Patent Publication Number: US-9412537-B2

Title: Bend switch for wired headset

Description:
The present application is a continuation of co-pending, commonly-assigned U.S. patent application Ser. No. 11/650,001, filed Jan. 5, 2007, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention is directed to a switch for electrical and electronic devices. 
     Electrical switches for controlling functions of electronic devices are well known in the art. For example, media or communication devices include switches that are used to activate particular functions of the device (e.g., on/off, play, select or volume switch). To provide control of functions at a location remote from the media or communication device, switches that are incorporated in wires attached to the device have been developed (e.g., switches in wired headsets plugged into an audio device with a jack). For example, a headset can include a wheeled switch for controlling the volume of music provided by a media device (e.g., a portable music player). As another example, a headset can include a plurality of buttons for controlling playback of music (e.g., play, next, last, fast forward and rewind buttons). 
     A drawback of such switches that have been implemented in headset wires is that they tend to be bulky and have limited control functions. There is a need, therefore, for a switch that can be incorporated in a wire, that features a small and unobtrusive profile, and that can control one or more device functions. There is also a need for the switch to be easy to use without requiring a user to look at the switch. 
     SUMMARY OF THE INVENTION 
     In accordance with the principles of the present invention, a bend switch that can be incorporated in a wire, that features a small and unobtrusive profile, and that can control one or more device functions is provided. Features for using the switch without requiring a user to look at the switch are also provided. 
     The switch of the present invention includes two substantially co-linear elongated bodies that have contact surfaces that oppose each other and that, in an open switch position, do not contact each other. The elongated bodies can be secured inside a sleeve to prevent undesired interferences with the switch and to provide an interface for a user to access or actuate the switch. To close the switch, the user can bend the elongated bodies relative to each other such that the contact surfaces of the elongated bodies come into contact. When contact is made, a signal can pass from one elongated body to the other by passing through the contact surfaces. Because the switch of the present invention is actuated by bending the elongated bodies with respect to each other, the switch will be referred to as a “bend switch” in the following discussion. 
     The switch can include a movable space member that is placed between the elongated bodies to maintain the contact surfaces of the elongated bodies a predetermined distance apart in the open switch position, while still allowing users to bend the elongated bodies relative to each other to close the switch. The movable space member may provide unlimited bending orientations, or may instead define several preferred and/or non-preferred bending orientations. 
     The contact surface of an elongated body may be partitioned to include several conductive portions, separated by an isolating or non-conductive material, that a user can selectively actuate. The portions of the contact surfaces can be distributed in the elongated bodies such that a particular portion is placed in contact with the opposing elongated body only when the user bends the elongated bodies relative to each other in a specific orientation. 
     A bend switch may combine elongated bodies with contact surfaces having several conductive portions and a movable space member having several preferred and/or non preferred orientations to assist the user in bending the switch in orientations that cause specific portions of a contact surface to come into contact with the opposing elongated body (e.g., associate a preferred bending orientation to each of the portions of a contact surface). 
     The movable space member can include one or more equilibrium positions for holding elongated bodies at specific angles and orientations with respect to each other. The movable space member can also include a potentiometer that varies the strength of a signal based on the angle at which the elongated bodies are bent relative to each other. 
