Lens driving device, camera device and electronic equipment

Abstract

The utility model discloses a lens driving device, a camera device and an electronic device, a movable lens assembly and a driving assembly are arranged on a base, the driving assembly drives the movable lens assembly to slide in the direction of an optical axis, and a magnetic unit is arranged to move synchronously with the movable lens assembly. The displacement sensor is arranged to be fixed relative to the base; the driving assembly is arranged to output vibration in the optical axis direction through the piezoelectric vibrator, and through friction connection between the driving friction piece and the lens friction piece, the movable lens assembly is driven to move in a friction sliding mode. An elastic unit is arranged to cooperatively absorb the impact force of the movable lens assembly on the driving friction piece and the piezoelectric vibrator when the whole device is impacted by external force; due to the arrangement of the elastic unit, the piezoelectric vibrator, the driving friction piece and the lens friction piece can still have stable connection and driving performance when the whole device is in different postures.

Description

[0001] This application claims priority to the patent application filed on February 4, 2024, with China National Intellectual Property Administration, application number 202420273695X, entitled "A Lens Driving Device, Camera Device and Electronic Equipment". Technical Field

[0002] This utility model belongs to the field of camera device technology, and particularly relates to a lens driving device, camera device and electronic device. Background Technology

[0003] Currently, handheld camera devices, especially mobile phone cameras, almost entirely rely on voice coil motors for autofocus. While voice coil motors offer advantages such as mature technology, low cost, and low noise, their disadvantages—including magnetic interference, insufficient thrust, and insufficient displacement—are becoming increasingly apparent as camera requirements increase. These disadvantages arise from factors like increased load and displacement due to increased pixel counts, and the need for magnetic interference-free drivers when using multiple cameras. Employing piezoelectric ceramic actuators for high-speed focusing of camera lenses is a new trend, offering advantages such as no magnetic interference, high thrust, high driving precision, and fewer structural components.

[0004] However, achieving stable connection and driving performance for the lens mount remains a major challenge in existing periscope lens driving devices that use piezoelectric ceramic drive mechanisms. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a lens driving device, a camera device, and an electronic device to solve the problem that existing periscope telephoto lenses are difficult to provide stable connection and driving performance.

[0006] The location detection feedback system suffers from high costs, complex structural design, and difficult control issues.

[0007] To solve the above problems, the technical solution of this utility model is as follows:

[0008] This utility model provides a lens driving device, comprising:

[0009] Base;

[0010] A movable lens assembly is configured to be slidably connected to the base along the optical axis;

[0011] A drive assembly, mounted on the base and configured to drive the movable lens assembly to move along the optical axis;

[0012] The magnetic unit is configured to move synchronously with the movable lens assembly;

[0013] A displacement sensor is fixed in position relative to the base, and the displacement sensor is configured to detect the magnetic field strength generated by the magnetic unit at the displacement sensor.

[0014] The driving assembly includes a piezoelectric vibrator, a driving friction element, a lens friction element, and an elastic unit. The lens friction element is fixedly connected to the movable lens assembly. The driving friction element is installed at the output end of the piezoelectric vibrator. When the piezoelectric vibrator is activated, the driving friction element reciprocates along the optical axis. The driving friction element is frictionally connected to the lens friction element, and the lens friction element is configured to be driven by the driving friction element to move along the optical axis. The elastic unit is arranged on the piezoelectric vibrator, and at least a portion of the elastic unit is located between the piezoelectric vibrator and the base. The elastic unit is configured to cooperate with the base to absorb the impact force exerted by the movable lens assembly on the driving friction element and the piezoelectric vibrator.

[0015] The lens driving device of this utility model includes a first elastic element and a second elastic element in the elastic unit.

[0016] The first elastic element is connected to the end of the piezoelectric vibrator away from the driving friction element, and the first elastic element is spaced out or slidably connected to the base; the second elastic element is arranged around the driving friction element, and the second elastic element is connected to the end of the piezoelectric vibrator facing the driving friction element, and the second elastic element is spaced out or slidably arranged to the base.

[0017] In the lens driving device of this utility model, the elastic unit is a first elastic element;

[0018] The first elastic element is connected to the end of the piezoelectric vibrator away from the driving friction element, and the first elastic element is fixedly connected to the base.

[0019] In the lens driving device of this utility model, a counterweight is provided at the end of the piezoelectric vibrator away from the driving friction member, and the counterweight is arranged between the first elastic member and the piezoelectric vibrator.

[0020] In the lens driving device of this invention, the elastic coefficient of the first elastic element is greater than that of the second elastic element.

[0021] The lens driving device of this utility model includes a driving friction component as a friction rod and a lens friction component as a friction retainer.

[0022] The axis of the friction rod is parallel to the optical axis, and the friction retainer clamps and frictionally connects to the friction rod.

[0023] The lens driving device of this utility model also includes an FPC circuit board;

[0024] The FPC circuit board is arranged on the base, and the FPC circuit board and the piezoelectric vibrator are electrically connected through the FPC bending section.

[0025] The lens driving device of this utility model also includes an FPC circuit board and conductive connectors;

[0026] The FPC circuit board is arranged on the base, and the FPC circuit board and the piezoelectric vibrator are electrically connected through the conductive connector.

