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] The application claims priority to the patent application with the application number 202420273695X, the title of invention as "lens driving device, camera device and electronic equipment", which was filed on February 4, 2024, to the State Intellectual Property Office of China. TECHNICAL FIELD

[0002] The utility model belongs to camera device technical field, especially relate to a lens driving device, camera device and electronic equipment. BACKGROUND

[0003] At present, handheld camera device, especially the automatic focusing of the camera of the mobile phone is basically completed by using the voice coil motor, although the voice coil motor has the advantages of mature technology, low cost, low noise, etc., but with the increasing requirements of the camera device for the camera, such as the increasing load and displacement caused by the increasing pixels, the requirements of no magnetic interference of the driver caused by the use of multiple cameras, etc., the disadvantages of the voice coil motor, such as magnetic interference, insufficient thrust and insufficient displacement, are becoming more and more obvious. It has become a new trend to use piezoelectric ceramic driving device to realize the high-speed focusing function of the camera lens, which has the advantages of no magnetic interference, large thrust, high driving precision and fewer structural parts.

[0004] However, how to realize stable connection and driving performance of the lens seat in the existing periscopic lens driving device using piezoelectric ceramic driving device is a big problem. UTILITY MODEL CONTENTS

[0005] The technical problem to be solved by the utility model is to provide a lens driving device, camera device and electronic equipment to solve the problem that the existing periscopic long-focus lens cannot provide stable connection and driving performance.

[0006] The problems of high cost, difficult structure setting and control of position detection feedback exist.

[0007] In order to solve the above problems, the technical scheme of the utility model is as follows:

[0008] The utility model relates to a lens driving device, which comprises:

[0009] A base;

[0010] A moving lens assembly is configured to be slidingly connected to the base along the optical axis direction;

[0011] A driving assembly is installed on the base and is configured to drive the moving lens assembly to move along the optical axis direction;

[0012] A magnetic unit is configured to move synchronously with the moving lens assembly;

[0013] A displacement sensor is fixedly positioned opposite the base, and the displacement sensor is configured to detect a magnetic field strength generated by the magnetic unit at the displacement sensor;

[0014] At least one non-magnetic area is arranged between two ends of the optical axis direction of the magnetic unit.

[0015] The lens driving device further comprises a magneto-resistive sensor assembly, at least a portion of the magneto-resistive sensor assembly is arranged on the base, and at least another portion of the magneto-resistive sensor assembly is arranged on the moving lens assembly.

[0016] In the movement direction of the moving lens assembly, the magnetic unit and the portion of the magneto-resistive sensor assembly arranged on the moving lens assembly are arranged on two sides of the moving lens assembly, respectively.

[0017] The lens driving device further comprises a magneto-resistive sensor assembly, at least a portion of the magneto-resistive sensor assembly is arranged on the base, and at least another portion of the magneto-resistive sensor assembly is arranged on the moving lens assembly.

[0018] A magnetic grid is arranged on the moving lens assembly, and the length direction of the magnetic grid is the same as the movement direction of the moving lens assembly.

[0019] A magneto-resistive sensor body is arranged on the base corresponding to the magnetic grid.

[0020] The lens driving device further comprises a magnetic blocking sheet, and the magnetic blocking sheet is arranged on the side of the magnetic grid away from the magneto-resistive sensor.

[0021] The ratio between the length of the magnetic unit in the optical axis direction and the mechanical stroke of the moving lens assembly on the base is 1.4 to 1.6.

[0022] The lens driving device further comprises a multi-stage magnetized magnet, and the non-magnetic area is arranged in the middle of the multi-stage magnetized magnet in the optical axis direction, and the interval span of the non-magnetic area in the optical axis direction is greater than or equal to 1mm.

[0023] The distance between the displacement sensor and the magnetic unit is 0.3mm to 0.5mm.

[0024] The lens driving device further comprises a multi-stage magnetized magnet, and the non-magnetic area is arranged in the middle of the multi-stage magnetized magnet in the optical axis direction, and the interval span of the non-magnetic area in the optical axis direction is greater than or equal to 1mm.

[0025] The lens driving device further comprises a multi-stage magnetized magnet, and the non-magnetic area is arranged in the middle of the multi-stage magnetized magnet in the optical axis direction, and the interval span of the non-magnetic area in the optical axis direction is greater than or equal to 1mm.

[0026] The utility model discloses a following technical scheme makes it with the prior art compared with the following advantages and positive effect of having:

[0027] 1, the utility model discloses an embodiment through setting up mobile lens assembly and drive assembly on the base, by drive assembly drive mobile lens assembly slide in the optical axis direction, and set up the magnetic unit as with mobile lens assembly synchronous motion, set up displacement sensor as opposite fixed with the base, and further set up drive assembly as including piezoelectric vibrator, drive friction piece, lens friction piece and elastic unit, by piezoelectric vibrator output vibration along the optical axis direction, through the friction connection between drive friction piece and lens friction piece, and then through the mode of friction sliding drive mobile lens assembly moves, and set up the elastic unit cooperation absorption mobile lens assembly in the whole device under the action of external force to drive friction piece and piezoelectric vibrator impact force, play the required buffering effect, the setting of elastic unit makes the whole device still can have stable connection and drive performance between piezoelectric vibrator, drive friction piece, lens friction piece under different postures.

[0028] 2, the utility model discloses an embodiment through setting the elastic coefficient relation of first elastic part and second elastic part and the connection relation of two elastic parts and the base and whether the counterweight is configured, or, through setting the connection relation of first elastic part and counterweight and piezoelectric vibrator and the base, so that can further control piezoelectric vibrator power when deforming output power along the given direction, improve power output utilization and focusing accuracy.

[0029] 3, the utility model discloses an embodiment through setting the magnetic unit as being provided with at least one non-magnetic area between both ends in its optical axis direction, and then increase the magnetic field intensity change curvature of displacement sensor detected based on the optical axis direction stroke at both ends in the optical axis direction of magnetic unit, that is, improve the magnetic field intensity of both ends in the optical axis direction of magnetic unit, improve the magnetic field intensity variation, and then improve the displacement sensor induction sensitivity, which is beneficial to the periscopic long focus lens closed loop drive control precision, the embodiment has low cost, simple structure and control, and is easy to realize, and solves the problems of high cost, difficult structure and control in the position detection feedback of the existing periscopic long focus lens. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is the whole schematic view of the lens drive device of the utility model embodiment one;

[0031] Figure 2 It is the explosion drawing of the lens drive device of the utility model embodiment one;

[0032] Figure 3 It is the schematic view of the lens drive device of the utility model embodiment one of removing mobile lens assembly;

[0033] Figure 4 A schematic view of a moving lens assembly of the lens driving device of the first embodiment of the present application;

[0034] Figure 5 A schematic view of a driving assembly of the lens driving device of the first embodiment of the present application;

[0035] Figure 6 A side view of the lens driving device of the first embodiment of the present application;

[0036] Figure 7 An optical axis direction view of the lens driving device of the first embodiment of the present application;

[0037] Figure 8 A schematic view of the lens driving device of the first embodiment of the present application with a counterweight;

[0038] Figure 9 A schematic view of the driving assembly of the lens driving device of the first embodiment of the present application with a counterweight;

[0039] Figure 10 An optical axis direction view of the driving assembly of the lens driving device of the first embodiment of the present application;

[0040] Figure 11 A side view of the lens driving device of the second embodiment of the present application;

[0041] Figure 12 A schematic view of a magnetic unit of the lens driving device of the first embodiment of the present application;

[0042] Figure 13 A schematic view of a position relationship between the magnetic unit of the lens driving device of the first embodiment of the present application and a position sensor when the magnetic unit is at a middle stroke;

[0043] Figure 14 A schematic view of a position relationship between the magnetic unit of the lens driving device of the first embodiment of the present application and a position sensor when the magnetic unit is at a maximum stroke;

[0044] Figure 15 A schematic view of a position relationship between the magnetic unit of the lens driving device of the first embodiment of the present application and a position sensor when the magnetic unit is at a minimum stroke;

[0045] Figure 16 A graph of a relationship between a magnetic field intensity sensed by a displacement sensor and a position (stroke) simulated by the magnetic unit of the present application;

[0046] Figure 17 A graph of a relationship between a magnetic field intensity sensed by a displacement sensor and a position (stroke) simulated by a conventional Hall magnet structure;

[0047] Figure 18 This is a schematic diagram showing the positional relationship between the movable lens assembly, magnetic unit, displacement sensor, and magnetoresistive sensor in Embodiment 5 of this utility model.

[0048] Figure 19 for Figure 18 An exploded view of part of the structure.

[0049] 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. Magnetoresistive sensor assembly; 161. Magnetic grating; 162. Magnetoresistive sensor body; 163. Magnetic blocking sheet. Detailed Implementation

[0050] 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.

[0051] Example 1

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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).

[0056] 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.

[0057] 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.

[0058] The specific structure of the lens driving device in this embodiment will be further described below:

[0059] 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.

[0060] In this embodiment, the aforementioned elastic unit may specifically include a first elastic element 5 and a second elastic element 6.

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] 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 ).

[0070] 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.

[0071] 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).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] Example 2

[0081] See Figure 11 Based on Embodiment 1 above, this embodiment adjusts the structure of the elastic unit portion as follows:

[0082] 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).

[0083] 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.

[0084] Example 3

[0085] 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.

[0086] Example 4

[0087] 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.

[0088] Example 5

[0089] like Figure 18 and Figure 19 As shown, compared with Embodiment 1, the lens driving device in this embodiment further includes a magnetoresistive sensor assembly 16. At least a portion of the magnetoresistive sensor assembly 16 is disposed on the base 1, and at least another portion of the magnetoresistive sensor assembly 16 is correspondingly disposed on the movable lens assembly 3.

[0090] In this embodiment, the magnetic unit 12 can be a Hall magnet, and the displacement sensor 11 can be a Hall sensor. The magnetoresistive sensor assembly 16 includes: a magnetic grating 161, which is disposed on the movable lens assembly 3 and the length direction of the magnetic grating 161 is the same as the movement direction of the movable lens assembly 3; and a magnetoresistive sensor body 162, which is disposed on the base 1 corresponding to the magnetic grating 161.

[0091] Furthermore, in this embodiment, both the magnetic unit 12 and the magnetic grating 161 can be disposed on the bottom surface of the movable lens assembly 3, and grooves for accommodating the magnetic unit 12 and the magnetic grating 161 can be provided on the bottom surface of the movable lens assembly 3.

[0092] Therefore, in this embodiment, the cooperation of the Hall magnet and the Hall sensor, as well as the cooperation of the magnetic grating 161 and the magnetoresistive sensor body 162, enables a long-stroke full-stroke position detection function. The Hall magnet and the Hall sensor work together to coarsely locate the full-stroke position of the moving lens assembly 3, and then the magnetoresistive sensor assembly 162 performs fine positioning, giving the AF focusing capability long-stroke position detection and closed-loop control. The combined sensing signals from the Hall sensor and the magnetoresistive sensor body 162, combined with a preset algorithm, can accurately determine the moving position of the moving lens assembly 3, thereby achieving precise focusing.

[0093] In this embodiment, the magnetoresistive sensor body 162 can be any one of a tunnel magnetoresistive (TMR) sensor, anisotropic magnetoresistive (AMR) sensor, giant magnetoresistive (GMR) sensor, or ordinary magnetoresistive (OMR) sensor. The magnetoresistive sensor body 162 is used to sense changes in the magnetic field of the magnetic grating 161 and transmit the sensed signal to the processor.

[0094] Optionally, in the direction of movement of the moving lens assembly 3, the portions of the magnetic unit 12 and the magnetoresistive sensor assembly 16 disposed on the moving lens assembly 3 are respectively disposed on both sides of the moving lens assembly 3, that is, the magnetic unit 12 and the magnetic grating 161 are respectively disposed on both sides of the moving lens assembly 3. This arrangement can effectively avoid mutual interference between the detection part composed of the magnetic unit 12 and the displacement sensor 11 and the magnetoresistive sensor assembly 16, thereby effectively improving the detection effect of the magnetic unit 12 and the displacement sensor 11, as well as the detection effect of the magnetoresistive sensor.

[0095] Of course, in this embodiment, the positions of the magnetic unit 12 and the magnetic grating 161 can be adjusted adaptively according to the actual usage, and the positions of the displacement sensor 11 and the magnetoresistive sensor body 162 can be adjusted accordingly.

[0096] Optionally, the magnetoresistive sensor assembly 16 further includes a magnetic shield 163, which is disposed on the side of the magnetic grating 161 away from the magnetoresistive sensor. In this embodiment, by setting the magnetic shield 163, the magnetic grating 161 can be provided with a certain degree of magnetic isolation, thereby enhancing the sensing effect between the magnetic grating 161 and the magnetoresistive sensor, and thus effectively improving the performance of the lens driving device.

[0097] 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. At least one non-magnetic region is provided between the two ends of the magnetic unit along the optical axis.

2. The lens driving device as described in claim 1, characterized in that, The lens driving device further includes a magnetoresistive sensor assembly, at least a portion of which is disposed on the base, and at least another portion of which is correspondingly disposed on the movable lens assembly.

3. The lens driving device as described in claim 2, characterized in that, In the direction of movement of the movable lens assembly, the portions of the magnetic unit and the magnetoresistive sensor assembly disposed on the movable lens assembly are respectively disposed on both sides of the movable lens assembly.

4. The lens driving device as described in claim 2, characterized in that, The magnetoresistive sensor assembly includes: A magnetic grating is disposed on the movable lens assembly, and the length direction of the magnetic grating is the same as the movement direction of the movable lens assembly; A magnetoresistive sensor body is disposed on the base corresponding to the magnetic grating.

5. The lens driving device as described in claim 4, characterized in that, The magnetoresistive sensor assembly also includes a magnetic deflector, which is disposed on the side of the magnetic grating away from the magnetoresistive sensor.

6. The lens driving device as claimed in claim 1, 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.

7. The lens driving device as claimed in claim 1, 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.

8. The lens driving device as claimed in claim 1, characterized in that, The distance between the displacement sensor and the magnetic unit is 0.3 mm to 0.5 mm.

9. A camera device, characterized in that, Includes the lens driving device as described in any one of claims 1 to 8.

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

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