Electronic device with adjustable lens having two adjustable surfaces - Patents.com

Abstract

The lens module may include a first lens element, a lens shaping structure coupled to the first lens element, and a plurality of actuators configured to adjust a position of the lens shaping structure to adjust the first lens element. The lens module may also include a second lens element and a fluid-filled chamber between the first lens element and the second lens element. The second lens element may be a semi-rigid lens element to allow dynamic adjustment of the second lens element without the need for an additional actuator. When the actuator adjusts the curvature of the first lens element, a gauge pressure applied to the second lens element is changed, which changes the curvature of the second lens element. Thus, the actuator may adjust the curvature of both the first and second lens elements even if neither actuator is attached to the second lens element.

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 174,840, filed April 14, 2021, which is incorporated by reference in its entirety.

[0002] The present application relates generally to electronic devices, and more particularly, to wearable electronic device systems. [Background technology]

[0003] An electronic device may be configured to be worn by a user. For example, a head-mounted device is provided with a head-mounting structure that allows the device to be worn on the user's head. The head-mounted device may include an optical system having a lens that allows a display within the device to present visual content to the user.

[0004] Head-mounted devices typically include lenses with certain shapes and characteristics that, if not careful, can be difficult to adjust to optimally present content to each user of the head-mounted device. Summary of the Invention

[0005] The head-mounted device may have a display that displays content to a user, and a head-mounted support structure within the device supports the display on the user's head.

[0006] The lens module in the head mounted device may include a first transparent lens element, a lens molding structure coupled to the first transparent lens element, and a plurality of actuators configured to adjust a position of the lens molding structure to adjust the first transparent lens element. The lens module may also include a second transparent lens element and a fluid-filled chamber between the first and second transparent lens elements.

[0007] To allow dynamic adjustment of the second transparent lens element without the need for additional actuators in the lens module, the second transparent lens element may be a semi-rigid transparent lens element. When the actuator adjusts the curvature of the first transparent lens element, a gauge pressure applied to the second transparent lens element is changed, which changes the curvature of the second transparent lens element. Thus, the actuator may adjust the curvature of both the first transparent lens element and the second transparent lens element without either actuator being attached to the second transparent lens element.

[0008] The second transparent lens element may optionally be coupled to a biasing structure or a flexible seal to cause the second transparent lens element to gradually change curvature as the curvature of the first transparent lens element is updated. In some configurations, the second transparent lens element may be a bi-stable lens element that is convex in a first stable state and concave in a second stable state.

[0009] The lens module may also include a second fluid-filled chamber in addition to the first fluid-filled chamber. A channel between the first and second fluid-filled chambers may allow fluid to move between the first and second fluid-filled chambers. Valves in the channel may be opened and closed to allow fluid exchange. An actuator that manipulates the first transparent lens element may be used to control the amount of fluid in each of the first and second fluid-filled chambers. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of an exemplary electronic device, such as a head mounted display device, according to one embodiment. [Diagram 2] FIG. 2 illustrates a top view of an exemplary head-mounted device according to one embodiment. [Figure 3A]1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a rigid lens element according to one embodiment. [Figure 3B] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a rigid lens element according to one embodiment. [Figure 4] FIG. 13 is a top view of an exemplary lens shaping element including extensions for coupling to individual actuators in accordance with one embodiment. [Figure 5A] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a semi-rigid lens element according to one embodiment. [Figure 5B] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a semi-rigid lens element according to one embodiment. [Figure 6A] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a semi-rigid lens element coupled to a biasing structure according to one embodiment. [Figure 6B] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a semi-rigid lens element coupled to a biasing structure according to one embodiment. [Figure 7A] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a semi-rigid lens element coupled to a flexible seal according to one embodiment. [Figure 7B] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a semi-rigid lens element coupled to a flexible seal according to one embodiment. [Figure 8] 1 is a cross-sectional side view of an exemplary lens module including first and second fluid-filled chambers and a valve for controlling flow between the first and second fluid-filled chambers according to one embodiment. [Figure 9A] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a bi-stable semi-rigid lens element according to one embodiment. [Figure 9B] 1 is a cross-sectional side view of an exemplary lens module including an elastomeric lens element and a bi-stable semi-rigid lens element according to one embodiment. [Figure 10] 1 is a graph of an exemplary profile of the radius of curvature of a lens element as a function of gauge pressure for the lens element according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The electronic device may include a display and other components for presenting content to a user. The electronic device may be a wearable electronic device. A wearable electronic device, such as a head-mounted device, may have a head-mounted support structure that allows the head-mounted device to be worn on the head of a user.

[0012] The head mounted device may include a display formed of one or more display panels (displays) for displaying visual content to a user. A lens system may be used to enable the user to focus on the display and view the visual content. The lens system may have a left lens module aligned with the user's left eye and a right lens module aligned with the user's right eye.

[0013] The lens module in the head mounted device may include adjustable lenses, for example fluid filled adjustable lenses, to adjust the displayed content for a particular viewer.

[0014] A schematic diagram of an exemplary system having an exemplary electronic device with a lens module is shown in Figure 1. As shown in Figure 1, system 8 may include one or more electronic devices, such as electronic device 10. The electronic devices of system 8 may include computers, mobile phones, head-mounted devices, watch devices, and other electronic devices. Configurations in which electronic device 10 is a head-mounted device are sometimes described herein as an example.

[0015] As shown in FIG. 1, an electronic device such as electronic device 10 can have a control circuit 12. The control circuit 12 can include storage and processing circuitry that controls the operation of device 10. The control circuit 12 can include storage, such as, for example, hard disk drive storage, non-volatile memory (e.g., electrically programmable read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random access memory). The processing circuitry of the control circuit 12 can be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, graphics processing units, application specific integrated circuits, and other integrated circuits. Software code can be stored on a storage device in the circuit 12 and executed on the processing circuitry in the circuit 12 to perform control operations of the device 10 (e.g., data collection operations, operations involving processing three-dimensional facial image data, operations involving adjusting components using control signals, etc.). The control circuit 12 can include wired communication circuitry and wireless communication circuitry. For example, control circuitry 12 may include radio frequency transceiver circuitry, such as cellular telephone transceiver circuitry, wireless local area network (WiFi) transceiver circuitry, millimeter wave transceiver circuitry, and / or other wireless communication circuitry.

