Abstract:
Embodiments are directed to a watch having a touch-sensitive display and a switch assembly positioned along or within an enclosure. The switch assembly includes a shaft extending into an opening of the enclosure and is configured to receive rotational and translational input. A first sensor, positioned within the enclosure, is configured to detect the rotational input. A second sensor, positioned within the enclosure, is configured to detect the translational input. The watch also includes a touch-sensitive display configured to receive touch input and to depict a graphical output of the watch. The graphical output may be responsive to various inputs, including a touch input provided at the display, the translational input provided at the switch assembly, and the rotational input provided at the switch assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application is a nonprovisional patent application of and claims priority to U.S. Provisional Application No. 61/864,389, filed Aug. 9, 2013, and titled “Tactile Switch for an Electronic Device,” the disclosure of which is hereby incorporated herein in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to electronic devices, and more specifically, to input devices for computing devices. 
       BACKGROUND 
       [0003]    Many types of electronic devices, such as smart phones, gaming devices, computers, watches, and the like, use input devices, such as buttons or switches, to receive user input. However, many input devices, such as buttons or switches, may allow only a single type of input. For example, a button may only transmit one type of signal, which is a compression of a button that completes a circuit. As electronic devices reduce in size, it may be desirable to have fewer input buttons or devices, without reducing functionality or the number of input types that can be used by a user to provide information to a device. Further, in instances where the button or switch may be movable or rotatable, the button may not be able to include a sensor or other electronic element that requires data and/or power to be transferred between the button and one or more components of the electronic device, as the movement may make an electrical connection difficult. 
       SUMMARY 
       [0004]    One example of the present disclosure takes the form of an input module. The input module includes a switch, a rotatable and translatable input member operably connected to the switch and configured to actuate the switch, and an electrical contact operably connected to the switch and in electrical communication with the input member. During operation, the electrical connection between the input member and the electrical contact is maintained during translation and rotation of the input member. The input module may be used with a variety of electronic devices and can be used by a user to provide input to those devices. 
         [0005]    Another example of the disclosure takes the form of a switch assembly. The switch assembly includes a rotatable and translatable input member, a coupling operable connected to the input member and moveable therewith, a tactile switch operably connected to the coupling, and an electrical contact operably connected to the tactile switch and in electrical communication with the coupling. The input member is configured to actuate the electrical component when the input member translates, and the coupling rotates as the input member rotates. Additionally, the electrical connection between the coupling and the electrical contact is maintained during translation and rotation of the input member. 
         [0006]    Yet another example of the disclosure includes a wearable electronic device. The wearable electronic device includes an enclosure defining a cavity and a button aperture defined through the enclosure. The wearable electronic device also includes one or more processing elements received within the cavity, and a switch module operably connected to the enclosure. The switch module includes a tactile switch in communication with the processing element, a rotatable and translatable input member operably connected to the tactile switch, and a contact operably connected to the tactile switch and electrically coupled to the input member. During operation, the electrical coupling between the input member and the contact is maintained during translation and rotation of the input member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a top plan view of a wearable electronic device including a multi-input device. 
           [0008]      FIG. 2  is a simplified block diagram of the wearable electronic device. 
           [0009]      FIG. 3  is a cross-section view of the wearable electronic device taken along line  3 - 3  in  FIG. 1 . 
           [0010]      FIG. 4  is a cross-section view similar to  FIG. 3  showing a user input force being applied to a button of a tactile switch assembly for the electronic device. 
           [0011]      FIG. 5  is a front elevation view of another example of a tactile switch that may be used with the tactile switch assembly of  FIG. 4 . 
           [0012]      FIG. 6  is a top plan view of the tactile switch of  FIG. 5 . 
           [0013]      FIG. 7  is a bottom plan view of the tactile switch of  FIG. 5 . 
           [0014]      FIG. 8  is a front elevation view of the tactile switch of  FIG. 5  as a translating force is applied thereto. 
           [0015]      FIG. 9  is a front elevation view of the tactile switch of  FIG. 5  as a rotating force is applied thereto. 
           [0016]      FIG. 10  is a front elevation view of yet another example of a tactile switch that can be used with the tactile switch assembly of  FIG. 4 . 
           [0017]      FIG. 11  is a top plan view of the tactile switch of  FIG. 10 . 
           [0018]      FIG. 12  is a bottom plan view of the tactile switch of  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
     Overview 
       [0019]    Some embodiments of the present disclosure include a tactile switch assembly. The tactile switch assembly may be implemented in a number of electronic devices. In some embodiments, the tactile switch assembly may be incorporated into a portable electronic device such as a wearable electronic device, laptop computer, tablet, or the like. The wearable electronic device may be a watch, portable music player, computing or gaming device, smart phone, or the like. In some embodiments, the wearable electronic device is a watch that can be worn around the wrist of a user. In these embodiments, the tactile switch assembly may include a button that forms a crown for the watch and is connected to a sidewall of an enclosure for the device. 
         [0020]    The tactile switch assembly includes a tactile switch, a user input member, and a shear plate or an electrical contact. The user input member, which may be a button, switch, flange, or the like, can provide a first type of input to the tactile switch by mechanically activating the switch. For example, the tactile switch may include a dome that compresses due to a translating user force to the input button and, upon compression, the tactile switch creates a signal indicating the user input. In this example, the compression of the dome may also provide feedback to a user, e.g., tactile feedback. 
         [0021]    The shear plate may electrically connect the tactile switch and the user input button so that electrical signals are transmittable between the tactile switch and the user input button and/or between the tactile switch and one or more electrical components (e.g., sensors) on the user input button. In other embodiments, electrical signals, power and the like may be routed between the switch and button by a flex, wire, trace or other electrical element that is attached to the shear plate and button. The shear plate also acts to prevent shear forces from being transmitted to the tactile switch, preventing the tactile switch from being damaged. The user input button may also provide a second type of input to the tactile switch assembly. For example, the user input member may be rotatable relative to the tactile switch. Continuing with this example, the shear plate may be positioned between the tactile switch and the user input button, allowing the user input member to remain in communication with the shear plate even as the user input member is rotated relative thereto. For example, the shear plate may include a brush contact that maintains an electrical connection with the user input member as the user input button is rotated. 
         [0022]    In some embodiments the tactile switch assembly may be used as a physiologic sensor and/or may be used in connection with a biometric sensor, although it should be appreciated that the sensor may be omitted from certain embodiments. In a specific embodiment, the wearable electronic device may be used to measure electrical parameters of a user&#39;s body, such as heart rate, electrical activity of the heart, and so on. As one example, the tactile switch assembly may be used to capture a user&#39;s electrocardiography. In this example, the wearable device may include a first user contact location and the user input button may form a second user contact location when touched by a user. In this embodiment, the two contacts may create an electrical path between the user and the device that allows the device to sense the user&#39;s heart rate. In these embodiments, either a contact on the shear plate may be conductive and/or the tactile switch itself may include a conductive nub or contact point for interacting with the button. These embodiments allow the tactile switch to be electrically connected to one or more elements within the housing. 
         [0023]    In some embodiments, the tactile switch assembly may also include one or more sensing elements and/or input/output elements on, or incorporated into, the user input button. Because the communicating component electrically connects the user input button to one or more internal components of the wearable device, the sensors and/or other electronic components on the user input button may be in communication with the shear plate and signals from the sensors and/or other components may be transmitted from the user input button via an electrical contact on the shear plate to one or more processing elements. In some embodiments, a wire, flex, trace or other electrical element may electrically connect the shear plate and input/output element, such as the user input button. 
         [0024]    The tactile switch assembly may be configured to receive multiple types of user inputs, such as, but not limited to, rotational inputs, translating inputs, and/or electrical inputs. For example, in one embodiment, the tactile switch assembly may include the shear plate and may be configured to receive rotational inputs, as well as translating inputs, without damaging the tactile switch. Additionally or alternatively, the tactile switch assembly may be in electrical communication with one or more components within the electronic device, even as the input member is moved (e.g., translated and/or rotated). In these examples, if rotational input is not desired or if the rotational input will be limited, the shear plate may be omitted and the tactile switch itself may include a conductive contact, such as an electrically conductive nub. 
         [0025]    Turning now to the figures, an illustrative wearable electronic device will now be discussed in more detail.  FIG. 1  is a top plan view of a wearable electronic device.  FIG. 2  is a simplified block diagram of the wearable electronic device of  FIG. 1 . With reference to  FIGS. 1 and 2 , the wearable electronic device  100  may include a hub  102  or computing center. In embodiments where the electronic device  100  is configured to be worn by a user, the device  100  may include one or more straps  104 ,  106  that may connect to opposite sides of the hub  102 . Each of the straps  104 ,  106  may wrap around a portion of a wrist, arm, leg, chest, or other portion of a user&#39;s body to secure the hub  102  to the user. For example, the ends of each of the straps  104 ,  106  may be connected together by a fastening mechanism  108 . The fastening mechanism  108  can be substantially any type of fastening device, such as, but not limited, to, hook and loop, magnetic fasteners, snaps, buttons, clasps or the like. However, in one embodiment, such as the one shown in  FIG. 1 , the fastening mechanism  108  is a buckle including a prong  134  or element that can be inserted into one or more apertures  112  in the second strap  106  to secure the first and second straps  104 ,  106  together. 
         [0026]    The hub  102  of the wearable electronic device generally contains the computing and processing elements of the wearable electronic device  100 .  FIG. 3  is a partial cross-section view of the hub  102  taken along line  3 - 3  in  FIG. 1 . With reference to  FIGS. 1-3 , the hub  102  may include a display  116  at least partially surrounded by an enclosure  114 . In some embodiments, the display  116  may form a face of the hub  102  and the enclosure  114  may wrap around the edges and backside of the display  116 . Additionally, the internal components of the wearable device  100  may be contained within the enclosure  114  between the display  116  and the enclosure  114 . The enclosure  114  protects the internal components of the hub  102 , as well as connects the display  116  to the hub  102 . 
         [0027]    The enclosure  114  may be constructed out of a variety of materials, such as, but not limited to, plastics, metals, alloys, and so on. The enclosure  114  includes a button aperture  172  (see  FIG. 3 ) to receive the tactile switch assembly  110  or a portion thereof. The button aperture  172  forms a channel within a sidewall  188  of the enclosure  114  and extends from an outer surface  188  of the enclosure  114  to an interior surface  190 . The button aperture  172  generally is configured to correspond to a button of the tactile switch assembly  110 . That said, the button aperture  172  may be otherwise shaped and sized. 
         [0028]    With reference to  FIG. 3 , in some embodiments, the enclosure  114  may include a sleeve  220  lining the button aperture  172 . In these embodiments, the button and/or other portions of the tactile switch assembly may be received into the sleeve  220 , which connects the tactile switch assembly  110  to the enclosure  114 . The sleeve  220  may act to help seal the cavity  139  of the enclosure  114 , as well as help to secure one or more components of the tactile switch assembly to the enclosure. In some embodiments the sleeve  220  may be an insulating material and may insulate the tactile switch or portions thereof, such as the head and coupling, from the enclosure. As will be discussed in more detail below, this may allow the tactile switch assembly to measure one or more characteristics of a user&#39;s body, such as a user&#39;s heart rate. 
         [0029]    The enclosure  114  may also include a groove  186  defined on a top surface to receive the display  116 . With reference to  FIGS. 1 and 3 , the display  116  may be connected to the enclosure  114  through adhesive or other fastening mechanisms. In this example, the display is seated within a recessed portion or groove of the enclosure and the enclosure wraps around the edges of the display. However, in other embodiments, the display and enclosure may be otherwise connected together. 
         [0030]    The display  116  may be substantially any type of display screen or device that can provide a visual output for the wearable device  100 . As an example, the display  116  may be a liquid crystal display, a light emitting diode display, or the like. Additionally, the display  116  may also be configured to receive a user input, such as a multi-touch display screen that receives user inputs through capacitive sensing elements. In many embodiments, the display  116  may be dynamically variable; however, in other embodiments, the display  116  may be a non-electronic component, such as a painted faceplate, that may not dynamically change. 
         [0031]    The display  116  includes a plurality of icons  118 ,  120  or other graphics that are selectively modifiable. As an example, a first graphic  118  may include a time graphic that changes its characters to represent the time changes, e.g., numbers to represent hours, minutes, and seconds. A second graphic  120  may include a notification graphic, such as, battery life, messages received, or the like. The two graphics  118 ,  120  may be positioned substantially anywhere on the display  116  and may be varied as desired. Additionally, the number, size, shape, and other characteristics of the graphics  118 ,  120  may be changed as well. 
         [0032]    The tactile switch assembly  110  is operably connected to the enclosure  114 . The tactile switch assembly  110  will be discussed in more detail below, but generally allows a user to provide input to the wearable electronic device  100 , as well can provide haptic feedback to a user. 
         [0033]    With reference to  FIG. 2 , the wearable electronic device includes a plurality of processing or computing elements. For example, the wearable electronic device  100  may include a power source  122 , one or more processing elements  124 , a memory component  128 , one or more optional sensors  126 , and an input/output component  130 . Each of the internal components may be received within the enclosure  114  and may be in communication through one or more systems buses  132 , traces, printed circuit boards, or other communication mechanisms. 
         [0034]    The power source  122  provides power to the hub  102  and other components of the wearable device  100 . The power source  122  may be a battery or other portable power element. Additionally, the power source  122  may be rechargeable or replaceable. 
         [0035]    The processing element  124  or processor is substantially any type of device that can receive and execute instructions. For example, the processing element  124  may be a processor, microcomputer, or the like. Additionally, the processing element  124  may include one or more processors and in some embodiments may include multiple processing elements. 
         [0036]    The one or more sensors  126  may be configured to sense a number of different parameters or characteristics that may be used to influence one or more operations of the wearable electronic device  100 . For example, the sensors  126  may include accelerometers, gyroscopes, capacitive sensors, light sensors, image sensors, pressure or force sensors, or the like. As will be discussed in more detail below, one or more of the sensors  126  may be used in conjunction with the tactile switch assembly  110  or separate therefrom, to provide user input to the hub  102 . Certain embodiments may omit the sensor or sensors  126 . 
         [0037]    With continued reference to  FIG. 2 , the memory component  128  stores electronic data that may be utilized by the wearable device  100 . For example, the memory component  128  may store electrical data or content e.g., audio files, video files, document files, and so on, corresponding to various applications. The memory  128  may be, for example, non-volatile storage, a magnetic storage medium, optical storage medium, magneto-optical storage medium, read only memory, random access memory, erasable programmable memory, or flash memory. 
         [0038]    The input/output interface  130  may receive data from a user or one or more other electronic devices. Additionally, the input/output interface  130  may facilitate transmission of data to a user or to other electronic devices. For example, the input/output interface  130  may be used to receive data from a network, or may be used to send and transmit electronic signals via a wireless or wired connection (Internet, WiFi, Bluetooth, and Ethernet being a few examples). In some embodiments, the input/output interface  130  may support multiple network or communication mechanisms. For example, the network/communication interface  130  may pair with another device over a Bluetooth network to transfer signals to the other device, while simultaneously receiving data from a WiFi or other network. 
         [0039]    The tactile switch assembly  110  will now be discussed in more detail. The tactile switch assembly  110  may include a button  148 , a coupling  218 , a shear plate  156 , and a tactile switch  214 . The components of the tactile switch may be operably connected together and select components may be in electrical communication with one another. 
         [0040]    With reference to  FIG. 3 , the button  148  forms a user interface for the tactile switch assembly  110  and extends outwardly from the enclosure  114 . For example, the button  148  may be an input member, such as a button or switch that is translatable and/or rotatable relative to the housing. The ability of the button  148  to translate and rotate relative to the enclosure allows a user to provide a rotational force and/or translating force to the tactile switch assembly. In some embodiments, the button  148  may form a crown for the wearable electronic device  100  and in other embodiments the button  148  may form an input button or switch for the electronic device. The button  148  may generally be a flange shaped member that may have a cylindrical body and a rounded or flat top. The button  148  includes an outer surface  232  that is configured to receive a user input and a stem  150  that extends from an interior surface  234  of the button  148 . The stem  150  may define a coupling aperture  236  that extends longitudinally along a length or a portion of a length of the stem  150 . In other words, the stem  150  may be hollow or partially hollow. In some embodiments, the button  148  and/or stem  150  may be made of an electrically conductive material and/or may be laced or doped with an electrically conductive material. 
         [0041]    With continued reference to  FIG. 3 , the coupling  218  may be a linkage, such as a shaft, that mechanically and/or electrically couples the button  148  to the tactile switch  214 . The coupling  218  may be integrally formed with the button  148  or may be a separate component operably connected thereto. For example, the stem  150  of the button  148  may form the coupling member that is integrally formed with the button. The coupling  218  may be made of a conductive material, such as one or more metals or metal alloys. Due to the conductive characteristics, the coupling  218  may further act to electrically couple the button  148  to the tactile switch  214  and shear plate  156 , although in other embodiments a wire, flex or other circuit may electrically couple the button and switch, either with or without including the shear plate in such an electrical connection. The coupling may also include a low-friction material, such as graphite, on its bottom surface, which allows the coupling to more easily rotate, even as it is operably associated with the shear plate. 
         [0042]    The coupling  218  may include a shaft  240  extending from a bottom end  222 . The bottom end  222  may have a larger diameter than the shaft  240 . The bottom end  222  may include an annular shelf  228  that extends around an outer surface. The annular shelf  228  may be configured to seal against the inner surface of the enclosure  114  and/or sleeve  220 . Additionally, the annular shelf  228  may be configured to secure a trackable element  146 , sensor, or sealing member to the coupling  218 . 
         [0043]    The bottom end  222  of the coupling  218  forms a joint to operably connect the coupling  218  to the shear plate  156 . In these embodiments, the coupling  218  may include an engagement feature  226  connected to the bottom end  222 . The engagement feature  226  is configured to rotatably connect to the shear plate  156  and maintain an electrical connection to the shear plate  156  either while the coupling is rotating or stationary; this will be discussed in more detail below. As shown in  FIG. 3 , in one embodiment, the engagement feature  226  includes a recess  224  formed into the bottom surface  244  of the bottom end  222 . An annular wall  242  extends from the bottom surface  244  surrounding the recess  224 . 
         [0044]    With continued reference to  FIG. 3 , the shear plate  156  may be positioned between the coupling  218  and the tactile switch  214 . In some embodiments, the shear plate  156  may be integrated with the tactile switch  214 , one example of which is shown in  FIG. 10 . In other embodiments, such as the one shown in  FIG. 3 , the shear plate  156  may a separate component operably connected to the tactile switch  214 . As will be discussed in more detail below, the shear plate  156  may substantially prevent shearing forces from the coupling from being transmitted to the tactile switch  214 . 
         [0045]    The shear plate  156  may include an electrical contact  158  that extends upwards from a main body  250 . The electrical contact  158  is a conductive material or otherwise laced with a conductive material such that the electrical contact  158  may transmit electrical signals. The main body  250  may be shaped as a plate or otherwise be configured to extend across a length and/or width of the tactile switch  214 . The shear plate  156  may be at least partially rigid and configured to transfer a force from the coupling  218  to the tactile switch  214 , which will be discussed in more detail below. Additionally, the shear plate  156  may include one or more terminals or connection mechanisms to connect the electrical contact  158  to the processing element  124  and/or power source. 
         [0046]    The tactile switch  214  may include a nub  216  and a collapsible dome  252 . The nub  216  interacts with a contact element on an interior of the dome  252  to indicate when the switch sensor  160  has been activated. For example, when the contact element  168  contacts the bottom of the switch, a circuit may be completed, a signal may be stimulated or created, or the like. The dome  252  is a resilient and flexible material that collapses or flexes upon a predetermined force level and returns to its original shape when a force is removed. The dome  252  may be a thin metal dome, a plastic dome, or other may be constructed from other materials. The dome  252  may produce an audible sound, as well as an opposing force, in response to a collapsing force exerted by a user. The audible sound and opposing force provide feedback to a user when a user compresses the dome  252 . The nub  216  is connected to the dome  252  and when a force is applied to the nub  216 , the nub  216  collapses the dome  252 . 
         [0047]    In some embodiments, the wearable electronic device may include a trackable element  146  and a sensing element  142 . The sensing element  142  is configured to detect the trackable element  146  in order to detect inputs to the button  148 . For example, in some embodiments, the button  148  (or other button) may be rotatable to provide a first input and compressible to provide a second input. In this example, the sensing element  142  may sense rotational input by tracking the position of the trackable element  146  which may be mounted to the coupling  218  and/or stem  150 . As one example, the trackable element  146  may be a magnetic element and the sensing element  142  may include a magnetic field sensor, such as one or more Hall effect sensors, that may be used to track rotation of the trackable element  146 . As yet another option, rotation may be optically sensed. The trackable element  146  may be a pattern, such as a series, set or other pattern of light and dark marks, stripes, or the like, or areas of varying reflectance, polish, and so on. The sensing element  142  may receive light generated by a light source (not shown) and reflected off the trackable element. The reflected light may vary with the pattern of the trackable element, such that the reflected light may be sensed and the pattern of the trackable element on which the light impinged may be determined. Thus, if the pattern of the trackable element is sufficiently unique along its surface, the button input may be sensed. As still another option, the pattern of the trackable element may vary along a circumference of the trackable element and the trackable element may rotate as the shaft  240  rotates. Thus, a rotational position of the shaft may be determined from the trackable element  146 . As still another option, the trackable element may be incorporated onto the shaft itself, and may not be a separate piece. That is, the shaft may be marked as discussed above in certain embodiments. 
         [0048]    The tactile switch assembly  110  optionally may further include one or more sensors  126  positioned within or connected to the button  148 . The sensors  126  may be electrically connected to the coupling  218 , either via one or more wires or pathways within the button  148  or in instances where the button  148  may be a conductive material. The sensor  126  may be configured to sense one or more characteristics and relay data to the processing element  124  via the coupling  218 . 
         [0049]    With reference to  FIG. 3 , assembly of the tactile switch assembly  110  within the wearable electronic device  100  will now be discussed in more detail. The tactile switch  214  is connected to a substrate  166  or other supporting structure within the cavity  139  of the wearable device  100 . The substrate  166  and/or switch  214  may be in electrical communication with the processing element  124  (see,  FIG. 2 ). The dome  252  is oriented towards the wall  190  of the enclosure  114  such that the nub  216  is substantially aligned with the button aperture  172 . The shear plate  156  is positioned over and operably connected the tactile switch  214 . The shear plate  156  is orientated such that the electrical contact  158  may be substantially aligned with the nub  216  of the switch  214 . 
         [0050]    With continued reference to  FIG. 3 , the coupling  218  is operably connected to the shear plate  156  and electrically connected to the contact  158 . In particular, the electrical contact  158  may be received into the recess  224  formed in the bottom surface  244  of the coupling  218 . The annular wall  242  surrounds the electrical contact  158 . In some embodiments, the electrical contact  158  may be in contact with the interior of the annular wall  242  and/or the end wall of the recess  224  of the coupling. In this manner, the coupling  218  may be connected to shear plate  156  and may also be in electrically communication therewith. 
         [0051]    The shaft  240  of the coupling  218  extends through the button aperture  172  and is received into the coupling aperture  236  of the stem  150 . A sealing member  154 , such as an O-ring, cup seal, or membrane, is received around the shaft  240  and seals against the sleeve  220  or the interior walls of the enclosure  114 . The button  148  extends outwards from the coupling  218  and extends past the outer edge of the enclosure  114 . 
         [0052]    Operation of the tactile switch assembly  110  with the wearable device  100  will now be discussed in more detail. If a user provides a rotational force to the button  148 , the stem  150  and button  148  will rotate in the direction of the force. The rotation of the button  148  causes the coupling  218  to rotate along with the button  148 . As the coupling  218  rotates, the trackable element  146  rotates, allowing the sensing element  142  to track the rotation of the coupling  218 , which may be correlated to the user input to the button  148 . Additionally, the coupling  218  rotates around the electrical contact  158  of the shear plate  156 . The annular wall  242  prevents the coupling  218  from rotating off-axis from the contact  158 , as well as help to secure the two components together. In some embodiments the electrical contact  158  may be a brush contact or may otherwise be configured to maintain an electrical connection between the walls defining the recess  224  and the annular wall  242  of the coupling  218 , without substantially hindering the rotation of the coupling  218 . Additionally, because the coupling  218  rotates around the electrical contact  158 , the rotational force experienced by the coupling  218  may not be transmitted to the tactile switch  214  positioned below the shear plate to which the electrical contact is connected. By preventing the shearing forces from being transmitted to the tactile switch  214 , the tactile switch  214  may be prevented from rotating, which could damage the switch, cause the switch to become displaced relative to the coupling, and/or otherwise damage the tactile switch. In some embodiments, the electrical contact  158  may be configured to experience shear forces around 20N and torque at least higher than 10N-mm. This allows the tactile switch assembly  110  to receive rotational inputs to the button  148 , while maintaining an electrical connection between the coupling and the contact, without damaging either of the components. 
         [0053]      FIG. 4  is a cross-section view of the wearable electronic device  100  similar to  FIG. 3  but illustrating a compression force applied to the button  148 . With reference to  FIG. 4 , as the user applies a force, either an angled force AF or an on-axis force F, the button  148  moves towards the sidewall  260 , such that the bottom surface  262  of the button  148  abuts against the enclosure  114 . Lateral movement of the button  148 , causes the coupling  218  to move correspondingly and slide further into the cavity  139 . As the coupling  218  moves into the cavity  139 , it transmits the force AF, F to shear plate  156 . In particular, the end wall of the recess presses against the electrical contact  158 , which compresses against the nub  216  of the dome  252 . In some embodiments the tactile switch assembly  110  may be configured to receive user input forces ranging between 1 to 3 Newtons. Because the shear plate  156  may be at least somewhat rigid, the shear plate  156  transmits the force from the coupling  218  to the dome  252  causing it to collapse. As the dome  252  collapses, an electrical contact within the tactile switch  214  touches the interior surface of the dome to complete an electrical connection, indicating the user input. 
         [0054]    Once the force has been removed from the button  148 , the dome resiliently returns to its original position, providing a biasing force against the coupling  218  to return both the button and the coupling to their original positions. In some embodiments, the tactile switch may include a separate biasing element, such as a spring, that exerts a force (either directly or indirectly via the shear plate) against the coupling. In these embodiments, the button  148  and the coupling  218  may return to their original positions prior to the user translation force F applied to the button  148 . 
         [0055]    In some embodiments, the button aperture  172  may be sufficiently large that the tactile switch  214  can be activated by the angled force AF, even when the tactile switch  214  is positioned directly beneath the coupling. In other words, the angled force AF or other off-axis force may activate the tactile switch  214  when the frictional engagement of the stem  150  and/or coupling  218  within the button aperture  172  sidewall is insufficient to resist the angled force AF. As the angle increases, the frictional force acting on the stem and/or coupling increases and by varying the size of the stem and/or button aperture, a predetermined angle range may be selected for which the angled force AF can activate the switch. For example, a maximum angle of the input force can be selected and when the force is below that angle, the angled force can activate the tactile switch  214  and when the angled force is at or above the maximum angle, the input button may not be activated. As an example, a force applied to the input button at an angle up to 30 or 45 degrees may be able to activate the tactile switch  214 . 
         [0056]    With continued reference to  FIG. 4 , as the tactile switch  214  is compressed by the coupling  218 , the coupling  218  remains in electrical communication with the electrical contact  158 . This allows the sensor  126  to remain in communication with the one or more processing elements  124  via the shear plate  156  and/or the button  148  to remain electrically connected to the shear plate  156 . 
         [0057]    The tactile switch  214  of the present disclosure allows a user to provide multiple types of inputs to the wearable device  100 , e.g., rotational, translational, and angled. Additionally, the tactile switch assembly  110  allows the movable components, in particular the button  148  and coupling  218 , to remain in electrical communication with the shear plate  156  (and thus other electrical components within the device), without restricting movement. This allows one or more sensing elements  126  on the button  148  to provide signals to non-movable components or other components positioned within the enclosure  114 . The sensing elements  126  may receive power via the coupling  218  and the button  148 . 
         [0058]    In some embodiments, the tactile switch assembly  110  optionally may be used as a physiological sensor, although this functionality may be omitted from certain embodiments. For example, in one embodiment, the enclosure  114  may be electrically conductive and when worn by a user may be in communication with the user&#39;s skin. With reference to  FIG. 3 , in this embodiment the sleeve  220  may be an insulating material, such as rubber, plastic, or the like, and isolates the button  148 , stem  150 , and coupling  218  from the conducive housing  114 . To measure one or more characteristics of the user&#39;s heart, such as by an electrocardiograph (ECG), the user may press his or her finger on the button  148 . In this example, the wearable device  100  may be worn around a user wrist and the finger placed on the button  148  may be from the opposite arm as the arm wearing the device  100 . The connection between the user&#39;s finger and the head  148  may act as a first lead for the ECG and the connection between the user&#39;s wrist (or other portion of the arm) may act as the second lead for the ECG. 
         [0059]    As the user places his or her finger on the button  148 , an electrical connection via the coupling  218  and electrical contact  158  allows for a second reference point. In this manner, voltage signals detected at the first location can be compared with voltage signals detected at the second location and subtracted to detect rise and falls between the two signals. These rise and falls can be correlated to the rhythm of a user&#39;s heart. Additionally, in some embodiments, the device  100  may use one of the connections to the user&#39;s skin to send a pulse or signal through the user in order to measure the ECG characteristics of the user&#39;s heart. 
       Brush Contact 
       [0060]    In some embodiments, the tactile switch itself may include an electrical contact and the shear plate may be omitted or integrated with the tactile switch.  FIGS. 5-7  illustrate various views of another examples of the tactile switch removed from the wearable electronic device. In these embodiments, the tactile switch assembly may be configured to receive one or more input types, as well as remain in electrical communication with one or more elements within the device. The tactile switch  314  of  FIGS. 5-7  may be substantially the same as the tactile switch  114  but may be integrally formed with an electrical contact on an outer surface of the dome. With reference to  FIGS. 5-7 , in this embodiment, the tactile switch  314  may include a substrate  366 , one more supports  368  extending from a bottom surface  374  of the substrate  366 . The supports  368  support the tactile switch  314  within the wearable electronic device  100 , such as on the substrate  166 . 
         [0061]    The tactile switch  314  may include a nub  316  extending form a top surface  372  of the substrate  366 . The nub  316  forms an electrical contact for the dome  352 , which will be discussed in more detail below. The nub  316  may be in electrical communication with one or more of the connection terminals  360   a ,  360   b ,  360   d ,  360   e , which may be in communication with the processing element  124  (see,  FIG. 2 ). The nub  316  may be a conductive protrusion or may include a contact pad or other conductive segment that is configured to be in selective communication with a corresponding dome contact. 
         [0062]    With reference to  FIG. 5 , the dome  352  may be resilient and may be configured to collapse under a predetermined user force and spring back to its an initial position. The dome  352  may include a leg  370  extending form one side of the dome  352 . The leg  370  may support one or more electrical communication mechanisms, such as, but not limited to, flexible circuit (flex), wiring, or the like. The dome  352  may also define a dome cavity  320  which is positioned over the base contact  316 . A top surface  322  of the dome  352  may be configured to be spatially separated from a top surface of the nub  316  such that the dome may only touch the contact  316  when a sufficient force is applied to the top surface  322  of the dome. A dome contact  318  may be operably connected to an interior surface of the dome  352  and be at least partially aligned with the nub  316 . 
         [0063]    The dome  352  may be a non-conductive material, such as plastic. In one embodiment, the dome  352  may be an injection molded plastic. However, as mentioned above, one or more components of the dome  352  may include electrically conductive components, such as a flexible circuit (flex), copper wiring, and so on. Alternatively, the dome  352  may be a metal element or other material that is electrically conductive and may include one or more insulating elements connected thereto. 
         [0064]    With reference to  FIGS. 5 and 6 , the tactile switch  314  may further include an electrical contact  358 , which may replace the contact  158  of the shear plate  156 , such that the shear plate may be omitted. The electrical contact  358  may be operably connected to the top surface  322  of the dome  352 . In embodiments where the tactile switch may be used to receive rotational inputs, the electrical contact  358  may form a brush contact for the coupling  318  to electrically connect the tactile switch  314  and the coupling  318 . In this manner, the electrical contact may be substantially similar to the electrical contact  158 ; however, in this embodiment, the electrical contact  358  may be formed integrally with the dome  352 . However, in embodiments where rotational inputs are not desired, the electrical contact  358  may be a conductive surface that does not receive shear forces. 
         [0065]    The electrical contact  358  is in communication with one of the connection terminals  360   a ,  360   b ,  360   c ,  360   d . For example, the electrical contact  358  may be in communication with lead  360   a . In some embodiments, the dome may include a flex or other shear plate that couples the electrical contact  358  to the lead  360   a  or alternatively, the dome  352  itself may be conductive and act to couple the two components together. 
         [0066]    As shown in  FIG. 3 , the electrical contact  158  may be received into the coupling  218 . However, in some embodiments, such as the embodiment illustrated in  FIG. 6 , the electrical contact  358  may define a receiving cavity  384  surrounded by an annular wall  382 . In these embodiments, one or more portions of the coupling  318  may be received into a recess or aperture defined within the electrical contact. In this manner, the coupling  218  may rotate within the electrical contact  358 , contacting the interior walls of the annular wall  382 . 
         [0067]    Operation of the tactile switch assembly will now be discussed in more detail. With reference to  FIGS. 3 and 8 , as the coupling  218  is compressed, e.g., due to the user input force F, the coupling  218  comprises the electrical contact  358 . As the electrical contact  358  is compressed, the force is transmitted to the dome  352 , which collapses, pressing the dome contact  318  onto a top surface of the nub  316 . As the dome contact  318  touches the nub  316 , an electrical signal is created and transmitted via one of the terminals  360   a ,  360   b ,  360   c ,  360   d  to the processing element  124  (see,  FIG. 2 ). The processing element  124  then registers the user input to the tactile switch  314 . 
         [0068]      FIG. 9  is a simplified front elevation view of the tactile switch and coupling as the user applies a rotational force. With reference to  FIG. 9 , in instances where the user may provide a rotational input force R to the tactile switch assembly  310 , the coupling  218  may receive the force applied to the button  148 , causing the coupling  218  to rotate correspondingly. In embodiments where the coupling  218  is received into a recess  384  (see,  FIG. 6 ) of the electrical contact  358 , the coupling  218  may rotate within the annular wall  382 , maintaining a connection between the walls and/or bottom surface  383  (see,  FIG. 6 ) of the electrical contact  358 . This allows the coupling  218  to rotate along with a rotational input from the user, while still maintaining an electrical connection to the tactile switch  314 . 
       Conductive Nub 
       [0069]    In some embodiments, the nub of the tactile switch may be conductive and the shear plate may be omitted. For example, in some embodiments, the user input surface may be configured to translate, such as moving horizontally or vertically relative to the housing, and in these embodiments, the tactile switch may not receive shearing forces. Alternatively, the nub of the tactile switch may be configured to receive shear forces, while still activating the tactile switch. 
         [0070]      FIGS. 10-12  illustrate various views of another example of the tactile switch. With reference to  FIGS. 10-12 , the tactile switch  414  in this embodiment may be substantially similar to the tactile switches  114 ,  314 , but may include a conductive nub. In other words, the shear plate may be integrated with the nub of the tactile switch. In particular, the tactile switch  414  may include a substrate  466 , one or more substrate supports  468 , a plurality of connection terminals  460   a ,  460   b ,  460   c ,  460   d , and the nub  416 . 
         [0071]    With reference to  FIGS. 10 and 11 , the nub  416  may be operably connected to the top surface  472  of the substrate  466 . In some embodiments, the substrate  466 , or at least portions of the top surface  472 , may be insulated to electrically separate the various terminals of the switch  414 , as well as the nub  416  for certain components of the switch  414 . The nub  416  may include a conductive portion, such as pad  421  on a top surface of the nub  416 , or the nub  416  may be made of a conductive material, or another material laced with conductive elements. One or more of the terminals is in electrical communication with the nub  416 . For example, terminal  460   d  may be in communication with the nub  416 , whereas terminals  460   a ,  460   b ,  460   c  may be used as one or more contacts for the switch contact within the substrate  466 . In these embodiments, the nub  416  may act as a brush contact to allow the coupling to rotate. 
         [0072]    The tactile switch  414  may be used with the tactile switch assembly  110  of  FIG. 3 . In these embodiments, the nub  416  may be received into the recess  224  of the coupling  218 . Similarly to the electrical contact  158 , the nub  416  may be received between the sidewalls of the annular wall  226 , which operably connects the nub and the coupling  218 . 
         [0073]    In embodiments where the tactile switch assembly  110  includes the tactile switch  414  of  FIGS. 10-12 , the nub  416  may be configured to not only be conductive, but may also resist shear forces and overload. For example, with the shear plate omitted, the nub  416  may experience shear forces as the coupling  218  rotates on top of the nub  416  and around the nub  416 . Additionally, the nub is configured to receive mechanical inputs, such as the force of the coupling  218 , and under the load of the force, the nub  416  completes a switch circuit by connecting one or more of the terminals together. As one example, the nub  416  may at least partially compress when a compressive force is applied to the button  148 , allowing the nub  416  to function as the dome, to provide tactile feedback to a user as well as create a signal corresponding to the user&#39;s input. 
       CONCLUSION 
       [0074]    The foregoing description has broad application. For example, while examples disclosed herein may focus on a wearable electronic device, it should be appreciated that the concepts disclosed herein may equally apply to substantially any other type of electronic device. Similarly, although the input button may be discussed with respect to a crown for a watch, the devices and techniques disclosed herein are equally applicable to other types of input button structures. Accordingly, the discussion of any embodiment is meant only to be exemplary and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples.