PATENT DOCUMENT

Publication Number: US-10174444-B1
Application Number: US-201514938661-A
Country: US
Kind Code: B1

Title: Weaving equipment with strand modifying unit

Abstract:
Weaving equipment may include warp strand positioning equipment that positions warp strands and weft strand positioning equipment that inserts weft strands among the warp strands to form fabric. One or more of the warp strands may be selectively modified along its length using a warp strand modification unit. The warp strand modification unit may be interposed between the fabric and a reed, may be interposed between the fabric and the warp strand positioning equipment, may be mounted to the reed, or may be incorporated elsewhere in the weaving equipment. Warp strand modifications may include adding segments of metallic paint coatings or other conductive coatings, adding insulating coatings, applying other liquids to segments of the warp strand, modifying the stretchiness of warp strands, removing material from segments of the warp strand, and attaching electrical components to the warp strand.

Claims:
What is claimed is: 
     
       1. Apparatus for weaving warp strands and weft strands, comprising:
 warp strand positioning equipment that positions the warp strands to create a shed; 
 weft strand positioning equipment that inserts the weft strands into the shed so that the warp and weft strands are woven to form fabric; and 
 a computer-controlled warp strand modification unit that selectively modifies at least a given one of the warp strands before the given warp strand is woven with the weft strands to form the fabric, wherein the given warp strand has an insulating segment, wherein the computer-controlled warp strand modification unit selectively modifies the given warp strand by applying a conductive coating to a portion of the warp strand to form a conductive segment adjacent to the insulating segment, and wherein the conductive segment is positioned to overlap a conductive weft strand among the weft strands. 
 
     
     
       2. The apparatus defined in  claim 1  wherein the computer-controlled warp strand modification unit is interposed between the warp strand positioning equipment and the fabric. 
     
     
       3. The apparatus defined in  claim 1  further comprising a reed that pushes the weft strand in the shed against the fabric. 
     
     
       4. The apparatus defined in  claim 3  wherein the computer-controlled warp strand modification unit is interposed between the reed and the fabric. 
     
     
       5. The apparatus defined in  claim 3  wherein the computer-controlled warp strand modification unit is attached to the reed. 
     
     
       6. The apparatus defined in  claim 3  wherein the computer-controlled warp strand modification unit is interposed between the reed and the warp strand positioning equipment. 
     
     
       7. The apparatus defined in  claim 1  wherein the warp strand positioning equipment comprises computer-controlled warp strand positioning equipment that independently controls where each warp strand is positioned. 
     
     
       8. The apparatus defined in  claim 1  wherein the warp strand positioning equipment comprises peddles and wherein each peddle has an eye through which a respective one of the warp strands passes. 
     
     
       9. The apparatus defined in  claim 8  wherein the computer-controlled warp strand modification unit is interposed between a given one of the eyes and the fabric and selectively processes warp strand passing through the given one of the eyes. 
     
     
       10. The apparatus defined in  claim 1  wherein the computer-controlled warp strand modification unit comprises a coating application tool that selectively applies a coating to the given warp strand. 
     
     
       11. The apparatus defined in  claim 10  wherein the coating comprises a coating selected from the group consisting of: a metallic paint, a colorant, an insulating coating, a coating that dissolves insulation, and an adhesive. 
     
     
       12. The apparatus defined in  claim 10  wherein the coating application tool comprises at least one pad that contains liquid coating material. 
     
     
       13. The apparatus defined in  claim 10  wherein the coating application tool comprises multiple independently controlled pads that apply different respective liquid coating materials to the given warp strand. 
     
     
       14. The apparatus defined in  claim 10  wherein the computer-controlled warp strand modification unit comprises a strand rotator that rotates the given warp strand so that the coating is applied to opposing surfaces of the warp strand. 
     
     
       15. The apparatus defined in  claim 1  wherein the computer-controlled warp strand modification unit comprises a tool for selectively removing a portion of the given warp strand. 
     
     
       16. Apparatus for weaving warp strands and weft strands, comprising:
 warp strand positioning equipment that positions the warp strands to create a shed; 
 weft strand positioning equipment that inserts the weft strands into the shed so that the warp and weft strands are woven to form fabric; and 
 a computer-controlled warp strand modification unit that selectively modifies at least a given one of the warp strands before the given warp strand is woven with the weft strands to form the fabric, wherein the computer-controlled warp strand modification unit comprises a tool that attaches an electrical component to the given warp strand, and wherein the electrical component is selected from the group consisting of: an integrated circuit, a sensor, and a light-emitting diode. 
 
     
     
       17. The apparatus defined in  claim 16  wherein the electrical component has terminals and wherein the tool that attaches the electrical component comprises a crimping tool that crimps the terminals to attach the electrical component to conductive portions of the given warp strand. 
     
