Actuator assembly

Abstract

A shape memory alloy actuator assembly comprising: a support member wherein a first plane is defined relative to the support member; a movable member movable relative to the support member in at least two different non-parallel directions within the first plane; more than one unit of shape memory alloy wire, each unit connected between the movable member and the support member so as to be capable of being driven to produce motion in at least two directions without applying any net torque to the movable member within the first plane; wherein at least one of the units comprises a series of two or more lengths of shape memory alloy wire, the shape memory alloy wire comprising a first section and a second section, wherein the first section and the second section are oriented at a non-zero angle relative to each other and are coupled to each other such that when the unit is driven, contraction of the first section causes displacement of the second section, which provides a contribution to the motion of the movable member in addition to the contribution provided by contraction of the second section.

Description

Technical Field

[0001] The present application relates to an actuator assembly, and more particularly to an actuator assembly comprising a plurality of lengths of shape memory alloy (SMA) wire. Background Art

[0002] For example, such an actuator assembly may be used in a camera to move a lens assembly in a direction perpendicular to the optical axis, thereby providing optical image stabilization (OIS). Where such a camera is to be incorporated into a portable electronic device such as a mobile phone, miniaturization may be important.

[0003] WO 2019 / 086855 A1 describes a camera with an actuator assembly, which includes a supporting platform, a moving platform supporting a lens assembly, an SMA wire connected to the supporting platform and the moving platform, a support member supporting the moving platform on the supporting platform, and two arms extending between the supporting platform and the moving platform. Summary of the Invention

[0004] According to a first aspect of the present invention, there is provided a shape memory alloy actuator assembly, comprising:

[0005] a support member, wherein a first plane is defined relative to the support member;

[0006] a movable member movable relative to the support member in at least two different non-parallel directions within a first plane;

[0007] more than one unit of shape memory alloy wire, each unit connected between the movable member and the support so as to be actuatable to produce motion in at least two directions without applying any net torque to the movable member in a first plane;

[0008] wherein at least one of the cells comprises a series of two or more lengths of shape memory alloy wire, the series of two or more lengths of shape memory alloy wire comprising a first section and a second section, wherein the first section and the second section are oriented at a non-zero angle relative to each other and are coupled to each other such that when the cell is actuated, contraction of the first section causes displacement of the second section, which provides a contribution to the motion of the movable member in addition to the contribution provided by contraction of the second section.

[0009] The term "shape memory alloy (SMA) wire" may refer to any element comprising an SMA. An SMA wire may have any shape suitable for the purposes described herein. The SMA wire may be elongated and may have a circular cross-section or any other cross-section. The cross-section may vary along the length of the SMA wire. The length of an SMA wire (however defined) may also be similar to one or more of its other dimensions. An SMA wire may be compliant, or in other words, flexible. In some examples, when connected in a straight line between two elements, the SMA wire can only exert a tensile force that pushes the two elements together. In other examples, the SMA wire can be bent around an element and, when the SMA wire tends to straighten under tension, can exert a force on the element. An SMA wire may be beam-shaped or rigid and may exert different (e.g., non-tensile) forces on an element. An SMA wire may or may not include non-SMA materials and / or components. For example, an SMA wire may include an SMA core and a coating of a non-SMA material. Unless the context requires otherwise, the term "SMA wire" may refer to any configuration of an SMA wire that functions as a single actuation element, e.g., one that can be individually controlled to generate a force on the element. For example, an SMA wire may include two or more SMA wire sections mechanically arranged in parallel and / or in series. In some arrangements, an SMA wire may be part of a larger SMA wire. Such a larger SMA wire may include two or more individually controllable sections, thereby forming two or more SMA wires.

[0010] The SMA wires can be formed from any suitable shape memory alloy material, typically a nickel-titanium alloy (e.g., Nitinol), which may also contain a third component such as copper. The SMA wires can have any cross-sectional profile and diameter suitable for the application. For example, the SMA wires can have a cross-sectional diameter of 25 μm, or 30 μm, or 35 μm, which is capable of generating a maximum force between 120 mN and 400 mN while keeping the strain in the SMA wire within safe limits (e.g., a length reduction of 2%-3% from the original length). Increasing the diameter of each SMA wire from 25 μm to 35 μm approximately doubles the cross-sectional area of the SMA wire and, therefore, approximately doubles the force provided by each SMA wire.

[0011] In some embodiments, an SMA actuator assembly includes a support and more than one movable component (e.g., one or more intermediate movable stages and a final movable stage) in a stacked (and / or nested) configuration. The final movable stage can be considered the movable component that provides the total travel of all other stages combined. More specifically, the SMA actuator assembly can include a plurality of stacked SMA actuator assemblies according to the first aspect. That is, the one or more stacked movable stages are each movable along a first plane relative to the support or an intermediate stage adjacent to the respective movable stage.

[0012] In embodiments where the SMA actuator assembly includes only one intermediate level and a final level, the intermediate level can be movable relative to the support and can itself form a support for the final level. For example, in such embodiments, the final level can move with the intermediate level and relative to the support structure (e.g., when only the intermediate level is moved), or the final level can move only relative to the intermediate level (e.g., when the intermediate level maintains its position relative to the support). The intermediate level can move relative to both the final level and the support, preferably in the same direction to achieve as much travel as possible in that direction.

[0013] Each level can move along a single axis or at least two non-parallel directions by contraction of the corresponding SMA wire. That is, in some embodiments where each level moves only on a discrete axis, X and Y movement can be independently controlled by the corresponding level.

[0014] Optionally, the more than one shape memory alloy wire unit includes two or four shape memory alloy wire units. Optionally, the more than one shape memory alloy wire unit is a paired unit. For example, one unit in a pair can be arranged in an opposite direction to the other unit in the pair. Advantageously, such an arrangement can reduce or eliminate net torque during operation.

[0015] The first segment and the second segment can be coupled to each other by a coupling component that is configured to move relative to the support and / or relative to the movable component to provide the coupling between the first segment and the second segment. The first segment and the second segment can be attached to the coupling component by any suitable means (e.g., a crimp and an adhesive). Alternatively, the first segment and the second segment can slide on the surface of the coupling component. That is, the first segment and the second segment of the shape memory alloy wire can be retained on the coupling component by tension in the shape memory alloy wire.

[0016] At least one of the coupling components may be connected to the support. At least one of the coupling components may be connected to the movable component. In some embodiments, a coupling component may be connected to the support and the other coupling component may be connected to the movable component.

[0017] At least one of the coupling components is included in and / or attached to a flexure that flexes in a first plane to provide a coupling between the first segment and the second segment. Advantageously, such an arrangement can eliminate friction that may be present in known actuators that allow the shape memory alloy wire to slide over protrusions or pulleys.

[0018] The flexure may comprise a first component which is subjected to tension when the flexure is flexed in a first plane and a second component which is subjected to compression when the flexure is flexed in the first plane. The second component of the flexure may have a higher stiffness than the first component of the flexure. The first and second components of the flexure may be located in the same plane. The second component may be a rigid frame. For example, the first and second components of the flexure may extend at least partially in parallel and be joined together at one end of the flexure. Upon actuation, the first component may be placed in tension, causing it to bend, thereby compressing the second component of the flexure. Such an arrangement may advantageously allow the flexure to rotate on its own, thereby reducing the space required to accommodate the flexure. That is, the second flexure component rotates about the first flexure component to effect movement in the coupling component.

[0019] The flexure may include a component that is generally subjected to compression when the flexure flexes in a first plane. The component has a higher compliance in the first plane than in a direction perpendicular to the first plane. The component may have a cross-section that is elongated in a direction perpendicular to the first plane.

