PATENT DOCUMENT

Publication Number: US-10566151-B1
Application Number: US-201715416177-A
Country: US
Kind Code: B1

Title: Items with fabric domes

Abstract:
An item such as a fabric-based item may have one or more input devices. The input devices may have terminals that are electrically coupled to control circuitry. The control circuitry may make resistance measurements, capacitance measurements, and other measurements on the input devices to determine whether the input devices have been pressed by a user&#39;s finger or have otherwise received input. The input devices may be used to form an array of switches for a keyboard, may form buttons on an electronic device housing or case, may be part of an item of clothing, or may be incorporated into other items such as fabric-based items. The input devices may have collapsible fabric structures such as collapsible fabric domes. The terminals of the input devices may be formed from conductive strands of material in the fabric domes or may be supported by other structures that buckle under applied pressure.

Claims:
What is claimed is: 
     
       1. An item, comprising:
 a first fabric layer that forms a fabric dome with a first conductive portion; 
 a structure with a second conductive portion that is associated with the first conductive portion, wherein the structure defines a first plane; 
 control circuitry coupled to the first and second conductive portions; and 
 a second fabric layer overlapping the first fabric layer, wherein the second fabric layer completely covers the fabric dome, wherein the second fabric layer has first and second portions, wherein the first portion overlaps a center of the fabric dome and the second portion does not overlap the fabric dome, wherein the second portion defines a second plane that is parallel to the first plane, and wherein the first portion lies in the second plane. 
 
     
     
       2. The item defined in  claim 1  wherein the structure with the second conductive portion comprises a layer of fabric. 
     
     
       3. The item defined in  claim 1  wherein the first conductive portion is formed from conductive strands of material. 
     
     
       4. The item defined in  claim 1  wherein the structure with the second conductive portion comprises fabric having insulating strands of material and conductive strands of material and wherein the second conductive portion is formed from the conductive strands of material. 
     
     
       5. The item defined in  claim 1  wherein the first conductive portion is formed from conductive strands of material in the fabric dome and wherein the item comprises walls that serve as a case for an electronic device. 
     
     
       6. The item defined in  claim 5  wherein the fabric dome and the structure with the second conductive portion form a switch on one of the walls of the case. 
     
     
       7. The item defined in  claim 1  wherein the fabric dome and the structure form a switch and wherein the first and second conductive portions form first and second terminals for the switch, the item further comprising a keyboard key that includes the switch. 
     
     
       8. The item defined in  claim 7  wherein the keyboard key comprises one of a plurality of keys in a keyboard each of which has a respective fabric dome. 
     
     
       9. The item defined in  claim 1  further comprising a polymer layer, wherein the first fabric layer has portions embedded within the polymer layer. 
     
     
       10. The item defined in  claim 1  further comprising speakers that are electrically coupled to the first and second conductive portions. 
     
     
       11. A fabric-based device, comprising:
 first and second contacts; and 
 a fabric structure that buckles in response to applied pressure, wherein the fabric structure separates the first and second contacts by an air gap when the applied pressure is not present and the fabric structure is not buckled, wherein the first and second contacts contact each other and are electrically shorted to each other when the fabric structure is buckled in response to the applied pressure, and wherein the fabric structure comprises an open-topped fabric cone. 
 
     
     
       12. The fabric-based device defined in  claim 11  wherein the fabric structure comprises a fabric dome having conductive strands that form the first contact. 
     
     
       13. The fabric-based device defined in  claim 11  wherein the first contact is formed from first conductive strands and wherein the second contact is formed from second conductive strands. 
     
     
       14. The fabric-based device defined in  claim 13  wherein the first and second conductive strands include dielectric cores and metal coatings on the dielectric cores. 
     
     
       15. An input device that a user controls by applying pressure with a finger, comprising:
 a fabric layer comprising a fabric dome having a first terminal, wherein the fabric layer has flat portions surrounding the fabric dome; 
 a second terminal that is separated by a gap from the first terminal when the finger is not applying the pressure and that is contacted by the first terminal in response to collapse of the fabric dome against the second terminal due to application of the pressure to the fabric dome with the finger; and 
 an elastomeric material in which the flat portions of the fabric layer are embedded, wherein the fabric dome is uncovered by the elastomeric material to allow movement of the fabric dome relative to the elastomeric material. 
 
     
     
       16. The input device defined in  claim 15  wherein the fabric dome comprises conductive strands that form the first terminal. 
     
     
       17. The input device defined in  claim 16  wherein the input device is a switch that is open when the first and second terminals are separated by the gap and that is closed when the first terminal contacts the second terminal. 
     
