Actuator assembly

Abstract

An actuator assembly comprising: a first component and a second component movable relative to each other along two orthogonal axes perpendicular to a main axis and / or tiltable relative to each other about two orthogonal axes perpendicular to the main axis; and at least one pair of actuating units, each actuating unit configured to apply an actuating force to the second member, the actuating force being capable of moving the second member relative to the first member, where each actuating unit includes: a body portion; an SMA element connected between the body portion and the first component and arranged to apply an input force to the body portion upon actuation; a force adjusting element connected between the main body portion and the first component and configured to adjust an input force to generate an actuation force; a coupling link connected between the body portion and the second component, where the coupling link is configured to transmit the actuating force from the body portion to the second component, and where the coupling link is flexible in a direction perpendicular to the actuating force direction; the coupling links of each pair of actuating units overlap when viewed along the main axis, and wherein one of the actuating units of each pair is configured to apply an actuating force parallel to the first axis in a plane formed by two orthogonal axes, and the other actuating unit of each pair of actuating units is configured to apply an actuating force parallel to a second axis in a plane formed by the two orthogonal axes, and the second axis is not parallel to the first axis.

Description

field

[0001] The present application relates to an actuator assembly having one or more actuation units, each of which comprises a shape memory alloy (SMA) element. background

[0002] SMA actuator assemblies may be used in a variety of applications for moving a movable component relative to a support structure.

[0003] For example, WO 2013 / 175197 A1 describes a camera in which four SMA wires are arranged to move a lens element relative to an image sensor in a plane perpendicular to the optical axis of the lens element, thereby achieving optical image stabilization (OIS). WO 2010 / 029316 A1 describes SMA actuator wires for providing OIS in a camera by tilting the camera module. WO 2011 / 104518 A1 describes an actuator assembly with eight SMA wires that enables position control of a movable element in multiple degrees of freedom.

[0004] Typically, the range of motion (also called "stroke") of such an SMA actuator assembly is limited by the maximum contraction of the SMA wire, and the actuation force is limited by the maximum force that the SMA wire can generate. To increase the range of motion or actuation force, longer or thicker SMA actuator wires can be used, but this may come at the expense of increased cost, size, and / or power, which may not be practical in miniature applications.

[0005] WO 2022 / 084699 A1 discloses an actuator assembly comprising at least one actuation unit (comprising an SMA wire) which, when actuated, moves a movable part relative to a support structure. The actuation unit may be configured to amplify the range of motion of the movable part, thereby amplifying the actuation force acting on the movable part, or redirect the force applied by the SMA wire. Overview

[0006] The present application provides an SMA actuator assembly, which includes a force-modifying mechanism that adjusts the magnitude of the actuation force using a given input force, and the force-modifying mechanism can advantageously amplify the displacement of the movable component using a given amount of contraction in the SMA wire. Advantageously, such an arrangement can allow a larger stroke (i.e., displacement) to be achieved, or it can allow a larger force to be applied in order to move a heavier lens or image sensor, thereby improving actuator performance and, for example, OIS capabilities. In addition, the length of the SMA wire used to achieve the desired stroke can be shortened, thereby reducing the footprint of the SMA actuator assembly, as well as reducing the overall cost and power consumption of the actuator.

[0007] According to aspects of the present invention, an actuator assembly is provided, the actuator assembly comprising: a first component and a second component, the first component and the second component being capable of moving relative to each other along two orthogonal axes perpendicular to a main axis and / or tilting relative to each other around two orthogonal axes perpendicular to the main axis; and at least one pair of actuating units, each actuating unit being configured to apply an actuating force to the second component, the actuating force being capable of causing the second component to move relative to the first component, wherein each actuating unit comprises: a main body portion; an SMA element, which is connected between the main body portion and the first component and is arranged to apply an input force to the main body portion during actuation; a force adjustment element, which is connected between the main body portion and the first component and is configured to adjust the input force so as to generate the actuating force; a coupling link; link), which is connected between the main body and the second part, wherein the connecting link is configured to transmit the actuating force from the main body to the second part, and wherein the connecting link is flexible in a direction perpendicular to the direction of the actuating force; and wherein the connecting links of each pair of actuating units overlap when viewed along the main axis, wherein one actuating unit in each pair of actuating units is configured to apply the actuating force parallel to a first axis in a plane formed by two orthogonal axes, and the other actuating unit in each pair of actuating units is configured to apply the actuating force parallel to a second axis in a plane formed by the two orthogonal axes, wherein the second axis is not parallel to the first axis.

[0008] Allowing the coupling flexures to overlap provides a more compact assembly of the actuating unit than would be the case if such overlap were not allowed. In particular, for a given minimum length of the coupling link, the actuating unit can be arranged closer to the center of the actuating unit. Avoiding overlap between the main body parts of the actuator unit can reduce the extension of the actuating unit along the main axis. Thus, this aspect of the invention allows an overall compact actuator to be provided while maintaining good actuator assembly performance.

[0009] In some embodiments, the coupling link includes a coupling flexure.

[0010] In some embodiments, at least one coupling flexure of one actuation unit in each pair of actuation units includes a kinked portion located in a region overlapping with the coupling flexure of the other actuation unit in each pair of actuation units, thereby avoiding contact between the coupling flexures.

[0011] In some embodiments, each pair of actuation units is arranged offset relative to each other along the main axis so as to avoid contact between the coupling flexures.

[0012] In some embodiments, a coupling flexure is wider in a region where it overlaps another coupling flexure than in an adjacent region. This can reduce the risk of damaging the coupling flexure due to an impact event.

[0013] In some embodiments, the actuation units are substantially identical. This may make manufacturing simpler and more cost-effective.

[0014] In some embodiments, each actuating unit includes a first surface parallel to a plane formed by two orthogonal axes and a second surface parallel to a plane formed by the two orthogonal axes, wherein the first surface and the second surface are arranged on opposite sides of the actuating unit, and wherein, for each pair of actuating units, the first surface of one actuating unit and the second surface of the other actuating unit face the same direction along the main axis.

[0015] In some embodiments, at least one actuation unit (preferably each actuation unit) is configured such that, when viewed orthogonally to the SMA element, the SMA element extends past the point at which the coupling link connects to the body portion.

[0016] In some embodiments, at least one actuation unit (preferably each actuation unit) is configured such that, when viewed along the primary axis, the SMA element is arranged on the same side of the body portion as the point at which the force adjustment element connects to the first component or the second component.

[0017] In some embodiments, at least one actuation unit (preferably each actuation unit) is configured to place the force adjustment element in tension when the SMA element contracts.

[0018] In some embodiments, at least one actuation unit (preferably each actuation unit) is configured such that the force adjustment element amplifies an amount of contraction of the SMA element into a relatively larger amount of movement between the first component and the second component.

[0019] In some embodiments, at least one actuation unit (preferably each actuation unit) is configured such that the angle between the force adjustment element and the SMA element is in the range of 0 to 45 degrees, preferably in the range of 13 to 40 degrees.

[0020] In some embodiments, at least one actuation unit, preferably each actuation unit, is configured such that the force adjustment link is integrally formed with at least a portion of the body portion.

[0021] In some embodiments, at least one actuation unit, preferably each actuation unit, is configured such that the coupling link is integrally formed with at least a portion of the body portion.

[0022] Some embodiments include a total of four actuation units, wherein the four actuation units consist of two pairs of actuation units.

[0023] In some embodiments, none of the actuation forces applied by the four actuation units are collinear.

[0024] In some embodiments, the four actuation units are arranged so as to apply an actuation force between the first component and the second component so as to move the first component and the second component relative to each other to any position within a range of movement within a plane of movement formed by two orthogonal axes without applying any net torque between the first component and the second component.

[0025] In some embodiments, two of the four actuation units are arranged to apply an actuation force so as to generate a torque between the first component and the second component in a first direction around the main axis, and the other two of the four actuation units are arranged to apply an actuation force so as to generate a torque between the first component and the second component in a second opposite direction around the main axis.

[0026] In some embodiments, two of the four actuation units are arranged to apply the actuation force in a corner of the actuator assembly, and another two of the four actuation units are arranged to apply the actuation force in another opposite corner of the actuator assembly.

[0027] In some embodiments, two of the four actuation units are arranged to apply an actuation force to move the first component and the second component relative to each other in two opposite directions parallel to the first axis, and the other two of the four actuation units are arranged to apply an actuation force to move the first component and the second component relative to each other in two opposite directions parallel to the second axis.

[0028] In some embodiments, each actuation unit extends parallel to two orthogonal axes.

[0029] Some embodiments further comprise a bearing arrangement between the first component and the second component, and the bearing arrangement is arranged to allow relative movement between the first component and the second component.

[0030] According to another aspect of the present invention, an actuator assembly is provided, the actuator assembly comprising: a first component and a second component, the first component and the second component being movable relative to each other in a moving plane perpendicular to a main axis; and at least one pair of actuating units, each actuating unit being connected between the first component and the second component and being arranged to apply a corresponding actuating force between the first component and the second component, wherein one actuating unit in each pair of actuating units comprises: a main body portion; an SMA element connected between the main body portion and the first component and being arranged to apply an input force to the main body portion during actuation; a force adjustment element connected between the main body portion and the first component and being configured to adjust the input force so as to generate the actuating force; and a connecting rod connected to the main body portion. The invention relates to a pair of actuating units, wherein the actuating unit is connected between the main part and the second part, wherein the connecting link is configured to transmit the actuating force from the main part to the second part, and wherein the connecting link is flexible in a direction perpendicular to the direction of the actuating force; and wherein the other actuating unit in each pair of actuating units comprises: a main part; an SMA element, which is connected between the main part and the second part and is arranged to apply an input force to the main part when actuated; a force adjustment element, which is connected between the main part and the second part and is configured to adjust the input force to generate the actuating force; and a connecting link, which is connected between the main part and the first part, wherein the connecting link is configured to transmit the actuating force from the main part to the first part, and wherein the connecting link is flexible in a direction perpendicular to the direction of the actuating force.

[0031] In some embodiments, none of the actuation units overlap when viewed along the major axis.

[0032] Some embodiments include a total of four actuation units, wherein the four actuation units consist of two pairs of actuation units.

[0033] In some embodiments, the four actuation units are arranged to apply an actuation force between the first component and the second component so as to move the first component and the second component relative to each other to any position within a range of motion within a plane of motion without applying any net torque between the first component and the second component.

[0034] According to another aspect of the present invention, an actuator assembly is provided, which includes a first component and a second component, which are capable of moving relative to each other along two orthogonal axes perpendicular to the main axis and / or tilting relative to each other around two orthogonal axes perpendicular to the main axis, and the two orthogonal axes form a movement plane; and one or more actuating units, each of which is configured to apply an actuating force to the second component, and the actuating force is capable of moving the second component relative to the first component, wherein each actuating unit includes: a main body; an SMA element, which is connected between the main body and the first component and is arranged to apply an input force to the main body when actuated; and a connecting rod, which is connected between the main body and the second component, wherein the connecting rod is configured to transmit the actuating force from the main body to the second component, and wherein the connecting rod is flexible in a direction perpendicular to the direction of the actuating force; wherein when viewed along the main axis, one or more actuating units overlap with both the area defined by the first component and the area defined by the second component.

[0035] In some embodiments, the force modulation element and / or the SMA element and / or the coupling link overlap the region when viewed along the primary axis.

[0036] In some embodiments, one or more actuation units are located within both the region defined by the first component and the region defined by the second component when viewed along the primary axis.

[0037] In some embodiments, the first component and the second component comprise elements of an imaging system, and the one or more actuation units are at least partially located outside of an optical path between the elements.

[0038] In some embodiments, the first component and / or the second component is rectangular in shape when viewed along the major axis, and wherein at least a portion of the SMA element extends along a line that is obliquely angled relative to the sides of the rectangle.

[0039] In some embodiments, the straight line is longer than the length of the longest side of the rectangle.

[0040] In some embodiments, the actuation unit is arranged between the first component and the second component when viewed perpendicularly to the main axis.

[0041] Some embodiments comprise four actuating units, wherein two of the four actuating units are configured such that the corresponding body parts are located in a first plane, and wherein the other two of the four actuating units are configured such that the corresponding body parts are located in a second plane, wherein the first plane and the second plane are different planes parallel to each other. When viewed along the main axis, the body parts of the actuating units located in different planes may overlap, thereby allowing the actuating units to be assembled even more tightly. Such an arrangement is particularly advantageous in embodiments in which the actuating unit is arranged below the second component, i.e. between the first component and the second component when viewed perpendicular to the main axis.

[0042] Some embodiments include four actuating units, wherein the main bodies of the four actuating units are arranged in a common plane. In some embodiments, the force adjustment elements of the four actuating units are additionally arranged in a common plane. Such an arrangement can be simpler to manufacture. The four actuating units can be formed from a single sheet of material such as a metal sheet.

[0043] In some embodiments, the force adjustment element comprises a force adjustment flexure.The force adjustment element may be arranged to be in tension when the SMA element is actuated.

[0044] In some embodiments, the force modulation element is arranged at an angle relative to the SMA wire, preferably at an angle in the range of 13 degrees to 77 degrees, optionally at an angle in the range of 13 degrees to 40 degrees or 77 degrees to 50 degrees.

[0045] In some embodiments, each actuation unit is configured to amplify an actuation of the SMA element into a relatively greater movement of the second component relative to the first component, optionally by a factor greater than 1.5, preferably greater than 2, and even more preferably greater than 3.

[0046] In some embodiments, each actuation unit is configured to amplify the input force such that the actuation force is greater than the input force, optionally by a factor greater than 1.5, preferably greater than 2, and even more preferably greater than 3.

[0047] In some embodiments, the coupling link comprises a coupling flexure.The coupling link may be arranged to be in tension when the SMA element is actuated.

[0048] In some embodiments, the angle between the coupling link and the SMA element is in the range of 70 degrees to 110 degrees.

[0049] In some embodiments, each actuation unit extends substantially in an actuation plane, wherein a body portion of the actuation unit is arranged to move in the actuation plane upon actuation of the SMA element.The actuation planes of the actuation units may be parallel or coincident.

[0050] In some embodiments, the body portion and the force adjustment flexure are integrally formed of the same material, and optionally, the coupling link is also formed of the same material. The body portion, the force adjustment flexure and the coupling link may be formed of sheet material such as sheet metal.

[0051] Some embodiments include a total of four actuation units arranged to apply the actuation forces such that none of the actuation forces are non-collinear.

