PATENT DOCUMENT

Publication Number: US-8872771-B2
Application Number: US-49902809-A
Country: US
Kind Code: B2

Title: Touch sensing device having conductive nodes

Abstract:
A touch sensing device having conductive nodes is disclosed. The device can include a first structure having one or more conductive electrodes disposed on a surface opposite the structure&#39;s touchable surface and a second structure having one or more conductive nodes disposed on a surface. The two surfaces can be placed with the conductive electrodes and conductive nodes facing each other in close proximity so that the electrodes and the nodes can form capacitive elements for sensing a touch on the touchable surface. Separately disposing the conductive nodes from the touchable surface structure can make the touch sensing device thin. An example touch sensing device can be a click wheel.

Claims:
What is claimed is: 
     
       1. A touch sensing device comprising:
 a first structure having a touchable surface and an opposite surface; 
 multiple conductive electrodes associated with the opposite surface of the first structure; 
 a second structure having a surface; 
 multiple force sensors associated with the surface of the second structure and 
 multiple conductive nodes distinct from the multiple force sensors and associated with the surface of the second structure, 
 the opposite surface of the first structure and the surface of the second structure being proximate to each other, and the conductive electrodes and the conductive nodes configured to form capacitive elements between the opposite surface of the first structure and the surface of the second structure to sense a touch at the touchable surface, the force sensors and the conductive nodes being coplanar with each other and being cofacially centered with the conductive electrodes. 
 
     
     
       2. The device of  claim 1 , wherein the conductive electrodes and the conductive nodes capacitively couple with each other to form the capacitive elements. 
     
     
       3. The device of  claim 1 , wherein the conductive nodes are configured to extend away from the surface of the second structure to be proximate to the conductive electrodes. 
     
     
       4. The device of  claim 1 , comprising a conductive ring, wherein the conductive nodes form extensions from the conductive ring. 
     
     
       5. The device of  claim 4 , wherein the conductive ring comprises high dielectric material and the conductive nodes comprise conductive material. 
     
     
       6. The device of  claim 1 , wherein the conductive nodes are deformable. 
     
     
       7. The device of  claim 1  incorporated into at least one of a digital media player, a mobile telephone, or a personal computer. 
     
     
       8. A touch sensing device comprising:
 a first element comprising multiple conductive touch sensitive electrodes; 
 a second element comprising multiple conductive force sensitive switches, the switches associated with a first group of the electrodes; and 
 the second element comprising multiple conductive nodes, the nodes associated with a second group of the electrodes, 
 the switches and the nodes being coplanar with each other and being cofacially centered with the electrodes. 
 
     
     
       9. The device of  claim 8 , wherein the switches are dome switches. 
     
     
       10. The device of  claim 8 , wherein the switches are deformable in order to sense a force applied to the device. 
     
     
       11. The device of  claim 8 , wherein the switches and the first group of the electrodes form capacitive sensors to sense a touch at the device. 
     
     
       12. The device of  claim 8 , wherein the nodes and the second group of the electrodes form capacitive sensors to sense a touch at the device. 
     
     
       13. The device of  claim 8 , wherein the switches and the nodes are of equal length and form similar capacitive coupling with the electrodes. 
     
     
       14. The device of  claim 8 , wherein the switches and the second group of the electrodes are of equal length and provide similar capacitive coupling between the switches and the first group of the electrodes and between the second group of the electrodes and the nodes. 
     
     
       15. A touch sensing device comprising:
 a cover configured to move in response to a force applied to the cover and to receive a touch at the cover, the cover comprising at least one conductive electrode; and 
 a flexible circuit proximate to the cover, the flexible circuit configured to sense a force applied to the cover and a touch received at the cover, the flexible circuit comprising at least one conductive force sensitive switch and at least one conductive node proximate to the conductive electrode, 
 the conductive electrode and the conductive node disposed between the cover and the flexible circuit, 
 the conductive force sensitive switch and the at least one conductive node being coplanar with each other and being cofacially centered with the conductive electrode. 
 
     
     
       16. The device of  claim 15 , wherein the cover comprises: a center button; and an outer portion surrounding the center button. 
     
     
       17. The device of  claim 16 , wherein the center button is configured to move in response to the applied force so that a function associated with the device executes. 
     
     
       18. The device of  claim 16 , wherein the outer portion is configured to move in response to the applied force so that a function associated with the device executes. 
     
     
       19. The device of  claim 15 , wherein the flexible circuit is configured to be stationary. 
     
     
       20. The device of  claim 15 , wherein the cover and the flexible circuit are in electrical contact during operation. 
     
     
       21. The device of  claim 15 , comprising an insulating layer between the cover and the at least one conductive electrode, wherein the cover and the flexible circuit are electrically isolated from each other during operation. 
     
     
       22. A click wheel comprising:
 a movable cover having a touchable surface and an opposite surface with multiple conductive electrodes associated with the opposite surface; and 
 a flexible circuit having a surface with multiple deformable conductive nodes and multiple conductive switches associated with the surface, 
 the conductive electrodes configured to align with the deformable conductive nodes and the conductive switches to form capacitive sensors for sensing a touch at the touchable surface, and 
 the conductive switches configured to form force sensors for sensing a force applied to the touchable surface, 
 the conductive switches and the conductive nodes being coplanar with each other and being cofacially centered with the conductive electrodes. 
 