     
       18. A force-based input device, comprising:
 a fabric dome; 
 a strain gauge aligned with the fabric dome that senses when the fabric dome has been compressed against the strain gauge; and 
 a support layer with an opening, wherein the strain gauge is aligned with the opening.

Description:
This application claims the benefit of provisional patent application No. 62/297,290, filed on Feb. 19, 2016, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to fabric structures and, more particularly, to fabric domes and other structures that may be used to form input devices. 
     BACKGROUND 
     Keyboards and other electronic devices sometimes include input devices such as switches. For example, each key in a keyboard may have a dome switch and a movable key member that bears against the dome switch when depressed by a user. 
     If care is not taken, switches and other input devices may be excessively bulky or may not be compatible with the structures used in forming a keyboard or other electronic device of interest. 
     SUMMARY 
     An item such as a fabric-based item or other item may have one or more input devices. The input devices may have terminals that are electrically coupled to control circuitry. The control circuitry may make resistance measurements, capacitance measurements, and other measurements on the terminals of the input devices to determine whether the input devices have been pressed by a user&#39;s finger or have otherwise received input from a user. 
     The input devices may serve as switches, force sensors, touch sensors, or proximity sensors. For example, the input devices may serve as switches that have open and closed states. In the open state of an input device, first and second terminals in the device may be separated by an air gap. In the closed state of the input device, a fabric structure in the input device such as a fabric dome or other collapsible structure may buckle under pressure from the user&#39;s finger so that the first and second terminals contact each other and form an electrical short circuit. 
     The input devices may be used to form an array of switches for a keyboard, may form buttons on an electronic device housing or case, may form part of an item of clothing, or may be incorporated into other items such as fabric-based items. The terminals of the input devices may be formed from conductive strands of material in fabric domes or other structures that buckle under applied pressure and that exhibit satisfactory restoring forces when the applied pressure is removed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative item of the type that may be provided with one or more fabric-based input devices in accordance with an embodiment. 
         FIG. 2  is a diagram of an illustrative fabric-based input device and associated control circuitry in accordance with an embodiment. 
         FIGS. 3, 4, 5, and 6  are cross-sectional side views of illustrative strands of material that may be used in forming a fabric-based input device in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of a layer of woven fabric in accordance with an embodiment. 
         FIG. 8  is a top view of an illustrative layer of knit fabric in accordance with an embodiment. 
         FIG. 9  is a cross-sectional side view of an illustrative fabric dome in accordance with an embodiment. 
         FIG. 10  is a perspective view of an illustrative electronic device case having buttons formed from fabric domes in accordance with an embodiment. 
         FIG. 11  is a perspective view of a portion of a keyboard with fabric-based input devices such as keys formed from fabric overlapping fabric dome switches in accordance with an embodiment. 
         FIG. 12  is a top view of an illustrative fabric structure such as a band or strap that has been provided with input devices such as switches based on fabric domes in accordance with an embodiment. 
         FIG. 13  is a perspective view of an illustrative fabric structure such as a portion of a shirt, jacket, or other item of clothing with fabric dome input devices in accordance with an embodiment. 
         FIG. 14  is a perspective view of an illustrative pair of earbuds with input devices based on fabric domes in accordance with an embodiment. 
         FIG. 15  is a perspective view of an illustrative fabric dome for an input device such as a switch in accordance with an embodiment. 
         FIG. 16  is a cross-sectional side view of an illustrative fabric dome input device having a fabric dome structure interposed between a flexible cover layer and a supporting structure in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view of a fabric dome showing how selected portions of the fabric dome may be provided with conductive strands that form terminals for an input device in accordance with an embodiment. 
         FIG. 18  is a cross-sectional side view of an illustrative fabric-based input device with a post-shaped buckling fabric structure in accordance with an embodiment. 
         FIG. 19  is a perspective view of an illustrative open-topped fabric cone for a fabric-based input device in accordance with an embodiment. 
         FIG. 20  is a cross-sectional side view of an illustrative fabric-based input device such as a fabric-based input device including a fabric cone of the type shown in  FIG. 19  in accordance with an embodiment. 
         FIG. 21  is a cross-sectional side view of an illustrative fabric-based input device in accordance with an embodiment. 
         FIG. 22  is a cross-sectional side view of an illustrative fabric-based input device that includes a flat-topped fabric structure such as a cone in accordance with an embodiment. 
