PATENT DOCUMENT

Publication Number: US-11809619-B1
Application Number: US-202017077823-A
Country: US
Kind Code: B1

Title: Display systems with optical sensing

Abstract:
A head-mounted device may have catadioptric lenses that each include a partial mirror, a quarter wave plate, and a polarizer. An optical system in the head-mounted device may have an infrared light-emitting device and an infrared light-sensing device. The optical system may illuminate a user&#39;s eyes in eye boxes and may gather measurements from the illuminated eye boxes for eye tracking and other functions. The optical system may operate through the catadioptric lenses. To enhance optical system performance, the polarizers may be wire grid polarizers that are formed from conductive lines that exhibit enhanced infrared transmission and/or the quarter wave plates may be formed from cholesteric liquid crystal layers that serve as quarter wave plates at visible wavelengths and that do not serve as quarter wave plates at infrared wavelengths.

Claims:
What is claimed is: 
     
       1. A head-mounted device, comprising:
 a display; 
 a lens through which the display is visible from an eye box; 
 an infrared sensor system having an infrared light-emitting device that emits infrared light that serves as illumination in the eye box and an infrared light-sensing device that detects infrared light from the eye box; and 
 a head-mounted support structure, wherein the head-mounted support structure is configured to support the display, the lens, and the infrared sensor system, wherein the lens comprises a catadioptric lens having a wire grid polarizer formed from parallel lines and wherein the parallel lines each include first regions of a first material and second regions of a second material. 
 
     
     
       2. The head-mounted device defined in  claim 1  wherein the first material comprises a metal. 
     
     
       3. The head-mounted device defined in  claim 2  wherein the second material comprises a non-metal. 
     
     
       4. The head-mounted device defined in  claim 3  wherein the second material comprises a semiconductor. 
     
     
       5. The head-mounted device defined in  claim 4  wherein the second material comprises silicon. 
     
     
       6. The head-mounted device defined in  claim 4  wherein the second material comprises germanium. 
     
     
       7. The head-mounted device defined in  claim 1  wherein the first regions form islands within the second regions. 
     
     
       8. The head-mounted device defined in  claim 1  wherein the first regions are first continuous regions and wherein the second regions are second continuous regions. 
     
     
       9. The head-mounted device defined in  claim 1  wherein the infrared light-emitting device has a quarter wave plate and wherein the infrared light that is emitted by the infrared light-emitting device is circularly polarized after passing through the quarter wave plate. 
     
     
       10. The head-mounted device defined in  claim 1  wherein the infrared light-emitting device is between the wire grid polarizer and the eye box. 
     
     
       11. The head-mounted device defined in  claim 1  wherein the infrared light-sensing device is between the eye box and the wire grid polarizer. 
     
     
       12. The head-mounted device defined in  claim 1  wherein the catadioptric lens comprises a layer that forms a visible-light quarter wave plate and that is transparent at infrared wavelengths and does not form a quarter wave plate at the infrared wavelenghts. 
     
     
       13. The head-mounted device defined in  claim 12  wherein the layer comprises a cholesteric liquid crystal layer. 
     
     
       14. The head-mounted device defined in  claim 1  wherein the infrared light-sensing device comprises a two-dimensional infrared image sensor. 
     
     
       15. A head-mounted device, comprising:
 a display; 
 a lens through which the display is visible from an eye box; 
 an infrared sensor system having a light-emitting device that emits infrared light that serves as illumination in the eye box and an infrared two-dimensional image sensor that detects infrared light from the eye box; and 
 a head-mounted support structure, wherein the head-mounted support structure is configured to support the display, the lens, and the infrared sensor system and wherein the lens comprises a catadioptric lens having a wire grid polarizer that exhibits more infrared light transmission than visible light transmission. 
 
     
     
       16. The head-mounted device defined in  claim 15  wherein the polarizer is formed from parallel conductive lines, wherein the parallel conductive lines each include first regions of a first material and second regions of a second material, and wherein the wire grid polarizer exhibits, for light that is linearly polarized orthogonal to a pass axis of the polarizer, a first light transmission at a wavelength of 0.5 microns and a second light transmission at a wavelength of 0.81 microns that is greater than the first light transmission. 
     
     
       17. The head-mounted device defined in  claim 16  wherein the first regions are first continuous filaments and wherein the second regions are second continuous filaments and wherein the first material is a metal. 
     
     
       18. The head-mounted device defined in  claim 16  wherein the first material is a metal and the second material is a semiconductor. 
     
