Flex Hinge Actuator Assembly

Abstract

Embodiments of the present invention relate to a flex hinge actuator. This actuator comprises a base and a moving carriage configured to move in a certain direction (e.g., the X direction). The flex hinge assembly comprises a structure positioned on multiple sides (e.g., two sides or four sides). The structure of the flex hinge assembly restricts unfavorable movement of the moving carriage by restricting it from moving in directions other than the Z direction. The actuator described herein may have a simple structure that restricts tilt in pitch and yaw during Z-direction movement of the payload. This actuator can move the carriage up and down (or in the Z direction) by pressing on the side(s) of the structure.

Description

Technical Field

[0001] The present invention generally relates to an actuator. More specifically, it relates to an actuator provided with a flexure hinge assembly for restricting unwanted movement of the actuator.

Background Art

[0002] (Cross-reference to related applications) This application claims the benefit and priority of U.S. Provisional Application No. 63 / 530,825, filed on August 4, 2023, and U.S. Patent Application No. 18 / 787,919, filed on July 29, 2024, the contents of which are hereby incorporated by reference in their entirety.

[0003] Actuators can be used in various contexts. For example, an actuator may be used to move a lens back and forth (translate) to focus the lens as part of an autofocus system. Often, it may be desirable to move components that move in a desired direction (e.g., the Z direction) to increase the efficiency of implementing such an autofocus system.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in many actuator designs, moving components may move in directions other than the desired direction (e.g., pitch, yaw, roll). Such undesirable movements (motions) cause stress on the actuator, for example, by applying unwanted torque or out-of-plane bending forces to it. Therefore, during the movement of the payload in the Z-direction, it is desirable to have an actuator design that constrains unwanted movements (e.g., tilt in pitch and yaw). [Means for solving the problem]

[0006] Embodiments of the present invention relate to a flex hinge actuator. The actuator may comprise a base and a movable carriage configured to move in a certain direction (e.g., the Z direction). The flex hinge assembly may comprise a structure positioned on multiple sides (e.g., two sides, four sides). The structure of the flex hinge assembly is made capable of restricting adverse motion (unwanted movement) of the movable carriage by restricting its movement (movement, motion, action, motion) in directions other than the Z direction. The actuator described herein may comprise a simple structure that restricts tilt, pitch, and yaw during Z-direction movement of the payload. The actuator can move the carriage up and down (or in the Z direction) by pressing on the side(s) of the structure.

[0007] In an example of the first embodiment, a flex hinge actuator is provided. The flex hinge actuator may comprise a static base and a movable carriage configured to move in the Z direction relative to the static base. The flex hinge actuator may also comprise a flex hinge assembly. The flex hinge assembly is configured to allow the movable carriage to move in the Z direction while restricting movement in other directions. The flex hinge assembly may comprise at least two flex hinge structures located on corresponding sides of the flex hinge actuator.

[0008] In some cases, the flex hinge assembly includes flex hinge structures positioned on each of the four sides of the flex hinge actuator. In some cases, each flex hinge structure comprises a first link and a second link. The first link is connected to the static base at a first hinge joint and to the second link at a second hinge joint. The second link is connected to the movable carriage at a third hinge joint. In some cases, one of the first, second, or third hinge joints may be a flexible metal hinge.

[0009] In some cases, each flex hinge structure may further include at least one link connecting a moving carriage to the flex hinge structure, and a bimorph actuator configured to push that at least one link. The bimorph actuator may comprise a beam having a first end fixed to the flex hinge structure and a second end having a free end. The movement of the free end is configured to push at least one link. In some cases, the bimorph actuator may further comprise a shape memory alloy (SMA) material pre-placed along the beam between the fixed and free ends of the beam.

[0010] In some cases, the flex hinge structure may include at least a first flex hinge structure oriented in a first direction and a second flex hinge structure oriented in a second direction opposite to the first direction.

[0011] In some cases, the flex hinge actuator may further include a lens connected to the moving carriage, an outer housing, and four bimorph actuators. These four bimorph actuators, located in the outer housing, provide movement of the moving carriage in the X / Y directions.

[0012] In some cases, the flex hinge actuator may further include a cover mounted on part of the moving carriage and the external housing. The cover includes end stops to restrict the moving carriage from moving beyond a predetermined stroke range.

[0013] In some cases, the flex hinge actuator may further include an image sensor assembly positioned beneath the flex hinge assembly, and a flexible sensor circuit connected to both the flex hinge assembly and the image sensor assembly.

[0014] In an example of another embodiment, a device is provided. The device may comprise a static base and a movable carriage configured to move in the Z direction relative to the static base. The device may also comprise a flex hinge assembly. The flex hinge assembly is configured to allow the movable carriage to move in the Z direction while restricting movement in other directions. The flex hinge assembly may comprise at least two flex hinge structures positioned on corresponding sides of a flex hinge actuator. Each flex hinge structure may comprise a first link and a second link. The first link is connected to the static base at a first hinge joint and to the second link at a second hinge joint. The second link is connected to the movable carriage at a third hinge joint.

[0015] In some cases, the device may further include a bimorph actuator configured to push a first link of each flex hinge structure. The bimorph actuator comprises a beam, which has a first end fixed to the flex hinge structure and a second end with a free end. The movement of the free end is configured to push at least one link. The bimorph actuator may further include a shape memory alloy (SMA) material positioned along the beam between the fixed and free ends.