     
       18. A method of weaving fabric from warp and weft strands, comprising:
 with warp strand positioning equipment, positioning the warp strands to create a shed; 
 with weft strand positioning equipment, inserting the weft strands into the shed so that the warp and weft strands are woven together to form fabric; and 
 with a computer-controlled warp strand modification unit that is interposed between the warp strand positioning equipment and the fabric, selectively modifying at least a given one of the warp strands before the given warp strand is woven with the weft strands to form the fabric, wherein the given warp strand has an insulating segment, wherein selectively modifying the given warp strand comprises applying a conductive coating to a portion of the warp strand to form a conductive segment adjacent to the insulating segment, and wherein the conductive segment is positioned to overlap a conductive weft strand among the weft strands. 
 
     
     
       19. The method defined in  claim 18  wherein selectively modifying the given warp strand comprises applying a coating to a segment of the given warp strand. 
     
     
       20. The method defined in  claim 18  wherein selectively modifying the given warp strand comprises removing a portion of a segment of the given warp strand. 
     
     
       21. The method defined in  claim 18  wherein selectively modifying the given warp strand comprises altering stretchiness for a segment of the given warp strand. 
     
     
       22. The method defined in  claim 18  wherein selectively modifying the given one of the warp strands comprises applying an insulating layer to the given warp strand so that the insulating layer is interposed between the given warp strand and an overlapping one of the weft strands in the fabric.

