Piezoelectric motor, camera module and electronic equipment

Abstract

The utility model relates to a piezoelectric motor, a camera module and electronic equipment. The piezoelectric motor comprises a motor base, an AF carrier, a friction plate, piezoelectric ceramics, a pre-tightening elastic sheet, an electrode elastic sheet and an FPC board. The AF carrier is arranged in the motor base; the friction plate is fixedly arranged on the outer side wall of the AF carrier; the pre-tightening elastic piece is fixedly arranged on the inner side wall of the motor base, and the piezoelectric ceramic is connected to the pre-tightening elastic piece and tightly attached to the friction plate through pre-tightening force provided by the pre-tightening elastic piece. The piezoelectric ceramic is electrically connected with the FPC board; wherein the piezoelectric motor is configured as follows: when the piezoelectric ceramic is electrified, the friction plate and the AF carrier are driven to move in the vertical direction through the deformation of the piezoelectric ceramic; and when the piezoelectric ceramic is powered off, the AF carrier is fixed through the friction force between the friction surface of the piezoelectric ceramic and the friction plate. According to the utility model, the water ripple phenomenon of the motor under high-frequency vibration can be relieved or eliminated.

Description

Technical Field

[0001] This utility model relates to the field of camera module technology, specifically to a piezoelectric motor, a camera module, and an electronic device. Background Technology

[0002] In the mobile phone camera industry, module types are mainly divided into two categories: AF modules and FF modules. Among them, AF modules, or autofocus modules, widely use VCM (Voice Coil Motor) as their core driving component. The VCM motor generates Lorentz force through the interaction between a magnet and a coil, thereby driving the lens to move in the AF direction to achieve the function of autofocus.

[0003] However, as people's pursuit of photographic technology continues to improve, especially with the increasing demand for shooting video content such as VLOGs, the requirements for camera stability and image quality are also becoming higher. In practical applications, traditional VCM motors often exhibit a ripple effect when recording under high-frequency vibration. The root cause of this problem lies in the spring structure of the VCM motor. Under high-frequency vibration, the spring will vibrate, and the degree of vibration is closely related to the spring's K-value (stiffness coefficient). The smaller the K-value, the more obvious the spring vibration, and the larger the resulting ripple effect; while a larger K-value can reduce the spring vibration, the deformation of the spring will also decrease accordingly, requiring a larger Lorentz force to achieve the same positional movement. This necessitates increasing the parameters of the magnet, coil, or current, and these changes directly affect the size and power consumption of the VCM motor, bringing many limitations to its design and application.

[0004] Therefore, how to eliminate resonance caused by high-frequency vibration while ensuring the performance of the VCM motor, and improve the stability and image quality of the camera, has become a pressing technical problem in the current mobile phone camera industry. Summary of the Invention

[0005] The purpose of this invention is to provide a piezoelectric motor, camera module, and electronic device that can effectively alleviate or eliminate the water ripple phenomenon of the motor under high-frequency vibration.

[0006] In a first aspect, the piezoelectric motor described in this utility model includes a motor base, an AF carrier, a friction plate, a piezoelectric ceramic, a preload spring, an electrode spring, and an FPC plate;

[0007] The AF carrier is disposed inside the motor base;

[0008] The friction pad is fixedly disposed on the outer side wall of the AF carrier;

[0009] The preload spring is fixedly mounted on the inner wall of the motor base;

[0010] The piezoelectric ceramic is connected to the preload spring and is in close contact with the friction plate by the preload force provided by the preload spring;

[0011] The piezoelectric ceramic is electrically connected to the FPC board;

[0012] The piezoelectric motor is configured as follows:

[0013] When the piezoelectric ceramic is energized, the deformation of the piezoelectric ceramic drives the friction plate and AF carrier to move in the up and down direction;

[0014] When the piezoelectric ceramic is de-energized, the AF carrier is fixed by the friction force between the friction surface of the piezoelectric ceramic and the friction plate, so as to eliminate the water ripple phenomenon during high-frequency movement.

