Lens drive device

Abstract

The present invention provides a lens driving device. [Solution] The lens drive device includes a housing, a first holder, a second holder, a first drive assembly, and a second drive assembly, the housing including a bottom plate and an upper cover, the first holder being elastically supported on the bottom plate, the second holder being elastically supported on the first holder and used to mount a lens module, there are two first drive assemblies, the two first drive assemblies used to drive the lens module to move along the optical axis of the lens module, the first drive assembly includes a first magnetic circuit system fixed to the first holder and a drive coil fixed to the second holder, the second drive assembly used to drive the second holder to move along a direction perpendicular to the optical axis of the lens module, the second drive assembly includes a second magnetic circuit system fixed to the bottom plate and an image stabilization coil fixed to the first holder. The lens drive device of the present invention not only reduces the risk of the lens module barrel falling and becoming invalid, but can also suppress the locking mode of the lens module barrel.

Description

Technical Field

[0001] The present invention belongs to the technical field of imaging devices, and particularly relates to a lens driving device.

Background Art

[0002] With the improvement of living standards, devices having imaging functions such as digital cameras, digital video cameras, smart phones, tablet PCs, etc. all have autofocus cameras, and the autofocus cameras need to be driven by a lens driving device so as to achieve autofocus and optical shake correction.

[0003] The lens driving device includes a housing, a first holder, a second holder spaced apart from the first holder, and a driving assembly for driving the lens module to move along its optical axis direction and a direction perpendicular to the optical axis. The second holder is for attaching the lens module, and the driving assembly mainly includes a common magnetic circuit system, a driving coil and a shake correction coil.

[0004] In the related art, the magnetic circuit system is mainly provided on two pairs of straight edges of the holder, and an open-loop magnetic circuit is adopted. The driving coil is fixed to the second holder, and the shake correction coil is fixed to the bottom plate of the housing. In such a driving method using the same open-loop magnetic circuit system, the lens module appears as ineffective mass when it moves.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Embodiments of the present invention provide a lens driving device for solving the problem that in a driving method where a lens driving device in the related art uses the same open-loop magnetic circuit system, the lens module appears as ineffective mass when it moves.

Means for Solving the Problems

[0006] Embodiments of the present invention provide a lens drive device, the lens drive device comprising a housing, a first holder, a second holder, a first drive assembly, and a second drive assembly. The housing is rectangular in shape and includes a bottom plate and an upper cover that covers the bottom plate and is arranged around the bottom plate to form a storage space. The bottom plate and the upper cover are each provided with through holes that connect the storage space to the outside. The first holder has a rectangular annular shape, is elastically supported by the bottom plate, and is located within the housing space. The second holder is elastically supported inside the first holder and is installed at a distance from the first holder, and the second holder faces the through hole and is used to mount the lens module. There are two first drive assemblies, each provided at a pair of diagonal positions on the first holder and used to drive the second holder to move along the optical axis of the lens module, the first drive assembly includes a first magnetic circuit system fixed to the first holder and a drive coil fixed to the second holder, the first magnetic circuit system includes a magnetic bowl fixed to the first holder, a first magnetic steel assembly stacked and fixed within the magnetic bowl, and an upper clamp plate stacked and fixed at the open end of the magnetic bowl, the magnetic bowl having two notches on opposite sides, the drive coil being provided around and spaced apart from the first magnetic steel assembly, the drive coil extending outward from the magnetic bowl through the notches and fixed to the second holder, The second drive assembly is used to drive the second holder to move along a direction perpendicular to the optical axis of the lens module, and the second drive assembly includes a second magnetic circuit system fixed to a bottom plate and an image stabilization coil fixed to the first holder and facing the second magnetic circuit system at a distance from it.

[0007] Preferably, the magnetic bowl includes a bowl bottom and a side wall that bends and extends from the circumferential side of the bowl bottom, and both of the notches are opened in the side wall, and the first magnetic steel assembly includes a first drive magnetic steel laminated and fixed to the bowl bottom, a first pole core laminated and fixed to the side of the first drive magnetic steel away from the bowl bottom, and a second drive magnetic steel laminated and fixed to the side of the first pole core away from the first drive magnetic steel, and the upper clamp plate laminated and fixed to the side of the second drive magnetic steel away from the first pole core.

[0008] Preferably, a pair of diagonally opposite positions on the inner circumference of the first holder are provided, each with two recessed grooves formed inward, and the magnetic bowls in the two first drive assemblies are fixed within the two grooves, respectively.

