Lens-driving device

Abstract

A lens-driving device, comprising a housing with an accommodating space, an elastic bracket, a circuit board assembly, a driving coil, a magnetic steel assembly and an image sensor, wherein the driving coil is spaced apart from the magnetic steel assembly; the driving coil comprises a first coil group and a second coil group, the first coil group being arranged along one diagonal of the circuit board assembly, and the second coil group being arranged along the other diagonal of the circuit board assembly; and the magnetic steel assembly comprises a first magnetic steel unit spaced apart from the first coil group and a second magnetic steel unit spaced apart from the second coil group, the first coil group interacting with the first magnetic steel unit to drive the circuit board assembly to move in a first direction, the second coil group interacting with the second magnetic steel unit to drive the circuit board assembly to move in a second direction, and the first direction and the second direction being perpendicular to each other and both being perpendicular to an optical axis direction. The lens-driving device of the present invention has a compact structure and a good image-stabilization driving effect.

Description

Lens drive device Technical Field

[0001] This utility model relates to the field of image stabilization technology, and in particular to a lens driving device. Background Technology

[0002] As consumers demand a better shooting experience, image stabilization features of lens drive mechanisms are widely used in various video recording devices. The integration of lens drive mechanisms with various portable electronic devices such as mobile phones, camcorders, and computers is also gaining popularity among consumers. Technical issues

[0003] Image stabilization devices in related lens drive systems generally include a housing, a circuit board housed within the housing, magnets or coils fixed to the circuit board, coils or magnets fixed to the housing, and a lens mount fixed to the circuit board. The lens module is fixed to the lens mount, and the circuit board is elastically supported by spring contacts. When current is applied to the coil, the coil and the magnet assembly generate an electromagnetic field. The coil experiences a Lorentz force from this electromagnetic field, driving the lens mount to move in a direction perpendicular to the optical axis, thereby achieving image stabilization for the lens module. However, in this image stabilization device, the driving effect of a single coil and magnet mutually driving each other is poor, resulting in inadequate image stabilization.

[0004] Therefore, it is necessary to provide a new lens driving device to solve the above-mentioned technical problems. Technical solutions

[0005] The purpose of this invention is to provide a lens driving device with low overall cost, good driving effect, and better image stabilization.

[0006] To achieve the above objectives, this utility model provides a lens driving device, including a housing, an elastic bracket fixed within the housing, a circuit board assembly supported by the elastic bracket, a drive coil stacked and fixed to the circuit board assembly and electrically connected to the circuit board assembly, a magnet assembly fixed to the housing, and an image sensor fixed to the circuit board assembly; the housing has an opening extending through it along the optical axis of the image sensor, the drive coil is disposed at a corner position of the circuit board assembly, and the drive coil is spaced apart from the magnet assembly;

[0007] The driving coil includes a first coil group and a second coil group spaced apart. The first coil group is arranged along one diagonal of the circuit board assembly, and the second coil group is arranged along the other diagonal of the circuit board assembly. The magnet assembly includes a first magnet unit spaced apart from the first coil group and a second magnet unit spaced apart from the second coil group. The first magnet unit is a Helbeck magnetic circuit. The first coil group interacts with the first magnet unit to drive the circuit board assembly to move along a first direction. The second coil group interacts with the second magnet unit to drive the circuit board assembly to move along a second direction. The first direction and the second direction are perpendicular to each other and both are perpendicular to the optical axis direction.

[0008] Preferably, the first coil group includes a first coil and a second coil fixed to the circuit board assembly and arranged side by side along the first direction;

[0009] The first magnet unit includes a first magnet, a second magnet, a third magnet, a fourth magnet, a fifth magnet, and a sixth magnet that are fixed to the housing and arranged side by side along the first direction;

[0010] The first magnet, the second magnet, and the third magnet are directly opposite the first coil, and the fourth magnet, the fifth magnet, and the sixth magnet are directly opposite the second coil.

