PATENT DOCUMENT

Publication Number: US-10698489-B1
Application Number: US-201816024680-A
Country: US
Kind Code: B1

Title: Compact pivoting input device

Abstract:
An input device includes an input structure, a magnet attached to the input structure, and an electromagnet. The magnet rotates when the electromagnet is activated, thereby rotating the input structure. The magnet and input structure rotate about a pivot in order to provide haptic and/or visual feedback to a user. The pivot may attach the magnet and input structure to a body, which in turn may be affixed to, or part of, an electronic device. The electromagnet can encircle the body and/or magnet.

Claims:
What is claimed is: 
     
       1. An input device for use with an electronic device, comprising:
 a button defining an input surface; 
 a force sensor configured to sense an input force applied to the input surface along an input direction oriented perpendicular to the input surface; 
 a permanent magnet attached to the button; 
 a body; 
 a pivot coupling the body to the button, the pivot having a pivot axis, the input direction intersecting the pivot axis; and 
 an electromagnet adjacent the permanent magnet; wherein 
 the electromagnet is configured to generate a magnetic field in response to the force sensor sensing the input force, thereby rotating the permanent magnet and the button about the pivot axis to provide haptic feedback to the button. 
 
     
     
       2. The input device of  claim 1 , further comprising:
 the button extends through an enclosure of the electronic device; 
 the body is affixed to the electronic device; 
 the body, permanent magnet, and electromagnet are within the enclosure; 
 the electromagnet defines an interior volume; 
 the permanent magnet is at least partially within the interior volume; 
 the electromagnet encircles the body; and 
 the electromagnet is stationary relative to the body. 
 
     
     
       3. The input device of  claim 1 , wherein:
 the button and permanent magnet rotate about the pivot axis and within a plane defined by a major axis and a minor axis of the input device; and 
 the pivot axis is parallel to the input surface. 
 
     
     
       4. The input device of  claim 1 , wherein the permanent magnet is positioned within a space defined the body. 
     
     
       5. The input device of  claim 1 , wherein the button and permanent magnet are configured to oscillate to provide the haptic feedback. 
     
     
       6. The input device of  claim 5 , wherein:
 the pivot comprises a pair of pins; and 
 the pair of pins rotate with the permanent magnet. 
 
     
     
       7. The input device of  claim 1 , wherein an end of the permanent magnet is positioned within an interior volume defined by the electromagnet. 
     
     
       8. The input device of  claim 1 , wherein:
 the electronic device is a mobile device comprising a display; 
 the button is oblong and extends through a sidewall of the electronic device; and 
 information on the display is modified in response to the input force. 
 
     
     
       9. An electronic device, comprising:
 an enclosure defining an opening; 
 a body attached to the enclosure; 
 a button extending through the opening and defining an input surface, the button pivotally attached to the body through a pivot axis; 
 a sensor configured to detect an input force applied to the input surface along an input direction intersecting the pivot axis; 
 a permanent magnet attached to the button and positioned within the enclosure; and 
 an electromagnet attached to the body, positioned within the enclosure, and encircling the permanent magnet; wherein 
 motion of the button is configured to provide haptic feedback at the input surface. 
 
     
     
       10. The electronic device of  claim 9 , wherein the electromagnet encircles the body. 
     
     
       11. The electronic device of  claim 9 , wherein:
 the electromagnet is positioned within the body; and 
 the permanent magnet is positioned within the body. 
 
     
     
       12. The electronic device of  claim 9 , further comprising a processor disposed in the enclosure; wherein:
 the sensor is configured to generate a signal in response to an input on the input surface; 
 the processor is configured to receive the signal from the sensor; and 
 the processor is further configured to activate the electromagnet in response to receiving the signal from the sensor, thereby moving the button with respect to the body to provide haptic feedback. 
 
     
     
       13. The electronic device of  claim 12 , wherein:
 the sensor is a force sensor; and 
 the button moves if the input exceeds a threshold. 
 
     
     
       14. An input device, comprising:
 an input structure defining an input surface; 
 a sensor configured to detect a force applied in a direction oriented into the input surface; 
 a pivot below the input surface and about which the input structure rotates; and 
 an actuator configured to rotate the input structure about the pivot to provide haptic feedback at the input structure in response to the sensor detecting the force; wherein: 
 rotation of the input structure moves the input surface in a direction substantially transverse to a direction of the force. 
 
     
     
       15. The input device of  claim 14 , wherein a major vector of the input surface&#39;s movement is tangential to an object applying the force. 
     
     
       16. The input device of  claim 14 , wherein the input surface is curved. 
     
     
       17. The input device of  claim 14 , wherein the pivot passes through the input structure and is contained within the actuator. 
     
     
       18. The input device of  claim 14 , wherein the pivot limits motion of the input structure to rotation about the pivot. 
     
     
       19. An input device, comprising:
 an input structure defining an input surface; 
 a sensor configured to detect a force applied in a direction oriented into the input surface; 
 a pivot below the input surface and about which the input structure rotates; and 
 an actuator configured to rotate the input structure about the pivot in response to the sensor detecting the force; wherein: 
 rotation of the input structure moves the input surface in a direction substantially transverse to a direction of the force; and wherein: 
 the sensor is a first sensor; 
 the actuator is an electromagnet; 
 the input device further comprises a second sensor configured to detect a back electromotive force of the electromagnet; and 
 the electromagnet is configured to receive additional power if the back electromotive force exceeds a threshold. 
 
     
     
       20. The input device of  claim 19 , wherein the sensor is a Hall effect sensor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a nonprovisional patent application of and claims the benefit of U.S. Provisional Patent Application No. 62/652,242, filed Apr. 3, 2018 and titled “Compact Pivoting Input Device,” the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The described embodiments relate generally to input mechanisms for electronic device, and more particularly to input surfaces that pivot about a pivot point beneath the input surface, in response to an input provided on the input surface. 
     BACKGROUND 
     Many traditional electronics include buttons, switches, keys, or other types of components as input devices. It is desirable that input devices provide haptic feedback to a user. 
     Many traditional input devices are mechanical buttons. Mechanical buttons are generally reliable and provide inherent haptic feedback, as a user can often feel the mechanism of the button moving, for example between button positions. However, mechanical switches typically have set haptic outputs or feedback, dictated by their design. Also, as electronic devices have become more space-constrained, mechanical buttons have presented problems and design limitations. Many mechanical switches need a minimum amount of space to operate. For example, a typical dome switch needs about 200 microns of travel for the dome to collapse and close the switch. This is especially problematic in very thin electronic devices. 
     Pivoting input structures may allow increased haptic design flexibility and may allow the haptics to change with environmental or use conditions. A pivoting button may provide an adjustable haptic feedback to the user. Also, pivoting input structures may greatly reduce required space and particularly travel. Many pivoting buttons travel 10 microns or less when force is exerted thereon. Pivoting buttons can use force sensors to determine when the button is pressed, for example. The force sensor registers a change in capacitance, resistance, current, voltage, or other electrical value when the pivoting button moves or flexes, even though such motion may be very small. 
     Many pivoting input structures, such as buttons, require physical movement of some portion of the input structure to register an input and/or to trigger haptic feedback of a user input. Although the physical movement of pivoting systems is reduced to that of mechanical systems, a pivoting system that does not require physical movement may combine several advantages of traditional mechanical switches and pivoting input structures. For example, a pivoting system devoid of vertical or inward movement may provide the increased reliability of mechanical buttons with the lower profile and variable haptics of a pivoting system. 
     SUMMARY 
     One embodiment described herein takes the form of an input device for use with an electronic device comprising: a button; a force sensor configured to sense an input on the button; a permanent magnet attached to the button; a body; a pivot coupling the body to the button; and an electromagnet adjacent the permanent magnet; wherein the electromagnet is configured to generate a magnetic field in response to the force sensor sensing the input, thereby rotating the permanent magnet and the button about the pivot to provide haptic feedback. 
     Another embodiment described herein takes the form of an electronic device, comprising: an enclosure defining an opening; a body attached to the enclosure; a button extending through the opening and defining an input surface, the body pivotally attached to the button; a sensor configured to detect an input on the input surface; a permanent magnet attached to the button and positioned within the enclosure; and an electromagnet attached to the body, positioned within the enclosure, and encircling the permanent magnet; wherein the button is configured to provide haptic feedback. 
     Still another embodiment takes the form of an input device, comprising: an input structure defining an input surface; a sensor configured to detect a force on the input surface; a pivot below the input surface and about which the input structure rotates; and an actuator configured to rotate the input structure about the pivot; wherein: rotation of the input structure moves the input surface substantially transverse to a direction of the force. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  illustrates one example of an electronic device with a pivoting input device; 
         FIG. 2  illustrates a sample input device that pivots in response to an input force, rather than translating; 
         FIG. 3A  is a cross-sectional view of a sample pivoting input device, implemented as a button; 
         FIG. 3B  is a second cross-sectional view of the sample pivoting input device of  FIG. 3A , taken along line  3 B- 3 B of  FIG. 3A ; 
         FIG. 4A  is a sample view of one embodiment of a pivoting input device in an unactuated state; 
         FIG. 4B  is a cross-section view of the pivoting input device of  FIG. 3A  taken along line  4 B- 4 B; 
         FIG. 4C  is a cross-section view of the pivoting input device of  FIG. 3A  in an actuated state; 
         FIG. 5A  is a sample side view of another embodiment of a pivoting input device in an unactuated state; 
         FIG. 5B  is a cross-section view of the pivoting input device of  FIG. 4A  taken along line  4 B- 4 B; 
         FIG. 5C  is a cross-section view of the pivoting input device of  FIG. 4A  in an actuated state; 
         FIG. 6  is a sample cross-section view of another embodiment of a pivoting input device fitted to an enclosure of an electronic device; 
         FIG. 7  is a sample exploded view of a pivoting input device; 
         FIG. 8A  is shows another embodiment of a pivoting input device; 
         FIG. 8B  is a cross-section view of the pivoting input device of  FIG. 8A  taken along line  8 A- 8 B; 
         FIG. 9A  shows another embodiment of a pivoting input device; 
         FIG. 9B  is a cross-section view of the pivoting input device of  FIG. 9A  taken along line  9 B- 9 B; 
         FIG. 10A  shows yet another embodiment of a pivoting input device; 
         FIG. 10B  is a cross-section view of the pivoting input device of  FIG. 10A  taken along line  10 B- 10 B; 
         FIG. 11A  is a sample side view of another embodiment of a pivoting input device; 
         FIG. 11B  is a sample side view of another embodiment of a pivoting input device; 
         FIG. 11C  is a sample side view of another embodiment of a pivoting input device; 
         FIG. 11D  is a sample side view of another embodiment of a pivoting input device; 
         FIG. 11E  is a sample side view of another embodiment of a pivoting input device; and 
         FIG. 12  is a sample block diagram of a pivoting input device and associated electronic components. 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented there between, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the disclosure to any preferred or particular embodiments. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     As used herein, the term “input device” refers generally to a set of elements to cooperate to provide a signal to an electronic device in response to an input. The term “input structure” refers generally to a specific element that accepts a touch, force, or the like as an input. The term “input surface” refers to the portion of the input structure with which a user interacts to provide or initiate an input. An “input” is any interaction with an input surface (and thus an associated input structure and input device) provided by a user that results in the generation of a signal to the electronic device. Thus, touch, force, motion, gaze, and the like are all different types of inputs that may operate with different input surfaces, structures, and/or devices. 
     Embodiments described herein relate generally to an input device that pivots about a pivot point in response to an input force. The pivot point is generally located beneath the input surface of the input device. Further, the pivot point is generally in line (or nearly in line) with a direction in which an input is exerted or otherwise provided. The input device (or at least the input structure) generally pivots about the pivot point in response to the input. Insofar as the input device or structure rotates about the pivot point, its motion may be decomposed into two vectors along two axes. A “major” or “primary” vector of a force is the largest vector of a decomposed force. Generally, the major vector of the input device&#39;s rotation is transverse to the direction in which the input is provided rather than parallel. As used herein, “transverse” means perpendicular to, or at a substantially right angle to, the input force. Thus, the input device (or input structure) does not primarily move in the direction of the input but instead primarily perpendicular to it, or along it. Put another way, the major vector of a haptic output force is tangential to a surface exerting the input force. 
     In many embodiments, the input device may move in order to provide haptic output. The input itself may not perceptibly displace the input device, but instead an actuator may move the input device, or the input structure or input surface, in response to the input. Any displacement caused by the force of an input may be negligible or imperceptible to a typical person. Such negligible or imperceptible displacement may be less than 50 microns in some embodiments, less than 25 microns in some embodiments, less than 10 microns in some embodiments, or even less than five microns in some embodiments. Put another way, primary and/or perceptible motion of an input device (or input structure, or input surface) results not directly from an input exerted thereon but instead from an actuator&#39;s operation. The actuator may move the input structure (or, in some cases, the input device) when an input is sensed. As mentioned above, this motion may be primarily transverse to a direction in which an input is exerted or otherwise provided. 
     In sum, certain embodiments described herein may: sense an input force on an input surface of an input structure; rotate the input structure about a pivot, thereby moving the input surface transverse to the input force; and initiate an input to an associated electronic device. Generally, motion of the input surface is also tangential to a user&#39;s finger, or to whatever object is exerting the input force. It should be appreciated that rotating the input structure and initiating the input generally happen in response to sensing the input force. 
     Any of a variety of actuators may be used to pivot an input structure, and in many embodiments the actuator is part of the input device. In others, the actuator may be separate from the input device. 
     Thus, not only is the motion of input structures/devices discussed herein different from typical hinged structures that collapse or move primarily in a direction of an exerted force, but a person interacting with input devices described herein experiences an entirely different sensation. Embodiments described herein effectively create a haptic sensation through skin shear (e.g., lateral or tangential movement of skin induced by the input surface) rather than having the input surface press into or compress skin. Embodiments described herein may harness this tangential motion of the input device relative to a user&#39;s skin to provide unique, highly controllable, complex haptic outputs to a person. Further, the energy required to pivot an input structure may be less than the energy required to translate it. 
     One sample embodiment described herein is an electromagnetic pivoting input device for use in an electronic device. An electromagnetic pivoting input device may be actuated in response to a relatively small movement as compared to a traditional mechanical input device (such as a button with a dome switch). Additionally, electromagnetic pivoting input devices may move laterally with respect to an enclosure or other surface through which the input device protrudes, thereby reducing internal volume necessary to operate the input device. Further, such a device may provide variable or controllable haptic feedback to a user of the input device. 
     A sample input device may include a button or other input structure defining an input surface. The button (or other input structure) and an associated permanent magnet are affixed to, and pivot on or around, a structural body. An adjacent electromagnet generates a magnetic field that displaces the permanent magnet, in turn pivoting the button between a neutral, unactuated first button position and an actuated, second button position. As the button actuates, the input surface may pivot with the button. A user touching the input surface will feel the pivoting or actuation of the button and thus receive haptic feedback that the button has actuated. Furthermore, the user may be able to see the pivoting of the button between the neutral unactuated first position and the actuated second position. It should be appreciated that the distance the button pivots may be small enough that its rotational/pivoting motion is indistinguishable to a user from a lateral motion (e.g., translation into or out of an enclosure of an electronic device). 
     A permanent magnet is a material or an object made from a material that creates a persistent magnetic field. A permanent magnet has a pair of opposing magnetic poles, termed a north and a south magnetic pole. Magnetic field lines run between the two opposing magnetic poles. A permanent magnet will attract metallic materials, and may also attract or repel another magnet, depending on the polarity of the magnets. A permanent magnet is influenced by a magnetic field, meaning a permanent magnet may be displaced by an external magnetic field. 
