PATENT DOCUMENT

Publication Number: US-11754779-B1
Application Number: US-202117376460-A
Country: US
Kind Code: B1

Title: Electronic devices with coherent fiber bundles

Abstract:
An electronic device may have a display, a display cover layer, and an image transport layer formed from a coherent fiber bundle. The coherent fiber bundle may have an input surface that receives an image from the display and a corresponding output surface to which the image is provide through the coherent fiber bundle. The coherent fiber bundle may be placed between the display and the display cover layer and mounted to a housing. The coherent fiber bundle may have fiber cores with bends that help conceal the housing from view and make the display appear borderless. A central portion of the coherent fiber bundle may be formed from different materials and/or structures than a surrounding border portion of the layer.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a display configured to produce an image; and 
 a coherent fiber bundle having opposing input and output surfaces and configured to receive the image at the input surface, wherein the coherent fiber bundle has a central portion, wherein the coherent fiber bundle has a border portion with bent fibers that surrounds the central portion and is attached to the central portion by adhesive, wherein the bent fibers are bent away from the central portion toward the output surface of the coherent fiber bundle, wherein the border portion comprises first fiber cores, first fiber cladding, and a first binder, wherein the central portion comprises second fiber cores, second fiber cladding, and a second binder, wherein at least one of: the first and second fiber cores, the first and second fiber cladding, and the first and second binders are formed from different materials, wherein the output surface at the central portion is planar, and wherein the output surface at the border portion has a curved cross-sectional profile. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the bent fibers each include at least two bends. 
     
     
       3. The electronic device defined in  claim 2  wherein the central portion is free of bent fibers. 
     
     
       4. The electronic device defined in  claim 1  wherein the coherent fiber bundle in the border portion comprises a ledge. 
     
     
       5. The electronic device defined in  claim 4  further comprising a housing attached to the ledge. 
     
     
       6. The electronic device defined in  claim 1  wherein the first fiber cores include a first fiber core material and wherein the second fiber cores include a second fiber core material that is different than the first fiber core material. 
     
     
       7. The electronic device defined in  claim 1  wherein the first fiber cores have a first refractive index and wherein the second fiber cores have a second refractive index that is different than the first refractive index. 
     
     
       8. The electronic device defined in  claim 7  wherein the first refractive index is higher than the second refractive index. 
     
     
       9. The electronic device defined in  claim 1  wherein the display is planar. 
     
     
       10. The electronic device defined in  claim 1  wherein the display has a bent portion and wherein the border portion has a corresponding curved input surface portion. 
     
     
       11. The electronic device defined in  claim 1  wherein there is a thickness step between the border portion and the central portion and wherein the display has a first substrate coupled to the input surface of the border portion and has a separate second substrate coupled to the input surface of the central portion. 
     
     
       12. An electronic device, comprising:
 a display configured to produce an image; and 
 a coherent fiber bundle overlapping the display, wherein the coherent fiber bundle has an input surface that receives the image and an output surface to which the image is provided through the coherent fiber bundle, the coherent fiber bundle having a border portion that includes first fibers in a first binder and having a central portion that is fused to the border portion and that includes second fibers in a second binder, wherein at least one material in the first fibers and the first binder differs from a corresponding material in the second fibers and the second binder, wherein the output surface at the central portion is planar, and wherein the output surface at the border portion has a curved cross-sectional profile. 
 
     
     
       13. The electronic device defined in  claim 12  wherein the first fibers of the border portion have fiber cores of a first refractive index and wherein the second fibers of the central portion have fiber cores of a second refractive index that is different than the first refractive index. 
     
     
       14. The electronic device defined in  claim 13  wherein the first refractive index is higher than the second refractive index. 
     
     
       15. The electronic device defined in  claim 12  further comprising a housing attached to the border portion, wherein the border portion has bent fibers configured to conceal at least part of the housing from view. 
     
     
       16. The electronic device defined in  claim 15  wherein the at least one material in the first fibers and the first binder that differs from the corresponding material in the second fibers and the second binder comprises fiber core material. 
     
