PATENT DOCUMENT

Publication Number: US-12153229-B2
Application Number: US-202117168008-A
Country: US
Kind Code: B2

Title: Electronic devices with adjustable lenses

Abstract:
A head-mounted device may include one or more adjustable lens elements. The adjustable lens element may include a transparent substrate, a collapsible wall that forms an enclosed perimeter on the transparent substrate, and a flexible membrane on the collapsible wall that together define an interior volume. The interior volume may be filled with a fluid. The adjustable lens element may include a lens shaping component that applies a force to the collapsible wall to adjust a height of the collapsible wall relative to the transparent substrate, which in turn may be used to adjust the shape of the flexible membrane and thus the lens power of the lens element. The collapsible wall may have bellows that allow the collapsible wall to fold on itself when compressed, thereby minimizing unintended lateral movement of the collapsible wall.

Claims:
What is claimed is: 
     
       1. A system, comprising:
 a head-mounted support structure; 
 a display that emits light; 
 a lens module supported by the head-mounted support structure that receives the light from the display, wherein the lens module comprises a fluid-filled lens element having a flexible membrane supported by a foldable sidewall and an outer flexible sidewall that surrounds the foldable sidewall; and 
 control circuitry configured to control the lens module to adjust a curvature of the flexible membrane, wherein the foldable sidewall and the outer flexible sidewall are configured to fold in response to forces applied to the flexible membrane. 
 
     
     
       2. The system defined in  claim 1  wherein the fluid-filled lens element comprises a transparent substrate on which the foldable sidewall is formed. 
     
     
       3. The system defined in  claim 2  wherein the transparent substrate comprises glass. 
     
     
       4. The system defined in  claim 2  wherein the fluid-filled lens element comprises a lens shaping component that adjusts a height of the foldable sidewall relative to the transparent substrate to adjust the curvature of the flexible membrane. 
     
     
       5. The system defined in  claim 4  further comprising a reinforcement ring in the foldable sidewall. 
     
     
       6. The system defined in  claim 5  further comprising an additional reinforcement ring in the foldable sidewall, wherein the reinforcement ring and the additional reinforcement ring are laterally offset from one another and have different perimeter lengths. 
     
     
       7. The system defined in  claim 5  wherein the reinforcement ring comprises metal. 
     
     
       8. The system defined in  claim 1  further comprising a fluid interposed between the foldable sidewall and the outer flexible sidewall. 
     
     
       9. The system defined in  claim 1  further comprising a sensor that detects leaks in the fluid-filled lens element, wherein the sensor is selected from the group consisting of: a pressure sensor, a capacitive sensor, a resistive sensor, and a force sensor. 
     
     
       10. An adjustable lens, comprising:
 a transparent substrate; 
 a wall that forms a closed perimeter on the transparent substrate, wherein the wall comprises bellows, and wherein the wall comprises first and second reinforced regions that are strengthened relative to other regions of the wall, and wherein the first reinforced region has a first perimeter length and the second reinforced region has a second perimeter length that is greater than the first perimeter length; 
 a flexible membrane attached to the wall, wherein the transparent substrate, the wall, and the flexible membrane define an interior volume that contains a fluid; and 
 a lens shaping component that applies a force to the wall to adjust a height of the wall relative to the transparent substrate. 
 
     
     
       11. The adjustable lens defined in  claim 10  wherein the transparent substrate comprises glass and wherein the wall comprises polymer. 
     
     
       12. The adjustable lens defined in  claim 10  wherein the lens shaping component has a non-uniform modulus of elasticity. 
     
     
       13. The adjustable lens defined in  claim 10  wherein the wall folds on itself when compressed by the lens shaping component. 
     
     
       14. The adjustable lens defined in  claim 10  wherein the first and second reinforced regions are laterally offset from one another. 
     
     
       15. A system, comprising:
 a head-mounted support structure; 
 a display that emits light; 
 an adjustable lens element supported by the head-mounted support structure that receives the light from the display, wherein the adjustable lens element comprises a flexible membrane that is supported by a collapsible sidewall and an outer sidewall, and wherein the adjustable lens element has a liquid located between the collapsible sidewall and the outer sidewall; and 
 control circuitry configured to control the adjustable lens element to adjust a shape of the flexible membrane. 
 
     
     
       16. The system defined in  claim 15  wherein the adjustable lens element comprises a rigid substrate and wherein the rigid substrate, the flexible membrane, and the collapsible sidewall define an interior volume that is at least partially filled with a fluid. 
     
     
       17. The system defined in  claim 16  wherein the collapsible sidewall has first and second curved portions that extend around a perimeter of the collapsible sidewall. 
     
     
       18. The system defined in  claim 17  wherein the first and second curved portions face towards the fluid. 
     
     
       19. The system defined in  claim 18  further comprising a reinforced ring portion interposed between the first and second curved portions. 
     
     
       20. The system defined in  claim 16  further comprising a lens shaping component having actuators that adjust a height of the collapsible sidewall relative to the rigid substrate to adjust the shape of the flexible membrane.