     An electromagnet is a device which generates a magnetic field by way of an electric current. Ampere&#39;s law provides that an electric current flowing in a wire generates a magnetic field. Such a magnetic field dissipates and eventually stops when the electric current stops flowing. A typical electromagnet is formed from a wire coil. It creates a magnetic field that encircles the coil and is strongest within the coil. The configuration of the electromagnet determines the character of the generated magnetic field. For example, the materials of the electromagnet, the geometry of the electromagnet such as the number of turns in the coil windings, and the current running in the coiled wire, will influence the generated magnetic field. 
     In one embodiment, a permanent magnet is attached below a button and positioned to fit within an interior of an electromagnet (such as in a space defined by windings of a coil). The permanent magnet and button are on opposing sides of a pivot. 
     The windings define a height of the electromagnet and an interior volume within the electromagnet. When the electromagnet is not operating, meaning no electric current is flowing through the wire windings and thus no magnetic field is generated, the permanent magnet is in a neutral position approximately in the middle of the interior volume. The button likewise is in a neutral position such that the input surface is horizontal (or substantially horizontal) with respect to a major axis of the input device. However, when the electromagnet is turned on, a resulting magnetic field moves the permanent magnet within the interior volume. More specifically, the permanent magnet rotates about the pivot such that it moves closer to one side of the interior of the interior volume of the wire windings of the electromagnet. The magnet&#39;s motion causes the button to rotate about the pivot as well, moving in an opposite direction to the motion of the permanent magnet. Put another way, while the magnet and button both rotate in the same direction, their directions of motion are opposite one another. Thus, the button&#39;s input surface tilts relative to the major axis (and typically, though not necessarily, relative to an enclosure of an electronic device incorporating the input device). 
     The button may be positioned in, or protrude from, an opening defined in an exterior surface of an electronic device, such that the input surface is accessible by a user. The button may be conformal with the exterior surface, or may project from the exterior surface of the electronic device. In one embodiment, the input surface is substantially aligned or parallel with an adjacent exterior surface of the electronic device when the button is in the neutral position. The button input surface may be tilted with respect to the adjacent exterior surface when the button is in the actuated position. 
     In one embodiment, the input is oblong-shaped and is positioned along an exterior edge of an electronic device, such as a mobile phone. The input device may be or include a key, switch, toggle, or the like instead of a button. 
     The button may actuate in any of several ways. For example, the input device may have a major axis, a minor axis, and a pivot axis such that the button rotates about a pivot axis and within a plane defined by the major axis and the minor axis. In some embodiments, the button may slide or translate along one or both of the major and minor axes. Alternatively or additionally, the major or minor axes may also be the pivot axis. In many embodiments, the pivot axis is parallel to the input surface. 
     In some embodiments and as described in more detail herein, the pivot axis may be adjustable. By adjusting the pivot axis of the input structure, the distance the input surface moves may be changed. As the pivot axis moves further away from the input surface, the travel distance of the input surface increases. Increased travel distance yields greater (and more easily sensed) haptic output, and likewise increases a velocity of the input surface. Some embodiments may permit a user to choose a distance of the pivot point from the input surface in order to customize a feel and/or magnitude of haptic output by adjusting the travel distance and/or velocity of the input surface. 
     In one embodiment, although the button may actuate, the actuation is not required to register a button input for the electronic device. Stated another way, the physical movement or actuation of the button is not required to initiate or terminate an input. Instead, the button actuation may be effected, for example, to provide a type of haptic feedback to the user. 
     Various configurations of a permanent magnet and an electromagnet are disclosed. By varying the relative positions of the permanent magnet and the electromagnet, and/or by varying the configuration of the electromagnet, the strength and/or location of the magnetic field relative to the permanent magnet varies, which in turn adjusts the input device&#39;s actuation kinematics. For example, a permanent magnet positioned closer to a relatively higher strength magnetic field area, as generated by the electromagnet, will be relatively more responsive to the magnetic field, and thus the attached button will be relatively more responsive to the electromagnet. Generally, a more responsive button reacts faster and with fewer time lags to an actuation input. 
     In another embodiment, a permanent magnet is coupled to a button positioned to fit at least partially within or above an electromagnet. The button is configured to rotate, pivot, slide or otherwise move on or about a structural body placed within an electronic device. The permanent magnet, when in its neutral position, extends approximately to the middle of the interior volume of the electromagnet (e.g., an end of the permanent magnet is positioned within the interior volume). The electromagnet produces a magnetic field extending upward and across or through the permanent magnet, resulting in a force that moves the permanent magnet. More specifically, the permanent magnet moves relative to an upper surface of the electromagnet and closer to one edge of the interior volume of the electromagnet wire windings. This second permanent magnet position corresponds to an actuated second button position. 
     In another embodiment of an input device described herein, a permanent magnet is coupled to a button and rests at least partially within an electromagnet. The button is attached to the permanent magnet. The button, in concert with the permanent magnet, is configured to pivot on a structural body. The permanent magnet typically has an axis that is parallel with a pivot axis of the input device. The permanent magnet rotates about the pivot axis in response to the electromagnet generating a magnetic field, in turn rotating or pivoting the button about the structural body. 
     In another embodiment, a permanent magnet attached below a button is positioned to fit within an electromagnet, the electromagnet formed by a set of wire windings. The button is attached to the permanent magnet. The button and permanent magnet are configured to pivot on a structural body placed within an electronic device. The permanent magnet is positioned such that one end rests within an interior volume of the electromagnet. The permanent magnet is positioned in a neutral position within the interior volume of the electromagnet, with the lateral sides of the permanent magnet aligned with interior sides of the encircled electromagnet. The configuration of the electromagnet produces, when a current is flowing through the windings of the electromagnet, a magnetic field extending vertically along the sides of the permanent magnet. The generated magnetic field imparts a torque force to the permanent magnet. The permanent magnet rotates about the pivot axis upon receipt of a magnetic field, as generated by the electromagnet. The rotation of the permanent magnet results in rotation of the button. 
     In some embodiments, the button may also include a force sensor. The force sensor may be coupled the electromagnet or permanent magnet, or may be affixed to another part of the input device and/or associated electronic device. The force sensor may be a Hall Effect sensor, strain sensor, capacitive sensor, resistive sensor, pyroelectric sensor, or optical sensor. 
     Electronic circuits, processors, and/or electro-mechanical systems may control or adjust the magnetic field generated by the electromagnet, which in turn controls or adjusts the actuation of the input device. For example, the amount of current passing through the electromagnet will determine the magnitude of the generated magnetic field, which in turn will determine the kinematics of the button actuation. A processor may also communicate with one or more sensors coupled to the input surface, such as input force sensors, touch sensors, and proximity sensors. 
     Generally, an “input surface” is any surface configured to receive an input, such as a force or touch. An input surface may be a surface of an “input structure,” which is an element configured to accept an input, such as a touch or force, from a user or object. An input structure may be one element of an “input device,” which is any device configured to receive an input and facilitate generating an output in response. Sample input devices may incorporate input structures such as a button, a switch, a key, a trackpad plate, a mouse, and so on. In some embodiments, an edge, side, or other external portion of an electronic device housing may be a single input device, or may be formed from multiple input devices. 
     These and other embodiments are discussed below with reference to  FIGS. 1-12 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  illustrates a sample electronic device that may incorporate a pivoting input device, as described herein. Although a mobile phone is shown in  FIG. 1 , other embodiments may take forms of other electronic devices. Other types of computing or electronic devices can include a laptop computer, desktop computer, tablet computing device, wearable computing or display device (such as a watch, glasses, jewelry, clothing or the like), a digital camera, a printer, a scanner, a video recorder, a copier, a touch screen, and so on. 
       FIG. 1  illustrates an example of an electronic device  100 , here configured as a mobile phone. The electronic device  100  is depicted as a mobile phone with pivoting input device  101 , an enclosure  120 , and a display  103 . A button of the input device  101  extends through a sidewall of the electronic device. The electronic device  100  may include a variety of internal components configured to work with the pivoting input device  101 . 
     The display  103  can be implemented with any suitable technology, taking the form of an LCD display, LED display, CCFL display, OLED display, and so on. The display  103  provides a graphical output, for example associated with an operating system, user interface, and/or applications of the electronic device  100 . Functions of the electronic device  100 , including the display of information, graphics, and the like on the display  103 , may be modified in response to an input provided via the pivoting input device  101 . As some non-limiting example, providing input through the pivoting input device  101 , may wake or sleep the display, may scroll a list of icons (or other information) on the display, may change a state or parameter of the electronic device  100 , may cause a graphic, icon, or other information shown on the display  103  to be modified in some fashion (such as becoming bigger, smaller, appearing, disappearing, and so on), or the like. 
     In various embodiments, a graphical output of the display  103  is responsive to inputs provided in response to the pivoting input device  101 . The enclosure  120  provides a device structure and houses device components, such as a processor. In various embodiments, the enclosure  120  may be constructed from similar materials to the enclosure  120  of  FIG. 1 .  FIG. 12 , discussed below, provides additional details of a sample electronic device. 
       FIG. 2  shows a sample schematic of a pivoting input device  200 . The input device  200  includes an input structure  210  and pivot  220 . An input force  230  may be exerted on an input surface  250  of the input structure  210 . A force sensor  240  may detect the input force  230 . 
     The input structure  210  may rotate about the pivot  220  either clockwise or counterclockwise, as shown by the directional arrows  270   a ,  270   b . As the input structure  210  rotates, the input surface  250  moves substantially transverse (e.g., perpendicularly) to the direction in which the input force  230  is exerted. Although the input surface  250  rotates about the pivot point, a major vector  260  of its motion is transverse to the input force  230  as shown. This transverse motion may induce skin shear in a finger or other body part of a user touching the input surface  250 , which may register to the user as a haptic input. 
       FIG. 3A  is a cross-sectional view of an input device  300  similar to that shown in  FIG. 2 , here implemented as a button for an electronic device. The button  300  may be at least partially contained within, and protrude from, a housing  380  of the electronic device. As shown, in response to an input force the input surface  350  moves primarily tangentially or laterally to the surface of the finger  390  touching the surface, which is also substantially transverse to the input force. The input surface  350  is the top of a button (e.g., input structure)  310 . The button rotates about the pivot  320 ; this rotational motion induces the aforementioned transverse motion of the input surface  350  as illustrated by the directional arrows. A gasket  360  may provide a seal between the input structure  310  and the housing  380  against dust, water, and debris. 