     
       17. The electronic device defined in  claim 12  wherein the first fibers comprise bent fibers that are bent away from the central portion toward the output surface of the coherent fiber bundle.

Description:
This application claims the benefit of provisional patent application No. 63/059,075, filed Jul. 30, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to coherent fiber bundles for electronic devices with displays. 
     BACKGROUND 
     Electronic devices may have displays. Displays have arrays of pixels for displaying images for a user. To protect sensitive display structures from damage, displays may be provided with display cover layers. 
     SUMMARY 
     An electronic device may have a display, a display cover layer, and a coherent fiber bundle. The coherent fiber bundle may be placed between the display and the display cover layer and mounted to a housing. The coherent fiber bundle may have an input surface that receives an image from the display and a corresponding output surface to which the image is transported. The coherent fiber bundle may have fiber cores with bends that help conceal the housing from view and make the display appear borderless. 
     A central portion of the coherent fiber bundle may have a first set of fibers and a border portion of the coherent fiber bundle that runs around a peripheral edge of the central portion may have a second set of fibers. One or more of the properties of the central and border portions may differ. For example, different materials and/or fiber dimensions may be used for the central and border portions of the coherent fiber bundle. In this way, the central and border portions may be configured to overcome potentially different challenges. For example, in the border portions, the fibers may be formed from more formable materials and/or may be provided with structures that exhibit better light confinement to accommodate fiber bending, whereas the central portion may be provided with materials and/or structures that enhance transparency. The use of potentially different materials and/or structures in the border and central portions of a coherent fiber bundle may also help enhance manufacturability and/or reduce cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a cross-sectional side view of an illustrative electronic device with an image transport layer formed from a coherent fiber bundle 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 perspective view of a portion of an image transport layer surface with compound curvature in accordance with an embodiment. 
         FIG.  4    is a top view of an illustrative electronic device in accordance with an embodiment. 
         FIG.  5    is a side view of illustrative equipment for forming filaments from elongated strands of binder with embedded fibers in accordance with an embodiment. 
         FIG.  6    is a cross-sectional side view of illustrative coherent fiber bundle material in a tool that is forming the material into a desired shape in accordance with an embodiment. 
         FIG.  7    is a top view of illustrative blocks of image transport material being assembled together to form a central portion and a surrounding border portion in accordance with an embodiment. 
         FIG.  8    is a top view of the illustrative blocks of image transport material of  FIG.  7    following assembly in accordance with an embodiment. 
         FIG.  9    is a cross-sectional side view of sheet-stacked fiber bundle material in accordance with an embodiment. 
         FIG.  10    is a cross-sectional side view of a block of image transport material with different central and border portions formed from sheet-stacked fiber bundle material in accordance with an embodiment. 
         FIG.  11    is a cross-sectional side view of an illustrative image transport layer formed from first and second portions joined by adhesive in accordance with an embodiment. 
         FIG.  12    is a cross-sectional side view of an image transport layer formed from first and second portions joined by adhesive in an illustrative configuration in which at least one of the portions has been formed to deform fibers into a desired shape in accordance with an embodiment. 
         FIG.  13    is a cross-sectional side view of an illustrative image transport layer formed from first and second portions fused together without adhesive in accordance with an embodiment. 
         FIG.  14    is a cross-sectional side view of an image transport layer formed from first and second portions fused together without adhesive in an illustrative configuration in which at least one of the portions has been formed to deform fibers into a desired shape in accordance with an embodiment. 
         FIG.  15    is a cross-sectional side view of an illustrative electronic device with an image transport layer coupled to a housing in accordance with an embodiment. 
