PATENT DOCUMENT

Publication Number: US-10725595-B2
Application Number: US-201815961742-A
Country: US
Kind Code: B2

Title: Electronic devices with covers

Abstract:
An electronic device such as a portable electronic device may have display with a capacitive touch sensor. A cover may have a front portion and a rear portion that bend along a bend axis. The front portion may overlap the display when the cover is closed. Conductive structures such as a patterned conductive layer having elongated strips of conductive material separated by gaps or another predetermined pattern may be formed in the front portion of a cover or other portion of a cover that overlaps the display and capacitive touch sensor when the cover is closed. Control circuitry in the device can gather capacitance images with the touch sensor and can detect when the cover has transitioned from open to closed or from closed to open from whether the predetermined pattern becomes present or becomes absent in the capacitance images.

Claims:
What is claimed is: 
     
       1. An electronic device operable within a removable cover having at least first and second portions that move relative to each other, wherein the first portion includes a conductive layer having a predetermined conductive layer pattern, the electronic device comprising:
 a housing; 
 a display in the housing that has a capacitive touch sensor; 
 control circuitry configured to:
 capture capacitance images with the touch sensor; 
 in response to detecting that the cover has been closed by detecting that the conductive layer pattern has become present in the capacitance images, taking a first action; and 
 in response to detecting the cover has been opened by detecting that the conductive layer pattern has become absent from the capacitance images, taking a second action that is different than the first action. 
 
 
     
     
       2. The electronic device defined in  claim 1  wherein the first action comprises placing the control circuitry in a sleep state and wherein the second action comprises placing the control circuitry in a wake state having a larger power consumption than the sleep state. 
     
     
       3. The electronic device defined in  claim 2  further comprising:
 an optical proximity sensor, wherein the control circuitry is configured to use information from the optical proximity sensor in determining whether to take the first and second actions. 
 
     
     
       4. The electronic device defined in  claim 1  wherein the predetermined conductive layer pattern is configured to enhance the recognizability of the predetermined conductive layer pattern to the control circuitry. 
     
     
       5. A cover for an electronic device, comprising:
 a conductive structure with a predetermined pattern configured to be detected in capacitance images gathered with a touch sensor in the electronic device; and 
 a dielectric covering that overlaps the conductive structure. 
 
     
     
       6. The cover defined in  claim 5  wherein the conductive structure comprises a layer of conductive polymer having the predetermined pattern, the cover further comprising a grounding path between the layer of conductive polymer and the electronic device. 
     
     
       7. The cover defined in  claim 5  wherein the predetermined pattern of the conductive structure is configured to enhance the recognizability of the predetermined pattern to the touch sensor. 
     
     
       8. A cover for an electronic device having a display with a capacitive touch sensor, comprising:
 a rear cover portion configured to receive the electronic device; and 
 a front cover portion configured to move relative to the rear cover portion, wherein the front cover portion includes a layer of conductive material that has a predetermined pattern configured to be measured by the capacitive touch sensor when the front cover portion overlaps the display. 
 
     
     
       9. The cover defined in  claim 8  wherein the front cover portion has a dielectric outer layer that covers the layer of conductive material and wherein the predetermined pattern comprises elongated strips of the layer of conductive material that extend across the display when the front cover portion overlaps the display. 
     
     
       10. The cover defined in  claim 9  wherein the layer of conductive material comprises a layer of conductive polymer. 
     
     
       11. The cover defined in  claim 10  wherein the dielectric outer layer comprises a polymer layer. 
     
     
       12. The cover defined in  claim 10  wherein the dielectric outer layer comprises leather. 
     
     
       13. The cover defined in  claim 10  wherein the dielectric outer layer comprises fabric. 
     
     
       14. The cover defined in  claim 8  further comprising a bend sensor configured to measure relative rotation between the front and rear portions. 
     
     
       15. The cover defined in  claim 8  further comprising a grounding path between the layer of conductive material and the electronic device. 
     
     
       16. The cover defined in  claim 15  wherein the grounding path comprises an electrode that is configured to capacitively couple to the electronic device when the electronic device is received in the rear cover portion. 
     
     
       17. The cover defined in  claim 15  wherein the grounding path comprises a terminal that is configured to ohmically contact the electronic device. 
     
     
       18. The cover defined in  claim 8  further comprising a component on the front cover portion that is configured to communicate with the electronic device. 
     
     
       19. The cover defined in  claim 18  wherein the component comprises a button coupled to electrode structures that are configured to be monitored by the capacitive touch sensor. 
     
     
       20. The cover defined in  claim 8  further comprising a cover touch sensor configured to provide cover touch sensor input to the electronic device. 
     
     
       21. The cover defined in  claim 20  further comprising a bend sensor, wherein the cover touch sensor is configured to gather the cover touch sensor input in response to detection, with the bend sensor, of a state in which the front cover portion and the rear cover portion lie in a common plane. 
     
     
       22. The cover defined in  claim 21  wherein the cover touch sensor comprises capacitive touch sensor electrodes in the front cover portion.