       FIG. 3B  is a second cross-sectional view of the input device  300  shown in  FIG. 3A , taken along line  3 B- 3 B in  FIG. 3A . The cross-sectional view of  FIG. 3B  is offset by 90 degrees from the cross-sectional view of  FIG. 3A . As shown in  FIG. 3B , a cap or upper portion of the button  310  may rest on a gasket  360 . The gasket may not provide physical support to the button, although in some embodiments it may. Rather, the button is held in place by the pivot  320 , which may be a pin running through a shaft of the button  310 . The pivot  320  is secured to a mount  325 . One mount  325  is located at either end of the pivot  320 . The mount is, in turn, affixed to a shelf  335  or other internal structure within the housing  380 . Thus, the input structure  310  is coupled to the shelf  335  though the pivot  320  and mount  325 . 
     An actuator  325  may be physically, electrically, and/or magnetically coupled to the button  310  (e.g., input structure). In the embodiment shown in  FIG. 3B , the actuator  325  is an electromagnet, although in other embodiments the actuator  325  may be a different mechanical, electrical, or magnetic element. The actuator  325  causes the button  310  to rotate about the shaft running through the pivot  320 , in response to an input force. Operation of sample actuators is discussed in more detail below. 
       FIG. 3B  also illustrates a number of alternative pivots  320 A,  320 B,  320 C. In some embodiments the location of the pivot  320  along the input structure  310  may be changed by a user or otherwise as a function of the electronic device (or of software or firmware of the electronic device). Generally, the closer the pivot  320  is to the input surface  350 , the smaller the distance of travel of the input surface  350  is. The travel distance (also referred to as “displacement” or “translation”) directly impacts the force imparted by the input surface  350  to a user&#39;s finger  390  as well as the velocity of the input surface. Accordingly, the closer the pivot  320  is to the input surface  350 , the smaller and less perceptible the haptic output may be. Thus, the location of the pivot  320  along the shaft of the input structure  310  may be varied in order to adjust haptic output provided through the input surface  350 . For example, if the input structure  310  rotates about pivot  320   c . the travel distance of the input surface  350  is less than if the structure rotates about pivot  320   b , which in turn yields less travel for the input surface  350  than if the input structure rotates about pivot  320   a.    
     The pivot  320  also only limits motion of the input structure  310  to rotation, limiting or eliminating pure planar motion of the input surface  350 . Further, the pivot  320  and mounts  325  cooperate to provide structural support for the input structure  310 . Additionally, the pivot  320  and mounts  325  ensure that the force of the haptic output transmitted through the input surface  350  and to the user does not directly oppose the input force. Rather the haptic output force is primarily tangential (and, to some extent, in the same direction as) the input force. Because the input structure  310  does not actively work directly against the input force, the amount of energy required for the actuator to produce the haptic output may be reduced as compared to an actuator that pushed “upward” or against an input force. This may reduce overall power consumption of an electronic device incorporating an input device  300 . 
       FIGS. 4A-4C  illustrate one embodiment of a pivoting input device  401 . The pivoting input device  401  is depicted with button  410  (e.g., an input structure) defining an input surface  412 . A permanent magnet  426  is attached to a lower surface of the button  410 . The permanent magnet  426  may be rigidly attached to the button  410 , such that permanent magnet  426  moves or displaces in concert with the button  410 . 
     The button  410  rotates relative to the body  430  about a pair of pivots  424  (or, in some embodiments, a single pivot). The pair of pivots  424  are attached to body  430  and positioned on each of first and second projections  433 ,  434 , both of which are part of the upper body  432 . Each of the two pivots  424  are positioned between a respective projection  433 ,  434  and a lower surface of the button  410 . Thus, the pivots  424  are below the button  410  (or other input structure) and its input surface  412 . More specifically, one pivot  424  is positioned between the first projection  433  and a first lower end of the button, and another pivot  424  is positioned between the second projection  434  and a second lower end of the button  410 . One pivot  424  is disposed on the first projection  433  and another pivot  424  is disposed on the second projection  434 . The pivot(s)  424  may rotate with respect to the body  430  or may be stationary while permitting the button  410  to rotate relative to the body  430 . 
     The input surface  412  of the button/input structure  410  may be touched, pressed, or otherwise interacted with by a user. In some embodiments, the input surface  410  may translate, deflect, bend, or otherwise move a relatively small distance in response to user input and/or in response to a movement of the permanent magnet  426 . In other embodiments, the input surface  412  does not translate, deflect, bend, or otherwise move in response to a user input. Input may be detected through a force sensor, touch sensor, or combination of the two. Such sensors are not shown for simplicity&#39;s sake. 
     The button  410  may include one or more steps or shelves. The one or more shelves may aid in fitting the button to a host electronic device, such as fitting the button  410  within an opening along an exterior of a host electronic device. The one or more shelves may receive a gasket, the gasket engaging one or more shelves. More description of the fitting of the button  410  to a host electronic device and/or to a gasket is found below with respect to  FIGS. 5A-5C, 6, and 7 . 
     With attention to  FIGS. 4A-4B , the button  410 , in order from an upper portion (e.g., a portion extending from or facing an exterior of a host electronic device) portion to a lower portion (e.g., a portion extending into an interior of a host electronic device), includes an input surface  412 , first upper portion  413 , collar  416 , first shelf  418 , and a second shelf  420 . The collar  416  is narrower and/or thinner than the first upper portion  413  of the button  410 . The collar  416  and first upper portion  413  of the button  410  may have the same general shape or may be of different shapes. As one example, both may be oblong (e.g., lozenge-shaped). The collar  416  is positioned above or otherwise disposed on the first shelf  418 . Generally, the upper button portion  413 , collar  416 , first shelf  418 , and second shelf  420  may all be formed integrally with one another or may be formed separately and affixed to one another. 
     The first shelf  418  of the button  410  is typically wider and/or longer than the collar  416 . In some embodiments, the first shelf  418  is of similar or identical width to the first upper portion  413 . The first shelf  418  may have the same shape as either or both of the upper portion  413  and collar  416 , or may have a different shape. 
     The first shelf  418  and/or the collar  416  may receive a gasket (see, for example,  FIG. 7 .) More specifically, the first shelf  418  and/or the collar  416  may receive a gasket that encircles one or more of the first shelf  418  and/or the collar  416 . The first shelf  418  is positioned above or otherwise disposed on the second shelf  420 . The first shelf  418  is positioned between the collar  416  and the second shelf  420 . 
     The second shelf  420  of the button  410  is generally wider and/or longer than the first shelf  418 . The second shelf  420  may have a similar shape as one or more of the first upper portion  413 , the collar  416 , and the first shelf  418  of the button  410 , or may be differently-shaped. The second shelf  420  may receive a gasket (see, for example,  FIG. 7 .) More specifically, the second shelf  420  may receive a gasket that is disposed on the second shelf  420 . The second shelf  420  is positioned below the first shelf  418 . The second shelf  420  is positioned between the first shelf  418  and connector  422 . 
     Generally, the first shelf, collar, and second shelf cooperate to define a grove, annulus, or the like extending around a perimeter of the button  410 . A gasket or other seal may be seated in this groove, as discussed in more detail below and mentioned above. 
     The connector  422  is positioned below the second shelf  420  and connects the button  410  to the permanent magnet  426 . The connector  422  may be positioned at a central portion of the upper surface of the permanent magnet  426 . The connector  422  may be connected to the permanent magnet  426  along substantially all of the length of an upper surface of the permanent magnet  426 . The permanent magnet may be rigidly connected to the button  410  by way of the connector  422 . In some embodiments, the permanent magnet  426  extends into a space within the body  430 . That is, the body may be hollow or may have multiple projections defining a space receiving at least part of the permanent magnet  430 . 
     The body  430  includes an upper body  432  and a lower body  436 . Each of first projection  433  and second projection  434  are part of upper body  432 ; the first and second projections define a volume or space therebetween in which part of the permanent magnet  426  rests. The upper body  432  and a lower body  436  are separated by a region of reduced width configured to receive an electromagnet  440 . The body may be attached to an enclosure of the electronic device, or a structure within the enclosure. 
     The electromagnet  440  is configured to attach to body  430  and positioned relative to the permanent magnet  426  such that a magnetic field generated by the electromagnet  440  is received by the permanent magnet  426  sufficient to displace or move the permanent magnet  426 . The electromagnet  440  encircles the body  430  (specifically, the first and second projections  433 ,  434  and is positioned between the upper body  432  and the lower body  436 . More specifically, the electromagnet  440  is positioned to fit around a region of reduced width formed between the upper body  432  and the lower body  436 . The electromagnet  440  has a sidewall  446 . Generally, the electromagnet  440  is located below the button  410  (or other input structure) and its input surface  412 . 
     The positioning of the permanent magnet  426  relative to the electromagnet  440  modifies the operation (e.g., actuation) of the button  410 . More specifically, the magnetic interaction between the electromagnet  440  and the permanent magnet  426  is influenced by the relative positioning of the permanent magnet  426  with respect to the electromagnet. In the embodiment of  FIGS. 4A-4C , the lower surface  428  of the permanent magnet  426  is positioned between ends of the electromagnet  440 . Stated another way, a horizontal plane extending from the lower surface  428  of the permanent magnet  426  intersects a sidewall of the electromagnet  440 . In one embodiment, the horizontal plane extending from the lower surface  428  of the permanent magnet  426  intersects the sidewall  446  of the electromagnet  440  at a midpoint of the sidewall  446  (e.g., the end of the permanent magnet  426  is coplanar with a midpoint of the sidewall  446 ). Thus, the permanent magnet  426  extends halfway through the electromagnet  440 . 
     In some embodiments, the permanent magnet  426  may be replaced by a second electromagnet, or may be supplemented by a second electromagnet. Using an electromagnet in place of, or in addition to, the permanent magnet  426  may facilitate fine control of the magnetic force exerted on the button  410  (or other input structure), thereby likewise providing fine control of the force of the haptic output. It should be appreciated that haptic output via the button  410  or other input structure may be increased by increasing the field strength of the second electromagnet or decreased by decreasing its field strength. Likewise, field strength of the first electromagnet  440  may be varied to vary haptic output force even when a permanent magnet  426  is used instead of a second electromagnet. 
     Further, it should be noted that such variations in field strength generally vary haptic output force, but not travel; a distance traveled by the input structure (e.g., button  410 ) and associated input surface varies with the distance of the pivot point from the input surface, as discussed above. Increases in both haptic output force and travel distance may increase force and/or perceptibility of a haptic output. 
     The electromagnet  440  is formed of multiple windings of wire. In one embodiment, the windings of wire comprise copper. In some embodiments, the windings of wire include any of copper, aluminum, metals, and/or or metal alloys that may be used as wire windings to generate a magnetic field, as known to those skilled in the art. In some embodiments, the strength of the magnetic field generated by the electromagnet  440  is supplemented with placement of a core material within the interior volume of an electromagnet formed by windings of wire. Such a magnetic core may be made of, for example, a ferromagnetic material such as iron. A magnetic core increases the strength of a generated magnetic field. Such a magnetic core may be inserted in any of several ways, such as one or more plates positioned within the interior volume of a wire-wounded electromagnet. 
     With attention to  FIGS. 4B-4C , the button  410 , and attached permanent magnet  426 , are depicted in a neutral, unactuated first button position (as shown in  FIG. 4B , which is a cross-section taken along line  4 A- 4 A of  FIG. 4A ) and in an actuated second button position ( FIG. 4C ). The button  410  actuates or pivots between the first button position and the second button position through reaction of the permanent magnet  428  to a magnetic field generated by the electromagnet  440 . 
     The button  410  is attached to the permanent magnet  426  by way of connector  422 ; in many embodiments, the ends of the connector  422  define the pivots  424 . The button  410  is configured to pivot on the body  430  by way of the pair of pivots  424 . In other embodiments, the connector and pivot(s) may be separate elements. The body  430 , permanent magnet  426 , and electromagnet  440  may be disposed within a host electronic device. 
     The electromagnet  440 , which may encircle at least a portion of the permanent magnet  426 , generates a magnetic field which interacts with the permanent magnet  426 , in turn pivoting the button  410  between a neutral, unactuated first button position and an actuated, second button position as discussed in more detail below. 
     When no electric current is flowing through the wire windings of the electromagnet  440 , no magnetic field is generated by the electromagnet  440  and the permanent magnet  426  is in a neutral position that is approximately in the middle of the electromagnet&#39;s interior volume  444 , as shown in  FIG. 4B , with one end within the interior volume. This corresponds to a neutral, unactuated first button position. However, when the electromagnet  440  is turned on, the resulting magnetic field moves (e.g., tilts) the permanent magnet  426  within the interior volume  444 . More specifically, the permanent magnet  426  tilts or rotates about the pivot(s)  423 ,  424  such that its end  428  moves closer to one side of the electromagnet  44 , as shown in  FIG. 43C . Since the button  410  is attached to the permanent magnet  426 , it also moves about the pivot(s) in a direction opposite the motion of the permanent magnet. Put another way, the button (or other input surface) and permanent magnet both rotate in the same direction (e.g., clockwise or counterclockwise) but move in opposite directions, since they are positioned on opposing sides of the pivot(s). Thus, when the electromagnet is activated, the button  410  moves into an actuated position. This motion may provide haptic feedback to a person touching the button  410  (and typically, the button&#39;s input surface  412 ) to indicate the input device  401  has been actuated. In some embodiments, the button  410  and permanent magnet  426  may oscillate back and forth about the pivot  424  to provide haptic feedback. 
     The permanent magnet  426 , when influenced by the magnetic field, moves from its neutral position (as shown in  FIG. 4B ) to its actuated position, as shown in  FIG. 4C . In its neutral position, the permanent magnet&#39;s  426  centerline is generally aligned with a major axis of the input device  401 , as is a centerline of the button  410 . In the actuated position shown in  FIG. 4C , the centerline of the button  412  and permanent magnet  426  is offset from the major axis  439  of the input device  401  by an angle  411 . The angle between the centerline of the button  412  and the major axis  439  is generally the same as the angle between the centerline of the permanent magnet  426  and the major axis  439 . 
     The button/permanent magnet centerline  419  and the major axis  439  intersect at a pivot point  425 . The pivot point  425  is positioned at the bottom of a pivot  424 ; the pivot  424  is not visible in  FIGS. 4B-4C  but is shown in  FIG. 4A . The permanent magnet  426 , and thus the button  410 , rotates about the pivot point in a plane defined by the major axis  439  and the minor axis  441  of the input device  401 . Typically, although not necessarily, the major axis  439  passes through the input surface  412  and button  410 , while the minor axis  441  is parallel to the input surface and button. Likewise, the pivot axis (which passes through the pivot point  425 ) is generally parallel to the input surface. 
     The direction of rotation about the pivot point  425  may change with the direction of current passing through the electromagnet  440 ; thus, the button  410  and permanent magnet  426  may both rotate in two directions (e.g., clockwise or counterclockwise about the pivot point  425 ). As previously mentioned, the permanent magnet  426  and button  410  generally move in opposite directions while rotating about the pivot point  425  and any associated pivot(s)  424 . 
     A user receives haptic feedback from the button  410  actuation in that the input surface  412  of the button  410  pivots with the button  410 . A user touching the input surface  412  may sense the pivoting or actuation of the button  410 . Furthermore, the user may be able to see the pivoting of the button  410  from the neutral, unactuated first position to the actuated, second position. 
     The button  410  (or other input structure) may include a force sensor  417  below the input surface  412  and within the upper portion  413 ; the force sensor is shown in  FIG. 4B , although it should be appreciated that the location of the force sensor  417  may vary in alternative embodiments. For example, the force sensor  417  may be positioned below the input surface  412  and the upper portion  413  instead of within the upper portion, or may be positioned below or to the side of the permanent magnet  426 , or anywhere else within the input device (or on a portion of an associated electronic device&#39;s enclosure). The force sensor  417  senses an input force on the input surface  412  and produces an output signal. The force sensor  417  may be any type of force sensor  417  known to those skilled in the art, such as a strain gauge, a capacitive sensor, a resistive sensor, an optical sensor, and so on. If the force sensor  417  is a capacitive sensor, for example, changes in capacitance may be sensed by the sensor  417  and output as an electrical output signal to the processor. In one embodiment, the force sensor is a strain gauge. The output signal produced by the force sensor  417  is received by a processor. More discussion regarding force sensors as components of a pivoting input device is provided with respect to  FIGS. 11A-11E  below. 
     In one embodiment, a processor is electrically connected to the input device  401 , for example to the force sensor  417 . In one embodiment, the processor is disposed within an enclosure of an electronic device incorporating the input device  401 . 
     The output signal generated by the force sensor  417  allows the processor to control, for example, the electromagnet  440  (or other actuator) to effect actuation of the button  410  and may also be used as a system input to the electronic device. For example, the force sensor output may be used to indicate that a user has pressed or otherwise interacted with the button  410  and thus control or change some function of the electronic device. 
     The processor also may control any of several inputs to the electromagnet  440  to vary the magnetic field generated by the electromagnet  440 . For example, the processor may control the current running through the wire of the actuator  440 . Generally, an increased current will result in an increase in magnetic field strength, thereby moving the permanent magnet  426  more quickly and increasing the haptic output&#39;s strength. 
     The processor may control additional aspects of the electromagnet  440 . For example, upon receipt of the force sensor&#39;s  417  signal, the processor may power up the electromagnet and/or alter the state of the electromagnet so as to ready the electromagnet  440  to generate a magnetic field to actuate the button  410 . Such a scenario may occur if the electromagnet is consistently powered on but at a level that generates a magnetic field of a size and/or strength that does not pivot the permanent magnet  426 . Upon receipt of the output signal from the force sensor  417 , the processor may control the electromagnet  440  to move from stand-by status to a full power-on mode, thereby actuating the button  410  by moving the permanent magnet  426 . In some embodiments, the input device  401  may be configured to actuate (e.g., the button moves) only upon receiving an input exceeding a threshold force level, below which no actuation is triggered. The processor may also receive an output signal from a touch sensor (discussed below with respect to  FIG. 6 .) Additional description of processor operations is found below with respect to  FIG. 12 . 
     In some embodiments, motion of the permanent magnet  426  within the electromagnet  440  may be sensed by measuring the back electromotive force (EMF) of the electromagnet. Generally, the EMF induced in the electromagnet will vary with a magnitude of the permanent magnet&#39;s  426  travel. Further, as a user presses harder on the input surface  412  or otherwise more rigidly constrains the input surface with his or her finger, the permanent magnet&#39;s travel reduces. Thus, if a user has a “stiff” input, the input structure  410  (e.g., button) travel is constrained and this may be sensed by measuring the back EMF of the electromagnet  440  via a sensor. A user may provide a stiff input if the user is exerting high force on the input surface  412 , is wearing gloves, has dry skin, a calloused finger, and so on. Generally, conditions that yield a stiff input also reduce sensitivity to haptic output. Accordingly, when the back EMF of the electromagnet  440  is exceeds a threshold, a processing unit of the input device  401  may direct additional power to the electromagnet  440  to increase the force and perceptibility of haptic output. 
     The button  410  may be positioned in an opening along an exterior surface of an electronic device, such that the button presents an input surface to a user. The button  410  may be conformal with the exterior surface, or may project from the exterior surface of a host electronic device. In one embodiment, the button  410  is oblong and fits along an exterior edge of an electronic device, such as a mobile phone. 
     The button  410  may actuate (e.g., move) in any of several ways. In the embodiment of  FIGS. 4A-4C , the button  410  pivots off the major axis  439  of the input device  401 , which is generally perpendicular to its pivot axis. However, other configurations are possible. For example, the button  410  may be configured to actuate along a minor axis. In some embodiments, the button  410  may actuate in a seesaw manner. In some embodiments, the button  410  moves along a surface or edge of a host electronic device. 
     In one embodiment, although the button  410  may actuate, the actuation is not required to register a button input to an electronic device, such as to register a button input by a processor of an electronic device. Stated another way, the physical movement or actuation of the button  410  is not required to register a button on or off input. Instead, the button actuation is effected to provide a type of haptic feedback to the user. 
     The button  410  may have a variety of shapes, including defining a curved or convex input surface  412 , and/or may be rectangular, square, and so on. As another example, the input surface  412  may be substantially flat. The input surface  412  and/or other parts of the button  410  may include texture such as bumps, ridges, or the like. The button  410  may have radiused, beveled, or flat edges. Generally, the smaller the curvature of the input surface  412 , the greater the shear (e.g., transverse displacement) of the user&#39;s skin contacting the input surface and thus the greater the perceptibility of the haptic output. Accordingly, travel of planar input surfaces  412  may be more easily perceived by a user than the same travel of a curved input surface. The curvature of the input surface  412  may be selected to impart a particular haptic output or particular perceptibility of a haptic output. 
     Generally, if the curvature of the input surface  412  equals the curvature of an arc segment along which the input surface  412  travels during rotation of the input structure  410  about the pivot, the skin of a user&#39;s finger in contact with the input surface  412  experiences purely tangential motion from the input surface. The “arc segment” is the portion of a circle through which a point on the input surface moves while the input structure rotates. Put another way, if every point of an input surface  412  lies on a single arc circumscribed by the entirety of the input surface  412  while haptic output is provided, then the curvature of the input surface equals the curvature of an arc segment. Put still another way, if the distance from the pivot  424  to every point of the input surface within the rotational plane is equal, then the curvature of the input surface  412  matches the curvature of the arc segment during rotation. Purely tangential motion of the input surface  412  against a user&#39;s skin yields a high degree of skin shear and a unique feeling of haptic output. Generally, such haptic output is indistinguishable or near-indistinguishable from a “click” or depress of a typical button that moves in the direction of an input force. 
     By changing the curvature of the input surface  412 , the feel of the haptic output may be varied. The more the curvature of the input surface varies from the arc segment along which the input surface  412  travels during rotation, the more the haptic output feels like a “rocking” motion to a user as opposed to a “clicking” or depressing/collapsing motion. The curvature of the input surface  412  may be tuned to provide particular haptic outputs, as desired or necessary. 
       FIGS. 4A-C  illustrate another embodiment of a pivoting input device  501 . The pivoting input device  501  is similar to the embodiment of  FIGS. 4A-4C  except that the pivoting input device  501  includes a retainer  550  and gasket  522  coupled to an upper portion of a button  510  (or other input structure), and employs a pair of pins  554  rather than pivots. The pins  554  fit between the body  530  and the button  510 , and allow the button and permanent magnet  526  to rotate relative to the body  530 . 
     The button  510  defines an input surface  512  and incorporates a force sensor  517 , although in other embodiments the force sensor may be positioned in different areas as described above with respect to  FIGS. 4B-4C . The input surface  512  of button  510  may be touched, pressed, or otherwise interacted with by a user. The button  510  engages the retainer  550 , which is located below the button  510 . A gasket  522  is disposed below the retainer  550  and above pins  554 . 
     The retainer  550  may be disposed or positioned between the button  510  and the body  530 . More specifically, the retainer  550  may be positioned at a first end of the body  530 , between an edge of the body adjacent the first body surface  533  and an outer edge of the button  510 . The retainer may conceal the pins  542 , permanent magnet  526 , and/or electromagnet  540  from view when the input device  501  is installed in an electronic device. The retainer may contrast with the button  510  to enhance visibility of the button and/or retainer. This may call attention to the button  510 , thereby indicating to a user where he or she can provide input. 
     The gasket  522  is positioned below the retainer  550 . In some embodiments, it may encircle the retainer  550  and/or a portion of the button  510 , although this is not necessary. The gasket  522  may provide a seal between the button  510  and the interior volume  544  of the electromagnet  540 . A “seal,” as used herein, may be used to refer to closing off an opening or a connection. When referenced to a part or component, the term “seal” may refer to an element or a group of elements that blocks or inhibits the ingress or entry of foreign debris or contaminants. 
     The body  530  includes an upper body  532  and a lower body  536 . A portion of the upper body  532  has a reduced thickness and is encircled by an electromagnet  540 . The lower body  536  may be attached to a structure within an enclosure of a host electronic device, or directly to the enclosure itself, in order to anchor the input device  501  to the electronic device. 
     The pins  554  connect the body  530  to the permanent magnet  526  (or, in some embodiments, the button  510 ). Each pin  554  extends into the body  530  and also extends into the electromagnet  526  or button  510 . The pins  554  are axially aligned with one another and are positioned on opposite ends of the electromagnet  526  or button  510 . The pins  554  allow the button to rotate relative to the body  530 , similar to the pivots in the embodiment of  FIGS. 4A-4C . 
     The permanent magnet  526  is attached to a lower surface of the button  510 . The permanent magnet  526  may be rigidly attached to the button  510 , such that the permanent magnet  526  moves or displaces in concert with the button  510 . The permanent magnet  526  may be affixed to the button  510  by a connector as with the embodiment of  FIGS. 4A-4C , or may be affixed directly to the button  510 . As shown in  FIGS. 5A-5C , the electromagnet  526  is affixed directly to the body  510 . 
     The button  510  pivots relative to the body  530  about the pins  554 . The pins  554  may rotate within an interior volume disposed within the body  530  and/or rotate within an interior volume disposed within the button  510 . In one embodiment, the pins  554  may be fixed and not rotate within an interior volume disposed within the body  530  or within an interior volume disposed within the button  510 . 
     The electromagnet  540  is positioned relative to the permanent magnet  526  such that a magnetic field generated by the electromagnet  540  passes through the permanent magnet  526 . As with prior embodiments, the permanent magnet  526  may move (e.g., rotate) when the electromagnet  540  generates its magnetic field. The electromagnet  540  encircles the body  530 , as previously mentioned. The electromagnet  540  has a sidewall  546 . 
     As discussed with regards to the embodiment of  FIGS. 4A-4C , the positioning of the permanent magnet relative to the electromagnet influences the operation or actuation of the button. More specifically, the magnetic interaction between the electromagnet  540  and the permanent magnet  526  is influenced by the relative positioning of the permanent magnet  526  with respect to the electromagnet  540 . In the embodiment of  FIGS. 5A-5C , the lower surface  528  of the permanent magnet  526  is positioned within the electromagnet  540  while a portion of the permanent magnet projects above the electromagnet. 
     The electromagnet  540  may be formed from multiple wire windings, similar to the electromagnet  440  of the embodiment of  FIGS. 4A-4C . In some embodiments, an actuator other than an electromagnet  540  may be used. For example, an actuator made of a shape-memory alloy, such as nitinol, may be used. The nitinol may be heated by an electric current, as one example; once the nitinol is heated sufficiently, its shape may change. The nitinol may be affixed to the button  510  such that a change in shape of the nitinol exerts sufficient force to rotate the button  510  about the pins  554  extending through the pivot point  525 . In some embodiments, piezoelectric actuators and/or reluctance actuators may be used. Other mechanical (e.g., springs, levers, detents, and the like) or electrical (such as electrostatic) actuators may be employed in this or any other embodiment discussed herein instead of electromagnets and/or magnets. 
       FIGS. 5B-5C  are simplified cross-sectional views of the input device  510  shown in  FIG. 5A  and illustrate actuation of the device. In the cross-sectional view of  FIG. 5B , which is taken along line  5 B- 5 B of  FIG. 5A , the button  510  and attached permanent magnet  526 , are depicted in a first neutral, unactuated position.  FIG. 5C  shows the button  510  and permanent magnet  526  is a second, actuated position. The button  510  actuates or pivots between the first button position and the second button position in response to motion of the permanent magnet  526  caused by a magnetic field generated by the electromagnet  540 , as discussed above with respect to  FIGS. 4A-4C . 
     As discussed, the button  510  rotates about a pivot point  525  defined by the pins  554  and thus rotates, tilts, or pivots relative to the body  530 . The body  530  may be disposed within a host electronic device (see, for example,  FIG. 6 ) and remain stable with respect to the electronic device. 
     Similar to the embodiment of  FIGS. 4A-4C , when no electric current is flowing through the wire windings of the electromagnet  540 , no magnetic field is generated by the electromagnet  540 , and the permanent magnet  526  is positioned in a neutral position, with one end approximately in the middle of the electromagnet&#39;s interior volume  544  as shown in  FIG. 5B . However, when the electromagnet  540  is turned on, the permanent magnet  526  is influenced by the magnetic field and pivots/rotates within the interior volume  544  of the wire windings of the electromagnet  540 . More specifically, an end of the permanent magnet  526  moves closer to one side of the electromagnet  540 . This causes the button to likewise move, albeit in an opposite direction, to its actuated position. 
     The permanent magnet  526  is influenced by the magnetic field so as to pivot to an angle  511  from a body centerline  539 . The angle  511  is defined by the button centerline  519  and the body centerline  539 . The button centerline  519  and the body centerline  539  intersect at the pivot point  525 . The pivot point  525  is positioned at the axial centerline of the pair of pins  554 . The button  510  may also rotate in a direction opposite to that shown in  FIG. 5C . The pivot point  525  defines a pivot axis; the pivot axis is generally parallel to the input surface. 
     The permanent magnet  526 , when influenced by the magnetic field, moves from its neutral position of  FIG. 5B  to its actuated position, as shown in  FIG. 5C . In its neutral position, the permanent magnet&#39;s  526  centerline  519  is generally aligned with a major axis of the input device  501 , as is a centerline of the button  510 . In the actuated position shown in  FIG. 5C , the centerline  519  of the button  512  and permanent magnet  526  is offset from the major axis  539  of the input device  501  by an angle  511 . The angle between the centerline of the button  512  and the major axis  539  is generally the same as the angle between the centerline of the permanent magnet  526  and the major axis  539 . 
     The button/permanent magnet centerline  519  and the major axis  539  intersect at a pivot point  525 . The pivot point  525  is defined by the position of the pins  554 ; the pins  554  are not visible in  FIGS. 5B-5C  but are shown in  FIG. 5A . The permanent magnet  526 , and thus the button  510 , rotates about the pivot point  525  in a plane defined by the major axis  539  and the minor axis  555  of the input device  401 . The direction of rotation about the pivot point  525  may change with the direction of current passing through the electromagnet  540 ; thus, the button  510  and permanent magnet  526  may both rotate in two directions. As previously mentioned, the permanent magnet  526  and button  510  generally move in opposite directions about the pivot point  525  and any associated pins  554 , although they both rotate either clockwise or counterclockwise together about the pivot point  525 . Such rotation (whether a single motion in one direction or oscillation) generates haptic feedback to a user, as described above. 
     The embodiment shown in  FIGS. 5A-5C  may incorporate a force sensor  517 . The function of the force sensor  517  and its operation are similar to the function and operation of the force sensor  417  described with respect to  FIGS. 4A-4C . 
       FIG. 6  is a cross-section of another embodiment of a pivoting input device  601 . The pivoting input device  601  is similar to the embodiment of  FIGS. 4A-4C  except that the pivoting input device  601  includes a gasket  652  coupled to an upper portion of a button  610 , and a touch sensor  619  in addition to a force sensor  617 . The touch sensor may be positioned on the input surface  612 , at an edge of the button  610 , below the button  610 , and so on (as may the force sensor  617 ). The button  610  of the pivoting input device  601  is fitted within an opening  604  of an enclosure  603  of an electronic device  600 . 
     The button  610  is an input structure that defines an input surface  612 . A permanent magnet  626  is attached to a lower surface of the button  610 . The permanent magnet  626  may be rigidly attached to the button  610 , such that permanent magnet  626  moves or displaces in concert with the button  610 , as discussed above with respect to other embodiments. 
     Similar to the embodiment of  FIGS. 4A-4C , the button  610  pivots relative to the body  630  about one or more pivots  624  located below the input surface  612  of the button  610 . The pivots  624  are attached to body  630  on each of two sides of the button  610 , although a single pivot may run through or below the button. 
     The button  610  defines a groove, annulus, or other groove or recess, in which a gasket  652  is seated. The gasket  652  encircles the button  610  and functions as a seal between the button  610  and the opening  604  of the electronic device  600 . 
     The body  630  secures the pivots  624  and surrounds the electromagnet  640 . Each of the pivots  624  are disposed on an upper surface of the body  630 . The body  630  may be attached to a structure within the interior volume  644  of the electronic device  600  or directly to the enclosure  603 . 
     The electromagnet  640  is disposed within, and attached to, the body  630 . As discussed above, an actuator other than the electromagnet  640  may be incorporated into the pivoting input device  601  in order to provide haptic output. 
     Generally, the input device  601  operates as discussed with respect to  FIGS. 4A-4C , in that the electromagnet  640  generates a magnetic field that tilts or rotates the permanent magnet  626  and button  610  about the pivots  624 . Haptic feedback may be provided to a user through the button  610  as described above; this haptic feedback may be a single motion (for example, a “click”) or oscillation. Likewise, operation of the force sensor  617  is analogous to operation of the force sensor  417  of  FIGS. 4A-4C . The touch sensor  619  may operate in place of, or in addition to, the force sensor  417  to sense an input. The touch sensor  619  may also function as a proximity sensor or may be replaced by a proximity sensor in some embodiments, or may be omitted entirely. The electromagnet  640  may remain off until the touch sensor  619  detects an input, or a proximity sensor detects an object (such as a finger, stylus, or the like) near the input surface  612 . 
     In some embodiments, the proximity sensor may be fitted to or incorporated into the enclosure  603 . In one embodiment, the proximity sensor is disposed within the interior volume  644  of the enclosure  603  and/or is embedded in the input surface  612 . 
       FIG. 7  is a sample exploded view of portions of a pivoting input device  701  and a portion of an enclosure  703  of an electronic device. 
     One or more openings  704  are defined in the enclosure  703 . The opening  704  is shaped to receive a button  710  of the input device  701 . More specifically an upper portion of button  710 , when fitted within opening  704 , protrudes or projects from the enclosure  703 . As previously discussed the button  710  defines an input surface  712 . The input surface  712  may protrude from, or be accessible through, the opening  704 . A force sensor (not shown in  FIG. 7 ) may be positioned within the button  710  below the input surface, on a mounting plate supporting the input device  701 , below the button  710  and input surface in another location, on a sidewall of the enclosure  703 , and so on. 
     Gasket  762  is shaped to fit around a perimeter of the button  710 . More specifically, gasket  762  fits around and/or contacts a groove defined by one or more of the set of shelves  418 ,  420  and collar  416 , as described with respect to the embodiment of  FIGS. 4A-4C . For example, with respect to  FIG. 4B , in one embodiment, the gasket  762  may be disposed on second shelf  420  and encircle first shelf  418 . In one embodiment, the gasket  762  may be disposed on second shelf  420  and encircle both first shelf  418  and collar  416 . Returning to  FIG. 7 , the gasket  762  may be positioned around button  710  and below the enclosure  703 . 
     The permanent magnet  726  is below the button  710  and attached to a lower surface of the button  710 . In one embodiment, the permanent magnet  726  is attached to the button  710  by way of a connector, such as the connector  422  described with respect to the embodiment of  FIGS. 4A-4C . In other embodiments, the permanent magnet  726  is attached to the button  710  directly. 
     Electromagnet  740  fits around a boss  706  of a mounting plate  732 , and generally sits within the body  730 . A front portion of the body  730  is removed in order to show the boss  706 . One or more pivot points  725  are defined on the top of the body  730 . The electromagnet  740  may be connected to the body  730 , which in turn may be attached to an enclosure of an electronic device or a structure (such as the mounting plate  732 ) that is affixed to, or stationary with respect to, the enclosure. Likewise, a pivot  724  or pivots may connect the electromagnet  740  or button  710  to the body, as discussed above. As shown in  FIG. 7  and discussed elsewhere herein, the pivot(s)  724  are generally below the button  710 , or at least below the input surface  712  of the button. 
     The combined button  710  and gasket  762 , with attached permanent magnet  726 , are positioned such that at least a portion of the permanent magnet is received within an inner volume of the electromagnet  740 . 
     As discussed above, the configuration of an electromagnet and the relative positioning of a permanent magnet to the electromagnet determine the kinematics of the permanent magnet (and thus the button attached to the permanent magnet.) More specifically, different configurations of the electromagnet produce different magnetic field configurations, and different relative positioning between the electromagnet and the permanent magnet result in different responses to the magnetic field. 
       FIGS. 8A-8B  illustrate another sample pivoting input device  801 . The pivoting input device  801  is similar to the embodiment of  FIGS. 4A-4C . Here, the pivoting input device  801  employs one or more pins  824  affixing the button  810  to the electromagnet  840 , and the electromagnet  840  is positioned entirely below the permanent magnet  826 . The pins  824  allow the button  810  to rotate relative to a host electronic device. Note that  FIG. 8B  is a cross-section taken along line  8 B- 8 B of  FIG. 8A . 
     With attention to  FIGS. 8A-8B , the pivoting input device  801  includes a button  810  attached to a permanent magnet  826  by one or more pins  824 . The button  810  also is attached by the more pins  824  to a central post affixed to the base  838  or one or both of the sidewalls (the post is omitted in order to show details of the input device  801 ). Generally, there is a central post at each end of the button but only one is visible in  FIG. 8A . The pins  824  also pass through a permanent magnet  826  that is affixed to the button  810 . As with other embodiments, the button  810  defines an input surface  812  that may be touched or pressed by a user. 
     Sidewalls  832 ,  834  are positioned on either side of the permanent magnet  826 ; the sidewalls  832 ,  834  are separated from the permanent magnet  826  by a gap. The sidewalls may be made from a ferritic (or magnetic) material and function to provide a path for, and contain, the magnetic field  846  generated by the electromagnet  840 , as discussed below. In some embodiments the sidewalls are made from a non-ferritic material. In some embodiments, the sidewalls  832 ,  834  are magnetic and repel the permanent magnet  826  when the permanent magnet is in its neutral position, thereby keeping the permanent magnet in such a position. 
     The sidewalls  832 ,  834  may be mounted to the electromagnet  840 , which in turn may be mounted on a base  838 . Accordingly, the electromagnet  840  is positioned below the permanent magnet  826 . The central post(s) are likewise typically mounted to the base  838 . The base, in turn, may be attached to an enclosure of an electronic device. 
     Generally and as shown in  FIGS. 8A-8B , the button  810  does not contact either sidewall  832 ,  834  in its neutral position or during operation. Likewise, the permanent magnet  826  does not contact the sidewalls  832 ,  834  in its neutral position. The permanent magnet  826  may contact the sidewalls during operation, or the magnetic field may be controlled to prevent such contact. 
     In order to cause the permanent magnet  826  and button  810  to pivot about the pins  824 , the electromagnet  840  is actuated. The electromagnet produces a magnetic field  846  as represented by the dashed arrows in  FIG. 8B . It should be appreciated that flux of the magnetic field may be reversed from the direction shown in  FIG. 8B  as well. The magnetic field passes through, and is optionally shaped by, the sidewalls  832 ,  834 . Put another way, the sidewalls  832 ,  834  may form part of a return path for the magnetic field. 
     The magnetic field  846  also passes through the permanent magnet  826 . The permanent magnet  826  experiences force along the field lines of the magnetic field  846 . Since the permanent magnet  826  is constrained by the pin(s)  824 , it cannot translate or otherwise move laterally. Rather, the force causes the permanent magnet  826  to rotate or pivot about the pin(s)  824 . As with other embodiments, this induces an opposite pivoting motion in the button  810  attached to the permanent magnet. This, in turn, may provide haptic and/or visual feedback to a user. 
     The direction and strength of the magnetic field  846  may be controlled to re-center and stabilize the permanent magnet  826  (and thus the affixed button  810 ) in its neutral position. 
       FIGS. 9A-9B  illustrate another embodiment of a pivoting input device  901 .  FIG. 9B  is a cross-section taken along line  9 B- 9 B of  FIG. 9A . The pivoting input device  901  is similar to the embodiment of  FIGS. 8A-8B , but here the electromagnet  940  encircles the permanent magnet  926 , and the permanent magnet  926  is attached to the button  910  at locations at or adjacent to the pins  924 . The pins  924  allow the button  910  to rotate relative to the electromagnet  940 . The electromagnet may be at least partially contained within a body  930  through which the pins  924  pass. The electromagnet  940  is generally stationary with respect to the body  930  while the button  910  and permanent magnet  926  rotate and/or translate relative to the body during actuation. 
     The permanent magnet  926  is positioned in a neutral position within, and approximately in the middle of, an interior volume of the electromagnet  940 . The permanent magnet  926  is generally cylindrical or rectangular, optionally with rounded corners. The permanent magnet  926  is configured to fit, at each end point, around a respective pin  924 . The permanent magnet  926  and the electromagnet  940  are fitted between opposing sides of end bodies  939 . 
     With attention to  FIG. 9B , when a current flows through the windings of the electromagnet  940 , the electromagnet  940  produces a magnetic field  946  extending around and encircling the permanent magnet  926 , resulting in a torque or twisting force on the permanent magnet  926 . This rotates the permanent magnet  926  about the pins  924 , thereby rotating or actuating the attached button  901 . 
       FIGS. 10A-10B  illustrate another embodiment of a pivoting input device  1001 .  FIG. 10B  is a cross-section taken along line  10 B- 10 B of  FIG. 10A . The pivoting input device  1001  is similar to the embodiment of  FIGS. 9A-9B  except that the electromagnet  1040  is rotated 90 degrees with respect to the prior embodiment. The electromagnet  1040  encircles the permanent magnet  1026 . The permanent magnet  1026  is attached to the button  1010 , as with prior embodiments. A set of two pins  1024  are located at opposite ends of the button  1010  and attached to the body  1030 . The pins  1024  allow the button  1010  to rotate relative to the body and any electronic device to which the body is attached. With attention to  FIG. 10A , the permanent magnet  1026  is configured to fit within the electromagnet  1040 . The permanent magnet  1026  is positioned in a neutral position within an interior volume of the electromagnet  1040 . 
     With attention to  FIG. 10B , the electromagnet  1040  produces, when a current flows through the windings of the electromagnet  1040 , a magnetic field  1046  extending around and encircling the permanent magnet  1026  in longitudinal planes, resulting in a torque or twist force on the permanent magnet  1026 . This rotates the permanent magnet  1026  about the pins  1024 , thereby rotating or actuating the button  1010 . In the orientation shown in  FIG. 10B , the magnetic field extends in and out of the page (e.g., is generally in a plane parallel to the pins  1024 ), while rotation of the permanent magnet  1026  is in-plane with the cross-section as shown. 
       FIGS. 11A-11E  illustrate various embodiments of an electromagnetically-driven pivoting input device with a force sensing capability. The force sensing capability may be coupled to electromagnetic components of the button, or may operate independently of the electromagnetic components. The force sensor may be any of several types known in the art, including Hall effect sensors, strain sensors, capacitive sensors, and optical sensors. 
     With attention to  FIG. 11A , another embodiment of a pivoting input device  1101  is depicted. The pivoting input device  1101  is similar to the embodiment of  FIGS. 4A-4C  except that the pivoting input device  1101  includes a Hall effect force sensor  1170  and the button  1110  includes a pair of pivots  1124  integrated with the button  1110 . 
     The pivoting input device  1101  is depicted as a button system with button  1110  fitted to an enclosure  1103  of an electronic device. A permanent magnet  1126  is attached to a lower surface of the button  1110 . The permanent magnet  1126  may be rigidly attached to the button  1110 , such that permanent magnet  1126  moves or displaces in concert with the button  1110 . 
     The button  1110  pivots relative to the body  1130  by way of an integrated pair of pivots  1124 . The pair of pivots  1124  are formed from the button  1110  on a lower surface of the button  1110 . Each of the two pivots  1124  are positioned between the lower surface of the button  1110  and an upper surface of the body  1130 . An input surface of the button  1110  may be touched, pressed, or otherwise interacted with by a user. 
     The electromagnet  1140  is configured to attach to body  1130  and positioned relative to the permanent magnet  1126  such that a magnetic field generated by the electromagnet  1140  is received by the permanent magnet  1126  sufficient to displace or move the permanent magnet  1126 . The electromagnet  1140  is positioned to encircle the body  1130 . 
     A Hall effect sensor  1170  is positioned on a lower portion of the body  1130 , below the permanent magnet  1126 . The Hall effect sensor  1170  may be positioned such that a portion of the Hall effect sensor  1170  is within a portion of the interior volume defined by the electromagnet  1140 . In some embodiments, the Hall effect sensor  1170  is positioned entirely below the electromagnet  1140 . Other positions for the Hall effect sensor  1170  are possible, such as along an edge of the body  1130 . 
     Generally, a Hall effect sensor provides a voltage output in response to a magnetic field. In one Hall effect sensor configuration, a metal strip provides a current along a length. In the presence of a magnetic field, the flowing electrons of the current will deflect to an edge of the metal strip, perpendicular to the metal strip length, causing a measurable voltage change across the width of the metal strip. 
     The Hall effect sensor  1170  may be calibrated to detect a change in magnetic field caused by a vertical movement of the button  1110 . More specifically, a vertical movement of the button  1110  (caused by, for example, a force input to a surface of the button  1110 ), will vertically move the permanent magnet  1126  attached to the button  1110 , thereby causing a change in the magnetic field of the electromagnet  1140 , as measured by the Hall effect sensor  1170 . The Hall effect sensor  1170  may be calibrated to remove magnetic field change measurements caused by rotation of the button  1110  about pivots  1124 , and therefore solely measure an input force imparted by a user to a surface of the button  1110 . The measurements of the Hall effect sensor may be output to a processor of the electronic device such that a determination of the input force may be generated. More discussion of the processor of a host electronic device is provided below with respect to  FIG. 12 . 
     With attention to  FIG. 11B , another embodiment of a pivoting input device  1101  is depicted. The pivoting input device  1101  is similar to the embodiment of  FIG. 11A  except that a set of strain gauges  1172 ,  1173  are provided. The set of strain gauges  1172 ,  1173  provide a measurement of force input to the button  1110 . The pivoting input device  1101  is positioned to fit with an enclosure  1103  of an electronic device. 
     A pair of first strain gauges  1173  are positioned between a lower surface of the enclosure  1103  of an electronic device and the body  1130  of the pivoting input device  1101 . A second strain gauge  1172  is mounted to a lower surface of the body  1130 . Other locations for the set of strain gauges  1172 ,  1173  are possible, such as between a lower surface of the pair of pivots  1124  and an upper surface of the body  1130  receiving the pair of pivots  1124 . 
     Generally, a strain gauge measures a change in electrical resistance in response to a deformation. The resistance change may be correlated to the stress or force that caused the deformation or induced strain in the strain gauge. A common strain gauge includes a set of conductive wires arranged in a long, thin strip. 
     In some embodiments, the first and second strain gauges  1172 ,  1173  measure different components of a force, or forces exerted along different axes. Thus, the first strain gauge  1172  may measure forces along a first axis while the second strain gauge  1173  measures forces exerted along a second axis perpendicular to the first axis. The measurements of the strain gauges  1172 ,  1173  may be output to a processor of the electronic device such that a determination of the input force may be generated. 
     With attention to  FIG. 11C , another embodiment of a pivoting input device  1101  is depicted. The pivoting input device  1101  is similar to the embodiment of  FIG. 11A  except that a capacitive gap sensor is provided. The capacitive gap sensor provides a measurement of force input to the button  1110 . 
     The capacitive gap sensor includes a first capacitive plate  1175  coupled to a first body  1174 , a second capacitive plate  1177  coupled to a second body  1176 , and a gap  1178  between the first capacitive plate  1175  and the second capacitive plate  1177 . 
     Generally, a capacitive gap sensor measures a change in capacitance between two parallel electrically charged plates. The capacitance changes with distance between the plates. The change in capacitance may be correlated to the change in force that caused the change in distance between the plates. The gap may be an air gap or may be fitted with a material, such as a compressible material and/or a dielectric material. 
     With a force input to a surface of the button  1110 , the gap  1178  between the first capacitive plate  1175  and the second capacitive plate  1177  will be reduced, causing a change in capacitance. The change in capacitance may be output to a processor of the electronic device such that a determination of the input force may be generated. 
     With attention to  FIG. 11D , another embodiment of a pivoting input device  1101  is depicted. The pivoting input device  1101  is similar to the embodiment of  FIG. 11A  except that an induction loop formed by components of the pivoting input device  1101  is used to provide a measurement of force input to the button  1110 . 
     A vertical movement of the permanent magnet  1126  will cause a change to the magnetic field  1146  generated by the electromagnet  1140 . If the magnetic field  1146  is kept constant, a change to the voltage of the electromagnet  1140  will occur. The change in voltage  1180  may be correlated to the vertical movement of the permanent magnet  1126 , which in turn may be correlated to a force input to a surface of the button  1110 . The change in voltage may be output to a processor of the electronic device such that a determination of the input force may be generated. 
     In one embodiment, the permanent magnet  1126  may comprise a first magnet and a second magnet. The first magnet may be used to rotate an attached button  1110  as described in prior embodiments. The second magnet may be used in the induction force sensor as described above. More specifically, movement of the second magnet, caused by a user input to an input surface of the button  1110 , is measured by a voltage  1180  change of the electromagnet  1140 , which is calibrated to a magnitude of force input. 
     With attention to  FIG. 11E , another embodiment of a pivoting input device  1101  is depicted. The pivoting input device  1101  is similar to the embodiment of  FIG. 11A  except that a pair of optical sensors  1191 ,  1192  are provided. The pair of optical sensors  1191 ,  1192  provide a measurement of force input to the button  1110 . 
     Generally, an optical sensor measures distance by measuring time of receipt of a transmitted signal. The time is reduced with reduced distance. A reduced distance may in turn be correlated to a force required to reduce the distance, and thus provide a measure of force. 
     A first optical sensor  1191  is positioned on a lower surface of the permanent magnet  1126 . A second optical sensor  1192  is positioned on an inside upper surface of the body  1130 . The first optical sensor  1191  may be aligned vertically with the second optical sensor  1192  such that the first optical sensor  1191  cooperates with the second optical sensor  1192 . For example, the first optical sensor  1191  may broadcast an optical signal sensed by the second optical sensor  1192 , and vice versa. The measures of changed distance provided by the first optical sensor  1191  and/or the second optical sensor  1192  are correlated to a force required to change the measured distance, thereby providing a measure of force input to an input surface of the button  1110 . The measurements of the first optical sensor  1191  and/or the second optical sensor  1192  may be output to a processor of the electronic device such that a determination of the input force may be generated. 
     Other configurations of optical sensors are possible. For example, the first optical sensor  1191  may be replaced with a reflective surface which receives and reflects an optical emission from the second optical sensor  1192 . The reflective surface, disposed on the permanent magnet  1126 , will move vertically with vertical movement of the button  1110 . The second optical sensor  1192  will detect the vertical movement of the reflective surface, and thus vertical movement of the permanent magnet  1126  and the button  1110 , by detecting a reduced travel time of an optical emission. 
     As mentioned above, the force sensor may be any of several types known in the art, to include those described above with respect to  FIGS. 11A-11E . Other force sensor types may include piezoelectric force sensors, linear variable differential transducers, load cells such as pneumatic load cells and hydraulic load cells, etc. 
     The force sensor may be used for purposes other than or in addition to force measurement. For example, the force sensor may be used to prepare the pivoting input device to move or otherwise operate the electromagnetically-sensitive button by, for example, turning on the electromagnet upon receipt of a threshold level of force by the button. In another example, the force sensor may be used to activate an alternate notification, such as an audio notification, to the user upon receipt of a threshold level of force by the button. 
     In one embodiment, the kinematics of the button movement are influenced or coupled to the level of force measured by the force sensor. For example, a first level of force received may result in a button rotation of a first rotation speed, whereas a higher second level of force received may result in a button rotation of a second higher rotation speed. 
       FIG. 12  illustrates an example pivoting input device  1200  according to various embodiments. The pivoting input device  1200  includes an input structure  1202  (such as a button), a sensor  1203 , a processor  1204 , an actuator  1206  such as an electromagnet, and optionally a permanent magnet  1208 . A user applies an input to the input structure  1202 . The presence of the user input is identified by the sensor  1203  which in turn sends a signal to the processor  1204 . 
     The processor  1204  determines the appropriate response for the identified input. For example, for a pivoting input device  1200  similar to the embodiment of  FIGS. 5A-5C , the processor  1204  may determine if the input force exceeds a selectable threshold value. If the threshold value is exceeded, the processor  1204  instructs the actuator  1206  to rotate the input structure  1202 . If the actuator  1206  is an electromagnet, it may generate a magnetic field, the magnetic field in turn moving the permanent magnet  1208  and thus moving the input structure  1202  from a neutral position to an actuated position or otherwise providing a haptic and/or visual output to a user, such as a vibration of the input structure  1202 . If, however, the input force does not exceed the threshold value, the actuator  1206  does not generate any magnetic field and the input structure  1202  remains in its unactuated position. In some embodiments, no threshold force value is considered, and any non-zero input force would trigger actuation of the input device. Note that a threshold value operation may avoid accidental or nuisance activation of the input device. This is an example of an open-loop system. 
     Embodiments alternatively may operate as closed-loop systems. For example, a sensor may monitor a pivot angle, degree of rotation, exerted force, or the like of the input device  1200  while haptic output is provided. These sensed parameters may be used as feedback for the actuator in order to adjust operation of the input device  1200 . As one example, more or less power may be provided to the actuator  1206  in order to adjust rotation of the input structure. 
     Some embodiments described herein may rotate or oscillate sufficiently quickly not only to provide a haptic output but also to provide audio output. The input structure&#39;s  1202  rotation (or other motion) may occur at frequencies that enable audible sound, typically from 20 Hertz to 20,000 Hertz. Input waveforms to the actuator  1206  may be shaped to provide both haptic output and audio output substantially simultaneously. For example, the actuator  1206  may rotate the input structure  1202  at haptic frequencies for a brief time and then at audio frequencies for a brief time. So long as each haptic output is sufficiently close in time to the next, a continuous haptic sensation may be felt. Likewise, so long as each audio output is sufficiently close in time to the next, a user may perceive continuous audio even if the input device  1200  switches to a haptic output in between audio outputs. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20180629
Publication Date: 20200630
Grant Date: 20200630
Priority Date: 20180403
Inventors: BEYHS, MICHAEL J.
SALADA, MARK A.
MCCLAIN, MEGAN A.
BAUGH, BRENTON A.
GLEESON, BRIAN T.
Miller, Thayne M.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H2003/008", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0338", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/236", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H3/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H9/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2215/05", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/236", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2221/01", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0338", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/236", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0338", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0202", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H9/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/022", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2221/01", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2215/05", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H3/12", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 71125068