[0027] In the lens driving device of this utility model, at least a portion of the conductive connector is a deformable structure.

[0028] The lens driving device of this utility model has at least one non-magnetic region between the two ends of the magnetic unit in the optical axis direction, so as to increase the curvature of the magnetic field strength change based on the optical axis direction stroke detected by the displacement sensor at the two ends of the magnetic unit in the optical axis direction.

[0029] In the lens driving device of this invention, the ratio between the length of the magnetic unit in the optical axis direction and the mechanical stroke of the movable lens assembly on the base is 1.4 to 1.6.

[0030] The lens driving device of this utility model has a magnetic unit that is a multi-level magnetized magnet. The non-magnetic area is centrally arranged on the multi-level magnetized magnet in the optical axis direction, and the span of the non-magnetic area in the optical axis direction is greater than or equal to 1 mm.

[0031] In the lens driving device of this invention, the distance between the displacement sensor and the magnetic unit is 0.3mm to 0.5mm.

[0032] The lens driving device of this utility model includes a driving friction member, which is a friction rod with its axis parallel to the optical axis. The lens friction member includes a friction plate disposed on the movable lens assembly, and at least a portion of the circumferential sidewall of the friction rod is in frictional contact with the friction plate.

[0033] The lens driving device of this utility model has a friction plate with a V-shaped groove. The length direction of the V-shaped groove is the same as the axial direction of the friction rod. At least a portion of the friction rod is disposed in the V-shaped groove and makes frictional contact with the inner sidewall of the V-shaped groove.

[0034] The lens driving device of this utility model further includes an elastic pressure plate in the lens friction component. One end of the elastic pressure plate is disposed on the movable lens assembly, and the other end of the elastic pressure plate extends toward the friction rod and abuts against the friction rod to provide a force toward the friction plate for the friction rod.

[0035] The present invention provides a camera device, comprising the lens driving device described in any one of the above-mentioned claims.

[0036] An electronic device according to this utility model includes the camera device described above.

[0037] Because of the adoption of the above technical solution, this utility model has the following advantages and positive effects compared with the prior art:

[0038] 1. One embodiment of this utility model involves setting a movable lens assembly and a driving assembly on a base. The driving assembly drives the movable lens assembly to slide along the optical axis, and the magnetic unit is set to move synchronously with the movable lens assembly. The displacement sensor is set to be fixed relative to the base. Furthermore, the driving assembly is set to include a piezoelectric vibrator, a driving friction element, a lens friction element, and an elastic unit. The piezoelectric vibrator outputs vibration along the optical axis, which is transmitted through frictional connection between the driving friction element and the lens friction element, thereby driving the movable lens assembly to move by frictional sliding. The elastic unit is set to absorb the impact force on the driving friction element and the piezoelectric vibrator when the device as a whole is subjected to external force, thus playing the necessary buffering role. The setting of the elastic unit ensures that the piezoelectric vibrator, the driving friction element, and the lens friction element can still maintain stable connection and driving performance in different postures of the device as a whole.

[0039] 2. In one embodiment of this utility model, by setting the elastic coefficient relationship between the first elastic element and the second elastic element, as well as the connection relationship between the two elastic elements and the base and whether or not a counterweight is configured, or by setting the connection relationship between the first elastic element and the counterweight and the piezoelectric vibrator and the base, it is possible to further control the piezoelectric vibrator to deform and output power in a predetermined direction when energized, thereby improving the power output utilization rate and focusing accuracy.

[0040] 3. In one embodiment of this utility model, the magnetic unit is configured with at least one non-magnetic region between its two ends in the optical axis direction. This increases the curvature of the magnetic field strength change detected by the displacement sensor at both ends of the magnetic unit in the optical axis direction based on the optical axis direction travel. In other words, it improves the magnetic field strength at both ends of the magnetic unit in the optical axis direction, increases the amount of magnetic field strength change, and thus improves the sensing sensitivity of the displacement sensor, which is beneficial to the closed-loop drive control accuracy of the periscope telephoto lens. This embodiment has low cost, simple structure and control, and is easy to implement. It solves the problems of high cost, difficult structure and control of existing periscope telephoto lens position detection feedback. Attached Figure Description

[0041] Figure 1 This is an overall schematic diagram of the lens driving device according to Embodiment 1 of this utility model;

[0042] Figure 2This is an exploded view of the lens driving device according to Embodiment 1 of this utility model;

[0043] Figure 3 This is a schematic diagram of the lens driving device for removing the moving lens assembly according to Embodiment 1 of this utility model;

[0044] Figure 4 This is a schematic diagram of the moving lens assembly of the lens driving device according to Embodiment 1 of this utility model;

[0045] Figure 5 This is a schematic diagram of the drive assembly of the lens drive device according to Embodiment 1 of this utility model;

[0046] Figure 6 This is a side view of the lens driving device according to Embodiment 1 of this utility model;

[0047] Figure 7 This is a view along the optical axis of the lens driving device according to Embodiment 1 of this utility model;

[0048] Figure 8 This is a schematic diagram of the lens driving device with a counterweight according to Embodiment 1 of this utility model;

[0049] Figure 9 This is a schematic diagram of the drive assembly of the lens drive device according to Embodiment 1 of the present invention, which includes a counterweight.

[0050] Figure 10 This is a view of the optical axis direction of the drive assembly of the lens drive device according to Embodiment 1 of this utility model;

[0051] Figure 11 This is a side view of the lens driving device according to Embodiment 2 of this utility model;

[0052] Figure 12 This is a schematic diagram of the magnetic unit of the lens driving device according to Embodiment 1 of this utility model;

[0053] Figure 13 This is a schematic diagram showing the positional relationship between the magnetic unit of the lens driving device in Embodiment 1 of the present invention and the position sensor when the magnetic unit is located in the middle stroke.

[0054] Figure 14 This is a schematic diagram showing the positional relationship between the magnetic unit of the lens driving device in Embodiment 1 of the present invention and the position sensor when the magnetic unit is at its maximum stroke.

[0055] Figure 15 This is a schematic diagram showing the positional relationship between the magnetic unit of the lens driving device in Embodiment 1 of the present invention and the position sensor when the magnetic unit is at its minimum stroke.

[0056] Figure 16This is a graph showing the relationship between the magnetic field strength sensed by the displacement sensor simulated by the magnetic unit of this invention and the position (stroke).

[0057] Figure 17 The graph shows the relationship between the magnetic field strength sensed by the displacement sensor and the position (stroke) for a conventional Hall magnet structure.

[0058] Figure 18 This is a schematic diagram showing the positional relationship between the FPC circuit board, conductive connector, friction rod, friction plate, and elastic pressure plate of the lens driving device of this utility model.

[0059] Figure 19 This is a schematic diagram showing the positional relationship of the FPC circuit board, conductive connector, friction rod, friction plate, and elastic pressure plate of the lens driving device from another angle of this utility model.

[0060] Explanation of reference numerals in the attached drawings: 1. Base; 101. Power output space; 2. Fixed lens assembly; 3. Moving lens assembly; 301. Moving lens; 302. Moving lens mount; 3021. Clearance groove; 3022. V-shaped guide groove; 3023. U-shaped guide groove; 3024. Supporting boss; 4. Piezoelectric vibrator; 5. First elastic element; 6. Second elastic element; 7. Friction rod; 8. Friction retaining ring; 9. FPC circuit board; 10. FPC bending section; 11. Displacement sensor; 12. Magnetic unit; 1201. Non-magnetic area; 13. Guide rod; 14. Magnetic adsorption element; 15. Counterweight; 16. Conductive connector; 17. Friction plate; 18. Elastic pressure plate. Detailed Implementation

[0061] The lens driving device, camera device, and electronic device proposed in this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this utility model will become clearer from the following description and claims.

[0062] Example 1

[0063] See Figures 1 to 7 In one embodiment, a lens driving device includes a base 1, a movable lens assembly 3, a driving assembly, a magnetic unit 12, and a displacement sensor 11.

[0064] The movable lens assembly 3 is configured to slide along the optical axis and be connected to the base 1. A drive assembly is mounted on the base 1 and configured to drive the movable lens assembly 3 to move along the optical axis. The magnetic unit 12 is configured to move synchronously with the movable lens assembly 3. The displacement sensor 11 is arranged and fixed in a position relative to the base 1, and is configured to detect the magnetic field strength generated by the magnetic unit 12 at the displacement sensor 11.

[0065] Specifically, the driving component may include a piezoelectric vibrator 4 (which may be a piezoelectric ceramic), a driving friction element, a lens friction element, and an elastic unit.

[0066] The lens friction element is fixedly connected to the movable lens assembly 3. A driving friction element is installed at the output end of the piezoelectric vibrator 4. When the piezoelectric vibrator 4 is activated, the driving friction element reciprocates along the optical axis. The driving friction element is frictionally connected to the lens friction element, and the lens friction element is configured to be driven by the driving friction element to move along the optical axis (i.e., the reciprocating motion along the optical axis output by the piezoelectric vibrator 4 drives the lens friction element and the connected movable lens assembly 3 to move through frictional sliding).

[0067] The elastic unit is arranged on the piezoelectric vibrator 4, and at least some of the elastic units are located between the piezoelectric vibrator 4 and the base 1. The elastic unit is configured to cooperate with the base 1 to absorb the impact force of the moving lens assembly 3 on the driving friction element and the piezoelectric vibrator 4.

[0068] In this embodiment, a movable lens assembly 3 and a driving assembly are arranged on the base 1. The driving assembly drives the movable lens assembly 3 to slide along the optical axis. The magnetic unit 12 is set to move synchronously with the movable lens assembly 3, and the displacement sensor 11 is set to be fixed relative to the base 1. Furthermore, the driving assembly is set to include a piezoelectric vibrator 4, a driving friction element, a lens friction element, and an elastic unit. The piezoelectric vibrator 4 outputs vibration along the optical axis, which is connected by friction between the driving friction element and the lens friction element, thereby driving the movable lens assembly 3 to move through friction sliding. The elastic unit is set to absorb the impact force of external force on the driving friction element and the piezoelectric vibrator when the device as a whole is subjected to external force, thus playing the necessary buffering role. The setting of the elastic unit ensures that the piezoelectric vibrator 4, the driving friction element, and the lens friction element can still maintain stable connection and driving performance in different postures of the device as a whole.

