actuating device

Abstract

An actuation device is disclosed. The actuation device comprises a first part (2), a second part (10) and a bearing arrangement (20) supporting the second part on the first part. The bearing element is arranged to guide movement of the second part relative to the first part. The bearing arrangement comprises a bearing having a first bearing surface (31) on the first part and a second bearing surface (32) on the second part, and a rolling bearing (33, 38) configured to be disposed between the first and second bearing surfaces such that the first and second bearing surfaces are spaced apart by a gap. One of the first and second bearing surfaces is configured such that the bearing surface has a single point of contact with the rolling bearing at any one time, and the other of the first and second bearing surfaces is configured such that the bearing surface has two points of contact with the rolling bearing at any one time. The two points of contact of the first or second bearing surface are located closer to an axis of rotation of the rolling bearing than the single point of contact of the other of the first or second bearing surface, such that the distance that the rolling bearing moves relative to the first part is different to the distance that the second part moves relative to the rolling bearing.

Description

[0001] field

[0002] This application relates to actuation devices, particularly shape memory alloy (SMA) actuation devices.

[0003] background

[0004] It is known that SMA lines are used in actuators to drive the movement of movable elements relative to a support structure. Such SMA actuators offer particular advantages in miniature devices such as smartphones. For example, SMA actuators can be used in optical devices such as compact camera modules (also simply called camera modules) to drive lens assemblies to move along their optical axis to achieve focusing (autofocus, AF) or zooming.

[0005] Miniaturization is an important design principle in many applications. For example, in a camera module where an SMA actuator moves a lens assembly along the optical axis, it is desirable to minimize the module's size along the optical axis (i.e., the direction of movement). For instance, in smartphones, reducing the height of such an SMA actuator can result in a lower camera module height, and thus reduce or eliminate the "camera bump." A lower camera module height can also facilitate positioning the front-facing camera below the screen.

[0006] Overview

[0007] According to a first aspect of the invention, an actuation device is provided. The actuation device includes a first portion, a second portion, and a bearing arrangement for supporting the second portion on the first portion. The bearing arrangement is arranged to guide movement of the second portion relative to the first portion. The bearing arrangement includes a total of three or more support members, each support member including a first support surface on the first portion and a second support surface on the second portion, and including a rolling support element configured between the first and second support surfaces such that the first and second support surfaces are spaced apart by a gap. One of the first and second support surfaces is configured such that it has at least one contact point with the rolling support member at any given time, and the other of the first and second support surfaces is configured such that it has two contact points with the rolling support member at any given time. The two contact points of the first or second support surface are positioned closer to the axis of rotation of the rolling support element than at least one contact point of the other of the first or second support surface, such that the distance the rolling support element moves relative to the first portion is different from the distance the second portion moves relative to the rolling support element.

[0008] The actuation device is preferably a shape memory alloy (SMA) actuator assembly and / or a micro actuator assembly.

[0009] In some embodiments, at least one contact point may be located on a first line extending parallel to the axis of rotation, and two contact points may be located on a second line extending parallel to the axis of rotation.

[0010] In some embodiments, the distance between the second line and the axis of rotation can be substantially in the range of 1% to 50% of the distance between the first line and the axis of rotation.

[0011] In some embodiments, the distance between the second line and the axis of rotation can be substantially in the range of 1% to 25% of the distance between the first line and the axis of rotation.

[0012] In some embodiments, the distance between the plane of the two contact points and the axis of rotation can be substantially in the range of 1% to 90% of the distance between the single contact point and the axis of rotation of the support.

[0013] In some embodiments, the distance between the plane of the two contact points and the axis of rotation can be substantially in the range of 1% to 75% of the distance between the single contact point and the axis of rotation of the support.

[0014] In some embodiments, the support device may be a helical support device arranged to guide the helical movement of the second part relative to the first part about a helical axis, and each of three or more support members may be a helical support member.

[0015] In some embodiments, the helical support device may include a total of five helical support members, wherein each helical support member may include only one rolling support element, and wherein a support surface of each helical support member may have a single contact point with the rolling support element at any given time.

[0016] In some embodiments, at any point within the helical movement range of the second portion relative to the first portion, a support surface of each helical support may extend in a plane that is different from and not parallel to the plane in which a support surface of each other helical support extends, wherein the plane in which the helical support extends may be defined as a plane parallel to the helical axis and tangent to a support surface at the point of contact.

[0017] In some embodiments, the five helical supports can together provide constraints corresponding to the five degrees of freedom in the helical coordinate system.

[0018] In some embodiments, the helical support device may include a total of three helical support members, wherein each helical support member includes only one rolling support element. The first and second support surfaces of two helical support members each have two contact points with the corresponding rolling support element at any given time. One support surface of a helical support member may have a single contact point, and the other support surface of a helical support member may have two contact points with the rolling support element at any given time.

[0019] In some embodiments, the three helical supports can together provide constraints corresponding to the five degrees of freedom in the helical coordinate system.

[0020] In some embodiments, the helical support members may be spaced apart around the helical axis.

[0021] In some embodiments, the rolling support element of each helical support may be located in the same plane orthogonal to the helical axis at least at the limit point of the helical movement of the second part relative to the first part.

[0022] In some embodiments, at least one of the helical support members may include a plurality of rolling support elements.

[0023] In some embodiments, the first support surface in the first portion may be configured such that the first support surface includes two contact points with the rolling support element.

[0024] In some embodiments, the first support surface may include a groove in the surface of the first portion.

[0025] In some embodiments, the groove may include a first surface and a second surface that is not parallel to the first surface.

[0026] In some embodiments, the first surface of the groove may extend at an acute angle to the second surface of the groove.

[0027] In some embodiments, the angle formed between the surface of the first portion and one surface of the groove can be greater than 90 degrees and less than 180 degrees, preferably about 95 degrees.

[0028] In some embodiments, the first surface may form a first edge with the surface of the first portion, and the second surface may form a second edge with the surface of the first portion.

[0029] In some embodiments, the angle formed between the surface of the first portion and the first surface of the groove can be the same as the angle formed between the inner surface of the first portion and the second surface of the groove, such that the cross-section of the groove is symmetrical.

[0030] In some embodiments, the groove may have a cross-section that is substantially an isosceles trapezoid.

[0031] In some embodiments, the distance between the first edge and the second edge may be greater than the diameter of the rolling support, and one of the two contact points may be located on the first surface of the groove, while the other of the two contact points may be located on the second surface of the groove.

[0032] In some embodiments, the distance between the first edge and the second edge may be less than the diameter of the rolling support, and the two contact points may be located on the first edge and the second edge of the groove.

[0033] In some embodiments, the second support surface in the second portion may be configured such that the second support surface includes at least one contact point with the rolling support element, wherein the at least one contact point may be a single contact point.

[0034] In some embodiments, the second support surface may include a smooth surface.

[0035] According to a second aspect of the invention, an actuating device is provided. The actuating device includes a first portion, a second portion, and a helical support device supporting the second portion on the first portion. The helical support is arranged to guide helical movement of the second portion relative to the first portion about a helical axis. The support device includes a plurality of support members. Each support member includes a raceway configured to define a range of motion of the second portion relative to the first portion. Each raceway includes a first end wall located at one limit point and a second end wall located at another limit point. At least one of the plurality of support members is offset relative to at least one of the other support members, such that the first end wall of one of the plurality of support members is offset in the direction of the helical axis from the first end wall of at least one of the other support members.

[0036] In some embodiments, at least one support member may be offset relative to at least one other support member, such that the second end wall of at least one support member may be offset from the second end wall of at least one other support member in the direction of the helical axis.

[0037] In some embodiments, each of the plurality of supports may include a support surface on the second portion having a normal vector thereto, and the support may be of a first type if the normal vector has a component in a first direction along the helical axis, and the support may be of a second type if the normal vector has a component in a second direction opposite to the helical axis; and at least one support may be of the first type, and at least one other support may be of the second type, and at least one support may be offset relative to at least one other support such that the first end wall and / or the second end wall are offset in the first direction if located on the first portion, and offset in the second direction if located on the second portion.

[0038] In some embodiments, for each support member having a first end wall and / or a second end wall included in the first portion, when the second portion is at one limit point of its range of movement, the gap between the second portion and the end wall at another limit point of the raceway may be less than the diameter of the support element of the support member; and for each support member having a first end wall and / or a second end wall included in the second portion, when the second portion is at one limit point of its range of movement, the gap between the first portion and the end wall at the same limit point of the raceway may be less than the diameter of the support element of the support member.

[0039] In some embodiments, for each support element and each limit point of its range of motion, the gap may be less than 2rcos(θ / 2), where θ is the angle between the end wall and one of the first and second portions that move relative to the end wall, and r is the radius of the support element.

[0040] In some embodiments, for at least one support member and / or at least one other support member, the gap at one limit point of its range of motion may be substantially the same as the gap at another limit point of its range of motion.

[0041] According to a third aspect of the invention, an actuation device is provided. The actuation device includes a first portion, a second portion configured to move relative to the first portion about a helical axis, and at least one length segment of shape memory alloy (SMA) wire. The at least one length segment of SMA wire is connected between a static connector on the first portion and a movable connector on the second portion. When the second portion is in its intermediate position, the movable connector is offset from the static connector (along the helical axis) such that the at least one length segment of SMA wire extends at an acute angle to a plane orthogonal to the helical axis. The second portion can be configured to move relative to the first portion within a range of motion between two extreme positions along the helical axis. The intermediate position of the second portion can be substantially halfway between the two extreme positions along the helical axis.

[0042] In some embodiments, the static connector and the movable connector may be positioned toward the first end of the first portion and the first end of the second portion, respectively, the first end of the first portion and the first end of the second portion defining the maximum extension range of the first portion and the second portion in a first direction along the helical axis, and when the second portion is in its intermediate position, the movable connector may be offset from the static connector in the opposite second direction along the helical axis.