Description:
This application claims the benefit of provisional patent application No. 62/083,078 filed on Nov. 21, 2014, which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to weaving and, more particularly, to equipment for processing strands during weaving. 
     It may be desirable to form fabric from strands of material that are treated differently at different locations along their lengths. Strands may, for example, be dyed with different colors at different locations. Strands of this type may be woven together to produce fabric with colored patterns. 
     In warp ikat fabrics, warp threads are printed with specific patterns. It can be challenging to use traditional weaving equipment to form fabrics such as warp ikat fabrics in which the printed patterns are aligned as desired with the underlying structures of a fabric (i.e., the connecting warp and weft threads that determine the fabric&#39;s construction and properties). In most looms, there is a relatively long distance between the warp beam and the fabric being woven. As a result, it can be difficult to accurately position warp strands with respect to each other and with respect to the weft strands that are being used to form the fabric. Adjacent warp strands can become misaligned with respect to each other and may not align properly with the weft strands. This can make it impossible to form precise patterns in the fabric. More accurate weaving would allow improved fabric-based items to be formed. 
     It would therefore be desirable to be able to process strands at various locations along their lengths in a way that facilitates accurate weaving with the processed strands. 
     SUMMARY 
     Fabric may be formed by weaving warp strands and weft strands together using weaving equipment. The weaving equipment may include warp strand positioning equipment that positions the warp strands to produce a shed and weft strand positioning equipment that inserts weft strands into the warp strands to form the fabric. Strands may be selectively modified prior to weaving. For example, one or more of the warp strands may be selectively modified along its length using a warp strand modification unit. 
     A warp strand modification unit may be located adjacent to the edge of the fabric that is being woven. This allows warp strand segments that have been modified to be accurately aligned with desired weft strands. For example, a segment of a warp strand may be positioned to overlap a particular weft strand. 
     The warp strand modification unit may be interposed between the fabric and a reed, may be interposed between the fabric and the warp strand positioning equipment, may be mounted to the reed, or may be incorporated elsewhere in the weaving equipment. 
     The warp strand modification unit may add segments of metallic paint coatings or other conductive coatings, may add insulating coatings, may apply liquids to segments of the warp strands such as liquids that modify the stretchiness of warp strands and that remove material from segments of the warp strands, may attach electrical components to the warp strands, and may otherwise selectively modify the warp strands. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative strand-based item in accordance with an embodiment. 
         FIG. 2  is a side view of illustrative weaving equipment that may be used to form fabric in accordance with an embodiment. 
         FIG. 3  is a diagram showing how strands may be processed as the strands are being incorporated into a fabric in accordance with an embodiment. 
         FIG. 4  is a cross-sectional diagram of illustrative equipment for selectively applying adhesive or other materials to a strand as the strand is being woven with other strands to form a fabric in accordance with an embodiment. 
         FIG. 5  is a perspective view of an illustrative tool for selectively applying various materials to a strand as the strand is being woven with other strands to form a fabric in accordance with an embodiment. 
         FIG. 6  is a perspective view of illustrative strand rotating equipment for rotating a strand to allow portions of the outer surface of the strand to be exposed to coating equipment or other equipment for processing the strand as the strand is being woven with other strands in accordance with an embodiment. 
         FIG. 7  is a cross-sectional axial view of an illustrative strand that has been treated along an upper portion of the strand in accordance with an embodiment. 
         FIG. 8  is a cross-sectional axial view of an illustrative strand that has been treated along opposing upper and lower portions of the strand in accordance with an embodiment. 
         FIG. 9  is a cross-sectional axial view of an illustrative strand that has been treated around its circumference by rotating the strand in accordance with an embodiment. 
         FIG. 10  is a perspective view of an illustrative electrical component that has been attached to a strand before the strand is woven with other strands to form a fabric in accordance with an embodiment. 
         FIG. 11  is a top view of an illustrative woven fabric in which a strand with an electrical component of the type shown in  FIG. 10  has been incorporated in accordance with an embodiment. 
         FIG. 12  is a top view of an illustrative woven fabric showing how selectively modified strands may be woven into a fabric to create a desired pattern of modified strand segments in accordance with an embodiment. 
         FIG. 13  is a top view of an illustrative woven fabric showing how selectively modified strands may be woven into a fabric to create a desired signal path in accordance with an embodiment. 
         FIG. 14  is a top view of an illustrative woven fabric showing how a portion of a conductive strand with a selectively applied insulating coating may be aligned with an intersecting conductive strand in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of an illustrative portion of the fabric of  FIG. 14  in which a selectively applied insulating coating has been interposed between overlapping conductive strands in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Selectively modified strands may be incorporated into strand-based items such as strand-based item of  FIG. 1 . Item  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, an embedded system such as a system in which fabric-based item  10  is mounted in a kiosk, in an automobile, airplane, or other vehicle, other electronic equipment, or equipment that implements the functionality of two or more of these devices. If desired, item  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, etc.), or may be any other suitable fabric-based item. 