[0011] Preferably, the first magnet, the third magnet, the fourth magnet, and the sixth magnet are all magnetized along the extension direction of the optical axis, while the second magnet and the fifth magnet are magnetized along a direction perpendicular to the optical axis.

[0012] Preferably, the first coil and the second coil are integrally wound; or the first coil and the second coil are two independent coils, and the first coil and the second coil are connected in series.

[0013] Preferably, the third magnet and the fourth magnet are integrally formed.

[0014] Preferably, the third magnet and the fourth magnet are configured as separate structures.

[0015] Preferably, the lens driving device further includes a first magnetic sheet, which is stacked and fixed on the side of the magnet assembly away from the driving coil; the housing has an opening therethrough, and the first magnetic sheet is disposed in the opening.

[0016] Preferably, the lens driving device further includes a second magnetic sheet, which is fixed to the housing and located on the side of the driving coil away from the magnet assembly, and is positioned opposite to the magnet assembly.

[0017] Preferably, the elastic bracket includes a first fixing part fixed to the housing, a second fixing part fixed to the circuit board assembly, and a connecting part connecting the first fixing part and the second fixing part.

[0018] Preferably, the circuit board assembly includes a first circuit board and a second circuit board stacked on the first circuit board, the drive coil is fixedly connected to the second circuit board, and the first circuit board and the second circuit board are soldered and fixed.

[0019] Preferably, the lens driving device further includes a shock absorber disposed opposite to the circuit board assembly on the surface away from the magnet assembly.

[0020] Preferably, the lens driving device further includes anti-collision blocks fixed to each side of the circuit board assembly, and the second fixing part of the elastic bracket is fixedly connected to the anti-collision blocks.

[0021] Preferably, the lens driving device further includes a connector for connecting adjacent anti-collision blocks. Beneficial effects

[0022] Compared with the prior art, in the lens driving device of this utility model, the driving coil and the magnet assembly are respectively fixed on the circuit board assembly and the housing. The housing has an opening that runs through it along the optical axis of the image sensor. The driving coil is located at the corner of the circuit board assembly, and the driving coil is spaced apart from the magnet assembly. The driving coil includes a first coil group and a second coil group arranged at intervals. The first coil group is arranged along one diagonal of the circuit board assembly, and the second coil group is arranged along the other diagonal of the circuit board assembly. The magnet assembly includes a first magnet unit spaced apart from the first coil group and a second magnet unit spaced apart from the second coil group. The first magnet unit is a Helbeck magnetic circuit. The first coil group and the first magnet unit interact to drive the circuit board assembly to move along a first direction. The second coil group and the second magnet unit interact to drive the circuit board assembly to move along a second direction. The first direction and the second direction are perpendicular to each other and both are perpendicular to the optical axis. By setting up the coil and magnet with a specific structure, the driving force can be increased in a micro-space, thereby making the lens driving device have a good driving and image stabilization effect. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0024] Figure 1 is a three-dimensional structural schematic diagram of the lens driving device provided in an embodiment of the present utility model;

[0025] Figure 2 is a partial exploded view of the lens driving device provided in an embodiment of the present invention;

[0026] Figure 3 is an exploded perspective view of the lens driving device provided in an embodiment of the present invention.

[0027] Figure 4 is a cross-sectional view along line AA in Figure 1;

[0028] Figure 5 is a cross-sectional view along line BB in Figure 1.

[0029] Figure 6 is a schematic diagram of the magnetic pole structure of the first magnet unit provided in this embodiment of the present invention;

[0030] Figure 7 is a schematic diagram of the structure of the elastic support provided in the embodiment of this utility model.

[0031] In the diagram, 100 is the lens drive device; 1 is the housing; 101 is the bottom cover; 102 is the top cover; 103 is the opening; 104 is the perforation; 2 is the elastic bracket; 21 is the first fixing part; 22 is the second fixing part; 23 is the connecting part; 3 is the circuit board assembly; 31 is the first circuit board; 32 is the second circuit board; 33 is the through hole; 4 is the drive coil; 41 is the first coil group; 411 is the first coil; 412 is the second coil; 42 is the second coil group; 5 is the magnet assembly; 51 is the first magnet unit; 511 is the first magnet; 512 is the second magnet; 513 is the third magnet; 514 is the fourth magnet; 515 is the fifth magnet; 516 is the sixth magnet; and 52 is the second magnet unit. 6. First magnetic sheet, 7. Second magnetic sheet, 8. Shock absorber, 9. Anti-collision block, 91. First anti-collision block, 92. Second anti-collision block, 93. Connector, 10. Conductive connecting plate, 11. Frame, 12. Image sensor, 13. Filter, 14. First driving chip, 15. Second driving chip, 16. Sensor bracket. Embodiments of the present invention

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0033] Referring to Figures 1 to 7, this embodiment of the present invention provides a lens driving device 100, including a housing 1, an elastic bracket 2 fixed within the housing 1, a circuit board assembly 3 supported by the elastic bracket 2, a drive coil 4 stacked and fixed to the circuit board assembly 3 and electrically connected to the circuit board assembly 3, a magnet assembly 5 fixed within the housing 1, and an image sensor 12 fixed to the circuit board assembly 3. The housing 1 has an opening 103 through which the optical axis of the image sensor 12 passes. The drive coil 4 is located at a corner of the circuit board assembly, and the drive coil 4 is spaced apart from the magnet assembly 5.

[0034] Optionally, the lens driving device 100 further includes a frame 11 and a filter 13, wherein the frame 11 is directly opposite to the opening 103 and fixed to the circuit board assembly 3, and the filter 13 is mounted and fixed to the frame 11.

[0035] Specifically, the drive coil 4 includes a first coil group 41 and a second coil group 42 spaced apart; the first coil group 41 is arranged along one diagonal of the circuit board assembly 3, and the second coil group 42 is arranged along the other diagonal of the circuit board assembly 3; the magnet assembly 5 includes a first magnet unit 51 spaced apart from the first coil group 41 and a second magnet unit 52 spaced apart from the second coil group 42, the first magnet unit 51 being a Helbeck magnetic circuit, the first coil group 41 interacting with the first magnet unit 51 to drive the circuit board assembly 3 to move along a first direction (X-axis); the second coil group 42 interacting with the second magnet unit 52 to drive the circuit board assembly 3 to move along a second direction (Y-axis); the first direction and the second direction are perpendicular to each other and both are perpendicular to the optical axis direction. By arranging multiple coils and multiple magnets, the driving force can be increased in a micro-space, thereby making the lens drive device 100 have a good driving image stabilization effect.

[0036] Optionally, the lens driving device 100 further includes a first driving chip 14 and a second driving chip 15. The first driving chip 14 is disposed within the first coil group 41, and the second driving chip 15 is disposed within the second coil group 42. The first driving chip 14 is used to control the first coil group 41 to move along a first direction. The second driving chip 15 is used to control the second coil group 42 to move along a second direction.

[0037] In this embodiment, the first coil group 41 includes a first coil 411 and a second coil 412 fixed to the circuit board assembly 3 and arranged side-by-side along the first direction, with the first driving chip 45 located within the first coil 411. The first magnet unit 51 includes a first magnet 511, a second magnet 512, a third magnet 513, a fourth magnet 514, a fifth magnet 515, and a sixth magnet 516 fixed to the housing 1 and arranged side-by-side along the first direction. The first magnet 511, the second magnet 512, and the third magnet 513 are fixedly connected and face the first coil 411; the fourth magnet 514, the fifth magnet 514, and the sixth magnet 516 are fixedly connected and face the second coil 412. By arranging multiple coils and multiple magnets, the driving force can be increased within a micro-space, thereby improving the image stabilization effect of the lens driving device 100.

[0038] In this embodiment, as shown in FIG6, the first magnet 511, the third magnet 512, the fourth magnet 514, and the sixth magnet 516 are all magnetized along the extension direction of the optical axis, while the second magnet 512 and the fifth magnet 515 are magnetized along the direction perpendicular to the optical axis.

[0039] Specifically, the magnetic poles of the first magnet 511 and the sixth magnet 516 on the side away from the driving coil 4 are both N poles, and the magnetic poles of the first magnet 511 and the sixth magnet 516 on the side closer to the driving coil 4 are both S poles. The magnetic poles of the third magnet 513 and the fourth magnet 514 on the side away from the driving coil 4 are both S poles; the magnetic poles of the third magnet 513 and the fourth magnet 514 on the side closer to the driving coil 4 are both N poles. The second magnet 512 has an N pole on the side closer to the first magnet 511, and an S pole on the side farther from the first magnet 511. The fifth magnet 515 has an N pole on the side closer to the sixth magnet 516, and an S pole on the side farther from the sixth magnet 516.

[0040] In this embodiment, the second coil group 42 is a single coil soldered onto the circuit board assembly 3, and the second magnet unit 52 includes three magnets. This can save some costs while ensuring sufficient driving force.

[0041] In other embodiments, the second magnet unit 52 can also be a Heilbeck magnetic circuit, and the coils of the second coil group 42 are also correspondingly arranged with the second magnet unit 52. With this arrangement, the lens drive device 100 has excellent driving force in both the X and Y directions, resulting in better image stabilization.

[0042] In this embodiment, the orthographic projection of the first coil 411 toward the second coil 412 falls at least partially or completely within the range of the second coil 412.

[0043] In this embodiment, the first coil 411 and the second coil 412 are integrally wound; or the first coil 411 and the second coil 412 are two independent coils, and the first coil 411 and the second coil 412 are connected in series. Integral winding can save two solder pads and save installation space.

[0044] In this embodiment, the third magnet 513 and the fourth magnet 514 are integrally formed.

[0045] In this embodiment, the second magnet 513 and the third magnet 514 are configured as separate structures. This facilitates the installation of the third magnet 513 and the fourth magnet 514, while also improving magnetic field performance.

[0046] In this embodiment, the lens driving device 100 further includes a first magnetic conductive sheet 6, which is stacked and fixed on the side of the first magnet unit 51 away from the first coil group 41. The first magnetic conductive sheet 6 enhances the magnetic conductivity of the magnet. The housing 1 has a through-hole 104, and the first magnetic conductive sheet 6 is disposed within the through-hole 104; this facilitates the installation of the first magnetic conductive sheet 6 and saves the overall stacking space of the lens driving device 100. Optionally, the first magnetic conductive sheet 6 is completely disposed within the through-hole 104.

[0047] In this embodiment, the lens driving device 100 further includes a second magnetic conductive sheet 7, which is fixed to the housing 1. The second magnetic conductive sheet 7 is located on the side of the driving coil 4 away from the magnet assembly 5, and is positioned directly opposite the magnet assembly 5. This enhances the magnetic conductivity.

[0048] In this embodiment, the elastic bracket 2 includes a first fixing part 21 fixed to the housing 1, a second fixing part 22 fixed to the circuit board assembly 3, and a connecting part 23 connecting the first fixing part 21 and the second fixing part 22. By fixing the first fixing part 21 to the housing 1, fixing the circuit board assembly 3 to the second fixing part 22, and using the connecting part 23 to form an elastic connection between the first fixing part 21 and the second fixing part 22, when the drive coil 4 and the magnet assembly 5 drive each other, the image sensor 12 is moved to achieve image stabilization.

[0049] In this embodiment, the circuit board assembly 3 includes a first circuit board 31 and a second circuit board 32 stacked on the first circuit board 31. The first circuit board 31 and the second circuit board 32 are soldered and fixed, and the drive coil 4 is fixedly connected to the second circuit board 32. Optionally, the drive coil 4 is soldered and fixed to the second circuit board 32. The first circuit board 31 is a PCB (Printed Circuit Board), and the second circuit board 32 is an FPC (Flexible Printed Circuit Board). Soldering the drive coil 4 to the second circuit board 32 can reduce malfunctions in the output movement of the second circuit board 32, and the control circuit is processed separately and then merged with the first circuit board 31.

[0050] In this embodiment, the lens driving device 100 further includes shock absorbers 8 disposed opposite to each other, the shock absorbers 8 being fixed to the surface of the circuit board assembly 3 away from the magnet assembly 5. The shock absorbers 8 can be used to dampen the vibration of the moving circuit board assembly 3. Optionally, the shock absorbers 8 can also be fixed at the four corners of the surface of the circuit board assembly 3 away from the magnet assembly 5 for even better shock absorption.

[0051] In this embodiment, the shock absorber 8 can be made of silicone or rubber material.

[0052] In this embodiment, the lens driving device 100 further includes anti-collision blocks 9 fixed to each side of the circuit board assembly 3, and the second fixing part 22 of the elastic bracket 2 is fixedly connected to the anti-collision blocks 9. The anti-collision blocks 9 include first anti-collision blocks 91 fixed to one or both sides of the circuit board assembly 3 and second anti-collision blocks 92 fixed to the other two sides of the circuit board assembly 3. The frame 11 is located between the first anti-collision blocks 91 and the second anti-collision blocks 92. The first anti-collision blocks 91 and the second anti-collision blocks 92 can also be used to limit the rotational position of the circuit board assembly 3, preventing the image sensor 12 from rotating too much. Optionally, the first anti-collision blocks 91 and the second anti-collision blocks 92 have a large contact area with the elastic bracket 2, which facilitates improving the stability of the first anti-collision blocks 91 and the second anti-collision blocks 92.

[0053] In this embodiment, the lens driving device 100 further includes a connector 93, the two ends of which are fixed to the first anti-collision block 91 and the second anti-collision block 92 respectively, so that they are connected as a whole and the stability is improved.

[0054] In this embodiment, the housing 1 includes a bottom cover 101 and an upper cover 102 fixed to the bottom cover 101; the elastic bracket 2 is fixed to the bottom cover 101. The magnet assembly 5 is fixed to the upper cover 102. The opening 103 is formed in the upper cover 102.

[0055] In this embodiment, the lens driving device 100 further includes a conductive connecting plate 10. One end of the conductive connecting plate 10 is fixed to the circuit board assembly 3, and the other end of the conductive connecting plate 10 extends to the outside of the housing 1 for connection with an external power source.

[0056] In this embodiment, the lens driving device 100 further includes a sensor bracket 16 fixed to the second circuit board 32. The sensor bracket 16 is fixed to the second circuit board 32 and covers the through hole 33. The image sensor 10 is fixed to the side of the sensor bracket 16 facing the opening 103 and located inside the through hole 33.

[0057] Compared with the prior art, in the lens driving device of this utility model, the driving coil and the magnet assembly are respectively fixed on the circuit board assembly and the housing. The housing has an opening that runs through it along the optical axis of the image sensor. The driving coil is located at the corner of the circuit board assembly, and the driving coil is spaced apart from the magnet assembly. The driving coil includes a first coil group and a second coil group arranged at intervals. The first coil group is arranged along one diagonal of the circuit board assembly, and the second coil group is arranged along the other diagonal of the circuit board assembly. The magnet assembly includes a first magnet unit spaced apart from the first coil group and a second magnet unit spaced apart from the second coil group. The first magnet unit is a Helbeck magnetic circuit. The first coil group and the first magnet unit interact to drive the circuit board assembly to move along a first direction. The second coil group and the second magnet unit interact to drive the circuit board assembly to move along a second direction. The first direction and the second direction are perpendicular to each other and both are perpendicular to the optical axis. By setting up the coil and magnet with a specific structure, the driving force can be increased in a micro-space, thereby making the lens driving device have a good driving and image stabilization effect.