     The bend switch can be used to control any suitable function of any suitable electronic device. Suitable electronic devices may include, for example, a computer, a media system, a portable media device (e.g., a portable music player such as an iPod), a cellular telephone, a personal media device which may include telephone communication and digital music player capabilities, or any other suitable device. Suitable functions can include, for example, microphone or speaker mute, volume control, media playback functions (e.g., next, previous, pause, play), dial, hang-up, and any other suitable function. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present invention, its nature and various advantages will be more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of an illustrative bend switch in an open switch position in accordance with one embodiment of the present invention; 
         FIG. 2  is a perspective view of the bend switch of  FIG. 1  in closed switch position in accordance with one embodiment of the present invention; 
         FIG. 3A  is a schematic view of the inner surface of an elongated body of a bend switch that includes several contact surfaces in accordance with one embodiment of the present invention; 
         FIG. 3B  is a perspective view of an illustrative bend switch that includes elongated portions that both have several contact surfaces in accordance with one embodiment of the present invention; 
         FIG. 4  is a perspective view of an illustrative bend switch that includes a movable space member that is placed between the elongated bodies of the switch and that is constructed to allow a full range of bending orientations in accordance with one embodiment of the present invention; 
         FIG. 5A  is a perspective view of an illustrative bend switch including a movable space member having a preferred bending orientation in accordance with one embodiment of the present invention; 
         FIG. 5B  is cross-section of the bend switch of  FIG. 5A  taken along lines  5 B- 5 B of  FIG. 5A  in accordance with one embodiment of the present invention; 
         FIG. 5C  is cross-section of another illustrative bend switch in accordance with one embodiment of the present invention; 
         FIGS. 6A and 6B  are perspective views of an illustrative bend switch including a movable space member that has two equilibrium positions in accordance with one embodiment of the present invention; 
         FIG. 7  is a perspective view of an illustrative bend switch that includes a potentiometer located between the elongated bodies of the switch in accordance with one embodiment of the present invention; 
         FIG. 8  is a circuit diagram for an analog circuit having a bend switch for toggling a microphone in accordance with one embodiment of the present invention; 
         FIG. 9  is a circuit diagram for an analog circuit having a bend switch with a potentiometer for controlling volume in accordance with embodiments of the present invention; 
         FIG. 10  is a perspective view of an implementation of a bend switch in a stereo headset in accordance with one embodiment of the present invention; 
         FIG. 11  is a perspective view of an implementation of a bend switch in a mono headset in accordance with one embodiment of the present invention; 
         FIG. 12  is a perspective view of an illustrative bend switch that incorporates a microphone in accordance with one embodiment of the present invention; and 
         FIG. 13  is an exploded view of the illustrative bend switch of  FIG. 12  in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with the present invention, a switch that is activated by bending portions of the switch is provided. 
       FIG. 1  shows a perspective view of an illustrative bend switch in an open switch position in accordance with the principles of the present invention. Illustrative bend switch  100  includes sleeve  102 , first elongated body  110 , and second elongated body  120 . In the example shown in  FIG. 1 , elongated bodies  110  and  120  are cylindrical. It is understood that this is merely illustrative and that any other shape, including non-cylindrical and/or non-elongated shapes, can be used for the elongated bodies. 
     First and second elongated bodies  110  and  120  are placed substantially co-linearly in sleeve  102  such that contact surfaces  112  and  122  of the first and second elongated bodies, respectively, oppose each other, and when in an open switch position, do not contact each other. Switch  100  can be biased to remain in an open switch position unless external factors (e.g., a user&#39;s bending of at least elongated body  110  or  120 ) cause surfaces  112  and  122  to contact each other, thus closing the switch. 
     To maintain a normally open switch position, switch  100  can be constructed such that elongated bodies  110  and  120  are positioned a predetermined distance from each other within sleeve  102 . The distance between elongated bodies  110  and  120  can be such that contact surfaces  112  and  122  do not touch when the elongated bodies are co-linear. To cause contact surfaces  112  and  122  to contact each other, a user can bend the switch (e.g., bend the elongated bodies towards each other). 
     In some embodiments, the predetermined distance can be maintained by placing elongated bodies  110  and  120  in a frictional or permanently fixed relationship with respect to sleeve  102 . For example, sleeve  102  can be shrunk (e.g., shrunk-wrapped) around elongated bodies  110  and  120  such that bodies  110  and  120  are not normally in contact. As another example, the elongated bodies can be attached (e.g., using an adhesive or static cling) to sleeve  102  such that bodies  110  and  120  are not normally in contact. 
     Sleeve  102  can be made from any suitable material including, for example, fabric, rubber, polymers, elastomers, plastic, thermoplastic, or any other suitable material. 
     Elongated bodies  110  and  120  can be coupled to wires  116  and  126 , respectively, and are adapted to conduct signals from the wires to their respective contact surfaces  112  and  122 . For example, elongated bodies  110  and  120  can be constructed from an electrically conductive material (e.g., a metal such as copper, silver, or gold, or a semiconductive material). As another example, contact surfaces  112  and  122  can be connected to wires  116  and  126 , respectively, using a conductive or semiconductive element (e.g., a wire) incorporated in bodies  110  and  120 . 
     In some embodiments, bend switch  100  can include movable space member  104  that is positioned between contact surfaces  112  and  122 . Movable space member  104  may prevent elongated body  110  from coming into contact with elongated body  120  by maintaining bodies  110  and  120  a predetermined distance apart unless an external force is applied to close the switch. Movable space member  104  may be permanently fixed to one or both of bodies  110  and  120 . 
     Movable space member  104  can be selected from an insulating material to ensure that no signal is passed through bodies  110  and  120  when switch  100  is in the open position. Movable space member  104  may be movable or bendable to permit electrical connections between contact surfaces  112  and  122 . For example, movable space member  104  may be an elastomeric material that can bend in any suitable orientation to permit electrical contact between elongated bodies  110  and  120 . As another example, movable space member  104  may be constructed to move in a “ball and socket” fashion, where one portion of movable space member  104  may have a ball portion movably retained in a socket portion of a first body (e.g., body  110 ) and a connector potion permanently fixed to a second body (e.g., body  120 ). During movement, the second body may pivot with respect to the first body to form an electrical connection between the first and second bodies. Other examples of movable space members  104  are discussed in more detail below in connection with the description accompanying  FIGS. 4-7 . 
     It is understood that in various embodiments, particularly those which include movable space member  104 , sleeve  102  can be omitted. For example, movable space member  104  can be constructed to maintain bodies  110  and  120  in a normally open switch position without the assistance of any positional support that may otherwise be provided by sleeve  102 . 
       FIG. 2  shows a perspective view of bend switch  100  of  FIG. 1  in a closed switch position in accordance with an embodiment of the invention. Switch  100  may be closed, for example, when a user bends elongated bodies  110  and  120  relative to each other such that a portion of contact surfaces  112  and  122  contact each other. As shown when switch  100  is closed, electrical coupling between bodies  110  and  120  may occur when contact surfaces  112  and  122  contact each other at, for example, contact point  230 . In some embodiments, contact surfaces  112  and  122  may be angled (e.g., angled inward) to promote contact and electrical coupling. When contact surfaces  112  and  122  are placed in contact, signals may be provided from switch  100  to, for example, a personal media device (not shown), which may process the signal and perform a function in response to receiving that signal. 
     Bend switch  100  can be coupled to any suitable device (not shown) to control a function of the device. The device may be any suitable electronic device including, for example, a computer, media system, portable media device, cellular telephone, or any other suitable device. Software implemented on the device can control functions of the device in response to user issued instructions. In particular, the software can process signals received when bend switch  100  is placed in a closed switch position by detecting the presence of a signal in an input/output port in which the wire coupled with bend switch  100  is connected, and convert the processed signal into a software instruction that controls a function. 
     In some embodiments, the software can process different types of signals provided by bend switch  100  to control different device functions. For example, if the bend switch includes several conductive portions on a contact surface, as discussed below in connection with  FIGS. 3A and 3B , different signals can be provided by each conductive portion when that conductive portion contacts the opposing elongated body. As another example, if the bend switch is open and closed repeatedly, providing a sequence of signals, the software implemented on the device can process the sequence of signals to control a function (e.g., increase or decrease volume). 
       FIG. 3A  shows a schematic view of contact surface  313  of elongated body  310  of a bend switch that includes several conductive portions in accordance with an embodiment of the invention. Conductive portions  332 ,  334 ,  336  and  338  of elongated body  310  are separated by isolating portion  330 , which may be a portion of body  310  or a separate element of body  310 . Conductive portions  332 ,  334 ,  336  and  338  can be constructed with any suitable conductive material such as, for example, gold, silver, copper or another metal, silicone or other semiconductive materials, or any other suitable conductive material. Isolating portion  330  can be constructed with any suitable isolating material such as, for example, rubber, polymers, elastomers, plastic, thermoplastic, or any other suitable isolating or non-conductive material. 
     Elongated body  310  can be constructed in any suitable manner. For example, elongated body  310  can be constructed by molding, stamping, extruding, casting, or machining (or any other suitable manufacturing process) non-conductive or isolating material to form cavities configured to receive conductive portions  332 ,  334 ,  336 , and  338 . As another example, elongated body  310  can be formed by introducing non-conductive isolating material around conductive portions  332 ,  334 ,  336  and  338  using, for example, an injection process, a dipping process, or any other suitable process. 
     Conductive portions  332 ,  334 ,  336  and  338  may be any suitable shape. For example, conductive portions  332 ,  334 ,  336  and  338  may be thin pads that are placed on or extend from contact surface  313 . As another example, conductive portions  332 ,  334 ,  336  and  338  may be longer extruded shapes that extend from contact surface  313  into elongated body  310 . In addition, conductive portions  332 ,  334 ,  336  and  338  may have any suitable cross-section. For example, the cross-section may be a portion of a disc, as shown in  FIG. 3A . Conductive portions  332 ,  334 ,  336  and  338  may be positioned on or adjacent the perimeter of contact surface  313 , and/or may be raised with respect to contact surface  313  and isolating portion  330  to facilitate closing the bend switch in response to the application of an external force. 