     Strands in strand-based item  10  may form all or part of a housing wall for an electronic device, may form internal structures in an electronic device, or may form other strand-based structures. Strand-based item  10  may be soft (e.g., item  10  may have a fabric surface that yields to a light touch), may have a rigid feel (e.g., the surface of item  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. 
     Item  10  may include intertwined strands  12 . The strands may be intertwined using strand intertwining equipment such as weaving equipment, knitting equipment, or braiding equipment. Intertwined strands  12  may, for example, form woven fabric. 
     Strands  12  may be single-filament strands or may be threads, yarns, or other strands that have been formed by intertwining multiple filaments of material together. Strands may be formed from polymer, metal, glass, graphite, ceramic, natural fibers such 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 strands (e.g., plastic cores) to make them conductive. Reflective coatings such as metal coatings may be applied to strands to make them reflective. Strands may also be formed from single-filament metal wire, multifilament wire, or combinations of different materials. Strands may be insulating or conductive. Strands may be conductive along their entire length or may have conductive segments (e.g., metal portions that are exposed by locally removing insulation or that are formed by adding a conductive layer to a portion of a non-conductive strand.). Threads and other multifilament yarns that have been formed from intertwined filaments may contain mixtures of conductive fibers and insulating fibers (e.g., metal strands or metal coated strands with or without exterior insulating layers may be used in combination with solid plastic fibers or natural fibers that are insulating). 
     Item  10  may include additional mechanical structures  14  such as polymer binder to hold strands  12  together, support structures such as frame members, housing structures (e.g., an electronic device housing), and other mechanical structures. 
     Circuitry  16  may be included in item  10 . Circuitry  16  may include components that are coupled to strands  12 , components that are housed within an enclosure formed by strands  12 , components that are attached to strands  12  using welds, solder joints, adhesive bonds (e.g., conductive adhesive bonds), crimped connections, or other electrical and/or mechanical bonds. Circuitry  16  may include metal structures for carrying current, integrated circuits, discrete electrical components such as resistors, capacitors, and inductors, switches, connectors, light-emitting components such as light-emitting diodes, audio components such as microphones and speakers, vibrators, solenoids, piezoelectric devices, and other electromechanical devices, connectors, microelectromechanical systems (MEMs) devices, pressure sensors, light detectors, proximity sensors, force sensors, moisture sensors, temperature sensors, accelerometers, gyroscopes, compasses, magnetic sensors, touch sensors, and other sensors, components that form displays, touch sensors arrays (e.g., arrays of capacitive touch sensor electrodes to form a touch sensor that detects touch events in two dimensions), and other input-output devices. Circuitry  16  may also include control circuitry such as non-volatile and volatile memory, microprocessors, application-specific integrated circuits, system-on-chip devices, baseband processors, wired and wireless communications circuitry, and other integrated circuits. 
     Item  10  may interact with electronic equipment or other additional items  18 . Items  18  may be attached to item  10  or item  10  and item  18  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.). 
     As shown in  FIG. 1 , circuitry  16  may include antennas and other structures for supporting wireless communications with item  18 . Item  18  may also interact with strand-based item  10  using a wired communications link or other connection that allows information to be exchanged. 
     In some situations, item  18  may be an electronic device such as a cellular telephone, computer, or other portable electronic device and strand-based item  10  may form a case or other structure that receives the electronic device in a pocket, an interior cavity, or other portion of item  10 . In other situations, item  18  may be a wrist-watch device or other electronic device and item  10  may be a strap of other strand-based item that is attached to item  18 . In still other situations, item  10  may be an electronic device, strands  12  may be used in forming the electronic device, and additional items  18  may include accessories or other devices that interact with item  10 . 
     If desired, magnets and other structures in items  10  and/or  18  may allow items  10  and  18  to interact wirelessly. One item may, for example, include a magnet that produces a magnetic field and the other item may include a magnetic switch or magnetic sensor that responds in the presence of the magnetic field. Items  10  and  18  may also interact with themselves or each other using pressure-sensitive switches, pressure sensors, force sensors, proximity sensors, light-based sensors, interlocking electrical connectors, etc. 
     The strands that make up item  10  may be intertwined using any suitable strand intertwining equipment. With one suitable arrangement, which may sometimes be described herein as an example, strands  12  may be woven together to form a fabric. The fabric may have a plain 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. 
     Illustrative weaving equipment for forming woven fabric for items such as item  10  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , weaving equipment  22  may be provided with strands such as strands  12  of  FIG. 1  from strand source  24 . The strands provided by strand source  24  may be single filaments of material or may be threads, yarns, or other multifilament strands that have been formed by intertwining multiple single-filament strands. Strands may be formed from insulating materials, conductive materials, and combinations of insulating and conductive materials. 
     Source  24  may supply warp strands  28  from warp beam  80 . Warp beam  80  may be implemented using a drum or other structure that rotates about rotational axis  78  in direction  76 . Warp strands  24  may be dispensed between rollers  26  as the drum rotates. 
     Warp strands  28  may be positioned using warp strand positioning equipment  74 . Equipment  74  may include strand positioning structures such as harness  80 . Harness  80  may be controlled using control circuitry  70  to control the positions of strands  28 . 