Description:
FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices with covers. 
     BACKGROUND 
     Electronic devices such as tablet computers include displays. A cover may be used to help protect a display in a tablet computer from damage. A magnet may be placed in a flexible cover and a corresponding magnetic sensor such as a Hall effect sensor may be provided in a tablet computer. During operation, the tablet computer can use the magnetic sensor to determine whether the magnet is present and therefore determine whether or not the flexible cover is open or closed. In response to determining the state of the cover, the tablet computer can take actions such as placing the device in a sleep state when the cover is present or awakening the device from the sleep state when the cover is not present. 
     Magnetic field interference from magnets in covers may give rise to challenges for sensitive components such as compass sensors and cameras. Covers may also fail to offer users desired functionality. 
     SUMMARY 
     An electronic device such as a portable electronic device may have a touch sensor. The touch sensor may be a capacitive touch sensor in a display. A cover may be provided for the electronic device. The cover may have one or more hinge areas that allow portions of the cover to rotate relative to each other. 
     A cover may have a front portion and a rear portion that bend along a bend axis. The front portion may lie in a common plane with the rear portion when the cover is open and may overlap the display when the cover is closed. A conductive structure such as a patterned conductive layer having elongated strips of conductive material separated by gaps may be formed in the front portion of a cover or other portion of a cover that overlaps the capacitive touch sensor when the cover is closed. 
     Control circuitry in the device can gather capacitance images with the touch sensor and can detect when the cover has transitioned from open to closed or from closed to open from whether the predetermined pattern becomes present or becomes absent in the capacitance images. Suitable actions such as transitioning between a wake state and a sleep state may be taken based on cover transitions. 
     If desired, touch sensors and other components may be incorporated into the cover. These components may be used to provide enhanced input to the electronic device. The electronic device can gather information from the components by monitoring the touch sensor, using magnetic sensor measurements or other sensor measurements, using wired and/or wireless communications, using a capacitively coupled or physically connected data path, and/or using other signaling arrangements. 
     In some configurations, the cover may include one or more magnets that are sensed by one or more magnetic sensors in the electronic device or other electronic device may use a proximity sensor to monitor whether the cover is closed or open. These measurements may be used, for example, to confirm whether the cover has in fact made a suspected transition in state before action is taken. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device and associated cover in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device and associated cover in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative electronic device and cover in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative cover in accordance with an embodiment. 
         FIG. 5  is a top view of an illustrative cover with an illustrative patterned conductive layer in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of illustrative conductive material that optionally includes fabric in accordance with an embodiment. 
         FIG. 7  is a perspective view of an illustrative cover and electronic device in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative cover and electronic device in an open configuration in which a touch sensor on an interior surface of the cover is gathering touch input in accordance with an embodiment. 
         FIG. 9  is cross-sectional side view of the illustrative cover of  FIG. 8  in a closed configuration in accordance with an embodiment. 
         FIG. 10  is a perspective view of an illustrative cover with a supplemental component and an associated electronic device in the cover in accordance with an embodiment. 
         FIG. 11  is a cross-sectional side view of an illustrative cover with an external button in accordance with an embodiment. 
         FIG. 12  is a flow chart of illustrative steps involved in using an electronic device and cover in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with protective covers (sometimes referred to as cases or enclosures). An illustrative system that includes an electronic device and an associated cover is shown in  FIG. 1 . As shown in  FIG. 1 , system  8  may include electronic device  10  and removable cover  12 . Electronic device  10  may be a portable electronic device. Cover  12  may have any suitable shape that allows cover  12  to mate with electronic device  10 . In the example of  FIG. 1 , cover  12  has a folio shape (sometimes referred to as a folio cover) with a rear portion  12 R and front portion  12 F. Rear portion  12 R may have a rectangular recess  14  surrounded by peripheral sidewalls  12 W or other suitable structures (straps, clips, a sleeve, corner pockets, etc.) that allow cover  12  to receive and couple to device  10 . 
     The portion of cover  12  that extends along fold axis  22  between rear portion  12 R and front portion  12 F may have hinge structures (e.g., flexible cover material that serves as a hinge or other hinge structures that couple portions  12 F and  12 R while allowing these portions to rotate relative to each other). In some configurations, additional bendable portions may be provided (e.g., one or more strips of cover portion  12 F parallel to axis  22  may be flexible to allow additional folds to be formed in cover  12 ). 
     Electronic device  10  may be a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a laptop computer, a smaller device such as a wrist-watch device, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone or tablet computer having a display such as display  24  mounted in a housing such as housing  26 . 
