PATENT DOCUMENT

Publication Number: US-10289210-B1
Application Number: US-201715499477-A
Country: US
Kind Code: B1

Title: Enabling touch on a tactile keyboard

Abstract:
Disclosed herein is a multi-function input device, such as a keyboard. The multifunction input device has a touch-sensing layer that enables a user to use the multifunction input device as a standard keyboard and also as a touch sensitive surface such as, for example, a trackpad.

Claims:
What is claimed is: 
     
       1. A touch-sensitive keyboard, comprising:
 a frame; 
 a base plate; 
 an array of keys positioned at least partially within the frame, each key comprising:
 a keycap; 
 a support mechanism connected to the keycap and the base plate and configured to bias the keycap upward in an absence of an exerted force; and 
 a touch-sensing layer attached to and positioned above the keycap, wherein the array of keys comprises a plurality of flexible electrical connectors, wherein each flexible electrical connector connects the touch-sensing layers of a respective pair of adjacent keys, and wherein each flexible electrical connector has a length that is longer than a distance that separates the respective pair of adjacent keys. 
 
 
     
     
       2. The touch-sensitive keyboard of  claim 1 , wherein each flexible electrical connector is configured to deform when one of the respective pair of adjacent keys is depressed. 
     
     
       3. The touch-sensitive keyboard of  claim 2 , wherein the flexible electrical connector is a flexible printed circuit board. 
     
     
       4. The touch-sensitive keyboard of  claim 1 , further comprising touch-sensing circuitry connected to the touch-sensing layer and configured to detect a location of a touch on the array of keys. 
     
     
       5. The touch-sensitive keyboard of  claim 1 , wherein the touch-sensing layer for each key comprises at least two touch-sensitive pixels. 
     
     
       6. The touch-sensitive keyboard of  claim 1 , wherein the touch-sensing layer on each key comprises at least a first touch-sensitive pixel and at least a portion of a second touch-sensitive pixel. 
     
     
       7. The touch-sensitive keyboard of  claim 1 , wherein the touch-sensing layer of each key further comprises a compliant element and is configured to detect an amount of force applied to a surface of the array of keys. 
     
     
       8. The touch-sensitive keyboard of  claim 7 , wherein the compliant element comprises at least one of a flexible silicone gel, a compliant foam, or an air gap. 
     
     
       9. The touch-sensitive keyboard of  claim 1 , wherein each touch-sensing layer and each flexible electrical connector each comprise at least one of a polyimide substrate or a polyethylene terephthalate substrate. 
     
     
       10. An input device, comprising:
 a first key comprising:
 a first collapsible dome; 
 a first keycap disposed over the first collapsible dome; and 
 a first touch-sensing layer disposed above the first keycap; 
 
 a second key comprising:
 a second collapsible dome; 
 a second keycap disposed over the second collapsible dome, wherein there is a gap between the first and second keycaps; and 
 a second touch-sensing layer disposed above the second keycap; and 
 a flexible electrical connector that extends across the gap from the first touch-sensing layer to the second touch-sensing layer. 
 
 
     
     
       11. The input device of  claim 10 , wherein the first key is configured to:
 generate a first output from the first collapsible dome; and 
 generate a second output from the first touch-sensing layer. 
 
     
     
       12. The input device of  claim 11 , wherein an insulating layer is positioned over the first touch-sensing layer and forms an outer surface of the first key. 
     
     
       13. The input device of  claim 11 , wherein:
 the flexible electrical connector deforms as the first key moves. 
 
     
     
       14. The input device defined in  claim 10 , wherein the flexible electrical connector has a length and a width that is smaller than the length, wherein the flexible electrical connector extends along the length between the first and second touch-sensing layers, and wherein the length of the flexible electrical connector is longer than a distance between the first and second touch-sensing layers. 
     
     
       15. The input device defined in  claim 10 , further comprising:
 a frame in the gap between the first and second keycaps; 
 an insulating layer that has a first portion formed over the first touch-sensing layer, a second portion formed over the second touch-sensing layer, and a third portion formed between the first and second portions that is formed over the flexible electrical connector and the frame, wherein the flexible electrical connector is interposed between the frame and the insulating layer and wherein the flexible electrical connector is not coupled to the third portion of the insulating layer. 
 
     
     
       16. An input device comprising:
 a frame; and 
 a key within the frame, comprising:
 an insulating layer; 
 a touch-sensing layer beneath the insulating layer; 
 a keycap beneath the touch-sensing layer; 
 a collapsible dome beneath the keycap; 
 a contact beneath the collapsible dome; and 
 a flexible electrical connector extending, at a non-right angle, from the touch-sensing layer and positioned beneath the insulating layer; wherein 
 
 the insulating layer is affixed to the touch-sensing layer; and 
 the insulating layer is not affixed to the flexible electrical connector. 
 
     
     
       17. The input device of  claim 16 , wherein:
 the contact generates a first input signal when the collapsible dome collapses; and 
 the touch-sensing layer generates a second input signal in response to a touch. 
 
     
     
       18. The input device of  claim 16 , wherein the insulating layer is formed from at least one of fabric, silicone, polyester, or nitrile. 
     
     
       19. The input device of  claim 16 , wherein the touch-sensing layer comprises at least two touch-sensitive pixels on the keycap. 
     
     
       20. The input device of  claim 16 , wherein the touch-sensing layer comprises at least a first touch-sensitive pixel and at least a portion of a second touch-sensitive pixel on the key.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a nonprovisional patent application of and claims the benefit of U.S. Provisional Patent Application No. 62/397,091, filed Sep. 20, 2016 and titled “Enabling Touch on a Tactile Keyboard,” the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The described embodiments relate generally to an input device, such as a keyboard for a computing device. More particularly, the present embodiments relate to an input device that enables a user to provide mechanical input and touch input. 
     BACKGROUND 
     Some portable computing devices, such as laptop computers, include a standard QWERTY keyboard for providing text input. These portable computing devices may also include a trackpad, a mouse and/or a touch sensitive display that enables the user to provide touch input to the computing device. 
     Although a variety of input devices may be provided, a user is typically required to move his or her hands from one input device to another in order to provide each type of input. For example, if a user is typing on the keyboard and wishes to select a particular icon on the display or move a cursor, the user&#39;s hands must be moved from the keyboard to a mouse, a trackpad or the display. Once the user has completed the desired action with the touch input device and wishes to return to typing, the user&#39;s hands are returned to the keyboard. 
     SUMMARY 
     Described herein is a multifunction input device that provides both mechanical and touch-sensing input in a single structure (such as a key stack) for operation with an electronic device. In some embodiments, the multifunction input device may be a touch-sensitive keyboard. The keyboard may include an enclosure and an array of keys positioned at least partially within the enclosure. Each of the array of keys may be formed from a key stack; the key stack may include a keycap, a base plate, a support mechanism operably connected to the keycap and the base plate and configured to move the keycap vertically, a touch-sensing layer attached to the keycap, and an electrical connection operably connected to the touch-sensing layer and a touch-sensing layer within an adjacent key. 
     Another embodiment may be a touch input device, including a first movable input component comprising a touch-sensing layer, a second movable input component comprising a touch-sensing layer, and a flexible electrical connection spanning between the first movable input component and the second movable input component. 
     Still another embodiment may be an input device comprising an array of keys. The input device may include a keycap associated with a key, a support mechanism operably connected to the first keycap and configured to move the keycap vertically, an array of force-sensitive structures attached to a top surface of the keycap, and a touch-sensing layer positioned above the array of force-sensitive structures. 
    
    
     
       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 structural elements. 
         FIG. 1A  depicts an example computing device that may use or otherwise incorporate the multifunction input device of the present disclosure. 
         FIG. 1B  depicts a user interacting with the example computing device of  FIG. 1A . 
         FIG. 1C  depicts a user providing a gestural input across a set of keys, utilizing the example computing device of  FIG. 1A . 
         FIG. 2  depicts a cross-sectional view of a key of a multifunction input device, taken along line A-A of  FIG. 1A  and according to a first embodiment. 
         FIG. 3  depicts a cross-sectional view of two keys of a multifunction input device, taken along line A-A of  FIG. 1A  and according to another embodiment. 
         FIG. 4A  depicts a cross-sectional view of an example touch-sensing layer. 
         FIG. 4B  depicts a cross-sectional view of another example touch-sensing layer. 
         FIG. 5A  depicts an array of touch-sensing layers interconnected by flexible electrical connectors. 
         FIG. 5B  depicts a cross-sectional view of a flexible electrical connector, taken along line B-B of  FIG. 5A  and according to a first embodiment. 
         FIG. 5C  depicts a cross-sectional view of a flexible electrical connector, taken along line B-B of  FIG. 5A  and according to another embodiment. 
         FIGS. 6A-6F  depict example flexible electrical connectors disposed between pairs of touch-sensing layers. 
         FIGS. 7A-D  depict example arrays of touch-sensitive pixels within touch-sensing layers. 
         FIG. 8  depicts an example multifunction input device, incorporated into a cover case. 
         FIG. 9  depicts an example multifunction input device in communication with a desktop computer. 
         FIG. 10  depicts example components of a multifunction input device in accordance with the embodiments described herein. 
     
    
    
     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 embodiment. To the contrary, they are intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The embodiments described herein are directed to a multifunction input device that utilizes movable input components to receive both mechanical input and touch input, and use both to generate one or more input signals to an electronic device. In some embodiments, the multifunction input device is a keyboard. The keyboard may be integrated with the computing device or it may be removably coupled to the computing device. 
     The multifunction input device may utilize, or otherwise enable a user to provide, mechanical input and touch input to the computing device, either simultaneously or at separate times. For example, the multifunction input device may have a number of keys or buttons that may be actuated by a user. In addition, the multifunction input device may enable a user to provide touch input to the keys or buttons in order to move a cursor, select a displayed icon, perform a gesture, and so on. 
     The multifunction input device may have a touch-sensing layer (or other touch-sensing input mechanism) disposed near the top of each of the buttons, keys, or other input surfaces, and a collapsible dome switch (or other mechanical input mechanism) beneath the touch-sensing layer and/or input surface. As such, the entire surface of the input device (or designated portions of the surface of the input device) may function together as a touch-sensitive input device. Thus, when a user wishes to move a cursor, select an icon or perform an action associated with a gesture, the user can provide the input directly to or along the surface of the keys (or buttons of the input device, or the like) without removing his or her fingers or hands from the keys. Thus, single gestures or inputs may be provided across multiple key surfaces. 
     The touch-sensing input mechanism or layer may be attached to the top of each keycap (or button), with the keys interconnected through flexible electrical connectors or other deformable electrical connections. These tendrils may take the form of electrical conductors (e.g., flexible printed circuit boards) spanning between the keys, extending from the touch-sensitive layers, and so on. The touch-sensing layer may capacitively sense a user&#39;s finger, a stylus, or the like, and may include various drive and sense electrodes arranged in a particular pattern. The touch-sensing layer may sense a touch even if the key(s) is not depressed. Likewise, a near touch (one example of which is a finger hovering above a key) may be sensed. 
     Further, the input mechanism may incorporate a collapsible dome switch or other mechanical input mechanism to provide a second type of input. When the input surface (e.g., keycap, button, or the like) is depressed with sufficient force, the mechanical input mechanism may collapse, deform, or the like. The input mechanism may move accordingly, and the deformation of the mechanical input mechanism may complete a circuit to generate an electrical signal. Thus, the single input mechanism may provide two different inputs and incorporate two different input mechanisms. 
     In one embodiment, the touch-sensing layer, or other touch-sensing input mechanism, includes at least two sense electrodes electrically connected in pairs. One or more drive electrodes are positioned between the pairs of sense electrodes. The sense electrodes and the drive electrodes may have various dimensions and be arranged in various ways and patterns. 
     For example, the sense electrodes may be arranged in rows while the drive electrodes are arranged in columns. In another arrangement, the sense electrodes may be arranged in columns while the drive electrodes are arranged in rows. In yet another embodiment, portions of the drive electrodes may be interlocked with portions of the sense electrodes to form an interdigitated pattern. In another example, the sense electrodes may be arranged in a first plane and the drive electrodes may be arranged on a second, different plane. In some embodiments, the dimensions of the drive and sense electrodes may vary. For example, the dimensions of the drive electrodes and/or the sense electrodes may have a first set of dimensions on a first portion of a keycap and may have a second set of dimensions at a second portion of the keycap. 
     In some embodiments, the multifunction input device may include an insulating layer, such as a fabric layer positioned over each of the keys and the touch-sensing layer. The fabric layer may be smooth to the touch and may also soften sharp edges of a keycap that a user contacts while moving a hand or finger across the surfaces of the keys (for example, when providing touch input). The fabric layer may also protect the flexible electrical connectors spanning between keys. The fabric layer may include embossed portions that correspond to each key of the input device. The embossed portions may be adhered to each keycap. 
     These and other embodiments are discussed below with reference to  FIGS. 1-10 . 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. 
       FIGS. 1A-1C  depict an example computing device  100  that may use or otherwise incorporate the multifunction input device of the present disclosure. In some embodiments, as depicted in  FIG. 1A , the multifunction input device is a keyboard and the computing device  100  is a laptop computer. Although a keyboard is specifically mentioned, the embodiments described herein may be incorporated by various input devices or mechanisms such as, for example, trackpads, mice, buttons, and so on. 
     In one implementation, the keyboard may be integrated with the computing device  100 . In another embodiment, the keyboard may be removably attached to a computing device. For example, the keyboard may be configured to be removably attached to a tablet computing device, a mobile phone, a personal digital assistant, or another portable computing device. An example of a removably attached keyboard is illustrated below with respect to  FIG. 8 . In another embodiment, the keyboard may not be attached to a computing device and may only be operably connected to the computing device. An example desktop computer and separate keyboard are illustrated below with respect to  FIG. 9 . 
     The computing device  100  may include an enclosure  101  housing a keyboard and a display  102 . The display  102  may function as both an input device and an output device. For example, the display  102  may output images, graphics, text, and the like to a user. The display  102  may also act as a touch input device that detects and measures a location of a touch input on the display  102 , via touch-sensing circuitry. The computing device  100  may also include one or more force sensors that detect and/or measure an amount of force exerted on the display  102 . 
     The keyboard of the computing device  100  includes an array of keys  104  or buttons (e.g., movable input components). Each of the array of keys  104  may correspond to a particular input. The keyboard may also include a frame  106  or key web. The frame  106  may define an aperture through which each key  104  protrudes, such that each of the array of keys  104  is at least partially positioned within the frame  106  and at least partially without the frame. The frame  106  may be made of various materials such as, but not limited to, aluminum, plastic, metal, rubber, and the like, and may be used to provide structural support for the keyboard and/or each individual key  104 . The frame  106  also separates one key  104  from an adjacent key  104  and/or a housing of the computing device  100 . Although not shown in  FIG. 1A , the keyboard may also include a fabric layer that is placed over each of the keys  104 . 
     In some embodiments, the computing device  100  may also include an input component  108 . The input component  108  may be a touch input device such as a trackpad. In some implementations, the input component  108  may be omitted from the computing device  100  as the keyboard may function as a touch input device and a keyboard. 
     For example, and as shown in  FIG. 1B , an input mechanism  110 , such as a user&#39;s finger, may actuate one of the keys  104  to cause the computing device  100  to produce an output  112  on the display  102 . In some embodiments, the key  104  may be a mechanical key having a switch, a contact, or other such mechanism that provides a signal when the key  104  is actuated. In other embodiments, actuation of the key  104  may be detected by one or more capacitive sensors. 
     In addition, the keyboard may act as a multi-touch input device. The multi-touch input device may include a touch-sensing layer, and appropriate touch-sensing circuitry, that can detect a location of a touch input, and may detect multiple touch inputs in more than one area concurrently. When a touch is determined, the computing device  100  performs a certain action. For example, and turning to  FIG. 1C , the user may move an input mechanism  110 , such as a finger, across one or more keys  104  of the keyboard and one or more portions of the frame  106  in the direction of arrow  114 . In response, a pointer  116  or other icon that is output on the display  102  may move in the direction of arrow  118 . In some embodiments, the keys  104  are not actuated (although they may be actuated) as the user moves a finger across the surface of each key  104  and across the fabric spanning between the keys  104 . 
     The touch-sensing layer may operate in accordance with a number of different touch sensing schemes. In some implementations, the touch-sensing layer may operate in accordance with a mutual-capacitance sensing scheme. Under this scheme, the touch-sensing layer may include two layers of intersecting conductive traces that are configured to detect the location of a touch by monitoring a change in capacitive or charge coupling between pairs of intersecting traces. In another implementation, the touch-sensing layer may operate in accordance with a self-capacitive sensing scheme. Under this scheme, the touch-sensing layer may include an array of capacitive electrodes or pads that are configured to detect the location of a touch by monitoring a change in self-capacitance of a small field generated by each electrode. In other implementations, a resistive, inductive, or other sensing scheme could also be used. 
     For example, under a mutual-capacitance sensing scheme the touch-sensing layer detects a change in capacitance at a given area and provides the detected change to a processing unit of the computing device  100 . The processing unit then determines the appropriate action to take based on the detected change in capacitance. For example, the processing unit may determine that the change in capacitance across various regions of the keyboard are equivalent to a scroll operation. In another embodiment, the detected change in capacitance may be equivalent to a gesture, a swipe, or other types of input. Although the keyboard acts as a multi-touch input device, similar functionality may be provided by the input component  108 . 
     In some embodiments, the touch-sensing layer may detect the placement of a user&#39;s hands and/or fingers on the keyboard. If placement is incorrect (e.g., the fingers are not properly placed on the home row of the keyboard) the computing device may notify the user of the incorrect placement. In some embodiments, the notification may be a haptic output that is provided by a haptic actuator associated with electronic device  100 . 
     Turning in more detail to the operation of a key  204 ,  FIG. 2  depicts a cross-sectional view of a key  204  or a button of a multifunction input device taken along line A-A of  FIG. 1A  according to a first embodiment. The key  204  includes a keycap  220  that is at least partially surrounded by a frame  222  or key web. In some instances, the frame  222  defines an aperture though which the keycap  220  protrudes or is placed. 
     The keycap  220  may be coupled to a restoring mechanism  224  (which may also be a support mechanism) that enables the keycap  220  to move from a first position to a second position within the frame  222  when actuated. The restoring mechanism  224  may be a scissor mechanism, a butterfly mechanism, a hinge mechanism, a spring mechanism, and the like that restores the keycap  220  to its nominal position when the keycap  220  is released or no longer actuated. 
     The key  204  may also include a membrane  226  positioned over a collapsible dome mechanism  228  (or other suitable mechanical input mechanism, as described below) and a contact  230 . In some embodiments, the membrane  226  is coupled to a contact housing  232  that contains the collapsible dome mechanism  228  and the contact  230 . In operation, the membrane  226  acts as a seal to prevent contaminants from interfering with the electrical and/or mechanical operation of the collapsible dome mechanism  228  and/or the contact  230 . In some embodiments, the membrane  226  may be made of rubber, plastic, or other such materials. Each of the collapsible dome mechanism  228 , the contact  230 , and the contact housing  232  may be positioned over a base plate  225 . 
     In some embodiments, the base plate  225  may be a printed circuit board or the like. In other embodiments, the base plate  225  may be a generally rigid substrate configured to accept an input force transmitted through the touch-sensing layer  234  (described below), the keycap  220 , the membrane  226 , and the collapsible dome mechanism  228 . The base plate  225  may be an internal support, as one example. As another example, the base plate  225  may be a portion of an enclosure, such as a bottom surface of an enclosure. 
     The contact housing  232  may secure or otherwise contain the collapsible dome mechanism  228  during actuation of the keycap  220 . For example, when the keycap  220  is actuated, the collapsible dome mechanism  228  is deformed, collapses, or is otherwise compressed so that it touches or otherwise connects to the contact  230 . The dome&#39;s collapse completes an electrical circuit, thereby indicating the key  204  has been actuated and generating an electrical input signal. In various embodiments, the collapsible dome mechanism  228  may be a metal dome, a rubber dome, a plastic dome, or it may be made from suitable other materials. Further, it should be appreciated that the membrane  226  and/or contact housing  232  may be omitted in certain embodiments. 
     Other support mechanisms may be used in the place of the collapsible dome mechanism  228  and/or the membrane  226 . For example, the keycap  220  may be coupled to a mechanical switch mechanism, a buckling-spring mechanism, or another suitable support mechanism; such support mechanisms are typically beneath the keycap and physically abutting the keycap. 
     A scissor-style support mechanism may be used in some embodiments, while in others a V-shaped or U-shaped support mechanism may be used. Generally, the support mechanism (whether a dome, scissor, V-shape, spring, or other type) biases the keycap  220  upward in the absence of any force exerted thereon, and returns the keycap  220  to its resting position when force is removed from the keycap. In certain embodiments, the collapsible dome  228  may be present but may not act as a support mechanism; rather, a separate support mechanism may operate as described herein to bias and support the keycap  220 . In some embodiments, the support mechanism may also function as the restoring mechanism, while in other embodiments the two may be separate structures. 
     In the place of a membrane  226  and/or contact  230  may be a mechanical switch, a capacitive sensor, a Hall Effect sensor, a resistive sensor, an optical sensor, or a similar sensor suitable for registering the vertical motion of the keycap  220  when pressed downward. 
     The key  204  also includes a touch-sensing layer  234 . The touch-sensing layer  234  may be integrated with or positioned on or near the keycap  220 . As will be described below, the touch-sensing layer  234  may be comprised of various sense electrodes and drive electrodes arranged in a particular pattern. The sense electrodes and drive electrodes are configured to detect a change in capacitance therebetween (in a given region or area of the multifunction input device and/or over a particular key  204 ) when an input mechanism, such as a user&#39;s finger, contacts the keycap  220  as it moves over the surface. The change in capacitance between a sense and drive electrode(s), or at a sense electrode, may initiate an input to an associated electronic device. Accordingly, when a user touches a key but does not exert sufficient force to collapse the associated dome, the touch may nonetheless be registered as an input and a corresponding electrical signal generated. Thus, a single key may provide two different inputs based on two different actions from a user, namely touch and force. Further, the inputs may be generated in response to an electrical phenomenon (e.g., a change in capacitance) and a mechanical phenomenon (e.g., the collapse of a dome or other physical closing of a switch, or travel of a key) associated with a single key. 
     Likewise, as a user&#39;s finger (or a stylus, or other suitable object) moves from the exterior surface of one key to another, the changes in capacitance at each successive key may be registered and used as input. The motion of the finger or other object may thus be tracked. In this fashion, multiple touch-sensitive keys may be used together to provide a single input, such as a gesture, to an associated electronic device. 
     The touch-sensing layer  234  may be formed on or within a flexible substrate (e.g., a flexible printed circuit board or similar substrate). The flexible substrate may be formed from a suitable material, such as polyimide or polyethylene terephthalate. The flexible substrate may be bonded to the keycap, for example using an adhesive layer such as a pressure sensitive adhesive. 
     Because the array of keys  204  on a keyboard may not form a continuous surface, flexible electrical connectors  236 , optionally including a conductive element (e.g., an electrical connection), may connect each key  204  to one or more adjacent keys  204 . The flexible electrical connectors  236  may be at least partially formed from the same material as the touch-sensing layer  234 , or may be formed from distinct materials. For example, the flexible electrical connectors  236  may be formed from the same material as the flexible substrate of the touch-sensing layer  234 . 
     In some cases, the touch-sensing layer  234  is formed as a flexible printed circuit board. The touch-sensing layer  234  may be a multi-layer flexible printed circuit board, such as depicted further with respect to  FIGS. 4A and 4B  below. In these cases, a flexible electrical connector  236  may also be formed as a flexible printed circuit board. In some embodiments the flexible electrical connectors  236  are formed as part of the same flexible printed circuit board as the touch-sensing layer  234 , while in other embodiments the flexible electrical connectors  236  are formed separately and coupled to the touch-sensing layer  234  (see  FIGS. 5A-5C ). 
     In some embodiments, the flexible electrical connectors  236  may extend from a side of one touch-sensing layer to another, as opposed to extending from a corner. The flexible electrical connector  236  may extend at a non-right angle, such that the length of the flexible electrical connector is greater than the distance between two adjacent keys (or two adjacent touch-sensing layers of two adjacent keys). The flexible electrical connector may thus be long enough that it does not transmit force between keys when one key is pressed. 
       FIG. 3  depicts a cross-sectional view of two keys  304  of a multifunction input device taken along line A-A of  FIG. 1A  according to another embodiment. The keys  304  include a keycap  320  positioned within an aperture defined by the frame  322 . In this embodiment, the keycap  320  may include a flange  321  that interacts with or otherwise contacts a portion of the frame  322  when the key  304  is in its nominal position. In this particular embodiment, the key  304  includes an insulating layer, such as a fabric layer  338  that is positioned over the keycap  320 . The fabric layer  338  may be bonded or otherwise coupled to the touch-sensing layer  334  and/or keycap  320  by an adhesive. The fabric layer  338  may be formed from any appropriate material, such as silicone, polyester, nitrile, or a similar material or combination of materials. 
     In some embodiments, the portion of the fabric layer  338  that is positioned above the keycap  320  includes a raised or an embossed portion. The embossed portion may have a surface area that is larger than a surface area of the keycap  320  and/or the touch-sensing layer  334 . The embossed portion may be defined by or otherwise include a transition region  340  that extends between an outer edge of the keycaps  320 . 
     The transition region  340  provides a smooth transition between each key  304  of the keyboard. For example, in typical keyboards, a space is present between each key  304 . As a user slides a finger over the keys, the user&#39;s finger contacts the rigid edges of each key. Continuous contact with these rigid edges may be uncomfortable for the user. 
     However, the transition region  340  provides a transition point between the edges of the keycaps  320  which reduces or eliminates the rigid transitions that may otherwise be present between the keys  304 . The transition region  340  may further protect the flexible electrical connectors  336  (or other electrical connection) spanning between the touch-sensing layers  334  on each keycap  320 . In some embodiments, the transition region  340  may be bonded with, or otherwise affixed to, the flexible electrical connectors  336 . In other embodiments, the fabric layer  338  may not be coupled to the flexible electrical connectors  336 . In some embodiments, and as shown in  FIG. 3 , the flexible electrical connector  336  is spaced apart from the insulating layer  338  forming the transition region  340 , thereby ensuring that the flexible electrical connector  336  and transition region  340  may deform separately without pulling or otherwise exerting force on one another. This may help ensure that pressing a first key  304  does not inadvertently translate or otherwise move an adjacent key  304  connected by the flexible electrical connector. 
     The flexible electrical connectors  336 , or other electrical connections, are generally sufficiently pliable and dimensioned to permit the adjacent keys  304  connected by the connectors  336  to move independently of one another. That is, pressing down on one key  304  will not move another key connected thereto by the flexible electrical connector  336 . Rather, the electrical connector  336  will deform while maintaining the physical connection between the pressed key  304  and adjacent key  304 . 
     In some instances, the fabric layer  338  and/or the flexible electrical connectors  336  may act as a restoring mechanism that returns the keycap  320  to its nominal position once the key  304  has been actuated. As such, a restoring mechanism, such as, for example, a scissor mechanism or a butterfly mechanism, may be omitted. In other embodiments the key  304  may also include a scissor, butterfly, or other restoring mechanism such as shown above with respect to  FIG. 2 . 
     The key  304  may also include membrane  326 , a collapsible dome mechanism  328  (and/or other suitable support mechanism to bias the keycap  320 ) and a contact  330 . The membrane  326  may be coupled to a contact housing  332 . Each of the dome mechanisms  328 , the contact  330 , and the contact housing  332  may be positioned over a base plate  325 . Each of these components may function in a similar manner to the similar components described above. The base plate  325  likewise may be any of the aforementioned structures. In some embodiments, the membrane  326  and contact housing  332  may cooperate to form a support mechanism to bias the keycap upward in the absence of an exerted force, while in other embodiments the collapsible dome mechanism may be such a support mechanism. 
     The key  304  may also include a touch-sensing layer  334  (or other suitable touch-sensing input mechanism) disposed above the keycap  320 . As described above, the touch-sensing layer  334  may detect a change in capacitance as a user moves a finger over the surface of the keycap  320  and the fabric layer  338 . 
     The touch-sensing layer  434  may be comprised of multiple further layers as shown in  FIGS. 4A and 4B .  FIG. 4A  depicts a cross-sectional view of the touch-sensing layer  434  according to a first embodiment. The touch-sensing layer  434  may include an array of sense electrodes  442  positioned near a top surface of the touch-sensing layer  434 . The sense electrodes  442  may include materials such as, but not limited to: silver, copper, gold, constantan, karma, isoelastic, indium tin oxide, or any combination thereof. The sense electrodes  442  may be disposed on a first substrate layer  444 . The first substrate layer  444  may be comprised of a number of suitable materials, such as, but not limited to: polyimide, polyethylene terephthalate, plastic, metal, ceramic, glass, or any combination thereof. 
     The sense electrodes  442  may be formed or deposited on the first substrate layer  444  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. If the keyboard includes transparent elements, it may be preferable for the sense electrodes  442  and first substrate layer  444  to be made from optically transparent materials, while optically opaque materials may be acceptable or preferable if the keyboard is opaque. 
     An array of drive electrodes  446  may be positioned on a layer below the sense electrodes  442 . Similar to the sense electrodes  442 , the drive electrodes  446  may include materials such as, but not limited to: silver, copper, gold, constantan, karma, isoelastic, indium tin oxide, or any combination thereof. The drive electrodes  446  may be comprised of the same material as the sense electrodes  442 , or they may be comprised of distinct materials. The drive electrodes  446  may be disposed on a second substrate layer  448 . The second substrate layer  448  may be comprised of a number of suitable materials (e.g., the same or a different material as the first substrate layer  444 ), such as, but not limited to: polyimide, polyethylene terephthalate, plastic, metal, ceramic, glass, or any combination thereof. 
     The drive electrodes  446  may be formed or deposited on the second substrate layer  448  using a suitable deposition technique (e.g., the same or a different technique as the sense electrodes  442 ) 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. If the keyboard includes transparent elements, it may be preferable for the drive electrodes  446  and second substrate layer  448  to be made from optically transparent materials, while optically opaque materials may be acceptable or preferable if the keyboard is opaque. 
     The sense electrodes  442  and the drive electrodes  446  may be separated by an insulating layer  450 . The insulating layer  450  may include materials such as, but not limited to: plastic, metal, ceramic, glass, polyimide, polyethylene terephthalate, or any combination thereof. The sense electrodes  442  and first substrate layer  444  may be bonded to the insulating layer  450  with an adhesive layer  452 . The adhesive layer  452  may be any suitable material that promotes adhesion between the sense electrodes  442 , the first substrate layer  444 , and the insulating layer  450 . According to some embodiments, the adhesive layer  452  can include a pressure sensitive adhesive. 
     The drive electrodes  446  and second substrate layer  448  may be similarly bonded to the insulating layer  450  with an adhesive layer  454 . The adhesive layer  454  may be any suitable material that promotes adhesion between the drive electrodes  446 , the second substrate layer  448 , and the insulating layer  450 . According to some embodiments, the adhesive layer  454  can include a pressure sensitive adhesive (e.g., the same or a different pressure sensitive adhesive used in adhesive layer  452 ). 
     The touch-sensing layer  434  may operate through capacitive sensing, and the sense electrodes  442  and drive electrodes  446  may have various dimensions and be arranged in various ways and patterns. For example, as depicted in  FIG. 4A , the touch-sensing layer  434  includes at least two sense electrodes  442  electrically connected in pairs. One or more drive electrodes  446  are positioned in between the pairs of sense electrodes  442 . 
     Additionally or alternatively, the sense electrodes  442  may be arranged in rows while the drive electrodes  446  are arranged in columns. In another arrangement, the sense electrodes  442  may be arranged in columns while the drive electrodes  446  are arranged in rows. In yet another embodiment, portions of the drive electrodes  446  may be interlocked with portions of the sense electrodes  442  to form an interdigitated pattern. In another example, the sense electrodes  442  may be arranged in a first plane and the drive electrodes  446  may be arranged on a second, different plane. In some embodiments, the dimensions of the drive electrodes  446  and sense electrodes  442  may vary. For example, the dimensions of the drive electrodes  446  and/or the sense electrodes  442  may have a first set of dimensions on a first portion of a keycap and may have a second set of dimensions on a second portion of the keycap. 
     In certain embodiments, the drive electrodes  446  may be omitted and/or replaced with one or more electrical grounds. In such embodiments, capacitances at the sense electrodes  442  may vary as a finger or other object approaches and/or touches the sense electrode(s)  442 . This change in capacitance may be measured and used as input, in a fashion similar to the change in capacitance between sense electrodes  442  and drive electrodes  446 . 
     The first substrate layer  444  may further be bonded to additional layers of a key, such as a fabric layer  448  or other external, covering material. The first substrate layer  444  may be bonded to the fabric layer  448  using an adhesive layer  456 . The adhesive layer  456  may be any suitable material that promotes adhesion between the first substrate layer  444  and the fabric layer  438 . The adhesive layer  456  may include a pressure sensitive adhesive, which may be the same pressure sensitive adhesive used in other adhesive layers or may be different. The second substrate layer  448  may similarly be bonded to additional layers, such as a stiffener layer  421 , keycap, or other rigid substrate, and may be bonded with an adhesive layer  458  which may be the same or different from other adhesive layers. 
     The layers, their arrangements, and the materials described in  FIG. 4A  are examples. Additional or fewer layers may be implemented in other embodiments. The arrangement of the various layers and the materials used may also differ in other embodiments. 
       FIG. 4B  depicts a cross-sectional view of the touch-sensing layer  434  according to another embodiment incorporating force sensing features. The touch-sensing layer  434  may include an array of sense electrodes  442  positioned near a top surface of the touch-sensing layer  434 . The sense electrodes  442  may be disposed on a first substrate layer  444  using suitable techniques, such as those described above with respect to  FIG. 4A . The sense electrodes  442  and the first substrate layer  444  may be comprised of a number of suitable materials, such as described above with respect to  FIG. 4A . 
     An array of drive electrodes  446  may be positioned on a second substrate layer  448  below the sense electrodes  442 . Similar to the sense electrodes  442 , the drive electrodes  446  and second substrate layer  448  may include materials such as those described above with respect to  FIG. 4A . 
     The touch-sensing layer may operate through a capacitive sensing scheme, and the sense electrodes  442  and drive electrodes  446  may have various dimensions and be arranged in various ways and patterns. For example, as depicted in  FIG. 4B , the sense electrodes  442  may be arranged in rows while the drive electrodes  446  are arranged in columns. Other arrangements are discussed above with respect to  FIG. 4A . 
     The sense electrodes  442  and the drive electrodes  446  may be separated by a layer of compliant elements  460 . The compliant elements  460  may operate to allow for the sense electrodes  442  and drive electrodes  446  to provide for force detection in addition to touch detection. When the user applies force to a surface of the key, the sense electrodes  442  and first substrate layer  444  may be caused to deform and press downward, compressing the one or more compliant elements  460 . The sense electrodes  442  may thus be allowed to deflect toward the drive electrodes  446 . 
     When the distance between the sense electrodes  442  and drive electrodes  446  is reduced, there may be a measurable change in an electrical attribute, such as a capacitance, between the electrodes. This allows circuitry connected to the sense electrodes  442  and drive electrodes  446  to determine an amount of applied force, a location of applied force, and a location of touch. 
     The compliant elements  460  may be comprised of a suitable material, such as a flexible silicone gel. In some embodiments, the compliant elements  460  may be comprised of a compliant foam or an air gap. The compliant elements  460  may be formed in dots, as depicted in  FIG. 4B , may be formed in other shapes, or may be formed in a continuous layer. The compliant elements  460  may be surrounded by another material, or may be surrounded by air or a vacuum. 
     The sense electrodes  442  and first substrate layer  444  may be bonded to the compliant elements  460  with an adhesive layer  452 . The adhesive layer  452  may be any suitable material that promotes adhesion between the sense electrodes  442 , the first substrate layer  444 , and the compliant elements  460 . According to some embodiments, the adhesive layer  452  can include a pressure sensitive adhesive. 
     The drive electrodes  446  and second substrate layer  448  may be similarly bonded to the compliant elements  460  with an adhesive layer  454 . The adhesive layer  454  may be any suitable material that promotes adhesion between the drive electrodes  446 , the second substrate layer  448 , and the compliant elements  460 . According to some embodiments, the adhesive layer  454  can include a pressure sensitive adhesive (e.g., the same or a different pressure sensitive adhesive used in adhesive layer  452 ). 
     The touch-sensing layer  434  may be further bonded to other materials forming a key, such as a fabric layer and/or a keycap. The layers, their arrangements, and the materials described in  FIG. 4B  are examples. Additional or fewer layers may be implemented in other embodiments. The arrangement of the various layers and the materials used may also differ in other embodiments. 
     For example, in some embodiments, the compliant elements  460  are not encapsulated within the touch sensing layer  434 . The touch sensing layer  434  may be formed as a flexible printed circuit board positioned over the compliant elements  460 , including one or more layers of electrodes  442 . The compliant elements  460  may be formed on or coupled to a surface of a separate substrate below the compliant elements  460 . The substrate on which the compliant elements are formed or coupled may be another flexible printed circuit board, which may include electrodes  446  for force and/or touch sensing, which may operate as described above. 
     Embodiments of the present invention may implement the touch-sensing layer  534  on an array of keys, with flexible electrical connectors  536  spanning between the keys, as illustrated in  FIG. 5A .  FIG. 5A  depicts an array of touch-sensing layers  534  interconnected by flexible electrical connectors  536 . Each touch-sensing layer  534  is configured to be attached to a keycap, with the flexible electrical connectors  536  spanning between the keycaps, as illustrated above with respect to  FIGS. 2 and 3 . The touch-sensing layers  534  and flexible electrical connectors  536  may be covered with an insulating layer, such as a fabric layer, as illustrated above with respect to  FIG. 3 . 
     The touch-sensing layers  534  may be formed substantially as illustrated above with respect to  FIG. 4A or 4B . A touch-sensing layer  534  may be formed from flexible materials in order to better conform to the keycap, with substrate layers formed from flexible materials such as polyimide or polyethylene terephthalate. A flexible electrical connector  536  may be similarly formed from flexible material, which may be similar to the flexible substrate layers of the touch-sensing layer  534 . 
     The flexible electrical connectors  536  include conductive material (e.g., an electrical connection), which may be formed as one or more wires, traces, or similar conducting paths. The flexible electrical connectors  536  may electrically connect the sense electrodes and drive electrodes of the touch-sensing layers  534  to form a larger array of sense electrodes and drive electrodes. The connections of the flexible electrical connectors  536  may thus create a set of virtual rows and columns of sense and drive electrodes across the keyboard to create a near-continuous touch input surface over the keys. 
     In some embodiments, the touch-sensing layers  534  and flexible electrical connectors  536  may be formed from the same materials. In these embodiments, the touch-sensing layers  534  and flexible electrical connectors  536  may be formed in the same process, and may further be formed as a single array covering an entire keyboard, or a sheet forming multiple keyboards which are later separated. 
     In addition to providing an electrical connection, the flexible electrical connector  536  material and its physical shape may also be formed in accordance with desired compliance and rigidity in order to improve the mechanical motion and feel of the keys. Example cross-sections of the flexible electrical connectors  536  are illustrated further below with respect to  FIGS. 5B and 5C . Example shapes are illustrated below with respect to  FIG. 6 . 
     A flexible electrical connector  536  may include multiple layers as shown in  FIGS. 5B and 5C .  FIG. 5B  depicts a cross-sectional view of a flexible electrical connector  536  according to a first embodiment. The flexible electrical connector  536  may include an array of conductors  541 , formed as one or more wires, traces, or similar conducting paths, positioned within a flexible substrate  557 . In some embodiments, the array of conductors  541  is disposed in a single layer, while in other embodiments the array of conductors  541  may be disposed in multiple layers. The conductors  541  may include materials such as, but not limited to: silver, copper, gold, constantan, karma, isoelastic, indium tin oxide, or any combination thereof. Each end of a conductor  541  may be bonded to or formed integral with conductors and/or sense electrodes in the touch-sensing layer on adjacent keys. 
     The conductors  541  may be disposed within a suitable flexible substrate  557  formed from polyimide, polyethylene terephthalate, plastic, or any combination thereof. In some embodiments, the flexible substrate  557  may be formed as a single substrate layer around the conductors  541 . In other embodiments, the flexible substrate  557  may include multiple layers of flexible material, wherein the conductors  541  may be deposited on one or more of the layers. The material of the flexible substrate  557  may be selected according to a desired flexibility, and additionally or alternatively may be selected for compliance, rigidity, durability, cost, ease of manufacturing, and similar features. 
     The layers, their arrangements, and the materials described in  FIG. 5B  are examples. Additional or fewer layers may be implemented in other embodiments. The arrangement of the various layers and the materials used may also differ in other embodiments. 
       FIG. 5C  depicts a cross-sectional view of a flexible electrical connector  536  according to another embodiment incorporating touch sensing (see  FIGS. 7C and 7D ). The flexible electrical connector  536  may include an array of electrodes  543 ,  547 , which may also operate as sense electrodes. An array of conductors, operating as sense electrodes  543 , is positioned near a top surface of the flexible electrical connector  536 . The sense electrodes  543  may include materials such as, but not limited to: silver, copper, gold, constantan, karma, isoelastic, indium tin oxide, or any combination thereof. The sense electrodes  543  may be disposed on a first substrate layer  545 . The first substrate layer  545  may be comprised of a number of suitable materials, such as, but not limited to: polyimide, polyethylene terephthalate, plastic, metal, ceramic, glass, or any combination thereof. 
     The sense electrodes  543  may be formed or deposited on the first substrate layer  545  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. If the keyboard includes transparent elements, it may be preferable for the sense electrodes  543  and first substrate layer  545  to be made from optically transparent materials, while optically opaque materials may be acceptable or preferable if the keyboard is opaque. 
     An array of drive electrodes  547  may be positioned on a layer below the sense electrodes  543 . Similar to the sense electrodes  543 , the drive electrodes  547  may include materials such as, but not limited to: silver, copper, gold, constantan, karma, isoelastic, indium tin oxide, or any combination thereof. The drive electrodes  547  may be comprised of the same material as the sense electrodes  543 , or they may be comprised of distinct materials. The drive electrodes  547  may be disposed on a second substrate layer  549 . The second substrate layer  549  may be comprised of a number of suitable materials (e.g., the same or a different material as the first substrate layer  545 ), such as, but not limited to: polyimide, polyethylene terephthalate, plastic, metal, ceramic, glass, or any combination thereof. Each end of a drive electrode  547  and each end of a sense electrode  543  may be bonded to or formed integral with conductors and/or sense electrodes in the touch-sensing layer on adjacent keys. 
     The drive electrodes  547  may be formed or deposited on the second substrate layer  549  using a suitable deposition technique (e.g., the same or a different technique as the sense electrodes  543 ) 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. If the keyboard includes transparent elements, it may be preferable for the drive electrodes  547  and second substrate layer  549  to be made from optically transparent materials, while optically opaque materials may be acceptable or preferable if the keyboard is opaque. 
     The sense electrodes  543  and the drive electrodes  547  may be separated by an insulating layer  551 . The insulating layer  551  may include materials such as, but not limited to: plastic, metal, ceramic, glass, polyimide, polyethylene terephthalate, or any combination thereof. The sense electrodes  543  and first substrate layer  545  may be bonded to the insulating layer  551  with an adhesive layer  553 . The adhesive layer  553  may be any suitable material that promotes adhesion between the sense electrodes  543 , the first substrate layer  545 , and the insulating layer  551 . According to some embodiments, the adhesive layer  553  can include a pressure sensitive adhesive. 
     The drive electrodes  547  and second substrate layer  549  may be similarly bonded to the insulating layer  551  with an adhesive layer  555 . The adhesive layer  555  may be any suitable material that promotes adhesion between the drive electrodes  547 , the second substrate layer  549 , and the insulating layer  551 . According to some embodiments, the adhesive layer  555  can include a pressure sensitive adhesive (e.g., the same or a different pressure sensitive adhesive used in adhesive layer  553 ). 
     The flexible electrical connector  536  may include capacitive sensing, and the sense electrodes  543  and drive electrodes  547  may have various dimensions and be arranged in various ways and patterns. For example, as depicted in  FIG. 5B , the flexible electrical connector  536  includes at least two sense electrodes  543  electrically connected in pairs. One or more drive electrodes  547  are positioned in between the pairs of sense electrodes  543 . 
     Additionally or alternatively, the sense electrodes  543  may be arranged in rows while the drive electrodes  547  are arranged in columns. In another arrangement, the sense electrodes  543  may be arranged in columns while the drive electrodes  547  are arranged in rows. In yet another embodiment, portions of the drive electrodes  547  may be interlocked with portions of the sense electrodes  543  to form an interdigitated pattern. In another example, the sense electrodes  543  may be arranged in a first plane and the drive electrodes  547  may be arranged on a second, different plane. In some embodiments, the dimensions of the drive electrodes  547  and sense electrodes  543  may vary. For example, the dimensions of the drive electrodes  547  and/or the sense electrodes  543  may have a first set of dimensions at a first portion near a keycap and may have a second set of dimensions at a second portion between a pair of keycaps. 
     In certain embodiments, the drive electrodes  547  may be omitted and/or replaced with one or more electrical grounds. In such embodiments, capacitances at the sense electrodes  543  may vary as a finger or other object approaches and/or touches the sense electrode(s)  543 . This change in capacitance may be measured and used as input, in a fashion similar to the change in capacitance between sense electrodes  543  and drive electrodes  547 . 
     The layers, their arrangements, and the materials described in  FIG. 5C  are examples. Additional or fewer layers may be implemented in other embodiments. The arrangement of the various layers and the materials used may also differ in other embodiments. 
       FIGS. 6A-6F  depict example flexible electrical connectors  636   a - 636   e  disposed between pairs of touch-sensing layers  634 . The flexible electrical connectors  636   a - 636   e  may be formed in a variety of shapes. Different shapes may offer varying advantages in terms of flexibility, compliance, rigidity, durability, cost, ease of manufacturing, and similar features. Example flexible electrical connectors  636   a - 636   e  are depicted, but these are for illustrative purposes and many other shapes and sizes of electrical connectors may be used. 
     As depicted in  FIG. 6F , in some embodiments multiple flexible electrical connectors  636   f ,  636   g ,  636   h  may span between (and connect) adjacent keys. In some examples, rows of touch-sensing pixels within adjacent touch-sensing layers  634  may be separately connected by flexible electrical connectors  636   f ,  636   g ,  636   h . In other embodiments, two or more flexible electrical connectors  636   f ,  636   g ,  636   h  may offer advantages in terms of flexibility, compliance, rigidity, and similar features, and only one flexible electrical connector  636   f  may electrically connect the touch-sensing layers  634 . In still other examples, one or more of the multiple flexible electrical connectors  636   g  may define or include a touch-sensitive pixel or partial touch-sensing pixel  662  (see  FIGS. 7C and 7D ). 
     The touch-sensing layers  734  may be formed in a manner to create touch-sensitive pixels  762  where a touch may be detected and its location determined, as illustrated in  FIGS. 7A-D . For example, in a mutually-capacitive touch-sensing layer  734 , the touch-sensitive pixels  762  may correspond to intersection points of rows and columns of sense electrodes and drive electrodes. 
       FIG. 7A  depicts an example array of touch-sensitive pixels  762  within touch-sensing layers  734  interconnected by flexible electrical connectors  736 . Each touch-sensing layer  734  may correspond to a key on a keyboard, and may consist of multiple touch-sensitive pixels  762 . While the touch-sensitive pixels  762  are illustrated having the same size and spacing, with four disposed within each touch-sensing layer  734 , other embodiments may employ different sizes, arrangements, and numbers of touch-sensitive pixels  762 . 
       FIG. 7B  depicts another example array of touch-sensitive pixels  762  within touch-sensing layers  734  interconnected by flexible electrical connectors  736 . As depicted in  FIG. 7B , the touch-sensitive pixels  762  may be arranged such that each touch-sensing layer  734  has a touch-sensitive pixel (or partial touch-sensitive pixel) near the corner. This may allow for a processing device or other touch-sensing circuitry to create a virtual super-pixel  764  using inputs from adjoining corner touch-sensitive pixels  762 . This may allow for the multi-function input device to correct for any lack of touch-sensitive pixels  762  between keys. Further, information from multiple pixels (such as adjacent pixels) may be used to estimate or otherwise determine a location of a touch between pixels, or that overlaps multiple pixels. Changes in capacitances of neighboring pixels may indicate that a touch has occurred between the pixels, or on both pixels, for example. In some embodiments, the touch-sensitive pixels  762  may be arranged differently. For example, one or more large touch-sensitive pixels  762  may be positioned in a central portion of a key, and small or partial touch-sensitive pixels  762  may be positioned at corners and/or edges of a key in order to create virtual pixels across two or more keys. 
     Additionally or alternatively, touch-sensitive pixels (or partial touch-sensitive pixels)  762  may be disposed within the flexible electrical connectors  736 .  FIG. 7C  depicts another example array of touch-sensitive pixels  762  within touch-sensing layers  734  and interconnecting flexible electrical connectors  736 . As depicted in  FIG. 7C , the touch-sensitive pixels  762  may be arranged such that touch-sensitive pixels  762  are positioned within both the touch-sensing layers  734  and each flexible electrical connector  736 . This may also allow for a more continuous input surface and correct for any lack of touch-sensitive pixels  762  between keys. 
       FIG. 7D  depicts another example array of touch-sensitive pixels  762   a ,  762   b ,  762   c ,  762   d  within touch-sensing layers  734  and interconnecting flexible electrical connectors  736 . As depicted in  FIG. 7D , the touch-sensing layer  734  over each key may include at least one touch-sensitive pixel  762   a  and multiple partial touch-sensitive pixels  762   b ,  762   d . The partial touch-sensitive pixels  762   b ,  762   d  of adjacent keys may form virtual pixels across the keys. For example, a first partial touch-sensitive pixel  762   b  at an edge of a first key may be paired with a second partial touch-sensitive pixel  762   d  to form a touch-sensitive pixel or virtual touch-sensitive pixel. 
     In some embodiments, a flexible electrical connector  736  may include a touch-sensitive portion  763 , wherein a third partial touch-sensitive pixel  762   c  may be formed. In these embodiments, the first partial touch-sensitive pixel  762   b , the second partial touch-sensitive pixel  762   d , and the third partial touch-sensitive pixel  762   c  may together form a touch-sensitive pixel or virtual touch-sensitive pixel. 
     It should be understood that the example touch-sensitive pixels and partial touch-sensitive pixels depicted in  FIGS. 7A-7D  are illustrative in nature. The size, arrangement, number, location, and so on of the touch-sensitive pixels and partial touch sensitive pixels may vary in other embodiments. 
     As illustrated in  FIGS. 8 and 9 , a multifunction input device according to the present invention may be implemented in many forms. A multifunction input device according to the present invention may take the form of a keyboard, mouse, trackpad, or other input device. An input device may be incorporated into devices such as a laptop computer, as shown above with respect to  FIGS. 1A-1C , or it may be a separate device in communication with a host computer or other device as illustrated in  FIG. 9 . The multifunction input device of the present invention may also be incorporated into separate multipurpose devices or accessories, such as a case for a portable electronic device as illustrated with respect to  FIG. 8 . 
       FIG. 8  depicts an example multifunction input device  800 , incorporated into a cover case. The cover case may have an enclosure  801  and be attached to and in communication with a portable tablet computing device  866 . The multifunction input device  800  may be in communication with the tablet  866  through a wired connection, an electrical contact connection, or a wireless connection. The enclosure  801  of the multifunction input device  800  includes an array of keys  804 , which may include the touch-sensing layer described above with respect to  FIGS. 1A-7D . 
       FIG. 9  depicts an example multifunction input device  900  in communication with a desktop computer  967 . The input device  900  may be in communication with the desktop  967  through a wired or wireless connection. The multifunction input device  900  may be implemented as a stand-alone keyboard having an enclosure  901  housing an array of keys  904 . The keys  904  may include the touch-sensing layer described above with respect to  FIGS. 1A-7D . 
     The example devices illustrated in the above figures are intended to be illustrative in nature, and can be implemented in a number of other manners. Further, while the above examples are illustrated with keys within a keyboard, they may be implemented in other input devices with movable input components configured to receive both touch and mechanical inputs. 
       FIG. 10  depicts example components of a multifunction input device in accordance with the embodiments described herein. The schematic representation depicted in  FIG. 10  may correspond to components of the devices depicted in  FIGS. 1A-9 , described above. However,  FIG. 10  may also more generally represent other types of devices with movable input components having both touch-sensitive input mechanisms (such as capacitive sensors) and mechanical input mechanisms (such as collapsible dome switches). 
     As shown in  FIG. 10 , a device  1000  includes a processing unit  1068  operatively connected to computer memory  1070 . The processing unit  1068  may be operatively connected to the memory  1070  component via an electronic bus or bridge. The processing unit  1068  may include one or more computer processors or microcontrollers that are configured to perform operations in response to computer-readable instructions. Where incorporated into a larger device such as a laptop computer, the processing unit  1068  may be the central processing unit (CPU) of the larger device. Additionally or alternatively, the processing unit  1068  may include other processors within the device  1000  including application specific integrated chips (ASIC) and other microcontroller devices. The processing unit  1068  may be configured to perform functionality described in the examples above. 
     The memory  1070  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  1070  is configured to store computer-readable instructions, sensor values, and other persistent software elements. 
     In this example, the processing unit  1068  is operable to read computer-readable instructions stored on the memory  1070 . The computer-readable instructions may adapt the processing unit  1068  to perform the operations or functions described above with respect to  FIGS. 1-11 . The computer-readable instructions may be provided as a computer-program product, software application, or the like. 
     The device  1000  may also include a battery  1072  that is configured to provide electrical power to the components of the device  1000 . The battery  1072  may include one or more power storage cells that are linked together to provide an internal supply of electrical power. The battery  1072  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  1000 . The battery  1072 , via power management circuitry, may be configured to receive power from an external source, such as an AC power outlet. The battery  1072  may store received power so that the device  1000  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  1000  includes one or more input components  1074 . The input component  1074  is a device that is configured to receive user input. The input component  1074  may include, for example, a push button, a touch-activated button, or the like. In some embodiments, the input components  1074  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 touch sensor  1034  and force sensor  1035  are depicted as distinct components within the device  1000 . 
     The device  1000  may also include a touch sensor  1034  that is configured to determine a location of a finger or touch over one or more keys or other input surface of the device  1000 . The touch sensor  1034  may be implemented in a touch-sensing layer, and may include a capacitive array of electrodes or nodes that operate in accordance with a mutual-capacitance or self-capacitance scheme. 
     The device  1000  may also include a force sensor  1035  in accordance with the embodiments described herein. As previously described, the force sensor  1035  may be configured to receive force touch input over one or more keys or other input surface of the device  1000 . The force sensor  1035  may also be implemented in a touch-sensing layer, and may include one or more force-sensitive structures that are responsive to a force or pressure applied to an external surface of the device. In accordance with the embodiments described herein, the force sensor  1035  may be configured to operate using a dynamic or adjustable force threshold. The dynamic or adjustable force threshold may be implemented using the processing unit  1068  and/or circuitry associated with or dedicated to the operation of the force sensor  1035 . 
     The device  1000  may also include a haptic element  1076 . The haptic element may be implemented with a number of devices and technologies, such as an electromechanical actuator. The haptic element  1076  may be controlled by the processing unit  1068 , and may be configured to provide haptic feedback to a user interacting with the device  1000 . 
     The device  1000  may also include a communication port  1078  that is configured to transmit and/or receive signals or electrical communication from an external or separate device. The communication port  1078  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  1078  may be used to couple the device  1000  to a host computer. 
     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.

Metadata:
Filing Date: 20170427
Publication Date: 20190514
Grant Date: 20190514
Priority Date: 20160920
Inventors: WANG, PAUL X.
TAN, LIQUAN
MAHALATI, REZA NASIRI
LEHMANN, Alex J.
ZIMMERMAN, AIDAN N.
MARIC, IVAN S.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H2239/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/84", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K2217/96054", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/125", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2203/038", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03K17/965", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/962", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/9622", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2003/0293", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0213", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0447", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/03547", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0234", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0219", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/017", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03547", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0213", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0447", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/00", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 66439451