[0015] Optionally, a first groove for accommodating a friction plate is formed on the outer side wall of the AF carrier, and the friction plate is fixedly disposed in the first groove. By forming the first groove and fixing the friction plate therein, a stable connection between the friction plate and the AF carrier can be ensured, while reducing the shaking of the friction plate during movement and improving the working accuracy and stability of the piezoelectric motor.

[0016] Optionally, a second groove is provided on the inner sidewall of the motor base, and the preload spring is fixedly disposed in the second groove, with the outer end of the piezoelectric ceramic extending into the second groove. The second groove provides a stable mounting position for the preload spring while ensuring that the outer end of the piezoelectric ceramic can extend into the second groove. This structure helps to provide a stable preload force, allowing the piezoelectric ceramic and the friction plate to fit tightly together, thereby improving the driving efficiency and stability of the piezoelectric motor.

[0017] Optionally, a guiding and fixing structure is also included. This structure comprises a guide groove disposed on the AF carrier and a slide rod adapted within the guide groove. The lower end of the slide rod is fixed to the motor base, and the AF carrier can slide along the slide rod in the vertical direction. The guiding and fixing structure, including the guide groove and the slide rod, together ensures stable sliding of the AF carrier in the vertical direction. This structure helps reduce the offset and swaying of the AF carrier during movement, improving the accuracy and stability of the piezoelectric motor. Simultaneously, the uniform distribution of the slide rod and piezoelectric ceramics ensures uniform force distribution on the AF carrier during movement, further improving the working performance of the piezoelectric motor.

[0018] Optionally, the number of guide grooves and slide rods is at least two, and the slide rods and piezoelectric ceramics are evenly distributed with the center of the AF carrier as the center to ensure that the AF carrier is subjected to uniform force when moving.

[0019] Optionally, a third groove is provided on the outer wall of the AF carrier, and a magnet is disposed in the third groove. A Hall sensor is disposed on the FPC board at a position corresponding to the third groove. Through the cooperation of the magnet and the Hall sensor, the position of the AF carrier in the vertical direction can be monitored in real time, making it possible to precisely control the piezoelectric motor. This structure helps to realize closed-loop control of the piezoelectric motor and improve the positioning accuracy and stability of the piezoelectric motor.

[0020] Optionally, electrode springs are respectively provided on both sides of the piezoelectric ceramic, and the piezoelectric ceramic is electrically connected to the FPC board through the electrode springs. The electrode springs provide a reliable channel for the electrical connection between the piezoelectric ceramic and the FPC board, ensuring that the piezoelectric ceramic can normally receive electrical signals and achieve deformation. This structure helps to simplify the circuit structure of the piezoelectric motor and improve the reliability and stability of the piezoelectric motor.

[0021] Optionally, the friction plate and the AF carrier, as well as the preload spring and the motor base, are fixed together using adhesive dispensing. This adhesive dispensing method ensures a stable connection between the friction plate and the AF carrier, and between the preload spring and the motor base. This structure helps reduce loosening and deformation at the connection points, improving the durability and stability of the piezoelectric motor.

[0022] Secondly, the camera module described in this utility model includes a piezoelectric motor as described in this utility model.

[0023] Thirdly, the electronic device described in this utility model includes the camera module as described in this utility model.

[0024] This utility model has the following advantages:

[0025] (1) This utility model significantly improves the quality of video shooting:

[0026] When shooting video, especially in high-frequency shaking scenes such as running or cycling, traditional autofocus systems often fail to meet shooting needs and may even degrade video quality due to unstable focus. This invention, through a special design of a piezoelectric motor, automatically shuts off autofocus and switches to fixed-focus (FF) mode when encountering high-frequency vibrations. This innovative design effectively avoids image quality degradation caused by unstable focus, significantly improving the quality and stability of video shooting.