[0016] In some cases, the flex hinge structure may include at least a first flex hinge structure oriented in a first direction and a second flex hinge structure oriented in a second direction opposite to the first direction.

[0017] In some cases, the device may further include a lens connected to the moving carriage, an external housing, and four bimorph actuators. These four bimorph actuators are located in the external housing and provide movement of the moving carriage in the X / Y directions.

[0018] In some cases, the device may further include a cover mounted on part of the moving carriage and the external housing. The cover includes an end stop to restrict the moving carriage from moving beyond a predetermined stroke range.

[0019] In some cases, the device may further include an image sensor assembly positioned beneath the flex hinge assembly, and a flexible sensor circuit connected to both the flex hinge assembly and the image sensor assembly.

[0020] In another embodiment, an actuator is provided. The actuator may comprise a static base, a movable carriage configured to move relative to the static base, and a flex hinge assembly configured to allow the movable carriage to move in a first direction while restricting movement in other directions. The flex hinge assembly may comprise four flex hinge structures positioned on each side of the flex hinge actuator.

[0021] In some cases, each flex hinge assembly comprises a first link and a second link. The first link is connected to the static base at a first hinge joint and to the second link at a second hinge joint. The second link may be connected to the movable carriage at a third hinge joint.

[0022] In some cases, the actuator further comprises a lens connected to the moving carriage, an external housing, and four bimorph actuators. These four bimorph actuators are located in the external housing to provide movement of the moving carriage in the X / Y directions. The actuator also includes a cover mounted on part of the moving carriage and the external housing. The cover includes end stops to restrict the moving carriage from moving beyond a predetermined stroke range.

[0023] In some cases, the actuator may include an external housing, four bimorph actuators, an image sensor assembly disposed under the flexure hinge assembly, and a flexible sensor circuit connected to the flexure hinge assembly and the image sensor assembly. Each of the four bimorph actuators is disposed in the external housing to provide movement of the moving carriage in the X / Y directions.

[0024] Other features and advantages of embodiments of the present invention will become apparent from the accompanying drawings and the following detailed description. Embodiments of the present invention are illustrative and not restrictive, and are shown in the figures of the accompanying drawings, with like elements being given the same reference numerals.

Brief Description of the Drawings

[0025] [Figure 1] Examples of two-sided flexure hinge assembly actuators according to some embodiments are shown. [Figure 2] Examples of four-sided flexure hinge actuators according to some embodiments are shown. [Figure 3A] Various views of a two-sided flexure hinge actuator with a pivot hinge according to some embodiments are shown. [Figure 3B-3C] Various views of a two-sided flexure hinge actuator with a pivot hinge according to some embodiments are shown. [Figure 4A] A view of a two-sided flexure hinge actuator assembly according to some embodiments is shown. [Figure 4B] A view of a two-sided flexure hinge actuator assembly according to some embodiments is shown. [Figure 4C] A view of a two-sided flexure hinge actuator assembly according to some embodiments is shown. [Figure 4D]The image shows two-sided views of a flex hinge actuator assembly according to several embodiments. [Figure 5A] The image shows four-sided views of a flex hinge actuator assembly according to several embodiments. [Figures 5B-5D] The image shows four-sided views of a flex hinge actuator assembly according to several embodiments. [Figure 6] Examples of actuators configured to move in the Z direction are shown according to several embodiments. [Figure 7A] This shows illustrative views of a flex hinge according to several embodiments. [Figure 7B] This shows illustrative views of a flex hinge according to several embodiments. [Figure 8A] This shows a flex hinge actuator as part of an autofocus system, according to several embodiments. [Figure 8B] This shows a flex hinge actuator as part of an autofocus system, according to several embodiments. [Figure 9A] The image shows views of a flex hinge lens shift actuator according to several embodiments. [Figure 9B] The image shows views of a flex hinge lens shift actuator according to several embodiments. [Figure 10A] This document shows an example of a flexible hinge sensor-shift actuator equipped with both optical image stabilization (OIS) and autofocus (AF), according to several embodiments. [Figure 10B] This document shows an example of a flexible hinge sensor-shift actuator equipped with both optical image stabilization (OIS) and autofocus (AF), according to several embodiments. [Figure 11A] A top view of an actuator with X / Y movement and Z movement according to several embodiments. [Figure 11B]Isometric projection of an actuator with X / Y movement and Z movement according to several embodiments. [Figure 12] Examples of actuators with a W force index, according to several embodiments, are shown. [Figure 13] This shows the representation of forces applied to an actuator according to several embodiments. [Figure 14A] Examples of actuators showing simulated results for inputs and outputs according to several embodiments are provided. [Figure 14B] Examples of actuators showing simulated results for inputs and outputs according to several embodiments are provided. [Figure 15A] This shows a view of a prior art bimorph actuator that may be used in the embodiments described herein. [Figure 15B] This shows a view of a prior art bimorph actuator that may be used in the embodiments described herein. [Figure 15C] This shows a view of a prior art bimorph actuator that may be used in the embodiments described herein. [Modes for carrying out the invention]

[0026] Embodiments of the present invention relate to a flex hinge actuator. The actuator may comprise a base and a moving carriage configured to move in a predetermined direction (e.g., the Z direction). The flex hinge assembly may comprise a structure arranged on multiple faces (e.g., two or four faces). The structure of the flex hinge assembly is made possible by restricting undesirable movements of the moving carriage (e.g., in the X, Y, or pitch, yaw, roll, etc.) by restricting the moving carriage from moving in directions other than the Z direction. The actuator described herein may comprise a simple structure that restricts tilt with pitch and yaw during Z-direction movement of the payload. The actuator can move the carriage up and down (or in the Z direction) by pushing the sides of the structure.