[0043] In some embodiments, at least one length segment of SMA wire may include a first length segment of SMA wire and a second length segment of SMA wire; the static connector and the movable connector of the first length segment of SMA wire may be positioned toward a first end of the first portion and a first end of the second portion, respectively, and when the second portion is in its intermediate position, the movable connector of the first length segment of SMA wire may be offset from the static connector of the first length segment of SMA wire in a second direction; and the static connector and the movable connector of the second length segment of SMA wire may be positioned toward a second end of the first portion and a second end of the second portion, respectively, the second end of the first portion and the second end of the second portion defining the maximum extension range of the first portion and the second portion in a second direction along the helical axis, and when the second portion is in its intermediate position, the movable connector of the second length segment of SMA wire may be offset from the static connector of the second length segment of SMA wire in a first direction.

[0044] In some embodiments, the movable connector may be offset such that when the second part moves to the limit of its range of motion, the movable connector does not move substantially beyond the static connector on the first part along the helical axis.

[0045] In some embodiments, the second portion may include an end surface having a recessed section, to which a movable connector is attached such that when the second portion is in its intermediate position, the movable connector may be offset from the static connector in the direction of the helical axis.

[0046] In some embodiments, the actuation device may further include at least one spring arm attached at one end to the second portion and at the other end to the first portion, and extending about a helical axis between its ends, wherein the second portion may include a helical surface configured to allow a range of movement of the second portion relative to the first portion without the spring arm contacting the second portion.

[0047] In some embodiments, the spring arm can be connected to the movable connector via a connecting section connected to the end of the second part and via a torsion section configured to offset the movable connector relative to the static connector.

[0048] According to a fourth aspect of the invention, an actuation device is provided. The actuation device includes a first portion and a second portion. A first length segment of SMA wire is connected to the first portion via a first static connector at a first corner of the actuation device and to the second portion via a first movable connector at a second corner of the actuation device. A second length segment of SMA wire is connected to the first portion via a second static connector at the second corner of the actuation device and to the second portion via a second movable connector at the first corner of the actuation device. The actuation device further includes a helical support device supporting the second portion on the first portion. The helical support device is arranged to guide helical movement of the second portion relative to the first portion about a helical axis. The second length segment of SMA wire is spaced apart from the first length segment of SMA wire in a first direction along the helical axis. The first portion or the second portion, or each of the first portion and the second portion, includes a side portion between the first corner and the second corner, the side portion extending generally in a plane oriented at an acute angle to a plane orthogonal to the helical axis.

[0049] In some embodiments, the plane may extend from a first corner of the actuator to a second corner in a first direction.

[0050] In some embodiments, for each of the SMA lines of the first length segment and the SMA lines of the second length segment, when the second portion is at a limit point of its range of movement, the side portion may include a generally planar surface parallel to the SMA line of that length segment.

[0051] In some embodiments, the actuation device may be a shape memory alloy actuator.

[0052] According to a fifth aspect of the invention, a camera system is provided, the camera system comprising: an actuation device, an image sensor, and a lens system, wherein the lens system is mounted to one of a first part and a second part, and wherein the lens system is mounted to the other of the first part and the second part. Brief description of the attached diagram

[0054] Some embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0055] Figure 1 A schematic diagram of a shape memory alloy (SMA) actuator is shown, which is a camera;

[0056] Figure 2 A schematic perspective view of the support device is shown;

[0057] Figure 3 A schematic top-down cross-sectional view of the support device is shown;

[0058] Figures 4a to 4c A schematic top view of a known support device at various stages of its range of motion is shown;

[0059] Figures 5a to 5c A schematic top view of the support device at various stages of its range of motion is shown;

[0060] Figure 6 A schematic top-down cross-sectional view of a shape memory alloy actuator is shown.

[0061] Figures 7a to 7c A schematic cross-sectional side view of the helical support at different points on the shape memory alloy actuator is shown;

[0062] Figures 8a to 8c A schematic side view of the shape memory alloy actuator at various positions within its range of motion is shown; for clarity, the first part is omitted; and

[0063] Figure 9 A schematic cross-sectional side view of a shape memory alloy actuator is shown.

[0064] Detailed description

[0065] Unless the context otherwise requires, the term "support" is used herein as follows: The use of the term "support" herein encompasses the terms "sliding bearing," "plain bearing," "rolling bearing," "ball bearing," "roller bearing," "air bearing" (where pressurized air buoys the load), and "flexure." The term "support" herein generally refers to any element or combination of elements used to constrain motion to only the desired motion and reduce friction between moving parts. The term "sliding bearing" is used to mean a support element that slides on a support surface and includes "plain bearings." The term "rolling bearing" is used to mean a support element (e.g., a ball or roller) that rolls on a support surface. Such a rolling support element can be a compliant element, such as a gas-filled bladder. In embodiments, the support may be disposed on a non-linear support surface or may include a non-linear support surface.

[0066] In some embodiments of this technology, more than one type of support element may be used in combination to provide support functionality. Therefore, the term "support element" as used herein includes any combination of, for example, planar supports, ball supports, roller supports, and flexural elements.

[0067] Figure 1The actuation device 1 is schematically shown as a camera. In this embodiment, the actuation device 1 is a shape memory alloy (SMA) actuation device. The SMA actuation device 1 described herein is an autofocus actuator. Those skilled in the art will understand that the autofocus SMA actuation device 1 can be placed on top of an optical image stabilization (OIS) actuator.

[0068] SMA actuator 1 includes a first part 2 having an image sensor 3 mounted thereon. The first part 2 is also referred to herein as a support structure 2. The first part 2 or support structure 2 can take any suitable form, typically including a base 4 to which the image sensor is fixed. The first part 2 or support structure 2 may also support an IC chip 5, which will be described in more detail below.

[0069] The SMA actuator 1 also includes a second part 10. The second part 10 is also referred to herein as a movable element 10. In this example, the second part 10 or movable element 10 is a lens element. The lens element 10 may include a lens 11, although alternatively the lens element 10 may include multiple lenses. The lens 11, the movable element 10, has an optical axis O aligned with the image sensor 3 and is arranged to focus an image onto the image sensor 3.

[0070] SMA actuators are micro-devices. In some examples of micro-devices, the movable element 10 and the lens (or multiple lenses, when provided) may have a diameter of up to 20 mm, preferably up to 15 mm, and more preferably up to 10 mm.

[0071] Although the SMA actuator 1 is a camera in this example, this is generally not necessary. Those skilled in the art will understand that in some examples, the SMA actuator 1 can be an optical device in which the movable element 10 is a lens element but no image sensor. In other examples, the SMA actuator 1 can be a device that is not an optical device, and in which the movable element 10 is not a lens element and there is no image sensor. Examples include devices for depth mapping, facial recognition, game consoles, projectors, and security scanners.

[0072] SMA actuator 1 also includes support device 20 (in Figure 1 (Illustrated schematically) The support device 20 supports the movable element 10 on the support structure 2. In this embodiment, the support device 20 is a helical support device; however, it should be understood that the support device does not necessarily have to be helical.

[0073] The helical support device 20 is arranged to guide the helical movement of the movable element 10 about the helical axis H relative to the support structure 2. In this embodiment, the helical axis H coincides with the optical axis O. The helical movement of the movable element 10 is... Figure 1 The helical motion is indicated by arrow M. Preferably, the helical motion is along a cylindrical helix. That is, the helical motion is along a helix with a constant radius. However, in general, any helix is ​​possible. The pitch of the helix can be constant or variable along the helical motion. Preferably, the helical movement is typically only a small fraction (less than a quarter) of a full turn of the helix.

[0074] The helical motion of the movable element 10, guided by the helical support device 20, includes a translational component along the helical axis H and a rotational component about the helical axis H. The translational movement along the helical axis H is typically the desired movement of the movable element 10, such as changing the focal length of the image on the image sensor 3 and / or changing the magnification (zoom) of the image on the image sensor 3. In this example, the rotational movement about the helical axis H is not desired for optical purposes, but is generally acceptable because the rotation of the movable element 10 (such as a lens) does not change the focal length of the image on the image sensor 3.

[0075] Now for reference Figure 2 The support device 20 will now be described in more detail. The support device 20 may be a helical support device. The support device 20 includes a plurality of support members 30. Each support member 30 may be a helical support member 30. Each support member 30 includes a pair of support surfaces. The pair of support surfaces includes a first support surface 31 and a second support surface 32. The first support surface 31 is located on the support structure 2. The second support surface 32 is located on the movable element 10.

[0076] Each support member 30 also includes a rolling support element 33, which is configured to be disposed between the first support surface 31 and the second support surface 32. The rolling support element 33 is configured to be disposed between the first support surface 31 and the second support surface 32 such that the first support surface 31 and the second support surface 32 are separated by a gap 34, as will be described in more detail below.

[0077] Each helical support 30 guides the helical movement of the movable element 10 relative to the support structure 2, as indicated by arrow M. This is achieved by the first support surface 31 and the second support surface 32 extending helically around the helical axis H (i.e., extending along the path of the helix). In a practical embodiment, if the helical support 30 of the helical support device 20 guides the helical movement of the movable element 10 relative to the support structure 2, the lengths of the first support surface 31 and the second support surface 32 can be short compared to the distances of the first support surface 31 and the second support surface 32 from the helical axis H, such that their shapes are nearly straight or even each is straight.

[0078] Multiple helical support members 30 are located at different angular positions around the helical axis H, and the helical support members 30 have different orientations, so that the helical support members 30 cooperate and maintain sufficient constraint to guide the helical movement of the movable element 10 relative to the support structure 2.

[0079] Reference Figure 3 One of the first support surface 31 and the second support surface 32 is configured such that the support surfaces 31 and 32 have a single contact point X1 with the rolling support element 33 at any given time. The other of the first support surface 31 and the second support surface 32 is configured such that the support surfaces 31 and 32 have two contact points Y1 and Y2 with the rolling support element 33 at any given time.

[0080] The two contact points Y1 and Y2 of the first support surface 31 or the second support surface 32 are positioned closer to the rotation axis R of the rolling support element 33 than the single contact point X1 of the other of the first support surface 31 or the second support surface 32. Therefore, the distance that the rolling support element 33 moves relative to the support structure 2 is different from the distance that the movable element 10 moves relative to the rolling support element 33.

[0081] In this embodiment, the first support surface 31 in the support structure 2 is configured such that the first support surface 31 includes two contact points Y1 and Y2 with the rolling support element 33. Furthermore, the second support surface 32 in the movable element 10 is configured such that the second support surface 32 includes one contact point X1 with the rolling support element 33.