     
       19. A head-mounted device, comprising:
 a display; 
 a lens through which the display is visible from an eye box; 
 an infrared sensor system having a light-emitting device that emits infrared light that passes through the lens and that serves as illumination in the eye box and an infrared two-dimensional image sensor that detects infrared light from the eye box that has passed through the lens; and 
 a head-mounted support structure, wherein the head-mounted support structure is configured to support the display, the lens, and the infrared sensor system, wherein the lens comprises a catadioptric lens having a polarizer, a layer that serves as a quarter wave plate at visible light wavelengths and that does not serve as a quarter wave plate at infrared wavelengths, and a partial mirror. 
 
     
     
       20. The head-mounted device defined in  claim 19  wherein the layer comprises a cholesteric liquid crystal layer. 
     
     
       21. The head-mounted device defined in  claim 19  wherein the polarizer comprises parallel conductive lines on a transparent substrate and wherein each of the parallel conductive lines comprises a metal and a non-metal. 
     
     
       22. The head-mounted device defined in  claim 21  wherein the non-metal comprises a semiconductor. 
     
     
       23. An electronic device, comprising:
 a support structure; 
 a transparent structure coupled to the support structure; and 
 an infrared sensor system comprising an infrared light-emitting device that emits infrared light through the transparent structure and an infrared light-sensing device that detects infrared light through the transparent structure, wherein the transparent structure comprises a wire grid polarizer that exhibits more infrared light transmission than visible light transmission. 
 
     
     
       24. The electronic device defined in  claim 23  wherein the wire grid polarizer comprises parallel lines and wherein the parallel lines each include first regions of a first material and second regions of a second material. 
     
     
       25. The electronic device defined in  claim 24  wherein the first material comprises a metal and the second material comprises a non-metal. 
     
     
       26. The electronic device defined in  claim 23  wherein the support structure is a head-mountable support structure. 
     
     
       27. The electronic device defined in  claim 26  wherein the transparent structure is a lens, the electronic device further comprising:
 a display visible through the lens from an eye box.