[0069] The specific structure of the lens driving device in this embodiment will be further described below:

[0070] In this embodiment, the aforementioned driving friction component is a friction rod 7, and the lens friction component can be a friction retainer 8. One end of the friction retainer 8 is fixedly connected to the movable lens assembly 3, and the other end is clamped to the friction rod 7 by friction clamping. The friction rod 7 is arranged along the optical axis, and one end of the friction rod 7 is fixedly connected to the piezoelectric vibrator 4. The friction rod 7 can be made of a high-hardness, lightweight material, such as preferably ceramic, carbon rod, or polymer material (e.g., PEEK). Lightweight material is beneficial for the piezoelectric ceramic to output power to the driving rod side. High hardness (low elastic coefficient) is beneficial for reducing the deformation / driving stroke of the driving rod "eating" the piezoelectric ceramic.

[0071] In this embodiment, the aforementioned elastic unit may specifically include a first elastic element 5 and a second elastic element 6.

[0072] The first elastic element 5 is connected to the end of the piezoelectric vibrator 4 facing away from the driving friction element, and the first elastic element 5 is gap-arranged or slidably connected to the base 1; the second elastic element 6 is arranged around the driving friction element, and the second elastic element 6 is connected to the end of the piezoelectric vibrator 4 facing the driving friction element, and the second elastic element 6 is gap-arranged or slidably arranged to the base 1. (That is, the two end faces of the piezoelectric ceramic facing away from and facing the driving friction element in the optical axis direction are the facing surface and the facing surface, respectively. One end of the first elastic element 5 is connected to the facing surface, and the other end is slidably or gap-arrangedly connected to the base 1. Lubricating oil can be applied to the gap or sliding surface to increase the lubrication effect when the piezoelectric vibrator 4 moves with the moving lens assembly 3, reduce resistance, and move smoothly; similarly, one end of the second elastic element 6 is connected to the facing surface, and the other end is slidably or gap-arrangedly connected to the base 1. Lubricating oil can be applied to the gap or sliding surface to increase the lubrication effect when the piezoelectric vibrator 4 moves with the moving lens assembly 3, reduce resistance, and move smoothly).

[0073] The first elastic element 5 and the second elastic element 6 can be elastic layers or elastic elements arranged on the piezoelectric vibrator 4. Specifically, they can be lightweight materials with a large elastic coefficient, such as silicone, rubber, foam, etc.

[0074] When the lens drive device is subjected to an external impact (such as during reliability testing: drop, roller, vibration), the moving lens assembly 3 will "break free" from the base 1 and "grab" the friction rod 7, driving the piezoelectric vibrator 4 and the connected first elastic element 5 and second elastic element 6 to move. If the connection is fixed, the friction rod 7 and the piezoelectric vibrator 4 will be pulled, resulting in uneven force on the friction rod 7, which may cause damage or breakage. At this time, the first elastic element 5 and the second elastic element 6 can move with the piezoelectric vibrator 4 and absorb the impact force, thus playing a buffering role.

[0075] See Figures 8 to 10 In this embodiment, a counterweight 15 can also be provided between the first elastic element 5 and the piezoelectric vibrator 4. One end of the first elastic element 5 is connected to one end of the counterweight 15, and the other end of the counterweight 15 is connected to the back surface of the piezoelectric vibrator 4. Specifically, the counterweight 15 can be configured as a metal layer / block attached to the back surface of the piezoelectric vibrator 4, and can be made of a high-density metal, such as tungsten alloy. By configuring a heavy metal layer / block on the back surface of the piezoelectric vibrator 4 and a lightweight drive rod on the facing surface, it is beneficial for the piezoelectric vibrator 4 to output power (deformation / displacement) to the friction rod 7 side.

[0076] In this embodiment, the elastic coefficient of the first elastic element 5 can be set to be greater than the elastic coefficient of the second elastic element 6. This setting of the elastic coefficient is beneficial for the piezoelectric vibrator 4 to output vibration motion toward the moving lens assembly 3.

[0077] In this embodiment, by setting the elastic coefficient relationship between the first elastic element 5 and the second elastic element 6, as well as the connection relationship between the two elastic elements and the base 1 and whether or not a counterweight 15 is configured, or by setting the connection relationship between the first elastic element 5 and the counterweight 15 and the piezoelectric vibrator 4 and the base 1, it is possible to further control the piezoelectric vibrator 4 to deform and output power in a predetermined direction when energized, thereby improving the power output utilization rate and focusing accuracy.

[0078] In this embodiment, since the piezoelectric vibrator 4 reciprocates during the driving process, and to ensure a stable electrical connection, the FPC circuit board 9 is arranged on the base 1, and the FPC circuit board 9 and the piezoelectric vibrator 4 are electrically connected through an FPC bending section 10. This FPC bending section 10 specifically includes a first vertical section, a first horizontal section, a second vertical section, a second horizontal section, and a vertical connecting section connected in sequence. The first vertical section, the second vertical section, and the vertical connecting section can all be configured to be perpendicular to the optical axis, while the first horizontal section and the second horizontal section are parallel to the optical axis. The ends of the two horizontal sections facing away from the moving lens assembly 3 are respectively connected to the upper and lower ends of the second vertical section (i.e., the first horizontal section, the second vertical section, and the second horizontal section cooperate to form a U-shaped structure).