     
     
       23. A method comprising:
 providing a device having a movable structure and a stationary structure; 
 providing a flexible circuit on the stationary structure; 
 disposing multiple deformable conductive nodes on the flexible circuit; 
 disposing multiple conductive switches on the flexible circuit; 
 disposing multiple conductive electrodes on the movable structure; and 
 positioning the deformable conductive nodes on the flexible circuit close to the conductive electrodes on the movable structure so that the provided device is thin, positioning the conductive switches and the conductive nodes to be coplanar with each other and cofacially centered with the conductive electrodes.

Description:
FIELD 
     This relates generally to touch sensing devices used in portable electronic devices and, more particularly, to a touch sensing device having conductive nodes for improved touch sensing. 
     BACKGROUND 
     There can be many factors that determine the size of compact portable electronic devices such as laptops, PDAs, media players, mobile phones, etc. In many cases, the size of the portable electronic device can be limited by the size of the operational components used therein. These components can include for example microprocessor chips, printed circuit boards, displays, memory chips, hard drives, batteries, interconnectivity circuitry, indicators, input mechanisms and the like. As such, there can be a desire to make these operational components smaller, thinner, more cost effective, and more power efficient, while maintaining or increasing their functionality to perform operations. 
     There exist today many styles of input mechanisms for performing operations in a portable electronic device. The operations can generally correspond to moving objects and making selections. By way of example, the input mechanisms can include buttons, keys, dials, wheels, mice, trackballs, touch pads, joy sticks, touch screens and the like. Touch devices are becoming increasingly popular in portable electronic devices because of their ease and versatility of operation, their declining price as well as their space saving ability (e.g., planarity). Touch devices can allow a user to make selections and move objects by simply moving a finger (or stylus) relative to a touch sensing surface. In general, the touch device can recognize a touch and in some circumstances the characteristics of the touch and a host controller of the portable electronic device can interpret the touch data and thereafter perform action based on the touch data. 
     Capacitive sensing is becoming an increasingly popular way to implement an input mechanism. However, although capacitive sensing devices can work well in portable electronic devices, improvements are still desired, such as thinner and power savings devices. 
     SUMMARY 
     This relates to a touch sensing device that can have conductive nodes for capacitive sensing. One device structure can have one or more conductive electrodes disposed on a surface opposite the structure&#39;s touchable surface. Another device structure can have one or more conductive nodes disposed on a surface. The two surfaces can be placed opposite each other in close proximity so that the conductive electrodes and the conductive nodes can form capacitive elements for sensing a touch on the touchable surface. This can advantageously provide a thinner device that can realize power savings and performance improvements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a top view of an exemplary touch sensing device according to various embodiments. 
         FIG. 2  illustrates a cross sectional view of an exemplary touch sensing device according to various embodiments. 
         FIG. 3  illustrates a bottom view of an exemplary flexible circuit for a touch sensing device according to various embodiments. 
         FIG. 4  illustrates a top view of an exemplary touch sensing device according to various embodiments. 
         FIG. 5  illustrates a cross sectional view of an exemplary touch sensing device according to various embodiments. 
         FIG. 6  illustrates a bottom view of an exemplary movable cover of a touch sensing device according to various embodiments. 
         FIG. 7  illustrates a top view of an exemplary flexible circuit for a touch sensing device according to various embodiments. 
         FIG. 8  illustrates a top view of another exemplary flexible circuit for a touch sensing device according to various embodiments. 
         FIG. 9  illustrates a top view of still another exemplary flexible circuit for a touch sensing device according to various embodiments. 
         FIG. 10  illustrates a top view of an exemplary touch sensing device according to various embodiments. 
         FIG. 11  illustrates a cross sectional view of an exemplary touch sensing device according to various embodiments. 
         FIG. 12  illustrates a bottom view of an exemplary movable cover of a touch sensing device according to various embodiments 
         FIG. 13  illustrates a top view of an exemplary flexible circuit for a touch sensing device according to various embodiments. 
         FIG. 14  illustrates a cross sectional view of an exemplary touch sensing device according to various embodiments 
         FIG. 15  illustrates a cross sectional view of another exemplary touch sensing device according to various embodiments. 
         FIG. 16  illustrates an exemplary method for forming a touch sensing device according to various embodiments. 
         FIG. 17  illustrates an exemplary digital media player according to various embodiments. 
         FIG. 18  illustrates an exemplary mobile telephone according to various embodiments. 
         FIG. 19  illustrates an exemplary personal computer according to various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of various embodiments, reference is made to the accompanying drawings which form a part hereof, and in which it is shown by way of illustration specific embodiments which can be practiced. It is to be understood that other embodiments can be used and structural changes can be made without departing from the scope of the various embodiments. 
     This relates to a touch sensing device that can have conductive nodes for capacitive sensing. One device structure can have one or more conductive electrodes disposed on, or similarly associated with, a surface opposite the structure&#39;s touchable surface. Another device structure can have one or more conductive nodes disposed on, or similarly associated with, a surface. The two surfaces can be placed opposite each other in close proximity so that the conductive electrodes and the conductive nodes can form capacitive elements for sensing a touch on the touchable surface. 