[0082] Therefore, the distance that the rolling support element 33 moves relative to the support structure 2 is less than the distance that the movable element 10 moves relative to the rolling support element 33, as will be explained in more detail below.

[0083] Preferably, the two contact points Y1 and Y2 lie in a plane extending parallel to the axis of rotation R of the rolling support 33, as will be explained in more detail below. Furthermore, the plane Y extends perpendicularly to a diameter line extending from the single contact point X1.

[0084] It will be understood that, in alternative embodiments, the first support surface 31 may be configured such that the support structure 2 includes a single contact point X1 with the rolling support element 33, and the second support surface 32 may be configured such that the movable element 10 includes two contact points Y1, Y2 with the rolling support element 33. In such embodiments, the distance the rolling support element 33 moves relative to the support structure will be greater than the distance the movable element 10 moves relative to the rolling support element 33.

[0085] In another alternative embodiment (not shown), both the first support surface 31 and the second support surface 32 can be configured such that the support structure 2 and the movable element 10 each include a pair of contact points with the rolling support element 33. The distance between one pair of contact points and the rotation axis R can be greater than the distance between the other pair of contact points and the rotation axis R. In this embodiment, the rolling support element 33 will move a greater distance relative to one pair of contact points than it will move relative to the other pair of contact points.

[0086] Reference Figure 2 and Figure 3 The first support surface 31 on the support structure 2 includes a groove 35. A rolling support element 33 is located within the groove 35 of the first support surface 31. In this embodiment, the movable element 10 is located inside the support structure 2. That is, the support structure 2 is farther from the helical axis H than the movable element 10. Therefore, in this embodiment, the groove 35 is located within the inner surface of the support structure 2.

[0087] The second support surface 32 on the movable element 10 includes a smooth surface 36. The smooth surface 36 is smooth, meaning it is a uniform and regular surface. The smooth surface 36 may have no perceptible protrusions, bumps, and / or depressions. The smooth surface 36 is a surface that is not a groove and provides only a single point of contact with the rolling support element 33. In other words, the second support surface 32 is practically smooth across the entire width scale of the rolling support element 33, although it is helical on a larger scale.

[0088] For example, as shown in the figure, the smooth surface 36 is helical, forming a line in the cross-section of the helical coil along the direction of movement M, maintaining a single point of contact with the ball at all times. Alternatively, and as described above, in a practical embodiment, if the helical support member 30 of the helical support device 20 guides the helical movement of the movable element 10 relative to the support structure 2, the lengths of the first support surface 31 and the second support surface 32 may be short. In this case, the second support surface 32 may be helical, planar, nearly planar, or substantially planar.

[0089] Reference Figure 2Each helical support 30 includes a single rolling support element 33. However, in an alternative embodiment, at least one helical support 30 may include a plurality of rolling support elements 33.

[0090] In some examples, each helical support 30 may include a single rolling support element 33. In that case, each helical support 30 itself does not constrain the rotational movement of the movable element 10 relative to the support structure 2 about the single rolling support element 33 (i.e., about an axis transverse to the direction of movement indicated by arrow M). However, this minimizes the overall size of the helical support 30, and in particular minimizes the height of the helical support 30 projecting along the helical axis H, as it only needs to accommodate the size and range of travel of the rolling support element 33 to allow the required movement between the first support surface 31 and the second support surface 32.

[0091] In other examples, at least one helical support 30 may include a plurality of rolling support elements 33. In this case, the helical support 30 restricts the rotational movement of the movable element 10 relative to the support structure 2 about any one of the rolling support elements 33 (i.e., about an axis transverse to the direction of movement indicated by arrow M). However, this increases the overall size of the helical support 30 compared to using a single rolling support element 33, and in particular increases the height of the helical support 30 projecting along the helical axis H.

[0092] The helical support device 20 may typically include any suitable number of helical support elements 30, wherein the configuration of the helical support elements 30 is selected to guide the helical movement of the movable element 10 relative to the support structure 2, while constraining the movement of the movable element 10 relative to the support structure 2 in other degrees of freedom.

[0093] Reference Figure 3 As can be seen, there is a single contact point X1 between the planar surface 32 of the second support surface 32 and the rolling support element 33. The rolling support element 33 rolls around its rotation center, which is the center of the rolling support member, i.e., the center of the sphere. The distance between the single contact point X1 and the rotation center of the rolling support element 33 is the radius of the rolling support element 33.

[0094] The groove 35 includes a first surface 41. The first surface 41 of the groove 35 may be helical. When viewed in a cross-section perpendicular to the helical axis H, the first surface 41 of the groove 35 forms a smooth surface, which may be planar, i.e., a line, such as... Figure 3As shown. The first surface 41 of the groove 35 is spirally coiled along the direction of movement M. The first surface 41 of the groove 35 extends at an angle to the surface of the support structure 2 in which the first support surface 31 is formed. Therefore, the first surface 41 of the groove 35 extends at an angle to the second support surfaces 32, 36 of the movable element 10. More specifically, the first surface 41 of the groove 35 extends at an angle to the tangential plane T of the rolling support element 33 at a single contact point X1.

[0095] The groove 35 also includes a second surface 42. The second surface 42 of the groove 35 can be helical. When viewed in a cross-section perpendicular to the helical axis H, the second surface 42 of the groove 35 forms a planar surface, i.e., a line, such as... Figure 3 As shown. The second surface 42 of the groove 35 is spirally coiled along the moving direction M. The second surface 42 of the groove 35 extends at an angle to the surface of the support structure 2 where the first support surface 31 is formed. Therefore, the second surface 42 of the groove 35 extends at an angle to the second support surfaces 32, 36 of the movable element 10. More specifically, the second surface 42 of the groove 35 extends at an angle to the tangential plane T of the rolling support element 33 at a single contact point X1.

[0096] The first surface 41 and the second surface 42 of the groove 35 extend at an acute angle. That is, the first surface 41 and the second surface 42 of the groove 35 do not extend parallel to each other. (See reference...) Figure 3 The first surface 41 and the second surface 42 converge as they extend away from the surface of the support structure 2. That is, the farther a point on the first surface 41 or the second surface 42 of the groove 35 is from the tangent plane T of the rolling support element 33 at a single contact point X1, the closer that point on the first surface 41 or the second surface 42 is to the other of the first surface 41 or the second surface 42 of the groove 35.

[0097] The groove 35 also includes a third surface 43. The third surface 43 of the groove 35 can be helical. When viewed in a cross-section perpendicular to the helical axis H, the third surface 43 of the groove 35 forms a planar surface, i.e., a line, such as... Figure 3 As shown. The third surface 43 of the groove 35 is spirally coiled along the moving direction M.

[0098] The third surface 43 of the groove 35 forms the base of the groove 35. The third surface 43 extends between the first surface 41 and the second surface 42. Preferably, the third surface 43 extends parallel to the tangential plane of the rolling support element 33 at a single contact point X1. Therefore, the groove 35 has a quadrilateral cross-section. The third surface 43 of the groove 35 is configured such that it is spaced apart from the rolling support element 33. That is, there is no contact between the third surface 43 and the rolling support element 33.

[0099] As described above, one end of the first surface 41 of the groove 35 is in contact with the third surface 43 of the groove 35. At the other end of the first surface 41 is the first edge 45 of the groove 35. The first edge 45 of the groove 35 is formed at the junction of the first surface 41 of the groove 35 and the inner surface of the support structure 2. Similarly, one end of the second surface 42 of the groove 35 is in contact with the third surface of the groove 35. A second edge 46 is located at the other end of the second surface 42 of the groove 35. The second edge 46 of the groove 35 is formed at the junction of the second surface 42 of the groove 35 and the inner surface of the support structure 2.

[0100] The angle formed between the first surface 41 or the second surface 42 of the groove 35 and the inner surface of the support structure 2 is an obtuse angle. Therefore, the first surface 41 and the second surface 42 of the groove 35 can converge. In this embodiment, the angle of the first edge 45 formed between the inner surface of the support structure 2 and the first surface 41 of the groove 35 is the same as the angle of the second edge 46 formed between the inner surface of the support structure 2 and the second surface 4 of the groove 35. The angle formed between the inner surface of the support structure 2 and the first surface 41 of the groove 35 can be in the range of 90 degrees to 180 degrees. Preferably, this angle is in the range of greater than 90 degrees to less than 180 degrees. The angle formed between the inner surface of the support structure 2 and the second surface 42 of the groove 35 can be in the range of 90 degrees to 180 degrees. Preferably, this angle is in the range of greater than 90 degrees to less than 180 degrees.

[0101] More preferably, the aforementioned angle ranges from 95 degrees to 175 degrees. This angle range helps prevent the rolling support element 33 from becoming unrestrained, which could occur outside this range due to manufacturing tolerances. The closer the angle is to 90 degrees or 95 degrees (and therefore the closer the angle between the first surface 41 and the second surface 42 of the groove 35 is to 0 degrees or 5 degrees), the smaller the range of travel of the rolling support element 33 along the support structure 2.

[0102] Therefore, the cross-section of the groove 35 is symmetrical. Furthermore, the cross-section of the groove 35 is an isosceles trapezoid. However, it should be understood that in alternative embodiments, the cross-section of the groove 35 may take another form. For example, in an embodiment where the third surface 43 of the groove 35 is omitted, the cross-section of the groove 35 may be triangular.

[0103] The distance between the first edge 45 and the second edge 46 of the groove 35 is greater than the diameter of the rolling support element 33. Therefore, the two contact points Y1 and Y2 between the rolling support element 33 and the groove 35 of the first support surface 31 are located on the first surface 41 and the second surface 42 of the groove 35. That is, the first contact point Y1 between the rolling support element 33 and the first support surface 31 is on the first surface 41 of the groove 35, and the second contact point Y2 between the rolling support element 33 and the first support surface 31 is on the second surface 42 of the groove 35. For the right-hand helical support 30, the above is true at any point along the movement range of the movable element 10.

[0104] In embodiments where the distance between the first edge 45 and the second edge 46 of the groove 35 is greater than the diameter of the rolling support element 33, it is advantageous because it reduces the distance by which the rolling support element 33 protrudes from the groove 35. Therefore, the overall size of the SMA actuator 1 can be reduced.

[0105] In an alternative embodiment not shown in the figure, the distance between the first edge 45 and the second edge 46 of the groove 35 may be less than the diameter of the rolling support element 33. In such an embodiment, the two contact points Y1 and Y2 of the rolling support element 33 with the groove 35 of the first support surface 31 are located on the first edge 45 and the second edge 46 of the groove 35. That is, the first contact point Y1 between the rolling support element 33 and the first support surface 31 is on the first edge 45 of the groove 35, and the second contact point Y2 between the rolling support element 33 and the first support surface 31 is on the second edge 46 of the groove 35. For the right-hand helical support 30, the above is true at any point along the range of movement of the movable element 10.

[0106] In an alternative embodiment where both the first support surface 31 and the second support surface 32 are configured such that the support structure 2 and the movable element 10 each include a pair of contact points with the rolling support element 33, both the first support surface 31 and the second support surface 32 may include the grooves described above with respect to the first support surface 31. The angle formed between the first surface 41 and the second surface 42 of the groove included in one of the support surfaces 31 and 32 is greater than the angle formed between the first surface 41 and the second surface 42 of the groove included in the other support surface 31 and 32.

[0107] Brief Reference Figures 5a to 5c , Figures 5a to 5cA schematic top view of the support device 30 is shown. It can be seen that, in any of the above scenarios, the plane or line Y containing the two contact points Y1 and Y2 between the rolling support element 33 and the first support surface 31 on the support structure 2 is closer to the rotation center R of the rolling support element 33 than the tangent plane or line T at the single contact point X1 between the rolling support element 33 and the second support surface 32 of the movable element 10.

[0108] In comparison, Figures 4a to 4c A schematic top view of a known support device 30 is shown, wherein the rolling support element 33 has a single contact point with the first support surface 31 of the support structure 2 and a single contact point with the second support surface 32 of the movable element 10. In the known arrangement, each contact point of the rolling support element 33 is spaced from the rotation center R of the rolling support element 33 by a distance equal to the radius r of the rolling support element 33, such as... Figure 4a As shown. Therefore, as Figure 4b and Figure 4c As can be seen, the movement of the movable element 10 relative to the rolling support element 33 is the same as the movement of the rolling support element 33 relative to the support structure 2.

[0109] More specifically, see reference Figure 4b It can be seen that when Figure 1 When the SMA actuation device 1 shown is actuated, the movable element 10 moves relative to the support structure 2. When the movable element 10 moves a distance equal to one-quarter of the circumference of the rolling support element 33, as indicated by the arrow πr / 2 in the figure, the rolling support element 33 rotates one-quarter of a turn around its rotation center R due to friction at a single contact point between the rolling support element 33 and the second support surface 32 of the movable element 10.

[0110] Due to the friction between the rolling support element 33 and the first support surface 31 of the support structure 2, when the rolling support element 33 rotates around its rotation center R, the rolling support element 33 rolls along the first support surface 31 of the support structure 2 a distance equal to one-quarter of the circumference of the rolling support element 33, as indicated by the arrow mark πr / 2.

[0111] Therefore, when the movable element 10 moves a distance equal to one-quarter of the circumference of the rolling support element 33, the total distance the movable element 10 moves relative to the support structure 2 is half the circumference of the rolling support element 33. Therefore, in order to obtain the desired range of the movable element 10, the track or raceway formed by the first support surface 31 on the support structure 2 must be at least half the desired range. This necessary track length of the first support surface 31 on the support structure limits the minimum size of the support structure 2, and thus limits the SMA actuation device 1 (such as...). Figure 1 The overall dimensions are shown in the figure.

[0112] Brief reference Figure 4c For completeness, it can be seen that the movable element 10 has moved an additional distance equal to one-quarter πr / 2 of the circumference of the rolling support element 33. Furthermore, the rolling support element 33 has rolled an additional distance equal to one-quarter πr / 2 of the circumference of the rolling support element 33 along the support structure 2. Therefore, the movable element 10 has moved a distance equal to half πr of the circumference of the rolling support element 33 relative to the rolling support element 33, and the rolling support element 33 has moved a distance equal to half πr of the circumference of the rolling support element 33 relative to the support structure 2. Thus, overall, the movable element 10 has moved a distance equal to the circumference of the rolling support element 33 relative to the support structure 2.

[0113] Figures 4a to 4c The effect illustrated in the diagram (i.e., the distance the movable element moves relative to the rolling support element is equal to the distance the rolling support element moves relative to the support structure) is also provided by a support device in which the rolling support element is located in two similar grooves, namely a first groove in a first support surface and a second groove in a second support surface, the second groove having the same shape as the first groove. Such grooves can be considered to reduce the "effective radius" of the rolling support element (where the effective radius of the rolling support element relative to a particular groove can be defined as the distance between the axis of rotation of the rolling support element and a line parallel to the axis of rotation that includes the contact point between the groove and the rolling support element).

[0114] Reference Figures 5a to 5c The support device is shown. For clarity, the first support surface 31 of the support structure 2 is shown by a straight line 49, although in practice the line could be helical. The line 49 shown represents the contact points Y1, Y2 between the first support surface 31 of the support structure 2 and the rolling support element 33 as the rolling support element 33 moves along the support structure 2. The line 49 could be the contact points Y1, Y2 on the first surface 41 and the second surface 42 of the groove 35 of the first support surface 31, or alternatively, the line 49 could be the contact points Y1, Y2 along the first edge 45 and the second edge 46 of the groove 35.

[0115] Reference Figure 5a The single contact point X1 between the rolling support element 33 and the movable element 10 is located at a certain distance from the rotation center R of the rolling support element 33, which is equal to the radius r of the rolling support element 33. However, the plane Y of the two contact points Y1 and Y2 between the rolling support element 33 and the first support surface 31 of the support structure 2 is located at a certain distance from the rotation center R of the rolling support element 33, which is equal to half the radius r / 2 of the rolling support element 33.

[0116] Two different sets of contact points on the rolling support element 33 Figures 5a to 5c The images are shown as concentric circles. The outer circle, or larger circle, represents the circumference of the rolling support element 33 and thus a single contact point with the second support surface 32 of the movable element 10. The inner circle, or smaller circle, represents two contact points between the rolling support element 33 and the first support surface 31 of the support structure 2 (i.e., the first surface 41 or first edge 45 of the groove 35 and the second surface 42 or second edge 46 of the groove 35).

[0117] like Figure 5a As illustrated in the diagram, the distance between the tangential planes containing a single contact point X1 is twice the distance between the planes containing the two contact points Y1 and Y2. Furthermore, since each point of the rolling support element 33 rotates at the same angular velocity, when the initial single contact point X1 rotates through 90 degrees, the two contact points Y1 and Y2 also rotate through only 90 degrees. However, because the radial distance between the plane Y containing the two contact points Y1 and Y2 and the rotation center R is less than the radial distance between the single contact point X1 and the rotation center R, the movable element 10 moves more relative to the rolling support element 33 than the rolling support element 33 moves relative to the support structure 2. Figure 5c As shown and will be described in more detail below.

[0118] Reference Figure 5b It can be seen that when Figure 1 When the SMA actuation device 1 shown is actuated, the movable element 10 moves relative to the support structure 2. When the movable element 10 moves a distance equal to one-quarter of the circumference of the rolling support element 33, as indicated by the arrow πr / 2 in the figure, the rolling support element 33 rotates one-quarter of a turn around its rotation center R due to friction at a single contact point between the rolling support element 33 and the second support surface 32 of the movable element 10.

[0119] Due to friction between the rolling support element 33 and the first support surface 31 of the support structure 2, when the rolling support element 33 rotates about its rotation center R, in this invention, the rolling support element 33 rolls along the first support surface 31 of the support structure 2 a distance equal to one-eighth of the circumference of the rolling support element 33, as indicated by the arrow πr / 4. Because the smaller radius between the rotation center R and the two contact points creates a shorter arc of curvature, the rolling support element 33 moves less relative to the support structure 2. Therefore, the rolling support element 33 moves along a shorter arc of curvature than the circumference. Consequently, the distance the rolling support element 33 moves along the support structure 2 is smaller than the distance the movable element 10 moves relative to the rolling element 33.

[0120] Therefore, when the movable element 10 moves a distance equal to one-quarter of the circumference of the rolling support element 33, the total distance the movable element 10 moves relative to the support structure 2 is three-eighths of the circumference of the rolling support element 33. Thus, to achieve the required range of motion of the movable element 10, the track or raceway formed by the first support surface 31 on the support structure 2 only needs to be one-third of the required range of motion of the movable element 10. This necessary track length of the first support surface 31 on the support structure limits the minimum size of the support structure 2, and therefore limits the SMA actuation device 1 (such as...). Figure 1 The overall dimensions (shown) are as follows. However, the required track length is less than that required in known support devices. Therefore, the present invention allows for a reduction in the height of the support structure 2, and thus the device 1.

[0121] The height of the SMA actuator device 1 is typically limited by the height of the movable element 10 and the stroke length of the movable element 10. Therefore, for a given stroke, the minimum height of the SMA actuator device 1 is determined by the height of the movable element 10. However, as will be referred to below... Figures 7a to 7c To explain in more detail, when the movable element 10 is at the limit of its range of motion, there should still be sufficient overlap between the movable element 10 and the support structure 2 to minimize the risk of the rolling support element 33 running off the support 30 in certain scenarios such as impacts.

[0122] The end walls 61, 62 of the support member 30 are defined (i.e. included) by the support structure 2 (see...). Figures 7a to 7c In this example, by reducing the length of the required track on support structure 2, the height of support structure 2 can be reduced, and thus the height of SMA actuator device 1 can be reduced. Alternatively, or additionally, the overlap described in the previous paragraph can be increased.

[0123] In other examples, such as in the case where the movable element 10 includes one or both of the end walls of the support 30, the height of the SMA actuator device 1 and / or the overlap can be reduced by alternatively reducing the length of the required track on the movable element 10.

[0124] In general, the “gearing” described herein provides a way to adjust the track length of the (helical) support and thus advantageously adjust the performance of a particular SMA actuator device 1.

[0125] Brief reference Figure 5cFor completeness, it can be seen that the movable element 10 has moved another distance equal to one-quarter πr / 2 of the circumference of the rolling support element 33. Furthermore, the rolling support element 33 has rolled another distance equal to one-eighth πr / 4 of the circumference of the rolling support element 33 along the support structure 2. Therefore, the movable element 10 has moved relative to the rolling support element 33 by a distance equal to half πr of the circumference of the rolling support element 33, and the rolling support element 33 has moved relative to the support structure 2 by a distance equal to one-quarter πr / 2 of its circumference. Thus, overall, the movable element 10 has moved relative to the support structure 2 by a distance equal to one and a half circumferences of the rolling support element 33.

[0126] The exemplary embodiment described above reduces the required size of the track or raceway formed by the first support surface 31 of the support structure 2 by 25%. However, it should be understood that by moving the plane containing the two contact points Y1, Y2 closer to the rotation center R of the rolling support element 33, the required size of the track and therefore the support structure 2 and thus the entire device 1 will be further reduced without impairing the range of motion of the movable element 10.

[0127] In some embodiments, the distance between the plane Y containing the two contact points Y1 and Y2 and the rotation center R is substantially within the range of 1% to 75% of the distance between the single contact point X1 and the rotation center R of the rolling support element 33. That is, the plane Y containing the two contact points Y1 and Y2 is located at a distance from the rotation center R that is less than 75% of the radius.

[0128] In some embodiments, the distance between the plane Y containing the two contact points Y1 and Y2 and the rotation center R is substantially within the range of 1% to 50% of the distance between the single contact point X1 and the rotation center R of the rolling support element 33. That is, the plane Y containing the two contact points Y1 and Y2 is located at a distance from the rotation center R that is less than 50% of the radius.

[0129] In some embodiments, the distance between the plane Y containing the two contact points Y1 and Y2 and the rotation center R is substantially within the range of 1% to 25% of the distance between the single contact point X1 and the rotation center R of the rolling support element 33. That is, the plane Y containing the two contact points Y1 and Y2 is located at a distance from the rotation center R that is less than 25% of the radius.

[0130] Figures 5a to 5cThe effect illustrated in the diagram (e.g., the movable element 10 moves a greater distance relative to the rolling support element 33 than the rolling support element 33 moves relative to the support structure 2) is also provided by a support device 30 in which the rolling support element 33 is located in two different recesses 35 (e.g., a first recess in a first support surface and a second recess in a second support surface that is shallower than the first recess). As described above, the effective radius of the rolling support element 33 relative to a particular recess can be defined as the distance between the axis of rotation of the rolling support element 33 and a line parallel to the axis of rotation that includes the contact point between the recess and the rolling support element. In this support device, the effective radius of the rolling support element relative to the second recess is reduced by a greater amount than the effective radius of the rolling support element relative to the second recess, thereby still providing the effect of... Figures 5a to 5c The adjustment is illustrated in the diagram. As will be understood, in this support device, each of the first and second support surfaces has two contact points with the rolling support element.

[0131] Now for reference Figure 6 The diagram shows a schematic top-down cross-sectional view of the shape memory alloy actuator 50. The shape memory alloy actuator 50 is substantially the same as the shape memory alloy actuator 1 described above, and therefore, a detailed description thereof will be omitted. Similarly, features of the shape memory alloy actuator 50 that are similar to those of the shape memory actuator 1 described above will retain their respective terminology and reference numerals.

[0132] The shape memory alloy actuation device 50 includes a support structure 2 and a movable element 10. The shape memory alloy actuation device 50 also includes a helical support device 20, which supports the movable element 10 on the support structure 2 and is arranged to guide the movable element 10 to move helically about the helical axis H relative to the support structure 2.

[0133] Reference Figure 6 The helical support device 20 includes a plurality of helical support members 30 (iv). The helical support members 30 are preferably related to the above-mentioned... Figures 2 to 5c The described helical support 30 is the same. However, they can also be another type of helical support 30.

[0134] Similar to the spiral support 30 described above, the spiral support 30i of this embodiment includes a first support surface 31 on one of the support structure 2 and the movable element 10, and a second support surface 32 on the other of the support structure 2 and the movable element 10. The first support surface 31 and the second support surface 32 extend spirally around a spiral axis H. That is, the first support surface 31 and the second support surface 32 form a raceway 39 extending spirally around the spiral axis H, the angle at which the raceway 39 extends relative to the spiral axis H being the helix angle α of the raceway 39. Figure 2 The optimal arrangement is shown in the diagram. Therefore, the raceway 39 extends within the helical support plane h. Additionally, each helical support member 30i includes a rolling support element 33 disposed between the support surfaces 31 and 32. Throughout its entire range of motion, at least one rolling support element 33 moves helically along the helical support plane h (i.e., the helical path around the helical axis H), the helical support plane being in... Figure 2 The clearest illustration is shown below. Therefore, the trajectory of the rotation center R of the rolling support element 33 is along the helical support plane h.

[0135] In this embodiment, the support structure 2 includes a first support surface 31. The first support surface 31 of the support structure 2 preferably includes a groove 35, as described above. Figures 1 to 5c As described. Furthermore, in this embodiment, the movable element 10 includes a second support surface 32. Preferably, the second support surface 32 of the movable element 10 is smooth.

[0136] It should be understood that, in alternative embodiments, the first support surface 31 of the support structure 2 may be smooth, and / or the second support surface 32 of the movable element 10 may include a groove 35, as described above. Alternatively, the first support surface 31 including the groove 35 may be located on the movable element 10, and / or the smooth second support surface 32 may be located on the support structure 2.

[0137] Reference Figure 6 At least one of the helical support members 30i has a second support surface 32 extending in the first plane A. Furthermore, at least one other helical support member 30ii has a second surface 32 extending in the second plane B. The second plane B extends at an angle to the first plane A. That is, the first plane A and the second plane B do not extend parallel to each other.

[0138] In some embodiments, plane A (in which the helical support 30i extends) is parallel to the helical axis H at any cross-sectional point along the helical axis H. That is, plane A is defined by a tangent extending from the contact point X1 between at least one support element 33 and the second support surface 32 on the movable element 10. In other words, the helical support 30i extends within the tangential plane of the contact point X1 between the rolling support element 33 and the movable element 10.

[0139] More specifically, the plane in which the helical support 30 extends is defined at any point along the helical axis H by a tangential plane (AE) containing the contact point X1 between the rolling support element 33 and the movable element 10. That is, the plane in which the second support surface 32 of the helical support 30 extends is defined at any point along the helical axis H by a tangential plane extending from the contact point X1 between at least one support element 33 and the second support surface 32 on either the support structure 2 or the movable element 10. Therefore, since the rolling support element 33 moves helically (i.e., vertically and circumferentially when the movable element 10 is actuated), the tangential plane A in which the helical support 30 extends will change as the position of the rolling support element 33 along the helical axis H changes.

[0140] Each of the plurality of helical support members 30 in the helical support device 20 extends helically about the helical axis H. Furthermore, as described above, each of the plurality of helical support members 30 includes a raceway 39 extending in the helical support plane h with a helix angle α. The helix angle α is the angle between the helical support plane h in which the raceway 39 extends and the helical axis H. In the embodiments described so far, each of the plurality of helical support members 30 extends in the helical support plane h having the same helix angle α.

[0141] Therefore, the first plane A and the second plane B do not extend parallel to each other at any point along the helical axis H (i.e., in any plane perpendicular to the helical axis H). In other words, the first plane A and the second plane B extend at an angle to each other at every point along the helical axis H in any given plane perpendicular to the helical axis H.

[0142] Preferably, the plane of the second support surface 32 of each of the spiral support members 30 extends at an angle to the plane of the second support surface 32 of each of the other spiral support members 30. Therefore, the second support surfaces 32 of the spiral support members 30 of the spiral support device 20 do not extend parallel to each other.

[0143] The helical support members 30 of the helical support device 20 may be evenly spaced around the helical axis H. Alternatively, the helical support members 30 of the helical support device 20 may be unevenly spaced around the helical axis H. The helical support device 20 preferably includes five helical support members 30i, 30ii, 30ii, 30iv, and 30v. Arranging the five helical support members 30 such that no two support members extend parallel to each other allows the movement of the movable element 10 to be constrained only to helical movement around the helical axis H. However, it should be understood that the support device 20 may include different numbers of helical support members 30.

[0144] In some embodiments, the rolling support elements 33 of each helical support 30 are located in the same plane orthogonal to the helical axis H, such as... Figure 6 As shown. However, it should be understood that in an alternative embodiment, the rolling support element 33 of at least one of the helical supports 30 is located in a plane orthogonal to the helical axis H, which is offset in the direction of the helical axis H relative to the plane in which the rolling support element 33 of at least one of the other helical supports 30 is located.

[0145] In some embodiments, at least one of the helical support members 30 may include a plurality of support elements 33. Furthermore, at least one rolling support element 33 of at least one of the helical support members 33 may include a rolling support member 33.

[0146] Now for reference Figures 7a to 7c A schematic cross-sectional side view of the actuation device 60 is shown. In this embodiment, the actuation device 60 is a shape memory alloy (SMA) actuation device. The shape memory alloy actuation device 60 is substantially the same as the shape memory alloy actuation devices 1 and 50 described above, and therefore, a detailed description thereof will be omitted. Similarly, features of the shape memory alloy actuation device 60 that are similar to those of the shape memory actuation devices 1 and 50 described above will retain their terminology and reference numerals.

[0147] The shape memory alloy actuation device 60 includes a support structure 2 and a movable element 10. The shape memory alloy actuation device 60 also includes a helical support device 20, which supports the movable element 10 on the support structure 2 and is arranged to guide the movable element 10 to move helically about the helical axis H relative to the support structure 2.

[0148] The support device 20 includes multiple support members 30a, 30b, and 30c, such as Figures 7a to 7c As shown. Figures 7a to 7c The illustrated support device includes three helical support members 30. The support members 30 are spaced apart at three of the four corners of the device 1. However, it should be understood that in alternative embodiments, the number of support members 30 and the spacing between each of them may be different.

[0149] Each support member 30 includes a raceway 39. The raceway 39 of the support member 30 is configured to define the range of motion of the movable element 10 relative to the support structure 2.

[0150] The raceway 39 includes a first support surface 31 on one of the support structure 2 and the movable element 10, and a second support surface 32 on the other of the support structure 2 and the movable element 10. In this embodiment, the first support surface 31 is on the support structure 2, and the second support surface 32 is located on the movable element 10. The first support surface 31 and the second support surface 32 can be as described above.

[0151] Each support member 30 includes a support element 33. The rolling support element 33 contacts a first support surface 31 on the support structure 2 and a second support surface 32 on the movable element 10.

[0152] Each raceway 39 includes a first end wall 61. The first end wall 61 is located at a critical point of the raceway 39. In this example, the first end wall 61 is located at the top end 63 of the raceway 39. Furthermore, the first end wall 61 is located on the support structure 2. The first end wall 61 may be integrally formed with the support structure 2.

[0153] Each raceway 39 may also include a second end wall 62. The second end wall 62 is located at another extreme point of the raceway 39. The second end wall 62 is located at the bottom end 64 of the raceway 39. In addition, the second end wall 62 is located on the support structure 2. The second end wall 62 may be integrally formed with the support structure 2.

[0154] It should be understood that, in alternative embodiments, the first end wall 61 and the second end wall 62 may alternatively or additionally be located on the movable element 10.

[0155] The rolling support element 33 spaces the movable element 10 from the support structure 2, and in particular, spaces the movable element 10 from the first end wall 61 and the second end wall 62. Therefore, there is a gap between the second support surface 32 of the movable element 10 and the end walls 61, 62 of the support structure 2.

[0156] The first end wall 61 and the second end wall 62 serve as stops for the rolling support element to prevent the rolling support element 33 from ejecting from the support member 30 in an impact scenario. As described above, the height of the SMA actuator device 1 is generally limited by the height of the movable element 10 and the stroke of the movable element 10. Therefore, when the movable element 10 moves to the limit of its range of motion, the movable element 10 extends beyond the support structure 2.

[0157] However, the movable element 10 must be large enough that the gap between the end of the movable element 10 that overlaps with the support structure 2 (i.e. the end that does not extend from the support structure 2) and the end of the raceway 39 on the support structure 2 is small enough to retain the rolling support element 33 in an impact scenario.

[0158] At least one of the plurality of support members 30 is offset relative to at least one of the other support members, such that the first end wall 61 of one of the plurality of support members is offset from the first end wall of at least one of the other support members in the direction of the helical axis.

[0159] Each of the plurality of support members 30 includes a support surface 32 on the second portion 10, the support surface having a normal vector extending thereto. If the normal vector has a component extending generally along or parallel to the helical axis H in a first direction (e.g., upward), the support member 30 is of the first type. If the normal vector has a component extending generally along or parallel to the helical axis H in a second direction opposite to the first direction (e.g., downward), the support member 30 is of the second type.

[0160] At least one support member 30 may be a first type of support member, and at least one other support member 30 may be a second type of support member. Furthermore, at least one support member 30 may be offset relative to at least one other support member 30 such that the first end wall 61 and / or the second end wall 62 are offset in a first direction if located on the first portion, and offset in a second direction if located on the second portion.

[0161] Reference Figure 7a and Figure 7c It can be seen that in the first raceway 39a and the third raceway 39c, the movable element 10 or the second part 10 is positioned above the support structure 2 in the direction of the helical axis H. Therefore, the normal component of the support surface 32 on the movable element 10 is downward along the helical axis H in the second direction. Therefore, the first support 30a and the third support 30c are of the second type. As a result, purely downward vertical movement of the movable element 10 relative to the support structure 2 is prevented. (Refer to...) Figure 7b As can be seen, in the second raceway 39b, the support structure 2 is positioned above the movable element 10 in the direction of the helical axis H, i.e., opposite to the first raceway 39a and the third raceway 39c. Therefore, the normal component of the support surface 32 on the movable element 10 is upward along the helical axis H in the first direction. Thus, the second support 30b is of the first type. As a result, purely upward vertical movement of the movable element relative to the support structure 2 is prevented.

[0162] Raceways 39a, 39b, and 39c extend at a certain angle to the helical axis H, which is called the helical support angle θ. Known raceways typically extend parallel to the helical axis H to allow movement between the movable element 10 and the support structure 2.

[0163] The advantage of extending the first raceway 39a and the third raceway 39c at a certain angle so that the movable element 10 is located above the support structure 2 is that when the movable element is at the bottom of its range of motion, the gap between the first end wall 61 of the support structure 2 and the end of the movable element 10 is smaller than that under the same conditions in the vertical raceway arrangement.

[0164] However, due to the inclination of the first raceway 39a and the third raceway 39c, when the movable element 10 is at the top of its range of motion, the gap between the second end wall 62 of the support structure 2 and the end of the movable element 10 is greater than the same condition in the vertical raceway.

[0165] The situation is exactly the opposite for the second raceway 39b. The advantage of extending the second raceway 39b at a certain angle so that the support structure 2 is located above the movable element 10 is that when the movable element is at the bottom of its range of motion, the gap between the second end wall 62 of the support structure 2 and the end of the movable element 10 is smaller than under the same conditions in the vertical raceway arrangement.

[0166] However, due to this inclination of the second raceway 39b, when the movable element 10 is at the top of its range of motion, the gap between the first end wall 61 of the support structure 2 and the end of the movable element 10 is greater than the same condition in the vertical raceway.

[0167] As in Figures 7a to 7c As shown, at least one 30b of the plurality of supports is offset relative to at least one 30a, 30c of the other plurality of supports, such that a first end wall 61b of one of the plurality of supports 30b extends in a plane spaced apart in the direction along the helical axis H from the plane in which the first end walls 61a, 61c of at least one of the other plurality of supports 30a, 30c extend.

[0168] Furthermore, at least one of the plurality of support members 30b is offset relative to at least one of the other support members 30a, 30c, such that the second end wall 62b of at least one of the plurality of support members 30b extends in a plane that is spaced apart in the direction along the helical axis H from the plane in which the second end walls 62a, 62c of at least one of the other support members 30a, 30c extend.

[0169] That is, each of the end walls 61, 62 may be substantially planar. The first end wall 61 and / or the second end wall 62 of at least one support member 30 may extend in a plane spaced apart from the planes extending from the first end wall 61 and / or the second end wall 62 of at least one other support member in the direction along the helical axis.

[0170] One of the portions (e.g., first portion 2) may include each of the first end wall 61 and the second end wall 62. For each of the plurality of support members 30, another portion (e.g., second portion 10) may include a support surface whose extension along the helical axis H corresponds to the extension of portion 10 along the helical axis H.

[0171] By offsetting at least one of the helical supports 30b relative to at least one of the other helical supports 30a, 30c, the gap 65 between the movable element 10 and the first end wall 61 or the second end wall 62 can be reduced. Furthermore, offsetting the supports 30 means that the overall height of the movable element 10 does not need to be increased, and therefore the overall size of the device 1 can be reduced.

[0172] like Figure 7a and Figure 7c As shown, the raceways 39a and 39c on the support structure 2 are moved downward along the direction of the helical axis H, and as... Figure 7b As shown, the raceway 39b on the support structure 2 is moved upward along the direction of the helical axis H, which will be explained in more detail below. This reduces the likelihood that the rolling support element 33 will escape from the raceway 39 through the gap 65 during impact. Furthermore, by offsetting the raceway 39, the gap 65 generated at either extreme point of the raceway 39 can be made to have the same size. Therefore, the probability that the support element 33 will escape from one raceway 39 is no greater than that of the other raceway 39. Therefore, it is preferable that each raceway 39 is offset upward or downward by the same amount compared to a vertical arrangement, so that equal gap sizes are achieved at both ends of each raceway 39 when the movable element 10 is at the top or bottom of its range of motion.

[0173] For a support member 30 having a first part 2 or support structure including a first end wall 61 and / or a second end wall 62, when the second part 10 or movable element is at one extreme point of its range of motion, the gap 65 between the movable element 10 and the end walls 61, 62 at the other extreme point of the raceway 39 is smaller than the diameter of the support element 33 of the support member 30.

[0174] Furthermore, for a support 30 having a second portion 10 or a movable element including a first end wall 61 and / or a second end wall 62, when the movable element 10 is at an extreme point of its range of motion, the gap 65 between the first portion 2 or support structure and the end walls 61, 62 at the same extreme point of the raceway 39 is smaller than the diameter of the support element 33 of the support 30.

[0175] In other words, the raceway 39 is configured such that when the movable element 10 is at one extreme point of its range of motion, at the opposite end of the raceway 39 to the movable element 10, the gap 65 between the movable element and one of the end walls 61, 62 of the raceway 39 is smaller than the diameter of the rolling support element 33. Furthermore, when the movable element 10 is at one extreme point of its range of motion, the gap 65 between the movable element 10 and the end walls 61, 62 at the other extreme point of the raceway 39 should be substantially smaller than the diameter of the rolling support element 33 in order to maintain contact between the movable element 10 and the rolling support element 33. Preferably, for each support 30 and each extreme point of its range of motion, the gap is less than 2rcos(θ / 2), where θ is the angle between the end wall and one of the support structures or movable elements moving relative to the end walls 61, 62, and r is the radius of the rolling support element.

[0176] As previously stated, for the at least one support member 30 and / or the at least one other support member 30, the gap 65 at one extreme point of its range of motion is substantially the same as the gap 65 at the other extreme point of its range of motion.

[0177] Contact between the movable element 10 and the rolling support element 33 is desirable because if there is no contact, the movable element 10 is no longer constrained by the support element 30 and may tilt. Tilt of the movable element 10 may cause other problems in the SMA actuator device 1, such as damage to the precision parts of the device 1 during an impact scenario.

[0178] Figures 7a to 7c The schematic diagram shows the movable element 10 at the lower limit point of its range. However, the rolling support element 33 is shown at the top of the raceway 39 to illustrate that the rolling support element 33 is too large to pass through the gap between the movable element 10 and the first end wall 61 (or the second end wall 62).

[0179] Now for reference Figures 8a to 8c A schematic side view of the actuation device 70 is shown. In this embodiment, the actuation device 70 is a shape memory alloy actuation device. The shape memory alloy actuation device 70 is substantially the same as the shape memory alloy actuation devices 1, 50, and 60 described above, and therefore, a detailed description thereof will be omitted. Similarly, features of the shape memory alloy actuation device 70 that are similar to those of the shape memory actuation devices 1, 50, and 60 described above will retain their respective terminology and reference numerals.

[0180] The shape memory alloy actuator 70 includes a support structure 2 (such as...) Figure 1 (as shown), movable element 10, which is configured to move helically about the helical axis H relative to the support structure 2.

[0181] The shape memory alloy actuation device 70 also includes at least one shape memory alloy wire 71. The at least one shape memory alloy wire 71 is connected between the static connector 72 on the support structure 2 and the movable connector 73 on the movable element 10.

[0182] like Figure 8a As illustrated in the diagram, when the movable element 10 is in its intermediate position, the movable connector 73 is offset from the static connector 72, such that at least one segment of shape memory alloy wire 71 extends at an acute angle to a plane orthogonal to the helical axis H. The movable connector 73 is positioned closer to the center of the support structure 2 in the direction of the helical axis H than the static connector 72. That is, the movable connector 73 is offset toward the center of the support structure 2 in the direction of the helical axis H. Therefore, when the movable element 10 is in its intermediate position, the movable connector 73 is located below the static connector 72 along the helical axis H.

[0183] That is, the static connector 72 and the movable connector 73 are positioned toward the first end of the support structure 2 and the first end of the movable element 10, respectively. The first (e.g., upper) end of the support structure 2 and the first (e.g., upper) end of the movable element 10 define the maximum extension range of the support structure 2 and the movable element 10 in a first direction along the helical axis H. When the movable element 10 is in its intermediate position, the movable connector 73 is offset from the static connector 72 in the opposite second direction along the helical axis H.

[0184] The movable element 10 also includes an end surface 75. The end surface 75 includes a recessed portion 76. The movable connector 73 is attached to the recessed portion 76 of the movable element 10. Therefore, when the movable element 10 is in its intermediate position, the movable connector 73 is offset from the static connector 72 in the direction of the helical axis H.

[0185] Furthermore, the movable connector 73 is offset such that when the movable element 10 moves to the limit of its range of motion, the movable connector 73 will not move along the helical axis to substantially exceed the static connector 72 on the support structure 2.

[0186] The shape memory alloy actuation device 70 includes at least one spring arm 77. The spring arm 77 is attached to a movable element 10 at one end 81. The spring arm 77 is attached to a support structure 2 at the other end 82. The spring arm 77 extends between its ends about a helical axis H. The spring arm 77 may extend in an arc shape about the helical axis H.

[0187] Additionally, the spring arm 77 is connected to the movable connector 73 via a connecting section that connects to the end of the movable part 10. Furthermore, the spring arm 77 includes a torsion section 78. Preferably, the torsion section 78 of the spring arm 77 is located near the movable element end 81 of the spring arm 77. The spring arm 77 is connected to the movable connector 73 via the connecting section and the torsion section connected to the end of the movable element 10.

[0188] The torsion section 78 is configured to offset the movable connector 73 relative to the static connector 72. That is, the spring arm 77 is torn toward the center of the support structure 2 in the direction of the helical axis H. Therefore, the torsion section 78 offsets the movable connector 73 relative to the static connector 72.

[0189] The spring arm 77, the connecting section, and the torsion section 78 can be integrated. Preferably, each connector 72, 73 is a crimping member.

[0190] The torsion section 78 of the spring arm 77 is configured such that when the movable element 10 moves to the limit of its range of motion, as Figure 8b and Figure 8c As shown, the movable connector 73 will not move beyond the static connector 72 on the support structure 2. That is, when the movable element 10 moves to the limit of its range, the movable connector 73 will not move completely beyond the static connector 72.

[0191] The description of the shape memory alloy actuation device 70 involves a single segment of SMA line 71a connecting a single static connector 72a and a single movable connector 73a, the SMA line being arranged on one side (e.g., the upper side) of the device 70. That is, a static connector 72a on the upper surface of the support structure 2 and a movable connector 73a on the upper surface of the movable element 10. However, the arrangement on one side of the device 70 may itself only enable movement of the movable element 10 away from its intermediate position in one direction.

[0192] Therefore, the second arrangement of SMA line 71b is connected between the static connector 72b and the movable connector 73b on the opposite side (e.g., the lower side) of the device 70.

[0193] That is, at least one length segment of the SMA line 71 includes a first length segment 71a and a second length segment 72a of the SMA line 71. The static connector 72 and the movable connector 73 of the first length segment of the SMA line 71 are positioned toward the first (e.g., upper) end of the support structure 2 and the movable element 10, respectively. When the movable element 10 is in its intermediate position, the movable connector 73 of the first length segment 71a of the SMA line 71 is offset from the static connector 72 of the first length segment 71a of the SMA line 71 in a second direction.

[0194] The static connector 72 and the movable connector 73 of the second length segment 71b of the SMA line 71 are positioned toward the second (e.g., lower) ends of the support structure 2 and the movable element 10, respectively. The second ends of the support structure 2 and the movable element 10 define the maximum extension range of the support structure 2 and the movable element 10 in a second direction about a helical axis H. When the movable element 10 is in its intermediate position, the movable connector 73 of the second length segment 71b of the SMA line 71 is offset from the static connector 72 of the second length segment 71b of the SMA line 71 in a first direction.

[0195] It should be understood that the first length segment 71a and the second length segment 71b of the SMA line 71 may be spaced apart from each other along the helical axis. The first length segment 71a and the second length segment 71b of the SMA line 71 may be configured to apply torque to the movable element 10 in opposite directions around the helical axis H.

[0196] Brief Reference Figure 8b This illustrates the lowest limit point of the movable element 10's movement within its range. In this position, the upper movable connector 73a moves downwards away from the upper static connector 72a, and the lower movable connector 73b moves downwards toward the lower static connector 72b. When the movable element 10 is in its lowest position, the lower movable connector 73b and the lower static connector 72b are in the same plane extending perpendicular to the helical axis H.

[0197] Brief Reference Figure 8c The diagram shows the highest limit point of the movable element 10's movement within its range. In this position, the upper movable connector 73a moves upward toward the upper static connector 72a, and the lower movable connector 73b moves upward away from the lower static connector 72b. When the movable element 10 is in its highest position, the upper movable connector 73b and the upper static connector 72b are in the same plane extending perpendicular to the helical axis H.

[0198] Therefore, since the range of motion of the movable connector 73 does not extend beyond the static connector 72 located on the upper surface of the structural support 2, the required height of the device 70 is reduced because the movable connector 73 moves away from the center of the support structure 2 in the direction of the helical axis H as far as the static connector 72 moves away from the center of the support structure 2.

[0199] The movable element 10 also includes a helical surface 86. The helical surface 86 is configured to allow the movable element 10 to move relative to the support structure 2 without the spring arm 77 contacting the movable element 10 throughout its travel length.

[0200] At least one spring arm 77 may include a first spring arm 77a and a second spring arm 77b. The movable element 10 may include corresponding first helical surfaces 86a and 86b. The first helical surfaces 86a and 86b may form a portion of a first end and a second end of the movable element 10. The first end may define the maximum extension range of the movable element 10 in a first direction along the helical axis, and the second end may define the maximum extension range of the movable element 10 in a second direction opposite to the helical axis H.

[0201] That is, the upper helical surface 86a can be configured such that when the movable element 10 is in its highest position, the upper helical surface 86a extends parallel to the spring arm 77a. The lower helical surface 86b can be configured such that when the movable element 10 is in its lowest position, the lower helical surface 86b extends parallel to the spring arm 77b. In some embodiments, when the movable element 10 is at a limit point of its range of motion, the spring arm 77 can contact the helical surface 86.

[0202] The helical surface 86 can extend to the inner periphery of the movable element 10. Therefore, the area on the inner surface of the movable element 10 can be maximized, which is advantageous, for example, for attaching a lens thereto.

[0203] Furthermore, the movable connector 73 is attached to the movable element 10 such that when the movable element 10 is in its intermediate position, the movable connector 73 is as close as possible to the static connector 72, while when the movable element 10 is at one of its extreme points, the movable connector 73 does not cross the static connector 72. Therefore, the movable connector 73 sweeps across as small an area as possible, allowing a larger area of ​​the movable element 10 to be used for attaching devices (such as lenses) to the movable element 10.

[0204] Now for reference Figure 9 A schematic cross-sectional side view of the actuating device 90 is shown. In this embodiment, the actuating device 90 is a shape memory alloy actuating device. The shape memory alloy actuating device 90 is substantially the same as the shape memory alloy actuating devices 1, 50, 60, and 70 described above, therefore, detailed descriptions thereof are omitted. Similarly, features of the shape memory alloy actuating device 90 that are similar to those of the shape memory actuating devices 1, 50, 60, and 70 described above will retain their respective terminology and reference numerals.

[0205] The shape memory alloy actuator 90 includes a support structure 2 and a movable element 10 (in Figure 1 (shown in the figure), and a helical support device 20 that supports the movable element 10 on the support structure 2 and is arranged to guide the helical movement of the movable element 10 relative to the support structure 2 about the helical axis H.

[0206] The shape memory alloy actuator 90 also includes a first length segment 71a of the SMA line 71 of the support structure 2, which is connected to the first corner of the actuator 90 (e.g., on the left side of the figure) via a first static connector 72a. The first length segment 71a of the SMA line 71 is also connected to the movable element 10 via a first movable connector 73a at the second corner of the actuator 90 (e.g., on the right side of the figure).

[0207] The shape memory alloy actuation device 90 also includes a second length segment 71b of an SMA wire 71, which is connected to a support structure via a second static connector 72b at a second corner of the actuation device 90 and to a movable element 10 via a second movable connector 73b at a first corner of the actuation device 90. The second length segment 71b of the SMA wire 71 is spaced apart from the first length segment 71a of the SMA wire 71 in a first direction along the helical axis H (e.g., downward in this example).