[0020] The assembly may include at least one stack of two flexures, wherein the flexures in the stack are spaced apart from one another in a direction perpendicular to the first plane. More specifically, the flexures are stacked in a direction perpendicular to the first plane. Advantageously, such an arrangement can reduce the footprint of the flexures and the coupling components, and can allow other components to be placed within a confined space.

[0021] Optionally, the assembly may further include a spacer sandwiched between the coupling components of the corresponding flexures in each stack, wherein the spacer is configured to prevent (e.g., limit) excessive flexural movement in a direction perpendicular to the first plane. The spacer may abut one or both of the coupling components, for example, the coupling component may slide on a surface of the spacer. Such an arrangement may allow for guided lateral movement in the coupling components.

[0022] Alternatively, a gap can be provided between the spacer and the coupling components. That is, in such an arrangement, the spacer does not guide the movement of the coupling components, but instead acts as an end stop in the event of sudden movement. For example, in the event of a sudden drop, the coupling components can be prevented from colliding with each other.

[0023] Optionally, the spacer may further include an end stop for limiting excessive flexural motion in a first plane (e.g., the motion plane). That is, the spacer may extend in a portion of the motion path of the coupling member and / or the first or second flexure member and thereby define the extreme motion in the coupling member and / or minimize damage in the event of sudden motion.

[0024] Alternatively, the flexures do not overlap when viewed perpendicular to the first plane. That is, the flexures may not be stacked. Instead, the flexures may be substantially evenly distributed in the first plane around the center of the support member and / or movable component. In some embodiments, at least portions of the flexures may extend in the same plane. Advantageously, such an arrangement can reduce the height of the assembly, thereby resulting in a thinner, more compact actuator.

[0025] Optionally, the flexure includes at least two portions arranged perpendicular to one another, the at least two portions including a first planar portion and a second portion, the first planar portion being configured to flex in a first plane, and the second portion being configured to resist deformation in the first plane. More specifically, the first planar portion may be an elongated member having a minimum dimension extending in the first plane. Advantageously, the stiffness of the flexure can be specified by varying the thickness of the first planar portion.

[0026] Optionally, the second portion is a planar portion. Optionally, the second planar portion may provide an attachment surface for attachment to a support or movable component.

[0027] Alternatively, the first planar portion and the second portion may be integrally formed from a single sheet of metal. For example, the flexure may be formed by cutting or stamping the sheet metal to shape before bending along a predetermined line to form the vertically arranged portion. Advantageously, this arrangement may allow for a simplified manufacturing process.

[0028] Alternatively, the flexure may be formed by welding or adhering together separate first and second planar portions.

[0029] Optionally, the first flexure member includes a void, or a thinned or thickened section, for modifying the stiffness of the first flexure member. The first flexure member may include one or more flexure members, with a void, thinned section, or thickened section adjacent to each flexure member. The first flexure member may include one or more voids, thinned sections, or thickened sections to provide different local stiffnesses. The voids, thinned sections, or thickened sections may be formed by etching or stamping. Advantageously, the desired stiffness of the flexure member can be achieved by varying the size of the voids.

[0030] Optionally, the coupling component comprises a groove extending substantially in the first plane for accommodating the shape memory alloy wire. Advantageously, the groove may help retain the shape memory alloy wire on the surface of the coupling component.

[0031] Optionally, the connector component includes a wire capture component for accommodating the shape memory alloy wire, the wire capture component including a groove extending substantially in the first plane. Optionally, when viewed in a direction perpendicular to the first plane, the wire capture component includes multiple radii, and the wire capture component has a largest radius toward the periphery of the wire capture component. More specifically, along the length of the groove, the curvature can be largest toward the midpoint and gradually decrease toward the ends of the groove. Advantageously, such an arrangement can reduce the degree of bending in the portion of the shape memory alloy wire adjacent to the edge of the connector component during actuation.

[0032] Optionally, the wire capture component is formed from two stacked components, wherein the groove is defined at an interface between the two stacked components.Alternatively, the groove may be formed by etching a surface of the coupling component.

[0033] Optionally, one or each of the stacked components includes an outwardly extending tab, wherein the tab is configured to connect to a corresponding tab of the preassembled frame, wherein the connection is detachable during the assembly process. The tab can be severed by mechanical cutting or laser cutting. In some embodiments, the preassembled frame can include more than one connector component (and flexure), wherein the use of the preassembled frame can allow for efficient and precise alignment of the connector components during the assembly process. Advantageously, providing the outwardly extending tab can reduce physical and thermal damage to the shape memory alloy wire when the connection is severed during the cutting process.

[0034] Optionally, the shape memory alloy wire is adhered to the coupler component at an adhesion point distal to the perimeter of the wire capture component. More specifically, the shape memory alloy wire is adhered to the coupler component at a location along the length of the groove toward the midpoint. Advantageously, by allowing the shape memory alloy wire to freely move toward the edges of the groove, such an arrangement can reduce the likelihood of sharp bends forming in the shape memory alloy wire during actuation, thereby improving reliability and actuator performance.

[0035] Optionally, the line capture component comprises at least one recess near the adhesion point for accommodating excess adhesive. That is, a receiving portion may be provided in the groove for receiving and accommodating overflowing adhesive during assembly.

[0036] The movable member may have a generally quadrilateral shape; each of the more than one units may include the first segment and the second segment; and each of the first segment and the second segment may be arranged along an outer edge of the movable member and may overlap with the other of the first segment and the second segment. Each of the first segments may be connected to the support via a first connector, and each of the second segments may be connected to the movable member via a second connector; the first connector and the second connector may be located at a first pair of diagonally opposite corners of the movable member; and the first segment and the second segment may be coupled to each other at a second, different pair of diagonally opposite corners of the movable member.

[0037] Alternatively, each of the first segments is connected to the support via a first connector, and each of the second segments is connected to the movable part via a second connector; the first connector and the second connector may be located at diagonally opposite corners of the movable part; the first segment and the second segment are coupled to each other at different pairs of diagonally opposite corners of the movable part.

[0038] The assembly may comprise a stack of two flexures located at each of the second diagonal corners.

[0039] Each of the four units may be composed of a single shape memory alloy wire.

[0040] Each of the four units may be composed of a first shape memory alloy wire corresponding to a first segment and a second shape memory alloy wire corresponding to a second segment.

[0041] At least one of the coupling members may be connected to a lever.

[0042] Optionally, at least one of the coupling components does not move in translation (eg, is fixed or only rotates).

[0043] According to a second aspect of the present invention, there is provided a method of producing an assembly according to the first aspect, comprising:

[0044] providing a subassembly comprising a subassembly frame coupled to more than one coupler;

[0045] aligning the coupler to its predetermined position on the support and / or movable member and attaching it thereto;

[0046] Cutting the connection between the subassembly frame and the coupler;

[0047] Remove the subassembly frame to form the assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Certain embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0049] Figure 1 is a schematic cross-sectional view of a camera including an SMA actuator assembly;

[0050] Figure 2 yes Figure 1 a top plan view of the illustrated SMA actuator assembly;

[0051] Figure 3 yes Figure 1 a top angled view of the illustrated SMA actuator assembly;

[0052] Figure 4 yes Figure 1 An exploded perspective view of the illustrated SMA actuator assembly unfolded along the optical axis O;

[0053] Figure 5A and Figure 5B yes Figure 1 A top plan view of the SMA wires and components connected to the SMA wires of the illustrated actuator assembly;

[0054] Figure 6A and Figure 6B They are included in Figure 1 a top plan view and a top angled view of a lower coupler in the illustrated SMA actuator assembly;

[0055] Figure 7 yes Figure 1 a top angled view of a stack of two of the couplers included in the illustrated SMA actuator assembly;

[0056] Figure 8A and Figure 8B are a perspective view and a side plan view, respectively, of a stack of two of the couplings according to a second embodiment of the present invention;

[0057] Figure 9 is a perspective view of one of the couplings according to the third embodiment of the present invention.