[0027] In some cases, a flex hinge actuator may have a multi-face (e.g., two or more faces) hinge link structure (e.g., three hinges and two links on each face of the actuator). A two-face flex hinge assembly may have a minimum number of components to control the Z-direction movement of the payload. Both hinge link structures can be designed to allow Z-direction movement of the moving carriage while minimizing other degrees of freedom (X, Y, pitch, yaw, roll).

[0028] In some cases, when applying force to move in the Z direction, an unbalanced force can act on the hinge, resulting in undesirable motion (adverse motion) due to torsional torque or out-of-plane bending forces. This undesirable motion may include unwanted movements such as translational motion of the moving carriage in the X and Y directions, or tilt across all three axes of movement. The hinge stiffness and the actuator's pushing position in the actuator design can minimize this undesirable motion.

[0029] Figure 1 shows an exemplary two-sided flexible hinge assembly actuator (100). As shown in Figure 1, the actuator 100 may comprise a static (stationary) base 102, a movable carriage 104, and hinge link structures 106A, 106B. The movable carriage 104 may be configured to move relative to the static base 102 (in the direction of the arrows shown in Figure 1). Furthermore, the movable carriage 104 may be circular and configured to accept a lens.

[0030] The hinge link structures 106A and 106B allow movement of the movable carriage 104 in the Z direction while minimizing movement in other directions. Each hinge link structure (e.g., 106A, 106B) may include a lower link connected to the static base 102 and an upper link connecting the base portion to the movable carriage 104. As detailed below, the hinge link structures 106A and 106B may include hinges to move and stabilize the movable carriage 104 while allowing movement of the link portion.

[0031] Another design example of a flex hinge actuator is one featuring a four-sided flex hinge assembly. This design of flex hinge actuator is essentially balanced by placing hinge link structures on all four sides of the actuator. Furthermore, this actuator design is characterized by little to no unfavorable movement when a force is applied to move it in the Z direction.

[0032] Figure 2 shows an exemplary four-sided flex hinge actuator (200). As shown in Figure 2, the actuator 200 may comprise a static (stationary) base 202 and a movable member 204 configured to move relative to the static base 202. The hinge link assembly 206 may comprise four-sided flex hinge assemblies (e.g., flex hinge structures 206A-206D) positioned on all four sides of the actuator 200.

[0033] Another design example is a two-sided flex hinge actuator design with a pivot hinge. The concept involves welding a wire (e.g., piano wire) to the stainless steel (SST) portion of the actuator and using it as the pivot. A suitable socket for the actuator is then injection molded. The desired Z-stroke movement is achieved by input forces (input loads) applied at various positions. The pivot can either push the sides of both first links together or directly push the moving carriage. In such a design, unwanted tilt is constrained by the structure.

[0034] Figures 3A to 3C show various views of exemplary two-sided flex hinge actuators 300A to 300C equipped with pivot hinges. As shown in Figure 3A, actuator 300A may comprise a static (stationary) base 302, a movable carriage 304, and a hinge link structure 306. The hinge link structure 306 may comprise the pivot hinge described herein.

[0035] For example, as shown in Figure 3B, the actuator 300B may have a hinge link structure comprising first and second links 308A to 308B and first to third hinges 310A to 310C. The first and second links 308A to 308B and the first to third hinges 310A to 310C are located in a first position where the movable carriage 304 is stroked upward (stroke up). Furthermore, in Figure 3C, the first and second links 308A to 308B and the first to third hinges 310A to 310C of the actuator 300C are located in a second position where the movable carriage 304 is stroked downward (stroke down). The first position 312A is the primary input force location for the stroke. The second position 312B may be an alternative input force location for the stroke.

[0036] Furthermore, each hinge may be configured to rotate via first to third pivots 314A to 314C to move the link to various positions. For example, the first pivot 314A is located between the moving carriage 304 and the second link 308B. The second pivot 314B connects the second link 308B and the second hinge 310B. The third pivot 314C is located between the static base 302 and the first link 308A. Each hinge section may have a rod positioned to stabilize the hinge and allow the rotation of the pivot that moves the first to second links 308A to 308B, respectively.

[0037] Another design example involves a two-plane flex hinge actuator assembly. This design allows for the use of thin, flexible metal hinge material. The bimorph arm can press on both sides of the components of the first link. This design enables excellent dynamic tilt without hinge play or backlash. The hinge thickness is 20–25 μm, and by using an etched pattern, the actuator force acceptable for a shape memory alloy (SMA) actuator can be obtained. In some cases, when force is applied to move the two-plane design in the Z direction, unbalanced forces can cause unwanted movement in the X / Y and tilt directions. In some cases, the flex hinge can be made from steel, Nitinol, high-strength copper alloy, or other suitable spring material. The thickness of the flex hinge may range from 20–25 μm or 15–30 μm.