[0052] In some embodiments, the four actuation units are arranged such that a first pair of actuation units applies actuation forces in two opposite directions parallel to a first axis in a plane, and a second pair of actuation units applies actuation forces in two opposite directions parallel to a second axis in a plane, wherein the first axis and the second axis are not parallel.

[0053] In some embodiments, the first pair of actuation units are arranged to apply torque to the second component relative to the first component in a first orientation, and the second pair of actuation units are arranged to apply torque to the second component relative to the first component in a second orientation, wherein the second orientation is opposite to the first orientation.

[0054] Some embodiments include an image sensor and / or lens assembly wherein the image sensor or lens assembly is fixed relative to the second component and / or the lens assembly or image sensor is fixed relative to the first component.

[0055] According to another aspect of the present invention, a camera device is provided, which includes an actuator assembly and an image sensor, the image sensor being connected to one of a first component and a second component of the actuator assembly; and a lens assembly being connected to the other of the first component and the second component of the actuator assembly, wherein an optical axis defined by the lens assembly is aligned with a main axis of the actuator assembly.

[0056] According to another aspect of the invention, a camera assembly comprising an actuator assembly is provided, wherein the second component comprises an image sensor as an element of an imaging system, the image sensor having an imaging axis perpendicular to the plane of movement, wherein the actuator assembly provides optical image stabilization (OIS) for the camera assembly.

[0057] In some embodiments, the image sensor is located between an element of the imaging system included in the first component and at least a portion of the one or more actuation units.

[0058] In some embodiments, one or more actuation units at least partially overlap the image sensor when viewed along the primary axis.

[0059] According to another aspect of the present invention, an actuator assembly is provided, which includes: a first component and a second component, the first component and the second component are capable of moving relative to each other in a moving plane perpendicular to the main axis; and one or more actuating units. Each actuating unit includes: a force adjustment mechanism, which is connected to the first component; a connecting rod, which is connected between the force adjustment mechanism and the second component; and an SMA wire, which is connected between the first component and the force adjustment mechanism, for applying an input force on the force adjustment mechanism, so that the force adjustment mechanism applies an output force on the connecting rod, and the connecting rod applies an actuating force on the second component. The connecting rod is flexible in a direction perpendicular to the direction of the actuating force. When viewed along the main axis, one or more actuating units overlap with both the area defined by the first component and the area defined by the second component. The force adjustment mechanism may include a main body and a force adjustment element.

[0060] Herein, “a region defined by a component” may mean, for example, a smallest region including all features of the component.

[0061] The actuator assembly may be a microactuator for a camera or a mobile phone. The first component may correspond to a support structure, and the second component may correspond to a movable component. The actuator assembly may include one or more (e.g., elongated) SMA wires, which may be connected to the second component via a force adjustment mechanism. That is, this SMA actuator assembly differs from the prior art actuator in that the SMA wire may not be directly connected between the support structure and the movable component. Instead, one end of the SMA wire may be attached to the force adjustment mechanism, whereby the actuation force may be transmitted to the movable component via a connecting rod. In particular, the connecting rod is not an SMA wire.

[0062] The force modulation mechanism and / or the SMA wire and / or the coupling link may overlap this region when viewed along the primary axis.

[0063] The overlap may be >50% or >75% or more. Thus, at least 50% or at least 75% of the area of ​​the actuation unit (when viewed perpendicular to the main axis) may overlap with the zone defined by the first component and the zone defined by the second component. In some examples, one or more actuation units may be (entirely) located within both the zone defined by the first component and the zone defined by the second component when viewed along the main axis.

[0064] As will be explained, the second component may comprise or may be configured to carry a substantially planar element, such as an image sensor.When viewed along the main axis, the one or more actuation units may overlap the planar element.

[0065] Thus, by overlapping the first and second components in this manner, the actuation unit can have a variety of advantageous configurations without unduly increasing the size of the actuator assembly in a direction perpendicular to the main axis ("footprint").

[0066] Furthermore, the first component and the second component may comprise elements of an imaging system, and one or more actuating units may be located at least partially outside a zone defined by the elements of the imaging system in the direction of the main axis. For example, the actuating unit may be located behind the image sensor, whereby the actuating unit may overlap with the image sensor without blocking light from reaching the image sensor. This allows greater design freedom for the force adjustment mechanism. Alternatively, one or more actuating units may be arranged at one or more corners of the actuator assembly so as not to block the light path of the imaging system.

[0067] The SMA wire can be configured to achieve relative movement between the first component and the second component in a direction in a moving plane that is substantially orthogonal to the optical axis when contracted. The connecting rod can be flexible in any direction in the moving plane. Therefore, the connecting rod can adapt to movement in a direction perpendicular to the actuation force, which can be generated by other actuation units, for example. Such an arrangement can be such that at least optical image stabilization (OIS) is performed when the SMA wire or each SMA wire is actuated. For example, the SMA wire can extend in a direction substantially perpendicular to the optical axis. In some embodiments, the SMA wires can each be arranged on a respective side of the first component.

[0068] The term "shape memory alloy (SMA) wire" may refer to any element including SMA, and is also referred to herein as an SMA device. The 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 a cross section of any other shape. The cross section may vary along the length of the SMA wire. It is also possible that the length of the SMA wire (regardless of the definition) may be similar to one or more of the other dimensions of the SMA wire. The SMA wire may be pliable, or in other words, may be flexible. In some examples, when connected in a straight line between two elements, the SMA wire can only apply a tensile force that pushes the two elements together. In other examples, the SMA wire may be bent around the element, and when the SMA wire tends to straighten under tension, the SMA wire may apply force to the element. The SMA wire may be beam-shaped or rigid and may be able to apply different (e.g., non-tensile) forces to the element. The SMA wire may or may not include (one or more) materials and / or (one or more) devices that are not SMA. For example, the SMA wire may include a core of SMA 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 acts as a single actuating element, e.g., one that can be individually controlled to generate a force acting on the element. For example, an SMA wire may include two or more portions of an SMA wire that are mechanically arranged in parallel and / or in series. In some arrangements, an SMA wire may be part of a larger segment of an SMA wire. Such a larger segment of an SMA wire may include two or more components that can be individually controlled, thereby forming two or more SMA wires.

[0069] The SMA wires may be formed of 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 may have any cross-sectional profile and diameter suitable for the application. For example, the SMA wires may have a cross-sectional diameter of 25 μm, or 30 μm, or 35 μm, and the SMA wires may be 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% to 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.

[0070] The connecting rod can form part of the force adjustment mechanism and / or can be formed separately from other parts of the force adjustment mechanism (e.g., the main body). In an embodiment, the connecting rod can be formed of the same or different material as other parts of the force adjustment mechanism. For example, other parts of the force adjustment mechanism can be rigid, or at least have a higher stiffness than the connecting rod. In an embodiment, the connecting rod can be attached to the other parts of the force adjustment mechanism by any suitable attachment method (such as welding, adhesives, and mechanical methods). In some embodiments, the connecting rod can be integrally formed with the other parts of the force adjustment mechanism. Advantageously, such an arrangement can lead to a more efficient manufacturing process and lower production costs.

[0071] In some embodiments, the coupling link can be considered as the device primarily responsible for transmitting the actuation force to the second component. The coupling link can be implemented by any element or device capable of achieving the dual functions of transmitting the actuation force to the second component and providing flexibility in a direction perpendicular to the actuation force direction.

[0072] Optionally, the coupling link is or includes a flexible member. The flexible member may be elongated and may be rigid along its length and flexible in a direction perpendicular to its length. That is, the coupling link may be referred to as a flexible arm that is configured to be easily bent within the plane of movement, particularly in a direction orthogonal to the actuation force, but may be rigid or non-flexible in other directions.

[0073] Optionally, the coupling link may be configured to exert a lateral biasing force on the second component to return the second component to a default (or center) position and / or to maintain the second component in a default (or center) position. This may be achieved in particular in embodiments where the coupling link comprises a flexible member.

[0074] Alternatively, the coupling link may constrain movement of the second component in a direction perpendicular to the direction of the actuation force. For example, in embodiments where the first component or the second component comprises a lens or an image sensor, the coupling link may constrain movement along or parallel to the optical axis. With respect to an image sensor, the optical axis may be considered to be an axis perpendicular to the photosensitive surface of the image sensor. The coupling link may be a preformed flexible arm that constrains movement along the optical axis.

[0075] Alternatively, the coupling link may be a rigid member, such as a rod, with a pin joint that allows the coupling link to pivot within the plane of movement. For example, the pivot may be a column extending from the force adjustment mechanism and hingedly attached to one of the first and second components, in particular the first component. Advantageously, such an arrangement may allow precise control of the displacement of the second component.

[0076] Optionally, the force adjustment mechanism is configured such that in response to a change in the length of the SMA wire, an end of the SMA wire connected to the force adjustment mechanism moves a first distance relative to the first component, and an end of the coupling link connected to the force adjustment mechanism moves a second distance relative to the first component, the second distance being greater than the first distance. Such an arrangement can be used to amplify the stroke achievable by the SMA actuator assembly.

[0077] Alternatively, the force adjustment mechanism is configured such that in response to a change in the length of the SMA wire, the end of the SMA wire connected to the force adjustment mechanism moves a first distance relative to the first component, and the end of the coupling link connected to the force adjustment mechanism moves a second distance relative to the first component, the second distance being less than the first distance. For example, such an arrangement can be configured to increase the applicable actuation force given an input force by the SMA wire.

[0078] Broadly speaking, the present invention uses the force adjustment mechanism as a lever to amplify or at least adjust the displacement of the movable member that can be achieved by a given amount of SMA wire contraction. That is, for example, by virtue of the rotation of the movable member relative to the force adjustment mechanism, the present embodiment can reduce the length of the SMA wire required to achieve a desired stroke. Thus, such an arrangement can provide a more compact and energy-efficient SMA actuator assembly.

[0079] In operation, the coupling link may be generally in tension. The force adjustment mechanism may pull the movable component via the coupling link so as to apply the actuation force to the movable component. This is particularly preferred, for example, when the coupling link comprises a flexible member. The end of the coupling link connected to the second component may be fixed relative to the second component. The coupling link may extend in substantially the same direction as the output force. The actuation force may be substantially in the same direction as the output force.

[0080] Alternatively, the coupling link may be normally in a compressed state.The force adjustment mechanism may push the movable component via the coupling link so as to apply the actuation force to the movable component.

[0081] Optionally, the SMA wire extends from the force adjustment mechanism to the first component in a first direction, and the coupling link extends from the force adjustment mechanism to the second component in a second direction, the first direction and the second direction being substantially perpendicular to each other. The angle between the first direction and the second direction may be in the range of 75° to 105°. Thus, the input force and the output force may be substantially perpendicular to each other.

[0082] Alternatively, the first direction and the second direction may be in substantially opposite directions. The input force and the output force may be in substantially opposite directions. In such an embodiment, the force adjustment mechanism may act as a lever, for example, where the SMA wire pulls on a side of the lever where the movable component is not disposed.

[0083] Alternatively, the first direction and the second direction may be in substantially the same direction. The input force and the output force may be in substantially the same direction. In such an embodiment, the force adjustment mechanism may act as a lever, for example, where the SMA wire pulls on one side of the lever where the movable component is disposed.

[0084] The SMA wire and the coupling link may be substantially coplanar, such as in the plane of movement of the movable component. The actuation force may be in a direction in the plane of movement. The SMA wire may extend along the first side surface of the second component. The coupling link may extend along the second side surface or along the first side surface of the second component. This arrangement of the SMA wire and the coupling link may provide a compact SMA actuator assembly.

[0085] Optionally, the first component is a rectangle when viewed along the major axis and at least a portion of the SMA wire extends along a straight line at an oblique angle relative to a side of the rectangle. Optionally, the straight line is longer than the length of the long side of the rectangle (or the length of each side if the rectangle has equal sides (i.e. is a square)). By providing a longer SMA wire, the achievable travel may be increased.

[0086] Optionally, the force adjustment mechanism includes a main body portion and a force adjustment flexure, the SMA wire and the coupling link are connected to the main body portion, and the force adjustment flexure is connected between the main body portion and the first component and is configured to bend or deform in response to the input force. Further optionally, the coupling link includes a coupling flexure. Such an embodiment may be particularly preferred due to improved manufacturability and reduced cost.

[0087] The body portion may be rigid or flexible. The body portion may be more rigid than the force modulating flexure in the plane of movement so that the body portion resists deformation when the SMA device contracts. The body portion may be an extension of the coupling link and / or the force modulating flexure.

[0088] The force adjustment flexure may be configured to flex so as to cause the second component to move in a direction in the aforementioned plane of movement.

[0089] For example, a force adjustment flexure may be connected to the first component at a first connection point. By deforming the force adjustment flexure (due to contraction of the SMA wire), the main body portion rotates around the first connection point in the plane of motion and / or translates relative to the first connection point. This rotation and / or translation of the main body portion amplifies the displacement of the second component.

[0090] In such an embodiment, when the SMA wire contracts, it can pull the main body portion in the direction of contraction, thereby exerting a force on the force adjustment flexure. This may cause the force adjustment flexure to deform (or bend) when under compression, and the connecting link generally deforms when under tension. The force adjustment flexure can be considered as a flexible arm that is primarily responsible for displacement amplification. The force adjustment flexure can allow the main body portion to rotate about the first connection point and / or translate relative to the first connection point, thereby changing its orientation. Advantageously, the bending of the force adjustment flexure can allow a greater displacement of the second component than the degree of contraction of at least one SMA device along the plane of movement.

[0091] Broadly speaking, the force adjustment mechanism can connect the movable component and the support structure in two configurations. In the first configuration, the main body is connected to the support structure by the SMA wire and the force adjustment mechanism. When the SMA wire is retracted, the connecting rod pulls the movable component. In the second (reverse) configuration, the main body is connected to the movable component (rather than the support structure) by the SMA wire and the force adjustment flexible member. When the SMA wire is retracted, the connecting rod pulls the support structure. Therefore, although the first component and the second component are referred to as the support structure and the movable component in this article for the purpose of illustration, it should be understood that the two components move only relative to each other. Although the movable component is described as moving relative to the support structure, this movement is due to the movement defined relative to the reference frame on the support structure. It is likely that in a larger device in which the SMA actuator assembly is integrated, the support structure moves while the movable component remains stationary, or both the support structure and the movable component move.

[0092] Optionally, for example, in embodiments where the force adjustment mechanism and the coupling link include a flexure, the force adjustment flexure and / or the coupling link are configured to have the same or different stiffness in the direction along the plane of movement. For example, the force adjustment flexure may include a proximal portion adjacent to the first connection point and a distal portion distal to the first connection point, wherein the proximal portion of the force adjustment flexure is configured to have the same stiffness as the distal portion, or a lower stiffness than the distal portion, or a higher stiffness than the distal portion along its length in the direction along the plane of movement. Such an arrangement may advantageously allow deformation characteristics in the force adjustment flexure and / or the coupling link to be adjusted so as to achieve a desired rotation / translation in the main body portion.

[0093] Optionally, for example in embodiments where the force adjustment mechanism and the coupling link include a flexure, the coupling link is configured along its length to have a higher stiffness than the force adjustment flexure or substantially the same stiffness as the force adjustment flexure. Higher stiffness in the coupling link can advantageously allow for more precise movement control.

[0094] Alternatively, for example in embodiments where the force adjustment mechanism and the coupling link comprise a flexure, the coupling link is configured along its length to have a lower stiffness than the force adjustment flexure. The coupling link is only responsible for transmitting motion in a direction along the plane of movement, so during contraction of the SMA wire, the coupling link may generally be in tension, so the coupling link may be flexible in any other direction. In some embodiments, the coupling flexure may be replaced by a cable or wire.

[0095] Optionally, the connecting rod extends along the side surface of the second component.For example, the connecting rod can pull the movable component in the direction along the connecting rod to achieve movement.

[0096] Optionally, for example, in embodiments where the force adjustment mechanism and the coupling link include a flexure, at least one of the force adjustment flexure and the coupling link is configured to have a lower stiffness in a direction along the plane of movement than in any other direction to facilitate rotation and / or translation of the main body portion. For example, the force adjustment flexure may be formed of a thin strip that is flexible only in the plane of movement but is rigid along the optical axis (e.g., perpendicular to the plane of movement). Preferably, both the force adjustment flexure and the coupling link are flexible in a direction perpendicular to the actuation force. Advantageously, such an arrangement can ensure that the second component moves only within the plane of movement, thereby providing more precise movement control and constraining movement along the optical axis.

[0097] Optionally, during rotation and / or translation of the body portion, the orientation of the body portion relative to the first connection point changes within any range of less than 20 degrees, less than 10 degrees or less than 8 degrees. Preferably, the range is less than 5 degrees.

[0098] Optionally, the orientation of the force adjustment flexure relative to the SMA wire corresponds to or contributes to the degree of amplification of the displacement of the second component. Optionally, the force adjustment flexure extends from the main body portion to the SMA wire at an obtuse angle, but preferably, the force adjustment flexure extends from the main body portion to the SMA wire at an acute angle. A smaller angle can allow a higher degree of displacement amplification, but can also reduce the output force used to move the second component. More specifically, the SMA wire can extend from the main body portion to the first component in a first direction, and the force adjustment flexure extends from the main body portion to the first component in a third direction, and the angle between the first direction and the third direction is less than 45°, preferably less than 40°, preferably less than 20°, and preferably less than 10°. This can be applied at least to the center of the operating range of movement of the second component relative to the first component. For a given contraction of the SMA wire, a smaller angle can advantageously allow the force adjustment flexure to bend more. The bending of the force adjustment flexure can advantageously increase the stroke. Optionally, the angle between the first direction and the third direction is greater than 2°, preferably greater than 5°, optionally at least 10° and optionally at least 20°.

[0099] Advantageously, such an arrangement can ensure that the force output of the flexure means is sufficient to achieve a desired displacement in the movable member. More preferably, the angle is in the range between 10 and 35 degrees, and preferably in the range between 10 and 20 degrees.

[0100] Optionally, a force adjustment flexure is located between the SMA wire and the coupling link, the force adjustment flexure comprising a first portion connected to the main body portion, the first portion being normally in compression during operation; and a second portion connected between the first portion and the first member, the second portion being normally in tension during operation and configured to bend more than the first portion. That is, although most of the force adjustment flexure is normally in compression during operation, there may be a portion of the force adjustment flexure that is normally in tension, wherein the portion of the force adjustment flexure that is normally in tension may yield to a greater degree during operation.

[0101] Alternatively, the force regulating flexure may be a simple flexure that is normally in compression during operation.

[0102] Optionally, the actuation unit comprises another SMA wire connected between the first component and the coupling link and configured to apply another force to the coupling link, so that the coupling link applies another actuation force to the second component in a direction perpendicular to the actuation force.

[0103] The further SMA wire may be connected to a midpoint of the coupling link.The further SMA wire may extend in a direction substantially perpendicular to the direction in which the coupling link extends.

[0104] The force adjustment mechanism may include a force adjustment flexure connected between the first component and the coupling link. The SMA wire may be connected to the force adjustment flexure (eg, a midpoint of the force adjustment flexure) and may extend in a direction substantially perpendicular to the direction in which the force adjustment flexure extends.

[0105] Optionally, the force modulating flexure is elongated and rigid along its length and flexible in a direction perpendicular to its length.

[0106] Optionally, the force modulating flexure and / or coupling link are formed from a sheet material (eg, a metal sheet) having a vertically extending portion. Optionally, the body portion includes an integrally formed crimp for retaining the SMA wire.

[0107] Optionally, the sheet material (eg metal sheet) has a thickness ranging from 40 μm to 80 μm.

[0108] Optionally, in a plan view, the SMA wire extends from the first connection point at a first offset distance, and the second flexible arm extends from the first connection point at a second offset distance, wherein a ratio of the second offset distance to the first offset distance corresponds to a degree of amplification of the displacement of the movable component, and the ratio of the second offset to the first offset is at least greater than 1, or at least 1.2, or at least 1.5, or at least 2. The force adjustment mechanism (the main body and the force adjustment flexible member) can be regarded as a lever system, so the relative positions of the force input to the lever system and the force output from the lever system can affect the degree of displacement amplification.

[0109] Optionally, the force adjustment mechanism is configured to provide a conductive path between the SMA wire and the first component, in particular a conductive circuit of the first component. This allows an electrical control signal to be applied to the SMA wire without requiring additional electrical connections of the SMA wire.

[0110] Optionally, the force adjustment mechanism includes an electrical break for routing the conductive path. For example, the force adjustment mechanism may include at least two conductive paths, wherein the electrical break is formed on one of the conductive paths to allow current to flow in two opposite directions in the two conductive paths. Advantageously, such an arrangement may allow electromagnetic interference from the two conductive paths to at least partially cancel each other out.

[0111] Optionally, the actuator assembly comprises a support located between one of the one or more actuation units and the first component or the second component along the main axis.The support may help to maintain the actuation unit (eg the flexure means) substantially in a plane.

[0112] Optionally, the support is in contact with a portion of the actuating unit that is wider in the plane of movement than the coupling link, optionally, wherein the main body portion is wider in the plane of movement than the coupling link and the support is in contact with the main body portion of the actuating unit. The main body portion provides a convenient location for contacting the support due to its greater width. The support device can be provided without significantly reducing the design freedom of the flexible device of the actuating unit.

[0113] Optionally, the actuator assembly includes two supports, one support is located between one of the one or more actuating units and the first component, and the other support is located between the actuating unit and the second component. The combination of supports helps to keep the actuating unit in its target plane. Alternatively, the support is located between the actuating unit and one of the first component and the second component, and the actuating unit is pre-stressed toward the one of the first component and the second component. Optionally, a part of the actuating unit extends at an oblique angle relative to the moving plane so as to bias the actuating unit onto the support in a tension state. Optionally, the component is an SMA wire, a connecting rod, or a force adjustment flexible member of a force adjustment mechanism. These devices may be desirable to reduce the number of moving parts and reduce manufacturing costs.

[0114] Optionally, the force adjustment mechanism includes: a rolling element, the SMA wire and the coupling link are connected to the rolling element; and at least one surface, the rolling element rolling on the at least one surface in response to the input force applied by the SMA wire, thereby applying the output force to the coupling link. The rolling element can help increase the effective total length of the SMA wire, thereby increasing the achievable travel.

[0115] Optionally, the actuator assembly comprises two actuation units arranged to apply an actuation force to the second component in a perpendicular direction, such that a connecting link of each of the two actuation units is flexible in the direction of the actuation force of the other of the two actuation units.

[0116] For example, the force adjustment mechanisms of more than one actuation unit may be disposed on two diagonally opposite corners of the actuator assembly. That is, each actuation unit may include a force adjustment flexure configured to provide displacement amplification in a corresponding direction.

[0117] For each of the force adjustment mechanisms, the coupling link is flexible, which can be defined by the coupling link generating a relatively small "reaction" force on the movable part in response to the actuation force of the other of the two actuation units. For example, within the operating range of movement of the second part relative to the first part, the reaction force can be less than 25%, or less than 10%, or less than 5%, or less than 1% of the actuation force.

[0118] Alternatively or additionally, the two force adjustment mechanisms of the actuation unit are stacked along the optical axis, or at least partially overlap each other. They can be arranged on the same corner of the actuator assembly and can be placed in a mirror configuration. That is, each actuation unit can include a force adjustment flexure configured to provide displacement amplification in the corresponding direction.

[0119] Optionally, a force adjustment mechanism of a respective actuation unit is provided at each corner portion of the actuator assembly, wherein each actuation unit may be configured to provide displacement amplification in a respective direction perpendicular to the other.

[0120] Optionally, each force adjustment mechanism has at least one coupling link connected to a respective side of the second component.

[0121] Optionally, each force adjustment mechanism is attached to the first component by a corresponding SMA wire, wherein each SMA wire is configured to deform the force adjustment flexure when contracted, thereby moving the second component in a corresponding direction along the translation plane. More specifically, each force adjustment mechanism is configured to amplify the displacement in the corresponding direction.

[0122] Optionally, the actuator assembly comprises more than one force adjustment mechanism, wherein the second component is formed from more than one component, each component being integrally formed with a respective force adjustment mechanism.

[0123] Optionally, the actuator assembly comprises an actuation unit arranged to enable the second component to rotate relative to the first component about the main axis. Alternatively, the actuator assembly may comprise four actuation units arranged to enable the second component to move relative to the first component in any direction within the plane of movement without applying any net torque to the second component about the main axis perpendicular to the plane of movement.

[0124] Optionally, each of the first pair of actuation units is configured to apply a torque to the second component in one direction about the main axis, and each of the second pair of actuation units is configured to apply a torque to the second component in another direction about the main axis.

[0125] Optionally, the four actuation units are arranged such that their flexures are arranged in a ring at different angular positions around the main axis and such that the angular position of the coupling link of each actuation unit at least partially overlaps the angular position of the SMA wire of another actuation unit.

[0126] The SMA wire of each actuation unit may be substantially parallel to the coupling link of another actuation unit.

[0127] Optionally, the actuator assembly comprises a plurality of actuating units arranged in the same plane perpendicular to the main axis. The actuating units may be positioned side by side, thereby limiting the extension of the actuator assembly in the direction of the main axis. Optionally, the actuator assembly comprises two actuating units arranged in different planes perpendicular to the main axis. The actuating units may be stacked, thereby avoiding an increase in the occupied area of ​​the actuator assembly in a plan view.

[0128] Optionally, one or more actuation units are of a first type, and the actuator assembly further comprises: One or more actuation units of a second type, each actuation unit of the second type comprising: - a force adjustment mechanism connected to the second component; - a connecting rod connected between the force adjustment mechanism and the first component; and - an SMA wire connected between the second component and the force adjustment mechanism for applying an input force to the force adjustment mechanism, thereby causing the force adjustment mechanism to apply an output force to the coupling link, and causing the coupling link to apply an actuation force to the first component; Therein, the connecting rod is flexible in a direction perpendicular to the direction of the actuating force.

[0129] The second type of actuation unit may have any of the above-described features of the first type of actuation unit, with the exception that references to the first component should be replaced by references to the second component and references to the second component should be replaced by references to the first component.

[0130] In some arrangements, for each pair of actuation units (i.e., the aforementioned first pair and second pair), the angular position of the coupling link of each actuation unit in the pair at least partially overlaps the angular position of the SMA wire of the other actuation unit in the pair. Thus, the force adjustment mechanisms of the actuation units in the pair may have similar angular positions. The force adjustment mechanisms of the actuation units in the pair (and / or the actuation units as a whole) may be offset from each other in a direction parallel to the main axis. The force adjustment mechanisms of the actuation units in different pairs may be angularly spaced apart from each other by about 180°.

[0131] In some arrangements, for each actuation unit, the angular position of the coupling link at least partially overlaps with the SMA wire of another actuation unit, and the angular position of the SMA wire at least partially overlaps with the coupling link of a different another actuation unit. Thus, the force adjustment mechanisms of the actuation units can be at different angular positions and can be angularly spaced about 90° from each other, for example.

[0132] Two of the four actuation units may be of the first type and two of the four actuation units may be of the second type.

[0133] The four actuation units may have a substantially square or rectangular footprint when viewed along the major axis, with the SMA wires along each edge of the square or rectangle and the force adjustment mechanisms at each corner of the square or rectangle.

[0134] According to another aspect of the present invention, there is provided an actuator assembly, the actuator assembly comprising: a first component and a second component, the first component and the second component being movable relative to each other; One or more actuation units, each actuation unit comprising: a force adjustment mechanism connected to the first component; a connecting rod connected between the force adjustment mechanism and the second component; and an SMA wire connected between the first component and the force adjustment mechanism for applying an input force to the force adjustment mechanism, thereby causing the force adjustment mechanism to apply an output force to the coupling link, and causing the coupling link to apply an actuation force to the second component; wherein the coupling link is flexible in a direction perpendicular to the direction of the actuation force; and One or more supports for each of the one or more actuation units, each support being located between an actuation unit and the first component or the second component.

[0135] This arrangement differs from prior art systems in that one or more supports are provided to maintain a target position of the one or more actuation units along the primary axis.The one or more supports reduce the likelihood of the flexure means deforming (eg buckling) and thereby suffering reduced functionality.

[0136] The support may have any of the features described above.

[0137] According to another aspect of the present invention, there is provided a camera assembly comprising an actuator assembly according to the first aspect or the second aspect, wherein the first component or the second component comprises a lens having an optical axis perpendicular to the plane of movement, wherein the actuator assembly moves the lens to provide optical image stabilization (OIS) for the camera assembly.

