Lens driving device

Abstract

A lens driving device (100), comprising a fixing frame (10), a lens barrel (20) for carrying a lens assembly having an optical axis (X), an elastic connector (30) connecting the fixing frame (10) and the lens barrel (20), and a driving assembly (40) for driving the lens barrel (20) to move in the direction of the optical axis (X), wherein the driving assembly (40) is arranged at a corner (101) of the fixing frame (10); the driving assembly (40) comprises a magnetic circuit system (41) fixed to the fixing frame (10) and a coil (42) fixed to the lens barrel (20); the magnetic circuit system (41) comprises a magnetic frame (411) and a magnet part (412) accommodated in the magnetic frame (411); the magnetic frame (411) comprises a top wall (4111) and a bottom wall (4112) which are arranged opposite each other in the direction of the optical axis, and a side wall (4113) connecting the top wall (4111) and the bottom wall (4112); the magnet part (412) is sandwiched between the top wall (4111) and the bottom wall (4112); the coil (42) is sleeved on the magnet part (412); the side wall (4113) is provided with two notches (4114) respectively arranged on two sides of the coil (42); and the lens barrel (20) has a pair of supporting arms (21) extending towards the coil (42) for clamping the coil (42), the pair of supporting arms (21) respectively entering the magnetic frame (411) through the two notches (4114) of the side wall (4113) and clamping the coil (42). The lens driving device (100) has a good driving effect and can reduce magnetic interference.

Description

Lens driving device TECHNICAL FIELD

[0001] The present application relates to the field of voice coil motor, in particular to a lens driving device. BACKGROUND

[0002] The lens driving device of the related art comprises a fixed frame, a lens barrel for bearing a lens assembly, and a driving assembly for driving the lens barrel to move along the direction of the optical axis of the lens assembly, wherein the driving assembly comprises a magnetic circuit system fixed to the four straight side walls of the fixed frame and a coil sleeved on the outer periphery of the lens barrel. TECHNICAL PROBLEM

[0003] However, since the magnetic circuit system is open-loop, on the one hand, the magnetic leakage leads to low power conversion efficiency, resulting in poor driving effect; on the other hand, the magnetic leakage also causes magnetic interference to other ferromagnetic components and electronic elements.

[0004] Therefore, it is necessary to provide a new lens driving device to solve the above technical problems. TECHNICAL SOLUTION

[0005] The purpose of the present application is to overcome the above technical problems, and to provide a lens driving device with good driving effect and reduced magnetic interference.

[0006] In order to achieve the above purpose, the present application provides a lens driving device, comprising a fixed frame, a lens barrel for bearing a lens assembly with an optical axis, which is accommodated in the fixed frame, an elastic connecting piece connecting the fixed frame and the lens barrel and supporting the movement of the lens barrel relative to the fixed frame, and a driving assembly for driving the lens barrel to move along the direction of the optical axis, wherein the driving assembly is arranged at the corner of the fixed frame, the driving assembly comprises a magnetic circuit system fixed to the fixed frame and a coil fixed to the lens barrel, the magnetic circuit system comprises a magnetic frame and a magnet part accommodated in the magnetic frame, the magnetic frame comprises a top wall and a bottom wall arranged oppositely along the direction of the optical axis, and a side wall connecting the top wall and the bottom wall, the magnet part is clamped between the top wall and the bottom wall, the coil is accommodated in the magnetic frame and sleeved on the magnet part, the side wall is provided with two notches respectively arranged on both sides of the coil, and the lens barrel extends a pair of support arms for clamping the coil towards the coil, and the pair of support arms respectively enter the magnetic frame from the two notches of the side wall and clamp the coil.

[0007] Preferably, the magnet part comprises a first magnetic steel fixed to the top wall, a second magnetic steel fixed to the bottom wall, and a pole core clamped between the first magnetic steel and the second magnetic steel, the first magnetic steel and the second magnetic steel are magnetized along the direction of the optical axis, and the magnetization directions of the first magnetic steel and the second magnetic steel are opposite.

