezoelectric vibrator 431 while ensuring that the piezoelectric vibrator 431 has advantages such as a large stroke.

[0083] In addition, the piezoelectric vibrator 431 is fixed using the spring positioning hole 4343 of the spring 434, wherein the spring positioning hole 4343 is arranged in the middle section area of ​​the outer surface 4312 of the piezoelectric vibrator 431. When fixed in this way, the resonant frequency of the piezoelectric vibrator 431 in the Y-axis and Z-axis directions is almost the same, and the motion trajectory of the piezoelectric friction head 432 is an elliptical motion, thereby driving the movable carrier 42 to move in the Z-axis direction to achieve AF zoom.

[0084] The above describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and description merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A piezoelectric motor, characterized in that: include: A fixing assembly, the fixing assembly comprising a base and a shell, wherein the shell is located above the base; a movable carrier, the movable carrier being arranged above the base; A piezoelectric actuator includes a piezoelectric vibrator and a spring, wherein one side of the spring is arranged on a surface of the piezoelectric vibrator and the other side of the spring is connected to the housing; the spring abuts against the piezoelectric vibrator and contacts the two short sides of the rectangle of the piezoelectric vibrator; wherein the long side of the rectangle of the spring is perpendicular to the long side of the rectangle of the piezoelectric vibrator. A guide mechanism maintains parallelism between the piezoelectric vibrator and the movable carrier.

2. The piezoelectric motor according to claim 1, wherein The piezoelectric actuator further comprises: The piezoelectric friction head is arranged at the center of one surface of the piezoelectric vibrator.

3. The piezoelectric motor according to claim 2, wherein The piezoelectric actuator further includes a piezoelectric friction plate, which is in contact with the piezoelectric friction head.

4. The piezoelectric motor according to claim 3, wherein The piezoelectric friction plate is arranged parallel to one surface of the piezoelectric vibrator, and the piezoelectric friction head is located at the center of the piezoelectric friction plate.

5. The piezoelectric motor according to claim 1, wherein The spring piece has a spring piece frame, the middle area of ​​the spring piece frame is a rectangular hollow structure, and the size of the spring piece frame is larger than the area size of the surface of the piezoelectric vibrator.

6. The piezoelectric motor according to claim 5, wherein The spring frame of the spring provides pre-pressure on at least two short sides of the rectangle of the piezoelectric vibrator.

7. The piezoelectric motor according to claim 1, wherein The pre-pressed edge where the spring and the piezoelectric vibrator are in contact is parallel to the driving direction of the piezoelectric vibrator.

8. The piezoelectric motor according to claim 1, wherein The elastic sheet further includes at least one elastic sheet extension arm. The elastic sheet extension arm has a groove structure. The elastic sheet extension arm is embedded in the shell and a certain gap is maintained between the elastic sheet extension arm and the shell.

9. The piezoelectric motor according to claim 1, wherein The spring piece further has at least one spring piece positioning hole, through which the spring piece is fixed to the piezoelectric vibrator. The spring piece positioning hole is located at the position where the amplitude of the piezoelectric vibrator in the direction of the long side of the rectangle is the smallest.

10. The piezoelectric motor according to claim 8, wherein The fixing assembly further includes an FPC soft board, which is arranged in the groove structure of the elastic sheet extension arm and is attached to the elastic sheet.

11. A piezoelectric actuator, characterized in that: include: A piezoelectric vibrator, wherein the piezoelectric vibrator has electrodes and is in the shape of a rectangular parallelepiped; A piezoelectric friction head, the piezoelectric friction head being arranged on a surface of the piezoelectric vibrator; a piezoelectric friction plate, the piezoelectric friction plate abutting against the piezoelectric friction head; a spring piece, the spring piece being arranged on the other surface of the piezoelectric vibrator; The plane formed by the short sides of the rectangle of the piezoelectric vibrator is divided into four regions, and the regions that are diagonally opposite to each other are connected by electrodes.

12. The piezoelectric actuator according to claim 11, wherein The four regions of the piezoelectric vibrator are, in clockwise order, a first region, a second region, a third region, and a fourth region.

13. The piezoelectric actuator according to claim 11, wherein Each of the four regions of the piezoelectric vibrator has electrodes at upper and lower ends.

14. The piezoelectric actuator according to claim 12, wherein: The upper electrode of the first region of the piezoelectric vibrator is connected to the lower electrode of the third region, and the upper electrode of the second region of the piezoelectric vibrator is connected to the lower electrode of the fourth region, that is, the electrodes of the two diagonal regions are connected.

15. The piezoelectric actuator according to claim 11, wherein The spring piece further has at least one spring piece positioning hole, through which the spring piece is fixed to the piezoelectric vibrator, and the resonance frequency of the piezoelectric vibrator in the direction of the long side of the rectangle is the same as that in the direction of the short side of the rectangle.

16. The piezoelectric actuator according to claim 11, wherein The piezoelectric vibrator further includes a first phase electrode, a second phase electrode, a third phase electrode, and a fourth phase electrode. The first region of the piezoelectric vibrator has the first phase electrode and the second phase electrode, the second region of the piezoelectric vibrator has the second phase electrode and the third phase electrode, the third region of the piezoelectric vibrator has the first phase electrode and the fourth phase electrode, and the fourth region of the piezoelectric vibrator has the third phase electrode and the fourth phase electrode.

17. The piezoelectric actuator according to claim 16, wherein: The first phase electrode, the second phase electrode, the third phase electrode and the fourth phase electrode of the piezoelectric vibrator are stacked on each other in the long side direction of the rectangle.

18. The piezoelectric actuator according to claim 16, wherein: The second phase electrode of the piezoelectric vibrator is connected to the first and second regions of the piezoelectric vibrator as a common potential electrode, and the fourth phase electrode of the piezoelectric vibrator is connected to the third and fourth regions of the piezoelectric vibrator as a common potential electrode.

19. The piezoelectric actuator according to claim 16, wherein: The piezoelectric vibrator further includes at least one substrate, which is disposed on a surface of the piezoelectric vibrator in a direction of a short side of a rectangle, and the substrate is connected to the electrode layer of the piezoelectric vibrator.

20. The piezoelectric actuator according to claim 19, wherein The substrate includes a first substrate connected to the first phase electrode of the first region and the first phase electrode of the third region of the piezoelectric vibrator, and a second substrate connected to the third phase electrode of the second region and the third phase electrode of the fourth region of the piezoelectric vibrator.

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