Controllable lens actuated via a flexible joint

Abstract

The present invention relates to a controllable lens with variable optical power. The lens includes: first and second cover members (111, 112); a transparent, deformable non-fluid body (105) sandwiched between the first and second transparent cover members, such that the first and second transparent cover members and the non-fluid body constitute the lens; one or more actuators arranged to provide displacement along the optical axis; and one or more elastic elements (130, 130_1, 130_2) connecting actuator displacement elements to the first cover members, wherein at least a portion of each of the one or more elastic elements is arranged to elastically deform in response to relative radial displacement between the first transparent cover member and the actuator displacement element.

Description

Technical Field

[0001] The present invention relates to lenses with variable focal length, such as variable lenses used in small cameras. Background Technology

[0002] The use of variable focal length lenses in cameras and other electronic devices is of great interest because such lenses can replace multi-lens systems equipped with motors to shift the lens to achieve variable focal length. Variable focal length lenses can be used to improve the performance of electronic devices and / or to reduce their size. However, there is still a need to improve the performance and quality of variable lenses, such as reducing wavefront error. Summary of the Invention

[0003] The object of this invention is to improve variable focal length lenses. In particular, the object of this invention is to provide a suitable actuator mechanism comprising a method for transmitting actuator motion to a lens diaphragm in a manner that does not cause deformation of the diaphragm, which could lead to aberrations and wavefront errors.

[0004] In a first aspect of the invention, a controllable lens with variable optical power is provided, the lens comprising:

[0005] - A first covering member and a second covering member, wherein one of the first covering member and the second covering member is transparent, while the other of the first covering member and the second covering member is transparent or reflective.

[0006] A transparent, deformable, non-fluid body is sandwiched between the first and second covering members, such that the first and second transparent covering members and the non-fluid body together constitute a lens having an optical axis that intersects with the first and second covering members and the non-fluid body.

[0007] - One or more actuators, comprising a plurality of actuator displacement elements arranged to shift in a direction parallel or substantially parallel to the optical axis.

[0008] - One or more elastic elements that connect the actuator displacement element to the first cover member, wherein at least a portion (e.g., an elastic portion) of each of the one or more elastic elements is arranged to elastically deform in response to relative radial displacement between the first cover member and the actuator displacement element, wherein each of the one or more elastic elements has a first stiffness in the radial direction and a second stiffness in the direction of the optical axis, wherein the first stiffness is less than the second stiffness.

[0009] The stiffness of an elastic element can be elastic stiffness, such as the spring constant or viscoelastic stiffness of a spring. Stiffness can be given by a combination of the dimensions of the elastic element and the properties of the elastic material (such as the Young's modulus of the material). The first and second stiffnesses give the relationship between deformation in the radial and axial directions (along the optical axis) and the radial force or radial torque that causes radial deformation and the axial force that causes axial deformation.

[0010] Advantageously, the actuator output is connected to the cover member (i.e., the lens film) via an elastic connecting element. This elastic element can accumulate changes in the radial extension of the cover member caused by the actuator. The elastic connecting element can be designed to elastically deform at least in the radial direction in response to bending of the cover member. Relative radial displacement is understood as at least one component of the relative radial displacement having a direction perpendicular to the optical axis in the radial direction.

[0011] The elastic element includes a structure having a bendable shape designed to bend in the radial direction (i.e. towards the optical axis), while the structure is not very bendable or inflexible or only allows small compression or tension in the axial direction along the optical axis, wherein the design specifies a first stiffness or radial stiffness less than a second stiffness or axial stiffness.

[0012] Elastic deformation can include deformation in the radial direction toward the optical axis and deformation in the rotational direction due to torque. Radial deformation can include deformation in the range of 0.05 μm to 500 μm, for example, deformation in the range of 0.1 μm to 250 μm, 0.1 μm to 50 μm, 0.5 μm to 50 μm, 1 μm to 25 μm, 2 μm to 500 μm, 5 μm to 500 μm, 5 μm to 250 μm, for example, deformation in the range of 7 μm to 150 μm.

[0013] The first covering member is a first transparent covering member, while the second covering member is a second transparent covering member or a second reflective covering member. Alternatively, the first covering member is a first transparent covering member or a first reflective covering member, while the second covering member is a second transparent covering member.

[0014] According to one embodiment, each of the elastic elements is arranged to elastically deform in response to a torque acting about an axis tangential to the path surrounding the optical axis, wherein the torque is generated by the relative radial displacement between the first cover member and the actuator displacement element.

[0015] Advantageously, the elastic element is able to support the rotational component caused by the bending of the first covering member with low elastic resistance.

[0016] According to one embodiment, each elastic element has a first portion fixed to a first cover member and a second portion fixed to an actuator displacement element or at least one actuator displacement element, wherein the first and second portions are elastically connected, for example, by a portion of the elastic element arranged to elastically deform in response to relative radial displacement.

[0017] Advantageously, the fixed connection provides a rigid connection, thereby allowing the actuator motion to be effectively transmitted to the first cover member.

[0018] The first and second parts can be elastically connected via associated elastic portions of one or more elastic elements, which are arranged to elastically deform. The first and second parts can form a more rigid portion of the elastic element, such as a portion that does not deform or deforms less in response to relative radial displacement between the first transparent cover member and the actuator displacement element. Therefore, the first and second parts can differ in elasticity from the elastic portions of the elastic element, such as exhibiting lower elasticity (high stiffness) against relative radial displacement between the first transparent cover member and the actuator displacement element.

[0019] According to one embodiment, a first portion of the elastic element is connected to a first covering member at a separate location distributed along a path surrounding the optical axis.

[0020] For example, one or more actuators may be arranged to generate force along a path around the optical axis of the first cover member in order to produce a controllable change in the curvature of the first cover member and / or the second cover member.

[0021] According to one embodiment, each elastic element has a first spring constant in the radial direction and a second spring constant in the direction of the optical axis, wherein the first spring constant is smaller than the second spring constant.

[0022] According to one embodiment, the controllable lens includes one or more other elastic elements that connect the actuator displacement element to the second cover member.

[0023] Therefore, the controllable lens may include a first elastic element and a second elastic element, which are positioned such that they face the first covering member and the second covering member, respectively.

[0024] According to one embodiment, each elastic element includes an elastic adhesive. Alternatively or additionally, the elastic element may include a non-metallic material or a viscoelastic material, with the elastic adhesive being one example.

[0025] Advantageously, glue or adhesive can be used as an elastic component or in combination with other types of elastic components, such as elastic hinges, flexural structures and other spring elements.

[0026] According to one embodiment, each elastic element includes one or more spring elements, wherein each spring element includes a first portion.

[0027] According to one embodiment, each elastic element includes a support member, wherein the support member includes a second portion. The support member may be arranged as a common support for a plurality of displacement elements and / or for a plurality of elastic portions of each of one or more elastic elements.

[0028] Therefore, the support member (e.g., a force distribution support member) can be connected to multiple displacement elements and / or multiple elastic parts (e.g., spring elements). According to one embodiment, each of the spring elements is constructed as an individual spring element. Thus, each spring element is capable of deforming independently of the other spring elements.

[0029] According to one embodiment, the support member is positioned radially closer to the optical axis than the spring element.

[0030] According to one embodiment, the controllable lens includes a first elastic element connecting an actuator displacement element to a first cover member and / or a second elastic element connecting other actuator displacement elements to a second cover member.

[0031] According to one embodiment, each elastic element includes one or more spring elements and an elastic material (such as an elastic adhesive) connected to the first part and / or the second part.

[0032] Advantageously, the combination of spring elements with other elastic materials can enhance the ability of elastic elements to provide low stiffness in response to deformation in the radial direction and in response to rotation (such as rotation about an axis tangent to the circumference of the lens), while providing high stiffness in the displacement direction of the actuator displacement element (e.g., along the optical axis).

[0033] A second aspect of the invention relates to an electronic device comprising a controllable lens according to the first aspect. For example, the electronic device may be a camera module or other devices listed in the specification.

[0034] The electronic device includes a control system for powering and controlling one or more actuators to produce controllable variations in the optical power of the lens. The control system can be configured to switch between predetermined optical powers of the lens. The control system may include electronic circuitry and / or a digital processor arranged to generate control or power signals, optionally to acquire measurement data for determining the control or power signals, and to control the actuators using a feedforward or feedback control algorithm based on the measurement data and reference values ​​(such as the desired optical power of the lens).

[0035] The third aspect of the invention relates to using the controllable lens according to the first aspect for imaging, projecting light, beam scanning, light detection, and other purposes.

[0036] Generally, various aspects and embodiments of the present invention can be combined and coupled in any possible manner within the scope of the invention. These and other aspects, features, and / or advantages of the invention will be elucidated with reference to and will become apparent from the embodiments described below. Attached Figure Description

[0037] Embodiments of the invention will be described by way of example only with reference to the accompanying drawings, in which...

[0038] Figure 1A-1B A lens with controllable variable focal length is shown.

[0039] Figure 2A This demonstrates the deformability of one of the elastic elements of the variable lens.

[0040] Figure 2B An alternative solution for the contact between the actuator and the first cover member based on sliding contact is shown.

[0041] Figures 3A-3C The first example of an elastic element is shown.

[0042] Figures 4A-4D A second example of an elastic element is shown.

[0043] Figure 5 An electronic device including a variable lens is shown.

[0044] Figures 6A-6C A third example of an elastic element based on an elastic hinge structure is shown.

[0045] Figure 7 Another example of a spring element is shown, and

[0046] Figure 8 The main requirements for elastic elements are shown. Detailed Implementation

[0047] Figure 1A and Figure 1B The side and top views of the controllable variable focal length lens 100 are shown.

[0048] Lens 100 includes a first cover member 111 and a second cover member 112. At least one of the first cover member and the second cover member is configured to bend by a force provided by an actuator. In one example, both the first cover member 111 and the second cover member 112 are transparent cover members, such as those made of glass or plastic.

