CN116366950A

CN116366950A - SMA driving piece, focusing assembly and camera module

Info

Publication number: CN116366950A
Application number: CN202310372619.4A
Authority: CN
Inventors: 蔡锐林; 郭延春; 许德光; 黄国平; 李斌; 幸帅超; 姜学伟; 王玉会
Original assignee: Baotou Jiangxin Micro Motor Technology Co ltd
Current assignee: Baotou Jiangxin Micro Motor Technology Co ltd
Priority date: 2023-04-10
Filing date: 2023-04-10
Publication date: 2023-06-30
Anticipated expiration: 2043-04-10
Also published as: CN116366950B

Abstract

The invention discloses an SMA driving piece, a focusing assembly and a camera module, and belongs to the field of cameras; the SMA driving piece provided by the application utilizes the characteristic that the shape memory alloy has the functions of electrifying, heating and shrinking, and pulls the moving end of the elastic support body to move upwards so as to push the image sensor assembly supported above the elastic support body to move towards one side of the lens for focusing; secondly, the focusing assembly supports the image sensor assembly through the elastic sheet, an SMA driving piece is arranged at the bottom of the elastic sheet, and the image sensor assembly on the elastic sheet is pushed to move and focus through the SMA driving piece; furthermore, the camera module that this application provided is on focusing the subassembly direct mount camera lens, and is simple structure than traditional voice coil motor, and the thrust is bigger.

Description

SMA driving piece, focusing assembly and camera module

Technical Field

The invention relates to the field of cameras, in particular to an SMA driving piece, a focusing assembly and a camera module.

Background

Fig. 1 is a schematic structural diagram of a common mobile phone camera module. The camera module mainly comprises the following parts: lens (Lens): converging light onto an image sensor; voice Coil Motor (VCM): completing automatic focusing of the camera; infrared filter (IR-cutFilter): filtering invisible light of human eyes; image Sensor (Sensor): converting the optical signal into an electrical signal; flexible Printed Circuit Board (FPCB): and connecting the camera module with the main processor and carrying out data transmission.

In the prior art, a voice coil motor drives a lens to move to realize focusing; voice coil motors (voicecoil motors), which are also known as voice coil motors, are similar in principle to speakers in that a coil is placed in a permanent magnetic field, and when the coil is energized, a magnetic field (ampere's law) is generated, thereby generating attraction or repulsion with the surrounding permanent magnets, causing the coil to move under force. The lens is arranged on the coil, so that the coil can drive the lens to move back and forth by changing the current, and the position of the lens is controlled, so that the focusing function is completed.

In addition, there is another design concept in the art that the focusing purpose is achieved by driving the image sensor assembly. For example, chinese patent publication No. CN101533145a discloses an image sensor floating image tracking auto focusing system, in which an image sensor assembly is connected to a floating mechanism driven by electromagnetic force to achieve focusing, and the structure is complex.

Disclosure of Invention

The invention aims to provide an SMA driving piece, a focusing assembly and a camera module, which are used for driving an image sensor assembly to move so as to realize a focusing function.

The technical scheme adopted by the invention is as follows:

according to a first aspect of the present disclosure, the present disclosure provides an SMA driving piece, including a support plate, on which a partially suspended elastic support body is provided, the suspended portion of the elastic support body is connected to the support plate as a moving end through a shape memory alloy, and the shape memory alloy contracts after being electrified, so as to pull the suspended portion of the elastic support body to bend and deform.

In some embodiments, the elastic support is in the shape of an elongated sheet and the shape memory alloy is in the shape of a wire; the two ends of the shape memory alloy are connected with a driving power supply through two circuits.

In some embodiments, the suspended end of the elastic support body is formed with a mounting plane, and a stepped bending part is formed between the mounting plane and the connecting end of the elastic support body and the supporting plate, and protrudes from the lower surface of the supporting plate.

In some embodiments, the shape memory alloy is mounted above the resilient support with one end attached to the mounting plane and the other end attached to the upper surface of the support plate across the stepped bend.

In some embodiments, the mounting plane has a support portion formed thereon that is higher than the shape memory alloy.

In some embodiments, a partially suspended terminal connection is formed on the mounting plane; one end of the shape memory alloy is connected to the terminal connection portion of the mounting plane.

In some embodiments, two elastic supporting bodies with opposite directions are formed on the supporting plate, and one shape memory alloy is arranged on each of the two elastic supporting bodies, so that the pulling directions of the two shape memory alloys are opposite.

According to a second aspect of the present disclosure, the present invention provides a focusing assembly, including any one of the SMA driving pieces described above, and further including a spring piece, the spring piece including an outer frame and an inner platform, the inner platform being connected to the outer frame by an elastic arm; the upper surface of the inner platform is provided with an image sensor component; and an SMA driving piece is arranged on the lower surface of the inner platform.

In some embodiments, the focusing assembly further comprises a base and a cover body, the base and the cover body are assembled into a hollow shell, the SMA driving piece is arranged on the base, and the elastic sheet and the image sensor assembly are sequentially arranged above the SMA driving piece; the cover body is provided with a through hole which is covered by the optical filter.

According to a third aspect of the present disclosure, the present invention provides a camera module, including the above focusing assembly, and further including a lens holder and a lens, wherein the lens is installed in a central through hole of the lens holder, and is installed on an upper surface of a cover body through the lens holder, and the lens is located above an optical filter.

The invention has the beneficial effects that: the invention provides an SMA driving piece, a focusing assembly and a camera module, wherein the SMA driving piece provided by the application utilizes the characteristic that a shape memory alloy has the characteristics of electrifying and heating so as to shrink, and pulls the moving end of an elastic support body to move upwards so as to push an image sensor assembly supported above the SMA driving piece to move to one side of a lens for focusing; secondly, the focusing assembly supports the image sensor assembly through the elastic sheet, an SMA driving piece is arranged at the bottom of the elastic sheet, and the image sensor assembly on the elastic sheet is pushed to move and focus through the SMA driving piece; furthermore, the camera module that this application provided is on focusing the subassembly direct mount camera lens, and is simple structure than traditional voice coil motor, and the thrust is bigger.

Drawings

Fig. 1 is a schematic structural diagram of a conventional mobile phone camera module.

Fig. 2 is a schematic structural view of an SMA actuator according to embodiment 1 of the application.

Fig. 3 is an explanatory view of the internal structure of the SMA actuator of embodiment 1 of this application.

Fig. 4 is a detailed representation of the elastic support of example 1 of the present application.

Fig. 5 is a side view of fig. 4.

Fig. 6 is a detailed view showing a mounting plane on the elastic support body of embodiment 1 of the present application.

Fig. 7 is a schematic structural view of an SMA actuator according to embodiment 2 of this application.

Fig. 8 is an explanatory view of the internal structure of the SMA actuator of embodiment 2 of this application.

Fig. 9 is a top view of a focusing assembly of the present application.

Fig. 10 is a bottom view of fig. 9.

Fig. 11 is a schematic structural diagram of a spring plate in a focusing assembly according to the present application.

FIG. 12 is a schematic view of a spring top surface mount image sensor assembly.

Fig. 13 is an exploded view of the focus assembly of the present application including a base and a cover.

Fig. 14 is an assembly structure showing the focusing assembly of the present application.

Figure 15 is a schematic view of the SMA drive member mounted in a recess in a base.

Fig. 16 is a top view of the cover of the present application.

Fig. 17 is a bottom view of the cover of the present application.

Fig. 18 is a perspective view of a camera module provided in the present application.

In fig. 1: lens 1, voice coil motor 2, optical filter 3, image sensor 4.

Fig. 2 to 18: the device comprises a supporting plate 1, an elastic supporting body 2, a mounting plane 201, a step-shaped bending part 202, an arc transition section 202.1, a horizontal section 202.2, a supporting part 203, a cutting gap 203.1, an insulating cushion block 204 and a terminal connecting part 205; shape memory alloy 3, first circuit 4, first short side 401, first long side 402, second short side 403, second long side 404, fracture 405, independent connection 406, serial body 407, first elastic support 407.1, second elastic support 407.2, first terminal 408; a second circuit 5, a third short side 501, a third long side 502, a fourth short side 503, a second terminal 504; spring 6, outer frame 601, inner platform 602, elastic arm 603; the image sensor 7, the flexible printed circuit board 8, the base 9, the mounting groove 901, the cover 10, the optical filter 11, the lens mount 12 and the lens 13.

Description of the embodiments

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In order to drive the image sensor assembly to move to achieve the focusing function, the application firstly provides an SMA driving element, and a specific structural representation of the SMA driving element is shown in fig. 2, which is used for explaining the principle of the SMA driving element; the SMA driving piece mainly comprises a supporting plate 1, an elastic supporting body 2 in a strip sheet shape and a shape memory alloy 3 in a wire shape; one end of the elastic support body 2 is connected with the support plate 1 to serve as a fixed end, the other end of the elastic support body is suspended to serve as a moving end, and the moving end is used for being supported on the lower surface of the image sensor assembly; the shape memory alloy 3 is arranged above the elastic support body 2, one end of the shape memory alloy is connected to the moving end of the elastic support body 2 as a traction end, and the other end of the shape memory alloy is connected to the support plate 1; the two ends of the shape memory alloy 3 are connected with the driving circuit, the connection mode shown in the figure is only one type of illustration, the anode and the cathode of the shape memory alloy 3 and a specific circuit can be designed according to actual conditions, for example, the two ends of the shape memory alloy 3 can be directly connected with the driving circuit through wires; for example, the support plate 1 itself is designed as a circuit board, and the drive circuit is integrated on the support plate 1.

The SMA driving piece is based on the principle that the shape memory alloy 3 has the characteristics of heating by electrifying and shrinking, the shape memory alloy 3 shrinks relative to the original length, the traction end pulls the moving end of the elastic support body 2 to move upwards, and the image sensor component supported above the traction end is pushed to move to one side of the lens 13 for focusing; the elastic support body 2 has the elastic characteristic of being capable of resetting, and the elastic support body 2 is bent upwards to deform in the pulling process; after the power is off, the shape memory alloy 3 is restored to the original length, the traction end of the shape memory alloy gradually releases the moving end of the elastic support body 2, and meanwhile, the elastic sheet 6 rebounds, and the moving end returns to the initial position downwards.

In some embodiments of the present application, the shape memory alloy 3 may be made of nickel-titanium alloy, and the nickel-titanium alloy is powered on and heated to be shortened, and is powered off and cooled to restore the original length. The elastic support body 2 may be made of copper alloy.

Example 1

As shown in fig. 3, the embodiment of the present application provides a design of a built-in circuit structure of an SMA driving piece, in this scheme, two circuits are disposed in a supporting board 1, and for convenience of description, the circuits are named as a first circuit 4 and a second circuit 5, and the first circuit 4 and the second circuit 5 are isolated from each other; the details of both circuits are described in detail below.

As shown in fig. 3, the first circuit 4 includes a first terminal 408 and a first conductor made of a conductive material, such as copper or a copper alloy; the first conductor is in a non-closed square shape and consists of two short sides which are oppositely arranged and two long sides which are oppositely arranged; for convenience of description, four sides are respectively named as: a first short side 401, a first long side 402, a second short side 403, a second long side 404; the four sides are sequentially connected into a whole, wherein the tail part of the second long side 404 is disconnected with the head part of the first short side 401 to form a fracture 405; the first short side 401 is connected to the first terminal 408; the second long side 404 directly serves as the elastic support body 2, and this structural design has the advantage that: the elastic support body 2 is used as a part of the integral structure of the first conductor, has better integrity and better elastic deformation capability than the elastic support body 2 is made into a single body. In addition, the movable end of the elastic support body 2 of the structure is positioned in the SMA driving piece, so that an image sensor assembly mounted on the elastic support body can be mounted right above the SMA driving piece, and the size of the finally assembled camera module is reduced. The camera module will be described later to show this effect.