[0038] Figures 4A to 4D show two-sided views of the flex hinge actuator assemblies 400A to 400D. For example, as shown in Figure 4A, actuator 400A may comprise bimorph actuators 414A to 414B that push the side of a first link element (e.g., 410A). Furthermore, Figure 4B shows that actuator 400B comprises a static (stationary) base 402, a movable carriage 404, and a hinge link structure 406. As shown in Figure 4C, the hinge link structure may comprise first to second links 410A to 410B and first to third flex hinges 408A to 408C. Figure 4D is a side view of actuator 400D described herein. The first to third flex hinges 408A to 408C shown in Figures 4A to 4D are further described in Figure 7.

[0039] The first to third flex hinges 408A to 408C may comprise a movable carriage and a patterned flexible material connecting to one of the first to second links 410A to 410B. The first to third flex hinges 408A to 408C may have gaps between the patterned flex hinge components to ensure the flexibility of the hinge. Furthermore, the link portion may be bent to match or correspond to the curvature of the movable carriage. The link portion may also have two contact points that contact the movable carriage. The pattern of the flex hinge is described in more detail in Figures 7A to 7B. The pattern comprises a set of long, narrow slots, with each row of slots offset from the previous row. The purpose of this pattern is to maintain in-plane stiffness and torsional stiffness while reducing the bending stiffness of the material in only one direction.

[0040] In some cases, the flex hinge may be full thickness without slots. Slot patterns are used to optimize performance (reducing bending stiffness while maintaining high lateral and torsional stiffness of the hinge), and the performance of slot patterns described here can also be achieved by creating patterns or areas through partial etching.

[0041] Another design example involves a four-sided flex hinge actuator assembly. This design is characterized by a balanced structure with little to no unwanted movement. The actuator is designed to generate movement in the ±Z directions by applying inward forces to all four sides. This design further includes two upward (UP) hinge link structures and two downward (DOWN) hinge link structures. The upward (UP) and downward (DOWN) structures are positioned at a 90° angle to each other. The designs of the upward and downward components are identical except that they are positioned upside down to each other.

[0042] Flex hinges allow for precise positioning control due to the absence of backlash and play. Thin materials may be used, such as stainless steel (SST), nickel and / or copper alloys, or superelastotinol. In some cases, the hinge portion may be etched to reduce bending stiffness. The links are rigid and may be made of metal or plastic. A base is used to mount the flex hinge structure. Furthermore, the carriage moves in one axis direction, enabling it to hold the payload.

[0043] Figures 5A to 5D show views of exemplary four-sided flex hinge actuator assemblies 500A to 500D. As shown in Figure 5A, an unfolded view of actuator 500A can show a static (stationary) base 502, a hinge link structure 504, a lower hinge 506, a lower link 508, an upper link 510, an upper hinge 512, and a movable carriage 514. Figure 5B shows actuator 500B with the hinge link structure in the "upper" position. As shown in Figure 5B, the hinge link structure comprises first to third hinges 514A to 514C and first to second links 516A to 516B, and this structure is configured to move in the positive Z direction. Figure 5C shows actuator 500C configured to move in the Z direction. Figure 5D shows actuator 500D with the hinge link structure in the "down" position. Figure 5D shows that the actuator force is applied to link 516A by the first to third hinges 514A to 514C and the first to second links 516A to 516B pushing the actuator in the "-Z" direction.

[0044] The upper hinge 512 is made capable of connecting the upper link 510 to the movable carriage 514. The upper hinge 512 may be equipped with either a flex hinge or a pivot hinge as described here. The upper link 510 serves to connect the movable carriage to the hinge link structure. Furthermore, the lower link 508 connects the static base 502 to the upper link 510.

[0045] In some cases, a four-sided flex hinge assembly can generate uniaxial Z-axis movement through controlled forces. Figure 6 shows an example of actuator 600 configured to move in the Z-axis direction. Such actuators have a fundamentally balanced structure with little to no unwanted tilt or movement in the X / Y directions. For example, forces applied to the four sides can generate movement in the Z-axis direction.

[0046] In the example simulation, the Z stroke is assumed to be approximately 0.6 mm, the maximum tilt angle approximately 0.0002 degrees, and the maximum pushing force (pressing force) approximately 70 mN.

[0047] In some cases, flex hinges may have low bending stiffness and high lateral stiffness. Low bending stiffness means that less force is required to operate the actuator. For actuators for small cameras, the thickness may range from 18 μm to 25 μm. Materials such as SST, copper alloy (Cu-alloy), nickel alloy (Ni-alloy), and superelastic nitinol may be used. Etched patterns (slots) help to reduce bending stiffness. High lateral stiffness provides resistance to unwanted tilting motion. Etched patterns (slots) can widen the hinge and increase lateral stiffness. The length of the hinge can range from 0.1 mm to 0.4 mm. The width of the hinge is set to approximately 1 mm for actuators for small cameras (adjustable according to stiffness and space requirements).

[0048] Figures 7A and 7B show exemplary views of the flex hinge 702. As shown in Figure 7A, the flex hinge 702 has a patterned surface 706 on which a space 708 is located. The space 708 is patterned to have rounded edges and is located on the surface according to the pattern. The flex hinge 702 may have a hinge width of 1 mm and a hinge length of 0.3 mm. Furthermore, in Figure 7B, the flex hinge may have three flex hinges 710A to 710C.