[0009] Preferably, there are two second drive assemblies, the image stabilization coils in the two second drive assemblies are respectively located at diagonal positions of another pair of the first holder, and the second magnetic circuit system includes two sets of second lower clamp plates fixed at two opposing corner positions of the bottom plate, and two sets of second magnetic steel assemblies fixed in a stacked manner on the sides of the two sets of second lower clamp plates away from the bottom plate.

[0010] Preferably, the second magnetic steel assembly includes a first image stabilization magnetic steel, a second image stabilization magnetic steel, and a third image stabilization magnetic steel, which are stacked and fixed on the second lower clamp plate and arranged sequentially along a direction perpendicular to the optical axis, and the first image stabilization magnetic steel, the second image stabilization magnetic steel, and the third image stabilization magnetic steel are fixed to each other.

[0011] Preferably, the lens driving device further includes a first elastic member, the first elastic member being connected to the first holder and the bottom plate, respectively, and elastically supporting the first holder to the bottom plate.

[0012] Preferably, each of the second drive assemblies includes two of the image stabilization coils, the two image stabilization coils respectively parallel to two sides at the same corner position of the corresponding first holder, the lens drive further includes a flexible circuit board fixed to the side of the first elastic member away from the first holder, all of the image stabilization coils in the second drive assembly are electrically connected to the flexible circuit board, and the flexible circuit board extends through the bottom plate to the outside of the housing.

[0013] Preferably, the lens drive device further includes an elastic assembly, the elastic assembly being connected to the second holder and the first holder, respectively, and elastically supporting the second holder so as to suspend it within the first holder.

[0014] Preferably, the elastic assembly includes a second elastic member, a third elastic member, and a fourth elastic member spaced apart from each other, the second elastic member being connected to the top region of the second holder and the top region of the first holder, the third elastic member being connected to the central region of the second holder and the central region of the first holder, and the fourth elastic member being connected to the bottom region of the second holder and the bottom region of the first holder, respectively.

[0015] Preferably, there are four of the fourth elastic members, and the four fourth elastic members are fixed to the four corner positions corresponding to the second holder and the first holder, respectively. [Effects of the Invention]

[0016] Compared to the prior art, the lens drive device of the present invention limits the placement of two first drive assemblies at a pair of diagonal positions on the first holder, and provides two notches on opposing sides of the magnetic bowl. Furthermore, by fixing the upper clamp plate to the open end of the magnetic bowl, the first magnetic circuit system forms a closed vertex magnetic circuit. Simultaneously, by fixing the second magnetic circuit system in the first drive assembly to the bottom plate and fixing its image stabilization coil to the first holder, the second magnetic circuit system in the second drive assembly does not participate in the movement of the lens module along its optical axis. This reduces the total mass of the lens module moving along its optical axis, improves the sensitivity of the first magnetic circuit system in driving the lens module to move along its optical axis, reduces the risk of the lens module falling and becoming inoperable, and also effectively balances the mass of the image stabilization coil and the mass of the first magnetic circuit system, suppressing the locking mode of the lens module while reducing the total mass of the lens module. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram showing the overall structure of a lens drive device provided in an embodiment of the present invention. [Figure 2] This is an exploded view schematically showing the structure of a lens drive device provided in an embodiment of the present invention. [Figure 3] This is a cross-sectional view along line AA in Figure 1. [Figure 4] This is a cross-sectional view along line BB in Figure 1. [Modes for carrying out the invention]

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings that need to be used in the description of the embodiments or the prior art. However, the drawings in the following description are only some embodiments of the present invention, and it is obvious that those skilled in the art belonging to the technical field to which the present invention pertains can obtain other drawings based on these drawings without creative labor.

[0019] In the following, in order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in more detail by combining the drawings and the embodiments. It should be understood that the specific embodiments described herein are only used for explaining the present invention and are not used for limiting the present invention.

[0020] Embodiments of the present invention provide a lens driving device 100. As shown in FIGS. 1 to 4, it includes a housing 1, a first holder 2, a second holder 3, a first driving assembly 5, and a second driving assembly 6.

[0021] Here, the housing 1 is rectangular, and includes a bottom plate 11 and an upper cover 12 that is covered on the bottom plate 11 and peripherally arranged with the bottom plate 11 to form an accommodation space. Through holes 10 for communicating the accommodation space with the outside are provided on each of the bottom plate 11 and the upper cover 12. The first holder 2 is rectangular annular, elastically supported on the bottom plate 11, and located in the accommodation space. The second holder 3, also called a lens barrel, is annular, elastically supported inside the first holder 2, and installed at an interval from the first holder 2. The second holder 3 faces the through hole 10 and is used for mounting the lens module 4.

[0022] At a set of diagonal positions on the inner peripheral side of the first holder 2, two concave grooves 21 formed by concave inward are respectively provided.

[0023] Specifically, the first driving assembly � includes a first magnetic circuit system 51 fixed to the first holder 2 and a driving coil 52 fixed to the second holder 3.

[0024] Here, the first magnetic circuit system 51 comprises a magnetic bowl 511 fixed to the first holder 2, a first magnetic steel assembly 512 stacked and fixed to the magnetic bowl 511, and an upper clamp plate 513 stacked and fixed to the open end of the magnetic bowl 511. Two notches are provided on opposite sides of the magnetic bowl 511, and the drive coil 52 is provided surrounding the first magnetic steel assembly 512, spaced apart from the first magnetic steel assembly 512, the drive coil 52 extends to the outside of the magnetic bowl 511 through the notches and is fixed to the second holder 3.

[0025] The magnetic bowl 511 comprises a bowl bottom 5111 and a side wall 5112 formed by bending and extending from the circumferential side of the bowl bottom 5111, and both notches are opened in the side wall 5112.

[0026] The first magnetic steel assembly 512 comprises a first drive magnetic steel 5121 stacked and fixed on the magnetic bowl 511, a first pole core 5122 stacked and fixed on the side of the first drive magnetic steel 5121 away from the magnetic bowl 511, and a second drive magnetic steel 5123 stacked and fixed on the side of the first pole core 5122 away from the first drive magnetic steel 5121. The upper clamp plate 513 is stacked and fixed on the side of the second drive magnetic steel 5123 away from the first pole core 5122.

[0027] There are two first drive assemblies 5, each positioned at a diagonal location on the first holder 2, and the magnetic bowls 511 in each of the two first drive assemblies 5 are fixed in two grooves 21, and the two first drive assemblies 5 are used to drive the second holder 3 to move along the optical axis of the lens module 4.

[0028] Specifically, the second drive assembly 6 is used to drive the second holder 3 to move along the optical axis perpendicular to the lens module 4. The second drive assembly 6 comprises a second magnetic circuit system 61 fixed to the bottom plate 11 and an image stabilization coil 62 fixed to the first holder 2 and facing the second magnetic circuit system 61 at a distance from it.

[0029] Here, there are two second drive assemblies 6, and the image stabilization coils 62 in the two second drive assemblies 6 are respectively provided at diagonal positions of the other pair of first holders 2, and the second magnetic circuit system 61 comprises two pairs of second lower clamp plates 611 fixed at two opposing corner positions of the bottom plate 11, and two pairs of second magnetic steel assemblies 612 fixed in stacked on the sides of the two pairs of second lower clamp plates 611 away from the bottom plate 11.

[0030] Each set has two second lower clamp plates 611, and these two second lower clamp plates 611 are parallel to two adjacent sides of the base plate 11, that is, parallel to the two sides that form the corners of the base plate 11.

[0031] The second magnetic steel assembly 612 is stacked and fixed on the second lower clamp plate 611 and comprises a first image stabilization magnetic steel 6121, a second image stabilization magnetic steel 6122, and a third image stabilization magnetic steel 6123, which are sequentially arranged along a direction perpendicular to the optical axis, and the first image stabilization magnetic steel 6121, the second image stabilization magnetic steel 6122, and the third image stabilization magnetic steel 6123 are fixed to each other.

[0032] Specifically, the lens drive device 100 further comprises a first elastic member 7, which is connected to the first holder 2 and the bottom plate 11, respectively, and elastically supports the first holder 2 so as to suspend it from the bottom plate 11.

[0033] Specifically, each second drive assembly 6 comprises two image stabilization coils 62, the two image stabilization coils 62 respectively parallel to two sides at the same corner position of the corresponding first holder 2, the two image stabilization coils 62 are spaced apart and opposite each other to two identical sets of second magnetic steel assemblies 612, the lens drive device 100 further comprises a flexible circuit board 8 fixed to the side of the first elastic member 7 away from the first holder 2, all image stabilization coils 62 in the second drive assembly 6 are electrically connected to the flexible circuit board 8, and the flexible circuit board 8 extends outside the housing 1 through the bottom plate 11.

[0034] Specifically, the lens drive device 100 further comprises an elastic assembly 9, which is connected to the second holder 3 and the first holder 2, respectively, and elastically supports the second holder 3 so as to suspend it within the first holder 2.

[0035] Here, the elastic assembly 9 comprises a second elastic member 91, a third elastic member 92, and a fourth elastic member 93 spaced apart from each other. The second elastic member 91 is connected to the top region of the second holder 3 and the top region of the first holder 2, respectively. The third elastic member 92 is connected to the central region of the second holder 3 and the central region of the first holder 2, respectively. The fourth elastic member 93 is connected to the bottom region of the second holder 3 and the bottom region of the first holder 2, respectively. In other words, the second holder 3 is elastically supported by the first holder 2 via the second elastic member 91, the third elastic member 92, and the fourth elastic member 93, respectively.

[0036] The second elastic member 91 is annular and wavy, the third elastic member 92 comprises an annular first fixed arm fixed to the second holder 3, two elastic arms formed by bending and extending from opposite ends of the first fixed arm, and a second fixed arm formed by extending from one end of the elastic arm away from the first fixed arm, the second fixed arm fixed to the first holder 2, and there are four fourth elastic members 93, the four fourth elastic members 93 are spaced apart and each has a wavy shape.

[0037] The third elastic member 92 is connected to the flexible circuit board 8 via a connecting member 921 fixed to the first holder 2. The third elastic member 92 is an elastic circuit board that is electrically connected to the two drive coils 52 in the first drive assembly 5, and provides an electrical connection between the drive coils 52 and the flexible circuit board 8 at a pitch (spacing) interval.

[0038] There are four fourth elastic members 93, and each of the four fourth elastic members 93 is fixed to one of the four corner positions corresponding to the second holder 3 and the first holder 2.

[0039] In this embodiment, the lens drive device 100 is configured such that two first drive assemblies 5 are installed at diagonal positions on a pair of first holders 2, and two notches are provided on opposing sides of the magnetic bowl 511. Furthermore, by fixing the upper clamp plate 513 to the open end of the magnetic bowl 511, the first magnetic circuit system 51 forms a closed vertex magnetic circuit. At the same time, the second magnetic circuit system 61 in the first drive assembly 5 is fixed to the bottom plate 11, and the image stabilization coil 62 is fixed to the first holder 2, thereby forming a second magnetic circuit in the second drive assembly 6. The circuit system 61 can be made so as not to be involved in the movement of the lens module 4 along its optical axis, reducing the total mass of the lens module 4 moving along its optical axis, improving the sensitivity of the first magnetic circuit system 51 in driving the lens module 4 to move along its optical axis, reducing the risk of the lens module 4 becoming inoperable due to falling, and also effectively balancing the mass of the image stabilization coil 62 and the mass of the first magnetic circuit system 51, thereby suppressing the locking mode of the lens module 4, provided that the total mass of the lens module 4 is reduced.

[0040] The foregoing description is merely a preferred embodiment of the present invention and does not limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the invention should all be within the scope of protection of the present invention. [Explanation of Symbols]

[0041] 100 Lens drive unit, 1 Housing, 10 Through hole, 11 Bottom plate, 12 Top cover, 2 First holder, 21 Groove, 3 Second holder, 4 Lens module, 5 First drive assembly, 51 First magnetic circuit system, 511 Magnetic bowl, 5111 Bowl bottom, 5112 Side wall, 512 First magnetic steel assembly, 5121 First drive magnetic steel, 5122 First pole core, 5123 Second drive magnetic steel, 513 Upper clamp plate, 52 Drive coil, 6 Second drive assembly, 61 Second magnetic circuit system, 611 Second lower clamp plate, 612 Second magnetic steel assembly, 6121 First image stabilization magnetic steel, 6122 Second image stabilization magnetic steel, 6123 Third image stabilization magnetic steel, 62 Image stabilization coil, 7 First elastic member, 8 Flexible circuit board, 9 Elastic assembly, 91 Second elastic member, 92 Third elastic member, 921 Connecting member, 93 Fourth elastic member

Claims

1. A lens drive device comprising a housing, a first holder, a second holder, a first drive assembly, and a second drive assembly, The housing is rectangular in shape and includes a bottom plate and an upper cover that covers the bottom plate and is arranged around the bottom plate to form a storage space. The bottom plate and the upper cover are each provided with through holes that connect the storage space to the outside. The first holder has a rectangular annular shape, is elastically supported by the bottom plate, and is located within the housing space. The second holder is elastically supported inside the first holder and is installed at a distance from the first holder, and the second holder faces the through hole and is used to mount the lens module. There are two first drive assemblies, each provided at a pair of diagonal positions on the first holder and used to drive the second holder to move along the optical axis of the lens module, the first drive assembly includes a first magnetic circuit system fixed to the first holder and a drive coil fixed to the second holder, the first magnetic circuit system includes a magnetic bowl fixed to the first holder, a first magnetic steel assembly stacked and fixed within the magnetic bowl, and an upper clamp plate stacked and fixed at the open end of the magnetic bowl, the magnetic bowl has two notches on opposite sides, the drive coil is provided so as to surround the first magnetic steel assembly and spaced apart from the first magnetic steel assembly, the drive coil extends outward from the magnetic bowl through the notches and is fixed to the second holder, The lens drive device is characterized in that the second drive assembly is used to drive the second holder to move along a direction perpendicular to the optical axis of the lens module, and the second drive assembly includes a second magnetic circuit system fixed to a bottom plate and an image stabilization coil fixed to the first holder and facing the second magnetic circuit system at a distance from it.

2. The lens driving device according to claim 1, wherein the magnetic bowl includes a bowl bottom and a side wall that is bent and extends from the circumferential side of the bowl bottom, and both of the notches are opened in the side wall, and the first magnetic steel assembly includes a first drive magnetic steel laminated and fixed to the bowl bottom, a first pole core laminated and fixed to the side of the first drive magnetic steel away from the bowl bottom, and a second drive magnetic steel laminated and fixed to the side of the first pole core away from the first drive magnetic steel, and the upper clamp plate laminated and fixed to the side of the second drive magnetic steel away from the first pole core.

3. Two recessed grooves are provided at diagonal positions on the inner circumference of the first holder, each recessed inward. The lens drive device according to claim 1, characterized in that the magnetic bowls in the two first drive assemblies are each fixed in the two grooves.

4. The lens drive device according to claim 1, wherein there are two second drive assemblies, the image stabilization coils in the two second drive assemblies are respectively provided at diagonal positions of another pair of the first holder, and the second magnetic circuit system includes two sets of second lower clamp plates fixed at two opposing corner positions of the bottom plate, and two sets of second magnetic steel assemblies fixed in a stacked manner on the sides of the two sets of second lower clamp plates away from the bottom plate.

5. The lens drive device according to claim 4, wherein the second magnetic steel assembly includes a first image stabilization magnetic steel, a second image stabilization magnetic steel, and a third image stabilization magnetic steel, which are stacked and fixed on the second lower clamp plate and sequentially arranged along a direction perpendicular to the optical axis, and the first image stabilization magnetic steel, the second image stabilization magnetic steel, and the third image stabilization magnetic steel are fixed to each other.

6. The lens driving device according to claim 1, further comprising a first elastic member, the first elastic member being connected to the first holder and the bottom plate, respectively, and elastically supporting the first holder on the bottom plate.

7. Each of the second drive assemblies includes two of the image stabilization coils, and the two image stabilization coils are parallel to the two sides at the same corner position of the corresponding first holder. The lens drive device according to claim 6, further comprising a flexible circuit board fixed to the side of the first elastic member away from the first holder, all of the image stabilization coils in the second drive assembly being electrically connected to the flexible circuit board, and the flexible circuit board extending through the bottom plate to the outside of the housing.

8. The lens driving device according to claim 1, further comprising an elastic assembly, the elastic assembly being connected to the second holder and the first holder, respectively, and elastically supporting the second holder so as to suspend it within the first holder.

9. The lens driving device according to claim 8, wherein the elastic assembly includes a second elastic member, a third elastic member, and a fourth elastic member spaced apart from each other, the second elastic member being connected to the top region of the second holder and the top region of the first holder, the third elastic member being connected to the central region of the second holder and the central region of the first holder, and the fourth elastic member being connected to the bottom region of the second holder and the bottom region of the first holder, respectively.

10. The lens driving device according to claim 9, characterized in that there are four of the fourth elastic members, and the four fourth elastic members are fixed to four corner positions corresponding to the second holder and the first holder, respectively.

Images