PATENT DOCUMENT

Publication Number: US-11886246-B2
Application Number: US-202217900266-A
Country: US
Kind Code: B2

Title: Electronic devices with shape-transforming displays

Abstract:
An electronic device may have a housing with a display. The display may be overlapped by an image transport layer such as a coherent fiber bundle or layer of Anderson localization material. The image transport layer may have an input surface that receives an image from the display and a corresponding output surface to which the image is transported. The input surface and output surface may have different shapes. A wristwatch device may, as an example, have a rectangular or hexagonal input surface and may have an output surface such as a rectangular output surface with rounded corners or a circular output surface. A region of the output surface may have compound curvature. A portion of the image transport layer may protrude laterally over an inactive portion of the display.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an image transport layer configured to receive light at an input surface having a first shape and to transport the light from the input surface to an output surface having a second shape; and 
 an optical sensor configured to receive the light from the output surface of the image transport layer. 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the optical sensor comprises a semiconductor die. 
     
     
       3. The electronic device defined in  claim 2 , wherein the semiconductor die has a rectangular shape and the second shape of the output surface of the image transport layer is the rectangular shape. 
     
     
       4. The electronic device defined in  claim 3 , wherein the first shape of the input surface of the image transport layer is a circular shape. 
     
     
       5. The electronic device defined in  claim 1  further comprising:
 a housing having a window region, wherein the image transport layer is mounted in the window region. 
 
     
     
       6. The electronic device defined in  claim 5 , wherein the input surface of the image transport layer faces an exterior of the electronic device. 
     
     
       7. The electronic device defined in  claim 6 , wherein the light received at the input surface of the image transport layer comprises ambient light. 
     
     
       8. The electronic device defined in  claim 1 , wherein the optical sensor comprises a proximity sensor. 
     
     
       9. The electronic device defined in  claim 1 , wherein the optical sensor comprises an optical touch sensor. 
     
     
       10. The electronic device defined in  claim 1 , wherein the optical sensor comprises an ambient light sensor. 
     
     
       11. The electronic device defined in  claim 1 , wherein the optical sensor has a shape that is the same as the second shape of the output surface of the image transport layer. 
     
     
       12. The electronic device defined in  claim 1 , wherein the optical sensor has an active photodetector area, and the active photodetector area has a shape that is the same as the second shape of the output surface of the image transport layer. 
     
     
       13. The electronic device defined in  claim 1 , wherein the image transport layer comprises a coherent fiber bundle. 
     
     
       14. The electronic device defined in  claim 1 , wherein the image transport layer comprises Anderson localization material. 
     
     
       15. An electronic device comprising:
 a housing having an opening; and 
 a button mounted in the opening of the housing, the button including:
 an image transport layer having an input surface and an output surface, the input surface of the image transport layer facing an interior of the electronic device and having a first shape, and the output surface of the image transport layer facing an exterior of the electronic device and having a second shape; and 
 a light source configured to provide light to the input surface of the image transport layer. 
 
 
     
     
       16. The electronic device defined in  claim 15 , wherein the image transport layer and the light source form a button member of the button, and the button comprises a switch configured to be compressed by the button member to detect a press input. 
     
     
       17. The electronic device defined in  claim 15 , wherein the button comprises a diffuser layer between the light source and the image transport layer. 
     
     
       18. The electronic device defined in  claim 17 , wherein at least one of the diffuser layer or the light source has a shape that matches the first shape of the input surface of the image transport layer. 
     
     
       19. The electronic device defined in  claim 17 , wherein the light source is an electrically adjustable light source, and the diffuser layer has a masking pattern configured to pattern the light provided to the input surface of the image transport layer. 
     
     
       20. An electronic device comprising:
 a semiconductor die with a rectangular shape at least partly forming a photodetector; and 
 an image transport layer configured to receive light at an input surface having a non-rectangular shape and to transport the light from the input surface to an output surface having a shape that matches the rectangular shape of the semiconductor die, wherein the photodetector is configured to receive the light from the output surface of the image transport layer.

