CN212207817U

CN212207817U - SMA actuator and lens automatic focusing device

Info

Publication number: CN212207817U
Application number: CN202021072519.8U
Authority: CN
Inventors: 刘述伦; 耿新龙; 计树标
Original assignee: Dongguan Yadeng Electronics Co Ltd
Current assignee: Guangdong haideya Technology Co.,Ltd.
Priority date: 2020-06-11
Filing date: 2020-06-11
Publication date: 2020-12-22
Anticipated expiration: 2030-06-11

Abstract

The utility model relates to a SMA actuator and camera lens auto-focusing device, wherein SMA actuator, including elasticity actuating arm and SMA line, elasticity actuating arm has stiff end, actuating end and elastic part, the elastic part is located between stiff end and actuating end, elasticity actuating arm passes through the stiff end location installation, the actuating end of elasticity actuating arm passes through flexible hinge connection moving part; the SMA wire is connected with the elastic part of the elastic actuating arm, and an included angle is formed between the axial direction of the SMA wire and the direction of the actuating end; the actuating force generated by the heated contraction of the SMA wire is transmitted to the moving part through the elastic actuating arm and the flexible hinge, so that the moving part moves, and the flexible hinge provides follow-up deformation. The utility model discloses the size is little to effectively simplified the drive structure, utilized the follow-up deformation that flexible hinge gave simultaneously to match the motion, reduce frictional resistance and loss, promote driven precision and accuracy, obtain the performance of better driving lens along the optical axis motion, the practicality is strong, accords with the industry and utilizes widely.

Description

SMA actuator and lens automatic focusing device

Technical Field

The utility model belongs to the technical field of the electronic equipment technique and specifically relates to a realize camera lens motion actuator.

Background

With the development and popularization of portable electronic devices such as mobile phones and tablet computers, the requirement for the camera function attached to the portable electronic devices is relatively increased. In order to focus and zoom the lens, a driving device needs to be disposed in a small space of the lens to drive the lens to move along the optical axis. The space is small, which limits the types of drive mechanisms that can be used. In the lens in the prior art, the driving is mainly realized by using a magnet and coil structure, but the structure is relatively complex, the volume is difficult to reduce, and the requirement of product miniaturization cannot be met.

A drive scheme has subsequently emerged in which the actuation force is provided by Memory alloy (SMA) wires which are characterized by thermal contraction. The present applicant earlier proposed a driving device for lens auto-focusing in chinese patent No. 201911097795.1, which comprises two driving arms, an SMA wire and two conductive supports, wherein the conductive supports are fixed on a support module and electrically connected to a control system of the lens, the conductive supports are provided with openable elastic arms, the two driving arms and the SMA wire form a movable triangular relationship, two ends of the SMA wire are respectively connected to the elastic arms on the two conductive supports, one end of the driving arm is connected to the elastic arm corresponding to the conductive support, and the other end of the driving arm is hinged to a moving part. When the structure works, the actuating force obtained by the heating shrinkage of the SMA wire is utilized, and the actuating force is transmitted through the elastic arm and the actuating arm and then acts on the moving part, so that the focusing, zooming and other work of the lens are achieved. However, in the operation process, because the hinge joint of the driving arm and the moving part is an action point, when the moving part moves, the driving arm also rotates relatively to generate friction, thereby also influencing the precision and accuracy of driving.

Disclosure of Invention

An object of the utility model is to provide a SMA actuator solves above-mentioned technical problem well, and simple structure satisfies the miniaturized requirement of product, obtains the performance of better drive lens along the motion of optical axis.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

an SMA actuator comprising: a resilient actuator arm and an SMA wire, wherein,

the elastic actuating arm is provided with a fixed end, an actuating end and an elastic part, the elastic part is positioned between the fixed end and the actuating end, the elastic actuating arm is positioned and installed through the fixed end, and the actuating end of the elastic actuating arm is connected with the moving part through a flexible hinge;

the SMA wire is connected with the elastic part of the elastic actuating arm, and an included angle is formed between the axial direction of the SMA wire and the direction of the actuating end; the actuating force generated by the heating contraction of the SMA wire is transmitted to the moving part after sequentially passing through the elastic part, the actuating end and the flexible hinge, so that the moving part moves, and the flexible hinge provides follow-up deformation.

In the above scheme, the number of the elastic actuating arms is two, two ends of the SMA wire are respectively connected to the elastic parts of the two elastic actuating arms, and the actuating ends of the two elastic actuating arms point to intersect and are respectively connected to the moving part through the flexible hinges, so that the two elastic actuating arms and the SMA wire form a triangular relationship.

In the above solution, the flexible hinge is integrally formed with the elastic actuator arm, and a narrowing design is partially formed at an actuating end of the elastic actuator arm, so as to obtain the flexible hinge.

The flexible hinge and the elastic actuating arm are manufactured separately, and two ends of the flexible hinge are riveted, welded, locked by screws or adhered to the actuating end of the elastic actuating arm and the moving part respectively.

Further, the elastic portion of the elastic actuator arm may be bent into a U-shape, a V-shape, or a W-shape.

An automatic focusing device for lens, comprising:

a support structure;

a moving part with a lens thereon, the moving part being assembled on the support structure and being movable relative to the support structure along an optical axis of the lens; and

at least one SMA actuator, wherein the SMA actuator comprises an elastic actuating arm and an SMA wire, a fixed end of the elastic actuating arm is positioned and installed on the supporting structure and gives the SMA wire an electrical connection, and an actuating end of the elastic actuating arm is connected with the moving part through a flexible hinge; the SMA wire is connected with the elastic part of the elastic actuating arm, and an included angle is formed between the axial direction of the SMA wire and the direction of the actuating end; the actuating force generated by the heating contraction of the SMA wire is transmitted to the moving part after sequentially passing through the elastic part, the actuating end and the flexible hinge, so that the moving part moves, and the flexible hinge provides follow-up deformation.

The utility model utilizes the characteristic that the SMA (shape Memory alloys) wire is heated and contracted, is used for manufacturing the actuator of the lens module of the mobile phone or the tablet personal computer, has small size, effectively simplifies the driving structure, meets the miniaturization requirement of the product, has light and compact product structure and reduces the manufacturing cost; meanwhile, the actuating end of the elastic actuating arm is connected with the moving part through the flexible hinge, the follow-up deformation given by the flexible hinge is utilized to match the movement, the friction resistance and the loss are reduced, the driving precision and accuracy are improved, the better performance of driving the lens to move along the optical axis is obtained, the practicability is high, and the industrial popularization and utilization are met.

Description of the drawings:

FIG. 1 is a schematic structural diagram of a preferred embodiment of the present invention;

FIG. 2 is an exploded view of the embodiment of FIG. 1;

FIG. 3 is a schematic view of the embodiment of FIG. 1 showing the flexible hinge and the resilient actuator arm integrally formed;

FIG. 4 is a schematic diagram of an assembled embodiment of the embodiment of FIG. 1;

FIG. 5 is a schematic diagram of the embodiment of FIG. 1 in two-component implementation.

The specific implementation mode is as follows:

the conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings, so as to fully understand the objects, the features and the effects of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Referring to fig. 1, 2 and 3, which are schematic views of a preferred embodiment of the present invention, the present invention relates to an SMA actuator, which includes an elastic actuating arm 1 and an SMA wire 2, wherein the elastic actuating arm 1 has a fixed end 11, an actuating end 12 and an elastic portion 13, the elastic portion 13 is located between the fixed end 11 and the actuating end 12, and the elastic portion 13 can be designed into a U shape, a V shape or a W shape as required to obtain the corresponding characteristics of opening and recovering. The elastic actuator arm 1 of the present embodiment is made of a metal sheet, the elastic actuator arm 1 is positioned and installed by a fixed end 11, and an actuating end 12 of the elastic actuator arm is connected with a moving part by a flexible hinge 3. The SMA wire 2 is connected with the elastic part 13 of the elastic actuating arm, an included angle is formed between the axial direction of the SMA wire 2 and the direction of the actuating end 12, and the included angle is preferably an acute angle, so that actuating force generated by heating and shrinking of the SMA wire is sequentially transmitted to the moving part after passing through the elastic part 13, the actuating end 12 and the flexible hinge 3, the moving part is made to move, the flexible hinge 3 provides follow-up deformation to perform matching movement, the friction resistance and the loss are reduced, the use is prolonged, the driving precision and accuracy are improved, better performance of driving the lens to move along the optical axis is obtained, the practicability is high, and the industrial popularization and utilization are met.

Referring to fig. 1 and 2, the SMA actuator of this embodiment includes two elastic actuation arms 1, two ends of the SMA wire 2 are respectively connected to the elastic portions 13 of the two elastic actuation arms, and the actuation ends 12 of the two elastic actuation arms are oriented to intersect and are respectively connected to the moving part through the flexible hinges 3, so that the two elastic actuation arms and the SMA wire form a triangular relationship. When the device works, actuating force generated by heating contraction of the SMA wire 2 is transmitted to the moving part from two ends of the SMA wire sequentially through the elastic parts 13 of the two elastic actuating arms, the actuating ends 12 and the flexible hinges 3 to obtain equidirectional pushing force, so that the moving part moves towards the appointed direction, the flexible hinges 3 provide follow-up deformation to perform matching movement, and friction resistance and loss are reduced.

