actuator assembly

Abstract

The actuator assembly (23) includes a first portion (24), a second portion (25), and a support device (26) mechanically connecting the first portion (24) to the second portion (25). The actuator assembly (23) also includes a drive device (11, 20) comprising four segments of shape memory alloy wire (141, 142, 143, 144). Each segment of shape memory alloy wire (141, 142, 143, 144) is connected between the first portion (24) and the second portion (25). The drive device (11, 20) and the support device (26) are configured such that the first portion (24) is movable toward or away from the second portion (25) along the main axis (z) passing through the actuator assembly (23). The drive unit (11, 20) and the support unit (26) are configured such that the first part (24) is tiltable relative to the second part (25) about the first axis (x, x') and / or the second axis (y, y') 15, which are not parallel, pass through the pivot point, and are perpendicular to the main axis (z).

Description

field

[0001] This application relates to an actuator assembly, and more particularly to an actuator assembly comprising four shape memory alloy (SMA) wires. background

[0002] Such actuator components can be used, for example, in cameras, to move a lens assembly in a direction perpendicular to the optical axis to provide optical image stabilization (OIS) and to move the lens assembly along the optical axis to provide autofocus (AF). Miniaturization may be important when such a camera is to be integrated into a portable electronic device such as a mobile phone.

[0003] WO2013 / 175197A1 describes an SMA actuation device that uses a total of four SMA actuator lines to move a movable element relative to a support structure in two orthogonal directions. Each SMA actuator line is connected at both ends between the movable element and the support structure and extends perpendicular to the main axis. The SMA actuator lines are not collinear, but are arranged such that they can be selectively driven to move the movable element to any position within the range of motion relative to the support structure without applying any net torque to the movable element in the two orthogonal directions around the main axis.

[0004] WO2019 / 243849A1 describes a shape memory alloy actuation device including a support structure and a movable element. A helical support device supporting the movable element on the support structure guides the movable element to helical movement about a helical axis relative to the support structure. At least one shape memory alloy actuator wire is connected between the support structure and the movable element in a plane orthogonal to the helical axis or at an acute angle to the plane to drive the movable element to rotate about the helical axis, and the helical support device converts this rotation into the helical movement.

[0005] WO2019 / 086855A1 describes a camera with an actuator assembly including a support platform, a movable platform supporting a lens assembly, an SMA line connecting the support platform and the movable platform, a support member supporting the movable platform on the support platform, and two arms extending between the support platform and the movable platform. Overview

[0006] According to a first aspect of the invention, an actuator assembly is provided, including a first portion, a second portion, and a support device mechanically connecting the first portion to the second portion. The actuator assembly further includes a drive device comprising four segments of shape memory alloy wire. Each segment of shape memory alloy wire is connected between the first portion and the second portion. The drive device and the support device are configured such that the first portion is movable toward or away from the second portion along a main axis passing through the actuator assembly. The drive device and the support device are configured such that the first portion is tiltable relative to the second portion about a first axis and / or a second axis that is not parallel to and perpendicular to the main axis.

[0007] The movement of the first part toward or away from the second part along the main axis, the tilt of the first part relative to the second part about the first axis, and the tilt of the first part relative to the second part about the second axis can be substantially independent of each other. The movement of the first part toward or away from the second part along the main axis can be controlled substantially independently of the tilt of the first part relative to the second part about the first axis and / or the second axis.

[0008] The drive unit may include a total of four shape memory alloy wire segments. Neither the actuator assembly nor the drive unit may include any additional shape memory alloy wire segments or other drive mechanisms. The actuator assembly includes up to four shape memory alloy wire segments. The drive unit includes up to four shape memory alloy wire segments. A first axis and / or a second axis may be perpendicular to the main axis. The first axis may be perpendicular to the second axis. The first and second axes may pass through a pivot point. The pivot point may be offset from the first and / or second portions along the main axis.

[0009] Each of the four shape memory alloy wire segments corresponds to a section of the shape memory alloy wire in which the drive current can be independently controlled. For example, a pair of shape memory alloy wire segments can be provided by a single physical wire having a first current source connected to one end, a second current source connected to the other end, and a current return connection at a point between the two ends.

[0010] The support device can be configured to guide the movement of the first part relative to the second part along the main axis, and to guide the tilting of the first part relative to the second part about the first axis and / or the second axis.

[0011] The support device can be configured to constrain the movement of the first part relative to the second part along a first axis and / or a second axis. The support device can be configured to constrain the rotation of the first part relative to the second part about a main axis.

[0012] The support device may include a first support member. The first support member may include a first pair of flexible members, each extending generally parallel to a first axis and connecting a first portion to a second portion. The first pair of flexible members may be spaced parallel to a second axis to support the first portion. The first support member may include a second pair of flexible members, each extending generally parallel to the second axis and connecting a first portion to a second portion. The second pair of flexible members may be spaced parallel to the first axis to support the first portion. Each of the first and second pairs of flexible members may be configured to be compliant in a direction corresponding to the movement of the first portion relative to the second portion along a main axis.

[0013] The first support element can take the form of a single flexural element. The term "parallel" generally refers to a range of ±5 degrees or ±10 degrees. The first part can be flat. The first part can typically be circular (i.e., a disc), elliptical (i.e., an elliptical disc or plate), or polygonal (i.e., a polygonal plate), such as rectangular (i.e., a rectangular plate), and especially square (i.e., a square plate). The first part can be rigid or more rigid than the flexural element.

[0014] One or more, or all, of the first pair of flexural members and / or the second pair of flexural members may be flat. One or more, or all, of the first pair of flexural members and / or the second pair of flexural members may include at least one bend (or “turn” or “elbow”). One or more, or all, of the first pair of flexural members and / or the second pair of flexural members may include a corresponding arm, which may include at least one bend. One or more arms, or all arms, may include a first portion extending away from the platform and a second portion extending along a corresponding side of the platform. The first and second portions may be straight.

[0015] When the flexural members are not flexed, the first pair of flexural members and the second pair of flexural members are coplanar. When the flexural members are not flexed, the first pair of flexural members and the second pair of flexural members can be coplanar in a plane perpendicular to the principal axis. Any two of the first pair of flexural members and / or the second pair of flexural members can be formed as a single piece. The first pair of flexural members and the second pair of flexural members can be formed as a single piece. The first pair of flexural members and the second pair of flexural members can be attached to or combined with the first part. The first pair of flexural members and the second pair of flexural members can be integrally formed with the first part.

[0016] The first support member may include a flexure device. The flexure device may include a first pair of flexure members extending from the first portion and constraining movement of the first portion along a first axis. The flexure device may include a second pair of flexure members extending from the first portion and constraining movement of the first portion along a second axis.

[0017] The support device may include a second support member configured to generate movement of the first portion toward or away from the second portion along the main axis in response to a torque applied by the drive device about the main axis.

[0018] The second support member guides helical movement about and along the main axis. The second support member mechanically connects rotation about the main axis with translation along the main axis.

[0019] The second support member can be configured such that the movement of the first portion relative to the second portion along the first axis is coupled with the tilt of the first portion relative to the second portion about the first axis, and wherein the movement of the first portion relative to the second portion along the second axis is coupled with the tilt of the first portion relative to the second portion about the second axis.

[0020] The second support member can take the form of a helical flexure. The helical flexure can take the form of a flat ring and at least three flexures extending from the flat ring. There can be four or more flexures extending from the flat ring. The flexures can be attached around the flat ring at equally spaced angles. The flat ring and the flexures can be single pieces.

[0021] The second support member may include a first set of helical flexures configured to be compliant in a direction corresponding to the movement of the first portion relative to the second portion along the main axis and / or the first axis. The second support member may include a second set of helical flexures configured to be compliant in a direction corresponding to the movement of the first portion relative to the second portion along the main axis and / or the second axis.

[0022] The second support member may include a first set of four ramps arranged in a circle around the main axis and connected to the first part. The second support member may also include a second set of four ramps arranged in a circle around the main axis and connected to the second part. The first and second sets of ramps may be arranged opposite each other such that the inclined surface of each ramp in the first set engages with the inclined surface of the corresponding ramp in the second set.

[0023] The second support member may take the form of an under-constrained helical support member. The inclined surfaces of the first or second set of ramps form an angle greater than zero and less than ninety degrees with the plane containing the first and second axes. The actuator may include one or more resilient biasing devices configured to push the first set of ramps toward the second set of ramps along the main axis.

[0024] Each of the four shape memory lines may not be perpendicular to the main axis.

[0025] The drive unit can be configured to provide a force having a component along the main axis. The first and second shape memory alloy wire segments can be oriented at corresponding angles to the main axis and can be generally located in a plane parallel to the main axis and the first axis. The third and fourth shape memory alloy wire segments can be oriented at corresponding angles relative to the main axis and can be generally located in a plane parallel to the main axis and the second axis. The four shape memory alloy wire segments, oriented at corresponding angles relative to the main axis, can be configured to apply a net force along the first axis in conjunction with a torque about the first axis, apply a net force along the second axis in conjunction with a torque about the second axis, and / or apply a net force along the main axis in conjunction with a torque about the main axis.

[0026] The four shape memory alloy wire segments are substantially coplanar in a plane parallel to the first and second axes. These substantially coplanar shape memory alloy wire segments can be configured to apply a net force along the first and / or second axes and / or a torque about the main axis. The four shape memory alloy wire segments of the drive unit are substantially coplanar with the top or bottom of the first support member along the main axis.

[0027] The camera may include an actuator assembly, an image sensor supported by one of the first and second portions, and a lens supported by the other of the first and second portions.

[0028] The camera may also include a controller configured to control the actuator assembly to achieve autofocus by moving the first portion toward or away from the second portion along the main axis. The controller may also be configured to achieve optical image stabilization by tilting the first portion relative to the second portion about the first axis and / or the second axis.

[0029] According to a second aspect of the invention, a method is provided comprising using an actuator assembly to implement optical image stabilization and / or autofocus functions of a camera. Brief description of the attached diagram

[0030] Some embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0031] Figure 1 The camera is shown schematically;

[0032] Figure 2 As shown Figure 1 Possible translations and rotations of the lens assembly of the camera shown;

[0033] Figure 3 The first drive unit using four shape memory alloy (SMA) wires is schematically shown;

[0034] Figure 4 It is a projection diagram of the planar actuator assembly;

[0035] Figures 5A to 5C The second drive unit using four shape memory alloy (SMA) wires is schematically shown;

[0036] Figure 6 A two-bar linkage support is schematically shown;

[0037] Figure 7A This is a top view of a single flexural support. Figure 7B It is a side view of the deformation state of a single flexural support;

[0038] Figure 8 This is a plan view of the second single flexural support;

[0039] Figure 9 It is an exploded projection view of the Z-shaped flexural support;

[0040] Figure 10A This is a side view of the first planar support member. Figure 10B This is an exploded projection view of the first plane support component;

[0041] Figure 11 This is a side view of the second plane support member;

[0042] Figure 12 It is a projection drawing of the helical flexural support;

[0043] Figure 13 It is a projection drawing of an under-constrained helical support component;

[0044] Figure 14 This is an exploded projection of the first combined OIS and AF actuator assembly;

[0045] Figure 15 This is a projection diagram of the first combined OIS and AF actuator assembly;

[0046] Figure 16 This is a top view of the first combined OIS and AF actuator assembly;

[0047] Figure 17 This is a side view of the first combined OIS and AF actuator assembly;

[0048] Figure 18 The first combined OIS and AF actuator assembly is schematically shown;

[0049] Figure 19 This is an exploded projection of the second combined OIS and AF actuator assembly;

[0050] Figure 20 This is a projection diagram of the second combined OIS and AF actuator assembly; and

[0051] Figure 21 The first combined OIS and AF actuator assembly is schematically shown. Detailed description

[0052] In the following, similar parts are indicated by similar reference numerals.

[0053] camera

[0054] Reference Figure 1 The image shows a camera 1 incorporating an SMA actuator assembly 2 (also referred to herein as the “SMA actuator” or simply the “actuator”).

[0055] Camera 1 includes a first part in the form of a lens assembly 3, which is suspended on a second part in the form of a support structure 4 by an SMA actuator assembly 2. The SMA actuator assembly 2 supports the lens assembly 3 in a manner that allows the lens assembly 3 to move (or have one or more degrees of freedom) relative to the support structure 4. The lens assembly 3 has an optical axis O.

[0056] The second part of the support structure 4 includes a base 5. An image sensor 6 is mounted on the front side of the base 5. An integrated circuit (IC) 7 is mounted on the rear side of the base 5 (i.e., between the lens assembly 3 and the rear side), in which control circuitry is implemented, and also on which a gyroscope sensor (not shown) is mounted. The support structure 4 also includes a can 8 protruding forward from the base 5 to enclose and protect other components of the camera 1.

[0057] The first part of the lens assembly 3 includes a lens holder 9 in the form of a cylindrical body, which supports two lenses 10 arranged along the optical axis O. Typically, any number of lenses 10 can be included. Preferably, each lens 10 has a diameter of up to about 30 mm. Therefore, the camera 1 can be referred to as a miniature camera.

[0058] Lens assembly 3 is arranged to focus an image onto image sensor 6. Image sensor 6 captures images and can be any suitable type, such as a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) device.

[0059] Lens 10 is supported on lens holder 9, and lens holder 9 is supported by SMA actuator assembly 2, such that lens assembly 3 is movable relative to support structure 4 along optical axis O, for example to provide focusing or zooming. Although all lenses 10 are fixed to lens holder 9 in this example, typically one or more lenses 10 can be mounted to components other than lens holder 9 and can be fixed in place relative to image sensor 6, such that at least one of lenses 10 is attached to lens holder and movable relative to image sensor 6 along optical axis O.

[0060] Typically, in use, the lens assembly 3 can be moved orthogonally to the optical axis O relative to the image sensor 6, effectively shifting the image on the image sensor 6. For example, if a set of right-handed orthogonal axes x, y, z are arranged such that the third principal axis z is oriented substantially parallel to the optical axis O, the lens assembly 3 can be moved in a direction parallel to the first axis x and / or parallel to the second axis y. This is used to provide optical image stabilization (OIS), compensating for movement of the camera 1 that may be caused by hand shake, etc. The movement for providing OIS does not need to be limited to the xy plane. Alternatively or additionally, OIS functionality can be provided by tilting the lens assembly 3, or both the lens assembly 3 and the image sensor 6, about an axis parallel to the first axis x and / or about an axis parallel to the second axis y. Furthermore, the lens assembly 3, or at least one of its lenses 10, can be moved parallel to the optical axis O (along / parallel to the principal axis z) to provide focusing on the image formed on the image sensor 6, for example, as part of an autofocus (AF) function.

[0061] This specification relates to an example of an SMA actuator assembly 2, which provides a combination of autofocus (AF) and optical image stabilization (OIS) based on at least one lens 10 tilted relative to the image sensor 6 lens assembly 3.

[0062] Also refer to Figure 2 This illustrates the possible types of motion (or degrees of freedom) that can be provided by the SMA actuator assembly 2.

[0063] The first degree of freedom (DOF) Tx corresponds to a movement parallel to (along) the first axis x. The second DOF Ty corresponds to a movement parallel to (along) the second axis y. The third DOF Tz corresponds to a movement parallel to (along) the principal axis z, which is generally parallel to the optical axis O. The third DOF Tz corresponds to the movement of the lens assembly 3 toward or away from the image sensor 6. The first axis x, the second axis y, and the principal axis z form a right-handed Cartesian coordinate system. The fourth DOF Rx corresponds to a rotation about an axis parallel to the first axis x. The fifth DOF Ry corresponds to a rotation about an axis parallel to the second axis y. The sixth degree of freedom Rz corresponds to a rotation about an axis parallel to the principal axis Z. In some examples, one or more axes may be attached to the first part, the second part, or any other element of the SMA actuator assembly 2 or the camera 1 (and move and / or rotate / tilt together with the first part, the second part, or any other element of the SMA actuator assembly 2 or the camera 1). For example, the origin may be an element of the camera 1, such as the image sensor 6 or the lens 10 of the lens assembly 3.

[0064] The motion of lens assembly 3 relative to support structure 4 can be decomposed into any one or all of the first to sixth DOF (translation) components Tx, Ty, Tz, Rx, Ry, Rz. Although described as degrees of freedom, translation and rotation may be associated in some cases. For example, a given translation Tz along the principal axis z can be associated with a corresponding rotation Rz, making the motion of lens assembly 3 helical. Such associated motion can be referred to using a pair enclosed in square brackets to avoid confusion with more independent motions; for example, [Tz, Rz] would represent the helical motion described below.

[0065] This specification relates to an SMA actuator assembly 2 that provides a relative movement Tz of a first portion relative to a second portion along (or parallel to) a principal axis z, and / or a rotation Rx, Ry of the first portion relative to the second portion about an axis parallel to the first axis x and / or the second axis y. The relative movement of the first portion toward or away from the second portion along the principal axis z can be a simple translation, or it can be in the form of a helical motion that associates translation along the principal axis z with rotation about the principal axis z. Rotation Rx, Ry provides OIS functionality herein, while movement Tz along the principal axis z or movement [Tz, Rz] along and about the principal axis z provides AF functionality. Other movements are constrained by the SMA actuator assembly 2 described herein.

[0066] Shape memory alloy drive components

[0067] Also refer to Figure 3 The diagram schematically illustrates a first type of drive device 11 (first drive device) that may be included in the SMA actuator assembly 2.

[0068] The first drive unit 11 includes a first structure 12 and a second structure 13. The second structure 13 is typically supported within the boundary defined by the first structure 12, for example, using one or more support members as described below. The second structure 12 typically does not need to provide a complete or uninterrupted boundary. The first structure 12 and the second structure 13 may take the form of corresponding patterned metal sheets (e.g., etched or machined stainless steel) and may be coated with an electrically insulating dielectric material.

[0069] Four-segment shape memory alloy wires 141, 142, 143, 144 ( Figure 3 The dashed lines (in the diagram) form a loop around the second structure 13. For simplicity, the SMA segments will be referred to as "SMA lines" in the following text. The first SMA line 141 and the third SMA line 143 extend generally parallel to the first axis x and are spaced apart in a direction parallel to the second axis y. The contraction of the first SMA line 141 will exert a force on the second structure 13 in the negative -x direction, while the contraction of the third SMA line 143 will exert a force on the second structure 13 in the positive +x direction. The second SMA line 142 and the fourth SMA line 144 extend generally parallel to the second axis y and are spaced apart in a direction parallel to the first axis x. The contraction of the second SMA line 142 will exert a force on the second structure 13 in the negative -y direction, while the contraction of the fourth SMA line 144 will exert a force on the second structure 13 in the positive +y direction.

