PATENT DOCUMENT

Publication Number: US-10775890-B2
Application Number: US-201715717682-A
Country: US
Kind Code: B2

Title: Electronic device having a piezoelectric body for friction haptics

Abstract:
An electronic device is disclosed which includes a conductive layer for providing haptic feedback at an input surface of the electronic device. The conductive layer includes conductive particles within an organic compound, such as an epoxy. When the conductive layer is activated it may provide frictional or other tactile feedback at the input surface.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; and 
 a cover assembly coupled to the housing and comprising:
 a cover layer; 
 an electrostatic output layer below the cover layer configured to receive a voltage to capacitively couple to a user touching the cover layer, the electrostatic output layer comprising:
 an epoxy layer coupled to the cover layer; 
 an array of nonconductive particles disposed within the epoxy layer; 
 an array of conductive particles dispersed to a predetermined density within the epoxy layer and among the array of nonconductive particles; and 
 
 a piezoelectric body below the cover layer and defining an upper surface and a lower surface; 
 a first electrode group disposed on the upper surface; and 
 a second electrode group disposed on the lower surface and comprising:
 a touch sense electrode coupled to a capacitive touch sensor; and 
 a haptic drive electrode configured to apply a voltage across the piezoelectric body to generate haptic feedback through the cover assembly. 
 
 
 
     
     
       2. The electronic device of  claim 1 , further comprising processing circuitry coupled to the first and second electrode groups. 
     
     
       3. The electronic device of  claim 2 , wherein the processing circuitry is configured to apply the voltage across the piezoelectric body in response to a touch. 
     
     
       4. The electronic device of  claim 1 , wherein the touch sense electrode is disposed adjacent to the haptic drive electrode. 
     
     
       5. The electronic device of  claim 1 , wherein:
 the touch sense electrode is a member of a set of touch sense electrodes; and 
 the haptic drive electrode is a member of a set of haptic drive electrodes. 
 
     
     
       6. The electronic device of  claim 5 , wherein the set of haptic drive electrodes are interstitially disposed between the set of touch sense electrodes. 
     
     
       7. The electronic device of  claim 1 , wherein the second electrode group is arranged as a set of columns and the first electrode group is arranged as a set of rows, perpendicular to the set of columns. 
     
     
       8. The electronic device of  claim 1 , wherein the touch sense electrode has a first trace width and the haptic drive electrode has a second trace width. 
     
     
       9. The electronic device of  claim 8 , wherein the second trace width is greater than the second trace width. 
     
     
       10. The electronic device of  claim 1 , wherein the first electrode group and the second electrode group are optically transparent. 
     
     
       11. An electronic device, comprising:
 a transparent cover; 
 an electrostatic output layer below the transparent cover configured to receive a voltage to capacitively couple to a user touching the transparent cover, the electrostatic output layer comprising:
 an epoxy layer coupled to and extending across the transparent cover; and 
 an array of conductive particles disposed at a predetermined density within a defined region of the epoxy layer; 
 
 a display below the transparent cover defining an active display area below the epoxy layer of the electrostatic output layer, the defined region within the active display area; 
 a user input sensor positioned below the transparent cover and above the display, the predetermined density selected to not interfere with operation of the user input sensor; 
 a stiffener layer below the user input sensor; 
 a piezoelectric body below the user input sensor and defining an upper surface and a lower surface; 
 a haptic reference electrode group disposed on the upper surface; and 
 a haptic drive electrode group disposed on the lower surface and configured to apply a voltage across the piezoelectric body to generate haptic feedback through the user input sensor and the transparent cover. 
 
     
     
       12. The electronic device of  claim 11 , wherein the display is disposed below the piezoelectric body. 
     
     
       13. The electronic device of  claim 11 , wherein the user input sensor is a force input sensor. 
     
     
       14. The electronic device of  claim 11 , wherein the user input sensor is a touch input sensor. 
     
     
       15. The electronic device of  claim 11 , wherein the display is disposed below the piezoelectric body. 
     
     
       16. The electronic device of  claim 15 , wherein the stiffener layer is positioned below the display. 
     
     
       17. A cover assembly for an electronic device, comprising:
 a transparent cover layer; 
 an electrostatic output layer below the transparent cover layer configured to receive a voltage to capacitively couple to a user touching the transparent cover layer, the electrostatic output layer comprising:
 an epoxy layer coupled to the transparent cover layer; 
 a nonconductive particle array disposed at a first density within the epoxy layer; and 
 a conductive particle array disposed at a second density within the epoxy layer, the conductive particle array dispersed among the nonconductive particle array; 
 
 a piezoelectric body below the transparent cover layer and the electrostatic output layer and defining an upper surface and a lower surface; 
 a first electrode group disposed on the upper surface; and 
 a touch sense electrode group disposed on the lower surface and coupled to a capacitive touch sensor; and 
 a haptic drive electrode group disposed on the lower surface and arrange interstitially with the touch sense electrode group, the haptic drive electrode group configured to apply a voltage across the piezoelectric body to generate haptic feedback through the cover assembly. 
 
     
     
       18. The cover assembly of  claim 17 , further comprising a display positioned below the piezoelectric body. 
     
     
       19. The cover assembly of  claim 17 , further comprising a stiffener layer positioned above the piezoelectric body. 
     
     
       20. The cover assembly of  claim 17 , wherein the first electrode group is arranged perpendicular to the touch sense electrode group and the haptic drive electrode group. 
     
     
       21. The cover assembly of  claim 17 , wherein the first density is different from the second density. 
     
     
       22. The cover assembly of  claim 21 , wherein the first density is greater than the second density. 
     
     
       23. The cover assembly of  claim 21 , wherein the conductive particle array is disposed at the second density within a defined region of the nonconductive particle array.

Description:
FIELD 
     The described embodiments relate generally to an electronic device which provides haptic output. More particularly, the present embodiments relate to providing electrostatic haptic output through coating a surface of an electronic device with a conductive coating and a passivation coating over the conductive coating. 
     BACKGROUND 
     Many electronic devices provide feedback to a user through various stimuli, such as visual representations, audible sound, and tactile responses. Feedback from an electronic device may enhance user experience in interacting with the electronic device. For example, entry of inputs may be confirmed to a user through a visual alert, through a particular sound, and so on. 
     Electronic devices may also provide tactile feedback to a user. As an example, a mechanical button may provide feedback through the actions of a spring, collapsible dome, or similar resistive component. In other devices, vibratory feedback may be provided to a user in contact with the electronic device, such as through an actuating haptic motor. 
     SUMMARY 
     Embodiments described herein relate to an electronic device providing electrostatic haptic feedback at an input surface of the electronic device. The electronic device may include a cover with an input surface, which may include a rigid transparent sheet. An electrostatic conductive layer may be disposed over the transparent sheet, and a passivation layer may be placed over the electrostatic conductive layer to form the input surface. A part of the electrostatic conductive layer may be activated through an electric field to provide friction feedback at the input surface. 
     In an example embodiment, an electronic device includes a housing forming an external surface of the electronic device. A cover assembly is coupled to the housing and defines an input surface. The cover assembly includes a cover sheet layer, a touch sensor layer coupled to the cover sheet layer and configured to detect a touch on the input surface, and an electrostatic conductive layer coupled to the cover sheet layer. The electronic device also includes processing circuitry configured to drive the touch sensor layer, causing at least a portion of the electrostatic conductive layer to experience an electric field. In response to the electric field, the electrostatic conductive layer causes variable friction feedback at the input surface. 
     In some cases, the processing circuitry drives the touch sensor layer, causing a region of the electrostatic conductive layer corresponding to a location of the touch to experience the electric field. A display may be positioned below the cover assembly and configured to visually indicate a feedback region. The electrostatic conductive layer causes variable friction feedback at a region of the input surface corresponding to the feedback region. 
     In another example embodiment, an electronic device includes a housing, a display at least partially enclosed by the housing, and a transparent cover assembly coupled to the housing and positioned over the display. The transparent cover assembly includes a cover sheet layer and a drive touch electrode and a sense touch electrode coupled to and positioned below the cover sheet layer. The drive touch electrode and the sense touch electrode operate to detect a location of a touch on the external surface. 
     An electrostatic conductive layer is coupled to and positioned above the cover sheet layer. The electrostatic conductive layer includes conductive particles in an organic matrix. The passivation layer includes a dielectric material and forms an external surface of the electronic device. The electrostatic conductive layer is configured to increase friction between a finger and the external surface in response to the drive touch electrode receiving a drive signal. A passivation layer is coupled to and positioned above the electrostatic conductive layer. 
     In some examples, the electrostatic conductive layer also includes non-conductive particles, and the conductive particles are formed into a conductive region corresponding to the drive touch electrode surrounded by non-conductive particles. The organic matrix may include an epoxy and the conductive particles may include at least one of indium tin oxide, tin oxide, aluminum zinc oxide, indium zinc oxide, or a transparent conductive oxide. 
     In another example embodiment, a method is provided for forming a cover assembly for an electronic device to provide electrostatic feedback on an input surface. The method includes the operations of forming an organic compound and distributing conductive particles within the organic compound. The organic compound is deposited over a cover sheet formed from a rigid transparent material. The organic compound is cured, and a dielectric layer is deposited over the organic compound. The method also includes coupling a touch sensor to the cover sheet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like elements. 
         FIG. 1  depicts an electronic device incorporating a hybrid conductive coating for electrostatic haptic feedback according to the present disclosure. 
         FIG. 2A  depicts a cross-section of a cover assembly, taken along section A-A of  FIG. 1 , illustrating providing electrostatic haptic feedback through activation of an electrostatic conductive layer. 
         FIG. 2B  depicts the cross-section of  FIG. 2A , illustrating providing electrostatic haptic feedback through activation of the electrostatic conductive layer. 
         FIG. 2C  depicts the cross-section of  FIG. 2A , illustrating providing electrostatic haptic feedback through activation of the electrostatic conductive layer. 
         FIG. 2D  depicts the cross-section of  FIG. 2A , illustrating providing electrostatic haptic feedback through activation of the electrostatic conductive layer. 
         FIG. 2E  depicts the cross-section of  FIG. 2A , illustrating providing electrostatic haptic feedback through activation of the electrostatic conductive layer. 
         FIG. 3  depicts another cross-section of a cover assembly, taken along section A-A of  FIG. 1 , illustrating capacitive coupling of the electrostatic conductive layer to a touch sensor layer. 
         FIG. 4  depicts another cross-section of a cover assembly, taken along section A-A of  FIG. 1 , illustrating particles within an electrostatic conductive layer and a passivation layer. 
         FIG. 5  depicts another cross-section of a cover assembly, taken along section A-A of  FIG. 1 . 
         FIG. 6A  depicts a cross-section of a touch sensor, such as described herein, particularly illustrating electrodes of the touch sensor and a piezoelectric haptic element disposed on the same surface. 
         FIG. 6B  depicts the touch sensor of  FIG. 6A  when viewed along section line B-B. 
         FIG. 7A  depicts a cross-section of a cover assembly, such as described herein, particularly illustrating a piezoelectric haptic element disposed above a display. 
         FIG. 7B  depicts a cross-section of a cover assembly, such as described herein, particularly illustrating a piezoelectric haptic element disposed below a display. 
         FIG. 8A  depicts an example particle arrangement for an electrostatic conductive layer. 
         FIG. 8B  depicts another example particle arrangement for an electrostatic conductive layer. 
         FIG. 8C  depicts another example particle arrangement for an electrostatic conductive layer. 
         FIG. 9A  depicts a top view of an electronic device according to the present disclosure, illustrating electrostatic haptic feedback on a portion of an input surface. 
         FIG. 9B  depicts another top view of an electronic device according to the present disclosure, illustrating electrostatic haptic feedback on another portion of an input surface. 
         FIG. 9C  depicts another top view of an electronic device according to the present disclosure, illustrating electrostatic haptic feedback on another portion of an input surface. 
         FIG. 10  depicts an example method of forming a cover assembly for an electronic device to provide electrostatic feedback at an input surface. 
         FIG. 11  depicts a schematic view illustrating components of an electronic device according to the present disclosure. 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented therebetween, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred implementation. To the contrary, the described embodiments are intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the disclosure and as defined by the appended claims. 
     The following disclosure relates to an electronic device which provides electrostatic haptic feedback over an input surface of the electronic device. The electrostatic haptic feedback may provide tactile sensations to a user in contact with the input surface, such as changes in friction. The electronic device may include a hybrid conductive coating, which may include inorganic conductive and non-conductive particles within an organic matrix. The hybrid conductive coating may include an electrostatic conductive layer, and the device may be configured to apply an electrostatic charge to an input surface or other exterior surface of the device through the electrostatic conductive layer. 
     The electrostatic charge may alter or modify a tactile or touch-based stimulus that is perceived by a user. In some cases, the tactile feedback may cause an increased (or decreased) friction or surface roughness between an object (e.g., the user&#39;s finger) and the exterior/input surface as the object is moved along the input surface, for example by electrostatically attracting the user&#39;s finger to the input surface. 
     The input surface may include an electrostatic conductive layer below a passivation layer. Electrostatic haptic feedback may be provided by an electric field interacting with the electrostatic conductive layer to produce an attractive force between the electrostatic conductive layer and an object (e.g., the user&#39;s finger). The passivation layer may be a dielectric layer, sealing the electrostatic conductive layer from moisture and the external environment while providing an electrically insulating surface between the electrostatic conductive layer and the user&#39;s finger. 
     Additional components, such as touch sensors, may be placed below the electrostatic conductive layer. In order to provide haptic feedback to an input surface, the electrostatic conductive layer may have a low resistance level relative to the passivation layer. In some embodiments, it may also be desirable to avoid the electrostatic conductive layer interfering with or blocking performance of other sensors, such as capacitive touch sensor below the electrostatic conductive layer. 
     Accordingly, the electrostatic conductive layer may be formed with conductive particles within a non-conductive substrate. The non-conductive substrate may be an organic compound or matrix, such as an epoxy. For example, conductive particles may be dispersed within an organic epoxy, and the epoxy may be deposited over a cover sheet layer and cured. In some embodiments, the conductive particles may be patterned over the cover sheet layer, or the conductive particles may be dispersed. 
     A drive electrode may be positioned below the electrostatic conductive layer. All or a portion of the conductive layer may be activated by driving the drive electrode with an electrical signal. Driving the drive electrode may cause an electric field to be generated, which may induce an attractive force in the conductive particles of at least a portion of the electrostatic conductive layer. 
     In some embodiments, the conductive particles nearest the drive electrode may become electrically coupled to the drive electrode, which may localize the haptic feedback produced. In some embodiments, the electrostatic feedback may not be localized. The drive electrode may be one of a set or array of drive electrodes. In some embodiments, the drive electrode may also be a drive electrode of a capacitive touch sensor. 
