Lens driving device

Abstract

The present invention provides a lens driving device. 【Solution means】 It includes a base, a support frame, a lens barrel holder, an elastic assembly, a shake correction coil, and a magnet steel. A central hole penetrating it is provided at the center of the base. The elastic assembly is fixed to both opposite sides of the support frame in the optical axis direction. The shake correction coil is fixed to the base. The magnet steel is fixed to the support frame and faces the shake correction coil with a gap therebetween. The shake correction coil drives the lens barrel holder to move synchronously. The shake correction coil cooperates with the magnet steel to drive the support frame to move along a direction perpendicular to the optical axis of the lens barrel holder. The shake correction coil is in a ring shape, and an arc-shaped structure that bends and recesses in a direction away from the central hole is provided on the side of the shake correction coil close to the central hole. The arc-shaped structure matches the outer peripheral shape of the central hole so that the shake correction coil is completely located outside the range of the central hole. Compared with the prior art, the lens driving device of the present invention has a good shake correction effect, saves mounting space, and provides a good user experience.

Description

Technical Field

[0001] The present invention relates to a driving device, and particularly to a lens driving device.

Background Art

[0002] With the development of imaging technology, lens driving devices are widely applied to various imaging devices. Combinations of lens driving devices and various portable electronic devices such as mobile phones, video cameras, and personal computers are preferred by consumers.

[0003] In the driving mechanism of a lens driving device in the prior art, a coil and a magnet steel are usually combined to form a driving structure. A support frame is supported by a base, a lens barrel holder is provided in a central hole of the base, a driving coil and a driving magnet steel are fixed to the lens barrel holder and the support frame respectively, an OIS coil (coil for optical image stabilization) is fixed to the housing and located above the support frame, and an optical image stabilization magnet steel is fixed to a side away from the base of the support frame. When an electric current is applied to the optical image stabilization coil, an electromagnetic field is generated in the optical image stabilization coil and the optical image stabilization magnet steel, and the optical image stabilization coil receives the Lorentz force of the electromagnetic field and drives the optical image stabilization magnet steel to move along a direction perpendicular to the optical axis, driving the lens barrel to realize the optical image stabilization function.

[0004] However, in the lens driving device in the prior art, since one side of the optical image stabilization coil is close to the central hole of the base, the optical image stabilization coil is likely to exceed the central hole due to the influence of deformation and assembly tolerance, occupying the mounting space and having poor overall assemblability.

[0005] Therefore, it is necessary to provide a new lens driving device to solve the above problems.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The technical problem to be solved by the present invention is to provide a lens driving device that is small, easy to assemble, and saves mounting space.

Means for Solving the Problem

[0007] To solve the above technical problem, the present invention provides a lens driving device, which includes a base, a support frame, a lens barrel holder, an elastic assembly, a shake correction coil, and a magnet steel. A central hole penetrating it is provided at the center of the base. The support frame has an accommodation space, and the support frame is installed facing the base with a gap therebetween. The lens barrel holder is accommodated in the accommodation space and is spaced apart from the support frame, and is used for attaching a lens module. The elastic assembly is fixed to both opposite sides of the support frame in the optical axis direction, and elastically suspends the lens barrel holder in the accommodation space. The shake correction coil is fixed to the base, the magnet steel is fixed to the support frame, and is opposed to the shake correction coil with a gap therebetween. So as to drive the lens barrel holder to move synchronously, the shake correction coil cooperates with the magnet steel to drive the support frame to move along a direction perpendicular to the optical axis of the lens barrel holder. The shake correction coil is in a ring shape, and an arc-shaped structure that bends and recesses in a direction away from the central hole is provided on the side of the shake correction coil close to the central hole. The arc-shaped structure matches the outer peripheral shape of the central hole so that the shake correction coil is completely located outside the range of the central hole.

[0008] Preferably, the shake correction coil is in a track shape, and includes two long sides installed opposite to each other and two short sides installed opposite to each other. The arc-shaped structure is provided on the long side close to the central hole.

[0009] Preferably, the base has a rectangular structure, there are four shake correction coils, the four shake correction coils are provided so as to surround the central hole, and are respectively fixed to four sides of the base. The four shake correction coils are respectively parallel to the four sides of the base. There are four magnet steels, which are respectively fixed to the support frame, and the four shake correction coils are respectively provided in a one-to-one correspondence with the four magnet steels.

[0010] Preferably, the lens driving device further includes a flexible substrate for connecting to an external power source. The flexible substrate is fixed to the side of the base close to the magnet steel. The shake correction coil is laminated and fixed to the flexible substrate and is electrically connected to the flexible substrate.

[0011] Preferably, the elastic assembly includes an upper elastic sheet and a lower elastic sheet. The upper elastic sheet includes a first fixed arm fixed to the support frame, a second fixed arm fixed to the lens barrel holder, and a plurality of first elastic arms connecting the first fixed arm and the second fixed arm. The first elastic arms are installed at intervals from the support frame along the optical axis direction of the lens barrel holder. The lower elastic sheet includes a third fixed arm fixed to the side of the support frame close to the base, a fourth fixed arm fixed to the lens barrel holder, and a second elastic arm connecting the third fixed arm and the fourth fixed arm. The second elastic arms are installed at intervals from the support frame along the optical axis direction of the lens barrel holder.

[0012] Preferably, the lens driving device further includes a plurality of suspension wires, which are installed at intervals. Both ends of each suspension wire are respectively fixed to the base and the support frame, and the support frame is suspended from the base.

[0013] Preferably, the lens driving device further includes a horizontal support elastic member, and the horizontal support elastic member includes a first arm fixed to the suspension wire, a second arm fixed to the support frame, and an elastic arm connecting the first arm and the second arm.

[0014] Preferably, the support frame includes a frame body having a rectangular shape and four fixing structures respectively located at four corner portions of the support frame. There are two upper elastic sheets which are oppositely arranged with a gap therebetween. Each upper elastic sheet includes two first elastic arms spaced apart from each other. The four first fixing arms respectively correspond one-to-one to the four fixing structures. The magnet steel is fixed to the side of the frame body close to the lens barrel holder.

[0015] Preferably, the base has a rectangular structure. There are four shake correction coils which are respectively fixed to four sides of the base. There are four magnet steels which are respectively fixed to the support frame. The four shake correction coils are respectively provided corresponding one-to-one to the four magnet steels.

[0016] Preferably, the lens driving device further includes a focus coil. The focus coil is fixedly externally fitted to the lens barrel holder and is arranged at a distance from the magnet steel. The focus coil and the magnet steel cooperate to drive the lens barrel holder to move along the optical axis direction to realize an autofocus function.

[0017] Preferably, the flexible substrate further includes a substrate body fixed to the base and pins bent and extending from one side of the substrate body to the base.

Advantages of the Invention

[0018] Compared with the prior art, in the lens driving device of the present invention, an arc-shaped structure that bends and recesses in a direction away from the central hole is provided on the side close to the central hole of the shake correction coil, and by matching the arc-shaped structure with the outer peripheral shape of the central hole, the shake correction coil is completely positioned outside the range of the central hole. In this way, by making the intermediate portion on the side close to the central hole of the shake correction coil have a concave structure with a predetermined shape, it is possible to prevent it from exceeding the central hole while maintaining the dimensional driving force of the shake correction coil. Thereby, the space of the product can be fully utilized, the entire lens driving device can be miniaturized, and the user experience can be improved.

Brief Description of the Drawings

[0019] To more clearly explain the technical solution in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative labor. Among them,

Figure 1

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Modes for Carrying Out the Invention

[0020] The technical concept in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment 1

[0021] As shown in FIGS. 1 to 6, a lens driving device 100 is provided, which includes a base 1, a support frame 2, a suspension wire 12, a housing 3, a lens barrel holder 4, a shake correction coil 6, a magnet steel 7, a focus coil 8, an elastic assembly 5, and a flexible substrate 10.

[0022] A central hole 14 penetrating the base 1 is provided at the center of the base 1, and the lens barrel holder 4 is easily installed through the central hole 14. The base 1 is used to support and fix the flexible substrate 10 and the shake correction coil 6.

[0023] The support frame 2 has an accommodation space 9, and the support frame 2 is installed facing the base 1 with a gap therebetween.

[0024] In this embodiment, the lens driving device 100 further includes a housing 3 provided so as to cover the base 1 and forming an accommodation space 31 together with the base 1, and a suspension wire 12 that movably supports the support frame 2 in the accommodation space 31. One end of the suspension wire 12 is connected to the base 1, and the other end is connected to the elastic assembly 5. The suspension wire 12 is made of a metal conductive material, consists of a plurality of wires, and is peripherally provided around the support frame 2 at intervals. Each suspension wire 12 has one end fixed to the base 1 and the other end fixed to and electrically connected to the upper elastic sheet 51. The suspension wire 12 is used to provide a restoring force to the support frame 2 when the shake correction function is used.

[0025] The lens barrel holder 4 is used for attaching a lens module that is accommodated in the accommodation space 9 and has an optical axis (Z-axis).

[0026] The elastic assembly 5 is fixed to both opposite sides of the support frame 2 in the optical axis direction, and elastically supports the lens barrel holder 4 in the accommodation space 9. Thereby, when a current is applied to the shake correction coil 6, an electromagnetic field is generated between the shake correction coil 6 and the magnet steel 7, and the shake correction coil 6 is subjected to the action of the Lorentz force of the electromagnetic field, and the magnet steel 7 is driven to move along a direction perpendicular to the optical axis, which contributes to driving the lens barrel to realize the OIS shake correction performance.

[0027] The shake correction coil 6 is fixed to the base 1. The shake correction coil 6 is fixed to the base 1, the magnet steel 7 is fixed to the side of the support frame 2 close to the lens barrel holder 4, the shake correction coil 6 is located within the magnetic field range of the magnet steel 7, and drives the magnet steel 7 to move in a direction perpendicular to the optical axis. Here, the shake correction coil 6 is formed by pre-winding, and the plane where the winding direction of the shake correction coil 6 is located is perpendicular to the optical axis direction. Thereby, its cost can be significantly reduced.

[0028] The magnet steel 7 is fixed to the support frame 2 and faces the shake correction coil 6 with a gap therebetween. The shake correction coil 6 cooperates with the magnet steel 7 to drive the lens barrel holder 4 to move synchronously, and drives the support frame 2 to move along a direction perpendicular to the optical axis of the lens barrel holder. The magnet steel 7 includes a first drive magnet steel 7 fixed to both opposite sides of the support frame 2 along a direction perpendicular to the optical axis, and a second drive magnet steel 7 fixed to both opposite sides of the other side of the support frame 2, and each magnet steel 7 is a single-pole magnetized. Single magnetic poles are provided on both opposite sides of the magnet steel 7.

[0029] The flexible substrate 10 is fixed to the base 1 and used for being connected to an external power supply. The flexible substrate 10 is fixed to the side of the base 1 close to the magnet steel 7, the shake correction coil 6 is laminated and fixed to the flexible substrate 10 and is electrically connected to the flexible substrate 10.

[0030] The shake correction coil 6 has a ring shape, and an arc-shaped structure 61 that curves and recesses in a direction away from the central hole 14 is provided on a side of the shake correction coil 6 close to the central hole 14. The arc-shaped structure 61 matches the outer peripheral shape of the central hole 14 so that the shake correction coil 6 is completely located outside the range of the central hole 14. By forming the intermediate portion on the side of the shake correction coil 6 close to the central hole 14 into the arc-shaped structure 61 with a predetermined shape, it is possible to prevent the shake correction coil from exceeding the central hole 14 while maintaining the dimensional driving force of the shake correction coil. Thereby, the space of the product can be fully utilized, the entire lens driving device 100 can be miniaturized, and the user experience can be improved.

[0031] Specifically, the lens driving device 100 further includes a focus coil 8. The focus coil 8 is fixedly externally fitted to the lens barrel holder 4 and is installed at a distance from the magnet steel 7. The focus coil 8 and the magnet steel 7 cooperate to drive the lens barrel holder 4 to move along the optical axis direction to realize an autofocus function. The focus coil 8 is externally fitted and fixed to the outer periphery of the lens barrel holder 4 and is at a distance from the magnet steel 7. The focus coil 8 is electrically connected to the upper elastic sheet 51. The magnetization direction of the magnet steel 7 is parallel to the winding plane of the focus coil 8 and drives the focus coil 8 to move along the optical axis direction. By moving the lens barrel holder 4 along the optical axis direction by the focus coil 8, an autofocus (AF) function can be realized. In this embodiment, the magnetization direction of the magnet steel 7 is parallel to the winding plane of the focus coil 8.

[0032] Of course, the magnetization direction of each magnet steel 7 may be perpendicular to the optical axis direction.

[0033] Here, the lens barrel holder 4, the focus coil 8, the shake correction coil 6, the magnet steel 7, and the flexible substrate 10 are all housed in the housing 3.

[0034] In the present embodiment, the shake correction coil 6 has a track shape and includes two long sides 62 installed opposite to each other and two short sides 63 installed opposite to each other, and the arc-shaped structure 61 is provided on the long side 62 close to the central hole 14. Thereby, the space of the product can be utilized to the maximum, the entire lens driving device 100 can be miniaturized, and the user experience can be improved.

[0035] In the present embodiment, the base 1 has a rectangular structure, there are four shake correction coils 6, the four shake correction coils 6 are provided so as to surround the central hole 14, and are respectively fixed to the four sides of the base 1. The four shake correction coils 6 are respectively parallel to the four sides of the base 1, there are four magnet steels 7, and they are respectively fixed to the support frame 2. The four shake correction coils 6 are respectively provided in a one-to-one correspondence with the four magnet steels 7. By installing the plurality of shake correction coils 6 and the magnet steels 7 in correspondence, the driving force in different directions can be adjusted. For example, the driving directions set perpendicular to each other in the same plane are defined as the first direction and the second direction. Here, the first direction is the X-axis direction, and the second direction is the Y-axis direction. By electrically connecting different shake correction coils 6, shake correction adjustment in different directions becomes possible, and the operation is convenient.

[0036] In this embodiment, the elastic assembly 5 includes an upper elastic sheet 51 and a lower elastic sheet 52. The upper elastic sheet 51 includes a first fixing arm 511 fixed to the support frame 2, a second fixing arm 512 fixed to the lens barrel holder 4, and a plurality of first elastic arms 513 connecting the first fixing arm 511 and the second fixing arm 512. The first elastic arms 513 are installed at intervals from the support frame 2 along the optical axis direction of the lens barrel holder 4. The lower elastic sheet 52 includes a third fixing arm 521 fixed to the side of the support frame 2 close to the base 1, a fourth fixing arm 522 fixed to the lens barrel holder 4, and a second elastic arm 523 connecting the third fixing arm 521 and the fourth fixing arm 522. The second elastic arm 523 is installed at intervals from the support frame 2 along the optical axis direction of the lens barrel holder 4.

[0037] One end of the upper elastic sheet 51 is fixed to the upper end of the support frame 2 along the optical axis direction of the lens barrel holder 4, and the other end of the upper elastic sheet 51 is fixed to the upper end of the lens barrel holder 4 along the optical axis direction, thereby elastically suspending the lens barrel holder 4 in the accommodation space 9. In this embodiment, a conductive path for realizing the transport of electrical signals is provided on the upper elastic sheet 51. For example, when the upper elastic sheet 51 is an FPC, the conductive path is realized by the conductive line in the FPC.

[0038] The two upper elastic sheets 51 are provided insulated from each other and together form a surrounding ring shape. Each upper elastic sheet 51 forms a conductive path, thereby enabling the transport of electrical signals at both the positive and negative electrodes. In this embodiment, the two upper elastic sheets 51 are provided symmetrically about the center with respect to the lens barrel holder 4. Of course, the two upper elastic sheets 51 may be of an integral structure, and the two conductive paths may be insulated from each other, which is easy to understand.

[0039] One end of the lower elastic sheet 52 is fixed to the bottom end of the support frame 2 along the optical axis direction, and the other end of the lower elastic sheet 52 is fixed to the bottom end of the lens barrel holder 4 along the optical axis direction. The upper elastic sheet 51 and the lower elastic sheet 52 both elastically support the lens barrel holder 4 in the accommodation space 9. The lower elastic sheet is used to provide a restoring force to the lens barrel holder 4 when the autofocus (AF) function is used.

[0040] In this embodiment, the lens driving device 100 further includes a horizontal support elastic member 13, and the horizontal support elastic member 13 includes a first arm 131 fixed to the suspension wire 12, a second arm 132 fixed to the support frame 2, and an elastic arm 133 connecting the first arm 131 and the second arm 132. By fixing the two suspension wires 12 to the first arm 131 and the base 1 respectively, the suspension of the base 1 and the support frame 2 can be realized.

[0041] In this embodiment, the support frame 2 includes a frame body 21 having a rectangular shape and four fixing structures 22 respectively located at four corners of the support frame 2. There are two upper elastic sheets 51, which are installed opposite to each other with a gap therebetween. Each upper elastic sheet 51 includes two first elastic arms 52 spaced apart from each other. The four first fixing arms 511 respectively correspond one-to-one to the four fixing structures 22. The magnet steel 7 is fixed to the side of the frame body 21 close to the lens barrel holder 4. Thereby, it becomes easy to fix the upper elastic sheet 51 to the fixing structure 22, the fixing effect of the lens barrel holder 4 can be enhanced, and the lens barrel holder 4 becomes more stable. Optionally, a plurality of mounting holes penetrating therethrough are provided in the first fixing arm 511, and the fixing structure 22 is a plurality of fixing posts corresponding to the plurality of mounting holes. The plurality of mounting holes are externally fitted to the plurality of fixing posts respectively to form a fixed connection.

[0042] In this embodiment, the flexible substrate 10 further includes a substrate body 101 fixed to the base 1 and a pin 102 that bends and extends from one side of the substrate body 101 to the base 1. The pin 102 contributes to the connection with an external signal line.

[0043] Compared with the prior art, in the lens driving device of the present invention, an arc-shaped structure that bends and recesses in a direction away from the central hole is provided on the side close to the central hole of the shake correction coil, and by matching the arc-shaped structure with the outer peripheral shape of the central hole, the shake correction coil is completely positioned outside the range of the central hole. In this way, by making the intermediate portion on the side close to the central hole of the shake correction coil have a concave structure in a predetermined shape, it is possible to prevent the shake correction coil from exceeding the central hole while maintaining the dimensional driving force of the shake correction coil. As a result, the space of the product can be fully utilized, the entire lens driving device can be miniaturized, and the user experience can be improved.

[0044] What has been described above is only an embodiment of the present invention. For those skilled in the art, improvements can be made without departing from the creative concept of the present invention, and it is hereby noted that all of these are included in the protection scope of the present invention.

Claims

1. A lens driving device comprising a base, a support frame, a lens barrel holder, an elastic assembly, a shake correction coil, and a magnet steel, a central hole penetrating the base is provided at the center of the base, the support frame has an accommodation space, and the support frame is installed facing the base with a gap therebetween, the lens barrel holder is accommodated in the accommodation space and spaced apart from the support frame, and is used for attaching a lens module, the elastic assembly is fixed to both opposite sides of the support frame in the optical axis direction, and elastically suspends the lens barrel holder in the accommodation space, the shake correction coil is fixed to the base, the magnet steel is fixed to the support frame and faces the shake correction coil with a gap therebetween. The shake correction coil is a lens driving device that cooperates with the magnet steel to drive the support frame to move along a direction perpendicular to the optical axis of the lens barrel holder so as to drive the lens barrel holder to move synchronously, the shake correction coil has a ring shape, and an arc-shaped structure that bends and recesses in a direction away from the central hole is provided on a side of the shake correction coil close to the central hole. The arc-shaped structure matches the outer peripheral shape of the central hole so that the shake correction coil is completely located outside the range of the central hole, characterized in that.

2. the shake correction coil has a track shape, and includes two long sides installed opposite to each other and two short sides installed opposite to each other. The arc-shaped structure is provided on the long side close to the central hole, The lens driving device according to claim 1, characterized in that.

3. the base has a rectangular structure, there are four shake correction coils, and the four shake correction coils are provided so as to surround the central hole and are respectively fixed to the four sides of the base. The four shake correction coils are respectively parallel to the four sides of the base. There are four magnet steels, and they are respectively fixed to the support frame. The four shake correction coils are respectively provided in a one-to-one correspondence with the four magnet steels, The lens driving device according to claim 1, characterized in that.

4. The lens driving device further includes a flexible printed circuit board for connection to an external power source. The flexible printed circuit board is fixed to the side of the base closer to the magnet steel. The shake correction coil is laminated and fixed to the flexible printed circuit board and is electrically connected to the flexible printed circuit board. The lens driving device according to claim 1, characterized in that.

5. The elastic assembly includes an upper elastic sheet and a lower elastic sheet. The upper elastic sheet includes a first fixed arm fixed to the support frame, a second fixed arm fixed to the lens barrel holder, and a plurality of first elastic arms connecting the first fixed arm and the second fixed arm. The first elastic arms are installed at intervals from the support frame along the optical axis direction of the lens barrel holder. The lower elastic sheet includes a third fixed arm fixed to the side of the support frame closer to the base, a fourth fixed arm fixed to the lens barrel holder, and a second elastic arm connecting the third fixed arm and the fourth fixed arm. The second elastic arm is installed at intervals from the support frame along the optical axis direction of the lens barrel holder. The lens driving device according to claim 1, characterized in that.

6. The lens driving device further includes a plurality of suspension wires installed at intervals. Both ends of each suspension wire are fixed to the base and the support frame respectively to suspend the support frame from the base. The lens driving device according to claim 1, characterized in that.

7. The lens driving device further includes a horizontal support elastic member including a first arm fixed to the suspension wire, a second arm fixed to the support frame, and an elastic arm connecting the first arm and the second arm. The lens driving device according to claim 6, characterized in that.

8. The support frame includes a frame body presenting a rectangle and four fixing structures respectively located at four corner portions of the support frame. The upper elastic sheets are two in number and are installed oppositely with a gap therebetween. Each of the upper elastic sheets includes two first elastic arms spaced from each other. The four first fixing arms respectively correspond one-to-one to the four fixing structures. The magnet steel is fixed to a side of the frame body close to the lens barrel holder. The lens driving device according to claim 7, characterized in that.

9. The lens driving device further includes a focus coil. The focus coil is fixedly externally fitted to the lens barrel holder and is installed with a gap from the magnet steel. The focus coil and the magnet steel cooperate to drive the lens barrel holder to move along the optical axis direction, thereby realizing an autofocus function. The lens driving device according to claim 1, characterized in that.

10. The flexible substrate further includes a substrate body fixed to the base and pins bent and extending from one side of the substrate body to the base. The lens driving device according to claim 4, characterized in that.

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