Description:
This application claims the benefit of U.S. provisional patent application No. 62/988,865, filed Mar. 12, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and, more particularly, to wearable electronic device systems. 
     Electronic devices are sometimes configured to be worn by users. For example, head-mounted devices are provided with head-mounted structures that allow the devices to be worn on a user&#39;s head. The head-mounted devices may include optical systems with lenses. The lenses allow displays in the devices to present visual content to users. 
     Head-mounted devices typically include lenses with fixed shapes and properties. If care is not taken, it may be difficult to adjust these types of lenses to optimally present content to each user of the head-mounted device. 
     SUMMARY 
     A head-mounted device may have a display that displays content for a user. Head-mounted support structures in the device support the display on the head of the user. 
     The head-mounted device may have respective left and right lens modules and respective left and right portions of a display. The left lens module may direct images from the left portion of the display to a left eye box whereas the right lens module may direct images from the right portion of the display to a right eye box. 
     A lens module in the head-mounted device may include one or more adjustable lens elements. An adjustable lens element may include a transparent substrate, a collapsible wall that forms an enclosed perimeter on the transparent substrate, and a flexible membrane on the collapsible wall that together define an interior volume. The interior volume may be filled with a fluid. The adjustable lens element may include a lens shaping component that applies a force to the collapsible wall to adjust a height of the collapsible wall relative to the transparent substrate, which in turn may be used to adjust the shape of the flexible membrane and the lens power of the lens element. The collapsible wall may have bellows that allow the collapsible wall to fold on itself when compressed, thereby minimizing unintended lateral movement of the collapsible wall. The collapsible wall may include one or more reinforced portions (e.g., with embedded reinforcement structures and/or where portions of the wall are locally thickened or otherwise modified to be stiffer). If desired, the reinforced portions of the wall may be laterally offset from one another to avoid colliding with one another when the wall is compressed. 
     Control circuitry in the head-mounted device may control the actuators in the lens shaping component to dynamically adjust the lens power of the adjustable lens element. The lens shaping component may have non-uniform construction (e.g., non-uniform modulus of elasticity). One or more sensors and/or coatings may be used to detect leaks in the adjustable lens element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an illustrative electronic device such as a head-mounted display device in accordance with an embodiment. 
         FIG.  2    is a cross-sectional side view an illustrative head-mounted device with a lens module that receives light from a display portion in accordance with an embodiment. 
         FIG.  3    is a cross-sectional side view of an illustrative adjustable lens element having a flexible membrane supported by a collapsible sidewall with bellows in accordance with an embodiment. 
         FIG.  4    is a cross-sectional side view of the adjustable lens element of  FIG.  3    in a compressed state in accordance with an embodiment. 
         FIG.  5    is a cross-sectional side view of an illustrative adjustable lens element having a flexible membrane supported by a collapsible sidewall with reinforcement structures in accordance with an embodiment. 
         FIG.  6    is a cross-sectional side view of a portion of an illustrative adjustable lens element with reinforcement structures that are aligned with one another in accordance with an embodiment. 
         FIG.  7    is a cross-sectional side view of a portion of an illustrative adjustable lens element with reinforcement structures that are offset with respect to one another in accordance with an embodiment. 
         FIG.  8    is a cross-sectional side view of an illustrative adjustable lens element having inner and outer sidewalls and having leakage detection components in accordance with an embodiment. 
         FIG.  9    is a top view of an illustrative adjustable lens element having a lens shaping component in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may include displays and other components for presenting content to users. The electronic devices may be wearable electronic devices. A wearable electronic device such as a head-mounted device may have head-mounted support structures that allow the head-mounted device to be worn on a user&#39;s head. 
     A head-mounted device may contain a display formed from one or more display panels (displays) for displaying visual content to a user. A lens system may be used to allow the user to focus on the display and view the visual content. The lens system may have a left lens module that is aligned with a user&#39;s left eye and a right lens module that is aligned with a user&#39;s right eye. 
     The lens modules in the head-mounted device may include lenses that are adjustable. For example, fluid-filled adjustable lenses may be used to adjust the display content for specific viewers. 
     A schematic diagram of an illustrative system having an electronic device with a lens module is shown in  FIG.  1   . As shown in  FIG.  1   , system  8  may include one or more electronic devices such as electronic device  10 . The electronic devices of system  8  may include computers, cellular telephones, head-mounted devices, wristwatch devices, and other electronic devices. Configurations in which electronic device  10  is a head-mounted device are sometimes described herein as an example. 
     As shown in  FIG.  1   , electronic devices such as electronic device  10  may have control circuitry  12 . Control circuitry  12  may include storage and processing circuitry for controlling the operation of device  10 . Circuitry  12  may include storage such as hard disk drive storage, nonvolatile 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), etc. Processing circuitry in control circuitry  12  may 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 may be stored on storage in circuitry  12  and run on processing circuitry in circuitry  12  to implement control operations for device  10  (e.g., data gathering operations, operations involved in processing three-dimensional facial image data, operations involving the adjustment of components using control signals, etc.). Control circuitry  12  may include wired and wireless communications 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 communications circuitry. 
     During operation, the communications circuitry of the devices in system  8  (e.g., the communications circuitry of control circuitry  12  of device  10 ), may be used to support communication between the 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 use wired and/or wireless communications circuitry to communicate through one or more communications networks (e.g., the internet, local area networks, etc.). The communications circuitry may be used to allow data to be received by device  10  from external equipment (e.g., a tethered computer, a portable device such as a handheld device or laptop computer, online computing equipment such as a remote server or other remote computing equipment, or other electrical equipment) and/or to provide data to external equipment. 
     Device  10  may include input-output devices  22 . Input-output devices  22  may be used to allow a user to provide device  10  with user input. Input-output devices  22  may also be used to gather information on the environment in which device  10  is operating. Output components in devices  22  may allow device  10  to provide a user with output and may be used to communicate with external electrical equipment. 
     As shown in  FIG.  1   , input-output devices  22  may 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 left and right displays) that are in alignment with the user&#39;s left and right eyes, respectively. In other configurations, display  14  includes a single display panel that extends across both eyes. 
     Display  14  (sometimes referred to as pixel array  14 ) may be used to display images. The visual content that is displayed on display  14  may be viewed by a user of device  10 . Displays in device  10  such as display  14  may be organic light-emitting diode displays or other displays based on arrays of light-emitting diodes, liquid crystal displays, liquid-crystal-on-silicon displays, projectors or displays based on projecting light beams on a surface directly or indirectly through specialized optics (e.g., digital micromirror devices), electrophoretic displays, plasma displays, electrowetting displays, or any other suitable displays. 
     Display  14  may present display content for a computer-generated reality such as virtual reality content or mixed reality content. 
     A physical environment refers to a physical world that people can sense and/or interact with without aid of electronic systems. Physical environments, such as a physical park, include physical articles, such as physical trees, physical buildings, and physical people. People can directly sense and/or interact with the physical environment, such as through sight, touch, hearing, taste, and smell. 
     In contrast, a computer-generated reality (CGR) environment refers to a wholly or partially simulated environment that people sense and/or interact with via an electronic system. In CGR, a subset of a person&#39;s physical motions, or representations thereof, are tracked, and, in response, one or more characteristics of one or more virtual objects simulated in the CGR environment are adjusted in a manner that comports with at least one law of physics. For example, a CGR system may detect a person&#39;s head turning and, in response, adjust graphical content and an acoustic field presented to the person in a manner similar to how such views and sounds would change in a physical environment. In some situations (e.g., for accessibility reasons), adjustments to characteristic(s) of virtual object(s) in a CGR environment may be made in response to representations of physical motions (e.g., vocal commands). 
     A person may sense and/or interact with a CGR object using any one of their senses, including sight, sound, touch, taste, and smell. For example, a person may sense and/or interact with audio objects that create 3D or spatial audio environment that provides the perception of point audio sources in 3D space. In another example, audio objects may enable audio transparency, which selectively incorporates ambient sounds from the physical environment with or without computer-generated audio. In some CGR environments, a person may sense and/or interact only with audio objects. Examples of CGR include virtual reality and mixed reality. 
     A virtual reality (VR) environment refers to a simulated environment that is designed to be based entirely on computer-generated sensory inputs for one or more senses. A VR environment comprises a plurality of virtual objects with which a person may sense and/or interact. For example, computer-generated imagery of trees, buildings, and avatars representing people are examples of virtual objects. A person may sense and/or interact with virtual objects in the VR environment through a simulation of the person&#39;s presence within the computer-generated environment, and/or through a simulation of a subset of the person&#39;s physical movements within the computer-generated environment. 
     In contrast to a VR environment, which is designed to be based entirely on computer-generated sensory inputs, a mixed reality (MR) environment refers to a simulated environment that is designed to incorporate sensory inputs from the physical environment, or a representation thereof, in addition to including computer-generated sensory inputs (e.g., virtual objects). On a virtuality continuum, a mixed reality environment is anywhere between, but not including, a wholly physical environment at one end and virtual reality environment at the other end. 
     In some MR environments, computer-generated sensory inputs may respond to changes in sensory inputs from the physical environment. Also, some electronic systems for presenting an MR environment may track location and/or orientation with respect to the physical environment to enable virtual objects to interact with real objects (that is, physical articles from the physical environment or representations thereof). For example, a system may account for movements so that a virtual tree appears stationery with respect to the physical ground. Examples of mixed realities include augmented reality and augmented virtuality. 
     An augmented reality (AR) environment refers to a simulated environment in which one or more virtual objects are superimposed over a physical environment, or a representation thereof. For example, an electronic system for presenting an AR environment may have a transparent or translucent display through which a person may directly view the physical environment. The system may be configured to present virtual objects on the transparent or translucent display, so that a person, using the system, perceives the virtual objects superimposed over the physical environment. Alternatively, a system may have an opaque display and one or more imaging sensors that capture images or video of the physical environment, which are representations of the physical environment. The system composites the images or video with virtual objects, and presents the composition on the opaque display. A person, using the system, indirectly views the physical environment by way of the images or video of the physical environment, and perceives the virtual objects superimposed over the physical environment. As used herein, a video of the physical environment shown on an opaque display is called “pass-through video,” meaning a system uses one or more image sensor(s) to capture images of the physical environment, and uses those images in presenting the AR environment on the opaque display. Further alternatively, a system may have a projection system that projects virtual objects into the physical environment, for example, as a hologram or on a physical surface, so that a person, using the system, perceives the virtual objects superimposed over the physical environment. 
     An augmented reality environment also refers to a simulated environment in which a representation of a physical environment is transformed by computer-generated sensory information. For example, in providing pass-through video, a system may transform one or more sensor images to impose a select perspective (e.g., viewpoint) different than the perspective captured by the imaging sensors. As another example, a representation of a physical environment may be transformed by graphically modifying (e.g., enlarging) portions thereof, such that the modified portion may be representative but not photorealistic versions of the originally captured images. As a further example, a representation of a physical environment may be transformed by graphically eliminating or obfuscating portions thereof. 
     An augmented virtuality (AV) environment refers to a simulated environment in which a virtual or computer generated environment incorporates one or more sensory inputs from the physical environment. The sensory inputs may be representations of one or more characteristics of the physical environment. For example, an AV park may have virtual trees and virtual buildings, but people with faces photorealistically reproduced from images taken of physical people. As another example, a virtual object may adopt a shape or color of a physical article imaged by one or more imaging sensors. As a further example, a virtual object may adopt shadows consistent with the position of the sun in the physical environment. 
     There are many different types of electronic systems that enable a person to sense and/or interact with various CGR environments. Examples include head mounted systems, projection-based systems, heads-up displays (HUDs), vehicle windshields having integrated display capability, windows having integrated display capability, displays formed as lenses designed to be placed on a person&#39;s eyes (e.g., similar to contact lenses), headphones/earphones, speaker arrays, input systems (e.g., wearable or handheld controllers with or without haptic feedback), smartphones, tablets, and desktop/laptop computers. A head mounted system may have one or more speaker(s) and an integrated opaque display. Alternatively, a head mounted system may be configured to accept an external opaque display (e.g., a smartphone). The head mounted system may incorporate one or more imaging sensors to capture images or video of the physical environment, and/or one or more microphones to capture audio of the physical environment. Rather than an opaque display, a head mounted system may have a transparent or translucent display. The transparent or translucent display may have a medium through which light representative of images is directed to a person&#39;s eyes. The display may utilize digital light projection, OLEDs, LEDs, uLEDs, liquid crystal on silicon, laser scanning light source, or any combination of these technologies. The medium may be an optical waveguide, a hologram medium, an optical combiner, an optical reflector, or any combination thereof. In one embodiment, the transparent or translucent display may be configured to become opaque selectively. Projection-based systems may employ retinal projection technology that projects graphical images onto a person&#39;s retina. Projection systems also may be configured to project virtual objects into the physical environment, for example, as a hologram or on a physical surface. 
     Configurations in which display  14  is used to display virtual reality content to a user through lenses are described herein as an example. 
     Input-output circuitry  22  may include sensors  16 . Sensors  16  may include, for example, three-dimensional sensors (e.g., three-dimensional image sensors such as structured light sensors that emit beams of light and that use two-dimensional digital image sensors to gather image data for three-dimensional images from light spots that are produced when a target is illuminated by the beams of light, binocular three-dimensional image sensors that gather three-dimensional images using two or more cameras in a binocular imaging arrangement, three-dimensional lidar (light detection and ranging) sensors, three-dimensional radio-frequency sensors, or other sensors that gather three-dimensional image data), cameras (e.g., infrared and/or visible digital image sensors), gaze tracking sensors (e.g., a gaze tracking system based on an image sensor and, if desired, a light source that emits one or more beams of light that are tracked using the image sensor after reflecting from a user&#39;s eyes), touch sensors, buttons, force sensors, sensors such as contact sensors based on switches, gas sensors, pressure sensors, moisture sensors, magnetic sensors, audio sensors (microphones), ambient light sensors, microphones for gathering voice commands and other audio input, sensors that are configured to gather information on motion, position, and/or orientation (e.g., accelerometers, gyroscopes, compasses, and/or inertial measurement units that include all of these sensors or a subset of one or two of these sensors), fingerprint sensors and other biometric sensors, optical position sensors (optical encoders), and/or other position sensors such as linear position sensors, and/or other sensors. Sensors  16  may include proximity sensors (e.g., capacitive proximity sensors, light-based (optical) proximity sensors, ultrasonic proximity sensors, and/or other proximity sensors). Proximity sensors may, for example, be used to sense relative positions between a user&#39;s nose and lens modules in device  10 . 
     User input and other information may be gathered using sensors and other input devices in input-output devices  22 . If desired, input-output devices  22  may include other devices  24  such as haptic output devices (e.g., vibrating components), light-emitting diodes and other light sources, speakers such as ear speakers for producing audio output, and other electrical components. Device  10  may include circuits for receiving wireless power, circuits for transmitting power wirelessly to other devices, batteries and other energy storage devices (e.g., capacitors), joysticks, buttons, and/or other components. 
     Electronic device  10  may have housing structures (e.g., housing walls, straps, etc.), as shown by illustrative support structures  26  of  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 structures  26  may include head-mounted support structures (e.g., a helmet housing, head straps, temples in a pair of eyeglasses, goggle housing structures, and/or other head-mounted structures). The head-mounted support structures may be configured to be worn on a head of a user 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 . 
     In configurations in which electronic device  10  is a head-mounted device, support structures  26  may include, for example, structures that form housing walls and other structures for a main housing unit (e.g., exterior housing walls, lens module structures, other support structures for housing electronic components such as left and right display modules, etc.) and straps or other supplemental support structures that help to hold the main housing unit on a user&#39;s face so that the user&#39;s eyes are located within eye boxes. 
     Display  14  may include left and right display panels (e.g., left and right pixel arrays, sometimes referred to as left and right displays or left and right display portions) that are mounted respectively in left and right display modules.  FIG.  2    is a cross-sectional side view of an illustrative display module  70  that may be used as a left display module  70  and/or a right display module  70  in device  10 . A left display module  70  may correspond to a user&#39;s left eye (and left eye box  60 ) and a right display module  70  may correspond to a user&#39;s right eye (and right eye box  60 ). 
     Each display module  70  includes a display portion  14  and a corresponding lens module  72  (sometimes referred to as lens stack-up  72  or lens  72 ). Lenses  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., with any desired refractive index). The lens elements may have unique shapes and refractive indices that, in combination, focus light from display  14  in a desired manner. Each lens element of lens module  72  may be formed from any desired transparent material (e.g., glass, a polymer material such as polycarbonate or acrylic, a crystal such as sapphire, a combination of rigid and flexible materials, fluids, etc.). 
     The left and right display modules  70  in device  10  may optionally be individually positioned relative to the user&#39;s eyes and relative to some of the housing wall structures of a main housing unit using positioning circuitry such as respective left and right positioners  58 . Positioners  58  may be stepper motors, piezoelectric actuators, motors, linear electromagnetic actuators, and/or other electronic components for adjusting the position of displays  14  and lens modules  72 . Positioners  58  may be controlled by control circuitry  12  during operation of device  10 . For example, positioners  58  may be used to adjust the spacing between left and right display modules  70  (and therefore the lens-to-lens spacing between the left and right lenses of modules  70 ) to match the interpupillary distance of a user&#39;s eyes. If desired, positioners  58  may also be used to adjust distance  94  between lens module  72  and display  14  (e.g., to account for users with different eyesight). 
     As shown in  FIG.  2   , display module  70  in head-mounted device  10  may include a source of images such as pixel array  14  (sometimes referred to as display  14 ). Pixel array  14  may include a two-dimensional array of pixels P that emits image light. Pixels P in pixel array  14  may include organic light-emitting diode pixels, light-emitting diode pixels formed from semiconductor dies, liquid crystal display pixels with a backlight, liquid-crystal-on-silicon pixels with a frontlight, and/or any other suitable type of pixels. 
     If desired, display module  70  may include a catadioptric optical system. A polarizer such as linear polarizer  82  may be placed in front of pixel array  14  and/or may be laminated to pixel array  14  to provide polarized image light. Linear polarizer  82  may have a pass axis aligned with the X-axis of  FIG.  2    (as an example). A quarter wave plate  84  may also be provided on display  14 . The quarter wave plate may provide circularly polarized image light. The fast axis of quarter wave plate  84  may be aligned at 45 degrees to the pass axis of linear polarizer  82 . Quarter wave plate  84  may be mounted in front of polarizer  82  (between polarizer  82  and lens module  72 ). If desired, quarter wave plate  84  may be attached to polarizer  82  (and display  14 ). 
     Lens module  72  may include one or more lens elements such as lens element  208 . The arrangement of  FIG.  2    in which lens element  208  has a convex surface facing display  14  and a convex surface facing eye box  60  is merely illustrative. If desired, lens element  208  may have surfaces with other shapes (e.g., planar, convex, concave, etc.). In some arrangements, lens element  208  may be a rigid lens element formed from glass, a polymer material such as polycarbonate or acrylic, a crystal such as sapphire, etc. In other arrangements, lens element  208  may be a flexible lens element that can be adjusted to have different shapes (e.g., lens element  208  may have surfaces that can change between convex shapes, concave shapes, planar shapes, etc.). 
     Optical structures such as partially reflective coatings, wave plates, reflective polarizers, linear polarizers, antireflection coatings, and/or other optical components may be incorporated into head-mounted device  10 . These optical structures may allow light rays from display  14  to pass through and/or reflect from surfaces in lens element  208 , thereby providing lens module  72  with a desired lens power. 
     For example, a partially reflective mirror (e.g., a metal mirror coating or other mirror coating such as a dielectric multilayer coating with a 50% transmission and a 50% reflection) such as partially reflective mirror  86  may be formed on lens element  208  (e.g., between the lens element and display  14 ). Quarter wave plate  90  and reflective polarizer  92  may be formed on the opposing surface of lens element  208  (e.g., between lens element  208  and eye box  60 ). Light such as light  44  may pass through the lens. The example of  FIG.  2    in which a catadioptric lens is used in lens module  72  is merely illustrative. In general, lens module  72  may include any desired combination of optical structures (e.g., partially reflective coatings, wave plates, reflective polarizers, linear polarizers, antireflection coatings, etc.) at any desired location within the lens module. Additional lens elements may be incorporated into lens module  72  and each lens element may have any desired shape. 
     If desired, head-mounted device  10  may include positioner  58  for adjusting the distance  94  between lens module  72  (e.g., lens element  208 ) and display  14 . Positioner  58  may include one or more stepper motors, piezoelectric actuators, motors, linear electromagnetic actuators, and/or other electronic components for adjusting the position of pixel array  14  (and/or adjusting the position of lens module  72 ). Positioner  58  may be controlled by control circuitry  12  ( FIG.  1   ) during operation of device  10  to adjust the position of pixel array  14  relative to lens module  72 . 
     It may be desirable to be able to adjust the lens power of lens module  72  to accommodate users with different vision. For example, some users may have myopia (nearsightedness) whereas other users may have hyperopia (farsightedness). Additionally, the vision of a user&#39;s left eye may be different from the vision of the user&#39;s right eye. In addition to or instead of adjusting the position of pixel array  14  relative to lens module  72 , each lens module  72  may include one or more adjustable lens elements such as adjustable lens element  88  having a tunable (adjustable) lens power. Adjustable lens element  88  may be located between eye box  60  and lens  208 , may be located between lens  208  and pixel array  14 , and/or may be located in other suitable locations. Control circuitry  12  may, if desired, independently control the lens power of each adjustable lens element to accommodate users with different vision and/or to accommodate left and right eyes with different vision. 
       FIG.  3    is a cross-sectional side view of an illustrative lens module in device  10  having one or more adjustable lens elements. As shown in  FIG.  3   , adjustable lens element  88  may include substrate  122 . Substrate  122  may be formed from a rigid, transparent material such as glass, polymer such as polycarbonate or acrylic, a crystal such as sapphire, or other suitable material. A flexible sidewall such as flexible wall  128  (e.g., a material having a relatively low modulus of elasticity such as polyurethane or other polymer that is molded, cast, or otherwise formed into the desired shape) may form an enclosed perimeter on substrate  122 . The lateral footprint (e.g., in the X-Y plane of  FIG.  3   ) of flexible wall  128  on substrate  122  may be circular, oval, elliptical, rectangular, or any other suitable shape. Arrangements in which flexible wall  128  follows a meandering path or any other arbitrary path along its perimeter may also be used. A flexible membrane such as flexible membrane  124  (e.g., a thin sheet of elastomeric material or other suitable flexible material) may be attached on top of flexible wall  128  and may cover the area on substrate  122  that is enclosed by flexible wall  128 . 
     Substrate  122 , flexible wall  128 , and flexible membrane  124  may together define an interior volume V. The interior volume V may be partially or completely filled with a fluid such as fluid  110 . Fluid  110  may be a liquid, gel, or gas with a predetermined index of refraction. Fluid  110  may sometimes be referred to as an index-matching oil, an optical oil, an optical fluid, an index-matching material, an index-matching liquid, etc. The amount of fluid  110  in volume V may be fixed, or the amount of fluid  110  in volume V may be adjusted during operation of device  10 , if desired. 
     The lens power of lens element  88  may be adjusted using lens shaping component  132 . In particular, lens shaping component  132  may include one or more actuators (e.g., one or more stepper motors, piezoelectric actuators, motors, linear electromagnetic actuators, and/or other electronic components that apply a force) that are used to adjust the height of flexible wall  128  in response to control signals from control circuitry  12  (e.g., by pushing and pulling flexible wall  128  in directions  150  and/or by leaving flexible wall  128  in a relaxed state in which lens shaping component  132  applies no forces to flexible wall  128 ). Adjusting the height of flexible wall  128  relative to substrate  122  may adjust the shape of flexible membrane  124 , which in turn changes the lens power of lens element  88 . For example, when flexible wall  128  is distance D 1  from substrate  122 , outer surface  124 P of membrane  124  may have a concave shape (thus providing lens element  88  with a negative lens power), whereas when flexible wall  128  is compressed to distance D 2  from substrate  122  (e.g., a distance less than D 1 ), outer surface  124 P may have a convex shape (thus providing lens element  88  with a positive lens power), as shown in  FIG.  4   . In general, wall  128  may be adjusted in any suitable fashion to achieve any desired shape in membrane  124 . The examples of  FIGS.  3  and  4    are merely illustrative. 
     If desired, an additional adjustable lens element such as lens element  88 ′ may optionally be stacked with lens element  88 . The additional lens element  88 ′ may include similar or identical components as lens element  88 , such as flexible wall  128 ′, lens shaping component  132 ′, and flexible membrane  124 ′. Additional lens element  88 ′ may share substrate  122  with lens element  88  or may have its own separate substrate, if desired. Lens element  88 ′ may be oriented in the opposite direction as lens element  88  such that its adjustable surface  124 P′ (e.g., the outer surface of flexible membrane  124 ′) faces the opposite direction as adjustable surface  124 P. The adjustable surface of one lens element (e.g., surface  124 P or surface  124 P′) may face pixel array  14 , and the adjustable surface of the opposite lens element (e.g., surface  124 P′ or surface  124 P) may face eye box  60  ( FIG.  2   ). In this way, control circuitry  12  may control the lens power of lens module  72  by providing appropriate control signals to lens shaping element  132  and lens shaping element  132 ′. If desired, control circuitry  12  may independently control lens elements  88  and  88 ′ so that surfaces  124 P and  124 P′ can have different shapes and/or so that lens elements  88  and  88 ′ have different lens powers. Arrangements in which surfaces  124 P and  124 P′ have the same shape and/or in which lens elements  88  and  88 ′ have the same lens power may also be used. 
     The use of two adjustable lens elements  88  in module  72  is merely illustrative. If desired, there may only be a single lens element  88  in lens module  72 , or there may be two, three, four, or more than four stacked lens elements  88  in lens module  72 . For explanation purposes, the features of a single lens element  88  may be described herein, but it should be understood that similar features may be used in any or all of the additional lens elements  88  in device  10 . 
     It may be desirable to ensure that flexible wall  128  is displaced only or mostly along the Z-direction when lens shaping component  132  presses or pulls in directions  150 . For example, there may be additional components located laterally adjacent to lens element  88 . If care is not taken, flexible wall  128  may bulge outward when pressed toward substrate  122 . Excessive lateral movement of flexible wall  128  (e.g., movement in the X-Y plane of  FIG.  3   ), may cause flexible wall  128  to collide with the other components that are adjacent to lens element  88 . 
     To minimize lateral movement of flexible wall  128  in the X-Y plane, flexible wall  128  may have one or more accordion-like folds or pleats such as bellows  130 . Bellows  130  (sometimes referred to as folds, pleats, zig-zags, curves, ridges, etc.) may allow wall  128  to be pushed and pulled in directions  150  while minimizing lateral movement in the X-Y plane. For example, as shown in the compressed state of  FIG.  4   , bellows  130  allow wall  128  to collapse and fold on itself when pressed toward substrate  122  by lens shaping component  132 , with no outward bulging that could cause collisions with adjacent components. When wall  128  includes one or more bellows, pleats, or folds, wall  128  may sometimes be referred to as a foldable sidewall, a collapsible sidewall, a pleated sidewall, a zig-zag sidewall, etc. 
     In the example of  FIGS.  3  and  4   , the curved surfaces of bellows  130  such as curved surfaces  130 P face towards interior volume V, which may help further reduce outward bulging of wall  128 . This is merely illustrative, however. If desired, curved surfaces  130 P of bellows  130  may face the opposite direction (e.g., may face away from interior volume V). Additionally, the use of two bellows  130  (e.g., with two curved surfaces  130 P that sweep around the perimeter of lens  88 ) is merely illustrative. In general, flexible wall  128  may have any suitable number of bellows (e.g., three bellows, four bellows, five bellows, more than five bellows, less than five bellows, etc.). 
     If desired, the height of flexible wall  128  relative to substrate  122  may vary across the perimeter of flexible wall  128 . For example, the height of flexible wall  128  relative to substrate  122  may be uniform across its perimeter when flexible wall  128  is in a relaxed state, but may be adjusted locally by applying appropriate forces to portions of wall  128  using lens shaping component  132 . Arrangements where the height of flexible wall  128  relative to substrate  122  is non-uniform across its perimeter when flexible wall  128  is in a relaxed state may also be used. In general, the shape, size, construction, material, and/or any other suitable property of wall  128  may be varied to achieve the desired structure for lens  88 . 
     Outward bulging and/or non-uniform bulging may also be minimized by incorporating one or more reinforcement or stiffening structures into flexible wall  128 . This type of arrangement is illustrated in  FIG.  5   . 
     As shown in  FIG.  5   , flexible wall  128  may incorporate one or more reinforcement rings  142 . Reinforcement rings  142  may be partially or entirely embedded in flexible wall  128 , may be attached to an outer or inner surface of flexible wall  128 , and/or may be formed from a locally thickened portion or otherwise locally modified portion of wall  128 . Reinforcement ring  142  may form a continuous loop around the perimeter of interior volume V, or reinforcement ring  142  may be broken up into segments or sections that each extend only partly around the perimeter of interior volume V. Reinforcement rings may be formed form metal, polymer, or other suitable material and may, if desired, have a higher modulus of elasticity than the material that forms wall  128 . 
       FIGS.  6  and  7    show illustrative locations for reinforcement rings  142 . In both examples, reinforcement rings  142  are located at the corners of bellows  130  (e.g., the local peaks or troughs along wall  128 ). This is merely illustrative. If desired, reinforcement rings  142  may be incorporated into other locations of wall  128  such as regions between peaks and troughs. 
     In the example  FIG.  6   , some of reinforcement rings  142  are vertically aligned with one another along the Z-dimension of  FIG.  6   . When wall  128  is compressed, the aligned reinforcement rings  142  may travel towards one another (e.g., along line  162 ) and may, if desired, come into contact with one another during compression. This may, for example, be used in arrangements where it is desired to limit the maximum compression of lens element  88 . 
     In the example if  FIG.  7   , reinforcement rings  142  are staggered so that rings  142  are laterally offset from one another. In this way, reinforcement rings  142  may not collide with one another when wall  128  is compressed, which may in turn allow for greater compression of lens element  88  than in an aligned ring arrangement of the type shown in  FIG.  6   . To achieve the offset configuration of  FIG.  7   , bellows  130  and/or rings  142  may have different perimeter lengths (e.g., may have different circumferences or perimeters so that some ridges of wall  128  are located further outward than other ridges). 
     If desired, lens element  88  may incorporate more than one sidewall structure to help contain fluid  110  in the event of a leak. This type of arrangement is illustrated in  FIG.  8   . 
     As shown in  FIG.  8   , lens element  88  may include inner wall  128 A and outer wall  128 B. Inner wall  128 A may include one or more bellows  130  to minimize lateral bulging of inner wall  128 A. Outer wall  128 B, which may be formed from the same or different materials as inner wall  128 A, may have be curved, may be straight, may have one or more folds, pleats, or bellows, may have one or more concave surfaces facing inner wall  128 A, may have one or more convex surfaces facing inner wall  128 A, and/or may have any other suitable shape. Outer wall  128 B may form a seal around inner wall  128 A. In the event that inner wall  128 A becomes compromised, any liquid  110  that leaks out of inner wall  128 A will be contained within outer wall  128 B. The volume between inner wall  128 A and outer wall  128 B may be sealed, if desired, and may be partially or completely filled with air, pressurized gas, dye, liquid, or other fluid such as fluid  144 . 
     In addition to containing liquid in the event of a leak, outer wall  128 B may be used to help detect when a leak has occurred. For example, fluid  144  between inner wall  128 A and outer wall  128 B may be a gas, a pressurized gas, or a liquid that is initially trapped between inner wall  128 A and outer wall  128 B. If inner wall  128 A becomes compromised, bubbles or other artifacts may appear in fluid  110 . The appearance of bubbles in fluid  110  may indicate that a leak has occurred and that lens element  88  may need to be repaired or replaced. 
     In another illustrative arrangement, fluid  144  between inner wall  128 A and outer wall  128 B may contain a dye or pigment that is initially trapped between inner wall  128 A and outer wall  128 B. If inner wall  128 A becomes compromised, the dye or pigmented fluid  144  may seep through inner wall  128  and may pollute fluid  110 . The appearance of this type of pollution in fluid  110  may indicate that a leak has occurred and that lens element  88  may need to be repaired or replaced. 
     If desired, lens element  88  may be tested during manufacturing to determine if any leaks are present. For example, lens element  88  may be compressed one or more times to observe whether bubbles appear in fluid  110 , to observe whether a dye or pigment or other fluid  144  seeps into fluid  110 , to measure whether a pressure change occurs between inner wall  128 A and outer wall  128 B, and/or to otherwise determine whether lens element  88  has any leaks. 
     If desired, one or more sensors such as sensor  146  may optionally be incorporated into lens element  88  to determine whether lens element  88  has a leak. Sensor  146  may be a pressure sensor (e.g., a sensor that measures the pressure of fluid  110  and/or fluid  144 ), a capacitive sensor, a resistive pressure sensor, a force sensor, and/or other suitable sensor. For example, sensor  146  may be a liquid pressure sensor that detects when an amount of fluid  110  in volume V changes, may be an air pressure sensor that detects when the air pressure between inner wall  128 A and outer wall  128 B changes, may be a strain gauge in inner wall  128 A and/or outer wall  128 B that detects changes in the force applied (e.g., by fluid  110  and/or fluid  144 ) on inner wall  128 A and/or outer wall  128 B, and/or may have any other suitable configuration. If desired, a coating or other material that changes properties (e.g., that changes color or otherwise changes appearance) when contacted by fluid  110  may be used outside of inner wall  128 A to detect when fluid  110  escapes inner wall  128 A. This type of coating or other material may be used in addition to or instead of sensor  146 . 
       FIG.  9    is a top view of an illustrative lens element  88  having a lens shaper component  132 . In the example of  FIG.  9   , lens shaper  132  is shown as having a round shape. This is, however, merely illustrative. If desired, lens shaper  132  may be circular, oval, elliptical, rectangular, or any other suitable shape. Lens shaper component  132  may have one or more actuators that apply forces at actuation points such as actuation points  148 . At each actuation point  148 , an actuator may be used to push, pull, or otherwise apply a force to lens shaper component  132  at location  148  to thereby adjust the shape of flexible membrane  124 . There may be one, two, three, six, eight, ten, fifteen, less than fifteen, or more than fifteen actuation points  148 , which may be distributed evenly or unevenly around the periphery of lens shaper component  132 . 
     If desired, lens shaper component  132  may have a non-uniform construction to achieve a desired performance with respect to how lens shaper component  132  changes the lens power of lens element  88 . For example, lens shaper component  132  may have non-uniform thickness (e.g., thickness in the Z-dimension and/or thickness in the X-Y plane), non-uniform materials, non-uniform modulus of elasticity, non-uniform shape, and/or other non-uniform properties. For example, the modulus of elasticity may gradually change along the circumference or perimeter of lens shaper component  132  (e.g., so that regions  152  between actuation points  148  are stiffer or less stiff than at actuation points  148 ). Different moduli of elasticity may be obtained by using different materials and/or by changing the geometry of component  132  in certain regions (e.g., by locally thinning certain regions or forming perforations in certain regions to reduce the modulus of elasticity in those regions). This is, however, merely illustrative. If desired, lens shaper component  132  may have a uniform construction. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20210204
Publication Date: 20241126
Grant Date: 20241126
Priority Date: 20200312
Inventors: TOPLISS, Richard J.
STAMENOV, Igor
HE, RAN
LI, YUAN
LV, PENG
PEDDER, JAMES E.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B26/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B3/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B3/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B26/004", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B3/14", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 77663674