Description:
This application is a continuation of U.S. non-provisional patent application Ser. No. 16/921,750, filed Jul. 6, 2020, now U.S. Pat. No. 11,493,958, which claims the benefit of U.S. provisional patent application No. 62/905,558, filed Sep. 25, 2019. The disclosures of these two applications are hereby incorporated by reference herein in their entireties. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices with displays. 
     BACKGROUND 
     Electronic devices may have displays. Displays have arrays of pixels for displaying images for a user. The shape of many displays can pose challenges during integration into an electronic device, particularly in situations where space is limited. 
     SUMMARY 
     An electronic device may have a housing with a display. An image transport layer may overlap the display. The image transport layer may have a coherent fiber bundle or a layer of Anderson localization material. The image transport layer may have an input surface that receives an image from the display and a corresponding output surface to which the image is transported. A protective layer of glass or other transparent material may overlap the output surface of the image transport layer. 
     The input surface and output surface of the image transport layer may have different shapes. A wristwatch device may, as an example, have an image transport layer with a rectangular or hexagonal input surface or other and may have an output surface such as a rectangular output surface with rounded corners or a circular output surface. A region of the output surface may have compound curvature. 
     In some configurations, the display may have an active area in which an array of pixels generates an image and an inactive area that is free of pixels and contains only non-light-emitting circuitry such as display driver circuitry. The display driver circuitry and the pixels may be formed on a common substrate. To help integrate the display into the interior of an electronic device, a portion of the image transport layer may protrude laterally over the inactive portion of the display. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view of an illustrative electronic device with an image transport layer in accordance with an embodiment. 
         FIG.  2    is a cross-sectional view of a portion of an illustrative image transport layer formed using a coherent fiber bundle in accordance with an embodiment. 
         FIG.  3    is a cross-sectional view of a portion of an illustrative image transport layer formed using Anderson localization material in accordance with an embodiment. 
         FIG.  4    is a perspective view of a portion of an image transport layer surface with compound curvature in accordance with an embodiment. 
         FIG.  5    is a top view of an illustrative electronic device in accordance with an embodiment. 
         FIGS.  6 ,  7 ,  8 ,  9 , and  10    are illustrative shapes that may be used for image transport layer input surfaces and that may be used for corresponding image transport layer output surfaces in accordance with embodiments. 
         FIG.  11    is a perspective view of the underside and input surface of an illustrative image transport layer in accordance with an embodiment. 
         FIG.  12    is a cross-sectional side view of the illustrative image transport layer structure of  FIG.  11    in accordance with an embodiment. 
         FIG.  13    is a cross-sectional side view of an illustrative device with an asymmetric image transport layer in accordance with an embodiment. 
         FIG.  14    is a cross-sectional side view of an illustrative button with image transport layer material in accordance with an embodiment. 
         FIG.  15    is a perspective view of an image transport layer structure having a circular input surface for gathering light and a rectangular output surface at which the gathered light is supplied to a sensor in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device may have a display. The display may have an array of pixels for creating an image. The image may pass through a display cover layer that overlaps the array of pixels. To minimize display borders or to otherwise create a desired appearance for the display, the display cover layer may include an image transport layer. The image transport layer may have an input surface that receives an image from the array of pixels and a corresponding output surface to which the image is transported from the input surface. A user viewing the image transport layer will view the image from the array of pixels as being located on the output surface. 
     In configurations in which the input and output surfaces have different shapes, the image transport layer may be used to warp the image produced by the array of pixels. For example, the shape of the image can be transformed and the effective size of the image can be changed as the image passes through the image transport layer. In some configurations, edge portions of the image are stretched outwardly to help minimize display borders. 
     Image transport layers can be formed from coherent fiber bundles (sometimes referred to as fiber optic plates) and/or Anderson localization material. Glass and/or polymer may be used in forming image transport layer structures. To help protect the output surface of an image transport layer, an optional transparent protective layer may be included on the outer surface of the display cover layer. This transparent protective layer may be, for example, a glass plate, or a protective layer formed from other transparent material such as clear polymer or sapphire or other crystalline materials. In some arrangements, image transport layers and/or protective layers can be formed over components other than displays. 
     A cross-sectional side view of a portion of an illustrative electronic device with a display cover layer that includes an image transport layer is shown in  FIG.  1   . In the example of  FIG.  1   , device  10  is a portable device such as a cellular telephone, wristwatch, or tablet computer. In general, any type of electronic device may have an image transport layer such as a desktop computer, a voice-control speaker, a television or other non-portable display, a head-mounted device, an embedded system such as a system built into a vehicle or home, an electronic device accessory, and/or other electronic equipment. 
     Device  10  includes a housing such as housing  12 . Housing  12  may be formed from polymer, metal, glass, crystalline material such as sapphire, ceramic, fabric, fibers, fiber composite material, natural materials such as wood and cotton, other materials, and/or combinations of such materials. Housing  12  may be configured to form housing walls. The housing walls may enclose one or more interior regions such as interior region  24  and may separate interior region  24  from exterior region  22 . In some configurations, an opening may be formed in housing  12  for a data port, a power port, to accommodate audio components, or to accommodate other devices. Clear housing regions may be used to form optical component windows. Dielectric housing structures may be used to form radio-transparent areas for antennas and wireless power components. 
     Electrical components  18  may be mounted in interior region  24 . Electrical components  18  may include integrated circuits, discrete components, light-emitting components, sensors, and/or other circuits and may, if desired, be interconnected using signal paths in one or more printed circuits such as printed circuit  20 . If desired, one or more portions of the housing walls may be transparent (e.g., so that light associated with an image on a display or other light-emitting or light-detecting component can pass between interior region  24  and exterior region  22 ). 
     Electrical components  18  may include control circuitry. The control circuitry may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other 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 used to control the operation of device  10 . For example, the processing circuitry may use sensors and other input-output circuitry to gather input and to provide output and/or to transmit signals to external equipment. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. The control circuitry may include wired and/or wireless communications circuitry (e.g., antennas and associated radio-frequency transceiver circuitry such as cellular telephone communications circuitry, wireless local area network communications circuitry, etc.). The communications circuitry of the control circuitry may allow device  10  to communicate with other electronic devices. For example, the control circuitry (e.g., communications circuitry in the control circuitry) may be used to allow wired and/or wireless control commands and other communications to be conveyed between devices such as cellular telephones, tablet computers, laptop computers, desktop computers, head-mounted devices, handheld controllers, wristwatch devices, other wearable devices, keyboards, computer mice, remote controls, speakers, accessory displays, accessory cameras, and/or other electronic devices. Wireless communications circuitry may, for example, wirelessly transmit control signals and other information to external equipment in response to receiving user input or other input from sensors or other devices in components  18 . 
     Input-output circuitry in components  18  of device  10  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. The input-output circuitry may include input devices that gather user input and other input and may include output devices that supply visual output, audible output, or other output. 
     Output may be provided using light-emitting diodes (e.g., crystalline semiconductor light-emitting diodes for status indicators and/or displays, organic light-emitting diodes in displays and other components), lasers, and other light-emitting devices, audio output devices (e.g., tone generators and/or speakers), haptic output devices (e.g., vibrators, electromagnetic actuators, piezoelectric actuators, and/or other equipment that supplies a user with haptic output), and other output devices. 
     The input-output circuitry of device  10  (e.g., the input-output circuitry of components  18 ) may include sensors. Sensors for device  10  may include force sensors (e.g., strain gauges, capacitive force sensors, resistive force sensors, etc.), audio sensors such as microphones, touch and/or proximity sensors such as capacitive sensors (e.g., a two-dimensional capacitive touch sensor integrated into a display, a two-dimensional capacitive touch sensor and/or a two-dimensional force sensor overlapping a display, and/or a touch sensor or force sensor that forms a button, trackpad, or other input device not associated with a display), and other sensors. Touch sensors for a display or for other touch components may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. If desired, a display may have a force sensor for gathering force input (e.g., a two-dimensional force sensor may be used in gathering force input on a display). 
     If desired, the sensors may include optical sensors such as optical sensors that emit and detect light, optical touch sensors, optical proximity sensors, and/or other touch sensors and/or proximity sensors, monochromatic and color ambient light sensors, image sensors, fingerprint sensors, ultrasonic sensors, temperature sensors, sensors for measuring three-dimensional non-contact gestures (“air gestures”), pressure sensors, sensors for detecting position, orientation, and/or motion (e.g., accelerometers, magnetic sensors such as compass sensors, gyroscopes, and/or inertial measurement units that contain some or all of these sensors), health sensors, radio-frequency sensors (e.g., sensors that gather position information, three-dimensional radio-frequency images, and/or other information using radar principals or other radio-frequency sensing), depth sensors (e.g., structured light sensors and/or depth sensors based on stereo imaging devices), optical sensors such as self-mixing sensors and light detection and ranging (lidar) sensors that gather time-of-flight measurements, humidity sensors, moisture sensors, gaze tracking sensors, three-dimensional sensors (e.g., time-of-flight image sensors, pairs of two-dimensional image sensors that gather three-dimensional images using binocular vision, three-dimensional structured light sensors that emit an array of infrared light beams or other structured light using arrays of lasers or other light emitters and associated optical components and that capture images of the spots created as the beams illuminate target objects, and/or other three-dimensional image sensors), facial recognition sensors based on three-dimensional image sensors, and/or other sensors. 
     In some configurations, components  18  may include mechanical devices for gathering input (e.g., buttons, joysticks, scrolling wheels, key pads with movable keys, keyboards with movable keys, and other devices for gathering user input). During operation, device  10  may use sensors and/or other input-output devices in components  18  to gather user input (e.g., buttons may be used to gather button press input, touch and/or force sensors overlapping displays can be used for gathering user touch screen input and/or force input, touch pads and/or force sensors may be used in gathering touch and/or force input, microphones may be used for gathering audio input, etc.). The control circuitry of device  10  can then take action based on this gathered information (e.g., by transmitting the information over a wired or wireless path to external equipment, by supplying a user with output using a haptic output device, visual output device, an audio component, or other input-output device in housing  12 , etc.). 
     If desired, electronic device  10  may include a battery or other energy storage device, connector ports for supporting wired communications with ancillary equipment and for receiving wired power, and other circuitry. In some configurations, device  10  may serve as an accessory and/or may include a wired and/or wireless accessory (e.g., a keyboard, computer mouse, remote control, trackpad, etc.). 
     Device  10  may include one or more displays such as display  14 . The displays may, for example, include an organic light-emitting diode display, a liquid crystal display, a display having an array of pixels formed from respective light-emitting diodes (e.g., a pixel array having pixels with crystalline light-emitting diodes formed from respective light-emitting diode dies such as micro-light-emitting diode dies), and/or other displays. The displays may include rigid display structures and/or may be flexible displays. For example, a light-emitting diode display may have a polymer substrate that is sufficiently flexible to be bent. Display  14  may have a rectangular pixel array or a pixel array of another shape for displaying images for a user and may therefore sometimes be referred to as a pixel array. Display  14  may also sometimes be referred to as a display panel, display layer, or pixel layer. Each pixel array in device  10  may be mounted under a transparent housing structure (sometimes referred to as a transparent display cover layer). 
     In the example of  FIG.  1   , display (pixel array)  14  is mounted under display cover layer  32 . Display cover layer  32  (which may be considered to form a portion of the housing of device  10 ), covers front face F of device  10 . Configurations in which opposing rear face R of device  10  and/or sidewall portions of device  10  have transparent structures covering displays and other optical components may also be used. 
     As shown in  FIG.  1   , display cover layer  32  may include image transport layer  16  and protective layer  30 . Protective layer  30  may be formed from a layer of glass, clear polymer, crystalline material such as sapphire or other crystalline material, and/or other transparent material. The presence of layer  30  may help protect the outer surface of layer  16  from scratches. If desired, layer  30  may be omitted (e.g., in configurations in which a thin-film protective coating is present on the outer surface of layer  16 , in configurations in which layer  16  is formed from hard material such as glass, and/or in other configurations in which layer  16  is resistant to scratching). A layer of adhesive and/or other structures may be formed between protective layer  30  and image transport layer  16  and/or may be included elsewhere in the stack of layers on display  14 . 
     During operation, the pixels of display  14  produce image light that passes through image transport layer  16 . In configurations in which image transport layer  16  is formed from a coherent fiber bundle, image transport layer  16  has optical fibers  16 F. The fibers or other optical structures of image transport layer structures such as image transport layer  16  transport light (e.g., image light and/or other light) from one surface (e.g., an input surface of layer  16  that faces display  14 ) to another (e.g., an output surface of layer  16  that faces viewer  28 , who is viewing device  10  in direction  26 ). As the image presented to the input surface of layer  16  is transported to the output surface of layer  16 , the integrity of the image light is preserved. This allows an image produced by an array of pixels to be transferred from an input surface of a first shape at a first location to an output surface with a different shape (e.g., a shape with a footprint that differs from that of the input surface, a shape with a curved cross-sectional profile, a shape with a region of compound curvature, and/or a shape with other desired features). 
     Image transport layer  16  may therefore move the location of an image and may optionally change the shape of the surface on which the image is presented. In effect, viewer  28  will view the image from display  14  as if the image were generated on the output surface of image transport layer  16 . In arrangements in which the image from display  14  is warped (geometrically distorted) by image transport layer  16 , digital pre-distortion techniques or other compensation techniques may be used to ensure that the final image viewed on the output surface of image transport layer  16  has a desired appearance. For example, the image on display  14  may be prewarped so that this prewarped image is warped by an equal and opposite amount upon passing through layer  16 . In this way, the prewarped image is effectively unwarped by passage through layer  16  will not appear distorted on the output surface. 
     In configurations of the type shown in  FIG.  1   , device  10  may have four peripheral edges and a rectangular footprint when viewed in direction  26  or may have other suitable shapes. To help minimize the size of inactive display borders as a user is viewing front face F of device  10  as shown in  FIG.  1   , the shapes of fibers  16 F along the periphery of layer  16  may be deformed outwardly as shown in  FIG.  1   . These fibers  16 F each have an outwardly bent segment that bends away from surface normal n of the center of layer  30  (e.g., away from an axis parallel to the Z axis of  FIG.  1   ) and each have an inwardly bent segment that bends back towards surface normal n to help direct output light towards viewer  28 . 
     The deformed shapes of fibers  16 F (and/or the corresponding deformations made to optical filaments in Anderson localization material in layer  16 ) may help distribute image light laterally outwards in the X-Y plane so that the effective size of display  14  is enlarged and the image produced by display  14  covers some or all of the sidewalls of housing  12  or other peripheral portions of device  10  when the image on front face F is being viewed by viewer  28 . For example, the bent shapes of fibers  16 F of  FIG.  1    may help shift portion of the displayed image laterally outward in the X-Y plane along the edges and corners of device  10  to block the edges of device  10  from view. In some arrangements, the portions of fibers  16 F at the outermost surface of layer  16  are oriented parallel or nearly parallel with viewing direction  26  and the Z axis of  FIG.  1   , which helps ensure that some or all of the light that has passed through layer  16  will travel in the Z direction and be viewable by viewer  28 . 
       FIG.  2    is a cross-sectional view of a portion of image transport layer  16  in an illustrative configuration in which image transport layer  16  is formed from a coherent fiber bundle. Fibers  16 F for layer  16  may have any suitable configuration. As shown in the example of  FIG.  2   , fibers  16 F may each have a core such as core  16 F- 1 . Cores  16 F- 1  and the other structures of image transport layer (e.g., cladding structures, binder, etc.)  16  may be formed from materials such as polymer, glass, crystalline material such as sapphire, and/or other materials. Some or all of these materials may be transparent. Arrangements in which some of the materials absorb light and/or have non-neutral colors or other light filtering properties may also be used. 
     Fiber cores  16 F- 1  may be formed from transparent material of a first refractive index and may be surrounded by cladding of a second, lower refractive index to promote light guiding in accordance with the principal of total internal reflection. In some arrangements, a single coating layer on cores  16 F- 1  may be used to form the cladding. In other arrangements, two or more coating layers on cores  16 F- 1  may be used to form the cladding. Clad fibers may be held together using binder  16 FB, which serves to fill the interstitial spaces between the clad fibers. In some configurations, stray light absorbing material may be incorporated into layer  16  (e.g., into some of the cores, cladding, and/or binder). The stray light absorbing material may be, for example, polymer, glass, or other material into which light-absorbing material such as dye and/or pigment has been incorporated. 
     In an illustrative configuration, layer  16  may have inner coating layers  16 F- 2  that are formed directly on the outer surfaces of cores  16 F- 1  and outer coating layers  16 F- 3  that are formed directly on the outer surfaces of layers  16 F- 2 . Additional coating layers (e.g., three or more coating layers) or fewer coating layers (e.g., a single coating layer) may be formed on fiber cores  16 F- 1 , if desired. Stray light-absorbing material may be used in layers  16 F- 2  and/or  16 F- 3  or other coating layer(s) on cores  16 F- 1 . In an illustrative arrangement, layers  16 F- 2  and  16 F- 3 , which may sometimes be referred to as forming first and second cladding portions (or first and second claddings) of the claddings for fiber cores  16 F- 1 , may respectively be formed from transparent material and stray light-absorbing material. Other arrangements may be used, if desired (e.g., arrangements in which stray light absorbing material is incorporated into some or all of binder  16 FB, arrangements in which cores  16 F- 1  are coated with inner and outer transparent claddings and an interposed intermediate stray-light-absorbing cladding, arrangements in which cores  16 F- 1  are covered with a single stray-light-absorbing cladding, arrangements in which some or all of fibers  16 F are provided with longitudinally extending filaments  16 F- 4  of stray light absorbing material located, for example, on or in any of the cladding layers, etc.). 
     In configuration in which fibers  16 F have claddings formed from two or more separate cladding layers, the cladding layers may have the same index of refraction or the outermost layers may have lower refractive index values (as examples). Binder  16 FB may have a refractive index equal to the refractive index of the cladding material or lower than the refractive index of the cladding material to promote total internal reflection (as examples). For example, each fiber core  16 F- 1  may have a first index of refraction and the cladding material surrounding that core may have a second index of refraction that is lower than the first index of refraction by an index difference of at least 0.05, at least 0.1, at least 0.15, at least 10%, at least 20%, less than 50%, less than 30%, or other suitable amount. The binder refractive index may be the same as that of some or all of the cladding material or may be lower than the lowest refractive index of the cladding by an index difference of at least 0.05, at least 0.1, at least 0.15, at least 10%, at least 20%, less than 50%, less than 30%, or other suitable amount. 
     The diameters of cores  16 F- 1  may be, for example, at least 5 microns, at least 7 microns, at least 8 microns, at least 9 microns, less than 40 microns, less than 17 microns, less than 14 microns, less than 11 microns, or other suitable diameter. Fibers  16 F (including cores and claddings) may have diameters of at least 6 microns, at least 7 microns, at least 8 microns, at least 9 microns, less than 50 microns, less than 17 microns, less than 14 microns, less than 11 microns, or other suitable diameter. 
     Fibers  16 F may generally extend parallel to each other in image transport layer  16  (e.g., the fibers may run next to each other along the direction of light propagation through the fiber bundle). This allows image light or other light that is presented at the input surface to layer  16  to be conveyed to the output surface of layer  16 . 
     If desired, image transport layer  16  may be formed from Anderson localization material in addition to or instead of fibers  16 F. Anderson localization material is characterized by transversely random refractive index features (higher index regions and lower index regions) of about two wavelengths in lateral size that are configured to exhibit two-dimensional transverse Anderson localization of light (e.g., the light output from the display of device  10 ). These refractive index variations are longitudinally invariant (e.g., along the direction of light propagation, perpendicular to the surface normal of a layer of Anderson localization material). 
       FIG.  3    is a cross-sectional view of a portion of an image transport layer formed from Anderson localization material. In the example of  FIG.  3   , image transport layer  16  includes a random (pseudorandom) set of elongated optical structures of different refractive index values. These structures may, for example, be optical filaments that run into and out of the page of FIG.  3  and that have different refractive index values such as first filaments  16 H with higher refractive index values and second filaments  16 L with lower refractive index values. The refractive indices of filaments  16 L and  16 H may differ by any suitable amount (e.g., by at least 0.05, at least 0.1, at least 0.2, at least 0.3, by less than 0.8, etc.). The filaments may be distributed laterally (in dimensions X and Y) with a random pattern and may have any suitable cross-sectional shape (circular, rectangular, etc.). Anderson localization material preforms can be formed by drawing and assembling individual filaments of different refractive index values into bundles and/or can be formed by extruding lengths of material that include laterally interspersed areas of different respective refractive index values. Preforms can then be formed into layer  16  using one or more fusing and drawing operations. Other fabrication techniques may be used, if desired. To absorb stray light within an image transport layer formed from Anderson localization material, the Anderson localization material may include light absorbing material (e.g., light-absorbing filaments interspersed with transparent filaments or other light-absorbing structures). 
     Image transport layers can be used to transport an image from a first surface (e.g., the surface of a pixel array) to a second surface (e.g., a surface in device  10  with compound curvature or other curved and/or planar surface shape) while preserving the integrity of the image. A perspective view of an illustrative corner portion of image transport layer  16  is shown in  FIG.  4   . In the example of  FIG.  4   , device  10  has edge portions  40  and  42  with surfaces that curve about axes  44  and  46 , respectively. These portions of layer  16  may extend parallel to the straight sides of device  10  (as an example) and are characterized by curved surfaces that can be flattened into a plane without distortion (sometimes referred to as developable surfaces). At the corner of image transport layer  16  of  FIG.  4   , image transport layer  16  has curved surface portions CP with compound curvature (e.g., a surface that can only be flattened into a plane with distortion, sometimes referred to as a surface with Gaussian curvature). In a rectangular layout with curved corners, image transport layer  16  may have four corners with compound curvature. Image transport layers of other shapes (e.g., circular outlines, etc.) may also have surfaces with compound curvature (e.g., dome-shaped surfaces). When overlapped by protective layer  30 , the overlapping portions of protective layer  30  may have corresponding surfaces with compound curvature. When selecting the size and shape of the output surface of layer  16  and therefore the size and shape of the image presented on the output surface, the use of an image transport layer material with compound curvature can provide design flexibility. 
     In some arrangements, device  10  may include support structures such as wearable support structures. This allows device  10  to be worn on a body part of a user (e.g., the user&#39;s wrist, arm, head, leg, or other portion of the user&#39;s body). As an example, device  10  may include a wearable band, such as band  50  of  FIG.  5   . Band  50 , which may sometimes be referred to as a wristband, wrist strap, or wristwatch band, may be formed from polymer, metal, fabric, leather or other natural materials, and/or other material, may have links, may stretch, may be attached to housing  12  in a fixed arrangement, may be detachably coupled to housing  12 , may have a single segment or multiple segments joined by a clasp, and/or may have other features that facilitate the wearing of device  10  on a user&#39;s wrist. 
     In the example of  FIG.  5   , device  10  has a rectangular outline with curved corners. By shaping image transport layer  16  (e.g., by molding, polishing, slumping, and/or by otherwise shaping the fibers and/or Anderson localization material of layer  16  appropriately), the input surface of layer  16  at which image light is received and the corresponding output surface of layer  16  to which the received image is transported may have any suitable shapes. These shapes and the overall three-dimensional configuration of layer  16  may be selected to enhance packing efficiency, reduce pixel array fabrication complexity, and/or otherwise enhance the manufacturability and/or performance of device  10  while providing device  10  with a desired appearance. As an example, a square or rectangular shape may be used for the input surface of layer  16 , which is well matched to a pixel array having a corresponding square or rectangular outline, whereas a shape with rounded corners, curved edges, a circular outline, or other attractive shape may be used for the output surface of layer  16  where the image from the pixel array is viewed by a user of device  10 . 
     Illustrative shapes for input and output surfaces of layer  16  are shown in  FIGS.  6 ,  7 ,  8   , and  9 . These shapes, which may sometimes be referred to as footprints or outlines, correspond to the shape of the input or output surface of layer  16  when viewed from above or below. In the example of  FIG.  6   , surface  60  has a square shape with rounded corners. In the example of FIG.  7 , surface  62  has a circular shape. A non-circular shape (e.g., a hexagonal shape) is used for illustrative surface  64  of  FIG.  8   . As shown by illustrative surface  66  of  FIG.  9   , non-circular shapes such as rectangular shapes may be used for input and output surfaces. The input and output surfaces of layer  16  may, in general, have straight edges, curved edges, or a combination of straight and curved edges. For example, surface  60  of  FIG.  6    and surface  66  of  FIG.  9    have both straight edge segments and curved corner edge segments. Surface  62  of  FIG.  7    has only a curved peripheral edge and no straight edges. As shown by surface  68  of  FIG.  10   , a rectangular (e.g., a square) surface for image transport layer  16  may have sharp corners (e.g., uncurved corners). Input surfaces characterized by rectangular shapes with uncurved corners may mate well with pixel arrays (displays  14 ) that have corresponding rectangular shapes with uncurved corners. Some shapes may improve fill factor. For example, a non-circular active area shape such as a hexagonal display active area that produces a non-circular image such as a hexagonal image and an associated non-circular input surface such as a hexagonal input surface in layer  16  may be effective at providing image light to a circular output surface, because a hexagon has a shape that is close to being a circle. 
     In general, display  14  may have any suitable shape, the corresponding input surface of layer  16  that receives an image from display  14  may have a matching shape (e.g., a shape identical to that of the active area and received image), and the corresponding output surface of layer  16  to which the received image is transported may have any suitable shape that is warped (or unchanged) with respect to the input surface. 
     Consider, as an example, the arrangement of  FIGS.  11  and  12   . As shown in the perspective view of layer  16  of  FIG.  11   , layer  16  may have a first surface such as input surface  70  and a second surface such as output surface  72 . Input surface  70  may have a rectangular shape (e.g., a square shape) with uncurved corners for receiving light from a rectangular display (e.g., a display with a shape such as surface  68  of  FIG.  10   ). Fibers  16 F and/or the filaments in Anderson localization material forming layer  16  may be formed into a shape that is characterized by a circular output surface, as shown by the circular shape of output surface  72  of  FIG.  11   . The circular shape of output surface  72  may be used to present a circular watch face or other circular image to viewer  28 . The square image produced by the display at input surface  70  can be digitally predistorted (prewarped). Digital prewarping of the image on display  14  can compensate for the subsequent optical image warping produced by layer  16  as the image passes through layer  16 , thereby ensuring that the distorted image on display  14  appears normal and undistorted (unwarped) to the user viewing the output image on output surface  72 . 
     A cross-sectional side view of image transport layer  16  of  FIG.  11    taken along line  74  and viewed in direction  76  is shown in  FIG.  12   . As shown in  FIG.  12   , input surface  70  may be planar, which allows input surface  70  to mate with a planar pixel array (e.g., display  14 ). A layer of adhesive or other material may optionally be placed between display  14  and input surface  70  (e.g., to help reduce reflection and to help mount display  14  within device  10 ). Output surface  72  may have a planar surface and/or may have one or more portions with curved cross-sectional profiles. If desired, some or all of output surface  72  may be characterized by compound curvature, as described in connection with  FIG.  4   . This allows output surface  72  (and, if desired, the corresponding inner and outer surfaces of an overlapping protective layer such as layer  30  of  FIG.  1   ) to have attractive compound curvature (e.g., an attractive dome shape with a circular outline for a watch crystal). 
       FIG.  13    is a cross-sectional side view of device  10  in an illustrative configuration in which the three-dimensional shape of image transport layer  16  is asymmetric to accommodate inactive portions of display  14 . As shown in  FIG.  13   , display  14  may have an active area AA with an array of pixels to display an image and may have an inactive area IA. Inactive area IA may share a flexible substrate or other display substrate with active area AA. Display driver circuitry for display  14  may be formed using one or more integrated circuits such as integrated circuit  77  and/or thin-film display driver circuitry. This display driver circuitry may be formed in inactive area IA (e.g., on the same substrate used to form thin-film organic light-emitting diode pixels in active area AA). Signal paths  78  (e.g., metal traces) may be used in routing signals between the display driver circuitry in inactive area IA and pixels in the pixel array of active area AA. 
     Active area AA may have a rectangular (e.g., square) outline in the X-Y plane and may have uncurved corners. Inactive area IA may protrude from one or more edges of active area AA. In the example of  FIG.  13   , inactive area IA protrudes in the —X direction from active area AA. To accommodate the protruding inactive area IA of display  14 , image transport layer  16  of  FIG.  13    has been provided with an asymmetric shape. Portion  80  of image transport layer  16  is characterized by more bending (e.g., more bending of fibers  16 F and/or Anderson localization material deformation) than portion  82  of image transport layer  16 . Portion  80  may therefore protrude laterally outward over inactive area IA (in the −X direction) to cover inactive area IA. This helps hide inactive area IA from view by viewer  28 . Axis  84  is located in the center of protective layer  30  and the center of output surface  86 . Output surface  86  of image transport layer  16  may have a circular shape that is rotationally symmetric about axis  84  (as an example). The rectangular pixel array of active area AA may have a center (center  84 ′) that is laterally offset with respect to axis  84  in the X-Y plane. Mating rectangular input surface  88  of image transport layer  88  may also be offset laterally in the X-Y plane with respect to axis  84 . 
       FIG.  14    shows how electronic device  10  may include a button formed from image transport layer material. In the example of  FIG.  14   , button  92  has been mounted in an opening in housing  12  of device  10 . Image transport layer  16  may have a curved output surface (exterior surface) or other suitable surface shape that receives button press input from a user&#39;s finger (finger  90 ). A protective cover layer may be included over the output surface of layer  16 , if desired. When pressed in the downward direction of  FIG.  14   , a button member formed from image transport layer  16  and components  102  and  96  moves downwards to compress an associated button switch such as switch  98 . Switch  98  may be a dome switch or other suitable switch for detecting button press events. Switch  98  or other biasing structures may provide an upwards restoring force that helps the button member return to its original undepressed position when released. 
     Switch  98  may be mounted on a printed circuit such as printed circuit  100  that has signal lines that couple switch  98  to the control circuitry of device  10 . Components  102  and  96  may be used in presenting a desired image to the input surface associated with image transport layer  16  (e.g., the lower surface of layer  16  of  FIG.  14   ). In an illustrative arrangement, component  96  is an electrically adjustable light source such as one or more light-emitting diodes or lasers and component  94  is a diffuser layer. Component  94  may be provided with an optional masking pattern (e.g., a black ink layer or other mask with a clear opening or diffuse white opening in the shape of an alphanumeric label, an icon, or other button label) to pattern the light presented to the input surface of image transport layer  16 . The lower surface (input surface) of layer  16  may have a square shape with uncurved corners, a circular shape, or other shape that is matched to the outline of components  94  and  96  (e.g., components with rectangular shapes, circular outlines, etc.) and the upper surface (output surface) of layer  16  may have a shape with a desired appealing appearance for the user (e.g., a rectangular shape with curved corners and a surface with regions of compound curvature, a circular shape with an output surface of compound curvature, etc.). Illustrative input and output surface shapes for image transport layer  16  of button  92  are shown in  FIGS.  6 ,  7 ,  8 ,  9 , and  10    (as examples). 
     In the illustrative arrangements of  FIG.  15   , optical sensor  110  (e.g., a semiconductor photodetector) has a die (e.g., a semiconductor die) with a rectangular shape (e.g., a square shape or other shape). Image transport layer  16  of  FIG.  15    may be mounted in a window region of housing  12  (e.g., to capture incoming ambient light  112  or other incoming light from exterior  22  of device  10  during operation of device  10 ). Sensor  110  may, as an example, be an optical sensor such as a proximity sensor, optical touch sensor, ambient light sensor, etc. To ensure that the outward appearance of the window region for sensor  110  is satisfactory, image transport layer  16  may have an outwardly facing input surface  106  with a circular shape or other attractive shape. The light  112  that is received at circular input surface  106  may be transported to a rectangular (e.g., square) output surface such as output surface  108 . Output surface  108  may have the same shape (or nearly the same shape) as sensor  110  and/or the active photodetector area of sensor  110 . 
     Device  10  may be operated in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     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: 20220831
Publication Date: 20240130
Grant Date: 20240130
Priority Date: 20190925
Inventors: KAKUDA, TYLER R.
GLAZOWSKI, CHRISTOPHER E.
PORTER, Elizabeth C.
DONG, Hao
GUILLOU, Jean-Pierre S.
RIEUTORT-LOUIS, WARREN S.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/163", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G17/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G9/0023", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/163", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "G04G17/045", "inventive": false, "first": false, "tree": "[]"}, {"code": "G04G9/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G9/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/163", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1684", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G17/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/04", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 83902572