PATENT DOCUMENT

Publication Number: US-11180873-B2
Application Number: US-202016854777-A
Country: US
Kind Code: B2

Title: Items with wire actuators

Abstract:
An item such as a fabric-based item or other item may have one or more actuators. An actuator may have a conductive strand of material. A control circuit may supply a current to the conductive strand that induces a length change in the conductive strand due to ohmic heating and associated thermal expansion effects. The control circuit may be used to activate the actuator in response to user input that is supplied to an associated input device such as a switch, capacitive sensor, force sensor, light-based sensor, or other input component. The fabric-based item may include fabric such as woven fabric or knit fabric. Strands of conductive material may serve as signals paths for supplying current to conductive strands in actuators. Magnetic-field-based actuators may be formed by coiling conductive strands around tubular support structures such as piping in fabric-based items.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a magnetic-field-based actuator formed from a conductive strand that is coiled around a tubular structure with a non-circular cross-sectional shape; and 
 a control circuit that applies current to the conductive strand to generate a magnetic field that causes the tubular structure to acquire a circular cross-sectional shape. 
 
     
     
       2. The apparatus defined in  claim 1  further comprising a layer of material to which the tubular structure is attached. 
     
     
       3. The apparatus defined in  claim 2  wherein the layer of material comprises a layer of fabric and wherein the tubular structure comprises piping on the layer of fabric. 
     
     
       4. The apparatus defined in  claim 3  wherein the non-circular profile is an oval profile. 
     
     
       5. The apparatus defined in  claim 4  wherein the oval profile is characterized by a minor axis and a major axis that is larger than the minor axis, and wherein the major axis is parallel to the layer of fabric. 
     
     
       6. The apparatus defined in  claim 1  wherein the magnetic-field-based actuator provides haptic feedback. 
     
     
       7. The apparatus defined in  claim 1  wherein the tubular structure is formed from a material selected from the group consisting of: foam, fabric, and elastomeric polymer. 
     
     
       8. The apparatus defined in  claim 1  further comprising an electrical component that is aligned with the magnetic-field-based actuator. 
     
     
       9. The apparatus defined in  claim 8  wherein the electrical component comprises a sensor and wherein the control circuit applies the current based on an output from the sensor. 
     
     
       10. A fabric-based item, comprising:
 fabric formed from strands of material; 
 a magnetic-field-based actuator formed from a conductive strand in the strands of material, wherein the conductive strand forms a loop; 
 non-conductive strands in the strands of material, wherein the non-conductive strands pass through the loop; and 
 control circuitry that applies a signal to the magnetic-field-based actuator to change a shape of the loop and generate haptic output. 
 
     
     
       11. The fabric-based item defined in  claim 10  wherein the control circuitry changes the shape of the loop from a non-circular shape to a circular shape in response to a user input. 
     
     
       12. The fabric-based item defined in  claim 10  further comprising a keyboard having keys covered with the fabric, wherein the actuator is aligned with one of the keys. 
     
     
       13. Apparatus, comprising:
 a fabric, wherein the fabric includes first, second, and third fabric layers; 
 a conductive thread, wherein a first portion of the conductive thread is interposed between the first layer and the second layer and a second portion of the conductive thread is interposed between the second layer and the third layer; and 
 control circuitry that applies a signal to the conductive thread to move the conductive thread and generate haptic output. 
 
     
     
       14. The apparatus defined in  claim 13  wherein the conductive thread forms an actuator pad. 
     
     
       15. The apparatus defined in  claim 14  wherein the actuator pad forms a keyboard key. 
     
     
       16. The apparatus defined in  claim 14  wherein a layer of dielectric material overlaps the actuator pad. 
     
     
       17. The apparatus defined in  claim 16  wherein the dielectric material comprises elastomeric material. 
     
     
       18. The apparatus defined in  claim 13  wherein the fabric comprises woven fabric. 
     
     
       19. The apparatus defined in  claim 13  wherein the control circuitry applies the signal in response to a user input. 
     
     
       20. The apparatus defined in  claim 13  wherein the control circuitry generates the haptic output in a first pattern in response to a first user input and wherein the control circuitry generates the haptic output in a second pattern that is different from the first pattern in response to a second input.

Description:
This application is a divisional of U.S. patent application Ser. No. 15/448,832, filed Mar. 3, 2017, which claims the benefit of provisional patent application No. 62/311,600, filed Mar. 22, 2016, both of which are hereby incorporated by reference herein in their entireties. 
    
    
     FIELD 
     This relates generally to actuators and, more particularly, to actuators for items such as items with fabric. 
     BACKGROUND 
     Cellular telephones and other devices sometimes include vibrating actuators. An actuator formed from a motor with a rotating eccentric mass may be used, for example, to provide a vibrating alert when an incoming telephone call is received. Actuators may also be used to provide haptic feedback for displays, touch pads, or other input devices. 
     If care is not taken, actuators may be too bulky, may consume more power than desired, or may not be compatible with the structures used in forming an item of interest. 
     SUMMARY 
     An item such as a fabric-based item or other item may have one or more actuators. The actuators may be used to provide a user of an item with haptic output. For example, in an item such as a fabric covered keyboard, keys may be provided with actuators so that haptic feedback may be provided as a user presses the keys. 
     An actuator may have a conductive strand of material. When it is desired to activate the actuator, a control circuit may supply a current to the conductive strand. The current may heat the conductive strand through ohmic heating and may thereby increase the length of the conductive strand due to thermal expansion effects. When the current is removed, the conductive strand may rapidly cool and contract. Changes in the length of the conductive strand may supply haptic output. 
     A control circuit in an item may be used to activate an actuator in response to user input that is supplied to an associated input device such as a switch, capacitive sensor, force sensor, light-based sensor, or other input component that is aligned with the actuator. The fabric-based item may include fabric such as woven fabric or knit fabric. Strands of conductive material may serve as signals paths for supplying current to conductive strands in actuators. 
     Magnetic-field-based actuators may be formed by coiling conductive strands around cylindrical support structures such as piping in a fabric-based item. The cylindrical support structure may initially have a non-circular cross-sectional shape such as an oval shape. When current is applied to a coiled conductive strand, the coiled conductive strand may assume a circular cross-sectional shape. The change in shape of the actuator due to the applied current may serve as haptic output for a user. 
    
    
     
       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 actuators in accordance with an embodiment. 
         FIG. 2  is a diagram of an illustrative actuator and associated control circuitry in accordance with an embodiment. 
         FIG. 3  is a diagram showing illustrative control signals that may be provided to an actuator in accordance with an embodiment. 
         FIG. 4  is a diagram showing illustrative changes in the properties of an actuator such as actuator length in response to the control signal of  FIG. 3  in accordance with an embodiment. 
         FIGS. 5, 6, and 7  are cross-sectional side views of illustrative strands of material that may be used in forming an actuator in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of a layer of woven fabric in accordance with an embodiment. 
         FIG. 9  is a top view of an illustrative layer of knit fabric in accordance with an embodiment. 
         FIG. 10  is a perspective view of an illustrative layer of material into which a length of wire for an actuator has been incorporated in accordance with an embodiment. 
         FIG. 11  is a cross-sectional side view of an illustrative item with an actuator and other circuitry in accordance with an embodiment. 
         FIGS. 12 and 13  are top views of illustrative woven fabric layers having signal paths for providing control signals to actuators in accordance with embodiments. 
         FIG. 14  is a top view of an illustrative electronic device having lengths of wire that serve as actuators in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of an illustrative actuator having a moving member that is controlled by a wire actuator in accordance with an embodiment. 
         FIG. 16  is a cross-sectional side view of an illustrative actuator having wires embedded in a layer of material in accordance with an embodiment. 
         FIG. 17  is a side view of an illustrative loop of wire in an actuator in accordance with an embodiment. 
         FIG. 18  is a side view of the loop of wire of  FIG. 17  following application of current to the wire to change the shape of the wire in accordance with an embodiment. 
         FIG. 19  is a perspective view of an oval tube structure such as a length of piping on a fabric layer with an actuator formed from a coiled wire in accordance with an embodiment. 
         FIGS. 20 and 21  are cross-sectional side views of illustrative multilayer fabric layers having wires for actuators in accordance with embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     It may be desirable to provide an electronic device or other item with actuators. Actuators may be used to provide tactile output to a user of a device. For example, haptic feedback may be provided to a user in connection with a key press event or a tactile alert may be generated. 
     An illustrative item of the type that may be provided with one or more actuators is shown in  FIG. 1 . Item  10  of  FIG. 1  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 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 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. 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, 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 part of sensors (e.g., capacitive touch sensor electrodes, resistive touch sensor electrodes, etc.). To provide a user with tactile (haptic) output, conductive strands of material may be used in forming actuators. 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), 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 actuators such as one or more actuators formed using conductive strands  12 . The actuators may be aligned with respective electrical components in circuitry  16  and item  10 . For example, each actuator in circuitry  16  may be aligned with a respective switch, sensor, or other input component. Control circuitry in circuitry  16  may be used to control 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  12  may be used in forming the electronic device, 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 . 
     The fabric that makes up 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. 
     To provide tactile output to a user of item  10 , item  10  may have one or more actuators. The actuators may be formed from one or more conductive strands of material. When current is applied to a conductive strand of material, the strand of material heats through ohmic heating. This cause the conductive strand to change shape and thereby create a force that is detectable by a user&#39;s fingertips or other body part. Current may be applied to the entire conductive strand of material (e.g., from a node at one end of the strand to a node at the other end of the strand) or may be applied to a segment of a conductive strand (e.g., between first and second nodes located at two different respective points along the length of the strand). 
     As shown in  FIG. 2 , circuitry  16  of item  10  may include control circuitry  40 . Control circuitry  40  may supply control signals to actuator  52  using conductive paths such as paths  44 . Paths  44  may be formed from one or more conductive strands  12  and/or other conductive structures (e.g., conductive housing structures, metal plates, strips of metal foil, traces on printed circuits, metal brackets, etc.). Actuator  52  may have one or more conductive strands such as illustrative conductive strand  42  of  FIG. 2 . As shown in the example of  FIG. 2 , strand  42  may extend along longitudinal axis  50  and may have at least a portion of length L (i.e., strand  42  has opposing ends and is characterized by a length L extending between these ends or strand  42  represents a segment of length L within a longer strand extending along axis  50 ). Configurations in which strand  42  of actuator  52  is a stand-alone strand of length L may sometimes be described herein as an example, but, in general, actuator  52  may include one or more strands  42  of length L that are portions of larger strands of material. Strand  42  may be formed from a segment of material such as a wire or yarn formed from multiple monofilaments that have been intertwined together (as examples). Other configurations for strand  42  may be used, if desired. 
     Strand  42  may be formed from a material such as metal (e.g., an elemental metal such as platinum, an alloy such as nickel-chrome, etc.) or other conductive material. When current is applied to strand  42 , ohmic heating will cause the temperature of strand  42  to rapidly rise. This will cause the material of strand  42  to expand due to thermal expansion effects (when the material of strand  42  has a positive coefficient of thermal expansion) or will cause the material of strand  42  to contract (when the material of strand  42  has a negative coefficient of thermal expansion). For example, assuming a positive coefficient of thermal expansion for strand  42 , application of current to strand  42  by control circuitry  40  and paths  44  will cause the length L of strand  42  to increase in directions  46 . Upon removing the applied current, air or other material surrounding strand  42  will cause strand  42  to cool and contract in directions  48  (i.e., length L may shrink). Changes in the length L of strand  42  along longitudinal axis  50  of strand  42  (i.e., elongations of strand  42 ) can be sensed by a user&#39;s finger or other body part that is in contact with strand  42 . The rise in temperature of strand  42  and the subsequent cooling of strand  42  tend to be more difficult for a user to sense than the shear forces and other forces on the user&#39;s finger that are produced by changes in length L in directions  46  and  48 . Accordingly, actuator  52  is generally effective at producing haptic output due to the ability of actuator  52  to produce dimensional changes such as length changes (i.e., longitudinal expansions and contractions in response to pulses of current). 
     Strand  42  may have any suitable size. As an example, length L of strand  42  (i.e., the length of the heated portion of a strand) may be 1-100 mm, may be 5-10 mm, may be 2-30 mm, may be more than 5 mm, more than 10 mm, less than 15 mm, less than 10 mm, or other suitable length. The diameter of strand  42  may be about 0.05 to 0.1 mm, 0.03 to 0.2 mm, more than 0.05 mm, more than 0.1 mm, less than 0.15 mm, or other suitable diameter. The conductive material that forms strand  42  may have a resistance of 1-3 ohm/cm, more than 0.5 ohm/cm, less than 5 ohm/cm, or other suitable value. Paths  44  may have a resistance that is less than the resistance of strand  42 , so that strand  42  is heated rapidly without heating paths  44  or, if desired, paths  44  may have other resistance values. 
     The control signal that control circuitry  40  applies to strand  42  may include one or more pulses  54  of current I of the type shown in  FIG. 3  (e.g., pulses with a duration T of about 1-10 ms, more than 3 ms, less than 20 ms, or other suitable pulse width), resulting in noticeable changes in strand length L (i.e., elongation of the heated strand material) and/or strand diameter, as shown in  FIG. 4 . 
     As shown in the illustrative cross-sectional side view of strand  42  of  FIG. 5 , strand  42  may be formed from a solid conductive material (e.g., strand  42  may be formed from an elemental metal or a metal that is an alloy).  FIG. 6  shows how strand  42  may have a coating layer such as coating  42 - 2  on a core such as core  42 - 1 . Core  42 - 1  may be a metal or other conductive material and coating  42 - 2  may be a polymer or other dielectric or, if desired, core  42 - 1  may be a polymer or other dielectric and coating  42 - 2  may be a metal coating layer or other conductive coating layer. Configurations in which layers  42 - 1  and  42 - 2  are both metals or are both other conductive materials may also be used. In the illustrative configuration of  FIG. 7 , strand  42  has three portions:  42 A,  42 B, and  42 C. Core  42 A, which may be formed from metal or which may be formed from polymer or other dielectric, inner coating  42 B, which may be formed from metal or which may be formed from polymer or other dielectric, and outer coating  42 C, which may be formed from metal or which 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  42  in  FIG. 7 . One or more, two or more, or three or more of the layers of material in strand  42  of  FIG. 7  may be formed from a conductive material such as metal (elemental or alloy) so that current may pass through strand  42  during actuation of actuator  52 . 
       FIG. 8  is a cross-sectional side view of an illustrative fabric. Fabric  20  of  FIG. 8  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. 9 , fabric  20  may be a knit fabric. In the illustrative configuration of  FIG. 9 , 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 . Other fabric constructions may be used for fabric  12  if desired. 
     Strands of material for actuator  52  such as illustrative strand  42  of  FIG. 7  may be incorporated into fabric  20  (e.g., by weaving one or more strands such as strand  42  into fabric  20  as a warp or weft strand in place of one of the warp or weft strands  12  of  FIG. 8  or by knitting one or more strands such as strand  42  into fabric  20  in place of one of strands  12  of  FIG. 9 ). Strands of material such as illustrative strand  42  may also be incorporated into fabric  20  by sewing or other techniques. As shown in  FIG. 10 , for example, strand (strand segment)  42  of length L may be sewn into layer  20  or otherwise incorporated into layer  20 . Layer  20  of  FIG. 10  may be a layer of fabric and/or one or more other layers of material such as plastic, leather, metal foil, etc. 
       FIG. 11  is a cross-sectional side view of item  10  in an illustrative configuration in which item  10  includes layer(s) of material such as fabric  20  that form walls for item  10  or other portions of item  10  (e.g., straps, handles, pockets, etc.). Item  10  may include circuitry  16 . Circuitry  16  may include components in interior  70  of item  10  such as electrical components  74 . Components  74  may be mounted on one or more substrates such as printed circuit board  72  and/or may be soldered, crimped, welded, or otherwise attached to conductive strands  12  in fabric  20 . Printed circuit board  72  may be a rigid printed circuit board (e.g., a printed circuit board formed from rigid printed circuit board substrate material such as fiberglass-filled epoxy) or may be a flexible printed circuit (e.g., a printed circuit formed from a sheet of polyimide or other flexible polymer substrate material). Components  74  may include integrated circuits and other components. 
     One or more actuators may be incorporated into item  10 . In the example of  FIG. 11 , actuator  52  is incorporated into a portion of fabric  20  in a location that can be touched by a user&#39;s finger (see, e.g., finger  60 ). This location may overlap a component such as component  68  of circuitry  16  (i.e., actuator  52  may be aligned with component  68 ). Component  68  may be mounted to printed circuit  72  or may be coupled to cables or other signal paths in item  10 . Components such as component  68  may include light-emitting components, may include input devices such as switches (e.g., a switch for a keyboard key or a switch for a stand-alone button, capacitive sensors that serve as touch sensors or capacitive buttons, force sensors such as force sensors based on strain gauges or other structures, light-based input devices such as light-based touch sensors or light-based proximity sensors, other input devices, or other suitable electrical devices). As shown in  FIG. 11 , component  68  or a light-emitting diode associated with component  68  may emit light  66  that is visible to a user such as viewer  62  who is viewing item  10  in direction  64 . Because actuator  52  is aligned with component  68 , actuator  52  can provide tactile output to finger  60  when finger  60  is adjacent to component  68  (e.g., when finger  60  is supplying input to an input device). Other types of arrangement may be used for item  10  if desired. The arrangement of  FIG. 11  in which components such as component  68  are aligned with actuators  52  is merely an example. 
     With one illustrative configuration for item  10 , components such as component  68  may be used to form a keyboard with illuminated keys. For example, item  10  may be a cover for a tablet computer or other device that includes a keyboard and each component  68  may include a dome switch or other switch for a respective keyboard key in the keyboard. With this arrangement, each component  68  may be associated with a light-emitting diode or other light-emitting structure that emits light  66  in a trim pattern for the keyboard key and/or in the shape of a symbol that serves as a label for the key. 
     During operation, a user may place fingers on the keyboard such as illustrative finger  60  of  FIG. 11  and may push downwards on the keyboard (item  10  in this example). The downward pressure from finger  60  may close the dome switch or may activate the capacitive sensor device, force sensor device, light-based sensor, or other component  68  that senses user key press activity. To provide the user with tactile feedback (sometimes referred to as haptic feedback), control circuitry  40  ( FIG. 2 ) of circuitry  16  may actuate actuator  52  in response to detection of the closing of the dome switch or other input device state change indicating detection of a key press event. Circuitry  40  may, for example, supply one or more current pulses to a conductive strand. As control circuitry  40  supplies one or more current pulses to strand  42  of actuator  52 , actuator  52  will change shape and this physical change in the state of actuator  52  will be detected by the user at finger  60  as a shear force or other physical force. The use of haptic feedback in this way may provide the user with confirmation that the user successfully pressed a desired key. In general, any type of force sensor, capacitive touch sensor, light-based sensor, switch, or other user input device may be provided with haptic feedback structures based on one or more of actuators  52 . The use of actuator  52  to provide a fabric keyboard key with haptic feedback is merely illustrative. 
       FIG. 12  is a top view of a portion of a fabric layer in which strand  42  of actuator  52  has been coupled to conductive strands  44  in a fabric made up of other strands  12  (e.g., insulating strands). Strands  44  may be formed from metal that is more conductive than the metal of strand  42  (as an example). At connection points such as connections  76 , solder, welds, crimped connections, or other connection structures may be used to join and electrically short strands  44  to strand  42 , which may be a stand-alone length of material or which may be a segment of a longer strand. During operation of actuator  52 , current may be applied to strand  42  from control circuitry  40  ( FIG. 2 ) using strands  44  and connections  76 . Because strands  44  are more conductive per unit length than strand  42  (in this example), there will be less heating in strands  44  (e.g., between nodes P and Q and between nodes R and S) than in strand  42  between nodes Q and R. 
     If desired, strands  44  may be collinear with strand  42  (i.e., strand  42  may be a resistive segment of conductive material within a longer strand formed up of less resistive conductive material), as shown in illustrative fabric  20  of  FIG. 13 . In this type of arrangement, there will be less ohmic heating in strands  44  between nodes A and B and between nodes C and D than in strand  42  between nodes B and C due to the lower resistance per unit length of strands  44  than strand  42 . 