[0138] According to another aspect of the present invention, there is provided a camera assembly comprising an actuator assembly according to the first aspect or the second aspect, wherein the first component or the second component comprises an image sensor having an imaging axis perpendicular to the plane of movement, wherein the actuator assembly moves the image sensor or provides optical image stabilization (OIS) for the camera assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0139] Certain embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figures 1A to 1E are schematic cross-sectional views of different variations of camera modules including actuator assemblies; Figure 2 is a schematic perspective view of an actuator assembly; Figure 3A and Figure 3B are perspective and plan views of an actuation unit forming part of an actuator assembly; Figure 4 is a schematic plan view of an arrangement of four actuation units; Figure 5 is a schematic perspective view of an arrangement of eight actuation units; Fig. 6A and Figure 6B schematically depicts an embodiment of an actuator assembly comprising an actuation unit; Figure 7 schematically illustrates the height of the actuator assembly of FIG. 6 ; FIG. 8A to FIG. 8B schematically depicts an actuator assembly comprising an actuation unit; Fig. 9 schematically depicts an actuation unit for use in an actuator assembly; Fig.10schematically depicts an embodiment of an actuator assembly comprising an actuation unit; Fig.11A and Fig. 11B schematically depicts an embodiment of an actuator assembly comprising an actuation unit; Fig. 12A and Fig. 12B schematically depicts another actuator assembly according to the present invention; and FIG. 13A to FIG. 13C Structural details of the actuator assembly are schematically depicted.

[0140] Fig.14 is a schematic plan view of an SMA actuator assembly including four actuation units located in two planes; Fig.15 is a schematic plan view of an SMA actuator assembly including four actuation units located in one plane; Fig.16 yes Figure 4 A schematic perspective view of an SMA actuator assembly is shown; Fig.17 is a schematic plan view of an SMA actuator assembly including four actuation units; Fig.18 is a schematic diagram of a flexure and wire that biases an actuation unit against a support; Fig.19 is a schematic diagram of an actuation unit having an integral crimping member; Figure 20 to Figure 25 is a schematic plan view of an alternative SMA actuator assembly, each SMA actuator assembly including four actuation units; and Fig.26 is a schematic diagram showing the line on the pulley. Detailed Description

[0141] Camera Module Figures 1A to 1E Different variants of a device 1 comprising an actuator assembly 2 are schematically shown. The device 1 is, for example, a camera module 1. Typically, the device 1 will be incorporated into a portable electronic device such as a smartphone. Therefore, miniaturization may be an important design criterion.

[0142] Figure 2The actuator assembly 2 is schematically shown. The actuator assembly 2 comprises a support structure 10 and a movable part 20. The movable part 20 is movable relative to the support structure 10. When the actuator assembly 2 is included in, for example, an apparatus 1, the support structure 10 may be fixed relative to the body of the apparatus 1. However, in general, the support structure 10 need not be stationary and may be movable relative to the apparatus 1 or movable within the apparatus 1. The actuator assembly 2 comprises one or more actuation units 30. Each actuation unit 30 is configured to apply an actuation force to the movable part 20, which actuation force is capable of causing the movable part 20 to move relative to the support structure 10.

[0143] The movable part 20 may be supported on the support structure 10 (i.e. suspended on the support structure 10) only by the actuation unit 30. Alternatively, the actuator assembly 2 may include a support device 40 that supports the movable part 20 on the support structure 10. The actuation unit 30 and the support device 40 may together support the movable part 20 on the support structure 10. The support device 40 may have any suitable form that allows the movable part 20 to move with one or more degrees of freedom (DOF) relative to the support structure 10. The actuation unit 30 and / or the support device 40 may constrain (i.e. reduce or prevent) other degrees of freedom of movement of the movable part 20 relative to the support structure 10. To this end, the support device 40 may, for example, include one or more of the following bearings: a rolling bearing (such as a ball bearing), a flexible bearing (i.e. an arrangement of flexible members or other elastic elements that guide the movement) or a sliding (i.e. sliding contact) bearing.

[0144] The principal axis P may be defined with reference to the actuator assembly 2 and / or the support structure 10. The principal axis P may extend through the actuator assembly 2, for example through the center of the actuator assembly 2. In some examples, the actuator assembly 2, the support structure 10 and / or the movable component 20 extend primarily in a direction perpendicular to the principal axis P. In other words, the actuator assembly 2, the support structure 10 and / or the movable component 20 extend less along the principal axis P than in any direction perpendicular to the principal axis P. Alternatively or additionally, the support structure 10 and / or the movable component 20 may include a planar component extending perpendicular to the principal axis P. Alternatively or additionally, in examples where the device 1 includes an optical element having an optical axis (such as a lens assembly 3) or an imaging element having an imaging axis (such as an imager sensor 4), when the movable component 20 is in a central position or central orientation (e.g., see Figure 3A ), the main axis P can be parallel to such an axis and / or can coincide with such an axis.

[0145] Typically, the movable component 20 can be movable relative to the support structure 10 with up to six degrees of freedom (DOF). In the context of describing the degrees of freedom of movement, the main axis P can also be referred to as the z-axis, and the other two axes perpendicular to the main axis P and to each other can be referred to as the x-axis and the y-axis. The movable component 20 can be movable relative to the support structure 10 in all or any subset of the following degrees of freedom (including only one degree of freedom):

[0146] Tx and Ty: translational movement in the xy plane. In other words, the movable part 20 can be independently moved along the x-axis and the y-axis. The movable part 20 can be moved to any position in the xy plane within the range of movement. Instead of such a planar movement, the movable part 20 can be linearly movable, for example along the x-axis or the y-axis.

[0147] Rx and Ry: rotational movement (or simply rotation or tilt) about the x-axis and the y-axis. In other words, the movable part 20 can rotate about any line perpendicular to the main axis P. The movable part 20 can be rotated to any rotational position (i.e., to any orientation) within the range of movement. Instead of such a dual-axis rotation, the movable part 20 can rotate about a single axis (e.g., about the x-axis or the y-axis).

[0148] Tz: translational movement along the z axis. The movable component 20 can be moved to any translational position along the z axis within the movement range.

[0149] Rz: rotational movement about the z axis (or simply rotation). The movable part 20 can be rotated to any rotational position (ie, to any orientation) within the range of movement.

[0150] In some examples, the movable part 20 can be supported, for example, by a support device 40 so as to allow translational movement (Tx, Ty) in the xy plane and / or rotational movement (Rz) about the z axis. The translational movement (Tz) along the z axis and the rotational movement (Rx, Ry) about the x axis and the y axis can be constrained. For example, such support can be provided by a support device 40 having a suitable arrangement of ball bearings or sliding bearings that generate a support force in the +z direction and a biasing device that generates a biasing force in the -z direction. Examples of actuator assemblies having such support devices are disclosed in WO 2013 / 175197 A1 and WO 2017 / 072525 A1, each of which is incorporated herein by reference.

[0151] In some examples, the movable part 20 may be supported to allow tilting (Rx, Ry) about the x-axis and the y-axis and optionally rotation (Rz) about the z-axis. Other degrees of freedom of movement (i.e., Tx, Ty, Tz, Rz or Tx, Ty, Tz) may be constrained. Such support may be provided by a support device 40, for example in the form of a gimbal. An example of such a support device 40 is disclosed in WO 2021 / 209770 A1, which is incorporated herein by reference. Alternatively, such support may be provided only by the actuation unit 30, similar to WO 2011 / 104518 A1, which discloses an actuator assembly having 8 SMA wires connected between the support structure 10 and the movable part 20. WO 2011 / 104518 A1 is incorporated herein by reference.

[0152] In some examples, the movable part 20 may be supported to allow three-dimensional translational movement (Tx, Ty, Tz), while rotational movement (Rx, Ry, Rz) may be constrained. Such support may be provided by a support device 40 (e.g. in the form of nested linear supports). An example of such a support device 40 is disclosed in WO 2021 / 209769 A1, which is incorporated herein by reference. Alternatively, similar to WO 2011 / 104518 A1, such support may be provided only by the actuation unit 30.

[0153] Alternatively or additionally, the movable part 20 can move in other degrees of freedom. The movable part 20 can move in a degree of freedom that is a combination of any two or more of Tx, Ty, Tx, Rx, Ry and Rz. For example, the movable part 20 can move along a spiral path around the z axis (i.e., move spirally), and thus simultaneously move along the z axis and rotate around the z axis. In other words, Tz and Rz movements can be combined. An example of such a spiral actuator assembly is disclosed in WO2019 / 243849 A1, which is incorporated herein by reference.

[0154] The actuation unit 30 is connected between the support structure 10 and the movable part 20. The actuation unit 30 is arranged to apply an actuation force F between the movable part 20 and the support structure 10 (see, for example Figure 4 and Figure 5 ). Selectively varying the actuation force F can cause the movable part 20 to move relative to the support structure 10, for example within the degrees of freedom allowed by the bearing device 40. Thus, the actuation unit 30 is capable of driving the movement of the movable part 20 relative to the support structure 10.

[0155] The support means 40 may move the movable part 20 in a direction different from the direction of the actuation force F. In a simple example in this respect, one component of each actuation force F causes a movement of the movable part 20 and another component of each actuation force F opposes the force generated by the support means 40 .

[0156] The camera module 1 also includes a lens assembly 3 and an image sensor 4. The lens assembly 3 includes one or more lenses configured to focus an image on the image sensor 4. The lens assembly 3 defines an optical axis O. The lens assembly 3 may include a lens holder, which supports the one or more lenses (e.g., in the form of a cylindrical body). The image sensor 4 captures the image and may be of any suitable type, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device. The camera module 1 may be a compact camera module in which each lens has a diameter of 20 mm or less, such as a diameter of 12 mm or less.

[0157] exist Figure 1A In the illustrated ("sensor-shift") variant of the camera module 1, the movable part 20 comprises an image sensor 4. The lens assembly 3 may be fixed relative to the support structure 10, or may be movable relative to the support structure 10 along an optical axis O (as described below).

[0158] In a ("lens-shift") variation, the image sensor 4 is fixed relative to the support structure 10, and the movable part 20 comprises a lens assembly 3. The lens assembly 3 may be movable relative to the movable part 20 along an optical axis O, as described below.

[0159] In both variants, the actuator assembly 2 is configured to move the lens assembly 3 relative to the image sensor 4 in any direction in a plane perpendicular to the main axis P and therefore perpendicular to the optical axis O. This movement has the effect of shifting the image on the image sensor 4 and enables optical image stabilization (OIS) to be implemented in the camera module 1. In the sensor-shift variant, the movable part 20 may also be rotatable about the main axis P so as to also be able to compensate for roll.

[0160] exist Figure 1C In the illustrated (“module-tilt”) variation, the movable part 20 includes both the lens assembly 3 and the image sensor 4. Again, as described below, the lens assembly 3 can be moved relative to the movable part 20 along the optical axis O. The actuator assembly 2 is configured to tilt the movable part 20 about two axes perpendicular to the main axis P and perpendicular to each other, and optionally to rotate the movable part 20 about the main axis P, so that OIS can be implemented in the camera module 1.

[0161] exist Figure 1D In the illustrated ("autofocus") variant, the movable part 20 comprises a lens assembly 3 and the actuator assembly 2 moves the movable part 20 relative to the support structure 10 along the main axis P and thus along the optical axis O. Such movement has the effect of adjusting the focus of the image on the image sensor 4. Thus, an autofocus (AF) or zoom function can be implemented in the camera module 1.

[0162] In some examples (not shown), the camera module 1 may include a Figures 1A to 1C The first actuator assembly of the OIS shown in FIG. Figure 1D AF shown. One or both of the first actuator assembly and the second actuator assembly may correspond to the actuator assembly 2 as described herein. One of the first actuator assembly and the second actuator assembly may be another type of SMA actuator assembly or may be a non-SMA actuator assembly, such as a voice-coil motor (VCM) actuator assembly. As will be appreciated, in the lens shift and module tilt variations, the support structure 10 of the second actuator assembly 2 is fixed to (or corresponds to) the movable part 20 of the first actuator assembly 2.

[0163] exist Figure 1E In the illustrated (“AF+OIS”) variation, the movable part 20 comprises a lens assembly 3 and the actuator assembly 2 produces a three-dimensional translational movement of the movable part 20 relative to the support structure 10 , enabling both AF and OIS to be achieved using one actuator assembly 2 .

[0164] Other variations are possible. For example, in an autofocus variation or an AF+OIS variation, the movable part 20 may include an image sensor 4 instead of a lens assembly 3. The camera module 1 may include a combination of the above features, such as (a) lens shift and sensor shift, (b) module tilt and lens shift or sensor shift and autofocus, or (c) module tilt and AF+OIS.

[0165] The camera module 1 further comprises a controller 8. The controller 8 may be implemented in the form of an integrated circuit (IC) chip. The controller 8 generates a drive signal for the actuation unit 30, in particular for the SMA wire 34 forming part of the actuation unit 30. The SMA material has the property that when heated it undergoes a solid-state phase change causing the SMA material to contract. Therefore, applying a drive signal to the SMA wire 34, thereby heating the SMA wire 34 by allowing current to flow, will cause the SMA wire 34 to contract and thus actuate the actuation unit 30 so as to move the movable part 20. The drive signal is selected to drive the movement of the movable part 20 in a desired manner, for example, so as to achieve OIS by stabilizing the image sensed by the image sensor 4, or to achieve AF / zoom by adjusting the focus of the image sensed by the image sensor 4. The controller 8 provides the generated drive signal to the SMA wire 34.

[0166] Optionally, the camera module 1 also includes a motion sensor (not shown), which may include a 3-axis gyroscope and a 3-axis accelerometer. The motion sensor may generate a signal representing the motion (specifically vibration or "shake") of the camera module 1, which may be processed to generate a signal representing the desired movement of the movable component 20 to compensate for such shake. The controller 8 receives such a signal and may generate a drive signal for the SMA wire 34 to implement OIS.

[0167] Although the actuator assembly 2 is described in conjunction with the camera module 1, it will be understood that the actuator assembly 2 may be used in any device in which it is desired that the movable component 20 be moved relative to the support structure 10, for example, to provide tactile feedback in a tactile feedback device or to move a projector or display in an augmented reality (AR) or virtual reality (VR) device.

[0168] Actuating unit Figure 3A A perspective view of an example of an actuation unit 30 is shown. Figure 3B A portion of the actuation unit 30 is shown in a plan view.

[0169] exist Figure 3A and Figure 3B A single actuation unit 30 is shown in FIG. 1 , but it should be understood that the actuator assembly 2 typically has a plurality of actuation units 30, each of which may include a reference Figure 3A and Figure 3B Same parts as described.

[0170] The actuation unit 30 includes a body portion 31 to which several other components of the actuation unit 30 are connected, as described below. Typically, the body portion 31 is relatively rigid compared to the other components of the actuation unit and does not deform significantly when the actuation unit 30 is actuated. In some examples, the body portion 31 is not a separate component of the actuation unit 30. For example, the body portion 31 can be defined as part of one of the other components of the actuation unit 30, or simply as a connection point between the other components of the actuation unit 30.

[0171] The actuation unit 30 further includes a force adjustment flexible member 32. The force adjustment flexible member 32 is connected between the main body portion 31 and the support structure 10. One end of the force adjustment flexible member 32 is connected to the main body portion 31. The other end of the force adjustment flexible member 32 is connected to the support structure 10, for example, via a foot portion 36. The foot portion 36 is fixed relative to the support structure 10. In the depicted design, the force adjustment flexible member is integrally formed with the foot portion 36 and the main body portion 31, for example, formed from a single sheet of material (such as metal). The force adjustment flexible member 32 allows the main body portion 31 to pivot relative to the support structure 10 about an effective pivot point P. Although the effective pivot point P is Figure 3B 10 is shown as being positioned in the middle of the force adjustment flexure 32, but the effective pivot point P can have a different location and need not be located on the force adjustment flexure 32. This pivotal movement of the main body portion 31 relative to the support structure 10 is initially performed in a direction substantially perpendicular to the force adjustment flexure 32.

[0172] The actuation unit 30 further comprises an SMA element 34. In this example, the SMA element 34 is an SMA wire 34. The SMA wire 34 is connected between the body portion 31 and the support structure 10. One end of the SMA wire 34 is connected to the support structure 10, for example, by a crimp 15. The other end of the SMA wire 34 is connected to the body portion 31, for example, by a crimp 35.

[0173] The actuation unit 30 further includes a coupling link 33. In this example, the coupling link 33 is a coupling flexible member 33. The coupling flexible member 33 is connected between the main body portion 31 and the movable part 20. One end of the coupling flexible member 33 is connected to the main body portion 31. The other end of the coupling flexible member 33 is connected to the movable part 20. The coupling link 33 transfers or transmits the actuation force F from the main body portion 31 to the movable part 20. The coupling link 33 is flexible (i.e., deformable) in a direction (or multiple directions) perpendicular to the actuation force F. This allows the movable part 20 to move in a direction other than the direction of the coupling flexible member 33 and the actuation force F. For example, this may be required in a case where different actuation units 30 move the movable part 20 in different directions.

[0174] The SMA wire 34 is arranged to apply an input force Fi to the main body portion 31 when contracted. The input force Fi acts parallel to the length of the SMA wire 34. The force adjustment flexure 32 and the main body portion 31 are arranged to adjust the input force Fi so as to generate an actuation force F, which is transmitted from the main body portion 31 to the movable member 20 through the coupling flexure 33. In particular, the input force Fi deforms the force adjustment flexure 32, thereby causing the main body portion 31 to pivot about the effective pivot point P. In simple terms, the force adjustment flexure 32 and the main body portion 31 act like a lever. The force adjustment flexure 32 and the main body portion 31 can adjust the direction and / or magnitude of the input force Fi so as to generate the actuation force F.

[0175] exist Figure 3A and Figure 3B In the example shown, the coupling flexure 33 is at an angle of approximately 90° relative to the SMA wire 34. Furthermore, in this example, the force adjustment flexure 32 is arranged at an angle α of approximately 30° relative to the SMA wire 34, and when the SMA wire 34 contracts, the force adjustment flexure 32 is placed in tension. Therefore, upon contraction of the SMA wire 34 and the resulting deformation of the force adjustment flexure 32, the main body portion 31 initially moves at an angle of approximately 60° (90°-α) relative to the length of the SMA wire 34. Therefore, it should be understood that in this example, the force is de-amplified and the stroke is amplified, while the direction of the force / movement is changed by an angle of approximately 90°.

[0176] More generally, the change in direction of the force depends on the angle between the SMA wire 34 and the coupling flexure 33. Also more generally, the change in magnitude of the force depends on the ratio of i) the distance Ds from the effective pivot point P to the line where the SMA wire 34 is located and ii) the distance Dc from the effective pivot point P to the line where the coupling flexure 33 is located. In particular, F / Fi is proportional to Ds / Dc. If the line where the SMA wire 34 is located is closer to the effective pivot point P than the line where the coupling flexure 33 is located, the input force Fi is de-amplified. At the same time, the movement of the movable part 20 is amplified, that is, increased relative to the change in the length of the SMA wire 34. Alternatively, if the line where the SMA wire 34 is located is farther away from the effective pivot point P than the line where the coupling flexure 33 is located, the input force Fi is amplified. At the same time, the movement of the movable part 20 is de-amplified, that is, reduced relative to the change in the length of the SMA wire 34. Thus, the actuation unit 30 can be configured to amplify the movement caused by the contraction of the SMA wire 34 or to amplify the force caused by the contraction of the SMA wire 34. The actuation unit 30 can also be configured to change the direction of the input force Fi. In some examples, the actuation unit 30 is configured to change the direction of the input force Fi without changing the magnitude of the force or movement.

[0177] The ratio Ds / Dc depends on the position of the end of the SMA wire 34 connected to the main body portion 31 and the position of the end of the coupling flexure 33 connected to the main body portion 31. As an example, the coupling flexure 33 may be connected to the main body portion 31. Figure 3B The distance Ds is increased by moving the main body portion 31 further to the left as shown in FIG. 1 , thereby reducing Ds / Dc and thus increasing the amount of travel amplification. The ratio Ds / Dc also depends on the orientation of the SMA wire 34 and the orientation of the coupling flexure 33. Such orientations can be defined with reference to the force adjustment flexure 32 (as above) or any suitable reference line. As an example, the force adjustment flexure 32 can be defined by using Figure 3B The SMA wire 34 shown in FIG. 1 is angled so that Figure 3B The SMA wire 34 shown in FIG. 1 extends closer to the effective pivot point P to reduce the distance Ds, thereby reducing Ds / Dc and thus increasing the amount of stroke amplification. In summary, the amount by which the force adjustment flexure 32 amplifies or de-amplifies the force / stroke of the SMA wire 34 can be customized in the following ways:

[0178] adjusting the angle of the SMA wire 34 (and therefore the input force Fi); adjusting the location of the connection point between the SMA wire 34 and the body portion 31 (and therefore adjusting the location at which the input force Fi acts on the body portion 31); Adjusting the angle of the coupling flexure 33 (and therefore the actuation force F); and / or The position of the connection point between the coupling flexure 33 and the main body portion 31 is adjusted (and thus the position of the main body portion 31 at which the actuation force F is applied).

[0179] In some examples, at least one actuation unit 30 (preferably each actuation unit 30) is configured to cause the force adjustment flexible member 32 to amplify the amount of contraction of the SMA wire 34. For example, such amplification factor may be greater than 1.5, preferably greater than 2, and further preferably greater than 3. To this end, in Figure 3A and Figure 3B In the example shown, the angle α between the SMA wire 34 and the force adjustment flexure 32 can be in the range of 0 to 45 degrees, preferably in the range of 13 to 40 degrees. However, in general, the angle α can have other values, and the connection point of the SMA wire 34 and / or the coupling flexure 33 to the main body portion 31 can be adjusted to achieve the desired amount of amplification.

[0180] As mentioned above, in Figure 3A and Figure 3B In the example shown, the coupling flexure 33 is at an angle of about 90 degrees relative to the SMA wire 34. This allows the actuation unit 30 to turn around the corner of the movable part 20 in a compact manner. The angle between the coupling flexure 33 and the SMA wire 34 can be in the range of 70 to 110 degrees, preferably in the range of 80 to 100 degrees. However, in general, the angle between the coupling flexure 33 and the SMA wire 34 can be outside these ranges.

[0181] For example, in Figure 3C In the illustrated actuation unit 30 , the coupling flexure 33 is substantially perpendicular to the SMA wire 34 .

[0182] In the above example, the actuation unit 30 is arranged in a plane. In particular, at least when the actuator assembly 2 is in an initial configuration, the SMA wire 34, the connecting flexure 33 and the force adjustment flexure 32 are arranged to extend substantially in a common plane. This allows a compact configuration of the actuation unit 30. When implemented as a plate, the main body portion 31 can also be arranged to extend in this plane. However, in general, the components of the actuation unit 30 do not have to be arranged in a common plane. For example, the SMA wire 34 and / or the connecting flexure 33 can be angled relative to the plane.

[0183] In the above example, the force adjustment flexure 32 is placed in tension when the SMA wire 34 is contracted. This reduces the risk of the force adjustment flexure 32 bending and thus reduces the risk of damage to the actuator assembly and makes the actuator assembly 2 more reliable. However, the force adjustment flexure 32 may alternatively be arranged to be placed in compression when the SMA wire 34 is contracted. Figure 3BFor example, the force adjustment flexure 32 may extend from the connection point between the main body portion 31 and the force adjustment flexure 32 to the lower right side and thus be placed in a compressed state when the SMA wire 34 is contracted. An arrangement for placing the force adjustment flexure 32 in a compressed state is disclosed in WO 2022 / 084699 A1, which is incorporated herein by reference.

[0184] In the above example, the force adjustment flexure 32 and the SMA wire 34 are connected to the support structure 10 at one end, and the coupling flexure 33 is connected to the movable part 20 at one end. Generally, this arrangement can also be reversed, where the force adjustment flexure 32 and the SMA wire 34 are connected to the movable part 20 at one end, and the coupling flexure 33 is connected to the support structure 10 at one end.

[0185] In the above example, the actuation unit 30 includes a coupling link 33 in the form of a coupling flexible member 33. The purpose of the coupling link 33 is to allow the movable part 20 to move in a direction perpendicular to the actuation force F. However, in general, the actuation unit 33 does not need to include the coupling link 33 (for example, in an example in which the movable part 20 does not move in a direction perpendicular to the actuation force F). In addition, the coupling link 33 can be implemented as a component other than the coupling flexible member 33, for example, as a ball bearing or a sliding bearing, which is configured to transmit the actuation force F to the movable part 20 while allowing the movable part 20 to move in a direction perpendicular to the actuation force F. Such an alternative example of the coupling link 33 is disclosed in WO 2022 / 084699 A1.

[0186] Arrangement of four actuating units Figure 4 A plan view of an example of an actuator assembly 2 is schematically shown, showing the arrangement of the actuation units 30. In this example, the actuator assembly 2 comprises a total of four actuation units 30. The four actuation units 30 can apply an actuation force F between the movable part 20 and the support structure 10. The actuation force F is applied to the movable part 20 relative to the support structure 10.

[0187] Figure 4 The arrangement of the actuation unit 30 may for example be used in examples in which the movable part 20 is movable in a movement plane relative to the support structure 10. Thus, Tx, Ty and optionally Rz movements of the movable part 20 may be allowed.

[0188] Figure 4 The four actuation units 30 are in an arrangement capable of applying an actuation force F in order to move the movable part 20 relative to the support structure 10 to any position within a range of movement. The range of movement may be within a plane of movement perpendicular to the main axis P.

[0189] In particular, two actuation units 30 (eg, Figure 4 The top actuation unit and the bottom actuation unit in the embodiment of the present invention are arranged parallel to the first axis (e.g., Figure 4 The other two actuating units (e.g., Figure 4 The left actuation unit and the right actuation unit in the embodiment of the present invention are arranged in parallel to the second axis (for example, Figure 4 An actuation force F is applied in two opposite directions (the y-axis in FIG. 1 ), the second axis being perpendicular to the first axis. By appropriately varying the difference in the amount of actuation between the opposing actuation units 30, the movable component 20 can thus be independently moved along the first axis and the second axis. The opposing actuation forces F are not collinear, but are offset from each other in a direction perpendicular to the actuation forces. Providing opposing actuation units 30 allows control of the tension in the SMA wires 30 of the respective actuation units 30, which allows more accurate and reliable positioning of the movable component 20 compared to a case where the actuation units 30 are not opposed to each other.

[0190] In the example, none of the actuation forces F are collinear. This allows the arrangement of the actuation unit 30 to move the movable part 20 translationally without applying any net torque to the movable part 20. Thus, the movable part 20 can be moved translationally in the plane of movement without causing the movable part 20 to rotate in the plane of movement. In general, the arrangement of the actuation unit 30 is able to precisely control the torque or moment of the movable part 20 about the main axis P. Thus, the actuation unit 30 is able to rotate (or not rotate) the movable part 20 relative to the support structure about the main axis P.

[0191] In particular, two actuation units 30 (eg, Figure 4 The top actuation unit and the bottom actuation unit in the embodiment of the present invention are arranged to apply an actuation force F so as to generate a torque or moment between the movable part 20 and the support structure 2 in a first direction (e.g., clockwise) about the main axis P. The other two actuation units 30 (e.g., Figure 4 The left actuation unit 30 and the right actuation unit 30 in the two actuation units 30 are arranged to apply an actuation force F so as to generate a torque or moment between the movable part 20 and the support structure 2 in a second opposite direction (e.g., counterclockwise) about the main axis P. This allows the movable part 20 to be rotated by increasing or decreasing the tension of the SMA wire in either of the two actuation units 30 at the same time.

[0192] As shown, two actuation units 30 may be arranged to apply an actuation force in a corner portion of the actuator assembly 2. Another two actuation units 30 may be arranged to apply an actuation force in another opposite corner portion of the actuator assembly 2. The actuator assembly 2, in particular the movable component 20 and / or the support structure 10, may have a square or rectangular footprint. Each actuation unit 30 may be disposed on one of the four sides of the actuator assembly 2. In particular, each actuation unit 30 may be bent around a corner portion of the movable component 20 so that the SMA wire 34 and the connecting flexure 33 of each actuation unit 30 extend along an adjacent edge of the movable component 20. Thus, the actuation units 30 may, for example, be arranged as in Figure 3A and Figure 3B The four SMA wires 32 of the four actuation units 32 may extend along four different edges of the movable component 20 .

[0193] The arrangement of the actuation force F applied between the movable part 20 and the support structure 10 corresponds to the arrangement of the SMA wire 30 described in WO 2013 / 175197 A1, which is incorporated herein by reference.

[0194] In this example, the actuation force F is perpendicular to the main axis P and may be parallel to the plane of movement. However, in general, the actuation force F may be angled relative to the plane of movement. Thus, the actuation force F may have a component along the main axis P. This component along the main axis P may be resisted by the support device 40, for example, to provide for movement of the movable part 20 in the degrees of freedom allowed by the support device 40. In some examples, it may even be desirable that the actuation force F has a component parallel to the main axis P, for example in order to pressurize a sliding bearing or a rolling bearing arranged between the movable part 20 and the support structure 10.

[0195] Although for illustrative purposes, the arrangement of the actuation unit 30 is described as moving the movable part 20 in a movement plane (e.g., moving translationally along the x-axis and the y-axis, or moving rotationally about the main axis P), in other examples, the movable part 20 may be moved in different ways. For example, due to appropriate movement constraints provided by the support device 40, the same arrangement of the actuation force F can be used to tilt the movable part 20 relative to the support structure 10 about an axis perpendicular to the main axis. For example, the support device 40 may include a plurality of flexures for guiding the movable part 20 to tilt about an axis perpendicular to the main axis P. An example of such a support device 40 is described in WO2022 / 029441 A1, which is incorporated herein by reference.

[0196] Although the actuator assembly 2 is described herein in the context of four actuation units 30, typically the actuator assembly 2 may include fewer actuation units 30. For example, the actuator assembly 2 may include two actuation units 30, such as Figure 4 The two actuation units 30 are depicted in the upper left corner of FIG. The force applied to the movable part 20 by the two actuation units 30 can be opposed by the biasing force of one or more elastic elements (such as springs). Figure 4 , the two actuation units 30 in the lower right corner may be replaced by springs applying a biasing force along the corresponding depicted arrows, for example.

[0197] Arrangement of eight actuator units Figure 5 Schematically shown is a perspective view of an actuator assembly 2 with a total of eight actuation units 30. The eight actuation units 30 can apply an actuation force F between the movable part 20 and the support structure 10. The actuation force F is applied to the movable part 20 relative to the support structure 10.

[0198] Figure 5 A and Figure 5 An arrangement of the actuation unit 30 of B can be used, for example, in which the movable part 20 can be moved relative to the support structure 10 in three translational degrees of freedom (Tx, Ty, Tz) (see Figure 1E ) or with two or three rotational degrees of freedom (Rx, Ry or Rx, Ry, Rz) (see Figure 1C ) example of moving.

[0199] The eight actuation units 30 may be arranged such that the actuation force F of the eight actuation units 30 is oriented or arranged in a manner equivalent to the orientation or arrangement of the forces applied by the eight SMA wires in the actuator assembly disclosed in WO 2011 / 104518 A1.

[0200] More specifically, the actuation force F (e.g., when visualized as a vector at a specific position in space) is arranged on each of the four sides (i.e., the first side, the second side, the third side, and then the fourth side) around the main axis P. When viewed perpendicularly to the main axis, the two actuation forces F on each side are inclined in opposite directions relative to each other. The four sides on which the actuation forces F are arranged extend into a ring around the main axis. In this example, the sides are vertical and therefore form a square (when viewed along the main axis), but alternatively, the sides can take different shapes, such as a quadrilateral shape. In this example, the actuation forces F are parallel to the outer surface of the square envelope of the movable part 6, but this is not required.

[0201] The four actuation forces F, including one force on each side, form a "first" group having a component in one direction (the "upward" or +z direction), and the other four actuation forces F form a "second" group having a component in the opposite direction (the "downward" or -z direction). In this document, "up" and "down" refer to opposite directions along the main axis P.

[0202] These actuation forces F have a symmetrical arrangement, wherein their magnitudes and inclination angles are identical, so that the first set of actuation forces F and the second set of actuation forces F are each arranged with a two-fold rotational symmetry about the main axis.

[0203] As a result of this symmetrical arrangement, different combinations of actuation forces F can drive movement of the movable part 6 in multiple degrees of freedom, as described below.

[0204] The first set of actuation forces F when generated together drives upward (+z) movement, and the second set of actuation forces F when generated equally drives downward (-z) movement.

[0205] Within each group, adjacent pairs of actuation forces F, when generated differently, drive a tilt (Rx or Ry) about a transverse axis perpendicular to the main axis z. Tilt in any direction can be achieved as a linear combination of tilts about two transverse axes.

[0206] A set of four actuation forces F, including two actuation forces F from each group, when generated together, drives movement (Tx or Ty) along a transverse axis perpendicular to the main axis P. Movement in any direction perpendicular to the main axis z can be achieved as a linear combination of movements along the two transverse axes.

[0207] The SMA actuator may have other specific arrangements of the actuation unit 30, such as Figure 5 . For example, strict symmetry is not required. In addition, instead of having an up-pulling actuating unit 30 and a down-pulling actuating unit 30 on each side, there may be two up-pulling actuating units 30 on each of two opposite sides (e.g., the first side and the third side), and two down-pulling actuating units 30 on the other two sides (e.g., the second side and the fourth side).

[0208] Arrangement of the actuator unit In general, the present invention relates to a particularly advantageous arrangement of two or more actuation units 30. In particular, in miniature applications, such as cameras for smartphones or other applications in handheld devices, the space available for the actuator assembly 2 may be constrained. The present invention relates to maximizing the performance of the actuator assembly 2 within the given space constraints and / or making the actuator assembly 2 more compact.

[0209] When combined with Figure 4 When the arrangement of four actuation units 30 is described, the arrangement of the actuation units 2 described below, in particular the way in which more than one actuation unit 2 overlaps each other and / or overlaps the first component and the second component, is particularly advantageous. More than one actuation unit 30 can generally extend in parallel planes. The actuation planes in which more than one actuation unit 30 actuates (i.e., in which the main body 31 of more than one actuation unit 30 can move when actuated) can coincide with each other or be parallel.

[0210] Overlap joint flexures for reduced height The inventors have found that a particularly advantageous arrangement of two actuation units 30 allows an overlap of the coupling flexures 33 of two different actuation units 30 .

[0211] Therefore, according to some embodiments, when viewed along the main axis P, the coupling flexible members 33 of two different actuation units 30 (particularly adjacent actuation units 30) overlap. The two different actuation units 30 are also referred to herein as a pair of actuation units 30. In particular, only the coupling flexible members 33 of the two actuator units 30 overlap. When viewed along the main axis P, the main body portions 31 and the force adjustment flexible members 32 of the adjacent actuator units 30 do not overlap. For example, this is Figure 6B One of the two different actuation units 30 applies a respective actuation force F parallel to the x-axis, and the other of the two different actuation units 30 applies a respective actuation force F parallel to the y-axis. When viewed along the main axis P, Figure 6B The coupling flexible members 33 of the two actuating units 30 which are not shown in the cutaway view also overlap.

[0212] In particular, when viewed along the main axis, the coupling flexible members 33 of the two different actuation units 30 cross or intersect. The coupling flexible members 33 of the two different actuation units 30 may form an angle of about 90 degrees therebetween, preferably in the range of 70 to 110 degrees, preferably in the range of 80 to 100 degrees.

[0213] Providing such an overlap between the coupling flexures 33 allows the height of the actuator assembly 2 to be reduced while maintaining a relatively compact footprint, compared to a situation where the coupling flexures 33 do not overlap. Fig. 8A and Figure 8BThis is apparent when comparing the actuator assembly 2 depicted in FIG. Fig. 8A and Figure 8B In the actuator assembly 2 of FIG. 1 , the coupling flexures 33 do not overlap. Instead, an overlap is provided between the main body portions 31 of two adjacent actuating units 30. As a result, Fig. 8A and Figure 8B The height of the actuator assembly 2 is greater than that of Figures 6 and Figure 7 A to Figure 7 B is the height of the actuator assembly 2. In addition, a hypothetical example in which the coupling flexures 33 and other components of the actuating units 30 of adjacent actuator assemblies 2 do not overlap will have a height greater than that of FIGS. 6 and 7. Figure 7 A to Figure 7 The actuator assembly 2 of B has a much larger footprint (in the xy plane). Specifically, the coupling flexures 33 of adjacent actuator units 30 are allowed to overlap, thereby providing a substantially compact actuator assembly 2.

[0214] In other words, the body portion 31, the force adjustment flexible member 32, and the foot portion 36 of one actuation unit 30 are located between the SMA wire of one actuation unit 30 and the coupling flexible member 33 of the other actuation unit 30 of two adjacent actuation units 33. Compared with the actuator assembly 2 of FIG. 8 , the distance between the SMA wire 34 of one actuation unit 30 and the coupling flexible member 33 of the other actuation unit 30 is increased.

[0215] Despite the overlap when viewed along the primary axis P, the coupling flexures 33 may be configured so as not to directly contact one another as the movable component 20 moves, particularly as the movable component 20 moves throughout its range of movement relative to the support structure 10 .

[0216] This can be achieved, for example, by providing at least one coupling flexure 33 (optionally two coupling flexures 33) with a turning portion (not shown) in the overlapping area. The turning portion can also be referred to as a jog or offset formed in the coupling flexure 33 along the main axis. Therefore, the main parts of the two coupling flexures 33 can extend in the same plane, and only the turning portion is offset from the plane to avoid collision between the coupling flexures 33.

[0217] Alternatively, the coupling flexures 33 of the two actuating units 33 may be arranged to be offset along the main axis P so as to avoid direct contact. Fig. 9An embodiment of the actuation unit 30 is depicted in a multi-layer arrangement. In particular, the main body portion 31 comprises at least two layers stacked or offset from each other along the main axis P. In the depicted embodiment, the force adjustment flexure 34 and the foot portion 36 also comprise two layers stacked along the main axis P, but generally only one layer may also be provided. The coupling flexure 33 is a single flexure whose height along the main axis P is less than the height of the main body portion 31 (in particular less than half the height of the main body portion 31).

[0218] Therefore, generally, the coupling flexible member 33 may have an extension along the main axis P that is smaller than the extension of the main body portion 31 along the main axis P, and in particular, smaller than half of the extension of the main body portion 31 along the main axis P. This allows one of two adjacent actuation units 30 to be arranged with one side facing upward, and the other of the two adjacent actuation units 30 to be arranged with the other side facing upward. Therefore, the two actuation units 30 may be structurally identical but arranged on the actuator assembly 2 with different sides facing a given direction along the main axis P. Therefore, collision of the coupling flexible member 33 may be avoided. Fig. 11B An embodiment with such an arrangement of an actuator unit 30 is shown.

[0219] Specifically, each actuating unit 30 may include a first surface parallel to a plane orthogonal to the main axis P and a second surface parallel to the plane. The first surface and the second surface are disposed on opposite sides of the actuating unit 30. Two adjacent actuating units 30 may be arranged on the actuator assembly 2, wherein the first surface of one actuating unit 30 and the second surface of the other actuating unit 30 face the same direction along the main axis P.

[0220] Figure 6 Fig.10 11, when viewed orthogonally to the SMA wire, the SMA wire 34 extends through the point where the coupling flexure 33 is connected to the main body portion 31. For example, Figure 6B , the SMA wire 34 extends further to the left than the connection point between the coupling flexure 33 and the main body portion 31. As a result, the length of the SMA wire 34 is similar to the case where the SMA wire 34 stops at the point where the coupling flexure 33 is connected to the main body portion 31 (e.g., as shown in FIG. Figure 8B A longer SMA wire 34 allows for increased travel and / or more precise control of the positioning of the movable component 20.

[0221] Fig.106 and 8, the SMA wire 34 is arranged on the same side of the body portion 31 as the point where the force adjustment flexure 32 is connected to the support structure 10. In particular, the foot portion 36 is provided on the same side of the body portion 31 as the SMA wire 34. This reduces the extension of the actuation unit 30 in the lateral direction (i.e., in the direction along the actuation force F). Therefore, the footprint of the actuator assembly 2 can be reduced.

[0222] In some embodiments, each coupling flexure 33 may be wider in the region where it overlaps with another coupling flexure 33. Thus, when viewed along the primary axis P, the region where the coupling flexures 33 overlap may be wider (in a direction perpendicular to the length of the coupling flexures) than adjacent portions of the coupling flexures 33. This may reduce the risk of damage to the coupling flexures 33 in the overlapping region due to collision of the coupling flexures, for example during an impact event such as a fall. Fig.10 Such a wider portion 33b of the coupling flexure 33 is schematically shown.

[0223] Fig.11A and Fig. 11B 6 and 8 , the SMA wire 34 is arranged to overlap the body portion 31 when viewed along the main axis P. This allows the extension of the actuation unit 30 in the lateral direction (i.e. in the direction of the actuation force F) to be reduced. As a result, the footprint of the actuator assembly 2 can be reduced.

[0224] Connecting the actuator to different components As discussed above, the coupling flexure 33 may be connected to either of the support structure 10 and the movable member 20 , and the SMA wire 34 and the force amplifying flexure 32 may be connected to either of the movable member 20 and the support structure 10 , respectively.

[0225] Fig. 12A and Fig. 12B An embodiment of an actuator assembly 2 is shown in which some of the actuation units 30 are arranged with their coupling flexures 33 connected to the movable part 20 and some other actuation units 30 are arranged with their coupling flexures connected to the support structure 10 . Fig. 12A This is shown conceptually, while Fig. 12B Further details of the arrangement of the actuator unit 30 are shown.

[0226] In particular, the actuation units 30 that apply the actuation force F along the y-axis are referred to herein as static actuation units 30s. These actuation units 30s are connected between the movable part 20 and the support structure 10 through force adjustment flexures 32s and SMA wires 34s, the SMA wires 34s are connected to the support structure 10, and the coupling flexures 33s are connected to the movable part 20. The actuation units 30 that apply the actuation force F along the x-axis are referred to herein as movable actuation units 30m. These actuation units 30m are connected between the movable part 20 and the support structure 10 through force adjustment flexures 32m and SMA wires 34m, the SMA wires 34m are connected to the movable part 20, and the coupling flexures 33m are connected to the support structure 10. Of course, in other arrangements, the static actuation units 30s can apply the actuation force F along the x-axis, and the movable actuation units 30m can apply the actuation force F along the y-axis.

[0227] In some other embodiments, one static actuation unit 30s may apply an actuation force F along the x-axis, and another static actuation unit may apply an actuation force F along the y-axis. Similarly, one movable actuation unit 30m may apply an actuation force F along the x-axis (opposite to the actuation force F of the corresponding static actuation unit 30s), and another movable actuation unit 30m may apply an actuation force F along the y-axis (opposite to the actuation force F of the corresponding static actuation unit 30s).

[0228] Providing the static actuation unit 30s and the movable actuation unit 30m in combination can reduce the amount of overlap of the actuation units 30m when viewed along the main axis. Fig. 12A and Fig. 12B As shown, overlap can be completely avoided. Therefore, the height of the actuator assembly 2 can be reduced. This is achieved without significantly increasing the footprint of the actuator assembly 2.

[0229] Additional details of the actuator assembly Fig.13A and Fig. 13B Other details of the actuator assembly 2 are shown. In particular, Fig.13A An example of a static crimp 15 mounted to a support structure 10 is shown. Fig. 13B An example of a foot portion 36 of an actuation unit 30 mounted to a support structure 10 is shown.

[0230] like Fig.13A As shown, the static crimp 15 may be raised or offset from the surface of the support structure 10. In particular, a turning portion or a bend may be provided in a portion connected to or integrally formed with the static crimp 15 so as to raise the static crimp.

[0231] Similarly, if Fig. 13BAs shown, the foot portion 36 may include a transition or bend. This allows the main body portion 31 and the crimping member 35 and the force adjustment flexible member 32 connected to the main body portion 31 to be raised or offset from the surface of the support structure 10. Therefore, the two crimping members 15, 35 connected to the SMA wire 34 can be raised above the surface of the support structure 10, thereby allowing the two crimping members 15, 35 to be aligned in a common plane. The SMA wire 34 can extend parallel to the surface of the support structure 10 and / or parallel to the actuation force F and / or parallel to the moving plane.

[0232] The force adjustment flexures 32 and / or the main body parts 31 of different actuation units 30 can also be arranged at different offsets along the main axis P in this way, so that collisions between the actuation units 30 are avoided even in the event of overlap when viewed along the main axis P.

[0233] Fig. 13C A raised feature 20r is shown on the movable part 20. A coupling flexure 33 of the actuation unit 30 may be connected to the raised feature 20r. The height of the raised feature 20r may be designed to allow the coupling flexure 33 to extend substantially parallel to the surface of the support structure 10 and / or parallel to the actuation force F and / or parallel to the plane of movement.

[0234] Actuating unit overlapping the movable part Another aspect of the invention relates to allowing an overlap of the actuation unit 2 with both the movable part 20 and the support structure 10 when viewed along the main axis.

[0235] Special References Figures 14 to 18 , several actuator assemblies 2 according to other aspects of the invention will now be described. Here, the actuation unit 30 overlaps (or is located within) the region defined by the movable part 20 when viewed along the main axis. In this context, the main axis may be an axis perpendicular to the plane in which the movable part 20 can move (the "movement plane"). It will be apparent that by overlapping with the movable part 20 in this manner, rather than being positioned around the movable part 20, the actuation unit 30 may have a variety of different (and advantageous) configurations.

[0236] For example, the SMA wire 34 may be longer than the length of any side of the movable component 20 without increasing the footprint of the actuator assembly 2. This may improve the performance of the actuator assembly while meeting given dimensional constraints.

[0237] In some embodiments, the support structure 10 and the movable part 20 include elements of an imaging system, such as an image sensor and / or a lens assembly. The elements of the imaging system included in the support structure 10 and the movable part 20 can form opposite ends of the imaging system. The elements can define a zone between them. The optical path can extend between the elements, and the zone can define the optical path. It may be desirable to keep the zone free of devices that may obstruct the optical path through the imaging system. Optionally, the actuation unit 30 is at least partially located outside the zone defined by the elements of the imaging system in the direction of the main axis. For example, the flexible device 72 can be positioned behind the image sensor 6 (i.e., below the image sensor 6 in the orientation shown in Figure 1). The image sensor 6 can be located between the actuation unit 30 and the lens 22 in the direction of the main axis.

[0238] "Dual Plane" Actuator Assembly Fig.14 is a schematic plan view of an actuator assembly 2 comprising four actuation units 30 located in two planes. In particular, the actuation units 30 may be arranged in two parallel actuation planes.

[0239] The actuation unit 30 will be described with reference to the flexible means 72a to 72d. The actuation unit 30 includes the flexible means 72a to 72d. The flexible means 72a to 72d correspond to the combination of the main body portion 31, the force adjustment element 32 and the optional coupling link 33. The depicted flexible means 72a to 72d are functionally similar to those described with respect to Figure 3A and Figure 3B The combination of the force adjustment flexible member 32, the connecting flexible member 33 and the main body portion 31 is described.

[0240] This configuration uses the design concept of (i) bending a flexure fulcrum beam orthogonal to itself through a shallow angle wire, and (ii) a first-class lever to amplify displacement in exchange for force in travel. Shallow angle refers to the angle between the SMA wire 34 and the force adjustment flexure 32. Shallow angle means an angle less than 45°, optionally less than 40°, optionally less than 30°, optionally less than 20°, and optionally less than 10°. For example, in one of the actuator units 30, as shown, the force adjustment flexure 32 extends from the upper left portion of the actuator assembly 2, and the SMA wire extends toward the lower right portion of the actuator assembly 2.

[0241] For angled wire amplification, the SMA wire 34 is attached to the moving crimp 35 and at a small angle to the force adjustment flexure 32. This allows amplification in a direction orthogonal to the flexure direction since the flexure must bend a lot to accommodate small changes in wire length.

[0242] For the amplification of the first type of lever, the pivot point is provided by the force adjustment flexure 32, allowing the main part 31 (which can be shaped as a beam) to rotate in this position. The amplified displacement is then transmitted to the actuator via the coupling flexure 33, which allows the transmission of the displacement but also bends when the actuator moves in the direction opposite to the positive displacement of the separate flexure system.

[0243] The amplification factor can be adjusted by adjusting the ratio of the distance between (a) the line load (i.e., the crimp 35 where the SMA wire 34 applies force to the body portion 31) and the fulcrum (i.e., where the force adjustment flexure 32 engages the body portion 31) to the distance between (b) the displacement amplification load (i.e., where the body portion 31 engages the coupling flexure 33) and the fulcrum. The relationship between this ratio and the amplification factor is approximately 1:1, but additional travel will be observed due to the flexure pivoting and bending.

[0244] like Fig.14 As shown, optionally, the angle between the connecting flexible member 33 and the side of the supporting structure 10 is in the range of 30 degrees to 60 degrees. Fig.14 As shown, optionally, the angle between the force adjustment flexure 32 and the side of the support structure 10 is in the range of 30 to 60 degrees. The advantage of making the coupling flexure 33 and the force adjustment flexure 32 at an angle of about 45 degrees is that they can bend when the other is in compression. This reduces or eliminates the possibility of buckle failure.

[0245] Both the force adjustment flexure 32 and the connecting flexure 33 are thin and highly flexible and are arranged to be in tension. In order to maximize the line length, an additional section in compression is formed between the force adjustment flexure 32 and the connecting flexure 33, namely the main body 31 (for example, by forming the main body 31 as a beam). Since this section does not need to be flexible to form a high magnification or to connect the components and allow orthogonal movement, the section can be very wide and rigid. This helps to avoid a reduction in stroke and also helps to help the compressed section, namely the main body 31, to avoid lateral bending deformation. The compressed section helps to make the package as small as possible, so that, for example, it is suitable for being located behind the image sensor 6, while still having sufficient line length to achieve a high stroke.

[0246] Optionally, the actuator assembly 2 has a stretch-flex design. This allows the actuator to be positioned completely behind the image sensor 6. This can reduce the footprint of the combination of the actuator unit and the image sensor 6. This is because the increase in line travel allows for high travel with a small footprint, small enough to be located behind the sensor.

[0247] The wires used for this stretch flex amplification also have the advantage of routing the wires through the actuator to fully utilize the actuator footprint for maximum wire length. The maximum possible wire length is increased from the actuator side length to the actuator corner-to-corner length compared to a standard 4 wire configuration.

[0248] "Single Plane" Actuator Assembly The actuation unit 30 may be located in a single plane (eg Fig.15 as shown) or multiple planes (as Fig.14 As shown), to aid packaging or to aid material properties. For a single planar format, all flex systems can be etched together in a single etched sheet, saving cost and reducing complexity.

[0249] Fig.15 is a schematic plan view of an actuator assembly 2 comprising four actuating units located in one plane. Fig.16 yes Fig.15 A schematic perspective view of an actuator assembly 2 is shown in FIG.

[0250] "Class 3 lever" actuator assembly Fig.17 is a schematic plan view of an actuator assembly 2 comprising four actuation units 30 having different configurations.

[0251] In this configuration, the action from the third type lever is amplified. The force adjustment flexure 32 allows the amplification beam (i.e., the portion of the main body portion 31 extending between the force adjustment flexure 32 and the connecting flexure 33) and the input force beam (i.e., the portion of the main body portion 31 extending between the crimping member 35 and the force adjustment flexure 32) to pivot. Taking the flexure device 72b shown in the upper left portion of the figure as an example, there is a small angle between the SMA wire 34 and the force adjustment flexure 32. The SMA wire 34 applies a force when contracted, which has a primary component in the direction of the force adjustment flexure 32 (thereby keeping the force adjustment flexure 32 in tension) and a secondary component in the downward direction in the orientation shown in the figure. This secondary component causes the force adjustment flexure 32 and the main body portion 31 to rotate clockwise.

[0252] Likewise, the amplification factor can be adjusted by adjusting the ratio of the distance between the linear load and the fulcrum to the distance between the displacement amplification load and the fulcrum.

[0253] This configuration includes the coupling flexures 33 of different actuation units that are not orthogonal to each other. This results in a greater travel in one direction than in another direction. Generally, it is preferred to have orthogonal coupling flexures 33 to have uniform travel in each direction.

[0254] Support for an actuating unit Fig.18 is a schematic diagram of a force adjustment flexure 32 and an SMA wire 34 that biases the actuation unit against a support 55. The upper right side of the figure shows a schematic plan view of the actuation unit. The lower left side of the figure shows a side view of the same actuation unit. The lower left figure is provided to show that the force adjustment flexure 32 (and / or the connecting flexure 33) and / or the SMA wire 34 can extend in the direction of the main axis (i.e., extend between planes) so as to apply a force to keep the flexure 72 in contact with the support 55. By angling the wire slightly on the optical axis or by angling the flexure also on the optical axis, wire stressing can be used to bias the flexure downward onto the support system so that the wire pulls the system onto the support 55 when in tension.

[0255] The flexure 72 may not be able to resist out of plane forces. Fig.18 As shown, supports 55 are optionally provided to prevent movement out of the plane (i.e. in the optical direction). One way to apply these supports 55 is to use sliding supports under the designed wide compression section (i.e. the main body 31), between this part and the support structure 10, and between the compression section of the flexible device 72 and the movable part 20 (which may include the image sensor 6). An alternative option is to use rolling supports, such as ball bearings, in one or both of these gaps.

[0256] Furthermore, the system can be pre-stressed in the optical direction, thus providing only one set of supports 55. For example, the force adjustment flexure 32 and / or the coupling flexure 33 can be pre-stressed towards the support structure 10, and then the sliding support 55 can be placed between the support structure 10 and the flexure.

[0257] Additionally, by placing the support member 55 on the compression section, this will reduce the possibility of lateral bending deformation of the compression section.

[0258] Such a support member 55 may also be used for other flexible devices, such as those included in the reference examples (eg, examples that do not overlap with the movable part 20 ).

[0259] One-piece crimping parts Fig.19 is a schematic diagram of an actuation unit with an integral crimp 35. The crimp etching can be integrated with the flex system etching to reduce or minimize the amount of etching required and avoid the need for soldering on the crimp.

[0260] Alternative configurations Figure 20 to Figure 24 Some alternative configurations of the actuator assembly 2 are shown in FIG.

[0261] Fig. 20 is a schematic plan view of one such actuator assembly 2 having a particularly simple layout. Optionally, the flexure 72 is provided using a single etch (ie from a single sheet of metal).

[0262] Fig.21 is a schematic plan view of another actuator assembly 2. Again, the flexure 72 may be provided using a single etch (ie, from a single sheet of metal). This configuration may be particularly suitable for devices such as cameras having a square footprint. It will be apparent that the travel magnification may be particularly high.

[0263] Fig. 22 2 is a schematic plan view of another actuator assembly 2. In terms of the pivoting action, this configuration is similar to Fig.21 More specifically, in Fig.21 In the embodiment, the connecting link 33 is usually in a compressed state, and the force adjustment mechanism presses the movable part 20 via the connecting link 33 to apply the actuating force to the movable part 20. In contrast, in Fig. 22 In the embodiment, the coupling link 33 is usually in a tension state, and the force adjustment mechanism pulls the movable part 20 via the coupling link 33 so as to apply the actuation force to the movable part 20. For example, when the coupling link includes a flexible member, tension is particularly preferred.

[0264] Fig.23 is a schematic plan view of another actuator assembly 2. This configuration allows rotational movement of the movable part 20 about a main axis relative to the support structure 10. Optionally, the flexure 72 is provided in two planes and may be etched from two metal sheets.

[0265] Fig.24 is a schematic plan view of another actuator assembly 2. This configuration allows the movable part 20 to be moved in rotation about the main axis relative to the support structure 10. Optionally, the flexible device 72 is provided using a single etching (ie from a single metal sheet). Optionally, the length of the connecting flexible member 33 can be increased to greater than Fig.24 Length shown in .

[0266] Fig.25is a schematic plan view of another actuator assembly 2. This configuration includes a force adjustment flexible member 32 and a coupling flexible member 33 which are normally maintained in a tension state, and are combined with a main body portion 31 which is normally maintained in a compression state.

[0267] Turn Line Example Fig.26 is a schematic diagram showing an SMA wire 34 turned about a feature 57 (e.g., a pulley) such that the SMA wire 34 includes a first length segment and a second length segment oriented at a non-zero angle relative to each other, and the length segments are coupled to each other such that contraction of the first length segment causes displacement of the second length segment, which displacement, combined with contraction of the second length segment itself, provides a contribution to movement of the movable component. Further details are provided in WO2017 / 111131 A1, which is incorporated herein by this reference. Fig.26 As shown, any of the configurations described herein may be combined with such a steerable SMA wire 34 to provide additional travel.

[0268] Other variants It will be appreciated that many other variations of the above examples are possible. For example, Fig.16 The flexible device 72 shown may be provided with Fig.18 The one-piece crimping piece 35 is shown. Fig.16 The actuator assembly 2 shown in FIG. 2 may be provided with support members 55 on one or both sides of the flexible device 72. When only one side is provided with support members 55, the flexible members 34, 33 and / or the SMA wire 34 may be pre-stressed or may be slightly extended in the direction of the main axis to provide a biasing force for the support member 55, for example, as Fig.18 Example shown. Can be adjusted Fig.16 , so that the main body portion 31 acts as a Type 3 lever rather than a Type 1 lever. The actuator assembly can be used in other devices instead of being used in a camera assembly. For example, the actuator assembly 2 can correspond to (a component of) an illumination source that can be used in a 3D sensing system (such as described in WO2020 / 030916) or an augmented reality (AR) display system, or the actuator assembly 2 can be used to move a display.

[0269] SMA Components The above-mentioned SMA actuator assembly includes at least one SMA element. The term "shape memory alloy (SMA) element" may refer to any element including SMA. The SMA element may be described as an SMA wire. The SMA element may have any shape suitable for the purposes described herein. The SMA element may be elongated and may have a circular cross section or a cross section of any other shape. The cross section may vary along the length of the SMA element. The SMA element may have a relatively complex shape, such as a spiral spring shape. It is also possible that the length of the SMA element (however defined) may be similar to one or more of the other dimensions of the SMA element. The SMA element may be sheet-like, and such a sheet may be planar or non-planar. The SMA element may be flexible, or in other words, the SMA element may be flexible. In some examples, when connected in a straight line between two components, the SMA element can only apply tension that forces the two components together. In other examples, the SMA element may be bent around the component, and when the SMA element tends to straighten under tension, the SMA element may apply force to the component. SMA elements can be beam-shaped or rigid and can apply different forces (e.g., non-tension) to the elements. SMA elements may or may not include non-SMA materials and / or components. For example, an SMA element may include a core of SMA and a coating of non-SMA material. Unless the context requires otherwise, the term "SMA element" may refer to any configuration of SMA material that acts as a single actuating element, for example, the single actuating element can be individually controlled to generate a force acting on the element. For example, an SMA element may include two or more parts of SMA material that are mechanically arranged in parallel and / or in series. In some arrangements, an SMA element may be part of a larger SMA element. Such a larger SMA element may include two or more parts that can be individually controlled, thereby forming two or more SMA elements. SMA elements may include SMA wires, SMA foils, SMA films, or any other configuration of SMA materials. SMA elements may be manufactured using any suitable method (e.g., by methods involving drawing, rolling, deposition, and / or other molding processes). The SMA element may exhibit any shape memory effect, such as a thermal shape memory effect or a magnetic shape memory effect, and may be controlled in any suitable manner (eg, by Joule heating, another heating technique, or by applying a magnetic field).

Claims

1. An actuator assembly, comprising: a first component and a second component, the first component and the second component being movable relative to each other along two orthogonal axes perpendicular to the main axis and / or being tiltable relative to each other about two orthogonal axes perpendicular to the main axis; and at least one pair of actuation units, each actuation unit being configured to apply an actuation force to the second component, the actuation force being capable of moving the second component relative to the first component, wherein each actuation unit comprises: - the main part; - an SMA element connected between the body portion and the first component and arranged to apply an input force to the body portion upon actuation; - a force adjustment element connected between the main body portion and the first component and configured to adjust the input force in order to generate the actuation force; - a coupling link connected between the main body portion and the second component, wherein the coupling link is configured to transmit the actuation force from the main body portion to the second component, and wherein the coupling link is flexible in a direction perpendicular to the direction of the actuation force; and wherein the connecting links of each pair of actuating units overlap when viewed along the main axis, wherein one actuating unit in each pair of actuating units is configured to apply the actuating force parallel to a first axis in a plane formed by the two orthogonal axes, and the other actuating unit in each pair of actuating units is configured to apply the actuating force parallel to a second axis in the plane formed by the two orthogonal axes, wherein the second axis is not parallel to the first axis.

2. The actuator assembly according to claim 1, wherein: The connecting link includes a connecting flexible member, wherein at least one connecting flexible member of one actuating unit in each pair of actuating units includes a turning portion, and the turning portion is located in an area overlapping with the connecting flexible member of the other actuating unit in each pair of actuating units, thereby avoiding contact between the connecting flexible members.

3. The actuator assembly according to claim 1, wherein: The connecting link comprises connecting flexible members, wherein the arrangement of each pair of actuating units is offset relative to each other along the main axis so as to avoid contact between the connecting flexible members, optionally wherein the connecting flexible members are wider in the area overlapping with another connecting flexible member than in an adjacent area.

4. An actuator assembly according to any one of the preceding claims, wherein: The actuation units are substantially identical.

5. The actuator assembly according to claim 4, wherein: Each actuating unit comprises a first surface parallel to the plane formed by the two orthogonal axes and a second surface parallel to the plane formed by the two orthogonal axes, wherein the first surface and the second surface are arranged on opposite sides of the actuating unit, wherein, for each pair of actuating units, the first surface of one actuating unit and the second surface of the other actuating unit face the same direction along the main axis.

6. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit is configured such that, when viewed orthogonally to the SMA element, the SMA element extends past the point at which the coupling link connects to the body portion.

7. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit is configured such that, when viewed along the primary axis, the SMA element is arranged on the same side of the body portion as the point at which the force adjustment element is connected to the first component or the second component.

8. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit is configured to place the force adjustment element in tension when the SMA element is contracted.

9. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit, is configured such that the force adjustment element amplifies a contraction of the SMA element into a relatively larger movement between the first component and the second component.

10. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit is configured such that the angle between the force adjustment element and the SMA element is in the range of 0 to 45 degrees, preferably in the range of 13 to 40 degrees.

11. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit, is configured such that the force adjustment link is integrally formed with at least a portion of the body portion.

12. An actuator assembly according to any one of the preceding claims, wherein: At least one actuation unit, preferably each actuation unit is configured such that the coupling link is integrally formed with at least a portion of the body portion.

13. An actuator assembly according to any one of the preceding claims, comprising a total of four actuation units, wherein: The four actuating units are composed of two pairs of actuating units.

14. The actuator assembly of claim 13, wherein: None of the actuation forces applied by the four actuation units are collinear.

15. An actuator assembly according to claim 13 or 14, wherein: The arrangement of the four actuation units enables an actuation force to be applied between the first component and the second component so as to move the first component and the second component relative to each other to any position within a range of movement within a movement plane formed by the two orthogonal axes without applying any net torque between the first component and the second component.

16. An actuator assembly according to any one of claims 13 to 15, wherein: Two of the four actuation units are arranged to apply an actuation force so as to generate a torque between the first component and the second component in a first direction around the main axis, and the other two of the four actuation units are arranged to apply an actuation force so as to generate a torque between the first component and the second component in a second opposite direction around the main axis.

17. An actuator assembly according to any one of claims 13 to 16, wherein: Two of the four actuation units are arranged to apply an actuation force in one corner of the actuator assembly, and the other two of the four actuation units are arranged to apply an actuation force in another opposite corner of the actuator assembly.

18. An actuator assembly according to any one of claims 13 to 16, wherein: Two of the four actuation units are arranged to apply an actuation force to move the first component and the second component relative to each other in two opposite directions parallel to the first axis, and the other two of the four actuation units are arranged to apply an actuation force to move the first component and the second component relative to each other in two opposite directions parallel to the second axis.

19. An actuator assembly according to any one of claims 13 to 16, wherein: Each actuating unit extends parallel to the two orthogonal axes.

20. An actuator assembly according to any preceding claim, further comprising a bearing arrangement located between the first component and the second component and arranged to allow relative movement between the first component and the second component.

21. An actuator assembly comprising: a first component and a second component, the first component and the second component being movable relative to each other in a translation plane perpendicular to the main axis; and at least one pair of actuation units, each actuation unit being connected between the first component and the second component and arranged to apply a respective actuation force between the first component and the second component, Wherein, one actuating unit in each pair of actuating units comprises: - the main part; - an SMA element connected between the body portion and the first component and arranged to apply an input force to the body portion upon actuation; - a force adjustment element connected between the main body portion and the first component and configured to adjust the input force in order to generate the actuation force; and - a coupling link connected between the main body portion and the second component, wherein the coupling link is configured to transmit the actuation force from the main body portion to the second component, and wherein the coupling link is flexible in a direction perpendicular to the direction of the actuation force; and Wherein, the other actuating unit in each pair of actuating units comprises: - the main part; - an SMA element connected between the body portion and the second component and arranged to apply an input force to the body portion upon actuation; - a force adjustment element connected between the main body portion and the second component and configured to adjust the input force in order to generate the actuation force; and - a coupling link connected between the main body portion and the first component, wherein the coupling link is configured to transmit the actuation force from the main body portion to the first component, and wherein the coupling link is flexible in a direction perpendicular to the direction of the actuation force.

22. The actuator assembly of claim 21, wherein: When viewed along the main axis, none of the actuation units overlap.

23. An actuator assembly according to claim 21 or 22, comprising a total of four actuation units, wherein: The four actuating units are composed of two pairs of actuating units.

24. An actuator assembly according to any one of claims 21 to 24, wherein: The four actuation units are in an arrangement capable of applying an actuation force between the first component and the second component so as to move the first component and the second component relative to each other to any position within a range of movement within the movement plane without applying any net torque between the first component and the second component.

25. A camera device comprising: An actuator assembly according to any one of the preceding claims; an image sensor coupled to one of the first component and the second component of the actuator assembly, and a lens assembly coupled to the other of the first component and the second component of the actuator assembly, Wherein an optical axis defined by the lens assembly is aligned with the principal axis of the actuator assembly.

26. An actuator assembly comprising: a first component and a second component, the first component and the second component being movable relative to each other along two orthogonal axes perpendicular to the main axis and / or being tiltable relative to each other about two orthogonal axes perpendicular to the main axis, the two orthogonal axes forming a plane of movement; and one or more actuation units, each actuation unit being configured to apply an actuation force to the second component, the actuation force being capable of moving the second component relative to the first component, Wherein, each actuation unit comprises: - the main part; - an SMA element connected between the body portion and the first component and arranged to apply an input force to the body portion upon actuation; and - a coupling link connected between the main body portion and the second component, wherein the coupling link is configured to transmit the actuation force from the main body portion to the second component, and wherein the coupling link is flexible in a direction perpendicular to the direction of the actuation force; Wherein, when viewed along the main axis, the one or more actuation units overlap both the area defined by the first component and the area defined by the second component.

27. The actuator assembly of claim 26, wherein: When viewed along the primary axis, the force adjustment element and / or the SMA element and / or the coupling link overlap with the zone.

28. An actuator assembly according to claim 26 or 27, wherein: When viewed along the main axis, the one or more actuation units are located both within a zone defined by the first component and within a zone defined by the second component.

29. An actuator assembly according to any one of claims 26 to 28, wherein: The first component and the second component comprise elements of an imaging system, and the one or more actuation units are at least partially located outside an optical path between the elements.

30. An actuator assembly according to any one of claims 26 to 29, wherein: The first component and / or the second component may be rectangular in shape when viewed along the major axis, and wherein at least a portion of the SMA element extends along a line at an oblique angle to a side of the rectangle.

31. The actuator assembly of claim 30, wherein: The straight line is longer than the length of the longest side of the rectangle.

32. An actuator assembly according to any one of claims 26 to 31, wherein: The actuation unit is arranged between the first component and the second component when viewed perpendicularly to the main axis.

33. An actuator assembly according to any one of claims 26 to 32, comprising four actuation units, wherein: Two of the four actuation units are configured so that the corresponding body parts are located in a first plane, and the other two of the four actuation units are configured so that the corresponding body parts are located in a second plane, wherein the first plane and the second plane are different planes parallel to each other.

34. An actuator assembly according to any one of claims 26 to 32, comprising four actuation units, wherein: The main body parts of the four actuating units are arranged in a common plane.

35. An actuator assembly according to any one of claims 34, wherein: The force adjustment elements of the four actuation units are also arranged in the common plane.

36. An actuator assembly according to any one of the preceding claims, wherein: The force adjustment element includes a force adjustment flexure.

37. An actuator assembly according to any one of the preceding claims, wherein: The force adjustment element is arranged to be placed in tension upon actuation of the SMA element.

38. An actuator assembly according to any one of the preceding claims, wherein: The force adjustment element is arranged at an angle relative to the SMA wire, preferably at an angle in the range of 13 to 77 degrees, optionally at an angle in the range of 13 to 40 degrees or 77 to 50 degrees.

39. An actuator assembly according to any one of the preceding claims, wherein: Each actuation unit is configured to amplify an actuation amount of the SMA element into a relatively larger movement amount of the second component relative to the first component, optionally with a factor greater than 1.5, preferably greater than 2, and further preferably greater than 3.

40. An actuator assembly according to any one of the preceding claims, wherein: Each actuation unit is configured to amplify the input force so that the actuation force is greater than the input force. Optionally, the amplification factor is greater than 1.5, preferably greater than 2, and further preferably greater than 3.

41. An actuator assembly according to any one of the preceding claims, wherein: The connecting link includes a connecting flexible member.

42. An actuator assembly according to any one of the preceding claims, wherein: The coupling link is arranged to be placed in tension upon actuation of the SMA element.

43. An actuator assembly according to any one of the preceding claims, wherein: An angle between the coupling link and the SMA element is in a range of 70 degrees to 110 degrees.

44. An actuator assembly according to any one of the preceding claims, wherein: Each actuation unit extends substantially in an actuation plane, wherein a body portion of the actuation unit is arranged to move in the actuation plane upon actuation of the SMA elements.

45. An actuator assembly according to any one of the preceding claims, wherein: The main body portion and the force adjustment flexure are integrally formed from the same material, and optionally, wherein the coupling link is also formed from the same material.

46. ​​An actuator assembly according to any one of the preceding claims, comprising a total of four actuation units arranged to apply actuation forces such that none of the actuation forces are non-collinear.

47. An actuator assembly according to claim 46, wherein: The four actuation units are arranged so that a first pair of actuation units applies actuation forces in two opposite directions parallel to a first axis in a plane, and a second pair of actuation units applies actuation forces in two opposite directions parallel to a second axis in the plane, wherein the first axis and the second axis are not parallel.

48. An actuator assembly according to claim 47, wherein: The first pair of actuation units is arranged to apply a torque to the second component relative to the first component in a first orientation, and the second pair of actuation units is arranged to apply a torque to the second component relative to the first component in a second orientation, wherein the second orientation is opposite to the first orientation.

49. An actuator assembly according to any preceding claim, comprising an image sensor and / or a lens assembly, wherein: The image sensor or the lens assembly is fixed relative to the second component and / or the lens assembly or the image sensor is fixed relative to the first component.

50. A camera assembly comprising an actuator assembly according to any one of the preceding claims, wherein: The second component includes an image sensor as a component of an imaging system, the image sensor having an imaging axis perpendicular to the plane of movement, wherein the actuator assembly provides optical image stabilization (OIS) for the camera assembly.

51. The camera assembly of claim 51, wherein: The image sensor is located between the element of the imaging system included in the first component and at least a portion of the one or more actuation units.

52. A camera assembly according to claim 51 or 52, wherein: When viewed along the main axis, the one or more actuation units at least partially overlap the image sensor.

Images