[0027] (2) This utility model is compatible with multiple shooting modes:

[0028] This invention is not only suitable for video shooting in high-frequency vibration scenarios, but also provides accurate AF focusing during regular handheld shooting, ensuring the clarity of the captured image. This design allows the invention to be compatible with low-frequency still photography and high-frequency motion video recording, meeting the needs of users in different shooting scenarios.

[0029] (3) This utility model can improve the imaging quality of mobile camera terminals:

[0030] For handheld cameras, such as mobile camera terminals like smartphones, action camcorders, and drones, this invention significantly improves image quality by optimizing the focusing system. Whether in still photography or video recording, it provides users with clearer and more stable images, thereby enhancing the overall shooting experience.

[0031] In summary, this invention enables the use of FF (Focus-Free) focusing while disabling AF in high-frequency vibration scenarios, while maintaining AF focusing accuracy in regular shooting modes, effectively improving the imaging quality and shooting experience of electronic devices. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the piezoelectric motor described in the embodiments of this application;

[0033] Figure 2 This is a top view of the piezoelectric motor described in the embodiments of this application;

[0034] Figure 3 The diagram shows the AF carrier, magnet, and Hall sensor described in the embodiments of this application.

[0035] Figure 4 This is an analytical diagram of the motor base, AF carrier, friction plate, etc., described in the embodiments of this application;

[0036] Explanation of the markings in the attached figures:

[0037] In the figure: 1. Motor base, 11. Second groove, 2. AF carrier, 21. First groove, 22. Guide groove, 23. Third groove, 3. Friction plate, 4. Piezoelectric ceramic, 5. Electrode spring, 6. FPC board, 61. Positive and negative electrode pads, 7. Preload spring, 8. Slide rod, 9. Magnet, 10. Hall sensor. Detailed Implementation

[0038] The following description, with reference to the accompanying drawings and preferred embodiments, illustrates the implementation of the technical solution of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be understood that the preferred embodiments are only for illustrating this utility model and not for limiting the scope of protection of this utility model.

[0039] like Figures 1 to 4 As shown in the embodiment of this application, a piezoelectric motor includes a motor base 1, an AF carrier 2, a friction plate 3, a piezoelectric ceramic 4, a preload spring 7, an electrode spring 5, and an FPC plate 6. The AF carrier 2 is disposed inside the motor base 1. The friction plate 3 is fixedly disposed on the outer side wall of the AF carrier 2. The preload spring 7 is fixedly disposed on the inner side wall of the motor base 1. The piezoelectric ceramic 4 is connected to the preload spring 7 and is tightly fitted with the friction plate 3 by the preload force provided by the preload spring 7. The piezoelectric ceramic 4 is electrically connected to the FPC plate 6. The piezoelectric motor is configured such that: when the piezoelectric ceramic 4 is energized, the deformation of the piezoelectric ceramic 4 drives the friction plate 3 and the AF carrier 2 to move in the vertical direction; when the piezoelectric ceramic 4 is de-energized, the friction force between the friction surface of the piezoelectric ceramic 4 and the friction plate 3 fixes the AF carrier 2, thereby eliminating the water ripple phenomenon during high-frequency movement.

[0040] like Figure 4 As shown, in one possible embodiment, a first groove 21 for accommodating the friction plate 3 is provided on the outer side wall of the AF carrier 2, and the friction plate 3 is fixedly disposed in the first groove 21. By providing the first groove 21 and fixing the friction plate 3 therein, a stable connection between the friction plate 3 and the AF carrier 2 can be ensured, while reducing the shaking of the friction plate 3 during movement and improving the working accuracy and stability of the piezoelectric motor.

[0041] like Figure 4 As shown, in one possible embodiment, a second groove 11 is provided on the inner sidewall of the motor base 1. The preload spring 7 is fixedly disposed in the second groove 11, and the outer end of the piezoelectric ceramic 4 extends into the second groove 11. The second groove 11 provides a stable mounting position for the preload spring 7, while ensuring that the outer end of the piezoelectric ceramic 4 can extend into the second groove 11. This structure helps to provide a stable preload force, allowing the piezoelectric ceramic 4 to fit tightly against the friction plate 3, thereby improving the driving efficiency and stability of the piezoelectric motor.