As shown in fig. 3, the second circuit 5 includes a second terminal 504 and a second conductor made of a conductive material, such as copper or a copper alloy; the second conductor consists of two short sides and one long side which are oppositely arranged; for convenience of description, the three sides are respectively named as: a third short side 501, a third long side 502, a fourth short side 503; the three sides are sequentially connected to form a semi-enclosed whole; the second conductor is surrounded by the first conductor and is isolated from the first conductor.

The first conductor and the second conductor are embedded in the insulated supporting plate 1 except the elastic supporting body 2, and can be embedded on the surface of the supporting plate 1; the second conductor semi-surrounds and sets up in the first conductor outside for SMA driving piece overall structure is compact, and first conductor, second conductor have improved the intensity of backup pad 1 as the bearing structure of backup pad 1. In this application, the first terminal 408 and the second terminal 504 are used to connect to a driving power source.

In this embodiment, the present application further provides an elastic support body 2, as shown in fig. 4, the elastic support body 2 is in a strip shape, and the right side end of the elastic support body is connected with the support plate 1; the elastic support body 2 is further subjected to bending processing, so that the elastic support body has better elastic deformation capability; specifically, the left side end of the elastic support body 2 is used as a moving end, and a mounting plane 201 is formed; a step-shaped bending part 202 is formed by bending downwards between the mounting plane 201 and the right side end of the elastic support body 2, and the step-shaped bending part 202 specifically comprises arc-shaped transition sections 202.1 at two sides and a middle horizontal section 202.2; as shown in fig. 5, which is a side view of the support plate 1, a stepped bent portion 202 formed by bending downward protrudes from the lower surface of the support plate 1. The shape elastic support body 2 has better rebound resilience. Further, as shown in fig. 3, the width of the stepped bending portion 202 formed by bending downward is smaller than the width of the connecting portion of both ends, so that the bending point is located in the stepped bending portion 202 during the upward pulling of the left mounting plane 201 of the elastic support body 2.

Further, since the upper surface of the left side end mounting plane 201 of the elastic support body 2 is required to mount one end of the shape memory alloy 3 while supporting the image sensor assembly; if the mounting plane 201 is designed to be horizontal, the connecting end of the shape memory alloy 3 will directly contact the image sensor assembly, wearing the shape memory alloy 3 during pushing; for this purpose, the left edge of the mounting plane 201 is bent further upwards in this application to form a support 203 (shown in fig. 4 and 5) above the upper surface of the support plate 1, the support 203 being higher than the shape memory alloy 3 such that the support 203 is in direct contact with the image sensor assembly and the shape memory alloy 3 is located below the image sensor assembly and is separated from contact with the image sensor assembly.

In a specific embodiment, the support 203 is arched in shape, the highest point of the arched support 203 is higher than the shape memory alloy 3, and the arched support 203 is in line contact with the image sensor assembly. The advantages of this shape are as follows: in this application, when the elastic supporting body 2 is bent upwards to push the touch image sensor assembly to move, the supporting portion 203 will move on the lower surface of the touch image sensor assembly, and the linear contact of the arched supporting portion 203 can greatly reduce friction.

Further, as shown in fig. 6, the arch-shaped supporting portion 203 may be further cut into at least two supporting claws; in the specific cutting, the cutting is performed along the center line of the elastic support body 2 in the longitudinal direction, and the cutting slit 203.1 is located in the middle of the arch-shaped support portion 203. Such claw-shaped supporting portions 203 further reduce the contact area with the image sensor assembly.

As shown in fig. 4, the embodiment of the present application provides a specific connection structure of the shape memory alloy 3; as shown in the figure, the left end of the wire-shaped shape memory alloy 3 is attached to the mounting plane 201 at the left end of the elastic support body 2 and is located on the right side of the arch-shaped support portion 203; the wire-like shape memory alloy 3 extends rightward across the stepped bent portion 202, and the right end thereof is connected to the upper surface of the support plate 1 and is connected to the second conductor. Further, a spacer block 204 is provided on the mounting plane 201 on the right side of the left connecting end of the shape memory alloy 3, and the spacer block 204 will extend to the right higher than the shape memory alloy 3 frame, so as to avoid the contact between the rightwards extending part of the shape memory alloy 3 and the elastic support body 2.

Referring to fig. 3, a connection circuit of the wire-like shape memory alloy 3 is constructed by the above-described structure in the present application. Specifically, both ends of the wire-like shape memory alloy 3 are connected to the first terminal 408 and the second terminal 504 through the first circuit 4 and the second circuit 5 isolated from each other, and the first terminal 408 and the second terminal 504 are connected to a driving power source.

Further, as shown in fig. 6, in the embodiment of the present application, the mounting plane 201 at the left side end of the elastic support body 2 is further improved; as shown, a portion of material is removed from the center of the mounting plane 201 to form a partially suspended terminal connection 205; specifically, the removed portion is U-shaped to form a long strip-shaped connection portion, and the terminal connection portion 205 is connected to the left arch-shaped support portion 203 only with the left end left; the left end of the wire-shaped shape memory alloy 3 is mounted on the upper surface of the suspended terminal connection part 205. In addition, the cutting slit 203.1 in the center of the arched support 203 extends close to the terminal connection 205, so that a "preferential deformation area" is formed on the mounting plane 201; the function principle of the improved structure is as follows: the wire-shaped shape memory alloy 3 is electrified to shrink, firstly, the suspended terminal connection part 205 is pulled to be bent upwards, and the terminal connection part 205 gradually forms an included angle with the installation plane 201; then, the installation plane 201 is further pulled to drive the stepped bending part 202 to bend upwards; this stage deformation structure enables the connection end of the wire-like shape memory alloy 3 and the mounting plane 201 to be repeatedly deformed a plurality of times, improving durability thereof.

Example 2

As shown in fig. 7, the second SMA driving piece is provided in the embodiment of the present application, and is different from embodiment 1 in that two elastic supporting bodies 2 with opposite directions are provided on the SMA driving piece, one shape memory alloy 3 is provided on each of the two elastic supporting bodies 2, and the pulling directions of the two shape memory alloys 3 are opposite. The SMA drive is capable of providing greater thrust than the SMA drive of example 1, and one SMA drive may provide two points of thrust for an image sensor assembly.

Fig. 8 is a diagram showing the internal structure of the SMA actuator support plate 1 of this embodiment; the support board 1 is still provided with an inner circuit and an outer circuit, and compared with embodiment 1, the structure of the second circuit 5 outside in this embodiment is the same as that of embodiment 1, including a second terminal 504 and a second conductor, the second conductor is composed of two short sides and one long side which are oppositely arranged, and the two short sides and one long side are respectively: a third short side 501, a third long side 502, a fourth short side 503; the three sides are sequentially connected to form a semi-enclosed whole; the second conductor half surrounds the outside of the first circuit 4, being isolated between them.

This embodiment differs from embodiment 1 in that: the first conductor in the first circuit 4 is modified in this embodiment. Specifically, in this embodiment, the first conductor is further divided into an independent connection 406 and a series body 407 isolated therefrom; as shown in fig. 8, the serial body 407, the independent connection portion 406, and the second conductor are isolated from each other; the independent connection part 406 is used for connecting the first terminal 408; two elastic supports 2 disposed in parallel and opposite to each other are formed on the serial body 407, and for convenience of description, the elastic support 2 in the same direction as that of the embodiment 1 is designated as a first elastic support 407.1 in this embodiment, and a second elastic support 407.2 is disposed between the first elastic support 407.1 and the third long side 502 of the second conductor; the movable ends of the first elastic support body 407.1 and the second elastic support body 407.2 are suspended, and the other ends are connected together. The first wire-shaped shape memory alloy 3 on the first elastic support 407.1 is arranged along the length direction of the first elastic support 407.1, one end of the first wire-shaped shape memory alloy is connected to the mounting plane 201 of the first elastic support 407.1, and the other end of the first wire-shaped shape memory alloy is connected to the second conductor; the second wire-shaped shape memory alloy 3 on the second elastic support body 407.2 is arranged along the length direction of the second elastic support body 407.2, one end of which is connected to the mounting plane 201 of the second elastic support body 407.2, and the other end of which is connected to the independent connection part 406.

In this embodiment, a series circuit of two wire-like shape memory alloys 3 is constructed by the above-described structure. After the SMA driving piece is electrified, the two wire-shaped shape memory alloys 3 deform simultaneously to drive the two elastic supporting bodies 2 to bend upwards, so that an image sensor assembly arranged above the two elastic supporting bodies is jacked up.

The present application further provides a focusing assembly, as shown in fig. 9, which is a top view of the focusing assembly of the present application, and fig. 10, which is a bottom view of fig. 9; the focusing assembly comprises a spring plate 6, wherein an image sensor assembly is arranged on the upper surface of the spring plate 6, and an SMA driving piece is arranged on the lower surface of the spring plate 6; as shown in fig. 11, the elastic sheet 6 includes an outer frame 601 and an inner platform 602, in this embodiment, the outer frame 601 is a square frame, the center of the outer frame is provided with the square inner platform 602, the inner platform 602 is connected with the outer frame 601 through elastic arms 603 around, and in this embodiment, the elastic arms 603 are serpentine. As shown in fig. 12, an image sensor assembly is mounted on the upper surface of the spring plate 6, the image sensor assembly comprises an image sensor 7 and a flexible printed circuit board 8, the flexible printed circuit board 8 is laid on the upper surface of the spring plate 6, and the image sensor 7 is mounted above the flexible printed circuit board 8 and is located on the inner platform 602. As shown in fig. 10, the SMA driving member is mounted on the lower surface of the elastic sheet 6, and in this embodiment, the SMA driving member having two elastic supporting bodies 2 in the above embodiment 2 is used, and of course, the SMA driving member in embodiment 1 may also be used; in this embodiment, two SMA driving members are disposed on the lower surface of the inner platform 602, and four support points are provided. After the SMA driving piece is electrified, the inner platform 602 is pushed to move upwards (the direction of installing the lens 13 above the inner platform), and then the image sensor assembly is driven to move so as to achieve the purpose of focusing. After power failure, the inner platform 602 is pulled back to the original position by the spring arms 603.

As shown in fig. 13 and 14, the focusing assembly further comprises a base 9 and a cover 10, the upper surface of the base 9 is provided with a groove, a mounting groove 901 is arranged in the groove, and the mounting groove 901 is used for accommodating a part of the SMA driving piece protruding from the lower surface; the SMA drive is mounted at the recess (as shown in fig. 15); the elastic sheet 6 is arranged on the base 9, the outer frame 601 of the elastic sheet 6 is matched with the edge of the upper surface of the base 9 in shape, the outer frame 601 of the elastic sheet 6 is pressed on the edge of the upper surface of the base 9, the inner platform 602 in the center of the elastic sheet 6 is suspended, and the lower surface of the inner platform 602 is driven to move upwards through the elastic support body 2 of the SMA driving piece.

As shown in fig. 16 and 17, top and bottom views of the cover 10 are shown. Grooves are respectively arranged on the upper surface and the lower surface of the cover body 10, and a through hole is arranged in the center of each groove. As shown in fig. 14, the cover body 10 covers the base 9 to clamp the elastic sheet 6 in the middle, and the cover body 10 and the groove in the center of the base 9 form a cavity for accommodating the SMA driving piece and the image sensor assembly inside; the filter 11 is installed in the groove on the upper surface of the cover body 10, and the filter 11 covers the through hole.

The application also provides a camera module, as shown in fig. 18, the camera module includes the above-mentioned subassembly that focuses, still includes lens mount 12 and camera lens 13, installs camera lens 13 in the lens mount 12 central authorities through-hole, installs camera lens 13 at lid 10 upper surface through lens mount 12, and camera lens 13 is located directly over the light filter 11.

It will be understood that the invention has been described in terms of several embodiments, and that various changes and equivalents may be made to these features and embodiments by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. The SMA driving piece is characterized by comprising a supporting plate (1), wherein a part of an elastic supporting body (2) which is suspended is arranged on the supporting plate (1), the suspended part of the elastic supporting body (2) is used as a moving end and is connected with the supporting plate (1) through a shape memory alloy (3), the shape memory alloy (3) contracts after being electrified, and the suspended part of the elastic supporting body (2) is pulled to enable the suspended part to be bent and deformed.

2. SMA drive according to claim 1, characterized in that the elastic support body (2) is in the form of an elongated sheet, the shape memory alloy (3) being in the form of a wire; two ends of the shape memory alloy (3) are connected with a driving power supply through two circuits.

3. The SMA drive according to claim 2, characterized in that the suspended end of the elastic support body (2) is formed with a mounting plane (201), and a stepped bending portion (202) is formed by bending between the mounting plane (201) and the connecting end of the elastic support body (2) and the support plate (1), and the stepped bending portion (202) protrudes from the lower surface of the support plate (1).

4. A SMA actuator according to claim 3, characterized in that the shape memory alloy (3) is mounted above the elastic support body (2) with one end connected to the mounting plane (201) and the other end connected to the upper surface of the support plate (1) across the stepped curvature (202).

5. An SMA drive according to claim 4, characterized in that the mounting plane (201) has a support (203) formed thereon above the shape memory alloy (3).

6. An SMA actuator according to claim 4, characterized in that the mounting plane (201) has a partially suspended terminal connection (205); one end of the shape memory alloy (3) is connected to a terminal connection portion (205) of the mounting plane (201).

7. SMA drive according to claim 1, characterized in that two elastic supports (2) are formed on the support plate (1) in opposite directions, one shape memory alloy (3) being provided on each of the two elastic supports (2), the pulling directions of the two shape memory alloys (3) being opposite.

8. A focusing assembly, characterized by comprising the SMA drive piece according to any one of claims 1-7, further comprising a spring (6), the spring (6) comprising an outer rim (601) and an inner platform (602), the inner platform (602) being connected to the outer rim (601) by an elastic arm (603); an image sensor assembly is mounted on the upper surface of the inner platform (602); an SMA drive is mounted to the lower surface of the inner platform (602).

9. The focusing assembly according to claim 8, further comprising a base (9) and a cover (10), wherein the base (9) and the cover (10) are assembled into a hollow shell, the SMA driving piece is mounted on the base (9), and the spring piece (6) and the image sensor assembly are sequentially mounted above the SMA driving piece; the cover body (10) is provided with a through hole, and the through hole is covered by the optical filter (11).

10. A camera module, characterized in that, including the focusing subassembly of claim 9, still include lens mount (12) and camera lens (13), install camera lens (13) in the central through-hole of lens mount (12), install camera lens (13) at lid (10) upper surface through lens mount (12), camera lens (13) are located light filter (11) top.