[0058] Figure 10A 、 Figure 10B and Figure 10C are a plan view, a perspective view, and a side sectional view, respectively, of a stack of two of the couplings according to a fourth embodiment of the present invention;

[0059] Figure 10Dand Figure 10E They are Figures 10A-10C an enlarged plan view of the wire capture member of the coupling and a lower portion of the wire capture member;

[0060] Figure 10F and Figure 10G They are connected to Figures 10A-10E an enlarged plan view and an enlarged perspective view of a subassembly frame of the wire capture component of the coupling shown;

[0061] Figure 10H 、 Figure 10I and Figure 10J They are Figures 10A-10G a perspective view, an enlarged side sectional view, and an enlarged plan view of the actuator assembly shown;

[0062] Figure 11A and Figure 11B Perspective views of couplings according to fifth and sixth embodiments of the present invention, respectively;

[0063] Figure 12 is a perspective view of a coupling according to a seventh embodiment of the present invention;

[0064] Figure 13A and Figure 13B are a perspective view and a side sectional view, respectively, of a coupling according to an eighth embodiment of the present invention;

[0065] Figure 14A and Figure 14B are a plan view and an exploded perspective view, respectively, of an SMA actuator according to a ninth embodiment of the present invention; and

[0066] Figure 14C and Figure 14D They are Figure 14A and Figure 14B A perspective view of two adjacent corners of an SMA actuator. DETAILED DESCRIPTION

[0067] camera

[0068] Reference Figure 1 , a camera 1 is shown including an SMA actuator assembly 2 (also referred to herein as an "SMA actuator" or simply "actuator").

[0069] The camera 1 includes a lens assembly 3 suspended from a support structure 4 by an SMA actuator assembly 2 that supports the lens assembly 3 in a manner that allows movement of the lens assembly 3 relative to the support structure 4 in a direction perpendicular to an optical axis O.

[0070] The support structure 4 includes a base 5. An image sensor 12 is mounted on the front side of the base 5. An integrated circuit (IC) 7 (in which a control circuit is implemented) and a gyro sensor 8 are mounted on the back side of the base 5. The support structure 4 also includes a container 9 that protrudes forward from the base 5 to enclose and protect the other components of the camera 1.

[0071] The lens assembly 3 comprises a lens holder 10 in the form of a cylindrical body supporting two lenses 11 arranged along an optical axis O. Generally, any number of one or more lenses 11 may be included. Preferably, each lens 11 has a diameter of at most about 20 mm. Therefore, the camera 1 may be referred to as a miniature camera.

[0072] The lens assembly 3 is arranged to focus the image onto an image sensor 12. The image sensor 12 captures the image and may be of any suitable type, for example a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor) device.

[0073] The lenses 11 are supported on the lens holder 10 such that the lenses 11 are movable relative to the lens holder 10 along the optical axis O, for example, to provide focusing or zooming. Specifically, the lenses 11 are fixed to a lens carrier 13 that is movable relative to the lens holder 10 along the optical axis O. Although all of the lenses 11 are fixed to the lens carrier 13 in this example, typically, one or more of the lenses 11 may be fixed to the lens holder 10 and thus unable to move relative to the lens holder 10 along the optical axis O, leaving at least one lens 11 fixed to the lens carrier 13.

[0074] An axial actuator arrangement 14 disposed between the lens holder 10 and the lens carrier 13 is arranged to drive the lens carrier 10 and the lens 11 to move relative to the lens holder 10 along the optical axis O. The axial actuator arrangement 14 may be of any suitable type, for example a voice coil motor (VCM) or an SMA wire arrangement.

[0075] In operation, the lens assembly 3 moves relative to the image sensor 12 orthogonally to the optical axis O, with the effect that the image on the image sensor 12 is moved. This serves to provide optical image stabilisation (OIS), compensating for movement of the camera 1 which may be caused by hand shake or the like.

[0076] Actuator assembly

[0077] Now refer to Figures 2 to 7 , the SMA actuator assembly 2 will now be described in more detail.

[0078] Specific reference Figures 2 to 4 The actuator assembly 2 includes a supporting platform 21 and a moving platform 23 .

[0079] Each of the support platform 21 and the mobile platform 23 generally takes the form of a flat, thin ring having a rectangular outer edge (or "perimeter edge") and a circular inner edge. The outer edge of the mobile platform 23 is located inside the outer edge of the support platform 21, but the inner edges of the platforms 21, 23 generally have the same extent.

[0080] The mobile platform 23 supports the lens assembly 3 ( Figure 1 ), and connected to the lens holder 10 ( Figure 1 ).

[0081] The support platform 21 is formed of two separate parts, namely a support part 24 and a conductive part 25 , which are fixed to each other.

[0082] The actuator assembly 2 may include a base member 26 that is fixed to the support platform 21 and to the camera 1 ( Figure 1 )'s base 5( Figure 1 ).

[0083] Each of the moving platform 23, the support member 24 and the conductive member 25 may take the form of a patterned metal sheet, such as etched or machined stainless steel. The support member 24 may be coated with an electrically insulating dielectric material.

[0084] Other example configurations may be used, and further details are provided in WO 2017 / 055788 A1 and WO 2019 / 086855 A1, which are incorporated herein by this reference.

[0085] The supporting platform 21, the moving platform 23 and the base member 26 are respectively provided with corresponding central holes aligned with the optical axis O, allowing light to pass through the lens assembly 3 ( Figure 1 ) by reaching the image sensor 12 ( Figure 1 ).

[0086] The movement of the mobile platform 23, and therefore the lens assembly 3, relative to the support platform 21 is driven by a lateral actuation arrangement comprising four SMA wires 27 (ie, SMA wires 270 and 272-274).

[0087] The supporting platform 21 includes a first set of four crimping parts 31 (hereinafter referred to as "static crimping parts"), namely static crimping parts 310-313. The moving platform 23 includes a second set of four crimping parts 33 (hereinafter referred to as "moving crimping parts"), namely moving crimping parts 330 and 332-334.

[0088] The first and second sets of crimping portions 31 and 33 crimp four SMA wires 27 to connect them to the support platform 21 and the moving platform 23. The SMA wires 27 may be perpendicular to the optical axis O or tilted at a small angle relative to a plane perpendicular to the optical axis O.

[0089] The crimping portions 31 , 33 are provided with respective arms which extend generally inwardly to landing points on the respective platforms 21 , 23 to which the arms are suitably attached.

[0090] Each SMA wire 27 comprises a first segment 27 A and the second paragraph 27 B The first segment and the second segment are oriented at an angle of ˜90° relative to each other. The first segment 27 A and the second paragraph 27 B The first and second segments 27 are coupled to each other via couplings 32 (also referred to herein as "flexure pulley couplings"). Each coupling 32 connects the first segment 27 to the second segment 27. A , 27 B When the SMA wire 27 is driven, the first section 27 A Contraction causes the second paragraph 27 B This provides the displacement of the second segment 27 B The contribution to the movement of mobile platform 23 is in addition to the contribution to the movement of mobile platform 23 provided by the contraction.

[0091] As will be described in more detail below, the coupling 32 has a component 32c ( Figure 7 ) to provide such a connection between the first segment and the second segment.

[0092] This “shrinkage attachment” is described in more detail in WO 2018 / 206768 A1, which is incorporated herein by this reference.

[0093] Thus, the operation of the SMA actuator assembly 2 is comparable to that described in WO 2013 / 175197 A1, except that the length of each SMA wire 27 is multiplied, for example to approximately 2 times (without significantly increasing the footprint), and therefore the range of lateral motion (or "stroke") perpendicular to the optical axis O is increased to the same or a similar multiple.

