PATENT DOCUMENT

Publication Number: US-10275040-B2
Application Number: US-201715681322-A
Country: US
Kind Code: B2

Title: Low-travel illuminated key mechanism

Abstract:
Embodiments are directed to a low profile key for a keyboard having an overmolded support structure. In one aspect, an embodiment includes a key cap having an illuminable symbol. A support structure having a pair of overmolded wings may pivotally couple to the key cap. A switch housing may surround the support structure and connect each of the first and second wings. A tactile dome may be at least partially positioned within the switch housing and configured to bias the key cap upward. A sensing membrane may be positioned along an underside surface of the tactile dome and configured to trigger a switch event in response to a collapsing of the tactile dome caused by a depression of the key cap. A feature plate may be positioned below the sensing membrane. A light guide panel may define at least one light extraction feature that may be configured to propagate light toward the key cap and cause illumination of the illuminable symbol.

Claims:
What is claimed is: 
     
       1. A key for a keyboard, comprising:
 a key cap; 
 a tactile switch; 
 a support structure supporting the key cap above the tactile switch and comprising:
 a hinge formed from an elastically deformable material; 
 a first wing molded over a first end of the hinge and comprising a first protrusion; and 
 a second wing molded over a second end of the hinge and comprising a second protrusion; 
 
 a switch housing positioned within a cavity defined by the first and the second wings, the switch housing least partially surrounding the tactile switch and defining:
 a first retention feature configured to receive the first protrusion; and 
 a second retention feature configured to receive the second protrusion; and 
 
 a light guide positioned below the switch housing and configured to illuminate a symbol on the key cap; wherein 
 depression of the key cap causes:
 rotation of the first protrusion within the first retention feature; and 
 rotation and translation of the second protrusion within the second retention feature. 
 
 
     
     
       2. The key of  claim 1 , wherein:
 the first retention feature constrains translational movement of the first protrusion; and 
 the second retention feature allows translational movement of the second protrusion. 
 
     
     
       3. The key of  claim 1 , wherein:
 the first protrusion is a cantilevered structure extending from the first wing; 
 the second protrusion is a cantilevered structure extending from the second wing; 
 each of the first and second wings includes an upstop feature positioned between the first and second protrusions; 
 the switch housing defines an up stop track positioned between the first and second retention features and configured to receive the upstop feature; and 
 the upstop track limits upward expansion of the support structure when depression of the key cap ceases. 
 
     
     
       4. The key of  claim 1 , wherein the tactile switch comprises:
 a tactile dome configured to buckle in response to depression of the key cap; and 
 a sensing membrane positioned along an underside of the tactile dome and having a first electrical contact and a second electrical contact that are configured to close in response to buckling of the tactile dome, thereby triggering a switch event. 
 
     
     
       5. The key of  claim 4 , wherein:
 the sensing membrane comprises:
 a first deformable layer having a first electrical contact; 
 a second deformable layer having a second electrical contact; 
 a spacer positioned between the first and second deformable layers and having an opening that defines a cavity separating the first electrical contact and second electrical contact; and 
 
 the switch event is triggered when the first and second electrical contacts contact one another within the cavity. 
 
     
     
       6. A keyboard, comprising:
 an enclosure defining an array of openings; 
 a first key assembly positioned within a first opening of the array of openings and comprising:
 a key cap defining a first illuminable symbol; 
 a support structure coupled to the key cap; and 
 a switch housing pivotally coupled with, and surrounded by, the support structure; 
 
 a second key assembly positioned within a second opening of the array of openings, the second key assembly comprising a keycap defining a second illuminable symbol; 
 a light source positioned within the enclosure and along a periphery of the first key assembly and the second key assembly; and 
 a light guide optically coupled with the light source and extending below the first and second key assembly, wherein 
 the light guide is configured to illuminate the first illuminable symbol of the first key assembly differently from the second illuminable symbol of the second key assembly corresponding to a contour, shape, or area attribute of the first and second illuminable symbols. 
 
     
     
       7. The keyboard of  claim 6 , wherein:
 the light guide defines a first light extraction feature having a first optical characteristic and positioned below the first key assembly; and 
 the light guide defines a second light extraction feature having a second optical characteristic and positioned below the second key assembly. 
 
     
     
       8. The keyboard of  claim 7 , wherein:
 the light guide is configured to propagate light from the first light extraction feature toward the key cap of the first key assembly, thereby illuminating the first illuminable symbol in accordance with the first optical characteristic; and 
 the light guide is configured to propagate light from the second light extraction feature toward the key cap of the second key assembly, thereby illuminating the second illuminable symbol in accordance with the second optical characteristic. 
 
     
     
       9. The keyboard of  claim 8 , wherein:
 the first optical characteristic corresponds to a contour of the first illuminable symbol; and 
 the second optical characteristic corresponds to a contour of the second illuminable symbol. 
 
     
     
       10. The keyboard of  claim 6 , wherein:
 the support structure comprises:
 a hinge formed from an elastically deformable material; 
 a first wing molded over the hinge; and 
 a second wing molded over the hinge; 
 
 the switch housing is positioned within a cavity defined by the first wing, the second wing, and the hinge; and 
 the first key assembly further comprises:
 a tactile dome overmolded on the switch housing and within a switch opening defined by the switch housing. 
 
 
     
     
       11. A key for a keyboard, comprising:
 a key cap having an illuminable symbol; 
 a support structure having first and second wings pivotally coupled to the key cap; 
 a switch housing surrounded by the support structure and having a first retention feature connected to the first wing and a second retention feature connected to the second wing, the switch housing configured to guide movement of the first wing differently than the second wing; 
 a tactile dome at least partially positioned within an opening of the switch housing and configured to bias the key cap upward; 
 a feature plate positioned below the tactile dome and coupled with one or both of the support structure or the switch housing; and 
 a light guide defining at least one light extraction feature and configured to propagate light toward the illuminable symbol. 
 
     
     
       12. The key of  claim 11 , wherein:
 the support structure further comprises a set of hinges formed from an elastically deformable material; 
 the first and second wings are at least partially molded over the set of hinges; and 
 the first and second wings define a cavity that separates the set of hinges. 
 
     
     
       13. The key of  claim 12 , wherein:
 the switch housing is positioned within the cavity; 
 the support structure further comprises:
 a first protrusion extending into the cavity and the first retention feature; 
 a second protrusion extending into the cavity and the second retention feature; 
 
 the first protrusion is configured to rotate within the first retention features in response to depression of the key cap; 
 the second protrusion is configured to rotate within the second retention feature in response to depression of the key cap; and 
 one of the first retention feature or second retention feature constrains translational movement of one of the first or second protrusions during depression of the key cap. 
 
     
     
       14. The key of  claim 11 , wherein:
 the key further comprises a sensing membrane positioned along an underside of the tactile dome and configured to trigger a switch event in response to a collapse of the tactile dome; 
 the sensing membrane defines a series of membrane openings; and 
 the feature plate comprises an engagement structure that extends through one of the series of membrane openings and couples to the switch housing. 
 
     
     
       15. The key of  claim 14 , wherein:
 the feature plate defines a series of feature plate openings; 
 at least one of the switch housing or the tactile dome comprises a partially transparent region; and 
 the at least one light extraction feature is configured to propagate light through:
 at least one of the series of membrane openings: 
 at least one of the series of feature plate openings; and 
 the partially transparent region. 
 
 
     
     
       16. The key of  claim 11 , wherein:
 the first and second wings are adjacent one another; 
 each wing comprises:
 a major arm; and 
 a minor arm shorter than the major arm; 
 
 the support structure includes a hinge formed from an elastically deformable material; 
 each of the major arms is molded over the hinge; 
 the switch housing is positioned between the wings and defines a semi-circular recess; and 
 the tactile dome is positioned at least partially within the semi-circular recess. 
 
     
     
       17. The keyboard of  claim 6 , wherein the first key assembly comprises a first light extraction feature and the second key assembly comprises a second light extraction feature, the first light extraction feature having a different shape characteristic relative to the second light extraction feature.