[0008] Preferably, the coil comprises a first coil wall and a second coil wall arranged in parallel and spaced apart, and a pair of third coil walls connecting the first coil wall and the second coil wall, the first coil wall is closer to the lens barrel relative to the second coil wall, the length of the orthographic projection of the first coil wall along the direction of the optical axis is greater than the length of the orthographic projection of the second coil wall along the direction of the optical axis, and the pair of supporting arms are fixedly connected with the pair of third coil walls, respectively.

[0009] Preferably, the coil and the magnet part have a matching contour shape as viewed along the direction of the optical axis.

[0010] Preferably, the driving assembly is provided in two groups, and the two groups of driving assemblies are arranged at a pair of oppositely arranged corners of the fixed frame.

[0011] Preferably, the elastic connecting member is made of a high polymer material.

[0012] Preferably, the high polymer material at least includes one of silica gel, nitrile rubber, ethylene acrylic ester rubber, acrylic ester rubber, butyl rubber, polyether ether ketone plastic, and polyimide plastic.

[0013] Preferably, the elastic connecting member comprises a first elastic member arranged at the top of the lens barrel and a second elastic member arranged at the bottom of the lens barrel, the first elastic member is a complete annular structure, and the second elastic member is provided with four and arranged at four corners of the fixed frame.

[0014] Preferably, the elastic connecting member comprises a deformation part with a wave-shaped cross section, a first fixed part extending from the inner periphery of the deformation part, and a second fixed part extending from the outer periphery of the deformation part, the first fixed part is fixed to the lens barrel, and the second fixed part is fixed to the fixed frame. Advantages

[0015] The lens driving device of the present application, the driving assembly is arranged at the corner of the fixed frame, the magnetic frame comprises a top wall, a bottom wall and a side wall, the magnet part is clamped between the top wall and the bottom wall, the coil is sleeved on the magnet part, the lens barrel extends a pair of support arms for clamping the coil towards the coil, the pair of support arms enter the magnetic frame from two notches of the side wall and clamp the coil. The lens driving device of the present application ingeniously designs the position and structure of the driving assembly, and the closed magnetic circuit system formed by the magnetic frame and the magnet part can obviously reduce the magnetic leakage. On the one hand, the power conversion efficiency is improved, the volume of the driving assembly can be smaller under the condition of providing the same driving force of the driving assembly, more design options can be provided for other components, or the driving assembly can provide greater driving force under the condition of the same volume of the driving assembly, and the driving sensitivity can be improved. On the other hand, the magnetic interference of the driving assembly on other ferromagnetic components and electronic elements is also reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0017] Fig. 1 is a perspective structural schematic view of the lens driving device of the present application;

[0018] Fig. 2 is a perspective exploded schematic view of the lens driving device shown in Fig. 1;

[0019] Fig. 3 is a combined structural schematic view of the lens barrel, the coil and part of the magnetic circuit system of the lens driving device shown in Fig. 1;

[0020] Fig. 4 is a perspective structural schematic view of the driving assembly of the lens driving device shown in Fig. 1;

[0021] Fig. 5 is a perspective structural schematic view of the coil of the lens driving device shown in Fig. 1;

[0022] Fig. 6 is a partial cross-sectional structural schematic view of the elastic connecting piece of the lens driving device shown in Fig. 1. Best mode for carrying out the present application

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0024] Referring to FIGS. 1-6, the present application provides a lens driving device 100, which includes a fixed frame 10, a lens barrel 20 received in the fixed frame 10 for carrying a lens assembly having an optical axis X, an elastic connecting member 30 connecting the fixed frame 10 and the lens barrel 20 and supporting the lens barrel 20 to move relative to the fixed frame 10, and a driving assembly 40 driving the lens barrel 20 to move along the direction of the optical axis X.

[0025] The driving assembly 40 is arranged at a corner 101 of the fixed frame 10.

[0026] In the present embodiment, the driving assembly 40 is provided in two sets, which are arranged at a pair of opposite corners 101 of the fixed frame 10.

[0027] The driving assembly 40 includes a magnetic circuit system 41 fixed to the fixed frame 10 and a coil 42 fixed to the lens barrel 20.

[0028] The magnetic circuit system 41 includes a magnetic frame 411 and a magnet portion 412 received in the magnetic frame 411.

[0029] The magnetic frame 411 includes a top wall 4111 and a bottom wall 4112 arranged opposite along the direction of the optical axis X, and a side wall 4113 connecting the top wall 4111 and the bottom wall 4112, the magnet portion 412 is clamped between the top wall 4111 and the bottom wall 4112, and the coil 42 is received in the magnetic frame 411 and sleeved on the magnet portion 412.

[0030] The side wall 4113 is provided with two notches 4114 arranged at two sides of the coil 42.

[0031] The lens barrel 20 extends a pair of support arms 21 for clamping the coil 42 towards the coil 42, the pair of support arms 21 respectively enter the magnetic frame 411 from the two notches 4114 of the side wall 4113 and clamp the coil 42.

[0032] The magnet portion 412 includes a first magnetic steel 4121 fixed to the top wall 4111, a second magnetic steel 4122 fixed to the bottom wall 4112, and a pole core 4123 clamped between the first magnetic steel 4121 and the second magnetic steel 4122, the first magnetic steel 4121 and the second magnetic steel 4122 are magnetized along the direction of the optical axis X, and the magnetization directions of the first magnetic steel 4121 and the second magnetic steel 4122 are opposite.

[0033] The coil 42 comprises a first coil wall 421 and a second coil wall 422 arranged in parallel and spaced apart, and a pair of third coil walls 423 connecting the first coil wall 421 and the second coil wall 422. The first coil wall 421 is closer to the lens barrel 20 relative to the second coil wall 422, and the length d1 of the orthographic projection of the first coil wall 421 along the direction of the optical axis X is greater than the length d2 of the orthographic projection of the second coil wall 422 along the direction of the optical axis X. The coil 42 and the magnet portion 412 have matching profile shapes as viewed along the direction of the optical axis X.

[0034] The pair of support arms 21 are fixedly connected with the pair of third coil walls 423, respectively.

[0035] In the embodiment, the elastic connecting member 30 is made of a high polymer material. The high polymer material at least comprises one of silica gel, nitrile rubber, ethylene acrylate rubber, acrylate rubber, butyl rubber, polyether ether ketone plastic, and polyimide plastic. Of course, the elastic connecting member 30 can also be a metal spring sheet.

[0036] The elastic connecting member 30 comprises a first elastic member 31 arranged at the top of the lens barrel 20 and a second elastic member 32 arranged at the bottom of the lens barrel 20. The first elastic member 31 is a complete annular structure, and the second elastic member 32 is provided with four and arranged at the four corners 101 of the fixed frame 10.

[0037] The elastic connecting member 30 comprises a deformation portion 301 with a wave-shaped cross section, a first fixed portion 302 extending from the inner periphery of the deformation portion 301, and a second fixed portion 303 extending from the outer periphery of the deformation portion 301. The first fixed portion 302 is fixed to the lens barrel 20, and the second fixed portion 303 is fixed to the fixed frame 10.

[0038] In the lens driving device, the driving assembly is arranged at the corner of the fixed frame, the magnetic frame comprises a top wall, a bottom wall and a side wall, the magnet portion is clamped between the top wall and the bottom wall, the coil is sleeved on the magnet portion, the lens barrel extends towards the coil and is provided with a pair of support arms for clamping the coil, and the pair of support arms enter the magnetic frame from two notches of the side wall and clamp the coil. The lens driving device ingeniously designs the position and structure of the driving assembly, and the closed magnetic circuit system formed by the magnetic frame and the magnet portion can obviously reduce magnetic leakage. On the one hand, the power conversion efficiency is improved, the volume of the driving assembly can be smaller under the condition that the driving assembly provides the same driving force, more design options can be provided for other components, or the driving assembly can provide greater driving force under the condition that the driving assembly has the same volume, and the driving sensitivity can be improved. On the other hand, the magnetic interference of the driving assembly on other ferromagnetic components and electronic elements is also reduced.

[0039] The above merely describes the embodiments of the present application, and it should be pointed out that those skilled in the art can make improvements without departing from the inventive concept, and these improvements shall fall within the protection scope of the present application.

Claims

1. A lens driving apparatus comprising a fixed frame, a lens barrel housed in the fixed frame for carrying a lens assembly having an optical axis, an elastic connecting member connecting the fixed frame and the lens barrel and supporting movement of the lens barrel relative to the fixed frame, and a driving assembly driving movement of the lens barrel in the direction of the optical axis, characterized in that, The driving assembly is arranged at a corner of the fixed frame, and comprises a magnetic circuit system fixed to the fixed frame and a coil fixed to the lens barrel. The magnetic circuit system comprises a magnetic frame and a magnet part accommodated in the magnetic frame. The magnetic frame comprises a top wall and a bottom wall oppositely arranged along the direction of the optical axis, and a side wall connecting the top wall and the bottom wall. The magnet part is clamped between the top wall and the bottom wall. The coil is accommodated in the magnetic frame and sleeved on the magnet part. The side wall is provided with two notches arranged at two sides of the coil. The lens barrel extends a pair of support arms for clamping the coil towards the coil. The pair of support arms respectively enter the magnetic frame from the two notches of the side wall and clamp the coil.

2. The lens driving device according to claim 1, wherein The magnet part comprises a first magnetic steel fixed to the top wall, a second magnetic steel fixed to the bottom wall, and a pole core clamped between the first magnetic steel and the second magnetic steel. The first magnetic steel and the second magnetic steel are magnetized along the direction of the optical axis, and the magnetization directions of the first magnetic steel and the second magnetic steel are opposite.

3. The lens driving device according to claim 1, wherein The coil comprises a first coil wall and a second coil wall arranged in parallel and spaced apart, and a pair of third coil walls connecting the first coil wall and the second coil wall. The first coil wall is closer to the lens barrel than the second coil wall. The length of the orthogonal projection of the first coil wall along the direction of the optical axis is greater than the length of the orthogonal projection of the second coil wall along the direction of the optical axis. The pair of support arms are respectively fixedly connected with the pair of third coil walls.

4. The lens driving device according to claim 1, wherein When viewed along the direction of the optical axis, the coil and the magnet part have a matching contour shape.

5. The lens driving apparatus according to claim 1, wherein The driving assembly is provided with two groups, and the two groups of driving assemblies are arranged at a pair of oppositely arranged corners of the fixed frame.

6. The lens driving apparatus according to claim 1, wherein The elastic connecting piece is made of a high polymer material.

7. The lens driving apparatus according to claim 6, wherein The high polymer material at least comprises one of silica gel, nitrile rubber, ethylene acrylate rubber, acrylate rubber, butyl rubber, polyether ether ketone plastic and polyimide plastic.

8. The lens driving apparatus according to claim 6, wherein The elastic connecting piece comprises a first elastic piece arranged at the top of the lens barrel and a second elastic piece arranged at the bottom of the lens barrel. The first elastic piece is a complete annular structure. The second elastic piece is provided with four and arranged at four corners of the fixed frame.

9. The lens driving apparatus according to claim 6, wherein The elastic connecting piece comprises a deformation part with a wave-shaped cross section, a first fixed part extending from the inner periphery of the deformation part, and a second fixed part extending from the outer periphery of the deformation part. The first fixed part is fixed to the lens barrel, and the second fixed part is fixed to the fixed frame.

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