[0094] Special References Figure 5A and Figure 5B The arrangement of the SMA wire 27 , the static crimp 31 , the coupler 32 , and the moving crimp 33 will now be described in more detail.

[0095] A pair of static crimping portions 31 and a pair of moving crimping portions 33 are located at each of a first pair of diagonally opposite corners (also referred to herein as “crimping corners”) of the moving platform 23 .

[0096] A pair of couplers 32 is located at each of a second, different pair of diagonally opposed corners (also referred to herein as “coupler corners”) of the mobile platform 23 .

[0097] The first section 27 of each SMA wire 27 A The second section 27 of each SMA wire 27 is connected to the static crimping portion 31 at one end thereof, extends along at least a portion of the outer edge of the moving platform 23, and is engaged with the connector 32 at the other end thereof. B It is engaged with the coupling 32 at one end thereof, extends along at least a portion of the adjacent outer edge of the moving platform 23 , and is connected to the moving crimping portion 33 at the other end thereof.

[0098] Therefore, the first paragraph 27 A and the second paragraph 27 B Each of the first paragraph 27 A and the second paragraph 27 B The other one overlaps along the outer edge of the moving platform 23.

[0099] The elements holding the SMA wire 27 (ie, the static crimp 31, the coupler 32, and the moving crimp 33) are configured so that the first section 27 on the same side of the actuator 2 is A and the second paragraph 27 B The static crimping portions 31 are spaced apart from each other vertically (i.e., in a direction along the optical axis O) and to some extent laterally (i.e., in a direction away from the optical axis O). In this example, this is achieved by vertically stacking the pairs of connectors 32, as described below. At the same time, all the static crimping portions 31 are located at the same height (i.e., at the same position along the z-axis), and all the moving crimping portions 33 are located at the same height, and the moving crimping portions 33 are located on a smaller diameter (i.e., closer to the optical axis O) than the static crimping portions 31.

[0100] In operation, the SMA wires 27 are selectively driven to move the mobile platform 23 in any lateral direction (ie, perpendicular to the optical axis O) relative to the support platform 21 .

[0101] Further details are also provided in WO 2013 / 175197 A1, which is incorporated herein by this reference.

[0102] The position of the lens assembly 3 relative to the support structure 4 perpendicular to the optical axis O ( Figure 1 ) is controlled by selectively varying the temperature of the SMA wire 27. This is accomplished by passing a selective drive signal that provides resistive heating through the SMA wire 27. Heating is provided directly by the drive current. Cooling is provided by reducing or stopping the drive current to allow the SMA wire 27 to cool by conduction, convection, and radiation with its surroundings.

[0103] When one of the SMA wires 27 is heated, the stress in the SMA wire 27 increases and the SMA wire 27 contracts, causing movement of the lens assembly 3. As the SMA temperature increases, a series of movements occur within the temperature range where the SMA material transitions from the martensite phase to the austenite phase. Conversely, when one of the SMA wires 27 is cooled to reduce the stress in the SMA wire 27, the SMA wire 27 expands under the force of the opposing SMA wire 27. This allows the lens assembly 3 ( Figure 1 ) moves in the opposite direction.

[0104] The SMA wire 27 may be made of any suitable SMA material, such as Nitinol or another titanium alloy SMA material.

[0105] The drive signal for the SMA wire 27 is generated and provided by the control circuit implemented in IC 7 ( Figure 1 The driving signal is generated by the control circuit in response to the gyro sensor 8 ( Figure 1 ) output signal is generated, thereby driving the movement of the lens assembly 3 to stabilize the lens assembly 3 ( Figure 1 ) in the image sensor 12( Figure 1 ) to provide OIS. The drive signal can be generated using a resistive feedback control technique, for example, as described in WO 2014 / 076463 A1, which is incorporated herein by reference.

[0106] Special References Figure 4 , the actuator assembly 2 includes four planar supports 50 spaced about the optical axis O to support the moving platform 23 on the support platform 21. Generally, a different number of supports 50 may be used. Preferably, at least three supports 50 are used to help provide stable support.

[0107] Each planar support 50 comprises a support member, which in this case is cylindrical. The support member can be secured to the support platform 21, for example, by adhesive. In this case, a surface 52 of the support member on the side opposite the support platform 21 (the "upper surface") and a surface (not shown) of the mobile platform 23 (the "lower side" or "downward-facing side") are planar, conforming surfaces in contact with each other. Alternatively, the support member can be secured to the mobile platform 23.

[0108] The contact between the conforming surfaces thus supports and bears the mobile platform 23 on the supporting platform 21, allowing relative movements parallel to their extension (ie perpendicular to the optical axis O).

[0109] The support 50 may be made of a suitable metal or alloy, such as phosphor bronze with a diamond-like carbon coating or stainless steel.

[0110] The actuator assembly 2 also includes a set of four arms 60 connected between the support platform 21 and the moving platform 23. The arms 60 are resilient and are configured to provide an appropriate retention force along the optical axis O and also allow lateral movement with an appropriate lateral biasing force. The arms 60 also provide electrical connections from the support structure 21 to the moving platform 23.

[0111] In the assembled state of the actuator assembly 2, the arm 60 is deflected from its relaxed state so that the arm 60 provides a force (i.e., a holding force) that biases the platforms 21, 23 together and maintains contact in the planar support 50. At the same time, the arm 60 can be deflected laterally to allow the mobile platform 23 to move relative to the support platform 21 in a direction perpendicular to the optical axis O.

[0112] The arm 60 provides a force (ie, a lateral biasing force) that biases the moving platform 23, and thereby the lens assembly 3, toward the center position from any direction about the center position. Figure 1 ), where the center position corresponds to the image sensor 12 ( Figure 1 ) is substantially aligned with the optical axis O of the lens assembly 3. As a result, without adjusting the lens assembly 3 ( Figure 1 ) of the lateral movement of the drive, the lens assembly 3 ( Figure 1 ) will tend towards the center position from any direction around the center position. This ensures that the camera 1 still maintains normal image capture functionality even without actuation of the SMA wire 27. The magnitude of the lateral bias force is kept low enough so as not to interfere with OIS, while preferably high enough to keep the lens assembly 3 ( Figure 1 ) in the center.

[0113] Each arm 60 is generally "L"-shaped and extends about the optical axis O. The angular extent of each arm 60 is preferably at least 90° (measured between the end points of the arm 60).

[0114] In this example, the arm 60 is integrally formed with the mobile platform 23 at one end thereof and is connected to the support platform 21 at the other end of the mobile platform 23. Alternatively, the arm 60 may be integrally formed with the support platform 21 and connected to the mobile platform 23, or the arm 60 may be a separate part connected to both platforms 21, 23. The arm 60 may be connected to the plates 21, 23 by welding (providing both mechanical and electrical connections).

[0115] The arm 60 is made of a suitable material that provides the desired mechanical properties and is electrically conductive. Typically, the material is a metal with a relatively high yield strength, for example steel, such as stainless steel.

[0116] As shown, the arm 60 follows the outer edge of the mobile platform 23 .

[0117] Special References Figure 6A 、 Figure 6B and Figure 7 , the flexure pulley coupling 32 will now be described in more detail.

[0118] Each coupling 32 includes a first flexure member 32a and a second flexure member 32b. Each coupling 32 also includes a wire capture member 32c and a leg 32d.

[0119] A portion of the wire capture member 32c, the first flexure member 32a, the second flexure member 32b and the leg 32d are located in the same plane and may be formed from a metal plate.

[0120] As described above, the pair of couplers 32 are stacked vertically. The legs 32d of the lower coupler 32 are attached to the support platform 21, for example welded to an electrically insulating feature of the conductive component 25. The legs 32d of the upper coupler 32 are attached to the static component of the lower coupler 32, namely legs 32d.