     As shown in  FIG. 2 , harness  80  may include heddles  36 . Heddles  36  may each include an eye  30  mounted on a wire that extends between a respective one of springs  38  and a respective one of wire positioners  42  or may use other structures for positioning warp strands  28 . Wire positioners  42  may be motors (e.g., stepper motors) or other electromechanical actuators. Some or all of heddles  36  may be independently positioned. During operation, control circuitry  70  may supply control signals on outputs  72  that move each heddle by a desired amount (e.g., up or down in directions  32 ). By raising and lowering the heddles in various patterns in response to control signals from control circuitry  70 , different patterns of gaps (sheds)  66  between warp strands  28  may be created. 
     Weft strand  58  may be inserted into sheds  66  during weaving to form fabric  60 . Weft strand positioning equipment  62  may be used to place weft strand  58  between the warp strands forming each shed  66 . Weft strand positioning equipment  62  may include one or more shuttles or may include shuttleless weft strand positioning equipment (e.g., needle weft strand positioning equipment, rapier weft strand positioning equipment, or other weft strand positioning equipment such as equipment based on projectiles, air or water jets, etc.). 
     After each pass of weft strand  64  is made through shed(s)  66 , reed  48  may be moved in direction  50  (e.g., reed  48  may be rotated about axis  46 ) to push the weft strand that has just been inserted into the shed between respective warp strands  28  against previously woven fabric  60 , thereby ensuring that a satisfactorily tight weave is produced. Fabric  60  that has been woven in this way may be gathered on take-down roller  82  as roller  82  rotates in direction  86  about rotational axis  84 . Reed  48  and weft strand positioning equipment  62  may be controlled by control signals from control outputs  72 . 
     Strand modification equipment such as strand modification unit  52  may be used in processing one or more warp strands  28 . As shown in  FIG. 2 , strand modification unit  52  may have positioning equipment such as computer-controlled positioner  54  and strand processing head  56  (or, if desired, multiple positioners  54  coupled to multiple respective heads  56 ). 
     Each positioner  54  and processing head  56  may be controlled by control circuitry  70  using control signals on control outputs  72 . The position of head  56  may, for example, be adjusted by positioner  54  to place head  56  in and out of use. As one example, head  56  may contain a liquid-soaked pad. The liquid may be a colored ink or other colorant or may be other liquid. When it is desired to apply the liquid to warp strand  28 , positioner  54  may move head  56  into contact with warp strand  28 . When it is desired to terminate the liquid application process, positioner  54  may pull head  56  away from warp strand  28 . The positions of strands  28  relative to heads such as head  56  may also be controlled using warp strand positioning equipment  74  (whether or not equipment  74  is being used to position strands  28  to form sheds  66  to accommodate weft strand  64 ). 
     The application of liquids such as inks to strand  28  is merely an illustrative example of a potential strand modification that may be made using unit  52 . Other liquids may also be applied (e.g., metallic paint, material for removing selected portions of strand  28 , insulating material such as adhesive, etc.). In general, unit  52  may be used to apply material, remove material, change strand  28  or portions of strand  28  by application of energy, may mechanically alter strand  28 , or may otherwise process strand  28 . 
     Strand modification unit  52  may, for example, be used to apply material to strand  28 . The applied material may be used to selectively adjust the properties of strands  28 . For example, material may be applied to strand  28  that changes the stiffness of strand  28 . If strand  28  is relatively flexible and stretchable, the applied material may locally increase the stiffness of strand  28  and thereby reduce flexibility and stretchability. If strand  28  is relatively stiff, the applied material may locally increase the flexibility and/or stretchability of strand  28 . 
     Unit  52  may also be used to apply conductive material (e.g., conductive adhesive, metallic paint, etc.) to strand  28 . The conductive material may selectively increase the conductivity of strand  28 . If, as an example, strand  28  is formed from a polymer strand or other dielectric strand, use of unit  52  to apply a conductive adhesive or metallic paint to strand  28  to one or more segments of strand  28  can render the one or more segments of strand  28  conductive. 
     If desired, unit  52  may also be used to apply a solvent such as an etchant or other substance that removes material from strand  56  (e.g., to strip polymer insulation from the outer surface of a metal wire, etc.). With this type of arrangement, strand  28  may have an insulating coating except where strand  28  has been stripped of insulation with the solvent to allow electrical components to be attached to strand  28 . 
     Other techniques may also be used to selectively remove material from strand  28  or to selectively texture or otherwise treat exterior of portions of strand  28 . These techniques may involve applying energy (light, heat, electricity, plasma, etc.) to strand  28 . The application of energy to strand  28  may locally remove a conductive or insulating exterior coating. For example, a conductive coating on a dielectric strand may be locally removed to form an insulating segment between two conductive segments or an insulating coating on a metal strand may be locally removed to form a strand segment with a conductive surface between two insulated strand portions. 
     Cutting blades and other mechanical equipment may be used to process strand  28  (e.g., to remove insulation, to remove a conductive coating, to roughen the exterior of strand  28 , etc.). The coatings that are applied to strand  28  by unit  52  may include colored materials (e.g., colored inks), may include dyes, pigments, adhesives, polymers, conductive materials, etchants and other solvents for selectively removing dielectric and/or metallic materials from strand  28 , etc. 
     As part of the processing of strand  28  by unit  52 , electrical components may be crimped into place on strand  28  or may be electrically and mechanically mounted on strand  28  using other techniques (e.g., soldering, etc.). 
