PATENT DOCUMENT

Publication Number: US-10273600-B1
Application Number: US-201715685862-A
Country: US
Kind Code: B1

Title: Devices having fabric with adjustable appearance

Abstract:
An electronic device may include intertwined strands of material such as strands forming fabric. A strand in the fabric may include a light-emitting core surrounded by a coaxial light modulator layer. The light-emitting core may be formed from an optical fiber, light-emitting diodes mounted to a polymer core, or a layer of light-emitting diodes sandwiched between coaxial inner and outer conductive layers. The light modulator layer may have coaxial transparent inner and outer electrodes and may have a light modulating material such as electrochromic material, liquid crystal material, or other material that exhibits optical properties such as color and/or light transmission that can be electrically controlled.

Claims:
What is claimed is: 
     
       1. A fabric-based item comprising:
 a layer of fabric formed from intertwined strands including a strand having:
 a light-emitting core configured to emit light; 
 an electrochromic light modulator layer surrounding the light-emitting core, wherein the electrochromic light modulator layer has coaxial inner and outer electrodes and has electrochromic material between the inner and outer electrodes; and 
 
 control circuitry that is configured to adjust transmission of the light through the electrochromic light modulator layer by applying a signal to the electrochromic material using the inner and outer electrodes. 
 
     
     
       2. The fabric-based item defined in  claim 1  wherein the light-emitting core comprises:
 a polymer core strand; 
 a first conductive layer on the polymer core strand; 
 a second conductive layer; and 
 light-emitting diodes between the first and second conductive layers. 
 
     
     
       3. The fabric-based item defined in  claim 2  wherein the second conductive layer comprises transparent conductive material. 
     
     
       4. The fabric-based item defined in  claim 3  wherein the inner and outer electrodes comprise transparent conductive material. 
     
     
       5. The fabric-based item defined in  claim 4  further comprising a transparent polymer layer, wherein the light modulator layer is interposed between the light-emitting core and the transparent polymer layer. 
     
     
       6. The fabric-based item defined in  claim 1  wherein the light-emitting core comprises:
 a polymer core strand; 
 signal lines on the polymer core strand that have portions that form contacts; and 
 light-emitting diodes coupled to the contacts. 
 
     
     
       7. The fabric-based item defined in  claim 1  wherein the strands include a conductive strand, wherein the outer electrode is electrically coupled to the conductive strand, and wherein the control circuitry is configured to adjust a portion of the electrochromic material in the light modulator layer by applying a signal to the conductive strand. 
     
     
       8. The fabric-based item defined in  claim 1  wherein the layer of fabric is woven fabric and wherein the fabric-based item further comprises a battery. 
     
     
       9. The fabric-based item defined in  claim 1  wherein the light-emitting core comprises an optical fiber. 
     
     
       10. An electronic device, comprising:
 a strand having a light-emitting core, wherein the light-emitting core comprises:
 a polymer core strand; 
 light-emitting diodes configured to emit light; 
 coaxial first and second conductive layers, wherein the first conductive layer is formed on the polymer core strand and wherein the light-emitting diodes are interposed between the first and second conductive layers; and 
 
 control circuitry that is configured to adjust the light-emitting diodes by applying a signal to the light-emitting diodes using the first and second conductive layers. 
 
     
     
       11. The electronic device defined in  claim 10  wherein the strand further comprises:
 a light modulator layer surrounding the light-emitting core, wherein the control circuitry is configured to adjust transmission of the emitted light through the light modulator layer by applying a signal to the light modulator layer. 
 
     
     
       12. The electronic device defined in  claim 11  wherein the strand is intertwined with additional strands to form fabric. 
     
     
       13. The electronic device defined in  claim 11  wherein the light modulator layer has coaxial inner and outer electrodes and wherein the control circuitry is configured to apply the signal using the inner and outer electrodes. 
     
     
       14. The electronic device defined in  claim 13  wherein the light modulator layer comprises a layer of electrochromic material between the inner and outer electrodes. 
     
     
       15. The electronic device defined in  claim 13  wherein the light modulator layer comprises a layer of liquid crystal material between the inner and outer electrodes. 
     
     
       16. The electronic device defined in  claim 13  wherein the inner and outer electrodes comprise transparent conductive material. 
     