[0079] Because periscope telephoto lenses have a large focusing / zoom travel, simply increasing the pole length of a conventional Hall magnet is insufficient to detect the magnetic field strength throughout the entire drive stroke of the magnetic sensor: when the position sensor is at the limit of its drive stroke, the change in magnetic field strength at both ends of the extended Hall magnet is weak (as shown in the attached figure). Figure 17 As shown in the diagram, the magnetic sensor exhibits poor driving accuracy near the magnetic extreme point due to its low sensing sensitivity. Current technologies for driving long-stroke lenses typically utilize magnetic gratings and magnetic sensors to form position detection components, or combine multiple sets of magnets with magnetic sensors to achieve long-stroke position detection and feedback. However, this approach suffers from high cost, complex structural design, and difficult control.

[0080] See Figures 12 to 16 In this embodiment, at least one non-magnetic region 1201 is provided between the two ends of the magnetic unit 12 in the optical axis direction to increase the curvature of the magnetic field strength change based on the optical axis direction travel detected by the displacement sensor 11 at both ends of the magnetic unit 12 (see details). Figure 16 ).

[0081] This embodiment sets a movable lens assembly 3 and a driving assembly on the base 1. The driving assembly drives the movable lens assembly 3 to slide in the optical axis direction. The magnetic unit 12 is set to move synchronously with the movable lens assembly 3, and the displacement sensor 11 is set to be fixed relative to the base 1. Furthermore, the magnetic unit 12 is set to have at least one non-magnetic region 1201 between its two ends in the optical axis direction, thereby increasing the curvature of the magnetic field strength change based on the optical axis direction stroke detected by the displacement sensor 11 at both ends of the magnetic unit 12. That is, it improves the magnetic field strength at both ends of the magnetic unit 12 in the optical axis direction, increases the amount of magnetic field strength change, and thus improves the sensing sensitivity of the displacement sensor 11, which is beneficial to the closed-loop drive control accuracy of the periscope telephoto lens. This embodiment has low cost, simple structure and control, and is easy to implement. It solves the problems of high cost, difficult structure and control of the existing position detection feedback of periscope telephoto lenses.

[0082] See Figure 16 By arranging the non-magnetic region 1201, the nonlinearity at both ends of the magnetic field can be well corrected, making the nonlinear error of the magnetic field strength change curve within the entire driving stroke small. Even when the displacement sensor 11 passes through the regions corresponding to both ends of the optical axis of the magnetic unit 12, the change in magnetic field strength in this part of the stroke remains large (i.e., the curve formed by the relationship between the magnetic field strength sensed by the displacement sensor 11 and the position is steep). That is, when the corresponding magnetic unit 12 moves within the stroke in the optical axis direction, the aforementioned curve will not have a smooth interval (small change in magnetic field strength). This allows the length of the magnetic unit 12 in the optical axis direction of this embodiment to be set to be approximately the same as the stroke of the moving lens assembly 3 (further reducing the volume and weight of the moving lens assembly 3 and the module as a whole), without having to adopt the existing complex scheme (the magnetic grating and magnetic sensor form a position detection component, or multiple sets of magnets and magnetic sensors are combined to achieve large stroke position detection and feedback), and without having to adopt the scheme of lengthening the Hall magnet for the accuracy of detection within the stroke (leading to an increase in the volume and weight of the moving lens assembly 3 and the module as a whole).

[0083] In this embodiment, the length (L1) of the non-magnetic region 1201 in the optical axis direction is set to 0.4 to 0.6 times the mechanical travel (L2, typically ≥ 3mm) of the moving lens assembly 3 on the base 1, i.e., L1 = (0.4 to 0.6)L2. Due to the setting of the non-magnetic region 1201, the size of the magnetic unit 12 can be reduced as much as possible. The ratio between the length of the magnetic unit 12 in the optical axis direction and the mechanical travel of the moving lens assembly 3 on the base 1 can be specifically 1.4 to 1.6.

[0084] In this embodiment, the magnetic unit 12 can specifically be a multi-stage magnetized magnet. The non-magnetic region 1201 is centrally arranged in the multi-stage magnetized magnet along the optical axis. Since the multi-stage magnetized magnet itself has a non-magnetic region, in order to improve the driving performance (thrust) of the multi-stage magnetized magnet and the driving coil, the prior art usually requires that the span of the non-magnetic region in the polarization direction be as small as possible (the more concentrated the magnetic field strength, the greater the thrust). Currently, the span of the non-magnetic region in the polarization direction is usually set to less than or equal to 0.4 mm. In this embodiment, in order to achieve a better change in magnetic field strength at the end, the span of the non-magnetic region 1201 in the optical axis direction can be set to greater than or equal to 1 mm.

[0085] Furthermore, the displacement sensor 11 described above can specifically be a Hall chip, and in order to obtain a better detected magnetic field strength change curvature, the distance between the Hall chip and the multi-level magnetized magnets can be set to 0.3mm to 0.5mm (the distance between the Hall chip and the multi-level magnetized magnets in the direction perpendicular to the optical axis), such as... Figure 16 The simulation uses N52SH multi-stage magnetized magnets, with the span of the non-magnetic zone 1201 set to 1.7mm and the spacing between the Hall chip and the multi-stage magnetized magnets set to 0.4mm, to measure the change in magnetic induction intensity within a driving stroke of ±1625mm. Figure 17 The simulation curve of magnetic induction intensity change within a drive stroke of ±1625mm is obtained by using N52SH multi-level magnetized magnets, setting the span of the non-magnetic zone 1201 to 0.2mm and the distance between the Hall chip and the multi-level magnetized magnets to 0.4mm.

[0086] In this embodiment, the base 1 can be specifically configured to have a lens space that is disposed on the optical axis and extends along the optical axis direction, and a drive space that is parallel to the lens space; wherein, the lens space includes a fixed lens space and a movable lens space, the drive space includes a power output space 101 and a power transmission space, the power output space 101 corresponds to the fixed lens space, and the power transmission space is connected to the movable lens space.

[0087] A fixed lens assembly 2 is fixedly installed within the fixed lens space, and a portion of this fixed lens assembly 2 can extend into the aforementioned power output space 101, thereby forming a piezoelectric vibrator 4 mounting cavity located within the power output space 101. Alternatively, the piezoelectric vibrator 4 mounting cavity can directly be the aforementioned power output space 101, without specific limitation. The piezoelectric vibrator 4 and the two elastic elements connected thereto form an integral arrangement within this piezoelectric vibrator 4 mounting cavity. Specifically, this piezoelectric vibrator 4 mounting cavity can be configured as the inner cavity of an approximately rectangular shell. An opening for the friction rod 7 to extend is provided on the surface of the rectangular shell facing the power transmission space, and an area for the FPC bending section to extend into is provided on the surface of the rectangular shell facing away from the optical axis.

[0088] The aforementioned movable lens assembly 3 may specifically include a movable lens 301 and a movable lens mount 302. The movable lens 301 is fixed to the movable lens mount 302. The movable mount is slidably connected to the movable lens space along the optical axis. Specifically, the sliding connection can be achieved by setting two guide rods 13 parallel to the optical axis on the bottom surface of the base 1 corresponding to the movable lens space. A V-shaped guide groove 3022 and a U-shaped guide groove 3023 corresponding to these two guide rods 13 can be formed on the movable mount. The guide rods 13 abut against the corresponding guide grooves to achieve the guiding and limiting function. Furthermore, the clearance fit between the guide rods 13 and the U-shaped guide groove 3023 can release insufficient assembly machining precision. For example, a bearing boss 3024 can be set at the bottom surface of the U-shaped guide groove 3023, so that when the guide rods 13 are in the U-shaped guide groove 3023, a certain gap is formed between them and the bottom surface of the U-shaped guide groove 3023 (e.g., ...). Figure 4 This can further prevent the movable fixed seat from getting stuck or sliding unevenly.

[0089] Furthermore, a magnetic adsorption component 14 can be embedded in the groove surface of the V-shaped guide groove 3022 and the U-shaped guide groove 3023. The two guide rods 13 can be set as magnetic guide rods. After the magnetic adsorption component 14 is limited by the guide rods 13 and the corresponding V-shaped guide groove 3022 and U-shaped guide groove 3023, it forms a gap fit with the guide rods 13 to prevent collision and realize the adsorption between the two. This allows the movable fixed seat to stably adsorb and slide to connect with the magnetic guide rods below.

[0090] In this embodiment, the aforementioned movable fixed base may further include a fixed base extension extending into the power transmission space. The fixed extension is provided with a clearance groove 3021 corresponding to the insertion of the friction rod 7, and the aforementioned friction retaining ring 8 is disposed within this clearance groove 3021. The aforementioned multi-level magnetized magnet can be embedded on the bottom surface of the fixed extension, and the FPC circuit board 9 can be disposed on the bottom surface of the base 1 corresponding to the power transmission space. The aforementioned Hall effect chip is disposed on the FPC circuit board 9.

[0091] Example 2

[0092] See Figure 11 Based on Embodiment 1 above, this embodiment adjusts the structure of the elastic unit portion as follows:

[0093] In this embodiment, the elastic unit described above may be configured to include only the first elastic element 5 and the counterweight 15. The counterweight 15 is arranged between the first elastic element 5 and the piezoelectric vibrator 4. The first elastic element 5, the counterweight 15, and the piezoelectric vibrator 4 are connected sequentially in the optical axis direction. That is, one end of the counterweight 15 is connected to the end of the piezoelectric vibrator 4 away from the driving friction element (i.e., the aforementioned away surface), and the other end of the counterweight 15 is connected to the first elastic element 5. The other end of the first elastic element 5 is fixedly connected to the base 1 (i.e., the first elastic element 5, the counterweight 15, and the piezoelectric vibrator 4 form a whole and are fixed to the surface of the rectangular shell away from the power transmission space by the first elastic element 5).