[0208] The first length segment 71a of the SMA line 71 can drive the movable element 10 to rotate about the helical axis H in a first direction (e.g., clockwise) relative to the support structure 2, and the second length segment 71b of the SMA line 71 can drive the movable element 10 to rotate about the helical axis H in the opposite second direction (e.g., counterclockwise) relative to the support structure 2.

[0209] The support structure 2 or the movable element 10, or each of the support structure 2 and the movable element 10, includes a side portion between the first corner and the second corner, which generally extends in a plane oriented at an acute angle to a plane orthogonal to the helical axis H.

[0210] The side portion can be positioned between the first length segment 71a and the second length segment 71b of the SMA line 71, at least at the extreme points of the movement range of the movable element 10. This allows for a reduction in the xy-area footprint of the actuator assembly. The angled structure of the support structure 2 and / or the movable element 10 ensures that the movement of the first length segment 71a and the second length segment 71b of the SMA line 71 is unimpeded at the extreme points of the movement range of the movable element 10.

[0211] The angled support structure 2 allows for the use of more material, which in turn makes the support structure 2 more rigid and reliable. Furthermore, by angled the support structure 2, the space between the static connectors 72a and 72b can be maximized without hindering the movement of the movable connectors 73a and 73b. For example, when the movable part 10 is in… Figure 9 When the movable part 10 moves upward (e.g., when the first length segment 71a retracts), the support structure 2 does not impede the movement of the movable connector 73b. Figure 9 When the middle moves downward (e.g., when the second length segment 71b retracts), the support structure 2 does not impede the movement of the movable connector 73a.

[0212] A plane extending at an acute angle to a plane orthogonal to the helical axis H can extend in a first direction from a first corner of the actuator 90 (e.g., downward from left to right) to a second corner.

[0213] The side portion includes a generally planar surface that extends parallel to a length segment of the SMA line 71 (whether it is the first length segment 71a or the second length segment 71b of the SMA line 71) when the movable element 10 is at a limit point of its range of motion.

[0214] Preferably, as described throughout the description, the actuation device is a shape memory alloy actuator device, although this disclosure is not limited thereto.

[0215] In all the examples above, the SMA actuator lines are driven by control circuitry implemented in IC chip 5. Specifically, the control circuitry generates a drive signal for each SMA actuator line and provides the drive signal to the SMA actuator line. The control circuitry receives an input signal representing the desired position of the movable element 10 along the optical axis O and generates a drive signal selected to drive the movable element 10 to the desired position. The drive signal can be generated using a resistive feedback control technique, in which the control circuitry measures the resistance of a length segment of the SMA actuator line and uses the measured resistance as a feedback signal to control the power of the drive signal.

[0216] This resistive feedback control technique can be implemented as disclosed in any of WO 2013 / 175197, WO 2014 / 076463, WO 2012 / 066285, WO 2012 / 020212, WO 2011 / 104518, WO 2012 / 038703, WO 2010 / 089529 or WO 2010 / 029316, each of which is incorporated herein by reference.

[0217] Alternatively, the control circuit may include a sensor that senses the position of the movable element 10, such as a Hall sensor that senses the position of a magnet fixed to the movable element 10. In this case, the drive signal uses the sensed position as a feedback signal to control the power of the drive signal.

[0218] Those skilled in the art will understand that, although the foregoing has described what is considered the best mode for carrying out this technology and other modes for carrying out this technology where appropriate, this technology should not be limited to the specific configurations and methods of the preferred embodiments disclosed in this specification. Those skilled in the art will recognize that this technology has a wide range of applications and that embodiments can be modified extensively without departing from any inventive concept defined by the appended claims.

[0219] The actuation device can be any type of actuator that includes a first part and a second part that is movable relative to the first part.

[0220] The actuation device is not necessarily an SMA actuation device, but can be a voice coil motor (VCM) actuation device or any other type of actuation device.

[0221] The actuation device can be any of the following devices or can be provided in any of the following devices: smartphone, protective cover or case for smartphone, functional cover or case for smartphone or electronic device, camera, foldable smartphone, foldable smartphone camera, foldable consumer electronic device, camera with foldable optics, image capture device, array camera, 3D sensing device or system, servo motor, consumer electronic device (including home appliances such as vacuum cleaners, washing machines, and lawnmowers), mobile or portable computing device, mobile or portable electronic device, laptop, tablet computing device, e-reader (also known as e-book device), computing accessory or computing peripheral (e.g., mouse, keyboard, headphones, handset, etc.), audio device (e.g., headphones, headset, handset, etc.), security The list includes: full systems, gaming systems, gaming accessories (e.g., controllers, headsets, wearable controllers, joysticks, etc.), robots or robotic devices, medical devices (e.g., endoscopes), augmented reality systems, augmented reality devices, virtual reality systems, virtual reality devices, wearable devices (e.g., watches, smartwatches, fitness trackers, etc.), drones (aerial, waterborne, underwater, etc.), aircraft, spacecraft, submersibles, vehicles and autonomous vehicles (e.g., driverless cars), tools, surgical instruments, remote controls (e.g., for drones or consumer electronics), clothing (e.g., garments, shoes, etc.), switches, dials or buttons (e.g., light switches, thermostat dials, etc.), displays, touchscreens, flexible surfaces, and wireless communication devices (e.g., near field communication (NFC) devices). It should be understood that this is a non-exhaustive list of exemplary devices.

[0222] The actuation devices described herein can be used in applications suitable for image capture, 3D sensing, depth mapping, aerial surveying, land surveying, surveying in or from space, hydrography, underwater surveying, scene detection, collision warning, security, facial recognition, augmented and / or virtual reality, advanced driver assistance systems in vehicles, autonomous vehicles, gaming, gesture control / recognition, robotic devices, robotic device control, contactless technology, home automation, medical devices, and tactile devices / systems.

Claims

1. An actuating device, comprising: Part One; Part Two; as well as A support device that supports the second part on the first part and is arranged to guide the movement of the second part relative to the first part; The support device includes a total of three or more support members, each support member including a first support surface on the first portion and a second support surface on the second portion and including a rolling support element, the rolling support element being configured to be disposed between the first support surface and the second support surface such that the first support surface and the second support surface are spaced apart by a gap; Wherein, one of the first support surface and the second support surface is configured such that the support surface has at least one contact point with the rolling support element at any time, and the other of the first support surface and the second support surface is configured such that the support surface has two contact points with the rolling support element at any time; The two contact points of the first support surface or the second support surface are positioned closer to the axis of rotation of the rolling support element than at least one contact point of the other of the first support surface or the second support surface, such that the rolling support element moves a different distance relative to the first portion than the second portion moves a different distance relative to the rolling support element. The first support surface in the first portion includes a groove in the surface of the first portion, and the first support surface in the first portion is configured such that the first support surface includes the two contact points with the rolling support element, wherein the groove includes a first surface and a second surface that is not parallel to the first surface, and the first surface of the groove extends at an acute angle to the second surface of the groove.

2. The actuation device according to claim 1, wherein, The at least one contact point is located on a first line extending parallel to the axis of rotation, and the two contact points are located on a second line extending parallel to the axis of rotation.

3. The actuation device according to claim 2, wherein, The distance between the second line and the axis of rotation is substantially in the range of 1% to 50% of the distance between the first line and the axis of rotation.

4. The actuation device according to claim 3, wherein, The distance between the second line and the axis of rotation is substantially in the range of 1% to 25% of the distance between the first line and the axis of rotation.

5. The actuation device according to any one of the preceding claims, wherein, The support device is a helical support device, which is arranged to guide the second part to move helically relative to the first part about a helical axis, and each of the three or more support members is a helical support member.

6. The actuation device according to claim 5, wherein, The helical support device comprises a total of five helical support members, wherein each helical support member includes only one rolling support element, and wherein a support surface of each helical support member has a single contact point with the rolling support element at any given time.

7. The actuation device according to claim 6, wherein, At any point within the helical movement range of the second part relative to the first part, a support surface of each helical support extends in a plane that is different from and not parallel to the plane in which a support surface of each other helical support extends, wherein the plane in which the helical support extends is defined as a plane parallel to the helical axis and tangent to the support surface at the contact point.

8. The actuation device according to any one of claims 5 to 7, wherein, The helical support members are spaced apart around the helical axis.

9. The actuation device according to any one of claims 5 to 8, wherein, At least at the limit point of the helical movement of the second part relative to the first part, the rolling support element of each helical support is located in the same plane orthogonal to the helical axis.

10. The actuation device according to claim 5, wherein, At least one of the spiral support members includes a plurality of rolling support elements.

11. The actuation device according to claim 1, wherein, The first surface forms a first edge with the surface of the first portion, and the second surface forms a second edge with the surface of the first portion.

12. The actuation device according to claim 11, wherein, The angle formed between the surface of the first portion and the first surface of the groove is the same as the angle formed between the inner surface of the first portion and the second surface of the groove, such that the cross-section of the groove is symmetrical.

13. The actuation device according to claim 12, wherein, The groove has a cross-section that is substantially an isosceles trapezoid.

14. The actuation device according to any one of claims 11 to 13, wherein, The distance between the first edge and the second edge is greater than the diameter of the rolling support, and one of the two contact points is located on the first surface of the groove and the other of the two contact points is located on the second surface of the groove.

15. The actuation device according to any one of claims 11 to 13, wherein, The distance between the first edge and the second edge is less than the diameter of the rolling support, and the two contact points are located on the first edge and the second edge of the groove.

16. The actuation device according to any one of the preceding claims, wherein, The second support surface in the second portion is configured such that the second support surface includes at least one contact point with the rolling support element, wherein the at least one contact point is a single contact point.

17. The actuation device according to claim 16, wherein, The second support surface includes a smooth surface.

18. The actuation device according to any one of the preceding claims, wherein, The actuation device is a shape memory alloy actuator.

19. A camera system comprising: The actuating device according to any one of the preceding claims Image sensors, and Lens system, The lens system is mounted on one of the first part and the second part, and The image sensor is mounted in another of the first and second parts.

Images