     
       17. The electronic device defined in  claim 13  wherein the strand further comprises a transparent polymer layer and wherein the light modulator layer is interposed between the light-emitting core and the transparent polymer layer. 
     
     
       18. A fabric-based item comprising:
 a layer of fabric formed from intertwined strands including a strand having:
 a light-emitting core configured to emit light; 
 a liquid crystal light modulator layer surrounding the light-emitting core, wherein the liquid crystal light modulator layer has coaxial inner and outer electrodes and liquid crystal material between the inner and outer electrodes; and 
 
 control circuitry that is configured to adjust transmission of the light through the liquid crystal light modulator layer by applying a signal to liquid crystal material using the inner and outer electrodes. 
 
     
     
       19. The fabric-based item defined in  claim 18  wherein the light-emitting core comprises an optical fiber and a light-emitting diode coupled to the optical fiber and wherein the control circuitry is configured to adjust the light emitted from the light-emitting core by adjusting the light-emitting diode. 
     
     
       20. The fabric-based item defined in  claim 18  wherein the light-emitting core comprises:
 a polymer core strand; 
 a first conductive layer on the polymer core strand; 
 a second conductive layer; and 
 light-emitting diodes between the first and second conductive layers.

Description:
FIELD 
     This relates generally to fabric-based items and, more particularly, to fabric-based items having adjustable components. 
     BACKGROUND 
     It may be desirable to form bags, furniture, clothing, wearable electronic devices, and other items from materials such as fabric. If care is not taken, however, fabric-based items may not offer desired features. For example, fabric-based items may not include visual output devices to provide a user with visual information or may include visual output devices that are unattractive, bulky, and heavy. 
     SUMMARY 
     An electronic device may have intertwined strands of material. The intertwined strands may form fabric. The appearance of portions of the fabric can be adjusted using control circuitry that controls adjustable strands within the fabric. 
     An adjustable strand may include a light-emitting core. The light-emitting core may be formed from an optical fiber that is provided by light from a light-emitting diode, light-emitting diodes mounted to a dielectric core, or a layer of light-emitting diodes sandwiched between coaxial inner and outer conductive layers. The control circuitry can adjust light-emitting diodes associated with adjustable strands to adjust light emission from the adjustable strands. 
     The light-emitting core of an adjustable strand may be surrounded by a coaxial light modulator layer. The light modulator layer may have transparent coaxial inner and outer electrodes and may have a light modulating material interposed between the inner and outer electrodes. The light modulating material may be a material such as electrochromic material, liquid crystal material, or other material that exhibits optical properties such as color and/or light transmission that can be electrically controlled by the control circuitry. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of an illustrative illuminated strand with an adjustable appearance in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative fabric-based item in accordance with an embodiment. 
         FIG. 3  is a side view of an illustrative light-emitting core strand formed from an illuminated optical fiber with light scattering structures in accordance with an embodiment. 
         FIG. 4  is a perspective view of light-emitting diodes mounted to an illustrative flexible substrate in accordance with an embodiment. 
         FIG. 5  is a cross-sectional view of an illustrative strand with a circular cross-sectional shape having embedded light-emitting diodes on a flexible substrate such as the flexible substrate of  FIG. 4  in accordance with an embodiment. 
         FIGS. 6, 7, and 8  are cross-sectional views of illustrative mounting arrangements for light-emitting diodes in a strand in accordance with embodiments. 
         FIG. 9  is a cross-sectional view of an illustrative illuminated strand with light-emitting diodes coupled between inner and outer coaxial electrodes formed from layers of conductive material in accordance with an embodiment. 
         FIG. 10  is a perspective view of an illustrative overlapping strand configuration that may be used in controlling the appearance of strands in fabric in accordance with an embodiment. 
         FIG. 11  is a perspective view of an illustrative strand with longitudinal conductive paths for supplying signals to components such as light-emitting diodes in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as wearable devices and other items may include fabric structures. To provide the fabric structures with an adjustable appearance, strands of material in the fabric may include electrically adjustable light sources and/or electrically adjustable light modulators. For example, strands can include light-emitting diodes for emitting light and/or can include electrically adjustable materials (e.g., electrochromic inks, liquid crystals with dye, etc.) that exhibit an electrically adjustable appearance. 
     Control circuitry in a device may adjust the appearance of entire strands or large portions of strands (e.g., when it is desired to change the appearance of relatively large areas of a fabric item) and/or may be used in adjusting pixel-sized areas (e.g., when it is desired to display images on a portion of a fabric layer). In some configurations, the appearance of strands of material may be adjusted to adjust illumination that is being provided by the strands (e.g., interior bag lighting, etc.). Light modulator structures may, in some arrangements, adjust the color of emitted light. Light modulator structures may also be used in selectively dimming uniform light emitted from core structures. 
     Arrangements such as these may be used to adjust the visual appearance of fabric-based items, to display images, to illuminate logos, keyboard key symbols and other patterned areas, and/or to otherwise adjust the appearance of fabric in a wearable electronic device or other item with fabric. 
     A cross-sectional view of an illustrative strand with an adjustable appearance is shown in  FIG. 1 . In the example of  FIG. 1 , strand  30  is a monofilament. Multifilament strands (yarn) may be used in forming fabric, if desired. 
     As shown in  FIG. 1 , strand  30  may include a light-emitting core (core strand) such as core  32 . Core  32  may emit light  42  such as white light or light of non-neutral color(s) such as red light, green light, blue light, etc. In some configurations, core  32  may emit ultraviolet light or infrared light. Arrangements in which light  42  is white light may sometimes be described herein as an example. 
     The appearance of light  42  and therefore the outward appearance of strand  30  to an observer may be varied by modulating the color and/or intensity of light  42  with one or more light modulating layers surrounding core  32 . In general, any suitable light modulating structures may be incorporated into device  10 . With one illustrative arrangement, strand  30  includes a light modulator (light modulator layer) based on electrochromic technology. With another illustrative arrangement, the light modulator layer in strand  30  is based on liquid crystal light modulator technology. Other types of light modulators may be incorporated into strand  30 , if desired. 
     The light modulator structures in strand  30  may be adjusted by applying controlled electrical signals to electrodes in strand  30 . The electrodes may be formed on opposing sides of strand  30  (e.g., on left and right sides of strand  30  in the orientation of  FIG. 1 ) or may be formed in a coaxial arrangement. 
     In the example of  FIG. 1 , strand  30  includes coaxial electrodes such as inner electrode  34  and outer electrode  38 . Inner electrode  34  surrounds light-emitting core  32 . Outer electrode  38  surrounds inner electrode  34  in a coaxial fashion. A layer of light modulator material  36  is interposed between inner electrode  34  and outer electrode  38 . In this configuration, core  32 , inner electrode  34 , material  36 , and outer electrode  38  are all concentric. Strand  30  of  FIG. 1  has a longitudinal axis  61  that extends into the page. 
     Light modulator material  36  (e.g., electrochromic material, liquid crystal material, etc.) and electrodes  34  and  38  form an electrically adjustable light modulator. The signal applied to layer  36  when control circuitry  14  applies a signal across electrodes  34  and  38  adjusts the optical properties of layer  36  (e.g., light transmission, color, etc.) and thereby adjusts the intensity and color of emitted light  42 . Light  42  may also be adjusted using electrically adjustable components (e.g., light-emitting diodes) associated with core  32 . 
     To allow light  42  to pass through the light modulator layer, electrodes  34  and  38  may be formed from transparent conductive material. For example, electrodes  34  and  38  may be formed from a thin layer of silver or other metal (e.g., a layer sufficiently thin to be at least partly transparent to light), a transparent conductive material such as indium tin oxide, transparent conductive polymer such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate conductive polymer (PEDOT:PSS), nanostructures (e.g., carbon nanotubes), graphene (e.g., a monolayer of graphene), mesh-shaped layers (e.g., a metal mesh such as a silver mesh or other conductive layer with openings, etc.), or other conductive materials. These conductive electrode materials may be sufficiently flexible to resist cracking when strand  30  bends and stretches. Electrode layers and other layers of material in strand  30  may be deposited using printing, dipping, electroplating, physical vapor deposition, and/or other deposition and patterning techniques. 
     Material  36  may be electrochromic material (e.g., an electrochromic ink formed from particles or electrochromic dye that exhibits a chromic effect and that changes its color and light transmission characteristics when placed in a different electronic state by oxidation or reduction reactions) or may be a guest-host liquid crystal material (e.g., a material having a mixture of liquid crystal host molecules and anisotropic guest dye molecules that changes color and light transmission based on whether the liquid crystals (and therefore the guest dye molecules) are rotated into or out of alignment with rays of light  42 . 
     One or more optional additional layers such as outer protective layer  40  may also be included in strand  30 . For example, an outer protective layer of clear polymer may be formed on strand  30  such as a layer of polypropylene, polyamide (nylon), or other polymer. 
     Strands such as strand  30  may have any suitable diameter (e.g., 10-1000 microns, at least 20 microns, at least 100 microns, less than 3000 microns, less than 2000 microns, less than 500 microns, less than 100 microns, less than 75 microns, less than 50 microns, etc.). Strands  30  may be woven or otherwise intertwined with other strands of material to form fabric for a fabric-based item such as a wearable electronic device. Light-emitting strands such as illustrative strand  30  of  FIG. 1  include light-emitting cores such as light-emitting core  32 . If desired, a non-light-emitting core (e.g., a core formed from glass, metal, and/or polymer that does not emit light  42 ) may be used in forming strand  30 . 
     An illustrative electronic device such as a wearable electronic device with fabric or other fabric-based item is shown in  FIG. 2 . Device  10  may be an electronic device or an accessory for an electronic device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, a remote control, an embedded system such as a system in which device  10  is incorporated into a kiosk, automobile, airplane, or other vehicle, other electronic equipment, or equipment that implements the functionality of two or more of these devices. If desired, device  10  may be a removable external case for electronic equipment, may be a strap, may be a wrist band or head band, may be a removable cover for a device, may be a case or bag that has straps or that has other structures to receive and carry electronic equipment and other items, may be a necklace or arm band, may be a wallet, sleeve, pocket, or other structure into which electronic equipment or other items may be inserted, may be part of a chair, sofa, or other seating (e.g., cushions or other seating structures), may be part of an item of clothing or other wearable item (e.g., a hat, belt, wrist band, headband, sock, glove, shirt, pants, etc.), or may be any other suitable fabric-based item. 
     Device  10  may include intertwined strands of material that form fabric  12 . Fabric  12  may form all or part of a housing wall or other layer in an electronic device, may form internal structures in an electronic device, or may form other fabric-based structures. Device  10  may be soft (e.g., device  10  may have a fabric surface that yields to a light touch), may have a rigid feel (e.g., the surface of device  10  may be formed from a stiff fabric), may be coarse, may be smooth, may have ribs or other patterned textures, and/or may be formed as part of a device that has portions formed from non-fabric structures of plastic, metal, glass, crystalline materials, ceramics, or other materials. 
     The strands of material in fabric  12  may be single-filament strands (sometimes referred to as fibers or monofilaments), may be yarns or other strands that have been formed by intertwining multiple filaments (multiple monofilaments) of material together, or may be other types of strands. Monofilaments for fabric  12  may include polymer monofilaments and/or other insulating monofilaments and/or may include bare wires and/or insulated wires. Monofilaments formed from polymer cores with metal coatings and monofilaments formed from three or more layers (cores, intermediate layers, and one or more outer layers each of which may be insulating and/or conductive) may also be used. 
     Yarn in fabric  12  may be formed from polymer, metal, glass, graphite, ceramic, natural materials as cotton or bamboo, or other organic and/or inorganic materials and combinations of these materials. Conductive coatings such as metal coatings may be formed on non-conductive material. For example, plastic yarns and monofilaments in fabric  12  may be coated with metal to make them conductive. Reflective coatings such as metal coatings may be applied to make yarns and monofilaments reflective. Yarns may be formed from a bundle of bare metal wires or metal wire intertwined with insulating monofilaments (as examples). 
     Strands of material such as these and light-modulating strands such as strand  30  of  FIG. 1  may be may be intertwined to form fabric  12  using intertwining equipment such as weaving equipment, knitting equipment, or braiding equipment. Intertwined strands may, for example, form woven fabric, knit fabric, braided fabric, etc. As shown in  FIG. 2 , for example, fabric  12  may be woven fabric that includes strands such as warp strands  22  and weft strands  24  and which may contain strands such as strand  30  and/or other strands of material. In the illustrative configuration of  FIG. 2 , fabric  12  has a single layer of woven strands. Multi-layer fabric constructions may be used for fabric  12  if desired. Woven fabric  12  may a plain weave, a basket weave, a satin weave, a twill weave, or variations of these weaves, may be a three-dimensional woven fabric, or may be other suitable fabric. 
     Conductive strands and insulating strands may be woven, knit, braided, or otherwise intertwined to form contact pads that can be electrically coupled to conductive structures in device  10  such as the contact pads of an electrical component (e.g., using solder or conductive adhesive). The contacts of an electrical component may also be directly coupled to an exposed metal segment along the length of a conductive yarn or monofilament. 
     In some configurations, conductive strands may also be woven, knit, or otherwise intertwined to form fabric with conductive paths. The conductive paths may be used in forming signal paths (e.g., signal buses, power lines, etc.), may be used in forming part of a capacitive touch sensor electrode, a resistive touch sensor electrode, or other input-output device, or may be used in forming other patterned conductive structures. Conductive structures in fabric  12  may be used in carrying power signals, digital signals, analog signals, sensor signals, control signals, data, input signals, output signals, or other suitable electrical signals. 
     Light-emitting strands such as strand  30  of  FIG. 1  that contain light-emitting cores such as light-emitting core  32  and/or other strands  30  can be woven, knit, or otherwise intertwined to form light-emitting areas in fabric  12 . These light-emitting areas may form decorative trim, interior lighting for a bag or other item, logos, keyboard key labels, button labels and trim, text, etc. In some configurations, patterned light-emitting areas formed from strands  30  in fabric  12  may be used in forming instructions or otherwise providing a user with guidance on the use of device  10 . In other configurations, light-emitting areas formed from strands  30  may be used to form status indicators (e.g., an indicator in which an area of fabric  12  is illuminated to indicate how much power remains in a battery, to indicate a signal strength level for a wireless transceiver, to indicate a current volume level or other media playback status information as media is being played for a user of device  10 , etc.). Light-emitting areas formed from one or more strands  30  may also be used to provide a user of device  10  with alerts (e.g., notifications) such as an alert that a message has been received, that a timer has expired, that a calendar entry is present for the current time/day, etc. In some configurations, small pixel-sized segments of strands  30  may be controlled individually. In these configuration, an area of fabric  12  in item  30  containing an array of pixels formed from strands  12  may be used in displaying images for a user. 
     Device  10  may include additional mechanical structures  14  such as polymer binder to hold strands in fabric  12  together, support structures such as frame members, housing structures (e.g., an electronic device housing), and other mechanical structures. 
     Input-output circuitry  16  may be included in device  10 . Circuitry  16  may include electrical components that are coupled to fabric  12 , electrical components that are housed within an enclosure formed by fabric  12 , electrical components that are attached to fabric  12  using welds, solder joints, adhesive bonds (e.g., conductive adhesive bonds such as anisotropic conductive adhesive bonds or other conductive adhesive bonds), crimped connections, or other electrical and/or mechanical bonds. Circuitry  16  may include metal structures for carrying current, electrical components such as integrated circuits, light-emitting diodes (see, e.g., light-emitting diodes  18 ), battery  20 , and other input-output devices (e.g., sensors, buttons, keyboards, track pads, capacitive touch sensors, and other electrical devices). Control circuitry  14  (e.g., control circuitry formed from one or more integrated circuits such as microprocessors, microcontrollers, application-specific integrated circuits, digital signal processors, etc.) may be used to control the operation of device  10  by controlling electrically controllable (electrically adjustable) components in circuitry  16  and may be used to support communications with external equipment such as electronic equipment  26 . 
     Electronic equipment  26  may be attached to device  10  or device  10  and equipment  26  may be separate items that are configured to operate with each other (e.g., when one item is a case and the other is a device that fits within the case, etc.). Circuitry  16  may include antennas and other structures for supporting wireless communications with equipment  26 . Equipment  26  may also interact with device  10  using a wired communications link or other connection that allows information to be exchanged. 
     In some situations, equipment  26  may be an electronic device such as a cellular telephone, computer, or other portable electronic device and device  10  may form a cover, case, bag, or other structure that receives the electronic device in a pocket, an interior cavity, or other portion of device  10 . In other situations, equipment  26  may be a wrist-watch device or other electronic device and device  10  may be a strap or other fabric-based item that is attached to equipment  26  (e.g., device  10  and equipment  26  may be used together to form a fabric-based item such as a wristwatch with a strap). In still other situations, device  10  may be an electronic device (e.g., a wearable device such as a wrist device, clothing, etc.), fabric  12  may be used in forming the electronic device, and additional equipment  26  may include accessories or other devices that interact with device  10 . Signal paths formed from conductive yarns and monofilaments (e.g., insulated and bare wires) may be used to route signals in device  10  and/or equipment  26 . 
     Device  10  may include non-fabric materials (e.g., structures that are formed from plastic, metal, glass, ceramic, crystalline materials such as sapphire, etc.). These materials may be formed using molding operations, extrusion, machining, laser processing, and other fabrication techniques. In some configurations, some or all of fabric-based device  10  may include one or more layers of material. The layers in device  10  may include layers of polymer, metal, glass, fabric, adhesive, crystalline materials, ceramic, substrates on which components have been mounted, patterned layers of material, layers of material containing patterned metal traces, thin-film devices such as transistors, and/or other layers. 
       FIG. 3  is a cross-sectional side view of light-emitting core  32  in an illustrative configuration in which core  32  has been formed from optical fiber  50 . Optical fiber  50  may be formed from transparent materials such as plastic or glass. Optical fiber  50  may have fiber core  54  and fiber cladding  52 , which surrounds fiber core  54 . Fiber core  54  may have a higher index of refraction than fiber cladding  52  so that light  42  that has been emitted into the end of fiber  50  from light-emitting diode  18  will be guided in fiber  54  in accordance with the principal of total internal reflection. Light-scattering features  56  (e.g., pits, bumps, embedded particles, etc.) may be formed along the length of fiber  50  to help scatter light  42  out of fiber core  54 . In this way, light  42  may be emitted radially as shown in the cross-sectional view of strand  30  of  FIG. 1 . 
     Another illustrative arrangement for forming light-emitting core  32  is shown in  FIGS. 4 and 5 . In this type of configuration, light-emitting diodes  18  are mounted along the length of an elongated substrate such as substrate  60  (e.g., a flexible printed circuit formed from a layer of flexible polymer such as a polyimide layer). Substrate  60  may be characterized by a longitudinal axis  61 . Diodes  18  may have contacts (solder pads) that are soldered or otherwise electrically and mechanically coupled to mating contacts (e.g., solder pads formed from metal traces) on substrate  60 . Light-emitting diodes  18  may be mounted on opposing upper and lower surfaces of substrate  60 . As shown in  FIG. 5 , following the attachment of light-emitting diodes  18  to substrate  60 , substrate  60  may be covered with a protective polymer coating such as coating  62  (e.g., a clear polymer that permits light  42  emitted by diodes  18  to escape). 
     In the example of  FIG. 6 , light-emitting diodes  18  have been mounted (e.g., soldered) to metal traces in polymer core (core strand)  64 . Polymer core strand  64  may serve as a substrate for light-emitting diodes  18  and may include metal traces with contact pads to receive solder and thereby couple to solder pads or other contacts (terminals) of light-emitting diodes  18 . Core strand  64  may have a cross-sectional profile that is circular, polygonal, rectangular, hexagonal, or that has any other suitable profile shape. If desired, a protective layer of material such as clear polymer 72 may be formed on top of core strand  64  and light-emitting diodes  18  (e.g., to help encapsulate light-emitting diodes  18  before forming additional structures of the type shown in  FIG. 1 . 
     If desired, light-emitting core strand  32  may be formed by wrapping a strip of flexible printed circuit substrate material into a tube, as shown in  FIG. 7 . As shown in  FIG. 7 , light-emitting diodes  18  may be mounted to one of the surfaces of substrate  68  (e.g., a flexible printed circuit). Substrate  68  may have an elongated strip shape (extending into the page of  FIG. 7 ). After light-emitting diodes  18  have been soldered or otherwise mounted to substrate  68 , substrate  68  can be wrapped into a tube shape surrounding core strand  66 . Core strand  66  may be, for example, a strand of polymer with a circular cross-sectional shape. Adhesive and/or heat and pressure may be used in coupling flexible printed circuit substrate  68  to the outer surface of core strand  66 . Core strands such as core strands  64  of  FIG. 6  and core strand  66  of  FIG. 7  may be formed from polymer such as polyamide (nylon), poly-paraphenylene terephthalamide (Kevlar®), or other polymers. After core strand  66  has been wrapped with substrate  68 , the left and right edges of substrate  68  will join at seam  70 , which extends along the length of strand  66  (e.g., parallel to longitudinal strand axis  61 ). 
     As shown in  FIG. 8 , light-emitting diodes  18  may be mounted onto first and second elongated substrates  68 - 1  and  68 - 2  (e.g., flexible printed circuits). After light-emitting diodes  18  have between soldered to the traces of substrates  68 - 1  and  68 - 2 , a heated die or other tool may be used to press substrates  68 - 1  and  68 - 2  onto the outer surface of polymer core strand  66 . Adhesive and/or heat and pressure from the die may curve substrate  68 - 2  downward onto the upper surface of core strand  66  and may curve substrate  68 - 2  upward onto the lower surface of core strand  66 , producing two longitudinal seams  70  running along the length of light-emitting core  32  parallel to longitudinal axis  61 . 
       FIG. 9  is a cross-sectional side view of a portion of light-emitting core  32  in an illustrative configuration in which light-emitting diodes  18  have been interposed between an inner electrode such as inner conductive layer  82  and an outer electrode such as outer conductive layer  80  (e.g., electrodes  80  and  82  may be coaxial). Inner conductive layer  82  may be formed on core strand  86 . Core strands such as core strand  86  may be formed from polymer such as polyamide (nylon), poly-paraphenylene terephthalamide (Kevlar®), or other polymer. Inner conductive layer  82  may be formed from a layer of silver or other metal, a conductive polymer such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate conductive polymer (PEDOT:PSS), nanostructures (e.g., carbon nanotubes), graphene (e.g., a monolayer of graphene), mesh-shaped layers (e.g., a metal mesh such as a silver mesh or other conductive layer with openings, etc.), or other conductive materials. Inner conductive layer  82  is formed in the interior of light-emitting core strand  32  and therefore need not be transparent. Outer conductive layer  80  may be transparent to allow light  42  from light-emitting diodes  18  to pass. If desired, an outer layer such as layer  88  may be formed on outer layer  80  to form a protective outer layer for device  10 . 
     In the illustrative configuration of  FIG. 9 , layers  82  and  84  may be formed from blanket films (e.g., layers  82  and  84  need not be patterned to form individual conductive lines and contact pads). Light-emitting diodes  18  may be deposited onto the exterior surface of inner electrode  82  in the form of a slurry (e.g., layer  84 , which may be a mixture of light-emitting diode dies and a liquid carrier). Light-emitting diodes  18  may be GaN diodes or other suitable semiconductor light-emitting diodes. Light-emitting diodes  18  may be formed from semiconductor dies having dimensions of 10-60 microns, at least 10 microns, less than 100 microns, less than 40 microns, less than 30 microns, or other suitable size. Each die may have a positive contact and a negative contact. When depositing the dies of diodes  18  in a slurry, some of the dies will have their positive and negative contacts oriented for forward biasing as a voltage is applied across layers (electrodes)  82  and  84  and some of the dies will be oriented for reverse biasing (and will therefore not emit light when voltage is applied). There may be a sufficient number of diodes  18  in layer  84  that the presence of some non-active (reverse-biased) light-emitting diodes  18  among the active (forward-biased) light-emitting diodes  18  will not significantly degrade the light output from core  32 . 
     Layer  84  may be formed on the exterior of layer  82  using a technique such as printing, dipping, spraying, etc. Heat may be applied to layer  84  to remove excess liquid. Outer layer  84  may be formed by depositing a conductive coating onto layer  84 . Optional protective outer layer  88  (e.g., a clear polymer layer) may be used to protect the exterior of light-emitting core strand  32 . Layer  88  may be transparent to allow light  42  to pass to through layer  88  from light-emitting diodes  18 . 
     If desired, light-emitting diode structures for layer  84  may be formed using other arrangements (e.g., by depositing organic light-emitting diodes in the form of coatings between electrodes  82  and  80 , by using ZnO structures or other semiconductor structures to form light-emitting diodes in layer  84 , and/or using other light-emitting diode structures to form light-emitting diodes to emit light  42  from strand  32 ). 
     After forming a light-emitting core for strand  30  such as light-emitting cores  32  of  FIGS. 3, 4, 5, 6, 7, 8, and 9 , strand  30  can be electrically controlled to produce light  42  of desired intensity and/or color. Control circuitry  14  may, for example, control the intensity of light  42  that is produced by light-emitting diodes  18  by adjusting the amount of current flowing through diodes  18 . Control signals for diodes  18  may be supplied to light-emitting diodes  18  from control circuitry  14  using signal lines (e.g., metal traces) in flexible printed circuits or other substrates to which diodes  18  are coupled and/or using electrodes such as electrodes formed from layers  82  and  80  of  FIG. 9 . The color and intensity of light  42  that is emitted from strand  30  can also be adjusted by controlling the light modulation effects produced by the light-modulation layer of strand  30  (e.g., by using control circuitry  14  to apply control signals to inner light modulator layer electrode  34  and outer light modulator electrode  38  of  FIG. 1 ). 
       FIG. 10  is a perspective view showing how strands in fabric  12  may cross each other (e.g., warp and weft strands may be oriented perpendicularly to each other). In this type of arrangement, signals that are distributed using one strand can be used in controlling the operation of a localized portion of a crossing strand. Consider, as an example, a scenario in which strand  90  is a light-emitting strand such as strand  30  of  FIG. 1 . In this scenario, the signal applied to outer electrode  38  may be provided to outer electrode  38  from an outer conductive layer of a crossing strand such as strand  92 . Strand  92  may, for example, cross strand  90  at a right angle as shown in  FIG. 10  and may form an electrical contact such as electrical contact  96  where the outer conductive layer of strand  92  crosses and contacts the outer conductive electrode of strand  90  (e.g., electrode  38  of  FIG. 1  in a scenario in which some or all of outer protective layer  40  has been removed or omitted). 
     Inner electrode  34  may be held at a fixed potential (e.g., ground). When a signal is applied to the outer conductive layer in strand  92  (e.g., a positive signal), this signal will be applied to a localized portion of outer electrode  38  in strand  90  in the vicinity of contact  96  such as region  94 . In region  94 , there will be a sufficient signal across electrodes  38  and  34  of strand  90  to modify the light transmission properties and/or color of layer  36  between electrodes  38  and  34 . In this way, a pixel-sized region of strand  90  (e.g., region  94 ) may be selectively adjusted to exhibit different amounts of light transmission and/or different colors. If desired, the properties of strands  30  may be varied along their lengths (e.g., to create segments of strands  30  that emit different colors of light when the light is unmodulated). In this type of scenario, regions such as regions  94  may be aligned with the segments of different colors (e.g., red, green, and blue), allowing control circuitry  12  to regulate the output of red, green, and blue light (as an example). 
     If desired, light  42  emitted from core  32  can be adjusted in segments. For example, core  32  may have patterned signal lines (e.g., metal traces  102 ) and associated contacts such as solder pads  104  on a polymer core such as core  100  to which light-emitting diodes  18  are soldered in locations  18 ′. During operation, control circuitry  12  can provide individually adjusted control signals to different light-emitting diodes  18  by using appropriate signal lines  102 . 
     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: 20170824
Publication Date: 20190430
Grant Date: 20190430
Priority Date: 20170824
Inventors: BHARADWAJ, SHRAVAN
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/13725", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/157", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/1503", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/134309", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2401/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/001", "inventive": false, "first": false, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/001", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D27/085", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D27/085", "inventive": false, "first": false, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/15165", "inventive": false, "first": false, "tree": "[]"}, {"code": "D02G3/441", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2401/20", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/001", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/15165", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D27/085", "inventive": false, "first": false, "tree": "[]"}, {"code": "D02G3/441", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2401/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "D02G3/441", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2401/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "D10B2401/20", "inventive": false, "first": false, "tree": "[]"}, {"code": "D10B2401/16", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 66248214