         FIG. 23  is a cross-sectional side view of an illustrative fabric-based input device with layers such as plastic layers or additional fabric layers for protecting the fabric-based input device in accordance with an embodiment. 
         FIG. 24  is a cross-sectional side view of an illustrative fabric-based input device having a layer of fabric with a dome portion and portions that are embedded within a support structure such as a polymer layer in accordance with an embodiment. 
         FIG. 25  is a cross-sectional side view of an illustrative fabric-based input device having a fabric dome and strain gauge structures in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Items such as item  10  of  FIG. 1  may include one or more input devices. The input devices may include fabric-based structures that buckle under applied pressure from a finger of a user or other external force. Upon buckling, changes in resistance, capacitance, or other attributes may be detected. The fabric-based structure may exhibit a buckling resistance behavior and corresponding restoring force after buckling that provide the input device with a satisfactory mechanical button behavior. This allows the fabric-based structures to serve as switches in a keyboard or as other input devices. 
     Item  10  may be a stand-alone electronic device or may be an electronic device or other equipment that serves as an accessory for a stand-alone electronic device. For example, item  10  may be a 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 wristwatch 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 keyboard, a pair of earbuds or other device with speakers, a navigation device, an embedded system such as a system in which 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. Item  10  may also 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, shirt, pants, shoes, etc.), or may be any other suitable item with one or more actuators. 
     In some arrangements, item  10  may include intertwined strands of material  12  that form fabric. The strands of material in item  10 , which may sometimes be referred to herein as yarns, may be single-filament strands (sometimes referred to as fibers or monofilaments) or may be strands of material formed by intertwining multiple monofilaments of material together. The strands of material may be formed from one or more layers of dielectric such as plastic, glass, etc. and/or one or more layers of conductive material such as metal, conductive polymer materials, polymer with sufficient embedded electrically conductive filler material to render the polymer conductive, graphene, or other conductive substances. Strands  12  that include metal may sometimes be referred to as wires. 
     Fabric formed from strands  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, may form clothing, may form a strap, may form a wall for a bag or other enclosure, or may form other fabric-based structures. 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 an item that has portions formed from non-fabric structures of plastic, metal, glass, crystalline materials, ceramics, or other materials. 
     Strands  12  may be formed from polymer, metal, glass, graphite, ceramic, natural materials 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 material. For example, plastic strands  12  in a fabric layer may be coated with metal to make them conductive. Reflective coatings such as metal coatings may be applied to make strands reflective. Strands may be formed from bare metal wires or metal wire intertwined with insulating monofilaments (as examples). Bare metal strands and strands of polymer covered with conductive coatings may be provided with insulating polymer jackets. 
     Strands  12  may be intertwined to form fabric using intertwining equipment such as weaving equipment, knitting equipment, or braiding equipment. Intertwined strands may, for example, form knitted fabric or woven fabric. Conductive strands and strands with insulating surfaces may be woven, knit, or otherwise intertwined to form conductive paths. The conductive paths may be used in forming signal paths (e.g., signal buses, power lines, control signal interconnects, etc.) and may be used in forming conductive portions of fabric-based input devices such as capacitive touch sensor electrodes, resistive touch sensor electrodes, switch electrodes (sometimes referred to as contacts or terminals), force sensor electrodes, etc. In general, conductive strands  12  in a fabric or other structure 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. 
     Item  10  may include additional mechanical structures  14  such as polymer binder to hold strands  12  in a fabric or other structure together, support structures such as frame members, housing structures (e.g., an electronic device housing), layers of material that overlap fabric structures and/or that support fabric structures, and other mechanical structures. 
     To enhance mechanical robustness and electrical conductivity at strand-to-strand connections, additional structures and materials  14  (e.g., solder, crimped metal connections, welds, conductive adhesive such as anisotropic conductive film and other conductive adhesive, non-conductive adhesive, fasteners, etc.) may be used to help form strand-to-strand connections. These strand-to-strand connections may be formed where strands  12  cross each other perpendicularly or at other strand intersections where connections are desired. Insulating material can be interposed between intersecting conductive strands at locations in which it is not desired to form a strand-to-strand electrical connection. The insulating material may be plastic or other dielectric, may include an insulating strand or a conductive strand with an insulating coating, etc. Solder connections may be formed between conductive strands by melting solder so that the solder flows over conductive strands. The solder may be melted using an inductive soldering head to heat the solder, using a reflow oven to heat the solder, using a laser or hot bar to heat the solder, or using other soldering equipment. During soldering, outer dielectric coating layers (e.g., outer polymer layers) may be melted away in the presence of molten solder, thereby allowing underlying metal strands to be soldered together. 