[0094] When the overall structure is subjected to external impact (such as during reliability testing: drop, roller, vibration), the moving lens assembly 3 "breaks free" from the base 1 and "grabs" the friction rod 7, driving the piezoelectric vibrator 4 to move. At this time, the first elastic element 5 pulls the piezoelectric vibrator 4 and the friction rod 7 and absorbs the impact force, playing a buffering role. The function of the counterweight 15 is also to facilitate the output of power (deformation / displacement) from the piezoelectric vibrator 4 to the friction rod 7 by arranging a heavy counterweight 15 on the opposite side of the piezoelectric vibrator 4 and a light-weight drive rod on the facing side.

[0095] Example 3

[0096] This invention provides a camera device, including the lens driving device described in Embodiment 1 or Embodiment 2. A movable lens assembly 3 and a driving assembly are mounted on a base 1. The driving assembly drives the movable lens assembly 3 to slide along the optical axis. A magnetic unit 12 is configured to move synchronously with the movable lens assembly 3, and a displacement sensor 11 is fixed relative to the base 1. The driving assembly further comprises a piezoelectric vibrator 4, a driving friction element, a lens friction element, and an elastic unit. The piezoelectric vibrator 4 outputs vibrations along the optical axis, which, through frictional connection between the driving friction element and the lens friction element, drive the movable lens assembly 3 to move via frictional sliding. The elastic unit absorbs the impact force exerted on the driving friction element and piezoelectric vibrator when the device as a whole is subjected to external force, providing the necessary buffering effect. The elastic unit ensures that the piezoelectric vibrator 4, the driving friction element, and the lens friction element maintain stable connection and driving performance under different postures.

[0097] Example 4

[0098] This embodiment provides an electronic device, including the camera device of Embodiment 3 described above. A movable lens assembly 3 and a driving assembly are mounted on a base 1. The driving assembly drives the movable lens assembly 3 to slide along the optical axis. The magnetic unit 12 is configured to move synchronously with the movable lens assembly 3, and the displacement sensor 11 is fixed relative to the base 1. The driving assembly further comprises a piezoelectric vibrator 4, a driving friction element, a lens friction element, and an elastic unit. The piezoelectric vibrator 4 outputs vibrations along the optical axis, which, through frictional connection between the driving friction element and the lens friction element, drive the movable lens assembly 3 to move via frictional sliding. The elastic unit absorbs the impact force on the driving friction element and the piezoelectric vibrator when the device as a whole is subjected to external force, providing the necessary buffering effect. The elastic unit ensures that the piezoelectric vibrator 4, the driving friction element, and the lens friction element maintain stable connection and driving performance under different postures.

[0099] Example 5

[0100] like Figure 18 and Figure 19 As shown, in this embodiment, unlike Embodiment 1, the lens driving device may include an FPC circuit board 9 and a conductive connector 16. The FPC circuit board 9 is arranged on the base 1, and the FPC circuit board 9 and the piezoelectric vibrator 4 are electrically connected through the conductive connector 16. Unlike the above method of setting a bending section on the FPC circuit board 9, in this application, the electrical connection between the FPC circuit board 9 and the piezoelectric vibrator 4 can be achieved by adding a conductive connector 16. Therefore, in this embodiment, since it is not necessary to set a bending section on the FPC circuit board 9, the assembly difficulty of the FPC circuit board 9 can be effectively reduced.

[0101] Optionally, at least a portion of the conductive connector 16 is a deformable structure. This arrangement ensures that the conductive connector 16 is dragged during the movement of the piezoelectric vibrator 4, thereby guaranteeing the connection stability between the conductive connector 16, the piezoelectric vibrator 4, and the FPC circuit board 9.

[0102] Optionally, the conductive connector 16 in this application can be a metal wire. Furthermore, the conductive connector 16 can include at least two metal wires. The deformable structure of the metal wires can be bent into any arc shape or other shapes. Additionally, the two ends of the metal wires can be soldered to the piezoelectric vibrator 4 and the FPC circuit board 9, respectively.

[0103] Example 6

[0104] like Figure 18 and Figure 19As shown, in this embodiment, the driving friction component is a friction rod 7, the axis of which is parallel to the optical axis. The lens friction component includes a friction plate 17 disposed on the movable lens assembly 3, and at least a portion of the circumferential sidewall of the friction rod 7 is in frictional contact with the friction plate 17. Therefore, compared with Embodiment 1, this embodiment uses the friction plate 17 instead of the friction retainer 8 in Embodiment 1. In this application, the friction retainer 8 is more difficult to manufacture, thus requiring higher assembly precision for the friction rod 7. In this embodiment, using the friction plate 17 instead of the friction retainer 8 can effectively reduce the manufacturing difficulty of the lens driving device.

[0105] Specifically, the friction plate 17 has a V-shaped groove, the length direction of which is the same as the axial direction of the friction rod 7. At least a portion of the friction rod 7 is disposed within the V-shaped groove and rubs against the inner sidewall of the V-shaped groove. This arrangement effectively improves the contact effect between the friction rod 7 and the friction plate 17.