[0049] Instead of the two transparent covering members 111, 112, either the first covering member or the second covering member can be reflective, for example, provided with a reflective metal layer to provide complete or partial reflection, such that the incident light beam is reflected back to the opposing transparent covering member. For convenience, the examples and embodiments herein refer to transparent covering members 111, 112.

[0050] Lens 100 includes a transparent, deformable, non-fluid body 105 sandwiched between a first transparent cover member 111 and a second transparent cover member 112. The non-fluid body 105 is adjacent to the inward-facing surfaces of the first cover member 111 and the second cover member 112.

[0051] The first transparent cover member 111, the second transparent cover member 112, and the non-fluid body 105 constitute a lens having an optical axis 150 intersecting the first transparent cover member, the second transparent cover member, and the non-fluid body. The optical axis can be defined as an axis passing through the center of the first transparent cover member 111, the second transparent cover member 112, and the non-fluid body 105 and perpendicular to the plane of one of the cover members. The optical axis can be defined according to conventional optical definitions.

[0052] The transparent, deformable, non-fluid lens body 105 is preferably made of an elastic material. Because the lens body is non-fluid, a fluid-tight housing is not required to encapsulate the lens body to prevent leakage. In a preferred embodiment, the lens body is made of a soft polymer, which may include a variety of different materials, such as silicone, polymer gels, polymer networks of cross-linked or partially cross-linked polymers, and miscible oils or combinations of oils. The elastic modulus of the non-fluid lens body can be greater than 300 Pa, thereby avoiding deformation due to gravity during normal operation. The refractive index of the non-fluid lens body can be greater than 1.3. The non-fluid body 205 may have a refractive index that is equal to, substantially equal to, or close to the refractive index of the first cover member 111 and the second cover member 112, in order to reduce reflections at the boundaries of the non-fluid body 105.

[0053] The transparent covering members 111 and 112 can be made of a wide variety of different materials, such as acrylic resin, polyolefin, polyester, silicone resin, polyurethane, glass, etc. At least one of the first covering member 111 and the second covering member 112 is arranged to deform by an actuator, and at least one of the first covering member 111 and the second covering member 112 has a stiffness suitable for bending by actuation of the actuator 121. Generally, the material of the first covering member 111 and / or the second covering member 112 can be formed from a material with a Young's modulus in the range of 5 MPa to 100 GPa to provide the necessary stiffness. For example, borosilicate glass has a Young's modulus of 63 GPa, while fused silica glass has a Young's modulus of 72 GPa.

[0054] The bending of the first cover member 111 and / or the second cover member 112 is at least partly caused by the reaction force from the radial variation of the lens body 105, which affects the sag of the cover members 111, 112 and thus the optical power, rather than simply compressing the lens body vertically without changing the sag. A full explanation of the effect of the lens body 105 on the curvature of the cover members is described in WO2019002524A1, which is incorporated herein by reference.

[0055] The lens 100 further includes one or more actuators 121, which include a plurality of actuator displacement elements 122 arranged to be displaced in a direction parallel or substantially parallel to the optical axis 150.

[0056] One or more actuators 121 are arranged to generate force on the first cover member 111 or the second cover member 112 along a path 151 around the optical axis 150 (e.g., a circle on the surface of the first cover member 111 or the second cover member 112). One or more actuators may be arranged such that the displacement element acts on the outward-facing surface as shown, or on the inward-facing surface of one or both of the first cover member 111 and the second cover member 112.

[0057] For example, actuator 121 may be a linear displacement actuator, such as a linear piezoelectric motor or linear electromagnetic motor, a piezoelectrically actuated cantilever actuator, a shape memory alloy, a linear helical driver, or a linear voice coil actuator, which is arranged to apply displacement at several points (eight points are shown here) along path 151.

[0058] In one example, the elastic element 130 is configured as a rubber ring or ring body surrounding an optical axis, for example, arranged along path 151. A force distribution ring (such as a metal ring or a ring made of other sufficiently rigid material so that the ring does not bend or substantially does not bend in the axial direction) is arranged on top of the circular rubber ring. The force distribution ring may be embodied by a support member 302 (see elsewhere for a description of the support member). Two or more displacement elements (actuated by one or more actuators) are arranged to displace the force distribution ring in the axial direction to cause bending of the first or second cover member. In this example, the annular elastic element 130 formed of elastic rubber may have a thickness in the axial direction ranging from 0.05 mm to 0.2 mm, for example, a thickness of 0.1 mm, and may have a width of the annular body (the difference between the inner and outer radii, i.e., the ring thickness) ranging from 0.1 mm to 0.5 mm, for example, a width of 0.2 mm. When the adhesive cures or hardens, its hardness can range from 2 to 200 MPa, based on Young's modulus; for example, the hardness of the adhesive is 25 MPa.

[0059] In one example, the actuator is fixed to a fixed support 190, causing the displacement element 122 to shift relative to the support 190. Similarly, an unactuated cover member, such as... Figure 2A-2B The second cover member 112 shown can be supported by the fixed support member 190 unless the second cover member 112 is actuated by the other actuator displacement element 122 of the other actuator 121.

[0060] In an example where one or more actuators are arranged to act on the inward-facing surfaces of the first cover member 111 and the second cover member 112, actuator 121 may be connected to one of the cover members via an elastic element, while displacement element 122 is connected to the opposing cover member via an elastic element. In this way, displacement of the actuator will cause bending of both cover members. Alternatively, actuator 121 (i.e., the portion configured to be fixed) is fixed to a fixed support 190, while displacement element 122 is connected to the inward-facing surface of one of the first cover member 111 and the second cover member 112. The other cover member not connected to the displacement element may be connected to the fixed support 190.

[0061] The actuator can be arranged between the first cover member 111 and the second cover member 112, that is, sandwiched only between the first cover member 111 and the second cover member 112.

[0062] Path 151 may surround the transparent, deformable non-fluid body 205, such that the non-fluid body 205 is enclosed by path 151, as shown. However, path 151 may also be located within the extension of the non-fluid body 205. Actuators 121 may also be positioned such that they act on or near the edge of the first cover member 111 or the second cover member 112.

[0063] Actuator 121 is arranged to produce displacement along path 151 in a direction perpendicular or substantially perpendicular to the surfaces of cover members 111, 112. In this case, substantially perpendicular may mean a deviation relative to the normal as high as, for example, 10-15 degrees. The angular variation of the angle between the direction of the linear displacement and the surface of the cover member is produced according to the curvature of the cover member.

[0064] As described in more detail below, the actuator's action alters the curvature of the first and / or second cover members based on the force, torque, or displacement provided by the actuator. Therefore, by controlling the actuator, the bending of the lens 100 and consequently its optical power can be controlled. If the actuator is arranged to connect to the first cover member, the second cover member can also bend, and vice versa, depending on the thickness or stiffness of the cover member. Alternatively, the actuator may be arranged to connect to the first cover member 111, but the first cover member 111 has high stiffness, such that the second cover member 112 bends primarily due to the displacement of the actuator acting on the first cover member 111. In this case, the second cover member 112 can be supported by a fixed support 190.

[0065] Note that actuator 121 may be arranged to act on either the first cover member 111 or the second cover member 112. Alternatively, actuator 121 may be arranged to act on the first cover member 121 and the second cover member 122, such that the two cover members are forced to bend by the action of actuator 121, potentially allowing the actuators on both sides to be controlled independently, i.e., such that the displacement / force applied to one cover member is independent of the displacement / force applied to the other cover member.

[0066] The actuator displacement element 122 of actuator 121 is connected to the first transparent cover member 111 via elastic element 130.

[0067] The elastic element 130 elastically deforms in response to the relative displacement between the first transparent cover member 111 and the actuator displacement element 122.

[0068] According to one embodiment, the elastic element 130 includes an elastic material, such as an elastic adhesive. Therefore, the elastic connection between each of the cover members 121, 122 and the actuator displacement element 122 can be achieved by performing a bonding process, for example by applying a specific volume of adhesive, and by ensuring that a specific distance and orientation are maintained between the actuator displacement element 122 and the cover members 111, 112 during the curing of the adhesive.

[0069] For example, a single elastic element 130 made of elastic adhesive connecting a single actuator displacement element 122 to one of the cover members 121, 122 can be formed as a cylindrical (e.g., barrel-shaped) element, and the single elastic element has a thickness in the axial direction (along the optical axis) ranging from 0.01 mm to 1 mm, and a width or radius perpendicular to the axial direction (i.e., in the radial direction) ranging from 0.02 mm to 2 mm. In terms of Young's modulus, the hardness of the adhesive can be in the range of 2 to 200 MPa, for example, 25 MPa.

[0070] Generally, elastic adhesive joints can have a thickness in the range of 0.01-5.00 mm, a radial width in the range of 0.02-2.00 mm, and are made of adhesive with a Young's modulus in the range of 1-1000 MPa.

[0071] Figure 2A The deformability of one of the elastic elements 130 is shown. A fixed xyz coordinate system is defined relative to the initial position of the elastic element 130, for example, when the elastic element 130 is in a non-deformable state. In this example, the z-axis is parallel to the optical axis 150.

[0072] In the diagram on the left, the first cover member 111 has an initial curvature, which may be due to pre-formed curvature or due to the initial displacement of the actuator displacement element 122. The contact point 281 on the first cover member 111 has xz coordinates x0, z0 at the interface between the elastic element 130 and the first cover member 111.

[0073] In the diagram on the right, actuator 121 has been controlled to move or extend actuator displacement element 122 along the z-axis by a distance ΔL1. This displacement produces a bending or additional bending of the first cover member 111, causing contact point 281 to move from x0,z0 to x1,z1 due to radial displacement of contact point 281 toward the optical axis (i.e., displacement along the x-axis of the local xyz coordinate system) and due to displacement along the z-axis.

[0074] Due to the bending of the first transparent member 111, the surface at the interface between the elastic element 130 and the first covering member 111 rotates about the y-axis, that is, it rotates about an axis that is tangent to the path 151 around the optical axis 150.

[0075] As shown in the figure, the elastic element 130 is configured to elastically deform in the radial direction (here along the x-axis) in response to the relative radial displacement between the first transparent cover member 111 and the actuator displacement element 122.

[0076] Furthermore, the elastic element 130 is configured to elastically deform in response to a torque Ty acting about the y-axis or tangential axis. The torque Ty is generated by the bending of the first transparent member 111, which includes rotation about the y-axis, or the torque is generally generated by the relative displacement between the first transparent cover member and the actuator displacement element.

[0077] Preferably, the elastic element 130 has low stiffness in response to deformation in the radial direction and to rotation (e.g., rotation about a tangential axis, which is the y-axis in this case). Low stiffness is preferred to allow the first transparent member 111 to bend without being exposed to surface stresses that could unduly affect the curvature of the first transparent member, causing the modified curvature to lead to an increase in wavefront error. Undesirable stresses may be caused, for example, by forces and torques acting radially and about the tangential or y-axis from the elastic element 130.

[0078] On the other hand, it is preferable that the elastic element has high stiffness in the displacement direction of the actuator displacement element 122 (i.e., along the z-axis or along the optical axis 150) so as to transmit the actuator displacement to the cover member.

[0079] Therefore, according to one embodiment, the elastic element has a first spring constant k1 in the radial direction and a second spring constant k2 in the direction of the optical axis 150, wherein the first spring constant k1 is greater than the second spring constant k2.

[0080] The table below provides examples of the dimensions of the deformation related to the resulting optical power and the diameter of the first transparent cover member 111 or the second transparent cover member 112. The diameter can be specified as the distance between the diameter-relative actuator displacement elements 122. The bending height specifies the distance from the apex of the curved cover member 111, 112 to the undeformed cover member.

[0081]

[0082] Therefore, the table values ​​provide examples of radial and rotational deformation of the elastic element 130.

[0083] The elastic element 130 can be defined as having a first portion 201 fixed to the first transparent covering member or the second transparent covering member (e.g., Figure 2AThe middle contact covering member 111) and the second part 202 fixed to the actuator displacement element (e.g., Figure 2A The structure of the surface of the contact actuator displacement element 122. The first part 201 and the second part 202 are elastically connected so that they can elastically displace relative to each other, for example in the radial direction toward the optical axis. The elastic element 130 can be integrally manufactured from an elastic material such as silicone, polymer, metal, plastic and other materials.

[0084] like Figure 1B As shown in other examples herein, the first portion 201 of the elastic element 130 is connected to the first transparent covering member at a separate location distributed along a path around the optical axis.

[0085] Generally, one or more elastic elements 130 should be configured to allow radial deformation at a given location (i.e., the location of actuator displacement element 122), which is independent of or substantially independent of the deformation of other elastic elements 130 at other locations. Therefore, at least a portion of one or more elastic elements 130 (e.g., the first portion 201) should be arranged to displace at other locations independently of or substantially independently of the first portion 201. Obviously, as... Figure 1A As shown, this can be achieved when a single elastic element 130 is used for each actuator displacement element 122. However, this can also be achieved when the elastic element 130 is configured with multiple deformable portions (e.g., multiple first portions 201) that are not individually and independently connected to the corresponding multiple actuator displacement elements 122.

[0086] Figure 2B An alternative solution for avoiding stress in the first cover member 111 or the second cover member 112 is shown. According to this alternative solution, the controllable lens 100 is configured with a sliding contact 239 instead of an elastic element 130.

[0087] The sliding contact 239 can be embodied by a low-friction contact between the actuator displacement element 122 and the first cover member 111 or the second cover member 112. This low-friction contact can be achieved by a pair of low-friction materials, such as the material of the contact portion of the actuator displacement element 122, which provides low or sufficiently low friction relative to the surface of the first cover member 111 or the second cover member 112. Examples include polyethylene and other plastic materials. Therefore, the sliding contact 239 does not need to be a separate element, but can be formed by direct contact between the actuator displacement element 122 and the first cover member 111 or the second cover member 112. Alternatively, the sliding contact can be embodied by a low-friction material attached to the end of the actuator displacement element 122.

[0088] The sliding contact 304 is configured such that when the cover member bends due to the displacement ΔL1 along the z-axis by the actuator displacement element 122, the sliding contact 239 can slide over the surfaces of the first cover member 111 and the second cover member 112. In this example, the displacement produces a bending or additional bending of the first cover member 111, causing the contact point 281 to move from x0,z0 to x1,z1 due to radial displacement of the contact point 281 toward the optical axis (i.e., displacement along the x-axis of the local xyz coordinate system) and due to displacement along the z-axis. During the bending process, the sliding contact 239 slides over the surface of the cover member, as... Figure 2B As shown.

[0089] Figures 3A-3C An example of an elastic element 130 is shown, which is configured with multiple deformable portions in the form of multiple spring elements 301.

[0090] Spring element 301 includes a first portion 201. For example, the first portion 201 may be represented by an end face representing a cantilever structure of the spring element. The cantilever structure bends in response to bending of the first cover member 111 or the second cover member 112. The bending of the cantilever structure includes a combination of tilting of the cantilever toward the optical axis and rotation of the cantilever. Thus, the bending of the cantilever spring 301 contributes to the requirement that the elastic element 130 provides low stiffness in response to deformation in the radial direction and in response to rotation (such as rotation about the tangential axis or the y-axis).

[0091] Each of the spring elements 301 is separated from the adjacent spring element so that each of the spring elements 301 can deform independently or substantially independently of the adjacent spring element 301. Thus, the spring elements are constructed as individual spring elements.

[0092] The elastic element includes a support member 302. As mainly shown, the actuator displacement element 122 is arranged to act on the surface of the support member 302. Therefore, the support member 302 includes a second portion 202, and the support member is configured for common support of a plurality of displacement elements 122, that is, the plurality of displacement elements 122 are arranged to act together on the support member 302, such that the displacement of the displacement elements 122 is commonly transmitted to the support member.

[0093] Alternatively or additionally, the support member 302, including the second part 202, is configured as a common support for a plurality of spring elements 301 or a plurality of elastic portions (e.g., elastic adhesive portions) typically used for elastic elements 130, wherein the plurality of spring elements 301 or elastic portions are arranged to act together on the support member 302, i.e., the plurality of spring elements 301 or elastic portions are connected together to the support member 302, such that the reaction forces of the spring elements 301 or elastic portions are transmitted together to the support member.

[0094] In this example, the second portion 202 constitutes a more rigid portion of the elastic element 130, i.e., a portion having a higher elastic coefficient than the radial elastic coefficient k1 of the elastic portion of the elastic element 130, such as an end portion. Similarly, the first portion 201 can also constitute a more rigid portion of the elastic element 130.

[0095] In this example, the support member 302 is formed as a ring structure having an opening that forms a through hole in the lens 100.

[0096] Figures 3A-3C The elastic element 130 can be formed integrally. In another example, the spring element 301 is made of a different material than the support member.

[0097] In this example, the first covering member 111 and the second covering member 112 are each independently actuated via the upper first elastic element 130 and the lower second elastic element 130a.

[0098] Figures 4A-4D Another example of an elastic element 130 configured with multiple spring elements 301 is shown.

[0099] like Figure 4B and 4D As shown, the spring element 301 is formed as a U-shaped element. The end portion of the spring element 301 includes a first portion 201.

[0100] The U-shaped design of spring element 301 allows for radial movement of the contact point (i.e., the first portion 201) and tilting along the y-axis (see Figure 2). The cross-sectional thickness of spring element 301 can vary from the first portion 201 to the second portion 202 to achieve the desired characteristics of the first spring constant k1 and the second spring constant k2. Due to the thickness t of spring element 301 in the direction of the optical axis 150... Figure 4C The spring constant k2 in the optical axis direction can be greater than the spring constant k1 in the radial direction. Furthermore, the torsional spring constant around the y-axis (see Figure 2) can be sufficiently low relative to the second spring constant k2.

[0101] The asymmetrical design and eccentric position of the first portion 201 supporting the cover members 111 and 112 are conducive to tilting along the y-axis. That is, when the first portion 201 is subjected to pressure, the asymmetrical design supports the tilting caused by the bending of the cover members 111 and 112.

[0102] Figure 4CThe elastic element 130 is shown to be formed as a flat structure, including an end portion of a first portion 201 that protrudes outward, such that the first portion 201 is away from the other portions of the elastic element 130 in the direction of the optical axis 150. Due to the protruding first portion 201, a first covering member 111 and / or a second covering member 112 can be connected to the first portion 201, while the gap between the covering member and the elastic element 130 is provided by the protruding first portion.

[0103] In particular, the gap provided by the protrusion of the spring 301 (such as the protruding first portion 201) allows the cover members 111, 112 to bend while still ensuring the gap between the cover member and the inner periphery of the support member 302, wherein the minimum gap occurs at the maximum size of the cover member.

[0104] In the same example, spring element 301 is constructed as a separate spring element.

[0105] In this example, a plurality of elastic elements 130_1, 130_2 are arranged such that the inner periphery of the plurality of elastic elements 130_1, 130_2 forms an opening that constitutes a perforation in the lens 100.

[0106] In this example, each elastic element 130 includes two springs 301, although each elastic element 130 may have one or more springs 301 and be configured, for example, such that a single elastic element 130 forms an aperture constituting a perforation in the lens 100, as... Figures 3A-3C As shown.

[0107] Similarly, for Figures 3A-3C Each elastic element 130 includes a support member 302. The actuator displacement element 122 is connected to the support member 302 via a second portion 202 of the elastic element 130.

[0108] Therefore, in this example, each of the support members 302 is configured as a common support for a plurality of spring elements 301 or for the elastic portion of the elastic element 130. As shown, the displacement element 122 is connected one-to-one with the support member 302, but each of the support members 302 may alternatively be configured as a common support for a plurality of displacement elements.

[0109] Figures 4A-4D Other supporting components 130 in the design can be integrally formed, for example, as a MEMS structure, by injection molding, 3D printing or other methods.

[0110] Compared to the spring element 301, the portion of the elastic element 130 that forms the support member 302 is positioned radially closer to the optical axis 150.

[0111] Figures 3A-3C and Figures 4A-4D The elastic element 130 can be configured such that, in addition to one or more spring elements 301, the elastic element 130 also includes an elastic material (e.g., an elastic adhesive) connected to the first portion 201 and / or the second portion 202, such that the first portion 201 is fixed to the actuator displacement element 122 via the adhesive and / or the second portion 202 is fixed to the first cover member 111 or the second cover member 112. The combination of the spring elements 301 and the elastic material (e.g., adhesive) provided to connect the first portion 201 and / or the second portion 202 to the displacement element 122 and the cover members 111, 112 respectively can advantageously improve the ability of the elastic element 130 to deform in response to the bending of the cover members 111, 112, thereby reducing stress generation in the cover members.

[0112] Figures 6A-6C An alternative configuration of the elastic element 130 is shown. Figure 6A The elastic element 130 is shown to include a ring structure, which includes a second part 202. Figures 6A-6B Only the actuator displacement element 122 fixed to the second portion is shown. The elastic element includes a plurality of spring elements 301 configured as a hinge structure. The spring elements are fixed to the first cover member 111 via their first portion 101.

[0113] Figure 6C Possible configurations of hinge structures 601 and 602 are shown, which are formed by creating a thin thickness along the direction defining the hinge axis. The xyz coordinate system shown is defined relative to surface 202a, which is here fixed to the second part 202 via a ring structure.

[0114] Therefore, the spring element 301 includes a first hinge structure 601 that defines a rotation axis that allows rotation about the y-axis or about an axis tangent to the path 151 surrounding the optical axis 150. Thus, the first hinge structure 601 supports relative rotation about the y-axis between the first transparent cover member 111 and the actuator displacement element 122. In other words, the first hinge structure is arranged to elastically deform in response to a torque Ty about the y-axis generated by the relative displacement between the first transparent cover member and the actuator displacement element.

[0115] The spring element 301 further includes a second hinge structure 602 that defines a rotation axis that allows rotation about the z-axis and is thereby supported. Due to the extension of the spring element 301 to rotate along the y-axis and z-axis, the second hinge structure 602 generates radial movement and thus supports relative radial displacement between the first transparent cover member 111 and the actuator displacement element 122.

[0116] The rotational stiffness of the first hinge structure 601 and the second hinge structure 602 depends on the material stiffness and is therefore designed as needed, but obviously has a lower limit. Similarly, by designing the first hinge structure 601 and the second hinge structure 602 to have sufficiently high lengths along the hinge axis, the hinge structure can be designed to have high stiffness in the z-axis direction.

[0117] Advantageously, the rotation of the y-axis and z-axis provided by the first hinge structure 601 and the second hinge structure 602 provides decoupled rotation.

[0118] Figure 7 An alternative spring structure 301 with a first hinge structure 601 and a second hinge structure 602 is shown, which is consistent with... Figure 6C Equivalent, but in a configuration that reduces height along the z-axis. Figure 7 and Figure 6C The two second hinge structures 602 allow the first portion 201 of the spring element 301 to be radially displaced, i.e., displaced in the x-direction, without rotating about the z-axis.

[0119] Figure 8 The requirements for the elastic element 130 are summarized. Therefore, the illustration on the left shows that the elastic element 130, or a portion thereof (including the spring element 301), is in a state where the actuator 121 does not generate force, i.e., F = 0. Therefore, the first cover member 111 is in a state where its curvature is not changed by the actuator.

[0120] In the illustration on the right, the actuator displacement element has been activated to cause a z-axis displacement of ΔL1. Due to the reaction force caused at least partially by the bending of the first cover member 111, the z-axis displacement generates a non-zero balancing force F1 in the z-direction (i.e., in the static bending state of the cover member). The z-axis displacement generated by actuator 121 causes the first cover member 111 to bend, as shown in the magnified view. In addition to the z-axis displacement ΔL1, the bending also causes a radial displacement of the first portion 201 along the x-axis and a rotation of the first portion 201 about the y-axis. Different examples of the elastic element 130 described herein provide the same response to the displacement of actuator displacement element 122, namely radial displacement and rotation, to support the bending of the first cover member 111 or the second cover member.

[0121] Figure 5A cross-sectional view of an electronic device 500 is shown, which may be part of a smartphone, tablet, laptop, or other device. Device 500 may include a camera module 501 arranged to image light received via a perforation 502 onto an image sensor. A controllable lens 100 forms part of the camera module 501 and optionally other lenses, as well as the image sensor. Examples of electronic devices 500 include portable computers, smartphones, watches, tablets, cameras, eyeglasses with variable lenses, measuring devices arranged for scanning distances, and image projectors arranged for creating images by scanning a light beam. Therefore, lens 100 can be used for a variety of purposes, such as imaging, light and image projection, beam scanning, light-detection lidar scanning, etc.

Claims

1. A controllable lens (100) with variable optical power, the lens comprising: - A first covering member (111) and a second covering member (112), wherein one of the first covering member and the second covering member is transparent, and the other of the first covering member and the second covering member is transparent or reflective. - A transparent, deformable non-fluid body (105) sandwiched between the first covering member and the second covering member, such that the first covering member, the second covering member, and the non-fluid body constitute a lens having an optical axis (150) intersecting the first covering member, the second covering member, and the non-fluid body. - One or more actuators (121) comprising a plurality of actuator displacement elements (122) arranged to displace in a direction parallel to the optical axis, and the one or more actuators arranged to cause at least a first cover member to bend in response to a force provided by the one or more actuators. - One or more elastic elements (130, 130_1, 130_2) connecting the actuator displacement element to the first cover member, wherein at least a portion of each of the one or more elastic elements is arranged to elastically deform in response to a relative radial displacement between the first cover member and the actuator displacement element (122), the relative radial displacement being generated in response to displacement of the actuator displacement element. Each of the one or more elastic elements has a first stiffness in the radial direction and a second stiffness in the direction of the optical axis, wherein the first stiffness is less than the second stiffness, and the first stiffness is configured to enable radial deformation in the range of 0.05 μm to 500 μm, and wherein the controllable lens is configured such that, in response to the displacement of the actuator displacement element (122) in a direction parallel to the optical axis and the resulting bending of the first cover member, the surface at the interface between the one or more elastic elements (130) and the first cover member (111) rotates about an axis tangential to a path (151) around the optical axis (150).

2. The controllable lens according to claim 1, wherein, Each of the one or more elastic elements is arranged to elastically deform in response to a torque (Ty) about an axis tangential to the path (151) surrounding the optical axis, wherein the torque is generated by the relative radial displacement between the first cover member and the actuator displacement element.

3. The controllable lens according to claim 1, wherein, Each of the one or more elastic elements has at least one first portion (201) fixed to the first cover member and a second portion (202) fixed to at least one actuator displacement element, wherein the first portion and the second portion are elastically connected.

4. The controllable lens according to claim 3, wherein, The controllable lens includes a plurality of first portions (201) of the one or more elastic elements (130), wherein the first portions are connected to the first covering member (101) at separate locations distributed along a path (151) around the optical axis.

5. The controllable lens according to claim 1, wherein, Each of the one or more elastic elements has a first spring constant (k1) in the radial direction and a second spring constant (k2) in the direction of the optical axis, wherein the first spring constant (k1) is smaller than the second spring constant (k2).

6. The controllable lens according to claim 1, wherein, The actuator is fixed to the fixed support (190) such that the displacement element (122) is arranged to be displaced relative to the fixed support.

7. The controllable lens according to claim 1, wherein, The controllable lens includes one or more second elastic elements (130a) that connect the actuator displacement element (122) to the second cover member (112).

8. The controllable lens according to claim 1, wherein, Each of the one or more elastic elements includes an elastic adhesive.

9. The controllable lens according to claim 1, wherein, Each of the one or more elastic elements (130) includes one or more spring elements (301), wherein each spring element includes the first portion (201) according to claim 3.

10. The controllable lens according to claim 9, wherein, Each of the spring elements is constructed as an individual spring element.

11. The controllable lens according to claim 9, wherein, Each of the spring elements is configured as a separate spring element and each of the one or more elastic elements includes a support member (302) arranged as a common support for a plurality of displacement elements (122) and / or for a plurality of elastic portions of each of the one or more elastic elements, wherein the support member includes the second portion (202) according to claim 3.

12. The controllable lens according to claim 9, wherein, Each of the spring elements is configured as an individual spring element, and each of the one or more elastic elements includes a support member (302) arranged as a common support for a plurality of displacement elements (122) and / or for a plurality of elastic portions of each of the one or more elastic elements, the support member including a second portion (202) according to claim 3, and wherein each of the one or more support members is positioned radially closer to the optical axis compared to the spring element.

13. The controllable lens according to claim 1, wherein, The controllable lens includes a first elastic element (130) that connects the actuator displacement element to the first cover member (111) and a second elastic element (130a) that connects other actuator displacement elements included in the controllable lens to the second cover member (112).

14. The controllable lens according to claim 3, wherein, Each of the one or more elastic elements includes one or more spring elements (301) and elastic material connected to the first and / or second portions (201, 202).

15. An electronic device comprising a controllable lens (100) according to claim 1.

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