[0070] Other example configurations may be used, and further details are provided in WO2017 / 055788A1 and WO2019 / 086855A1, which are incorporated herein by reference in their entirety.

[0071] The position of the second structure 13 relative to the first structure 12, perpendicular to the optical axis O, is controlled by selectively altering the temperature of the SMA lines 141, 142, 143, and 144. This is achieved by providing resistance heating through selective drive signals transmitted via the SMA lines 141, 142, 143, and 144. Heating is provided directly by the drive current. Cooling is provided by reducing or stopping the drive current to allow the SMA lines 141, 142, 143, and 144 to cool through conduction, convection, and radiation with their surroundings.

[0072] During operation, SMA lines 141, 142, 143, and 144 are selectively driven to move the second structure 13 relative to the first structure 12 (or the first structure 12 relative to the second structure 13) in any lateral direction (i.e., in a direction in a plane parallel to the first axis x and the second axis y and perpendicular to the optical axis O and the principal axis z).

[0073] Further details are also provided in WO2013 / 175197A1, which is incorporated herein by reference.

[0074] Taking a set of four SMA lines 141, 142, 143, and 144 as an example, the SMA lines 141, 142, 143, and 144 are arranged in a circle at different angular positions around the optical axis O (which corresponds to the principal axis z) to provide two pairs of opposing SMA lines 141 & 143, 142 & 144 that are generally perpendicular to each other. Therefore, each pair of opposing SMA lines 141 & 143, 142 & 144 can selectively drive the second structure 13 to move in one of two perpendicular directions orthogonal to the optical axis O. Thus, the SMA lines 141, 142, 143, and 144 can be selectively driven to move the second structure 13 relative to the first structure 12 to any position within a range of movement in the plane orthogonal to the optical axis O. Another way to observe this movement is that the contraction of any pair of adjacent SMA lines (e.g., SMA lines 143, 144) will cause the second structure 13 to move in the direction bisecting the pair of SMA actuator lines (in... Figure 3 (Diagonally) movement. Furthermore, SMA lines 141, 142, 143, and 144 can be actuated to generate torque about an axis parallel to the main axis z. Specifically, the contraction of a pair of opposing SMA lines (e.g., SMA lines 141, 143) will generate torque about an axis parallel to the main axis z in one direction on the second structure 13, and the contraction of another pair of opposing SMA lines (e.g., SMA lines 142, 144) will generate torque in another direction. The generation of torque and the resulting rotation can be substantially independent of translation along directions parallel to the first axis x and / or the second axis y, at least for a portion of the range of motion of the drive device 11. The size of the range of motion depends on the geometry and contraction range of the SMA lines 141, 142, 143, and 144 within their normal operating parameters.

[0075] When one of the SMA wires 141, 142, 143, and 144 is heated, the stress in the SMA wires increases and these SMA wires contract, causing the second structure 13 to move relative to the first structure 12. A series of movements occur as the SMA temperature increases within the temperature range where the SMA material undergoes a transformation from martensitic to austenitic phase. Conversely, when one of the SMA wires 141, 142, 143, and 144 is cooled, causing the stress in the SMA wires to decrease, the SMA wire expands under the force from the opposing SMA wires among the SMA wires 141, 142, 143, and 144 (in some cases, there are also biasing forces from one or more biasing devices such as springs, armatures, etc.). This allows the second structure 13 to move relative to the first structure 12 in opposite directions.

[0076] SMA lines 141, 142, 143, and 144 can be made of any suitable SMA material (such as Nitinol or another titanium alloy SMA material).

[0077] The drive signals for SMA lines 141, 142, 143, and 144 are generated and provided by control circuitry implemented in IC 7. For example, if the first structure 12 is fixed to the support structure 4 (or a portion of the support structure 4) and the second structure 13 is fixed to the lens assembly 3 (or a portion of the lens assembly 3), the control circuitry generates a drive signal in response to the output signal of the gyroscope sensor (not shown) to drive the lens assembly 3 to move, thereby stabilizing the image focused by the lens assembly 3 onto the image sensor 6, thus providing OIS. The drive signal can be generated using resistive feedback control techniques, such as those described in WO2014 / 076463A1, which is incorporated herein by reference.

[0078] Each of the SMA lines 141, 142, 143, and 144 corresponds to a segment of shape memory alloy wire, the drive current of which can be independently controlled. A pair of shape memory alloy wire segments can be provided by a single physical wire having a first current source connected to one end, a second current source connected to the other end, and a current return connector located at a point between the two ends. For example, in the first drive unit 11, the first SMA line 141 and the second SMA line 142 can be provided by a single physical wire, with current return provided through the second structure 13.

[0079] Also refer to Figure 4 An example of a "flat" SMA actuator assembly 15 implementing the first drive unit 11 is shown.

[0080] In the flat actuator assembly 15, the first structure 12 takes the form of a flat annular plate 16 having a rectangular outer perimeter (or "outer edge") and a circular inner perimeter (or "inner edge"), while the second structure 13 takes the form of a flat, thin annular sheet 17 having a rectangular outer perimeter and a circular inner perimeter. The first structure 12 in the form of plate 16 is supported on a base 5 in the form of a rectangular plate. Four SMA lines 141, 142, 143, 144 are each attached at one end to a corresponding first crimp 181, 182, 183, 184 (also referred to as a "stationary" crimp), which is fixedly attached to the first structures 12, 16 (or formed as part of the first structures 12, 16). The other end of each SMA line 141, 142, 143, 144 is attached to a corresponding second crimp 191, 192, 193, 194 (also referred to as a “moving” crimp), which is fixedly attached to the second structure 13, 17 (or formed as part of the second structure 13, 17).

[0081] The plate 16 and the sheet 17 can each be in the form of a patterned metal sheet (e.g., etched or machined stainless steel) and can be coated with an electrically insulating dielectric material. The plate 16 and the sheet 17 are each provided with a corresponding central hole aligned with the optical axis O, allowing light to be transmitted from the lens assembly 3 mounted on the sheet 17 to the image sensor 6 supported on the base 5.

[0082] The four SMA lines 141, 142, 143, and 144 can be perpendicular to the optical axis O or tilted at a small angle relative to a plane perpendicular to the optical axis O. Typically, in a set, the four SMA lines 141, 142, 143, and 144 are non-collinear.

[0083] The planar actuator assembly 15 includes a plurality of sliding supports spaced apart around the optical axis O. Figure 4 (not shown in the diagram) to support the second structures 13, 17 on the first structures 12, 16. Preferably, at least three support members are used to help provide stable support, but a different number of support members can usually be used. Each sliding support member ( Figure 4 (Not shown) can take the form of a cylindrical support member and can be attached to or formed as part of the first structure 12. Sliding support member ( Figure 4 (Not shown) can be made of a suitable metal or alloy (e.g., phosphor bronze or stainless steel with a diamond-like carbon coating). Sliding support ( Figure 4 (Not shown) may be made of a polymer or may include a polymer top layer or coating, such as polyoxymethylene (POM, acetal), polytetrafluoroethylene (PTFE), or PTFE-impregnated POM. Sliding support ( Figure 4(Not shown) may be made of stainless steel or phosphor bronze or may include a stainless steel or phosphor bronze top layer or coating having a titanium carbide coating, tungsten carbide coating, diamond-like carbon (DLC) coating, or chromium carbide DLC coating. These support materials may be bonded to a second support surface formed of one of these support materials, which may be polished or stamped to reduce the effects of friction caused by surface texture.

[0084] The flat actuator assembly 15 will also typically include biasing devices (not shown), such as one or more springs or flexure arms, which are arranged and configured to keep the first structure 12 and the second structure 13 in contact (via a sliding support) and / or push the first structure 12 and the second structure 13 toward a neutral (e.g., central) relative position when the SMA lines 141, 142, 143, 144 are not energized.

[0085] Details relating to the manufacture of actuator assemblies similar to the flat actuator assembly 15 can be found in WO2016 / 189314A1, which is incorporated herein by reference in its entirety.

[0086] Although Figure 4 Although not shown, the flat actuator assembly 15 may be provided with end stops to limit lateral movement of the second structure 13 relative to the first structure 12. This protects the SMA lines 141, 142, 143, and 144 from overstretching caused by impacts (e.g., drops) that may occur to, for example, a device (not shown) incorporating the flat actuator assembly 15.

[0087] The first drive unit 11 can drive translations Tx and Ty along the first axis x and / or the second axis y, and rotations Rz about an axis parallel to the main axis z (which is generally parallel to the optical axis O). At least for a portion of the range of motion of the first drive unit, each of these movements Tx, Ty, and Rz is generally independent of the others. However, in order to provide the translation Tz parallel to the main axis z, the first drive unit 11 must be combined with at least one support member capable of converting the torque applied about the optical axis O into a combination of rotation Rz and translation Tz (as described below for helical movement [Tz, Rz]).

[0088] Also refer to Figures 5A to 5C The diagram schematically illustrates a second type of drive device 20 that may be included in the SMA actuator assembly 2.

[0089] The second drive unit 20 is similar to the first drive unit 11, except that the first structure 12 includes a base 21 and a pair of first upright pillars 221 and second upright pillars 222, and the SMA lines 141, 142, 143, 144 are not generally limited to a plane perpendicular to the main axis Z.

[0090] Figure 5A The second drive unit 20 is shown as viewed from above along a direction parallel to the main axis Z.

[0091] Figure 5B The second drive unit 20 is shown as a side view along a direction parallel to the first axis x. Note that although the fourth SMA line 144 is largely obscured behind the second structure 13, it is superimposed on the image for visual purposes. Figure 5B superior.

[0092] Figure 5C The second drive unit 20 is shown as a side view along a direction parallel to the second axis y. Note that although the first SMA line 141 is largely obscured behind the second structure 13, for visual purposes, the first SMA line 141 has been superimposed on... Figure 5C superior.

[0093] When viewed along the main axis ( Figure 5A The base 21 extends beyond the edge of the second structure 13, and in this example, the base 21 is rectangular (or square). The first pillar 221 stands upright from the first corner of the base 21 and the second pillar 222 stands upright from the second corner, with the first pillar 221 and the second pillar 222 facing each other diagonally across the second structure 13.

[0094] The first SMA line 141 connects from the lower part of the second structure 13 (lower along the main axis z) to the upper part of the first pillar 221 (higher along the main axis z). The second SMA line 142 connects from the upper part of the second structure 13 to the lower part of the second pillar 222. The third SMA line 143 connects from the lower part of the second structure 13 to the upper part of the second pillar 222. The fourth SMA line 144 connects from the upper part of the second structure 13 to the lower part of the first pillar 221.

[0095] Thus, the first SMA line 141 and the third SMA line 143 are opposite each other in a direction parallel to the first axis x, the second SMA line 142 and the fourth SMA line 144 are opposite each other in a direction parallel to the second axis y, and the first SMA line 141 and the third SMA line 143 are opposite each other to the second SMA line 142 and the fourth SMA line 144 in a direction parallel to the principal axis Z.

[0096] Thus, the second drive unit 20 uses four angled (non-coplanar) SMA lines 141, 142, 143, and 144 to provide drive corresponding to Tx, Ty, Tz, Rx, Ry, and Rz motions. The motions are not completely independent degrees of freedom, and translation is typically associated with rotation, such as [Tx, Rx], [Ty, Ry], and [Tz, Rz], with the specific connection depending on the angles of the SMA lines 141, 142, 143, and 144.

[0097] SMA lines 141, 142, 143, and 144 are preferably inclined at an angle between 10° and 25° relative to a plane perpendicular to the principal axis Z.

[0098] Any one or both of the first structures 12, 21 and the second structure 13 may include a central aperture to allow light from the lens assembly 3 to form an image on the image sensor 6.

[0099] One or more of the movements driven by the first drive device 11 or the second drive device 20 can be fully or partially constrained by one or more support members mechanically connected between the first structure 12 and the second structure 13.

[0100] Support components

[0101] Generally, the SMA actuator 2 according to this specification will include at least one of a first drive unit 11 and a second drive unit 20, and a device of one or more mechanical support members (also referred to as "support device") for supporting, constraining and / or converting the motion generated by the first drive unit 11 or the second drive unit 20.

[0102] Also refer to Figure 6 The image shows a two-bar linkage support 1001.

[0103] The two-bar linkage support 1001 includes a first rigid portion 10021 and a second rigid portion 10022, which are connected by a first beam portion 10031 and a second beam portion 10032 (also referred to as a flexure). The rigid portions 10021 and 10022 are each elongated in a direction parallel to a first axis x and spaced apart from each other in a direction parallel to a second axis y. The beam portions 10031 and 10032 are each elongated in a direction parallel to the second axis y and spaced apart from each other in a direction parallel to the first axis x. The beam portions 10031 and 10032 are shown as perpendicular to the rigid portions 10021 and 10022; however, this is not mandatory, and any angle is acceptable as long as the beam portions 10031 and 10032 are parallel to each other. Beam sections 10031 and 10032 cannot rotate around the joints with rigid sections 10021 and 10022, for example, the connection is not a pin joint or a similar connection.

[0104] The relative bending stiffness of the beam portions 10031, 10032 and the rigid portions 10021, 10022 is selected (primarily using the dimensions and shape of the cross-sections) such that if the first rigid portion 10021 is clamped, the second rigid portion 10022 can move relative to the first rigid portion 10021 via the bending of the beam portions 10031, 10032 in the xy and / or xz planes. Thus, the two-bar linkage 1001 can provide relative movements Tx, Tz, Rx, and Ry between the first rigid portion 10021 and the second rigid portion 10022. Also... Figure 6 The deformation state of the second rigid part 10022, which is displaced parallel to the first axis by a distance d, is shown by dashed lines. The two-bar linkage support 1001 can rotate 90 degrees to provide a movement Ty parallel to the second axis y instead of Tx.

[0105] The relative bending stiffness can be selected by using the cross-sectional shape of beam sections 10031 and 10032 to control the relative bending resistance in the xy plane relative to the yz plane.

[0106] Also refer to Figure 7A This illustrates a tiltable Z-shaped flexure (also known as a single flexure) in the form of a two-by-two parallel rod type link support 1004.

[0107] A single flexure 1004 includes a central portion 1005 and two pairs of beam portions (or flexures) 10061, 10062, 10063, and 10064. Each beam portion (or flexure) 10061, 10062, 10063, and 10064 is rigidly connected to the central portion 1005 at one end and has a second free end 10071, 10072, 10073, or 10074. In some examples, the central portion 1005 may also have a central hole 1009 (…). Figure 8 The first beam portion (flexible element) 10061 and the third beam portion (flexible element) 10063 are elongated in a direction parallel to the first axis x and are deformable by beam bending in the xz plane. Similarly, the second beam portion (flexible element) 10062 and the fourth beam portion (flexible element) 10064 are elongated in a direction parallel to the second axis y and are deformable, for example, by beam bending in the yz plane. The lateral (perpendicular to the principal axis z) deflection of the beam portions (or flexible elements) 10061, 10062, 10063, and 10064 is constrained by the connection of all beam portions (or flexible elements) 10061, 10062, 10063, and 10064 to the central portion 1005 and / or by the cross-sectional shape of the beam portions 10061, 10062, 10063, and 10064.

[0108] Thus, if the free end 1007 is clamped, the single flexure 1004 can provide relative movement Tz, Rx and / or Ry between the central portion 1005 and the clamped free end 1007.

[0109] Also refer to Figure 7B , showed Figure 7A The deformation state 1004b of a single flexural member, wherein the central portion 1005 is displaced by a distance d parallel to the principal axis z.

[0110] Also refer to Figure 8 The second single flexure (tiltable Z-shaped flexure) 1008 is shown.

[0111] The second single flexure 1008 is identical to the single flexure 1004, except that the central portion 1005 includes a central hole 1009, and the ends of the beam portions 10061, 10062, 10063, and 10064 not connected to the central portion 1005 are connected to the outer ring 1010, and the beam portions 10061, 10062, 10063, and 10064 are curved rather than straight. The second single flexure 1008 functions in substantially the same manner as the single flexure 1004. In particular, if the outer ring is clamped, the central portion 1005 can move at Tz, Rx, and / or Ry.

[0112] The presence or absence of a center hole 1009 in the second single flexure 1008 or the single flexure 1004 may depend on its position within the device (such as the camera 1). Single flexures 1004 and 1008 located below the image sensor 6 typically do not require a center hole 1009, while single flexures 1004 and 1008 located above the image sensor 6 typically require a center hole 1009.

[0113] Also refer to Figure 9 The Z-shaped flexure 1011 is shown.

[0114] The Z-shaped flexure includes a pair of individual flexures 10041 and 10042, which are arranged perpendicular to the principal axis z (when undeformed) and spaced apart in a direction parallel to the principal axis z by a rigid structure 1012 sandwiched between the individual flexures 10041 and 10042. The individual flexures 10041 and 10042 are fixed to opposite faces of the rigid structure 1012. Each individual flexure 10041 and 10042 includes a central hole 1009. Figure 9 The illustrations in the figure show, for visual purposes, a rigid structure 1012 that is fixed to one of the single flexures 10041 and separate from the other single flexure 10042; however, in use, the two single flexures 10041 and 10042 are fixed to the rigid structure 1012. Figure 9 The dashed line in the figure shows the projected outline of the rigid structure 1012.

[0115] Thus, each individual beam portion 1006 of each individual flexure 10041, 10042 may deflect. However, the separation of the individual flexures 10041, 10042 in a direction parallel to the principal axis z and the fixed connection via the rigid structure 1012 constrain the movements Tx, Ty, Rx, Ry, Rz, while guiding the movement Tz in a direction parallel to the principal axis z.

[0116] In this example, the rigid structure 1012 is a hollow cylinder with an inner diameter equal to the diameter of the central hole 1009. However, the rigid structure 1012 can have any shape suitable for separating individual flexural elements parallel to the principal axis z and compatible with the intended application of the actuator.

[0117] Also refer to Figure 10A and Figure 10B The first planar support 1064 (also known as a three-point support) is shown.

[0118] Figure 10A It is a side view, and Figure 10B It is a decomposed projection diagram.

[0119] The first planar support 1064 includes a first plate 1065 that slides in contact with the second plate 1066. The first plate 1065 supports at least three cylindrical protrusions 1067, including at least a first cylindrical protrusion 10671, a second cylindrical protrusion 10672, and a third cylindrical protrusion 10673, which are not collinear, for example, arranged at points of a triangle. The second plate 1066 is supported by an offset device (…). Figure 10A and Figure 10B (Not shown) is pushed to contact the flat surface of the cylindrical protrusion 1067 and slides freely in a plane parallel to the first axis x and the second axis y, and rotates about an axis parallel to the principal axis z. Thus, the relative motion between the first plate 1065 and the second plate 1066 corresponds to Tx, Ty and / or Rz. Movements Tz, Rx and Ry are constrained unless the biasing force that pushes the plates 1065 and 1066 together is overcome.

[0120] exist Figure 10A and Figure 10B In the example shown, both plates 1065 and 1066 take the form of a ring with a rectangular outer perimeter and a circular inner perimeter defining a central hole 1009. However, the shapes of plates 1065 and 1066 are independent of the function of the first planar support 1064, and plates of any shape can be used instead. Although in Figure 10A and Figure 10B Three cylindrical protrusions 10671, 10672, and 10673 are shown; however, any number of cylindrical protrusions, three or more, can generally be used. Flat actuator assembly 15 ( Figure 4 (This is an example of an implementation that includes a first planar support member 1064.)

[0121] Also refer to Figure 11 The second planar support 1068 is shown.

[0122] The second planar support 1068 is identical to the first planar support 1064, except that the cylindrical protrusion 67 is replaced by ball bearings 10301, 10302, and 10303. The first plate 1065 can also be replaced by a third plate 1069, which includes recesses 10701, 10702, and 10703, such as circular notches, for receiving the corresponding ball bearings 10301, 10302, and 10303. Except that the second planar support 1068 is a rolling support rather than a sliding support, the second planar support 1068 functions in the same manner as the first planar support 1064.

[0123] Also refer to Figure 12 An example of a helical flexural support 1090 is shown.

[0124] The helical flexural support 1090 includes a circular ring 1091 having a central hole 1009 and connected to three or more (preferably four or five) helical beam portions 1092. Figure 12 In the example shown, there are four helical beam sections 10921, 10922, 10923, and 10924. At the ends not connected to the circular ring, each helical beam section 10921, 10922, 10923, and 10924 is connected to pads 10931, 10932, 10933, and 10934, for example, to connect to a layer or structure below the circular ring 1091 (relative to the main axis z shown).

[0125] Each helical beam portion 10921, 10922, 10923, 10924 is approximately tangent to the circular ring 1091 (in the same direction), and its span includes a first component parallel to a plane containing the first axis x and the second axis y, and a second component parallel to the principal axis z. If the pads 10931, 10932, 10933, 10934 are clamped and an upward (positive z-direction) force is applied to the circular ring 1091, the helical beam portions 10921, 10922, 10923, 10924 will deflect in the direction of the force in response. However, in doing so, the ends connected to the circular ring also deflect closer to the corresponding pads 10931, 10932, 10933, 10934, causing the circular ring 1091 to rotate clockwise about an axis parallel to the principal axis z. Conversely, applying a downward (negative z-direction) force to the circular ring 1091 will cause the circular ring 1091 to move downward and rotate counterclockwise.

[0126] Thus, the helical flexure support 1090 serves to convert relative displacement parallel to the principal axis z into rotation about the principal axis z, and rotation about the principal axis z into relative displacement parallel to the principal axis z. However, these movements are not independent of each other, and the circular ring 1091 is constrained to move along an approximately helical path relative to the clamping pads 10931, 10932, 10933, and 10934. Since this does not reflect independent degrees of freedom, the motion will be expressed as [Tz, Rz] to highlight the relationship between the translation Tz parallel to the principal axis z and the rotation Rz about the principal axis z for this type of support.

[0127] although Figure 12The helical beam portions 10921, 10922, 10923, and 10924 shown are curved; however, in other examples of the helical flexural support 1090, the helical beam portion 1091 may be straight. Further examples of the helical flexural support 1090 are described in WO2019 / 243849A1, the contents of which are incorporated herein by reference in their entirety. WO2019 / 243849A1 Figures 19 to 2 The accompanying description on page 22, lines 23 to 24, is particularly relevant to the helical flexural support 1090. Further examples of implementing the helical flexural support 1090 are also shown and described below.

[0128] Also refer to Figure 13 The image shows an under-constrained helical support 1099. Obscured features are shown in dashed lines.

[0129] The unrestrained helical support 1099 includes a first plate 1100 supporting first to fourth ramps 11011, 11012, 11013, and 11014, and a second plate 1102 supporting fifth to eighth ramps 11015, 11016, 11017, and 11018. The first plate 1100 is in the form of a ring having a rectangular outer perimeter and a circular inner perimeter defining a central hole 1009. The first to fourth ramps 11011, 11012, 11013, and 11014 are arranged in a circle around the central hole 1009. Similarly, the second plate 1102 is in the form of a ring having a rectangular outer perimeter and a circular inner perimeter defining the central hole 1009, and the fifth to eighth ramps 11015, 11016, 11017, and 11018 are arranged in a circle around the central hole 1009.

[0130] A biasing device (not shown) pushes plates 1100 and 1102 together such that the inclined surface of the first ramp 11011 contacts the inclined surface of the fifth ramp 11015. Similarly, the second ramp 11012 contacts the sixth ramp 11016, the third ramp 11013 contacts the seventh ramp 11017, and the fourth ramp 11014 contacts the eighth ramp 11018. If the first plate 1100 and the second plate 1102 rotate relative to each other about the principal axis z by a rotation Rz, the ramp 1101 acts to move the first plate 1100 and the second plate 1102 by a movement Tz, further separating them along the principal axis z. Thus, the under-constrained helical support 1099 provides helical motion [Tz, Rz].

[0131] Furthermore, the force pushing the second plate 1102 relative to the first plate 1100 along the first axis x will not only cause a movement Tx parallel to the first axis x, but also a rotation Rx about an axis parallel to the first direction x. For example, if the first plate 1100 is clamped, the translation in the positive x direction will cause the seventh ramp 11017 and the eighth ramp 11018 to rise parallel to the third principal axis z, while the fifth ramp 11015 and the sixth ramp 11016 will descend or remain at the same horizontal plane in contact with the first plate 1100 (depending on the construction of the ramp 1101). To represent the relationship between these movements, they will be denoted as [Tx, Rx]. Similarly, the associated movement [Ty, Ry] relative to the second axis y will be generated by the force pushing the second plate 1102 relative to the first plate 1100 along the second axis y.

[0132] Although shown and described for reference in a specific orientation relative to a set of right-hand Cartesian axes x, y, z, any of the supports described above can be oriented at any angle.

[0133] The support components described above can be formed from any suitable material and using any suitable manufacturing method. For example, plate-like or sheet-like components can be manufactured from sheet metal (e.g., stainless steel) and patterned by chemical or laser etching. Milling or stamping can be used, as long as this does not unacceptably introduce residual strain that causes deformation of the part. After patterning, these parts can be bent or pre-deformed as needed. Complex three-dimensional parts can be constructed by attaching the parts to plates, sheets, or other components, for example, using adhesives, welding, brazing, soldering, etc. Alternatively, complex three-dimensional parts can be formed by, for example, sintering or die casting of metals or by injection molding of polymers. Any support surface can be made of polymers or may include a polymer top layer or coating, such as polyoxymethylene (POM, acetal), polytetrafluoroethylene (PTFE), or PTFE-impregnated POM. Any support surface can be made of stainless steel or phosphor bronze or may include a stainless steel or phosphor bronze top layer or coating with titanium carbide coating, tungsten carbide coating, diamond-like carbon (DLC) coating, or chromium carbide DLC coating. These support materials can be bonded to a second support surface formed from one of these support materials, which can be polished or stamped to reduce the effects of friction caused by surface texture.

[0134] First combination of OIS and AF actuator assembly

[0135] Also refer to Figures 14 to 18 The first combined OIS and AF actuator assembly 23 (hereinafter referred to as the first actuator assembly) is shown.

[0136] Figure 14 An exploded projection view of the first actuator assembly 23 is shown. Figure 15 A projection diagram is shown. Figure 16 It is a top view. Figure 17 It is a side view, and Figure 18 This is a schematic diagram.

[0137] Special Reference Figure 18 The first actuator assembly 23 includes a first portion 24 and a second portion 25. A support device 26 mechanically connects the first portion 24 to the second portion 25. The first actuator assembly 23 also includes drive devices 11 and 20, which include a total of four shape memory alloy wires 141, 142, 143, and 144 that connect (or link) the second portion 25 to the first portion 24. Figures 14 to 17 In the example shown, the second drive unit 20 is used. However, depending on the construction of the support device 26, the first drive unit 11 can also be used. Figure 19 and Figure 20 ).

[0138] The drive units 11, 20 and the support unit 26 are configured such that the first portion 24 is movable Tz toward or away from the second portion 25 along the main axis z passing through the first actuator assembly 23, and such that the first portion 24 is tiltable (rotatable) Rx, Ry (or vice versa) relative to the second portion 25 about a first axis x and / or a second axis y that is not parallel to and perpendicular to the main axis z. The first axis x and the second axis y may pass through a pivot point. Depending on the specific configuration, the pivot point may coincide with the first portion 24 and the second portion 25, or be offset from both along the main axis Z. Tilting Rx, Ry may refer to small rotations, for example, rotations of less than or equal to 10 degrees, 5 degrees, or 1 degree about the respective axes x, y.

[0139] The support device 26 is configured to guide the movement Tz of the first portion 24 relative to the second portion 25 along the main axis z, and to guide the tilting of the first portion 24 relative to the second portion 25 about the first axis x and / or the second axis y (or to guide the tilting of the second portion 25 relative to the first portion 24 about the first axis x and / or the second axis y). The support device 26 is also configured to constrain the movement Tx, Ty of the first portion 24 relative to the second portion 25 along the first axis x and / or the second axis y, and to constrain the rotation Rz of the first portion 24 relative to the second portion 25 about the main axis z.

[0140] Special Reference Figures 14 to 17 An example implementation of the first actuator assembly 23 is shown in more detail.

[0141] The first actuator assembly 23 includes a second portion 25 in the form of a rectangular plate 27. A first support 281 and a second support 282 extend upward (relative to the main axis z) from opposite corners of the plate 27. The plate 27 and supports 281, 282 may correspond to the base 21 and supports 221, 222 of the second drive unit 20. Each support 281, 283 has a rectangular cross-section, with one corner truncated (or beveled). Each support 281, 282 has a first surface 29 generally perpendicular to the second axis y and a second surface 30 generally perpendicular to the x-axis. Figure 16 and Figure 17 As shown, the image sensor 6 can be mounted at the center of the rectangular plate 27 (second part 25).

[0142] In this example, the support device 26 includes a first support member 31 in the form of a modified single flexure. Similar to the single flexure 1004 and the second single flexure 1008, the first support member 31 includes four beam portions 10061, 10062, 10063, and 10064. The first beam portion 10061 extends from the second face 301 of the first pillar 281 generally parallel to the first axis x (in the positive direction +x). The second beam portion 10062 extends from the first face 292 of the second pillar 282 generally parallel to the second axis y (in the positive direction +y). The distal ends of the first beam portion 10061 and the second beam portion 10062 are connected by a first elbow joint 321.

[0143] The third beam portion 10063 extends from the second face 302 of the second support 282 generally parallel to the first axis x (in the negative direction -x). The fourth beam portion 10064 extends from the first face 291 of the first support 281 generally parallel to the second axis y (in the negative direction -y). The distal ends of the third beam portion 10063 and the fourth beam portion 10064 are connected by a second elbow joint 322.

[0144] The first part 24 takes the form of an annular sheet 33, which has a circular inner perimeter defining a central hole 1009 and an outer perimeter having a generally rectangular shape with truncated (or beveled) corners. The annular sheet 33 may optionally be described as having an (irregular) octagonal outer perimeter. The annular sheet 33 provides a lens holder 9 for mounting one or more lenses 10. The annular sheet 33 is secured to elbow joints 321, 322 of the first support member 31, for example by welding, adhesive, or other suitable attachment methods. During assembly, the first beam portion 10061 and the third beam portion 10063 support the annular sheet 33 along a second axis y, while the second beam portion 10062 and the fourth beam portion 10064 support the annular sheet 33 along a first axis x.

[0145] The first wire connection structure 341 and the second wire connection structure 342 extend from opposite corners of the annular sheet 33 (first portion 24). When the first actuator assembly 23 is assembled, the wire connection structures 341, 342 will correspond to corners not occupied by the supports 281, 282. Each wire connection structure 341, 342 takes the form of supports extending above and below the annular sheet 33 (relative to the main axis z). The wire connection structures 341, 342 take the form of trapezoidal prisms oriented such that the trapezoidal cross-section is perpendicular to the main axis z. Each wire connection structure 341, 342 includes an inner face 35 corresponding to the shorter side of the parallel trapezoidal sides, a first face 36 corresponding to an inclined side generally perpendicular to the second axis y, and a second face 37 corresponding to an inclined side generally perpendicular to the first axis x. Other shapes of wire connection structures 341, 342 providing the same function may be used instead of the trapezoidal prisms shown. Note that for visual purposes, Figure 14 The image shows dashed lines outlining the structure obscured by the first pillar 341.

[0146] Once the annular sheet 33 is secured to the elbow joints 321 and 322, the first SMA line 141 connects from the upper region (relative to the main axis z) of the second surface 371 of the first wire connection structure 341 to the lower region (relative to the main axis z) of the second surface 301 of the first post 281. The second SMA line 142 connects from the lower region (relative to the main axis z) of the first surface 361 of the first wire connection structure 341 to the upper region (relative to the main axis z) of the first surface 292 of the second post 282. The third SMA line 143 connects from the upper region (relative to the main axis z) of the second surface 372 of the second wire connection structure 342 to the lower region (relative to the main axis z) of the second surface 302 of the second post 282. The fourth SMA line 144 connects from the lower region (relative to the main axis z) of the first surface 362 of the second wire connection structure 342 to the upper region (relative to the main axis z) of the first surface 291 of the first post 281. This device corresponds to an embodiment of the second drive device 20.

[0147] The second drive unit 20 can cause the first portion 24 to move Tz toward the second portion 25 along the main axis z by contracting the first SMA line 141 and the third SMA line 143 to provide a net downward force. Similarly, the second drive unit 20 can cause the first portion 24 to move Tz away from the second portion 25 along the main axis z by contracting the second SMA line 142 and the fourth SMA line 144 to provide a net upward force. In either case, a torque about the main axis z is also generated, but the rotation Rz about the main axis z is constrained by the rigid connection of the beam portions 10061, 10062, 10063, 10064 to the annular sheet 33. Such a combination of contractions does not exert a net torque about the first axis x or the second axis y.

[0148] The second drive unit 20 can cause tilting of Rx', Ry' about the first rotated axis x' and / or the second rotated axis y'. Compared with the axes x, y, z mentioned in the description of the geometry of the first actuator assembly 1023, the rotated axes x', y', z are rotated 45 degrees counterclockwise about the main axis z.

[0149] The first SMA line 141 and the second SMA line 142 can be contracted to cause the first portion 24 to tilt clockwise by Rx' relative to the second portion 25 about the rotated first axis x'. Similarly, the third SMA line 143 and the fourth SMA line 144 can be contracted to cause the first portion 24 to tilt counterclockwise by Rx' relative to the second portion 25 about the rotated first axis x'. In either case, there is no net force along the principal axis z.

[0150] The second SMA line 142 and the third SMA line 143 can be contracted to cause the first portion 24 to tilt clockwise (Ry') relative to the second portion 25 about the rotated second axis y'. Similarly, the first SMA line 141 and the fourth SMA line 144 can be contracted to cause the first portion 24 to tilt counterclockwise (Ry') relative to the second portion 25 about the rotated second axis y'. In either case, there is no net force along the principal axis z.

[0151] Inclined points Rx' and Ry' are implicit pivot points around the center of beam segments 10061, 10062, 10063, and 10064. The general motion can be decomposed into components of these motions Rx', Ry', and Tz.

[0152] Thus, the first actuator assembly 23 can use a drive unit 20 comprising a total of four SMA lines 141, 142, 143, and 144 to provide an OIS function based on tilting Rx' and / or Ry' and an AF function based on translation Tz along the principal axis z. These two functions can be substantially independent over at least a portion of the range of motion.

[0153] Although reference Figures 14 to 17 The specific example shown is illustrated, but the first actuator component 23 can be varied in a large number of arrangements to provide the same functionality.

[0154] Although the first actuator assembly 23 has been described with plate 27 (second part 25) corresponding to the support structure 4 of the camera and annular sheet 33 (first part 24) corresponding to lens bracket 9 of lens assembly 3, the roles can be interchanged, such that second part 25 corresponds to lens bracket 9 and first part 24 provides support structure 4. Similarly, the first actuator assembly 23 is not necessarily limited to use in camera 1, and first part 24 and second part 25 can be any parts that require relative movement Rx, Ry, and / or Tz.

[0155] Plate 27 and sheet 33 may each be in the form of a patterned metal sheet (e.g., etched or machined stainless steel) and may be coated with an electrically insulating dielectric material. Either or both of plate 27 and sheet 33 may be provided with a corresponding center hole 1009.

[0156] Despite Figures 14 to 17 A specific first support member 31 is used, but typically the first support member 31 may include a first pair of flexures and a second pair of flexures. Each of the first pair of flexures may extend in a direction generally parallel to the first axis x and connect the second portion 25 to the first portion 24, wherein the first pair of flexures are spaced apart in a direction parallel to the second axis y to support the first portion 24. Each of the second pair of flexures may extend in a direction generally parallel to the second axis and connect the second portion 25 to the first portion 24, wherein the second pair of flexures are spaced apart in a direction parallel to the first axis x to support the first portion 24. Each of the first and second pairs of flexures should be configured to be compliant in a direction corresponding to a movement Tz of the first portion 24 relative to the second portion 25 along the principal axis z.

[0157] One or more, or all, of the first pair and / or the second pair of flexural members may be flat. One or more, or all, of the first pair and / or the second pair of flexural members may include at least one bend (or “turn” or “elbow”). One or more, or all, of the first pair and / or the second pair of flexural members may include a corresponding arm, which may include at least one bend. One or more, or all, of the arms may include a first portion extending away from the second portion 25 and a second portion extending along a corresponding side of the second portion 25. The first and second portions may be straight. When the flexural members are not flexed, the first pair of flexural members and the second pair of flexural members are coplanar. When the flexural members are not flexed, the first pair of flexural members and the second pair of flexural members may be coplanar in a plane perpendicular to the principal axis. Any two of the first pair of flexural members and / or the second pair of flexural members may be formed as a single piece. The first pair of flexural members and the second pair of flexural members may be formed as a single piece. The first pair of flexural members and the second pair of flexural members may be attached or joined to the first portion and / or the second portion. The first pair of flexural members and the second pair of flexural members may be integrally formed with the first part or the second part. The first support member 31 shown is a suitable example, having a first beam portion 10061 and a third beam portion 10063 corresponding to the first pair of flexural members, and a second beam portion 10062 and a fourth beam portion 10064 corresponding to the second pair of flexural members.

[0158] Using a single drive unit 20 comprising a total of four SMA lines 141, 142, 143, and 144, and eliminating the need for a fifth or more SMA lines, to provide OIS and AF functions can advantageously reduce the complexity and / or power consumption of the SMA actuator 2 for the camera 1. Furthermore, a second drive unit is neither included nor required, regardless of whether it is based on SMA lines or other technologies. Combined AF and OIS can reduce the cost of parts, assembly, and / or testing. The robustness of the combination / coupling between OIS and AF functions can also be improved. Moreover, there is no need for a moving electrical connection between a static part and a separate AF drive system that moves with OIS actuation.

[0159] Each of the four shape memory alloy wires 141, 142, 143, and 144 corresponds to a segment of the SMA wire from which the drive current can be independently controlled. For example, a pair of SMA wires (e.g., 141, 142) can be provided by a single physical wire having a first current source (not shown) connected to one end, a second current source (not shown) connected to the other end, and a current return connector (not shown) located at a point between the two ends.

[0160] As an added advantage of combining AF and OIS, the first actuator assembly 23 can potentially be controlled by the output of a single triaxial Hall sensor. Such a sensor can be mounted on the static portion of the first actuator assembly 23 (first portion 24 or second portion 25, depending on the construction) to avoid potential hysteresis during rotation that limits the lens holder's rotation. For example, in Figures 15 to 17 In the example shown, a magnet (not shown) can be mounted to the first part 24, and a triaxial Hall sensor (not shown) can be mounted to the second part 25.

[0161] The advantage of using the first support member 31 in the form of a single flexible element is that when the SMA line 14 is not powered, the beam portion 1006 can provide its own restoring force to push the first portion 24 and the second portion 25 to a balanced or neutral position. This avoids the need for separate springs, magnets, or other biasing devices.

[0162] Second combination of OIS and AF actuator assembly

[0163] Also refer to Figures 19 to 21 The second combined OIS and AF actuator assembly 40 (hereinafter referred to as the second actuator assembly) is shown.

[0164] Figure 19 An exploded projection view of the second actuator assembly 40 is shown. Figure 20 A projection diagram is shown. Figure 21 This is a schematic diagram.

[0165] Special reference Figure 21Similar to the first actuator assembly 23, the second actuator assembly 40 includes a first portion 24 and a second portion 25, which are connected together by a support device 26 that is connected in parallel with the drive devices 11 and 20. The second actuator assembly 40 differs from the first actuator assembly 23 in that either the first drive device 11 or the second drive device 20 can be used, and the first support member 31 can be replaced by the second support member 41.

[0166] The second support member 41 is configured to generate movement of the first portion 24 toward or away from the second portion 25 along the main axis z in response to a torque applied by the drive devices 11, 20 about the main axis z. The second support member 41 provides this function by guiding a helical movement [Tz, Rz] around and along the main axis z. In other words, the second support member can mechanically couple a rotation Rz about the main axis z with a translation Tz along the main axis z along a helical path [Tz, Rz].

[0167] The second support member 41 is also configured such that the movement Tx of the first portion 24 relative to the second portion 25 along the first axis x is coupled with the tilt Rx of the first portion 24 relative to the second portion 25 about the first axis x, and such that the movement Ty of the first portion 24 relative to the second portion 25 along the second axis y is coupled with the tilt Ry of the first portion 24 relative to the second portion 25 about the second axis y.

[0168] Special Reference Figure 19 and Figure 20 The second actuator assembly 40 includes a second portion 25 in the form of a flat annular plate 42 having a rectangular outer perimeter and a circular inner perimeter defining a central hole 1009. The flat annular plate 42 (second portion 25) can be supported on the base 5 of the camera 1. A first pillar 431 and a second pillar 432 are fixed to (or integral with) the diagonally opposite corners of the annular plate 42. The first pillar 431 and the second pillar 432 extend generally along the direction of the principal axis z. The first pillar 431 supports the first static crimp portion 181 and the fourth static crimp portion 184, and the second pillar 432 supports the second static crimp portion 182 and the third static crimp portion 183.

[0169] The first part 24 takes the form of a flat, thin annular sheet 44, which has the same shape as the sheet 17 of the flat actuator device 15. A first movable pressing part 191 and a second movable pressing part 192 are fixed to a corner of the annular sheet 44, and a third movable pressing part 193 and a fourth movable pressing part 194 are fixed to opposite corners. During assembly, the movable pressing parts 19 are arranged at corners not occupied by the supports 431, 432. The annular sheet 44 may correspond to or support lens holders 9 for attaching one or more lenses 10.

[0170] The first drive device 11 is implemented by connecting the first SMA line to the fourth SMA line 141, 142, 143, 144 between the corresponding static crimping parts 181, 182, 183, 184 and the movable crimping parts 191, 192, 193, 194.

[0171] The second support device 41 takes the form of a helical flexural support 1090 as described above. During assembly, each pad 10931, 10932, 10933, 10934 is fixed to the plate 42 (second part 25), and the circular ring 1091 is fixed to the annular sheet 44 (first part 24). (As described above regarding the helical flexural support 1090...) Figure 12 As described above, other types of helical flexures can be used. Helical flexures typically include a ring and at least three flexures extending from the ring.

[0172] Assembly can be accomplished by securing the housing 8 (shielding housing) to the second actuator assembly 40 to protect the components. The image sensor 6 is mounted on the base 5, to which the plate 42 (second part 25) is secured, and the image sensor 6 is aligned with the center hole 1009 of the plate 42 and the sheet 44.

[0173] It can be observed that the second support device 41 is similar to the planar actuator device 15 in many respects, with increased separation along the main axis z, and the planar support is replaced by the second support member 41.

[0174] If the first drive unit 11 applies a clockwise torque about the main axis z, each helical beam portion 1092 will deflect upward (relative to the main axis z) away from the plate 42 (second portion 25), while the circular ring 1091 and the attached sheet 44 (first portion 24) move away from the plate 42 (second portion 25) along the helical path [Tz, Rz]. Similarly, the applied counterclockwise torque will cause the sheet 44 (first portion 24) to move along the helical path [Tz, Rz] around and along the main axis z toward the plate 42 (second portion 25).

[0175] If the first drive unit 11 applies a net force along the first axis x (positive direction + x), the helical beam portion 1092 will deflect along the first axis x. For the second helical beam portion 10922 and the fourth helical beam portion 10924, this deflection is perpendicular to its extension in a relatively compliant direction. However, the deflection of the first helical beam portion 10921 along the first axis is also a downward deflection (relative to the main axis z), and similarly, the deflection of the third helical beam portion 10923 along the first axis is also an upward deflection (relative to the main axis z). Therefore, in addition to the movement Tx along the first axis x, the circular ring 1019 and the attached sheet 44 (first portion 24) tilt Rx about the first axis x.

[0176] Similarly, if the first drive unit 11 applies a net force along the second axis y, then the sheet 44 (first portion 24) will tilt Ry about the second axis y in addition to moving Ty along the second axis y. The effective pivot point is offset from the circular ring 1091 below the main axis z (relative to the main axis z).

[0177] Thus, the second actuator assembly 40 can use a drive device 11 comprising a total of four SMA lines 141, 142, 143, and 144 to provide an OIS function based on tilting Rx and / or Ry and an AF function based on translation Tz along the main axis z. The OIS function and the AF function can be substantially independent for at least a portion of the range of motion.

[0178] Although reference Figure 19 and Figure 20 The specific example shown illustrates this, but the second actuator assembly 40 can be varied in numerous arrangements to provide the same functionality.

[0179] Although the second actuator assembly 40 has been described with a plate 42 (second part 25) corresponding to the support structure 4 of the camera 1 and a sheet 44 (first part 24) corresponding to the lens bracket 9 of the lens assembly 3, the roles can be reversed, such that the second part 25 corresponds to the lens bracket 9 and the first part 24 provides the support structure 4. Similarly, the second actuator assembly 40 is not limited to use in the camera 1, and the first part 24 and the second part 25 can be any parts that require relative movement Rx, Ry and / or [Tz, Rz].

[0180] The plate 42 and the sheet 44 may each be in the form of a patterned metal sheet (e.g., etched or machined stainless steel) and may be coated with an electrically insulating dielectric material. Either or both of the plate 42 and the sheet 44 may be provided with a corresponding center hole 1009.

[0181] Although the examples shown in Figures 26 and 27 use an implementation of the first (flat) drive device 11, a second (angled) drive device 20 can be used instead. The angled drive device 20 can apply force along the main axis z and combine it with torque about the main axis z, which can facilitate a smoother helical movement [Tz, Rz] of the first support member 28.

[0182] although Figure 19 and Figure 20 The second support member 41 is shown in the form of a helical flexure support member 1090, but other types of helical supports that are partially unconstrained in the lateral (perpendicular to the principal axis z) direction can also be used. For example, an underconstrained helical support member 1099 (see...) Figure 13 A second support member 41 can be provided.

[0183] Using a single drive unit 11, 20 comprising a total of four SMA lines 141, 142, 143, 144 and eliminating the need for a fifth or more SMA lines to provide OIS and AF functions can advantageously reduce the complexity and / or power consumption of the SMA actuator 2 for camera 1. Furthermore, a second drive unit is neither included nor required, regardless of whether it is based on SMA lines or other technologies. Combined AF and OIS can reduce the cost of parts, assembly, and / or testing. The robustness of the combination / coupling between OIS and AF functions can also be improved. Moreover, a moving electrical connection between a static part and a separate AF drive system that moves with OIS actuation is not required.

[0184] Each of the four shape memory alloy wires 141, 142, 143, and 144 corresponds to a segment of the SMA wire from which the drive current can be independently controlled. For example, a pair of SMA wires (e.g., 141, 142) can be provided by a single physical wire having a first current source (not shown) connected to one end, a second current source (not shown) connected to the other end, and a current return connector (not shown) located at a point between the two ends.

[0185] As an added advantage of combining AF and OIS, the first actuator assembly 23 can potentially be controlled by the output of a single triaxial Hall sensor. Such a sensor can be mounted on the static region of the first actuator assembly 23 (first portion 24 or second portion 25, depending on the configuration) to avoid potential hysteresis during rotation that limits the lens holder's rotation. For example, in Figures 19 to 20 In the example shown, a magnet (not shown) can be mounted to the first part 24, and a triaxial Hall sensor (not shown) can be mounted to the second part 24.

[0186] The advantage of using the first support member 41 in the form of a flexible element is that when the SMA line 14 is not powered, the helical beam portion 1092 can provide its own restoring force to push the first portion 24 and the second portion 25 to the equilibrium or neutral position. This avoids the need for separate springs, magnets, or other biasing devices.

[0187] When the second support 41 is an underconstrained helical support 1099, the inclined surface of the ramp 1101 forms an angle greater than zero degrees and less than 90 degrees with a plane parallel to the first axis x and the second axis y. In such an example, the second actuator 40 will also include one or more biasing devices configured to push the first set of ramps toward the second set of ramps along the main axis z.

[0188] It should be understood that many other variations of the above embodiments may exist.

[0189] In the preceding description, the parts were described as rectangles, which should be interpreted as including square shapes. In the preceding description, the parts were described as circles, which should be interpreted as including elliptical shapes.

[0190] The first SMA lines to the fourth SMA lines 141, 142, 143, and 144 have been described and shown as directly connecting the first portion 24 and the second portion 25. However, in some examples, the first SMA lines to the fourth SMA lines 141, 142, 143, and 144 may be indirectly connected to the first portion 24 and the second portion 25, for example, via one or more intermediate structures (not shown). The intermediate structures (not shown) may be configured to help extend the travel of one or more SMA lines 141, 142, 143, and 144.

[0191] The actuator assembly can be any type of assembly, including a first portion that is movable relative to the first portion. The actuator assembly can be, or may be disposed in, any of the following devices: smartphones, protective covers or cases for smartphones, functional covers or cases for smartphones or electronic devices, cameras, foldable smartphones, foldable smartphone cameras, foldable consumer electronics devices, cameras with foldable optics, image capture devices, array cameras, 3D sensing devices or systems, servo motors, consumer electronics devices, mobile or portable computing devices, laptops, tablet computing devices, e-readers, computing accessories or computing peripherals, audio devices, security systems, gaming systems, gaming accessories, robots or robotic devices, medical devices, augmented reality systems, augmented reality devices, virtual reality systems, virtual reality devices, wearable devices, drones, aircraft, spacecraft, submarines, vehicles and autonomous vehicles, tools, surgical instruments, remote controls, clothing, switches, dials or buttons, displays, touchscreens, flexible surfaces, and wireless communication devices. It should be understood that this is a non-exhaustive list of exemplary devices.

[0192] The term "shape memory alloy (SMA) wire" or a segment of SMA wire can refer to any element that includes an SMA. An SMA wire can have any shape suitable for the purposes described herein. An SMA wire can be elongated and can have a rounded or any other shaped cross-section. The cross-section can vary along the length of the SMA wire. It is also possible that the length of the SMA wire (however defined) can be similar to one or more of its other dimensions. An SMA wire can be compliant, or in other words, flexible. In some examples, when connected in a straight line between two elements, the SMA wire can only exert a tensile force that pushes the two elements together. In other examples, the SMA wire can bend around the element and can apply a force to the element as the SMA wire tends to straighten under tension. An SMA wire can be beam-like or rigid and is capable of applying different (e.g., non-tensile) forces to the element. An SMA wire may or may not include one or more materials and / or one or more components that are not SMA. For example, an SMA wire may include a core of SMA and a coating of a non-SMA material. Unless the context otherwise requires, the term "SMA line" can refer to any configuration of an SMA line that acts as a single actuating element, such as an actuating element that can be individually controlled to generate force on an element. For example, an SMA line can comprise two or more sections of an SMA line arranged mechanically in parallel and / or in series. In some arrangements, an SMA line can be part of a larger SMA line. Such a larger SMA line can comprise two or more individually controllable sections, thereby forming two or more SMA lines.

Claims

1. An actuator assembly having a main axis passing through the actuator assembly, wherein a first axis and a second axis are perpendicular to each other and perpendicular to the main axis, the actuator assembly comprising: Part One; Part Two; A support device that mechanically connects the first part to the second part; A drive device comprising a total of four shape memory alloy wire segments, wherein each shape memory alloy wire segment is connected between a first portion and a second portion, wherein the contraction of the first segment of the shape memory alloy wire segments applies a force to the first portion in a negative direction along the first axis, the contraction of the second segment of the shape memory alloy wire segments applies a force to the first portion in a positive direction along the first axis, the contraction of the third segment of the shape memory alloy wire segments applies a force to the first portion in a negative direction along the second axis, and the contraction of the fourth segment of the shape memory alloy wire segments applies a force to the first portion in a positive direction along the second axis; The support device includes a first support member or a second support member, wherein the first support member includes a first pair of flexures and a second pair of flexures, each of the first pair of flexures extending generally parallel to the first axis and connecting the first portion to the second portion, each of the second pair of flexures extending generally parallel to the second axis and connecting the first portion to the second portion, and wherein the second support member is configured to guide helical movement about and along the main axis, and thereby generate movement of the first portion toward or away from the second portion along the main axis in response to a torque applied by the drive device about the main axis; The drive device and the support device are configured such that the first part can move toward or away from the second part along the main axis, and the first part can tilt relative to the second part about the first axis and / or the second axis.

2. The actuator assembly of claim 1, wherein the support device is configured to guide movement of the first portion relative to the second portion along the main axis, and to guide tilting of the first portion relative to the second portion about the first axis and / or the second axis.

3. The actuator assembly of claim 1, wherein the support device includes the first support member and is configured to constrain movement of the first portion relative to the second portion along the first axis and / or the second axis, and to constrain rotation of the first portion relative to the second portion about the main axis.

4. The actuator assembly of claim 3, wherein the first pair of flexures are spaced parallel to the second axis to support the first portion; The second pair of flexible members are spaced parallel to the first axis to support the first portion; and in, Each of the first and second pairs of flexures is configured to be compliant in the direction corresponding to the movement of the first portion relative to the second portion along the main axis.

5. The actuator assembly of claim 1, wherein the support device includes the second support member.

6. The actuator assembly of claim 5, wherein the second support is configured such that movement of the first portion relative to the second portion along the first axis is coupled with tilting of the first portion relative to the second portion about the first axis, and wherein movement of the first portion relative to the second portion along the second axis is coupled with tilting of the first portion relative to the second portion about the second axis.

7. The actuator assembly of claim 5, wherein the second support is in the form of a helical flexure.

8. The actuator assembly according to any one of claims 5 to 7, wherein, The second support member includes: The first set of helical flexures is configured to be compliant in the direction corresponding to the movement of the first portion relative to the second portion along the main axis and / or the first axis; The second set of helical flexures is configured to be compliant in the direction corresponding to the movement of the first portion relative to the second portion along the main axis and / or the second axis.

9. The actuator assembly according to claim 5 or 6, wherein the second support member comprises: The first group consists of four ramps arranged in a circle around the main axis and connected to the first part; The second group of four ramps is arranged in a circle around the main axis and connected to the second part; The first set of slopes and the second set of slopes are arranged opposite each other such that the inclined surface of each slope in the first set of slopes engages with the inclined surface of the corresponding slope in the second set of slopes.

10. The actuator assembly according to any one of claims 1 to 7, wherein each of the four segments of shape memory alloy wire is not perpendicular to the main axis.

11. The actuator assembly according to any one of claims 5 to 7, wherein the four shape memory alloy wires are substantially coplanar in a plane parallel to the first axis and the second axis.

12. A camera, comprising: The actuator assembly according to any one of claims 1 to 11; An image sensor, which is supported by one of the first part and the second part; The lens is supported by the first part and another of the second parts.

13. The camera of claim 12, further comprising a controller configured to control the actuator assembly to: The automatic focusing function is achieved by moving the first part toward or away from the second part along the main axis; Optical image stabilization is achieved by tilting the first portion relative to the second portion around the first axis and / or the second axis.

14. A method for implementing optical image stabilization and / or autofocus functions of a camera, the method comprising using an actuator assembly according to any one of claims 1 to 11 to implement the optical image stabilization and / or autofocus functions of the camera.

Images