     This also relates to a touch sensing device that can have a movable cover and a stationary flexible circuit for touch and force sensing. The movable cover can have conductive electrodes on, or associated with, its surface opposite its touchable surface. The flexible circuit can have conductive nodes on, or associated with, a surface. In some embodiments, the flexible circuit&#39;s conductive nodes can include different types of nodes for touch sensing and for force sensing. The conductive electrodes can align with the conductive nodes to form capacitive sensors for sensing a touch at the cover. Some of the conductive nodes can also form force sensors for sensing a force applied at the cover. 
     By locating the conductive nodes associated with a structure away from, but proximate to, the structure having the touchable surface, the touch sensing device can advantageously be made thinner because it can eliminate extra space and/or components needed for configurations in which the conductive nodes reside on the touchable surface structure. This can also advantageously result in power savings and improved performance for a reduced number of components. 
     Example touch sensing devices can include a click wheel, a touch wheel, a touch pad, a touch screen, and the like. 
       FIG. 1  illustrates a top view of an exemplary touch sensing device according to various embodiments. In the example of  FIG. 1 , touch sensing device  10  can include touchable cover  11 , which can have button  11   a  at the center of the cover and outer portion  11   b  separate from and surrounding the center button. The touchable cover  11  can be configured to receive a touch from an object and/or a force applied by the object on a surface (referred to as a touchable surface herein) of the structure. The touchable cover  11  can also be configured to cover and protect the underlying device components from dust and damage. An object&#39;s touch can be sensed by touch sensors  15  disposed under the touchable cover  11 . The touch sensors  15  can be disposed under the outer portion  11   b , the center button  11   a , or both, to sense a touch thereat. An applied force can be sensed by force sensors  13  also disposed under the touchable cover  11 . The force sensors  13  can be disposed under the outer portion  11   b , the center button  11   a , or both, to sense an applied force. The touch sensors  15  can be disposed at various locations under the touchable cover  11  where the object can be expected to touch. The force sensors  13  can be disposed at various locations under the touchable cover  11  where the object can be expected to apply force. In some embodiments, the force sensors and the touch sensors can be disposed at the same locations, thereby providing both touch and force sensing at those locations. 
     The touch sensing device  10  can also include flexible cable  17 , having signal lines (not shown) so that a processor (not shown) or other suitable components can determine force applied to the force sensors and touch at the touch sensors. 
     In some embodiments, the touch sensors  15  can be capacitance sensors, such that a sensed change in capacitance can indicate a touch at the device  10 . The capacitance can be either self capacitance or mutual capacitance. In self capacitance, each of the touch sensors  15  can be provided by an individually charged electrode. As an object approaches the touchable cover  11 , the object can capacitively couple to those electrodes in close proximity of the object, thereby stealing charge away from the electrodes. The amount of charge in each of the electrodes can be measured by the touch sensing device  10  to determine the positions of objects as they touch at the touchable cover  11 . In mutual capacitance, each of the touch sensors  15  can be provided by two spatially separated conductive nodes. During operation, one of the nodes can be charged and the charge can capacitively couple to the other node. As an object approaches the touchable cover  11 , the object can block electric field lines formed between the two nodes, thereby stealing charge away from the nodes. The amount of charge in each of the nodes can be measured by the touch sensing device  10  to determine the positions of multiple objects when they touch the touchable cover  11 . 
     In some embodiments, the force sensors  13  can be dome switches, such that a deformation of the switches to contact the dome of the switch with its associated conductive pad can indicate a force applied at the device  10 . Each dome switch can have a dome shape, where the dome of the switch can have conductive material applied to the inside of the dome. In addition to or alternatively, the dome can be made of conductive material. Each dome switch can also have a conductive pad proximate to the dome to generate a force signal when the dome contacts the pad. The signal generated by that contact can be sensed by the touch sensing device  10  to determine which dome switch was deformed by an object&#39;s applied force and thereby the position of the object when it applied force to the touchable cover  11 . 
     The center button  11   a  and the outer portion  11   b  can move independent of each other and can operate either together or separately, depending on the needs of the touch sensing device  10 . For example, the button  11   a  can be actuated by an applied force, thereby causing a function associated with the button to execute, such as a selection function. When the applied force actuates the button  11   a , the outer portion  11   b  can remain unaffected due to the separation between the button and the outer portion. Similarly, the outer portion  11   b  can be actuated by an applied force at a particular location of the portion, thereby causing the portion to tilt at that location and a function associated with that location to execute, such as a play/pause function, a menu function, a forward function, or a back function. In addition or alternatively, the applied force can cause the outer portion  11   b  to move below the plane of the cover  11  and a function associated with the location of the applied force (e.g., as sensed by the touch sensors at that location) to execute. When the applied force actuates the outer portion  11   b , the button  11   a  can remain unaffected due to the separation between the outer portion and the button. In another example, the button  11   a  and the outer portion  11   b  can operate together. An object can touch the outer portion  11   b  and/or make a gesture at the outer portion, e.g., a rotational motion around the outer portion, thereby causing a function associated with the touch to execute, such as a pointing function, or a function associated with the gesture to execute, such as a scroll function. After the object completes the touch and/or gesture at the outer portion  11   b , the object can touch the button  11   a , thereby causing a function associated with the touch to execute, such as a selection function to select an item identified during the outer portion operation. 
     In some embodiments, the center button  11   a  can have a spring action, where the button can move below the plane of the touchable cover  11  when force is applied and can move up to the plane of the cover when the force is removed. When force is applied, the force sensor  13  disposed under the button  11   a  can deform to generate a force signal. In some embodiments, the outer portion  11   b  can have a tilt action, where the outer portion can tilt at a particular location below the original plane of the touchable cover  11  when force is applied and can move back up to the original plane of the cover when the force is removed. When force is applied, the force sensor  13  disposed at the location of the applied force can deform to generate a force signal. In some embodiments, the outer portion  11   b  can have a rotational motion, where the outer portion can rotate around the center button  11   a  in either direction when touched. When a touch or a rotational motion occurs, the touch sensors  15  disposed at the locations of the touch or rotational motion can generate touch signals. In some embodiments, the outer portion  11   b  can have a spring action, similar to the center button  11   a , where the outer portion can move below the plane of the touchable cover  11  when force is applied and can move up to the plane of the cover when the force is removed. When force is applied, one or more of the force sensors  13  disposed under the outer portion  11   b  can deform to generate a force signal and one or more of the touch sensors  15  can sense the location of the applied force and generate a touch signal. 
       FIG. 2  illustrates a cross sectional view of the exemplary touch sensing device of  FIG. 1 . In the example of  FIG. 2 , touch sensing device  10  can include touchable cover  11 , having button  11   a  at the center of the cover and outer portion  11   b  separate from and surrounding the center button. The touch sensing device  10  can also include flexible circuit  24 , having touch sensors  15  embedded therein and force sensors  13  disposed thereon. The flexible circuit  24  can be adhered by adhesive  22  to an undersurface of the touchable cover  11 , i.e., a surface opposite the surface to which a touch can occur and a force can be applied. Flexible cable  17  can be connected to the flexible circuit  24  to receive drive signals for the touch sensors  15  and the force sensors  13  and to transmit touch signals from the touch sensors and force signals from the force sensors. The touch sensing device  10  can also include support structure  26  under the flexible circuit  24  for the force sensors  13  to press against when a force is applied to the touchable cover  11 , thereby deforming the force sensors to generate a force signal. 
       FIG. 3  illustrates a bottom view of the flexible circuit of the exemplary touch sensing device of  FIGS. 1 and 2 , where the bottom view can be the surface of the flexible circuit opposite the surface adhered to the touchable cover of the touch sensing device. In the example of  FIG. 3 , touch sensing device  10  can include flexible circuit  24 , having touch sensors  15  embedded therein and force sensors  13  disposed thereon. The flexible circuit  24  can also include center cutout  38  configured to allow outer portion  11   b  of touchable cover  11  to move without moving center button  11   a . Flexible cable  17  can be connected to the flexible circuit  24  as described previously. 
     The configuration of the touch sensing device  10  of  FIGS. 1-3  can result in the device being thicker than desired or preferred. This thickness can be due to the amount of space needed between the force sensors  13  and the support structure  26  so that the touchable cover  11  can have room to move and the force sensors can have space between them and the support structure to be in an undeformed state when no force is applied to the cover, e.g., when the cover rotates or when the cover incidentally wobbles. This thickness can also be due to the amount of space needed for the flexible cable  17  connected to the flexible circuit  24  to have sufficient length to comply with the tilt, translational, and rotational motion of the cover  11 . Other factors can also affect the thickness of the touch sensing device. With the trend toward smaller and thinner devices, a thinner touch sensing device may be desirable. 
       FIG. 4  illustrates a top view of an exemplary touch sensing device according to various embodiments, where the touch sensing device can be thinner than that of  FIGS. 1-3 . In the example of  FIG. 4 , touch sensing device  40  can include touchable cover  41 , which can have button  41   a  at the center of the cover and outer portion  41   b  separate from and surrounding the center button. The touchable cover  41  can be configured to receive a touch from an object and/or a force applied by the object at a touchable surface of the cover. The touchable cover  41  can also be configured to cover and protect the underlying device components from dust and damage. An object&#39;s touch can be sensed by touch sensors disposed under the touchable cover  41 , where the touch sensors can be formed from conductive electrodes  48  coupled with either conductive nodes  45  or force sensors  43 . The touch sensors can be disposed under the outer portion  41   b , the center button  41   a , or both, to sense a touch thereat. An applied force can be sensed by force sensors  43  also disposed under the touchable cover  41 . The force sensors  43  can be disposed under the outer portion  41   b , the center button  41   a , or both, to sense an applied force. The force sensors  43  can be used for both touch sensing and force sensing. 
     The touch sensing device  40  can also include stub  47 , having signal lines (not shown) so that a processor (not shown) or other suitable components can determine force applied to the force sensors and touch at the touch sensors. 
     In some embodiments, the touch sensors can be capacitance sensors, such that a sensed change in capacitance can indicate a touch at the device  40 . A conductive electrode  48  and a force sensor  43  can be in close proximity so as to form mutual capacitance therebetween. Similarly, a conductive electrode  48  and a conductive node  45  can be in close proximity so as to form mutual capacitance therebetween. During operation, the electrodes  48  can be charged and the charge can capacitively couple to the corresponding force sensor  43  or conductive node  45 . As an object approaches the touchable cover  41 , the object can change the capacitance between the electrodes  48  and the device ground and/or between some of the electrodes and others of the electrodes. This change in capacitance can be detected by electronics connected to the force sensors  43  and the conductive nodes  45 , because the total capacitances that the electronics can directly measure can be influenced, for example, by (a) the series capacitance coupling of the force sensors to the electrodes  48  and of the conductive nodes to the electrodes; and (b) the capacitance between some of the electrodes to others of the electrodes and between the electrodes and system ground. These total capacitances can include capacitance from some of the force sensors  43  to others of the force sensors, capacitance from the force sensors to the conductive nodes  45 , capacitance from some of the conductive nodes to others of the conductive nodes, capacitance from the force sensors to device ground, and capacitance from the conductive nodes to device ground. The change in capacitance can be measured by the touch sensing device  40  to determine the positions of multiple objects when they touch the touchable cover  41 . 
     In some embodiments, the force sensors  43  can be dome switches, such as described previously. 
       FIG. 5  illustrates a cross sectional view of the exemplary touch sensing device of  FIG. 4 . In the example of  FIG. 5 , touch sensing device  40  can include touchable cover  41 , having button  41 a at the center of the cover and outer portion  41 b separate from and surrounding the center button. The touchable cover  41  can also have conductive electrodes  48  disposed on the undersurface of the cover, i.e., a surface opposite the surface at which an object can touch or apply force to the cover. The touch sensing device  40  can also include flexible circuit  54 , having force sensors  43  and conductive nodes  45  disposed on a surface of the circuit. The flexible circuit  54  can be disposed on support structure  56 . The force sensors  43  and the conductive nodes  45  disposed on the flexible circuit  54  can be coplanar with each other and aligned with corresponding conductive electrodes  48  disposed on the undersurface of the touchable cover  41 , thereby capacitively coupling together as described previously. The conductive nodes  45  can be of similar height as the force sensors  43  so that the capacitive distances to their corresponding conductive electrodes  48  can be substantially the same, thereby forming similar capacitances. Stub  47  can be connected to the flexible circuit  54  to receive drive signals for the touch sensors and the force sensors and to transmit touch signals from the touch sensors and force signals from the force sensors. 
     Similar to the touch sensing device  10  of  FIGS. 1-3 , the touch sensing device  40  of  FIG. 4  can have the center button  41   a  and the outer portion  41   b  moving independent of each other and operating either together or separately, depending on the needs of the touch sensing device  40 . In some embodiments, the center button  41   a  can have a spring action, where the button can move below the plane of the touchable cover  41  when force is applied and can move up to the plane of the cover when the force is removed. When force is applied, the button  41   a  can move down to contact the force sensor  43  and deform the sensor to generate a force signal. In some embodiments, the outer portion  41   b  can have a tilt action, where the outer portion can tilt at a particular location below the original plane of the touchable cover  41  when force is applied and can move back up to the original plane of the cover when the force is removed. When force is applied, the outer portion  41   a  at the force location can tilt down to contact the force sensor  43  below and deform the sensor to generate a force signal. In some embodiments, the outer portion  41   b  can have a rotational motion, where the outer portion can rotate around the center button  41   a  in either direction when touched. When a touch or a rotational motion occurs, the touch sensors formed by the conductive electrodes  48  and corresponding force sensors  43  and conductive nodes  45  at the locations of the touch or rotational motion can generate touch signals. In some embodiments, the outer portion  41   b  can have a spring action, similar to the center button  41   a , where the outer portion can move below the plane of the touchable cover  41  when force is applied and can move up to the plane of the cover when the force is removed. When force is applied, one or more of the force sensors  43  disposed under the outer portion  41   b  can deform to generate a force signal and one or more of the touch sensors  45  can sense the location of the applied force and generate a touch signal. 
       FIG. 6  illustrates a bottom view of the touchable cover of the exemplary touch sensing device of  FIGS. 4 and 5 , where the bottom view can be the undersurface of the touchable cover  41 . In the example of  FIG. 6 , touch sensing device  40  can include touchable cover  41 , having conductive electrodes  48  disposed thereon. In some embodiments, the conductive electrodes  48  can be printed on the undersurface using a conductive material, such as carbon. Other fabrication techniques and conductive materials can also be used. The electrodes  48  can have any shape and/or configuration capable of providing capacitive sensing according to various embodiments. For example, the electrodes  48  can form zigzag shapes on the undersurface of the cover  11 . 
       FIG. 7  illustrates a top view of the flexible circuit of the exemplary touch sensing device of  FIGS. 4-6 , where the top view can be the surface proximate to the undersurface of the touchable cover  41 . In the example of  FIG. 7 , touch sensing device  40  can include flexible circuit  54 , having force sensors  43  and conductive nodes  45  disposed thereon. The force sensors  43  can be deformable so as to sense a force applied to the touchable cover  41 . The conductive nodes  45  can be deformable so as to accommodate a tilt or translation of the touchable cover  41  when force is applied. In some embodiments, the conductive nodes  45  can be deformable conductive pads. In some embodiments, the conductive nodes  45  can be conductive springs. Other deformable material can also be used. Stub  47  can be connected to the flexible circuit  54  as described previously. 