     A particular embodiment of the input device may be a portable electronic device, such as a mobile telephone or tablet. The electronic device may include a cover assembly coupled to a housing, with the cover assembly defining an input surface. The cover assembly may be transparent and enclose a display. 
     The cover assembly includes a cover sheet layer and a conductive layer deposited on the cover sheet layer. The conductive layer may provide a variable or configurable friction feedback to the input surface. A passivation layer may be deposited over the conductive layer, which may be a dielectric layer between the conductive layer and a finger or other object in contact with the passivation layer. A touch sensor may be disposed below the cover sheet layer to detect the presence and/or location of an object on the input surface of the cover assembly. 
     The touch sensor may include drive touch electrodes and sense touch electrodes, which may be arranged in a pattern. In some embodiments, the drive touch electrodes may be formed as linear electrodes formed in rows, and the sense touch electrodes may be formed as linear electrodes in columns. A substrate may separate the drive touch electrodes and the sense touch electrodes. The drive touch electrodes and/or sense touch electrodes may be monitored for changes in capacitance indicating a touch on the input surface. 
     Additionally, the drive touch electrodes may be driven with a haptic drive signal in order to provide the electrical field to activate the conductive layer and provide electrostatic haptic feedback at the input surface. The haptic drive signal may induce a variable electrostatic charge on the surface, which may produce sensations of higher and/or lower friction to a user operating the electronic device. 
     In some cases, an electronic device may incorporate a piezoelectric body that can be used as a haptic output element. The piezoelectric body may also serve as a dielectric layer separating sensing electrodes of a capacitive touch sensor, providing a single component to detect input and provide haptic output. In such examples, a ground electrode of the piezoelectric body can be used as a ground electrode of the capacitive touch sensor. 
     As a result of these constructions, an input/output interface can be manufactured to smaller dimensions, with fewer parts and materials, at increased speed, and reduced cost. It may be appreciated that any embodiment described herein—or any alternative thereto, or modification thereof—can incorporate one or more input sensors that share one or more elements, electrodes, components, or layers with a haptic output element. 
     Further, in some embodiments, a haptic output element of the cover assembly is configured to receive a voltage that is substantially higher than a system voltage or reference voltage of the electronic device. For example, a haptic output element may be configured to drive an electrostatic conductive layer positioned below the input surface with a high voltage signal in order to increase perceived friction between the user&#39;s finger and the interface surface via electroadhesion. In another example, a haptic output element may be configured to apply a high voltage signal to a piezoelectric body in order to mechanically agitate the interface surface (in-plane or out-of-plane) nearby the user&#39;s finger. 
     These and other embodiments are discussed below with reference to  FIGS. 1-11 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  depicts an electronic device incorporating a hybrid conductive coating for electrostatic haptic feedback according to the present disclosure. In the illustrated embodiment, the electronic device  100  is implemented as a portable electronic device, such as a mobile phone. Other embodiments can implement the electronic device differently. For example, an electronic device can be a tablet computing device, a laptop computer, a wearable computing device, a digital music player, a kiosk, a stand-alone touch screen display, a mouse, a keyboard, and other types of electronic devices that provide electrostatic haptic feedback at an external surface of the electronic device  100 . 
     The electronic device  100  includes a housing  102  at least partially surrounding a display  104 . The housing  102  can form an external surface or partial external surface for the internal components of the electronic device  100 . The housing  102  can be formed of one or more components operably connected together, such as a front piece and a back piece. Alternatively, the housing  102  can be formed of a single piece operably connected to the display  104 . 
     The display  104  can provide a visual output to the user. The display  104  can be implemented with any suitable technology, including, but not limited to, a liquid crystal display element, a light emitting diode element, an organic light-emitting display element, an organic electroluminescence element, and the like. A cover assembly  106  may be positioned over the display  104  and define an input surface  108  external to the electronic device  100 . 
     A cover assembly  106  may be positioned over the front surface (or a portion of the front surface) of the electronic device  100 . At least a portion of the cover assembly may function as an input surface  108  that receives touch and/or force inputs. In some embodiments, touch and/or force inputs can be received across other portions of the cover assembly  106  and/or portions of the housing  102 . The cover assembly  106  may include various layers and components, including a cover sheet layer formed of a suitable material, such as glass, plastic, sapphire, or combinations thereof. Example cross-sections of the layers of the cover assembly  106  are described with respect to  FIGS. 3-5 . 
     The cover assembly  106  may additionally include a touch sensor for detecting the presence and/or the location of one or more touches on the input surface  108  of the electronic device  100 . In many examples, the touch sensor is a capacitive touch sensor configured to detect the location and/or area of one or more touches of a user&#39;s finger and/or a passive or active stylus on the input surface  108 . 
     The cover assembly  106  may include a force sensor configured to detect a location and/or amount of force applied to the input surface  108 . The force sensor may be operably connected to force-sensing circuitry configured to estimate an amount of applied force. The force-sensing circuitry may output a signal or otherwise indicate an input in response to estimating an amount of force exceeding a threshold. The threshold amount may be fixed or variable, and more than one threshold may be provided corresponding to different inputs. 
     In a particular embodiment, the cover assembly  106  may also include a hybrid conductive coating, which may include inorganic conductive and non-conductive particles within an organic matrix. The hybrid conductive coating may include one or more layers for providing electrostatic haptic feedback at the input surface  108  of the electronic device  100 . The hybrid conductive coating of the cover assembly  106  may include an electrostatic conductive layer, which may be below a dielectric passivation layer. When activated, the electrostatic conductive layer may produce an electrostatic charge on the input surface  108 , which may produce tactile feedback to a user in the form of modified friction (e.g., variable friction feedback) as the user moves a finger across the input surface  108  where electrodes are active. Example operations of electrostatic haptic feedback are described below with respect to  FIGS. 2A-2E . 
     The electrostatic conductive layer may include conductive particles within a substrate, such as an organic matrix or compound. In some examples, the conductive particles may be arranged in a pattern, such as described below with respect to  FIGS. 8A-8C . The conductive particles may be individually controllable such that at a given time the level of friction may vary at multiple locations across the input surface  108 , such as described below with respect to  FIGS. 9A-9C . An example method for forming electrostatic feedback layers within the cover assembly  106  is described below with respect to  FIG. 10 . 
     In some examples, friction or other haptic feedback may be provided through a piezoelectric body, such as a piezoelectric substrate. A piezoelectric haptic output can, in some examples, be a localized decrease in perceived friction between the user&#39;s finger and the interface surface. In some examples, the piezoelectric body may also provide an insulating substrate for an input sensor, such as a touch sensor. Examples of an electronic device  100  incorporating a piezoelectric body for haptic output are further described below with respect to  FIGS. 6A-7B . 
     Various layers of the cover assembly  106  and/or the display  104  (such as the cover sheet, display  104 , touch sensor layer, force sensor layer, and so on) may be adhered together with an optically transparent adhesive and/or may be supported by a common frame or portion of the housing  102 . A common frame may extend around a perimeter, or a portion of the perimeter, of the display  104  and/or the cover assembly  106 . The common frame may be segmented around the perimeter, a portion of the perimeter, or may be coupled to the display  104  and/or the cover assembly  106  in another manner. 
     The common frame can be made from any suitable material such as, but not limited to: metal, plastic, ceramic, acrylic, and so on. The common frame, in some embodiments, may be a multi-purpose component serving an additional function such as, but not limited to: providing an environmental and/or hermetic seal to one or more components of the display  104 , the cover assembly  106 , or the electronic device  100 ; providing structural support to the housing  102 ; providing pressure relief to one or more components of the display  104 , the cover assembly  106 , or the electronic device  100 ; providing and defining gaps between one or more layers of the display  104  and/or the cover assembly  106  for thermal venting and/or to permit flexing of the layers in response to a force applied to the input surface  108 ; and so on. 
     In some embodiments, each of the layers of the display stack may be attached or deposited onto separate substrates that may be laminated or bonded to each other. The display stack may also include other layers for improving the structural or optical performance of the display  104 , including, for example, polarizer sheets, color masks, and the like. Additionally, the display stack may include a touch and/or force sensor layer for receiving inputs on the input surface  108  of the electronic device  100 . 
     In many cases, the electronic device  100  can also include a processor, memory, power supply and/or battery, network connections, sensors, input/output ports, acoustic components, haptic components, digital and/or analog circuits for performing and/or coordinating tasks of the electronic device  100 , and so on. For simplicity of illustration, the electronic device  100  is depicted in  FIG. 1  without many of these components, each of which may be included, partially and/or entirely, within the housing  102 . Examples of such components are described below with respect to  FIG. 11 . 
     The electronic device  100  may also include one or more input devices  110 , which may be coupled to the housing  102  and/or the cover assembly  106 . The input device  110  may be a mechanical button, a soft button (e.g., a button that does not physically move but still accepts inputs), an icon or image on a display, and so on. The input device  110  may receive touch inputs and/or force inputs. In some embodiments, the input device  110  may additionally or alternatively be operable to receive biometric data from a user, such as through a capacitive fingerprint sensor, or another biometric sensor implemented with ultrasonic, infrared, multi-spectral, RF, thermal, optical, resistance, piezoelectric, and other technologies. 