     In the illustrative configuration of item  10  shown in the top view of  FIG. 14 , item  10  is an electronic device having electronic device housing  78 . Housing  78  may be formed form metal, plastic, glass, ceramic, fiber-composite materials, and/or other materials. Strands  42  may be coupled to different locations on housing  78  (e.g., strands  42  may be coupled to housing  78  directly or may be coupled to housing  78  indirectly through structures that are coupled to housing  78 ). When current is passed through strands  42 , the change in length of strands  42  will cause housing  78  to vibrate or otherwise move and provide haptic output for item  10  (i.e., strands  42  will serve as actuators  52 ). Strands  42  may lengthen or may contract in response to applied current, depending on whether strands  42  exhibit a positive or negative coefficient of thermal expansion. 
     If desired, actuators  52  may be arranged in rows, in columns, in other linear one-dimensional arrays, in curved strips, in two-dimensional arrays with rectangular outlines, in arrays with circular outlines, in arrays having shapes with curved and/or straight edges, or in other arrangements on the surface of a fabric in item  10  and/or elsewhere in item  10 . Actuators  52  may be activated in patterns by control circuitry  40 . Different patterns may be used in different contexts. For example, control circuitry  40  may direct actuators  52  to produce a first pattern of haptic output in response to satisfaction of a first set of operating conditions and to produce a second pattern of haptic output in response to satisfaction of a second set of operating conditions. 
     Item  10  may include a series of actuators  52  that extend along a given dimension in item  10  (e.g., in a row along the surface of a fabric, etc.). With this type of arrangement, each actuator  52  may be momentarily actuated in sequence to create a wave-like haptic effect. Actuators  52  may, for example, be operated in sequence to generate a wave of fabric displacement that passes from left-to-right across item  10 . Actuators  52  may also be synchronized so as to generate a wave that moves in other directions, may be used to generate oscillating output at a given position (e.g., pulses of displacement in a stationary location), or may create haptic output in other patterns across the surface of item  10 . Control circuitry  40  may create timed pulses of current to produce effects such as these or other haptic output patterns. 
       FIG. 15  is a cross-sectional side view of actuator  52  in an illustrative configuration in which strand  42  is attached to a movable member such as member  80  to provide actuator  52  with mechanical advantage (i.e., to provide leverage). Strand  42  may have one end coupled to support structure  92  and another end coupled to member  80 . Member  80  may pivot about hinge  94 . Tip  88  of member  80  may be covered with fabric  20  or other covering structures. A user&#39;s finger such as finger  60  may touch tip  88  of member  80  through fabric  20  and may thereby sense whether actuator  52  is active (i.e., whether tip  88  is moving). When no current is applied to strand  42  by control circuitry  40  ( FIG. 2 ), strand  42  has a constant length and spring  84  may bias member  80  downwards in direction  86  until strand  42  has reached its maximum room temperature length, thereby preventing further downward movement of member  80 . In this configuration, member  80  and tip  88  do not move and the user&#39;s finger  60  will not sense any movement in tip  88  of actuator  52 . When current is applied to strand  42  by control circuitry  40 , strand  42  may increase in length due to the rise in temperature of strand  42  from ohmic heating. This allows spring  84  to pull member  80  farther downwards in direction  86 . 
     Due to the position of strand  42  near pivot  82  and the relatively long length of member  80  between pivot  82  and tip  88 , small changes in the length of strand  42  will give rise to relatively larger changes in the position of tip  88 . In particular, tip  88  may move downwards in direction  90  by more than the increase in length of strand  42 . This causes finger  60  to experience enhance movement in actuator  52 . If desired, other types of lever arm structures may be used to provide actuator  52  with mechanical advantage to amplify the vibrational output (or other movement) of actuator  52  in response to application of a given amount of current to strand  42 . The configuration of  FIG. 15  is merely illustrative. Actuator  52  may form part of a keyboard key in a fabric-based item such as a fabric cover for a tablet computer, may form part of an electronic device housing (e.g., a portion of a housing associated with a button for which it is desired to provide haptic feedback), or may be formed as part of other items (e.g., fabric based items such as straps for watches, handles for bags, clothing, etc.), or may be used in any other suitable item. 
     In the example of  FIG. 16 , item  10  includes a coating layer such as layer  98  on a structure such as support structure  96 . Support structure  96  may form part of a fabric-based item (e.g., structure  96  may be formed from a layer of fabric  20 ) or may be an electronic device housing structure or other suitable supporting structure. Coating layer  98  may be formed from a layer of dielectric such as a polymer or other material that contains embedded filler structures such as particles  100 . One or more strands such as strands  42  may be embedded within layer  98 . The polymer or other dielectric material of layer  98  may help electrically insulate strands  42  and/or may help protect strands  42  from damage. Layer  98  may be formed from an elastomeric material (e.g., silicone) to allow strands  42  to stretch and create shear forces that are detectable by finger  60 . Filler  100  may include particles or fibers with high thermal conductivity (e.g., graphite, metal, etc.) to help enhance the thermal conductivity of layer  98 . This may help strands  42  to rapidly cool after each pulse of current is applied to strands  42 . Structure  96  (e.g., a metal structure) may also serve as a heat sink that helps remove heat from strands  42 . 
     In some arrangements, conductive strands  12  may be arranged in a loop shape and may operate by creating magnetic fields that move the conductive strands. Initially, actuator  52  may have a strand such as strand  102  of  FIG. 17  that has a non-circular shape such as an oval shape. When current is applied to a loop-shaped strand such as strand  102  of  FIG. 17 , magnetic field B builds up within the interior of the loop. In the presence of magnetic field B within the interior of the loop, the shape of the loop tends to become circular to minimize potential energy in the system, as shown in  FIG. 18 . The change in shape of strand  102  from the oval (non-circular) coil shape of  FIG. 17  to the circular coil shape of  FIG. 18  and the movement of strand  102  that results from this change of shape is detectable by a user&#39;s finger (see, e.g., finger  60  of  FIG. 18 ). Because actuator  52  of  FIGS. 17 and 18  operates by producing magnetic fields B, actuators such as actuator  52  of  FIGS. 17 and 18  may sometimes be referred to as magnetic-field-based actuators or coiled strand actuators. 
     If desired, a coiled strand actuator may be formed by coiling strand  102  around a tubular structure such as tubular support structure  104  of  FIG. 19 . Tubular support structure  104  may be a fabric structure such as a length of fabric piping and may, if desired, be attached to fabric  20  (e.g., to serve as trim on fabric  20  in item  10 ). In general, tubular structure (tube)  104  may be formed from any suitable materials (foam, fabric, elastomeric polymer, or other materials). Tubular structure  104  may initially have an oval profile (e.g., a cross-sectional shape that is characterized by a minor axis  106  and larger major axis  108 ) or other non-circular profile. When current is applied to strand  102 , the non-circular cross-sectional shape of structure  104  will tend to change to a circular cross-sectional shape, as described in connection with actuator  52  of  FIGS. 17 and 18 . This will create movement in tubular structure  104  that can be detected by a user&#39;s finger or other body part that is touching tubular structure  104  (i.e., tubular structure  104  and coiled strand  102  will form actuator  52 ). 
       FIGS. 20 and 21  are cross-sectional side views of fabric  20  having multiple layers. Strands such as strand  102  may be woven, knit, sewn, or otherwise incorporated into the layers of fabric  20  in the shape of a loop or set of loops, as shown in  FIG. 20 . This loop shape may allow strand  102  to form a magnetic-field-based actuator structure for actuator  52 . A user&#39;s finger such as finger  60  may detect movement in actuator  52  through fabric  20 . 
     Strands such as strand  42  of  FIG. 21  may be incorporated into fabric  20  to form an actuator pad for actuator  52 . There may be one or more parallel strands  42  on the surface of fabric  20  (e.g., to form a rectangular pad in the shape of a keyboard key or to form multi-strand actuator pads of other suitable shapes). During operation, strands  42  may be contacted on the surface of fabric  20  in item  10  by user&#39;s finger  60 . 
     Actuators such as actuators  52  of  FIGS. 20 and 21  may be incorporated into the surface of item  10 , into a strap for item  10 , into a handle or pocket for item  10 , into a planar fabric cover layer for a keyboard in item  10 , and/or into any other structure for forming item  10 . 
     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: 20200421
Publication Date: 20211123
Grant Date: 20211123
Priority Date: 20160322
Inventors: CAMP, JOHN S.
COISH, ROBERT L.
NEKIMKEN, KYLE J.
PORCELLA, JOHN A.
DAMIANAKIS, MICHAEL A.
Assignee: APPLE INC
CPC Classifications: [{"code": "D03D15/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/85", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2215/05", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D31/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/941", "inventive": true, "first": false, "tree": "[]"}, {"code": "A47C5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2401/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F7/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/96", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01F7/064", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2203/0085", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03K17/9625", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2203/01", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F7/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/85", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K2217/96062", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D1/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "D04B1/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H03K17/962", "inventive": true, "first": false, "tree": "[]"}, {"code": "A47C5/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F7/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F7/064", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/85", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/962", "inventive": true, "first": false, "tree": "[]"}, {"code": "D04B1/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "D03D15/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/941", "inventive": true, "first": false, "tree": "[]"}, {"code": "A41D31/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/9625", "inventive": true, "first": false, "tree": "[]"}, {"code": "A41D1/005", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 70461471