     Item  10  may include circuitry  16 . Circuitry  16  may include electrical components that are coupled to fabric or other structures formed from strands  12 , electrical components that are housed within an enclosure that includes fabric or other structures formed from strands  12 , electrical components that are attached to fabric formed from strands  12  using welds, solder joints, conductive adhesive bonds, crimped connections, or other electrical and/or mechanical bonds, and electrical components mounted in electronic device housings formed from plastic, glass, metal, fabric, and/or other materials. Circuitry  16  may include metal structures for carrying current, electrical devices such as integrated circuits, light-emitting diodes, sensors, and switches, and other electrical components. Circuitry  16  may include one or more input devices such as input devices formed from fabric domes or other fabric-based input devices formed using strands  12 . Control circuitry in circuitry  16  may use signals from the input devices in controlling the operation of item  10 . 
     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, when one item is a wrist watch or pendant device and the other item is a strap for the item, etc.). Control circuitry in circuitry  16  may be used to support communications with item  18  and/or other devices. Circuitry  16  may include antennas and other structures for supporting wireless communications with item  18 . Item  18  may also interact with 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 item  10  may form a cover (e.g., a cover including a keyboard and/or other buttons or a cover that does not include a keyboard), a case, a bag, an item of clothing, 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 wristwatch device or other electronic device and item  10  may be a strap or other fabric-based item that is attached to item  18  (e.g., item  10  and item  18  may together form a fabric-based item such as a wristwatch with a strap). In still other situations, item  10  may be an electronic device, fabric formed from strands  12  may be used in forming the electronic device and/or input devices or other structures in item  10 , and additional items  18  may include accessories or other devices that interact with item  10 . Signal paths formed from conductive strands may be used to route signals in item  10  and/or item(s)  18 . Signal paths may also be formed using patterned metal traces in printed circuits, metal traces patterned onto fabric, and/or other conductive paths item  10 . 
     The fabric that makes up the input devices and other structures in item  10  may be formed from multifilament and/or monofilament yarns that are intertwined using any suitable intertwining equipment (knitting equipment, weaving equipment, braiding equipment, equipment for forming felt, etc.). The fabric may be knitted, woven, braided, or otherwise formed from intertwined strands  12 . Woven fabric may have 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. Knitted fabric may be weft knitted or warp knitted. 
     As shown in  FIG. 2 , item  10  may include input devices  52 . Input devices  52  may be formed from strands of material  12  and/or other structures in item  10  such as structures  14 . There may be one or more input devices  52  in item  10 . As shown in the example of  FIG. 2 , a component such as device  44  may be provided with multiple input devices  52 . An array of input devices  52  may form a keyboard, multiple input devices  52  may be used in forming a keypad, multiple input devices  52  may be used in forming a row of buttons, etc. 
     Circuitry  16  of item  10  may include control circuitry  40 . Input-devices  52  may be electrically coupled to control circuitry  40  of using signal paths  46 . Paths  46  may be conductive strands in a fabric, may be metal traces on a printed circuit, may be conductive traces on a fabric, and/or may be other conductive paths in item  10 . Control circuitry  40  may apply signals to devices  52  using paths  46  and may measure associated signals from devices  42  using paths  46 . Resistance measurements may be used by control circuitry  40  in determining the state of devices  52 , capacitance measurements may be used by control circuitry  40  in determining the state of devices  52 , or other types of measurements may be made on devices  52  by control circuitry  40  to determine whether input is being supplied to devices  52  by a user. Devices  52  may form resistance-based switches (e.g., switches that have open or closed states as determined by their resistance), may form capacitive switches (e.g., switches that are determined to be activated or not activated based on measured changes in capacitance), may form force-based input devices (e.g., input devices that use capacitive measurements, strain gauge measurements, or other types of force measurements to detect different amounts of applied force), may form touch-based input devices (e.g., capacitive touch sensors that measure capacitance changes when touched by a finger of a user), or may form other types of input devices. 
     Each device  52  may have a pair of terminals (sometimes referred to as electrodes) such as terminals  48  and  50 . Terminals  48  and  50  and/or other structures that form each device  52  may have any suitable shape. Preferably, the shapes of terminals  48  and  50  and/or the other structures of device  52  such as supporting structures are configured to allow some or all of device  52  to buckle when pressure is applied by an external object such as a user&#39;s finger (see, e.g., finger  54  of  FIG. 2 ) in direction  56 . With one illustrative configuration, terminals  48  may be dome shaped and terminals  50  may be planar, but other buckling structures may be used for forming devices  52  if desired. 
     In a resistance-based switch, circuitry  40  may measure the resistance between terminals  48  and  50 . When terminal  48  has an unbuckled dome shape, terminals  48  and  50  may be separated by an air gap. When terminals  48  and  50  are separated in this way, input device  52  will form an open circuit (i.e., the resistance-based switch will be open). When terminal  48  is pressed downwards in direction  56  by finger  54 , terminal  48  or structures associated with terminal  48  may buckle, thereby allowing terminal  48  to contact terminal  50 . In this situation, input device  52  will form a low-resistance closed circuit (i.e., the resistance-based switch will be closed). In other device configurations such as capacitance-based or strain-gauge based systems, capacitance measurements, strain gauge measurements, or other measurements may be made by circuitry  40  to detect whether a dome or other collapsible structure in device  52  has or has not buckled under pressure from finger  54 . 
     Input devices  52  (e.g., electrode  48 , electrode  50 , and/or other structures in input devices  52 ) may be formed from strands  12 . Strands  12  may include insulating strands (e.g., strands that are formed from a single polymer core and/or that are formed from a polymer core coated with one or more polymer coating layers, or other dielectric strands). Strands  12  may also include conductive materials so that they can conduct current. Illustrative conductive strands  12  (i.e., strands that include one or more conductive materials) are shown in  FIGS. 3, 4, 5, and 6 . Other types of arrangement may be used in forming conductive strands  12  if desired. The examples of  FIGS. 3, 4, 5, and 6  is merely illustrative. 
     As shown in the illustrative cross-sectional side view of conductive (conducting) strand  12  of  FIG. 3 , conductive strand  12  may be formed from a solid conductive material such as core  12 M (e.g., strand  12  may be formed from an elemental metal or a metal that is an alloy).  FIG. 4  shows how strand  12  may have a coating layer such as coating  12 - 2  on a core such as core  12 - 1 . Core  12 - 1  may be a metal or other conductive material and coating  12 - 2  may be a polymer or other dielectric. In the example of  FIG. 5 , strand  12  has a coating layer such as coating layer  12 B on a core such as core  12 A. Core  12 A may be a polymer or other dielectric and coating  12 B may be metal or other conductive material. Configurations in which the core and coating of a two layer conductive strand are both formed from metal or other conductive material may also be used (e.g., both portions  12 A and  12 B of strand  12  of  FIG. 5  may be metal). In the illustrative configuration of  FIG. 6 , conductive strand  12  has three portions:  12 A,  12 B, and  12 C. Core  12 A, may be formed from metal or may be formed from polymer or other dielectric, inner coating  42 B may be formed from metal or may be formed from polymer or other dielectric, and outer coating  42 C may be formed from metal or may be formed from polymer or other dielectric. Additional coating layers of polymer and/or metal may also be formed on the layers of strand  12  in  FIG. 6 . One or more, two or more, or three or more of the layers of material in strand  12  of  FIG. 6  may be formed from a conductive material such as metal (elemental or alloy) so that current may pass through strand  12  of  FIG. 6 . 
     In configurations for input device  52  in which device  52  serves as a switch and in which the switch closes due to bare metal contact between a pair of terminals (e.g., upper and lower electrodes), the strands for forming the terminals may have outer surfaces that are formed from metal or, in the situation in which the outer coatings of the strands are insulating, the insulating outer strand coatings such as selected portions of an insulating coating  12 - 2  of  FIG. 4  and selected portions of an insulating coating  12 C of  FIG. 6  may be removed so that the outer surface of the strands is conductive. 
     All or part of devices  52  and/or other structures in item  10  may be formed by intertwining strands  12  (conductive and/or insulating) to form fabric.  FIGS. 7 and 8  show illustrative fabrics that may be formed from strands  12 . 
     Fabric  20  of  FIG. 7  is a woven fabric formed from strands  12 . Strands  12  may include warp strands  12 A and weft strands  12 B. Each strand  12  may contain one or more monofilaments of material (see, e.g., illustrative monofilament strands  26 ). As shown in  FIG. 8 , fabric  20  may be a knit fabric. In the illustrative configuration of  FIG. 8 , fabric  20  has a single layer of knit strands  12  that form horizontally extending rows of interlocking loops (courses  22 ) and vertically extending wales  24 . 
     The fabric that is formed from strands  12  may have dome structures and other structures that form parts of input devices  52 . The examples of  FIGS. 7 and 8  are illustrative. Other fabric constructions may be used for fabric in devices  52  (e.g., electrode  48 , electrode  50 , other structures such as other buckling structures, etc.) and/or other portions of item  10  if desired. 
     The operation of an illustrative input device with a buckling (compressible) upper electrode is shown in  FIG. 9 . In the example of  FIG. 9 , electrode  48  has a curved cross-sectional shape in the absence of pressure from finger  54  in direction  54 . Electrode  48  may, for example, have a half-cylinder shape or a hemispherical dome shape. When pressed downwards in direction  56 , electrode  48  buckles and takes on shape  48 - 1 . Further pressure may cause electrode  48 - 1  to contact electrode  50  at electrical connection  60 . Due to the buckling nature of the structure that is being pressed by finger  54  (i.e., the structure forming electrode  48  in the  FIG. 9  example), downward pressure is initially met with substantial resistance that weakens once buckling starts. When pressure is released, the buckled structure will assertively spring back towards its original position. This type of compression and spring-back behavior helps provide a desired tactile response for device  52  (i.e., the use of a dome or other buckling structure in device  52  allows device  52  to be used as a keyboard key, button, or other device that operates under pressure from a user&#39;s finger). 
     During operation of device  52 , deflection of electrode  48  to position  48 - 1  may be detected using capacitance measurements (e.g., measurements of the changing capacitance between electrodes  48  and  50  as electrode  48  deflects from its original position) or resistance measurements (e.g., measurements that reveal whether electrodes  48  and  50  are isolated from each other by an intervening air gap or are shorted to each other at connection  60 ). Configurations in which strain gauges or other sensors are used to support the operation of devices  52  may also be used. 
     Dome-shaped structures such as fabric domes or other collapsible structures may be used in forming switches and other input devices  52 . For example, electrodes such as electrode  48  may be formed from conductive strands  12  in a fabric dome or other structure that buckles under pressure from finger  54 . In the example of  FIG. 10 , input devices  52  have been formed on walls  70  of item  10  (e.g., fabric electronic device housing walls, walls of a removable fabric case for a cellular telephone, tablet computer, or other device, or other structures formed from fabric and/or other materials). Input devices  52  may form volume control buttons, on-off buttons, sleep/wake buttons, menu buttons, or other buttons. Walls  70  may be sidewalls and may be coupled to other walls in item  10  such as rear housing wall  72  or a front housing wall. If desired, input devices  52  based on fabric domes or other collapsible fabric structures may be formed on walls such as wall  72  or a front housing wall. 
     As shown in the perspective view of illustrative item  10  of  FIG. 11 , item  10  may be a keyboard or other device that includes an array of input devices  52 . Input devices  52  may be, for example, labeled keys in a keyboard, keys in a key pad, buttons in a group of buttons on item  10 , etc. Each input device  52  in item  10  of  FIG. 11  may have a buckling structure such as a collapsible fabric dome, a buckling fabric structure with another shape, or other collapsible structure. 
     In the example of  FIG. 12 , item  10  is a watch having an electrical device portion such as watch unit  74  and having an associated strap such as strap  76 . Strap  76  may be formed from fabric that includes strands  12  and may have signal paths formed from strands  12  or other structures that are coupled to control circuitry in unit  74 . Input devices  52  may be formed on strap  76  and may include fabric dome structures or other collapsible structures (e.g., strap  76  and/or input devices  52  may be formed from strands  12 ). Input devices  52  may gather input that is provided to the control circuitry in unit  74 . 
     If desired, item  10  may be an item of clothing. As shown in  FIG. 13 , an item of clothing such as item  10  of  FIG. 13  may include fabric  78  with one or more input devices  52 . Devices  52  may be mounted on the exterior of a shirt, jacket, or pair of pants, may be mounted in the interior of a garment, or may be incorporated into other clothing items formed from fabric  78 . 
     In the example of  FIG. 14 , item  10  is an accessory such as a pair of headphones (earbuds). Item  10  may have earbuds  80  with speakers for producing sound for a user and may have cables  84  that couple electrical connector  84  (e.g., an audio jack, etc.) to earbuds  80 . Portion  86  of item  10  may be interposed along the length of cables  84  and may form a button controller for item  10 . Portion  86  may include one or more input devices  52 . Item  10  may include fabric. For example, devices  52  may have fabric domes or other collapsible structures and may be formed from fabric structures in portion  86 , cables  84 , and/or earbuds  80 . Devices  52  may form buttons for advancing or rewinding audio tracks, for pausing or stopping media playback, for adjusting volume, etc. 