Referring to fig. 1 and 2, in the embodiment, the flexible hinge 3 and the elastic actuating arm 1 are manufactured separately, and two ends of the flexible hinge 3 are riveted, welded, locked with screws or adhered to the actuating end 12 of the elastic actuating arm and the moving part respectively. Of course, it is also possible to make the flexible hinge 3 integrally with the elastic actuator arm 1, as shown in fig. 3, and to make a narrowing on the actuating end of the elastic actuator arm, so as to obtain the flexible hinge 3. When the flexible hinge works, the flexible hinge 3 provides follow-up deformation to match movement, friction between the elastic actuating arm and a moving part is reduced, and the flexible hinge works stably and reliably and is controlled more accurately.

Referring to fig. 4 and 5, the present invention further provides an automatic focusing apparatus for a lens, which comprises a supporting structure 100, a moving part 200, a lens (not shown) on the moving part 200, wherein the moving part 200 is assembled on the supporting structure 100 and can move along an optical axis of the lens relative to the supporting structure. And at least one SMA actuator, wherein the SMA actuator comprises an elastic actuating arm 1 and an SMA wire 2, a fixed end 11 of the elastic actuating arm is positioned and installed on the supporting structure 100 and electrically connected with the SMA wire 2, so that the SMA wire 2 is electrically heated and actuated, and an actuating end 12 of the elastic actuating arm is connected with the moving part 200 through the flexible hinge 3; the SMA wire 2 is connected with the elastic part 13 of the elastic actuating arm, and the axial direction of the SMA wire forms an included angle with the direction of the actuating end, thereby meeting the actuating requirement. When the actuating force generated by the heated contraction of the SMA wire 2 passes through the elastic part 13, the actuating end 12 and the flexible hinge 3 in sequence and is transmitted to the moving part 200, the moving part 200 moves, and the flexible hinge 3 provides follow-up deformation, so that the friction between an elastic actuating arm and the moving part is reduced.

In the present embodiment, shown in fig. 5, the SMA actuator assembled between the support structure 100 and the moving part 200 satisfies the requirement of forward and backward movement of the moving part 200, and is operated separately to meet the lens focusing requirement on the moving part 200. Of course, different numbers or different movement directions of SMA actuators may be arranged on multiple sides of the periphery of the moving member 200 as needed to achieve adjustment of lens focus, deflection, etc. on the moving member 200, and thus, no description is given here.

Although the preferred embodiments of the present invention have been described in connection with the accompanying drawings, the present invention should not be limited to the exact construction and operation as described and illustrated, and many equivalent modifications and variations of the above-described embodiments may be made by logical analysis, reasoning or limited experimentation by those skilled in the art without departing from the spirit and scope of the present invention, which should fall within the scope of the claims.

Claims

1. An SMA actuator, comprising: a resilient actuator arm and an SMA wire, wherein,

2. The SMA actuator according to claim 1, wherein there are two resilient actuator arms, and two ends of the SMA wire are connected to the resilient portions of the two resilient actuator arms, respectively, and the actuating ends of the two resilient actuator arms are oriented in a cross and are connected to the moving part via flexible hinges, respectively, such that the two resilient actuator arms and the SMA wire form a triangular relationship.

3. An SMA actuator according to claim 1 or 2, wherein the flexible hinge is made integral with the resilient actuator arm, with a local narrowing at the actuating end of the resilient actuator arm, to obtain the flexible hinge.

4. An SMA actuator according to claim 1 or 2, wherein the flexible hinge is made separately from the resilient actuator arm, and the two ends of the flexible hinge are riveted, welded, screwed or glued to the actuating end of the resilient actuator arm and the moving part, respectively.

5. An SMA actuator according to claim 1, wherein the spring bends of the resilient actuating arms are U-shaped, V-shaped or W-shaped.

6. The automatic focusing device of the lens is characterized by comprising the following components:

a support structure;

the SMA actuator comprises an elastic actuating arm and an SMA wire, wherein the fixed end of the elastic actuating arm is positioned and arranged on the supporting structure and is electrically connected with the SMA wire, and the actuating end of the elastic actuating arm is connected with the moving part through a flexible hinge; the SMA wire is connected with the elastic part of the elastic actuating arm, and an included angle is formed between the axial direction of the SMA wire and the direction of the actuating end; the actuating force generated by the heating contraction of the SMA wire is transmitted to the moving part after sequentially passing through the elastic part, the actuating end and the flexible hinge, so that the moving part moves, and the flexible hinge provides follow-up deformation.