     A bend switch having an elongated portion such as elongated portion  310  can provide different signals depending on which conductive portion is placed in contact with the other elongated body. For example, each conductive portion may be connected to a separate wire that provides a particular signal to the device to which the switch is coupled (e.g., a personal media device). When a particular conductive portion is placed in contact with the opposing elongated body and an electrical coupling occurs, a signal may be provided through the wire associated with the particular conductive portions. The device coupled to the switch may process the signal received with the wire, and perform a function associated with that signal. 
       FIG. 3B  shows a perspective view of illustrative bend switch  300  that includes elongated portions  310  and  320  that both have several conductive portions in accordance with an embodiment of the invention. In particular, in the example of  FIG. 3B , elongated body  310  includes conductive portions  332 ,  334 ,  336  and  338 , and elongated body  320  includes conductive portions  342 ,  344 ,  346  and  348 . Each of the conductive portions can be connected to a separate wire that carries a separate signal when the conductive portion is placed in contact with the opposing elongated body. In the example shown in  FIG. 3B , wires  352 ,  354 ,  356  and  358  are connected to conductive portions  332 ,  334 ,  336  and  338 , respectively. 
     Assuming a user has bent bend switch  300  as shown, conductive portions  336  and  346  may be in contact with each other, while the other conductive portions of elongated bodies  310  and  320  are not. As a result of this contact, a signal associated with conductive portions  336  and  346  may be transmitted via wire  356  to a personal media device (not shown), thereby causing the function associated with those conductive portions to be performed. 
     In some embodiments, only one of elongated bodies  310  and  320  can include several conductive portions. For example, one elongated body can include a plurality of conductive portions that are each associated with particular functions, and the other elongated body can include a single contact surface. As another example, more than one conductive portion of a first elongated body can be placed in contact with a single contact surface of a second elongated body. 
     As discussed above in connection with  FIG. 1 , a movable space member may be included within a bend switch in accordance with an embodiment of the invention. Such members may serve several functions including, for example, maintaining the elongated bodies in an open switch position and providing preferred bend switch movement paths. Examples and functions that may be performed by such members are discussed in more detail in connection with  FIGS. 4-6 . 
       FIG. 4  shows a perspective view of illustrative bend switch  400  that includes movable space member  404  that is placed between elongated bodies  410  and  420  and is constructed to allow a full range of bending orientations. By concentrically aligning movable space member  404  with respect to elongated bodies  410  and  420 , movable space member  404  can provide for omnidirectional movement of elongated body  410  with respect to elongated body  420 . For example, movable space member  404  can include a ball and socket joint, a spring, a cylindrical body, an elastomeric member, or any other suitable component or components. In some embodiments, movable space member  404  may include one or more magnets that provide, for example, a restoring force to align the bend switch after bending. 
     Movable space member  404  may be constructed such that its cross-sectional area is less than that of elongated bodies  410  and  420 . This can allow elongated bodies  410  and  420  to bend far enough in every orientation (360° bending) for contact surfaces of elongated bodies  410  and  420  to come into contact. For example, movable space member  404  may have a circular cross-section that has a diameter (and therefore an area) that is less than the diameter of the circular cross-section of elongated bodies  410  and  420 . Movable space member  404  can be a shell (e.g., a hollow structure) to allow wires or other components to pass through bend switch  400  and to facilitate bending of movable space member  404 . 
       FIG. 5A  shows a perspective view of illustrative bend switch  500  including movable space member  504  having a preferred bending orientation in accordance with an embodiment of the invention. As shown, movable space member  504  is placed between elongated bodies  510  and  520  and is constructed to influence or dictate preferred bending orientations as indicated by arrows  512  and  514 . In one approach for providing preferred bending orientations, movable space member  504  may be a cylindrical movable space member having an elliptical cross-section, as shown in  FIG. 5B .  FIG. 5B  shows a cross-section of switch  500  taken along lines  5 B- 5 B of  FIG. 5A . The long axis of the ellipse may be smaller than the diameter (or another representative distance) of elongated bodies  510  and  520 , and the short axis of the ellipse may be substantially smaller than the diameter of elongated bodies  510  and  520 . Such an arrangement results in a preferred bending orientation perpendicular to the long axis, also shown by arrows  512  and  514 . 
     As another example, movable space member  504  may include a hinge. The hinge may be placed in between elongated bodies  510  and  520  such that the hinge allows elongated bodies  510  and  520  to rotate with respect to each other in the orientations identified by arrows  512  and  514 . The hinge can be a pivot hinge, a continuous hinge, a concealed hinge, a living hinge, or any other suitable type of hinge. In some embodiments, the hinge may be an elastomer. 
     In some embodiments, movable space member  504  can be combined with elongated bodies having contact surfaces with several conductive portions such as that that discussed above in connection with  FIG. 3 . An advantage of such members is that they may prevent users from simultaneously placing two or more conductive portions in contact. In  FIG. 5B , elongated body  520  includes conductive portions  542  and  544 , which are located on opposite sides of movable space member  504 . When bend switch  500  is bent in the  512  direction, portion  542  of elongated body  520  may contact elongated body  510 . Similarly, when bend switch  500  is bent in the  514  direction, portion  544  of elongated body  520  may contact elongated body  510 . Because bend switch  500  is not constructed to permit easy bending in an orientation perpendicular to the short axis, a user may not (or at least may not easily) bend switch  500  such that both conductive portions  542  and  544  are simultaneously in contact with elongated body  510 . 
     In some embodiments, movable space member  504  can include a discreet number of posts that are distributed along the inner surfaces of elongated bodies  510  and  520  instead of a continuous structure (e.g., instead of a solid member having an elliptical cross-section).  FIG. 5C  shows a cross-section of another illustrative switch  500  in accordance with an embodiment of the invention, where the switch includes posts instead of elliptical movable space member  504 . Posts  550  and  552  are placed at the ends of the long axis of the elliptical cross-section  504  of  FIG. 5B . This may allow movable space member  504  to provide preferred bending orientations with less material, and therefore a lighter switch  500 . 
     Movable space member  504  can include any other suitable design that is configured to provide for at least one preferred bending orientation. For example, movable space member  504  can include a cross-section that that provides three, four, or more preferred bending orientations. Such a cross-section may be, for example, a triangular cross-section (e.g., with three preferred bending orientations along lines perpendicular to the sides of the triangle) or a square/rectangular/trapezoidal cross-section (e.g., with four preferred bending orientations along lines perpendicular to the sides of the cross-section). The triangular or four-sided cross-section may be defined by a continuous shape or by a series of posts placed along the periphery of the shape. 
       FIGS. 6A  and B show perspective views of illustrative bend switch  600  including movable space member  604  that has two equilibrium positions (e.g., is bi-stable) in accordance with an embodiment of the invention. As shown, movable space member  604  is placed between elongated bodies  610  and  620  and is constructed to maintain elongated bodies  610  and  620  in one or more positions (e.g., equilibrium positions, such as the two buckled positions of a rod that is placed in compression between elongated bodies  610  and  620 ) with respect to each other in the absence of an external force on switch  600  (e.g., a user actuation of switch  600 ). 
     Movable space member  604  can apply a bending moment to at least one of elongated bodies  610  and  620  to hold elongated bodies  610  and  620  in a position such that the angle between center axis  606  of elongated body  610  and center axis  608  of elongated body  620  remains fixed in the absence of an external force. In the example of  FIG. 6A , movable space member  604  is configured to maintain elongated bodies  610  and  620  in a position where the angle between center axes  606  and  608  is 0°, and in the example of  FIG. 6B , movable space member  604  is configured to maintain elongated bodies  610  and  620  in a position where the angle between center axes  606  and  608  is θ. 
     Movable space member  604  can provide the bending moment in any suitable manner. In the example of  FIGS. 6A  and B, movable space member  604  is a rod that is offset from center axes  606  and  608  of elongated bodies  610  and  620 , respectively. By placing movable space member  604  in an off-center position, movable space member  604  has leverage to apply a bending moment that forces elongated bodies  610  and  620  to maintain a position in which they remain co-linear and not in contact (e.g., an open switch position), as well as a position in which they are rotated with respect to each other around an axis that is perpendicular to both axis  606  and axis  608  (e.g., a closed switch position). 
     By its placement, movable space member  604  includes an inherent preferred bending orientation and an inherent non-preferred bending orientation. The existence of these inherent preferred and non-preferred bending orientations is related to the distance between movable space member  604  and the outer periphery of elongated bodies  610  and  620 . In particular, to apply the same bending moment to at least one of elongated bodies  610  and  620 , movable space member  604  may apply a larger force in the orientation where the distance between movable space member  604  and the outer periphery of elongated bodies  610  and  620  is smaller, and a smaller force in the orientation where the distance is larger. Thus, the preferred bending orientation is shown by arrows  642 , and the non-preferred bending orientation is shown by arrows  640 . 
       FIG. 6A  shows switch  600  in an open switch position with movable space member  604  in a first equilibrium position that maintains the open switch position. Movable space member  604  may hold bend switch  600  open by applying a bending moment to elongated bodies  610  and  620  in the orientation indicated by arrows  640 . The placement of movable space member  604  between axes  606  and  608  and the outer periphery of elongated bodies  610  and  620  may prevent movable space member  604  from forcing elongated bodies  610  and  620  to contact each other because achieving such contact may require a higher force to apply a sufficient bending moment than the force provided by movable space member  604  (e.g., because the distance between movable space member  604  and the periphery of elongated bodies  610  and  620  is shorter in the orientation identified by arrows  640 ). 
       FIG. 6B  shows switch  600  in a closed switch position with movable space member  604  in a second equilibrium position that maintains the closed switch position. Movable space member  604  may hold bend switch  600  closed by applying a bending moment to elongated bodies  610  and  620  in the orientation indicated by arrows  642 . The placement of movable space member  604  between axes  606  and  608  and the outer periphery of elongated bodies  610  and  620  may facilitate maintaining elongated bodies  610  and  620  in contact because the force required to generate a sufficient bending moment is relatively low (e.g., because the distance between movable space member  604  and the periphery of elongated bodies  610  and  620  is longer in the orientation identified by arrows  640 ). 
     In some embodiments, movable space member  604  may include one or more magnets. The magnets may be positioned to provide an equilibrium position (e.g., keeping elongated bodies  610  and  620  aligned). For example, the magnets may be rings at or around (e.g., under) the periphery of elongated bodies  610  and  620 . Once bend switch  600  is bent, the magnets may provide a magnetic force separating the portions of the magnets that were brought together, thus separating elongated bodies  610  and  620 . 
     Movable space member  604  can have any suitable number of equilibrium positions, each of which can be associated with one or more preferred and non-preferred bending orientations. In addition, movable space member  604  can be combined with elongated bodies having contact surfaces that include several conductive portions such as those discussed above in connection with  FIG. 3 . An advantage of such members is that they may allow users to maintain particular conductive portions in contact, thus allowing users to maintain access to a function associated with that particular conductive portion. 
       FIG. 7  shows a perspective view of illustrative bend switch  700  that includes potentiometer  704  located between elongated bodies  710  and  720  in accordance with an embodiment of the invention. Potentiometer  704  can vary the strength of the signal provided by bend switch  700  based on the degree to which elongated bodies  710  and  720  are bent with respect to each other. For example, the closer elongated bodies  710  and  720  are bent towards each other, the stronger the signal provided by bend switch  700 . The strength of the signal may be directly correlated to angle α, which is a measurement of the angle from plane  740  defined by the inner surface of elongated body  710  to plane  742  defined by the contact surface of elongated body  712 . By defining α as a directional angle, bend switch  700  may provide positive or negative signals based on the orientation in which elongated bodies  710  and  712  are bent with respect to each other. Each of the positive and negative signals may control a different function of a device (e.g., a portable media player) coupled to bend switch  700  (e.g., volume up and down). In some embodiments, the potentiometer can measure positive and negative voltage, based on the orientation in which the bend switch is bent. The polarity of the voltage can be used to activate different functions (e.g., volume up for positive voltage, and volume down for negative voltage). 
     In some embodiments, bend switch  700  can include several potentiometers  704  to control different functions using the same bend switch  700 . For example, each potentiometer  704  may be associated with a different function, where the strength of the signal provided by each potentiometer  704 , as measured by a bend angle α, can be processed by software on a device to set each of the different functions at a value (e.g., a particular volume) that corresponds to the bend angle α. This embodiment can be implemented, for example, to provide independent control of left and right audio channels using bend switch  700 . 
     Bend switch  700  can also control different functions of a device (not shown) using a single potentiometer  704 . The software implemented on the device can control several functions by assigning to each function a range of signal strengths. For example, the software may control a first function when the signal strength is between 1% and 33% of the maximum signal strength, a second function when the signal strength is between 34% and 66% of the maximum signal strength, and a third function when the signal strength is between 67% and 100% of the maximum signal strength. The user can access a particular function by bending elongated bodies  710  and  720  relative to each other at a bend angle α that corresponds to a signal strength that is within the range of the signal strengths associated with the particular function. Bend switch  700 , or more specifically potentiometer  704 , can include a component that provides tactile feedback (e.g., a clicking sound) that indicates to the user which function is controlled when elongated bodies  710  and  720  are bent relative to each other at bend angle α. As another example, a display screen on the device (e.g., the screen of a portable media device) can provide a visual indication of which function is currently controlled (e.g., by processing the signal and determining the range of the signal strength). 
     Using potentiometer  704 , bend switch  700  can provide a range of signal strengths that, when processed by a device, correspond to a range of values of a function of the device. Functions that are defined over a range of values, and therefore be controlled by bend switch  700 , may include, for example, volume (e.g., of speakers or a microphone), fast forward and rewind (e.g., at different rates), or any other suitable function. In some embodiments, potentiometer  704  can maintain elongated bodies  710  and  720  at one or more particular angles with respect to each other unless an external force is applied to bend switch  700 . 
     In some embodiments, the bend switch may be configured to provide tactile feedback in response to an activation of the switch. For example, the movable space member of a switch may having a plurality of equilibrium positions may hold the switch at an angle that makes it clear to the user whether the switch is open or closed. As another example, the movable space member may extend from the periphery of the elongated bodies when the switch is in one of the open or closed positions. 
     In some embodiments, the bend switch may include a dome switch in the contact area. The dome switch may provide a tactile and/or auditive feedback when the bend switch is closed (e.g., closing the bend switch causes the dome switch to collapse, providing the tactile and/or auditive feedback). In some embodiments, the bend switch may include an actuator for providing feedback. 
       FIG. 8  shows an illustrative circuit diagram for analog circuit  800  having bend switch  820  for toggling a microphone. Circuit  800  (and circuit  900 , discussed below in connection with  FIG. 9 ) can be implemented in any suitable electronic device such as, for example, in audio and/or video devices (e.g., a portable music player, such as an iPod), communications devices (e.g., a cellular telephone), personal media device which may include telephone communication and digital music player capabilities, or any other electronic device that can operate in connection with a switch. Circuit  800  will be described below in the context of a circuit coupled to a cellular telephone, but it will be understood that this is merely illustrative and that circuit  800  can be coupled to any other suitable device. 
     Circuit  800  includes jack  801 , right channel speaker  810 , left channel speaker  812 , and microphone  814  that can be activated by bend switch  820 . Jack  801 , which is plugged into a cellular telephone (not shown), includes four sections: left channel section  802 , right channel section  804 , microphone section  806 , and ground section  808 . Wires connect right channel speaker  810  to right channel section  804  and ground section  808 , left channel speaker  812  to left channel section  802  and ground  808 , and microphone  814  to microphone section  806  and ground  808  via bend switch  820 . In some embodiments, bend switch  820  can be coupled to each of the wires connecting microphone  814  to jack  801  (not shown). 
     The cellular telephone coupled to circuit  800  can respond to signals that are provided by switch  820  in any suitable manner. For example, when bend switch  820  is in a closed switch position, software implemented on the cellular telephone may detect the presence of a signal provided through microphone section  806  of jack  801 . The software may process the signal and determine that microphone  814  has been activated. The cellular telephone can then transmit the sounds (e.g. the voices) picked up by microphone  814  over the cellular connection to another cellular telephone. As another example, when bend switch  820  is in the open switch position, the software implemented on the cellular telephone may determine that no signals are received in microphone section  814  and turn off the microphone function of the cellular telephone. A more detailed description of how the cellular telephone responds to actuation of a switch can be found in commonly assigned U.S. Patent Application Publication No. 2008/0149417, published on Jun. 26, 2008, which is incorporated by reference herein in its entirety. 
       FIG. 9  shows a circuit diagram for analog circuit  900  having a bend switch with potentiometer  920  for controlling volume in accordance with an embodiment of this invention. Circuit  900  will be described below in the context of a circuit coupled to a portable media device, but it will be understood that this is merely illustrative and that circuit  900  can be coupled to any other suitable device. 
     Circuit  900  includes jack  901 , right channel speaker  910  and left channel speaker  912 . Jack  901  includes three sections, left channel section  902 , right channel section  904  and ground section  908 . Wires connect right channel section  904  and left channel section  902  to potentiometer  920 . Wires connect the output of potentiometer  920  to right channel speaker  910  and left channel speaker  912 . 
     The portable media device coupled to circuit  900  can modify the volume of audio output to speakers  910  and  912  in response to the strength of the signal provided by potentiometer  920 . For example, as a user bends the elongated bodies of a switch that includes potentiometer  920 , the magnitude of the signal that passes across the bend switch may increase. Software implemented on the portable media device may process the signal provided by potentiometer  920 , determine that the magnitude of the signal has increased, and cause the portable media device to increase the volume of audio that is output to speakers  910  and  912 . In some embodiments, potentiometer  920  may remain in a bent position (e.g., to maintain a constant signal strength and associated volume level). 