[0016] In operation, communication circuitry of devices in system 8 (e.g., communication circuitry of control circuitry 12 of device 10) may be used to support communication between electronic devices. For example, one electronic device may transmit video and / or audio data to another electronic device in system 8. Electronic devices in system 8 may communicate over one or more communication networks (e.g., the Internet, a local area network, etc.) using wired and / or wireless communication circuitry. The communication circuitry may be used to enable device 10 to receive data from and / or provide data to external devices (e.g., portable devices such as tethered computers, handheld devices or laptop computers, online computing devices such as remote servers or other remote computing devices, or other electrical devices).

[0017] Device 10 may include input / output devices 22. Input / output devices 22 may be used to allow a user to provide user input to device 10. Input / output devices 22 may also be used to gather information about the environment in which device 10 is operating. Output components within device 22 may allow device 10 to provide output to the user, and may be used to communicate with external electrical equipment.

[0018] 1, input / output device 22 can include one or more displays, such as display 14. In some configurations, display 14 of device 10 includes left and right display panels (sometimes referred to as left and right portions of display 14 and / or a left display and a right display) aligned with a user's left and right eyes, respectively. In other configurations, display 14 includes a single display panel that extends across both eyes.

[0019] Display 14 may be used to display images. A user of device 10 may view visual content displayed on display 14. A display of device 10, such as display 14, may be an organic light-emitting diode display or other display based on an array of light-emitting diodes, a liquid crystal display, a liquid-crystal-on-silicon display, a projector or display based on projecting a light beam onto a surface directly or indirectly via dedicated optical elements (e.g., digital micromirror devices), an electrophoretic display, a plasma display, an electrowetting display, or any other suitable display.

[0020] The display 14 can present display content for computer-generated reality, such as virtual reality content or mixed reality content. A configuration in which the display 14 is used to display virtual reality content to a user via lenses may be described herein as an example.

[0021] The input / output circuitry 22 may include a sensor 16, such as, for example, a three-dimensional sensor (e.g., a three-dimensional image sensor such as a structured light sensor that emits a light beam and uses a two-dimensional digital image sensor to collect image data for a three-dimensional image from a light spot that is generated when a target is illuminated by the light beam, a binocular three-dimensional image sensor that collects a three-dimensional image using two or more cameras in a binocular imaging configuration, a three-dimensional lidar (light detection and ranging) sensor, or a three-dimensional image sensor (e.g., a binocular three-dimensional image sensor that collects a three-dimensional image using two or more cameras in a binocular imaging configuration). The sensors 16 may include sensors such as a 3D ranging (radio, frequency, or other sensors that collect three-dimensional image data), cameras (e.g., infrared and / or visible digital image sensors), eye tracking sensors (e.g., eye tracking systems based on image sensors and, if desired, light sources that emit one or more light beams that are reflected from the user's eyes and then tracked using the image sensors), sensors such as touch sensors, buttons, force sensors, switch-based contact sensors, gas sensors, pressure sensors, humidity sensors, magnetic sensors, audio sensors (microphones), ambient light sensors, microphones for collecting voice commands and other audio inputs, sensors configured to collect information regarding movement, position, and / or orientation (e.g., accelerometers, gyroscopes, compasses, and / or inertial measurement units including all of these sensors or a subset of one or two of these sensors), and / or other sensors. The sensors 16 may include proximity sensors (e.g., capacitive proximity sensors, light-based (optical) proximity sensors, ultrasonic proximity sensors, and / or other proximity sensors). The proximity sensor may be used, for example, to sense the relative position between the user's nose and a lens module within the device 10.

[0022] User input and other information may be collected using sensors and other input devices in input / output device 22. If desired, input / output device 22 may include other devices 24, such as tactile output devices (e.g., vibrating components), light emitting diodes and other light sources, speakers, such as ear speakers, for generating audio output, and other electrical components. Device 10 may include circuitry for receiving wireless power, circuitry for transmitting power wirelessly to other devices, batteries and other energy storage devices (e.g., capacitors), joysticks, buttons, and / or other components.

[0023] Electronic device 10 may have a housing structure (e.g., housing walls, straps, etc.), as illustrated by exemplary support structure 26 in Fig. 1. In configurations in which electronic device 10 is a head-mounted device (e.g., a pair of glasses, goggles, a helmet, a hat, etc.), support structure 26 may include a head-mounted support structure (e.g., a helmet housing, a head strap, temples for a pair of glasses, a goggle housing structure, and / or other head-mounted structure). The head-mounted support structure may be configured to be worn on a user's head during operation of device 10 and may support display(s) 14, sensors 16, other components 24, other input / output devices 22, and control circuitry 12.

[0024] Figure 2 is a plan view of electronic device 10 in an exemplary configuration in which electronic device 10 is a head-mounted device. As shown in Figure 2, electronic device 10 may include support structures (see, e.g., support structure 26 in Figure 1) that house components of device 10 and are used to mount device 10 on a user's head. These support structures may include, for example, structures that form housing walls and other structures for main unit 26-2 (e.g., outer housing walls, lens module structures, etc.), and straps or other auxiliary support structures, such as structure 26-1 that help hold main unit 26-2 on the user's face.

[0025] The display 14 may include left and right display panels (e.g., also sometimes referred to as left and right pixel arrays, left and right displays, or left and right display portions) mounted on left and right display modules 70 corresponding to a user's left and right eyes, respectively. A display module corresponding to a user's left eye is shown in FIG.

[0026] Each display module 70 includes a display portion 14 and a corresponding lens module 72 (sometimes referred to as a lens stackup 72, a lens 72, or an adjustable lens 72). The lens 72 may include one or more lens elements arranged along a common axis. Each lens element may have any desired shape and may be formed from any desired material (e.g., having any desired index of refraction). The lens elements may have unique shapes and indexes of refraction that combine to focus light from the display 14 in a desired manner. Each lens element of the lens module 72 may be formed from any desired transparent material (e.g., glass, a polymeric material such as polycarbonate or acrylic, a crystalline material such as sapphire, etc.).

[0027] The modules 70 may optionally be individually positioned relative to the user's eyes and relative to some of the housing wall structures of the main unit 26-2 using positioning circuitry such as positioner 58. Positioner 58 may be a stepper motor, a piezoelectric actuator, a motor, a linear electromagnetic actuator, and / or other electronic components for adjusting the position of the display 14 and lens module 72. Positioner 58 may be controlled by control circuitry 12 during operation of device 10. For example, positioner 58 may be used to adjust the spacing between modules 70 (and thus the inter-lens spacing between the left and right lenses of module 70) to match the interpupillary distance IPD of the user's eyes.

[0028] In some cases, the distance between the lens module 72 and the display 14 is variable. For example, the distance between the lens module and the display can be adjusted to account for the field of view of a particular user. In other examples, the lens module can include adjustable lens elements. The curvature of the adjustable lens elements can be adjusted in real time to compensate for the user's vision, as one example.