       FIGS. 2A-2E  depict a cross-section of a cover assembly, taken along section A-A of  FIG. 1 , illustrating providing electrostatic haptic feedback through activation of the conductive layer.  FIG. 2A  illustrates an object, such as a user&#39;s finger  212 , in contact with an input surface  208  of a cover assembly  206 . The user&#39;s finger  212  in contact with the input surface  108  is illustrated at a second time in  FIG. 2B , at a third time in  FIG. 2C , at a fourth time in  FIG. 2D , and at a fifth time in  FIG. 2E , as the user&#39;s finger  212  moves across the input surface  208 . 
     As depicted in  FIG. 2A , the cover assembly  206  may be depicted as a single layer for clarity. In general, the cover assembly  206  may include a cover sheet layer, a touch sensor layer below the cover sheet layer, and additional layers above the cover sheet (e.g., an electrostatic conductive layer and a passivation layer) for providing electrostatic haptic feedback at the input surface  208 . Examples of these additional layers of the cover assembly  206  are described below with respect to  FIGS. 3-5 . At the first time depicted in  FIG. 2A  the cover assembly  206  may not generate electrostatic haptic feedback. 
     At the second time, as depicted in  FIG. 2B , the cover assembly  206  may generate electrostatic haptic feedback. For example, the cover assembly  206  may include an electrostatic conductive layer, which may be electrically coupled to a drive signal (such as depicted further with respect to  FIG. 3 ). The electrostatic conductive layer includes an array of conductive particles. 
     When activated, the electrostatic conductive layer may produce an electrostatic charge  214   a  on the input surface  208 . The electrostatic charge  214   a  at the input surface  208  may induce a corresponding and opposite charge  216   a  in the user&#39;s finger  212 , which may generate an attractive force between the user&#39;s finger  212  and the input surface  208 . This attractive force may produce tactile feedback to a user in the form of modified friction as the user&#39;s finger  212  moves across the input surface  208 . 
     The sensation of the electrostatic haptic feedback may controllably cause the perception of a rough sensation, or alternatively a sandy, wavy, or similar sensation. The sensations may further be controlled to provide more or less intense sensations. The electrostatic conductive layer of the cover assembly  206  may cause a uniform type and intensity of frictional sensation (e.g., through a uniform electrostatic charge  214   a ), or the type and intensity may vary across the user input region  212   a  (e.g., through a varying electrostatic charge  214   a ). For example, the sensation may become more intense as a user&#39;s finger nears particular regions of the input surface  208 , such as a virtual key or button (e.g., an input region) visually indicated by the display. Thus, the cover assembly  206  may provide variable friction feedback at the input surface  208 . 
     In some embodiments, the electrostatic charge  214   a  may be maintained constant, and in other embodiments the electrostatic charge may vary in polarity and/or intensity. For example, the polarity of the electrostatic charge may reverse. Accordingly, at the third time, depicted in  FIG. 2C , the input surface  208  becomes electrostatically neutral (e.g., uncharged), and at the fourth time, depicted in  FIG. 2D , the electrostatic conductive layer produces a reversed electrostatic charge  214   b  at the input surface  208 . 
     Similar to the second time depicted in  FIG. 2B , at the fourth time of  FIG. 2D  the reversed electrostatic charge  214   b  at the input surface  208  induces a corresponding and opposite charge  216   b  in the user&#39;s finger  212 , which may generate an attractive force between the user&#39;s finger  212  and the input surface  208 . The feedback sensations perceived by the user through the alternating electrostatic charges  214   a ,  214   b  may be controlled through changing the intensity and/or the frequency of the electrostatic charges  214   a ,  214   b.    
     Finally, at the fifth time, depicted in  FIG. 2E , the input surface  208  of the cover assembly  206  may become electrostatically neutral (e.g., uncharged). In some examples, the electrostatic conductive layer may cease to produce the electrostatic charge (e.g.,  214   a ,  214   b ) on the input surface  208  in response to changes in controlling signals. In other examples, only a portion of the input surface  208  may be electrostatically charged, and the user&#39;s finger  212  may move to another portion of the input surface  208  which is not electrostatically charged, where the user ceases to perceive the increased friction sensation. 
       FIG. 3  depicts another cross-section of a cover assembly, taken along section A-A of  FIG. 1 , illustrating capacitive coupling of the conductive layer to a touch sensor layer. The cover assembly  306  includes a cover sheet layer  322 , an electrostatic conductive layer  320 , a passivation layer  318 , and a touch sensor  332 . 
     At least a portion of the cover assembly  306  can function as an input surface  308  that receives touch and/or force inputs. The cover assembly  306  may also produce haptic feedback to an object, such as a user&#39;s finger  312 , in contact with the input surface  308 . Haptic feedback may be produced as an electrostatic haptic feedback, which may cause the user to perceive changes in friction between the user&#39;s finger  312  and the input surface  308 . 
     Generally, the cover sheet layer  322  provides structural rigidity to the cover assembly  306 , and may additionally enclose and protect the touch sensor  332  and a display (omitted from  FIG. 3  for clarity). The cover sheet layer  322  may be formed from a suitable dielectric material, such as glass, plastic, sapphire (alumina), acrylic, ceramic, and other non-conductive materials or combinations of materials. In some embodiments, such as a cover assembly  306  positioned over a display, the cover sheet layer  322  may be transparent. In other embodiments, the cover sheet layer  322  may be formed from an opaque material and/or include an opaque layer, such as an ink layer. 
     While in these examples the term “cover assembly” may refer to a cover for a display of a portable electronic device, it should be understood that the term “cover assembly” may also refer to another input surface, such as a trackpad of a laptop computer or a portion of a housing (such as the housing  102  depicted in  FIG. 1 ). In some examples, the cover assembly  306  may enclose a virtual keyboard having dynamically adjustable input regions, which may be indicated through electrostatic haptic feedback provided by the electrostatic conductive layer  320 . 
     An electrostatic conductive layer  320  may be coupled to the cover sheet layer  322 , and a passivation layer  318  may be coupled to the electrostatic conductive layer  320 . For example, the electrostatic conductive layer  320  may be deposited onto a top surface of the cover sheet layer  322  facing outward from the electronic device. The passivation layer  318  (which may be an insulating layer) may likewise be deposited over the electrostatic conductive layer  320 . 
     The electrostatic conductive layer  320  may be formed with conductive particles within a non-conductive compound, such as described further with respect to  FIG. 4 . As an example, conductive particles may be dispersed within an organic epoxy, and the epoxy may be deposited over the cover sheet layer  322  and cured to form the electrostatic conductive layer  320 . The passivation layer  318  may be formed with non-conductive particles within a similar compound, such as described further with respect to  FIG. 4   
     In some embodiments, the electrostatic conductive layer  320  may be indirectly electrically charged, such as through a capacitive coupling to another layer or component of the cover assembly  306 . For example, a touch sensor  332  positioned below the cover sheet layer  322  may include one or more drive touch electrodes  326  and sense touch electrodes  330  separated by an insulating substrate  328 . A drive touch electrode  326  may be coupled to a drive signal, which may induce an electric field, capacitively coupling the drive touch electrode  326  to at least a portion of the electrostatic conductive layer  320 . 
     Due to the electric field coupling the drive touch electrode  326  to the electrostatic conductive layer  320 , the electrostatic conductive layer  320  becomes electrostatically charged. The electrostatic charge generates or increases an attractive force between the electrostatic conductive layer  320  and a user&#39;s finger  312 , which may be due to a capacitive coupling between the user&#39;s finger  312  and the electrostatic conductive layer  320 . The passivation layer  318  may act as an insulating layer separating and facilitating the capacitive coupling of the user&#39;s finger  312  and the electrostatic conductive layer  320 . 
     The attractive force between the user&#39;s finger  312  and the electrostatic conductive layer  320  may cause the user&#39;s finger  312  to be pulled against the input surface  308  (e.g., against the passivation layer  318 ). This may in turn increase the friction between the user&#39;s finger  312  and the input surface  308  as the user&#39;s finger  312  slides along the input surface  308 . The aforementioned attractive force is generally perpendicular to the direction in which the user&#39;s finger  312  moves along the input surface  308 . Accordingly, when the attractive force is present, the user&#39;s finger is drawn into greater contact with the input surface  308 , thereby increasing friction between that layer and the user&#39;s finger  312  (or other object contacting the layer). 
     The sensation of friction induced by the electrostatic conductive layer  320  may controllably cause a user to perceive a rough sensation, or alternatively a sandy, wavy, or similar sensation. The sensations may further be controlled to provide more or less intense sensations. The electrostatic conductive layer  320  may cause a uniform type and intensity of frictional sensation, or the type and intensity may vary across the input surface  308  as different drive touch electrodes  326  receive distinct drive signals. For example, the sensation may become more intense as a user&#39;s finger  312  nears a given region, such as a virtual key or button (e.g., an input region). In some examples, distinct input regions may be driven by distinct drive signals, such that the intensity or sensation at a first input region is distinct from the intensity and/or sensation at a second input region. 
     The drive touch electrodes  326  may be controlled by processing circuitry and/or a signal generator (described further below with respect to  FIG. 11 ). Each of the drive touch electrodes  326  may be individually controlled, or a group of drive touch electrodes  326  may be controlled together. The control circuitry may apply a drive signal (e.g., an electrical signal) to a drive touch electrode  326  (or group of drive touch electrodes  326 ) to activate and/or energize all or a portion of the electrostatic conductive layer  320 . The drive signal may induce an electrostatic charge or potential (e.g., through capacitive coupling) within a corresponding portion of the electrostatic conductive layer  320  (e.g., a portion of the electrostatic conductive layer  320  substantially above the drive touch electrode  326  receiving the drive signal). 
     The processing circuitry may cause the signal generator to apply distinct signals (e.g., by varying a voltage or current waveform) to different drive touch electrodes  326 . This results in different electrostatic charges between one portion of the electrostatic conductive layer  320  and another, such that the attractive force (and therefore friction) varies as a user&#39;s finger moves along the input surface  308 . 
     In some examples, the processing circuitry may additionally be electrically coupled to the touch sensor  332 . The touch sensor  332  may detect the location of one or more objects, such as the user&#39;s finger  312 , in contact with the input surface  308 . As a result of the detected touch on the input surface, the processing circuitry may cause a drive signal to be coupled to one or more drive touch electrodes  326  (e.g., by causing the signal generator to transmit a drive signal to the drive touch electrodes  326 ) at a location corresponding to the detected touch. This may, in turn, generate friction feedback at a portion of the input surface  308  corresponding to the detected touch. 
     In other examples, the processing circuitry may operate the drive touch electrodes  326  in concert with other components of the electronic device, such as a display (e.g., display  104  depicted in  FIG. 1 ). For example, the display may visually indicate a location of a feedback region, such as a virtual key or button, or an image or icon displayed (e.g., a region that appears rough visually). A drive signal may be sent to a drive touch electrode  326  at a location corresponding to the feedback region, which may cause frictional feedback to be perceived by a user at the location of the feedback region (e.g., by causing a rough sensation over the region that appears rough). 
     In order to create perceptible friction sensations to a user, drive touch electrodes  326  may be energized with electrical drive signals of approximately 100 to 400 volts (or more, depending on the sizes and materials of the adhesive layer  324 , the cover sheet layer  322 , the electrostatic conductive layer  320 , and the passivation layer  318 ) and frequencies of approximately 100 to 500 Hertz. Varying the voltage and waveform of the drive signal may generate varying sensations (e.g., rough, sandy, wavy) and intensity levels to a user. For example, increasing the voltage of the signal to a drive touch electrode  326  may increase the attractive force between the user&#39;s finger  312  and the electrostatic conductive layer  320 , which in turn causes a more intense sensation of friction. 
     As described above, the touch sensor  332  may be formed from an array of drive touch electrodes  326  disposed on an insulating substrate  328 , and may additionally include an array of sense touch electrodes  330  disposed on the insulating substrate  328 . The drive touch electrodes  326  and sense touch electrodes  330  are configured to detect the location of a finger or object on or near the cover sheet layer  322 . 
     The touch sensor  332  may operate in accordance with a number of different sensing schemes. In some implementations, the touch sensor  332  may operate in accordance with a mutual-capacitance sensing scheme. Under this scheme, the drive touch electrodes  326  may be substantially linear transparent conductive traces disposed on a first surface of the insulating substrate  328 , the traces spanning along a first direction. The sense touch electrodes  330  may be intersecting conductive transparent conductive traces disposed on a second, parallel surface of the insulating substrate  328 , the traces spanning along a second direction transverse to the first direction. The touch sensor  332  is configured to detect the location of a touch by monitoring a change in capacitive or charge coupling between pairs of intersecting drive touch electrodes  326  and sense touch electrodes  330 . 
     In another implementation, the touch sensor  332  may operate in accordance with a self-capacitive sensing scheme. Under this scheme, the touch sensor  332  may include an array of drive touch electrodes  326 , which may be capacitive electrodes or pads disposed on a surface of the insulating substrate  328 . The drive touch electrodes  326  may be configured to detect the location of a touch by monitoring a change in self-capacitance of a small field generated by each drive touch electrode  326 . In other implementations, a resistive, inductive, or other sensing scheme could also be used, and in some of these embodiments another component may drive the electrostatic conductive layer  320 . 
     The drive touch electrodes  326  and sense touch electrodes  330  may be formed by depositing or otherwise fixing a transparent conductive material to the insulating substrate  328 . Potential materials for the insulating substrate  328  include, for example, glass or transparent polymers like polyethylene terephthalate or cyclo-olefin polymer. Example transparent conductive materials include polyethyleneioxythiophene, indium tin oxide, carbon nanotubes, graphene, piezoresistive semiconductor materials, piezoresistive metal materials, silver nanowire, other metallic nanowires, and the like. The transparent conductors may be applied as a film or may be patterned into an array on the surface of the substrate using a suitable disposition technique such as, but not limited to: vapor deposition, sputtering, printing, roll-to-roll processing, gravure, pick and place, adhesive, mask-and-etch, and so on. 
     The touch sensor  332  may be coupled to the cover sheet layer  322  through an adhesive layer  324 , which may be an optically clear adhesive. In some embodiments, the adhesive layer  324  may be omitted and all or a portion of the touch sensor  332  may be formed directly on the cover sheet layer  322  (e.g., by depositing an array of drive touch electrodes  326  directly onto a bottom surface of the cover sheet layer  322 ). 
     It should be understood that  FIG. 3  presents a cross-sectional view which may omit certain components for clarity. For example, the cover assembly may be coupled to a display and additional layers. The electronic device may also include additional components and structures, such as the components depicted in  FIG. 11 , support structures, and the like. In some embodiments, the arrangement of the layers depicted may also vary, in which some layers may be positioned differently relative to others (such as depicted in  FIG. 5 ), additional layers may be included, or some layers may be omitted. 
     Turning to  FIG. 4 , the electrostatic conductive layer and the passivation layer may be formed from particles within a compound.  FIG. 4  depicts another cross-section of a cover assembly, taken along section A-A of  FIG. 1 . The cover assembly  406  may include a cover sheet layer  422 , which may provide structural rigidity and support to other components of the cover assembly  406 . A touch sensor  432  may be coupled to a bottom of the cover sheet layer  422  (e.g., internal to the electronic device). 
     An electrostatic conductive layer  420  may be coupled to a top of the cover sheet layer  422 , and a passivation layer  418  may be coupled to a top of the electrostatic conductive layer  420  (e.g., forming an external surface of the electronic device). The electrostatic conductive layer  420  may be formed with conductive particles  438  and non-conductive particles  436  within a non-conductive compound, such as an organic matrix  440 . 
     In some examples, the organic matrix  440  may be an epoxy. The organic matrix  440  may be formed with any appropriate epoxy resin, such as bisphenol A resins, bisphenal F resins, novolac resins, aliphatic resins, glycidylamine resins, and so on. In some embodiments, the material of the organic matrix  440  may be selected to enhance the performance of the cover assembly  406 , such as impact resistance. In a particular embodiment, the cover assembly  406  may enclose a display, and the organic matrix  440  may be formed from an optically transparent epoxy. 
     The conductive particles  438  may be formed from transparent conductive materials, such as indium tin oxide, tin oxide, aluminum zinc oxide, indium zinc oxide, or a transparent conductive oxide. In embodiments in which the cover assembly  406  is opaque, the conductive particles  438  may be formed from opaque conductive materials, such as gold, copper, aluminum, tin, and other combinations and alloys of conductive materials. The non-conductive particles  436  may be formed from one or more suitable transparent non-conductive materials. In embodiments in which the cover assembly  406  is opaque, the non-conductive particles  436  may be formed from opaque materials. 
     In some embodiments, the conductive particles  438  may be disposed within the organic matrix  440  at a sufficient density to enable a sufficient electrostatic charge to be placed on the electrostatic conductive layer  420  to produce frictional haptic feedback at the input surface  408 . However, if the conductive particles  438  are disposed at a uniform high density, the electrostatic conductive layer  420  may become an electromagnetic shield, undesirably blocking the operation of the touch sensor  432  and other components of the electronic device. 
     Accordingly, non-conductive particles  436  and conductive particles  438  may be included within the organic matrix  440  to ensure the electrostatic conductive layer  420  operates to produce haptic feedback and does not interfere with the operation of other components. For example, the conductive particles  438  and non-conductive particles  436  may be disposed within the organic matrix  440  such that the electrostatic conductive layer  420  has a resistance of between 1 MΩ-per-square (one megaohm-per-square) and 100 MΩ-per-square (one hundred megaohms-per-square). 
     In some embodiments, the conductive particles  438  and non-conductive particles may be patterned to enhance the operation of the electrostatic conductive layer  420  and reduce interference with the operation of other components. Examples of such patterns are described below with respect to  FIGS. 8A-8C . 
     The electrostatic conductive layer  420  may be formed over the cover sheet layer  422  in an appropriate manner. For example, the organic matrix  440  may be formed as an epoxy resin, and conductive particles  438  and non-conductive particles  436  may be added to the organic matrix  440 . The organic matrix  440  may then be deposited onto the cover sheet layer  422  and cured to form a hardened electrostatic conductive layer  420 . The formation of the electrostatic conductive layer  420  is further described below with respect to  FIG. 10 . 
     The passivation layer  418  may be a suitable dielectric layer, which may seal the electrostatic conductive layer  420  and define the input surface  408 , which may be an external surface of the electronic device. In some embodiments, the passivation layer  418  may be formed as a single uniform layer, and in other embodiments the passivation layer  418  may be non-uniform and/or formed as multiple layers of distinct materials or combinations of materials. In some examples, the passivation layer  418  may include an organic or inorganic film, which may be bonded to the electrostatic conductive layer  420  through an adhesive or other appropriate technique. 
     In a particular embodiment, the passivation layer  418  may be formed from an organic matrix  444 , such as an epoxy resin. The epoxy resin may be the same as the organic matrix  440  of the electrostatic conductive layer  420 , or it may be a distinct epoxy resin having material properties to provide a durable external surface of the cover assembly  406  and the electronic device. The organic matrix  444  may be formed from a transparent epoxy resin, and may additionally include non-conductive particles  442 . 
     The non-conductive particles  442  may be formed from one or more suitable transparent non-conductive materials. In some embodiments, the non-conductive particles  442  may be formed from materials which improve the hardness, rigidity, scratch resistance, and other features of the passivation layer  418 , such as silicon carbide or a diamond-like carbon. In embodiments in which the cover assembly  406  is opaque, the non-conductive particles  442  may be formed from opaque materials. 
     The passivation layer  418  may be formed over the electrostatic conductive layer  420  in an appropriate manner. For example, the organic matrix  444  may be formed as an epoxy resin, and non-conductive particles  442  may be added to the organic matrix  444 . The organic matrix  444  may then be deposited onto the electrostatic conductive layer  420  and cured to form a hardened passivation layer  418 . In some embodiments, the passivation layer  418  may form the input surface  408 , while in other embodiments additional coatings or layers may be added to the passivation layer  418 , such as oleophobic coatings, anti-glare coatings, and so on. The formation of the electrostatic conductive layer  420  is further described below with respect to  FIG. 10 . 
       FIG. 5  depicts another cross-section of a cover assembly, taken along section A-A of  FIG. 1 . The cover assembly  506  includes a cover sheet layer  522 , an electrostatic conductive layer  520 , a passivation layer  518 , and a touch sensor  532 . 
     The touch sensor  532  may be coupled to a top surface (e.g., a surface facing the input surface  508 ) of the cover sheet layer  522 . The touch sensor  532  may be coupled to the cover sheet layer  522  through an adhesive layer  524 , which may be an optically clear adhesive. In some embodiments, the adhesive layer  524  may be omitted and all or a portion of the touch sensor  532  may be formed directly on the cover sheet layer  522  (e.g., by depositing an array of drive touch electrodes  526  directly onto a bottom surface of the cover sheet layer  522 ). 
     An electrostatic conductive layer  520  may be coupled to the touch sensor  532 , and a passivation layer  518  may be coupled to the electrostatic conductive layer  520 . An insulating substrate  534  may be positioned between the electrostatic conductive layer  520  and the touch sensor  532 . In some embodiments, the electrostatic conductive layer  520  and the passivation layer  518  may be formed separate from other components of the cover assembly  506 , and the insulating substrate may be an adhesive layer coupling the electrostatic conductive layer  520  and the passivation layer  518  to the touch sensor  532 . 
     In other embodiments, the insulating substrate  534  may be an epoxy or similar layer deposited over the touch sensor  532 , which is then cured. The electrostatic conductive layer  520  and the passivation layer  518  may then be deposited onto the insulating substrate  534  and cured to form hardened layers over the insulating substrate  534 . 
     The electrostatic conductive layer  520  may be formed with conductive particles within a non-conductive compound, such as described further with respect to  FIG. 4 . The passivation layer  518  may be formed with non-conductive particles within a similar compound, such as described further with respect to  FIG. 4   
     The touch sensor  532  may include one or more drive touch electrodes  526  and sense touch electrodes  530  separated by an insulating substrate  528 . A drive touch electrode  526  may be coupled to a drive signal, which may induce an electric field, capacitively coupling the drive touch electrode  526  to at least a portion of the electrostatic conductive layer  520 . 
     Due to the electric field coupling the drive touch electrode  526  to the electrostatic conductive layer  520 , the electrostatic conductive layer  520  becomes electrostatically charged. The electrostatic charge generates or increases an attractive force between the electrostatic conductive layer  520  and a user&#39;s finger  512 , which may be due to a capacitive coupling between the user&#39;s finger  512  and the electrostatic conductive layer  520 . The passivation layer  518  may act as an insulating layer separating and facilitating the capacitive coupling of the user&#39;s finger  512  and the electrostatic conductive layer  520 . 
     Other embodiments can implement haptic feedback in another manner. For example,  FIGS. 6A-7B  depict example cover assemblies incorporating a piezoelectric haptic element to provide vibratory and/or friction feedback at an input surface of an electronic device. A haptic output can, in some examples, be a localized decrease in perceived friction between the user&#39;s finger and the interface surface. To generate the haptic output, the input/output interface drives a piezoelectric body below the interface surface at a high frequency (e.g., ultrasonic), thereby causing the interface surface to vibrate. As a result, when the user&#39;s finger moves across the interface surface, the user may perceive decreased friction due to decreased contact area or time between the user&#39;s finger and the interface surface. 
     In this example, certain regions of the interface surface may be perceived to be higher friction regions (e.g., above a piezoelectric body not driven or driven to a lower voltage, at a lower frequency, or at a lower duty cycle) whereas other regions may be perceived to be lower friction regions (e.g., above a piezoelectric body to a higher voltage, at a higher frequency, or at a higher duty cycle). 
     In another example, the haptic output generated by an input/output interface can be a localized vibration, translation, or other mechanical agitation of the interface surface. To generate the haptic output, the input/output interface drives an electrode of a piezoelectric body below the interface surface at a low frequency (e.g., 100 Hz to 200 Hz), thereby mechanically agitating the interface surface. In this manner, when the user&#39;s finger moves across the interface surface, the user may perceive a mechanical agitation of the interface surface such as a click, a pop, a vibration, and so on. 
       FIGS. 6A-6B  depict a cross-section of a cover assembly  606  particularly illustrating electrodes of a touch sensor and a piezoelectric haptic element disposed on the same surface. More particularly, the cover assembly  606  includes an insulating substrate  628  that separates a first set of electrodes generally oriented in a first direction (one of which is visible, and identified as a sense touch electrode  630 ) from a second set of electrodes oriented in a second direction (one of which is identified as a drive touch electrode  626 , and another is identified as a drive haptic electrode  627 ). These components of the cover assembly  606  can be positioned below and (optionally) adhered or otherwise coupled to a cover sheet layer  622 . The cover assembly  606  can be configured to detect touch input, and in some embodiments may additionally or alternatively detect force input. 
     In some embodiments, the first set of electrodes is oriented perpendicular to the second set of electrodes to define a grid of overlapping regions that may be individually addressable by coupling specific electrodes of the first set and specific electrodes of the second set to drive and/or sense circuitry (e.g., coupling the drive touch electrode  626  to drive circuitry and coupling the sense touch electrode  630  to sense circuitry). In other examples, the first set of electrodes and/or the second set of electrodes can be arranged and/or segmented in a different manner. For example, one or both of the first set or the second set may be further segmented. 
     In this embodiment, the insulating substrate  628  of the cover assembly  606  is formed from a piezoelectric material. Example piezoelectric materials include both leaded and lead-free niobates and titanates such as PZT, KNN, NBT-BT, BCT-BZT, and so on. The piezoelectric material may be transparent or opaque and can be disposed and/or formed using any suitable technique such as, but not limited to, sputtering, physical layer deposition, sol gel deposition/printing/gravure, and so on. 
     In some embodiments, each of the layers of the cover assembly  606  may be deposited or otherwise formed onto the cover sheet layer  622 . For example, the sense touch electrodes  630  may be deposited onto the cover sheet layer  622  through an appropriate technique, such as vapor deposition, printing, gravure, roll-to-roll deposition, and so on. The insulating substrate  628  may then be deposited below the sense touch electrodes  630 . The drive touch electrodes  626  and drive haptic electrodes  627  may then be formed on the insulating substrate  628 , through an appropriate technique such as described with respect to the sense touch electrodes  630 . 
     In other embodiments, the sense touch electrodes  630 , drive touch electrodes  626 , and drive haptic electrodes  627  may be formed onto the insulating substrate  628 . This touch/haptic assembly may then be coupled to the cover sheet layer  622  through an optically clear adhesive or another appropriate technique. 
     As a result of this construction, the cover assembly  606  can be configured to simultaneously receive user input and provide haptic output. More particularly, a first subset of electrodes of the first and second set of electrodes can be associated with haptic output while a second subset of electrodes of the first and second set of electrodes can be associated with sensing input. For example, the drive haptic electrode  627  (of the second set of electrodes) may be associated with haptic output while the drive input electrode  626  is associated with touch input and/or force input detection. 
     Haptic output can be provided by the piezoelectric body of the insulating substrate  628  by applying a voltage across the insulating substrate  628  via the drive haptic electrode  627  while, simultaneously, touch and/or force input are received via the drive input electrode  626 . The sense touch electrodes  630  may provide a reference voltage for both touch sensing and haptic feedback. 
     In another embodiment, a cover assembly can provide piezoelectric feedback through a separate layer from the touch sensor. More particularly,  FIG. 7A  depicts a cover assembly  706  that includes a touch sensor  732 , which may include a substrate separating two electrode layers which have been omitted from  FIG. 7A  for clarity. The touch sensor  732  can be configured to detect touch input and/or force input from a user. A haptic output module is positioned below the touch sensor  732 , separated by a stiffener layer  725 . 
     The haptic output module includes a piezoelectric substrate  731  separating a first and second set of electrodes. The piezoelectric substrate  731  may be formed from an appropriate piezoelectric material, similar to the insulating substrate  628  depicted in  FIGS. 6A-6B . The first set of electrodes, oriented along a first direction, are identified as reference haptic electrodes  729 . The second set of electrodes, oriented along a second direction transverse to the first direction, are identified as drive haptic electrodes  727 . 
     As depicted in  FIG. 7A , a display  704  is positioned below the cover assembly  706 . Accordingly, the materials of the cover assembly  706  may be optically transparent, including the touch sensor  732 , the stiffener layer  725 , the reference haptic electrodes  729 , the piezoelectric substrate  731 , and the drive haptic electrodes  727 . These layers may be formed together as described above with respect to  FIGS. 6A-6B . 
     For example, the stiffener layer  725  may be formed from glass, silicon, plastic, or another sufficiently rigid material. The touch sensor  732  may be formed on a first surface of the stiffener  725 . Some or all of the components of the haptic output module, such as the reference haptic electrodes  729 , the piezoelectric substrate  731 , and the drive haptic electrodes  727  may be formed on a second surface of the stiffener layer  725 . By coupling the haptic output module to the stiffener layer  725 , the haptic effect of actuating the piezoelectric substrate  731  may be amplified. 
     As shown in  FIG. 7B , in some examples the haptic output module may be positioned below the display  704 , while the touch sensor  732  is positioned above the display  704 . Accordingly, the stiffener layer  725  may be below the display  704 , and the reference haptic electrodes  729 , the piezoelectric substrate  731 , and the drive haptic electrodes  727  may be coupled to or formed on the stiffener layer  725 . 
       FIGS. 8A-8C  depict example particle arrangements for an electrostatic conductive layer. The electrostatic conductive layer  820  includes conductive particles  838  and non-conductive particles  836  disposed within an organic matrix  840 , which may be an epoxy. The electrostatic conductive layer  820  may be substantially as described above with respect to  FIG. 4 , and may be formed by a method or technique similar to that described below with respect to  FIG. 10 . 
     As described above, the conductive particles  838  and non-conductive particles  836  may be disposed within the organic matrix  840  in a manner to ensure the electrostatic conductive layer  420  operates to produce haptic feedback and does not interfere with the operation of other components. For example, as depicted in  FIG. 8A , the conductive particles  838  and the non-conductive particles  836  may be evenly dispersed within the organic matrix  840  such that the conductive particles  838  are not concentrated in regions of the electrostatic conductive layer  820 . 
     In some embodiments, the conductive particles  838  and non-conductive particles  836  may be patterned to enhance the operation of the electrostatic conductive layer  820  and/or reduce interference with the operation of other components. For example, as depicted in  FIG. 8B , the electrostatic conductive layer  820  may be patterned such that the conductive particles  838  are concentrated within conductive regions formed as columns (or rows) which are separated by columns (or rows) of non-conductive particles  836 . 
     In some embodiments, the columns of the conductive regions may be along the same direction as the drive touch electrodes of a touch sensor (such as the drive touch electrodes  326  depicted in  FIG. 3 ) and may be positioned above and parallel to the drive touch electrodes. As an example, alignment of the conductive particles  838  in the conductive regions with the drive touch electrodes may enhance the capacitive coupling between the conductive particles  838  and the drive touch electrodes. In other embodiments the conductive particles  838  in the conductive regions may be offset from the drive touch electrodes, along a different direction, or otherwise unaligned with the drive touch electrodes to decrease interference with the operation of the touch sensor. 
     As another example, as depicted in  FIG. 8C , the conductive particles  838  may be concentrated into substantially equilateral conductive regions (e.g., square, round, or other geometric shapes), separated by concentrations of non-conductive particles  836 . In this pattern, the conductive particles  838  may be sufficiently concentrated within the conductive regions to provide electrostatic haptic feedback over those conductive regions, while leaving less concentrated regions for operation of the touch sensor and other components to operate without interference. 
     The conductive regions of concentrated conductive particles  838  depicted in  FIG. 8C  may effectively function as distinct electrodes, which may additionally enable the electrostatic conductive layer  820  to provide localized frictional feedback over the conductive regions. For example, the conductive regions may correspond to drive touch electrodes arrayed as conductive pads, which may be separately driven to provide varying electrostatic haptic feedback over distinct portions of the input surface of the electronic device. 
     It should be understood that  FIGS. 8A-8C  are illustrative in nature. A number of other patterns and arrangements of conductive and non-conductive particles within an epoxy may be used to create an electrostatic conductive layer according to similar principles. In addition, the depicted conductive particles  838  and non-conductive particles  839  may be representative of areas with higher concentrations of conductive particles and higher concentrations of non-conductive particles respectively. For example, the portions of the electrostatic conductive layer  820  depicted with only conductive particles  838  may also include non-conductive particles, but with relatively higher concentrations of conductive particles  838 . 
       FIG. 9A  depicts a top view of an electronic device according to the present disclosure, illustrating electrostatic haptic feedback on a portion of an input surface. The electronic device  900  of  FIG. 9A  includes a housing  902  at least partially enclosing a display  904 . A cover assembly  906  may be positioned over the display  904  and coupled to the housing  902 . The cover assembly  906  defines an input surface  908  for receiving touch and/or force inputs to the electronic device  900 . 
     The cover assembly  906  may also selectively provide electrostatic haptic feedback to a user&#39;s finger  912  in contact with the input surface  908 , such as through increased friction or similar sensations. The electrostatic haptic feedback may be provided through an electrostatic conductive layer in the cover assembly  906 . The electrostatic conductive layer may be energized by a drive touch electrode positioned below the electrostatic conductive layer (e.g., as depicted above with respect to  FIGS. 3 and 5 ). 
     As one or more drive touch electrodes are energized, the user&#39;s finger  912  may experience the electrostatic haptic feedback at a feedback region  950 , which may be a column across the input surface  908 , which may correspond to the location of the drive touch electrode. In other examples, the drive touch electrode may be arranged in rows, and the feedback region  952  of may be a row across the input surface corresponding to the activated drive touch electrode, such as depicted in  FIG. 9B . 
     The sensation of the electrostatic haptic feedback in a feedback region  950 ,  952  may controllably cause the perception of a rough sensation, or alternatively a sandy, wavy, or similar sensation. The sensations may further be controlled to provide more or less intense sensations. A feedback region  950 ,  952  may provide a constant frictional sensation, or the type and intensity of the frictional sensation may vary over time. 
     Turning to  FIG. 9C , another top view of an electronic device is depicted, illustrating electrostatic haptic feedback on another portion of an input surface. In some embodiments, the electrostatic conductive layer and/or the drive touch electrodes may be disposed and arranged to provide more localized electrostatic haptic feedback. For example, the drive touch electrodes may be substantially equilateral conductive pads arranged in a rectilinear pattern. The electrostatic conductive layer may also be patterned to concentrate conductive particles above the drive touch electrodes. 
     Accordingly, when a drive signal activates a drive touch electrode, electrostatic haptic feedback may be produced at a substantially localized feedback region  954 . The feedback region  954  may correspond to the size and/or shape of the drive touch electrode(s) which have been activated to induce the electrostatic haptic feedback. In some embodiments, additional feedback regions  956 ,  958  may also be produced by driving additional drive touch electrodes. In some examples, distinct drive signals may drive the additional drive touch electrodes, generating distinct haptic feedback at the additional feedback regions  956 ,  958 . 
       FIG. 10  depicts an example method of forming a cover assembly for an electronic device to provide electrostatic feedback. The method  1000  of  FIG. 10  may be implemented to form a cover assembly of an electronic device, which operates to produce electrostatic haptic feedback, such as described in the examples depicted above with respect to  FIGS. 1-9 . 
     The method begins at operation  1002 , in which a cover sheet is prepared for forming electrostatic feedback layers, including an electrostatic conductive layer and/or a passivation layer. A cover sheet may be formed in a separate process, and may be formed from a suitable material, such as glass, plastic, sapphire, or combinations thereof. At operation  1002 , the cover sheet may be prepared for the addition of an electrostatic conductive layer. 
     In some embodiments, at operation  1002  the cover sheet may be roughened through a chemical bath or mechanical process, which may introduce imperfections in a surface of the cover sheet to increase bonding between the cover sheet and the electrostatic conductive layer. In some embodiments, at operation  1002  the cover sheet may be treated through a chemical or other process to strengthen the cover sheet. In an example, the cover sheet may be strengthened through an ion exchange, which may place the cover sheet under tension and/or compressive stress. 
     Next, at operation  1004 , an epoxy (e.g., an organic matrix) for the electrostatic conductive layer may be formed. At operation  1006 , inorganic particles may be added to the epoxy. Prior to addition into the epoxy, the inorganic particles may be prepared through an appropriate technique. In some examples, inorganic materials may be formed into the inorganic particles through a sol-gel process, through a calcination and pulverization process, or similar techniques. 
     The inorganic particles may include conductive particles and non-conductive particles, which may be deposited in the epoxy at a sufficient density such that the electrostatic conductive layer may produce electrostatic haptic feedback, but the conductive particles may be sufficiently dispersed such that the electrostatic conductive layer does not interfere with the operation of other components of the electronic device. In some example, the conductive and non-conductive particles may be arranged in patterns, which may be through preparing epoxies at distinct densities and depositing the epoxies in patterns at operation  1008 . 
     In some embodiments, both conductive and non-conductive particles may be added to the epoxy at operation  1006 . In other embodiments, the epoxy may be formed with precursors which form the epoxy and inorganic particles in operation  1004 . For example, the epoxy may be formed from a mixture of tetramethoxysilane (TMOS), 3-glycidoxypropyl-trimethoxysilane (GPTMS), and titanium-tetraethylate (Ti(OEt) 4 ). After the epoxy and non-conductive particle mixture is formed at operation  1004 , conductive particles may be added to the epoxy mixture at operation  1006 . 
     Next, at operation  1008 , the epoxy is deposited over the cover sheet. The epoxy may be deposited using an appropriate technique, such as spin coating the cover sheet with the epoxy, spray coating, resin dispensing, and so on. In some examples, more than one epoxy may be formed in operations  1004  and  1006 , each epoxy having distinct concentrations of conductive particles. At operation  1008 , the different epoxies may be deposited in a pattern, resulting in different concentrations of conductive particles at different portions of the cover sheet. 
     Finally, at operation  1010  the epoxy may be cured. In some examples, the epoxy may be cured by heating the epoxy to an appropriate temperature, such as 110° C. After curing, the epoxy may form a cross-linked organic matrix with the inorganic particles (including conductive and non-conductive particles) embedded within the matrix. 
     As depicted in  FIG. 10 , once the epoxy is cured, the method  1000  may return to operation  1004 . One or more additional layers may be formed over the cured epoxy layer. For example, the electrostatic conductive layer may be formed through multiple layers. In some examples, the electrostatic conductive layer may be formed from a first layer with conductive particles at a first concentration and a second layer with conductive particles at a lower second concentration. Additional layers may be included with distinct concentrations of conductive particles. 
     As another example, a passivation layer may be formed over the electrostatic conductive layer through a similar method. The passivation layer may be formed by forming an epoxy at operation  1004 , which may be formed from the same or a different epoxy as the electrostatic conductive layer. At operation  1006 , non-conductive organic particles may be added to the epoxy. However, as described above, by using certain precursors at operation  1004  the non-conductive inorganic particles may be formed into the epoxy in one operation, and operation  1006  may be omitted. 
     At operation  1008 , the epoxy may be deposited over the electrostatic conductive layer through an appropriate technique, such as spin coating. The epoxy may be cured at operation  1010 , producing a hardened passivation layer with non-conductive inorganic particles embedded within an organic matrix. 
     One may appreciate that although many embodiments are disclosed above, the operations and steps presented with respect to methods and techniques are meant as exemplary and accordingly are not exhaustive. One may further appreciate that alternate operation order or fewer or additional operations may be required or desired for particular embodiments. For example, operation  1002 , preparing the cover sheet, may be omitted in some embodiments, or may occur concurrently with other operations. In another example, the operations of method  1000  may be performed on a large cover sheet, which may afterward be cut into smaller pieces to form cover sheets of electronic devices having an electrostatic conductive layer and a passivation layer. 
       FIG. 11  depicts example components of an electronic device in accordance with the embodiments described herein. The schematic representation depicted in  FIG. 11  may correspond to components of the devices depicted in  FIGS. 1-10 , described above. However,  FIG. 11  may also more generally represent other types of electronic devices with a cover assembly which provides electrostatic haptic feedback through a hybrid conductive coating, which may include inorganic conductive and non-conductive particles within an organic matrix. 
     As shown in  FIG. 11 , a device  1100  includes a drive electrode  1126  and a sense electrode  1130 , which may form a drive touch electrode and sense touch electrode of a touch sensor. The touch sensor may operate using the drive electrode  1126  and the sense electrode  1130  to determine a location of a finger or touch over the input surface of the device  1100 . The drive electrode  1126  and the sense electrode  1130  may operate in accordance with a mutual-capacitance or self-capacitance touch sensing scheme. 
     In addition, the drive electrode  1126  may be driven with a haptic drive signal (e.g., a haptic drive signal received from the signal generator  1166 ) in order to provide an electrical field to activate a conductive layer and provide electrostatic haptic feedback at an input surface of the device  1100 . The haptic drive signal may induce a variable electrostatic charge on the surface, which may produce sensations of higher and/or lower friction to a user operating the electronic device. 
     The device  1100  may also include a signal generator  1166 . The signal generator  1166  may be operatively connected to the drive electrode  1126 . The signal generator  1166  may transmit electrical signals to the drive electrode  1126  to control the electrostatic haptic feedback generated at the input surface. The signal generator  1166  is also operatively connected to processing circuitry  1160  and computer memory  1162 . The processing circuitry  1160  is configured to control the generation of the electrical signals for the drive electrode  1126 . 
     The memory  1162  can store electronic data that can be used by the signal generator  1166 . For example, the memory  1162  can store electrical data or content, such as timing signals, algorithms, and one or more different electrical signal characteristics that the signal generator  1166  can use to produce one or more electrical signals. The electrical signal characteristics include, but are not limited to, an amplitude, a phase, a frequency, and/or a timing of an electrical signal. The processing circuitry  1160  can cause the one or more electrical signal characteristics to be transmitted to the signal generator  1166 . In response to the receipt of the electrical signal characteristic(s), the signal generator  1166  can produce an electrical signal that corresponds to the received electrical signal characteristic(s). 
     The processing circuitry  1160  is operatively connected to components of the device  1100 , such as a signal generator and/or the drive electrode  1126 . In addition, the processing circuitry  1160  may be operatively connected to the computer memory  1162 . The processing circuitry  1160  may be operatively connected to the memory  1162  component via an electronic bus or bridge. The processing circuitry  1160  may include one or more computer processors or microcontrollers that are configured to perform operations in response to computer-readable instructions. The processing circuitry  1160  may include a central processing unit (CPU) of the device  1100 . Additionally or alternatively, the processing circuitry  1160  may include other processors within the device  1100  including application specific integrated chips (ASIC) and other microcontroller devices. The processing circuitry  1160  may be configured to perform functionality described in the examples above. 
     The memory  1162  may include a variety of types of non-transitory computer-readable storage media, including, for example, read access memory (RAM), read-only memory (ROM), erasable programmable memory (e.g., EPROM and EEPROM), or flash memory. The memory  1162  is configured to store computer-readable instructions, sensor values, and other persistent software elements. 
     In this example, the processing circuitry  1160  is operable to read computer-readable instructions stored on the memory  1162 . The computer-readable instructions may adapt the processing circuitry  1160  to perform the operations or functions described above with respect to  FIGS. 1-10 . The computer-readable instructions may be provided as a computer-program product, software application, or the like. 
     The device  1100  may also include a battery  1168  that is configured to provide electrical power to the components of the device  1100 . The battery  1168  may include one or more power storage cells that are linked together to provide an internal supply of electrical power. The battery  1168  may be operatively coupled to power management circuitry that is configured to provide appropriate voltage and power levels for individual components or groups of components within the device  1100 . The battery  1168 , via power management circuitry, may be configured to receive power from an external source, such as an alternating current power outlet. The battery  1168  may store received power so that the device  1100  may operate without connection to an external power source for an extended period of time, which may range from several hours to several days. 
     In some embodiments, the device  1100  also includes a display  1104  that renders visual information generated by the processing circuitry  1160 . The display  1104  may include a liquid-crystal display, light-emitting diode, organic light emitting diode display, organic electroluminescent display, electrophoretic ink display, or the like. If the display  1104  is a liquid-crystal display or an electrophoretic ink display, the display may also include a backlight component that can be controlled to provide variable levels of display brightness. If the display  1104  is an organic light-emitting diode or organic electroluminescent type display, the brightness of the display  1104  may be controlled by modifying the electrical signals that are provided to display elements. 
     In some embodiments, the device  1100  includes one or more input devices  1110 . The input device  1110  is a device that is configured to receive user input. The input device  1110  may include, for example, a push button, a touch-activated button, or the like. In some embodiments, the input devices  1110  may provide a dedicated or primary function, including, for example, a power button, volume buttons, home buttons, scroll wheels, and camera buttons. Generally, a touch sensor and a force sensor may also be classified as input components. However, for purposes of this illustrative example, the drive electrode  1126  and sense electrode  1130  of the touch sensor, as well as the force sensor  1172 , are depicted as distinct components within the device  1100 . 
     The device  1100  may also include a haptic actuator  1170 . The haptic actuator  1170  may provide additional haptic feedback to a user through vibratory or other haptic output. The haptic actuator may be implemented as a linear actuator, an eccentric rotational motor, a piezoelectric transducer, and similar haptic technologies. The haptic actuator  1170  may be controlled by the processing circuitry  1160  and/or the signal generator  1166 , and may be configured to provide haptic feedback to a user interacting with the device  1100 . In some embodiments, distinct signal generators  1166  may be connected to the drive electrode  1126  and the haptic actuator  1170 . 
     The device  1100  may also include a communication port  1164  that is configured to transmit and/or receive signals or electrical communication from an external or separate device. The communication port  1164  may be configured to couple to an external device via a cable, adaptor, or other type of electrical connector. In some embodiments, the communication port  1164  may be used to couple the device  1100  to a peripheral device or a computer. 
     The device  1100  also includes a force sensor  1172 , which may register the application of force to the input surface of the device  1100 . The force sensor  1172  may be a capacitive force sensor, a strain gauge, a piezoelectric force sensor, or another appropriate force-sensing device. In some embodiments, the force sensor  1172  may be a non-binary force sensor, or a force sensor which measures an amount of force with a range of values. In other words, the force sensor may exhibit a non-binary electrical response (e.g., a change in voltage, capacitance, resistance, or other electrical parameter) indicating the amount of force applied to the input surface of the electronic device. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings. 
     For example, features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Further, the term “exemplary” does not mean that the described example is preferred or better than other examples.

Metadata:
Filing Date: 20170927
Publication Date: 20200915
Grant Date: 20200915
Priority Date: 20170927
Inventors: WEN, XIAONAN
PEDDER, JAMES E.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06V40/1306", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06V40/1306", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04166", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/147", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/04166", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0412", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06K9/0002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/147", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 65806661