actuator assembly

Abstract

An actuator assembly (23) is described comprising a first part (24), a second part (25) and a bearing mechanism (26) mechanically coupling the first part (24) to the second part (25). The bearing mechanism (26) comprises a first bearing (27) mechanically coupling the first part (24) to a third part (28). The actuator assembly (23) further comprises a drive mechanism (11, 20). The drive mechanism (11, 20) comprises 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 third part (28) and the second part (25). The drive mechanism (11, 20) and the bearing mechanism (26) are configured to cause, in response to a torque applied by the drive mechanism (11, 20) about a main axis (z), the first bearing (27) to generate movement of the first part (24) along the main axis (z) towards or away from the second part (25) and the third part (28). The bearing mechanism (26) is configured to constrain rotation of the first part (24) relative to the second part (25) about the main (z) axis.

Description

[0001] field

[0002] This application relates to an actuator assembly, and more particularly to an actuator assembly comprising four shape memory alloy (SMA) wires.

[0003] background

[0004] For example, such actuator components can be used 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.

[0005] WO 2013 / 175197 A1 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 its end between the movable element and the support structure and extends perpendicular to the main axis. The SMA actuator lines are all non-collinear, but are arranged such that they can be selectively driven to move the movable element relative to the support structure to any position within the range of movement without applying any net torque to the movable element about the main axis in the planes of the two orthogonal directions.

[0006] WO 2019 / 243849 A1 describes a shape memory alloy actuation device comprising a support structure and a movable element. A helical support mechanism, supported on the movable element and mounted on the support structure, guides the movable element to move helically 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 normal to the helical axis or at an acute angle to the plane to drive the movable element to rotate about the helical axis, the helical support mechanism converting this rotation into the helical movement.

[0007] WO 2019 / 086855 A1 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.

[0008] Overview

[0009] According to a first aspect of the invention, an actuator assembly is provided, including a first component, a second component, and a support mechanism for mechanically coupling the first component to the second component. The support mechanism includes a first support member for mechanically coupling the first component to a third component. The actuator assembly also includes a drive mechanism. The drive mechanism includes four segments of shape memory alloy wire. Each segment of shape memory alloy wire is connected between the third component and the second component. The drive mechanism and the support mechanism are configured such that, in response to a torque applied by the drive mechanism about a main axis, the first support member generates movement of the first component along the main axis toward or away from the second and third components. The support mechanism is configured to constrain rotation of the first component relative to the second component about the main axis.

[0010] The support mechanism can be configured to constrain the movement of the first component relative to the second component along a first axis and / or a second axis, wherein the first and second axes are perpendicular to the main axis and the second axis is different from the first axis. The support mechanism can also be configured to constrain the rotation of the first component relative to the second component about any one of the first axis, the second axis, and the main axis.

[0011] The drive mechanism may include a total of four segments of shape memory alloy wire. Neither the actuator assembly nor the drive mechanism includes any other segments of shape memory alloy wire or other drive devices. The actuator assembly may include up to four segments of shape memory alloy wire. The drive mechanism may include up to four segments of shape memory alloy wire. The first axis and / or the second axis may be perpendicular to the main axis. The first axis may be perpendicular to the second axis.

[0012] Each of the four shape memory alloy wire segments corresponds to a portion of the shape memory alloy wire, on 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.

[0013] The first support member can guide helical movement about and along the main axis. The first support member can mechanically couple rotation about the main axis to translation along the main axis.

[0014] The first support member may include a helical flexible member, or take the form of a helical flexible member. The helical flexible member may take the form of a flat ring (or loop), and at least three flexible members extend from the flat ring. There may be four or more flexible members extending from the flat ring. The flexible members may be attached around the flat ring at equally spaced angles. The flat ring and the flexible members may be single pieces.

[0015] The first support member may include a helical support member, or may take the form of a helical support member. The first support member may include one or more helical tracks. The first support member may include multiple inclined surfaces arranged in a loop.

[0016] The first support member may include multiple flexible inclined surfaces arranged in a loop around the main axis. The flexible inclined surfaces may be prestressed in a balanced or neutral configuration of the first support member.

[0017] The support mechanism may further include a second support that mechanically connects the first component to the second component. The second support may be configured to guide movement of the first component toward or away from the second component along a main axis. The second support may be configured to constrain movement of the first component relative to the second component along a first axis and / or a second axis. The second support may be configured to constrain rotation of the first component relative to the second component about a main axis. The second support may be configured to constrain rotation of the first component relative to the second component about a first axis and / or a second axis.

[0018] The second support member may include a race aligned with the main axis, or may take the form of a ball bearing race aligned with the main axis. The ball bearing race aligned with the main axis may constrain the rotation of the first component relative to the second component about the first axis, the second axis, and / or the main axis.

[0019] The second support member may include a first set of flexible elements and a second set of flexible elements. Each flexible element in the first set of flexible elements and the second set of flexible elements may be configured to be compliant in the direction corresponding to the movement of the first component relative to the third component along the main axis. The first set of flexible elements and the second set of flexible elements may be connected in parallel (between the first component and the second component) and spaced apart along the main axis.

[0020] The first set of flexible elements and the second set of flexible elements can constrain the rotation of the first component relative to the second component about a first axis, a second axis, and / or a principal axis. One or more or all of the first set of flexible elements and / or the second set of flexible elements can be flat (perpendicular to the principal axis). One or more or all of the first set of flexible elements and / or the second set of flexible elements can include at least one bend (or "turn" or "elbow"). One or more or all of the first set of flexible elements and / or the second set of flexible elements can include a corresponding arm, which can include at least one bend. One or more arms or all arms can include a first portion extending away from the first component and a second portion extending along a corresponding side of the first component. The first and second portions can be straight.

[0021] The support mechanism may also include a third support member, which mechanically connects the third component to the second component in parallel with the drive mechanism.

[0022] The third support member can be configured to constrain the movement of the third component relative to the second component along the main axis. The third support member can also be configured to constrain the rotation of the third component relative to the second component about the first axis and / or the second axis.

[0023] The third support member may not constrain (may allow) the third component to rotate relative to the second component about the principal axis. The third support member may take the form of a three-point planar support member. The third support member may include at least three cylinders arranged at the vertices of a triangle, wherein the flat surface of each cylinder provides a sliding surface. The third support member may include more than three cylinders. The third support member may include at least three ball supports arranged at the vertices of the triangle. The third support member may include more than three ball supports.

[0024] The four-segment shape memory alloy wires are substantially coplanar in a plane parallel to the first and second axes (i.e., a plane perpendicular to the main axis).

[0025] The essentially coplanar shape memory alloy segments can be configured to apply a net force along a first axis and / or a second axis, and / or a torque about a principal axis. Within a range of motion, the net force along the first axis can be applied substantially independently of the net force along the second axis and / or the torque about the principal axis. Within this range of motion, the net force along the second axis can be applied substantially independently of the net force along the first axis and / or the torque about the principal axis. Within this range of motion, the torque about the principal axis can be applied substantially independently of the net force along the first axis and / or the net force along the second axis.

[0026] Each of the four segments of shape memory alloy wire may not be perpendicular to the main axis. In other words, each of the four segments of shape memory alloy wire may be tilted relative to the main axis at an angle greater than 0 degrees and less than 90 degrees. Each of the four segments of shape memory alloy wire may be tilted relative to a plane perpendicular to the main axis at an angle between 10 degrees and 25 degrees (inclusive).

[0027] The first and second shape memory alloy wires can be oriented at corresponding angles relative to the main axis and can lie substantially in a plane parallel to the main axis and the first axis. The third and fourth shape memory alloy wires can be oriented at corresponding angles relative to the main axis and can lie substantially in a plane parallel to the main axis and the second axis.