[0042] like Figure 2 and Figure 3As shown, in one possible embodiment, a piezoelectric motor further includes a guide and fixing structure. The guide and fixing structure includes a guide groove 22 disposed on the AF carrier 2 and a slide rod 8 adapted to be disposed within the guide groove 22. The AF carrier 2 can slide along the slide rod 8 in the vertical direction. The guide and fixing structure, including the guide groove 22 and the slide rod 8, together ensures the stable sliding of the AF carrier 2 in the vertical direction. This structure helps reduce the offset and swaying of the AF carrier 2 during movement, improving the accuracy and stability of the piezoelectric motor. Simultaneously, the uniform distribution of the slide rod 8 and the piezoelectric ceramic 4 ensures that the AF carrier 2 experiences uniform force during movement, further improving the working performance of the piezoelectric motor.

[0043] like Figure 2 and Figure 3 As shown, in one possible embodiment, the number of guide grooves 22 and slide rods 8 is at least two, and the slide rods 8 and piezoelectric ceramics 4 are evenly distributed with the center of the AF carrier 2 as the center, so as to ensure that the AF carrier 2 is subjected to uniform force when moving.

[0044] like Figure 3 As shown, in one possible embodiment, a third groove 23 is provided on the outer wall of the AF carrier 2, and a magnet 9 is disposed within the third groove 23. A Hall sensor 10 is disposed on the FPC board 6 at a position corresponding to the third groove 23. Through the cooperation of the magnet 9 and the Hall sensor 10, the position of the AF carrier 2 in the vertical direction can be monitored in real time, providing the possibility for precise control of the piezoelectric motor. This structure helps to realize closed-loop control of the piezoelectric motor and improve the positioning accuracy and stability of the piezoelectric motor.

[0045] like Figure 4 As shown, in one possible embodiment, electrode springs 5 ​​are respectively provided on both sides of the piezoelectric ceramic 4, and the piezoelectric ceramic 4 is electrically connected to the positive and negative pads 61 on the FPC board 6 through the electrode springs 5. The electrode springs 5 ​​provide a reliable channel for the electrical connection between the piezoelectric ceramic 4 and the FPC board 6, ensuring that the piezoelectric ceramic 4 can normally receive electrical signals and achieve deformation. This structure helps to simplify the circuit structure of the piezoelectric motor and improve the reliability and stability of the piezoelectric motor.

[0046] like Figure 4 As shown, in one possible embodiment, the friction plate 3 and the AF carrier 2, as well as the preload spring 7 and the motor base 1, are fixed by adhesive dispensing. This adhesive dispensing method ensures a stable connection between the friction plate 3 and the AF carrier 2, and between the preload spring 7 and the motor base 1. This structure helps reduce loosening and deformation at the connection points, improving the durability and stability of the piezoelectric motor.

[0047] In this application example, the piezoelectric ceramic 4, as a dielectric material with positive and negative electrodes and a friction surface, is in contact with the friction plate 3 made of alumina (or zirconium oxide). When the piezoelectric ceramic 4 is energized, its friction surface deforms, and this deformation causes the friction plate 3, which is in close contact with it, to move in the vertical direction. Since the friction plate 3 is fixedly mounted on the AF carrier 2, the vertical movement of the friction plate 3 directly causes the AF carrier 2 to move vertically accordingly.

[0048] To ensure the stability and uniform force distribution of the AF carrier 2 during movement, the piezoelectric motor is also equipped with at least two sliding rods 8. These sliding rods 8 are distributed in a circle with the center of the AF carrier 2 as the center, and are adapted to the guide structure (such as the guide groove 22) on the AF carrier 2. When the friction plate 3 is subjected to force and moves up and down, the sliding rods 8 play a guiding and supporting role, ensuring that the AF carrier 2 can move smoothly in the up and down direction without deviation.

[0049] Furthermore, when the piezoelectric ceramic 4 is de-energized, a certain amount of friction is generated between its friction surface and the friction plate 3. This friction is sufficient to fix the AF carrier 2 in its current position. Especially during high-frequency motion, the friction can effectively prevent minor vibrations or displacements of the AF carrier 2, thereby eliminating the water ripple phenomenon.

[0050] In this embodiment of the application, a camera module includes a piezoelectric motor as described in this embodiment. The lower end of the slide rod 8 is fixed to the motor base 1 to ensure stable sliding of the AF carrier 2 in the vertical direction.

[0051] In this application embodiment, an electronic device includes a camera module as described in this application embodiment.

[0052] In this application, the term "high frequency" does not have an absolute or unified definition, as it depends on various factors, including the response speed of the image stabilization system, the sensitivity of the sensor, and the requirements for image stabilization performance in specific application scenarios. Generally, vibrations with jitter information greater than or equal to a preset jitter threshold (obtained through calibration) can be considered high-frequency vibrations.

[0053] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A piezoelectric motor, characterized in that, It includes a motor base (1), an AF carrier (2), a friction plate (3), a piezoelectric ceramic (4), a preload spring (7), an electrode spring (5), and an FPC plate (6). The AF carrier (2) is disposed inside the motor base (1); The friction plate (3) is fixedly disposed on the outer side wall of the AF carrier (2); The pre-tightening spring (7) is fixedly disposed on the inner side wall of the motor base (1); The piezoelectric ceramic (4) is connected to the preload spring (7) and is in close contact with the friction plate (3) by the preload force provided by the preload spring (7); The piezoelectric ceramic (4) is electrically connected to the FPC board (6); The piezoelectric motor is configured as follows: When the piezoelectric ceramic (4) is energized, the deformation of the piezoelectric ceramic (4) drives the friction plate (3) and the AF carrier (2) to move in the up and down direction; When the piezoelectric ceramic (4) is de-energized, the AF carrier (2) is fixed by the friction force between the friction surface of the piezoelectric ceramic (4) and the friction plate (3).

2. The piezoelectric motor according to claim 1, characterized in that, The outer side wall of the AF carrier (2) is provided with a first groove (21) for accommodating the friction plate (3), and the friction plate (3) is fixedly disposed in the first groove (21).

3. The piezoelectric motor according to claim 1, characterized in that, The inner wall of the motor base (1) is provided with a second groove (11), the pre-tightening spring (7) is fixedly disposed in the second groove (11), and the outer end of the piezoelectric ceramic (4) extends into the second groove (11).

4. The piezoelectric motor according to claim 1, characterized in that, It also includes a guide fixing structure, which includes a guide groove (22) disposed on the AF carrier (2) and a slide rod (8) adapted to be disposed in the guide groove (22). The lower end of the slide rod (8) is fixed on the motor base (1), and the AF carrier (2) can slide along the slide rod (8) in the up and down direction.

5. The piezoelectric motor according to claim 4, characterized in that, The number of guide grooves (22) and slide bars (8) is at least two, and the slide bars (8) and piezoelectric ceramics (4) are evenly distributed with the center of the AF carrier (2) as the center.

6. The piezoelectric motor according to claim 1, characterized in that, The outer wall of the AF carrier (2) is also provided with a third groove (23), a magnet (9) is provided in the third groove (23), and a Hall sensor (10) is provided on the FPC board (6) at a position corresponding to the third groove (23).

7. The piezoelectric motor according to claim 1, characterized in that, Electrode springs (5) are respectively provided on both sides of the piezoelectric ceramic (4), and the piezoelectric ceramic (4) is electrically connected to the FPC plate (6) through the electrode springs (5).

8. The piezoelectric motor according to claim 1, characterized in that, The friction plate (3) and the AF carrier (2), as well as the pre-tightening spring (7) and the motor base (1) are fixed by adhesive dispensing.

9. A camera module, characterized in that, The piezoelectric motor included in any one of claims 1 to 8.

10. An electronic device, characterized in that, Includes the camera module as described in claim 9.

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