[0049] The slot pattern in Figure 7A allows for a reduction in the bending stiffness of the flex hinge 702 while maintaining in-plane stiffness and torsional stiffness. The slots can be made longer or shorter, and the distance between them can be widened or narrowed, thereby obtaining different stiffness values.

[0050] One primary application of flex hinges is in autofocus systems. A single-axis actuator can be configured to move in the Z-direction. Two to four bimorph actuators, positioned on the sides of the actuator, push inward. A two-bimorph design requires fewer parts and fewer manufacturing resources. A four-bimorph design can improve dynamic tilt and stroke performance. Further details on bimorph actuators are provided in Figures 15A–15C.

[0051] Flex hinge assemblies can generate movement in the Z direction by utilizing the difference in axial forces in opposite directions (FX-FY), resulting in little to no dynamic tilt. By applying equal forces on both sides (FX=FY), the Z position can be maintained.

[0052] Figures 8A and 8B show flex hinge actuators as part of autofocus systems 800A and 800B. As shown in Figure 8A, the lens is positioned on a moving carriage and configured to move the lens in the Z direction. In Figure 8B, the autofocus system may comprise an external housing 802, a bimorph actuator 804, a flex hinge assembly 806, a cover 808, and a lens 810. The carriage holds the lens and is capable of moving up and down in the Z direction.

[0053] Another application example is a flexible hinge lens shift system that incorporates both optical image stabilization (OIS) and autofocus (AF). This includes a 3-axis actuator that moves in the X / Y / Z directions. The actuator is a camera-type shape memory alloy (SMA) actuator with a total of four SMA wires. Four bimorph actuators are positioned on the sides and, by being pushed inward, are made possible to generate movement of the lens in the X / Y / Z directions (optical image stabilization OIS + autofocus AF).

[0054] The flat optical image stabilization (OIS) spring can be used for downward force to maintain posture and for X / Y stroke. The actuator is equipped with a sliding bearing, and the delta opposing force (coaxial force) is enabled to generate optical image stabilization (OIS) motion.

[0055] The flex hinge assembly generates movement in the Z direction through opposing axial forces (FX-FY) between its sides, resulting in little to no dynamic tilt. The Z position is maintained by applying equal opposing axial forces (FX=FY) between its sides. The cover protects the flex hinge from damage during impact or lens insertion, as the optical image stabilization (OIS) endstop is directly mounted to the moving carriage. The endstop may also come from an external housing (cam) instead of the cover (however, it must come from a static component).

[0056] Figures 9A and 9B show views of the flex hinge lens shift actuators 900A and 900B. The actuators include an external housing 902, a bimorph actuator 904, a slide bearing 906, a flat optical image stabilization (OIS) spring 908, a flex hinge assembly 910, a cover 912, a lens 914, and / or a moving carriage 916. The moving carriage 916 holds the lens and is configured to move in the X / Y / Z directions.

[0057] Another application of the actuator is a flexible hinge sensor shift actuator with both optical image stabilization (OIS) and autofocus (AF). This application includes a 3-axis actuator configured to move in the X / Y / Z directions. The actuator features a shape memory alloy SMA camera actuator using a total of four shape memory alloy SMA wires. Four bimorph actuators 904 are positioned on the sides and, by pushing inward, generate movement of the image sensor in the X / Y / Z directions (optical image stabilization (OIS) + autofocus (AF)).

[0058] The flat optical image stabilization (OIS) spring can be used for downward force for attitude holding and for X / Y stroke. A slide bearing 906 is used, allowing a delta opposite force (coaxial) to generate optical image stabilization (OIS) motion. The flex hinge assembly 910 hangs upside down from the external housing 902, and the flat optical image stabilization (OIS) spring 908 is positioned between the flex hinge assembly 910 and the external housing 902, enabling sensor shift. The image sensor assembly is coupled to the moving carriage 916, allowing it to move in the X / Y / Z directions for optical image stabilization (OIS) and autofocus (AF) movement. The flexible sensor circuit allows movement in the X / Y / Z directions, while the lens can remain static.

[0059] Figures 10A and 10B show an example of a flexible hinge sensor shift actuator with both optical image stabilization (OIS) and autofocus (AF). For example, as shown in Figure 10B, actuator 1000B includes a cover 1002, a flexible sensor circuit 1004, an image sensor assembly 1006, a flexible hinge assembly 1008, a flat optical image stabilization (OIS) spring 1010, a slide bearing 1012, a bimorph actuator 1014, an external housing 1016, a lens 1018, and a carriage 1020. The carriage 1020 is coupled to the image sensor assembly 1006 and is made movable in the X / Y / Z directions.

[0060] In some cases, the simulation of a flex-hinge lens shift actuator may include various boundary conditions. These conditions include applying forces to four faces to generate movement in the X / Y / Z directions. These forces simulate the output from a bimorph actuator, and the forces applied to each face are designed to take into account the interaction of optical image stabilization (OIS) and autofocus (AF) movements, enabling the achievement of the correct X / Y / Z position. Figures 11A and 11B show top views and iso-views of actuators 1100A and 1100B with movement in the X / Y and Z directions.

