Patent Publication Number: US-9430050-B2

Title: Touchsurface with level and planar translational travel responsiveness

Description:
RELATED APPLICATIONS 
     This application is related to and claims the benefit of priority of U.S. patent application Ser. No. 13/568,060, filed on Aug. 6, 2012, is related to and claims the benefit of priority of U.S. patent application Ser. No. 13/198,610, filed on Aug. 4, 2011, is related to and claims the benefit of priority of U.S. patent application Ser. No. 13/323,292, filed on Dec. 12, 2011, and claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/429,749, filed on Jan. 4, 2011 and U.S. Provisional Patent Application Ser. No. 61/471,186, filed on Apr. 3, 2011. 
    
    
     BACKGROUND 
     Depressible keys are widely used in a variety of input devices, including keypads for cellular phone, keyboards for laptop and desktop computers, and kiosks.  FIG. 1  illustrates a side elevation view of simplified key mechanics  100  of a conventional keyboard of a typical computer system. The key mechanics  100  include a key  110 , a collapsible elastomeric plunger (often called a “rubber dome”)  120 , a scissor-mechanism  130 , and a base  140 . 
     The scissor mechanism  130  includes at least a pair of interlocking rigid blades ( 132 ,  134 ) that connect the key  110  to the base  140  (which may or may not be part of the body of the keyboard). The interlocking blades move in a “scissor”-like fashion when the key  110  travels along its vertical path in the negative direction, as indicated by arrow  150 . 
     The scissor mechanism is disadvantageous in many ways. For example, it may add a degree of mechanical complexity to the key assembly, complicate manufacture and repair, obscure or complicate lighting of the key, and limit how thin a keyboard may be constructed. 
     SUMMARY 
     Described herein are one or more techniques related to a touchsurface with level and planar translational travel responsiveness. One or more of the described implementations include an input device having a rigid body including a touchsurface configured to travel along a depression path in response to being depressed by a user. The input device also includes a leveling mechanism that operates in manner to keep the touchsurface substantially level as the touchsurface travels along the depression path in response to being depressed by the user. Furthermore, the input device has a planar-translation-effecting mechanism that defines a planar translation component of the depression path, such that the touchsurface exhibits planar translation as the touchsurface travels along the depression path. 
     This Summary is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of simplified key mechanics of a conventional keyboard. 
         FIG. 2A  is a simplified elevation view of a first implementation of a touchsurface configured in accordance with the techniques described herein. The first implementation is an exemplary key assembly, and is shown in  FIG. 2A  in an unpressed, ready-to-be-pressed, position (i.e., ready position). 
         FIG. 2B  is an elevation view of the first implementation in a partially depressed position. 
         FIG. 2C  is an elevation view of the first implementation in a pressed position. 
         FIG. 3  is an isometric view of a second implementation configured in accordance with the techniques described herein. The second implementation is an exemplary key assembly, and is shown in an unpressed position. 
         FIG. 4  is top plan view that illustrates the second implementation. 
         FIG. 5  is a side elevation view that illustrates the second implementation. 
         FIG. 6  is an exploded isometric view that illustrates the second implementation. 
       Each of  FIGS. 7A and 8A  is a top plan view of the second implementation as shown in  FIG. 4 , with the key assembly shown in the ready position.  FIGS. 7A and 8A  include additional lines showing where cross-sections are taken for the cross-sectional views of the second implementation shown in  FIGS. 7B and 8B . 
       Each of  FIGS. 9A and 10A  is a top plan view of the second implementation as shown in  FIG. 4 , with the key assembly in a pressed position.  FIGS. 9A and 10A  include additional lines showing where cross-sections are taken for the cross-sectional views of the second implementation shown in  FIGS. 9B and 10B . 
         FIG. 11  shows several examples of ramp profiles that illustrate ramps that may comprise both leveling and planar-translation-effecting mechanisms. 
         FIGS. 12A, 12B, and 12C  are three different views of a keyboard that incorporates one or more implementations of key-based touchsurfaces configured in accordance with the techniques described herein.  FIG. 12A  is an isometric view,  FIG. 12B  is a top plan view, and  FIG. 12C  is a side elevation view. 
         FIG. 13  is an isometric view of a third implementation configured in accordance with the techniques described herein.  FIG. 13  depicts the third implementation in an unpressed, ready-to-be-pressed, position (i.e., ready position). 
         FIG. 14  is top plan view that illustrates the third implementation. 
         FIG. 15  is a side elevation view that illustrates the third implementation. 
         FIG. 16  is an exploded isometric view that illustrates the third implementation. 
         FIG. 17  is a cross-sectional view that illustrates the third implementation. 
         FIGS. 18A and 18B  show a cut-away portion of the third implementation as circled in  FIG. 17 .  FIG. 18A  shows the exemplary key assembly in its unpressed, ready position.  FIG. 18B  shows the exemplary key assembly in its pressed position. 
         FIG. 19  is an isometric view of a fourth implementation configured in accordance with the techniques described herein. The fourth implementation is an exemplary key assembly, and  FIG. 19  shows it in a pressed position. 
         FIG. 20  is top plan view that illustrates the fourth implementation. 
         FIG. 21  is an exploded isometric view that illustrates the fourth implementation. 
         FIGS. 22-25  show examples that illustrate one or more embodiments presented herein. 
     
    
    
     The Detailed Description references the accompanying figures. In the figures, the same numbers are used throughout the drawings to reference like features and components. 
     DETAILED DESCRIPTION 
     Described herein are one or more techniques related to a leveled touchsurface with planar translational responsiveness to vertical travel. That is, the techniques are related to effecting translation of the touchsurface along a depression path that includes a component along a press direction (also referred to as “vertical travel” in this application) and a component along a direction orthogonal to the press direction (also referred to as “planar translation” in this application). 
     Examples of touchsurfaces include a top surface of a key or button, an input surface of an opaque touchpad or a touchscreen, any other surface used for human-machine interactions, and the like. Additional example touchsurfaces are described later in this document. With the techniques described herein, the touchsurface can be kept in a level orientation, such that it does not substantially pitch, roll, or yaw when the touchsurface is moved from unpressed to depressed positions. The touchsurface may or may not pitch, roll, or yaw when it moves from pressed to unpressed positions. 
     Embodiments comprise leveling mechanisms that keep the touchsurface level when depressed, and planar-translation-effecting mechanisms that impart planar translation while the touchsurface travels “vertically” in response to pressing force. 
     At least one implementation described herein involves an ultra-thin keyboard with leveled keys having planar translational responsiveness to vertical travel. When a user presses a key, the key remains level in its orientation during its vertical travel. That is, the key (especially its touchsurface, located on the keytop) remains relatively level during its motion during the press. The leveling technology described herein reduces or eliminates any wobbling, rocking, or tilting of the keytop during a keypress. 
     A prototype key deflected only 0.036 mm when a force of forty grams was applied to a left side of the key. The deflection on both the left and right sides were measured and the magnitude of one was subtracted from the magnitude of the other to calculate the tilt deflection. With this test, the prototype key experienced about one-sixth of the tilt deflection of the conventional key. 
     With the techniques described herein, the touchsurface is configured to move along a depression path with components in a press direction and also in a plane orthogonal to the press direction. The depression path is the path followed by a reference point on the touch surface from unpressed to pressed positions. In some embodiments, the reference point is a central point, such as a center of mass, a geometric center, and the like. In some embodiments, the reference point is a location of press force application. 
     The press direction is the one that users consider “vertical” (often “downwards”) for the touchsurface. The press direction is often orthogonal to the touchsurface and towards an internal region of the system comprising the touchsurface. This overall touchsurface motion may be referred to as “diagonal”, since the overall motion includes both “vertical” and “lateral” components. This is even though the actual path following by the touchsurface may not be a straight line. Example paths may be linear, nonlinear, or piecewise linear. Thus, example paths may follow straight lines, arcs, simple or complex curves, etc. 
     In addition, at least as it travels downward along the depression path, the touchsurface is constrained from pitch and roll so that it stays level or substantially level in response to a press. Substantially level includes, for example, the touchsurface exhibiting little or no rotation, wobble, tilt, yawn, and the like while the touchsurface moves along the depression path in response to a press. Thus, average users pressing the touch surface do not perceive rotation, wobble, tilt, yawn, and the like of the touchsurface to a degree that distracts from the typical experience when, for example, typing on a conventional keyboard. 
     In some implementations, the touchsurface is more than substantially level. It is level. That is, at least as it travels downward along the depression path, the touchsurface is constrained in such a manner that the touchsurface exhibits little or no rotation, wobble, tilt, or yawn of any form when moving along the depression path in response to a press. In such implementations, typical human perception (e.g., visual or somatosensory perception) is unable to detect any rotation, wobble, tilt, yawn, or the like of the touchsurface without the aid of a mechanical or electronic device. 
     The examples herein often use a Cartesian coordinate system for ease of explanation. In this case, the press direction may be referred to as the “Z-direction,” “vertical,” or “down or up,” and the lateral directions may be referred to herein as the “X/Y”-direction, “horizontal,” “left or right”, “back and forth”, and “planar.” Often, the press direction is described as “downwards,” in the negative Z-direction. With this Cartesian coordinate system, the touchsurface configured in accordance with the techniques described herein translates in the X-Y plane even as it is pressed downwards in the negative Z-direction. In the embodiments described herein, this planar translation mostly focuses on translation in the positive-X direction. In various embodiments, the planar translation may comprise translation in the positive or negative X-direction, in the positive or negative Y-direction, or a combination thereof. 
     Using the Cartesian coordinate system, the touchsurface moves “diagonally” in response to a press by exhibiting movement that includes both a “Z” (or vertical) translation component as well as “X-Y” (or planar) translation components. The X-Y components together may be called “planar translation”, since it is within the X-Y plane. This planar translation occurs in response to the vertical travel of the touchsurface, and may be called “planar translational responsiveness to vertical travel” of the touchsurface (or “planar-translation-responsiveness-to-vertical-travel”). 
     In some embodiments, the touchsurface comprises a surface of a rigid body, such as that of a rigid rectangular body having greater width and breadth (i.e., X/Y dimensions) than depth (i.e., Z-dimension). In various embodiments, the touchsurface comprises a surface of a different shape, such as that of circles, trapezoids, and triangles, polygons with substantively rounded corners, etc. In various embodiments, the touchsurface comprises a surface of a pliant body. 
     The planar component of the planar translational responsiveness to vertical travel produces a tactile illusion of the touchsurface traveling a larger vertical distance than that which it actually travels. Moreover, after the downward press of the touchsurface, the touchsurface returns to its ready position using, for example, magnetic forces. The movement of the key against a user&#39;s finger as the key returns to its ready position also aids in the illusion. 
     For example, when the user presses an exemplary key on an embodiment of a keyboard employing the planar-translation-responsiveness-to-vertical-travel techniques described herein, the key travels in the negative Z-direction (e.g., down) a short distance (e.g., 0.5 to 1.0 millimeters) and returns that same distance when released. During its Z-direction travel, this exemplary key also travels in a lateral or planar direction (e.g., X/Y-direction) approximately the same distance. Of course, the planar direction of travel in proportion to the Z-direction travel may vary with differing implementations. 
     Although the key only traveled a shorter distance in the Z-direction, the user perceives that the exemplary key traveled a greater distance in the Z-direction. For example, in some embodiments, some users may perceive that the exemplary key traveled one-to-two or two-to-three times further in the negative Z-direction than the distance that the key actually did. That perception of extra Z-travel is due in large part to the tangential force imparted on the user&#39;s fingertip by the lateral or planar translation of the key during the Z-direction keypress. 
     The planar-translation-responsiveness-to-vertical-travel technology introduced herein takes advantage of a tactile perceptional illusion where a person misinterprets an atypical force experience of his fingertip as a typical force experience. For example, with the exemplary keyboard described above, when a person presses and releases a key of that keyboard, the person feels a force normal to his fingertip and tangential, lateral forces. These tangential forces are interpreted as normal forces by the person. In this way, the person obtains a “feel” of a typical key travel of the keys of the keyboard. This is so, at least in part, because most humans cannot somatosensorially perceive directionality for sufficiently small motions but can still perceive relative changes in force due to skin shear. 
     With the planar-translation-responsiveness-to-vertical-travel techniques discussed herein, the combination of normal and lateral forces exerted on the user&#39;s fingertip during a keypress simulates for the person a key that has traveled much farther in the negative Z-direction than it actually did. For example, a key of an exemplary keyboard with only a negative Z-direction key travel of about negative 0.8 mm and an appropriate amount of lateral motion may feel more like the key is traveling 1.5 mm, 2.0 mm, or more in the Z-direction. Consequently, thin keyboards of less than 3.0 mm thickness may be constructed without sacrificing the “feel” of a quality full travel keyboard. 
     Furthermore, the techniques described herein employ a ready/return mechanism designed to hold, retain, and/or suspend the key in a position where it is ready to be pressed by a user and also return the key back to its unpressed, ready-to-be-pressed (i.e., ready position) after the pressing force is removed. With at least one implementation described herein, this is accomplished by employing a set of magnets arrayed to be mutually attractive or attractive to ferrous material integrated with the key or base. The magnets hold the key in the ready position and pull the key back into the ready position after there is no longer a sufficient downward force to keep it pressed. Other embodiments may use any of a variety of other ready/return mechanisms. 
     While the implementations discussed herein primarily focus on a key and a keyboard, those of ordinary skill in the art should appreciate that other implementations may also be employed. Thus, descriptions associated with keys may be mapped to touchsurfaces other than those on keys. Examples of such non-key or non-keyboard implementations include those described later in this document. 
     Exemplary Key Assemblies 
       FIG. 2A  shows a simplified elevation view of an exemplary key assembly  200  in an unpressed, ready-to-be-pressed position (i.e., ready position).  FIGS. 2B and 2C  show the same key assembly  200  in its progression to a pressed position. The key assembly  200  is configured to implement the techniques described herein to provide a tactile user experience of a touchsurface (here, a key surface) with leveling, planar translation responsiveness to vertical travel. 
     The key assembly  200  includes a key  210 , a ready/return mechanism  220 , a leveling/planar-translation-effecting mechanism  230 , and base  240 . The key  210  is a specific implementation of the touchsurface that the user touches to interface with a computer. As discussed earlier, in other implementations, the touchsurface may be of something other than a key. 
     The components of the key assembly  200  may be made from any appropriate material, including plastics such as acetal, metals such as iron or aluminum, elastomers such as rubber, and the like. In various embodiments, the key  210  is configured to be substantially rigid, such that the touchsurface of the key  210  appears to unaided human senses to be in the same shape and to move without deformation, and with rigid body motion, to unaided human senses. 
     The ready/return mechanism  220  is configured to hold the key  210  in its ready position so that the key is ready to be pressed by a user. In addition, the ready/return mechanism  220  is configured to return the key  210  back into its ready position after the key  210  is depressed and released. As shown, the ready/return mechanism  220  accomplishes these tasks by the use of one or more pairs of magnets (stationary magnet  222  and key magnet  224 ) arranged to attract each other. In particular, the stationary magnet  222  is built into a perimeter of a bezel or housing defining a hole or space (which is not depicted in  FIGS. 2A-2C ) that receives the key  210  when depressed. The key magnet  224  is positioned in and/or under the key  210  in a manner that corresponds with the stationary magnet  222  and in a manner so that the two magnets  222 ,  224  are mutually attractive. 
     The mutual attraction of the magnets of the ready/return mechanism  220  holds the key  210  in its ready position as depicted in  FIG. 2A . Of course, alternative implementations may employ different mechanisms or combinations of mechanisms to accomplish the same or similar functionality. For example, alternative implementations may replace stationary magnet  222  or key magnet  224  with a ferrous, non-magnetic material such as various iron alloys. As additional examples, alternative implementations may employ electromagnets, springs such as compression or leaf springs, hydraulics, pneumatics, elastomeric material such as elastomeric domes, etc. In addition, implementations may push or pull the key  210  to return the key  210  to its ready position. Additional alternative ready/return mechanisms are discussed later in this document. 
     The amount of vertical force necessary to break the magnetical coupling can be customized based upon the size, type, shape, and positioning of the magnets involved. In some implementations, breakaway force ranges from forty to a hundred grams. 
     The key assembly  200  includes a leveling/planar-translation-effecting mechanism  230  located under the key  210 . Mechanism  230  is capable of performing both leveling and planar-translation-effecting functions. Thus, the mechanism  230  levels the key  210  and/or imparts a planar translation to the key  210  while it is depressed, depending on the details of the key assembly  200 . For the key assembly  200 , the leveling/planar-translation-effecting mechanism  230  includes multiple inclined planes or ramps (two of which are shown in  FIGS. 2A-2C ). The ramps are distributed about the perimeter of the underside of the key  210  in such a manner as to evenly support the key  210  when a pressing force is placed on the key. In this way, the surface of key  210  remains level during a keypress. 
     In at least one implementation, key  210  is a rectangular key, and mechanism  230  has four ramps, each positioned under one corner of the rectangular key. 
     In some implementations of mechanism  230 , at least one ramp is positioned in the interior region of the underside of the key  210  and provide interior support for the key surface. In some implementations of mechanism  230 , at least one ramp is positioned outside the periphery of the key  210 , and key  210  comprises extension arm(s) that ride and rest on the ramp. In various implementations of mechanism  230 , any number of ramps may be used with key  210 . For example, a rectangular key may be matched with three ramps, four ramps, five ramps, or other numbers of ramps. In some embodiments, other structures are positioned inside the perimeter of the underside of the key  210  to provide additional support to the key  210 . 
     As shown in  FIG. 2B  and as is typical of a key when pressed, the key  210  moves in a negative Z-direction when a pressing force  250  is applied to the top of the key  210 . In response, the key  210  moves in a lateral direction (motion in the X-direction is indicated in  FIG. 2 ) as well as in a vertical direction downwards. The key  210  rides the ramps of the leveling/planar-translation-effecting mechanism  230  downwards during the keypress, effectively using them as bearings. In so doing, the ramps impart a lateral force component and lateral motion, as represented by planar vector  252 , onto the key  210 . 
     In addition,  FIGS. 2B and 2C  show the magnets  222 ,  224  of the ready/return mechanism  220  separating in response to the translation of the key  210 . The attractive force of the magnets  222 ,  224  provides an additional degree of resistance to the initial keypress. This initial resistance and the ultimate breakaway of the magnets  222 ,  224  can be configured to contribute to the feel of the breakover portion of the snapover feel of a traditional full-travel key. A discussion of the snapover feel of a traditional full-travel key can be found in the co-owned U.S. Provisional Patent Application Ser. No. 61/429,749, filed on Jan. 4, 2011. 
       FIG. 2C  shows the key  210  depressed to an extent that the key  210  contacts the base  240  (or some other component that is not shown but disposed on the base  240 —such as a physical limiter, an electronic switch). Not shown in  FIG. 2C  is the sensor(s) used to detect that key  210  has been depressed. The sensor(s) may be based on any appropriate technology, including capacitive, resistive, inductive, and optical sensors, and also mechanical keyswitches. Thus, any suitable key switch or other sensor may be employed for the techniques described herein. 
     Furthermore, as part of a sensor system of one or more implementations, the  210  may have a conductive portion (e.g., the key magnet  224 ) as part of a capacitive keyswitch sensor system. Such a system may include a capacitive sensor electrode positioned underneath the key  210  so that the capacitive sensor electrode may capacitively couple with the conductive portion of the key and define a variable capacitance. The motion of the key as the key is pressed (i.e., along the depression path) changes the variable capacitance. 
     When the pressing force is removed (e.g. when the user lifts the pressing finger from the key  210 ) after the key  210  has been depressed, there is no longer a sufficient pressing force on the key  210  to keep it depressed. In that situation, the ready/return mechanism  220  returns the key  210  to its ready position as depicted in  FIG. 2A . The attractive forces between the magnets  222 ,  224  pulls the key  210  back up the ramps of the leveling/planar-translation-effecting mechanism  230 . Once the magnets  222 ,  224  return to their original position, the key  210  is in its ready position (as depicted in  FIG. 2A ) and the key  210  is ready to be depressed again. 
       FIG. 3  is an isometric view of another exemplary key assembly  300  configured to implement the techniques described herein and provide leveled touchsurface with planar translational responsiveness to vertical travel. The key assembly  300  includes a key podium  310  and a key  320 . As depicted, the key  320  is shown in its ready position relative to the podium  310 . In the ready position, the key  320  sits above the podium  310 . Indeed, the key  320  is suspended over and/or at least partially within a keyhole  312  (which is a key-shaped cavity) in the podium  310 . The key podium may also be called a keyframe or bezel. 
     From top to bottom, the key assembly  300  is about 2.5 mm thick. The key podium  310  is about 1.5 mm thick and the key  320  is about 0.75 mm thick. The key  320  is about 19 mm by 19 mm and the keyhole is slight larger at 19 mm by 20 mm. Of course, the dimensions may differ with other implementations. 
     Each of the double-headed arrows X/Y/Z, as shown in  FIG. 3 , indicate an axis of a three-dimensional Cartesian coordinate system that can be used to describe the motion of the key  320 . 
       FIG. 4  is a top plan view of the key assembly  300  with its podium  310  and key  320 . As seen from above, the keyhole  312  fits the key  320  snuggly except for one side where a lateral-movement gap  314  is shown. The gap  314  may be about 1.0 mm, and allows some space for the key  320  to travel laterally. In one or more implementations with such a gap, the dimension of the gap is just sufficient to allow for the planar translation. 
       FIG. 5  is a side elevation view of the key assembly  300  with its podium  310  and key  320 . 
       FIG. 6  is an exploded view of the key assembly  300  with its podium  310 , key  320 , and keyhole  312 . This figure also shows a key guide  610 , a podium magnet  620 , a key magnet  630 , and a key hassock  640 . 
     The key guide  610  is designed to fit into and/or under the key podium  310 . Where the key guide  610  is not integral with the key podium  310  in operation, the key guide  610  may be aligned with the key podium  310  in any appropriate way, including the use of various alignment features. Where the key guide  610  is integral with the key podium  310  in operation, the key guide  610  may be made as a separate piece that is later assembled with the key podium  310 . Any appropriate attachment method may be used, including adhering, snap fits or other mechanical interference fits, heat staking, fastening with mechanical fasteners, etc.  FIG. 6  shows guide-mounting tabs  612  and  614  of the key guide  610  fit into corresponding tab-receiving cavities in the podium  310 . One of such cavities is visible in  FIG. 6  at  615 . Alternatively, the key guide  610  and the key podium  310  may be formed as parts of the same piece of material. 
     In key assembly  610 , the podium magnet  620  is mounted into the key podium  310  by fitting the magnet into a recess  626  formed between the key guide  610  and the key podium  310 . In some embodiments, the recess  626  is smaller than the podium magnet  620 , and the podium magnet  620  is held in the recess  626  through a press fit. In some other embodiments, the recess  626  is as large as, or larger than, the podium magnet  620 , and the podium magnet is held in place by other means. The two magnetic poles of podium magnet  620  are illustrated as differently shaded sections  622  and  624 . The podium magnet  620  is mounted in such a way as to magnetically expose one pole (e.g., pole  624 ) to the interior of the keyhole  312 . That is, the magnets  620  is disposed such that magnetic field lines from the pole  624  extend toward the interior of the keyhole  312 . 
     While  FIG. 6  shows the podium magnet  620  as a single magnet, the podium magnet  620  may be an assembly comprising a plurality of magnets, and comprise more than one magnet. Where the podium magnet  620  comprises a plurality of magnets, that plurality of magnets may be called the “podium-magnet arrangement”. In various implementations, there may be two, three, or more magnets stacked together in a podium magnet arrangement. 
     The key magnet  630  is held in a recess under and/or in the key  320  using any appropriate method, including those discussed in conjunction with the podium magnet  620 . This key magnet  630  has two poles ( 632 ,  634 ). One pole ( 632 ) is magnetically exposed to the interior wall of the keyhole  312  when the key  320  is within and/or over the keyhole  312  (e.g., in the ready position). The pole  632  is opposite to the pole  624 . 
     While  FIG. 6  shows the key magnet  630  as a single magnet, the key magnet  630  may be an assembly comprising a plurality of magnets, and comprise more than one magnet. Where the key magnet  630  comprises a plurality of magnets, that plurality of magnets may be called the “key magnet arrangement”. In various implementations, there may be two, three, or more magnets in a key magnet arrangement. 
     Collectively, the key-magnet arrangement and the podium-magnet arrangement work together to keep the key  320  in a ready position, return the key  320  to the ready position, or both. Consequently, these magnet arrangements comprise a ready/return mechanism. In addition, the magnet arrangements may offer a degree of resistance to the initial downward force of a keypress. In this way, the magnet arrangements can contribute to the satisfactory approximation of a snap-over of a full-travel key of a keyboard. 
     Many variations on the ready/return mechanism of key assemble  300  are possible. For example, any of the key or podium magnets may be disposed so that the poles are aligned with the Y or Z axes, such that both poles are magnetically exposed to the interior of the keyhole. 
     For example, some embodiments may utilize a podium magnet arrangement comprising multiple magnets disposed at different locations around the keyhole  312  and at various Z-heights. Counterpart key magnets of a key magnet arrangement may be disposed in appropriate matching locations. This plurality of matching magnets may be configured to facilitate lateral translation of the key during a press or release, adjust the path of travel during a press or release, increase the attraction force, shape the magnetic forces applied at different points of the path of travel, etc. 
     As another example, the ready/return mechanism may comprise non-magnetic components instead, or in addition to, the podium magnet  620  and the key magnet  630 . As a specific example, the podium magnet  620  or the key magnet  630  may be replaced by a ferrous material. As yet another example, the ready/return mechanism may be based on techniques other than magnetic attraction, such as any of the other ready/return techniques described herein. 
     The key hassock  640  is attached to the underside of, and at a central region, of the key  320 . In this case, the hassock  640  has dual purposes. First, the hassock  640  aids in making a clean and reliable contact with a key switch (which is not shown) when the key  320  is fully pressed. The hassock  640  provides an unobstructed flat area for facilitating detection of keypresses. Where the key assembly  300  utilizes capacitive sensing technology for sensing key presses, the hassock  640  may also contain electrodes for facilitating sensing. Where the key assembly  300  utilizes membrane switch technology for sensing key presses, the hassock  640  may be configured with proper shapes and cushioning responses to provide reliable switch closure of a membrane keyswitch in response to key presses. Second, the hassock  640  provides a predetermined amount of cushioning (or lack thereof) at the bottom of the keypress to provide a satisfactory tactile response, such as an approximation of a snap-over associated with a full-travel key of a keyboard. Other implementations may use other techniques for sensing a key press and providing tactile feedback, including any of the examples described herein, which may or may not utilize a key hassock. 
     The key  320  has a set of key-retention tabs  661 ,  662 ,  663 ,  664  that are designed to retain the key in the ready position. In the ready position, the key-retention tabs  661 ,  662 ,  663 ,  664  fit into corresponding tab-receiving cavities in the formed cavities between the podium  310  and the key guide  610 . Portions of three of such cavities are visible in  FIG. 6  at  616 ,  618  and  619 . Cavities  616  and  618  are designed to receive key-retention tabs  661  and  662 . Cavity  619  is designed to receive key-retention tab  664 . Podium  310  acts as a retaining component that covers these cavities and captures the tabs therein, such that the key podium is more likely to stay in the ready position. 
     The key guide  610  has a key-guiding mechanism  650  built therein. The key-guiding mechanism  650  is a type of combination leveling/planar-translation-effecting mechanism. The key-guiding mechanism  650  includes key-guiding ramps  652 ,  654 ,  656 , and  658 . These ramps are positioned towards the four corners of the key guide  610 . Not shown in  FIG. 6 , inverse and complementary ramps are built into the underside of key  320 . For ease of explanation, the ramps of key guides (and similar components) are referred to as “ramps,” and the ramps of the keys (and similar components) are referred to as “chamfers” herein. 
     The key&#39;s chamfers slide down the key-guiding ramps during a downward keypress. Regardless of where on the key  320  that a user presses, the chamfer-ramp pairings in each corner keep the key  320  steady and level during a keypress. Therefore, the chamfer-ramp pairings level the key  320  and is a leveling mechanism, and may be called the key leveler. 
     A structure, such as a guide and rail system, may be used to further limit movement of the key  320  in the X or Y direction and/or rotation about the Z-axis. An arm structure  670  of the key guide  610  functions as a rail system to limit X-direction or Y-direction movement and rotation about the Z-axis. In an exemplary guide and rail system, protrusions such as pins extending from the key  320  is configured to ride on the rail system. 
     In general, the purpose of the key leveler is to reduce or eliminate wobbling, rocking, or tilting (pitch, yaw, roll rotation) of the key during a keypress. In the key assembly  300 , the arm structure  670  and the mating key-retention tabs and cavities function, at least in part, to help prevent the rotation of the key  320  about the Z-axis. 
     In addition, the chamfer-ramp pairings effectively translate at least some of the user&#39;s downward force into lateral force. Thus, the chamfer-ramp pairings convert the negative Z-direction force of the key  320  into both negative Z-direction (vertical) and X/Y direction (lateral) movement. Since the key-guiding mechanism  650  also translates negative Z-direction (i.e., vertical) force into X/Y direction (i.e., planar) movement, the key-guiding mechanism  650  may also be called a vertical-to-planar force translator. 
       FIGS. 7B and 8B  are cross-sectional views of the key assembly  300  with the key  320  shown in its ready position.  FIG. 7B  shows the cross-section taken at about the center of the key assembly (which is along line A-A as shown in  FIG. 7A ).  FIG. 8B  shows the cross-section taken off-center of the key assembly (which is along line B-B as shown in  FIG. 8A ). For context, in these drawings, a user&#39;s finger  710  is shown hovering over the key  320  shortly prior to pressing down on the key. 
     The vast majority of parts and components of the assembly  300  shown in  FIGS. 7A, 7B, 8A, and 8B  were introduced in  FIG. 6 . The cross-sectional view shows the arrangement of those already introduced parts and components. 
     As depicted in both  FIGS. 6 and 7B , the pole of the exposed end  632  of the key magnet  630  is the polar opposite of the exposed end  624  of the podium magnet  620 . Because of this arrangement, the key magnet  630  of the key  320  is attracted towards magnet  620  of the key podium  310 . Consequently, the magnetic attractive forces hold the key  320  against the podium  310  with sufficient force such that the key  320  is substantially horizontal even though it is held in a cantilevered fashion in its ready position. This cantilevered arrangement of the ready position of the key  320  is depicted in at least  FIG. 7B . 
     In addition to the parts and components of the assembly  300  introduced in  FIG. 6 ,  FIG. 7B  introduces a backlighting system  720  with one or more light emitters  722 . The lighting sources of the backlighting system  720 , as depicted, are implemented with a light emitter  722  per key. A light bulb is used to represent the light emitter  722  in  FIG. 9B , although light emitter  722  may be realized with components other than light bulbs in practice, and although implementation of the backlighting system  720  may involve no light bulbs. 
     Key lighting systems can be implemented using any suitable technology. By way of example and not limitation, light can be provided by light generators such as light bulbs, LEDs, OLEDs, LCDs or other displays, and/or electroluminescent panels to name just a few. In addition, light may be directed from a light generator by light guides such as light pipes and fiber optic mats. For example, some implementations use a light guide in the form of a sheet of material underlying the keys. One or more light emitters are disposed on the sheet, on one or more sides of the sheet, or both. The sheet may comprise a reflective backing to better guide the light. The sheet may comprise light diffusers located under keys to direct light outwards through the keys, or proximate keys to direct light outwards between or around the keys. 
     In some embodiments, the backlighting system is configured such that different keys are backlit differently, with different colors, brightness, intensities, locations in the key, etc. The processing system communicatively coupled to and used to operate the backlighting system may also be configured to dynamically change these or other backlighting parameters over time. This dynamic backlighting can be used to provide information to a person viewing the backlighting, including providing feedback for particular user input (such as lighting up in response to a touch or press on a key), highlighting particular keys that are pressed or may be pressed, indicating system status, etc. 
     In various embodiments, the backlighting of the keys employing the techniques described herein is facilitated by none or few light-impeding obstructions between the light source (e.g., backlighting system  720 ) and the key (e.g. key  320 ). For example, backlighting of keys employing the techniques described herein need not accommodate scissor mechanisms found in conventional keyboards. Consequently, the light emanating from below the key  320  reaches the keytop of the key  320  with little or insignificant impedance, or at least with less impedance as compared to various conventional keyboards. This can allow, for example, key legends to be illuminated for the user. 
       FIG. 8B  shows, in cross-section, two of the chamfers  810 ,  812  built into the underside of key  320 . Chamfer  810  is the inverse of the ramp  658  of the key guide  610 , and faces the ramp  658 . Similarly, chamfer  812  is the inverse of the ramp  654  of the key guide  610 , and faces the ramp  654 . The other ramps  652 ,  656  also face matching chamfers (not shown). When a pressing force is imposed upon the key  320  by, for example, finger  710 , the key  320  rides the key guide  610  down to the bottom of the keyhole  312 . More precisely, the chamfers and ramps working together convert at least some of the downward (i.e., negative Z-direction) force on the key  320  into a planar or lateral force on the key  320 . Consequently, the key  320  moves downward into the keyhole  312  and moves laterally into the lateral-movement gap  314 . 
     Alternatively, the key  320  have pins instead of chamfers; in this scenario, each pin (or plurality of pins) matched to a ramp would ride along the corresponding ramp of the key guide  610 . With this approach, multiple keys in the same device can be made the same, saving on design and tooling costs. Also, key guides for different keys may comprise ramps with different ramp profiles. These different ramp profiles may be configured to provide different tactile responses for the different keys. 
     Alternatively still, the key guide  610  may have pins instead of ramps; the chamfers of the key  320  would then ride on corresponding pins. With this approach, different keys may be produced with chamfers having differing chamfer profiles, enabling reconfigurable profiles by swapping out keys. 
       FIGS. 9B and 10B  are cross-sectional views of the key assembly  300  with the key  320  shown in a pressed position after a press.  FIG. 9B  shows the cross-section taken at a center of the key assembly (along line A-A as shown in  FIG. 9A ).  FIG. 10B  shows the cross-section taken off-center of the key assembly (along line B-B as shown in  FIG. 10A ). For context, in these drawings, the user&#39;s finger  710  is shown pressing the key  320  down into the keyhole  312 . 
       FIGS. 9A, 9B, 10A, and 10B  correspond to  FIGS. 7A, 7B, 8A, and 8B , respectively. While  FIGS. 7A, 7B, 8A, and 8B  show the key  320  in its ready position (where it is positioned over and/or in the keyhole  312 ) in anticipation of a keypress,  FIGS. 9A, 9B, 10A, and 10B  show the key  320  at the end of a keypress and thus at the end of the keyhole  312 . For the sake of simplicity, the backlighting system is shown only in  FIGS. 7B and 9B . 
     As shown in  FIGS. 9B and 10B , a negative Z-direction force (as indicated by vector  920 ) applied by finger  710  onto the key  320  imparts an X/Y-direction movement (as indicated by vector  922 ) on the key  320 . The X/Y-direction movement results from lateral forces resulting from the vertical-to-planar force translator. In key assembly  300 , the vertical-to-planar force translator is implemented by the chamfer-ramp relationships of the key  320  to the key guide  610 . This force translation is based on the reactive normal force from the ramp including a component in the X/Y direction. 
     In the embodiment shown in  FIGS. 7-10 , when the user lifts the finger  710  from the key  320 , the magnetic attraction between the opposite poles ( 632  and  624 ) of the key and podium magnets ( 630  and  620 ) pulls the key  320  back up the ramps  652 ,  654 ,  656 ,  658  to its ready position. That is, when the pressing force is released from the key  320 , the key  320  moves from the position depicted in  FIGS. 9A, 9B, 10A, and 10B  to the ready position depicted in  FIGS. 7A, 7B, 8A, and 8B . 
     As described above, the key guide  610  is fixed under the podium  310  in this embodiment. The key  320  moves both laterally (X/Y-direction) and vertically (Z-direction) in response to a press and when returning to its ready-position. 
     In other embodiments, the key guide is configured to move laterally while the key is constrained to move substantially vertically. With this alternative scenario, the downward press on the key does not cause lateral motion of the key. Instead, the key&#39;s downward motion applies a lateral force on ramps of the key guide and pushes the key guide to move laterally. A ready/return mechanism based on similar principles to those disclosed herein may be used to returns the key guide  610  to its original position and the key  320  to its ready position. 
     This alternative implementation may be used in various embodiments. For example, in some embodiments this alternate implementation of the laterally moving key guide is used where the touchsurface is a touchpad. In that situation, the user may press down on the touchpad to select an on-screen button, icon, section action, or any other action associated with the press of a pointing device button. In response to the press, the touchpad translates substantially vertically and pushes a touchpad guide with the ramps, analogous to the laterally-moving key guide with ramps discussed earlier, so that the guide slides in a lateral direction. When sufficient press force is removed, the ready/return mechanism based on similar principles to those disclosed herein may be used to urge the guide back into its original position and pushes the touchpad back to its ready position. 
     Exemplary Ramp Profiles 
       FIG. 11  shows various examples of ramp profiles  1110 ,  1120 ,  1130 ,  1140 ,  1150  that may be employed in various implementations using ramps. In at least some implementations, the ramp profile is the depression path of the touchsurface. 
     A ramp profile is the outline or contour of a cross section of the active surface of the ramps and/or chamfers used for the leveling/planar-translation-effecting mechanisms. In practice, the ramp profile informs or describes the motion of a touchsurface during its travel in response to a press and release, including any planar translation of the touchsurface (if the system is configured such that the touchsurface moves laterally in response to a press, or planar translation of a touchsurface guide if the system is configured such that the guide moves laterally in response to a press). 
     Each ramp profile  1110 ,  1120 ,  1130 ,  1140 ,  1150  actually shows two different profile options. For example, profile  1120  shows a first option to the left of the curve, and a second option to the right of the curve. Also, in some embodiments, different profiles that do not perfectly mesh are used for ramps for a guide and chamfers for a touchsurface. However, for ease of explanation here, the profile to the left of the curve is the one used on a ramp associated with a guide, the profile on the right is the one used on a chamfer associated with a touchsurface. Also, the discussion below presents comparisons between the profiles if they were of the same size. Thus,  FIG. 11  shows a first exemplary ramp profile  1110  with a single-angle acute slope, a second exemplary ramp profile  1120  with a roll-off slope, a third exemplary ramp profile  1130  with a stepped slope, a fourth exemplary ramp profile  1140  with a scooped slope, and a fifty exemplary ramp profile  1150  with a radius slope, and has the shape of an arc of a circle. 
     The first exemplary ramp profile  1110  offers even and steady planar motion throughout the downward travel of the touchsurface. An angle  1112  between a base and the inclined surface of the ramp may be set at any appropriate value, including a value between thirty-five and sixty-five degrees, such as forty-five degrees. The shallower that the angle  1112  is set, the more planar translation occurs for a given amount of vertical travel. In some embodiments, if the angle  1112  is too shallow, it may be difficult for a user to move the touchsurface effectively when pressing down on it. Conversely, in some embodiments, if the angle  1112  is too steep, the leveling of the key may be compromised. 
     The second exemplary ramp profile  1120  provides more of a snap or breakaway feel at the rollover portion of the ramp than would generally be felt with the first exemplary ramp profile  1110 . 
     The feel of a ramp with the third exemplary ramp profile  1130  is similar to the feel of the second exemplary ramp profile  1120 , but the snap or breakaway feel is generally more dramatic. 
     As compared to the feel of a ramp with the first exemplary ramp profile  1110 , the feel of a ramp using the fourth exemplary ramp profile  1140  is softer and, perhaps described by some as “spongy.” 
     The feel of a ramp using the fifth exemplary ramp  1150  is similar to that of the stepped profile  1130  but with a smoother transition. That is, there is less snap to the feel. 
     The profiles depicted in  FIG. 11  are informative of the behavior and/or feel of the planar-translational responsiveness of a touchsurface using such profiles. Of course, there are a multitude of alternative variations and combinations of the profiles depicted. In addition, many alternative profiles differ significantly from the ones depicted. In some embodiments, a single keyboard may employ a plurality of different ramp profiles in order to provide different tactile responses for different keys. 
     Exemplary Keyboard 
       FIGS. 12A-12C  offer three different views of an exemplary keyboard  1200  that is configured to implement the techniques described herein.  FIG. 12A  is an isometric view of the exemplary keyboard  1200 .  FIG. 12B  is top plan view of the exemplary keyboard  1200 .  FIG. 12C  is a side elevation view of the exemplary keyboard  1200 . As depicted, the exemplary keyboard  1200  has a housing  1202  and an array of keys  1204 . 
     The exemplary keyboard  1200  is exceptionally thin (i.e., low-profile) in contrast with a keyboard having conventional full-travel keys. A conventional keyboard is typically 12-30 mm thick (measured from the bottom of the keyboard housing to the top of the keycaps). The exemplary keyboard  1200  has a thickness  1206  that is less than that, such as 4.0 mm thick (measured from the bottom of the keyboard housing to the top of the keycaps). With other implementations, the keyboard may be less than 4.0 mm, such as 3.0 mm, 2.5 mm, or 2.0 mm. 
     The exemplary keyboard  1200  may employ a conventional keyswitch matrix, based on membrane switch technology. The key switch matrix may be located under the keys  1204  and arranged to signal a keypress when the users presses associated keys down firmly. Alternatively, the exemplary keyboard  1200  may employ other keypress detection technology. 
     The exemplary keyboard  1200  is a peripheral keyboard, and is not an integrated pointing device. Alternative implementations may be integrated within the housing or chassis of a mobile phone, laptop computer, or any other device. 
     A keyboard employing the techniques described herein may or may not have its keys placed in a contaminate-collecting depression like the keyboard trough found in many keyboards. As shown by the exemplary keyboard  1200  in  FIG. 12 , the keys  1204  are not located in a depression or trough. 
     The exemplary keyboard  1200  may be integrated with a handheld or laptop computing device with a mechanism that drops the keys  1204  into their respective keyholes when the lid of the laptop is closed. Such dropping mechanism may include a tether that pulls each key from its ready position into its keyhole. Alternatively, such a mechanism may involve shifting or moving of the podium magnets of each key so that such podium magnet no longer retains the key in the ready position. Consequently, each key will drop into their respective keyholes. 
     Various embodiments enable this drop capability utilize designs that produces little or no undue mechanical wear and tear on the keys or other components. For example, magnets of the keys  1204  may be used to provide the returning force to the ready position, much as in response to the release of a user-applied pressing force. Thus, when the screen/lid is lifted, the keys  1204  snap up into their ready position in response to the tension of the tether being released and/or the podium magnet is restored to its original position. Various embodiments may augment a non-contact mechanism such as magnets with other mechanisms, or use other mechanisms. 
     Other Exemplary Key Assemblies 
       FIG. 13  is an isometric view of still another exemplary key assembly  1300  configured to implement the techniques described herein to provide a satisfying tactile user experience using passive tactile response. The key assembly  1300  includes a key podium  1310  and a key  1320 . Notice that the key  1320  sits above the podium  1300 . Indeed, the key  1320  is suspended over (and/or partially in) a key-shaped hole  1312  (“keyhole”) in the podium  1310 . 
     In an embodiment of the  FIG. 13  example, the key assembly  1300  is about 2.5 mm thick from top to bottom. The key podium  1310  is about 1.5 mm thick and the key  1320  is about 0.75 mm thick. The key  1320  is about 19 mm by 19 mm and the keyhole is slightly larger at 19 mm by 20 mm. Of course, the dimensions may differ with other implementations. 
       FIG. 14  is a top plan view of the key assembly  1300  with its podium  1310  and key  1320 . As seen from above, the key-shaped hole  1312  fits the key snuggly except for one side where a gap exists (about 1.0 mm in some embodiments). This gap in the keyhole  1312  allows the key  1310  room for its lateral travel. 
       FIG. 15  is a side elevation view of the key assembly  1300  with its podium  1310  and key  1320 . 
       FIG. 16  is an exploded view of the key assembly  1300  with its podium  1310  and key  1320 . 
       FIG. 17  is a cross-section of the key assembly  1300 , with the cross-section being taken at the center of the key assembly  1300 . For context, a user&#39;s finger  1710  is shown hovering over the key  1320  in anticipation of pressing down on the key. 
     The views of  FIGS. 16 and 17  show three magnets ( 1610 ,  1620 ,  1630 ) which were not exposed in the previous views of the assembly  1300 . Magnets  1610  and  1620  are stacked together and disposed (such as by a press fit) into a form-fitting recess  1314  of the key podium  1310 . As depicted in both  FIGS. 16 and 17 , the magnet  1620  is stacked atop the magnet  1610  with the poles of one magnet ( 1622 ,  1624 ) directly over the opposite poles ( 1612 ,  1614 ). This arrangement locates the opposite poles of magnets to provide attractive forces. 
     The podium magnets are mounted into the podium  1310 . One pole (e.g.,  1622 ) of the upper magnet  1620  and an opposite pole (e.g.,  1614 ) of the lower magnet  1610  of the magnet stack are magnetically exposed to the interior of the keyhole  1312 . 
     Analogous to the discussion presented for the key assembly  300 , the two magnets  1610  and  1620  may be collectively called the “podium magnet arrangement,” and there may be any number of magnets in the podium magnet arrangement (including fewer or more than the two shown in  FIG. 16 ), arranged in any appropriate way to provide appropriate magnetic forces. 
     As depicted in both  FIGS. 16 and 17 , the key  1320  includes a keycap  1322  and key base  1324 . The key base  1324  includes a key leveler  1326 . In some implementations, the key leveler  1326  may be a biased component, configured to provide motion and reaction forces along particular axes. The key leveler  1326  keeps the key relatively level during its negative Z-direction travel. Other leveling mechanisms and approaches may be employed in combination or in alternative implementations. In one example alternative, magnets may be distributed around the periphery of the keyhole  1312  to hold the key  1320  and to facilitate an even breakaway in response to a downward force. Other leveling approaches are discussed later in this application. 
     A key magnet  1630  is snugly mounted/inserted into a form-fitting recess  1328  of the key base  1324 . The recess  1328  is shown in  FIG. 16 . This key magnet  1630  has two poles ( 1632 ,  1634 ). One pole ( 1634 ) is magnetically exposed to the interior walls of the keyhole  1312 . 
     For the purpose of the planar-translation-responsiveness-to-vertical-travel technology described herein, the pole  1634  of the exposed end of the key magnet  1630  is the opposite of the pole  1622  of the exposed end of the top magnet  1620  of the podium magnet arrangement. The magnet  1630  of the key  1320  is attracted towards magnet  1620  of the podium  1310 . Consequently, the magnetic attractive forces hold the key  1320  tightly against the podium  1310  and in a cantilevered fashion over and/or partially in the keyhole  1312 . This cantilevered arrangement is depicted in  FIG. 17 . 
     Collectively, the key-magnet arrangement and the podium-magnet arrangement of the key assembly  1300  forms a ready/return mechanism that simulates a snap-over feel, similar to that of the second implementation. 
       FIGS. 18A and 18B  show a cut-away portion  1720  as circled in  FIG. 17 .  FIG. 18A  shows the components of the key assembly  1300  as they are arranged in  FIG. 17 . The key  1320  is operatively associated via magnetic attraction to the key podium  1310 . An attraction  1810  between the opposite poles ( 1634 ,  1622 ) of the key magnet  1630  and the top podium magnet  1620  is indicated by a collection of bolt symbols ( ) therebetween. 
       FIG. 18B  shows the same components of the assembly  1300  but after a downward force (represented by a vector  1820 ) imparted on the key  1320  by a user&#39;s finger has moved the key  1320  downwards in the negative Z-direction. The downward force breaks the attraction  1810  between the key magnet  1630  and the top podium magnet  1620 . 
     As the key  1320  travels downward, it is also pushed laterally by a magnetic repulsive force between the like poles ( 1634 ,  1614 ) of the key magnet  1630  and lower podium magnet  1610 . The repulsion  1822  between the magnets is represented in  FIG. 18 b    by an arrow and a collection of bolt symbols ( ). 
     With this arrangement, the user&#39;s experience of a keypress can be made similar to the feel of a snap-over. The key assembly  1300  can be configured to simulate the feel of a breakover point of a rubber dome, and the release of the key  1320  from the magnetic hold can be made to feel similar to the collapsing of a rubber-dome. 
     The sidewalls of the keyhole  1312  act as guide to the key  1320  during the key&#39;s negative Z-direction travel. The gap between the key  1320  and the key podium  1310 , which is located away from the wall with the podium magnets  1610 ,  1620  mounted therein, allows the key  1320  to travel laterally during its downward travel of a keypress. The key leveler  1326  may touch or hit the wall at the bottom of the press. Alternatively, another key guide system may be used, such as the key guide system similar to that described for key assembly  300  can be used to aid in key leveling and lateral displacement. 
       FIG. 19  is an isometric view of still another exemplary key assembly  1900  configured to implement the techniques described herein to provide a satisfying tactile user experience using passive tactile response. The key assembly  1900  includes a key podium  1910  and a key  1920 . The key  1920  is suspended over (and/or partially in) a key-shaped hole  1912  (“keyhole”) in the key podium  1910 . 
       FIG. 20  is a top plan view of the exemplary key assembly  1900 , with the same key podium  1910  and key  1920 . 
       FIG. 21  is an exploded view of the exemplary key assembly  1900 , with the same key podium  1910  and key  1920 . Also, shown in  FIG. 21  is a key hassock  2010 . 
     As shown in  FIGS. 19-21 , this key assembly  1900  differs from the key assembly  1300  (shown in  FIGS. 13-18 ) in the arrangements of the magnets and in the key and podium configuration that designed to impart lateral force onto the key and to provide leveling to the key. 
     In the key assembly  1900 , the podium magnet arrangement includes one single magnet  1930 . The single, non-stacked magnet arrangement can be seen in  FIG. 21 . This sole magnet is disposed horizontally and only one pole is magnetically exposed into the keyhole  1912 . The magnetically exposed pole of magnet  1930  is opposite of the exposed pole of the key magnet  1940 . 
     As seen in  FIG. 21 , the podium  1910  has ramps  1950   a ,  1950   b ,  1950   c ,  1950   d  built proximate each corner region of the keyhole  1912 . Inverse and complementary chamfers are built into the key  1920 . Two such complementary chamfers ( 1960   c  and  1960   d ) are shown in  FIGS. 20 and 21 . In one or more implementations, the ramps  1950   a ,  1950   b ,  1950   c ,  1950   d  and the complementary chamfers are composed of acetal resin (e.g., DuPont™ brand Delrin®). The dynamic coefficient of friction (μ) for two acetal resin surfaces is around 0.2 in many embodiments. 
     Working in cooperation, the key  1920 &#39;s chamfers ( 1960   c - d , and two more chamfers not shown) slide down the podium  1910 &#39;s ramps  1950   a - d  during a downward keypress. Regardless of where on the key  1920  that a user presses, the ramp-pairings in each corner keep the key  1920  steady and level during a keypress. 
     In addition, the ramp-pairings effectively translate at least some of the user&#39;s downward force into lateral force. Thus, the ramp-pairings convert the negative Z-direction movement of the key  1920  into both negative Z-direction and lateral direction movement. Unlike key assembly  1300 , there is no lower podium magnet used in the key assembly  1900 . However, alternative implementations may employ a lower podium magnet to aid the ramps with the planar-translation effecting action. 
     In addition, the key  1920  comprises four flanges or protuberances, two of which are labeled  1970   a  and  1970   b . The other two protuberances are combined with chamfers  1960   c  and  1960   d , such that features  1960   c  and  1960   d  provide both ramp and protuberance functions. 
     As seen in  FIGS. 19, 20, and 21 , the podium  1910  has four protuberance-receiving recesses  1980   a ,  1980   b ,  1980   c , and  1980   d  formed in parts of the walls of the keyhole  1912 . Each of these recesses  1980   a ,  1980   b ,  1980   c , and  1980   d  is configured to receive a corresponding one of the key&#39;s protuberances  1970   a - b ,  1960   c - d .  FIGS. 19-21  show the magnetically coupled key  1920  with its protuberances  1970   a - b ,  1960   c - d  fitted into their corresponding recesses  1980   a - d.    
     In this arrangement, a finishing layer (not shown) may be extended over parts of the podium  1910  and over the recesses so as to retain the protuberances  1970   a - b ,  1960   c - d  underneath. In this way, a finishing layer would retain the key  1920  in its position suspended over and/or within the keyhole  1912 . The finishing layer may be made of any suitable material that is sufficiently strong and sturdy. Such material may include (but is not limited to metal foil, rubber, silicon, elastomeric, plastic, vinyl, and the like. 
     The key hassock  2010  of the fourth implementation is analogous to the key hassock  640  of the second implementation. 
     Magnets 
     Where used, the magnets for many embodiments are permanent magnets and, in particular, commercial permanent magnets. The most common types of such magnets include, in order of strongest magnetic strength to the weakest are: Neodymium Iron Boron; Samarium Cobalt; Alnico; and Ceramic. 
     Because of their relatively small size and impressive magnetic strength, some embodiments in accordance with the techniques described herein utilize Rare Earth Magnets, such as neodymium-based magnets. Rare Earth Magnets are strong permanent magnets made from alloys of rare earth elements. 
     Alternative implementations may employ non-rare earth permanent magnets or electromagnets. 
     Exemplary Computing System and Environment 
     The below describes an example of a suitable environment within which one or more implementations, as described herein, may be implemented. The exemplary computing environment is only one example environment, and is not intended to suggest any limitation as to the scope of use or functionality of the implementations. 
     The various implementations, as described herein, may comprise processing systems communicatively coupled to sensor electrodes configured to sense press states of touchsurfaces. The processing systems are configured to operate the sensor electrodes, and to process sensor signals to determine the press states. In some embodiments, the processing system is further configured to detect input to devices other than those with touchsurfaces embodying the techniques described herein. 
     The processing systems may comprise circuitry, processor-executable instructions, combinations thereof, and the like. For example, the processing system may comprise parts of or entireties of one or more integrated circuits. In some embodiments, the processing system may consist of an integrated circuit (IC) as well as processor-executable instructions stored in non-transitory media. These instructions may be program modules comprising routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. 
     A specific example operating environment is that of a laptop computer, which includes a keyboard with keys embodying the techniques described herein, a touchpad, and a display screen that may be a touch screen, and other components. In such a system, the processing system may comprise one or more ICs loaded with appropriate processor-executable instructions that direct the IC(s) to operate the keyboard sensors to detect presses of the keys, and to operate the touchpad to detect user input to the touchpad, and the display screen (or touch screen if it includes touch input functionality). 
     The IC(s) may direct the IC to detect and determine if a key has been pressed (or the extent of the press), and provide an indication of press status to a main CPU of the laptop. The IC(s) may also drive the touchpad (and touchscreen if applicable) to detect input to those devices. The IC(s) may also operate the display screens to display images. In some embodiments, the IC(s) are configured to update a displayed image in response to direction from the main CPU about changes to the image or what images to display. In some embodiments, the IC(s) are configured to update a displayed image in response to presses on keys or input to the touchpad (or touchscreen if applicable) without such direction from the main CPU. 
     Non-Tactile User Feedback 
     Implementations in accordance with the techniques described herein may be configured to provide feedback other than tactile feedback, such as visual and aural feedback. Any appropriate component, including those supporting touchsurfaces, ready/return mechanisms, key guides, key podiums, and leveling mechanisms, may also be configured to provide such feedback. 
     For example, visual feedback may be provided by the change in the position of a touchsurface in response to a press, with backlighting changes, with displayed images, etc. As another example, aural feedback may be provided by speakers or mechanically. In some embodiments, the materials, shapes, locations, inclusion of additional features (e.g. detents) of one or more of the following are configured for aural feedback: a component supporting a touchsurface, the ready/return mechanism, and the leveling/planar translation effecting mechanism. The configuration may be to provide a sound indicating breakaway, press to an intermediate level, press to the bottom of vertical travel, return to ready position, combination thereof, etc. As yet another example, Some embodiments for keys are configured to provide aural feedback similar to the clicking of conventional keys. 
     Additional and Alternative Implementation Notes 
     The implementations described herein are meant as examples, and many variations are possible. As one example, any appropriate feature described with one implementation may be incorporated with another. As a first specific example, the retention features of the key assembly  1900  may be incorporated in the key assembly  200 . As a second specific example, any of the implementations described herein may or may not utilize a finishing layer. As a third specific example, the materials of any of the key assemblies  1300 ,  1900  may comprise the materials described for the key assembly  200 . As a fourth specific example, ferrous material may be used to replace any of the magnets described herein, including parts of or entire podium magnet arrangements or key magnet arrangement. 
     In addition, the structure providing any function may comprise any number of appropriate components. For example, a same component may provide leveling, planar-translation-effecting, readying, and returning functions for a keypress. In some embodiments, bias-arms designs provide such functions. As another example, different components may be provide these functions, such that a first component levels, a second component effects planar translation, a third component readies, and a fourth component returns. As yet another example, two or more components may provide a same function. For example, in some embodiments, magnets and springs together provide the return function, or the ready and return functions. 
     Further, it should be understood that the techniques described in the various implementations herein may be used in conjunction with each other, even where the function may seem redundant. For example, the bias arms ready/return or leveling mechanism may be used to replace or to augment the magnets  220 ,  222  or the leveling/planar translation effecting mechanisms  230  of the key assembly  200 . 
     Also, while the implementations of the touchsurface described herein have primarily focused on a key of a keyboard, other implementations of leveled touchsurface with planar translational responsiveness to vertical travel are available. Similarly, while the implementations described herein have primarily focused on human fingers as the sources of input, other body parts or extensions of body parts (e.g. a pen) are contemplated. 
     For example, a touchsurface implementing the new techniques described herein may be any device with a human-machine interface (HMI) that a human touches. Examples of suitable HMI devices include (by way of illustration and not limitation) a surface of a touchscreen or touchpad, a surface of a key of a keyboard or key pad, a surface of a button, a surface associated with the clicking of a mouse, trackball, pointing stick, or other pointing device, a surface of a gamepad, paddle, foot mouse, steering wheel, jog dial, and the like. 
     Examples of computing systems that may employ a device constructed in accordance with the techniques described herein include (but are not limited to): phones, including mobile phones such as smartphones (e.g., the iPhone™), tablet computers (e.g., the iPad™), monitors, control panels, light switches or controls, vehicle dashboard panels, laptop or notebook computers, netbook computers, desktop computers, device accessories (such a tablet case with a build-in keyboard), peripheral keyboards, remote controls, gaming devices, electronic kiosks, automated teller machine (ATM)s, networked appliances, point-of-sale devices, medical workstation, and industrial workstations. 
     For instance, a touchscreen of a tablet computer or smartphone may be constructed in accordance with the techniques described herein. If so, the user may be able to select an on-screen icon or button by pressing on the touchscreen. In response, the touchscreen may translate downwards and laterally. 
     As another example, a laptop computer may comprise a touchpad constructed in accordance with the techniques described herein. Without having to press any other mechanical buttons, the user may select an on-screen icon or button by pressing down on the touchpad. In response, the touchpad surface may translate downward and laterally. Alternatively, the touchpad may just move downward substantially vertically without any substantive lateral motion of the touchpad surface. The switch actuation associated with the movement may result from the touchpad structure pushing a biased guide to slide in a lateral direction as it descends. 
     In some implementations, an exemplary touchsurface may be opaque. In other implementations, an exemplary touchsurface may be fully or partially translucent or transparent, such that visible light may pass through the touchsurface. 
     One or more of the implementations may employ force-sensing technology to detect how hard a user presses down on a touchsurface. 
     Examples of other touchsurface implementations and variations may include (by way of example and not limitation): a toggle key, slider key, slider potentiometer, rotary encoder or potentiometer, navigation/multi-position switch, and the like. 
     Toggle Key—A toggle key is a levered key that pivots at its base. A toggle key implementation may have mutually attractive magnets on both sides of a keyhole. With this construction, as a user moves the toggle away from one magnet, the key magnet creates a snap over feel and holds the toggle in the desired positions. 
     Slider Key—This is similar to the toggle key, except instead of pivoting, it slides. 
     Slide Potentiometer—This is similar to a slider key, except the travel is much longer. Magnets may be used to provide detents for the slider as it moves along the slider path. For example, magnets may be used at the ends and in the middle to define these points. Also, magnets of differing strengths may be used to provide different tactile responses. 
     Rotary encoder or potentiometer—Magnets could be used around the perimeter to provide detents. Implementations might use hard and soft detents enabled by different magnetic strengths. 
     Navigation/Multi-Position switch—This is a multi-direction switch. An implementation may use magnets in all directional quadrants and the switch would levitate between them. 
     Ready/Return Mechanisms 
     Ready/return mechanisms other than those already described herein can be utilized without departing from the spirit and scope of the claimed subject matter. For example, alternative return mechanisms might restore the touchsurface to its ready position using magnetic repulsion pushing the touchsurface back to the ready position. Other alternative return mechanisms might not use magnetic or electromagnetic forces. For example, biasing or spring forces may be used to push or pull the touchsurface to its ready position and keep the touchsurface in that position. Examples of alternative mechanisms include elastomeric domes such as those found in conventional keyboards. Other examples include (but are not limited to) springs, elastic bands, and other tactile domes (e.g., rubber dome, elastomeric dome, metal dome, and the like). 
     In addition, multiple mechanisms may be used to accomplish the return and ready functions separately. For example, one mechanism may retain the touchsurface in its ready position and a separate mechanism may return the touchsurface to its ready position. 
     Leveling/Planar-Translation-Effecting Mechanisms 
     Likewise, other types of leveling/planar-translation-effecting mechanisms can be utilized without departing from the spirit and scope of the claimed subject matter. For example, alternative leveling/planar-translation-effecting mechanisms might level a touchsurface without ramps and/or might impart a planar translation from a vertical movement without using ramps or magnetic or electromagnetic forces. 
     Examples of alternative leveling/planar-translation-effecting mechanisms include (but are not limited to) a biased-arms mechanism, a four-bar linkage mechanism, a double-barrel eccentric cam mechanism, an eccentric tilting cam-plates mechanism, a tilting plate with captured sliding peg mechanism, and a rib-and-groove mechanism. 
     Some of these examples are expanded upon below, and many features have been simplified and components excluded in those discussions for clarity of explanation. 
     Bias-arms mechanism I—With a bias-arms mechanism, one or more resilient arms support the touchsurface from underneath. The arms act as leveling mechanism, planar-translation-effecting mechanism, and return/ready mechanism. The arms bias or are “spring-loaded” when they bend in response to the downward force on the touchsurface. The bent arms act much like the ramps of implementations of the planar-translation-effecting mechanisms described herein. When released, the biasing of bent arms act much like the magnets of implementations of the return/ready mechanisms described herein. Generally, the biasing or resilient nature of the arms keep the arms leveled in much the same way as the leveling mechanisms described herein. In some embodiments, the bias arms comprise cantilevered arms configured to support keys. In response to a keypress, the cantilevered arms bend and push back against the press force. Once the press force is removed, the cantilevered arms urge the key back into the ready position. 
     With a double-barrel eccentric cam mechanism, the touchsurface is supported thereunder by at least two rotating bars or “barrels” with eccentric cams at the end of each barrel. For each eccentric cam, a cam-pin would extend from the edge of the touchsurface and fit into the eccentric cam end of a barrel. Both the eccentric cam and its corresponding cam-pin would fit into a space in the periphery of the podium that is fitted to receive the cam and cam-pin. The double-barrel eccentric cam mechanism is similar to a four bar linkage with short bars, where the side linkages coupling the key to the key podium have been reduced to cams. 
     With an eccentric tilting cam-plates mechanism, the touchsurface is supported thereunder by at least two plate-like cams (“cam-plates”) that each rest on their own eccentric tilting plates. Under a downward force, the tilting plates tilt or teeter-totter so as to allow the downward movement of the touchsurface. During the downward movement, each of the cam-plates slide and ride within a fitted recess in their associated tilting plates. In doing so, the touchsurface remains level while moving up and down. 
     With a tilting plate with captured sliding peg mechanism, the touchsurface is supported thereunder by at least one eccentric tilting plate that is arranged and fitted into the space below the touchsurface so as to tilt or teeter-totter to allow the downward movement of the touchsurface. One or more pegs extend from the edge of the touchsurface and is captured by a diagonal slot in the periphery of the podium. During the downward/upward movement of the touchsurface, the captured peg slides in the slot in a manner to keep the touchsurface level while the tilting plate tilts. 
     With a rib-and-groove mechanism, the touchsurface have ribs that would ride along a sloped path of grooves of the podium. The confined path of a groove would include a component of negative Z-direction travel and a planar direction travel. Of course, the touchsurface may have the grooves and the podium have the ribs. 
     In addition, multiple mechanisms may be used to accomplish one or more of the leveling, planar-translation-effecting, and ready/return functions. For example, one mechanism may level the touchsurface and a separate mechanism may impart the planar translation to the touchsurface. 
     Features, Aspects, Functions, Etc. of Implementations 
     In the above description of exemplary implementations, for purposes of explanation, specific numbers, materials configurations, and other details are set forth in order to better explain the invention, as claimed. However, it will be apparent to one skilled in the art that the claimed invention may be practiced using different details than the exemplary ones described herein. In other instances, well-known features are omitted or simplified to clarify the description of the exemplary implementations. 
     The inventors intend the described exemplary implementations to be primarily examples. The inventors do not intend these exemplary implementations to limit the scope of the appended claims. Rather, the inventors have contemplated that the claimed invention might also be embodied and implemented in other ways, in conjunction with other present or future technologies. 
     Moreover, the word “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts and techniques in a concrete fashion. The term “techniques,” for instance, may refer to one or more devices, apparatuses, systems, methods, articles of manufacture, and/or computer-readable instructions as indicated by the context described herein. 
     As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more,” unless specified otherwise or clear from context to be directed to a singular form. 
       FIG. 22  shows an example of a device ( 2200 ) having keys ( 2202 ), key holes ( 2204 ), a processing system ( 2206 ), and a lid ( 2208 ). The keys are connected to a leveling/planar translation-effecting mechanism ( 2210 ) and dropping mechanism ( 2212 ). The dropping mechanism ( 2212 ) is configured to drop the keys into respective keyholes. The dropping mechanism ( 2212 ) may include a tensioner ( 2214 ) that pulls the keys into respective keyholes. 
       FIG. 23  shows an example of a device ( 2300 ) having keys ( 2302 ), key holes ( 2304 ), and a processing system ( 2306 ). The keys are connected to a leveling/planar translation-effecting mechanism ( 2310 ). The leveling/planar translation-effecting mechanism ( 2310 ) includes linkage mechanisms ( 2312 ). 
       FIG. 24  shows an example of a device ( 2400 ) having key caps ( 2402 ), key holes ( 2404 ), a processing system ( 2406 ), and a lid ( 2408 ). The keys are connected to a leveling/planar translation-effecting mechanism ( 2410 ) and dropping mechanism ( 2412 ). The dropping mechanism ( 2412 ) is configured to drop the keys into respective keyholes. The dropping mechanism ( 2412 ) may include a tether ( 2414 ) that pull the keycap. 
       FIG. 25  shows an example of a device ( 2500 ) having touchsurface ( 2502 ), base ( 2504 ), a processing system ( 2506 ), and a leveling/planar translation-effecting mechanism ( 2508 ). The leveling/planar translation-effecting mechanism ( 2508 ) includes sidebar ( 2510 ) that is hinged to the base ( 2504 ) and to the touchsurface ( 2502 ). 
     The following enumerated paragraphs represent illustrative, non-exclusive descriptions of methods, systems, devices, etc. according to the techniques described herein:
         A. A touchsurface (e.g., key) having a lateral translation imparted upon it during a human-imparted Z-direction force on that key (especially when such lateral travel is not caused by a motor of any kind).
           A1. The touchsurface of paragraph A, wherein magnetic repulsion and/or attraction imparts the lateral travel.   A2. The touchsurface of paragraph A, wherein multiple ramps impart the lateral travel in response to a downward force.   A3. The touchsurface of paragraph A, wherein the touchsurface is part of a rigid body.   
           B. A cantilevered retention of a rigid key (especially when hold is by magnetic attraction) in its ready position.   C. Holding a rigid key laterally (e.g., interior of keyhole  1312  holding (e.g., via magnetic attraction) the key thereto) in its ready position.   D. Magnetic repulsion or attraction to impart a lateral travel to a key during Z-direction travel (which is the up/down movement of key in response to a keypress and key release).   E. Magnetic attraction to return the key to its original position—that attraction may impart both a lateral and Z-direction movement of the key.   F. Stacking and alternating pole arrangement of two of more podium magnets.   G. Arrangement of the key-receiving cavity (e.g., keyhole  1312 ) and shape of key to fit together for the purpose of allowing lateral translation of the key during a keypress.   H. Backlighting arrangement—lighting element under a transparent or translucent key.   I. Alternative magnet arrangement for a stack of multiple (3+) magnets with alternating poles (to impart multilateral movement (e.g., back and forth in X or Y direction) of key during Z-direction travel).   J. Such alternative magnet arrangement may include an array of magnets dispersed about a key-receiving cavity (e.g., keyhole  1312 ) to impart a multi-vectored lateral translation (e.g., in both X and Y directions) of the key during Z-direction travel.   K. Multiple ramp-pairings between the podium and the key to perform both leveling and Z-direction to lateral direction force transference on the key.   L. An apparatus comprising at least one touchsurface configured to provide a satisfying tactile keypress experience for a user via planar translation responsiveness to a vertical travel of the touchsurface.   M. An apparatus comprising at least one touchsurface configured to provide a satisfying tactile keypress experience for a user without a haptic motor.   N. An apparatus comprising at least one touchsurface configured to provide a satisfying tactile keypress experience for a user without an active actuator.   O. An apparatus comprising at least one touchsurface configured to translate in a multi-vectored manner in response to a single-vector force imparted by a user&#39;s contact with the surface.   P. An apparatus of paragraphs L-O, wherein the touchsurface is a key or a touchscreen.   Q. An apparatus of paragraphs L-O, wherein the touchsurface is transparent or translucent.   R. A human-machine (e.g., computer) interaction (HMI) device comprising:
           a podium defining a hole therein, wherein one or more podium magnets are mounted to the podium so as to magnetically expose at least one pole of the one or more podium magnets to the interior of the hole;   a touchsurface shaped to fit into the hole and suspended over and/or within the hole, wherein one or more touchsurface magnets are mounted to the touchsurface so as to magnetically expose at least one pole of the one or more touchsurface magnets, the exposed pole of the one or more touchsurface magnets being opposite of the exposed pole of the one or more podium magnets,   wherein a magnetic coupling between the exposed pole of the one or more touchsurface magnets and the exposed pole of the one or more podium magnets suspends the touchsurface over and/or into the hole of the podium.   
           S. A HMI device as recited in paragraph R, wherein the touchsurface is a key or a touchscreen.   T. A HMI device as recited in paragraph R, wherein the touchsurface is transparent or translucent.   U. A HMI device as recited in paragraph R, wherein the touchsurface is suspended in a cantilevered fashion over and/or in the hole of the podium.   V. A HMI device as recited in paragraph R, wherein the magnetic coupling between the exposed pole of the one or more touchsurface magnets and the exposed pole of the one or more podium magnets is configured to release when a downward force of a typical keypress is applied to the touchsurface.   W. A HMI device as recited in paragraph V, wherein the magnetic coupling between the exposed pole of the one or more touchsurface magnets and the upper pole of the one or more podium magnets is restored after the downward force of the keypress is released.   X. A HMI device as recited in paragraph W, wherein the restoration of the magnetic coupling moves the touchsurface, both up and laterally, back to its original suspended position.   Y. A HMI device as recited in paragraph R, wherein the podium and/or touchsurface includes one or more structures configured to redirect at least some of a downward force applied to the touchsurface to move the key laterally during its downward travel.   Z. A HMI device as recited in paragraph R, wherein the podium magnets include at least two magnets arranged in a stacked manner so that an upper magnet has the exposed pole coupled to the exposed pole of the touchsurface&#39;s magnet and the lower magnet has its own exposed pole, which is opposite on polarity to that of the upper magnet&#39;s exposed pole.   AA. A HMI device as recited in paragraph Z, wherein a magnetic repulsion between the like poles of the exposed pole of the one or more touchsurface magnets and the lower pole of the one or more podium magnets pushes the touchsurface laterally during the touchsurface downward movement into the hole in the podium.   BB. A HMI device comprising a cantilevered key suspended over a cavity configured to receive the key when a downward force is applied to the key.   CC. A HMI device comprising a magnetically coupled cantilevered touchsurface suspended over a cavity configured to receive the touchsurface when a downward force is applied to the touchsurface.   DD. A HMI device as recited in paragraph CC, wherein the touchsurface is a key and/or a touchscreen.   EE. A HMI device as recited in paragraph CC, wherein the device is further configured to magnetically repel the freed touchsurface in the cavity after a downward force moves the touchsurface into the cavity.   FF. A HMI device comprising a touchsurface suspended over a cavity configured to receive the touchsurface, wherein a sidewall of the touchsurface is magnetically coupled to an interior wall of the cavity.   GG. A human-machine (e.g., computer) interaction (HMI) device comprising:
           a podium with a cavity defined therein;   a touchsurface suspended over the cavity, the touchsurface being configured to fit into the cavity when a downward force is applied to the touchsurface to move the touchsurface into the cavity;   two or more magnets operatively connected to each of the podium and the touchsurface, the magnets being arranged to impart a lateral movement on the touchsurface when the downward force is applied to the touchsurface to move the touchsurface into the cavity.   
           HH. A HMI device as recited in paragraph GG, wherein the lateral movement is imparted by a magnetic repulsion between two or more magnets.   II. A HMI device as recited in paragraph GG, wherein the lateral movement is imparted by a magnetic attraction between two or more magnets.   JJ. A HMI device as recited in paragraph GG, wherein the lateral movement includes movement in more than one lateral direction.   KK. A method of passive-translational responsiveness comprising:
           receiving a force in a downward direction upon a magnetically coupled touchsurface that is suspended over and/or in a cavity configured to receive the touchsurface when a downward force is applied to the touchsurface;   in response to the receiving of the downward force,
               releasing the magnet coupling suspending the touchsurface;   imparting a lateral translation upon the touchsurface as it descends into the cavity.   
               
           LL. A method of passive-translational responsiveness as recited in paragraph KK, further comprising, in response to a release of sufficient force, returning the touchsurface to its original suspended position over and/or in the cavity.   MM. A method of passive-translational responsiveness as recited in paragraph KK, further comprising constraining the touchsurface from rotation in response to the receiving of the downward force.   NN. A key assembly comprising:
           a key presented to a user to be depressed by the user;   a leveling mechanism operatively associated with the key, the leveling mechanism being configured to constrain the key to prevent rotation thereof;   a diagonal-movement-imparting mechanism operatively associated with the key, the diagonal-movement-imparting mechanism being configured to impart a diagonal movement to the key while the key travels vertically in response to a user&#39;s downward press and/or removal of sufficient force to keep the key depressed.   
           OO. A touchpad assembly comprising:
           a touchpad presented to a user to be depressed by the user;   a leveling mechanism operatively associated with the touchpad, the leveling mechanism being configured to constrain the touchpad to prevent rotation thereof;   a biased guide mechanism operatively associated with the touchpad, the biased guide mechanism being configured to be slid laterally in response to being pushed by the touchpad during its substantially vertical downward travel and the biased guide mechanism being further configured to urge the touchpad back up to its original position.   
           PP. A laptop computer comprising:
           a hinged lid/screen;   a keyboard with magnetically suspended keys with each key having its own keyhole thereunder for receiving the key, the keyboard being opposite there of the hinged lid/screen;   a key-retraction system configured to retract the magnetically suspended keys into their respective keyholes, wherein the key-retraction system retracts the keys in response an indication of lid/screen closure.   
           QQ. A keyboard comprising:
           a keyboard chassis;   multiple key assemblies supported by the keyboard chassis, wherein each key assembly comprises:
               a key presented to a user to be depressed by the user;   a leveling mechanism operatively associated with the key, the leveling mechanism being configured to constrain the key to a level orientation while the key is depressed by the user;   a planar-translation-effecting mechanism operatively associated with the key, the planar-translation-effecting mechanism being configured to impart a planar translation to the key while the key travels downward as the key is depressed by the user   
               
           RR. A computing system comprising a keyboard as recited in paragraph QQ.   SS. A human-machine interaction (HMI) apparatus comprising:
           a touchsurface presented to a user to facilitate, at least in part, human to computer interaction therethrough by the user depressing the touchsurface;   a translational mechanism operatively associated with the touchsurface, the translational mechanism being configured to constrain the touchsurface to prevent rotation of the touchsurface but enable a translation in response to a downward force from the user depressing the touchsurface.   
           TT. An HMI apparatus as recited in paragraph SS, wherein the translational mechanism includes multiple supports positioned under and/or around the touchsurface so as to ameliorate and/or eliminate wobbling, shaking, and/or tilting of the touchsurface while the touchsurface travels downward as the user depresses the touchsurface.   UU. An HMI apparatus as recited in paragraph SS, wherein the translational mechanism includes multiple supports arrayed along a periphery of an underside of the touchsurface, along a perimeter of the touchsurface, and/or outside the periphery of the touchsurface.   VV. An HMI apparatus as recited in paragraph SS, wherein the translational mechanism is configured to impart a planar movement translation to the touchsurface while the touchsurface travels downward as the user depresses the touchsurface.   WW. An HMI apparatus as recited in paragraph SS, wherein the translational mechanism includes multiple ramps arrayed along a periphery of an underside of the touchsurface, along a perimeter of the touchsurface, and/or outside the periphery of the touchsurface.   XX. An HMI apparatus as recited in paragraph SS, wherein the translational mechanism includes a four-bar linkage mechanism, wherein a rigid sidebar is hinged to opposite edges of the touchsurface and also to a base thereunder the touchsurface.   YY. An HMI apparatus as recited in paragraph SS, wherein the translational mechanism includes a rib-and-groove mechanism, wherein one or more ribs of the touchsurface ride in one or more grooves of a structure defining a cavity within which a touchsurface descends when traveling vertically.