[0028] Four segments of shape memory alloy wire, oriented at corresponding angles relative to the principal axis, can be configured to apply a combination of a net force along the first axis and a torque around the first axis. Four segments of shape memory alloy wire, oriented at corresponding angles relative to the principal axis, can be configured to apply a combination of a net force along the second axis and a torque around the second axis. Four segments of shape memory alloy wire, oriented at corresponding angles relative to the principal axis, can be configured to apply a combination of a net force along the principal axis and a torque around the principal axis.

[0029] The net force along the first axis and the torque around the first axis can be applied substantially independently of the net force and torque along and around the second axis and / or the net force and torque along and around the principal axis. The combination of the net force along the second axis and the torque around the second axis can be applied substantially independently of the net force and torque along and around the first axis and / or the net force and torque along and around the principal axis. The combination of the net force along the principal axis and the torque around the principal axis can be applied substantially independently of the net force and torque along and around the first axis and / or the second axis.

[0030] A camera may include an actuator assembly, an image sensor supported by one of a first component and a second component, and a lens supported by the other of the first component and the second component.

[0031] The camera may also include a controller configured to control the actuator assembly to achieve autofocus by utilizing the movement of the first component toward or away from the second component along the main axis.

[0032] The camera may include one or more additional actuators configured to provide optical image stabilization. The additional actuators and the optical image stabilization function may be controlled by a controller.

[0033] The controller can be a microcontroller. The controller can be an application-specific integrated circuit (ASIC). The controller can be one or more digital electronic processors.

[0034] According to a second aspect of the invention, a method is provided that includes using an actuator assembly to implement an autofocus function of a camera.

[0035] According to a third aspect of the invention, an actuator assembly is provided, comprising a first component, a second component, and a support mechanism mechanically coupling the first component to the second component. The support mechanism includes a first support member mechanically coupling the first component to a third component. The actuator assembly further includes a drive mechanism. The drive mechanism includes one or more segments of shape memory alloy wire. Each segment of shape memory alloy wire is connected between the third component and the second component. The drive mechanism and the support mechanism are configured such that, in response to a torque applied by the drive mechanism about a main axis, the first support member generates movement of the first component along the main axis toward or away from the second and third components. The support mechanism is configured to constrain rotation of the first component relative to the second component about the main axis.

[0036] The term "shape memory alloy (SMA) wire" (or "SMA segment") can refer to any element containing 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 circular or any other shaped cross-section. The cross-section can vary along the length of the SMA wire. It is possible that the length of the SMA wire (regardless of its definition) can also 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 a force can be applied to the element as the SMA wire tends to straighten under tension. An SMA wire can be beam-like or rigid and capable of applying different (e.g., non-tensile) forces to the element. An SMA wire may or may not include one or more non-SMA materials and / or one or more components. For example, an SMA wire may include an SMA core and a coating of non-SMA materials. Unless the context otherwise requires, the term "SMA line" can refer to any configuration of an SMA line that functions as a single actuating element, such that the single actuating element can be individually controlled to generate force on the element. For example, an SMA line may comprise two or more SMA line sections arranged mechanically in parallel and / or in series. In some arrangements, an SMA line may be part of a larger SMA line. Such a larger SMA line may comprise two or more individually controllable components, thereby forming two or more SMA lines. Brief description of the attached diagram

[0038] Some embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0039] Figure 1 The camera is shown schematically;

[0040] Figure 2 As shown Figure 1Possible translations and rotations of the lens assembly of the camera shown;

[0041] Figure 3 The first drive mechanism using four segments of shape memory alloy (SMA) wire is schematically shown;

[0042] Figure 4 This is a projected view of the flat actuator assembly;

[0043] Figures 5A to 5C The second drive mechanism using four segments of shape memory alloy (SMA) wire is schematically shown;

[0044] Figure 6 A schematic diagram of a double-bar linkage support is shown.

[0045] Figure 7A This is a plan view of a simple flexible support. Figure 7B It is a side view of the deformation state of a simple flexible support;

[0046] Figure 8 This is a plan view of the second simple flexible support;

[0047] Figure 9 This is an exploded projection view of the z-axis flexible support;

[0048] Figure 10A This is a side view of the first planar support member. Figure 10B This is an exploded projection view of the first planar support member;

[0049] Figure 11 This is a side view of the second plane support member;

[0050] Figure 12A This is an exploded projection view of the z-axis translation support. Figure 12B It is a cross-section of a part of the z-axis translational support component;

[0051] Figure 13 This is a projected view of the helical flexible support;

[0052] Figure 14A This is an exploded projection view of the helical support component. Figure 14B This is a projected view of the spiral support component;

[0053] Figure 15 This is an exploded projection view of the AF actuator assembly;

[0054] Figure 16 This is a projected view of the AF actuator assembly; and

[0055] Figure 17 The AF actuator assembly is shown schematically.

[0056] Detailed description

[0057] In the following text, similar parts are indicated by similar reference numerals.

[0058] camera

[0059] See Figure 1 The image shows a camera 1 including an SMA actuator assembly 2 (also referred to herein as the “SMA actuator” or simply the “actuator”).

[0060] Camera 1 includes a first component in the form of a lens assembly 3, which is suspended from a second component 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.

[0061] The second component, in the form of 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 and a gyroscope sensor (not shown) are mounted on the rear side of the base 5 (i.e., between the base 5 and the lens assembly 3), in which control circuitry is implemented. Alternatively, the IC 7 can be mounted on the front side of the base 5, offset from the image sensor 6. Support structure 4 also includes a can 8 protruding forward from the base 5 to enclose and protect other components of the camera 1.

[0062] The first component, in the form of lens assembly 3, includes a cylindrical lens holder 9 that 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 at most about 30 mm. Therefore, camera 1 can be referred to as a miniature camera.

[0063] The lens assembly 3 is arranged to focus the image onto the image sensor 6. The image sensor 6 captures the image and can be of any suitable type, such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device.

[0064] 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, leaving at least one lens 10 attached to lens holder and movable relative to image sensor 6 along optical axis O.

[0065] Typically, the lens assembly 3 can be moved orthogonally to the optical axis O relative to the image sensor 6 during use, effectively shifting the image on the image sensor 6. For example, if a set of right-handed orthogonal axes x, y, z are aligned 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 providing OIS does not need to be constrained to the xy plane. Alternatively or alternatively, OIS functionality can be provided by tilting the lens assembly 3 or both the tilting 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. Alternatively or alternatively, 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 focus on the image formed on the image sensor 6, for example as part of an autofocus (AF) function.

[0066] This specification relates to an SMA actuator assembly 2 that provides a relative movement Tz of a first component relative to a second component along (or parallel to) a third (primary or optical) axis z, while limiting the movement Tx, Ty and all rotations Rx, Ry, Rz of the first component relative to the second component along (or parallel to) a first axis x and / or a second axis y. This specification relates to the SMA actuator assembly 2, which can be used, for example, to provide an autofocus function for a camera 1. When the SMA actuator assembly 2 according to this specification is used in a camera 1, one or more additional or supplementary actuator systems (not shown) may optionally be included to provide optical image stabilization.

[0067] Shape memory alloy drive components

[0068] See also Figure 3 The diagram schematically illustrates a first type of drive mechanism 11 (first drive mechanism) that may be included in the SMA actuator assembly 2.

[0069] The first drive mechanism 11 includes a second structure 12 and a first structure 13. The first structure 13 is typically supported within a boundary defined by the second structure 12, for example, by 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 13 and the second structure 12 may take the form of corresponding patterned metal sheets, such as etched or machined stainless steel, and may be coated with an electrically insulating dielectric material.