     Unit  52  may be located adjacent to edge  88  of fabric  60 , so that the accuracy with which the processed portion of strand  28  is placed within fabric  60  is enhanced. With this type of arrangement, modifications to warp strand  28  take place just as strand  28  is being incorporated into fabric  60 , so that there is a reduced possibility that the selectively modified portions of each strand  28  will shift out of desired alignment with respect to weft strands  64 . Accurate placement of the processed warp strand portions relative to weft strands  64  may allow electrical connections to be made for signal paths, may ensure that locally insulated strand segments are properly aligned with other strands, etc. 
     If desired, unit  52  may be mounted on reed  48  in a location such as illustrative mounting location  49 , may be placed between reed  48  and warp strand positioning equipment  74  (e.g., in a location such as illustrative mounting location  51 ), or may be mounted elsewhere in equipment  22 . The configuration of  FIG. 2  in which strand modification unit  52  is located between reed  48  and fabric  60  is merely illustrative. 
       FIG. 3  is a diagram showing different types of equipment that may be included in unit  52  for processing strand  28 . As shown in  FIG. 3 , unit  52  may include coating application tool  92 . Coating application tool  92  may be used to apply one or more coatings  90 . Coatings  90  may include conductive coatings, dielectric coatings, and other layers of material. Coating application tool  92  may include one or more pads impregnated with liquid coating materials, may include inkjet coating application equipment, may include equipment for applying liquid coatings using spraying or dipping, or may include other tools for applying coatings  90  to strand  28 . 
     Solvent application tool  96  may be used to apply solvent  94 . Solvent  94  may include chemicals that remove dielectric and/or conductive materials from strand  28  (e.g., metal etchant for removing metal, a polymer solvent for dissolving and removing polymer, an etchant for removing inorganic dielectric, etc.). Solvent application tool  96  may include equipment for ink-jet coating, spray coating, pad-based coating, dipping, or other or other tools for supplying liquid solvent  94  to strand  28 . 
     Unit  52  may include one or more mechanical treatment tools such as tool  98 . The mechanical treatment tools may be used to remove coatings, to change the texture of strand  28 , or to otherwise process strand  28 . Tool  98  may include equipment for cutting strand  28 , for scoring strand  28 , for roughening the surface of strand  28 , for bending strand  28 , or for otherwise mechanically processing strand  28 . 
     If desired, other equipment  100  may be used in processing strand  28 . Equipment  100  may include a heat source (e.g., a flame, a heated metal structure or other heated structure, a lamp that produces heat, etc.). Equipment  100  may also include a laser, light-emitting diode, or other light source (e.g., an infrared laser or infrared light-emitting diode, a visible laser or visible light-emitting diode, and/or an ultraviolet laser or light-emitting diode). By applying heat or light or other energy to strand  28 , coatings can be selectively removed, liquid polymers and other coating materials may be cured, the texture of strand  28  may be altered, or other strand modifications can be made. 
     Equipment  100  may be used in attaching electrical components such as electrical components in circuitry  16  of  FIG. 1  to strand  28 . For example, equipment  100  of unit  52  may be used to attach electrical components to strand  28  using solder joints, crimped metal connections, welds, conductive adhesive, or other conductive attachment structures. The electrical components that are attached to strand  28  in this way may include light-emitting components, integrated circuits, light-emitting diodes, light-emitting diodes that are packaged with transistor-based circuitry such as communications circuitry and/or light-emitting diode driver circuitry that allows each component to operate as a pixel in a display, discrete components such as resistors, capacitors, and inductors, audio components such as microphones and/or speakers, sensors such as touch sensors (with or without co-located touch sensor processing circuitry), accelerometers, temperature sensors, force sensors, microelectromechanical systems (MEMS) devices, transducers, solenoids, electromagnets, pressure sensors, light-sensors, proximity sensors, buttons, switches, two-terminal devices, three-terminal devices, devices with four or more contacts, etc. Electrical connections for attaching electrical components to strand  28  using equipment  100  may be formed using solder, conductive adhesive, welds, molded package parts, mechanical fasteners, wrapped strand connections, press-fit connections, crimped connections (e.g., bend metal prong connections), and other mechanical connections, portions of liquid coatings (e.g., metallic paint, conductive adhesive, etc.) that are selectively applied to strand  28  using unit  52 , or using any other suitable arrangement for forming an electrical short between conductive structures. 
       FIG. 4  is an end view of a unit  52  in an illustrative embodiment where unit  52  is dispensing patches of adhesive to strand  28 . Adhesive  106  may be conductive adhesive to help form conductive joints between overlapping warp and weft strands or may be insulating adhesive to help electrically isolate overlapping warp and weft strands. 
     As shown in  FIG. 4 , unit  52  may include rollers  102 . Rollers  102  may be controlled by motors that receive control signals from control circuitry  70 . Rotation of rollers  102  may be used to move belt  108  and thereby control the lateral position of adhesive pads  106  relative to strand  28 . Using pad  104  (e.g., a pad of a foam material or other compressible material), unit  52  can press adhesive  106  onto strand  28 , as shown in  FIG. 4 . Pad  104  can be pressed downward towards strand  28  using positioner  54  and/or positioning equipment  74  may control heddles  80  so that strand  28  is drawn upwards against pad  104  and belt  108 . 