Description:
FIELD 
     The described embodiments relate generally to electronic devices, and more particularly to input devices for electronic devices. 
     BACKGROUND 
     In computing systems, a keyboard may be employed to receive input from a user. Many traditional keyboards may suffer from significant drawbacks, including occupying a relatively large portion of available interior space of a housing. In many cases, traditional keyboards include various mechanical and electrical components that may impede illumination of the keyboard and contribute to an undesirable z-stackup of mechanisms. 
     SUMMARY 
     Embodiments of the present invention are directed to an electronic device having a hidden or concealed input region. 
     In a first aspect, the present disclosure includes a key for a keyboard. The key includes a key cap. The key further includes a support structure supporting the key cap above a tactile switch. The support structure includes a compliant hinge. The support structure further includes a first wing molded over a first end of the compliant hinge and comprising a first protrusion. The support structure further includes a second wing molded over a second end of the compliant hinge and comprising a second protrusion. The key further includes a switch housing positioned within the cavity at least partially surrounding the tactile switch. The switch housing may define a first retention feature configured to receive the first protrusion. The switch housing may further define a second retention feature configured to receive the second protrusion. The key further includes a light guide positioned below the switch housing and configured to illuminate a symbol on the key cap. The first wing and second wing cooperate to define a cavity. Depression of the key cap may cause rotation of the first protrusion within the first retention feature and rotation and translation of the second protrusion within the second retention feature. 
     A second aspect of the present disclosure includes a keyboard. The keyboard includes an enclosure defining an array of openings. The keyboard further includes a first key assembly positioned within a first opening of the array of openings. The first key assembly includes a key cap and a support structure coupled to the key cap. The support structure includes a compliant hinge and first and second wings molded over the compliant hinge. The keyboard further includes a second key assembly positioned within a second opening of the array of openings. The keyboard further includes a light source positioned within the enclosure and along a periphery of the pair of key assemblies. The keyboard further includes a light guide optically coupled with the light source and extending below the first and second key assembly. The light guide may be configured to illuminate the first key assembly differently from the second key assembly. 
     A third aspect of the present disclosure includes a key for a keyboard. The key includes a key cap having an illuminable symbol. The key further includes a support structure having first and second wings pivotally coupled to the key cap. The key further includes a switch housing surrounded by the support structure and having a first retention feature connected to the first wing and a second retention feature connected to the second wing. The switch housing may be configured to guide movement of the first wing differentially than the second wing using the first and second retention features. The key further includes a tactile dome at least partially positioned within an opening of the switch housing and configured to bias the key cap upward. The key further includes a sensing membrane positioned along an underside of the tactile dome and configured to trigger a switch event in response to a collapse of the tactile dome. The key further includes a feature plate positioned below the sensing membrane. The key further includes a light guide defining at least one light extraction feature and configured to propagate light toward the illuminable symbol. 
     A fourth aspect of the present disclosure includes a method for manufacturing a support structure. The method includes extending a strip of compliant material through a form. The method further includes causing a moldable material to flow into the form. The moldable material may form a first wing molded over and extending from a first edge of the strip of compliant material. The moldable material may also form a second wing molded over and extending from a second edge of the strip of compliant material opposite the first wing. The first and second wings may define a cavity and may be separated by a portion of the compliant material. The method further includes detaching the compliant material positioned within the cavity from the first and second wings. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like elements. 
         FIG. 1  depicts a sample electronic device including a keyboard; 
         FIG. 2A  depicts an exploded view of a key assembly of  FIG. 1 ; 
         FIG. 2B  depicts the support structure mechanism and the switch housing of  FIG. 2A ; 
         FIG. 3  depicts a cross-sectional view of the key assembly of  FIG. 1 , taken along line A-A of  FIG. 1 ; 
         FIG. 4A  depicts an embodiment of a sample support structure mechanism; 
         FIG. 4B  depicts the sample support structure mechanism of  FIG. 4A  molded over a compliant strip; 
         FIG. 4C  depicts multiple sample support structure mechanisms molded over a compliant strip; 
         FIG. 5A  depicts a top view of a sample support structure mechanism and switch housing; 
         FIG. 5B  depicts a side view of the sample support structure mechanism of  FIG. 5A  in an unactuated state; 
         FIG. 5C  depicts a side view of the sample support structure mechanism of  FIG. 5A  in an actuated state; 
         FIG. 6A  depicts a sample tactile dome and a sensing membrane in an unactuated state; 
         FIG. 6B  depicts a sample tactile dome and a sensing membrane in an actuated state; 
         FIG. 6C  depicts another embodiment of a sample tactile dome and a sensing membrane in an unactuated state; 
         FIG. 6D  depicts a perspective view of the sensing membrane  FIG. 6C ; 
         FIG. 7A  depicts a light guide panel of the key assembly of  FIG. 2A ; 
         FIG. 7B  depicts a cross-sectional view of the light guide panel of  FIG. 7A , taken along line C-C of  FIG. 7A ; 
         FIG. 7C  depicts a cross-sectional view of the light guide panel of  FIG. 7A  positioned below a key assembly, taken along line C-C of  FIG. 7A ; 
         FIG. 8A  depicts an embodiment of a feature plate; 
         FIG. 8B  depicts another embodiment of a feature plate; 
         FIG. 9  depicts an exploded view of another embodiment of a key assembly of  FIG. 1 ; 
         FIG. 10  depicts a top view of the modified-support structure mechanism and modified switch housing of  FIG. 9 ; 
         FIG. 11  depicts an exploded view of another embodiment of a key assembly of  FIG. 1A ; 
         FIG. 12  depicts a top view of the dome integrated switch housing and support structure mechanism of  FIG. 10 ; and 
         FIG. 13  is a flow diagram of a method for manufacturing a support structure mechanism. 
     
    
    