         FIG.  16    is a cross-sectional side view of an illustrative electronic device with an image transport layer with a stepped inner surface 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 be visible through transparent structures that overlap the array of pixels. These structures may include an image transport layer such as a coherent fiber bundle layer overlapped by a clear display cover layer. 
     A coherent fiber bundle may be included in an electronic device to help minimize display borders or to otherwise create a desired appearance for a display. The coherent fiber bundle may have an input surface that receives an image from an array of pixels and a corresponding output surface to which the image is transported from the input surface. A layer of glass, polymer, or other clear material may be used to form a display cover layer that protects the output surface. A user viewing the electronic device 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 of an image transport layer such as a coherent fiber bundle 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 can be stretched outwardly to help minimize display borders. 
     A cross-sectional side view of a portion of an illustrative electronic device having a display 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 . For example, housing  12  may have a rear housing wall on rear face R and this rear housing wall 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  (e.g., components  18 ) 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 light-emitting diodes formed from respective crystalline 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, protective cover layer structures, etc.). 
     In the example of  FIG.  1   , display (pixel array)  14  is mounted under protective layer(s)  32 . 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   , layer  32  may include image transport layer  16  and display cover layer  30 . Display cover layer  30  serves as a protective outer layer for device  10  and display  14 . Display cover 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 and layer  16  may serve as a protective display cover layer (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 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  (sometimes referred to as an image transfer layer). 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 (transfer) 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 (e.g., a circular outline when viewed in direction  26 ). 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 (e.g., the bends in fibers  16 F along their lengths) 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  (e.g., the periphery of housing  12 ) from view. This helps make the display of device  10  appear borderless to viewer  28 . 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  16  (e.g., cladding structures, binder, etc.) 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 and join fibers  16 F together. 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 formed directly in binder  16 FB without any intervening cladding, arrangements in which cores  16 F- 1  are covered with layers  16 F- 2  and embedded into binder  16 FB without any additional coating layers such as coating layers  16 F- 3 , 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, lower than the refractive index of the cladding material to promote total internal reflection, or higher than the refractive index of the cladding material (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 (or higher) 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. Coating layers such as coating layer  16 F- 2  (e.g. a transparent cladding layer) may have thicknesses of at least 0.1 microns, at least 0.4 microns, less than 2.5 microns, less than 0.8 microns, etc. 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 . 
     Image transport layers can be used to transport an image from a first (input) surface (e.g., the surface of a pixel array) to a second (output) 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.  3   . In the example of  FIG.  3   , layer  16  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.  3   , 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, an edge surface of compound curvature that runs along the circular periphery of a central circular planar region, etc.). When overlapped by layer  30 , the overlapping portions of 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 general, layer  30  and layer  16  may have planar surfaces and/or surfaces with curved cross-sectional profiles. 
     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.  4   . 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. 
     If desired, image transport layer material may be formed from filaments of material each of which include multiple fiber cores. Filaments may, as an example, be formed using an extrusion process. Subsequent attachment operations (e.g., sheet fusing operations) can create sheets of filaments that are stacked to form blocks of filaments. The blocks of sheet-stacked filaments can be used in forming layer  16  directly or may be drawn in a draw tower or other drawing equipment to reduce their lateral dimensions before being used in forming layer  16 . 
     An illustrative extrusion tool for forming filaments of image transport layer material is shown in  FIG.  5   . As shown in  FIG.  5   , extruder  60  may include hoppers  62  that contain different types of material to be extruded (e.g., different polymers such as binder polymer and fiber core polymer). The material from hoppers  62  may be provided to coextrusion die set  64 . During coextrusion, the material from hoppers  62  is coextruded through extrusion die set  64  and forms one or more elongated extruded members such as extruded filament  66 , which exits extrusion die set  64  in direction  68 . In the example of  FIG.  5   , filament  66  includes multiple fibers  16 F embedded in an elongated strand of binder  16 FB (see, e.g., binder  16 FB of  FIG.  2   ). Fibers  16 F may each have a core  16 F- 1  covered with a coating layer  16 F- 2  (e.g., a transparent cladding) as described in connection with  FIG.  2    or may be other suitable fibers (e.g., fibers having cores with or without cladding, cores with multiple cladding layers, cores and/or coatings with light-absorbing material and/or transparent material, etc.). 
     A single filament  66  is being extruded from extrusion die set  64  in  FIG.  5   . If desired, multiple filaments  66  may be extruded in parallel from die set  64  (e.g., to form bundles of filaments  66  at the output of die set  64 ). In such configurations, filaments  66  may be debundled prior to subsequent operations (e.g., before fusing or otherwise attaching a layer of filaments  66  together to form a sheet of image transport layer material). 
     Extrusion die set  64  may include one or more layers with channels configured to distribute fiber core material into multiple cores fibers  16 F embedded in binder  16 FB during extrusion. Filaments such as filament  66  may have circular cross-sectional shapes and may contain any suitable number of fiber cores and fibers (e.g., at least 3, at least 10, at least 30, at least 100, at least 500, at least 2500, fewer than 20,000, fewer than 4000, fewer than 500, fewer than 100, and/or other suitable number of fiber cores and fibers  16 F). 
     When it is desired to join the filaments produced by extruder  60  (e.g., extruded strands such as multi-core filament  66  of  FIG.  5    or other elongated polymer members), the filaments may, as an example, be placed in fusion equipment, which fuses the filaments by applying heat and pressure (e.g., heat and pressure that helps fuse the binder material of the filaments together). In-line fusion tools (e.g., fusers with rollers), laser-fusion equipment, fusion equipment that involves wrapping filaments into channels using computer-controlled equipment that maintains desired angular orientations and tensions computer-controlled, and/or other illustrative fusing tools may be used to fuse filaments together to form image transport layer material. 
     Heat and pressure may be applied to coherent fiber bundle material to deform the material into a desired shape (e.g., during fusion or in a subsequent forming operation performed after initial fusion operations). As shown in  FIG.  6   , for example, heated die structure such as structure  70  may press against fibers  16 F (e.g., fibers  16 F in filaments  66  and/or other fibers  16 F). This deforms fibers  16 F (e.g., to from image transport layer material of the type shown in  FIG.  1    to help minimize a display border). Following coherent fiber bundle deformation in a die under heat and pressure, mechanical shaping operations such as cutting, grinding, and polishing operations may be performed to create a desired shape for image transport layer  16 . For example, the deformed block of material shown in  FIG.  6    may be cut (and/or ground) and polished along dashed line  72  to form layer  16 . 
     Layer  16  may have a main portion such as central portion  16 - 2  and a border portion such as border portion  16 - 1 . Border portion  16 - 1  may run along the peripheral edge of central portion  16 - 2  and may surround central portion  16 - 2 . In central portion  16 - 2 , the input output surfaces of portion  16 - 2  may be planar or nearly planar. The fibers in portion  16 - 2  may, if desired, be free of bends. In border portion  16 - 1 , forming operations and subsequent mechanical shaping operations (e.g., cutting, grinding, and polishing) may provide portion  16 - 1  with curved cross-sectional profiles and deformed fibers  16 - 1 . 
     If desired, different materials and/or processes may be used in forming central portion  16 - 2  and border portion  16 - 1 . This allows each portion to be formed from a satisfactory set of material and process conditions, rather than compromising on a single set of materials and processes for forming layer  16 . As an example, in central portion  16 - 2 , where good optical quality is desired and where layer  16  may be partly or completely free of bent fibers  16 F, a first set of materials may be used in forming fiber cores, cladding material, and binder material, whereas in border portion  16 - 1 , where layer  16  is expected to undergo significant deformation and stress due to fiber bending, a second set of materials may be used in forming fiber cores, cladding material, and binder material. The first set of materials for forming portion  16 - 2  may have a fiber core material with a lower refractive index than the fiber core material used in the second set of materials for forming portion  16 - 1 . The higher core index in portion  16 - 1  may strengthen the light guiding properties (e.g., the light confinement ability) of fibers  16 F in portion  16 - 1  relative to fibers  16 F in portion  16 - 2 , whereas the materials forming portion  16 - 2  may enhance the quality of images viewed through portion  16 - 2 . If desired, the materials in portion  16 - 1  may also be selected to enhance the ability of portion  16 - 1  to be formed satisfactorily (e.g., using equipment of the type shown in  FIG.  6   ), whereas this consideration may be given less weight or no weight in the selection of the materials for portion  16 - 2 . Because portions  16 - 1  and  16 - 2  can be processed separately (if desired), portion  16 - 1  may, in an illustrative configuration, be subjected to a forming operation, whereas portion  16 - 2  may not be subjected to this forming operation. 
     In an illustrative arrangement, in border portion  16 - 1 , the material used in forming cores  16 F- 1  is optically clear polyester (e.g., polyester with a refractive index of 1.63-1.64), the material used in forming cladding  16 - 2  is a semicrystalline polymer (e.g., a fluorinated polymer such as THV, which is a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride), and the material used in forming binder  16 FB is acrylic (e.g., polymethyl methacrylate, sometimes referred to as PMMA), whereas in center portion  16 M, the material used in forming cores  16 F- 1  is polystyrene (e.g., polystyrene with a refractive index of 1.56-1.57), the material used in forming cladding  16 - 2  is a semicrystalline polymer (e.g., a fluorinated polymer such as THV), and the material used in forming binder  16 FB is acrylic (e.g., PMMA). 
     In some configurations, border portion  16 - 1  may be formed from image transport layer material and a central member that is surrounded by border portion  16 - 1  may be formed from a solid block of acrylic or other clear material (e.g., a transparent plate of material without any fibers, cladding, etc.). If desired, central portion  16 - 2  may be a coherent fiber bundle and a surrounding border structure may be formed from a solid clear material (e.g., acrylic, etc.) without any fibers, cladding, etc. In any of these arrangements, the border portion and central portion of these structures may be covered with display cover layer  30  to provide additional protection. 
     Border portion  16 - 1  and central portion  16 - 2  may be attached using adhesive (e.g., liquid adhesive that is cured by time, temperature, and/or application of light) and/or by fusion (e.g., joining polymers or other materials in portions  16 - 1  and  16 - 2  together under heat and pressure). Border portion  16 - 1  may be formed in a ring shape that fits around the periphery of central portion  16 - 2  and/or may be attached to central portion  16 - 2  by separately attaching a series of elongated strip-shaped border structures as shown in  FIG.  7   . 
     The bent fibers  16 F of layer  16  may be contained only in border portion  16 - 1  or central portion  16 - 2  may include some bent fibers.  FIG.  8    is a top view of layer  16  following forming to create bends in the fibers. Dashed lines  76  and  74  represent possible outlines for the portion of layer  16  that does not contain bent fibers. When forming occurs near line  74 , some of the bent fibers of layer  16  may be located in border portion  16 - 1  and some of the bend fibers of layer  16  may be located at the edge of central portion  16 - 2 . When forming occurs near line  76 , all fiber bending may, if desired, be confined to border portion  16 - 1 . 
     The materials used in forming portions  16 - 1  and  16 - 2 , the materials applied to portions  16 - 1  and  16 - 2 , and/or the fabrication processes applied to portions  16 - 1  and  16 - 2  (e.g., forming using heat and pressure, mechanical shaping operations such as cutting, grinding, and polishing, and/or other processing operations), may differ before, during, and/or after portions  16 - 1  and  16 - 2  are attached to form layer  16 . 
     To help ensure satisfactory alignment of filaments  66  with respect to each other in image transport layer  16  (e.g., to help ensure that filaments  66  and the fibers in filaments  66  are aligned during fusion), it may be desirable to place a single layer of filaments  66  together to form a filament sheet (sometimes referred to as a coherent fiber bundle sheet, a sheet of filaments, a sheet of image transport layer material, etc.). Multiple sheets can then be stacked and fused to form a coherent fiber bundle in which filaments are packed together with a desired filament alignment and density. Before stacking, sheets of filaments may optionally be partly or completely fused. Coherent fiber bundle material formed from sheets of filaments may sometimes be referred to as sheet-packed coherent fiber bundle material, sheet-packed image transport layer material, sheet-stacked image transport layer material, a sheet-packed coherent fiber bundle, sheet-packed filaments, etc. Following sheet stacking and fusion to form a block of coherent fiber bundle material, the coherent fiber bundle material may optionally be drawn (e.g., along a dimension parallel to fibers  16 F) to reduce the lateral dimensions of fibers  16 F. 
       FIG.  9    is a cross-sectional side view of coherent fiber bundle material for layer  16  showing how multiple sheets  80  of filaments  66  may be stacked together. 
     To form image transport layer material in which border portion  16 - 1  and central portion  16 - 2  differ (in materials, processing, etc.), different types of filaments may be sheet stacked and fused as shown in  FIG.  10   . In the example of  FIG.  10   , image transport layer  16  has been formed in a square shape having a width  92 . Sheets of filaments may be stacked by winding successive sheets of filaments about a roller (as an example) or by stacking sheets of filaments using other equipment. At the bottom of the stack of filaments sheets (e.g., in bottom portion  82 ), the filaments are all of a first type (filaments  66 B). This first filament type has a first type of binder and a first type of fibers (e.g., fibers with a first type of fiber core, a first type of cladding material, etc.). The sheets of filaments  66 B extend the full width (width  92 ) of layer  16 . After forming portion  82 , additional sheets of filaments for portion  84  may be stacked on top of portion  82 . In portion  84 , edge portions  88  contain filaments of the first type (filaments  66 B) and central portion  90  contains filaments of a second type (filaments  66 C) differing from the first type. The second type of filaments may, for example, have a second type of binder and a second type of fibers (e.g., fibers with a second type of fiber core, a second type of fiber cladding, etc.). Any or all of the properties (materials, dimensions, etc.) of the first type of filaments may differ from those of the second type of filaments. After forming portion  84 , additional sheets of filaments of the first type (filaments  66 C) may be stacked on portion  84  to form portion  86 . Fusion operations may be formed on the final assembly of stacked filaments to form a block of image transport layer material. 
     In the example of  FIG.  10   , filaments  66 C and filaments  66 B have been arranged into a desired pattern so that following fusion, an image transport layer is formed with a border portion  16 - 1  (filaments  66 B) that surrounds central portion  16 - 2  (filaments  66 C). Other types of attachment mechanism may be used, if desired. As shown in  FIG.  11   , for example, portion  16 - 1  may be attached to portion  16 - 2  using a layer of adhesive such as adhesive  90 . In a first illustrative arrangement, portions  16 - 1  and  16 - 2  may be processed after attachment (e.g., to form portion  16 - 1  into a desired shape with bent fibers by application of heat and pressure, to machine portion  16 - 1  and/or portion  16 - 2  into desired shapes such as shapes in which portion  16 - 1  has an upper surface with a curved cross-sectional profile, etc.). In this first illustrative arrangement, image transport layer  16  may appear as shown in  FIG.  12    following processing. If desired, a second illustrative arrangement may be used to form layer  16  of  FIG.  12   . In this second illustrative arrangement, portions  16 - 1  and  16 - 2  are processed separately (e.g., with forming operations and/or mechanical shaping operations, etc.). For example, portion  16 - 1  may be formed to bend fibers in portion  16 - 1  and may then be mechanically processed to provide portion  16 - 1  with an upper surface having a curved cross-sectional profile, whereas portion  16 - 2  may not be formed and may not be provided with a curved upper surface. After some or all of these separate processing operations, portions  16 - 1  and  16 - 2  may be joined using adhesive  90  and the optionally processed further to form image transport layer  16  of  FIG.  12   . 
     If desired, portions  16 - 1  and  16 - 2  may be attached using fusion operations rather than adhesive. This type of approach is illustrated in  FIGS.  13  and  14   . As shown in  FIG.  13   , for example, portion  16 - 1  may be attached to portion  16 - 2  by fusing portions  16 - 1  and  16 - 2  together under heat and pressure. Due to the use of fusion, no adhesive layer is present between portions  16 - 1  and  16 - 2 . 
     In a first illustrative fusion arrangement, portions  16 - 1  and  16 - 2  may be processed after fusion (e.g., to form portion  16 - 1  into a desired shape with bent fibers by application of heat and pressure, to machine portion  16 - 1  and/or portion  16 - 2  into desired shapes such as shapes in which portion  16 - 1  has an upper surface with a curved cross-sectional profile, etc.). In this first illustrative fusion arrangement, image transport layer  16  may appear as shown in  FIG.  14    following processing. If desired, a second illustrative fusion arrangement may be used to form layer  16  of  FIG.  14   . In this second illustrative arrangement, portions  16 - 1  and  16 - 2  are processed separately (e.g., with forming operations and/or mechanical shaping operations, etc.). For example, portion  16 - 1  may be formed to bend fibers in portion  16 - 1  and may then be mechanically processed to provide portion  16 - 1  with an upper surface having a curved cross-sectional profile, whereas portion  16 - 2  may not be formed. After some or all of these separate processing operations, portions  16 - 1  and  16 - 2  may be joined using fusion to form image transport layer  16  of  FIG.  14   , followed by optional additional processing. 
       FIG.  15    is a cross-sectional side view of device  10  in an illustrative configuration in which portions  16 - 1  and  16 - 2  have been joined to form layer  16  and in which layer  16  has been mounted over display  14  and attached to housing  12 . In this example, portion  16 - 1  has bent fibers configured to minimize the visible border of device  10  (e.g., by overlapping some or all of housing  12  so that housing  12  is partly or completely hidden from view by viewer  28 ). Portion  16 - 1  has a stepped ledge formed from a recessed portion along the outer edge of its lower surface that is used to help receive housing  12  and thereby join layer  16  to housing  12 . Housing  12  may be attached to the ledge of portion  16 - 1  using a layer of adhesive and/or other attachment structures. An optional display cover layer (e.g., display cover layer  30  of  FIG.  1    may overlap image transport layer  16  of  FIG.  15    and the other FIGS. Housing  12  may be attached to the display cover layer by a layer of adhesive (e.g., part of the same layer of adhesive that attaches housing  12  to the surface of the stepped ledge in portion  16 - 1 ). This type of configuration may be used in devices such as device  10  of  FIG.  1    and/or other devices  10 . 
     In the  FIG.  15    example, the lower (inwardly facing) surface of portion  16 - 1  has been provided with a curved cross-sectional profile. Central portion  16 - 2  includes portion  16 - 2 A and a portion such as portion  16 - 2 B adjacent to border portion  16 - 1 . Portion  16 - 2 A may have a planar inner surface. Portion  16 - 2 B may have an inner surface with a curved cross-sectional profile. The shapes of the inner surfaces of portions  16 - 1  and  16 - 2 B may be configured to create a smooth (e.g., stepless) transition between portions  16 - 1  and  16 - 2 B. Display  14  may be a flexible display (e.g., an organic light-emitting diode display or a flexible display having pixels formed from crystalline semiconductor light-emitting diode dies mounted on a flexible substrate). This allows display  14  to bend to conform to the curved inner surface of layer  16 . 
     In the example of  FIG.  16   , portion  16 - 1  and portion  16 - 2  have different thicknesses, resulting in a step height difference in the inner surfaces of portions  16 - 1  and  16 - 2 . This step change in the thicknesses of portions  16 - 1  and  16 - 2  may be accommodated by providing display  14  with a border portion such as portion  14 - 1  that is attached to the inner surface of portion  16 - 1  and a central portion such as portion  14 - 2  that is attached to the inner surface of portion  16 - 2 . Display portions  14 - 1  and  14 - 2  may, as an example, be formed from crystalline semiconductor light-emitting diode dies mounted on separate substrates. 
     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. 
     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: 20210715
Publication Date: 20230912
Grant Date: 20230912
Priority Date: 20200730
Inventors: WANG, Ying-da
CHANG, CHIH-YAO
CHANG, CHUN-CHIH
GUPTA, NATHAN K.
LIN, WEI
LI, XIANI
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B6/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/08", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/06", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 87933245