     Illustrative coating equipment for use in unit  52  of system  22  is shown in  FIG. 5 . In the example of  FIG. 5 , unit  52  has three coating application heads  56 A,  56 B, and  56 C having respective computer-controlled support structures  110 A,  110 B, and  110 C that adjust the positions of corresponding liquid-filled foam pads  112 A,  112 B, and  112 C. The positions of each head can be adjusted by a respective positioner such as positioner  54  of  FIG. 2 . Pads  112 A,  112 B, and  112 C may be filled with liquids of different properties (e.g., different colors of ink, different adhesives, different metallic paints, solvents, combinations of these liquids and/or other liquids, etc.). When it is desired to coat strand  28  with the liquid in pad  112 A, support structure  110 A may be moved towards strand  28 . When it is desired to coat strand  28  with the liquid in pad  112 B, support structure  110 B may be moved towards strand  28 . Support structure  110 C may be moved towards strand  28  when it is desired to coat strand  28  with the liquid in pad  112 C. 
     When using coating equipment of the type shown in  FIG. 5 , only one side of strand  28  may be coated absent rotation of strand  28  about its longitudinal axis.  FIG. 6  is a perspective view of a belt-based strand rotation device that may be used in unit  52  to help coat additional portions of strand  28 . As shown in  FIG. 6 , strand rotator  114  may have computer-controlled rollers  116  that are controlled by control signals from control circuitry  70 . Rollers  116  may be rotated to move belt  118  in direction  124  or in direction  126 . Strand  28  may extend along strand axis  122 . Belt  118  may contact the outer surface of strand  28 , so that movement of belt  118  in direction  126  or  124  rotates strand  28  respectively in direction  120  or  130  about axis  122 . 
     By rotating strand  28  with rotator  114 , head  56  or other coating equipment in system  22  can coat all surfaces (top and bottom) of strand  28 .  FIG. 7  is a cross-sectional view of strand  28  in a scenario in which the upper surface of strand  28  has been coated with coating  132  (e.g., dielectric, metallic paint, etc.). In the illustrative scenario of  FIG. 8 , the upper surface of strand  28  has been coated with coating  132  and, following rotation about axis  122  by strand rotation equipment  114  of  FIG. 6  or other equipment, the lower surface of strand  28  has been coated with coating  134 .  FIG. 9  is a cross-sectional view of strand  28  in a scenario in which both the upper and lower surfaces of strand  28  have been coated with coating  132  by rotating strand  28  about axis  122  during the coating process (e.g., using rotator  144  of  FIG. 6 ). 
       FIG. 10  is a perspective view of an illustrative electrical component mounted to strand  28 . As shown in  FIG. 10 , strand  28  may have a dielectric core  28 D and electrically isolated segments with respective conductive coatings  132 - 1  and  132 - 2 . Electrical component  140  (e.g., an integrated circuit, a light-emitting diode or other light source, a sensor, etc.) may have terminals  142 - 1  and  142 - 2 . Terminals  142 - 1  and  142 - 2  may be formed from metal and may be crimped using unit  52 . As shown in  FIG. 10 , for example, terminal  142 - 1  may be crimped to form a connection to metal coating segment  132 - 1  and terminal  142 - 2  may be crimped to form a connection to metal coating segment  132 - 2 . 
     In the illustrative configuration of  FIG. 10 , component  140  has two terminals. In general, component  140  may have any suitable number of terminals (three, four, etc.). Crimped connections, solder connections, conductive adhesive connections, welds, or other electrical connections may be used by unit  52  to couple the terminals of component  140  to the metal coating portions of strand  28 . If desired, strand  28  may have a metal core and an insulating coating. The configuration of  FIG. 10  in which metal segments have been formed on the exterior surface of a dielectric strand core is merely illustrative. 
       FIG. 11  is a top view of fabric  60  showing how warp strands  28  may be woven with weft strands  64 . Just prior to being woven into fabric  60 , unit  52  may modify strand  28  to add conductive segments  132 - 1  and  132 - 2  and to add electrical component  140 . Weaving can then continue using system  22  until fabric  60  of  FIG. 11  is formed. In the example of  FIG. 11 , some of weft strands  64  (i.e., strands  64 D) are formed from dielectric or have a dielectric coating and therefore have insulating surfaces, whereas other weft strands  64  (i.e., strands  64 C- 1  and  64 C- 2 ) are formed from metal or dielectric with metal coating and are therefore have conductive surfaces. By modifying warp strands such as warp strand  28  of  FIG. 11  just before the warp strand is woven with weft strands  64  to form fabric  60 , it is possible to accurately align and mate warp strand features such as conductive segments (terminals)  132 - 1  and  132 - 2  with respective overlapping weft strand features such as conductive weft strands  64 C- 1  and  64 C- 2 . This allows conductive weft strand  64 C- 1  to serve as a signal line to carry signals to conductive segment  132 - 1  on strand  28 , which is coupled to terminal  142 - 1  of component  140 . Conductive weft strand  64 C- 2  can serve as a signal line that carries signals to conductive segment  132 - 2  on strand  28 , which is coupled to terminal  142 - 2  of component  140 . Strands such as strands  64 C- 1  and  64 C- 2  may be interconnected with other conductive strands that form signal paths that couple component  140  into circuitry  16  for a fabric-based item such as strand-based item  10 . 
     In the illustrative example of  FIG. 12 , strand segments  132  (e.g., conductive coating, insulating coating, portions of an insulated wire that have been stripped of insulation, etc.) may be formed on warp strands  28  with unit  52  just before warp strands  28  are incorporated into fabric  60  with weft strands  64 . Because segments  132  (e.g., conductive coating, etc.) are patterned onto warp strands  28  just before fabric  60  is formed, segments  132  may be accurately aligned along dimension Y, so that each segment overlaps a desired one of weft strands  64  running along perpendicular dimension X. 
     Weft strands  64  of  FIG. 12  may include one or more bare metal wires or metal-coated wires that are shorted to conductive metal segments  132  wherever the conductive metal segments overlap strands  64 . The conductive segments  132  and weft strands  64  may be patterned to form a sensor (e.g., a capacitive touch sensor for a button), may be used to form interconnects (e.g., conductive paths for signals in circuitry  16  such as conductive paths that interconnect components such as component  140  to other circuitry), or may be used to form other suitable structures for item  10 . 