[0061] Various force equations can represent the forces used to generate the motion (movement) in the X / Y / Z directions described here. A delta force is the difference between forces in opposite directions. These forces generate motion in one direction, inversely proportional to the rigidity of the structure. Examples of force equations are shown below.

[0062] (X_Delta_Force) = (X_Motion) * (X_Stiffness) = W2 - W3. (Y_Delta_Force) = (Y_Motion) * (Y_Stiffness) = W1 - W0. (Z_Delta_Force) = (Z_Motion) * (Z_Stiffness) = (W1 + W0) - (W2 + W3).

[0063] In some cases, transient forces and friction are assumed to be negligible. Figure 12 shows an example of actuator 1200 with W force indicators. As shown in Figure 12, each W force indicator "W0-W3" indicates whether the force provides positive or negative movement in the X / Y / Z directions. The "W" in Figure 12 can indicate which shape memory alloy SMA wire (e.g., wire 0-3) is applying the force.

[0064] The combined force (total force) can be expressed as the sum of the optical image stabilization (OIS) force, the autofocus (AF) force, the interaction force (shift of the autofocus AF center), and the force related to the shift of the autofocus AF amplitude.

[0065] The equation for the force of optical image stabilization (OIS) is expressed as follows: W0 = -(Y_delta_force). W1 = + (Y_delta_force).

[0066] W2 = + (X_Delta_Force). W3 = -(X_Delta_Force). The equation for autofocus (AF) power is expressed as follows:

[0067] W0 or W1 = +(Z_Delta_Force) / 2 W2 or W3 = -(Z_Delta_Force) / 2 The equation for the interaction force related to the shift of the autofocus AF center is expressed as follows:

[0068] W0 or W1 = abs(±X_delta_force) / 2 W2 or W3 = abs(±Y_delta_force) / 2 The equation for the interaction force related to the shift in autofocus (AF) amplitude can be expressed as follows:

[0069] If Z_movement > 0: W0 or W1 = -abs(X_Delta_Force / 4) - abs(Y_Delta_Force / 4). W2 or W3 = 0.

[0070] If Z_movement < 0: W0 or W1 = 0. W2 or W3 = -abs(X_Delta_Force / 4) - abs(Y_Delta_Force / 4).

[0071] Figure 13 shows how the force applied to actuator 1300 is manifested. As shown in Figure 13, various forces may be applied to the actuator.

[0072] In some cases, the input force is calculated from the stroke in the X / Y / Z directions, and the output is motion in the X / Y / Z directions. Figures 14A and 14B show exemplary actuators 1400A and 1400B illustrating the simulation results for input and output. For example, Figure 14A shows a table relating stroke and force in several directions of motion. Furthermore, Figure 14B shows a graph of stroke and solution time.

[0073] As described above, bimorph actuators can be used as part of a flex hinge actuator. Figures 15A–15C show views of prior art bimorph actuators that may be used in the embodiments described herein. According to various embodiments, the bimorph actuator 1502 comprises a beam 1504 and one or more shape memory alloy SMA materials 1506 (e.g., a shape memory alloy SMA ribbon 1506b shown in the embodiment of Figure 15B, or a shape memory alloy SMA wire 1506a shown in the embodiment of Figure 15A). The shape memory alloy SMA materials 1506 are attached to the beam 1504 using a technique comprising the method described herein. According to some embodiments, the shape memory alloy SMA materials 1506 are attached to the beam 1504 using an adhesive film material 1508. The ends of the shape memory alloy SMA materials 1506 are electrically and mechanically connected to contacts 1510 configured to supply current to the shape memory alloy SMA materials 1506, in various embodiments. Contact 1510 (for example, as shown in Figures 15A and 15B) is a gold-plated copper pad in various embodiments.

[0074] According to some embodiments, a bimorph actuator 1502 with a length of approximately 1 millimeter is configured to generate a large stroke and a pressing force of 50 millinewtons (mN), and is used, for example, as part of a lens assembly shown in Figure 15C. According to some embodiments, using a bimorph actuator 1502 longer than 1 millimeter can provide a larger stroke but less force than one having a length of 1 millimeter. In some embodiments, the bimorph actuator 1502 comprises a shape memory alloy SMA material 1506 with a thickness of 20 microns, an insulator 1512 (e.g., a polyimide insulator) with a thickness of 20 microns, and a stainless steel beam (1504) or substrate with a thickness of 30 microns. In various embodiments, a second insulator 1514 may be placed between a contact layer having contacts 1510 and the shape memory alloy SMA material 1506. According to some embodiments, the second insulator 1514 is configured to insulate the shape memory alloy SMA material 1506 from the portion of the contact layer not used as contacts 1510. In some embodiments, the second insulator 1514 may be a cover coat layer and may be a polyimide insulator. It will be understood by those skilled in the art that other dimensions and materials may be used to satisfy the desired design characteristics.

[0075] In an example of the first embodiment, a flex hinge actuator is provided. This flex hinge actuator may comprise a static (stationary) base (e.g., 102) and a movable carriage (e.g., 104) configured to move in the Z direction relative to the static base. The flex hinge actuator may also comprise a flex hinge assembly (e.g., 106) configured to allow the movable carriage to move in the Z direction while restricting movement in other directions. The flex hinge assembly may comprise at least two flex hinge structures (e.g., the structure in Figure 1) located on corresponding sides of the flex hinge actuator.

[0076] In some cases, a flex hinge assembly may have pre-configured flex hinge structures on each side of the flex hinge actuator (for example, as shown in Figure 2).

[0077] In some cases, each flex hinge structure comprises a first link (e.g., 308A) and a second link (e.g., 308B). The first link is connected to a static base at a first hinge joint (e.g., 310A) and to the second link at a second hinge joint (e.g., 310B). The second link is connected to a movable carriage at a third hinge joint (e.g., 310C). In some cases, a flexible metal hinge (e.g., as shown in Figure 4C) may be used in one of the first, second, or third hinge joints.

[0078] In some cases, each flex hinge structure may further include at least one link connecting a movable carriage to the flex hinge structure, and a bimorph actuator configured to push that link. The bimorph actuator may comprise a beam having a first end fixed to the flex hinge structure and a second end having a free end. The movement of the free end is configured to push its link. In some cases, the bimorph actuator may comprise a shape memory alloy material (SMA material) pre-placed along the beam between the fixed and free ends.

[0079] In some cases, the flex hinge structure may include at least a first flex hinge structure oriented in a first direction and a second flex hinge structure oriented in a second direction opposite to the first direction.

[0080] In some cases, the flex hinge actuator may further include a lens connected to the moving carriage, an external housing, and four bimorph actuators. These four bimorph actuators, located in the external housing, provide movement of the moving carriage in the X / Y directions.

[0081] In some cases, the flex hinge actuator may further include a cover mounted on part of the moving carriage and the external housing. The cover includes end stops that restrict the moving carriage from moving beyond a predetermined stroke range.

[0082] In some cases, the flex hinge actuator may further include an image sensor assembly positioned beneath the flex hinge assembly, and a flexible sensor circuit connected to both the flex hinge assembly and the image sensor assembly.

[0083] In an example of another embodiment, a device is provided. The device may comprise a static (stationary) base and a movable carriage configured to move in the Z direction relative to the static base. The device may also comprise a flex hinge assembly configured to allow the movable carriage to move in the Z direction while restricting movement in other directions. The flex hinge assembly may comprise at least two flex hinge structures positioned on corresponding sides of a flex hinge actuator. Each flex hinge structure comprises a first link and a second link. The first link is connected to the static base at a first hinge joint and to the second link at a second hinge joint. The second link is connected to the movable carriage at a third hinge joint.

[0084] In some cases, the device may further include a bimorph actuator configured to push in the first link of each flex hinge structure. The bimorph actuator comprises a beam having a first end fixed to the flex hinge structure and a second end having a free end. The movement of the free end is configured to push in at least one link. The bimorph actuator may also include a shape memory alloy (SMA) material pre-placed along the beam between the fixed and free ends.

[0085] In some cases, the flex hinge structure may include at least a first flex hinge structure oriented in a first direction and a second flex hinge structure oriented in a second direction opposite to the first direction.

[0086] In some cases, the device may further include a lens connected to the moving carriage, an external housing, and four bimorph actuators. These four bimorph actuators are located in the external housing and provide movement of the moving carriage in the X / Y directions.

[0087] In some cases, the device may further include a cover mounted on part of the moving carriage and the external housing. The cover includes end stops that restrict the moving carriage from moving beyond a predetermined stroke range.

[0088] In some cases, the device may further include an image sensor assembly positioned beneath the flex hinge assembly, and a flexible sensor circuit connected to both the flex hinge assembly and the image sensor assembly.

[0089] In another embodiment, an actuator is provided. The actuator may comprise a static base, a movable carriage configured to move relative to the static base, and a flex hinge assembly. The flex hinge assembly is configured to allow the movable carriage to move in a first direction while restricting movement in other directions. The flex hinge assembly may comprise four flex hinge structures positioned on each side of the flex hinge actuator.

[0090] In some cases, each flex hinge assembly comprises a first link and a second link. The first link is connected to the static base at a first hinge joint and to the second link at a second hinge joint. The second link is connected to the movable carriage at a third hinge joint.

[0091] In some cases, the actuator may further comprise a lens connected to the moving carriage, an external housing, and four bimorph actuators. These four bimorph actuators, located in the external housing, provide movement of the moving carriage in the X / Y directions. The actuator also includes a cover mounted on part of the moving carriage and the external housing. The cover includes end stops that restrict the moving carriage from moving beyond a predetermined stroke range.

[0092] In some cases, the actuator may further comprise an external housing, four bimorph actuators (these four bimorph actuators are located in the external housing to provide movement in the X / Y directions of the moving carriage), an image sensor assembly located beneath the flex hinge assembly, and a flexible sensor circuit (connected to the flex hinge assembly and the image sensor assembly).

[0093] According to some embodiments, the processes described herein are used to form either or both mechanical and electromechanical structures. While these embodiments have been described in relation to the invention, the articulators acknowledge that modifications to the shape and details can be made without departing from the spirit and scope of the invention.

Claims

1. A flexible hinge actuator, wherein the flexible hinge actuator is Static base and, A movable carriage configured to move in the Z direction relative to the static base, and A flex hinge assembly configured to allow the moving carriage to move in the Z direction while restricting movement in other directions, It is equipped with, The flex hinge assembly comprises at least two flex hinge structures positioned on corresponding sides of the flex hinge actuator. Flex hinge actuator.

2. The flex hinge assembly comprises the flex hinge structure, which is positioned on each of the four faces of the flex hinge actuator. The flexible hinge actuator according to claim 1.

3. Each of the aforementioned flexible hinge structures comprises a first link and a second link, The first link is connected to the static base by a first hinge joint and to the second link by a second hinge joint. The second link is connected to the movable carriage by a third hinge joint. The flexible hinge actuator according to claim 1.

4. The first hinge joint, the second hinge joint, or the third hinge joint is equipped with a flexible metal hinge. The flexible hinge actuator according to claim 3.

5. Each of the aforementioned flexible hinge structures further, At least one link connecting the movable carriage to the flexible hinge structure, and A bimorph actuator configured to press in at least one of the aforementioned links, It is equipped with, The aforementioned bimorph actuator is equipped with a beam, The aforementioned beam, The first end is fixed to the aforementioned flexible hinge structure, The second end has a free end, It is equipped with, The movement of the free end is configured to push in at least one of the links. The flexible hinge actuator according to claim 1.

6. The bimorph actuator further comprises a shape memory alloy (SMA) material positioned along the beam between the fixed end and the free end of the beam. The flexible hinge actuator according to claim 5.

7. The aforementioned flexible hinge structure is, A first flex hinge structure oriented in the first direction, A second flex hinge structure oriented in a second direction opposite to the first direction, It has at least the following features: The flexible hinge actuator according to claim 1.

8. The aforementioned flexible hinge actuator further, The lens already connected to the aforementioned mobile carriage, External housing and, Four bimorph actuators, It is equipped with, The four bimorph actuators are arranged in the external housing to provide movement of the moving carriage in the X / Y direction. The flexible hinge actuator according to claim 1.

9. The flex hinge actuator further includes a cover mounted on a portion of the movable carriage and the external housing, The cover is equipped with end stops that restrict the movable carriage from moving beyond a predetermined stroke range. The flexible hinge actuator according to claim 8.

10. The aforementioned flexible hinge actuator further, The image sensor assembly positioned below the flex hinge assembly, and A flexible sensor circuit connected to the flex hinge assembly and the image sensor assembly, It is equipped with The flexible hinge actuator according to claim 8.

11. Apparatus, the apparatus, Static base and, A movable carriage configured to move in the Z direction relative to the static base, and A flex hinge assembly configured to allow the moving carriage to move in the Z direction while restricting movement in other directions, It is equipped with, The flex hinge assembly comprises at least two flex hinge structures positioned on corresponding sides of the flex hinge actuator. Each of the aforementioned flexible hinge structures comprises a first link and a second link, The first link is connected to the static base by a first hinge joint and to the second link by a second hinge joint. The second link is connected to the movable carriage by a third hinge joint. Device.

12. The apparatus further comprises a bimorph actuator configured to press the first link of each of the flex hinge structures, the bimorph actuator is A beam having a first end fixed to the flex hinge structure and a second end having a free end, wherein the movement of the free end is configured to push in at least one link, the beam and A shape memory alloy (SMA) material is arranged along the beam between the fixed end and the free end, It is equipped with The apparatus according to claim 11.

13. The aforementioned flexible hinge structure is, A first flex hinge structure oriented in a first direction, and, A second flex hinge structure oriented in a second direction opposite to the first direction, It has at least the following features: The apparatus according to claim 11.

14. The aforementioned device further, The lens already connected to the aforementioned mobile carriage, External housing and, Four bimorph actuators, It is equipped with, Each of these four bimorph actuators is located in the external housing, thereby providing movement of the moving carriage in the X / Y direction. The apparatus according to claim 11.

15. The device further includes a cover mounted on a portion of the movable carriage and the external housing, The cover is equipped with end stops that restrict the movable carriage from moving beyond a predetermined stroke range. The apparatus according to claim 14.

16. The aforementioned device further, The image sensor assembly already positioned below the aforementioned flex hinge assembly, A flexible sensor circuit connected to the flex hinge assembly and the image sensor assembly, It is equipped with The apparatus according to claim 14.

17. The apparatus further includes slide bearings and springs connected to the movable carriage and the static base, thereby allowing movement of the movable carriage in the X / Y direction and the Z direction. The apparatus according to claim 11.

18. An actuator, wherein the actuator is Static base and, A moving carriage configured to move relative to the static base, and A flex hinge assembly configured to allow the moving carriage to move in a first direction while restricting movement in other directions, It is equipped with, The flex hinge assembly comprises four flex hinge structures positioned on each side of the flex hinge actuator. Actuator.

19. Each of the aforementioned flex hinge assemblies comprises a first link and a second link, The first link is connected to the static base by a first hinge joint and to the second link by a second hinge joint. The second link is connected to the movable carriage by a third hinge joint. The actuator according to claim 18.

20. The actuator further, The lens already connected to the aforementioned mobile carriage, External housing and, Four bimorph actuators, each of which is located in the external housing and provides movement of the moving carriage in the X / Y direction, A cover mounted on a portion of the movable carriage and the external housing, the cover having end stops that restrict the movable carriage from moving beyond a predetermined stroke range, It is equipped with The actuator according to claim 18.

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