     A perspective view of an illustrative fabric dome structure for device  52  of item is shown in  FIG. 15 . In the example of  FIG. 15 , fabric dome  92  for device  52  is formed on layer  90  (i.e., fabric dome  92  and layer  90  may be formed from a common set of intertwined strands of material such as strands  12 ). Configurations in which layer  90  is formed from a polymer layer, a structure formed from metal, polymer, or other material, or in which other support structures  90  are used in place of a fabric layer under dome  92  may also be used. 
     Fabric dome structures for device  52  and other collapsible structures for device  52  may include conductive strands  12  or other conductive materials that form some or all of electrodes  48  and  50 . In the arrangement of  FIG. 15 , fabric dome  92  of input device  52  is uncovered by any additional layers of material. If desired, fabric dome  92  may be covered by additional layer(s) of material. For example, item  10  may have an outer surface formed by a layer such as layer  94  of  FIG. 16  that overlaps fabric dome  92 . Layer  94  may be a layer of plastic, leather, fabric, or other material and may form the exterior surface in a keyboard or other item. Fabric dome  92  may form part of layer  90  and/or layer  94  and may form input device  52 . 
     When a user&#39;s finger such as finger  54  presses downwards on layer  94 , fabric dome  92  may buckle into position  92 ′, so that dome  92  contacts layer  90 . Electrode  48  may be a metal layer or other conductive structure that is supported by fabric dome  92  and/or may be formed from conductive strands  12  that are part of fabric dome  92 . Electrode  50  may likewise be a metal layer or other conductive structure that is supported by layer  90  under dome  92  and/or may be formed from conductive strands  12  that are part of layer  90 . As shown in  FIG. 17 , for example, layer  94  may have insulating strands  12 IN, fabric dome  92  may be formed from insulating strands  12 IN and conducting strands  12 CN that form electrode  48 , and layer  90  may be formed from insulating strands  12 IN and conducting strands  12 CN that form electrode  50 . 
     If desired, buckling structures for input device  52  may be formed from fabric posts such as collapsible post  100  of input device  52  of item  10  in  FIG. 18 . Electrode  48  may be formed in upper layer  94  (e.g., a fabric layer) and electrode  50  may be formed in lower layer  90  (e.g., a fabric layer). Post  100  may be surrounded by air, so that post  100  may easily buckle under pressure. When pressure is applied by finger  54  in direction  56 , post  100  may buckle into position  100 ′ to allow electrodes  48  and  50  to contact each other or to allow portions of post  100  to contact other structures such as structure  90 ′, which may be a part of a fabric layer such as layer  90  or other fabric support structure. As an example, electrode  48  may be formed from conductive strands  12  in post  100  and electrode  50  may be formed from conductive strands  12  in portion  90 ′ of layer  90 . In this type of arrangement, the supporting structure of device  52  such as post  100  that forms electrode  48  may buckle and move in direction  102  into electrical contact with portion  90 ′ of layer  90  that forms electrode  50  when finger  54  presses downwardly (e.g., inwardly towards the interior of item  10 ) in direction  56 . Other structures (e.g., other fabric structures and/or other structures formed from strands  12 ) may be used in forming electrodes that move towards each other and away from each other in response to the application and removal of finger  54 . The buckling support post arrangement of  FIG. 18  is merely illustrative. 
       FIG. 19  is a perspective view of an illustrative bucking structure formed from an open-topped fabric cone. Fabric cone  104  may be formed from strands  12  and may be formed as a portion of layer  90  or may be attached to layer  90 . Layer  90  may be formed from strands  12  or other material. Opening  106  at the top of cone  104  may be circular or may have other suitable shapes. If desired, a fabric layer or other layer of material such as layer  94  (see, e.g.,  FIGS. 17 and 18 ) may overlap cone  104 . When pressed in direction  56 , an electrode formed on the overlapping layer or the upper part of cone  104  (e.g., electrode  48 ) may contact an electrode formed in a support structure such as layer  90  (e.g., electrode  50 ). 
       FIG. 20  is a cross-sectional side view of device  52  in an illustrative configuration in which an open-topped cone or other structure with buckling diagonal support structures  108  has been formed between layers  90  and  94 . Layers  94 , structures  108 , and layer  90  may be formed from intertwined strands  12 . When pressed in direction  56 , structures  108  may buckle inwardly towards positions  108 ′. Electrode  48  may be formed from conductive strands in layer  94 , portions of structure  108  or elsewhere in the structures of  FIG. 20  and electrode  50  may be formed from conductive strands in layer  90  under structure  108  or elsewhere in the structures of  FIG. 20 . Electrodes  48  and  50  may come into contact with each other when input device  52  of  FIG. 20  is pressed in direction  56  (as an example). 
     If desired, a structure such as structure  110  of  FIG. 21  may be incorporated into the upper portion of cone  104  Structure  110  may be formed from strands  12  that form an integral portion of both one  104  and structure  110  or structure  110 , may be formed from a separate piece of polymer, or may be formed from other structures. Structure  110  may be rigid (e.g., to limit key travel for device  52  in a configuration where the portion of layer  94  overlapping device  52  forms a labeled key structure for a key in a keyboard), may be elastomeric (e.g., structure  110  may be foam, may be a soft polymer such as silicone, etc.), may have a combination of flexible and rigid structures, may have conductive portions (e.g., conductive strands  12  and/or other conductive material for forming electrode  48 ), etc. Cone  104  or other buckling structures for device  52  may, if desired, have horizontally base portions such as base structure  104 ′. 
     As illustrated in the cross-sectional side view of device  52  of  FIG. 22 , cone-shaped support structures  104  or other buckling support structures for device  52  that buckle when pressed in direction  56  may be formed from fabric that also forms portions of layers  90  and  94  (i.e., intertwined strands  12  may form cone  104 , layer  90 , and layer  94  and these structures may represent portions of an integral fabric structure). 
       FIG. 23  is a cross-sectional side view of device  52  in item  10  in an arrangement in which fabric dome  92  and underlying layer  90  have been formed from fabric (e.g., integral portions of a fabric layer) and in which additional layers such as layers  120  and  122  have been formed respectively above and below fabric dome  92  and layer  90 . Layers  120  and  122  may be formed from flexible polymers, from fabric, or other materials and may help protect dome  92  from moisture and dust. 
     In the illustrative configuration of  FIG. 24 , fabric dome  92  for device  52  is formed from a layer of fabric having portions  92 ′ that are embedded within layer  130 . Layer  130  may be an elastomeric polymer, a rigid polymer, or other suitable material. Layer  130  and fabric dome  92  may be interposed between layers  120  and  122 , if desired. 
     Device  52  may be based on strain gauge structures. Consider, as an example, device  52  of  FIG. 25 . As shown in  FIG. 25 , device  52  may include fabric dome  92 . Fabric dome  92  may be mounted on support structure  144 . Layer  142  may be interposed between support structure  144  and the fabric that makes up dome  92 . Layer  142  may be a flexible printed circuit layer, a fabric layer, or other substrate that contains serpentine metal traces or other structures that form strain gauge  150 . Support structure  144  may be formed from a rigid printed circuit, fabric, a layer of polymer, or other support with an opening such as opening  146  that is aligned with strain gauge  150  and dome  92 . When dome  92  is pressed in direction  56 , the fabric of dome  92  may buckle and come into contact with layer  142 , as illustrated by deformed portion  92 D of dome  92 . This may bend portion  142 ′ of layer  142  and give rise to strain in portion  142 ′. Control circuitry  40  may use strain gauge  150  to measure the strain that is produced in portion  142 ′ and strain gauge  150 . Using this type of arrangement, the amount of force imposed in device  52  in direction  56  may be measured (i.e., device  52  may serve as a force detector). Strain gauge measurements may also be used in configurations in which device  52  serves as a switch. If desired, strain gauge structures may also be incorporated into dome  92 , as indicated by strain gauge structures  140  (e.g., strands  12 , metal traces, strain gauge structures attached to the fabric of dome  92 , etc.). 
     In addition to using resistance measurements (e.g., measurements with circuitry  40  that determine whether a switch formed from electrodes  48  and  50  and associated buckling structures is opened or closed) and in addition to using force measurements of the type described in connection with  FIG. 25 , capacitance measurements may be made in device  52  (e.g., by measuring the capacitance between electrodes (terminals)  48  and  50 ). Capacitance measurements may reveal, for example, the amount of separation (distance) between electrodes  48  and  50 . Capacitance measurements can be converted into binary switch state information (e.g., capacitance measurements may be compared to a predetermined capacitance threshold), may be converted into touch information (e.g., information indicating whether or not device  52  has been touched by a user&#39;s finger), may be converted into proximity sensor information (e.g., to determine whether a user&#39;s finger or other external object is within a predetermined distance of device  52 ), and/or may be converted into force information. Capacitance-based devices with fabric domes or other collapsible fabric structures such as device  52  may therefore serve as switches, force sensors, touch sensors, or proximity sensors. 
     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: 20170126
Publication Date: 20200218
Grant Date: 20200218
Priority Date: 20160219
Inventors: WANG, PAUL XIAOPENG
HEGDE, SIDDHARTHA
SUNSHINE, Daniel D.
GAO, ZHENG
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H2203/0085", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2203/0085", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2227/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2215/004", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/52", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2227/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2203/0085", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2215/004", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/52", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K2217/96015", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03K17/9647", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/9622", "inventive": true, "first": true, "tree": "[]"}, {"code": "H03K17/9625", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 69528399