     In the illustrative example of  FIG. 13 , the ability to accurately align warp strand portions  132  with desired weft strands  64  has been used to form conductive signal path  152 . As shown in  FIG. 13 , signal path  152  has been formed by overlapping end  150 A of conductive segment  132 A on warp strand  28 A with weft strand  64 CP and by overlapping end  150 B of conductive segment  132 B on warp strand  28 B with weft strand  64 CP. Weft strand  64 CP may, as an example, be a conductive strand and segments  132 A and  132 B may be conductive segments from metal coatings and/or bared metal cores of insulated strands. Path  152  may be formed by coupling these conductive strand portions together as shown in  FIG. 13 . 
     To prevent undesired short circuit paths in the illustrative configuration of  FIG. 13 , the weft strands in fabric  60  other then conductive signal path weft strand  64 CP and the warp strand portions other than segments  132 A and  132 B may be insulating. In general, any suitable pattern of interconnects may be formed using overlapping conductive warp strand and weft strand portions. For example, signals may be routed across one or more warp strands, across one or more weft strands, may traverse one or more warp-to-weft and one or more weft-to-warp connections, etc. 
     Electrical connections in fabric  60  may be made by ensuring that the overlapping strand portions in a signal path are formed from conductive material (e.g., metal, metal in metallic paint, etc.). The metallic paint, conductive adhesive, or other material that is applied to strands  28  to form segments  132  may be dried and/or cured before overlapping strands  28  and strands  64  or wet liquid metallic paint, uncured liquid conductive adhesive, or other moist applied material may be used in forming electrical connections (i.e., strand  28  may be coated with metallic paint and woven with weft strands  64  before the metallic paint has completely dried). 
     If desired, connections may be augmented using conductive materials such as conductive adhesive, solder, metallic paint, or other conductive materials applied to the bare metal or metal coating of segments  132  using equipment such as unit  52 . Adding conductive material to the joints between overlapping strands in a signal path may help reduce resistance along the path. In some situations, additional conductive material can be omitted (e.g., when overlapping conductive strands form low-contact-resistance connections). This may help reduce fabrication complexity. 
     In some designs, it may be desirable for conductive strands to pass over each other without forming an electrical connection. Consider, as an example, a fabric in which warp strands  28  contain a mixture of insulating strands and conductive strands and in which weft strands  64  contain a mixture of insulating strands and conductive strands. The insulating strands may be, for example, polymer strands and the conductive strands may be, for example, bare metal strands or polymer strands coated with metal. In this type of arrangement, a given conductive warp strand may cross over a given conductive weft strand even though an electrical connection is not desired between these two strands. The conductive strands may overlap to form a desired pattern of signal interconnects, to form a capacitive touch sensor array (with each sensing point corresponding to an overlap between a warp and weft strand), or to form other structures for item  10 . 
     As shown in  FIG. 14 , for example, conductive warp strand  28 ′ may be surrounded by adjacent insulating warp strands  28  and conductive weft strand  64 ′ may be surrounded by adjacent insulating weft strands  64 . In the portion of fabric  60  that is shown in  FIG. 14 , it is not desired to form an electrical connection between conductive warp strand  28 ′ and conductive weft strand  64 ′ even though these two strands overlap. Accordingly, insulating layer  1321  has been added to warp strand  28 ′ using unit  52  (e.g., equipment of the type shown in  FIG. 4 , equipment of the type shown in  FIG. 3  such as coating tool  92 , etc.). Insulating layer  1321  may be a polymer coating, a layer of adhesive such as adhesive  106  of  FIG. 4 , or other dielectric coating. Insulating layer  1321  may be placed on the upper surface of strand  28 ′ (see, e.g.,  FIG. 7 ) or may cover both the top and bottom of strand  28 ′ (see, e.g.,  FIGS. 8 and 9  in which strand  28 ′ is surrounded with coating material). 
     As shown in the cross-sectional side view of  FIG. 15 , strands  28 ′ and  64 ′ may be electrically isolated from each other using interposed insulating coating such as insulating layer  1321 . 
     When a dielectric material such as layer  1321  is interposed between respective conductive strands in fabric  60 , the conductive strands will not be electrically shorted to each other at direct current (DC) frequencies. This allows signals to be routed through the conductive strands without inadvertent shorts (i.e., the conductive strands may form a desired signal interconnect pattern in fabric  60 ). If desired, the intersections at which conductive warp and weft strands overlap may serve as capacitive touch sensor electrodes (e.g., touch sensor locations in a mutual capacitance touch sensor array). In a capacitive touch sensor arrangement, alternating current (AC) drive signals may be applied to weft strands and sense signals may be gathered at warp strands that are separated from the weft strands by insulating portions  1321  or drive signals may be applied to the warp strands while sense signals are gathered at weft strands. Other types of capacitive touch sensor may be formed in which warp and weft strands are separated by insulating portions  1321 , if desired. The use of overlapping sense and drive signal paths formed from perpendicular conductive strands in fabric  60  is merely illustrative. 
     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: 20151111
Publication Date: 20190108
Grant Date: 20190108
Priority Date: 20141121
Inventors: PODHAJNY, DANIEL A.
CREWS, KATHRYN P.
HAMADA, Yohji
Assignee: APPLE INC
CPC Classifications: [{"code": "D03J1/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D41/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03J1/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "D02H5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "D03J1/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "D02H5/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "D03D15/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/00", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 64815589