[0058] The above description is merely an embodiment of this utility model. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this utility model, but these improvements all fall within the protection scope of this utility model.

Claims

1. A lens driving device, comprising a housing, an elastic bracket fixed within the housing, a circuit board assembly supported on the elastic bracket, a drive coil stacked and fixed to the circuit board assembly and electrically connected to the circuit board assembly, a magnet assembly fixed to the housing, and an image sensor fixed to the circuit board assembly; the housing has an opening extending through it along the optical axis of the image sensor, the drive coil is disposed at a corner position of the circuit board assembly, and the drive coil is spaced apart from the magnet assembly; characterized in that, The driving coil includes a first coil group and a second coil group spaced apart. The first coil group is arranged along one diagonal of the circuit board assembly, and the second coil group is arranged along the other diagonal of the circuit board assembly. The magnet assembly includes a first magnet unit spaced apart from the first coil group and a second magnet unit spaced apart from the second coil group. The first magnet unit is a Helbeck magnetic circuit. The first coil group interacts with the first magnet unit to drive the circuit board assembly to move along a first direction. The second coil group interacts with the second magnet unit to drive the circuit board assembly to move along a second direction. The first direction and the second direction are perpendicular to each other and both are perpendicular to the optical axis direction.

2. The lens driving device according to claim 1, characterized in that, The first coil group includes a first coil and a second coil fixed to the circuit board assembly and arranged side by side along the first direction; The first magnet unit includes a first magnet, a second magnet, a third magnet, a fourth magnet, a fifth magnet, and a sixth magnet that are fixed to the housing and arranged side by side along the first direction; The first magnet, the second magnet, and the third magnet are directly opposite the first coil, and the fourth magnet, the fifth magnet, and the sixth magnet are directly opposite the second coil.

3. The lens driving device according to claim 2, characterized in that, The first magnet, the third magnet, the fourth magnet, and the sixth magnet are all magnetized along the extension direction of the optical axis, while the second magnet and the fifth magnet are magnetized along a direction perpendicular to the optical axis.

4. The lens driving device according to claim 2, characterized in that, The first coil and the second coil are wound together as one piece; or the first coil and the second coil are two independent coils, and the first coil and the second coil are connected in series.

5. The lens driving device according to claim 2, characterized in that, The third magnet and the fourth magnet are integrally formed.

6. The lens driving device according to claim 2, characterized in that, The third magnet and the fourth magnet are configured as separate structures.

7. The lens driving device according to claim 1, characterized in that, The lens driving device further includes a first magnetic sheet, which is stacked and fixed on the side of the magnet assembly away from the driving coil; the housing has an opening therethrough, and the first magnetic sheet is disposed in the opening.

8. The lens driving device according to claim 1, characterized in that, The lens driving device further includes a second magnetic sheet, which is fixed to the housing. The second magnetic sheet is located on the side of the driving coil away from the magnet assembly, and the second magnetic sheet is positioned opposite the magnet assembly.

9. The lens driving device according to claim 1, characterized in that, The elastic bracket includes a first fixing part fixed to the housing, a second fixing part fixed to the circuit board assembly, and a connecting part connecting the first fixing part and the second fixing part.

10. The lens driving device according to claim 1, characterized in that, The circuit board assembly includes a first circuit board and a second circuit board stacked on the first circuit board. The drive coil is fixedly connected to the second circuit board, and the first circuit board and the second circuit board are soldered and fixed together.

11. The lens driving device according to claim 1, characterized in that, The lens driving device also includes a shock absorber disposed opposite to the circuit board assembly on the surface away from the magnet assembly.

12. The lens driving device according to claim 9, characterized in that, The lens driving device also includes anti-collision blocks fixed to each side of the circuit board assembly, and the second fixing part of the elastic bracket is fixedly connected to the anti-collision blocks.

13. The lens driving device according to claim 12, characterized in that, The lens driving device also includes a connector that connects adjacent anti-collision blocks.

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