     Housing  26 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, fabric, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  26  may be formed using a unibody configuration in which some or all of housing  26  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  24  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes. Capacitive touch screen electrodes  28  may extend across the surface of display  24  to gather touch input from a user&#39;s fingers or other external objects. Capacitive touch screen electrodes  28  may be formed from an array of indium tin oxide pads, overlapping horizontal and vertical strips of indium tin oxide, indium tin oxide or other conductive material patterned in diamond shapes, or other transparent conductive structures (as examples). In some arrangements, thin-film metal traces on a display substrate may be used in forming touch sensor electrodes  28 . 
     Display  24  may include an array of pixels  30 . The array of pixels  30  in display  24  may form an active area such as a rectangular active area. Device  10  may have opposing front and rear faces. Pixels  30  may be formed on the front face of device  10  and may be used in displaying images for a user. Display  24  may be a liquid crystal display, an organic light-emitting diode display, or other suitable display. Display  24  may be protected using a display cover layer such as a layer of transparent glass or clear plastic. Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button, a speaker port (see, e.g., optional speaker port opening  32 ), or other component. If desired, openings may be formed in housing  26  to form communications ports (e.g., an audio jack port, a digital data port, etc.), to form openings for buttons, etc. 
     When it is desired to protect device  10  in cover  12 , housing  26  may be press fit into recess  14 , coupled to cover  12  using magnets, clips, or straps, or otherwise coupled to cover  12 . Cover  12  may, if desired, have a credit card pocket such as pocket  34  on front portion  12 F. Cover  12  may be formed from fabric, leather, polymer, other materials, and/or combinations of these materials. 
     A touch sensor that extends across the surface of display  24  may be formed using transparent capacitive touch sensor electrodes  28  that overlap pixels  30  and/or other capacitive touch sensor electrodes. Electrodes  28  may have any suitable shapes (e.g., squares, rectangles, elongated strips, lines, diamonds, and/or other shapes). In some configurations, electrodes  28  may be formed from transparent conductive material that overlaps pixels  30  (e.g., on a touch panel layer that is separate from the layers of display  24  that form pixels  30 ). Electrodes  28  may also be formed from metal traces on a display panel (e.g., metal lines that are formed on a common substrate with pixels  30 ). Other capacitive touch sensor arrangements for forming the touch sensor for display  24  may be used, if desired. Touch sensor control circuitry (e.g., one or more touch sensor integrated circuits) may be used to provide drive signals to capacitive sensor electrodes (e.g., in rows or columns) while gathering corresponding sense signals (e.g., in columns or rows). The touch sensor control circuitry may be used to determine the location or locations where a user&#39;s finger or fingers or other external objects (e.g., a touch stylus, etc.) touch display  24 . Control circuitry in device  10  may take suitable action based on user touch input. 
     In addition to gathering finger touch input from a user, the touch sensor of device  10  may be used in monitoring for the presence of patterned conductive material in case  12 . With one illustrative configuration, portion  12 F of cover  12  may include a patterned conductive layer. The patterned conductive layer may, as an example, include a unique pattern of metal strips (e.g., horizontal or vertical conductive strips of various predetermined widths that are spaced apart by gaps of various predetermined widths). A conductive layer may also be patterned to form openings of various sizes, shapes, and locations, to form conductive dots, rectangular patches of conductive material, staircase-shaped structures, and/or to form other patterned conductive layer structures. These patterns can be detected by the touch sensor of device  10  (e.g., the touch sensor can capture two-dimensional images of the conductive layer pattern). When the presence of the pattern is detected in the capacitance images collected by the touch sensor, device  10  can conclude that portion  12 F of cover  12  has been folded on top of device  10  and cover  12  is in a closed position. When the pattern is not detected by the touch sensor, device  10  can conclude that cover  12  is in an open configuration. Device  10  is therefore able to monitor the state of cover  12  (e.g., without using cover magnets in some configurations). 
     To help avoid undesired false detection events, the sizes and shapes of the conductive elements that form the conductive pattern in case  12  may be selected to be distinct from common everyday items such as coins, keys, and other common metal objects. For example, coins are typically round and commonly have diameters of more than 12 mm and less than 40 mm. Accordingly, conductive elements such as metal circles having diameters between 12 and 40 mm can be avoided to avoid a situation in which a coin or other foreign object with a coin shape that is present on device  10  produces a capacitive reading in the touch sensor of device  10  that mistakenly appears correspond to cover  12 . The conductive pattern may also be configured to contain elements (e.g., strip widths, gaps, etc.) that contain few or no redundancies. As an example, if the conductive pattern is formed from a set of N conductive strips of metal, the strip width of each of the N strips may differ from the strip widths of all other strips and the gaps separating adjacent strips may all have unique values. By configuring the conductive pattern to contain as many distinct shapes/sizes as practically possible within the limited area available on cover  12 , the conductive pattern will be exhibit a reduced (e.g., minimal) redundancy. This can help enhance pattern detection accuracy by device  10 . 
       FIG. 2  is a schematic diagram of system  8 . As shown in  FIG. 2 , electronic device  10  may have control circuitry  36 . Control circuitry  36  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  36  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. 
     Input-output circuitry in device  10  such as input-output devices  42  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  42  may include display  24  for displaying images to a user and other devices such as buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators and other haptic output devices, light-emitting diodes and other status indicators, data ports, etc. Input-output devices  42  may also include sensors  38 . Sensors  38  may include cameras (e.g., visible light and/or infrared image sensors), ambient light sensors, proximity sensors, orientation sensors, magnetic sensors (e.g., Hall effect sensors, magnetometers that serve as compasses, etc.), strain gauges and other force sensors, touch sensors (e.g., a capacitive touch sensor overlapping display  24 ), pressure sensors, fingerprint sensors, gas sensors, depth sensors such as structured light sensors, and other sensor circuitry. A user can control the operation of device  10  by supplying commands through input-output devices  42  and may receive status information and other output from device  10  using the output resources of input-output devices  42 . 
     Control circuitry  36  may be used to run software on device  10  such as operating system code and applications. During operation of device  10 , the software running on control circuitry  36  may capture and process touch sensor information gathered with the touch sensor formed from touch sensor electrodes  28  and may gather information from other sensors  38 . Based on this information, control circuitry  36  may take suitable action, such as adjusting images displayed on display  24 , adjusting the operation of sensors  38 , placing circuitry in device  10  (e.g., circuitry  36 ) in a low-power sleep state to conserve power, waking circuitry that is in a sleep state, and/or other actions associated with controlling the operation of device  10 . 
     Device  10  may receive wireless power from a wireless power transmitter and/or may receive wired power from a power adapter that is coupled to device  10  with a cable. Power that is received by device  10  may be used to charge battery  40 . During portable operation, battery  40  may be used to power the circuitry of device  10 . Battery power for powering device  10  may also be provided by a supplemental battery in cover  12  (e.g., optional battery  44 ). Cover  12  may have a connector that supplies battery power from battery  44  to device  10  (e.g., through a mating connector in device  10 ) and/or cover  12  may provide power to device  10  wirelessly. Cover  12  and device  10  may communicate via wired and/or wireless communications links (see, e.g., illustrative power and/or data link  52 ). 
     As described in connection with portion  12 F of cover  12  in  FIG. 1 , cover  12  may include patterned conductive material  46  (e.g., a patterned conductive layer having a predetermined pattern that can be recognized in the capacitance images captured by device  10 ). Patterned material  46  may be incorporated into cover  12  in a location that allows the patterned material to be imaged (sensed) using the capacitive touch sensor of device  10 . For example, patterned material  46  may be incorporated into front portion  12 F of cover  12  of  FIG. 1 . 
     If desired, cover  12  may include one or more magnets  48  or other components that help device  10  detect the position of cover  12 . For example, a magnet may be placed in a corner of front portion  12 F so that this magnet aligns with a magnetic sensor in device  10  when cover  12  is closed. To conserve power, device  10  may initially determine whether cover  12  is opened or closed by monitoring the conductive pattern of material  46  with the touch sensor over display  24 . In response to detecting the suspected presence of cover portion  12 F, control circuitry  36  can activate the magnetic sensor of device  10  and use readings from the magnetic sensor to determine whether the magnet of portion  12 F is present (e.g., adjacent to the magnetic sensor). In some configurations, device  10  may include and optical proximity sensor that can detect whether cover  12  is open (and not blocking the proximity sensor) or is closed (and blocking the proximity sensor). In this way, the touch sensor can be used to determine whether cover  12  is open or closed on a preliminary basis, whereas additional sensor circuitry such as the magnetic sensor or proximity sensor may be used to confirm the state of the cover when appropriate. 
     If desired, cover  12  may include additional devices  50  (e.g., additional components such as input-output devices  42  (e.g., a touch sensor for forming a touch pad or a touch sensor in a supplemental display), control circuitry (e.g., control circuitry such as control circuitry  36  of device  10 ), a display, force sensors and other sensors (e.g., sensors such as sensors  38  of device  10 ), status indicator lights, keyboard keys, buttons, and/or other input-output devices. Cover  12  may have a housing formed from polymer, metal, glass, ceramic, fabric, wood or other natural materials, other materials, and/or any combination of two or more of these materials. Control circuitry in cover  12  and/or device  10  may include wireless communications circuitry (e.g., radio-frequency transceiver circuitry and antenna(s)) and/or wired communications circuitry. Flexible printed circuits with metal traces and/or other layers of conductive material may be incorporated into cover  12  (e.g., for forming interconnect lines, for forming patterned conductive material  46 , etc.). 
       FIG. 3  is a cross-sectional side view of system  8  in an illustrative configuration in which cover  12  is closed so that front portion  12 F covers display  24  on device  10 . In this arrangement, device  10  is interposed between front portion  12 F and rear portion  12 R of cover  12 . Cover  12  may have patterned conductive material  46 . Conductive material  46  may be formed on portion  12 F so that conductive material  46  is detectable by the touch sensor formed from touch sensor electrodes  28  on display  24 . Conductive signal paths  56  may be formed from portions of material  46  and/or metal traces on flexible printed circuits, conductive strands of material (e.g., insulated wires and/or bare wires), metal foil, metal members (e.g., metal brackets), conductive adhesive (e.g., polymer that contains sufficient conductive filler to render the polymer conductive), and/or other conductive material. 
     The ability of the touch sensor of device  10  to detect the pattern formed from conductive material  46  may be enhanced by forming a grounding path between material  46  and the chassis (ground) of device  10 . With one illustrative configuration, housing  26  includes a metal sidewall that is grounded in device  10 . Path(s)  56  and conductive contact structure  58  (e.g., an electrical terminal such as a metal contact pad or other contact) can be formed in cover  12  so that path  56  (and thereby material  46 ) is shorted to the metal sidewall of housing  26  when device  10  is received within cover  12  as shown in  FIG. 3 . Grounding structures in cover  12  such as ground contact  60  (e.g., a pad, an elongated ring-shaped line or other elongated contact structures, etc.) may also be used to short (ohmically connect) conductive material  46  to a chassis ground formed from portions of a metal rear housing wall in housing  26  or other conductive structures in device  10 . 
     In one illustrative configuration, conductive material  46  may be grounded to ground in device  10  using capacitive coupling. With this type of arrangement, paths  56  short conductive material  46  to capacitive coupling electrode  62  in rear portion  12 R (as an example). Electrode  62  may be a rectangular metal pad or other conductive electrode structure that is in close proximity to conductive structures in device  10  (e.g., conductive housing  26  and/or capacitive coupling electrodes in device  10  such an illustrative electrode  64 ). Dielectric material in portion  12 R may separate electrode  62  from the ground structures in device  10 , but because electrode  62  is separated by a small distance from these structures (e.g., a distance of less than 5 mm, less than 2 mm, less than 1 mm, less than 0.5 mm, at least 0.01 mm, or other suitable distance), conductive material  46  will be effectively grounded to the ground structures in device  10  and capacitive touch sensor operation (e.g., capacitive sensor imaging of the pattern formed from material  46  overlapping display  24 ) may be enhanced. 
       FIG. 4  is a cross-sectional side view of a portion of cover  12 . In the example of  FIG. 4 , outer covering layer(s)  64  overlap and cover inner layer(s)  66 . Covering layer(s)  64  may be laminated to inner layer(s)  66  using heat and pressure and/or by attaching layer(s)  64  and layer(s)  66  using interposed layers of adhesive. Stiches (sewing), rivets, and/or other attachment mechanisms may also be used in forming cover  12  from materials such as covering layers  64  and inner layers  66 . 
     Inner layer(s)  66  may be formed from a layer of conductive material such as material  46 . In portion  12 F, layers  66  may be patterned to form a recognizable pattern (patterned conductive material  46 ) for detection by the touch sensor in device  10 . Some of layer  66  may also be used in forming signal paths  56 . Contacts  58  and  60  may be formed using conductive vias such as via  70  that extend through covering layers  64  and/or other structures. One or more vias may also be used in coupling portions of layers inner layers  66  together. Vias may be formed from metal traces, sewn wire, and/or other conductive structures that penetrate vertically through one or more layers of cover  12 . If desired, capacitive coupling electrodes  62  may be formed from conductive inner layer(s)  66 . Layer(s)  66  may include metal traces on flexible printed circuits or other substrates, conductive strands of material (e.g., insulated wires and/or bare wires), metal foil, metal members (e.g., metal brackets), conductive adhesive (e.g., polymer that contains sufficient conductive filler to render the polymer conductive), and/or other conductive material (see, e.g., patterned material  46  in portion  12 F of cover  12 . Material  46  may be patterned using screen printing, pad printing, spraying, dipping, machining, etching, shadow masking, die cutting, laser patterning, and/or other patterning techniques. 
     Outer layer(s)  66  may be formed from polymer, metal, glass, ceramic, wood, leather, other natural materials, natural fibers (e.g., cotton), fabric, other materials, and/or combinations of these materials. For example, in portion  12 F, a credit card pocket such a pocket  34  can be formed using layers  66  of leather, polymer, fabric, and/or other materials. The materials used in forming layers  66  and  64  may be sufficiently flexible to allow cover  12  to bend about one or more bend (fold) axes such as illustrative bend axis  22  (e.g., portions of cover  12  may be sufficiently flexible to form hinge structures). Hinges may also be formed from interlocking polymer or metal members (as examples). 
       FIG. 5  is a top view of cover  12  showing how patterned conductive material  46  (e.g., conductive material in layer(s)  66  of FIG. may have elongated portions such as horizontal strips  46 H. Strips  46 H may have different respective widths W 1 , W 3 , and W 5  and may be separated by gaps of different respective widths W 2  and W 4 , thereby providing strips  46 H with a readily detected predetermined pattern. Strips  46 H may extend horizontally across portion  12 F of cover  12  (e.g., parallel to the X axis of  FIG. 5 ). This may facilitate image recognition operations (e.g., when capturing capacitive sensor data with the touch sensor of device  10  along a line such as line  78  that extends vertically parallel to the Y axis and orthogonal to the horizontal longitudinal axes of elongated strips  46 H). The spacing and strip widths may be selected to reduce (e.g., to help minimize) redundancy and thereby enhance detection accuracy. For example, the edges of strips  46 H may be located in positions that are not integer multiples of each other, a pattern may be used which has distances between element edges that includes a minimum number of integer multiples of the smallest distance, and/or a pattern may be used in which edge distances have a minimum number of redundant spacings. By incorporating features such as these, patterned conductive material  46  may be configured to help enhance (e.g., maximize) the recognizability of the pattern formed in material  46  by control circuitry  36 . 
     Control circuitry  36  can process the capacitive sensor data (capacitance images) gathered from the touch sensor in device  10  using any suitable technique. Circuitry  36  may, for example, capture full two-dimensional capacitance images and can process these images using image recognition (pattern recognition) techniques to identify predetermined patterns in material  46 . Capacitance image data can also be gathered for a subset of the electrodes  28  in the touch sensor to help enhance processing speed and/or reduce power consumption. As an example, capacitance measurement may be made only for odd columns of the touch sensor, only for the left or right half of the touch sensor array, etc. The frequency with which touch sensor data is gathered may also be adjusted. For example, during normal operation gathering touch sensor input from the fingers of a user, the touch sensor of device  10  may be scanned at a frequency of 120 Hz, whereas during scanning operations to detect cover portion  12 F, the touch sensor of device  10  may be scanned at a lower frequency (e.g., 4-20 Hz, 1-60 Hz, at least 3 Hz., at least 6 Hz, at least 12 Hz, less than 30 Hz, or less than 18 Hz). 
     Portion  46 G of material  46  may extend into region  12 R (e.g., to facilitate capacitive coupling to ground in device  10  and/or to facilitated forming ohmic contact with ground in device  10  using contacts  58  and/or  60  of  FIG. 3 ). Vias  70  may be used in forming electrical connections with other conductive layers (e.g., contacts, capacitive coupling electrodes, etc.). If desired, material  46  may form a grounding path such as path  56 P that electrically connects strips  46 H to metal device structures in device  10  such as metal camera trim  80  (e.g., a grounded metal trim). Conductive paths such as path  56 PP may be used to electrically connect strips  46 H to contacts such as contacts  52  and/or  60 . Portion  46 G may have an opening such as opening  74  that overlaps an inductive charging coil in device  10  and thereby allows device  10  to receive wireless power when device  10  is in cover  12 . Areas  76  of cover  12  may be free of conductive material so that overlapped antennas in device  10  are not adversely affected. 
     Each cover  12  (or each batch of covers  12 ) may have an associated code formed by the pattern of strips  46 H in portion  12 F (e.g., the number of strips, strip widths, gaps widths, strip shapes, strip orientations, etc.). There may be 1-10 strips  46 H, at least 2 strips  46 H, at least 3 strips  46 H, fewer than 10 strips  46 H, and/or other suitable number of strips  46 H. Strip and gap widths may be at least 1 mm, at least 3 mm, at least 8 mm, at least 15 mm, at least 20 mm, less than 100 mm, less than 50 mm, less than 30 mm, or other suitable size. 
     Patterns of strips  46 H or other patterns formed in one or more layers of conductive material  46  may, if desired, be used to identify covers by their type. For example, covers  12  that share one or more features such as color, case material (e.g., the material of layers  64 ), color, style, hardware capabilities, model number, model series, and/or other cover features may be labeled using the same coded pattern of strips  46 H, thereby providing device  10  with this cover type information when cover  12  is placed on device  10 . In general, any suitable information can be encoded in a patterned layer of conductive material  46 . 
     One or more layers of conductive material  46  may be patterned to form a desired spatially encoded conductive pattern for cover  12  (e.g., for cover portion  12 F). Conductive material  46  may be formed from any suitable conductive structures. A side view of conductive material  46  in an illustrative configuration in which material  46  includes a layer of fabric is shown in  FIG. 6 . The fabric layer of  FIG. 6  may be a braided fabric layer, a knit fabric layer, a woven fabric layer having strands of material such as warp strands  82  and weft strands  84 , and/or other suitable fabric. The fabric may be formed from conductive strands of material and/or dielectric strands of material. The conductive strands may form a desired pattern of conductive material  46  and/or additional conductive material can be used to coat the fabric. 
     As shown in  FIG. 6 , for example, polymer  86  may include conductive filler  88  (e.g., metal particles, carbon fibers, etc.) that renders the coating formed from polymer  86  conductive. Conductive polymer (e.g., conductive pressure sensitive adhesive and/or other conductive adhesive, conductive ink, conductive paint, etc.) may be formed on one or both sides of a fabric layer and/or may be used in coating individual strands of material in a fabric layer. Screen printing, etching, and/or other patterning techniques may be used in patterning material  46 . Configurations for material  46  in which fabric is omitted may also be used. For example, a layer of patterned conductive material  46  may be formed by patterning metal traces on a flexible printed circuit substrate or other substrate, may be formed by cutting metal foil into a desired pattern, may be formed exclusively or primarily from conductive polymer, may be formed by depositing conductive polymer, metal, and/or other conductive coating layers onto leather, rigid enclosure structures, and/or other substrates, may be formed from stainless steel housing members or other rigid conductive structures that form interior and/or exterior portions of cover portion  12 F, etc. 
       FIG. 7  shows how cover  12  may include bend sensors  90 . Bend sensors  90  may be formed at portions of cover  12  that bend about bend axes  22 . Sensors  90  may be formed from strain gauges or other force sensors and/or may include other sensor circuitry that senses when portions of cover  12  bend (fold). Signal paths in cover  12  may couple sensors  90  to control circuitry  36  in device  10  and/or control circuitry  36  in device  10  may gather information from sensors  90  using control and communications circuitry in cover  12 . Control and communications circuitry in cover  12  can communicate sensor information from sensors  90  and/or other circuitry in cover  12  to device  10  using any suitable technique (e.g., wireless communications, communications through a connector that is physically and/or capacitively coupled to a corresponding connector in device  10 , etc.). 
     During operation of system  8 , device  10  and/or cover  12  may take actions based on bend sensor information. For example, the functionality of cover  12  and/or device  10  can be altered based on measurements from bend sensors  90  that are indicative of the state (e.g., the bending state) of cover  12 . As an example, device  10  may deactivate portion  24 - 1  of display  24  to conserve power while activating portion  24 - 2  of display  24  to display information and receive touch input from a user in response to detection with bend sensors  90  that portion  12 F- 2  of cover portion  12 F has been bend away from display  24  (e.g., by bending relative to portion  12 F- 1  of cover portion  12 F as shown in  FIG. 7 ). Sleep and wake states can also be adjusted based on bend sensor information. In some configurations, display modifications (e.g., selectively turning off portions of display  24 ) can be performed based on capacitance images (e.g., images that contain part of a patterned conductive layer). 
     In the example of  FIG. 8 , information from sensors  90  indicates that portion  12 F of cover  12  is lying flat on a surface with cover portion  12 R (e.g., portions  12 F and  12 R lie in a common plane so that cover  12  is open and flat). In response, control circuitry in device  10  and/or cover  12  activates user input components on portion  12 F and gathers user input to help in controlling device  10 . For example, portion  12 F may have a cover touch sensor formed from an array of cover capacitive touch sensor electrodes  92  that can be used to gather cover touch input from user finger  94  or other external objects. This touch input may be supplied to device  10  and used by device  10  as additional touch input (e.g., input in addition to the touch input gathered from the touch sensor of display  24 ). When bend sensors  90  of cover  12  of  FIG. 8  detect that cover portion  12 F is being folded under portion  12 R of cover  12  as shown in  FIG. 9 , the capacitive touch sensor in portion  12 F can be deactivated to avoid undesired touch input. 
       FIG. 10  shows how cover  12  (e.g., cover portion  12 F) may have supplemental input devices (e.g., sensors and other devices  50  of  FIG. 2 ). In the example of  FIG. 10 , device  10  has been received within portion  12 R of cover  12 . Device  10  may have a data port with a connector such as connector  100  that mates with a corresponding connector  102  in cover  12 . If desired, cover  12  may also include electrodes such as electrode  98  that form ohmic connections with conductive housing structures, that capacitively couple to mating electrodes in device  10 , and/or that otherwise facilitate the formation of capacitive sensor grounding connections and/or communications paths between the circuitry of cover  12  and the circuitry of device  10 . Signal paths such as signal paths  56  may couple components in cover  12  such as illustrative component  96  to the circuitry of device  10  through connector  102 , electrode(s)  98 , and/or other communications paths. Component  96  may be a button, keyboard, touch sensor, light sensor and/or other input device. Configurations in which components such as component  96  serve as output devices (e.g., light sources, speakers, etc.) may also be used. 
     If desired, input from a component in cover  12  may be supplied to device  10  using the touch sensor of display  24 . Consider, as an example, the arrangement of  FIG. 11 . As shown in  FIG. 11 , device  10  may be mounted in cover  12  so that cover portion  12 F overlaps display  24 . Cover portion  12 F may include electrodes such as electrodes  104 . Electrodes  104  may include floating electrode(s) and/or electrode(s)  104  that are shorted to ground in device  10  using paths  56 . Button  106  may have a dome switch or other switch  108  that is closed when a user&#39;s finger  94  presses button  106 . This shorts electrodes  104  together and/or selectively couples one or more electrodes  104  to ground to change the pattern of capacitances measured using the capacitive touch sensor of display  24  (e.g., electrodes  28  of  FIG. 1 ). Device  10  can then take suitable action based on this measured change (e.g., control circuitry  36  can conclude from the change in measured capacitance that button  108  has been pressed). If desired, button  106  or other components may alter current flow through electrodes  104  to produce a magnetic field (e.g., by shorting a conductive line formed from one or more electrodes  104  to a power supply path) and/or can make other changes to the electromagnetic properties of cover  12  that are detected by a magnetic sensor (e.g., a compass sensors) in device  10 . By monitoring the magnetic field present at the compass, device  10  can determine whether the user is pressing button  106  and/or otherwise activating a supplemental input device on cover  12  that affects the magnetic field. 
       FIG. 12  is a flow chart of illustrative operations involved in using system  8  to detect the presence of cover portion  12 F. 
     During the operations of block  120 , device  10  may the capacitive touch sensor of display  24  to gather touch sensor measurements (e.g., capacitance images formed using data from multiple touch sensor electrodes, sometimes referred to as capacitive touch sensor images). A lower-than-normal scan frequency may be used in gathering touch sensor data to conserve power. If cover  12  is in an open state, portion  12 F will not overlap display  24  and device  10  will not detect the presence of the patterned layer of conductive material  46 . If cover  12  is in a closed state, however, portion  12 F and the layer of patterned conductive material  46  of portion  12 F will overlap display  24  and will be detected by device  10 . 
     Device  10  can identify a coded pattern that is embedded in the patterning of material  46  and can use this identification to determine when cover  12 F is present rather than the user&#39;s fingers or other objects. For example, control circuitry  36  can determine whether cover  12  has been opened (transitioning from closed to open) by detecting from the capacitance images that the patterned conductive layer that was previously present in the capacitance images has become absent from the capacitance images. Likewise, control circuitry  36  can detect when cover  12  has been closed (transitioning from a cover open state to a cover closed state) by determining from the capacitance images that the previously absent patterned conductive layer has become present in the capacitance images. 
     Device  10  can take suitable action based on detected changes in the state of cover  12  (e.g., transitioning from open to closed or from closed to open). The capacitance images that are gathered during the cover state transition monitoring operations of block  120  can extend over the full two-dimensional extent of the touch sensor electrode array or can include subsets of the touch sensor electrodes (e.g., just odd numbered touch sensor electrode columns, only the first row of the touch sensor electrodes, the left or right or top or bottom half of the touch sensor area, other reduced portion of the maximum touch sensor electrode coverage area, etc.). 
     If desired, confirmation of the state of cover  12  (e.g., whether cover portion  12 F is overlapping display  24 ) can be obtained using one or more additional sensors before device  10  takes action based on a suspected (capacitively detected) cover state change. For example, cover portion  12 F may have a magnet and device  10  may have a magnetic sensor that can be activated during the operations of block  122  to detect whether the magnet is present and thereby confirm whether cover  12  is open or closed. Because the magnetic sensor need not be activated until device  10  strongly suspects that cover  12  has changed state, power consumption associated with continually operating the magnetic sensor may be reduced. 
     In some arrangements, other sensors can be used during the confirmation operations of block  122  in addition to or instead of a magnetic sensor. For example, the magnetic sensor and magnet need not be used in scenarios in which device  10  includes a proximity sensor such as an optical proximity sensor. This type of sensor may, for example, be located adjacent to speaker port  32  (e.g., under a display cover layer for display  24 ). The optical proximity sensor may include a light emitter such as an infrared light-emitting diode and a corresponding light detector such as an infrared photodiode. When objects are not located in the vicinity of the proximity sensor, little emitted infrared light will be reflected back to the infrared photodiode and device  10  can conclude that cover portion  12 F is not present. When cover  12 F overlaps display  24 , infrared light from the infrared light emitter will be detected by the infrared photodiode and device  10  can thereby confirm that cover  12 F is present. 
     If the operations of block  122  do not confirm that the state of cover  12  has changed as initially suspected, cover state monitoring operations can continue at block  120 . If, however, device  10  determines from one or more confirmatory sensor measurements at block  122  that the cover has changed state (e.g., been opened or closed by the user), processing can proceed to block  124 . 
     During the operations of block  124 , device  10  can take suitable action based on the detected change in the state of cover  12 . For example, if cover  12  had previously been closed and device  10  was in a low-power sleep state, detection of the opening of cover  12  may be used to cause device  10  to enter a higher power normal (wake) state (e.g., a state in which display  24  can be used and a user may supply input to the touch sensor of display  24 ). If cover  12  has previously been open and device  10  was in a normal awake (wake) mode of operation, detection of the closing of cover  12  can direct device  10  to place its circuitry in a low power sleep state (e.g., a state in which control circuitry  36  and other circuitry in device  10  consume less power than normal and in which display  24  is off and the touch sensor of display  24  is inactive for gathering normal input, while still being used to gather low-frequency touch sensor data during the monitoring operations of block  120 ). If desired, the operations of block  124  may involve monitoring for input from circuitry on cover  12  (e.g., a touch sensor of the type described in connection with portion  12 F of cover  12  in  FIG. 8 , a button of the type described in connection with button  106  of  FIG. 11 , a supplemental component such as supplemental component  96  of  FIG. 10 , bend sensors  90  of  FIG. 7 , etc.). 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20180424
Publication Date: 20200728
Grant Date: 20200728
Priority Date: 20180424
Inventors: SCHOOLEY, STEPHEN T.
HELBERT, KENDALL L.
BENBASAT, ARI Y.
MCCOY, CLAYTON J.
ROSNER, DEVON J.
HOOVER, JOSHUA A.
COLE, SEAN M.
ZHAO, YUFEI
LIU, ZHAO
REED, JUDD
Assignee: APPLE INC
CPC Classifications: [{"code": "A45C11/002", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y02D30/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02D10/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K5/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3215", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3287", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2200/1634", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1677", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/266", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3262", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1643", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1677", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1632", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3218", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/3265", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 68237762