[0121] The wire capture member 32c includes an upper plate, an arcuate inner wall, and a lower plate (these elements are not individually labeled in the drawings). The wire capture member 32c hooks the SMA wire 27, preventing inward lateral movement or upward or downward movement.

[0122] The radius of the arcuate inner wall is at least the minimum bending radius of the SMA wire 27 to ensure the safety feature of the SMA wire 27 contact.

[0123] The wire capture member 32c may be formed by welding the half-etched features of the crimp member (forming the upper plate and curved inner wall) to the first flexure member 32a (forming the lower plate and curved inner wall).

[0124] The first flexure member 32a extends laterally inwardly from the leg 32d, while the second flexure member 32b extends laterally inwardly from the line capture member 32c. The first flexure member 32a and the second flexure member 32b are connected to each other at their innermost ends.

[0125] When the length of the SMA wire 27 changes, causing the wire capture member 32c to move about the optical axis O (e.g., at a substantially constant distance from the optical axis O), the first flexure member 32a and the second flexure member 32b flex in the xy plane. As they do so, the first flexure member 32a experiences tension, while the second flexure member 32b experiences compression. To prevent buckling, the second flexure member 32b has a higher stiffness than the first flexure member 32a. In this example, this is achieved by having a relatively narrow first flexure member 32a positioned within two relatively wide arms that comprise the second flexure member 32b.

[0126] Each SMA wire 27 can be preassembled in a static crimp 31, a coupler 32, and a moving crimp 33. The preassembly can then be attached to the platforms 21, 23. This "off-site crimping" can be performed in a manner similar to that described in WO 2019 / 086854 A2, which is incorporated herein by reference.

[0127] Other variants

[0128] It will be appreciated that many other variations of the embodiments described above are possible.

[0129] The first and second segments of the wire may be oriented at an angle of less than about 90° relative to each other.

[0130] The coupling 32 may take different forms. For example, it may consist of a single flexure extending outwardly from the legs to the line capture member.

[0131] Instead of the described coupling, the coupling may be, for example, a rocker arm (or other type of lever) or a pin or a rotating pulley (or other type of coupling element that does not move in translation). An example of such a coupling is described in WO 2018 / 206768A1.

[0132] Instead of four SMA wires 27 (each wire comprising a first section 27 A and the second paragraph 27 B ), there can be eight SMA lines, each corresponding to the first segment 27 A or Section 27 B In this case, instead of the described wire capture member 32c, the coupling 32 may include a pair of crimping portions.

[0133] Instead of two paragraphs, the first paragraph 27 A and the second paragraph 27 B Each SMA wire 27 may include three or more segments. As described in WO 2018 / 206768 A1, these three or more segments may extend around three of the more sides of the actuator and may be appropriately separated from each other as described herein.

[0134] One or more of the couplers may be connected to the mobile platform.

[0135] The motion platform does not have to move only in the xy plane.

[0136] The actuator assembly need not be configured to support a lens assembly, and, for example, may be configured to support another type of optical element, an image sensor, etc. The platform need not include a hole.

[0137] This actuator assembly does not need to be used in the camera.

[0138] The z-axis does not necessarily correspond to the optical axis. The z-axis may correspond to a line perpendicular to a plane defined by the plane of the mobile platform and / or the support platform. The z-axis may correspond to a line perpendicular to a plane defined by the direction of movement of the mobile platform.

[0139] Other embodiments

[0140] Figure 8A and Figure 8B 132(above), 132(below) are functionally similar to the stacked connectors 132(above) and 132(below) according to the second embodiment of the present invention. Figure 7 The first embodiment of the corresponding couplings 32 (above) and 32 (below) is shown. For example, the couplings 132 each include a first flexure 132a and one or more second flexures 132b, as well as a line capture member 132c and a leg 132d. For the sake of simplicity, similar features are not described again.

[0141] Similar to the first embodiment, the wire capture member 132c includes an upper plate, an arcuate inner wall, and a lower plate that form a groove for receiving the SMA wire 127. The wire capture member 132c hooks the SMA wire 127, preventing inward lateral movement or upward or downward movement. The wire capture member 132c can be formed by welding half-etched features forming the lower plate and the arcuate inner wall to the first flexure member 132a (forming the upper plate and the arcuate inner wall). The radius of the arcuate inner wall is at least the minimum bend radius of the SMA wire 127 to provide a safety feature for contact with the SMA wire 127.

[0142] like Figure 8A and Figure 8B As shown, the wire capture member 132c includes a break between two discontinuous sections. More specifically, each second flexure member 132b is connected to one of the discontinuous sections of the wire capture member 132c, with the SMA wire 127 suspended between the two discontinuous sections. As shown, the two discontinuous sections have the same radius, but in other embodiments, they may have different radii. Thus, the discontinuous section of the wire capture member 132c may be an extension of the second flexure member 132b.

[0143] The second flexure member 132b is rigid, or at least stiffer, than the first flexure member 132a. Thus, when the SMA wire 127 is actuated, the second flexure member 132b and the wire capture member 132c can rotate relative to their respective legs 132d. That is, the second flexure member 132b can act as a lever for moving the movable member.

[0144] The removal of a portion of the wire capture member 132c reduces contact with the SMA wire 127. Thus, such an arrangement can reduce friction between the two components, thereby reducing energy consumption and wear.

[0145] Figure 9 2 is a perspective view of one of the couplers according to the third embodiment of the present invention. Coupler 232 is shown as a single coupler. Alternatively, it can be a lower coupler in a stack where a corresponding upper coupler is also present. Coupler 232 is similar in function to Figure 8A and Figure 8B The corresponding couplings 132 of the second embodiment are shown. For example, the couplings 232 each include a first flexure 232a and one or more second flexures 232b, as well as a line capture member 232c and legs 232d. For the sake of simplicity, similar features are not described again.

[0146] Similar to the second embodiment, the wire capture member 232c includes a break between two discontinuous sections. Figure 9 As shown, the first flexure member 232a extends through the gap between the two discontinuous sections of the wire capture member 232c. Thus, a longer first flexure member 232a can be employed, which advantageously allows for a wider range of rotational motion in the wire coupler member 232c. Furthermore, the first flexure member 232a can be constructed of a stiffer material to achieve a similar range of motion as the first embodiment (e.g., with a reduced degree of flexure).

[0147] Figure 10A 、 Figure 10B and Figure 10C are respectively a plan view, a perspective view and a side sectional view of a stack of two couplers according to a fourth embodiment of the present invention; the vertically stacked couplers 332 (upper), 332 (lower) are similar in function to Figure 7 The corresponding couplings 32(upper), 32(lower) of the first embodiment are shown, but have a different structure.

[0148] like Figure 10A 、 Figure 10B and Figure 10C As shown, each coupling 332(above), 332(below) includes a planar first flexure member 332a having a minimum dimension extending in the plane of motion (the XY plane), which allows it to flex only in the plane of motion. More specifically, the first flexure member 332a is compliant in the XY directions but resists movement in the Z direction.

[0149] Advantageously, while the various components of the coupling 332a are formed from the same material, this arrangement allows the stiffness of the flexure to be determined by the thickness of the first flexure member 332a. For example, a thicker first flexure member 332a will provide a greater biasing force in the XY plane, but will increase bending resistance. Therefore, it is preferable to provide a thin first flexure member to ensure its compliance in the XY direction.

[0150] The first flexure member 332 is integrally formed at each end with a vertically extending planar portion of the wire capture member 332c and the leg 332d. The second flexure arm is not represented in this embodiment. Due to the orientation of the planar wire capture member 332c and the leg 332d, they resist deflection in the plane of motion.