[0029] In some cases, the adjustable lens module may include a fluid-filled chamber. Figures 3A and 3B are cross-sectional side views of an adjustable lens module 72 having a fluid-filled chamber. As shown, a fluid-filled chamber 82 (sometimes referred to as chamber 82 or fluid chamber 82) containing a fluid 92 is interposed between lens elements 84 and 86.

[0030] The fluid 92 may be a liquid, gel, or gas having a predetermined refractive index (and may therefore be referred to as a liquid 92, gel 92, or gas 92). The fluid may also be referred to as an index-matching oil, optical oil, optical fluid, index-matching material, index-matching liquid, or the like. The lens elements 84, 86 may have the same or different refractive indices. The fluid 92 filling the chamber 82 between the lens elements 84 and 86 may have a refractive index that is the same as that of the lens element 84 but different from that of the lens element 86, may have a refractive index that is the same as that of the lens element 84 but different from that of the lens element 86 but different from that of the lens element 84, may have a refractive index that is the same as that of the lens element 84 and the lens element 86, or may have a refractive index that is different from that of the lens element 84 and the lens element 86. The lens elements 84, 86 may be circular, elliptical, or may have any other desired shape.

[0031] The amount of fluid 92 in chamber 82 can have a fixed volume or an adjustable volume. If the amount of fluid is adjustable, the lens module can also include a fluid reservoir and fluid control components (e.g., pumps, stepper motors, piezoelectric actuators, motors, linear electromagnetic actuators, and / or other electronic components that apply forces to the fluid in the fluid reservoir) for selectively transferring fluid between the fluid reservoir and the chamber.

[0032] Lens elements 84, 86 may be transparent lens elements formed from any desired material (e.g., glass, polymeric materials such as polycarbonate or acrylic, crystals such as sapphire, etc.). Each of lens elements 84, 86 may be elastomeric, semi-rigid, or rigid. Elastomeric lens elements may be formed from natural or synthetic polymers that have a low Young's modulus for high flexibility. For example, elastomeric lens element 84 (sometimes referred to as an elastic membrane) may be formed from a material having a Young's modulus of less than 1 GPa, less than 0.5 GPa, less than 0.1 GPa, etc.

[0033] The semi-rigid lens element may be formed from a semi-rigid material that is rigid and solid but not inflexible. The semi-rigid lens element may be formed from a thin layer of polymer or glass, for example. The semi-rigid lens element may be formed from a material having a Young's modulus of greater than 1 GPa, greater than 2 GPa, greater than 3 GPa, greater than 10 GPa, greater than 25 GPa, etc. The semi-rigid lens element may be formed from polycarbonate, polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), acrylic, glass, or any other desired material. The properties of the semi-rigid lens element allow the lens element to be rigid along a first axis when the lens element is curved along a second axis perpendicular to the first axis. This is in contrast to an elastomeric lens element, which is still flexible along a first axis even when the lens element is curved along a second axis perpendicular to the first axis. The properties of the semi-rigid lens elements may enable them to form a cylindrical lens with adjustable lens power and an adjustable axis. The semi-rigid lens elements may be stiffer than elastomeric lens elements, but less stiff than rigid lens elements.

[0034] The rigid lens elements may be formed from glass, polymeric materials such as polycarbonate or acrylic, crystals such as sapphire, etc. In general, the rigid lens elements may not deform when pressure is applied to the lens elements within the lens module. In other words, the shape and position of the rigid lens elements may be fixed. Each surface of the rigid lens elements may be flat, concave (e.g., spherically or cylindrically concave), or convex (e.g., spherically or cylindrically convex). The rigid lens elements may be formed from a material having a Young's modulus of greater than 25 GPa, greater than 30 GPa, greater than 40 GPa, greater than 50 GPa, etc.

[0035] 3A and 3B (and subsequent figures), the viewer may be configured to view the lens module in a positive Z direction. That is, lens element 86 is interposed between the viewer and lens element 84 when the viewer operates device 10. In other words, lens element 84 is interposed between lens element 86 and display 14 when the viewer operates device 10.

[0036] In addition to the lens elements 84, 86 and the fluid-filled chamber 82, the lens module 72 also includes a lens shaping element 88. The lens shaping element 88 may be coupled to one or more actuators 90. By way of example, multiple actuators may be positioned around the circumference of the lens shaping element, or a single actuator may control the deflection of the lens shaping element at multiple points around the circumference of the lens shaping element. The lens shaping element 88 may also be coupled to the lens element 84. The actuator 90 may be moved to position the lens shaping element 88 (which may also be referred to as a lens shaper 88, a deformable lens shaper 88, a lens shaping structure 88, a lens shaping member 88, an annular member 88, a ring-like structure 88, etc.). The lens shaping element 88 then manipulates the positioning / shaping of the lens element 84. In this manner, the curvature of the lens element 84 (and thus the lens power of the lens module 72) may be adjusted. An example of an actuator 90 and a lens shaper 88 used to change the curvature of the lens element 84 is shown in FIG. 3B. As shown, the lens shaper 88 is moved in a direction 94 by the actuator 90. As a result, lens element 84 has a different curvature in FIG. 3A (convex curvature) than in FIG. 3B (concave curvature).

[0037] FIG. 4 is a top view of an exemplary lens shaping element 88. As shown, the lens shaping element 88 may have an annular or ring shape in which the lens shaping element surrounds a central opening. The lens shaping element may have any desired shape. For example, the lens shaping element may have a circular, elliptical, or irregular shape. In the example of FIG. 4, the lens shaping element has an irregular shape (e.g., a non-uniform radius around the ring shape). For example, a first distance 96 (e.g., a minimum distance) from the center of the central opening to the edge of the lens shaping element may be less than a second distance 98 (e.g., a maximum distance) from the center of the central opening to the edge of the lens shaping element. The distances 96, 98 may be less than 100 millimeters, less than 60 millimeters, less than 40 millimeters, less than 30 millimeters, more than 10 millimeters, more than 20 millimeters, between 10 and 50 millimeters, etc.

[0038] The lens shaping element 88 has a number of tabs 88E extending from a main portion of the lens shaping element. Each of the tabs 88E (sometimes referred to as extensions 88E, actuator points 88E, etc.) may be coupled to a separate actuator (or a respective deflection control portion of a single actuator). In one example, each actuator tab may protrude into a slot in the actuator (e.g., a tongue-and-groove configuration). The slot may be selectively moved up or down (e.g., in the Z direction) to control the position of the tabs 88E in the Z direction. That is, the actuator 90 is a linear actuator. These examples are merely illustrative. In general, any desired type of actuator may be used (e.g., a tongue-and-groove actuator, an actuator having a hinged paddle, etc.).

[0039] 4 illustrates how multiple tabs 88E (and corresponding actuators) may be distributed around the circumference of the lens shaping element 88. The tabs 88E may be distributed evenly (e.g., with equal spacing between each pair of adjacent tabs 88E) or unevenly (e.g., with unequal spacing between at least two of the adjacent tabs 88E) around the circumference of the lens shaping element 88.

[0040] Between each pair of adjacent tabs 88E is a lens shaper segment 88S. In the example of FIG. 4, there are eight tabs 88E around the periphery of the lens shaping element 88. This example is illustrative only. In general, more tabs (and corresponding actuators) allow for greater control of the shape of the lens element (e.g., lens element 84) to which the lens shaping element 88 is coupled. Any desired number of tabs and actuators (e.g., 1, 2, 3, 4, more than 4, more than 6, more than 8, more than 10, more than 12, more than 20, less than 20, less than 10, between 4 and 12, etc.) can be used, depending on the particular target shape of the lens element, the target cost / complexity of the lens module, etc.

[0041] In general, each actuator may act as a point force that applies force in only one direction (e.g., parallel to the Z axis). To prevent unintentional application of torque or other forces to the lens shaping elements 88, the actuator slot may be larger than the extension 88E. This provides space for the tab 88E to rotate within the slot (preventing torque from being applied to the lens shaper). Additionally, the extension 88E may slide in and out of the slot to prevent unintentional stretching of the lens shaping elements.

[0042] Lens shaping element 88 may be elastomeric (e.g., a natural or synthetic polymer having a low Young's modulus for high flexibility, as described in more detail above) or semi-rigid (e.g., formed from a semi-rigid material that is rigid and solid but not inflexible, as described in more detail above). Semi-rigid lens shaping elements may be formed, for example, from thin layers of polymer, glass, metal, etc. Because lens shaping element 88 is formed in a ring around the lens module, lens shaping element 88 need not be transparent (and thus may be formed from an opaque material, such as metal).

[0043] 3A and 3B, the lens element 86 and / or the actuator 90 may be attached to a support structure 102 (sometimes referred to as a lens module support structure 102, a lens housing 102, etc.). The support structure 102 may be formed in a ring shape around the lens module and may be formed from an opaque or transparent material. The support structure 102 may be rigid and thus provide mechanical strength to the lens module 72. The chamber 82 may be defined by the lens elements 84, 86, the support structure 102, and / or a flexible bellows 104. The flexible bellows 104 may expand and contract to accommodate the chamber manipulated by the lens shaper 88 and the actuator 90.

[0044] In the example of FIGS. 3A and 3B, lens element 84 is an elastomeric lens element and lens element 86 is a rigid lens element (e.g., having a greater stiffness than lens element 84). In FIG. 3A, lens element 84 is manipulated by lens shaping element 88 to have a convex shape. In this type of configuration, a positive gauge pressure can be applied to rigid lens element 86 (e.g., a negative Z-direction force). In FIG. 3B, lens element 84 is manipulated by lens shaping element 88 to have a concave shape. In this type of configuration, a negative gauge pressure can be applied to rigid lens element 86 (e.g., a positive Z-direction force). However, in both FIGS. 3A and 3B, because lens element 86 is a rigid lens element, the shape of lens element 86 remains constant regardless of whether a positive or negative gauge pressure is applied. As shown in FIGS. 3A and 3B, rigid lens element 86 can maintain the same curvature regardless of how actuator 90 positions lens shaper 88.

[0045] In some cases, it may be desirable for lens element 86 to also have an adjustable shape. Additional actuators may be included in the lens module to directly manipulate the shape of lens element 84 (as well as lens element 86). However, to minimize device cost, complexity, and weight, it may be desirable to avoid including a dedicated actuator for lens element 86. To provide an adjustable lens element 86 without including additional actuators, lens element 86 may be a semi-rigid lens element. This type of configuration is shown in Figures 5A and 5B.

[0046] Figures 5A and 5B are cross-sectional side views of a lens module having an elastomeric lens element 84 and a semi-rigid lens element 86. The overall structure of the lens module is similar to that described in connection with Figures 3A and 3B, and the description of these overlapping portions will not be repeated for the sake of clarity. The elastomeric lens element 84 and the semi-rigid lens element 86 may be formed from the same or different materials.

[0047] FIG. 5A shows the lens module in a position manipulated by lens shaping element 88 such that lens element 84 has a convex shape. In this type of configuration, a positive gauge pressure can be applied to semi-rigid lens element 86 (e.g., a negative Z-direction force), which causes semi-rigid lens element 86 to assume a relatively flat shape with minimal curvature (as shown in FIG. 5A). The radius of curvature of lens element 86 shown in FIG. 5A (if lens element 84 has a convex curvature) may be relatively large. Alternatively, lens element 86 in FIG. 5A may be planar if lens element 84 has a convex curvature.

[0048] FIG. 5B, on the other hand, shows the lens module in a position manipulated by lens shaping element 88 such that lens element 84 has a concave shape. In this type of configuration, a negative gauge pressure can be applied to semi-rigid lens element 86 (e.g., a positive Z-direction force), causing semi-rigid lens element 86 to have a concave curvature with a smaller radius of curvature than in FIG. 5A. The radius of curvature of lens element 86 may change sign and / or may vary by more than 10%, more than 20%, more than 50%, more than 100%, more than 200%, etc., when comparing the configuration of FIG. 5B to the configuration of FIG. 5A.

[0049] In general, it may be desirable for the semi-rigid lens element 86 to have a smaller concave curvature when the lens element 84 has a larger convex curvature, and for the semi-rigid lens element 86 to have a larger concave curvature when the lens element 84 has a larger concave curvature. This type of configuration may be useful to mimic the lens structure of prescription eyewear, as an example. The lens module of FIG. 5A and FIG. 5B achieves this relationship (the concave curvature of the lens element 86 becomes smaller with increasing convex curvature) without requiring an additional actuator to directly control the shape of the lens element 86. In other words, the actuator in the lens module is not attached to the lens element 86. However, the pressure applied to the lens element 86 as a result of the lens element 86 being manipulated (by the actuator 90) causes the lens element 86 to assume the desired curvature. The curvature of the lens element 86 may change gradually as the actuator 90 changes the curvature of the lens element 84 (because the gauge pressure of the lens element 86 also changes gradually and the shape of the lens element 86 responds to the gauge pressure).

[0050] 5A and 5B, elastomeric lens element 84 may have a Young's modulus of less than 1 GPa, less than 0.5 GPa, less than 0.1 GPa, etc. Semi-rigid lens element 86, on the other hand, may be formed from a semi-rigid material that is rigid and solid but not inflexible. Semi-rigid lens element 86 may be formed from a thin layer of polymer or glass, for example. Semi-rigid lens element 86 may be formed from a material having a Young's modulus of greater than 1 GPa, greater than 2 GPa, greater than 3 GPa, greater than 10 GPa, greater than 25 GPa, etc. Thus, the Young's modulus of lens element 86 may be greater than the Young's modulus of lens element 84.

[0051] In the previous example (where semi-rigid lens element 86 has a greater Young's modulus than elastomeric lens element 84), elastomeric lens element 84 and semi-rigid lens element 86 may be formed from different materials. This example is merely illustrative. In other possible examples, elastomeric lens element 84 and semi-rigid lens element 86 may be formed from the same material, but have different thicknesses. For example, semi-rigid lens element 86 may have a greater thickness than lens element 84. Semi-rigid lens element may have a thickness greater than 1.5 times the thickness of lens element 84, greater than 2 times the thickness of lens element 84, greater than 3 times the thickness of lens element 84, greater than 5 times the thickness of lens element 84, greater than 10 times the thickness of lens element 84, greater than 50 times the thickness of lens element 84, between 1.5 and 10 times the thickness of lens element 84, less than 20 times the thickness of lens element 84, etc. In general, lens element 86 may have a greater thickness and / or Young's modulus than lens element 84.

[0052] Figures 6A and 6B are cross-sectional side views of a lens module having an elastomeric lens element 84 and a dynamically adjustable semi-rigid lens element 86. The overall structure of the lens module is similar to that described in connection with Figures 5A and 5B, and a description of these overlapping portions will not be repeated for the sake of clarity.

[0053] The lens module may also include a biasing structure 106 to gradually change the shape (curvature) of the lens element 86 in response to changes in gauge pressure. The biasing structure 106 may extend in a ring shape around the lens module and may apply a biasing force to the lens element 86 (having a disk shape). The biasing structure 106 may bias the edge of the lens element 86 towards the center of the lens element 86. For example, in the left side of FIG. 6B, the biasing structure 106 biases the semi-rigid lens element 86 in the positive X direction (towards the center of the lens element 86). In the right side of FIG. 6B, the biasing structure 106 biases the semi-rigid lens element 86 in the negative X direction (towards the center of the lens element 86). The biasing structure 106 may be formed of a spring, a flexible bellows structure, or any other desired structure that applies a biasing force to the edge of the lens element 86. The biasing structure 106 may be formed as a continuous ring around the lens element 86, or may include multiple separate biasing structures distributed around the periphery of the lens element, each of which applies a point force to the lens element 86 at a given location.

[0054] FIG. 6A shows the lens module in a position where lens element 84 is manipulated by lens shaping element 88 (and actuator 90) having a convex shape. In this type of configuration, a positive gauge pressure can be applied to semi-rigid lens element 86 (e.g., a negative Z-force). This causes the edge of semi-rigid lens element 86 to be pushed outward against biasing structure 106. Semi-rigid lens element 86 assumes a relatively flat shape with minimal curvature (as shown in FIG. 6A). The radius of curvature of lens element 86 shown in FIG. 6A (if lens element 84 has a convex curvature) may be relatively large. Alternatively, lens element 86 in FIG. 6A may be planar if lens element 84 has a convex curvature.

[0055] 6B, on the other hand, shows the lens module in a position where the lens element 84 is manipulated by the lens shaping element 88 to have a concave shape. In this type of configuration, a negative gauge pressure can be applied to the semi-rigid lens element 86 (e.g., a positive Z-direction force). This causes the semi-rigid lens element 86 to have a concave curvature with a smaller radius of curvature than in FIG. 6A. The biasing structure 106 helps to push the edge of the lens element toward the center of the lens element to give the lens element 86 the desired concave curvature. Thus, the biasing structure 106 (which may also be referred to as a spring 106, a flexible bellows structure 106, a flexible seal structure 106, etc.) helps the lens element 86 to gradually change shape (curvature) in response to changes in gauge pressure. With the aid of the biasing structure, lens element 86 gradually changes shape from a flat or high radius of curvature shape (as in FIG. 6A) to a concave shape with a lower radius of curvature (as in FIG. 6B) as actuator 90 gradually changes the shape of lens element 84 from convex (as in FIG. 6A) to concave (as in FIG. 6B).

[0056] The radius of curvature of lens element 86 may change sign and / or may vary by more than 10%, more than 20%, more than 50%, more than 100%, more than 200%, etc. when comparing the configuration of FIG. 6B to the configuration of FIG. 6A.

[0057] The biasing structure 106 may be attached to the edge of the lens element 86 using an adhesive or may be secured to the edge of the lens element 86 using another desired attachment mechanism (e.g., a mechanical interlock). As another possible example, the biasing structure 106 may be integrally formed with the lens element 86 (e.g., formed from the same material as the lens element 86 and / or molded in a single step with the lens element 86).

[0058] Figures 7A and 7B are cross-sectional side views of a lens module having an elastomeric lens element 84 and a dynamically adjustable semi-rigid lens element with a flexible seal 86. The overall structure of the lens module is similar to that described in connection with Figures 5A and 5B, and a description of these overlapping portions will not be repeated for the sake of clarity.

[0059] To help ensure that the shape (curvature) of the lens element 86 changes gradually in response to changes in gauge pressure, the lens module may also include a flexible seal 108. The flexible seal 108 may extend in a ring shape around the lens module or may be interposed between the lens element 86 and the support structure 102. The flexible seal 108 may form an airtight seal between the lens element 86 and the support structure 102 to prevent fluid 92 from leaking into or out of the chamber 82 at the seal.

[0060] The flexible seal (similar to biasing structure 106) can apply a biasing force to lens element 86 (which has a disk shape). Flexible seal 108 can bias the edge of lens element 86 toward the center of the lens element. For example, on the left side of Figure 7B, flexible seal 108 biases semi-rigid lens element 86 in the positive X direction (toward the center of lens element 86). On the right side of Figure 7B, flexible seal 108 biases semi-rigid lens element 86 in the negative X direction (toward the center of lens element 86).

[0061] The flexible seal 108 may be formed from the same material as the lens element 86. In this type of configuration, the flexible seal 108 may be thinner than the lens element 86. The flexible seal 108 may also be formed from a different material than the lens element 86 (e.g., a more elastic material having a lower Young's modulus). The flexible seal 108 (which may also be referred to as a biasing structure 108, a flexible lip 108, a flexible wall 108, etc.) may be formed as a continuous ring around the lens element 86.

[0062] FIG. 7A shows the lens module in a position where the lens element 84 is manipulated by the lens shaping element 88 to have a convex shape. In this type of configuration, a positive gauge pressure can be applied to the semi-rigid lens element 86 (e.g., a negative Z-direction force). This forces the edges of the semi-rigid lens element 86 outward against the flexible seal 108. The flexible seal 108 accommodates the lateral (e.g., X-direction) expansion of the lens element 86 in this position. The semi-rigid lens element 86 assumes a relatively flat shape with minimal curvature (as shown in FIG. 7A). The radius of curvature of the lens element 86 shown in FIG. 6A (if the lens element 84 has a convex curvature) may be relatively large. Alternatively, the lens element 86 in FIG. 7A may be planar if the lens element 84 has a convex curvature.

[0063] On the other hand, FIG. 7B shows the lens module in a position where the lens element 84 is manipulated by the lens shaping element 88 to have a concave shape. In this kind of configuration, a negative gauge pressure can be applied to the semi-rigid lens element 86 (e.g., a positive Z-direction force). This causes the semi-rigid lens element 86 to have a concave curvature with a smaller radius of curvature than in FIG. 7A. The flexible seal 108 helps to push the edge of the lens element toward the center of the lens element to give the lens element 86 the desired concave curvature. Thus, the flexible seal 108 helps to gradually change the shape (curvature) of the lens element 86 in response to the change in the gauge pressure. With the help of the flexible seal, the lens element 86 gradually changes shape from a flat or high radius of curvature shape (as in FIG. 7A) to a concave shape with a lower radius of curvature (as in FIG. 7B) as the actuator 90 gradually changes the shape of the lens element 84 from a convex shape (as in FIG. 7A) to a concave shape (as in FIG. 7B).

[0064] The radius of curvature of lens element 86 may change sign and / or may vary by more than 10%, more than 20%, more than 50%, more than 100%, more than 200%, etc. when comparing the configuration of FIG. 7B to the configuration of FIG. 7A.

[0065] The flexible seal 108 may be attached to the edge of the lens element 86 with an adhesive, or may be secured to the edge of the lens element 86 using another desired attachment mechanism (e.g., a mechanical interlock). As another possible example, the flexible seal 108 may be integrally formed with the lens element 86 (e.g., formed from the same material as the lens element 86 and / or molded in a single step with the lens element 86).

[0066] FIG. 8 is a cross-sectional side view of a lens module having first and second elastomeric lens elements and first and second chambers. Lens module 72 of FIG. 8 includes first fluid-filled chamber 82-1 and second fluid-filled chamber 82-2. Both first and second fluid-filled chambers 82-1 and 82-2 are filled with fluid 92 (as described above). Fluid-filled chamber 82-1 (sometimes referred to as chamber 82-1 or fluid chamber 82-1) is interposed between lens element 84-1 and lens element 86 (and is defined in part by lens element 84-1 and lens element 84-86). Fluid-filled chamber 82-2 (sometimes referred to as chamber 82-2 or fluid chamber 82-2) is interposed between lens element 84-2 and lens element 86 (and is defined in part by lens element 84-2 and lens element 86).

[0067] In Figure 8, lens elements 84-1, 84-2 are elastomeric lens elements and lens element 86 is a rigid lens element (more rigid than lens elements 84-1, 84-2). Lens element 84-1 may be attached to a lens shaper 88 (as described in previous figures) which controls the curvature of lens element 84-1. Lens module 72 of Figure 8 also includes a support structure 102, a flexible bellows 104, and one or more actuators as already shown and described above.

[0068] To allow control of the shape of elastomeric lens element 84-2 without the addition of an additional actuator, a valve 110 may be interposed in a channel 112 between chambers 82-1, 82-2. Channel 112 may allow fluid to flow between chambers 82-1, 82-2 when valve 110 is open. When valve 110 is closed, the volume of fluid in chambers 82-1 and 82-2 may remain fixed. Control circuitry (e.g., control circuit 12 of FIG. 1) may control valve 112 using control signal line 114.

[0069] 8, the channel 112 between chambers 82-1 and 82-2 may include an opening in the flexible bellows structure 104 (to allow access to chamber 82-1) and / or an opening in the support structure 102 (to allow access to chamber 82-2). This example is merely illustrative. In general, the channel 112 and valve 110 may be in any desired location that allows for fluid exchange between chambers 82-1, 82-2.

[0070] In addition to controlling the curvature of lens element 84-1, lens shaper 88 (and corresponding actuator) can effectively function as a pump to control the exchange of fluid between chambers 82-1, 82-2. Control circuitry within the device can control the actuator to move lens shaper 88 in the negative Z direction while opening valve 110. In this state, lens element 84-1 is given a convex curvature and a positive gauge pressure is applied to rigid lens element 86 (e.g., a force in the negative Z direction). This positive gauge pressure does not deform rigid lens element 86 (which maintains its curvature). However, pressure from the lens shaper / actuator pushes fluid 92 from chamber 82-1 into chamber 82-2 (via channel 112). The increase in volume within chamber 82-2 pushes elastomeric lens element 84-2 in the negative Z direction to decrease the curvature of lens element 84-2. The control circuitry can close valve 110 once the desired lens shape is achieved.

[0071] A control circuit within the device can control the actuator to move the lens shaper 88 in the positive Z direction while opening the valve 110. In this state, a concave curvature is imparted to lens element 84-1 (e.g., as in FIG. 7B) and a negative gauge pressure is applied to rigid lens element 86. This negative gauge pressure does not deform rigid lens element 86 (which maintains its curvature). However, the negative pressure from the lens shaper / actuator draws fluid 92 from chamber 82-2 into chamber 82-1. The reduction in volume in chamber 82-2 allows elastomeric lens element 84-2 to move in the positive Z direction to increase the curvature of lens element 84-2. The control circuit can close valve 110 once the desired lens shape is achieved. In this manner, the lens shaper / actuator and valve 110 can be used to control the curvature of both lens elements 84-1 and 84-2.

[0072] The radius of curvature of lens element 84-2 may change sign and / or may vary by more than 10%, more than 20%, more than 50%, more than 100%, more than 200%, etc., depending on the control of lens shaper 88 of FIG.

[0073] Figures 9A and 9B are cross-sectional side views of a lens module having an elastomeric lens element 84 and a bi-stable semi-rigid lens element 86. The overall structure of the lens module is similar to that described in connection with Figures 5A and 5B, and the description of these overlapping portions will not be repeated for the sake of clarity. The elastomeric lens element 84 and the semi-rigid lens element 86 may be formed from the same or different materials.

[0074] 9A shows the lens module in a position where lens element 84 is manipulated by lens shaping element 88 to have a concave shape. In this type of configuration, a negative gauge pressure can be applied to semi-rigid lens element 86 (e.g., a positive Z-direction force), which causes semi-rigid lens element 86 to have a concave curvature with a relatively small radius of curvature.

[0075] In Figures 9A and 9B, the semi-rigid lens element 86 may be prestressed when assembled into the lens module 72. In other words, to fit into the lens module, the semi-rigid lens element 86 may be laterally clamped (e.g., pressure is applied to the edge of the lens element toward the center of the lens element). The support structure 102 may apply this prestress, as an example. Due to the prestress applied to the semi-rigid lens element, the semi-rigid lens element may have two stable states. Thus, the semi-rigid lens element may be referred to as a bi-stable semi-rigid lens element. Instead of gradually changing from a first curvature to a second curvature (e.g., as in Figures 5A and 5B), the curvature of the lens element 86 may remain as depicted in Figure 9A when the lens shaper 88 moves in the negative Z direction. In other words, the curvature of lens element 86 remains fixed in the first stable state as the gauge pressure is varied (as in FIG. 9A) until a gauge pressure is reached that flips the lens element to its second stable state (as depicted in FIG. 9B).

[0076] In a second stable state, lens element 84 is manipulated by lens shaping element 88 to have a convex curvature. In this type of configuration, a positive gauge pressure can be applied to semi-rigid lens element 86 (e.g., a negative Z-direction force), which causes semi-rigid lens element 86 to have a convex curvature.

[0077] Thus, prestressed lens element 86 will force lens element 84 to a convex curvature if lens element 86 also has a convex curvature, and will force lens element 84 to a concave curvature if lens element 84 also has a concave curvature. This example is merely illustrative. In general, any desired relationship between the curvatures of lenses 84, 86 can be used. However, the curvature of lens element 86, in this configuration, can have two different stable states (due to the prestress applied to its edges).

[0078] In other possible configurations, the lens element may have more than two stable states and may switch between more than two stable states in response to an applied gauge pressure, but the curvature does not change between the three or more stable states.

[0079] The radius of curvature of lens element 86 may change sign and / or may vary by more than 10%, more than 20%, more than 50%, more than 100%, more than 200%, etc. when comparing the configuration of FIG. 9B to the configuration of FIG. 9A.

[0080] 10 is a graph of various radius of curvature profiles of lens elements as a function of gauge pressure on the lens elements. It should be noted that the gauge pressure is indicative of the curvature of the elastomeric lens element 84 within the lens module. For example, consider FIGS. 5A and 5B. When the lens element 84 is controlled to have a concave curvature, the associated gauge pressure acting on the lens element 86 is low (e.g., a negative gauge pressure P1). When the lens element 84 is controlled to have a convex curvature, the associated gauge pressure acting on the lens element 86 is high (e.g., a positive gauge pressure P2).

[0081] Profile 202 shows the radius of curvature of rigid lens element 86 of Figures 3A and 3B. As shown, because the lens element is rigid, the radius of curvature of the lens element remains constant from negative gauge pressure P1 to positive gauge pressure P2.

[0082] Profile 204 illustrates an exemplary profile of the radius of curvature of semi-rigid lens element 86 of FIGS. 5-7 (or lens element 84-2 of FIG. 8). As illustrated, the radius of curvature of the lens element gradually increases (e.g., becomes less curved) when moving from a negative gauge pressure P1 to a positive gauge pressure P2. In this manner, control circuitry within the device can control lens shaper 88 to manipulate the curvature of lens element 84, which changes the gauge pressure of lens element 86, which in turn changes the curvature of lens element 86 according to profile 204, as shown. Thus, the curvature of lens element 86 is dynamically updated in parallel with the updating of the curvature of lens element 84. Control circuitry within the device may control the lens element to have a curvature at P1 and P2 of FIG. 10, or any intermediate gauge pressure / curvature.

[0083] Profile 206 illustrates an example profile for the radius of curvature of the bi-stable semi-rigid lens element 86 of Figures 9A and 9B. As shown, the radius of curvature of the lens element remains constant in a first stable state when moving from a negative gauge pressure P1 to a positive gauge pressure P2. At some intermediate pressure, the lens element 86 may switch from the first stable state to a second stable state. Thus, the curvature of the lens element changes stepwise to a different curvature (e.g., a convex curvature in Figure 9B). The radius of curvature of the lens element then remains constant in the second stable state when the gauge pressure ends up moving to the positive gauge pressure P2.

[0084] The shapes of profiles 204 and 206 are merely exemplary. In general, any desired profile shape may be used (e.g., profile 204 may be non-linear).

[0085] According to one embodiment, a device includes a head mounted support structure, a display that emits light, and a lens module supported by the head mounted support structure that receives light from the display, the lens module comprising: first and second transparent lens elements defining a chamber, the first transparent lens element being an elastomeric lens element and the second transparent lens element being a semi-rigid lens element; a fluid in the chamber between the first transparent lens element and the second transparent lens element; and a plurality of actuators configured to adjust a first curvature of the first transparent lens element, where adjusting the first curvature of the first transparent lens element also causes a change in a second curvature of the second transparent lens element; A system is provided that includes:

[0086] According to another embodiment, the change in the second curvature of the second transparent lens element comprises a change in the radius of curvature of the second transparent lens element of more than 20%.

[0087] According to another embodiment, the first transparent lens element is thinner than the second transparent lens element.

[0088] According to another embodiment, the first transparent lens element has a lower Young's modulus than the second transparent lens element.

[0089] According to another embodiment, the lens module includes a lens molding structure mounted between the plurality of actuators and the first transparent lens element.

[0090] According to another embodiment, the lens molding structure has multiple extensions.

[0091] According to another embodiment, each extension of the plurality of extensions is coupled to a respective actuator of the plurality of actuators.

[0092] According to another embodiment, the lens molding structure extends in a ring shape around the central opening, with the first transparent lens element overlapping the central opening.

[0093] According to another embodiment, the second transparent lens element is a bistable lens element with first and second stable states, the second curvature being concave in the first state and the second curvature being convex in the second state.

[0094] According to another embodiment, adjusting the first curvature from concave to convex switches the second transparent lens element from a first stable state to a second stable state.

[0095] According to another embodiment, the radius of curvature of the second curvature is gradually increased by gradually adjusting the first curvature from concave to convex.

[0096] According to another embodiment, the lens module includes a biasing structure that applies a force to an edge of the second transparent lens element toward a center of the second transparent lens element.

[0097] According to another embodiment, the lens module includes a support structure, and the biasing structure forms a seal between the second transparent lens element and the support structure.

[0098] According to another embodiment, a plurality of actuators are formed on a support structure.

[0099] According to one embodiment, a device includes a head mounted support structure, a display that emits light, and a lens module supported by the head mounted support structure that receives light from the display, the lens module comprising first and second transparent lens elements defining a chamber, the first transparent lens element being an elastomeric lens element and the second transparent lens element being a semi-rigid lens element, a fluid in the chamber between the first transparent lens element and the second transparent lens element, and an actuator attached to the first transparent lens element configured to dynamically adjust the curvature of both the first and second transparent lens elements, where no actuator is attached to the second transparent lens element; A system is provided that includes:

[0100] According to another embodiment, the second transparent lens element has a greater stiffness than the first transparent lens element.

[0101] According to another embodiment, the lens module includes a lens molding structure mounted between the actuator and the first transparent lens element.

[0102] According to another embodiment, the first transparent lens element is thinner than the second transparent lens element.

[0103] According to another embodiment, dynamically adjusting the curvature of both the first and second transparent lens elements includes adjusting the radius of curvature of the second transparent lens element by greater than 20%.

[0104] According to one embodiment, a system includes a head mounted support structure, a display that emits light, and a lens module supported by the head mounted support structure that receives light from the display, the lens module including a rigid lens element, a first transparent lens element having a stiffness less than the rigid lens element, the first transparent lens element and the rigid lens element defining a first fluid filled chamber, a second transparent lens element having a stiffness less than the rigid lens element, the second transparent lens element and the rigid lens element defining a second fluid filled chamber, A system is provided that includes a second transparent lens element, where the first transparent lens element is an elastomeric lens element and the second transparent lens element is a semi-rigid lens element; a channel between the first and second fluid-filled chambers; a valve in the channel configured to open to allow flow through the channel between the first and second fluid-filled chambers; and a plurality of actuators configured to move the first transparent lens element while the valve is open to control flow between the first and second fluid-filled chambers.

[0105] According to another embodiment, the lens module includes a ring-shaped structure coupled to a first transparent lens element, and the plurality of actuators are configured to adjust the ring-shaped structure to move the first transparent lens element.

[0106] The above is merely illustrative and various modifications may be made to the described embodiments. The above embodiments may be implemented individually or in any combination.

Claims

1. 1. A system comprising: a head mounted support structure; A display that emits light; a lens module supported by the head mounted support structure to receive light from the display; The lens module comprises: first and second transparent lens elements defining a chamber, the first transparent lens element being an elastomeric lens element having a first thickness and a first Young's modulus, and the second transparent lens element being a semi-rigid lens element having a second thickness greater than the first thickness and a second Young's modulus greater than the first Young's modulus; a fluid in a chamber between the first transparent lens element and the second transparent lens element; a plurality of actuators configured to adjust a first curvature of the first transparent lens element, where adjusting the first curvature of the first transparent lens element also causes a change in a second curvature of the second transparent lens element; and A system comprising:

2. 10. The system of claim 1, wherein the change in the second curvature of the second transparent lens element comprises a change in the radius of curvature of the second transparent lens element of greater than 20%.

3. The system of claim 1, wherein the elastomeric lens element is formed from a first material having a Young's modulus less than 1 GPa, and the semi-rigid lens element is formed from a second material having a Young's modulus greater than 1 GPa.

4. The system of claim 1 , wherein the first transparent lens element has a lower Young's modulus than the second transparent lens element.

5. The system of claim 1 , wherein the lens module further comprises a lens molding structure mounted between the plurality of actuators and the first transparent lens element.

6. The system of claim 5 , wherein the lens forming structure comprises a plurality of extensions.

7. The system of claim 6 , wherein each extension of the plurality of extensions is coupled to a respective actuator of the plurality of actuators.

8. The system of claim 5 , wherein the lens molding structure extends in a ring shape around a central opening, and the first transparent lens element overlaps the central opening.

9. 2. The system of claim 1, wherein the second transparent lens element is a bistable lens element with first and second stable states, the second curvature being concave in the first state and the second curvature being convex in the second state.

10. 10. The system of claim 9, wherein adjusting the first curvature from concave to convex causes the second transparent lens element to switch from the first stable state to the second stable state.

11. The system of claim 1 , wherein the radius of curvature of the second curvature is gradually increased by gradually adjusting the first curvature from concave to convex.

12. The lens module includes: a biasing structure that applies a force to an edge of the second transparent lens element toward a center of the second transparent lens element; The system of claim 1 further comprising:

13. The lens module includes: a support structure, the biasing structure forming a seal between the second transparent lens element and the support structure, the plurality of actuators being formed on the support structure; The system of claim 12 further comprising:

14. 1. A system comprising: a head mounted support structure; A display that emits light; a lens module supported by the head mounted support structure to receive light from the display; The lens module comprises: first and second transparent lens elements defining a chamber, the first transparent lens element being an elastomeric lens element having a first thickness and a first Young's modulus, and the second transparent lens element being a semi-rigid lens element having a second thickness greater than the first thickness and a second Young's modulus greater than the first Young's modulus; a fluid in a chamber between the first transparent lens element and the second transparent lens element; an actuator attached to the first transparent lens element configured to dynamically adjust the curvature of both the first and second transparent lens elements, where no actuator is attached to the second transparent lens element; and A system comprising:

15. The system of claim 14 , wherein the second transparent lens element has a greater stiffness than the first transparent lens element.

16. 15. The system of claim 14, wherein the lens module further comprises a lens molding structure mounted between the actuator and the first transparent lens element.

17. The system of claim 14, wherein the elastomeric lens element is formed from a first material having a Young's modulus less than 1 GPa, and the semi-rigid lens element is formed from a second material having a Young's modulus greater than 1 GPa.

18. 15. The system of claim 14, wherein dynamically adjusting the curvature of both the first and second transparent lens elements comprises adjusting a radius of curvature of the second transparent lens element by greater than 20%.

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