[0106] Preferably, the lens friction component further includes an elastic pressure plate 18, one end of which is disposed on the movable lens assembly 3, and the other end of which extends toward the friction rod 7 and abuts against the friction rod 7 to provide a force toward the friction plate 17 for the friction rod 7. With this arrangement, the elastic pressure plate 18 can provide a pressing force toward the friction plate 17 for the friction rod 7, thereby effectively preventing the friction rod 7 from disengaging from the friction plate 17.

[0107] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A lens driving device, characterized in that, include: Base; A movable lens assembly is configured to be slidably connected to the base along the optical axis; A drive assembly, mounted on the base and configured to drive the movable lens assembly to move along the optical axis; The magnetic unit is configured to move synchronously with the movable lens assembly; A displacement sensor is fixed in position relative to the base, and the displacement sensor is configured to detect the magnetic field strength generated by the magnetic unit at the displacement sensor. The driving assembly includes a piezoelectric vibrator, a driving friction element, a lens friction element, and an elastic unit. The lens friction element is fixedly connected to the movable lens assembly. The driving friction element is installed at the output end of the piezoelectric vibrator. When the piezoelectric vibrator is activated, the driving friction element reciprocates along the optical axis. The driving friction element is frictionally connected to the lens friction element, and the lens friction element is configured to be driven by the driving friction element to move along the optical axis. The elastic unit is arranged on the piezoelectric vibrator, and at least a portion of the elastic unit is located between the piezoelectric vibrator and the base. The elastic unit is configured to cooperate with the base to absorb the impact force exerted by the movable lens assembly on the driving friction element and the piezoelectric vibrator.

2. The lens driving device as described in claim 1, characterized in that, The elastic unit includes a first elastic element and a second elastic element; The first elastic element is connected to the end of the piezoelectric vibrator away from the driving friction element, and the first elastic element is spaced out or slidably connected to the base; the second elastic element is arranged around the driving friction element, and the second elastic element is connected to the end of the piezoelectric vibrator facing the driving friction element, and the second elastic element is spaced out or slidably arranged to the base.

3. The lens driving device as described in claim 1, characterized in that, The elastic unit is a first elastic element; The first elastic element is connected to the end of the piezoelectric vibrator away from the driving friction element, and the first elastic element is fixedly connected to the base.

4. The lens driving device as described in claim 2 or 3, characterized in that, The piezoelectric vibrator has a counterweight at one end away from the driving friction element, and the counterweight is arranged between the first elastic element and the piezoelectric vibrator.

5. The lens driving device as described in claim 2, characterized in that, The elastic coefficient of the first elastic element is greater than that of the second elastic element.

6. The lens driving device as claimed in claim 1, characterized in that, The driving friction component is a friction rod, and the lens friction component is a friction retainer. The axis of the friction rod is parallel to the optical axis, and the friction retainer clamps and frictionally connects to the friction rod.

7. The lens driving device as claimed in claim 1, characterized in that, It also includes FPC circuit boards; The FPC circuit board is arranged on the base, and the FPC circuit board and the piezoelectric vibrator are electrically connected through the FPC bending section.

8. The lens driving device as claimed in claim 1, characterized in that, It also includes FPC circuit boards and conductive connectors; The FPC circuit board is arranged on the base, and the FPC circuit board and the piezoelectric vibrator are electrically connected through the conductive connector.

9. The lens driving device as described in claim 8, characterized in that, At least a portion of the conductive connector is a deformable structure.

10. The lens driving device as claimed in claim 1, characterized in that, At least one non-magnetic region is provided between the two ends of the magnetic unit along the optical axis.

11. The lens driving device as claimed in claim 10, characterized in that, The ratio between the length of the magnetic unit in the optical axis direction and the mechanical travel of the movable lens assembly on the base is 1.4 to 1.

6.

12. The lens driving device as claimed in claim 10, characterized in that, The magnetic unit is a multi-level magnetized magnet, and the non-magnetic region is centrally arranged on the multi-level magnetized magnet in the optical axis direction, and the span of the non-magnetic region in the optical axis direction is greater than or equal to 1 mm.

13. The lens driving device as claimed in claim 10, characterized in that, The distance between the displacement sensor and the magnetic unit is 0.3 mm to 0.5 mm.

14. The lens driving device as claimed in claim 1, characterized in that, The driving friction component is a friction rod, the axis of which is parallel to the optical axis. The lens friction component includes a friction plate disposed on the movable lens assembly, and at least a portion of the circumferential sidewall of the friction rod is in frictional contact with the friction plate.

15. The lens driving device as claimed in claim 14, characterized in that, The friction plate has a V-shaped groove, the length direction of which is the same as the axial direction of the friction rod, and at least a portion of the friction rod is disposed in the V-shaped groove and in frictional contact with the inner sidewall of the V-shaped groove.

16. The lens driving device as claimed in claim 14, characterized in that, The lens friction element also includes an elastic pressure plate, one end of which is disposed on the movable lens assembly, and the other end of which extends toward the friction rod and abuts against the friction rod to provide a force toward the friction plate for the friction rod.

17. A camera device, characterized in that, Includes the lens driving device as described in any one of claims 1 to 16.

18. An electronic device, characterized in that, Includes the camera device as described in claim 17.

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