     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 
     The description that follows includes sample systems, methods, and apparatuses that embody various elements of the present disclosure. However, it should be understood that the described disclosure may be practiced in a variety of forms in addition to those described herein. 
     The present disclosure describes systems, devices, and techniques related to a key assembly for an input device, such as a keyboard. The key assembly may enable substantially low travel distances of an input surface having an illuminable symbol, such as an illuminable key cap, with a desired tactile response. The key assembly uses a support structure having an overmolded living hinge to support and guide movement of the key cap. A switch housing may support and engage the support structure within the key assembly and may at least partially surround a tactile switch that is used to detect input or a mechanical press along the key cap. In many embodiments, the support structure may surround the switch housing, or otherwise be positioned outside the switch housing. For example, depression of the key cap may cause a collapsible dome of the tactile switch to collapse and close electrical contacts of a sensing membrane positioned below the tactile dome, thereby triggering a switch event. One or more light extraction features of a light guide panel (LGP) may propagate light through the key assembly, including through holes and/or transparent regions of the key assembly, and illuminate an illuminable symbol of the key cap. The illuminable symbol may remain illuminated during the substantially low-travel key stroke, which may be, in some embodiments, within a range of between 0.55 mm to 0.75 mm. However, other keystrokes are contemplated and described herein. In some cases, the tactile dome may bias the key cap upwards to deliver a desired tactile effect during the low-travel keystroke. 
     As used herein, the phrase “illuminable symbol” refers generally to any or all areas of (or adjacent to) a keycap or other input surface of a key that is intended to be illuminated by the light emitting element such that the location, size, and/or functionality of the key, or portion of the key, is visually emphasized. For example, a key may include a symbol or a glyph that defines an alphanumeric character, a punctuation mark, a word, an abbreviation, or any other linguistic, scientific, numeric, or pictographic symbol or set of symbols. The geometry of the key may also be an illuminable portion of the key, for example, such as a surface of the key defining a perimeter, a sidewall, a corner, and so on. 
     The support structure, as described herein, may be an overmolded component that pivots about a flexible or living hinge formed from a compliant material. For example, the support structure may include a pair of wings formed or molded over the compliant material and define a cavity. The pair of wings may be formed from a curable material having a greater rigidity than the compliant material such that the wings support or guide movement of the key cap while the compliant material deforms or bends to pivot the pair wings relative to one another during depression of the key cap. The wings may extend outward from the hinge in different or opposing directions, much like the wings of a butterfly. Wings can be positioned such that there is an oblique angle between them when the key is in a rest state (e.g., no exerted force on the key cap). Wings can flatten to be substantially planar when the key is fully depressed. 
     In an embodiment, the support structure may be formed from a substantially continuous strip of compliant material. This may improve manufacturability of the key assembly by allowing multiple support structures to be formed in succession. To illustrate, multiple pairs of wings may be molded over opposing edges of the compliant material. The compliant material may be configured to resist chemical or physical changes during a forming or curing of the wings, thereby maintaining its compliant characteristic and forming a flexible hinge between wings of a given set. After the wings are molded over to the compliant strip, the strip may be cut away or detached to yield an individual support structure that is suitable for use in a key assembly. 
     Various protrusions, pins, or other features may extend from the wings and engage corresponding features of the key assembly. For example, the support structure may include key cap engagement structures that extend away from a cavity defined by the wings and pivotally couple and support the key cap above the switch housing and tactile switch elements of the key assembly. Further, the support structure may include various sets of protrusions or other features that extend to the cavity defined by the wings, and which may be received by, and supportively engaged with, the switch housing. In some cases, at least some of the various sets of protrusions may be upstop features that limit upward expansion of the key cap. 
     The switch housing supports the support structure within the key assembly. Retention features formed along sides of the switch housing may receive and engage protrusions of the support structure. The protrusions may rotate within corresponding ones of the retention features during depression of the key cap. In some cases, at least one of the protrusions may also translate within the retention feature during depression of the key cap. For example, at least one of the retention features may be an elongated structure configured to facilitate sliding of the protrusion of the support structure therein. This may allow the wings of the support structure to move toward one another during depression of the key cap, which may improve the z-profile of the key assembly. 
     As described herein, the key assembly may be actuated using a tactile switch. The tactile switch may include a tactile or collapsible dome and a sensing membrane. The tactile dome may be a substantially non-conductive structure and may include a contact feature along an underside surface of the tactile dome that impacts electrical contacts of a sensing membrane when the tactile dome collapses or buckles. However, in other cases, the tactile dome may include a conductive puck or other electrical element used to trigger a switch event. In this regard, in a particular configuration, the sensing membrane may include two deformable layers separated by a spacer having an opening. The opening may define a cavity between the deformable layers and at least partially contain or surround electrical contacts of the sensing membrane attached to respective ones of the deformable layers. As the tactile dome buckles, the contact feature may pinch or press the deformable layer along the cavity and cause the sensing membrane to trigger a switch event in response to a contact between the electrical contacts. A relief or other void, for example, within a feature plate or other structure of the key assembly may allow the sensing membrane to momentarily move or otherwise deform downward and produce a desired tactile effect. 
     In addition to optionally providing a relief area for the depression or deformation of the sensing membrane, the feature plate may be used to structurally support the switch housing within the key assembly. For example, the feature plate may include various engagement features stamped or otherwise formed from a body of a substantially planar structure of the feature plate. The engagement features may extend upwards from the key cap and engage or couple with the switch housing. In certain embodiments, the engagement features may be barbs or tabs stamped or cut out from a body or sheet of metal material used to form the feature plate. 
     The key assembly may be a light-transmissible structure, such that light from below or within the key assembly may travel up towards the key cap and illuminate an illuminable symbol. To facilitate the foregoing, various openings or holes may be formed in one or more components of the key assembly. For example, the sensing membrane and/or the feature plate may define numerous openings or holes that allow light to pass through the key assembly. Further, some components of the key assembly may be transparent or include a partially transparent region, such as the switch housing and/or the tactile switch. 
     In an embodiment, an illuminable symbol of the key cap may be illuminated using a light guide panel (LGP) extending below the feature plate. In particular, the LGP may define or be coupled with light extraction features that expel light from the LGP and direct the expelled light toward the key cap. The light extraction features may be specifically tailored to exhibit an optical characteristic (e.g., light path, brightness, contrast, interference pattern, and so on) that correspond to a particular illuminable symbol of the key cap. This may allow the light extraction feature to illuminate the illuminable symbol according to a predetermined optical effect (e.g., such as maximizing a brightness of the illuminable symbol on the key cap). 
     The LGP may extend along and/or beneath multiple key caps and corresponding key assemblies. One or more light sources, which may be arranged substantially along a periphery of the keyboard, may emit light into the LGP. The LGP may thus transfer light from the light source toward the various key assemblies of the keyboard, and ultimately toward the respective key caps of the key assemblies via the light extraction features. In this regard, the LGP may define or be coupled with multiple distinct light extraction features positioned under corresponding ones of the key caps. Each light extraction feature or features may be tailored to exhibit an optical characteristic corresponding to the particular illuminable symbol of a given key assembly. This may allow the LGP to illuminate a first key cap in a manner that is distinct from a second key cap. This may be desirable in order to illuminate distinct alpha-numeric characters, or other characters or glyphs, formed by the various illuminable symbols of the key assemblies according to distinct predetermined optical effects. 
     It will be appreciated that while the foregoing key assemblies are described with respect to a full or complete support structure (e.g., one having a cavity defined by the respective first and second wings of a pair of wings), the embodiments described herein are not limited as such. For example, some embodiments may use a modified-support structure, which may be useful to support and engage relatively smaller keyboard keys, such as one or more keys having an illuminable symbol that defines an arrow. As such, the modified-support structure may be defined by a set of wings having a major arm and a minor arm that is shorter than the major arm. The major arms of the modified-support structure may be overmolded about a hinge formed from a compliant material, as described herein. The modified-support structure may be used within the keyboard assembly in conjunction with a modified switch housing. The modified switch housing may define a semi-circular recess that is positioned along a first side of the tactile dome opposite a second side of the tactile dome that is positioned along the hinge and major arms of the set of wings of the modified-support structure. Substantially analogous to that of the support structure introduced above, the modified-support structure may also include protrusions, pins, bars, or other features that engage an underside of the switch housing. In some cases, the modified-support structure may include a bar that extends between the major and minor arms of one or both of the wings, and through the switch housing, to support the modified-support structure during depression of the key cap. 
     Various other embodiments include other overmolded components, which may also aid in manufacturability and reduce the z-stackup of the key assembly. In a sample implementation, the switch housing may be an overmolded component that is molded over the tactile dome and, thus, collectively define an integrated dome switch housing. This may allow for various different shapes and sizes of the switch housing, which may accommodate different types of support structures and associated coupling structures. For example, the overmolded switch housing may allow the support structure to connect to the key assembly using a bar extending across one or both of the wings and through the switch housing. 
     One or both of the overmolded switch housing and/or the tactile dome may be transparent or include a partially transparent region such that light from within the key assembly (e.g., from a given light extraction feature) may travel through the tactile dome and/or overmolded switch housing and illuminate an illuminable symbol of the key cap. Additionally or alternatively, the overmolded switch housing may include light channels that direct light through the overmolded switch housing and toward an underside of the key cap. The light channels may exhibit various optical characteristics that support an optimal or maximum illumination of the illuminable symbol, as may be appropriate for a given application. 
     Reference will now be made to the accompanying drawings, which assist in illustrating various features of the present disclosure. The following description is presented for purposes of illustration and description. Furthermore, the description is not intended to limit the inventive aspects to the forms disclosed herein. Consequently, variations and modifications commensurate with the following teachings, and skill and knowledge of the relevant art, are within the scope of the present inventive aspects. 
       FIG. 1  depicts an electronic device  104  having a key assembly  108 , although other input mechanisms may incorporate the embodiments discussed herein. The key assembly  108  may be one of a set of key assemblies that collectively form a keyboard or other input structure of the electronic device  104 . The key assembly  108  may include a stack-up of components that cooperate to initiate an input signal in response to a force input. The key assembly  108  may enable substantially low-travel of an input surface with a desired tactile response. The key assembly  108  may include a support structure having an overmolded living hinge, such as the support structure discussed above and described in greater detail below. As described herein, the support structure may be pivotally coupled to a switch housing and used to support and guide movements of a key cap. The key cap may be used to trigger a switch event of the tactile switch by impacting a tactile dome such that electrical contacts of a sensing membrane close, although other embodiments are contemplated and described herein. 
     In a non-limiting example, as shown in  FIG. 1 , the electronic device  104  may be a laptop computer. However, it is understood that electronic device  104  may be any suitable device that operates with the key assembly  108  (or any other suitable device or input mechanism configured to receive a touch and/or force input from a user). Some example electronic devices may include data-entry devices, word-processing devices, desktop computers, notebook computers (as shown in  FIG. 1 ), smart phones, tablets, portable media players, or the like. Other examples of electronic devices may include health monitoring devices (including pedometers, heart rate monitors, or the like), and other electronic devices, including digital cameras, printers, scanners, security systems or devices, electronics for automobiles, among other electronic devices. Suitable input mechanisms may include trackpads, mice, joystick buttons, and so on. 
     For purposes of illustration,  FIG. 1  depicts the electronic device  104  as including the key assembly  108 , an enclosure  112 , a display  116 , and one or more input/output members  119 . It should be noted that the electronic device  104  may also include various other components, such as one or more ports (e.g., a charging port, a data transfer port, or the like), communications elements, additional input/output members (including buttons), and so on. As such, the discussion of any computing device, such as the electronic device  104 , is meant as illustrative only. 
     In a non-limiting example, the key assembly  108  may include a key cap  110 . The key cap  110  may have an illuminable portion or symbol at which light from a light source may visually emphasize a location, size, and/or functionality of the key cap  110 . The key cap  110  may be substantially surrounded by, and at least partially protrude from, the enclosure  112 . For example, the key cap  110  may be positioned within, or partially within, one of an array of openings defined in the enclosure  112 . The key cap  110  may be configured to receive a force input. The force input may depress the key cap  110  and trigger one or more input signals that may control the electronic device  104 . As depicted, the key assembly  108 , and associated keyboard, may be positioned within the electronic device  104  (e.g., within, or partially within, the enclosure  112 ). In other embodiments, the key assembly  108  may be a distinct, standalone component communicatively coupled with the electronic device  104  via a wireless or hardwired connection. 
       FIG. 2A  depicts an illustrative exploded view of an embodiment of the key assembly  108  shown in  FIG. 1 . As described above, the key assembly  108  may be formed from a stack-up of separate components. Each layer and/or component of the stack-up of the key assembly  108  may provide different functionality and/or operations for the electronic device  104 , as discussed herein. Although a key assembly  108  is shown as a single key stack-up, it is understood that any or all keys (including a subset of keys) of the electronic device  104  may be formed from similar components and/or layers in a similar configuration and/or function in a substantially similar manner as the single key stack-up shown in  FIG. 2A . 
     As described above with respect to  FIG. 1 , the key assembly  108  includes the key cap  110 . The key cap  110  may define an input surface of the key assembly  108  and is similar to other possible input surfaces such as mouse buttons, trackpads, joystick buttons, standalone buttons, and so on. For example, the key cap  110  may be configured to receive a force input or mechanical press to actuate one or more switches of the key assembly  108 . The key cap  110  may include an illuminable portion (e.g., a glyph, symbol, sign, and/or geometric feature, which may be formed on surfaces, regions, perimeters, sidewalls, corners, and so on) that is intended or configured to be illuminated by a light source of the key assembly  108 . As shown in  FIG. 2A , the key cap  110  includes an illuminable symbol  111 . 
     The key cap  110  may be seated on or within a collar  114 . The collar  114  may form a protective barrier between an interior of a device enclosure (e.g., enclosure  112  of  FIG. 1 ) and an external environment experienced by the key cap  110 . For example, the collar  114  may be positioned along, or coupled with, an underside surface of the key cap  110  and prevent dirt, dust, debris, oils, and/or other contaminates from entering the interior of the enclosure  112 . The collar  114  may define a key opening  115 . The key opening  115  may be configured to receive at least a portion of a tactile switch element, such as the tactile switch described below, to facilitate actuation of the key assembly  108 . The key opening  115  may also allow light to pass from the key assembly  108  toward the key cap  110  to illuminate or display the illuminable symbol  111 . It should be appreciated that the collar  114  is optional and may be omitted. 
     The key assembly  108  may include a support structure  120 . The support structure  120  functions as a moveable hinge that allows the key cap  110  to move in response to a force input. For example, the support structure  120  may be configured to support the key cap  110  within the enclosure  112  and guide movement of the key cap  110  during a user actuation or switch event. The support structure  120  may include wings  122   a ,  122   b , which are separate components coupled together by hinge  124 . For example, the wings  122   a ,  122   b  may be a pair of wings that are defined by a first wing  122   a  and a second wing  122   b , as described herein. The hinge  124  may be formed from a compliant material that allows the wings  122   a ,  122   b  to pivot relative to one another. As described herein, the wings  122   a ,  122   b  may be formed or molded over the compliant material of the hinge  124 . Wings  122   a ,  122   b  may each include a cutout such that when wings  122   a ,  122   b  are coupled together, cavity  123  exists. As such, the hinge  124  may be one of a set of hinges operable to pivotally couple the wings  122   a ,  122   b  on opposing sides of the cavity  123 . Cavity  123  may have any suitable shape such as, for example, a square, rectangle, circle, ellipse, and so on. The wings  122   a ,  122   b  can extend outward from the hinge  124  in different or opposing directions, much like the wings of a butterfly. Wings  122   a ,  122   b  can be positioned such that there&#39;s an oblique angle between them when the key cap  110  is in a rest state (e.g., no exerted force on key cap  110 ). Wings  122   a ,  122   b  can flatten to be substantially planar when the key cap  110  is fully depressed. 
     The support structure  120  may be supported within the key assembly  108  by a switch housing  128 . The switch housing  128  may be at least partially positioned within the cavity  123  (e.g., surrounded and/or within the wings  122   a ,  122   b  of the support structure  120 ) and pivotally coupled to the support structure  120 . For example, and as described in greater detail below with respect to  FIG. 2B , the support structure  120  may include various pins, protrusions, or other engagement features that are received by corresponding retention features, tracks, or other structures of the switch housing  128 . The switch housing  128  may be constructed from any appropriate material, including a moldable or curable material, as may be appropriate for a given application. In some cases, the switch housing  128  may be at least partially transparent (e.g., including a transparent region extending through a thickness of the switch housing  128 ) such that light from within the key assembly  108  may travel through the switch housing  128  and toward the key cap  110  to illuminate the illuminable symbol  111 . The switch housing  128  may define a switch opening  130 . The switch opening  130  may be configured to receive, and at least partially surround, a tactile switch element, such as a tactile dome. 
     As shown in  FIG. 2A , the key assembly  108  may be actuated by a tactile dome  132 . For example, the tactile dome  132  may be a component of a tactile switch that triggers a switch event in response to the tactile dome  132  collapsing. Such collapse may be caused by a depression of the key cap  110 . The tactile dome  132  may be formed from any appropriate material (e.g., including metal, rubber, silicon, plastic, or the like) that exhibits sufficiently elastic and/or resilient characteristics. For example, the tactile dome  132  may be sufficiently elastic or resilient such that it does not permanently deform from an applied force (e.g., the tactile dome  132  may substantially return to an original or undeformed shape after the force ceases). In this regard, depressing the key cap  110  may be collapse the tactile dome  132 , which in turn may trigger a switch event, as described below. Further, the tactile dome  132  may return to an undeformed shape when the key cap  110  returns to a neutral or undepressed condition. The tactile dome  132  may not be limited to the above example materials, and may also include other appropriate materials consistent with the various embodiments presented herein. In some cases, the tactile dome  132  may be a transparent or partially transparent structure that allows light to pass through the tactile dome  132  and toward the key cap  110  to illuminate the illuminable symbol  111 . 
     The tactile dome  132  may be positioned on or otherwise connect to a sensing membrane  136 , for example, such that the sensing membrane  136  extends below an underside of the tactile dome  132 . The sensing membrane  136 , described in greater detail below with respect to  FIGS. 6A-6D , may be used to initiate an input signal in response to depression of the key cap  110 . In this regard, the tactile dome  132  and the sensing membrane  136  jointly may form a tactile switch and trigger a switch event upon the depression of the key cap  110 . As one example, the tactile dome  132  may be a substantially non-conductive dome that causes electrical contacts of the sensing membrane  136  to contact one another and trigger a switch event when the tactile dome  132  collapses. Additionally or alternately, the tactile dome  132  may include an electrically conductive puck, strip, protrusion, or other electrical component that is used to complete a circuit or close a switch on the sensing membrane  136  when the tactile dome  132  collapses. Additionally, the sensing membrane  136  may define a series of membrane openings  138  that may allow light to propagate through the key assembly  108  and/or receive a structural component of the key assembly  108 , for example, such as an engagement structure of a feature plate. 
     In this regard, the key assembly  108  may include a feature plate  142 . The feature plate  142  may be positioned within the key assembly  108  proximate to an underside of the sensing membrane  136 . The feature plate  142  may be a structural portion of the key assembly  108  and may secure the switch housing  128  within the key assembly  108 . For example, the feature plate  142  may include, define, or be coupled with various support structures, engagement features, or the like that are configured to extend through one or more of the series of membrane openings  138  and engage a surface or feature of the switch housing  128 . In the embodiment of  FIG. 2A , feature plate  142  includes engagement structures  144  that may extend through the series of membrane openings  138  and engage an underside of the switch housing  128 . 
     To facilitate the foregoing, the feature plate  142  may be constructed from any suitable electrically conductive sheet metal, including, but not limited to: aluminum, steel, stainless steel, metal alloys, and so on. Additionally or alternatively, other materials and constructions of the feature plate  142  are contemplated, including embodiments in which the feature plate  142  is constructed from an electrically insulating material, a ceramic, or the like. In some cases, for example, as described with respect to  FIGS. 8A and 8B , the engagement structure  144  may be cut, stamped, and/or bent from the sheet metal, plastic, or other appropriate component, which may enhance the manufacturability of the key assembly  108 . The feature plate  142  may also include a series of feature plate openings  146 . The series of feature plate openings  146  may be used to allow light from within the key assembly  108  to propagate through the feature plate  142  and toward the key cap  110  to illuminate the illuminable symbol  111 . In the embodiment shown in  FIG. 2A , the feature plate  142  may also define a relief  148 . The relief  148  may be positioned below the tactile dome  132  in the key assembly  108  and be configured to receive a portion of the sensing membrane  136  during a key press. For example, and as described in greater detail below with respect to  FIGS. 6A and 6B , the sensing membrane  136  may be configured to deform into the relief  148  when the tactile dome collapses, which may help provide a desired tactile effect at the key cap  110 . 
     The key assembly  108  may be configured to illuminate the illuminable symbol  111 . For example, as shown in  FIG. 2A , the key assembly  108  may include a light guide panel (LGP)  150 . The LGP  150  may be a translucent or transparent layer that is used to direct or channel light through the enclosure  112  described with respect to  FIG. 1 . For example, the LGP  150  may be optically coupled with a light source, such as an LED or other light emitting element, along a periphery of the enclosure  112 . The LGP  150  redirects light from the light source and toward the key assembly  108 , which may cause the illuminable symbol  111  to illuminate. To facilitate the foregoing, the LGP  150  may define or be coupled with a light extraction feature  154  that is configured to expel light from the LGP  150  and direct the expelled light toward the key cap  110 . The light extraction feature  154  may be a textured surface, a lens, an aperture, and/or any other region of the LGP  150  that is configured to propagate light toward the key cap  110 . As described in greater detail below with respect to  FIGS. 7A-7C , the light extraction feature  154  may be configured to exhibit an optical characteristic (e.g., light path, brightness, contrast, interference pattern, and so on) that corresponds to the illuminable symbol  111 . This may allow the key assembly  108  to maximally or optimally illuminate the illuminable symbol  111  according to a predetermined optical effect (e.g., which may be used to enhance the brightness of the illuminable symbol  111 . 
       FIG. 2B  depicts detail  1 - 1  of the support structure  120  and the switch housing  128  of  FIG. 2A . As shown in the non-limiting example of  FIG. 2B , the support structure  120  includes wings  122   a ,  122   b , which are shown pivotally coupled about the hinge  124 . The wings  122   a ,  122   b  may be overmolded components that are formed over, and extend from, opposing ends of the hinge  124 . The hinge  124  may be formed from a compliant material. The wings  122   a ,  122   b  may pivot and/or move generally relative to one another about the hinge  124 . For example, the hinge  124  may elastically deform in response to movements of the wings  122   a ,  122   b , which may allow the wings  122   a ,  122   b  to move during depression of a key cap (e.g., key cap  110  of  FIG. 2A ). In the embodiment of  FIG. 2B , the wings  122   a ,  122   b  are shown in substantially flattened or planar configuration, for example, which may result when the key cap  110  is depressed. As described herein, when a force or key press exerted on the key cap  110  ceases, the wings  122   a ,  122   b  may be positioned such that there is an oblique angle between them, thereby resembling the wings of a butterfly. 
     The wings  122   a ,  122   b  may include various protrusions, pins, or other features that extend from the wings  122   a ,  122   b  and engage corresponding features of the key assembly  108 . As shown in  FIG. 2B , the support structure  120  may include key cap engagement structures  121 . The key cap engagement structures  121  may extend from the wings  122   a ,  122   b  and be configured to engage an underside of the key cap  110 . The key cap engagement structures  121  may be cantilevered structures that extend from the wings  122   a ,  122   b  and away from the cavity  123  (e.g., along an outer edge or outer surface of the wings  122   a ,  122   b ). As such, the key cap  110  may be positioned along the support structure  120  and receive or couple with the key cap engagement structures  121  around a periphery of the support structure  120 . This may help stabilize movement of the key cap  110  during actuation. 
     The support structure  120  may also include protrusions  125 . The protrusions  125  may extend from the wings  122   a ,  122   b  and into the cavity  123 . The protrusions  125  may be configured to engage the switch housing  128  to secure the support structure  120  within the key assembly  108 . For example, the protrusions  125  may be cantilevered structures that extend from the wings  122   a ,  122   b  into the cavity  123 . As such, the protrusions  125  may be used to pivotally couple the support structure  120  to the switch housing  128 . As explained in greater detail below, the protrusions  125  may be received by a retention feature, hole, recess, or the like of the switch housing  128  and rotate or translate therein during depression of the key cap  110 . This may support movement of the key cap  110  and allow the support structure  120  to pivot as the key cap  110  advances downward. 
     The support structure  120  may also include upstop features  126 . The upstop features  126  may extend from the wings  122   a ,  122   b  and be configured to limit upward expansion of the key cap  110  when the application of force on the key cap  110  ceases. The upstop features  126  may be cantilevered structures that extend from the wings  122   a ,  122   b  into the cavity  123 . As explained in greater detail below, the upstop features  126  may be received by a track or other feature of the switch housing  128  that provides or defines a physical barrier to limit or restrict the movement of the upstop features  126 , which may, in turn, limit the upward expansion of the key cap  110 . 
     The switch housing  128  may be configured to fit or otherwise be positioned within the cavity  123 . In this manner, the switch housing  128  may be surrounded by the support structure  120 . The switch housing  128  may be surrounded by the support structure  120  in a manner that allows the support structure  120  to pivotally connect and couple with the switch housing  128 . For example, the switch housing  128  may define retention features  129  defined along an outer surface of the switch housing  128 . The retention features  129  may be openings, holes, recesses, or the like that are configured to receive corresponding ones of the protrusions  125  of the support structure  120 . Depression of the key cap  110  may cause the protrusions  125  to rotate within the retention features  129  as the wings  122   a ,  122   b  of the support structure  120  transition from a v-shaped structure to a substantially flattened structure. In some cases, as described in greater detail below with respect to  FIGS. 5A-5C , one or more of the retention features  129  may be an elongated feature that allows a corresponding one of the protrusions  125  to translate with the retention feature  129  during depression of the key cap  110 . 
     The switch housing  128  may also include various features and structures that cooperate with the support structure  120  to limit the upward expansion of the key cap  110  when a force input exerted on the key cap  110  by a user ceases. As shown in the embodiment of  FIG. 2B , the switch housing  128  may define an upstop track  131 . The upstop track  131  may be configured to receive the upstop features  126  of the support structure  120 . The upstop track  131  may provide a physical barrier that limits or restricts movement of the upstop features  126 , which may, in turn, limit the upward expansion of the key cap  110 . In this regard, the upstop track  131  may limit the upward expansion of the key cap  110  by blocking or inhibiting movement of the upstop feature  126  beyond a predetermined position. 
       FIG. 3  is a cross-sectional view of the key assembly  108  of  FIG. 1 , taken along line A-A of  FIG. 1 . As illustrated, the key cap  110  is shown defining an input surface of the key assembly  108 , which may be similar to other possible input surfaces, such as mouse buttons, trackpads, joystick buttons, standalone buttons, and so on. The key cap  110  is supported within the key assembly  108  by the support structure  120 . As shown in  FIG. 3 , the key cap  110  is in an unactuated position. In this regard, the support structure  120  may resemble a v-shaped structure that supports the key cap  110  above the switch housing  128  and tactile switch elements of the key assembly  108 , such as tactile dome  132 . In an actuated configuration, the key cap  110  may press down onto the tactile dome  132  such that the tactile dome  132  collapses or buckles, which may cause the key assembly  108  to trigger a switch event. The downward motion of the key cap  110  may be guided by the support structure  120 , which may temporarily flatten as the key cap  110  is depressed, for example, as shown and described with respect to  FIGS. 5B and 5C . When an input force on the key cap  110  ceases, the key cap  110  may return to the unactuated position. To facilitate the foregoing, the tactile dome  132  may be configured to bias the key cap  110  upward. This may also help deliver a desired tactile effect to the key cap  110 . 
     The tactile dome  132  may be positioned within the switch opening  130  defined by the switch housing  128  and along the sensing membrane  136 . The sensing membrane  136  may include various electrical contacts that are used to trigger a switch event in response to the collapsing of the tactile dome  132  caused by a depression of the key cap  110 . In the embodiment of  FIG. 3 , the sensing membrane  136  may be a multi-layered structure that includes electrical contacts (not shown in  FIG. 3 ) separated by a gap. Collapsing of the tactile dome  132  closes the gap between the electrical contacts and causes the sensing membrane  136  to trigger a switch event. 
     The sensing membrane  136  includes, in a particular embodiment, first and second deformable layers  136   a ,  136   b . The first and second deformable layers  136   a ,  136   b  are separated within the sensing membrane  136  by a spacer  136   c . The spacer  136   c  may include an opening that defines a cavity  137  between the first and second deformable layers  136   a ,  136   b . The first and second deformable layers  136   a ,  136   b  may include electrical contacts of the sensing membrane  136  positioned within the cavity  137  (e.g., on opposing sides or top and bottom portions of the cavity  137 , respectively). As shown and described in greater detail with respect to  FIGS. 6A and 6B , when the tactile dome  132  collapses, the cavity  137  may be pinched such that the electrical contacts of the sensing membrane  136  contact and trigger a switch event. In this regard, the tactile dome  132  need not include any electrically conductive components in order for the sensing membrane  136  to trigger a switch event. It will be appreciated, however, that in other configurations, for example, such as that described with respect to  FIGS. 6C and 6D , the tactile dome  132  may include an electrically conductive puck or other structure that may be used to complete a switch defined on and/or in the sensing membrane  136 . 
     The sensing membrane  136  may be positioned above the feature plate  142 . As shown in  FIG. 3 , the feature plate  142  may include the relief  148 . The relief  148  may be a hole or other through feature extending partially or fully through the feature plate  142 . The relief  148  may be positioned below the cavity  137  of the sensing membrane  136  and below the tactile dome  132 . As such, the relief  148  may be configured to receive a portion of the sensing membrane  136  when the tactile dome  132  collapses. For example, the tactile dome  132  may pinch the first and second deformable layers  136   a ,  136   b  toward one another and cause the first and second deformable layers  136   a ,  136   b  to at least partially extend or bend into the relief  148 . This may help deliver a sensation of a longer key stroke, as the relief  148  allows the tactile dome  132  to extend further downward into the key assembly  108  during depression of the key cap  110 . 
     The feature plate  142  provides structural support to the switch housing  128  within the key assembly  108 . In one embodiment, the engagement structures  144  of the feature plate  142  may extend from a top surface of the feature plate  142  and couple with an underside of the switch housing  128 . For example, the engagement structures  144  may extend through corresponding ones of the series of feature plate openings  146  and corresponding ones of the series of membrane openings  138  and engage the switch housing  128 . In some cases, the engagement structures  144  may include barbs or other projections or protrusion features that are inserted into the underside surface of the switch housing  128 . Additionally or alternatively, the engagement structures  144  may include holes or other through portions that may receive a portion of the switch housing  128  or other coupling structure to secure the switch housing  128  within the key assembly  108  using the feature plate  142 . 
     The LGP  150  may be arranged within the key assembly  108  along an underside of the feature plate  142 . The LGP  150  may include the light extraction feature  154 . The light extraction feature  154  may be used to expel light from the LGP  150  and direct the expelled light toward the key cap  110  in order to illuminate the illuminable symbol  111 . As shown in  FIG. 3 , the light extraction feature  154  may direct light along light path L 1 . It will be appreciated that light path L 1 , and all light paths described herein (e.g., light paths L 2 , L 3 , L 4  of  FIGS. 7A-7C ), are depicted for purposes of illustration only. Rather than suggest that light expelled from the LGP  150  travels exclusively along a particular light path, the illustrated light paths are depicted to be a representation of diffuse light that propagates within the key assembly  108 . Notwithstanding the foregoing, light path L 1  may correspond to a contour, shape, area, or other attribute of the illuminable symbol  111 . For example, and as described in greater detail with respect to  FIGS. 7A-7C , the light extraction feature  154  may be configured to exhibit an optical characteristic or otherwise direct light in a manner that illuminates the illuminable symbol  111  according to a predetermined optical effect, such as illuminating the illuminable symbol  111  in a manner that maximizes light emitted from the key cap  110 . 
       FIGS. 4A-4C  depict the support structure  120  described with respect to  FIGS. 2A and 2B . In particular,  FIGS. 4A-4C  depict the support structure  120  in various stages of formation during a process of manufacturing the support structure  120 . 
     The wings  122   a ,  122   b  may be overmolded structures that are molded over the hinge  124 . For example, the wings  122   a ,  122   b  may be a pair of wings that are constructed or formed from a compliant and moldable material that is introduced into a form resembling a desired shape of the wings  122   a ,  122   b . For example, the form may define a shape of the wings  122   a ,  122   b , including the cavity  123  arranged between the wings  122   a ,  122   b , the key cap engagement structures  121 , the protrusions  125 , the upstop features  126 , and/or any other geometries or features of the wings  122   a ,  122   b . A strip of the compliant material may be placed within the form and used to construct the hinge  124 . In this regard, when introduced or flowed into the form, the moldable material of the wings  122   a ,  122   b  may be molded over the compliant material to form the overmolded hinge  124  of  FIG. 4A . 
     The compliant material used to form the hinge  124  may be a substantially heat-resistant material that inhibits physical or chemical changes of the hinge  124  when the moldable material is introduced and molded over the hinge  124 . As such, the moldable material may be subsequently cured or hardened, including through various mechanical and chemical techniques, to form the wings  122   a ,  122   b . This may cause the wings  122   a ,  122   b  to exhibit a rigidity greater than that of the hinge  124 , while maintaining the compliant or elastically deformable nature of the hinge  124  during the overmolding of the wings  122   a ,  122   b.    
     As shown in  FIG. 4A , the hinge  124  may be positioned within each of the wings  122   a ,  122   b . For example, the wings  122   a ,  122   b  may be molded over both a top and a bottom surface of the hinge  124  such that the hinge  124  is sandwiched within each of the wings  122   a ,  122   b . A region of the hinge  124  may also separate the wings  122   a ,  122   b . For example, joint  127  may be a portion of the hinge  124  that separates the wings  122   a ,  122   b . The joint  127  may deform, expand, contract, or the like in order to allow the wings  122   a ,  122   b  to pivot and/or move generally relative to one another. The joint  127  may be formed by molding the wings  122   a ,  122   b  over opposing ends of the hinge  124 . In this manner, the hinge  124  may extend into each of the wings  122   a ,  122   b  by a predetermined amount, which may help securely bond the wings  122   a ,  122   b  to the hinge  124 . As shown in  FIG. 4A , the hinge  124  may extend into the wings  122   a ,  122   b  beyond the upstop features  126 ; however, other configurations are contemplated within the scope of the present disclosure. 
     With reference to  FIG. 4B , the support structure  120  is shown in a state of manufacture in which the wings  122   a ,  122   b  are molded over a strip of compliant material  160 . The strip of compliant material  160  may be used to form the hinge  124  described herein. For example, the strip of compliant material  160  may be advanced through and extend across a form. Moldable material may be introduced into the form and molded over opposing edges of the strip of compliant material  160  to form the wings  122   a ,  122   b . For example, this may cause, as shown in  FIG. 4B , the first wing  122   a  to be formed and molded over a first edge  161   a  of the strip of compliant material  160  and the second wings  122   b  to be formed and molded over a second edge  161   b  of the strip of compliant material  160 . 
     The strip of compliant material  160  may include various holes, recesses, openings, or other features that may facilitate the manufacture of the support structure  120 . For example, the strip of compliant material  160  may include alignment hole  162 . The alignment hole  162  may be a through portion of the strip of compliant material  160  that may be used to advance the strip of compliant material  160  into and through the form and align the strip of compliant material  160  therein for adequate molding of the wings  122   a ,  122   b . In some cases, the alignment hole  162  may be configured to receive a mechanical feature or component of a manufacturing process that may advance the strip of compliant material  160  using the alignment hole  162 . The strip of compliant material  160  may also include voids  163 . The voids  163  may be through portions of the strip of compliant material  160  that may allow protrusions, pins, projections, or other features of the wings  122   a ,  122   b  to extend into a region defined by the strip of compliant material  160 . As shown in  FIG. 4B , the upstop feature  126  may extend into respective ones of the voids  163 . This may allow the hinge  124  to extend into the wings  122   a ,  122   b  beyond the upstop features  126 , while having the up stop features  126  extend into a region of the cavity  123  defined by the strip of compliant material  160 . 
     As shown in  FIG. 4B , the strip of compliant material  160  may extend through the wings  122   a ,  122   b  and across the cavity  123 . Subsequent to the molding of the wings  122   a ,  122   b  over the strip of compliant material  160 , excess portions of the strip of compliant material  160  may be removed to reveal the hinge  124  described with respect to  FIG. 4A . For example, the portion of the strip of compliant material positioned within the cavity  123  and the portion extending away from the wings  122   a ,  122   b , opposite the cavity  123 , may be removed or detached from the wings  122   a ,  122   b  to reveal the hinge  124 . 
     With reference to  FIG. 4C , a set of support structures  120 ′ is shown in a state of manufacture in which multiple discrete support structures, such as support structure  120  described with respect to  FIGS. 4A and 4B , may be formed using a single continuous strip of compliant material. In particular, each of the set of support structures  120 ′ may be molded and formed over the strip of compliant material  160 ′. Excess portions of the strip of compliant material  160 ′ may be separated from the set of support structures  120 ′ to reveal individual support structures. This may allow multiple support structures to be constructed in rapid succession, thereby improving manufacturability of the various support structures described herein. 
       FIGS. 5A-5C  depict the support structure  120  and the switch housing  128  described with respect to  FIGS. 2A and 2B . In particular,  FIGS. 5A-5C  depict the engagement of the support structure  120  and the switch housing  128 . 
     With reference to  FIG. 5A , a top view of the support structure  120  and the switch housing  128  is shown. The switch housing  128  is shown positioned within the cavity  123  defined by the wings  122   a ,  122   b  of the support structure  120 . The support structure  120  is shown engaged with the switch housing  128 . For example, the protrusions  125  may extend into the cavity  123  and be received by recesses, holes, openings, and/or other retention features of the switch housing  128 . As such, the support structure  120  may be secured within the key assembly  108  by the switch housing  128 . The protrusions  125  may also allow the support structure  120  to pivot relative to the switch housing  128 . 
     The switch housing  128  may include or be coupled with various different sizes, shapes, and configurations of retention features in order to support various types of movements of the support structure  120  within the key assembly  108 . For example, the retention features may have a size and/or shape that allows for a predetermined amount and direction of movement of the protrusions  125  when a key cap (e.g., key cap  110  of  FIG. 1 ) is depressed. This may help determine the keystroke of the key cap  110  and deliver a desired tactile response in response to a key press or other force input. 
     In the embodiment of  FIG. 5A , the switch housing  128  may include a first retention feature  129   a  and a second retention feature  129   b . The first and second retention features  129   a ,  129   b  may be recesses, grooves, or openings formed along a common exterior surface of the switch housing  128 . Protrusions  125  of the support structure  120  may be received by corresponding ones of the first and second retention features  129   a ,  129   b . For example, a first protrusion  125   a  of the protrusions  125  may extend from the first wing  122   a  and may be received by the first retention feature  129   a , and a second protrusion  125   b  of the protrusions  125  may extend from the second wing  122   b  and may be received by the second retention feature  129   b.    
     The first retention feature  129   a  may be defined by a shape that substantially conforms or matches a shape of the protrusions  125 . For example, the first retention feature  129   a  may have a cross-dimension or width that is substantially similar to (or slightly larger than) a cross-dimension or width of the protrusions  125 . In contrast, the second retention feature  129   b  may be an elongated structure that may have a cross-dimension or width that is greater than a cross-dimension or width of the protrusions  125 . Accordingly, the first and second retention features  129   a ,  129   b  may constrain movement of the protrusions  125  in a distinct manner during depression of the key cap  110 . For example, when the key cap  110  is depressed, the first protrusion  125   a  may rotate within the first retention feature  129   a , and the second protrusion  125   b  may rotate and translate within the second retention feature  129   b , as depicted and described with respect to  FIGS. 5B and 5C . 
     With reference to  FIG. 5B , the key cap  110  is shown in an unactuated position. The key cap  110  is supported above the switch housing  128  by the support structure  120 . The support structure  120  may be pivotally coupled to the key cap  110  and the switch housing  128  and guide movement of the key cap  110  as it is depressed toward the switch housing  128 . To facilitate the foregoing, the key cap engagement structure  121  may be pivotally coupled to an underside of the key cap  110 . Further, the protrusions  125  may be pivotally coupled with the switch housing  128 . Accordingly, as the key cap  110  is depressed, the wings  122   a ,  122   b  may pivot relative to the key cap  110  at the key cap engagement structures  121 , and the wings  122   a ,  122   b  may pivot relative to the switch housing  128 , for example, at the first and second retention features  129   a ,  129   b , described herein. 
     As shown in  FIG. 5B , the first retention feature  129   a  may have a substantially similar width as that of the first protrusion  125   a , whereas the second retention feature  129   b  may have an elongated width that is larger than that of the second protrusion  125   b . As such, the first retention feature  129   a  may be configured to constrain lateral or translational movement (e.g., movement along a direction extending across the first and second wings  122   a ,  122   b ) of the first protrusion  125   a  during depression of the key cap  110 , whereas the second retention feature  129   b  may be configured to allow lateral or translational movement of the second protrusion  129   b  during depression of the key cap  110 . For example, the second protrusion  125   b  may slide laterally within the second retention feature  129   b  when the key cap  110  is depressed. In the unactuated position, the support structure  120  may resemble a v-shaped structure. As such, the second protrusion  125   b  may be positioned along a rightmost side of the second retention feature  129   b  when the key cap  110  is in the unactuated position. 
     With reference to  FIG. 5C , the key cap  110  is shown in an actuated position. The key cap  110  may arrive in the actuated position in response to a force input F acting on the key cap  110 . When the key cap  110  is depressed, the key cap  110  may exert a force on the support structure  120  that causes the wings  122   a ,  122   b  to pivot relative to the key cap  110 . In turn, the support structure  120  may transition from resembling a substantially v-shaped structure to a substantially flattened structure as the key cap  110  is pressed down onto the support structure  120 . The key cap  110  may impact a tactile dome (not shown in  FIG. 5C ), and trigger a switch event. 
     The support structure  120  may also pivot and move relative to the switch housing  128  during the depression of the key cap  110 . For example, depression of the key cap  110  may cause the first protrusion  125   a  to rotate within the first retention feature  129   a  and the second protrusion  125   b  to rotate within the second retention feature  129   b . The second protrusion  125   b  may also translate or slide within the second retention feature  129   b  when the key cap  110  is depressed. For example, as shown in  FIG. 5C , the second protrusion  125   b  may slide from a right most portion of the retention feature  129   b  to a left most portion of the retention feature  129   b.    
     The pivoting action of the support structure  120  may be facilitated by the hinge  124 . As described above, the hinge  124  may be formed from or include a compliant material layer over which the wings  122   a ,  122   b  are molded over. As such, the hinge  124  may deform, bend, expand, contract, or the like as may be required to support the pivoting of the support structure  120  relative to the key cap  110  and the switch housing  128 , as described herein. In a particular embodiment, as shown in  FIG. 5C , the hinge  124  may move up toward the key cap  110  as the key cap  110  is depressed. The hinge  124  may also at least locally be contracted or compressed as the wings  122   a ,  122   b  move momentarily closer to one another as the key cap  110  is depressed. This may improve the z-profile or keystroke of the support structure  120  and deliver a desired tactile sensation to the key cap  110  during a key press. 
       FIGS. 6A-6D  depict various embodiments of the sensing membrane  136 . The sensing membrane  136 , as described herein, may be used to trigger a switch event in response to the collapsing of the tactile dome  132 . As described above, the sensing membrane  136  and the tactile dome  132  may cooperate to form a tactile switch. The sensing membrane  136  may include and/or be coupled with various different electrical components, including various different electrical contacts, switches, electrical traces, or the like. In some cases, the sensing membrane  136  may also include one or more elements of a capacitive-based sensor, magnetic-based sensor, optical sensor, and/or other sensor that may be used to trigger a switch event when the tactile dome  132  collapses. 
     With reference to  FIG. 6A , the key cap  110  is shown in an unactuated configuration and positioned above the tactile dome  132  and the sensing membrane  136 . As described with respect to  FIG. 3 , in one embodiment, the sensing membrane  136  may include first and second deformable layers  136   a ,  136   b , and a spacer  136   c . The first and second deformable layers  136   a ,  136   b  may be separated within the sensing membrane  136  by the spacer  136   c . The spacer  136   c  may include an opening that defines the cavity  137  between the first and second deformable layers  136   a ,  136   b . In the embodiment of  FIG. 6A , the sensing membrane  136  may include first and second electrical contacts  133   a ,  133   b . The first and second electrical contacts  133   a ,  133   b  may be electrically conductive contact elements of a contact based switch. The first electrical contact  133   a  may be attached or included within the first deformable layer  136   a  and the second electrical contact  133   b  may be attached or included within the second deformable layer  136   b . The first and second electrical contacts  133   a ,  133   b  may be positioned within the cavity  137  and separated by a gap. 
     Positioned above the sensing membrane  136  is the tactile dome  132 . The tactile dome  132  may include a contact feature  134  that extends from an underside surface of the tactile dome  132 . The contact feature  134  may be positioned or aligned within the cavity  137  and the first and second electrical contacts  133   a ,  133   b  contained therein. In this regard, the contact feature  134  may be configured to strike or contact the sensing membrane  136  at a region defined by the cavity  137 . The sensing membrane  136  is shown positioned over the feature plate  142 . As described herein, the feature plate may include the relief  148 . The relief  148  may be positioned below the region of the sensing membrane  136  defined by the cavity  137 . The relief  148  may also be positioned below and substantially aligned with the contact feature  134 . 
     With reference to  FIG. 6B , the key cap  110  is shown in an actuated configuration. In the actuated configuration, the key cap  110  presses down onto the tactile dome  132  in response to an external force F exerted on the key cap  110 . The downward motion of the key cap  110  may cause the tactile dome  132  to collapse or buckle, for example, as shown in  FIG. 6B . In a buckled state, the contact feature  134  of the tactile dome  132  may contact the sensing membrane  136 . In particular, the contact feature  134  may exert a force on the sensing membrane  136  that causes the first and second deformable layers  136   a ,  136   b  to be pinched or squeezed such that the first and second deformable layers  136   a ,  136   b  move toward one another and contact. Movement of the first and second deformable layers  136   a ,  136   b  may cause the first and second electrical contacts  133   a ,  133   b  to contact one another and trigger a switch event. As shown in  FIG. 6B , the first and second deformable layers  136   a ,  136   b  are pinched by the action of the contact feature  134 , and at least a portion of the sensing membrane  136  may extend into the relief  148 . 
     With reference to  FIG. 6C , the key cap  110  is shown in an unactuated configuration and positioned over the tactile dome  132  and the sensing membrane  136 , according to another configuration. In the configuration of  FIG. 6C , the tactile dome  132  may include an electrically conductive puck  135 . The electrically conductive puck  135  may be positioned along the contact feature  134 . The electrically conductive puck  135  may be used to complete a circuit or close a switch defined on or along the sensing membrane  136 . For example, in the embodiment of  FIG. 6C , the first and second electrical contacts  133   a ,  133   b  may be a set of alternating comb-like structures (depicted with respect to  FIG. 6D ) that are separated from one another along an exterior or top surface of the sensing membrane  136 . When the key cap  110  presses down into the tactile dome  132 , the tactile dome  132  may collapse or buckle and cause the electrically conductive puck  135  to contact the first and second electrical contacts  133   a ,  133   b , thereby triggering a switch event. In particular, the electrically conductive puck  135  may extend across a separation between the first and second electrical contacts  133   a ,  133   b  such that an electrical connection is made between the first and second electrical contacts  133   a ,  133   b . This may close a switch defined by the sensing membrane  136  and therefore trigger the switch event. 
     With reference to  FIG. 6D , the sensing membrane  136 , described with respect to the embodiment of  FIG. 6C , is shown. In the depicted embodiment, the sensing membrane  136  may include the first and second electrical contacts  133   a ,  133   b  defined along a surface of the sensing membrane  136 , for example, such as a top surface positioned along an underside of the tactile dome  132 . The first and second electrical contacts  133   a ,  133   b  may be separated from one another along the surface of the sensing membrane  136  and define respective terminals of a switch. In this regard, a circuit or switch may be completed when the electrically conductive puck  135  described with respect to  FIG. 6C  spans the gap and contacts the first and second electrical contacts  133   a ,  133   b . In one embodiment, as shown in  FIG. 6D , the first and second electrical contacts  133   a ,  133   b  may form complementary comb-like structures, each with interposed teeth that extend toward, and partially within, the other of the comb-like structures. This may help maximize the regions defined on the sensing membrane  136  when the electrically conductive puck  135  may strike to trigger a switch event. For example, the electrically conductive puck  135  may strike any two of the interposed teeth of the complementary comb-like structures formed by the first and second electrical contacts  133   a ,  133   b  to trigger a switch event. 
       FIGS. 7A-7C  depict the LGP  150  described with respect to  FIGS. 2A and 2B . In particular,  FIGS. 7A and 7B  depict the LGP  150  in a configuration in which the LGP  150  illuminates multiple different key assemblies across a keyboard. 
     With reference to  FIG. 7A , the LGP  150  is shown extending across multiple key assembly regions  109 . The key assembly regions  109  may correspond to regions of the electronic device  104  (described with respect to  FIG. 1 ) having a distinct key assembly (such as key assembly  108 ) or a distinct key of the keyboard. The LGP  150  may be connected to a light housing  170  along a periphery of the key assembly region  109 . The light housing  170 , as described in greater detail below with respect to  FIGS. 7B and 7C , may contain various light sources or light emitting elements that may couple light directly into the LGP  150 . This may allow the LGP  150  to direct light from the light housing  170  toward various ones of the key assembly region  109 , and ultimately illuminate illuminable symbols of corresponding key caps associated with the key assembly region  109 . 
     As described with respect to  FIGS. 2A and 2B , the LGP  150  may define or be coupled with light extraction features. The light extraction features may be used to expel light from the LGP  150  and direct the expelled light toward a key cap or other appropriate portion of a key assembly. The LGP  150  may have multiple light extraction features that allow the LGP  150  to direct light toward individual key assemblies, such as distinct pairs of key assemblies. For purposes of illustration, the LGP  150  is shown in  FIG. 7A  as having a first light extraction feature  154   a  and a second light extraction feature  154   b . However, it will be appreciated that the LGP  150  may have additional light extraction features, including having separate and distinguishable light extraction features at each of the key assembly regions  109 . 
     The light extraction features  154   a ,  154   b  may be lenses, textured surfaces, apertures, or other features of the LGP  150 . As shown in the embodiment of  FIG. 7A , the first light extraction feature  154   a  may be positioned along the LGP  150  at or near a first of the key assembly regions  109  and the second light extraction feature may be positioned along the LGP  150  at or near a second of the key assembly regions  109 . The first light extraction feature  154   a  may direct light from the LGP  150  along light path L 2  and the second light extraction feature  154   b  may direct light from the LGP  150  along light path L 3 . The light path L 2  may be used to illuminate a first illuminable symbol of a key cap associated with the first of the key assembly regions  109  and the light path L 3  may be used illuminate a second illuminable symbol of a key cap associated with the second of key assembly regions  109 . 
     The LGP  150  may be configured to illuminate the first of the key assembly regions  109  in a manner that is distinct from a second of the key assembly region  109 . For example, the first and second light extraction features  154   a ,  154   b  may exhibit distinct optical characteristics that direct light from the LGP  150  in distinct manners. For example, the first light extraction feature  154   a  may exhibit or define a first light path, brightness, interference pattern, and so on, and the second light extraction feature  154   b  may exhibit or define a distinct second light path, brightness, interference pattern, and so on. 
     The optical characteristics of the first and second light extraction features  154   a ,  154   b  may be specifically tailored to a particular illuminable symbol of the key caps associated with the key assembly regions  109 . This may allow the LGP  150  to optimally or maximally illuminate the illuminable symbol according to a size, shape, contour, or the like of the illuminable symbol, which may be different for each key cap across the key assembly regions  109 . As a sample illustration, the optical characteristics exhibited by the first light extraction feature  154   a  may be configured to illuminate an illuminable symbol indicative of the letter “A,” whereas the optical characteristics exhibited by the second light extraction feature  154   b  may be configured to illuminate an illuminable symbol indicative of the letter “B.” However, in other embodiments, the light extraction features may be configured to illuminate various other alpha-numeric characters, or other symbols, glyphs, or the like. Additionally or alternatively, the first and second light extraction features  154   a ,  154   b  may be configured to compensate for other transparent and non-transparent components of a key assembly that may impact the illumination of the illuminable symbol. 
     With reference to  FIG. 7B , a cross-sectional view of the LGP  150  and the light housing  170  is shown. The light housing  170  may be positioned along a periphery of the key assembly region  109  and contain one or more light sources or light emitting elements. For example, as shown in  FIG. 7B , the light housing  170  may include light source  172 . The light source  172  may be a light emitting diode (LED), micro-LED, liquid crystal display (LCD) element, organic light emitting diode (OLED), or other light emitting element that generates light. The light source  172  may be coupled with an electrical component  174  positioned within the light housing  170 . The electrical component  174  may be a printed circuit board (PCB), substrate, switch, or other component, which may be coupled with a processing unit and/or other component with appropriate control logic that is used to selectively operate the light source  172 . 
     The light housing  170  may be configured to direct light from the light source  172  into the LGP  150 . For example, the light housing  170  may form an opaque or light-blocking shell around the light source  172  that may substantially inhibit the leakage of light from the light housing  170 . To facilitate the foregoing, an outer perimeter of the light housing  170  may be coated, positioned along, and/or encapsulated within a non-transparent or opaque masking layer. Further, the light housing  170  may include angled surface  171 , which may also help channel light toward, and into, the LGP  150 . In particular, the light source  172  may have a thickness that is greater than the LGP  150 , and thus the light housing  170  may also be generally thicker than the LGP  150  to receive and contain the light source  172 . The angled surface  171  may therefore be a tapered surface of the light housing  170  that extends between a lower surface of the light housing  170  and a lower surface of the LGP  150 . Light emitted from the light source  172  may be redirected by the angled surface  171  into the LGP  150 . For example, as shown in  FIG. 7B , the light source  172  may emit light generally along light path L 4 , which may be channeled into the LGP  150  at least in part by angled surface  171 . 
     With reference to  FIG. 7C , the key assembly  108  is shown in a configuration in which the LGP  150  is used to illuminate the illuminable symbol  111 . The LGP  150  may be used to direct light from the light source  172  toward the illuminable symbol  111  of the key assembly  108 . For example, as described above with respect to  FIG. 7B , the light source  172  may emit light substantially along light path L 4 . The light path L 4 , due in part to the light housing  170  and the angled surface  171 , may couple light emitted from the light source  172  into the LGP  150 . The LGP  150  may propagate light through the keyboard in order to illuminate various illuminable features of the keyboard, such as illuminable symbol  111  of the key assembly  108 . 
     In particular, light may propagate through the LGP  150  until the light reaches one or more of the light extraction features described herein, for example, such as light extraction features  154   a ,  154   b  described with respect to  FIG. 7A . As shown in  FIG. 7C , the LGP  150  may include the light extraction feature  154   a . The light extraction feature  154   a  may be positioned below the key assembly  108 . The light extraction feature  154   a , as described above, may expel light from the LGP  150  and direct the expelled light toward the illuminable symbol  111 . For example, the light extraction feature  154   a  may direct light substantially along light path L 2 . The light path L 2  may pass through the key assembly  108 , including through various transparent regions of the key assembly  108  (e.g., optionally including a light-transmissible tactile dome, switch housing, and so on). This may cause the illuminable symbol  111  to illuminate along a surface of the key cap  110 . 
       FIGS. 8A and 8B  depict the feature plate  142  described with respect to  FIGS. 2A and 2B . In particular,  FIGS. 8A and 8B  depict the feature plate  142  having various embodiments of engagement structures that may be used to secure the switch housing  128  within the key assembly  108 . 
     With reference to  FIG. 8A , the feature plate  142  is shown as having engagement structures  144   a . The engagement structures  144   a  may be tabs, projections, protrusions, or other like structures that extend from a top surface of the feature plate  142 . The engagement structures  144   a  may be a stamped or cut out feature of the sheet metal used to form the feature plate  142 . For example, the engagement structures  144   a  may be a stamped or cut out portion of the sheet metal used to form the feature plate  142  that are subsequently bent or otherwise manipulated to extend from the top surface of the feature plate  142 . 
     The engagement structures  144   a  may be used to engage or secure one or more components within a key assembly (e.g., key assembly  108  of  FIG. 2A ). For example, the engagement structures  144   a  may be used to secure a switch housing or support structure within the key assembly  108 . To facilitate the foregoing, the engagement structures  144   a  may have one or more holes, openings, apertures, or the like that may be configured to receive one or more features (e.g., a pin, rod, clip, threaded feature, and/or other feature) in order to secure a particular component within a key assembly. 
     With reference to  FIG. 8B , the feature plate  142  is shown as having engagement structures  144   b . The engagement structures  144   b  may be tabs, projections, protrusions, or other like structures that extend from a top surface of the feature plate  142 . The engagement structures  144   b  may be a stamped or cut out feature of the sheet metal used to form the feature plate  142 . For example, the engagement structures  144   b  may be a stamped or cut out portion of the sheet metal used to form the feature plate  142  that are subsequently bent or otherwise manipulated to extend from the top surface of the feature plate  142 . 
     The engagement structures  144   b  may be used to engage or secure one or more components within a key assembly (e.g., key assembly  108  of  FIG. 2A ). For example, the engagement structures  144   b  may be used to secure a switch housing or support structure within the key assembly  108 . To facilitate the foregoing, the engagement structures  144   b  may include or define a barb, angular, or other serrated structure or edge. This may allow the engagement structures  144   b  to extend into, for example, an underside of a switch housing and prevent subsequent movement of the switch housing using the serrated edge. In particular, the engagement structure  144   b  may include a serrated edge configured to allow the engagement structures  144   a  to pierce the underside surface of the switch housing and advance therein, while substantially preventing the feature plate  142  from exiting the switch housing. 
       FIGS. 9 and 10  depict a key assembly  208 . The key assembly  208  may be configured to operate in a manner substantially analogous to the key assembly  108  described with respect to  FIG. 2A . For example, the key assembly  208  may be configured to receive a force input or mechanical press that is used to collapse or buckle a tactile dome or other element of a tactile switch. Upon buckling, the tactile dome may contact a sensing membrane or other contact-based sensing component and trigger a switch event that may be used to control a function of a computing device (e.g., electronic device  104  of  FIG. 1 ). Accordingly, the key assembly  208  may include similar components as that of key assembly  108 , including: key cap  210 ; illuminable symbol  211 ; tactile dome  232 ; sensing membrane  236 ; series of membrane openings  238 ; feature plate  242 ; engagement structures  244 ; series of feature plate openings  246 ; relief  248 ; LGP  250 ; and light extraction feature  254 . 
     Notwithstanding the foregoing, as shown in  FIG. 9 , the key assembly  208  may include a modified-support structure  220  that is pivotally coupled with a modified switch housing  228  below the key cap  210 . The half-support structure  220  may be used to support smaller keys of a keyboard, such as key cap  210 , which may correspond to an arrow key, although other keys, including larger keys, may be used. The smaller size of the key may limit the available volume for components of the key assembly  208 . The modified-support structure  220  and the modified switch housing  228  may help accommodate a relatively larger tactile dome for the smaller key, and may therefore contribute to delivering a desired tactile effect when the smaller key is depressed. 
     The modified-support structure  220  may include wings  222   a ,  222   b  that are pivotally coupled about a hinge  224 . Substantially analogous to the wings  122   a ,  122   b  and hinge  124  described with respect to  FIGS. 2A and 2B , the wings  222   a ,  222   b  may be a pair of wings that are overmolded components molded over the hinge  224 . The hinge  224  may be formed from a compliant material. In the embodiment of  FIG. 9 , however, the hinge  124  may only be present on one side of the modified-support structure  220  (e.g., the wings  222   a ,  222   b  may be connected via a single structure). The wings  222   a ,  222   b  may cooperate to define a cavity  223 . Rather than be encircled or enclosed by the wings  222   a ,  222   b , the cavity  223  may be open along a first side of the modified-support structure  220  and closed or otherwise defined by the hinge  224  on a second, opposing side of the modified-support structure  220 . 
     The modified switch housing  228  may be configured to be positioned within the cavity  223  defined by the wings  222   a ,  222   b . The modified switch housing  228  may include various retention features or the like that are configured to receive a portion of the wings  222   a ,  222   b  and support the wings  222   a ,  222   b  with the key assembly  208  as the key cap  210  is depressed. The modified switch housing  228  may include a recess  230 . The recess  230  may be a semi-circular recess or other recess defined by a curved edge of the modified switch housing  228 . The recess  230  and the cavity  223  may cooperate to allow the tactile dome  232  to extend between the modified-support structure  220  and the modified switch housing  228 . 
     With reference to  FIG. 10 , the modified-support structure  220  is shown pivotally coupled with the modified switch housing  228 . As shown in  FIG. 10 , each of the wings  222   a ,  222   b  may include non-symmetric arms that allow the wings  222   a ,  222   b  to be pivotally connected to one another about one side of the modified-support structure  220  (e.g., about hinge  224 ) and allow the modified switch housing  228  to be positioned within the cavity  223 . For example, the wings  222   a ,  222   b  may each include a major arm  291  and a minor arm  290 . The minor arm  290  may be shorter or smaller than the major arm  291 . The minor arm  290  may define a free end of a respective one of the wings  222   a ,  222   b  that is not pivotally coupled or overmolded with a compliant hinge. The major arm  291  of the respective one of the wings  222   a ,  222   b  may be an overmolded structure that is molded over the hinge  224 . 
     Each of the wings  222   a ,  222   b  may include a cross-support  225 . The cross-support  225  may extend between the respective ones of the major arm  291  and the minor arm  290 . The cross-support  225  may be used to pivotally couple the modified-support structure  220  with the modified switch housing  228 , or a portion thereof. For example, the cross-support  225  may extend across and through the modified switching housing  228 . The modified switch housing  228  may be configured to allow the cross-support  225  to rotate and/or translate within the modified switch housing  228  in response to a depression of the key cap  210 . In this regard, the modified-support structure  220  may also include key cap engagement structures  221  that extend from the wings  222   a ,  222   b  and are configured to pivotally engage a key cap as it is depressed into the key assembly  208  and toward the tactile dome  232 . 
       FIGS. 11 and 12  depict a key assembly  308 . The key assembly  308  may be configured to operate in a manner substantially analogous to the key assembly  108  described with respect to  FIG. 2A . For example, the key assembly  308  may be configured to receive a force input or mechanical press that is used to collapse or buckle a tactile dome or other element of a tactile switch. Upon buckling, the tactile dome may contact a sensing membrane or other contact-based sensing component and trigger a switch event that may be used to control a function of a computing device (e.g., electronic device  104  of  FIG. 1 ). Accordingly, the key assembly  308  may include similar components as that of key assembly  308 , including: key cap  310 ; illuminable symbol  311 ; collar  314 ; key opening  315 ; support structure  320 ; wings  322   a ,  322   b ; hinge  324 ; sensing membrane  336 ; series of membrane openings  338 ; feature plate  342 ; engagement structures  344 ; series of feature plate openings  346 ; relief  348 ; LGP  350 ; and light extraction feature  354 . 
     Notwithstanding the foregoing, the key assembly  308  includes a dome integrated switch housing  380 , as depicted in  FIG. 11 . The dome integrated switch housing  380  may be positioned above the sensing membrane  336  and used to support the support structure  320  within the key assembly  308 . In this regard, the dome integrated switch housing  380  may be a structural portion of the key assembly  308  that contains a deformable tactile dome or other tactile switch element used to detect actuation of the key cap  310 . The dome integrated switch housing  380  may also include various light extraction or illumination features that may direct light toward the illuminable symbol  311  of the key cap  310 . 
     As shown in  FIG. 11 , the dome integrated switch housing  380  may include an overmolded switch housing  328  and a tactile dome  332 . The overmolded switch housing  328  may be an overmolded component that is overmolded over a portion of the tactile dome  332  (e.g., such as about a periphery of the tactile dome  332 ). In this regard, the overmolded switch housing  328  may be used to support the tactile dome  332  within the key assembly  308 . The tactile dome  332  may be a deformable portion of the dome integrated switch housing  380  that may collapse or buckle in response to an applied force. In this regard, the tactile dome  332  may be used to contact the sensing membrane  336  positioned below the dome integrated switch housing  380  and trigger a corresponding switch event. 
     With reference to  FIG. 12 , the dome integrated switch housing  380  is shown pivotally coupled with the support structure  320 . In the embodiment of  FIG. 12 , the support structure  320  may include cross-supports  325 . The cross-supports  325  may extend through the cavity  323  between arms of each of the wings  322   a ,  322   b  of the support structure  320 . The cross-supports  325  may be received by a retention feature or other recess, cavity, opening, through portion, or the like of the dome integrated switch housing  380 . As shown in  FIG. 12 , the cross-supports  325  may extend through the dome integrated switch housing  380 ; however, in other cases, the cross-supports  325  may extend partially through and/or along an exterior surface of the dome integrated switch housing  380 . As such, the dome integrated switch housing  380  may be configured to allow the cross-supports  325  to rotate and/or pivot within the dome integrated switch housing  380  during depression of the key cap  310 . In this regard, the support structure  320  may also include key cap engagement structures  321  that may be configured to pivotally couple with the key cap  310  positioned above the dome integrated switch housing  380 . 
     The overmolded switch housing  328  may be a structural component of the key assembly  308 . For example, the overmolded switch housing  328  may structurally support the tactile dome  332  within the key assembly  308 . For example, the overmolded switch housing  328  may include or define feet  384 , as depicted in  FIG. 12 . The feet  384  may be configured to be secured to or received by the feature plate  342  and/or other components of the key assembly  308 , which may help secure the dome integrated switch housing  380  within the key assembly  308 . (e.g., the feet  384  may be coupled with the engagement structures  344 , described with respect to  FIG. 11A ). 
     Further, the overmolded switch housing  328  may also serve to enhance the acoustic performance of the key assembly  308 . In an embodiment, the overmolded switch housing  328  may include posts  386 . The posts  386  may be constructed from rubber or other acoustically insulating materials. The posts  386  may extend from a top surface of the overmolded switch housing  328 . The posts  386  may have a height or other dimension such that the key cap  310  impacts the posts  386  upon actuation. This may help dampen the sound associated with a key stroke. 
     The overmolded switch housing  328  may also include or define various light channels  382 . The light channels  382  may be configured to receive light from the LGP  350  positioned below the dome integrated switch housing  380  and direct the received light toward the illuminable symbol  311 . In this regard, the overmolded switch housing  328  may be used to illuminate the illuminable symbol  311  of the key cap  310 . In some cases, the light channels  382  may exhibit various properties, including defining a distinct light path, brightness, interference pattern, and so on that may be used to illuminate the illuminable symbol  311  in a manner corresponding to a shape, size, contour, or the like of the illuminable symbol  311 . 
     To facilitate the reader&#39;s understanding of the various functionalities of the embodiments discussed herein, reference is now made to the flow diagram in  FIG. 13 , which illustrates process  1300 . While specific steps (and orders of steps) of the methods presented herein have been illustrated and will be discussed, other methods (including more, fewer, or different steps than those illustrated) consistent with the teachings presented herein are also envisioned and encompassed with the present disclosure. 
     In this regard, with reference to  FIG. 13 , process  1300  relates generally to a method of manufacturing a support structure. The process  1300  may be used to manufacture any of the support structure described herein, for example, such as support structure  120  and support structure mechanism  320 . 
     At operation  1304 , a strip of compliant material may extend through a form. For example and with reference to  FIGS. 4A-4C , the strip of compliant material  160  may be extended through a form. For example, the strip of compliant material  160  may be advanced into a form resembling the shape of a support structure wing using the alignment holes  162 . In some cases, the alignment holes  162  may be configured to receive a pin, bar, or other advancement feature that causes the strip of compliant material  160  to advance into the form and extend entirely across a longitudinal dimension of the form. 
     At operation  1308 , a moldable material may be caused to flow into the form and form a first wing and a second wing over the compliant material. In particular, the first wing may be molded over a first edge of the strip of compliant material and the second wing may be molded over a second edge of the strip of compliant material. For example, and with reference to  FIGS. 4A-4C , an injection moldable material may be caused to flow into a form and envelop a portion of the strip of compliant material  160 . The form may resemble the shape of the wings  122   a ,  122   b  such that the injection moldable material envelops the strip of compliant material  160  and forms the wings  122   a ,  122   b  along opposing sides of the strip of compliant material  160 . The resulting wings  122   a ,  122   b  may be separated from one another by joint  127 , which may correspond to a portion of the strip of compliant material  160  having no or minimal overmolded structure. As such, the wings  122   a ,  122   b  may pivot relative to one another about the joint  127 . 
     In order to form the wings  122   a ,  122   b , the injection moldable material may be optionally cured within the form to achieve a desired mechanical or physical characteristic of the wings  122   a ,  122   b . This may involve inducing various temperature variations within the form such that the wings  122   a ,  122   b  exhibit a hardness greater than that of the strip of compliant material  160 . Due at least in part to the potential temperature variations, the strip of compliant material  160  may be formed from a heat-resistant material that inhibits physical or chemical changes of the strip of compliant material during curing and/or other steps used to produce the support structure  120 . 
     At operation  1312 , the compliant material may be detached from within a cavity defined by the wings of the support structure. For example, and with reference to  FIGS. 4A-4C , the strip of compliant material  160  may be removed or detached from the wings  122   a ,  122   b  to reveal a completed support structure  120 . The strip of compliant material  160  may be removed by various techniques, including mechanical and chemical treatments. In some cases, the strip of compliant material  160  may be detached or removed from a set of support structures  120 ′ in order to facilitate the manufacture of multiple support structure along a single, continuous strip of compliant material. 
     Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Further, the term “exemplary” does not mean that the described example is preferred or better than other examples. 
     The foregoing description, for purposes of explanation, uses 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 targeted 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: 20170818
Publication Date: 20190430
Grant Date: 20190430
Priority Date: 20170818
Inventors: GOLDBERG, MICHELLE R.
BERGERON, KATHLEEN A.
WANG, PAUL X.
LEHMANN, Alex J.
Yarak, III, William P.
ARMENDARIZ, KEVIN C.
GAO, ZHENG
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H2229/048", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/7073", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H3/122", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2219/044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/83", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/7065", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/83", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2203/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/83", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/88", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2219/056", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2219/062", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/88", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/7065", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H3/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H13/88", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/83", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2229/048", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2203/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/122", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/7065", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2219/056", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2219/044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2219/062", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 65360454