[0151] The coupling 332 may be formed from a single piece of material by bending along predetermined lines (or lines of weakness) between adjacent components. Advantageously, therefore, this arrangement may provide an efficient and economical manufacturing process.

[0152] If the actuator is placed under high impact conditions (e.g. a sudden drop), there is a risk that the flexure capacity in the first flexure member 332a will be damaged, particularly when the second flexure member 32b is not present in this embodiment. Therefore, the fourth embodiment also includes a pair of end stops 333, each end stop 333 anchored to a leg 332d of a respective connector 332. The end stop 333 is an elongated member sandwiched between the two line capture members 332a and extending in the same plane as the first flexure member 332a. The end stop 333 is preferably a rigid member, or at least stiffer than the first flexure member 332a. The end stop 333 is configured to define the endpoints of the range of motion in the first flexure member relative to the plane of motion, for example the endpoints being defined as points where the first flexure member 332a abuts the side of the end stop 333.

[0153] The end stop 333 is also configured to prevent damage to the actuator by limiting excessive axial movement in the inertia lower line capture member 332c.

[0154] exist Figure 10C In the illustrated example, the inward-facing surface of the wire capture member 332c is shown in contact with the end stop 333. In operation, the wire capture member 332c can slide over the surface of the end stop 333. Therefore, this contact does not hinder the lateral movement of the wire capture member 332c. In other embodiments, a small gap may exist between the wire capture member 332c and the end stop 333 to eliminate friction therebetween.

[0155] Figure 10D and Figure 10E They are Figure 10A 、 Figure 10B and Figure 10C An enlarged plan view of the wire capture member 332c and the lower portion 332cb of the coupling is shown. For example, the wire capture member 332c can be formed by welding or adhering the upper portion 332ca to the lower portion 332cb of the wire capture member. In other words, the groove for accommodating the shape memory alloy wire 327 can be formed by etching portions of each of the upper portion 332ca and the lower portion 332cb.

[0156] In the illustrated embodiment, the SMA wire 327 is adhered to the wire capture component 332c to eliminate slippage between the two components. Preferably, the SMA wire 327 is adhered toward the center area of the groove so that the portion of the SMA wire 327 toward the periphery of the groove can remain freely movable during operation. To facilitate this process, the upper portion 332ca is provided with a cutout 335a so that adhesive (or solder) can be more easily applied to the SMA wire 327 in the assembled wire capture component 332c. In addition, the upper portion 332ca and the lower portion 332cb are provided with a hole 335b and a recess 335c, respectively, to capture and retain excess adhesive during the bonding process.

[0157] like Figure 10D and Figure 10E As shown in the plan view of FIG, the groove in the wire capture component 332c includes multiple radii. That is, the groove can have a smaller radius toward its central portion and a larger radius toward its periphery. Such an arrangement ensures that the portion of the SMA wire closest to the edge of the wire capture component 332c is bent with a decreasing curvature. Advantageously, such an arrangement reduces the likelihood of sharp bends forming in the SMA wire during operation, thereby reducing wear.

[0158] Figure 10F and Figure 10G They are connected to Figures 10A-10E An enlarged plan view and an enlarged perspective view of a subassembly frame 332e of the wire capture component of the coupler are shown. That is, a subassembly including more than one coupler can be applied to a support structure or movable component so that the legs of the couplers can be aligned to their predetermined positions simultaneously, thereby achieving a more efficient assembly process.

[0159] exist Figure 10F and Figure 10G In the embodiment, the lower wire capture member 332cb includes an outwardly extending tab that connects to a corresponding tab of the subassembly frame 332e along a line of weakness 332f. Once the legs 332d are attached to the desired position, the subassembly can be easily disassembled by severing the connection, preferably using a laser. Alternatively, a mechanical device can be used to sever the connection.

[0160] The line of weakness 332f may be a localized thinned area formed by stamping, cutting, or etching. In some embodiments, a pigment may be applied along the line of weakness to increase local laser / heat absorption.

[0161] Figure 10H 、 Figure 10I and Figure 10J They are Figures 10A-10G a perspective view, an enlarged side sectional view, and an enlarged plan view of the actuator assembly shown;

[0162] like Figures 10H-10J As shown, the end stop 333 is manufactured in the same etching as the spring stiffener 333b (which stiffens the spring). This is beneficial from a manufacturing and cost perspective because it requires fewer assembly steps and reduces waste. The same reasons apply to using both the spring stiffener 333b and the conductor 25 to accommodate the ball bearing 50 in the actuator (if used instead of the planar bearing 50).

[0163] Figure 11A and Figure 11B 4 and 5. More specifically, couplers 432 and 532 are design alternatives that function in a manner similar to coupler 332 of the fourth embodiment.

[0164] like Figure 11A As shown, the coupler 432 includes a planar first flexure member 432a that is significantly thicker (or thinner in other embodiments) than the corresponding planar wire capture member 432c and the leg 432d. That is, the various components of the coupler 432 can be formed from different discrete components (connected by welding or adhesive). Or preferably, the various components of the coupler 432 can be formed integrally using the same process used to form the coupler 332, and additionally reducing the thickness of the first flexure member 432a or the thickness of both the wire capture member 432c and the leg 432d by an etching process to achieve different thicknesses. In this way, the stiffness of the first flexure member 432a can be easily specified.

[0165] like Figure 11B As shown, the connector 532 includes a planar first flexure member 532a having a void section 532aa. That is, the first flexure member 532a is similar to a frame surrounding the void section 532aa. The various components in the connector 532 can be integrally formed using the same process used to form the connector 332, and the void section 532aa is additionally formed by etching, cutting, or stamping. The formation of the void section 532aa reduces the overall stiffness of the first flexure member 532a. Alternatively, the void section 532aa can be a thinned section, wherein the thickness of the thinned section is thinner than any other portion of the first flexure member 532a. Providing the thinned section reduces the overall stiffness of the first flexure member 532a. Alternatively, the void section 532aa can be replaced by a thickened section, wherein the thickness of the thickened section is thicker than any other portion of the first flexure member 532a. The formation of thickened sections enhances the overall stiffness of the first flexure member 532a. In some embodiments, the first flexure member 532a can include any number of mixtures of void sections, thinned sections, and thickened sections to achieve different local stiffnesses of the first flexure member 532a.

[0166] In some embodiments, the frame in the first flexure 432a can be provided in other forms. For example, it does not necessarily need to surround the gap section, the thinned section, or the thickened section. The frame can be a half-frame extending along one side of the gap section. The frame can be a single beam provided with gap sections on either side. For example, the first flexure 432a can include a narrowed section.

[0167] Figure 12 is a perspective view of a connector according to a seventh embodiment of the present invention; vertically stacked connectors 632 (upper), 632 (lower) are functionally similar to Figure 8A and Figure 8B The first flexure 632a of the corresponding couplings 132(upper), 132(lower) of the first embodiment shown is similar to Figure 10B More specifically, the couplers 632 each include a first flexure 632a and a second flexure 632b similar to the flexure body frame, as well as a wire capture member 632c and a leg 632d. For the sake of simplicity, similar features are not described again.

[0168] More specifically, the rigid flexure body frame 632b is attached to the body by adhesion or welding. Figure 10B The connector 632 is formed by attaching the end of the first flexure member 332a shown. This arrangement allows the stiffness of the first flexure member 632a to depend on its thickness, wherein the wire capture member 632c can rotate about the leg 632d. In the embodiment shown, the wire capture member 632c is attached to the surface of the flexure body frame 632b. In other embodiments, the wire capture member 632c can be formed integrally with the flexure body frame 632b, and the flexure body frame 632b includes a groove at its leading edge. In some other embodiments, the wire capture member 632c can include a groove that is connected to the flexure body frame 632b. Figure 8A and Figure 8B The second embodiment shown has more than one discontinuous section. In this case, the flexible body frame 632b can be similar to a "C" shaped member.

[0169] Alternatively, the coupler 632 may be integrally formed by etching, or bending, or stamping from a single piece of material.

[0170] Figure 13A and Figure 13B The figure shows a perspective view and a side cross-sectional view of a connector according to an eighth embodiment of the present invention. The connector 732 is similar in function to the connector 733. Figure 10B An alternative design of the coupling 332. For the sake of brevity, similar features are not described again.

[0171] The coupling 732 includes an elongated leg 732d for providing an additional attachment surface for attachment to a movable member (or support structure). Furthermore, the first flexure members 732a of the stacked lower and upper couplings 732, 732 also substantially overlap (or stack) one another. This arrangement allows the first flexure members 732a to flex further within the plane of movement than in the previous embodiment, since the two first flexure members 732a do not extend in the same plane and, therefore, there is no risk of collision between them.

[0172] Figure 14A and Figure 14B are respectively a plan view and an exploded perspective view of an SMA actuator according to a ninth embodiment of the present invention, and Figure 14C and Figure 14D They are Figure 14A and Figure 14B A perspective view of two adjacent corners of an SMA actuator.

[0173] In summary, couplers 8320 and 8322-8324 are not stacked in actuator 802. Instead, couplers 8320 and 8322-8324 extend substantially in the same plane (the plane of movement) and are evenly distributed around the center of actuator 802.

[0174] Special References Figure 14A and Figure 14B , the actuator assembly 802 includes a supporting platform 821 and a moving platform 823 .

[0175] The actuator assembly 802 may include a base component secured to a support platform 821 .

[0176] Each of the moving platform 823, the support member 824, and the conductive member 825 may take the form of a patterned metal sheet, such as etched or machined stainless steel. The support member 824 may be coated with an electrically insulating dielectric material.

[0177] The layout of the structural components in the actuator assembly 802 is similar to Figure 7 Layout of structural components in the actuator assembly 2.

[0178] The movement of the mobile platform 823, and therefore the lens assembly 3, relative to the support platform 821 is driven by a lateral actuation device comprising four SMA wires 27 (ie, SMA wires 270 and 272-274).

[0179] The supporting platform 821 includes a first set of four crimping parts 831 (hereinafter referred to as "static crimping parts"), namely static crimping parts 8310 and 8312-8314. The moving platform 823 includes a second set of four crimping parts 833 (hereinafter referred to as "moving crimping parts"), namely moving crimping parts 8330 and 8332-8334.

[0180] The first and second crimping portions 831 and 833 crimp four SMA wires 827 to connect them to the support platform 821 and the moving platform 823. The SMA wires 827 may be perpendicular to the optical axis O or tilted at a small angle relative to a plane perpendicular to the optical axis O.

[0181] The crimping portions 831 , 833 have respective arms that extend generally inwardly to landing points on the respective platforms 821 , 823 to which the arms are suitably connected.

[0182] Each SMA wire 827 includes a first segment 827 A and the second paragraph 827 B The first segment and the second segment are oriented at an angle of approximately 90° relative to each other. A and the second paragraph 827 B are coupled to each other via couplings 832. Each coupling 832 connects the first segment 827 A and the second paragraph 827 B When the SMA wire 827 is driven, the first section 827 A Contraction causes the second segment 827 B displacement, which provides the difference between the second segment 827 B The contribution to the motion of mobile platform 823 provided by the contraction is in addition to the contribution to the motion of mobile platform 823.

[0183] The coupling 832 has a component 882c ( Figure 14C and Figure 14D ) to provide such a connection between the first segment and the second segment. The coupling 832 can take the form of any coupling described herein, such as coupling 32 or coupling 332.

[0184] Thus, the operation of the SMA actuator assembly 802 is comparable to that described in WO 2013 / 175197 A1, except that the length of each SMA wire 827 is multiplied, for example to approximately 2 times (without significantly increasing the footprint), and therefore the lateral range of motion (or "stroke") perpendicular to the optical axis O is increased to the same or similar multiple.

[0185] The static crimping portion 831 and the moving crimping portion 833 are located at each corner (also referred to herein as a “crimping corner”) of the moving platform 823 .

[0186] A coupler 832 is located at each corner of the mobile platform 823 (also referred to herein as a "coupler corner").

[0187] The first section 827 of each SMA wire 827 AThe second section 827 of each SMA wire 827 is connected to the static crimping portion 831 at one end thereof, extends along at least a portion of the outer edge of the moving platform 823, and is engaged with the connector 832 at the other end thereof. B It is engaged with the connector 832 at one end thereof, extends along at least a portion of an adjacent outer edge of the moving platform 823 , and is connected to the moving crimping portion 833 at the other end thereof.

[0188] Therefore, the first and second paragraphs 827 A 、827 B Each of the first and second segments 827 A 、827 B The other one partially overlaps along the outer edge of the mobile platform 823.

[0189] The elements holding the SMA wire 827 (ie, the static crimp 831, the coupler 832, and the moving crimp 833) are configured so that the first segment 827 on the same side of the actuator 802 is A and the second paragraph 827 B The movable platforms 823 are spaced apart vertically (i.e., in a direction along the optical axis O) from each other but extend parallel to each other. In this example, this is achieved by providing a coupler 832 at each corner of the movable platform 823. In some examples, all of the static crimping portions 31 are located at the same height (i.e., at the same position along the z-axis), and all of the movable crimping portions 33 are located at the same height.

[0190] In some examples, two ("upper") couplers 8320, 8324 are connected to the moving platform 823 at diagonally opposite corners of the actuator assembly 802, and two ("lower") couplers 8322, 8323 are connected to, for example, a support member 824. The upper couplers 8320, 8324 are at similar heights to each other and are vertically spaced from the lower couplers 8322, 8323, which are also at similar heights to each other. Each corner of the actuator assembly 802 also includes a static crimp 31 and a moving crimp 33. In an embodiment having an upper coupler 832 (see, for example, FIG. Figure 14C ) in each corner of the actuator assembly 802, the static crimping portion 31 and the moving crimping portion 33 are vertically spaced apart from the upper coupling 832 and are at similar heights to each other and to the lower coupling 832. Figure 14D ) in each corner of the actuator assembly 802, the static crimp 31 and the moving crimp 33 are vertically spaced apart from the upper coupler 832 and are at similar heights to each other and to the lower coupler. Thus, the SMA wires 270 and 272-274 are formed in two layers, an upper layer and a lower layer.

[0191] In operation, the SMA wires 827 are selectively driven to move the mobile platform 823 in any lateral direction (ie, perpendicular to the optical axis O) relative to the support platform 821, similar to the example of FIG. Figure 7 The SMA actuator 2 is shown.

[0192] In some embodiments (not shown), the SMA actuator assembly includes a support member and more than one movable member (e.g., one or more intermediate movable levels and a final movable level) in a stacked (and / or nested) configuration. The final movable level can be considered the movable member that provides the total travel summed with all other levels. More specifically, the SMA actuator assembly can include multiple stacked SMA actuator assemblies, such as Figure 2-14D The stacked SMA actuator assemblies may be identical or different depending on the application. That is, one or more stacked movable levels are each movable along a first plane relative to a support or an intermediate level adjacent to the respective movable level.

[0193] In embodiments where the SMA actuator assembly includes only one intermediate and final stages, the intermediate stage may be movable relative to the support and may itself form a support for the final stage. For example, in such embodiments, the final stage may move with the intermediate stage and relative to the support structure (e.g., when only the intermediate stage is moved), or the final stage may move only relative to the intermediate stage (e.g., when the intermediate stage maintains its position relative to the support). The intermediate stage may be movable relative to both the final stage and the support, preferably in the same direction, to achieve as much travel as possible in that direction.

[0194] Each level can move along a single axis or at least two non-parallel directions by contraction of the corresponding SMA wire. That is, in some embodiments where each level moves only on a discrete axis, the X and Y movements can be independently controlled by the corresponding level.

[0195] The actuator assembly can be any type of assembly comprising a first portion and a second portion movable relative to the first portion. The actuator assembly can be or can be arranged in any of the following devices: a smartphone, a protective cover or case for a smartphone, a functional cover or case for a smartphone or electronic device, a camera, a foldable smartphone, a foldable smartphone camera, a foldable consumer electronic device, a camera with folded optics, an image capture device, an array camera, a three-dimensional sensing device or system, a servo motor, a consumer electronic device, a mobile or portable computing device, a mobile or portable electronic device, a laptop, a tablet computing device, an e-reader, a computing accessory or computing peripheral device, an audio device, a security system, a gaming system, a gaming accessory, a robot or robotic device, a medical device, a virtual reality system, a virtual reality device, a wearable device, a drone, an aircraft, a spacecraft, a submersible, a vehicle, an autonomous vehicle, a tool, a surgical tool, a remote control, a garment, a switch, a dial or button, a display screen, a touch screen, a flexible surface, and a wireless communication device. It should be understood that this is a non-exhaustive list of exemplary devices.

Claims

1. A shape memory alloy actuator assembly, comprising: a support member, wherein a first plane is defined relative to the support member; a movable member movable relative to the support in at least two different non-parallel directions within the first plane; more than one unit of shape memory alloy wire, each unit connected between the movable member and the support so as to be actuatable to produce motion in the at least two directions without applying any net torque to the movable member in the first plane; wherein at least one of the units comprises a series of two or more lengths of shape memory alloy wire between the movable part and the support, the series of two or more lengths of shape memory alloy wire comprising a first section and a second section, wherein the first section and the second section are oriented at a non-zero angle relative to each other and are coupled to each other by a coupling member configured to move relative to the support and relative to the movable part, such that when the unit is actuated, contraction of the first section causes displacement of the second section, which provides a contribution to movement of the movable part in addition to the contribution provided by contraction of the second section.

2. The assembly according to claim 1, wherein The more than one units of shape memory alloy wire include two or four shape memory alloy wire units.

3. The assembly according to claim 1, wherein At least one of the coupling components is connected to the support.

4. The assembly according to claim 1, wherein At least one of the coupling members is connected to the movable member.

5. The assembly according to any one of claims 1 to 4, wherein At least one of the coupling components is included in and / or attached to a flexure that flexes in the first plane to provide the coupling between the first segment and the second segment.

6. The assembly according to claim 5, wherein The flexure includes a first component and a second component, the first component receiving a tensile force when the flexure is deflected in the first plane, and the second component receiving a compressive force when the flexure is deflected in the first plane.

7. The assembly according to claim 6, wherein The second component of the flexure has a higher stiffness than the first component of the flexure.

8. An assembly according to claim 6 or 7, wherein The first component and the second component of the flexure are located in the same plane.

9. An assembly according to claim 6 or 7, wherein The second member of the flexure rotates about the first member of the flexure to effect movement in the coupling member.

10. The assembly according to claim 5, wherein The flexure includes a component that generally experiences compression when the flexure flexes within the first plane.

11. The assembly according to claim 10, wherein The component has a higher compliance in the first plane than in a direction perpendicular to the first plane.

12. The assembly according to claim 11, wherein The member has a cross-section that is elongated in a direction perpendicular to the first plane.

13. The assembly of claim 5, comprising at least one stack of two flexures, wherein the flexures in the stack are spaced apart from each other in a direction perpendicular to the first plane.

14. The assembly of claim 13, further comprising a spacer sandwiched between the coupler components of the corresponding flexures in each stack, wherein the spacer is configured to prevent excessive flexural movement in a direction perpendicular to the first plane.

15. The assembly of claim 14, wherein: The spacer includes end stops for limiting excessive flexural movement in the first plane.

16. The assembly of claim 5, wherein: The flexures do not overlap when viewed in a direction perpendicular to the first plane.

17. The assembly of claim 16, wherein: When viewed in a direction perpendicular to the first plane, the flexures are evenly distributed around the center of the support and / or the movable part.

18. The assembly of claim 5, wherein: The flexure includes at least two portions arranged perpendicular to each other, the at least two portions including a first planar portion configured to flex in the first plane and a second portion configured to resist deformation in the first plane.

19. The assembly of claim 18, wherein The first planar portion and the second portion are integrally formed from a single metal plate.

20. The assembly of claim 6, wherein: The first part of the flexure comprises a void or a thinned or thickened section for modifying the stiffness of the first part of the flexure.

21. The assembly according to any one of claims 6-7 and 10-20, wherein The coupling member includes a wire capture member for receiving the shape memory alloy wire, the wire capture member including a groove extending substantially in the first plane.

22. The assembly of claim 21, wherein When viewed in a direction perpendicular to the first plane, the wire capture member comprises a plurality of radii, the wire capture member having a largest radius towards a periphery of the wire capture member.

23. The assembly of claim 21, wherein The wire capture component is formed from two stacked components, wherein the groove is defined at an interface between the two stacked components.

24. The assembly of claim 23, wherein One or each of the stacked components includes an outwardly extending tab, wherein the tab is configured to connect to a corresponding tab of a subassembly frame, wherein the connection is separable during assembly.

25. The assembly of claim 21, wherein A shape memory alloy wire is adhered to the coupler component at an adhesion point distal to the periphery of the wire capture component.

26. The assembly of claim 25, wherein The wire capture member includes at least one recess proximate the adhesion point for receiving excess adhesive.

27. The assembly of claim 21, wherein The groove includes more than one discrete section.

28. The assembly of claim 16, wherein: The movable member has a generally quadrilateral shape; Each of the more than one units includes the first segment and the second segment; and Each of the first segment and the second segment is arranged along an outer edge of the movable member and partially overlaps with the other of the first segment and the second segment.

29. The assembly of claim 28, wherein: each of the first segments is connected to the support via a first connector, and each of the second segments is connected to the movable member via a second connector; the first connector and the second connector are located at diagonally opposite corners of a first pair of the movable members; and The first and second segments are coupled to each other at a second different pair of diagonally opposed corners of the movable member.

30. The assembly of claim 29 including a stack of two flexures located at each of the second diagonal corners.

31. The assembly of claim 30, wherein: each of the first segments is connected to the support via a first connector, and each of the second segments is connected to the movable member via a second connector; the first connector and the second connector are located at diagonally opposite corners of the movable member; and The first and second segments are coupled to each other at different pairs of diagonally opposed corners of the movable member.

32. The assembly of any one of claims 1-4, 6-7, 10-20, and 22-31, wherein Each of the more than one units is composed of a single shape memory alloy wire.

33. The assembly of any one of claims 1-4, 6-7, 10-20, and 22-29, wherein Each of the more than one units is composed of a first shape memory alloy wire corresponding to the first segment and a second shape memory alloy wire corresponding to the second segment.

34. The assembly of any one of claims 1-4, 6-7, 10-20, and 22-31, wherein At least one of the coupling members is connected to a lever.

35. The assembly of any one of claims 1-4, 6-7, 10-20, and 22-31, wherein At least one of the coupling components does not move translationally, or at least one of the coupling components moves rotationally within a first plane.

36. A method of manufacturing an assembly according to any one of claims 1 to 35, comprising: providing a subassembly comprising a subassembly frame connected to more than one coupler; aligning the coupling to its predetermined position on the support and / or the movable part and attaching it to the predetermined position; severing the connection between the subassembly frame and the coupler; The subassembly frame is removed to form the assembly.

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