     Some differences in the configuration of the touch sensing device  40  of  FIGS. 4-7  from the touch sensing device  10   FIGS. 1-3  can result in the device  40  being thinner. For example, by the flexible circuit  54  being disposed on the support structure  56  rather than on the touchable cover  41 , the stub  47  can be used as the transmission medium for the touch and force signals rather than the flexible cable  17  of  FIGS. 1-3 . As a result, less space can be used to house the shorter stub  47 . This can be a result of the flexible circuit  54  being disposed on a stationary structure, i.e., the support structure  56 , rather than on a movable structure, i.e., the touchable cover  41 , such that the stub  47  need not have extra length to comply with tilt, translation, and/or rotation of the flexible circuit when the cover tilts, translates, and/or rotates. Similarly, by the force sensors  43  being disposed via the flexible circuit  54  on the support structure  56  rather than via the flexible circuit  24  on the touchable cover  11  as in  FIGS. 1-3 , the space between the force sensors and the structure used to deform them can be reduced because incidental movement of the cover  41  may not apply enough force to the sensors sufficient to deform the sensors. 
     The center cutout  38  in the flexible circuit  24  of  FIGS. 1-3  can optionally be omitted in the flexible circuit  54  of  FIGS. 4-7  since the flexible circuit  54  need not accommodate both movement of the outer portion  41   b  of the touchable cover  41  and non-movement of the center button  41   a.    
     To provide effective touch sensing, the touch sensors of  FIGS. 4-7  can be different from those of  FIGS. 1-3 . For example, disposing the flexible circuit  24  away from the touchable cover  11  could mean that embedded touch sensors  15  would also be disposed away from the cover, thereby increasing the distance from an object&#39;s touch and decreasing the ability of the sensors to sense capacitance changes caused by the touch. As a result, as in  FIGS. 4-7 , disposing portions of the touch sensors in the form of conductive electrodes  48  on the undersurface of the cover  11 , while capacitively coupling them with the force sensors  43 , can provide components close enough to an object&#39;s touch on the cover to effectively sense the touch. However, since the force sensors  43  may not be disposed at all the locations that the object may touch, additional elements to capacitively couple with the conductive electrodes  48  can be used in the form of the conductive nodes  45  at the non-force sensor locations. 
     In some embodiments, rather than having separate center button and outer portion, the touchable cover  41  can be a single structure, having a deformable region in the center of the cover to act as the center button  41   a  and a rigid region surrounding the center button to act as the outer portion  41   b . In some embodiments, the entire touchable cover  41  can be a single deformable structure, where the cover can deform to contact a force sensor, rather than tilting and/or translating. 
       FIG. 8  illustrates a top view of another flexible circuit of an exemplary touch sensing device according to various embodiments. Flexible circuit  84  of  FIG. 8  can be similar to the flexible circuit  54  of  FIG. 7  with some differences. The flexible circuit  84  of  FIG. 8  can include conductive nodes  85  disposed thereon, rather than both nodes and force sensors as in  FIG. 7 . The conductive nodes  85  can capacitively couple with corresponding conductive electrodes disposed on the undersurface of a touchable cover of the touch sensing device to form touch sensors. The conductive nodes  85  can be of a height sufficient to capacitively couple with the conductive electrodes to provide touch sensing capabilities. In some embodiments, the conductive nodes  85  can be rigid below a stationary touchable cover to sense touch and/or gestures, e.g., rotational motion, at the touchable cover of the touch sensing device. In some embodiments, the conductive nodes  85  can be deformable below a movable touchable cover to sense touch and/or gestures and to sense applied force based on a change in capacitance due to the change in distance between the conductive nodes and the touchable cover. 
       FIG. 9  illustrates a top view of still another flexible circuit of an exemplary touch sensing device according to various embodiments. Flexible circuit  94  of  FIG. 9  can be similar to the flexible circuit  54  of  FIG. 7  with some differences. The flexible circuit  94  of  FIG. 9  can include conductive ring  95  disposed thereon, rather than individual nodes and force sensors as in  FIG. 7 . The flexible circuit  94  can also include conductive node  96  at the center of the flexible circuit to align with a center button of the touch sensing device. The conductive ring  95  can have extensions  95   a  to align with corresponding conductive electrodes disposed on the undersurface of a touchable cover of the touch sensing device to form touch sensors. The conductive extensions  95   a  can be of a height sufficient to capacitively couple with the conductive electrodes to provide touch sensing capabilities. In some embodiments, to ensure that the conductive extensions  95   a  can not substantially interfere with each other via the conductive ring  95 , the ring can include high dielectric material around the ring, excluding the locations of the extensions. In some embodiments, the conductive extensions  95   a  can be rigid below a stationary touchable cover to sense touch and/or gestures, e.g., rotational motion, at the touchable cover of the touch sensing device. In some embodiments, the conductive extensions  95   a  can be deformable below a movable touchable cover to sense touch and/or gestures and to sense applied force based on a change in capacitance due to the change in distance between the conductive extensions and the touchable cover. 
     It is to be understood that other configurations of the underlying conductive nodes can also be used. 
       FIG. 10  illustrates a top view of another exemplary touch sensing device according to various embodiments, where the touch sensing device can be thinner than that of  FIGS. 1-3 . In the example of  FIG. 10 , touch sensing device  100  can include touchable cover  101 , which can have button  101   a  at the center of the cover and outer portion  101   b  separate from and surrounding the center button. The touchable cover  101  can be configured to receive a touch from an object and/or a force applied by the object on a touchable surface of the cover. The touchable cover  101  can also be configured to cover and protect the underlying device components from dust and damage. An object&#39;s touch can be sensed by touch sensors disposed under the touchable cover  101 , where the touch sensors can be formed from conductive electrodes  102  coupled with force sensors  103  and conductive electrodes  108  coupled with conductive nodes  105 . The touch sensors can be disposed under the outer portion  101   b , the center button  101   a , or both, to sense a touch thereat. An applied force can be sensed by force sensors  103  also disposed under the touchable cover  101 . The force sensors  103  can be disposed under the outer portion  101   b , the center button  101   a , or both, to sense an applied force. The force sensors  103  can be used for both touch sensing and force sensing. 
     The touch sensing device  100  can also include stub  107 , having signal lines (not shown) so that a processor (not shown) or other suitable components can determine force applied to the force sensors and touch at the touch sensors. 
     In some embodiments, the touch sensors can be capacitance sensors, as described previously, where the capacitance sensors can be formed by conductive electrodes  102  coupled with corresponding force sensors  103  and conductive electrodes  108  coupled with corresponding conductive nodes  105 . In some embodiments, the force sensors  103  can be dome switches, such as described previously. 
       FIG. 11  illustrates a cross sectional view of the exemplary touch sensing device of  FIG. 10 . In the example of  FIG. 11 , touch sensing device  100  can include touchable cover  101 , having button  101   a  at the center of the cover and outer portion  101   b  separate from and surrounding the center button. The touchable cover  101  can also have conductive electrodes  102  and  108  disposed on the undersurface of the cover, i.e., a surface opposite the surface at which an object can touch or apply force to the cover. The touch sensing device  100  can also include flexible circuit  114 , having force sensors  103  and conductive nodes  105  disposed on a surface of the circuit. The flexible circuit  114  can be disposed on support structure  116 . The force sensors  103  disposed on the flexible circuit  114  can be aligned with corresponding conductive electrodes  102  disposed on the undersurface of the touchable cover  101  and the conductive nodes  105  disposed on the flexible circuit can be aligned with corresponding conductive electrodes  108  disposed on the undersurface of the touchable cover, thereby capacitively coupling together as described previously. The conductive electrodes  108  can be of similar height as the force sensors  103  so that the capacitive distances between the conductive electrodes  108  and their corresponding conductive nodes  105  can be similar to the capacitive distances between the conductive electrodes  102  and their corresponding force sensors  103 , thereby forming similar capacitances. Stub  107  can be connected to the flexible circuit  114  to receive drive signals for the touch sensors and the force sensors and to transmit touch signals from the touch sensors and force signals from the force sensors. 
     Similar to the touch sensing device  40  of  FIGS. 4-7 , the touch sensing device  100  of  FIGS. 10 and 11  can have the center button  101   a  and the outer portion  101   b  moving independent of each other and operating either together or separately, depending on the needs of the touch sensing device  100 . 
       FIG. 12  illustrates a bottom view of the touchable cover of the exemplary touch sensing device of  FIGS. 10 and 11 , where the bottom view can be the undersurface of the touchable cover  101 . In the example of  FIG. 12 , touch sensing device  100  can include touchable cover  101 , having conductive electrodes  102  and  108  disposed thereon, where the conductive electrodes  108  can extend farther from the undersurface of the cover than the conductive electrodes  102 . In some embodiments, the conductive electrodes  102  and  108  can be printed on the undersurface using a conductive material, such as carbon. Other fabrication techniques and conductive materials can also be used. The electrodes  102  and  108  can have any shape and/or configuration capable of providing capacitive sensing according to various embodiments. For example, the electrodes  102  and  108  can form zigzag shapes on the undersurface of the cover  101 . In some embodiments, the conductive electrodes  108  can be deformable so as to accommodate a tilt or translation of the touchable cover  101  when force is applied. 
       FIG. 13  illustrates a top view of the flexible circuit of the exemplary touch sensing device of  FIGS. 10-12 , where the top view can be the surface adjacent to the undersurface of the touchable cover  101 . In the example of  FIG. 13 , touch sensing device  100  can include flexible circuit  114 , having force sensors  103  and conductive nodes  105  disposed thereon. The force sensors  103  can be deformable so as to sense a force applied to the touchable cover  101 . The conductive nodes  105  can be deformable so as to accommodate a tilt or translation of the touchable cover  101  when force is applied. In some embodiments, the conductive nodes  105  can be deformable conductive pads. In some embodiments, the conductive nodes  105  can be conductive springs. Other deformable material can also be used. Stub  107  can be connected to the flexible circuit  114  as described previously. 
       FIG. 14  illustrates a cross sectional view of an exemplary touch sensing device according to various embodiments. In the example of  FIG. 14 , touchable cover  141  via conductive electrodes  148  can have electrical contact with corresponding force sensors  143  and conductive nodes  145  at all times. This can ensure consistent capacitive touch sensing at various positions at the cover  141  because all the electrodes  148  and their corresponding sensors and nodes can have similar capacitances due to all of them having similar consistent contact with the cover. 
       FIG. 15  illustrates a cross sectional view of another exemplary touch sensing device according to various embodiments. In the example of  FIG. 15 , touchable cover  151  can be absent electrical contact with corresponding force sensors  153  and conductive nodes  155  at all times. Rather, insulating layer  152  can be disposed between the undersurface of the cover  151  and conductive electrodes  158  to minimize, isolate, or attenuate contact. This also can ensure consistent capacitive touch sensing at various positions at the cover  151  because all the electrodes  158  and their corresponding sensors and nodes can have similar capacitances due to all of them having similar consistent non-contact with the cover. 
       FIG. 16  illustrates an exemplary method for forming an exemplary touch sensing device according to various embodiments. In the example of  FIG. 16 , a flexible circuit can be placed on a support structure of the touch sensing device ( 162 ). The support structure can be stationary and the flexible circuit can be made stationary when placed on the structure. Conductive nodes can be placed on the flexible circuit at various locations, in various poses, configurations, and layouts, in various orientations, etc., according to the needs of the device ( 164 ). In some embodiments, the conductive nodes can include a combination of force sensors and touch sensors for devices having force and touch sensing capabilities. In some embodiments, the conductive nodes can include touch sensors for devices having touch sensing capabilities. Other types of nodes can also be used, depending on the needs of the device. Conductive electrodes can be printed on the undersurface of the touchable cover of the touch sensing device in locations corresponding to the locations of the conductive nodes on the flexible circuit ( 166 ). In addition to or alternatively, the electrodes can be plated, cast, laid, or otherwise disposed on the cover undersurface. The cover and the flexible circuit can be placed close together so that the conductive electrodes on the cover undersurface and the conductive nodes on the flexible circuit can be aligned facing each other in close proximity ( 168 ). This can result in a thinner touch sensing device with the touch sensing capabilities of a thicker device having force and/or touch sensors on the touchable cover undersurface. 
     Other and/or additional methods can also be used to form a touch sensing device according to various embodiments. 
     In some embodiments, the touch sensing device as described previously can be a click wheel, which can be used in a digital media player. In some embodiments, the touch sensing device as described previously can be a touch pad, which can be used in a mobile telephone, a personal computer, and the like. 
       FIG. 17  illustrates an exemplary digital media player having a click wheel as a touch sensing device according to various embodiments. In the example of  FIG. 17 , digital medial player  170  can include housing  172  for enclosing various electrical components of the player, display  176  for displaying a graphical user interface as well as information for a user, and click wheel  171  for providing touch and force input by the user to the player. By way of example, the media player  170  can correspond to any of those iPod™ music players manufactured by Apple Computer of Cupertino, Calif. (e.g., standard, mini, iShuffle™, Nano™, etc.). 
     The housing  172  can enclose internally various electrical components (including integrated circuit chips and other circuitry) to provide computing operations for the media player  170 . The integrated circuit chips and other circuitry can include a microprocessor, memory (e.g., ROM, RAM), a power supply (e.g., battery), a circuit board, a hard drive, and various input/output (I/O) support circuitry. In the case of music players, the electrical components can include components for outputting music such as an amplifier and a digital signal processor (DSP). In the case of video recorders or cameras the electrical components can include components for capturing images such as image sensors (e.g., charge coupled device (CCD) or complimentary oxide semiconductor (CMOS)) or optics (e.g., lenses, splitters, filters). In addition to the above, the housing can also define the shape or form of the media player. That is, the contour of the housing  172  can embody the outward physical appearance of the media player  170 . 
     The display  176  can be used to display a graphical user interface as well as other information to the user (e.g., text, objects, or graphics). The display  176  can be a liquid crystal display (LCD), for example. As shown, the display  176  can be visible to a user of the media player  170  through an opening in the housing  172 . The opening can include a transparent wall (not shown) that can be disposed in front of the display  172  to protect the display from damage and dust. 
     The click wheel  171  can be a touch sensing device according to various embodiments. The click wheel  171  can be configured to provide one or more control functions for controlling various applications associated with the media player  170 . For example, a touch and/or force initiated control function can be used to move an object or perform an action on the display  176  or to make selections or issue commands associated with operating the media player  170 . The manner in which the click wheel  171  receives input can vary. For example, the click wheel  171  can receive input from a finger tap, a finger press, a finger rotational motion, a finger linear motion, and so on. In some embodiments, a finger rotational motion at the click wheel  171  can cause a scrolling motion on the display  176 , e.g., through a menu of displayed items. In some embodiments, a finger press at the click wheel  171  can cause a selection on the display  176 , e.g., selection of a cursor identified or highlighted item being displayed. In addition to or alternatively, a finger press at the click wheel  171  can cause execution of an application associated with the media player  170 . 
       FIG. 18  illustrates an exemplary mobile telephone  180  that can include touch sensor panel  181  as a touch sensing device, display  186 , and other computing system blocks according to various embodiments. 
       FIG. 19  illustrates an exemplary personal computer  190  that can include touch sensor panel (trackpad)  191  as a touch sensing device, display  196 , and other computing system blocks according to various embodiments. 
     The digital media player, mobile telephone, and personal computer of  FIGS. 17-19  can realize space savings, power savings, and improved performance according to various embodiments. 
     Although various embodiments herein describe the touch sensing device as being circular, it is to be understood that the device can have other shapes, e.g., oval, rectangular, triangular, irregular, etc. It is further to be understood that the touch sensing device is not limited to the substantially flat structure described herein, but can include curved, sloped, etc., structures. 
     Although embodiments have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the various embodiments as defined by the appended claims.

Metadata:
Filing Date: 20090707
Publication Date: 20141028
Grant Date: 20141028
Priority Date: 20090707
Inventors: HOTELLING STEVEN PORTER
ZADESKY STEPHEN PAUL
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/044", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 43426650