PATENT DOCUMENT

Publication Number: US-10860142-B1
Application Number: US-201615248405-A
Country: US
Kind Code: B1

Title: Light-based devices with light guide arrays

Abstract:
A light-based device may provide images and other light output to a user and may gather user input. The device may include a light guide array formed from a bundle of fibers. The light guide array may have an entrance surface that receives light emitted by a light-emitting device. The light-emitting device may include one or more light-emitting diodes and may be a display having an array of pixels. Light from the light-emitting device may be conveyed from the entrance surface to the exit surface by the light guide array. The exit surface of the light guide array may have a compound curvature. Optical structures may be formed over the exit surface. The light-based device may form light-field display, may form a touch sensor, may form a controller, and may form other structures.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a light-emitting device, wherein the light-emitting device comprises a display having an array of pixels and wherein the display is bent about a bend axis; and 
 a light guide array having an array of light guide elements, wherein the light guide array has an entrance surface configured to receive light from the light-emitting device and has an exit surface with a compound curvature, wherein the entrance surface has a curvature that is different from the compound curvature of the exit surface, and wherein the light guide elements are configured to convey light received from the light-emitting device at the entrance surface to the exit surface. 
 
     
     
       2. The apparatus defined in  claim 1  wherein the display comprises an organic light-emitting diode display and wherein the light guide array is formed from a plurality of fibers. 
     
     
       3. The apparatus defined in  claim 1  wherein the light guide array is formed from a bundle of fibers. 
     
     
       4. The apparatus defined in  claim 3  wherein the fibers have faceted exit surfaces and wherein at least some of the faceted exit surfaces have surface normals that are oriented in a common direction. 
     
     
       5. The apparatus defined in  claim 3  further comprising a lens array that overlaps the exit surface so that the display, light-guide array, and lens array form a light-field display that displays three-dimensional images. 
     
     
       6. The apparatus defined in  claim 3  wherein the display is configured to present an image to the entrance surface and wherein the light-guide array has a flared cross-sectional shape so that the exit surface displays in image that is magnified relative to the image presented to the entrance surface. 
     
     
       7. The apparatus defined in  claim 3  further comprising an inorganic coating layer on the entrance surface, wherein the display is formed on the inorganic coating layer. 
     
     
       8. The apparatus defined in  claim 3  further comprising lenses interposed between the entrance surface and the display. 
     
     
       9. The apparatus defined in  claim 3  wherein the fibers have tips at the exit surface with respective lenses. 
     
     
       10. The apparatus defined in  claim 1  further comprising a touch sensor that overlaps the light guide array, wherein the exit surface has protruding features. 
     
     
       11. The apparatus defined in  claim 8  wherein the light guide array is configured to rotate relative to the display. 
     
     
       12. The apparatus defined in  claim 11  wherein the protruding features have ring shapes that surround virtual button locations on the exit surface. 
     
     
       13. The apparatus defined in  claim 1  further comprising a rotatable structure in which the light guide array is mounted. 
     
     
       14. The apparatus defined in  claim 13  further comprising a support, wherein the rotatable structure is coupled to the support and is configured to rotate about a rotational axis relative to the support and wherein the light-emitting device is stationary with respect to the support. 
     
     
       15. The apparatus defined in  claim 1  wherein the light guide elements comprise plastic and wherein the light guide elements have a first index of refraction, the apparatus further comprising cladding material that surrounds the light guide elements and that has a second index of refraction that is less than the first index of refraction. 
     
     
       16. The apparatus defined in  claim 1  wherein the light guide array is formed from a bundle of treated transparent wood fibers. 
     
     
       17. Apparatus, comprising:
 a first light-emitting device; 
 a first light guide array formed from a first bundle of fibers, wherein the first light guide array overlaps the first light-emitting device; 
 a second light-emitting device; 
 a second light guide array formed from a second bundle of fibers, wherein the second light guide array overlaps the second light-emitting device; 
 a first structure to which the first light-emitting device is mounted; and 
 a second structure to which the second light-emitting device is mounted, wherein the second structure and the second light-emitting device move relative to the first structure and the first light-emitting device, wherein the first structure and the second structure are separated by a seam, and wherein the first light guide array and the second light guide array cover the seam. 
 
     
     
       18. The apparatus defined in  claim 17  wherein the first and second structures comprise portions of a vehicle body. 
     
     
       19. A device having an outer surface, wherein the device gathers touch input from a finger of a user at a location on the outer surface, comprising:
 a light guide array having an input surface and an output surface, wherein the light guide array is formed from a bundle of elongated light guide elements including at least first and second elongated light guide elements each having a first end at the input surface and a second end at the output surface; 
 at least one light source that emits light into the first end of the first elongated light guide element, wherein the first elongated light guide element guides the light to the location; and 
 a light detector that receives reflected light from the first end of the second elongated light guide element, wherein the second elongated light guide element guides the light from the location to the detector, wherein the second elongated light guide element is interposed between the light detector and the outer surface.

Description:
This application claims the benefit of provisional patent application No. 62/210,811, filed Aug. 27, 2015, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic systems and, more particularly, to systems that include light-based devices. 
     Displays and other devices that emit light may be used to provide visual information to a user. Displays may have planar surfaces containing arrays of pixels. The pixels of a display can be used to display images. Some displays include integrated touch sensors to allow a user to supply touch input. 
     It can be challenging to use displays in certain operating environments. If care is not taken, a display may not fit within a desired system or may not operate as intended. 
     It would therefore be desirable to be able to provide improved systems with displays. 
     SUMMARY 
     A light-based device may be used in an electrical system to provide images and other light-based output to a user. If desired, the light-based device may include a sensor for gathering user input. For example, a capacitive touch sensor that overlaps the surface of a light-based device may be used to gather touch input from a user. 
     Light-based devices may be provided that include light guide arrays. A light guide array for a light-based device may be formed from a bundle of fibers. The fibers may be plastic fibers or other transparent fibers that are surrounded by a low index cladding material. 
     The light guide array may have an entrance surface that receives light emitted by a light-emitting device. The light guide array may also have a corresponding exit surface. The exit surface of the light guide array may have a compound curvature. Light from the light-emitting device may be conveyed from the entrance surface to the exit surface by the light guide array. The light-emitting device may include one or more light-emitting diodes. If desired, the light-emitting device may be a display that has an array of pixels. 
     Optical structures may be formed over the exit surface. The optical structures may be configured to form a light-field display that displays three-dimensional images, to direct light towards one viewer and away from another viewer, or to adjust the apparent location of a displayed image. 
     Light sources and detectors may convey light to a user&#39;s finger on the exit surface and may measure reflected light from the user&#39;s finger to determine the location of the user&#39;s finger. In some configurations, the light guide array may have non-planar features such as recesses and protrusions to provide tactile feedback as a user moves a finger across the exit surface. 
     Light-based devices may be configured to form knobs and other controllers, may be configured to cover gaps associated with seams between structures that move with respect to each other, may be tiled to form a unified display with an enlarged image area, or may be used in forming other systems. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of an illustrative system with a light-based device in accordance with an embodiment. 
         FIG. 2  is a perspective view of an illustrative light guide array having an array of elongated light guide elements such as a bundle of fibers in accordance with an embodiment. 
         FIG. 3  is a cross-sectional view of an illustrative light guide array with circular fibers that serve as light guide elements in accordance with an embodiment. 
         FIG. 4  is a cross-sectional view of an illustrative light guide array with hexagonal fibers that serve as light guide elements in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative pixel array in a display and an associated light guide array in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative light guide array having a surface on which display structures such as thin-film circuit structures have been formed in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative array of pixels with microlenses that is being used to couple light into a light guide array in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of a light-based device based on a light guide array with a planar surface in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of a light-based device based on a light guide array with a curved surface in accordance with an embodiment. 
         FIG. 10  is a cross-sectional side view of a light-based device based on a light guide array with a surface having compound curves such as a hemispherical surface in accordance with an embodiment. 
         FIG. 11  is a cross-sectional side view of an illustrative arrangement in which a light-based device has been formed from a tiled array of displays and an array of associated flared light guide arrays in accordance with an embodiment. 
         FIG. 12  is a front view of an illustrative control device such as a control knob that includes a light guide array in accordance with an embodiment. 
         FIG. 13  is a cross-sectional side view of the illustrative control knob of  FIG. 12  mounted to a supporting structure in accordance with an embodiment. 
         FIG. 14  is a cross-sectional side view of a portion of a system having mating structures such as vehicle body structures or other structures that move with respect to each other and that have corresponding displays with flared light guide arrays that overlap a gap between the mating structures in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of an illustrative display having a surface formed by a light guide array with a protrusion in accordance with an embodiment. 
         FIG. 16  is a perspective view of an illustrative display with non-planar features such as protrusions and recesses formed on the surface of a light guide array in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view of an illustrative light field display with a light guide array in accordance with an embodiment; 
         FIG. 18  is a cross-sectional side view of an illustrative light-based device having light redirecting structures on a curved light guide array surface in accordance with an embodiment. 
         FIG. 19  is a cross-sectional side view of an illustrative light-based device having a layer of Fresnel lenses or other optical structures on a curved surface of a light guide array in accordance with an embodiment. 
         FIG. 20  is a cross-sectional side view of an illustrative light-based touch sensor formed from a light guide array in accordance with an embodiment. 
         FIG. 21  is a perspective view of an illustrative light-based device formed from a light guide array with a curved surface overlapped by an array of touch sensor electrodes in accordance with an embodiment. 
         FIG. 22  is a perspective view of an illustrative light-based device having a light guide array with an exit surface of compound curvature and having a display layer that is bent about a bend axis in accordance with an embodiment. 
         FIG. 23  is a cross-sectional side view of an illustrative light guide array in which fibers have faceted exit surfaces oriented in a common direction in accordance with an embodiment. 
         FIG. 24  is a cross-sectional side view of an illustrative light guide array in which alternating fibers in the array have faceted surfaces oriented in different respective directions in accordance with an embodiment. 
         FIG. 25  is a cross-sectional side view of an illustrative light guide array in which fibers have convex lenses in accordance with an embodiment. 
         FIG. 26  is a cross-sectional side view of an illustrative system in which a covering layer and a cavity that can be filled with fluid overlap an array of fibers with lenses in accordance with an embodiment. 
         FIG. 27  is a cross-sectional side view of an illustrative light guide array having fibers with concave lenses in accordance with an embodiment. 
         FIG. 28  is a cross-sectional side view of an illustrative light guide array covered with a coating such as an antireflection coating in accordance with an embodiment. 
         FIG. 29  is atop view of an illustrative light guide array with an overlapping opaque covering layer having openings aligned with respective light guide elements in the array in accordance with an embodiment. 
         FIG. 30  is a cross-sectional side view of a light guide array having light guide elements formed from fibers in a layer of treated wood in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Light-based devices may be used to display images and provide other light-based output. Light-based devices may include light-emitting devices such as displays and light guide arrays. The light-based devices may be used in displaying light-based output such as images. The light-based devices may be used in systems such as office equipment systems, building systems, vehicle systems (e.g., dashboard systems for providing a user such as a vehicle occupant with vehicle information and for gathering user input), systems built into furniture, portable electronic devices (e.g., handheld devices, glasses, and other portable and miniature devices), or other electronic equipment. 
     An illustrative system that includes a light-based device is shown in  FIG. 1 . As shown in  FIG. 1 , system  10  may include one or more light-based devices such as light-based device  18 . Light-based device  18  may include light-emitting components such as light-emitting diodes, lamps, etc. As an example, light-based device  18  may include one or more light-emitting devices such as display  20 . Displays such as display  20  may be liquid crystal displays, organic light-emitting diode displays, displays based on array of micro-light-emitting diodes (e.g., crystalline semiconductor dies), electrophoretic displays, plasma displays, transreflective liquid crystal displays, organic liquid crystal displays, projectors, electrowetting displays, microelectromechanical systems (MEMs) displays, electrokinetic displays, electrofluidic displays, cholesteric liquid crystal displays, or other types of display. 
     Alight guide array such as a coherent light guide array based on a bundle of transparent glass or plastic fibers or other parallel elongated light guide elements (sometimes referred to as waveguides or light guides) may have a surface such as surface  24 . Surface  24  may have planar portions and/or curved portions. The light guide array may be used in displaying images that are generated by a light-emitting device. The light-emitting device may be formed from one or more light-emitting diodes, may include large predefined areas of light-emitting structures (e.g., for icons, alphanumeric characters, uniform areas of color, etc.) and/or may include an array of small pixels that form a general purpose display. Configurations in which the light-emitting device is formed from a display such as display  20  may sometimes be described herein as an example. The light guide array of device  18  may convey images that have been generated by display  20  to a user such as viewer  12  who is viewing device  18  in direction  14 . Surface  24  may be associated with the outer surface of a light guide array. After being guided through the light guide elements of the light guide array, the light output from the light-emitting device (e.g., images from display  20 ) may appear on surface  24 . Surface  24  may therefore sometimes be referred to as the outer surface or exit surface of the light guide array. 
     If desired, user input devices such as touch sensor  22  may be incorporated into light-based device  18 . As an example, a touch sensor may be formed on surface  24  of light-based device  18  to gather touch input from an external object such as one or more fingers of a user (see, e.g., finger  16 ). The touch sensor may be a capacitive touch sensor having an array of transparent capacitive sensor electrodes such as indium tin oxide electrodes that gather capacitive touch sensor measurements. If desired, light-based device  18  may include touch sensors based on other types of touch technology (e.g., resistive touch, acoustic touch, light-based touch, force-based touch, etc.). 
     Control circuitry  24  may be used to generate images to display on display  20  or to control the light output of other light-emitting devices in device  18  and may be used in processing input from input-output devices in system  10  such as touch sensor  22 . Control circuitry  24  may include storage and processing circuitry. 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 control circuitry  24  may be used to process user input from sensor  22  and other input devices and to display images on display  20  and take other appropriate actions in system  10 . 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, electronic control units, etc. 
     Alight guide array for device  18  may be formed from a bundle of elongated light guide elements. The light guide elements may be formed from transparent materials and may sometimes be referred to as fibers. As shown in  FIG. 2 , light guide array  28  may, for example, be formed from a set of fibers  26  each of which extends along a longitudinal axis such as axis  30 . Fibers  26  may be formed from transparent materials such as plastic or glass. Fiber bundle structures such as light guide array  28  of  FIG. 2  may sometimes be referred to as coherent fiber bundles or coherent light guide arrays. Light guide array  28  has a first surface (sometimes referred to as an entrance face) that receives light  32  (e.g., light from display  20  or other light-emitting device) and a corresponding second surface (sometimes referred to as an exit face) that emits light  32 . Light  32  that is associated with an image on display  20  and that enters the entrance face of light guide array  28  (e.g., the exposed bottom surfaces of fibers  26  of  FIG. 2 ) will be guided within fibers  26  to the exit face of light guide array  28  (i.e., upper surface  24  of light guide array  28  of  FIG. 2 ) for viewing by viewer  12 . 
     As shown in  FIG. 3 , fibers  26  may be embedded within cladding material  34 . The index of refraction of cladding material  34  may be less than the index of refraction of fibers  26  so that fibers  26  can serve as light guide elements (e.g., so that fibers  26  may guide light  32  in accordance with the principle of total internal reflection). Cladding material  34  may, as an example, be formed from a clear polymer. Fibers  26  may have circular cross-sectional shapes as shown in  FIGS. 2 and 3  or may have any other suitable shapes (see, e.g., the hexagonal shapes of fibers  26  of  FIG. 4 ). 
       FIG. 5  is a cross-sectional side view of a portion of an illustrative light-based device. As shown in  FIG. 5 , light-based device  18  may have a light-emitting device such as display  20 . Display  20  may have an array of pixels such as pixels  38  that emit light (e.g., light that forms images for a user of device  18 ). With the arrangement of  FIG. 5 , light guide array  28  has fibers  26  that each overlap multiple pixels  28 . Arrangements in which a single light-emitting diode or other light-emitting structure emits light into multiple fibers  26  may also be used, if desired. Layer  36  of  FIG. 5  may be used as an index-of-refraction matching layer to help reduce coupling losses when coupling light from pixels  38  into fibers  26 . Layer  36  may also help attach display  20  to entrance face  42  of light guide array  28 . 
     If desired, display structures may be deposited and patterned on the surface of a light guide array. As shown in  FIG. 6 , for example, surface  42  of light guide array  28  (e.g., the entrance face of light guide array  28 ) may be polished and covered with a coating layer such as layer  28 HC. Layer  28 HC may be, for example, a layer of inorganic materials (e.g., silicon oxide, silicon nitride, etc.). Display  20  may be formed by using low-temperature processing techniques and other display fabrication techniques to deposit and pattern display layers on layer  28 HC (e.g., by depositing and patterning thin-film transistors, organic light-emitting diodes, and/or other thin-film transistor circuitry and light-emitting structures on layer  28 HC). 
       FIG. 7  shows how optical structures such as lenses may be formed on a display to help couple light from the display into light guide array  28 . As shown in  FIG. 7 , display  20  may include microlenses  40 . Each microlens may cover one or more pixels  38  and may help direct light  32  that has been emitted from pixels  38  into respective fibers  26  in light guide array  28 . 
     The array of light guide elements  26  in light guide array  28  effectively moves the location of the images generated by display  20  from the surface of display  20  (and the entrance surface of light guide array  28  adjacent to display  20 ) to exposed outer surface (exit surface)  24  of light guide array  28 . Consider, as an example, the arrangement of  FIG. 8 . As shown in  FIG. 8 , pixels  38  of display  20  may be located adjacent to lower (inner) surface  42  of light guide array  28 . When an image is displayed by pixels  38 , the fibers in light guide array  28  translate the location of the image to outer surface  24 . Surfaces  42  and  24  may be planar or may have other shapes. As shown in  FIG. 8 , for example, edge portions  28 ′ of light guide array  28  may be curved (e.g., so that surface  24  curves along the edges of device  18 ). 
     The example of  FIG. 8  involves a translated image that is not magnified in size or reduced in size. In the illustrative configuration of  FIG. 9 , the curved shape of light guide structure  28  may magnify the image displayed on display  20  (i.e., the image on curved outer surface  24  of light guide array  28  may be magnified relative to the image on display  20 ). In configurations of the type shown in  FIG. 9  in which inner light guide array surface  42  is curved, it may be desirable to form display  20  from a flexible display layer (e.g., a flexible organic light-emitting diode display, etc.). 
     If desired, outer surface  24  may have a compound curvature, as shown by illustrative hemispherical surface  24  of light guide array  28  of  FIG. 10 . Display  20  may, if desired, be planar or may be bent about a single axis, whereas outer surface  24  may, in general, be planar, may be bent about a single axis, or may exhibit a compound curvature as illustrated by illustrative surface  24  of  FIG. 10 . 
     Light-based device  18  may include an array of light guide arrays. As shown in  FIG. 11 , for example, each of multiple displays  20  in device  18  may be provided with a respective light guide array  28 . The light guide arrays may have curved surfaces  24 , planar surfaces, surfaces  24  with compound curvature, or other suitable surface shapes. In the example of  FIG. 11 , each light guide array  28  has a flared shape that allows upper surfaces  24  to merge and overlap gaps  44  between respective displays  20 . In this way, displays  20  and light guide arrays  28  may be unified in a tiled fashion to form a single enlarged unitary display with an enlarged image area. Optional transparent display cover layer  46  may protect outer light guide surfaces  24  in the unitary display and may, if desired, include touch sensor structures (see, e.g., touch sensor  22 ). 
     Displays may be mounted on a support structure such as support structure  48 . Support structure  48  may have a curved or planar surface with which displays  20  are supported. The arrangement of  FIG. 11  may have a one-dimensional array of displays  20  and associated light guide arrays  28  or may have a two-dimensional array of displays  20  and associated light guide arrays  28  (e.g., a unitary display may be formed from either a one-dimensional or a two-dimensional tiled set of displays  20  whose display surfaces are each laterally expanded using the flared shape of light guide arrays  28  so as to hide inactive regions such as gaps  44  between displays  20  from view by a user). 
     If desired, light-based device  18  may include movable structures. An illustrative light-based device with a movable structure is shown in  FIG. 12 . As shown in  FIG. 12 , light-based device  18  may include a display mounted under a circular light guide array. Light guide array  28  may have a planar or curved surface. The display may produce an image. Due to the light guiding properties of light guide array  28 , the image may be presented on the surface of light guide array  28 , as illustrated by image  52 . Image  52  may be used to present information on the status of system  10  or other information to the user of system  10 . As an example, image  52  may contain information such as a current radio station identifier when device  18  is being used in a radio or other media system. In the example of  FIG. 12 , light-based device  18  has a rotating knob member such as ring  50 . Ring  50  may be rotated about rotational axis  54  in directions  55  as light guide array  28  and therefore image  52  remains stationary. 
     A cross-sectional side view of device  18  of  FIG. 12  is shown in  FIG. 13 . As shown in  FIG. 13 , light-based device  18  (e.g., a rotating control such as a rotatable knob) may be mounted to structure  56  in system  10 . Structure  56  may be part of a vehicle dashboard, may be part of a control panel surface in a computer or other electronic equipment, may be a part of a piece of furniture or a building wall, or may be any other suitable supporting structure. Coupling structure such as protrusions  62  and recesses  64  in ring  50  may be used to hold ring  50  and light guide array  28  in place on structure  56 . Light guide array  28  may be held in place within ring  50 . As ring  50  rotates about axis  54 , light guide array  28  may rotate about axis  54  in directions  55 . Nevertheless, because display  20  does not move with respect to structure  56 , the image displayed on outer display surface  24  of light guide array  28  will remain stationary relative to display  20  and structure  56 . 
     To monitor the rotational orientation of ring  50  about axis  54 , ring  50  and structure  56  may be provided with a rotational encoder. The encoder may be used to provide control circuitry  24  with information on the position of ring  50 . With one illustrative configuration, the encoder includes a ring of magnets  58  on ring  50  and a corresponding magnetic sensor such as sensor  60  in a fixed position on structure  56 . Sensor  60  can be used by control circuitry  24  to monitor the rotation of ring  50  about axis  54 . Other types of sensors (e.g., resistance sensors, etc.) for measuring the position of a controller such as ring  50  of  FIG. 13  may be used, if desired. The use of a magnetic encoder is merely illustrative. 
     Outwardly flared light guides  28  may be used to cover a seam between movable structures. As shown in  FIG. 14 , first and/or second structures such as structures  68  may move in directions such as directions  76 . When in the position shown in  FIG. 14 , structure  68  are joined along seam  70 . When at least one of structures  68  has been moved away from the other (e.g., by swinging on a hinge), structures  68  may separate along seam  70 . Structures  68  may be, for example, parts of a door or other portion of the body of a vehicle and seam  70  may be a panel gap in the body. Elastomeric gaskets  74  may help seal structures  68  to each other. As shown in  FIG. 14 , light guide arrays  28  may have flared cross-sectional shapes that overlap gaskets  74 , so that gaskets  74  are hidden from view while images are displayed on outer surfaces  24  of light guide arrays  28 . 
       FIG. 15  is a cross-sectional side view of light-based device  18  in an illustrative configuration in which surface  24  of light guide array  28  has been provided with a non-planar feature such as feature  80 . Feature  80  may include protruding portions (e.g., a ring-shaped ridge or other protrusion), recessed portions, or other portions that help catch a user&#39;s finger such as finger  16  as the user moves finger  16  across surface  24 . This may help vision-impaired users and other users interact with device  18 . 
     Display  20  may be used in displaying images on surface  24  that are aligned with non-planar features  80 . A perspective view of an illustrative light-based device with arrays of non-planar features  80  is shown in  FIG. 16 . As shown in  FIG. 16 , features  80  may be formed in ring shapes and other shapes. These shapes may form the outline of virtual buttons (e.g., locations where on-screen selectable options are displayed). During operation, a selectable option such as illustrative convent  82  of  FIG. 16  may be displayed in alignment with features  80  (e.g., in the middle of a ring-shaped protruding ridge that defines a virtual button location). Touch sensor structures in device  18  (e.g., capacitive touch sensor electrodes that overlap at least the virtual button locations within features  82 ) may be used to gather user touch input (e.g., button presses). 
     If desired, device  18  may be used to display three-dimensional images (e.g., device  18  may be a light-field display). A cross-sectional side view of an illustrative device of this type is shown in  FIG. 17 . As shown in  FIG. 17 , light guide array  28  may be used to convey light from an array of pixels  38  in display  20  to lower surface  84  of a layer of light redirecting structures such as lens array  86 . Lens array  86  may include a plurality of lenses  88 , each of which overlaps a respective set of pixels  38 . Lenses  88  may be elongated lenticular lenses (i.e., lenses  88  may be parallel ridges extending across display  20 ) or lenses  88  may be circular lenses that are arranged in a two-dimensional array. The pixels associated with each lens  88  may be selectively controlled to provide output light that varies as a function of viewer position, thereby creating a three-dimensional image for the viewer. As an example, pixel  38 A under lens  88 ′ may be adjusted to adjust the intensity of light  32  that is viewed when the viewer is in location  14 A and pixel  32 B under lens  88 ′ may be adjusted to adjust the intensity of light  32  that is viewed when the viewer is in location  14 B. By interposing light guide array  28  between display  20  and lens array  86 , surface  24  of light guide array  28  and therefore the outer surface of device  18  may be curved. As an example, surface  24  may have a compound curvature (e.g., device  18  may have the shape of a sphere, may have a hemispherical appearance, or may have other curved shapes). 
     The cross-sectional side view of illustrative light-based device  18  of  FIG. 18  shows how a prism array or other layer of light redirecting structures may be used to direct light  32  to viewer  14 . This type of arrangement may be used, for example, to block a driver&#39;s view of a passenger&#39;s video content on a shared dashboard display while the viewer (e.g., the passenger) is able to view the content. The prisms or other structures of layer  90  may be formed by etching, molding, by photolithographic techniques, by embossing, by laser-processing or machining, or by using other suitable optical layer patterning techniques. If desired, lenses (e.g., Fresnel lenses) or other light-redirecting structures may be formed in this way (see, e.g., illustrative light redirecting layer  92  of  FIG. 19 , which may contain an array of Fresnel lenses). The lenses or other structures in layer  92  may be used change the apparent position of the image created by display  20 . 
     If desired, light guide array  28  may be used informing a light-based touch sensor. As shown in  FIG. 20 , light  32  may be emitted through fibers  26  in upwards direction  100  from an array of light sources  102  (discrete or integrated on a common substrate) or from a single light source  102  that supplies light to multiple fibers  26 . Light  32  that is emitted from the upper surface  24  of light guide array  28  (e.g., a planar or curved surface) may be reflected from finger  16  as reflected light  32 ′ wherever finger  16  is present and may thereafter be conveyed by a corresponding adjacent fiber  26  in light guide array  28  to an associated light detector  104 . Light detectors  104  may be discrete detectors or may be part of an array of detectors that is formed on a common substrate (as examples). By analyzing the intensities of the detected light at detectors  104 , the position of finger  16  may be determined by control circuitry  24 . 
       FIG. 21  is a perspective view of an illustrative light-based device with touch sensor electrodes such as touch sensor electrodes  110 . Touch sensor electrodes  110  may be capacitive electrodes formed from indium tin oxide or other transparent conductive material for a capacitive touch sensor (e.g., touch sensor  22  of  FIG. 1 ). Touch sensor electrodes  110  may be formed at locations that overlap outer surface  24  of light guide array  28  on display  20 . Surface  24  may be curved (e.g., surface  24  may have compound curves). Light-based device  18  of  FIG. 21  may be, for example, a computer mouse with a touch sensitive upper surface (surface  24 ) that has the ability to display images from display  20 . 
     The light guide arrays may be fabricated from elastomeric materials such as silicones. This allows images to be displayed on the surface of a material that is deformable. This arrangement may be used to display images on the surface of an arm rest, while maintaining the surface as soft to the touch. An elastomeric wave guide would also allow for some degree of motion between display elements while maintaining the illusion of a continuous display. This could allow variable bending of a display, or display elements that could fold around an object. 
     As shown in  FIG. 22 , light-based device  18  may have a display such as display  20  that is bent about a first bend axis such as bend axis  120  and a light guide array such as light guide array  28  that is curved about axis  120  and is also curved about a second axis such as axis  122  to provide light guide array  28  and device  18  with an exterior surface that has compound curvature. Bend axis  120  may be oriented at a non-zero angle with respect to axis  122 . For example, axes  120  and  122  may be orthogonal to each other. With this type of arrangement, the opposing right and left edges of display  20  (see, e.g., edge E of  FIG. 22 ) are flat and the surface of display  20  is only bent about axis  120  and does not exhibit compound curvature, simplifying display fabrication. Bending display  20  about axis  120  helps reduce the thickness of light guide array  28  relative to a configuration in which display  20  is planar. As shown in  FIG. 22 , light guide array  28  may, if desired, be covered with one or more coatings, touch sensors, glass or plastic display cover layers, etc. (see, e.g., cover layer  124 ). If desired, cover layer  124  and/or other layers of the surface of array  28  may be omitted. Fibers  26  in light guide array  28  of  FIG. 22  may be tapered or may not be tapered. 
     As shown in  FIG. 23 , fibers  26  or other light guide elements in light guide array  28  may have faceted surfaces (e.g., faceted surfaces formed by cleaving fibers  26  at an angle, etc.). The faceted surface of each fiber  26  in array  28  (or a subset of array  28 ) may be oriented in the same direction (i.e., the surface normal of each faceted exit surface may be oriented in the same direction), so that light  32  is emitted evenly (i.e., so that light  32  does not exhibit intensity variations due to different angles of emission from different fibers). Faceted fibers  26  may be used in light guide arrays with planar surfaces and/or in light guide arrays such as array  28  of  FIG. 23  that have curved surfaces such as surface  24 . 
     In general, light guide elements such as fibers  26  may have faceted exit surfaces (and associated surface normals) that are aligned along one or more one directions.  FIG. 24  shows how alternating fibers or other distinct sets of fibers  26  in array  28  may be provided with facets having surface normals n 1  and n 2  that are oriented in different respective directions (e.g., to provide a viewer with different images in the viewer&#39;s right and left eyes to support three-dimensional display technologies, to provide first and second users or first and second viewpoints for a single user with different images, etc.). 
     As shown in  FIG. 25 , each fiber  26  in array  28  may be provided with an associated lens  26 L. Lenses  26 L may be formed, for example, be depositing a liquid polymer precursor material on the surface of fibers  26  so that surface tension forms convex lens shapes for lenses  26 L. The liquid polymer material can be cured by application of ultraviolet light, heat, etc., to form lenses  26 L. Convex lenses of the type shown in  FIG. 25  may be used to help spread light  32  over an enhanced range of emission angles. If desired, lenses  26 L may be formed by polishing the tips of fibers  26 , by melting the tips of fibers  26  and allowing molten tip material to resolidify, or using other lens formation techniques. 
       FIG. 26  shows how an array of fibers  26  with lenses  26 L may be incorporated into a system that has a covering layer such as layer  130  that is separated from lenses  26 L by a cavity such as cavity  132 . A pumping system may be used to place different fluids in cavity  132  (e.g., air, water, oil, a liquid with an index of refraction that matches the refractive index of fiber  26  and of layer  130 , etc.). The pumping system may be used to adjust the contents of cavity  132  in real time. For example, if it is desired for array  28  to emit light  32  over a wider range of angles, air or other gas with an index of refraction that is less than that of lenses  26 L and layer  130  may be placed in cavity  132 . In this state, lenses  26 L will help spread light  32  as light  32  is emitted by each fiber  26 . If it is desired for array  28  to emit light  32  over a smaller range of angles, index-matching liquid may be placed in cavity  132 . The index-matching liquid defeats the ability of lenses  26 L to refract light  32 , so that light  32  will be emitted over a narrower range of angles. This type of arrangement may, if desired, be used to provide a display with an adjustable privacy feature. When privacy is not desired, cavity  132  may be filled with gas. When privacy is desired, cavity  132  may be filled with index-matching liquid to narrow the angle-of-view of the display. 
       FIG. 27  shows how lenses  26 L may be concave lenses to help narrow the angular spread of the light (light  32 ) emitted by each fiber  26  in array  28 . 
     As shown in  FIG. 28 , a coating layer such as coating  134  may be formed over the surface of fibers  26  in array  28 . Coating  134  may include one or more layers such as an antireflection layer, an oleophobic layer, an antiscratch layer, etc. 
       FIG. 29  is a top view of array  28  in an illustrative configuration in which array  28  has been covered with a covering layer. Covering layer  138  may be formed from a material such as metal, leather, wood, plastic, ink, a fiber-composite material such as a carbon-fiber composite, glass, etc. For example, covering layer  138  may be formed from an opaque material (black ink, opaque metal, leather, wood, opaque plastic, opaque fiber-composite material, opaque glass, etc.). Openings  136  may be aligned with respective fibers  26  to allow light to pass through layer  138 . Fibers  26  may have high index of refraction cores surrounded by low index of refraction claddings to help concentrate light  32  under openings  136  or fibers  26  may be formed from glass, plastic or other material with only a single index of refraction. 
     Wood may be treated to form a light guide array, as illustrated in  FIG. 30 . In the example of  FIG. 30 , light-guide array  28  has transparent wood fibers  26  that guide light  32 . Wood fibers  26  may be rendered transparent by treating a piece of wood in a chemical bath (e.g., by bleaching a wood layer in a heated sodium hydroxide bath or other bleaching agent). The bleaching process may remove materials in the wood such as lignin that might otherwise absorb light  32 . 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20160826
Publication Date: 20201208
Grant Date: 20201208
Priority Date: 20150827
Inventors: NORTHCOTT, MALCOLM J.
POTTER, DANIEL E.
MAZUIR, Clarisse
TOH, WEISONG
DONDETI, PIYUSH PRASHANT
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B6/0008", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0006", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0008", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0008", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0421", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 73653892