Description:
This application claims the benefit of provisional patent application No. 62/934,143, filed Nov. 12, 2019, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices with optical components. 
     BACKGROUND 
     Electronic devices sometimes include optical components. For example, a wearable electronic device such as a head-mounted device may include a display for displaying an image. 
     Lenses may be used to allow a user of a head-mounted device to focus on a display and view an image. Lenses such as catadioptric lenses may help reduce lens size and weight, making a head-mounted device comfortable to wear. Catadioptric lenses may include optical components such as partial mirrors, wave plates, and polarizers. If care is not taken, there may be incompatibilities between these components and other components in a head-mounted device. For example, there may be a risk that the optical characteristics of these components will adversely affect the operation of optical sensors. 
     SUMMARY 
     An electronic device such as a head-mounted device may have a display that displays an image for a user. A user with eyes located in eye boxes may view the image through lenses that are interposed between the eye boxes and the display. The lenses may be catadioptric lenses. 
     A catadioptric lens for a head-mounted device may include a partial mirror, a quarter wave plate, and a polarizer. An optical system in the head-mounted device may be used for eye tracking and other functions. 
     The optical system may have an infrared light-emitting device and an infrared light-sensing device. The optical system may illuminate the eye boxes and may gather measurements on the illuminated eye boxes during operation of the head-mounted device. 
     The optical system may operate through catadioptric lens structures. For example, the light-emitting device may emit infrared illumination that passes through a catadioptric lens and corresponding reflected light from the eye boxes may pass through the catadioptric lens to the light-sensing device. 
     To enhance optical system performance, the polarizers in the catadioptric lenses may be may exhibit enhanced infrared transmission relative to visible light transmission. At visible light wavelengths, the polarizers serve as linear polarizers. At infrared light wavelengths, the polarizers are transparent and allow infrared light associated with the optical system to pass. 
     In some configurations, the quarter wave plates of the catadioptric lenses are formed from cholesteric liquid crystal layers that serve as quarter wave plates at visible wavelengths and that do not serve as quarter wave plates at infrared wavelengths. Arrangements may also be used in which light-emitting devices in the optical system are provided with polarizers that polarize emitted light to enhance transmission through the catadioptric lenses and/or in which light-emitting devices and/or light-sensing devices are located between the lenses and the eye boxes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a top view of an illustrative electronic device such as a head-mounted device in accordance with an embodiment. 
         FIG.  2    is a top view of a portion of an illustrative head-mounted device with a lens in accordance with an embodiment. 
         FIG.  3    is a graph showing how an optical component in a lens may have an optical property such as a light transmission parameter that varies as a function of wavelength in accordance with an embodiment. 
         FIG.  4    is a top view of an illustrative wire grid polarizer in accordance with an embodiment. 
         FIG.  5    is a cross-sectional side view of the wire grid polarizer of  FIG.  4    in accordance with an embodiment. 
         FIGS.  6  and  7    are top views of conductive layers that may be patterned into wires for a wire grid polarizer in accordance with an embodiment. 
         FIGS.  8 ,  9 ,  10 , and  11    are side views of illustrative arrangements for operating an infrared sensor through a lens with optical components 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 optical components such as a display for displaying visual content and lenses for allowing the user to view the visual content on the display. Optical sensors such as infrared sensors may be used to gather information on a user&#39;s eyes, facial features, or other body characteristics. This information may be used for eye tracking (sometimes referred to as gaze tracking), may be used for authentication (e.g., eye biometrics for user identification), facial recognition, and/or other device operations. 
     During operation, infrared sensors may emit and detect infrared light. This light may pass through the lenses in the head-mounted device. The lenses may be catadioptric lenses having optical components such as partial mirrors, wave plates, and polarizers. To help ensure compatibility between the infrared sensors and the lenses, one or more of the optical components in the lenses may be formed from material that is more transparent at infrared wavelengths than at visible wavelengths or has other wavelength-dependent properties. 
     A top view of an illustrative head-mounted device is shown in  FIG.  1   . As shown in  FIG.  1   , head-mounted devices such as electronic device  10  may have head-mounted support structures such as housing  12 . Housing  12  may include portion  12 T to allow device  10  to be worn on a user&#39;s head. Main housing portion  12 M may include optical components  14  (e.g., a display, lenses, etc.). Housing structures such as internal support structures  121  may support lenses and other optical components  14  (e.g., structures  121  may serve as lens support structures). 
     Front face F of housing  12  may face outwardly away from a user&#39;s head. Rear face R of housing  12  may face the user. During operation, a user&#39;s eyes are placed in eye boxes  18 . When the user&#39;s eyes are located in eye boxes  18 , the user may view content being displayed by optical components  14 . In some configurations, optical components  14  are configured to display computer-generated content that is overlaid over real-world images (e.g., a user may view the real world through components  14 ). In other configurations, which are sometimes described herein as an example, real-world light is blocked (e.g., by an opaque housing wall on front face F of housing  12  and/or other portions of device  10 ). 
     The support structures of device  10  may include adjustable components. For example, portion  12 T of housing  12  may include adjustable straps or other structures that may be adjusted to accommodate different head sizes. Support structures  121  may include motor-driven adjustable lens mounts, manually adjustable lens mounts, and other adjustable optical component support structures. Structures  121  may be adjusted by a user to adjust the locations of eye boxes  18  to accommodate different user interpupillary distances. For example, in a first configuration, structures  121  may place lenses and other optical components associated respectively with the user&#39;s left and right eyes in close proximity to each other so that eye boxes  18  are separated from each other by a first distance and, in a second configuration, structures  121  may be adjusted to place the lenses and other optical components associated with eye boxes  18  in a position in which eye boxes are separated from each other by a second distance that is larger than this distance. Lens position adjustments and other adjustments may be made on information gathered using image sensors and other sensors (e.g., information on a user&#39;s eye positions from eye tracking sensors). 
     In addition to optical components  14 , device  10  may contain other electrical components  16 . Components  14  and/or  16  may include integrated circuits, discrete components, printed circuits, and other electrical circuitry. For example, these components may include control circuitry and input-output devices. 
     The control circuitry of device  10  may include storage and processing circuitry for controlling the operation of device  10 . The control circuitry 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 the control circuitry 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 the control circuitry and run on processing circuitry in the control circuitry to implement control operations for device  10  (e.g., data gathering operations, operations involving the adjustment of the components of device  10  using control signals, etc.). Control circuitry in device  10  may include wired and wireless communications circuitry. For example, the control circuitry 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. 
     Device  10  may be used in a system of multiple electronic devices. During operation, the communications circuitry of device  10  may be used to support communication between device  10  and other electronic devices in the system. For example, one electronic device may transmit video and/or audio data to device  10  or another electronic device in the system. Electronic devices in the system 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. 
     The input-output devices of device  10  (e.g., input-output devices in components  16 ) may be used to allow a user to provide device  10  with user input. Input-output devices may also be used to gather information on the environment in which device  10  is operating. Sensors may be used in gathering eye position information, point-of-gaze information, eye biometric information (retina features, etc.), other biometric information, etc. Output components in the input-output devices may allow device  10  to provide a user with output and may be used to communicate with external electrical equipment. 
     The input-output devices of device  10  may include one or more displays. In some configurations, a display in device  10  may include left and right display devices (e.g., left and right components such as left and right scanning mirror display devices, liquid-crystal-on-silicon display devices, digital mirror devices, or other reflective display devices, left and right display panels based on light-emitting diode pixel arrays (e.g., organic light-emitting display panels or display devices based on pixel arrays formed from crystalline semiconductor light-emitting diode dies), liquid crystal display devices panels, and/or or other left and right display devices in alignment with the user&#39;s left and right eyes, respectively. In other configurations, the display includes a single display panel that extends across both eyes or uses other arrangements in which content is provided with a single pixel array. 
     The display of device  10  is used to display visual content for a user of device  10 . The content that is presented on the display may include virtual objects and other content that is provided to the display by control circuitry  12  and may sometimes be referred to as computer-generated content. An image on the display such as an image with computer-generated content may be displayed in the absence of real-world content or may be combined with real-world content. In some configurations, a real-world image may be captured by a camera (e.g., a forward-facing camera) so that computer-generated content may be electronically overlaid on portions of the real-world image (e.g., when device  10  is a pair of virtual reality goggles with an opaque display). 
     The input-output circuitry of device  10  may include sensors. The sensors 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, capacitive proximity sensors, light-based (optical) proximity sensors, other proximity sensors, force sensors, sensors such as contact sensors based on switches, gas sensors, pressure sensors, moisture sensors, magnetic sensors, audio sensors (microphones), ambient light sensors, light sensors that make user measurements, 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), and/or other sensors. 
     User input and other information may be gathered using sensors and other input devices in the input-output devices of device  10 . If desired, device  10  may include 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 used for input and output. If desired, 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. 
     Some or all of housing  12  may serve as support structures (see, e.g., housing portion  12 T). In configurations in which electronic device  10  is a head-mounted device (e.g., a pair of glasses, goggles, a helmet, a hat, etc.), portion  12 T and/or other portions of housing  12  may serve as head-mounted support structures (e.g., structures forming 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), lenses, sensors, other input-output devices, control circuitry, and/or other components. 
       FIG.  2    is a top view of a portion of electronic device  10  in an illustrative configuration in which electronic device  10  is a head-mounted device. As shown in  FIG.  2   , electronic device  10  may include display  14 A. Display  14 A may have an array of pixels P for displaying images for a user. A user with eyes located in a pair of eye boxes such as eye box  18  may view images on display  14 A through a pair of lenses such as lens  14 B. A single lens  14 B and eye box  18  are shown in  FIG.  2   . Display  14 A may include left and right display portions (sometimes referred to as left and right displays, left and right display devices, left and right display components, or left and right pixel arrays). 
     Optical sensing system  36  may have one or more components that emit light  40  such as light-emitting device  38  and one or more components that detect light  42  such as light-sensing device  44 . Optical sensing system  36  may operate at visible light wavelengths, infrared light wavelengths, and/or ultraviolet light wavelengths. In an illustrative configuration, which may sometimes be described herein as an example, optical sensing system  36  operates at infrared wavelengths. Optical sensing system  36  may therefore sometimes be referred to as an infrared sensing system or infrared sensor. Device  38  may be based on one or more light-emitting components such as light-emitting diodes and/or lasers and may operate at one or more wavelengths. As an example, device  38  may be an infrared light-emitting diode and/or infrared laser diode or may have a set of infrared light-emitting diodes and/or infrared laser diodes. Device  44  may be a light detecting component such as a single-element infrared photodetector, a set of multiple infrared photodetectors, a two-dimensional infrared image sensor, and/or other light-sensing components. 
     Optical sensing system  36  may operate through lens  14 B. For example, when a user&#39;s eyes are located in eye boxes  18 , sensor system  36  may gather information on the user&#39;s eyes. This information may be used to support authentication operations (eye biometrics), identification operations (e.g., discriminating between multiple users of device  10 ), eye position sensing, eye tracking (gaze tracking) operations in which the user&#39;s point-of-gaze (direction of view) is monitored, facial recognition operations, or other operations of device  10 . 
     Lens  14 B may be a catadioptric lens. During operation, light rays passing from display  14 A to eye box  18  follow a folded path through lens  14 B. This helps allow the size and weight of lens  14 B to be reduced. In the example of  FIG.  2   , lens  14 B has partial mirror (e.g., a half mirror or other mirror with a light transmission of 10-90%, 20-80%, 30-70%, or other suitable light transmission value and a light reflection of 90-10%, 80-20%, 70-30%, or other suitable light reflection value), a wave plate such as quarter wave plate  30 , and reflective polarizer  34  (e.g., a linear polarizer that passes light that is polarized along the Y axis and that reflects light that is polarized along the X axis). Mirror  26  may be formed on the outwardly facing surface of transparent lens element  28 . This outwardly facing lens element surface may be aspherically convex (as an example). Quarter wave plate  30  may be formed between a cylindrically concave inwardly facing surface of lens element  28  and a corresponding cylindrically convex outwardly facing surface of lens element  32  (e.g., using adhesive bonding that attaches lens element  28  to lens element  32 ). Reflective polarizer  34  may be formed on an aspherically concave inwardly facing surface of lens element  32 . As shown in  FIG.  2   , polarizer  34  faces eye box  18  and mirror  26  faces display  14 A. 
     In an illustrative arrangement, lens  14 B receives circularly polarized image light from display  14 A. Display  14 A may have an associated circular polarizer such as circular polarizer  20 . Linear polarizer  24  of polarizer  20  may receive unpolarized image light from pixels P and may allow linearly polarized light to pass to quarter wave plate  22 . Quarter wave plate  22  of circular polarizer  20  may convert linearly polarized light from linear polarizer  24  to circularly polarized light (e.g., right-hand circularly polarized light). In this way, light from display  14 A passes to lens  14 B as circularly polarized light. Reflections of this light from mirror  26  are suppressed by polarizer  20 . 
     Sensor system  38  and/or the optical components that make up lens  14 B may be configure to allow sensor system  38  to operate through lens  14 B. For example, one or more of the layers of lens  14 B such as the layers forming mirror  26 , wave plate  30 , and/or polarizer  34  may be configured to have different optical characteristics at visible and infrared wavelengths. This allows lens  14 B to pass visible light images from display  14 A to eye box  18  while allowing infrared light for system  36  to pass from system  36  through lens  14 B to a user&#39;s eye in eye box  18  and to subsequently pass from the user&#39;s eye in eye box  18  to system  36 . 
     In an illustrative configuration, polarizer  34  may be configured to be transparent at infrared wavelengths (e.g., at a wavelength of 810 nm and/or other near infrared wavelengths). When light is linearly aligned along the pass axis of polarizer  34 , polarizer  34  may exhibit a light transmission value of 100% or nearly 100% for visible light and infrared light. When light is linearly polarized orthogonally to the pass axis, visible light will be blocked and infrared light will be transmitted. As shown by curve  46  of the graph of  FIG.  3   , for example, polarizer  34  may, for light that is polarized orthogonal to the pass axis of polarizer  34 , exhibit a visible light transmission value T (e.g., at a visible light wavelength of 500 nm or other suitable visible light wavelength) that is less than 50%, less than 30%, less than 20%, less than 10%, or other suitable fraction of its infrared light transmission value (e.g. at an infrared wavelength of 810 nm or other suitable infrared wavelengths). By exhibiting more infrared light transmission than visible light transmission, the amount that infrared light associated with system  36  (e.g., emitted light  40  and/or sensed light  42 ) is attenuated by passing through lens  14 B may be reduced. If desired, other optical characteristics of the optical components in device  10  may be configured to be different between infrared and visible wavelengths. For example, other component(s) may have characteristics that differ by at least 40%, at least 50%, at least 80%, or other suitable amount between visible and infrared wavelengths (e.g., wave plate  30  may be effective as a quarter wave plate only at visible light wavelengths and not at infrared light wavelengths). Arrangements in which the infrared light transmission of polarizer  34  is enhanced relative to the visible light transmission of polarizer  34  may sometimes be described herein as an example. 
     A portion of an illustrative reflective polarizer such as polarizer  34  is shown in  FIG.  4   . In the example of  FIG.  4   , polarizer  34  is a wire grid polarizer (sometimes referred to as a wire grid film polarizer) having a series of parallel conductive lines  48 . Lines  48  (which may sometimes be referred to as elongated strips) may be formed from a conductive material separated by respective gaps G. Lines  48  of  FIG.  4    run parallel to each other along the X axis. In this type of arrangement, polarizer  34  will pass light that is linearly polarized along the Y axis (the pass axis of polarizer  34  is along the Y axis) and will reflect light (and thereby block light) that is linearly polarized along the X axis. 
     Lines  48  may be characterized by a width W of 50 nm, at least 15 nm, at least 30 nm, less than 200 nm, less than 100 nm, or other suitable width and a pitch PT of about 90-100 nm, at least 30 nm, at least 45 nm, less than 180 nm, less than 120 nm, or other suitable pitch. The thickness of lines  48  in dimension Z may be about 30 nm, at least 3 nm, at least 6 nm, at least 15 nm, less than 300 nm, less than 150 nm, less than 70 nm, 10-90 nm, and/or other suitable thickness. Lines  48  may be deposited on a dielectric substrate such as substrate  50  and may be pattered by etching, lift-off, shadow masking, printing, and/or other patterning techniques suitable for patterning a conductive thin-film layer. A cross-sectional side view of polarizer  34  of  FIG.  4    taken along line  47  and viewed in direction  49  is shown in  FIG.  5   . Substrate  50  may be a polymer film (e.g., optical polycarbonate or other transparent polymer) or an inorganic polymer material. The thickness of substrate  50  may be about 1-9 microns, 3 microns, at least 0.2 microns, at least 0.7 microns, at least 1.5 microns, less than 6 microns, less than 4 microns, or other suitable thickness. Optional coatings (e.g., to prevent degradation of lines  48 , etc.) may be formed on polarizer  34 . If desired, the structures of polarizer  34  and/or other optical layers in lens  14 B may be formed as coatings on lens elements such as lens elements  32  and/or  28 . Arrangements in which polarizer  34  and other optical layers are formed as stand-alone films that are attached to lens elements  32  and/or  28  using adhesive may sometimes be described herein as an example. 
     To enhance infrared light transmission of lines  48  relative to visible light, lines  48  may be formed from a material with enhanced infrared light transmission relative to visible light. This material may be a nanomaterial formed from a mixture of two or more materials having feature sizes of about 1-1000 nm, at least 10 nm, at least 100 nm, less than 500 nm, less than 200 nm, or other suitable size. The nanomaterial may have subwavelength features that form a photonic crystal (as an example). 
     With an illustrative configuration, the material of lines  48  contain a mixture of a first material with a second material. The first material may form islands within a film formed of the second material as illustrated by the islands of first material  52  that are formed within the layer of second material  54  in the illustrative discontinuous material of lines  48  of  FIG.  6    or the first material may form continuous filaments of material within the second material as illustrated by irregular strands (continuous filaments) of first material  52  within the irregular strands (continuous filaments) of second material  54  in the material of lines  48  of  FIG.  7   . In an illustrative arrangement, the first material is a metal (e.g., aluminum) and the second material is a semiconductor (e.g., silicon or germanium). The patterned Al—Si materials of  FIGS.  6  and  7    may be formed by co-sputtering the first and second materials (and, if desired, low-temperature annealing these materials under vacuum). 
     The structures of  FIGS.  6  and  7    (e.g., the first regions of the first material and the second regions of the second material) may have subwavelength feature sizes (e.g., widths less than 300 nm, less than 150 nm, less than 75 nm, less than 30 nm, or other suitable size). In the arrangement of  FIG.  7   , a distinct phase separation is created during processing (e.g., spinodal decomposition) to create a spinodal pattern. 
     Silicon and germanium are opaque at visible wavelengths and transparent at infrared wavelengths. The incorporation of semiconductors such as silicon and/or germanium into polarizer  34  may help allow polarizer  34  to operate as a reflective polarizer at visible light wavelengths and as a transparent (non-polarizing) layer at infrared wavelengths. Other materials (e.g., other non-metals such as other semiconductors and/or other dielectrics, etc.) may also be used to help enhance infrared light transmission relative to visible light transmission. 
     The infrared transmission of silicon is greater than the infrared transmission of germanium, so incorporation of silicon into the material of lines  48  may enhance infrared light transmission (e.g., at 810 nm). The infrared transmission of germanium cuts off at about 600 nm, whereas silicon may be transparent at shorter wavelengths (e.g., silicon may exhibit a cutoff wavelength of 350 nm). As a result, the incorporation of germanium into the material of layer  48  instead of silicon may help enhance the ratio of light transmission at a desired infrared wavelength associated with operation of system  36  (e.g., a wavelength of 810 nm for light  40  and  42  of  FIG.  2   , as an example) to light transmission at a given visible light wavelength (e.g., 500 nm, as an example). Other semiconductors, dielectric materials, and/or metals may be incorporated into the material forming lines  48  of polarizer  34  to enhance infrared light transmission relative to visible light transmission, if desired. 
     By using a two-part material such as an aluminum-silicon mixture with separate regions of aluminum and silicon or other material for lines  48  that exhibits enhanced infrared light transmission (e.g., relative to visible light transmission and/or relative to the infrared light transmission that would be present if lines  48  were formed from pure aluminum or other metal), the transmission of light  40  and  42  through lens  14 B may be enhanced and the performance of optical system  36  may be enhanced. 
     When polarizer  34  has enhanced infrared light transmission, the transmission of emitted light  40  through polarizer  34  and the transmission of counterpropagating light  42  that has reflected off of a user&#39;s eye in eye box  18  is enhanced, particularly when the polarization state of light  40  and/or  42  is orthogonal to the pass axis of polarizer  34  upon passing through polarizer  34 . Because infrared light transmission is enhanced and the light-blocking properties of polarizer  34  are reduced for infrared light, system  36  may, if desired, use unpolarized light-emitting and light-sensing components (e.g., component  38  may emit unpolarized infrared light and/or component  44  may detect unpolarized infrared light). 
     In addition to or instead of enhancing the infrared light transmission of polarizer  34  (e.g., by forming lines  48  from an aluminum-silicon material or other material with enhanced infrared transmission), the performance of sensor system  36  can be enhanced by controlling the polarization state of light  40  and  42  as light  40  and  42  passes through lens  14 B (e.g., so that light  40  and  42  are linearly polarized in alignment with the pass axis of polarizer  34 ). 
     Consider, as an example, the arrangement of  FIG.  8    in which device  38  has been provided with a circular polarizer so that emitted light  40  from device  38  has circular polarization. As shown in  FIG.  8   , light-emitting device  38  may be configured to emit light  40  that is right-hand circularly polarized (RCP). Device  38  of  FIG.  8    may have a polarizer such as circular polarizer  60 . Circular polarizer  60  may have linear polarizer  62  and quarter wave plate  64 . Linear polarizer  62  of circular polarizer  60  may be interposed between quarter wave plate  64  and device  38 . Light  40  that is emitted by device  38  may initially be linearly polarized or may become linearly polarized upon passing through linear polarizer  62 . After passing through quarter wave plate  64 , light  40  of  FIG.  8    has right hand circular polarization. Mirror  26  is partially reflective and partially transparent to visible light and to infrared light  40  (e.g., the transmission of mirror  26  is at least 10%, at least 40%, less than 90%, less than 60%, etc.). Light  40  remains right-hand circularly polarized after passing through mirror  26 . Quarter wave plate  30  converts circularly polarized light to linearly polarized light. Linearly polarized light  40  exiting quarter wave plate  30  is aligned with the pass axis of polarizer  34  and illuminates a user&#39;s eye in eye box  18 , thereby producing counterpropagating light  42  that is characterized by linear polarization aligned with the pass axis of polarizer  34 . After passing through quarter wave plate  30 , light  42  becomes left-hand circularly polarized and this polarization state is preserved as light  42  passes through mirror  26 . Light-sensing device  44  of  FIG.  8    may be polarization insensitive and may therefore can sense light  42 . As this example demonstrates, polarizer  34  need not be provided with infrared-transparent lines  48  in arrangements in which infrared light  40  and  42  is linearly polarized along the pass axis of polarizer  34  when passing through polarizer  34 . 
     Another illustrative arrangement is shown in  FIG.  9   . In the illustrative configuration of  FIG.  9   , quarter wave plate  30  does not serve as a quarter wave plate at infrared wavelengths and is transparent to infrared light. Light-emitting device  38  may have a polarizer such a linear polarizer  62  and/or may otherwise be configured to emit infrared light  40  that is linearly polarized. Mirror  26  is partially transparent and transmits light  40  without changing the polarization of light  40 . Quarter wave plate  30  may be formed from a cholesteric liquid crystal film or other material that is transparent to infrared light and that does not serve as a quarter wave plate at infrared wavelengths and that forms a quarter wave plate at visible light wavelengths. At visible light wavelengths, quarter wave plate  30  converts the polarization of light passing through quarter wave plate  30 . Because quarter wave plate  30  is only effective at visible light wavelengths, however, linearly polarized infrared light  40  that is received from mirror  26  passes through plate  30  without any change to its polarization state. This infrared light  40  remains linearly polarized in alignment with the pass axis of linear polarizer  40 . Reflected infrared light  42  is also linearly polarized in alignment with the pass axis of linear polarizer  40 . Reflected infrared light  42  passes through plate  30  without change to its polarization state. Linearly polarized infrared light  42  from plate  30  then passes through mirror  26  and is received as linearly polarized light by light-sensing device  44 , which may be insensitive to polarization. 
     Two additional illustrative configurations for device  10  are shown in  FIGS.  10  and  11   . 
     In the example of  FIG.  10   , light-emitting device  38  is located between polarizer  34  and eye box  18 , so light  40  does not pass through lens  14 B. Light  40  may have a linear polarization that is aligned with the pass axis of polarizer  34  (e.g., device  36  may have a linear polarizer or may otherwise be configured to emit linearly polarized light). Reflected light  42  will be linearly polarized in alignment with this pass axis when passing from eye box  18  through polarizer  34  to quarter wave plate  30 . Quarter wave plate  30  may convert the linear polarization of this light  42  to circular polarization. Circularly polarized light  32  from plate  30  will pass through mirror  26  without changing its polarization state. Device  44  may be insensitive to the polarization state of incoming light and can therefore sense circularly polarized light  42  passing through mirror  26 . 
     In the example of  FIG.  11   , light-sensing device  44  is located between lens  14 B and eye box  18 , whereas lens  14 B is located between light-emitting device  38  and eye box  18 . Light-emitting device  38  emits infrared light  40  that passes through mirror  26  without changing its polarization state. 
     In a first configuration of device  10  of  FIG.  11   , quarter wave plate  30  is transparent to infrared light and does not change the polarization of light  40 . In this first configuration, device  38  emits light  40  that is linearly polarized, so that light  40  that reaches polarizer  34  is linearly polarized in alignment with the pass axis of polarizer  34 . Reflected light from eye box  18  reaches light-sensing device  44  without passing through lens  14 B. Light-sensing device  44  may be insensitive to the polarization state of received light and can therefore sense light  42 . 
     In a second configuration of device  10  of  FIG.  11   , quarter wave plate  30  serves as a quarter wave plate for infrared light. Device  38  has a circular polarizer so that emitted light  40  from device  38  is circularly polarized when passing through mirror  26  and becomes linearly polarized in alignment with the pass axis of polarizer  34  when passing through quarter wave plate  30 . Reflected light (e.g., infrared light  42 ) reaches light-sensing device  44  without passing through lens  14 B. Light-sensing device  44  may be insensitive to the polarization state of received light and can therefore sense light  42 . 
     Regardless of the configuration used for device  10  (see, e.g., the arrangements of  FIGS.  2 ,  8 ,  9 ,  10   , and/or  11 ), infrared transparent structures may be incorporated into mirror  26  and/or into polarizer  34  to help enhance infrared light transmission and thereby enhance the performance of sensor system  36 . For example, polarizer  34  may include lines patterned from a thin film having first regions of first material and second regions of a second material where the first regions are discontinuous islands surrounded by the second material or where that the first and second regions form continuous filaments, mirror  26  may be formed from a thin film having first regions of first material and second regions of a second material where the first regions are discontinuous islands surrounded by the second material or where that the first and second regions form continuous filaments, and/or polarizer  34 , mirror  26 , or other lens structures may be formed from other structures that have an enhanced infrared transmission relative to visible light transmission. 
     As described above, one aspect of the present technology is the gathering and use of information such as sensor information. The present disclosure contemplates that in some instances, data may be gathered that includes personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, twitter ID&#39;s, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, username, password, biometric information, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables users to calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data may be used to provide insights into a user&#39;s general wellness, or may be used as positive feedback to individuals using technology to pursue wellness goals. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the United States, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA), whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide certain types of user data. In yet another example, users can select to limit the length of time user-specific data is maintained. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an application (“app”) that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data at a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of information that may include personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. 
     Physical environment: 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. 
     Computer-generated reality: 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. 
     Virtual 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. 
     Mixed reality: 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. Augmented reality: 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. Augmented virtuality: 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. 
     Hardware: 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. 
     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: 20201022
Publication Date: 20231107
Grant Date: 20231107
Priority Date: 20191112
Inventors: YOKOYAMA, YOSHIHIKO
BORDER, JOHN N.
MATSUYUKI, NAOTO
ISIKMAN, SERHAN O.
HSU, WEI-LIANG
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/013", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/013", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0093", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/013", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/18", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 88649856