[0070] Four shape memory alloy (SMA) wires 141, 142, 143, and 144 (chain wires) form a loop around the first structure 13. For simplicity, the SMA segments will be referred to as "SMA wires" in the following text. The first SMA wire 141 and the third SMA wire 143 extend substantially 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 wire 141 will exert a force on the first structure 13 in the negative x-axis direction, while the contraction of the third SMA wire 143 will exert a force on the first structure 13 in the positive x-axis direction. The second SMA wire 142 and the fourth SMA wire 144 extend substantially 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 wire 142 will exert a force on the first structure 13 in the negative y-axis direction, while the contraction of the fourth SMA wire 144 will exert a force on the first structure 13 in the positive y-axis direction.

[0071] Other example configurations can be used, and further details are provided in WO2017 / 055788A1 and WO2019 / 086855A1, which are incorporated herein by reference in their entirety.

[0072] The position of the first structure 13 relative to the second 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 sending a selective drive signal providing resistive heating through 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.

[0073] In operation, SMA lines 141, 142, 143, and 144 are selectively driven to move the first structure 13 relative to the second structure 12 (or vice versa) in any lateral direction (i.e., 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).

[0074] Further details are also provided in WO 2013 / 175197 A1, which is incorporated herein by reference.

[0075] 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 loops around the optical axis O (corresponding to the principal axis z) at different angular positions to provide two pairs of opposing SMA lines 141 & 143, 142 & 144, which are substantially perpendicular to each other. Therefore, each pair of opposing SMA lines 141 & 143, 142 & 144 can be selectively driven to move the first structure 13 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 first structure 13 relative to the second structure 12 to any position within a range of motion in a 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 first structure 13 to move in the direction bisecting the pair of SMA actuator lines (in... Figure 3 The SMA lines 141, 142, 143, and 144 can be driven 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 in one direction of rotation about an axis parallel to the main axis z on the first structure 13, and the contraction of another pair of opposing SMA lines (e.g., SMA lines 142, 144) will generate torque in another direction of rotation. The generation of torque and the resulting rotation can be substantially independent (at least for a portion of the range of motion of the drive mechanism 11) of translation along directions parallel to the first axis x and / or the second axis y. 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.

[0076] When one of the SMA wires 141, 142, 143, and 144 is heated, the stress in the SMA wires 141, 142, 143, and 144 increases and they contract, causing the first structure 13 to move relative to the second structure 12. As the SMA temperature increases, a range of movement is generated within the temperature range where the SMA material undergoes a transformation from the martensitic phase to the austenitic phase. Conversely, when one of the SMA wires 141, 142, 143, and 144 is cooled, the stress in the SMA wires 141, 142, 143, and 144 decreases, causing them to expand under the force from the opposing SMA wires 141, 142, 143, and 144 (and in some examples, also under the biasing force from biasing devices such as springs, armatures, etc.). This allows the first structure 13 to move relative to the second structure 12 in opposite directions.

[0077] SMA lines 141, 142, 143, and 144 can be made of any suitable SMA material, such as Nitinol or another titanium alloy SMA material.

[0078] 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 second structure 12 is fixed to the support structure 4 (the second component) (or a portion thereof), and the first structure 13 is fixed to the lens assembly 3 (the first component) (or a portion thereof), the control circuitry generates drive signals in response to the output signal of the gyroscope sensor (not shown) to drive the movement of the lens assembly 3, thereby stabilizing the image focused by the lens assembly 3 onto the image sensor 6, and thus providing OIS. The drive signals can be generated using resistive feedback control techniques, such as those described in WO 2014 / 076463 A1, which is incorporated herein by reference.

[0079] Each SMA wire 141, 142, 143, 144 corresponds to a segment of shape memory alloy wire, on which the drive current 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 connection at a point between the two ends. For example, in the first drive mechanism 11, the first SMA wire 141 and the second SMA wire 142 can be provided by a single physical wire, with current return provided through the first structure 13.

[0080] See also Figure 4 An example of a “flat” SMA actuator assembly 15 implementing the first drive mechanism 11 is shown.

[0081] In the flat actuator assembly 15, the second 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 first structure 13 takes the form of a flat thin annular sheet 17 having a rectangular outer perimeter and a circular inner perimeter. The second structure 12 in the form of plate 16 is supported on a base 5 in the form of a rectangular plate. Four SMA wires 141, 142, 143, 144 are each attached at one end to their respective first crimps 181, 182, 183, 184 (also referred to as “static” crimps), which are fixedly attached to the second structures 12, 16 (or formed as part of the second structures 12, 16). The other end of each SMA wire 141, 142, 143, 144 is attached to a corresponding second crimp portion 191, 192, 193, 194 (also referred to as a “moving” crimp portion), which is fixedly attached to the first structure 13, 17 (or formed as part of the first structure 13, 17).

[0082] Plate 16 and sheet 17 can each take the form of a patterned metal sheet, such as etched or machined stainless steel, and can be coated with an electrically insulating dielectric material. Plate 16 and sheet 17 each have a corresponding central hole aligned with the optical axis O, allowing light to pass from the lens assembly 3 mounted on sheet 17 to the image sensor 6 supported on the base 5.

[0083] 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.

[0084] The flat 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 first structures 13, 17 on the second structures 12, 16. Preferably, at least three support members are used to help provide stable support, although a different number of support members can usually be used. Each sliding support member ( Figure 4 (Not shown in the image) can take the form of a cylindrical support member and can be attached to the second structure 12 or formed as part of the second structure 12. Sliding support member ( Figure 4 (Not shown) can be made of a suitable metal or alloy, such as phosphor bronze or stainless steel with a diamond-like carbon coating. Sliding support ( Figure 4 (Not shown) can 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 an upper layer or coating of stainless steel or phosphor bronze, the stainless steel or phosphor bronze having a titanium carbide coating, a tungsten carbide coating, a diamond-like carbon (DLC) coating, or a chromium carbide DLC coating. These support materials may be bonded to a second support surface formed of one of these support materials, the second support surface being polished or stamped to reduce the effects of friction caused by surface texture.

[0085] The flat actuator assembly 15 will also typically include biasing means (not shown) such as one or more springs or flexible arms, which are arranged and configured to keep the first structure 13 and the second structure 12 in contact (via a sliding support) and / or push the first structure 13 and the second structure 12 toward a neutral (e.g., central) relative position when the SMA lines 141, 142, 143, 144 are not energized.

[0086] Details relating to the manufacture of actuator assemblies similar to the flat actuator assembly 15 can be found in WO 2016 / 189314A1, which is incorporated herein by reference in its entirety.

[0087] Although Figure 4 Although not shown, the flat actuator assembly 15 may be provided with end stops to limit lateral movement of the first structure 13 relative to the second structure 12. In this way, the SMA lines 141, 142, 143, and 144 can be protected from overstretching caused by impacts that may occur (e.g., falling) to a device, for example, incorporating the flat actuator assembly 15.

[0088] As described above, the first drive mechanism 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 substantially parallel to the optical axis O). At least for a portion of the range of motion of the first drive mechanism, each of these movements Tx, Ty, and Rz is substantially independent of the others. However, in order to provide the translation Tz parallel to the main axis z, the first drive mechanism 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 (helical movement [Tz, Rz] as described below).

[0089] See also Figures 5A to 5C The diagram schematically illustrates a second type of drive mechanism 20 (second drive mechanism) that may be included in the SMA actuator assembly 2.

[0090] The second drive mechanism 20 is similar to the first drive mechanism 11, except that the second 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 substantially confined to a plane perpendicular to the principal axis z.

[0091] Figure 5A The second drive mechanism 20 is shown as viewed from above along a direction parallel to the main axis z.

[0092] Figure 5B The second drive mechanism 20 is shown as a side view along a direction parallel to the first axis x. It should be noted that, for viewing purposes, the fourth SMA line 144 has been superimposed. Figure 5B Even though the fourth SMA line 144 is largely obscured behind the first structure 13.

[0093] Figure 5C The second drive mechanism 20 is shown as a side view along a direction parallel to the second axis y. It should be noted that, for viewing purposes, the first SMA line 141 has been superimposed on... Figure 5B Even though the first SMA line 141 is largely obscured behind the first structure 13.

[0094] When viewed along the main axis, the base 21 extends beyond the edge of the first structure 13. Figure 5A In this example, the base 21 is rectangular (or square). A first pillar 221 stands upright from a first corner of the base 21 and a second pillar 222 stands upright from a second corner, with the first pillar 221 and the second pillar 222 spanning the first structure 13 diagonally opposite each other.

[0095] The first SMA line 141 connects from the lower portion of the first structure 13 (along the lower part of the main axis z) to the upper portion of the first support 221 (along the upper part of the main axis z). The second SMA line 142 connects from the upper portion of the first structure 13 to the lower portion of the second support 222. The third SMA line 143 connects from the lower portion of the first structure 13 to the upper portion of the second support 222. The fourth SMA line 142 connects from the upper portion of the first structure 13 to the lower portion of the first support 221.

[0096] Thus, the first SMA line 141 is opposite to the third SMA line 143 in a direction parallel to the first axis x, the second SMA line 142 is opposite to the fourth SMA line 144 in a direction parallel to the second axis y, and the first SMA line 141 and the third SMA line 143 are opposite to the second SMA line 142 and the fourth SMA line 144 in a direction parallel to the principal axis z.

[0097] Thus, a second drive mechanism 20 using four angled (non-coplanar) SMA lines 141, 142, 143, and 144 can provide drive corresponding to the motions Tx, Ty, Tz, Rx, Ry, and Rz. 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 association depending on the angles of the SMA lines 141, 142, 143, and 144.

[0098] SMA lines 141, 142, 143, and 144 are preferably inclined at an angle between 10° and 25° relative to the plane perpendicular to the principal axis z.

[0099] Any one or both of the second structures 12, 21 and the first structure 13 may include a central aperture to allow light from the lens assembly 3 to form an image on the image sensor 6.

[0100] One or more of the movements driven by the first drive mechanism 11 or the second drive mechanism 20 can be fully or partially constrained by mechanically connecting one or more support members between the first structure 13 and the second structure 12.

[0101] Support components

[0102] Typically, the SMA actuator 2 according to this specification will include at least one of a first drive mechanism 11 and a second drive mechanism 20, and a mechanism of one or more mechanical supports (also referred to as "support mechanism") for supporting, constraining and / or converting the movement generated by the first drive mechanism 11 or the second drive mechanism 20.

[0103] See also Figure 6 The image shows a double-bar linkage support 1001.

[0104] The double-bar 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 flexible member). The rigid portions 10021 and 10022 are both elongated in a direction parallel to the first axis x and spaced apart from each other in a direction parallel to the second axis y. The beam portions 10031 and 10032 are both 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. As shown, the beam portions 10031 and 10032 are perpendicular to the rigid portions 10021 and 10022; however, this is not necessary, and any angle is effective as long as the beam portions 10031 and 10032 are parallel to each other. Beam sections 10031 and 10032 cannot rotate around the joints that connect them to rigid sections 10021 and 10022, for example, the connection is not a pin connection or a similar connection.

[0105] The relative bending stiffness of beam portions 10031, 10032 and rigid portions 10021, 10022 is selected (primarily using the dimensions and shape of the cross sections) so that if the first rigid portion 10021 is clamped, the second rigid portion 10022 can move relative to the first rigid portion 10021 in the xy and / or xz planes by the bending of beam portions 10031, 10032. Thus, the double-bar linkage 1001 can provide relative movement Tx, Tz, Rx, and Ry between the first rigid portion 10021 and the second rigid portion 10022. Figure 6 The deformation state of the second rigid portion 10022 is also shown using dashed lines, where the second rigid portion 10022 is displaced by a distance d parallel to the first axis. The double-bar linkage support 1001 can rotate 90 degrees to provide a movement Ty parallel to the second axis y, instead of Tx.

[0106] The relative bending stiffness can be selected by controlling the relative bending strength of the xy plane relative to the yz plane through the cross-sectional shape of beam sections 10031 and 10032.

[0107] See also Figure 7A The diagram shows a tiltable z-axis flexible member in the form of a 2×2 parallel rod link support 1004 (also known as a simple flexible member).

[0108] The simple flexible element 1004 includes a central portion 1005 and two pairs of beam portions (or flexible elements) 10061, 10062, 10063, and 10064. Each beam portion (or flexible element) 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 10061 (flexible element) and the third beam portion 10063 (flexible element) 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 10062 (flexible element) and the fourth beam portion 10064 (flexible element) 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 deflection (perpendicular to the principal axis z) 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.

[0109] In this way, if the free end 1007 is clamped, the simple flexible element 1004 is able to provide relative movement Tz, Rx and / or Ry between the central portion 1005 and the clamped free end 1007.

[0110] See also Figure 7B , showed Figure 7A The deformation state 1004b of the simple flexible member, wherein the central part 1005 is displaced by a distance d parallel to the principal axis z.

[0111] See also Figure 8 The second simple flexible element (tiltable z-axis flexible element) 1008 is shown.

[0112] 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 simple flexible member 1008 is the same as the simple flexible member 1004. The second simple flexible member 1008 functions in substantially the same manner as the simple flexible member 1004. Specifically, if the outer ring is clamped, then the central portion 1005 can move at Tz, Rx, and / or Ry.

[0113] The presence or absence of a center hole 1009 in the second simple flexible element 1008 or the simple flexible element 1004 may depend on its position within the device (e.g., camera 1). Simple flexible elements 1004 and 1008 located below the image sensor 6 typically do not require a center hole 1009, while simple flexible elements 1004 and 1008 located above the image sensor 6 typically require a center hole 1009.

[0114] See also Figure 9 The z-axis flexible element 1011 is shown.

[0115] The z-axis flexible element includes a pair of simple flexible elements 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 pair of simple flexible elements 10041 and 10042. The simple flexible elements 10041 and 10042 are fixed to opposite surfaces of the rigid structure 1012. Each of the simple flexible elements 10041 and 10042 includes a central hole 1009. Figure 9 The illustration shows, for visual purposes, a rigid structure 1012 fixed to one simple flexible member 10041 and separated from another simple flexible member 10042, although in use both simple flexible members 10041 and 10042 are fixed to the rigid structure 1012. Figure 9 The dashed lines in the figure show the projected outline of the rigid structure 1012.

[0116] In this way, each individual beam portion 1006 of each simple flexible element 10041, 10042 can be deflected. However, the separation of the simple flexible elements 10041, 10042 in a direction parallel to the principal axis z and the fixed connection via the rigid structure 1012 restrict the movements Tx, Ty, Rx, Ry, Rz, while guiding the movement Tz in the direction parallel to the principal axis z.

[0117] 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 spacing simple flexible elements parallel to the main axis z and compatible with the intended application of the actuator.

[0118] See also Figure 10A and Figure 10B The first planar support 1064 (also referred to herein as a three-point support) is shown.

[0119] Figure 10A It is a side view, and Figure 10B It is a decomposed projected view.

[0120] The first planar support 1064 includes a first plate 1065 in sliding 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. The first cylindrical protrusion 10671, the second cylindrical protrusion 10672, and the third cylindrical protrusion 10673 are not collinear, for example, arranged at the vertices of a triangle. The second plate 1066 is supported by an offset device (…). Figure 10A and Figure 10B (Not shown) is pressed into contact with the flat surface of the cylindrical protrusion 1067 and can slide in a plane parallel to the first axis x and the second axis y, and rotate about an axis parallel to the main axis z. Thus, the relative movement 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.

[0121] exist Figure 10A and Figure 10B In the example shown, both plates 1065 and 1066 are in the form of rings with a rectangular outer perimeter and a circular inner perimeter defining a central hole 1009. However, the shapes of plates 1065 and 1066 are irrelevant to the function of the first planar support 1064 and can be replaced with plates of any shape. Although in Figure 10A and Figure 10B Three cylindrical protrusions 10671, 10672, and 10673 are shown, but generally any number of cylindrical protrusions, greater than or equal to three, can be used. Flat actuator assembly 15 ( Figure 4 The implementation includes the first planar support member 1064.

[0122] See also Figure 11 The second planar support 1068 is shown.

[0123] The second planar support 1068 is identical to the first planar support 1064, except that the cylindrical protrusion 1067 is replaced by ball supports 10301, 10302, and 10303. The first plate 1065 can also be replaced by a third plate 1069 including recesses 10701, 10702, and 10703 (e.g., circular recesses), which receive the corresponding ball supports 10301, 10302, and 10303. The second planar support 1068 functions in the same manner as the first planar support 1064, except that it is a rolling support rather than a sliding support.

[0124] See also Figure 12A and Figure 12B The z-axis translation support 1081 is shown.

[0125] Figure 12A An exploded projected view is shown, and Figure 12B A cross section of block 1084 passing through assembled z-axis translation support 1081 is shown.

[0126] The z-axis translation support 1081 includes a first plate 1082 and a second plate 1083. Both plates 1082 and 1083 are in the form of annulus with a rectangular outer perimeter and a circular inner perimeter defining a central hole 1009. A block 1084 extends perpendicular to the surface of the first plate 1082. Figure 12A As shown, the first plate 1082 and the second plate 1083 are parallel to the first axis x and the second axis y, and the block 1084 extends in a direction parallel to the main axis z. The block 1084 is basically cubic, and except for the first and second surfaces of the block 1084 which include the V-shaped channels 10861 and 10862, the V-shaped channels 10861 and 10862 are oriented basically parallel to the main axis z.

[0127] A pair of ball supports 1030 are accommodated in each V-shaped channel 10861, 10862, and the ball supports 1030 are held in the V-shaped channels 10861, 10862 by corresponding cubic protrusions 10891, 10892 extending from the second plate 1083. At least one of the cubic protrusions 10891, 10892 (two in other examples) includes a V-shaped channel 10863 configured to be opposite to one of the V-shaped channels 10861, 10862 of the block 1084. A biasing device (not shown) for loading the supports and a ball retaining device (not shown) are also typically included.

[0128] In this way, the permissible relative motion between the first plate 1082 and the second plate 1083 corresponds to Tz, while all other movements Tx, Ty, Rx, Ry, Rz are constrained.

[0129] Although individual block 1084 and corresponding protrusions 10891, 10892 are in Figure 12A and Figure 12B As shown, in some examples, two or more blocks 1084 can be used in combination with corresponding protrusions 10891, 10892 of the corresponding group.

[0130] See also Figure 13 An example of a helical flexible support 1090 is shown.

[0131] The helical flexible 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 13 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 gaskets 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).

[0132] Each helical beam portion 10921, 10922, 10923, 10924 is approximately tangent to the circular ring 1091 (in the same helical direction), and its span includes both 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 shims 10931, 10932, 10933, 10934 are clamped and a force is applied upward (in the positive z-axis direction) to the circular ring 1091, then in response, the helical beam portions 10921, 10922, 10923, 10924 will deflect in the direction of that force. However, in doing so, the ends connected to the circular ring 1091 also deflect closer to the corresponding shims 10931, 10932, 10933, 10934, causing the circular ring 1091 to rotate clockwise about an axis parallel to the principal axis z. Conversely, a downward (negative z-axis direction) force applied to the circular ring 1091 will cause the circular ring 1091 to move downward and rotate counterclockwise.

[0133] In this way, the helical flexible support 1090 is used 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 clamped shims 10931, 10932, 10933, 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.

[0134] Although the spiral beam sections 10921, 10922, 10923, and 10924 are in Figure 13 The helical beam portion 1091 may be straight in other examples of the helical flexible support 1090, which is shown as curved. Further examples of the helical flexible support 1090 are described in WO 2019 / 243849A1, the contents of which are incorporated herein by reference in their entirety. Figures 19 to 22 and the corresponding description on page 22, line 23 to line 24 of WO 2019 / 243849 A1 specifically relate to the helical flexible support 1090. Additional examples of implementing the helical flexible support 1090 are also shown and described below.

[0135] Also refer to Figure 14A and Figure 14B An example of the helical support 1094 is shown.

[0136] Figure 14A This is an exploded projection view of the assembled spiral support component 1094. Figure 14B It is the projection of the assembled spiral support component 1094. Figure 14A The occluded features are represented by dashed lines.

[0137] The helical support 1094 includes a first structure 1095 and a second structure 1096, which are configured to engage together for sliding movement between the helical surfaces 10971, 10972 of the first structure 1095 and the helical surfaces 10981, 10982 of the second structure 1096. A biasing device (not shown) pushes the first structure 1095 and the second structure 1096 together to maintain contact between the paired helical surfaces 10971 and 10981, 10972, 10982. In this way, the relative movement between the first structure 1095 and the second structure 1096 is constrained within the helical path [Tz, Rz].

[0138] Figure 14A and 14BThe example shown prioritizes visual clarity of the helical support's function over the practicality of the implementation, and the specific embodiments described below include additional examples more suitable for incorporation into devices such as camera 1. Specifically, although the helical surfaces 1097, 1098 can be bent to follow such... Figure 14A and Figure 14B The spiral path shown is typical, but in other examples, the spiral surfaces 1097, 1098 can be substantially planar, such as inclined plane 34. Figure 15 ).although Figure 14A and Figure 14B The helical support 1094 shown is a sliding support, but a rolling support 31 can also be used. Figure 15 Other helical support elements in the form of ) are also described. Further examples of helical support element 1094 can be found in WO 2019 / 243849A1 (which has been incorporated by reference). See WO 2019 / 243849A1 for details. Figures 1 to 1 8. And the corresponding descriptions on page 7, line 10 to page 22, line 21.

[0139] Although shown and described for reference with specific orientations relative to a set of right-hand Cartesian axes x, y, z, any of the supports described above can be oriented at any angle.

[0140] 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 made from sheet metal (e.g., stainless steel) with patterns provided by chemical etching or laser etching. Milling or stamping can be used, provided that this does not introduce unacceptable residual strain that would cause deformation of the component. After patterning, these components can be bent or pre-deformed as needed. Complex three-dimensional components can be created by attaching the component to a plate, sheet, or other component, for example, using adhesives, welding, brazing, soldering, etc. Alternatively, complex three-dimensional components can be formed by, for example, sintering or die casting of metal, or by injection molding of polymers. Any support component surface can be made of polymer, or may include a polymer top layer or coating, such as polyoxymethylene (POM, acetal), polytetrafluoroethylene (PTFE), or PTFE-impregnated POM, etc. Any support surface can be made of stainless steel or phosphor bronze, or include an overlayer or coating of stainless steel or phosphor bronze, with a 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 of one of these support materials, the second support surface being polished or stamped to reduce the effects of friction caused by surface texture.

[0141] AF actuator assembly

[0142] See also Figures 15 to 17 The image shows the AF actuator assembly 23 (hereinafter referred to as the actuator assembly).

[0143] Figure 15 An exploded perspective view of actuator assembly 23 is shown. Figure 16 A perspective view is shown, and Figure 17 This is a schematic diagram.

[0144] See details Figure 17 The actuator assembly 23 includes a first component 24, a second component 25, a support mechanism 26 that mechanically connects the first component 24 to the second component 25, and drive mechanisms 11 and 20.

[0145] The function of the first actuator assembly 23 will be described with reference to a set of axes fixed to the second component 25. When used in the camera 1, the main axis z corresponds to a direction that coincides with or is parallel to the optical axis O. The first axis x and the second axis y are perpendicular to the main axis z and to each other.

[0146] The drive mechanisms 11 and 20 and the support mechanism 26 are configured such that the first component 24 is movable toward or away from the second component 25 along the main axis z. The support mechanism 26 is also configured to constrain the movement Tx and / or Ty of the first component 24 relative to the second component 25 along the first axis, and constrain the rotation Rx, Ry, Rz of the first component 24 relative to the second component 25 about any axis of the first axis x, the second axis y, and the main axis z.

[0147] The support mechanism 26 includes a first support 27 that mechanically connects the first component 24 to the third component 28. Each shape memory alloy wire 141, 142, 143, 144 of the drive mechanism 11 is connected between the second component 25 and the third component 28. The first support 27 is configured to produce movement of the first component 24 toward or away from the third component 28 (and the second component 25) along the main axis z in response to a torque applied by the drive mechanisms 11, 20 about the main axis z. The first support 27 provides this function by guiding helical movement [Tz, Rz] about and along the main axis z by coupling rotation Rz about the main axis z to translation Tz along the main axis z.

[0148] The rotation of the first support member 27 about the main axis z will correspond to the rotation of the third member 28 relative to the first member 24 (and the second member 25) about the main axis z. The first member 24 does not rotate relative to the second member 25 about the main axis z.

[0149] The support mechanism 26 further includes a second support 29 that mechanically connects the first component 24 to the second component 25 and is configured to guide the movement of the first component 24 toward or away from the second component 25 along the main axis z, while constraining the movement of the first component 24 relative to the second component 25 along the first axis x and / or the second axis y, and also constraining the rotation Rz of the first component 24 relative to the second component 25 about the main axis z.

[0150] The support mechanism 26 further includes a third support 30, which mechanically connects the third component 28 to the second component 25 in parallel with the drive mechanisms 11 and 20. The third support 30 may be configured to constrain the movement Tz of the third component 28 relative to the second component 25 along the principal axis z, and to constrain the rotation Rx and / or rotation Rey of the third component 28 relative to the second component 25 about the first axis x and / or about the second axis y. The third support 30 should not constrain (i.e., permit) the rotation Rz of the third component 28 relative to the second component 25 about the principal axis z.

[0151] See also Figure 15 and Figure 16 An example implementation of actuator assembly 23 will be described in more detail below. For visual purposes, Figure 16 The housing element 8 has been omitted.

[0152] Actuator assembly 23 includes flat actuator assembly 15 (see details) Figure 4 The annular plate 16 of the flat actuator assembly 15 provides a second component 25, and the annular plate 17 provides a third component 28. As described above (regarding...) Figure 4 The annular plate 17 is connected to the annular plate 16 using four SMA lines 141, 142, 143, and 144 and slides on the third support 30, which is in the form of three or more cylindrical protrusions. Figure 15 Not shown in the figure, see example Figure 10B Planar support components provided by (10671, 10672 and 10673).

[0153] A first support member 27, in the form of a helical rolling support 31, mechanically connects a third member 28, in the form of an annular piece 17, to a first member 24, in the form of a lens holder 32, which functions in the same manner as the lens holder 9 to support one or more lenses 10 of the lens assembly 3. The helical rolling support 31 includes a ring 33 having a circular inner circumference defining a central hole 1009 and an outer circumference alternating between rectangular and circular profiles. The ring 33 supports four bevels 341, 342, 343, 344, equally spaced in a ring around the central hole 1009. Each bevel 341, 342, 343, 344 takes the form of a rectangular frame with elongated holes 351, 352, 353, 354 extending along the length of the bevel 341, 342, 343, 344. The inclined planes 341, 342, 343, and 344 all form substantially equal angles with the ring 33 (which lies in a plane parallel to the first axis x and the second axis y). During assembly, each elongated hole 351, 352, 353, and 354 receives the corresponding ball support 10301, 10302, 10303, and 10304.

[0154] The lens holder 32 is generally cylindrical around a central hole 1009 for mounting one or more lenses 10. The lens holder 32 also includes four protrusions 361, 362, 363, and 364 extending radially outward from the generally cylindrical lens holder 32. A first protrusion 361 defines a first support surface 371 in the form of a V-shaped channel. The first support surface 371 is generally oriented upward (the normal to the first support surface 371 has a component in the positive z-axis direction, generally along the principal axis z). A second protrusion 362 defines a second support surface 372 in the form of a V-shaped channel, the second support surface 372 being generally oriented downward (the normal to the second support surface 372 has a component in the negative z-axis direction, generally along the principal axis z). A third protrusion 363 defines a third support surface 373 in the form of an angled plane, the third support surface 373 being generally oriented upward (the normal to the third support surface 373 has a component in the positive z-axis direction, generally along the principal axis z). The fourth protrusion 364 is defined as a fourth support surface 374 in the form of an angled plane, and the fourth support surface 374 is oriented generally downward (the normal of the fourth support surface 374 has a component in the negative z-axis direction, approximately along the principal axis z).

[0155] During assembly, each support surface 371, 372, 373, 374 rolls into contact with the corresponding inclined surfaces 341, 342, 343, 344 via corresponding ball bearings 10301, 10302, 10303, 10304. However, the first support surface 371 and the third support surface 373 will be located below the corresponding inclined surfaces 341, 343 (relative to the principal axis z); while the second support surface 372 and the fourth support surface 374 will be located above the corresponding inclined surfaces 342, 344. This arrangement allows for... Figure 16 This was observed in [the context].

[0156] For example, ring 33 is fixed to annular piece 17 (third component 28) by welding, adhesive, or other suitable attachment methods. The upper surface (relative to the principal axis z) of lens holder 32 (first component 24) is fixed to the central annular portion 38 of second support member 29. Second support member 29 is in the form of a double-bar linkage 1001, and further includes a central annular portion 38 rigidly attached to (or integral with) a second rigid portion 10022. Central annular portion 38 is in the form of a circular ring.

[0157] The first rigid portion 10021 is then rigidly connected to the annular plate 16 (second component 25) via the receiving member 8 and the base 5 to complete the connection between the second component 25 in the form of the annular plate 16 and the first component 24 in the form of the lens holder 32. For example, the first rigid portion 10021 is attached to the receiving member 8, and the dimensions of the inner boundary of the receiving member 8 are determined to be adjacent (or nearly adjacent) to the edges of the first beam portion 10031 and the second beam portion 10032, so as to prevent the second rigid portion 10022 from being offset relative to the first rigid portion 10021 along the second axis y (e.g., Figure 15 and Figure 16 The orientation shown indicates the movement Ty. This configuration allows the first beam portion 10031 and the second beam portion 10032, together with the lens support 32 (first component 24), to deflect along the principal axis z.

[0158] The combination of the first support member 27 and the second support member 29 constrains any response to the lateral force (which is substantially perpendicular to the main axis z) applied by the first drive mechanism 11. In use, the first drive mechanism 11 will not be forced to apply a lateral force (because this would not have a useful effect on the support member mechanism 26).

[0159] However, when the first drive mechanism 11 applies torque about the main axis z, in response, the third component 28 in the form of annular plate 17 and the attached ring 33, as well as the inclined surfaces 341, 342, 343, 344, will rotate Rz about the main axis z. This rotation will cause the ball supports 10301, 10302, 10303, 10304 to roll between the inclined surfaces 341, 342, 343, 344 and the support surfaces 371, 372, 373, 374, causing the lens holder 32 (first component 24) to move vertically (relative to the main axis z) according to the torque and the direction of the corresponding rotation Rz. However, due to the constraint provided by the second support, the lens holder 32 (first component 24) does not rotate Rz about the main axis z. In addition to facilitating the up-down movement of the lens support 32 (first component 24), the up-down-up-down configuration of the ramps 341, 342, 343, 344 and the support surfaces 371, 372, 373, 374 means that when the actuator assembly 23 is assembled, the ramps 341, 342, 343, 344 bend, thereby providing a loading force for the first support 27.

[0160] Despite Figure 15 and Figure 16 As shown, it uses a first (flat) drive mechanism 11, but can be replaced by a second (angled) drive mechanism 20. The angled drive mechanism 20 can apply a force along the main axis z and a torque around the main axis z, which can help the first support 27 to move more smoothly in a spiral motion [Tz, Rz].

[0161] In this way, an autofocus (AF) function can be provided using a single drive mechanism 11, 20 comprising a total of four SMA lines 141, 142, 143, 144, while also avoiding rotation Rz of the lens 10 about the principal axis z. This improves image quality by reducing the likelihood of aberrations caused by the imperfect circular symmetry of one or more lenses 10, compared to a simple helical flexible member or support member that would also cause the lens 10 to rotate Rz about the principal axis z. Converting torque into translation Tz along the principal axis z using the first support member 27 can be achieved by increasing the travel length using longer SMA lines 141, 142, 143, 144 (longer than SMA lines oriented along the principal axis) while maintaining a low profile of the camera 1 along the principal axis z.

[0162] When the actuator assembly 23 is used in the camera 1 to provide autofocus, one or more additional or supplementary actuator systems (not shown) may optionally be included to provide separate optical image stabilization.

[0163] Each of the four shape memory alloy wires 141, 142, 143, and 144 corresponds to a segment of the shape memory alloy wire, on which the drive current can be independently controlled. For example, a pair of shape memory alloy wires 141, 142, 143, and 144 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 connection (not shown) at a point between the two ends.

[0164] Although the actuator assembly 23 has been explained with the second component 25 corresponding to the support structure 4 of the camera 1 and the first component 24 corresponding to the lens supports 9, 32 of the lens assembly 3, the roles can be reversed, such that the second component 25 corresponds to the lens supports 9, 32, and the first component 24 provides the support structure 4. Similarly, the actuator assembly 23 need not be limited to use within the camera 1, and the first component 24 and the second component 25 can be any components that require relative movement Tz.

[0165] Despite Figure 15 and Figure 16 A specific type of helical rolling support 31 is used, but the first support 27 can be any type of support or flexible element, which responds to the applied torque with helical motion [Tz, Rz]. For example, helical flexible support 1090, helical support 1094, or any alternative described in WO 2019 / 243849 A1 and cited above. Typically, the helical flexible element can take the form of a flat ring (or loop) with at least three flexible elements extending from it. The flat ring and the flexible elements can be a single piece.

[0166] Despite Figure 15 and Figure 16 As shown, the lateral movement Ty is additionally constrained by the adjacency of the receiving member using the double-bar linkage 1001, but the second support member 29 can be implemented using any support member that guides movement Tz along the principal axis z while simultaneously constraining rotation Rz about the principal axis z. For example, the second support member 29 can take the form of a z-axis flexible member 1011, a z-axis translational support member 1081, or any other type of support member having the movement and constraint described above.

[0167] Despite Figure 15 and Figure 16 The third component 28 is shown as an annular piece 17, but it can generally be any structure suitable for mechanically connecting the first support 27 and the second support 29.

[0168] The third support 30 may be provided by any support suitable for guiding the rotation Rz of the third component 28 relative to the second component 25, such as the first planar support 1064 or the second planar support 1068.

[0169] As previously mentioned, when using a helical support / flexible element to generate a movement Tz along the principal axis z, actuator assembly 23 can help avoid any lens quality problems associated with the rotation of lens 10. Additionally, components such as the ring 33 and bevel 34 of the second support 29 and / or the first support 27 can be formed by chemical etching or laser etching of a sheet of metal (e.g., stainless steel). The etched part can be bent after etching to angle the bevel 34. Alternatively, such components can be formed by stamping a sheet of metal, combined with removing unwanted material and bending the component into shape, but this method is only possible if residual stress in the formed component does not lead to undue deformation. Stamping combined with in-situ heating can be considered to allow creep relaxation. This can reduce manufacturing complexity.

[0170] The construction of the second support member 29, fixed to and surrounded by the receiver 8, provides an effective end stop between the lens holder 32 and the receiver 8. This reduces the likelihood of damage to the surfaces of the ball support 1030 (e.g., ramp 34 and ball support surface 37) during impacts (e.g., drops) that the device incorporating the actuator assembly 23 may be subjected to. Because the SMA lines 141, 142, 143, 144 do not need to be in the same plane as the ball 1030 in the support, the end stop system can be more easily implemented to allow the relatively large mass of the lens 10 and lens holder 32 to be transferred directly to the receiver 8. Therefore, the support surface 37 and ramp 34 can be loaded only with the relatively small mass of the rotating ring 33 and the attached annular plate 17.

[0171] In actuator assembly 23, the flexible beam portions 10031, 10032 of the second support 29 provide a restoring force along the main axis z to push the lens holder 32 back to a balance distance from the annular plate 16 (second component 25). Therefore, no additional springs, magnets, or other biasing devices are required, simplifying actuator design and assembly. The inclined surfaces 341, 342, 343, 344 may be subjected to prestress applied by a small amount of bending at the balance position. This prestressed configuration also helps prevent significant tilting (rotation) of the lens holder 32 between powered and unpowered states of the SMA lines 141, 142, 143, 144.

[0172] It should be understood that many other variations of the above embodiments may exist.

[0173] In the preceding description, components were described as rectangular, which should be interpreted as encompassing square shapes. Components were described as circular, which should be interpreted as encompassing elliptical shapes.

[0174] The first to fourth SMA lines 141, 142, 143, and 144 have been described and shown as directly connecting the second component 25 and the third component 28. However, in some examples, the first to fourth SMA lines 141, 142, 143, and 144 may indirectly connect the second component 25 and the third component 28, for example, via one or more intermediate structures (not shown in the figures). These intermediate structures (not shown in the figures) may be configured to help extend the travel provided by the SMA lines 141, 142, 143, and 144. In some examples, there may be an additional SMA line 14.

[0175] In some examples, there may be fewer than four SMA lines 14 configured to apply torque to the third component 28. For example, there may be one or two SMA lines equivalent to the SMA lines described in WO 2019 / 243849 A1. However, in such examples, additional features (e.g., any suitable type of additional support) may be needed to constrain the movement of the third component 28 other than Rz. Such constraint may be provided (at least) in part by the aforementioned support mechanism 16.

[0176] The actuator assembly can be any type of assembly, which includes a first component that is movable relative to the second component.

[0177] In some examples, the first (movable) component may correspond to or include an optical element that is not (even nominally) circularly symmetric and / or should not rotate when moved along the principal axis. In such examples, an actuator assembly as described in WO 2019 / 243849 A1 may be unsuitable, and the actuator assembly described herein may be particularly advantageous. For example, the actuator assembly may be used as part of a time-of-flight system as described in WO 2020 / 030916 A1 or WO 2021 / 019230 A1 (which are incorporated herein by reference in their entirety), wherein the (movable) optical element is, for example, a diffractive optical element configured to produce light patterns such as dot patterns.

[0178] Actuator components 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 electronic devices, cameras with foldable optics, image capture devices, array cameras, 3D sensing devices or systems, servo motors, consumer electronic 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, 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.

[0179] This invention also relates to the following aspects:

[0180] 1. An actuator assembly, comprising:

[0181] First component;

[0182] Second component;

[0183] A support mechanism that mechanically connects the first component to the second component, the support mechanism including a first support that mechanically connects the first component to a third component;

[0184] A drive mechanism comprising four shape memory alloy wires, wherein each shape memory alloy wire is connected between the third component and the second component;

[0185] The drive mechanism and the support mechanism are configured such that, in response to a torque applied by the drive mechanism about a main axis, the first support generates movement of the first component toward or away from the second and third components along the main axis;

[0186] The support mechanism is configured to constrain the rotation of the first component relative to the second component about the main axis.

[0187] 2. The actuator assembly according to aspect 1, wherein the first support member comprises a helical flexible member.

[0188] 3. The actuator assembly according to aspect 1, wherein the first support member includes a helical support member.

[0189] 4. The actuator assembly according to aspect 3, wherein the first support member includes a plurality of flexible ramps arranged in a loop around the main axis.

[0190] 5. The actuator assembly according to aspect 4, wherein the flexible ramp is prestressed in the balanced or neutral configuration of the first support member.

[0191] 6. The actuator assembly according to any one of aspects 1 to 5, wherein the support mechanism includes a second support that mechanically connects the first component to the second component, and the second support is configured to guide movement of the first component toward or away from the second component along the main axis, while constraining movement of the first component relative to the second component along a first axis and / or a second axis, wherein the first axis and the second axis are perpendicular to the main axis, and the second axis is different from the first axis, and also constraining rotation of the first component relative to the second component about the main axis.

[0192] 7. The actuator assembly according to aspect 6, wherein the second support includes a ball support ring aligned with the main axis.

[0193] 8. The actuator assembly according to aspect 6, wherein the second support member includes a first set of flexible members and a second set of flexible members, each of the first set of flexible members and the second set of flexible members being configured to be compliant in a direction corresponding to the movement of the first member relative to the third member along the main axis, wherein the first set of flexible members and the second set of flexible members are connected in parallel and spaced apart along the main axis.

[0194] 9. The actuator assembly according to any one of aspects 1 to 8, wherein the support mechanism further comprises a third support that mechanically connects the third component to the second component in parallel with the drive mechanism.

[0195] 10. The actuator assembly according to aspect 9, wherein the third support is configured to constrain the third component to move relative to the second component along the main axis and to constrain the third component to rotate relative to the second component about a first axis and / or a second axis, wherein the first axis and the second axis are perpendicular to the main axis and the second axis is different from the first axis.

[0196] 11. The actuator assembly according to any one of aspects 1 to 10, wherein the four shape memory alloy wires are substantially coplanar in a plane perpendicular to the main axis.

[0197] 12. The actuator assembly according to any one of aspects 1 to 10, wherein each of the four segments of shape memory alloy wire is not perpendicular to the main axis.

[0198] 13. A camera, comprising:

[0199] Actuator assembly according to any one of aspects 1 to 12;

[0200] An image sensor supported by one of the first component and the second component;

[0201] A lens supported by the first component and another of the second components.

[0202] 14. The camera according to aspect 13 further includes a controller configured to control the actuator assembly to:

[0203] The autofocus function is implemented by moving the first component toward or away from the second component along the main axis.

[0204] 15. A method comprising implementing an autofocus function of a camera using an actuator assembly according to any one of aspects 1 to 12.

Claims

1. An actuator assembly, comprising: First component; Second component; A support mechanism that mechanically connects the first component to the second component, the support mechanism including a first support that mechanically connects the first component to a third component; A drive mechanism, the drive mechanism comprising one or more segments of shape memory alloy wire, wherein each segment of shape memory alloy wire is connected between the third component and the second component; The drive mechanism and the support mechanism are configured to respond to a torque applied to the third component by the drive mechanism about the main axis, the third component rotating about the main axis and the first support causing the first component to move along the main axis toward or away from the second component and the third component; The support mechanism is configured to constrain the rotation of the first component relative to the second component about the main axis.

2. The actuator assembly of claim 1, wherein the first support member comprises a helical flexible member.

3. The actuator assembly of claim 1, wherein the first support member comprises a helical support member.

4. The actuator assembly of claim 3, wherein the first support member comprises a plurality of flexible inclined surfaces arranged in a loop around the main axis.

5. The actuator assembly of claim 4, wherein the flexible ramp is prestressed in the balanced or neutral configuration of the first support member.

6. The actuator assembly according to any one of claims 1 to 5, wherein, The support mechanism includes a second support that mechanically connects the first component to the second component, and the second support is configured to guide the movement of the first component toward or away from the second component along the main axis, while constraining the movement of the first component relative to the second component along a first axis and / or a second axis, wherein the first axis and the second axis are perpendicular to the main axis, and the second axis is different from the first axis, and also constrains the rotation of the first component relative to the second component about the main axis.

7. The actuator assembly of claim 6, wherein the second support includes a ball bearing race aligned with the main axis.

8. The actuator assembly of claim 6, wherein the second support comprises a first set of flexible members and a second set of flexible members, each of the first set of flexible members and the second set of flexible members being configured to be compliant in a direction corresponding to the movement of the first member relative to the third member along the main axis, wherein the first set of flexible members and the second set of flexible members are connected in parallel and spaced apart along the main axis.

9. The actuator assembly according to any one of claims 1-5, 7 and 8, wherein the support mechanism further comprises a third support mechanically connecting the third component to the second component in parallel with the drive mechanism.

10. The actuator assembly of claim 6, wherein the support mechanism further comprises a third support mechanically connecting the third component to the second component in parallel with the drive mechanism.

11. The actuator assembly of claim 9, wherein the third support is configured to constrain the third component to move relative to the second component along the main axis and to constrain the third component to rotate relative to the second component about a first axis and / or a second axis, wherein the first axis and the second axis are perpendicular to the main axis and the second axis is different from the first axis.

12. The actuator assembly of claim 10, wherein the third support is configured to constrain the third component to move relative to the second component along the main axis and to constrain the third component to rotate relative to the second component about a first axis and / or a second axis, wherein the first axis and the second axis are perpendicular to the main axis and the second axis is different from the first axis.

13. The actuator assembly according to any one of claims 1-5, 7, 8 and 10-12, wherein the drive mechanism comprises four segments of shape memory alloy wire.

14. The actuator assembly of claim 6, wherein the drive mechanism comprises four segments of shape memory alloy wire.

15. The actuator assembly of claim 9, wherein the drive mechanism comprises four segments of shape memory alloy wire.

16. The actuator assembly of claim 13, wherein the four shape memory alloy wires are substantially coplanar in a plane perpendicular to the main axis.

17. The actuator assembly of claim 14 or 15, wherein the four shape memory alloy wires are substantially coplanar in a plane perpendicular to the main axis.

18. The actuator assembly of claim 13, wherein each of the four segments of shape memory alloy wire is not perpendicular to the main axis.

19. The actuator assembly according to any one of claims 14-16, wherein each of the four segments of shape memory alloy wire is not perpendicular to the main axis.

20. The actuator assembly of claim 17, wherein each of the four segments of shape memory alloy wire is not perpendicular to the main axis.

21. A camera, comprising: An actuator assembly according to any one of claims 1 to 20; An image sensor supported by one of the first component and the second component; A lens supported by the first component and another of the second components.

22. The camera of claim 21, further comprising a controller configured to control the actuator assembly to: The autofocus function is implemented by moving the first component toward or away from the second component along the main axis.

23. A method comprising implementing an autofocus function of a camera using an actuator assembly according to any one of claims 1 to 20.

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