     In the example shown in  FIG. 9 , a single potentiometer  920  is used to simultaneously control the volume of both right channel speaker  910  and left channel speaker  912 . In some embodiments, the circuit can include two potentiometers, one for each channel (or any other suitable number of potentiometers  920 ). The two potentiometers can be provided as part of the same bend switch, or the two potentiometers can be provided in two bend switches. 
     In some embodiments, the microphones of circuits  800  and  900 , and other suitable circuits, may remain electrically coupled to the electronic device to which the switch is connected independently of the state of the switch. Software on the electronic device may activate or de-activate the microphone input in response to a signal from the user. For example, the user may bend the switch to send a first signal activating the microphone (e.g., to receive a telephone call). The switch may be configured to automatically return to an open position (i.e., no signals provided by the switch to the electronic device) after the switch has been closed and released (e.g., using magnets or another movable space member). The user may then bend the switch a second time, sending a second signal (e.g., over the same wires as the first signal) to the electronic device. Software on the electronic device may then process the signal, and de-activate the active microphone. 
       FIGS. 10 and 11  show perspective views of illustrative wired headsets  1000  and  1100 , respectively, that include bend switches  1020  and  1120 , respectively.  FIG. 10  shows a perspective view of illustrative stereo headset  1000  that includes jack  1001 , right channel speaker  1010  and left channel speaker  1012 . Bend switch  1020  is incorporated in the wire connected to right channel speaker  1010 .  FIG. 11  shows a perspective view of illustrative mono headset  1100  that includes jack  1101  and speaker  1110 . Bend switch  1120  is incorporated in the wire connected to speaker  1110 . 
     The placement of bend switches  1020  and  1120  in  FIGS. 10 and 11  is merely illustrative, and the bend switches can be placed at any other suitable position in the wires of headsets  1000  and  1100 . In addition, bend switches  1020  and  1120  may control any suitable function. For example, bend switches  1020  and  1120  can incorporate a microphone that is turned on or muted by bending bend switch  1020  or  1120  to place it in the closed switch position or open switch position, respectively. Such illustrative bend switches are discussed in more detail in  FIGS. 12 and 13 . 
       FIG. 12  is a perspective view of illustrative bend switch  1200  that incorporates microphone  1230  in accordance with the invention, and  FIG. 13  is an exploded view of bend switch  1200  of  FIG. 12  in accordance with the invention. Bend switch  1200  includes first elongated body  1210  and second elongated body  1220  that are placed substantially co-linearly such that respective contact surfaces  1212  and  1222  oppose each other and, when in an open switch position, no contact exists between surfaces  1212  and  1222 . Spring  1204  serves as a movable space member that maintains elongated bodies  1210  and  1220  apart when the switch is in an open switch position. 
     Elongated bodies  1210  and  1220  include inner structures  1214  and  1224 , respectively, that support wires  1252  and  1254 . Wires  1252  and  1254  can pass through bend switch  1200  without being affected by bend switch  1200 . Inner structures  1214  and  1224 , and spring  1204  can be constructed with an aperture that extends through structures  1214  and  1224  and spring  1204  for receiving wires  1252  and  1254 . For example, wires  1252  and  1254  provide left and right stereo audio, and bend switch  1200  controls the activation of microphone  1230 . 
     Inner structure  1214  can receive microphone  1230  (e.g., in a cavity), the operation of which can be controlled by the bend switch. Microphone  1230  is coupled to contact surface  1212  using wires  1232 , which may couple the positive and negative poles of microphone  1230  to contact surface  1212  (e.g., two wire strands shown coupled to microphone  1230  in  FIG. 13 ). To activate the microphone, it may be necessary to close the circuit that includes microphone  1230  and wires  1232 . To do so, a user may bend elongated bodies  1210  and  1220  relative to each other such that contact portions  1212  and  1222  meet and electrical coupling occurs. A signal may then be passed from wires  1232  to opposing contact portion  1222 , which may in turn pass the signal to an electronic device (e.g., a cellular telephone). Contact portion  1222  may transmit the signal generated by closing bend switch  1200  in any suitable manner including, for example, using one of wires  1252  or  1254  (e.g., if one of wires  1252  and  1254  is coupled to contact portion  1222 ), or using a separate wire dedicated to microphone  1230  and coupled to contact surface  1222  (not shown). 
     The above described embodiments of the present invention are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow.