Low-travel key mechanisms using butterfly hinges

Technical Field

0001The disclosed embodiments relate generally to electronic devices, and more particularly to input devices for electronic devices.

Background

0002Many electronic devices typically include one or more input devices such as keyboards, touchpads, mice, or touchscreens to enable a user to interact with the device. These devices can be integrated into an electronic device or can stand alone as discrete devices that can transmit signals to another device either via wired or wireless connection. For example, a keyboard can be integrated into the housing of a laptop computer or it can exist in its own housing.

0003It is often desirable to reduce the size of electronic devices and minimize machining costs and manufacturing time of such devices. For example, laptops may be designed to be as small and light as possible, but input devices such as a keyboard may occupy relatively large portions of the available interior space. One way to alleviate design constrains of a keyboard is to minimize the z-stackup of key mechanisms. Accordingly, what is needed is an improved key mechanism design.

0004<patcit id="pcit0001" dnum="US6257782B"><text>US6257782</text></patcit> and <patcit id="pcit0002" dnum="US5986227A"><text>US5986227</text></patcit> disclose conventional key mechanisms.

Summary

0005In accordance with an aspect of the invention, there is provided a key mechanism according to appended claim 1. Preferable features of the invention are defined in the appended dependent claims.

Brief Description of the Drawings

0006The above and other aspects and advantages of the invention will become more apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which: <ul id="ul0001" list-style="none"><li><figref idref="f0001"><b>FIG. 1</b></figref> shows a perspective view of a computing device having a keyboard incorporated therein in accordance with an embodiment;</li><li><figref idref="f0002"><b>FIG. 2</b></figref> shows an illustrative perspective view of a section of a keyboard in accordance with an embodiment;</li><li><figref idref="f0003"><b>FIG. 3</b></figref> shows a generic and illustrative exploded view of a key mechanism;</li><li><figref idref="f0004"><b>FIGS. 4A-4B</b></figref> show respective illustrative partial cross-sectional views of a key mechanism in a non-depressed position and depressed position;</li><li><figref idref="f0005"><b>FIGS. 5A-5C</b></figref> show illustrative views of butterfly hinge;</li><li><figref idref="f0006"><b>FIG. 6</b></figref> shows illustrative top view of a key mechanism;</li><li><figref idref="f0007"><b>FIG. 7</b></figref> shows an illustrative exploded view of the key mechanism of <figref idref="f0006"><b>FIG. 6</b></figref>;</li><li><figref idref="f0008"><b>FIG. 8</b></figref> shows an illustrative perspective view of a keycap assembly;</li><li><figref idref="f0009"><b>FIG. 9</b></figref> shows an illustrative perspective view of an electronics package;</li><li><figref idref="f0010"><b>FIG. 10</b></figref> shows an illustrative perspective view of keycap assembly and electronics package;</li><li><figref idref="f0011"><b>FIG. 11</b></figref> shows an illustrative top view of a butterfly hinge;</li><li><figref idref="f0012"><b>FIG. 12</b></figref> shows an illustrative top view of a support structure;</li><li><figref idref="f0013"><b>FIG. 13</b></figref> shows an illustrative top view of a butterfly hinge coupled to support structure;</li><li><figref idref="f0014"><b>FIG. 14A</b></figref> shows an illustrative top view of an alternative support structure;</li><li><figref idref="f0015"><b>FIG. 14B</b></figref> shows an illustrative top view of a yet another alternative support structure;</li><li><figref idref="f0016"><b>FIGS. 15-16</b></figref> show illustrative cross-sectional views of a key mechanism;</li><li><figref idref="f0017"><b>FIG. 17</b></figref> shows an illustrative perspective view of another key mechanism;</li><li><figref idref="f0017"><b>FIG. 18</b></figref> shows an illustrative cross-sectional view of the key mechanism of <figref idref="f0017">FIG. 17</figref>;</li><li><figref idref="f0017"><b>FIG. 19</b></figref> shows an illustrative perspective view of a butterfly hinge and support structure;</li><li><figref idref="f0018"><b>FIG. 20</b></figref> shows an illustrative exploded view of a key mechanism;</li><li><figref idref="f0019"><b>FIG. 21</b></figref> shows an illustrative top view of a butterfly hinge;</li><li><figref idref="f0019"><b>FIG. 22</b></figref> shows an illustrative top view of a butterfly hinge coupled to a carrier structure;</li><li><figref idref="f0019"><b>FIG. 23</b></figref> shows an illustrative bottom view of a butterfly hinge coupled to a carrier structure;</li><li><figref idref="f0020"><b>FIG. 24</b></figref> shows an illustrative perspective view of a key mechanism;</li><li><figref idref="f0020"><b>FIG. 25</b></figref> shows an illustrative cross-sectional view of key mechanism;</li><li><figref idref="f0021"><b>FIG. 26</b></figref> shows an illustrative perspective view of a key mechanism;</li><li><figref idref="f0021"><b>FIG. 27</b></figref> shows an illustrative cross-sectional view of key mechanism;</li><li><figref idref="f0022"><b>FIG. 28</b></figref> shows an illustrative perspective view of carrier structure coupled to a support structure;</li><li><figref idref="f0023"><b>FIGS. 29A-29B</b></figref> show illustrative views of a butterfly hinge;</li><li><figref idref="f0024"><b>FIGS. 30A-30C</b></figref> show illustrative views of a butterfly hinge;</li><li><figref idref="f0025"><b>FIGS. 31A-31C</b></figref> show illustrative views of a butterfly hinge;</li><li><figref idref="f0026"><b>FIGS. 32A-32C</b></figref> show illustrative views of a butterfly hinge;</li><li><figref idref="f0027 f0028"><b>FIGS. 33A-33B</b></figref> show illustrative views of a butterfly hinge;</li><li><figref idref="f0029"><b>FIG. 34</b></figref> shows an illustrative exploded view of a key mechanism;</li><li><figref idref="f0030"><b>FIGS. 35A-35B</b></figref> show respective illustrative cross-sectional views of the key mechanism of <figref idref="f0029"><b>FIG. 34</b></figref> in a non-depressed position and depressed position;</li><li><figref idref="f0031 f0032"><b>FIGS. 36-39</b></figref> show various illustrative bottom views of a keycap assembly;</li><li><figref idref="f0033"><b>FIG. 40</b></figref> shows an illustrative view of a half-butterfly hinge in accordance with an embodiment;</li><li><figref idref="f0033"><b>FIG. 41</b></figref> shows an illustrative bottom view of a key mechanism with a half-butterfly hinge in accordance with an embodiment;</li><li><figref idref="f0034"><b>FIG. 42</b></figref> is an illustrative perspective view of a switch in accordance with an embodiment;</li><li><figref idref="f0034"><b>FIGS. 43-44</b></figref> show illustrative cross-sectional views of switch of <figref idref="f0034">FIG. 42</figref> in accordance with an embodiment;</li><li><figref idref="f0035 f0036"><b>FIGS. 45-49</b></figref> show various illustrative bottom views of a keycap assembly in accordance with an embodiment;</li><li><figref idref="f0037"><b>FIGS. 50-52</b></figref> show various illustrative cross-sectional views of a keycap assembly and a substructure in accordance with an embodiment;</li><li><figref idref="f0038"><b>FIG. 53</b></figref> shows an illustrative top view of a key mechanism in accordance with an embodiment;</li><li><figref idref="f0038"><b>FIG. 54</b></figref> shows an illustrative cross-sectional view of keycap assembly of <figref idref="f0038"><b>FIG. 53</b></figref> in accordance with an embodiment;</li><li><figref idref="f0039"><b>FIGS. 55-57</b></figref> show illustrative perspective views of a method for forming a keycap in accordance with an embodiment; and</li><li><figref idref="f0040 f0041"><b>FIGS. 58-61</b></figref> show illustrative perspective views of another method for forming a keycap in accordance with an embodiment.</li></ul>

Detailed Description

0007Some examples described herein provide a key mechanism for an input device such as a keyboard that includes a butterfly hinge. The butterfly hinged key mechanism can enable substantially low travel distances with desired tactile response. For example, a butterfly hinged key mechanism can enable keystrokes ranging between 0.1 mm to 2.0 mm, and in some examples, the keystroke can be 0.5 mm or 0.75 mm. The key mechanism uses a double wing design operative to move between a depressed position and non-depressed position. Corresponding arms of the butterfly hinge are coupled together with coupling mechanisms. The coupling mechanisms can be, for example, a flexible or living hinge or a gear hinge. The wings of the butterfly hinge articulate independently with each wing operative to pivot about its own pivot axis during a keystroke of the key mechanism.

0008Other embodiments described herein provide a key mechanism for an input device such as a keyboard that includes a half-butterfly hinge. The half-butterfly hinged key mechanism can enable similar low travel distances with desired tactile response in a smaller space. One arm of each wing is a full or major arm while the other arm is a shorter or minor arm. The two major arms are coupled together with a coupling mechanism. The coupling mechanism can be, for example, a flexible or living hinge or a gear hinge. The two minor arms are not coupled to each other but can be coupled to a component in the key mechanism, such as a switch housing. The wings of the half-butterfly hinge articulate independently with each wing operative to pivot about its own pivot axis during a keystroke of the key mechanism.

0009Various substructures are described herein that provide support to a keycap of a key mechanism. Additional support devices, such as rods or stiffener plates can be included in a key mechanism to provide support and/or to transfer an applied force across or over a key mechanism during a keystroke event.

0010Methods for producing a keycap or a top surface of a keycap are disclosed. One method bonds a first layer to a second layer and forms an opening through the first layer to expose the second layer. The first layer can be a foil layer, such as an aluminum foil layer. The first layer can have a thickness that is less than 100 microns. In some examples, the foil layer has a thickness of approximately 50 microns. The second layer can be a resin or thermoplastic layer. The opening can be in the shape of one or more glyphs that will be visible on the top surface of the keycap. Once the opening is formed in the first layer, pressure and/or heat is applied to the layers to cause the second layer to flow into the opening and produce the desired glyph or glyphs.

0011Another method bonds a first top layer and a second bottom layer together and forms an opening in the second bottom layer to expose the first top layer. The second bottom layer can be a foil layer, such as an aluminum foil layer. The first layer can have a thickness that is less than 100 microns. In some examples, the foil layer has a thickness of approximately 50 microns. The first top layer can be a liner layer. The opening can be in the shape of one or more glyphs that will be visible on the top surface of the keycap. Once the opening is formed in the second bottom layer, the opening is filled with a material to produce the desired glyph or glyphs. The opening can be filled, for example, using a liquid or ink.

0012<figref idref="f0001"><b>FIG. 1</b></figref> shows a perspective view of a computing device 10 having a keyboard 12 incorporated therein. Computing device 10 can be any suitable computing device, such as, for example, a laptop computer, a desktop computer, a telephone, smart phone, or gaming device. Keyboard 12 can be integrally formed within computing device 10. In other examples, a keyboard can be separate from the computing device and can stand alone as a self-contained device. For example, a keyboard may be a communication interface such as, for example, a wired keyboard or a wireless keyboard that can transmit data to and from a computing device.

0013<figref idref="f0002"><b>FIG. 2</b></figref> shows an illustrative perspective view of a section of keyboard 12 including a key 14. <figref idref="f0002"><b>FIG. 2</b></figref> also shows a stackup of web 30 and support structure 70. Web 30 can be a skeletal structure that surrounds each key of keyboard 12 and provides structural and cosmetic attributes to keyboard 12. Web 30 can be secured to support structure 70 using any suitable approach such as, for example, by adhesive, glue, weld, pins, interface fits, or any combination thereof. Support structure 70 can provide the platform for components contained within a keyboard. Support structure 70 is sometimes referred to as a feature plate. As defined herein, support structure 70 can include any combination of a feature plate, circuit board, and retaining mechanisms for use in various keyboard mechanism examples.

0014Key mechanisms discussed herein provide a substantially low travel keystroke while maintaining a desired tactile feel over the lifetime of the keyboard. Decreasing the keystroke distance enables keyboard 12 to be built thinner than contemporary keyboards. For example, key mechanisms described herein can enable keystrokes ranging between 0.1 mm to 2.0 mm, and in some particular examples, the keystroke can be 0.5 mm or 0.75 mm.

0015The tactile performance of the key mechanism is consistent regardless of where a user presses down on key 14. That is, the tactile response of key 14 is substantially the same if the user pressed down at the center (at region 15a), the corner (at region 15b), or the edge (at region 15c) of key 14. In addition to having a uniform tactile response, the movement of key 14 during a keystroke is also uniform regardless of where it is depressed. For example, imagine a reference plane exists at the top surface of key 14. When key 14 is pressed at region 15a, its movement is one in which the top planer surface of key 14 remains parallel to the reference plane throughout the keystroke. The same is true when key 14 is depressed at a corner or edge; the top planer surface remains parallel or substantially parallel to the reference plane throughout the keystroke. Maintaining this parallel movement, with a relatively low travel, and desired tactile response, is accomplished using a butterfly hinge mechanism.

0016Referring now to <figref idref="f0003"><b>FIG. 3</b></figref>, a generic and illustrative exploded view of key mechanism 12 is shown. Reference will also be made to <figref idref="f0004 f0005"><b>FIGS. 4-5</b></figref> to assist in the description of how key mechanism 12 operates. Key mechanism 12 can include keycap 14, substructure 20, web 30, switch 40, butterfly hinge 50, and support structure 70. Assembly of key mechanism is as follows. Keycap 14 is secured to substructure 20 to form a keycap assembly. The keycap assembly can fit within the inner perimeter of web 30, and web 30 is secured to an outer boundary of support structure 70. In other examples, the keycap assembly can exist above web 30. Butterfly hinge 50 is secured to substructure 20 and support structure 70, and is also contained within the inner perimeter of web 30. Switch 40 resides within cavity 53 of butterfly hinge 50 and can be secured to either the keycap assembly or support structure 70.

0017Keycap 14 is the portion of key mechanism that a user depresses during a keystroke. Keycap 14 can take any suitable shape and can be constructed from any suitable material. For example, keycap 14 can be constructed from plastic, glass, or metal. Keycap 14 can be constructed from a translucent material so that a backlight can shine through. Moreover, a translucent keycap can be masked so that it displays a character.

0018Substructure 20 can take any suitable shape and be constructed from any suitable material. Substructure 20 can fulfill several different functions in its use in key mechanism. In one function, it provides pin retaining mechanisms 22 for coupling to butterfly hinge 50. In particular, substructure can include four pin retaining mechanisms 22, each one operative to couple to one of keycap assembly pins 54 and 57 of butterfly hinge 50. Additional details of pin retaining mechanisms 22 are discussed in more detail below.

0019As another function, substructure 20 can serve as a light guide panel (hereinafter "LGP") for distributing backlight emitted from a light source such as, for example, a LED. In examples that use substructure 20 as a LGP, the shape of substructure 20 can be designed to minimize the impact of backlighting performance. For example, substructure 20 can occupy an outer periphery of keycap 14, thereby leaving an interior portion of keycap largely unobfuscated. The use of a LGP as part of substructure 20 is discussed in more detail below.

0020The combination of keycap 14 and substructure 20 (and potentially other components such as switch 40, electronics (not shown), and flex circuitry (not shown)) is sometimes referred to herein as a keycap assembly. Depending on the stiffness of keycap 14, a relatively strong substructure is needed to provide the rigidity needed for property operation of key mechanism 12. For example, if keycap 14 is constructed from a plastic, substructure 20 may be constructed from metal. In other examples, keycap 14 can be constructed from a relatively stiff material such as glass and substructure can be constructed from a plastic or metal material. In yet another example, keycap 14 and substructure 20 can be an integrally formed keycap assembly. For example, keycap 14 and substructure 20 can be formed from a single plastic mold or a single piece of machined glass.

0021Switch 40 can be any suitable mechanical switch such as a dome switch. A metal dome switch or an elastomeric dome switch may be used, for example. As will be explained more detail in connection with <figref idref="f0004"><b>FIG. 4</b></figref>, switch 40 can bias the keycap assembly to be in its natural, non-depressed position. In other words, when key mechanism is not undergoing a keystroke event, switch 40 can bias the keycap assembly to be in its non-depressed position. When key mechanism 12 is subjected to a keystroke event, switch 40 can buckle under the force applied to keycap 14, thereby enabling the keycap assembly to be in its depressed position. When the keycap assembly is in its depressed position, the keystroke can be registered by circuitry associated with switch 40 or by other circuitry contained within key mechanism (e.g., a parallel plate sensor membrane).

0022Butterfly hinge 50 functions as the movable hinge that enables the keycap assembly to move relative to support structure 70. Butterfly hinge 50 can include wings 51 and 52, which are separate components coupled together by coupling mechanisms 60. Wing 51 includes keycap assembly pins 54 and pivot pins 55, and wing 52 includes keycap assembly pins 57 and pivot pins 56. Wings 51 and 52 may each include a cutout such that when wings 51 and 52 are coupled together, cavity 53 exists. Cavity 53 can have any suitable shape such as, for example, a square, a rectangle, circle, or ellipse.

0023Keycap assembly pins 54 and 57 are coupled to pin retaining mechanisms 22a, 22b of substructure 20. Pivot pins 55 and 56 are coupled to pivot pin retaining mechanisms 75 and 76, respectively, of support structure 70. The manner in which pins are coupled to substructure 20 and support structure 70 vary depending on specific examples, discussed below.

0024Coupling mechanisms 60, though coupling wings 51 and 52 together, may enable wings 51 and 52 to move independent of each other. Thus, if one wing were locked in a position, the other wing would be free to move, and vice versa. However, as will be explained in <figref idref="f0004 f0005"><b>FIGS. 4-5</b></figref>, wings 51 and 52 are both secured to support structure 70 and are operative to move (or flap) in concert with each other, with coupling mechanism 60 changing between substantially flat-shaped and v-shaped positions. Many different examples of coupling mechanisms 60 can be used with butterfly hinge 50. These examples are discussed in more detail in connection with the description below accompanying <figref idref="f0004 f0005"><b>FIGS. 4-5</b></figref><b>.</b> In other examples, coupling hinges 60 can be omitted from butterfly hinge 50.

0025Support structure 70 can be constructed from any suitable material or combination of different materials. The specific construction and materials used depends on particular key mechanism example being employed, and thus these notable features are discussed in more detail below. One notable feature of structure 70 shown in <figref idref="f0003"><b>FIG. 3</b></figref> is cutouts 77. Cutouts 77 are positioned in predetermined positions on structure 70 so that pin retaining mechanism 22 of substructure 20 can fit into a respective cutout when the key mechanism is in its depressed position. This nestling of components within each other during a keystroke helps key mechanism 12 maintain its relatively thin z-height.

0026Referring now to <figref idref="f0004"><b>FIGS. 4A-4B</b></figref>, illustrative partial cross-sectional views of key mechanism 12 are shown in a non-depressed position (<figref idref="f0004"><b>FIG. 4A</b></figref>) and depressed position (<figref idref="f0004"><b>FIG. 4B</b></figref>)<b>.</b> Both figures show keycap 14, pin retaining mechanism 22a, 22b of substructure 20, wing 51 with pivot pin 55 and keycap assembly pin 54, wing 52 with pivot pin 56 and keycap assembly pin 57, coupling member 60, switch 40, support structure 70, and pivot pin retaining members 75 and 76. Other components of key mechanism 12 have been omitted to provide less cluttered figures and to promote ease of discussion.

0027<figref idref="f0004"><b>FIGS. 4A-4B</b></figref> also show keycap plane 400, pivot pin plane 410, and structure plane 420. Regardless of whether key mechanism 12 is in its depressed or non-depressed state, the position of pivot pin plane 410 and structure plane 420 remain fixed, as indicated by the set of double arrows demarcating the z-height (shown as Zfixed) between the two planes in both figures. The z-height between keycap plane 400 and the structure plane 420, however, changes depending on the position of key mechansim 12. In the depressed position, the z-height is Zdepressed, as shown, and in the non-depressed position, the z-height is Znon-depressed.

0028Pivot pin retaining mechanisms 75 and 76 are operative to securely hold pivot pins 55 and 56 in place, while enabling pivot pins 55 and 56 to rotate within pivot pins retaining mechanisms 75 and 76. Keycap assembly pin 57 is coupled to pin retaining mechanism 22a, which can secure keycap assembly pin 57 to substructure 20 (not shown) in a manner similar to how pivot pin retaining mechanisms 75 and 76 secure their pins. Thus, pin retaining mechanism 22a may rotate when keycap 14 is undergoing a keystroke. Keycap assembly pin 54 can be coupled to pin retaining mechanism 22b, which is operative to enable keycap assembly pin 54 to slide horizontally within the pin retaining mechanism as key mechanism 12 travels up and down. Thus, the pin retaining system uses three sets of pin retaining mechanisms (one set for each pair of pins 57, 56, and 55) for securing rotating pins 57, 56, and 55 in place with minimal horizontal movement, and a fourth set (for pins 54) for securing sliding pins 54 in place with a fixed amount of horizontal movement. Additional aspects and features on the retaining mechanisms are discussed in more detail below for various different examples.

0029Referring collectively now to <figref idref="f0004"><b>FIGS. 4A-4B</b></figref> and <figref idref="f0005"><b>FIGS. 5A-5C</b></figref>, wings 51 and wings 52 pivot about their own respective pivot axes. Wing 51 pivots about axis 510, which runs co-axially with the center axis of pivot pins 55, and wing 52 pivots about axis 520, which runs co-axially with the center axis of pivot pins 56. Since pivot pins 55 and 56 are secured in position with respect to structure 70 (as shown by fixed z-height Zfixed), it is the outer portions of wings 51 and 52 (particularly at keycap assembly pins 54 and 57) that move relative to pivot pins 55 and 56.

0030In the non-depressed position, switch 40 is in its natural unbuckled position. In this position, switch 40 biases keycap 14 upwards when key mechanism 12 is not being subjected to a keystroke event. With the upward bias of switch 40, it pushes keycap 14 up, resulting in having pin retaining mechanism 22a, 22b pull keycap assembly pins 54, 57 of wings 51, 52 up. Since, pivot pins 55 and 56 are secured in place, wings 51 and 52 pivot about their own respective pivot axes 510 and 520, and keycap assembly pin 57 remains fixed in position, keycap assembly pin 54 slides horizontally to the left (shown here as the -X direction) within pin retaining mechanism 22b. As shown, in the non-depressed position, wings 51 and 52 resemble a v-shaped hinge, with its outer portions (e.g., pin regions 57 and 54) raised relative to pin plane 410.

0031In the depressed position, switch 40 is buckled, and keycap 14 has moved down vertically, thereby pushing the outer portions of wings 51 and 52 down towards support structure 70. Pins 57, 56, and 55 are secured in place and rotate within their secured positions, whereas keycap assembly pin 54 slides horizontally within its retaining mechanism in the +X direction. As shown in <figref idref="f0004"><b>FIGS. 4A-4B</b></figref>, the relative position of keycap assembly pin 54 moves to the +X direction when the key mechanism 12 is in the depressed position. Moreover, in the depressed position, wings 51 and 52 resemble a log shaped hinge, with all pins 54-57 in substantially the same plane.

0032Use of the butterfly hinge 50 in key mechanism 12 provides not only a low travel keystroke, but a stable key mechanism. The double wing design of butterfly hinge 50 distributes loading evenly with respect to the keycap assembly. The evenly distributed loading is accomplished by placing the load bearing keycap assembly pins 57 and 54 at the outer portions of wings 51 and 52, respectively. This stable loading is translated to keycap 14 because regardless of where a user presses down on keycap 14, the load will be distributed across the key, resulting in a tactically desirable and non-wavering keystroke.

0033Referring now to <figref idref="f0006 f0007 f0008 f0009 f0010 f0011 f0012 f0013 f0014 f0015 f0016"><b>FIGS. 6-16</b></figref>, a low travel key mechanism according to an example is discussed. Features discussed above in connection with <figref idref="f0002 f0003 f0004 f0005"><b>FIGS. 2-5</b></figref> apply to similar features discussed in connection with <figref idref="f0006 f0007 f0008 f0009 f0010 f0011 f0012 f0013 f0014 f0015 f0016"><b>FIGS. 6-16</b></figref>, however, notable features will be discussed in more detail. <figref idref="f0006"><b>FIG. 6</b></figref> shows an illustrative top view of key mechanism 612, showing keycap 614 and a few internal features shown by solid lines, although the components may be hidden. In particular, substructure 620 (with integrated light guide panel) and LED 648 are shown by solid line, but may be hidden by keycap 614.

0034<figref idref="f0007"><b>FIG. 7</b></figref> shows an illustrative exploded view of key mechanism 612. As shown, key mechanism 612 can include keycap 614, substructure 620, web 630, electronic package 642, butterfly hinge 650, support structure 670, and cover plate 680. Support structure 670 includes pivot pin retaining members 675 and 676. Cover plate 680 can be a printed circuit board or a heat spreader. <figref idref="f0008"><b>FIG. 8</b></figref> shows an illustrative perspective view of the bottom of keycap 614 and substructure 620, with substructure 620 secured to keycap 614. In this example, substructure 620 doubles as a pin retaining structure and a LGP. The LGP aspect of substructure 620 is evident in that it occupies a majority of the surface area of keycap 614 and includes notch 624 for enabling a light source, such as LED 648, to fit adjacent to the LGP.

0035As shown, substructure 620 has pin retaining mechanisms 622a and 622b located near the corners of keycap 614. Pin retaining mechanisms 622a are operative to securely couple pins and allow the pins to rotate freely within. In particular, pin retaining mechanisms 622a can be c-clip retaining members. Pin retaining mechanisms 622b are operative to slidably couple pins therein. That is, the pins are retained within the mechanism, but are allowed to slide horizontally within the mechanism when the key mechanism is undergoing a keystroke event. Pin retaining mechanism 622b can have an extruded L-shape that extends a minimum distance sufficient to contain the sliding pin. Note that both pin retaining mechanisms 622b may face each other. It is understood that any suitable number of different configurations of pin retaining mechanisms 622b can be used to achieve the desired coupling effect.

0036<figref idref="f0009"><b>FIG. 9</b></figref> shows an illustrative perspective bottom view of electronics package 642. Electronics package can include switch 640, which is mounted to flexible printed circuit board (PCB) 643, connector portion 644, support portion 645, and LED 648. In other examples, electronics package 642 can include a display such as OLED display. Referring to both <figref idref="f0009"><b>FIGS. 9</b></figref> and <figref idref="f0010"><b>10</b></figref>, electronics package 642 is mounted to substructure 620. In this arrangement, the base of switch 640 is pressed against substructure 620, and LED 648 fits within notch 624 (<figref idref="f0008"><b>FIG. 8</b></figref>). Support portion 645 floats relative to PCB 643 via connector portion 644 and surrounds keycap 614 and substructure 620. Thus, when key mechanism 612 is assembled, the nipple side of switch 640 faces downward towards support structure 670 (not shown), and passes through cavity 653 of butterfly hinge 650 (shown in <figref idref="f0011"><b>FIG. 11</b></figref>). In addition, when assembled, support portion 645 can align with web 630 (<figref idref="f0007"><b>FIG. 7</b></figref>) and both web 630 and support portion 645 can be secured to support structure 670 (<figref idref="f0007"><b>FIG. 7</b></figref>).

0037<figref idref="f0011"><b>FIG. 11</b></figref> shows an illustrative top view of butterfly hinge 650. Butterfly hinge 650 includes wings 651 and 652. No coupling mechanisms are shown coupling wings 651 and 652 together in this detailed view. Wing 651 can include pivot pins 656, keycap assembly pins 657, and upstop members 658. Wing 652 can include pivot pins 655, keycap assembly pins 654, and upstop members 659. Both wings 651 and 652 are shaped so that cavity 653 exists when the wings are placed adjacent to one another. Pivot pins 655 and 656 and upstop members 658 and 659 extend away from the outside surface of butterfly hinge 650, whereas keycap assembly pins 654 and 657 extend within butterfly hinge 650. Pivot pins 655 and upstop members 659 may be coplanar with each other and extend about the same distance away from butterfly hinge 650. Similarly, pivot pins 656 and upstop members 658 may be coplanar with each other and extend about the same distance away from butterfly hinge 650.

0038<figref idref="f0012"><b>FIG. 12</b></figref> shows an illustrative top view of support structure 670. Support structure 670 has pivot pin retaining members 675 and 676, and upstops 678 and 679. Pivot pin retaining members 675 and 676 are operative to secure pivot pins 655 and 656, respectively, in place but enable the pins to rotate freely within. Pivot pin retaining members 675 and 676 may be c-clip types of retaining members. Upstops 678 and 679 may be hook shaped members operative to engage upstop members 658 and 659, respectively. Upstops 678 and 679 ensure that wings 651 and 652 do not travel up beyond a pre-determined vertical distance when key mechanism is in its natural, un-depressed position. Support structure 670 can also include cutouts 677.

0039<figref idref="f0013"><b>FIG. 13</b></figref> shows an illustrative top view of butterfly hinge 650 coupled to support structure 670. In this view, pivot pins 655 and 656 are secured to support structure 670 via pivot pin retaining members 675 and 676, respectively, and upstop members 658 and 659 are positioned under upstops 678 and 679, respectively. <figref idref="f0013"><b>FIG. 13</b></figref> also shows how end portions (centered around keycap assembly pins 654 and 657) are positioned over cutouts 677. <figref idref="f0016"><b>FIG. 15</b></figref> shows an illustrative cross-sectional view of key mechanism 612, showing the interaction of pivot pins 655 and 656 with pivot pin retaining members 675 and 676 and, upstop members 658 and 659 with upstops 678 and 679.

0040<figref idref="f0014 f0015"><b>FIGS. 14A-14B</b></figref> show perspective views of alternative support structures according to various examples. In particular, <figref idref="f0014"><b>FIG. 14A</b></figref> shows a different retaining member configuration for securing butterfly hinge 650 to support structure 1400. Support structure 1400 includes c-clip retaining members 1422, and hook retaining members 1432 for retaining pins of a butterfly hinge (not shown). Structure 1400 also includes upstop members 1440.

0041<figref idref="f0015"><b>FIG. 14B</b></figref> shows support structure 1450 that includes pivot pin retaining member 1462 and upstop members 1470. Pivot pin retaining member 1462 is a one piece construction including two circular eyes for holding pivot pins. Pivot pin retaining member 1462 can have a spring loaded bias to press against the butterfly hinge when its pivot pins are secured within the eyes.

0042<figref idref="f0016"><b>FIG. 16</b></figref> shows another illustrative cross-sectional view of key mechanism 612 in a non-depressed position. This view shows switch 640 in a non-buckled position, wings 651 and 652 in a v-shaped arrangement, pin retaining mechanisms 622a, 622b, keycap assembly pins 657 and 654, and other components.

0043<figref idref="f0017"><b>FIGS. 17-19</b></figref> show various illustrative views of another key mechanism according to an example. In particular, <figref idref="f0017"><b>FIG. 17</b></figref> shows an illustrative perspective view of key mechanism 1712 in a non-depressed position. <figref idref="f0017"><b>FIG. 18</b></figref> shows a cross-sectional view taken along line 18-18 in <figref idref="f0017"><b>FIG. 17</b></figref><b>.</b> And <figref idref="f0017"><b>FIG. 19</b></figref> shows an illustrative perspective view of key mechanism without a keycap assembly. Key mechanism 1712 exhibits many of the same attributes of the generic key mechanism of <figref idref="f0002 f0003 f0004 f0005"><b>FIGS. 2-5</b></figref>, but includes more details regarding its hinge and support structure. As shown in <figref idref="f0017"><b>FIG. 17</b></figref>, key mechanism 1712 can include keycap 1714, laminate layer 1716, substructure 1720, switch 1740, butterfly hinge 1750, and support structure 1770.

0044Butterfly hinge 1750 can include wings 1751 and 1752. Wing 1751 can include pivot pins 1755 and keycap assembly pins 1754. Wing 1752 can include pivot pins 1756 and keycap assembly pins 1757. Keycap assembly pins 1754 and 1757 are coupled to substructure 1720, and pivot pins 1755 and 1756 are coupled to support structure 1770. Pivot pins 1755 and 1756 are secured within slots 1775 and 1776 of support structure 1770. Slots 1775 and 1776 may be cavities in the structure 1770 that are covered by laminate material 1716. In some examples, laminate material 1716 can be the same as a web (such as web 30). In effect, laminate material 1716 locks pivot pins 1755 and 1756 in place within support structure 1770. In this example, pivot pins 1755, 1756 and keycap assembly pins 1754, 1757 all extend away from butterfly hinge 1750.

0045Switch 1740 can fit in a cavity existing between wings 1751 and 1752, as shown. In this particular example, the base of switch 1740 can reside on support structure 1770, as opposed to being fixed to substructure 1720. When key mechanism 1712 is in its non-depressed position, switch 1740 is in its unbuckled state and props or biases the keycap assembly up. When key mechanism 1712 is in its depressed position, switch 1740 will be buckled and wings 1751 and 1752 will be pressed down in a log shaped position, with all pins 1754, 1755, 1756, 1757 in substantially the same plane.

0046Each wing can include upstops 1910, which are operative to limit the up-travel of the wings when the key mechanism is in its undepressed position. Upstops 1910 may engage laminate layer 1716 in the undepressed position. Upstops 1910 may be shaped at an angle to enable flush interfacing with the laminate layer.

0047<figref idref="f0018 f0019 f0020 f0021 f0022"><b>FIGS. 20-28</b></figref> show various illustrations of a key mechanism 2012 using a carrier plate according to an example. References to key mechanism 2012 include all <figref idref="f0018 f0019 f0020 f0021 f0022"><b>FIGS. 20-28</b></figref>, with occasional specific reference to individual figures. The carrier plate, as opposed to the structural support is responsible for securing the pivot pins of the butterfly hinge in place. In addition, the carrier plate can also support an electronic package. Referring now to <figref idref="f0018"><b>FIG. 20</b></figref>, there is shown an exploded view of key mechanism 2012. Key mechanism 2012 can include keycap 2014, substructure 2020, carrier plate 2090, electronics package 2042, switch 2040, butterfly hinge 2050, web 2030, and circuit board 2080. Components discussed earlier in connection with <figref idref="f0002 f0003 f0004 f0005"><b>FIGS. 2-5</b></figref> may share characteristics with similar components of key mechanism 2012. For example, keycap 2014 and substructure 2020 and its interaction with keycap assembly pins of butterfly hinge 2050 is similar to how keycap 14 and substructure 20 interact with butterfly hinge 50.

0048Carrier plate 2090 is constructed to fit within cavity 2053 (<figref idref="f0019"><b>FIG. 21</b></figref>) of butterfly hinge 2050 and be secured to circuit board 2080. Carrier plate 2090 can be secured to circuit board 2080 in any number of suitable different ways. For example, it can be glued or welded to circuit board 2080. As another example, carrier plate 2090 can have several posts that extend from a bottom surface of the carrier plate and engage with corresponding cavities in circuit board 2080. As yet another example, carrier plate 2090 can be secured in place with two or more clips 2802, as shown in <figref idref="f0022"><b>FIG. 28</b></figref><b>.</b> When carrier plate 2090 is secured to circuit board 2080, it secures pivot pins 2056 and 2055 in place so that they are free to rotate in place within pivot pin retaining members 2095 and 2096. The pin arrangement of butterfly hinge 2050 is shown in more detail in <figref idref="f0019"><b>FIG. 21</b></figref>, and the pivot pin retaining members of carrier plate 2090 is shown in more detail in <figref idref="f0019"><b>FIGS. 22</b>, <b>23</b></figref>, <figref idref="f0020"><b>24</b>, and <b>25</b></figref>.

0049Butterfly hinge 2050 can include two wings 2051, 2052 connected together using a coupling mechanism (not shown). Any suitable coupling mechanism can be used. Various examples of such coupling mechanism are described in more detail below. Cavity 2053 can exist between the two wings 2051, 2052 when placed adjacent to each other.

0050Carrier plate 2090 can be constructed from any suitable material such as metal or plastic. The construction of carrier plate 2090 can include a flat plate 2091, which is flanked by two raised arm members 2092. Each raised arm member 2092 can include pivot pin retaining member 2095 and pivot pin retaining member 2096. In addition, each raised arm member 2092 can include two upstop protrusions 2099. Upstop protrusions 2099 are operative to engage upstops 2059 of butterfly hinge 2050 when key mechanism 2012 is in its non-depressed position. Protrusions 2099 prevent wings 2051, 2052 of butterfly hinge 2050 from traveling beyond a fixed vertical up direction.

0051Flat plate 2091 can serve as a platform for electronics package 2042, which can include among other features, switch 2040, LED, light guide panel, display, and/or flex circuitry. This arrangement promotes easy connections between circuit board 2080 and electronics package 2042 because carrier plate 2090 is directly connected to circuit board 2080. This is in contrast to the flex printed circuit board example associated with key mechanism 612 (described earlier). Moreover, as shown in this example, switch 2040 is mounted such that its dome is facing substructure 2020 and keycap 2014. Thus, when switch 2040 is in its unbuckled position, it is operative to bias keycap 2014 and substructure 2020 upwards.

0052Referring now to <figref idref="f0021"><b>FIGS. 26</b> and <b>27</b></figref>, there are shown pin retaining mechanisms 2022a, 2022b of substructure 2020 interfacing with keycap assembly pins 2054 and 2057. In particular, <figref idref="f0021"><b>FIG. 27</b></figref> shows the different pin retaining mechanisms, pin retaining mechanism 2022a for securing keycap assembly pin 2054 in place so that it rotates in place, and pin retaining mechanism 2022b for enabling keycap assembly pin 2057 to slide horizontally when key mechanism 2012 is being depressed.

0053<figref idref="f0023 f0024 f0025 f0026 f0027 f0028"><b>FIGS. 29-33</b></figref> show several different butterfly hinge examples that can be used in conjunction with a key mechanism. Each of the examples discussed in connection with <figref idref="f0023 f0024 f0025 f0026 f0027 f0028"><b>FIGS. 29-33</b></figref> include two wings that are coupled together with a coupling mechanism. The nature of the coupling mechanism varies and can include two general types: living hinge and gear hinge. A living hinge coupling mechanism can be a flexible material or combination of materials that physically attaches the two wings together. A gear hinge is a coupling mechanism built into the wings themselves that allows for a gear-like interaction between the wings.

0054<figref idref="f0023"><b>FIGS. 29A-29B</b></figref> show illustrative top and partial perspective views of butterfly hinge 2900 in accordance with an example. Hinge 2900 includes wings 2910 and 2920 coupled together with living hinge 2930. Wings 2910 and 2920 can include pins as shown and can be made, for example, from a glass-filled plastic. Living hinge 2930 can be made from a plastic material that is softer than the material used to make the wings. Wings 2910 and 2920 also include self-locking structures 2912 and 2922.

0055Butterfly hinge 2900 can be manufactured using a double-shot process, wherein the first shot creates wings 2910 and 2920, and the second shot forms living hinge 2930. When the second shot is applied, it self-locks itself to self-locking structures 2912 and 2922 to couple wings 2910 and 2920 together. Note that the thickness of living hinge 2930 is substantially thinner at center axis 2940 of butterfly hinge 2900 than at other portions of living hinge 2930. The thinner section at the junction between wings 2910 and 2920 can promote ease of flexing between wings 2910 and 2920.

0056<figref idref="f0024"><b>FIGS. 30A-30B</b></figref> show illustrative top and perspective views of butterfly hinge 3000 in accordance with an example. Butterfly hinge 3000 can be manufactured by insert molding wings 3010 and 3020 around living hinge 3030. Molded wings 3010 and 3020 can include the pins, as shown. Living hinges 3030 can be part of a metal strip 3050 containing several living hinges 3030 (as shown in <figref idref="f0024"><b>FIG. 30C</b></figref>). Including several living hinges 3030 on a single strip can increase manufacturing throughput of butterfly hinge 3000. After wings 3010 and 3020 are molded on to strip 3050, the strip can be cut away to yield an individual butterfly hinge 3000 that is suitable for use in a key mechanism. Wings 3010 and 3020 can be constructed, for example, with a plastic such as a glass filled plastic.

0057Living hinge 3030 can be a relatively thin piece of metal (e.g., steel) that is operative to bend to enable wings 3010 and 3020 to move when used in a key mechanism. Living hinge 3030 can include retention features 3012 and 3014 to promote adhesion to the wings when the wings are molded thereto. When wings 3010 and 3020 are molded onto strip 3050, shutoffs can be used to prevent wings from completely covering living hinge 3030, thereby leaving a portion of living hinge 3030 exposed.

0058<figref idref="f0025"><b>FIGS. 31A-31C</b></figref> show various views of butterfly hinge 3100 in accordance with an example. Butterfly hinge 3100 can be constructed by coupling metal wings 3110 and 3120 together with an injection molded living hinge 3130. Wings 3110 and 3120 can be constructed from a die cast or forged metal. In one example, wings can be formed from a zinc die cast. In this example the pins are also formed in the die cast or forged metal. Wings 3110 and 3120 can be constructed to have retention features 3112 and 3122 to assist living hinge 3130 retention. Living hinge 3130 can be any suitable compliant material capable of bending. For example, living hinge 3130 can be constructed from a plastic or rubber material.

0059<figref idref="f0026"><b>FIGS. 32A-32C</b></figref> show illustrative views of butterfly hinge 3200 in accordance with an example. Butterfly hinge 3200 can be constructed from two metal cores 3201 and 3202 (shown by hidden lines) that are overmolded with a molding material. The molding material fully encapsulates metal cores 3201 and 3202 to form wings 3210 and 3220, which each include pins formed by the overmold, and living hinge 3230. Cores 3201 and 3202 can be separate metal components with retention features 3205 incorporated therein. Retention features 3205 can enable the injected molded material to self-lock itself to cores 3201 and 3202.

0060Living hinge 3230 can be formed from the overmold that couples cores 3201 and 3202 together. It can be sized to be relatively narrow at the junction between wings 3210 and 3220 to promote ease of movement. Hinge 3200 can be constructed in batch fashion in that strip 3250 can contain several cores. The cores can be overmolded and then die cut to yield each butterfly hinge 3200.

0061In another example (not shown), a butterfly hinge can be constructed from two metal cores, having forged or die cast pins, that are at least partially overmolded with a molding material, but in a way so that the pins are left exposed. This way, the metal pins are exposed and formed from metal, as opposed to an injection molded plastic. A living hinge is formed from the injection molded plastic coupling the two cores together.

0062<figref idref="f0027 f0028"><b>FIGS. 33A-33B</b></figref> show illustrative views of butterfly hinge 3300 in accordance with an example. Hinge 3300 includes wings 3310 and 3320 that each include pins and upstops, as shown. Wing 3310 has gear members 3315 and wing 3320 has gear members 3325. Gear members 3315, 3325 interface with each other to form a gear hinge.

0063Referring to <figref idref="f0028"><b>FIG. 33B</b></figref>, a close up of the gear hinge is shown. In particular the teeth of the gear members are shown. Wing 3310 has upper tooth 3315U and lower tooth 3315L, and wing 3320 has lower tooth 3325L and upper tooth 3235U. Upper tooth 3315U interfaces with lower tooth 3325L and upper tooth 3325U interfaces with lower tooth 3315L. This upper/lower tooth configuration can promote coupling of wings 3310 and 3320 when used in a key mechanism.

0064<figref idref="f0029"><b>FIG. 34</b></figref> shows an illustrative exploded view of a key mechanism in accordance with an example. Key mechanism 3412 can include keycap 3414, substructure 3420, web 3430, butterfly hinge 3450, switch housing 3459, membrane 3460 with switch 3440, and feature plate 3470. Components discussed previously in connection with <figref idref="f0002 f0003 f0004 f0005"><b>FIGS. 2-5</b></figref> may share characteristics with similar components of key mechanism 3412. For example, keycap 3414 and substructure 3420 and its interaction with keycap assembly pins 3454, 3457 of butterfly hinge 3450 is similar to how keycap 14 and substructure 20 interact with butterfly hinge 50.

0065Butterfly hinge 3450 can include two wings 3451, 3452 connected together using a coupling mechanism (not shown). Any suitable coupling mechanism can be used. For example, living hinges or gear hinges can be used to connect wings 3451, 3452 together. Cavity 3453 can exist between the two wings 3451, 3452 when placed adjacent to each other. Pivot pins 3455, 3456 extend within cavity 3453 of butterfly hinge 3450, whereas keycap assembly pins 3454 and 3457 extend away from an outside surface of butterfly hinge 3450.

0066Switch housing 3459 is constructed to fit within cavity 3453 of butterfly hinge 3450 and be secured to feature plate 3470. Switch housing 3459 can be secured to feature plate 3470 in any number of suitable different ways. For example, switch housing 3459 can be glued or welded to feature plate 3470. As another example, heat staking can be used to secure switch housing 3459 to feature plate 3470 using studs 3472. Alternatively, pins (not shown) on switch housing 3459 can couple with studs 3472 (e.g., snap into studs).

0067Pivot pins 3455 and 3456 are secured to switch housing 3459 using pivot pin retaining members 3495 and 3496. Pivot pin retaining members 3495 and 3496 can be cavities or openings formed through the sides of switch housing 3459. Pivot pin retaining members 3495 secure pivot pins 3455 on wing 3451 and pivot pin retaining members 3496 secure pivot pins 3456 on wing 3452. Once secured, pivot pins 3455, 3456 are free to rotate in place within pivot pin retaining members 3495, 3496.

0068The keycap assembly pins 3454 on wing 3451 couple to pin retaining mechanisms 3422a of substructure 3420, and keycap assembly pins 3457 on wing 3452 couple to pin retaining mechanisms 3422b of substructure 3420.

0069Feature plate 3470 can be constructed from any suitable material such as metal or plastic. Membrane 3460 can be secured to feature plate 3470, for example, with pressure sensitive adhesive 3465. Switch 3440 can be implemented as a deformable or rubber dome switch in some examples. Switch 3440 is connected to membrane 3460, which can include the circuitry for switch 3440. Switch 3440 can be connected to membrane 3460 in any number of suitable different ways. For example, an adhesive layer can be used to secure switch 3440 membrane 3460. Switch 3460 is configured to fit into opening 3497 formed through the bottom surface of switch housing 3459. Moreover, as shown in this example, switch 3440 is mounted such that its dome is facing substructure 3420 and keycap 3414. Thus, when switch 3440 is in its unbuckled position, it is operative to bias keycap 3414 and substructure 3420 upwards.

0070Membrane 3460 includes openings 3461, 3462, 3463, and 3464 and PSA 3465 includes openings 3466, 3467, 3468, and 3469. Feature plate 3470 includes openings 3473 and 3474. Openings 3463, 3468, and 3473 and openings 3464, 3469, and 3474 align with respective arms of the wings 3451 and 3452 of butterfly hinge 3450. Openings 3461 and 3466 and openings 3462 and 3467 align with the outer portions of respective wings 3451 and 3452.

0071<figref idref="f0030"><b>FIGS. 35A-35B</b></figref> show respective illustrative cross-sectional views of the key mechanism of <figref idref="f0029"><b>FIG. 34</b></figref> in a non-depressed position and depressed position in accordance with an example. <figref idref="f0030"><b>FIG. 35A</b></figref> shows switch 3440 in a non-buckled position, wings 3451 and 3452 in a v-shaped arrangement, pin retaining mechanisms 3422a, 3422b, keycap assembly pins 3457 and 3454, and other components. In this position, switch 3440 can bias keycap 3414 upwards.

0072In the depressed position shown in <figref idref="f0030"><b>FIG. 35B</b></figref>, switch 3440 is buckled, and keycap 3414 has moved down vertically, thereby pushing the outer portions of wings 3451 and 3452 down towards feature plate 3470. Keycap assembly pin 3454 is secured in place and rotated within its secured position, whereas keycap assembly pin 3457 slides horizontally within its retaining mechanism in the +X direction. As shown in <figref idref="f0030"><b>FIGS. 35A-35B</b></figref>, the relative position of keycap assembly pin 3457 moves to the +X direction when the key mechanism 3412 is in the depressed position. Moreover, in the depressed position, wings 3451 and 3452 over-travel using openings 3461, 3466 and 3462, 3467, respectively to resemble a slightly inverted "v". In <figref idref="f0030"><b>FIG. 35A</b></figref>, wings 3451 and 3452 are positioned to resemble a "v" shape, whereas in <figref idref="f0030"><b>FIG. 35B</b></figref> wings 3451 and 3452 have moved to a position that resembles a "Λ" shape with the inner portions of the wings 3451, 3452 moved upwards toward substructure 3420. Wings 3451 and 3452 articulate up and nest against or within substructure 3420. For example, a cavity can be formed in the bottom of substructure 3420 for at least the portions of wings 3451 and 3452 connected together by coupling mechanisms. Nesting of the wings 3451, 3452 allows the key mechanism 3412 to travel or depress a greater distance.

0073Referring now to <figref idref="f0031 f0032"><b>FIGS. 36-39</b></figref>, there are shown various illustrative bottom views of a keycap mechanism in accordance with an example. The bottom element of the keycap mechanism, such as a feature plate or circuit board, is not shown in the figures for clarity. <figref idref="f0031"><b>FIG. 36</b></figref> depicts a square key mechanism that includes one switch (not shown; switch is attached to membrane 3660). For example, key mechanism 3612 can be used for an alphanumeric key mechanism, a page up and page down key mechanism, an arrow (< or >) key mechanism, and/or an end or home key mechanism in a keyboard. The key mechanism includes one butterfly hinge formed with wings 3651 and 3652 connected together by coupling mechanism 3630. The switch in switch housing 3659 is disposed in the cavity formed by wings 3651 and 3652 of the butterfly hinge.

0074A rectangular key mechanism is illustrated in <figref idref="f0031"><b>FIG. 37</b></figref><b>.</b> Key mechanism 3712 can be used, for example, for the tab, shift, enter, and/or the backspace key mechanisms in a keyboard. Key mechanism 3712 includes a butterfly hinge formed with wings 3751 and 3752 coupled together by coupling mechanism 3730. Switch housing 3759 is positioned in the cavity formed between the wings 3751 and 3752. Switch housing 3759 includes a switch (not shown) secured to a membrane 3760. Retaining mechanisms 3750 secure rods 3785 to wings 3751 and 3752. Rods 3785 can be formed with any suitable material, examples of which include steel and carbon rods. Rods 3785 extend substantially across the width of the outer portions of wings 3751 and 3752. When keycap 3714 is depressed, rods 3785 transfer the force across the wings 3751 and 3752. Thus, if a user depresses key mechanism 3712 at or near an edge or corner of key mechanism 3712, keycap 3714 will substantially maintain its horizontal position as the keycap travels downward, which can ensure the switch is depressed properly.

0075<figref idref="f0032"><b>FIG. 38</b></figref> depicts a larger rectangular key mechanism. The larger rectangular key mechanism 3812 can be used, for example, for the spacebar key mechanism in a keyboard. Key mechanism 3812 includes two butterfly hinges 3816 and 3818. Each butterfly hinge is formed with wings 3851 and 3852 coupled together by coupling mechanism 3830. Switch housing 3859 is positioned between the two butterfly hinges 3816 and 3818 and runs between wings 3851 and 3852 of butterfly hinges 3816 and 3818. Near the center of key mechanism 3812, switch housing 3859 includes a switch (not shown) secured to a membrane 3860. Retaining mechanisms 3850 secure rods 3885 to wings 3751 and 3752 of butterfly hinges 3816 and 3818. Rods 3785 extend substantially across the width of the outer portions of wings 3751 and 3752 and can transfer a depressing force at or near an edge or corner of key mechanism 3812 over the width of a respective butterfly hinge.

0076<figref idref="f0032"><b>FIG. 39</b></figref> illustrates another larger rectangular key mechanism. Key mechanism 3912 includes two butterfly hinges 3916 and 3918. Each butterfly hinge is formed with wings 3951 and 3952 coupled together by coupling mechanism 3930. Switch housing 3859 is positioned between the two butterfly hinges 3816 and 3818. Stiffener plates 3970 are attached to wings 3951 and stiffener plates 3980 are attached to wings 3952 of butterfly hinges 3916 and 3918. Stiffener plates 3970 and 3980 extend substantially across the width of the outer portions of wings 3951 and 3952 and increase the stiffness of key mechanism 3912. LGP 3990 and 3995 can be positioned at each end of key mechanism 3912.

0077Referring now to <figref idref="f0033"><b>FIG. 40</b></figref>, there is shown an illustrative view of a half-butterfly hinge in accordance with an embodiment. <figref idref="f0033"><b>FIG. 41</b></figref> shows an illustrative bottom view of a key mechanism with a half-butterfly hinge in accordance with an embodiment. The bottom element of the keycap mechanism 4112, such as a feature plate or circuit board, is not shown in the figures for clarity.

0078In some embodiments, a half-butterfly hinge can be included in key mechanisms having smaller keycaps. Other embodiments can include one or more half-butterfly hinge in larger keycaps. Half-butterfly hinge 4050 includes wing 4051 adjacent to wing 4052. One full or major arm of wing 4051 is connected by coupling mechanism 4030 to a corresponding major arm of wing 4052. The shorter or minor arms of wings 4051 and 4052 are secured to switch housing 4059 at 4056 and 4058. The minor arms can be connected to switch housing 4059 by any suitable means. For example, a pivot pin (not shown) can extend out from the inner surfaces of the minor arms and secure into corresponding openings or slots in the switch housing.

0079Keycap assembly pins 4054 and 4057 extend away from an exterior surface of wings 4051 and 4052, respectively. Keycap assembly pins 4054 and 4057 can attach to a keycap or substructure using pin retaining mechanisms 4122a and 4122b (<figref idref="f0033"><b>FIG 41</b></figref>). Switch 4040 is disposed in the cavity formed between wings 4051 and 4052.

0080Half-butterfly hinge 4050 can maintain the same travel distance as a butterfly hinge but in a smaller space. Additionally, key mechanism 4112 is stable when a user depresses a corner because the connection points 4056 and 4058 stabilize the key mechanism 4112 and transfer the applied force across wings 4051 and 4052. For example, if a user depresses a lower right corner of wing 4151, the force is transferred across the outer portion of wing 4151 to coupling mechanism 4130, which in turn transfers the force to wing 4152.

0081Referring now to <figref idref="f0034"><b>FIG. 42</b></figref>, there is shown an illustrative perspective view of a switch in accordance with an embodiment. Switch 4200 is a stacked dome switch that includes an upper conductive deformable structure 4205 and a lower conductive deformable structure 4210 disposed under the upper conductive deformable structure 4205. The upper and lower conductive deformable structures 4205 and 4210 can have any desired shape and can be made of any suitable conductive material. For example, both the upper and lower conductive deformable structures can be made of a metal. Alternatively, the upper conductive deformable structure 4205 can be made of a metal and the lower conductive deformable structure 4210 of a conductive elastomer such as a conductive rubber. When the switch is depressed, the upper conductive deformable structure 4205 compresses and can contact the lower conductive deformable structure 4210. The switch is closed or activated when the upper conductive deformable structure 4205 contacts the lower conductive deformable structure 4210.

0082<figref idref="f0034"><b>FIGS. 43-44</b></figref> depict cross-sectional views of switch 4200 of <figref idref="f0034"><b>FIG. 42</b></figref> in an embodiment. In <figref idref="f0034"><b>FIG. 43</b></figref>, upper conductive deformable structure 4205 is electrically connected to outer terminals 4302 and lower conductive deformable structure 4210 is electrically connected to inner terminals 4306. Outer and inner terminals 4302, 4306 connect to traces or leads that connect to other circuitry (not shown). The traces or leads can be disposed on or embedded within substrate 4308. When switch 4200 is in a relaxed or non-depressed state as shown, the switch is open or not activated because upper and lower conductive deformable structures 4205 and 4210 are not in contact with each other. When upper conductive deformable structure 4205 contacts lower conductive deformable structure 4210, the circuit path is complete and the switch is closed or activated.

0083Switch 4200 in <figref idref="f0034"><b>FIG. 44</b></figref> is similar in design and operation to the switch of <figref idref="f0034"><b>FIG. 43</b></figref> except for the shape of lower conductive deformable structure 4210. The upper conductive deformable structure in <figref idref="f0034"><b>FIGS. 43</b> and <b>44</b></figref> can provide the tactile feedback to a user while the lower conductive deformable structure can provide sound and/or feel to a key mechanism. The lower conductive deformable structure can be used to determine the travel distance of the key mechanism.

0084Referring now to <figref idref="f0035 f0036"><b>FIGS. 45-49</b></figref>, there are shown various illustrative bottom views of a keycap assembly in accordance with an embodiment. As described previously, a keycap assembly can be formed with a keycap secured to a substructure. In some embodiments, the keycap assembly can fit within the inner perimeter of another component, such as a web. The keycap assemblies shown in <figref idref="f0035 f0036"><b>FIGS. 45-49</b></figref> can be backlit with light, such as with an LGP.

0085<figref idref="f0035"><b>FIG. 45</b></figref> depicts a substructure 4520 that extends along the inner surface of the sides of keycap 4514 and includes two substructure components 4506, 4504 secured to two sides of the keycap 4514. Substructure components 4506, 4504 extend out from the sides of keycap 4514 into the inner bottom perimeter of keycap 4514. The substructure 4520 can be formed with any suitable material, such as, for example, a sheet metal. The substructure 4520 can be affixed to the sides of keycap 4514 by any suitable method. For example, substructure 4520 can be attached with an adhesive or welded to the sides of keycap 4514.

0086The first substructure component 4506 includes pin retaining mechanisms 4522a that are configured to couple to keycap assembly pins on a butterfly or half-butterfly hinge. Although not visible in <figref idref="f0035"><b>FIG. 45</b></figref>, second substructure component 4504 also includes pin retaining mechanisms configured to secure to keycap assembly pins on the butterfly or half-butterfly hinge. The pin retaining mechanisms are oriented toward the underside surface of keycap 4514 and can have any given shape. For example, in the illustrated embodiment, pin retaining mechanisms 4522a are configured as c-clip retaining members while pin retaining mechanisms of second substructure component 4506 can have an extruded L-shape similar to pin retaining mechanisms 622b shown in <figref idref="f0006"><b>FIG. 6</b></figref><b>.</b>

0087The keycap 4614 in <figref idref="f0035"><b>FIG. 46</b></figref> includes one or more pairs of opposing support shelves 4606 affixed to the inner surface of the sides of keycap 4614. Substructure 4620 extends between two opposing shelves 4606 and can be secured to a pair of opposing support shelves 4606 using any suitable attachment means. By way of example only, substructure 4620 can be bonded or welded to support shelves 4606.

0088Substructure 4620 includes pin retaining mechanisms 4622a and 4622b that couple with respective keycap assembly pins on a butterfly or half-butterfly hinge. In the illustrated embodiment, pin retaining mechanisms 4622a are c-clip retaining members and pin retaining mechanisms 4622b have an extruded L-shape similar to pin retaining mechanisms shown in <figref idref="f0006"><b>FIGS. 6</b></figref> and <figref idref="f0035"><b>45</b></figref><b>.</b>

0089Referring now to <figref idref="f0035"><b>FIG. 47</b></figref>, substructure 4720 is configured as a frame that extends along the underside surface perimeter of keycap 4714. Substructure 4720 can be made of any suitable material, such as a metal. Substructure 4720 is attached to the underside surface of keycap 4714 by any suitable method, such as with an adhesive or by welding. Substructure 4720 includes pin retaining mechanisms 4722a and 4722b that couple with respective keycap assembly pins on a butterfly or half-butterfly hinge. Pin retaining mechanisms 4722a and 4722b can be configured similarly to the pin retaining mechanisms shown in <figref idref="f0035"><b>FIGS. 45-46</b></figref><b>.</b>

0090In the embodiment of <figref idref="f0035"><b>FIG. 48</b></figref>, substructure 4820 is shaped like an "X" and extends across the underside surface of keycap 4814. Substructure 4820 includes pin retaining mechanisms 4822a and 4822b that couple with respective keycap assembly pins on a butterfly or half-butterfly hinge. In the illustrated embodiment, pin retaining mechanisms 4822a are c-clip retaining members and pin retaining mechanisms 4822b have an extruded L-shape similar to pin retaining mechanisms shown in <figref idref="f0035"><b>FIGS. 45-47</b></figref><b>.</b> Substructure 4820 can be made of any suitable material, such as a plastic, and can be attached to the underside surface of keycap 4814 by any suitable method.

0091<figref idref="f0036"><b>FIG. 49</b></figref> illustrates a sheet or plate substructure 4920 that is attached to the inner bottom surface of keycap 4914. Substructure 4920 includes pin retaining mechanisms 4922a and 4922b that couple with respective keycap assembly pins on a butterfly or half-butterfly hinge. The pin retaining mechanisms can be formed in any given shape and/or orientation. In the illustrated embodiment, pin retaining mechanisms 2922a are c-clip retaining members and pin retaining mechanisms 4922b have an extruded L-shape similar to pin retaining mechanisms shown in <figref idref="f0035"><b>FIGS. 45-48</b></figref><b>.</b>

0092Substructure 4920 can be made of any suitable material, such as a plastic, and can be attached to the underside of keycap 4914 by any suitable method. Substructure 4920 can include openings 4990 that emit light for a backlighting effect. In one embodiment, the light can be produced by an LED component and substructure 4920 can act as a LGP.

0093Referring now to <figref idref="f0037"><b>FIGS. 50-52</b></figref>, there are shown various illustrative cross-sectional views of a keycap assembly in accordance with an embodiment. Substructure 5020 includes pin retaining mechanisms 5022a and 5022b (<figref idref="f0037"><b>FIG. 50</b></figref>). As with the other embodiments described herein, pin retaining mechanisms 5022a and 5022b can be molded with, or affixed to substructure 5020. Keycap 5014 can be secured to substructure 5020 using any suitable method, such as an adhesive.

0094In <figref idref="f0037"><b>FIG. 51</b></figref>, pin retaining mechanisms 5122a, 5122b can be molded with, or affixed to beam 5130, which is secured to substructure 5120. Beam 5130 can be made of any suitable material, such as metal or plastic. Beam 5130 and keycap 5114 can be secured to substructure 5020 using any suitable method, including, but not limited to, an adhesive.

0095The substructure in <figref idref="f0037"><b>FIG. 52</b></figref> is separated into two components 5220 and 5221. Each component can be L shaped and attached to keycap 5214 in a spaced-apart relationship. Attachment component 5206 is disposed between the two L-shaped substructure components 5220 and 5221. Attachment component 5206 includes pin retaining mechanisms 5222a and 5222b, which can all be formed or molded in a single piece.

0096<figref idref="f0038"><b>FIG. 53</b></figref> shows an illustrative top view of a key mechanism in accordance with an embodiment. Key mechanism 5300 is single key that rocks about center axis 5306. Glyphs 5302 and 5304 indicate a function or operation of key mechanism. In the illustrated embodiment, glyph 5302 is an up arrow and glyph 5304 a down arrow. By way of example only, a user can press down on the up or down arrow to move a cursor displayed on a screen.

0097Key mechanism 5300 can be substantially horizontal when not depressed. If a user depresses the up arrow, the key mechanism rocks downward toward the up arrow. Similarly, the key mechanism rocks downward toward the down arrow when a user depresses the down arrow.

0098<figref idref="f0038"><b>FIG. 54</b></figref> shows an illustrative cross-sectional view of keycap assembly of <figref idref="f0038"><b>FIG. 53</b></figref> in accordance with an embodiment. Keycap 5414 is attached to structure 5470 through wings 5451 and 5452. Wings 5421 and 5422 can be included in a butterfly hinge or wings 5421, 5422 can be independent wings attached to structure 5470. A coupling mechanism can be omitted when the wings are included in a butterfly hinge to allow the wings and the key mechanism to be balanced with respect to the center axis (e.g., axis 5306).

0099Pin retaining mechanisms 5422a and 5422b on wings 5451 and 5452 secure keycap assembly pins 5454 and 5457, respectively. In the illustrated embodiment, pin retaining mechanisms 5422a, 5422b are attached to keycap 5414. Other embodiments can position pin retaining mechanisms 5422a, 5422b on a substructure that is attached to keycap 5412. Pivot pins (not shown) can be used to attach wings 5451 and 5452 to structure 5470. Switches 5440 are disposed under each glyph (not shown) on keycap 5414. Deformable structure 5490 can be disposed between wings 5421, 5422 to restrict the downward movement of keycap 5414 when depressed. For example, deformable structure 5490 can prevent keycap 5414 from activating both switches 5440 simultaneously or sequentially. Sequential activation of both switches is known as a double-click event.

0100Referring now to <figref idref="f0039"><b>FIGS. 55-57</b></figref>, there are shown illustrative perspective views of a method for forming a keycap in accordance with an embodiment. A first layer 5500 is bonded to a second layer 5502, as shown in <figref idref="f0039"><b>FIG. 55</b></figref><b>.</b> First layer 5500 can be a foil layer, such as an aluminum foil layer. The first layer can have a thickness that is less than 100 microns. In some embodiments, the foil layer has a thickness of approximately 50 microns. Second layer 5502 can be a resin or thermoplastic layer. The first and second layers can form a keycap in some embodiments, with the first layer forming the top surface of the keycap.

0101Glyph opening 5600 is formed in first layer 5500 to expose second layer 5502 (<figref idref="f0039"><b>FIG.</b> 56</figref>). Glyph opening 5600 can be formed, for example, by laser etching the top surface of first layer 5500. Pressure and/or heat can be applied to the first and second layers, causing second layer 5500 to flow into glyph opening 5600 <b>(</b><figref idref="f0039"><b>FIG 57</b></figref>). In one embodiment, second layer 5500 fills glyph opening 5600 to form a glyph 5700 on the top surface of a keycap. Although only one glyph is formed in the illustrated embodiments, the process depicted in <figref idref="f0039"><b>FIGS. 55-57</b></figref> can be used to produce one or more glyphs. The one or more glyphs can represent a letter, a number, a phrase, and a symbol, either individually or in various combinations. For example, on a QWERTY keyboard, the one or more glyphs can be formed on a keycap for a letter key mechanism, a number and symbol key mechanism, or a shift or tab key mechanism.

0102<figref idref="f0040 f0041"><b>FIGS. 58-61</b></figref> show illustrative perspective views of another method for forming a keycap in accordance with an embodiment. A first layer 5800 is bonded to a second layer 5802, as shown in <figref idref="f0040"><b>FIG. 58</b></figref><b>.</b> First layer 5800 can be a liner layer. Second layer 5802 can be a foil layer, such as an aluminum foil layer. The aluminum foil layer can have a thickness that is less than 100 microns. In some embodiments, the foil layer has a thickness of approximately 50 microns.

0103Glyph opening 5900 is formed in second layer 5802 to expose first layer 5800 (<figref idref="f0040"><b>FIG. 59</b></figref>). Glyph opening 5900 can be formed, for example, by laser etching the back surface of second layer 5500. A material 6000 is then deposited into glyph opening 5900 to fill glyph opening 5900 and form a glyph (<figref idref="f0041"><b>FIG. 60</b></figref>). For example, a liquid backfill can be performed to fill glyph opening 5900. Next, as shown in <figref idref="f0041"><b>FIG. 61</b></figref>, first layer 5800 is removed, leaving second layer 5802 and glyph 6002. The second layer and the glyph can form a keycap or a top surface of a keycap in some embodiments.

0104Various embodiments have been described in detail with particular reference to certain features thereof, but it will be understood that variations and modifications can be effected. For example, the switch can be constructed differently from the switch described herein. For example, the switch can include a first conductive structure positioned over a second conductive structure. The first conductive structure has a plunger that is positioned over the dome or top region of the second conductive structure. The switch is closed or activated when the plunger contacts the second conductive structure.

0105Even though specific embodiments have been described herein, it should be noted that the application is not limited to these embodiments. In particular, any features described with respect to one embodiment may also be used in other embodiments, where compatible. Likewise, the features of the different embodiments may be exchanged, where compatible.