PATENT DOCUMENT

Publication Number: US-8964352-B2
Application Number: US-79463310-A
Country: US
Kind Code: B2

Title: Mounting structures for components in electronic devices

Abstract:
An electronic device may be provided with a housing having housing sidewalls. A plate may be connected between a pair of the sidewalls. An audio jack may be mounted to the plate. A microphone may be mounted within the device between the audio jack and a given one of the sidewalls. A vibrator may be mounted between one of the sidewalls and the audio jack using a bracket. The vibrator may have a weight that is tapered along its length. A button may be formed in an opening in one of the housing sidewalls. The button may have a button member with a protrusion that extends through a button opening in the sidewall. A support structure may be interposed between a switch and the button member. The switch may have a portion that extends through an opening in the support structure and that is actuated by the button member.

Claims:
What is claimed is: 
     
       1. An apparatus, comprising: an electronic device housing comprising:
 a first wall portion positioned adjacent at least a portion of the button member; 
 a second wall portion abutting the first wall portion adjacent at least the portion of the button member, the second wall portion defining an opening and having a thickness less than a first wall portion thickness; 
 
       a switch structure positioned within the electronic device housing; a moveable switch member connected to and extending from the switch structure;
 a button member comprising: 
 a protrusion that protrudes through the opening of the second wall portion of the electronic device housing; and 
 a recess that receives the moveable switch member; 
 a support structure coupled to the first wall portion of the electronic device housing and the switch structure, the support structure fixing the switch structure within the electronic device housing; and 
 a lubricating coating interposed between the button member and the second wall portion; wherein 
 a portion of the support structure is interposed between the switch structure and the button member. 
 
     
     
       2. The apparatus defined in  claim 1  wherein the button member comprises metal and wherein the electronic device housing comprises a metal electronic device housing wall through which the opening is formed. 
     
     
       3. The apparatus defined in  claim 1 , wherein the first wall portion to extend to at least the recess. 
     
     
       4. The apparatus defined in  claim 1 , wherein the button member moves in a first direction and in a second direction. 
     
     
       5. The apparatus of  claim 1  further comprising a flexible printed circuit coupled to the switch structure. 
     
     
       6. The apparatus of  claim 1 , wherein the support structure comprises an opening, wherein the moveable switch member protrudes through the opening; and
 wherein the flexible printed circuit is coupled to the support structure and the switch structure. 
 
     
     
       7. The apparatus of  claim 1 , wherein the lubricating coating is formed of at least one of polytetrafluoroethylene, graphite, grease, and polyurethane. 
     
     
       8. The apparatus defined in  claim 2  further comprising a visual indicator on the button member, wherein the button member is movable between a first position in which the visual indicator is visible through the opening and a second position in which the visual indicator is covered by the first wall portion without touching the first wall portion. 
     
     
       9. The apparatus defined in  claim 4 , wherein the first direction is opposite the second direction. 
     
     
       10. The apparatus defined in  claim 4 , wherein moving the button member in the first direction activates the switch structure and moving the button member in the second direction de-activates the switch structure. 
     
     
       11. The apparatus of  claim 5 , wherein the switch structure is coupled to the flexible printed circuit by at least one heat stake. 
     
     
       12. The apparatus of  claim 5 , wherein the support structure is coupled to the flexible printed circuit, and wherein
 the support structure has a portion connected to the first wall portion of the electronic device housing structure. 
 
     
     
       13. The apparatus defined in  claim 8  wherein the visual indicator comprises a patch of ink. 
     
     
       14. The apparatus of  claim 8 , wherein the first position corresponds to moving the button member in a first direction and the second position corresponds to moving the button member in a second direction. 
     
     
       15. The apparatus of  claim 12 , wherein the support structure includes a bracket interposed between the switch structure and the button member such that pressure on the button member in a direction parallel to the button member protrusion causes an inner surface of the button member to press against an outer surface of the bracket. 
     
     
       16. An apparatus, comprising:
 an electronic device housing wall comprising:
 a first wall portion; 
 a second wall portion abutting the first wall portion; 
 an opening defined in the second wall portion; 
 
 a button member comprising a protrusion that protrudes through the opening and has a recess; 
 a switch that is actuated by the button member, the switch comprising a portion operable to be received by the recess; 
 a lubricating coating interposed between the button member and the housing wall; 
 a support structure to which the switch is mounted, the support structure comprising:
 an opening through which a portion of the switch extends; and 
 a bracket connected to the housing wall; and 
 
 a flexible printed circuit interposed between the switch and the bracket of the support structure; wherein 
 the first wall portion and the second wall portion lie above at least a portion of the button member; 
 the support structure is interposed between the switch and the button member, and is directly attached to the housing; and 
 the button member and the housing wall are formed from metal. 
 
     
     
       17. The apparatus of  claim 16 , wherein the switch member is actuated by the button member when the button member is moved in a first direction. 
     
     
       18. The apparatus of  claim 16 , wherein the bracket prevents movement in a first direction, wherein the first direction is perpendicular to a second direction and wherein the button member moves in the second direction to actuate the switch. 
     
     
       19. An apparatus, comprising:
 an electronic device housing wall having an opening; 
 a button member that has a protrusion that protrudes through the opening and has a recess; 
 a switch that is actuated by the button member, the switch comprising a portion operable to be received by the recess; 
 a support structure to which the switch is mounted, wherein the support structure is interposed between the switch and the button member; and 
 a flexible printed circuit including an opening that is interposed between the support structure and the switch, wherein the portion of the switch member received by the recess extends through the flexible printed circuit&#39;s opening and an opening of the support structure.

Description:
This application claims the benefit of provisional patent application No. 61/325,761, filed Apr. 19, 2010, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and components for electronic devices. 
     Electronic devices such as cellular telephones include numerous electronic and mechanical components. Care should be taken that these components are durable, attractive in appearance, and exhibit good performance. Tradeoffs must often be made. For example, it may be difficult to design a robust mechanical part that is attractive in appearance. The designs for attractive and compact parts and parts that perform well under a variety of operating environments also pose challenges. 
     It would therefore be desirable to be able to provide improved electronic devices and parts for electronic devices. 
     SUMMARY 
     Electronic devices may be provided that include mechanical and electronic components. These components may include mechanical structures such as mounting structures and electrical components such as integrated circuits, printed circuit boards, and electrical devices that are mounted to printed circuit boards. Optical components, connectors, antennas, buttons, and other structures may be included in an electronic device. 
     An electronic device may have a housing. Electronic components and mechanical structures may be formed within the housing. To ensure that the electronic device is attractive, attractive materials such as metal and plastic may be used to form parts of an electronic device. Compact size may be achieved by using compact internal mounting structures. Good electrical performance may be achieved by designing an electronic device to handle a variety of thermal and electrical loads. 
     Buttons may be included in electronic devices such as glass buttons, metal buttons, buttons that are assembled on printed circuit boards, and buttons that are partly formed from antenna structures. Button coatings may be used to improve the sliding performance of metal-on-metal buttons. Elastomeric members may be used to reduce button rattle. 
     Vibrator units may be used to vibrate an electronic device in response to an incoming telephone call, calendar entry, or other event. A tapered counterweight may be used to save space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative electronic device in accordance with an embodiment of the present invention. 
         FIG. 2A  is a front perspective view of an illustrative electronic device that may be provided with a button in accordance with an embodiment of the present invention. 
         FIG. 2B  is a rear perspective view of an illustrative electronic device that may be provided with a button in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of a conventional plastic cellular telephone button. 
         FIG. 4  is a perspective view of a glass button structure that may be used in a button in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative button in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of an illustrative button mounted within a portion of an electronic device in accordance with an embodiment of the present invention. 
         FIG. 7  is a flow chart of illustrative steps involved in forming a button in accordance with an embodiment of the present invention. 
         FIG. 8  is a perspective view of an illustrative electronic device in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional end view of an illustrative electronic device of the type shown in  FIG. 8  in accordance with an embodiment of the present invention. 
         FIG. 10  is a top interior view of an electronic device in accordance with an embodiment of the present invention. 
         FIG. 11  is a top view of an interior portion of an electronic device showing how a microphone may be mounted using an audio jack in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional view of a conventional button in a cellular telephone. 
         FIG. 13  is a cross-sectional view of a button assembly in an electronic device in accordance with an embodiment of the present invention. 
         FIG. 14  is a perspective view of an illustrative electronic device vibrator having a tapered weight having a conical surface in accordance with an embodiment of the present invention. 
         FIG. 15  is a perspective view of an illustrative electronic device vibrator having a tapered weight formed from cylindrical sections of different sizes in accordance with an embodiment of the present invention. 
         FIG. 16  is a top view of an illustrative electronic device vibrator with a conical tapered weight in accordance with an embodiment of the present invention showing how the tapered shape of the weight allows for additional components to be mounted in the vicinity of the vibrator. 
         FIG. 17  is a top view of an illustrative electronic device vibrator having a tapered weight formed from cylindrical sections of different sizes in accordance with an embodiment of the present invention. 
         FIG. 18  is a side view showing how a vibrator may be mounted between an electronic device housing structure and an audio jack in accordance with an embodiment of the present invention. 
         FIG. 19  is a perspective view of a button of the type shown in  FIG. 13  that has a button member that protrudes through a device housing and that has a visual indicator formed from a patch of ink on a portion of the button in accordance with an embodiment of the present invention. 
         FIG. 20  is a perspective view of a button of the type shown in  FIG. 19  after the button has been moved to a position that hides the visual indicator from view in accordance with an embodiment of the present invention. 
         FIG. 21  is a cross-sectional view of a button of the type shown in  FIGS. 19 and 20  showing how a coating may be provided on a portion of the button member to allow the button member to travel smoothly along the interior of a device housing in accordance with an embodiment of the present invention. 
         FIG. 22  is a cross-sectional view of an illustrative electronic device including a button that has a button support member with antenna structures in accordance with an embodiment of the present invention. 
         FIG. 23  is a perspective view of an exterior corner portion of an electronic device with a button in accordance with an embodiment of the present invention. 
         FIG. 24  is side view of an illustrative button assembly having an integral central spring in accordance with an embodiment of the present invention. 
         FIG. 25A  is a front perspective view of a button plate having button members in accordance with an embodiment of the present invention. 
         FIG. 25B  is a side view of a button plate having button members in accordance with an embodiment of the present invention. 
         FIG. 25C  is a rear perspective view of a button plate having button members in accordance with an embodiment of the present invention. 
         FIG. 26  is a perspective view of a portion of an electronic device housing having an integral spring in accordance with an embodiment of the present invention. 
         FIG. 27  is a perspective view of a button plate attached to a portion of an electronic device housing that has an integral spring in accordance with an embodiment of the present invention. 
         FIG. 28  is a perspective view of a dome switch assembly in accordance with an embodiment of the present invention. 
         FIG. 29  is a perspective view of a button plate attached to a portion of an electronic device housing four side springs in accordance with an embodiment of the present invention. 
         FIG. 30  is side view of a button assembly having four side springs in accordance with an embodiment of the present invention. 
         FIG. 31  is a perspective view of a button plate attached to a band-shaped housing structure using a clip in accordance with an embodiment of the present invention. 
         FIG. 32  is a side view of a button assembly having a clip in accordance with an embodiment of the present invention. 
         FIG. 33  is a cross-sectional side view of a button assembly having a layer of material such as plastic between a housing structure and button plates in accordance with an embodiment of the present invention. 
         FIG. 34  is a bottom perspective view of a layer of material such as plastic between a housing structure and button plates in accordance with an embodiment of the present invention. 
         FIG. 35  is a side view of a layer of material such as plastic that is flexed when as a button member is pressed by a user in accordance with an embodiment of the present invention. 
         FIG. 36  is a side cross-sectional view showing how nubs may be inserted in a button plate of a button assembly in accordance with an embodiment of the present invention. 
         FIG. 37  is a top perspective view of nubs inserted in a button plate in accordance with an embodiment of the present invention. 
         FIG. 38  is a side cross-sectional view of nubs inserted in button plates in accordance with an embodiment of the present invention. 
         FIG. 39  is a side cross-sectional view of a tool that may be used to form nubs in a button plate in accordance with an embodiment of the present invention. 
         FIG. 40  is a side cross-sectional view of a ring surrounding a button member in a button assembly in accordance with an embodiment of the present invention. 
         FIG. 41  is a bottom perspective view of a ring surrounding a button member in accordance with an embodiment of the present invention. 
         FIG. 42  is a side cross-sectional view of a button assembly having a coated anti-roll bar in accordance with an embodiment of the present invention. 
         FIG. 43  is a diagram of a coated anti-roll bar attached to a button member in accordance with an embodiment of the present invention. 
         FIG. 44  is a side view of a button assembly having a bias spring in accordance with an embodiment of the present invention. 
         FIG. 45  is bottom view of a button plate having bias springs in accordance with an embodiment of the present invention. 
         FIG. 46  is a side view of a button assembly having a bias spring that is compressed when a button member is pressed in accordance with an embodiment of the present invention 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices can be provided with mechanical and electronic components such as optical parts, camera mounting structures, cowlings and other cosmetic parts, printed circuits and support structures, thermal management structures, buttons, vibrators, and other mechanical and electrical structures. 
     Electronic devices that may be provided with these components include desktop computers, computer monitors, computer monitors containing embedded computers, wireless computer cards, wireless adapters, televisions, set-top boxes, gaming consoles, routers, portable electronic devices such as laptop computers, tablet computers, and handheld devices such as cellular telephones and media players, and small devices such as wrist-watch devices, pendant devices, headphone and earpiece devices, and other wearable and miniature devices. Portable devices such as cellular telephones, media players, and other handheld electronic devices are sometimes described herein as an example. 
     An electronic device may be provided with a glass button. Layers of patterned material may be formed on the underside of the glass button member. 
     A housing structure such as a plate may be connected to the housing sidewalls. Ports such as ports for an audio jack and a microphone may be formed in the housing sidewalls. An audio jack may be mounted to the housing plate adjacent to the audio jack port. A microphone may be mounted between the audio jack and the housing sidewall. A vibrator may be mounted between one of the sidewalls and the audio jack using a bracket. 
     A button may have a button member with a protrusion that extends through the button opening in the sidewall. A support structure may be interposed between a switch and the button member. The switch may have a portion that extends through an opening in the support structure. A lubricating coating may be formed between the button member and the housing sidewall. 
     Portions of a button may be provided with conductive features that form portions of an antenna. The conductive features may include sheet metal inserts and conductive traces that are formed directly on plastic parts. With one suitable arrangement, a button support member may be provided with a metal trace and a sheet metal insert. 
     Mounting structures may be provided for attaching button assemblies to the inside of electronic device housing. An integral spring may be attached to the inside of the housing. A button plate may have button members and an opening through which the spring may be inserted, attaching the button plate through the housing. 
     Button assemblies may be provided with a member such as a silicone sheet that is interposed between the housing and button plates. This layer of material may reduce undesired motion and rattle of the buttons. 
     An illustrative electronic device that may be provided with mechanical and electrical features to improve performance, aesthetics, robustness, and size is shown in  FIG. 1 . As shown in  FIG. 1 , device  10  may include storage and processing circuitry  12 . Storage and processing circuitry  12  may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory), volatile memory (e.g., static or dynamic random-access-memory), etc. Storage and processing circuitry  12  may be used in controlling the operation of device  10 . Processing circuitry in circuitry  12  may be based on processors such as microprocessors, microcontrollers, digital signal processors, dedicated processing circuits, power management circuits, audio and video chips, and other suitable integrated circuits. 
     With one suitable arrangement, storage and processing circuitry  12  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VoIP) telephone call applications, email applications, media playback applications, operating system functions, antenna and wireless circuit control functions, etc. Storage and processing circuitry  12  may be used in implementing suitable communications protocols. Communications protocols that may be implemented using storage and processing circuitry  12  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling cellular telephone communications services, etc. 
     Input-output devices  14  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Examples of input-output devices  14  that may be used in device  10  include display screens such as touch screens (e.g., liquid crystal displays or organic light-emitting diode displays), buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers and other devices for creating sound, cameras, sensors, etc. A user can control the operation of device  10  by supplying commands through devices  14  or by supplying commands to device  10  through an accessory that communicates with device  10  through a wireless or wired communications link. Devices  14  or accessories that are in communication with device  10  through a wired or wireless connection may be used to convey visual or sonic information to the user of device  10 . Device  10  may include connectors for forming data ports (e.g., for attaching external equipment such as computers, accessories, etc.). 
     Electronic devices are often controlled using buttons. Buttons are typically formed from metal or plastic. Metal is durable and can be used to form shiny buttons. Plastic may be provided in different colors and can be inexpensive. 
     For aesthetic reasons, it may be desirable for a button to have an appearance that matches surrounding structures. A device with a metal housing may, as an example, be provided with matching metal buttons. 
     Some devices have glass surfaces. For example, some cellular telephones have glass displays. In this type of environment, it may be desirable to form a button that matches the appearance of the glass display. Plastic buttons may not match the appearance of a glass display as well as desired and may be prone to scratches. Metal buttons might offer improved durability, but typically would be even more dissimilar in appearance to the glass display than a plastic button. 
     It would therefore be desirable to be able to provide an electronic device with improved button structures. 
     An electronic device such as a cellular telephone may have a display. The display may have a layer of cover glass on its exterior surface. Additional layers such as a layer of image pixels and a layer of capacitive electrodes for implementing a capacitive touch sensor array may be formed under the cover glass. 
     The cover glass may be provided with one or more openings. For example, a circular opening may be formed in the cover glass in an inactive portion of the display. 
     A button such as a glass button may be mounted in the circular opening. A user may actuate the button to make menu selections and perform other device functions during operation of the electronic device. 
     The button may have a glass button member such as a disk-shaped glass button member. The glass button member may be formed from transparent glass (e.g., a thin clear disk of glass). An optional concave indentation may be formed in the upper surface of the glass button member. 
     The glass button member may have an exterior surface that lies parallel to the exterior of the device and the exposed surface of the cover glass. The glass member may have a parallel planar underside that lies towards the interior of the electronic device. 
     Layers of patterned material may be formed on the underside of the glass button member. For example, a layer of patterned ink may be formed on the underside of the glass button member. Another layer of material such as a background layer of ink may be formed on top of the deposited layer of patterned ink. The layer of patterned ink may be, for example, a patterned white ink layer. The background layer may have a different color than the patterned ink layer, so that the patterned ink layer is visible to the user through the glass button member. The background layer may be, for example, a layer of black ink. 
     The glass button member may be mounted to a base structure. The base structure may include a plastic base layer. A layer of adhesive may be used to attach the glass button layer to the plastic base layer. The layer of adhesive may be interposed between the background layer of ink and the plastic base layer. 
     Protrusions or other portions of the plastic base layer may extend under edge portions of the cover glass. The cover glass edge portions may bear against the extensions in the plastic base, thereby capturing the button within the electronic device. 
     A dome switch or other switch mechanism may be coupled to the glass button member. As the glass button member reciprocates within the opening in the cover glass, the dome switch is activated. Processing circuitry within the electronic device may sense the state of the dome switch during operation. 
     In accordance with an embodiment, a button is provided that includes a glass button member having an exterior surface and a lower button member surface, and at least one patterned layer of material on the lower button member surface. 
     In accordance with another embodiment, a button is provided wherein the glass button member is clear and wherein the patterned layer of material comprises ink. 
     In accordance with another embodiment, a button is provided wherein the at least one patterned layer of material includes a first patterned layer of ink on the lower button member surface, and a second layer of ink that covers the lower button member surface and that covers the first patterned layer of ink. 
     In accordance with another embodiment, a button is provided wherein the first patterned layer of ink and the second layer of ink have different colors. 
     In accordance with another embodiment, a button is provided wherein the first patterned layer of ink has a first color, wherein the second layer of ink has a second color, and wherein the first color is lighter than the second color. 
     In accordance with another embodiment, a button is provided wherein the first color is white and wherein the second color is black. 
     In accordance with another embodiment, a button is provided wherein the glass button member comprises a clear circular glass disk member and wherein the at least one layer of patterned material comprises a patterned first layer of ink on the lower button member surface and a second layer of ink that covers substantially all of the patterned first layer of ink and that covers the lower button member surface. 
     In accordance with another embodiment, a button is provided wherein the glass button member comprises a disk with a chamfered edge, the button further comprising a dome switch attached to the glass button member. 
     In accordance with another embodiment, a button is provided that also includes a base member to which the button member is attached with a layer of adhesive. 
     In accordance with another embodiment, a button is provided wherein the at least one layer of patterned material comprises first and second layers of ink of different colors interposed between the button member and the layer of adhesive. 
     In accordance with an embodiment, a method of forming a button is provided that includes forming a patterned layer of ink on an underside of a transparent button member, wherein the patterned layer of ink has a first color, and forming a background layer of ink covering substantially all of the underside of the transparent button member and covering the patterned layer of ink, wherein the background layer of ink has a second color that is different than the first color. 
     In accordance with another embodiment, a method is provided wherein the first color is white, wherein the transparent button member comprises a clear glass disk, and wherein the second color is black, the method further comprising attaching the button member to a base member. 
     In accordance with another embodiment, a method is provided wherein the base member comprises a plastic member and wherein attaching the button member to the base member comprises using adhesive to attach the button member to the plastic member. 
     In accordance with another embodiment, a method is provided wherein using the adhesive to attach the button member to the plastic member comprises interposing a layer of adhesive between the background layer of ink and the plastic member. 
     In accordance with an embodiment, an electronic device is provided that includes a housing, a display in the housing, wherein the display comprises a layer of glass having an opening, and a glass button mounted in the opening. 
     In accordance with another embodiment, an electronic device is provided wherein the display comprises a touch screen display, wherein the glass button comprises a glass button member with an underside and a patterned layer of ink that is formed on the underside. 
     In accordance with another embodiment, an electronic device is provided wherein the glass button further comprises a background layer of ink that covers the patterned layer of ink. 
     In accordance with another embodiment, an electronic device is provided wherein the button further comprises a dome switch that is coupled to the glass button member. 
     In accordance with another embodiment, an electronic device is provided wherein the patterned layer of ink comprises ink of a first color and wherein the background layer of ink comprises ink of a second color that is different than the first color. 
     In accordance with another embodiment, an electronic device is provided wherein the button comprises a plastic base member to which the glass button member is attached using a layer of adhesive. 
     In accordance with these embodiments, buttons may be used in electronic devices to control menu functions or other operations. The electronic devices in which the buttons are used may be portable electronic devices such as laptop computers or small portable computers of the type that are sometimes referred to as ultraportables. Portable electronic devices may also be somewhat smaller devices. Examples of smaller portable electronic devices include wrist-watch devices, pendant devices, headphone and earpiece devices, and other wearable and miniature devices. 
     If desired, the electronic devices in which the buttons are provided may be, for example, handheld wireless devices such as cellular telephones, media players with wireless communications capabilities, handheld computers (also sometimes called personal digital assistants), remote controllers, global positioning system (GPS) devices, and handheld gaming devices. The electronic devices may also be hybrid devices that combine the functionality of multiple conventional devices. Examples of hybrid portable electronic devices include a cellular telephone that includes media player functionality, a gaming device that includes wireless communications capabilities, a cellular telephone that includes game and email functions, and a portable device that receives email, supports mobile telephone calls, has music player functionality and supports web browsing. These are merely illustrative examples. 
     An illustrative electronic device of the type that may be provided with a button is shown in  FIGS. 2A and 2B . Device  10  of  FIG. 2  may be, for example, a handheld electronic device that supports  2 G and/or  3 G cellular telephone and data functions, global positioning system capabilities, and local wireless communications capabilities (e.g., IEEE 802.11 and Bluetooth®) and that supports handheld computing device functions such as internet browsing, email and calendar functions, games, music player functionality, etc. 
     Device  10  may have housing  16 . Housing  16 , which is sometimes referred to as a case, may be formed of any suitable materials including, plastic, glass, ceramics, metal, or other suitable materials, or a combination of these materials. In some situations, housing  16  or portions of housing  16  may be formed from a dielectric or other low-conductivity material. Housing  16  or portions of housing  16  may also be formed from conductive materials such as metal. 
     Housing  16 , which is sometimes referred to as a case, may be formed of any suitable materials including, plastic, glass, ceramics, carbon-fiber composites and other composites, metal, other suitable materials, or a combination of these materials. A unibody construction may be used for device  10  in which case some or all of housing  16  may be formed from a single piece of material. Housing  16  may, for example, be formed from a piece of plastic or metal that covers the sidewalls of device  10  and that covers the rear surface of device  10 . Frame members and other components may be mounted in the unibody housing. With another illustrative arrangement, housing  16  may be implemented using multiple structures that are assembled together. For example, housing  16  may be formed from a central frame  5612  to which a front and/or rear panels  5616  and  7632  are attached (as an example). In some cases, the front and/or rear panels may include an outer transparent layer (e.g., cover glass). Other configurations may be used if desired. In one embodiment, the panels may be removable. For example, the rear panel may be detached from the rest of the housing in order to provide internal access to the electronic device. In one example, the rear panel is made to slide relative to the rest of the housing between a closed position, enclosing the device, and an open position, providing an opening. 
     A display such as display  7628  may be mounted in housing  16 . Display  7628  may, for example, be mounted on the front surface of device  10  as shown in  FIG. 2 . Display  7628  may be a liquid crystal display (LCD), an organic light emitting diode (OLED) display, an electronic ink display, a plasma display, or any other suitable display. The outermost surface of display  7628  may be formed from a layer of glass  5616  (sometimes referred to as the display&#39;s cover glass). Display  7628  may also have interior layers (e.g., a capacitive touch sensor array for providing display  7628  with touch sensing capabilities, a layer of thin-film transistors for controlling the image pixels in the display, etc.). 
     Display  7628  may have a central active region such as active region  5617  and inactive end regions such as regions  5621 . To hide interior portions of device  10  from view, the underside of display  7628  (e.g., the cover glass of the display) in inactive regions  5621  may be coated with an opaque substance such as black ink (as an example). An opening may be formed in one of regions  5621  to accommodate button  5619 . An opening such as opening  5623  may also be formed in one of regions  5621  (e.g., to form a speaker port). The end portions of housing  5612  may also be provided with openings such as openings  5622  and  5624  for microphone and speaker ports and opening  5620  for an input-output data port. A similar configuration can be provided for the rear panel whether or not another display is used, i.e., the rear panel may be formed with a transparent member with an opaque coating. 
     In one embodiment, device  10  may also include one or more cameras. Cameras may be implemented, for example, by mounting camera modules within the housing of device  10 . In one embodiment (as shown in  FIG. 2A ), device may include front-facing camera  26 . Front facing cameras may for example be mounted behind the front panel  5616  that covers display  1014 . Alternatively or additionally (as shown in  FIG. 2B ), device may include rear-facing camera  28 . Rear facing cameras may be mounted in device  10  behind the rear panel  7632  of device  10 . In other suitable configurations, the housing of device  10  may be formed from a plastic or metal housing in which a transparent plastic or glass camera window structure has been mounted. In this type of arrangement, camera modules may be mounted behind the window structure. 
     The device may include a variety of I/O components including for example buttons, connectors, jacks, receivers, speakers and/or the like. Button  5619  may be used as a menu button. A user may press on button  5619  to navigate through screens that are displayed on display  7628  or to control other functions during the operation of device  10 . 
     Button  5619  may be formed from any suitable material (e.g., plastic, glass, ceramic, metal, etc.). Particularly in arrangements in which button  5619  is surrounded by glass such as the glass in region  5621  of display  7628 , it may be desirable to form button  5619  at least partly from glass. Using a glass layer to form the outermost surface of button  5619  makes it possible to match the appearance and feel of button  5619  to the appearance and feel of the display cover glass in region  5621 . A glass surface layer on button  5619  may also help button  5619  resist scratching. Any suitable glass material may be used in forming button  5619  (e.g., soda lime glass, borosilicate glass, etc.). Glass-like plastic (e.g., transparent polycarbonate or other materials) may also be used to form button  5619  if desired. 
     A cross-sectional side view of a conventional cellular telephone menu button is shown in  FIG. 3 . As shown in  FIG. 3 , conventional button  5630  may have a clear plastic upper button member  5632  that is attached to a black lower button member  5634 . White ink  5638  may be formed on the backside of member  5634 . Opening  5636  in button member  5634  may allow white ink  5638  to be viewed in direction  5640  (i.e., from the exterior of the cellular telephone). Opening  5636  is square when viewed from direction  5640 . 
     A button of the type that may be used to implement button  5619  for device  10  of  FIG. 2  is shown in  FIG. 4 . As shown in  FIG. 4 , button  5619  may be formed from a glass button member such as button member  5650 . Button member  5650  may have a circular outline or other suitable shape (e.g., rectangular, etc.). Button member  5650  may have a planar upper surface such as surface  5644  in which a recessed (concave) dimple such as dimple  5646  is formed. Button member  5650  may have sidewalls such as vertical sidewalls  5642 . An optional chamfer such as chamfer  5648  may be provided around the outer edge of member  5650  to ensure that the edge of member  5650  at which surface  5644  meets sidewall  5642  is not too abrupt. Chamfer  5648  may be oriented at an angle of 45° or other suitable angle in the range of 30-60° with respect to vertical sidewall  5642 . 
     As shown in  FIG. 5 , button  5619  may have a base member such as base member  5652  to which glass button member  5650  is attached. Glass button member  5650  may have the shape of a disk (e.g., a circular disk). Base member  5652  may have an outline that is larger than the outline of glass button member  5650 . The central portion of base member  5652  may have a substantially circular shape to accommodate the outline of glass button member  5650 . Side portions of base member  5652  may have protrusions that help orient button  5619  within device  10  (e.g., by fixing the rotational orientation of button  5619 ). 
     The underside (lower planar surface  5662 ) of button member  5650  may be provided with one or more patterned layers of material. For example, multiple coats of patterned ink may be formed on the lower surface of button member  5650 . Layers of ink may be formed adjacent to one another (i.e., on different portions of lower surface  5662 ) and/or on top of each other). 
     In the example of  FIG. 5 , two layers of ink have been formed on lower surface  5662  of button member  5650 . First ink layer  5656  may be formed directly on lower surface  5662 . Second ink layer  5658  may be used to cover the portions of lower surface  5662  that are not covered by first ink layer  5656  and may be used to cover ink layer  5656 . First ink layer  5656  may have a pattern such as a square (i.e., a square with an open center), a solid square, other solid shapes, a circular or oval ring, a letter or icon shape, etc. Second ink layer  5658  may be a solid background layer that covers substantially all of lower surface  5662 . 
     When multiple layers of ink are formed on button member  5650  in this way, different ink colors may be used for each layer. For example, ink layer  5656  may be formed from a white ink or other lightly colored ink, whereas ink layer  5658  may be formed from a black ink or other darkly colored ink. Other combinations of colors may be used if desired. For example, first ink layer  5656  may be black or may have another dark color, whereas second ink layer  5658  may be white or may have another light color. By using contrasting colors in this way, the pattern that is formed by first ink layer  5656  may be visible against solid background layer  5658 . 
     If desired, first and second patterned materials  5656  and  5658  may be formed from metal, plastic, fibers, particles, paint, combinations of these substances, and other suitable substances. The use of ink for the layers of patterned material that are formed on the underside of button member  5650  is merely illustrative. 
     Member  5650  may be formed from clear (transparent) glass. This allows a user of device  10  to view the pattern formed by ink  5656  through member  5650  when observing button  5619  in direction  5654 . If desired, member  5650  may be formed from a semi-opaque or opaque substance (e.g., frosted glass, smoked or colored glass, black glass, etc.). When member  5650  is at least partly transparent, the pattern of ink  5656  may be viewed. When member  5650  is opaque, ink layers  5656  and  5658  may be omitted (if desired). 
     Member  5650  may be attached to one or more underlying structures. For example, member  5650  may be attached to base layer  5652  using adhesive layer  5660 . Adhesive  5660  may be, for example, a layer of pressure sensitive adhesive or an adhesive such as ultraviolet-cured or thermally cured epoxy. Other adhesives or attachments mechanisms (e.g., press-fit schemes, springs, clips, etc.) may also be used in attaching button member  5650  to base members such as base member  5652  if desired. 
     A cross-sectional view of button  5619  in electronic device  10  of  FIG. 2  is shown in  FIG. 6 . As shown in  FIG. 6 , base member  5652  may have portions  5664  that extend under protruding edge portions  5666  of display cover glass  5621 . Edge portions  5666  capture button  5619  and prevent button  5619  from falling out of device  10 . Portions  5664  and portions  5666  may extend around the entire circular periphery of button member  5650  or may be formed around only part of the button periphery. An asymmetric shape may be used for portions  5664  and a mating asymmetric shape may be used by the surrounding structures in device  10  to ensure that button  5619  can only be placed in device  10  in a particular orientation. Base  5652  may, for example, have one narrow protruding portion  5664  and one wide protruding portion  5666 . That mate with corresponding structures in device  10 , such as structures  5668 . 
     Structures  5668  may be formed from one or more internal members in device  10 , such as frame members, display portions, printed circuit boards, flexible printed circuits boards (“flex circuits”), electrical components, or other suitable structures. These structures are shown as structure  5668  in the example of  FIG. 6 . 
     A dome switch such as switch  5672  or other switch mechanism may be coupled to button  5619 . Dome switch  5672  may be placed in an upright orientation, or, as shown in  FIG. 6 , may be inverted so that nub  5674  bears downwards against surface  5676  of structure  5668 . A flex circuit such as flex circuit  5670  may contain conductive traces that form switch terminals for dome switch  5672 . The inner surface of the dome membrane portion of dome switch  5672  may be coated with metal. When button member  5650  is pressed downwards in direction  5654 , dome switch  5672  is compressed between button member  5650  and interior device structures  5668 . This causes the metal inner surface of the dome switch to form a short circuit between the dome switch terminals, thereby closing the switch. Conductive traces in flex circuit  5670  may route switch signals to processing circuitry in device  10 . The processing circuitry can monitor the state of the switch using the conductive traces. When the processing circuitry senses that the state of the dome switch has changed, appropriate actions may be taken. For example, different information may be display on screen  7628 , functions can be turned on or off, etc. 
     Illustrative steps involved in forming a button such as button  5619  are shown in  FIG. 7 . 
     At step  5678 , a first layer of patterned ink such as patterned ink  5656  of  FIG. 5  may be formed on the lower surface of button member  5650 . Any suitable technique may be used to form the first ink layer. For example, the ink layer may be formed by pad printing, screen printing, dripping, spraying, brush painting, etc. 
     At step  5680 , the second layer of ink may be formed on the lower surface of button member  5650 . For example, a patterned layer or a blanket background layer such as layer  5658  of  FIG. 5  may be formed over substantially all of the underside of button member  5650 , including first ink layer  5656  and any other previously deposited ink patterns. 
     Ink layers  5656  and  5658  may be formed from inks of different colors (shades), paint of different colors, plastics, metals, or other materials with different optical properties, etc. 
     At step  5682 , an optical alignment tool may be used to visually align button member  5650  and base layer  52 . For example, a visual image of button member  5650  and base layer  5652  may be captured using a digital camera. The visual image may be processed using a computer or may be examined manually while the angular and translational orientation of button member  5650  relative to base layer  5652  are adjusted using manually and/or automatically controlled rotation and translation stages. 
     Once aligned, button member  5650  may be attached to base layer  5652  to form button  5619  using a layer of pressure sensitive adhesive (e.g., by pressing these structures together using an assembly tool or moving portions of the alignment tool). 
     At step  5686 , button member  5650 , base layer  5652 , and dome switch  5672  may be assembled within device  10 , as described in connection with  FIG. 6 . 
     Electronic devices such as cellular telephones often contain components such as vibrators, switches, microphones, and audio jacks. Because of size and performance constraints, it can be challenging to mount these components within the confines of a device housing. If care is not taken, it may not be possible to use desired materials or to provide desired levels of performance within a device housing of a given size. In conventional device arrangements, components are sometimes constructed in a way that compromises performance or that uses more space than necessary. While such conventional arrangements can be used to produce an operational device, the compromises that are made in using these arrangements can result in devices with poor aesthetics, suboptimal performance, and unnecessary device bulk. 
     It would therefore be desirable to be able to provide improved electronic device components and mounting arrangements for these components. 
     In accordance with one embodiment, an electronic device may be provided with a housing having housing sidewalls. A housing structure such as a plate may be connected to the housing sidewalls. Ports such as ports for an audio jack and a microphone may be formed in the housing sidewalls. 
     An audio jack may be mounted to the housing plate adjacent to the audio jack port. A microphone may be mounted between the audio jack and the housing sidewall. A biasing structure such as a layer of compressed foam may be interposed between the audio jack and the microphone to bias the microphone against the housing sidewall in the vicinity of the microphone port. 
     A vibrator may be mounted between one of the sidewalls and the audio jack using a bracket. The vibrator may have a weight that is tapered along its length. 
     A button may be formed in a button opening in one of the housing sidewalls. The button may have a button member with a protrusion that extends through the button opening in the sidewall. A support structure may be interposed between a switch and the button member. The switch may have a portion that extends through an opening in the support structure. This portion of the switch may be received within the button member, so that the switch can be actuated by moving the button member within the button opening. A lubricating coating may be formed between the button member and the housing sidewall. 
     In accordance with an embodiment, apparatus is provided that includes an electronic device housing structure having an opening, a button member having a protrusion that protrudes through the opening, wherein the electronic device housing structure has a first wall portion that lies above the button member and a second wall portion, and a lubricating coating interposed between the button member and the second wall portion, wherein the first wall portion has a thickness that is smaller than the second wall portion. 
     In accordance with another embodiment, apparatus is provided wherein the button member includes metal and wherein the electronic device housing structure includes a metal electronic device housing wall through which the opening is formed. 
     In accordance with another embodiment, apparatus is provided that also includes a visual indicator on the button member, wherein the button member is movable between a first position in which the visual indicator is visible through the opening and a second position in which the visual indicator is covered by the first wall portion without touching the first wall portion. 
     In accordance with another embodiment, apparatus is provided wherein the visual indicator includes a patch of ink. 
     In accordance with an embodiment, an electronic device is provided that includes housing structures, an audio jack mounted in the housing structures, and a microphone interposed between the audio jack and the housing structures. 
     In accordance with another embodiment, an electronic device is provided wherein the housing structures include a housing wall with a microphone port opening, the electronic device further including a layer of compressed foam interposed between the microphone and the audio jack, wherein the layer of compressed foam biases the microphone toward the housing wall at the microphone port opening. 
     In accordance with another embodiment, an electronic device is provided that also includes a vibrator mounted to the audio jack. 
     In accordance with another embodiment, an electronic device is provided that also includes at least one bracket with which the vibrator is mounted to the audio jack. 
     In accordance with another embodiment, an electronic device is provided wherein the vibrator includes a tapered weight. 
     In accordance with another embodiment, an electronic device is provided wherein the vibrator includes a shaft to which the tapered weight is attached, wherein the shaft has a tip, wherein the tapered weight has a surface that is radially closer to the shaft at the tip than at other portions of the shaft. 
     In accordance with another embodiment, an electronic device is provided wherein at least part of the tapered weight has a conical surface. 
     In accordance with another embodiment, an electronic device is provided wherein the tapered weight has multiple sections each of which has a cylindrical surface having a different radial distance from the shaft. 
     In accordance with an embodiment, apparatus is provided that includes a vibrator motor for a vibrator, a shaft for the vibrator that is rotated by the vibrator motor, wherein the shaft has a rotational axis, and a weight for the vibrator that is rotationally asymmetric and that is tapered along the rotational axis. 
     In accordance with another embodiment, apparatus is provided that also includes electronic device housing structures, and a member with which the vibrator motor is mounted to the electronic device housing structures. 
     In accordance with another embodiment, apparatus is provided wherein the electronic device housing structures include a housing wall to which the member is attached, the apparatus also including an audio jack to which the member is attached. 
     In accordance with another embodiment, apparatus is provided also including a microphone interposed between the audio jack and the housing wall. 
     In accordance with another embodiment, apparatus is provided that also includes a layer of compressed foam interposed between the microphone and the audio jack, wherein the layer of compressed foam biases the microphone toward the housing wall at a microphone port opening in the housing wall. 
     In accordance with another embodiment, apparatus is provided wherein the shaft has a tip, wherein the tapered weight has a surface that is radially closer to the shaft at the tip than at other portions of the shaft. 
     In accordance with another embodiment, apparatus is provided wherein at least part of the tapered weight has a conical surface. 
     In accordance with another embodiment, apparatus is provided wherein the tapered weight has multiple sections each of which has a cylindrical surface having a different radial distance from the shaft. 
     In accordance with an embodiment, apparatus is provided that includes an electronic device housing wall having an opening, a button member that has a protrusion that protrudes through the opening, a switch that is actuated by the button member, and a support structure to which the switch is mounted, wherein the support structure is interposed between the switch and the button member. 
     In accordance with another embodiment, apparatus is provided wherein the support structure has an opening and wherein the switch has a portion that extends through the opening in the support structure and that is actuated by the button member. 
     In accordance with another embodiment, apparatus is provided wherein the support structure includes a bracket that is connected to the housing wall. 
     In accordance with another embodiment, apparatus is provided that also includes a flexible printed circuit, wherein the flexible printed circuit is interposed between the switch and the bracket. 
     In accordance with another embodiment, apparatus is provided wherein the button member and the housing sidewall are formed from metal and wherein the apparatus further includes a lubricating coating interposed between the button member and the housing sidewall. 
     In accordance with these embodiments, electronic devices contain numerous components. Examples of components that are included in electronic devices include buttons, audio jacks, vibrators, and microphones. Buttons are used as user input devices. Examples of functions that may be controlled using a button include power functions, ring/vibrator settings for a cellular telephone, volume settings, menu button operation, etc. Audio jacks can be used to receive mating plugs from external accessories. For example, an audio jack may have a cylindrical opening that receives an audio plug on a headset. Vibrators may be used to provide haptic feedback on a touch screen, to alert a user to an incoming cellular telephone call, to indicate the presence of an alarm, etc. Microphones may be used to gather audio input. For example, microphones may be used to record voice memos or to capture other audio clips, to gather ambient noise information in an electronic device that has noise cancellation functions, to monitor a user&#39;s voice during a telephone call, etc. 
     Components such as these may be used in cellular telephones and other electronic devices. For example, components such as these may be used in electronic devices such as cameras, handheld computers, tablet computers, computers integrated into computer monitor housings, laptop computers, set-top boxes, gaming devices, wrist watch devices, pendant devices, etc. With one suitable configuration, the components may be part of relatively compact electronic devices such as portable electronic devices. 
     One embodiment of device  10  is shown in  FIG. 8 . As shown in  FIG. 8 , portable electronic device  10  may include a device housing such as device housing  5812 . Display  5814  may be mounted to the front face of housing  5812 . 
     Openings in the cover glass layer  5616  may be provided for button  5619  and speaker port  5818 . Openings in housing sidewall  5812  may be provided for microphones, speakers, input-output connectors, etc. As shown in  FIG. 8 , for example, housing  5812  may have a circular opening that forms audio jack port  5820  and an opening such as opening  5822  that forms a microphone port. 
     The buttons in device  10  may be push buttons, toggling switches, momentary sliding buttons, rocker switches, or any other suitable types of buttons. As an example, buttons  5619  and  5824  may be momentary push buttons. Button  5826  may be, as an example, a two-position button that toggles in directions  5828 . In a first of its two positions, button  5826  may be closed. In a second of its two positions, button  5826  may be open. If desired, buttons of this type may be provided with three or more positions or may be implemented using a momentary switch design. Button  5834  may be, for example, a rocker switch. A user may press on portion  58 P 1  or portion  58 P 2  on the surface of button  5834 . When the user presses portion  58 P 1 , button  5834  rotates around axis  5832  in direction  5830 A and actuates a first switch. When the user presses portion  58 P 2 , button  5834  rotates around axis  5832  in direction  5830 B and actuates a second switch. Button  5834  may, if desired, be a momentary button (i.e., a button that is spring-loaded to return to its nominal position in the absence of user input). 
     Any suitable functions may be controlled by the buttons of device  10 . For example, button  5619  may serve as a menu button. Button  5824  may serve as a power (sleep) button. Button  5826  may serve as a cellular telephone ring mode button (e.g., toggling between a vibrate mode and a ring mode). Button  5834  may be used to adjust ring volume and speaker volume settings. Other arrangements may be used if desired. These illustrative button assignments are merely examples. 
     A cross-sectional side view of device  10  of  FIG. 8  is shown in  FIG. 9 . As shown in  FIG. 9 , housing  5812  may include sidewall structures such as housing sidewall structures  5812 A and  5812 B. Housing  5812  may, for example, have upper, lower, left, and right sidewalls (i.e., four peripheral sidewalls associated with the four edges that run along the periphery of a rectangular housing). In this type of arrangement, the housing sidewalls can be formed from a band-shaped peripheral member that surrounds device  10 . Housing sidewall structure  5812 A may correspond to a left-hand sidewall and housing sidewall structure  5812 B may correspond to a right-hand sidewall. Housing member  5812 C, which may be implemented using a plate or other hinge structure, may be used to connect and support sidewall structures  5812 A and  5812 B. Plate  5812 C may be formed from a planar metal member having a left edge welded or otherwise attached to left sidewall  5812 A and a right edge welded or otherwise attached to right sidewall  5812 B. There may be one or more structures such as plate  5812 C in device  10 . 
     As shown in  FIG. 9 , the front surface of device  10  may be occupied by display  5814 . Display  5814  may be formed using a touch screen display or other suitable display. Display  5814  may be mounted to housing  5812  using gaskets, plastic frame members, or other suitable attachment mechanism. The rear surface of device  10  may be occupied by housing layer  5812 D. Layer  5812 D may be formed from metal, glass, ceramic, composites, plastic, other materials, or combinations of these materials. As an example, layer  5812 D may be formed from a planar glass layer. If desired, layer  5812 D may be formed from part of a display (e.g., a cover glass for a rear-facing display that complements display  5814  on the front surface of device  10 ). Passive arrangements in which layer  5812 D is formed from a piece of plastic or glass may also be used. Layer  5812 D may be formed from a separate layer of material that has been attached to the sidewalls of housing  5812  or may be formed as an integral portion of housing  5812  (e.g., as a unibody housing in which the housing sidewalls have been formed from the same piece of material as layer  5812 D). 
     Components such as components  5836  may be mounted to printed circuit boards such as printed circuit boards  5838 . Printed circuit boards  5838  may be mounted to housing structure  5812 D as shown in  FIG. 9  or may be mounted within the housing of device  10  using other suitable arrangements. There are two printed circuit boards  5838  in the example of  FIG. 9 . This is merely illustrative. Any suitable number of components  5836  may be mounted within device  10  using any suitable number of printed circuit boards  5838 . Printed circuit boards  5838  may be formed from rigid printed circuit board substrates (e.g., rigid substrates of epoxy or fiberglass-filled epoxy), flexible printed circuits (e.g., flex circuits formed from thin layers of polymer such as sheets of polyimide), or other suitable substrates. 
     A top (front) view of the interior of device  10  is shown in  FIG. 10 . As shown in  FIG. 10 , device  10  may have an audio jack such as audio jack  5840 . Audio jack  5840  may be attached to housing member  5812 C using screws  5842  or other fastening mechanisms (e.g., adhesive, welds, solder, etc.). Audio jack  5842  may include a cylindrical cavity such as cavity  5848 . Cavity  5848  may have a circular opening that is aligned with a circular opening in housing  5812  (i.e., the opening in housing  5812  that forms audio jack port  5820  of  FIG. 8 ). The housing of audio jack  5842  may be formed from plastic, metal, or other suitable materials. 
     Device  10  may have an opening such as opening  5822  that forms microphone port. Opening  5822  may be covered with layers of screen material (e.g., an outer layer of metal mesh and an inner layer of plastic mesh). Microphone  5846  may be mounted at opening  5822 . Microphone  5846 , which is sometimes referred to as a microphone unit or microphone module, may be a microelectromechanical systems (MEMS) microphone that is housed in a plastic or metal housing (as an example). The microphone housing may have an opening that is aligned with opening  5822  in housing  5812 . A biasing member such as foam pad layer  5844  may be mounted between surface  5852  of audio jack  5840  and surface  5854  of microphone  5846 . Foam pad layer  5844  may be compressed. As a result, foam pad layer  5844  may generate a restoring force that biases microphone  5846  against opening  5822  in housing  5812 . This creates a seal around opening  5822  and ensures that foreign objects do not intrude into the interior of device  10 . 
     With an arrangement of the type shown in  FIG. 10 , the housing of audio jack  5840  is used in mounting microphone  5846  in device  10 . If desired, other components may be mounted in device  10  using audio jack  5840  (e.g., speaker modules, additional microphone modules, input-output connectors, circuit assemblies, sensors, batteries, etc. The use of audio jack  5840  to mount microphone  5846  is merely an example. 
     A more detailed view showing how microphone  5846  may be mounted using audio jack  5840  is shown in  FIG. 11 . As shown in  FIG. 11 , microphone  5846  may be biased against housing  5812  using compressed foam layer  5844 . Foam layer  5860  may be interposed between microphone  5846  and housing  5812  to provide sealing between microphone  5846  and housing  5812 . Microphone  5846  may have an associated printed circuit board such as printed circuit board  5862 . Circuitry on printed circuit board  5862  may be used in processing microphone signals. A communications path such as a bus formed from conductive traces on flexible printed circuit (“flex circuit”)  5858  may be used to route signals from microphone  5846  to circuitry on one of printed circuit boards  5838  ( FIG. 9 ). Layers of adhesive  5856  may be used in attaching housing  5812 , foam  5860 , flex circuit  5858 , printed circuit board  5862 , the housing for microphone  5846 , foam  5844 , and audio jack  5840 . 
     A cross-sectional side view of a conventional button in a cellular telephone is shown in  FIG. 12 . As shown in  FIG. 12 , button  84  has button member  5866 . Button member  5866  is formed from metal and protrudes through opening  5886  in plastic housing sidewall  5864 . Switch  5874  has protrusion  5878 . Protrusion  5878  is received in recess  5882  of button member  5866 . A user can move button member  5866  back and forth in directions  5868  to turn switch  5882  on or off. As the user moves button member  5866 , switch member  5866  engages switch protrusion  5882  and actuates switch  5874 . 
     Switch  5874  is mounted to bracket  5870  using heat stakes  5872 . Flex circuit  5888  has traces that are electrically connected to the switch terminals of switch  5874 . Bracket  5870  is connected to housing  5864 , so that bracket  5870  does not move during operation of switch  5874 . Bracket extensions  5876  help prevent button member  5866  from pressing excessively against switch  5874 . Nevertheless, the user activity that is involved in operating button  5884  may impart inward force on member  5866  that can undesirably load and potentially damage switch  5882 . 
     A button such as button  5826  of device  10  of  FIG. 8  is shown in the cross-sectional view of  FIG. 13 . As shown in  FIG. 13 , button  5826  may have a button member such as button member  5890 . Button member  5890  may have a protruding portion such as portion  5891  that extends through opening  58100  in housing wall  5812 . Button member  5890  may have a recess such as recess  58102  that receives a corresponding protruding switch member such as switch member  58104 . When button member  5890  is moved back and forth in directions  58112 , switch member  58104  is likewise moved back and forth in directions  58112 , thereby actuating switch  58106 . 
     A support structure such as bracket  58114  may be interposed between the main body of switch  58106  and button member  5890 . Switch  58106  may be mounted to bracket  58114  using heat stakes  58108  on switch  58106 . With this arrangement, inward pressure on button member  5890  in direction  58116  will cause inner surface  58118  of button member  5890  to press against outermost surface  58120  of bracket  58114 , but will not load switch  58106 . 
     Bracket  58114  may be connected to housing  5812  using portions  58134 , using bracket structures of other shapes, or using intermediate structures (i.e., structures that are connected between bracket  58114  and housing  5812 ). Bracket  58114  may be formed from metal and may be attached to housing  5812  using welds. If desired, other mechanisms may also be used to attach bracket  58114  and housing  5812  such as solder, screws or other fasteners, adhesive, etc. 
     Because surface  58118  bears against surface  58120 , the presence of bracket  58114  adjacent to button member  90  can help protect switch member  58104  and the rest of switch  58106  from undesirable inward forces in direction  58116  when a user operates button member  5890 . Switch  58106  may be electrically connected to traces in flex circuit  58122 . Flex circuit  58122  may have one end that is electrically connected to switch  58106  and another end that is electrically connected to one of printed circuit boards  5838  (as an example). To accommodate the movement of protruding switch member  58104  in directions  58112 , flex circuit  58122  may be provided with opening  58124  and bracket  58114  may be provided with opening  58126 . 
     Button member  5890  and housing  5812  may be formed from metal or other suitable materials. If desired, a lubricating coating such as lubricating coating  58128  may be formed between button member surface  58130  and housing surface  58132 . Coating  58128  may be formed from polytetrafluoroethylene or other fluorocarbon materials, graphite, grease, polyurethane, or other slippery coatings. The presence of coatings such as coating  58128  may help prevent binding between the metal surfaces of button member  5890  and housing  5812  during operation of button  5826 . If desired, portions of housing  5812  over surface  58130  may be recessed (see, e.g.,  FIG. 12 ). 
     It may be desirable to provide device  10  with vibrator functionality. A vibrator may be used to vibrate housing  5812  and device  10  when an incoming cellular telephone call is received, when an alarm is triggered, as part of a haptic feedback arrangement for a touch screen, etc. 
     An illustrative vibrator that may be used in device  10  is shown in  FIG. 14 . As shown in  FIG. 14 , vibrator  58146  may have a main body such as body  58136 . Weight  58138  may be mounted to shaft  58140 . Weight  58138  may be formed from metal or other suitable materials. Body  58136  may contain a motor that rotates shaft  58140  and thereby causes weight  58138  to rotate in direction  58144  about rotational axis  58142  of shaft  58140 . The mass of weight  58138  is asymmetrically distributed about shaft  58140  and rotational axis  58142 , so that when weight  58138  rotates, vibrator motor housing  58136  and the housing of device  10  in which vibrator  58146  is mounted vibrate. 
     Weight  58138  may have a tapered shape along length of rotational axis  58142 . At the end of shaft  58140  that is adjacent to motor  58136 , weight  58138  may have a relatively larger shape (i.e., the radial distance to the outer portions and surface of weight  58138  may be relatively large). At the far end of shaft  58140 , away from motor  58136 , weight  58138  may have a relatively smaller shape (i.e., the radial distance to the outer portions and surface of weight  58138  may be relatively small). This type of arrangement in which the radial distance from the shaft to the surface of the weight diminishes with increasing distance along the shaft, allows components and housing structures in device  10  to be mounted in the open space near the tapered end portion of weight  58138 . 
     If desired, weight  58138  may have a segmented structure as shown in  FIG. 15 . With this type of arrangement, the taper in the weight is achieved by using a larger weight structure such as weight structure  58138 A in the vicinity of motor housing  58136  and using a smaller weight structure such as weight structure  58138 B at the tip of shaft  58140 . In this example, tapered weight  58138  is formed from two half cylinders. If desired, more half cylinders (e.g., three or more) or other rotationally asymmetric weight structures of different sizes may be used. 
     Top views of illustrative tapered-weight configurations that may be used for vibrator  58146  are shown in  FIGS. 16 and 17 . As shown in  FIG. 16 , tapered weight  58138  has a larger size near motor  58136  than near the exposed tip of shaft  58140 . At a given radial distance from shaft  58140  such as radius R 1 , portions of weight  58138  are present at point A (near the motor), but are absent at point B (near the tip of shaft  58140 ). This makes is possible to mount component  5836  within radius R 1  of shaft  58140  near the tip of shaft  58140  (i.e., at point C). Similarly, the two-radius weight arrangement of  FIG. 17  allows component  5836  to be mounted within radius R 1  of shaft  58140  near the tip of shaft  58140  (i.e., at point C). 
       FIG. 18  shows how vibrator  58146  may be mounted to a member such as bracket  58150 . Bracket  58150  may be mounted to housing  5812  using screw  58148 . Bracket  58150  may be mounted to audio jack  5840  using screw  58154 . Housing  5812  may be provided with a threaded boss or other portion such as portion  58156  to receive threaded screw  148 . Portion  58156  may be formed as an integral part of housing  5812  or may be formed from a bracket or other structure that is attached to housing  5812 . Audio jack  5840  may be provided with a threaded bore that receives the threads of screw  58154 . If desired, bracket  58150  and vibrator  58146  may be mounted to housing structure  5812  and audio jack  5840  using other attachment mechanisms (e.g., welds, solder, adhesive, other fasteners, brackets, clips, springs, foam, press-fit members, etc.). The use of fasteners such as screws  58148  and  58154  is merely illustrative. As shown by connection  58152 , vibrator  58146  may be connected to bracket  58150  using welds, solder, adhesive, screws or other fasteners, clips, springs, foam, press-fit members, etc. 
     A perspective view of a button of the type shown in  FIG. 13  that has been formed in a sidewall of housing  5812  is shown in  FIG. 19 . As shown in  FIG. 19 , housing  5812  may have an opening that allows button member  5890  of button  5826  to move up and down in directions  58160  and  58162 . A visual indicator such as colored ink patch  58158  may be provided on button member surface  58130 . When button member  5890  is moved in direction  58160 , indicator patch  58158  is visible and may be viewed through opening  58100 . When button member  5890  is moved in direction  58162 , indicator patch  58158  is hidden from view, as shown in  FIG. 20 . 
     As shown in the cross-sectional side view of  FIG. 21 , the portion of housing  5812  that is nearest the protruding portion of button member  5890  (i.e., portion  58166 ) may have thickness T 2 , whereas the portion of housing  5812  that is farther from the protruding portion of button member  5890  may have thickness T 1 . Thickness T 1  and the thickness of lubricating coating  58128  may be collectively thicker than thickness T 2 , so that that housing portion  58166  will be offset from surface  58130  of button member  5890 . This ensures that ink layer  58158  will lie at a distance D below inner surface  58132 B of housing  5812  and thereby ensures that ink  58160  will not be scratched or otherwise damaged by lower surface  58132 B. Distance D may be, for example, 0.05 mm, 0.1 mm, more than 0.1 mm, etc. Lubricating coating  58128  may be formed from a slippery material such as polytetrafluoroethylene or other fluorocarbon materials, graphite, grease, polyurethane, etc. Coating  58128  may help ensure that surface  58130  of button member  5890  (e.g., a metal button member) and surface  58132 A of housing structure  5812  (e.g., a metal housing wall) are characterized by low amounts of friction. This allows button  5826  to be actuated by a user without excess force. 
     Any suitable technique may be used to form coatings such as coating  58128 . For example, coating  58128  may be deposited using physical vapor deposition, powder coating (e.g., using heat treatment), pad printing, screen printing, ink-jet printing, spraying, dipping, etc. A plastic coating may be provided on a metal member such as a metal button member or a portion of a metal housing injection molding or compression molding (e.g., by insert molding a plastic coating surface around a metal button or housing member, etc.). These techniques or other techniques may be used in forming coating  58128  between button member  5890  and housing structure  5812 . 
     It can be difficult to design antennas that fit within the confines of a portable electronic device such as a cellular telephone while exhibiting satisfactory performance. 
     It would be desirable to be able to provide improved antenna structures for electronic devices. 
     Structures in an electronic device (e.g., device  10  of  FIG. 1 ) such as portions of a button may be provided with conductive features that form portions of an antenna. The conductive features may include sheet metal inserts and conductive traces that are formed directly on plastic parts. With one suitable arrangement, a button support member may be provided with a metal trace and a sheet metal insert. A dome switch may be mounted on the button support member. When a button member in the button is pressed, the inner surface of the button compresses the dome switch. 
     According to an embodiment, apparatus is provided that includes a button support member having a surface that has at least some laser-activated portions, and a conductive antenna trace formed directly on the surface. 
     According to another embodiment, apparatus is provided that also includes housing sidewalls that are electrically connected to the conductive antenna trace. 
     According to another embodiment, apparatus is provided that also includes a spring that electrically connects the conductive antenna trace to the housing sidewalls. 
     According to another embodiment, apparatus is provided that also includes a conductive antenna structure on the button support member that is formed from a sheet of metal. 
     According to another embodiment, apparatus is provided that also includes a dome switch mounted on the button support member. 
     According to another embodiment, apparatus is provided that also includes a button member that bears against the dome switch. 
     According to another embodiment, apparatus is provided that also includes conductive housing structures that are electrically connected to the conductive antenna trace, wherein the conductive housing structures have an opening and wherein the button member reciprocates within the opening. 
     According to these embodiments, an electronic device such as device  10  of  FIG. 1  may be provided with an antenna. The antenna may be a patch antenna, a planar inverted-F antenna, an inverted-F antenna, a loop antenna, a monopole antenna, a dipole antenna, a helical antenna, or any other suitable antenna. Conductive portions of the antenna (antenna conductors) may be formed from strips of metal, patterned pieces of metal (e.g., patterned metal sheets), wires, traces on rigid and flexible printed circuit boards, metal that is formed on dielectric supports such as plastic supports, or other conductive structures that carry radio-frequency antenna signals. 
     If desired, space may be conserved by forming at least some portions of these conductive structures on a plastic support structure such as a button support. 
     An illustrative electronic device (e.g., device  10  of  FIG. 1 ) that includes a button with antenna traces is shown in  FIG. 22 . As shown in  FIG. 22 , button  7210  may have a button member such as button member  7214 . Button member  7214  may be mounted in opening  7224  in housing structures  7222 . Housing structures  7222  may be metal housing sidewalls. If desired, metal housing sidewalls  7222  may form part of an antenna (i.e., metal housing sidewalls  7222  may be antenna conductors). 
     Antenna conductors for an antenna in the electronic device may also be formed from metal members on a support structure such as button support  7240 . For example, metal structure  7238  and metal structure  7232  may be antenna conductors that are supported by button support  7240 . Because button support  7240  serves as a support for dome switch  7220  in button  7210  while simultaneously serving as a support for antenna conductors such as conductors  7232  and  7238 , space is conserved. 
     During operation of button  7210 , button member  7214  may be pressed inwards so that inner button member surface  7216  presses against tip  7218  of dome switch  7220 . This compresses and electrically closes dome switch  7220 . Dome switch  7220  may be mounted on a flexible printed circuit (“flex circuit”) that is supported on button support  7240 . 
     Button support  7240  may be attached to housing structures  7222  using fasteners such as screws  7230 . These screws may pass through openings  7228  in button support  7240  and may screw into threaded bores  7226  in housing structures  7222 . This type of arrangement or other mounting arrangement may be used to hold button support  7240  in a fixed position relative to housing structure  7222 . 
     Antenna conductor  7238  may be formed from a sheet of metal that is attached to button support  7240  (e.g., using adhesive). If desired, antenna conductor  7238  may be formed from a metal trace that is formed directly on button support  7240 , a part of a flex circuit, or other suitable conductive structures. Antenna conductor  7238  may be electrically connected to other structures using screws  7230  (e.g., to housing structures  7222 ). Antenna conductor  7232  may be electrically connected to housing structure  7222  via spring  7234 , which is welded to housing structures  7222  by welds  7236  (e.g., to form part of a loop antenna). 
     Button support  7240  may be formed from a dielectric such as plastic. Antenna conductor  7232  may be formed from a trace of metal that is patterned directly on the surface of support  7240 . 
     The pattern of antenna conductor  7232  (and, if desired, the pattern of antenna conductor  7238 ) may be formed by using a plastic member for support  7240  that has portions that are selectively activated by exposure to laser light. The plastic for support  7240  may be, for example, a thermoplastic that has an organo-metallic additive that is sensitive to light at the wavelengths produced by a laser. An antenna conductor pattern may be imposed on the plastic of support structure  7240  by exposing the plastic to laser light only in areas in which conductive antenna structures are desired. After exposing desired portions of the plastic to laser light to activate those portions, the plastic may be plated with a suitable conductor such as copper. During plating operations, the laser-activated portions of the plastic attract the plating conductor (e.g., copper), thereby forming conductive antenna trace  7232  directly on plastic support member  7240 . Techniques in which laser light is used to imprint a desired plating pattern on a plastic support are sometimes referred to as laser direct structuring (LDS) techniques. 
     In general, conductive antenna structures such a structures  7238  and  7232  may be formed on any suitable support structure. The foregoing examples, in which conductive antenna structure are formed by coating plastic button support structures with a patterns of metal (e.g., by plating) is merely illustrative. 
       FIG. 23  is a perspective view showing how button  7210  and button member  7214  may be formed along one of the sides of an electronic device (i.e., in an opening in housing sidewalls  7222 ). 
     Electronic devices such as portable electronic devices often have buttons. Buttons may protrude from a device housing. A user may operate a button by pressing on the button. 
     It is sometimes desirable to form portions of a device housing from metal. Care must be taken, however, to ensure that the metal on which a button is mounted is sufficiently robust to withstand wear from repeated use of the button. Improper button mounting arrangements may lead to damage to the device housing during use. 
     It would therefore be desirable to be able to provide improved ways to mount button structures to electronic device housings. 
     This can be accomplished by providing an electronic device having buttons that are pressed by a user. The electronic device may be a portable or handheld electronic device. The electronic device may have housing portions that are made from metal. The electronic device may, for example, have a metal housing portion that forms a band around the device. 
     Mounting structures may be provided for attaching button assemblies to the inside of electronic device housing. An integral spring may be attached to the inside of the housing. A button plate may have button members and an opening through which the spring may be inserted, attaching the button plate through the housing. The housing may have openings through which the button members protrude to the outside of the housing. 
     The spring may protrude though a hole in a button plate that is located between two button members. The button plate may have slots on either side of the hole to relieve stress in the button plate when the button members are pressed by a user. 
     One or more springs may be provided on the inside of the housing that grasp the sides of the button plate. For example, the housing portion may have two, four, or six springs that grip the sides of the button plate when the button plate is mounted in position against the inside of a portion of the housing. 
     An electronic device housing may have a mounting structure such as a clip that is welded to the housing and that holds a button plate in position within a recess in the housing. The button plate may be tilted into position under the clip. 
     A dome switch assembly may be attached to the housing so that each button member presses on a dome switch. A housing may have screw bosses that are used to attach the dome switch assembly. A spring that is used to attach the button plate to the housing may have a screw boss that is used to attach the dome switch assembly to the housing. 
     In accordance with an embodiment, an electronic device in provided that includes a button plate having at least one button member, a housing structure having at least one opening through which the button member protrudes for actuation by a user, and at least one spring that attaches the button plate to the housing. 
     In accordance with another embodiment, an electronic device is provided wherein the button plate has at least one opening and wherein the spring fits through the opening in the button plate. 
     In accordance with another embodiment, an electronic device is provided wherein the spring has leaves that retain the button plate against the housing portion. 
     In accordance with another embodiment, an electronic device is provided wherein the spring includes a threaded bore that forms a screw boss. 
     In accordance with another embodiment, an electronic device is provided that also includes a dome switch assembly attached to the screw boss. 
     In accordance with another embodiment, an electronic device is provided wherein the button plate has two slots on opposing sides of the opening. 
     In accordance with another embodiment, an electronic device is provided wherein the spring includes one of a plurality of springs, wherein the button plate has sides, and wherein the plurality of springs press against the sides of the button plate. 
     In accordance with another embodiment, an electronic device is provided wherein the plurality of springs include at least four springs. 
     In accordance with another embodiment, an electronic device is provided wherein the housing structure includes a metal housing structure. 
     In accordance with another embodiment, an electronic device is provided wherein the electronic device has four sides and wherein the housing structure includes a metal band that surrounds the four sides. 
     In accordance with another embodiment, an electronic device is provided that also includes a dome switch assembly having at least one dome switch that is controlled by moving the button member. 
     In accordance with another embodiment, an electronic device is provided wherein the at least one button member includes two button members, wherein the dome switch assembly includes two dome switches, wherein the housing structure has at least one screw boss, and wherein the dome switch assembly attaches to the screw boss so that each of the two button members controls a respective one of the two dome switches. 
     In accordance with an embodiment, apparatus is provided that includes an electronic device housing structure having first and second openings, first and second button members that protrude through the first and second openings, a button plate to which the first and second button members are attached, wherein the button plate has an opening, and a spring that is mounted to the electronic device housing structure and that passes through the opening in the button plate to hold the button plate to the electronic device housing structure. 
     In accordance with another embodiment, apparatus is provided that also includes wherein the button plate has at least one slot. 
     In accordance with another embodiment, apparatus is provided wherein the button plate has first and second slots on opposing sides of the opening in the button plate. 
     In accordance with another embodiment, apparatus is provided wherein the spring includes a threaded bore and wherein the apparatus further includes a dome switch assembly having first and second dome switches, wherein the dome switch assembly is attached to the spring with a screw that is screwed into the threaded bore. 
     In accordance with another embodiment, apparatus is provided wherein the electronic device housing structure includes a metal band that substantially surrounds four sides of an electronic device. 
     In accordance with another embodiment, apparatus is provided wherein the spring is welded to the electronic device housing structure and wherein the button plate has a plurality of slots. 
     In accordance with an embodiment, apparatus is provided that also includes an electronic device housing structure having at least one opening, at least one button member that reciprocates within the opening, and a button plate to which the button member is attached, and a spring that is attached to the metal electronic device housing structure and that holds the button plate to the electronic device housing structure. 
     In accordance with another embodiment, apparatus is provided wherein the button plate has an opening, wherein the spring passes through the opening in the button plate, wherein the electronic device housing structure includes at least part of a metal band, wherein the button plate includes a pair of slots, wherein the spring is welded to the electronic device housing structure, and wherein the spring has leaves that retain the button plate in place against the electronic device housing structure. 
     In accordance with these embodiments, structures are provided for mounting button assemblies to electronic device housings. 
     Housing structures  5612  may have openings for buttons such as buttons  7626  (see, e.g.,  FIG. 2A ). Buttons  7626  may be push buttons, switches, rocker switches, knobs, or other suitable types of buttons. Buttons may be pressed or otherwise actuated by a user to control the function of device  10 . For example, buttons  7626  may be used to switch device  10  on or off or may be used to turn display  7614  on or off. Buttons  7626  may also control audio volume (e.g., the volume of audio that is generated in association with a media playback event or a telephone call) or the volume of a ringer or other component. If device  10  has mobile telephone capabilities, buttons  7626  may be used to control mobile phone functions such as setting a vibration setting, or other suitable mobile phone functions. If device  10  has multimedia capabilities, buttons  7626  may control multimedia playback functions (e.g., play, stop, pause, forward, reverse, etc.). Device  10  may have any suitable number of buttons  7626 . For example, device  10  may have one or more buttons, two or more buttons, three or more buttons, etc. 
     In the example of  FIG. 2A , buttons  7626  are shown as being grouped together in a top left part of housing  5612 . In general, buttons  7626  may be located anywhere within housing  5612  and need not be grouped together. If desired, buttons may be located on front surface  7612  (such as button  5619 ) or on rear surface  7632  (see, e.g.,  FIG. 2B ). 
     Buttons such as buttons  7626  of  FIG. 2A  may be formed from button assemblies that are mounted within the interior of device  10 . Button structures on the button assemblies may protrude through openings in the housing of device  10 . 
     An illustrative button assembly that may be used for buttons such as buttons  7626  in  FIG. 2A  is shown in  FIG. 24 . In the example of  FIG. 24 , button assembly  7648  is shown as being mounted to housing structures  5612  (e.g., a metal band). Housing portion  5612  may have an exterior surface such as exterior (outside) surface  7641  and an interior surface such as interior (inner) surface  7643 . Button assembly  7648  may be mounted to inner surface  7643  of housing portion  5612  so that button members  7650  protrude through openings  7652  in housing portion  5612 . Button members  7650  may be push button members that may be pressed from the outside of housing portion  5612  by a user. When a user actuates the button members, the button members reciprocate within corresponding openings in the housing. Button members  7650  may be made from materials such as metal, glass, ceramic, composites, or plastic (as examples). 
     Button members  7650  in assembly  7648  may be mounted on a supporting plate such as button plate  7634  using welds, adhesive, fasteners, or other suitable attachment mechanisms. Button plate  7634  may be made from stainless steel, other metals, plastic, or other suitable materials. Button plate  7634  may be mounted to inner surface  7643  of housing portion  5612  (e.g., using welds, screws, adhesive, etc.). In the example of  FIG. 24 , housing portion  5612  has a spring (spring  7636 ) that is attached to inner surface  7643  of housing portion  5612 . Spring  7636  may be attached in a substantially permanent fashion to housing portion  5612  (e.g., using welds, adhesive, fasteners, etc.) and may therefore sometimes be referred to as an integral spring. Spring  7636  may, for example, be formed from a spring metal that is welded to housing portion  5612 . 
     Spring  7636  may protrude through an opening such as opening  7640  in button plate  7634 . Opening  7640  in button plate  7634  may be aligned with spring  7636  on housing portion  5612 . During assembly of device  10 , button plate  7634  may be pressed onto spring  7636  so that spring  7636  passes through opening  7640 . Spring  7636  may be compressed as it passes through opening  7640 . After passing through opening  7640 , spring  7636  may relax back to its original position, holding button plate  7634  against housing portion  5612 . Button plate  7634  may have slots such as slots  7638  on either side of opening  7640 . Slots  7638  may allow button plate  7634  to flex when either of button members  7650  is compressed. 
     Button assembly  7648  may have a dome switch assembly such as dome switch assembly  7651 . Dome switch assembly  7651  may have dome switches such as dome switches  7646 . Dome switches  7646  may be aligned with button members  7650 . When a given one of button members  7650  is pressed, its corresponding dome switch  7646  will be compressed and electrical contacts inside dome switch  7646  will become electrically connected, closing the switch. Dome switches  7646  may be mounted on a supporting structure such as button bracket  7644 . A rigid or flexible printed circuit board (“flex circuit”) with copper traces may be electrically connected to dome switches  7646 . The printed circuit may be used to interconnect dome switches to processing circuitry in device  10 . 
     Dome switch assembly  7651  may be mounted so as to bear against inner surface  7653  of button plate  7634 . To ensure that dome switch assembly  7651  is held in place when button members  7650  are depressed, dome switch assembly  7651  may be connected to housing portion  5612 . As shown in the example of  FIG. 24 , housing portion  5612  may have screw bosses such as screw bosses  7642 . Screw bosses  7642  may, for example, be welded to housing portion  5612 . Screws such as screws  7645  may be inserted through openings such as openings  7668  in button bracket  7644  to attach button bracket  7644  to housing portion  5612  (e.g., by screwing into threads in bosses  7642 ). If desired, spring  7636  may have a threaded bore that forms an integral screw boss such as screw boss  7666 . Button bracket  7644  may have an opening such as opening  7669  through which a screw such as screw  7647  may be inserted to attach button bracket  7644  to screw boss  7666  on housing portion  5612 . 
     In the example of  FIG. 24 , two buttons members  7650  are shown with corresponding dome switches  7646 . In general, button plates such as button plate  7634  may have any suitable number of button members  7650 . For example, button plate  7634 , may have one, three, four, five, or more button members  7650 . Dome switch assembly  7651  may have corresponding numbers of dome switches  7646 . Button plate  7634  may be attached to more than one spring  7636 . For example, if button plate  7634  has three button members  7650 , then button plate  7634  may have two springs  7636 , each of which is located between two button members  7650 . In configurations in which button plate  7634  has two button members  7650 , spring  7636  may be located in a central position, corresponding to an opening such as opening  7640 , which is located in the center of button plate  7634 . If button plate  7634  has more than two button members  7650 , springs  7636  may be located between pairs of respective button members  7650 , so that a button member is located on either side of each spring  7636 . Housing portions  5612  may have any suitable number of screw bosses for attaching to dome switch assembly  7651 . 
     A top perspective view of button plate  7634  is shown in  FIG. 25A . Button plate  7634  may have button members  7650  that protrude from a top surface (or outer surface) of button plate  7634  such as top surface  7657 . Button members  7650  may be formed as integral portions of button plate  7634  or may be separate structures that are attached to button plate  7634 . Button members  7650  may be attached to plate  7634  using welds, adhesive, fasteners, press-fitting techniques, etc. If desired, button plate  7634  may have openings through which button members  7650  are inserted. Button members  7650  may be fixed to button plate  7634 , or, if desired, button members  7650  may be allowed to slide through openings in button plate  7634  when button members  7650  are pressed by a user. 
     Button plate  7634  may have slots such as slots  7638  on either side of opening  7640 . Slots  7638  may allow button plate  7634  to flex. For example, if the button member on right portion  7654  of button plate  7634  is pressed, slot  7638  may allow right portion  7654  of button plate  7634  to move with the button press, while mid-portion  7656  and left portion  7658  of button plate  7634  remain stationary. If button plate  7634  has more than two button members  7650 , button plate  7634  may have more than one opening  7640  and more than one pair of slots  7638 . 
       FIG. 25B  is a side view of button plate  7634 . In the example of  FIG. 25B , button members  7650  have been inserted through openings  7662  of button plate  7634 . Button members  7650  protrude from top surface  7657  of button plate  7634 . Button members  7650  may have bases such as bases  7660  that are wider than openings  7662  in button plate  7634 . This type of arrangement is, however, merely illustrative. If desired, button members may have bases that are inset into bottom surface  7653  of button plate  7634  so that bases  7660  are flush with inner surface  7653 . Button members  7650  may also have bases  7660  that are no wider than openings  7662 . If desired, button members  7650  may be mounted directly on top surface  7657  of button plate  7634  (i.e., in a configuration in which button plate  7634  does not have any corresponding openings  7662 ). 
       FIG. 25C  is a bottom perspective view of button plate  7634 . In the illustrative example of  FIG. 25C , button members  7650  are visible in openings  7662  on the bottom surface  7653  of button plate  7634 . If desired, button members  7650  may be mounted directly to top surface  7657  of button plate  7634  so that button members  7650  are not visible on bottom surface  7653  of button plate  7634 . 
       FIG. 26  is a perspective view of housing portion  5612  in the vicinity of spring  7636 . As shown in  FIG. 26 , spring  7636  may be formed on inside surface  7643  of housing portion  5612 . Spring  7636  may have leaves such as leaves  7664 . Leaves  7664  may be springy and may be used to hold button plate  7634  to housing portion  5612 . Spring  7636  may have any suitable number of leaves  7664 . In the example  FIG. 27 , spring  7636  has four leaves  7664 . Spring  7636  may have optional screw boss  7666  that attaches to button bracket  7644  or other desired components. Housing portion  5612  may have screw bosses  7642  that attach to button bracket  7644  on either side of button plate  7634  (see, e.g.,  FIG. 24 ). Openings  7652  in housing portion  5612  may receive button members such as button members  7650  (see, e.g.,  FIG. 24 ). 
       FIG. 27  is a perspective view of button plate  7634  attached to housing portion  5612 . Button plate  7634  may be pressed onto spring  7636 . Leaves  7664  on spring  7636  may bend when being passed through hole  7640  on button plate  7634  (see, e.g.,  FIGS. 25A-25C ). After passing through hole  7640  on button plate  7634 , leaves  7664  may snap back into position, securing button plate  7634  to housing portion  5612 . Button members  7650  on button plate  7634  may pass through holes  7652  on housing portion  5612  (see, e.g.,  FIG. 26 ). Slots  7638  may allow button plate  7634  to flex when either of button members  7650  is pressed by a user. Screw bosses  7642  and screw boss  7666  may be used to attach bracket  7644  (see, e.g.,  FIG. 24 ). Screw boss  7666  may be part of spring  7636 . Screw bosses  7642  may lie on either side of button plate  7634 . If desired, screw bosses  7642  and  7666  may be used to attach additional components. 
       FIG. 28  is a perspective view of dome switch assembly  7651 . Dome switch assembly  7651  may have a supporting structure such as button bracket  7644 . Dome switches  7646  may be attached to button bracket  7644  using adhesive or other suitable fastening techniques. Button bracket  7644  may have screw holes  7668  and  7669  that are used to attach bracket  7644  to screw bosses  7642  and  7666  on housing portion  5612  (see, e.g.,  FIG. 24 ). 
     Another illustrative example of how button plate  7634  may be attached to housing portion  5612  is shown in the perspective view of  FIG. 29 . Housing portion  5612  may have one or more springs  7670 . In the example of  FIG. 29 , four springs  7670  are shown, although, in general, housing portion  5612  may have any suitable number of springs  7670 . For example, housing portion  5612  may have two or six springs. Springs  7670  may be welded to housing portion  5612  and may therefore sometimes be referred to as integral springs. Button plate  7634  may be pressed into position against inside surface  7643  of housing portion  5612 , between springs  7670 . For example, button plate  7634  may be pressed in the direction of arrow  7672  (i.e., straight into housing portion  5612 ). When button plate  7634  is in position against housing portion  5612 , springs  7670  will press against the edges of button plate  7634  such as edges  7671 . Button members  7650  may protrude through holes in housing portion  5612 . Screw boss  7666  may be welded to housing portion  5612  and may fit through a hole in button plate  7634 . A dome switch assembly of the type shown in  FIG. 28  may be attached to screw boss  7666  to housing  5612 . Screw bosses such as screw bosses  7642  may be located on either side of button plate  7634  and may also be used in attaching the dome switch assembly to housing  5612 . 
       FIG. 30  is a side view of button assembly  7648  having springs  7670  as shown in  FIG. 29 . As shown in  FIG. 30 , housing portion  5612  may have openings such as opening  7652 . Housing portion  5612  may have springs such as springs  7670 . Button plate  7634  may have button members such as button member  7650  that fits through opening  7652  in housing portion  5612 . Button plate  7634  may be mounted in recessed portion  7674  of housing  5612 . Springs  7670  are attached to housing portion  5612  and may hold button bracket  7644  in position. To insert button plate  7634  into position against housing  5612 , button plate  7634  may be pressed in direction  7672  (i.e., towards inner surface  7643  of housing  5612 ). Button bracket  7644  and dome switch  7646  of dome switch assembly  7651  may fit against underside  7653  of button plate  7634 . Housing portion  5612  may have a screw boss such as screw boss  7666  that attaches button bracket  7644  and other portions of dome switch assembly  7651  to housing portion  5612 . 
     Another illustrative example of how button plate  7634  may be attached to housing portion  5612  is shown in  FIG. 31 . Button plate  7634  of  FIG. 31  has button members  7650  that fit through corresponding openings in housing portion  5612  such as opening  7652  in  FIG. 32 . Housing portion  5612  may have a screw boss  7666  that protrudes though a corresponding opening in button plate  7634 . Screw bosses such as screw boss  7666  and screw bosses  7642  may be used to attach a dome switch assembly such as dome switch assembly  7651  of  FIG. 32 . Housing portion  5612  may have a clip such as clip  7676 . Clip  7676  may be formed from spring metal or other suitable materials. Clip  7676  may be welded to metal band  5612  or other housing structures. Clip  7676  may be used to attach button plate  7634  to metal band  5612 . Clip  7676  may be sufficiently rigid to hold plate  7634  in place. Button plate  7634  may be tilted into position. For example, button plate  7634  may be tilted in the direction of arrow  7678  in order to slide button plate  7634  under clip  7676 . Housing portion  5612  may have any suitable number of clips  7676 . 
       FIG. 32  is a side view of button assembly  7648  having a clip such as clip  7676 . Housing portion  5612  may have openings such as opening  7652 . Button plate  7634  may have button members such as button member  7650 . Button member  7650  may fit through opening  7652  in housing portion  5612 . Button plate  7634  may be tilted into position against inner surface  7643  of housing portion  5612 . Button plate  7634  may reside in a recessed portion  7674  of housing  5612 . During assembly of device  10 , button plate  7634  may be tilted in the direction of arrow  7678  in order to slide button plate  7634  under clip  7676 . Clip  7676  may be sufficiently rigid to retain plate  7634 . 
     After button plate  7634  has been inserted into position, dome switch assembly  7651  may be attached to housing portion  5612 . Dome switch assembly  7651  may have button bracket  7644  and dome switches such as dome switch  7646 . Housing portion  5612  may have screw bosses such as screw bosses  7666 . Screw boss  7666  may be used to attach button bracket  7644  to housing portion  5612 . 
     If desired, button mounting structures of the types shown in  FIGS. 27 ,  29 , and  31 , may be used in combination. For example, housing portion  5612  may have a spring such as spring  7636  of  FIG. 27  that protrudes through an opening in button plate  7634  as well as springs such as springs  7670  of  FIG. 29  that grip the edges of button plate  7634 . 
     Electronic devices such as portable electronic devices often have buttons. Buttons may protrude from a device housing. A user may operate a button by pressing on the button. 
     It is sometimes desirable to form portions of a device housing from metal. Metal housing may have improved structural or aesthetic properties. Buttons may also be formed from metal. 
     Button assemblies may sometimes have undesired friction or motion. Undesired wear and tear may result from friction between parts. Button members that are loosely held in button assemblies may have undesired movement and may rattle. Button members that rattle may feel unpleasant to a user and may generate undesired noise. Undesirable friction and rattle may be increased when a housing and button are formed from materials such as metal. 
     It would therefore be desirable to be able to provide ways to reduce unwanted friction and undesired motion in electronic device button assemblies. 
     This can be accomplished by providing an electronic device (e.g., device  10  of  FIGS. 1 ,  2 A, and  2 B) with buttons that are pressed by a user. The electronic device may have housing portions that are made from metal. The electronic device may, for example, have a metal housing portion that forms a band around the device. Protruding button members and planar button members (button plates) may be formed from metal. 
     Button assemblies may be provided with a member such as a silicone sheet that is interposed between the housing and button plates. This layer of material may reduce undesired motion and rattle of the buttons. This layer of material may also reduce wear on the buttons from metal-on-metal contact. 
     Button assemblies may have button plates with nubs that are inserted through holes in the button plates. The nubs may be silicone nubs and may protrude on each side of the button plate. The nubs may reduce motion of the button plates with respect to the device housing. 
     A button member may have a ring such as a silicone ring that encircles the base of the button member. The ring may reduce friction and wear between a button member and device housing when a button member is actuated by a user. If desired, the ring may be a coating on the button member. 
     An anti-roll bar may be attached to a button member to guide the motion of the button member when it is pressed by a user. The anti-roll bar may be coated to reduce friction and wear between the anti-roll bar and device housing. 
     A spring may be attached to a button plate having a button member. The spring may press against a button bracket having dome switches. The spring may reduce undesired movement of the button member. The spring may be compressed when the button member is pressed by a user and may guide the motion of the button member. 
     According to an embodiment, an electronic device button assembly is provided that includes a metal housing structure having an opening, a button member within the opening in the housing structure, a button plate formed on the button member, and a polymer layer interposed between the button plate and the housing structure. 
     According to another embodiment, an electronic device button assembly is provided wherein the polymer layer is attached with adhesive to the button plate and to the metal housing structure. 
     According to another embodiment, an electronic device button assembly is provided wherein the polymer layer includes a silicone layer. 
     According to another embodiment, an electronic device button assembly is provided wherein the polymer layer flexes when the button member is pressed and wherein the button member and button plate are formed from metal. 
     According to an embodiment, an electronic device button assembly that includes a metal housing structure having at least one opening, at least one button member corresponding to the at least one opening in the housing structure, a button plate attached to the button member, and polymer nubs inserted in the button plate that contact the metal housing structure and prevent the button plate from contacting the metal housing structure. 
     According to another embodiment, an electronic device button assembly is provided wherein the least one button member includes two button members, wherein the at least one opening in the metal housing structure includes two openings, and wherein the polymer nubs inserted in the button plate include polymer nubs inserted in the button plate between the two button members. 
     According to another embodiment, an electronic device button assembly is provided wherein the polymer nubs include four or more polymer nubs. 
     According to another embodiment, an electronic device button assembly is provided wherein the polymer nubs include silicone nubs. 
     According to another embodiment, an electronic device button assembly is provided wherein the polymer nubs are compression molded polymer nubs. 
     According to another embodiment, an electronic device button assembly is provided that also includes a ring surrounding the button member, wherein the ring is interposed between the button member and the metal housing structure and wherein the button member includes a metal button member. 
     According to an embodiment, an electronic device button assembly is provided that includes a metal housing structure having an opening, a metal button member mounted within the opening of the housing structure, and a ring surrounding the metal button member, wherein the ring is interposed between the metal button member and the metal housing structure. 
     According to another embodiment, an electronic device button assembly is provided wherein the ring includes an elastomeric ring. 
     According to another embodiment, an electronic device button assembly is provided wherein the ring includes a coating on the metal button member. 
     According to another embodiment, an electronic device button assembly is provided wherein the metal button member has a recessed portion and wherein the ring is mounted in the recessed portion of the metal button member. 
     According to an embodiment, an electronic device button assembly is provided that includes an electronic device housing structure having an opening, a button member within the opening of the housing structure, and an anti-roll bar attached to the button member, wherein the anti-roll bar has a coating. 
     According to another embodiment, an electronic device button assembly is provided wherein the coating includes a polymer coating, wherein the electronic device includes a handheld device, and wherein the electronic device housing structure includes a metal sidewall member. 
     According to an embodiment, a portable electronic device button assembly is provided that includes a portable electronic device housing structure having an opening, a button member that reciprocates within the opening in the portable electronic device housing structure, a button plate structure attached to the button member, a button support member, and a dome switch mounted on the button support bracket, wherein the button plate structure has at least one spring that presses against the button support member. 
     According to another embodiment, a portable electronic device button assembly is provided wherein the at least one spring includes two springs that contact the button support member on either side of the dome switch. 
     According to another embodiment, a portable electronic device button assembly is provided wherein the portable electronic device housing structure includes a metal housing wall and wherein the spring is configured to compress when the button member is pressed by a user. 
     According to another embodiment, a portable electronic device button assembly is provided wherein the portable electronic device housing structure is formed from metal and wherein the button plate structure is formed from metal. 
     Housing structures  5612  may have openings for buttons such as buttons  7626 . Buttons  7626  may be push buttons, switches, rocker switches, knobs, or other suitable types of buttons. Buttons may be pressed or otherwise actuated by a user to control the function of device  10 . For example, buttons  7626  may be used to switch device  10  on or off or may be used to turn display  7814  on or off. Buttons  7626  may also control audio volume (e.g., the volume of audio that is generated in association with a media playback event or a telephone call) or the volume of a ringer or other component. If device  10  has mobile telephone capabilities, buttons  7626  may be used to control mobile phone functions such as setting a vibration setting, or other suitable mobile phone functions. If device  10  has multimedia capabilities, buttons  7626  may control multimedia playback functions (e.g., play, stop, pause, forward, reverse, etc.). Device  10  may have any suitable number of buttons  7626 . For example, device  10  may have one or more buttons, two or more buttons, three or more buttons, etc. 
     In the example of  FIG. 2A , buttons  7626  are shown as being grouped together in a top left part of housing  5612 . In general, buttons  7626  may be located anywhere within housing  5612  and need not be grouped together. 
     Buttons such as buttons  7626  of  FIG. 2A  may be formed from button assemblies that are mounted within the interior of device  10 . Button structures on the button assemblies may protrude through openings in the housing of device  10 . 
     An illustrative button assembly that may be used for buttons such as buttons  7626  in  FIG. 2A  is shown in  FIG. 33 . In the example of  FIG. 33 , button assembly  7848  is shown as being mounted to housing structure  5612  (e.g., a metal band). Housing portion  5612  may have an exterior surface such as exterior (outside) surface  7841  and an interior surface such as interior (inner) surface  7843 . Button assembly  7848  may be mounted to inner surface  7843  of housing portion  5612  so that button members  7850  protrude through openings  7852  in housing portion  5612 . Button members  7850  may be push button members that may be pressed from the outside of housing portion  5612  by a user. When a user actuates the button members, the button members reciprocate within corresponding openings  7852  in the housing. Button members  7850  may be made from materials such as metal, glass, ceramic, composites, or plastic (as examples). 
     Button members  7850  in assembly  7848  may be mounted on supporting plates such as button plates  7834  using welds, adhesive, fasteners, or other suitable attachment mechanisms. If desired, each plate  7834  and its associated button member  7850  may be formed as an integral structure. Button plates  7834  may be made from stainless steel, other metals, plastic, or other suitable materials. Button plate  7834  may be also referred to as a button plate structure. In the example of  FIG. 33 , each button member  7850  is mounted to a corresponding button plate  7834 . However, if desired, more than one button member  7850  may be mounted on a single button plate (e.g., to form a rocker switch). 
     A layer of material such as layer  7870  may be interposed between housing structure  5612  and button plates  7834 . Layer  7870  may be made from a polymer or plastic such as silicone, or other materials. Layer  7870  may be planar and may sometimes be referred to as a planar member or plate. Layer  7870  may be attached to inner surface  7843  of housing structure  16  with an adhesive such as adhesive  7872 . Layer  7870  may be attached to the top surfaces of button plates  7834  with an adhesive such as adhesive  7872 . Layer  7870  may reduce unwanted wear from metal-on-metal contact. Layer  7870  may serve to minimize unwanted movement such as lateral movement that could lead to rattle. In particular, layer  7870  may reduce undesired motion of button members  7850  and button plate  7834  in side-to-side directions  7882  and  7884  parallel to the planar exterior surface of housing structure  5612 . Layer  7870  may also help secure button plate  7834  against housing structure  5612 . Adhesive  7872  may be applied along the surface of layer  7870 . Regions near button members  7850  such as regions  7871  may be left without adhesive  7872  so that layer  7870  may flex when button member  7850  is pressed by a user. 
     Button assembly  7848  may have a dome switch assembly such as dome switch assembly  7851 . Dome switch assembly  7851  may have dome switches such as dome switches  7846 . Dome switches  7846  may be aligned with button members  7850 . When a given one of button members  7850  is pressed, its corresponding dome switch  7846  will be compressed and electrical contacts inside dome switch  7846  will become electrically connected, closing the switch. Dome switches  7846  may be mounted on a supporting structure such as button bracket  7844 . Button bracket  7844  may be also referred to as a button support member. A rigid or flexible printed circuit board (“flex circuit”) with copper traces may be electrically connected to dome switches  7846 . The printed circuit may be used to interconnect dome switches to processing circuitry in device  10 . 
     Dome switch assembly  7851  may be mounted so that switches  7846  bear against inner surface  7853  of button plate  7834 . To ensure that dome switch assembly  7851  is held in place when button members  7850  are depressed, dome switch assembly  7851  may be connected to housing portion  5612 . As shown in the example of  FIG. 33 , housing portion  5612  may have screw bosses such as screw bosses  7842 . Screw bosses  7842  may, for example, be welded to housing portion  5612 . Screws such as screws  7845  may be inserted through openings such as openings  7868  in button bracket  7844  to attach button bracket  7844  to housing portion  5612  (e.g., by screwing into threads in bosses  7842 ). Housing portions  5612  may have any suitable number of screw bosses  7842  for attaching to dome switch assembly  7851 . 
       FIG. 34  is a perspective view of housing structure  5612  and layer  7870 . Layer  7870  may be attached to inner surface  7843  of housing structure  5612 . Button members  7850  (see, e.g.,  FIG. 33 ) may be inserted through openings in layer  7870  and housing structure  5612 . Button plates  7834  may be attached to button members  7850 . Button plates  7834  may be attached to layer  7870  with an adhesive such as adhesive  7872 . Screw bosses such as screw bosses  7842  may be attached to housing structure  5612  and may be used to attach structures such as dome assembly  7851  (see, e.g.,  FIG. 33 ). In the example of  FIG. 34 , two buttons are inserted through layer  7870 . In general, any number of buttons may be inserted through each layer  7870 . 
     Layer  70  may flex when button member  7850  is pressed by a user, as illustrated in the example of  FIG. 35 . In the example of  FIG. 35 , layer  7870  is attached with adhesive  7872  to housing structure  5612 . There may be regions without adhesive  7872  such as regions  7871  that are immediately adjacent to button member  7850 . When button member  7850  is pressed by a user (in a direction denoted by arrow  7876 ), portions of layer  7870  that are attached by adhesive  7872  to button plate  7834  may move in direction  7876  along with button plate  7834  and button member  7850 . The movement of layer  7870  may help guide button member  7850  in direction  7876 . The movement of layer  7870  may also serve as a motion dampener, dampening the motion of button member  7850 . When button member  7850  returns to its original position, layer  7870  may cushion the impact of button plate  7834  against housing structure  5612 . When button member  7850  is pressed by a user, such as in the example of  FIG. 35 , button member  7850  may be said to be in a depressed position, a pressed position, an actuated position, or a down position. When button member  7850  is not being pressed by a user, such as in the example of  FIG. 33 , button member  7850  may be said to be in an unpressed position, unactuated position, an initial position, or an up position. 
       FIG. 36  shows an example of a button plate having nubs such as nubs  7878 . Nubs  7878  may be formed from silicone or other suitable materials. Nubs  7878  may be inserted through holes  7880  in button plate  7834  and may protrude on either side of button plate  7834 . In  FIG. 36 , two button members  7850  are attached to button plate  7834  (e.g., to form a rocker switch in which plate  7834  pivots about pivot axis  7881 ). In general, any suitable number of button members  7850  may be attached to button plate  7834 . Button members  7850  protrude from openings  7852  in housing structure  5612 . Nubs  7878  may contact inside surface  7843  of housing structure  5612 . Nubs  7878  may reduce side-to-side motion of button members  7850  within openings  7852 . For example, nubs  7878  may reduce motion of button members  7850  and button plate  7834  in side-to-side directions  7882  and  7884 . Nubs may prevent metal-on-metal contact, such as contact between button plate  7834  and housing structure  5612  in region  7879 . 
     A top perspective view of button plate  7834  having elastomeric members such as nubs  7878  is shown in  FIG. 37 . In the example of  FIG. 37 , six nubs  7878  are shown positioned in rows and columns between button members  7850 . In general, any suitable number of nubs  7878  may be used. Button plate  7834  may have, for example, two nubs or more nubs, four or more nubs, six or more nubs, etc. Nubs  7878  may be arranged in arrays or other configurations. 
       FIG. 38  is a cross-sectional side view of two button plates  7834  each having one button member  7850 . Button plates  7834  may have nubs  7878  inserted in holes  7880 . Button members  7850  may protrude from openings  7852  in housing structure  5612 . Nubs  7878  may rest against inside surface  7843  of housing structure  5612 . In the example of  FIG. 38 , nubs  7878  are shown positioned on either side of each button member  7850 . In general, nubs  7878  may be positioned in any suitable configuration. 
     Nubs  7878  may be formed by compression molding.  FIG. 39  shows molds  7877  that may be used to form nubs  7878 . Molds  7877  may be placed around button plate  7834 . Button plate  7834  may have holes  7880 . An elastomeric material such as silicone may be placed in cavity  7883  of molds  7877 . Pressure and heat may be applied until the material has attained its desired form. 
       FIG. 40  is a side cross-section view of button member  7850  inserted through opening  7852  of housing structure  5612 . A ring such as ring  7886  may surround button member  7850 . Ring  7886  may be formed from an elastomeric material such as plastic or silicone. Ring  7886  may serve as a gasket that prevents button member  7850  from directly contacting housing structure  5612  when button member  7850  reciprocates in opening  7852 . Ring  7886  may be similar to an “O-ring” that is stretched over button member  7850 . Ring  7886  may be formed by depositing a coating on button member  7850  such as a plastic coating or other coating layer that is softer than metal. If desired, button member  7850  may have a recessed notch such as inset  7891  to accommodate ring  7886 . Button member  7850  may be attached to button plate  7834 . Button member  7850  may be welded at points  7888  to button plate  7834 . In the example of  FIG. 40  button plate  7834  is shown as having an opening  7890 . However this is merely illustrative. Ring  7886  may be serve as a rattle prevention ring. Ring  7886  may reduce the rattling of button member  7850  by preventing metal-on-metal collisions during movement of device  10 . Ring  7886  may also reduce the noise from the rattling of button member  7850 . Ring  7886  may aid in environmental sealing around button member  7850 .  FIG. 41  is a bottom perspective view of button member  7850  having ring  7886 . 
     If desired, buttons may have an associated anti-roll bar. As shown in the example of  FIG. 42 , anti-roll bar  7892  may be attached to button member  7850 . Anti-roll bar  7892  may prevent button member  7850  from tilting when button member  7850  is pressed by a user. Button member  7850  may be attached to button plate  7834 . Button member  7850  may reciprocate along axis  78101  within opening  7852  in housing structure  5612 . Button plate  7834  may press against dome switch  7846  mounted on button bracket  7844 . Anti-roll bar  7892  may pivot around pivot  78102  and may reciprocate within a groove such as groove  78104  between housing structure  5612  and button bracket  7844 . When a user presses on button member  7850  (i.e., in direction  78100 ), anti-roll bar  7892  may pivot counterclockwise around pivot  78102  and slide in direction  7898  within groove  78104 . Anti-roll bar  7892  may guide the movement of button member  7850  and may aid button member  7850  in pressing evenly against dome switch  7846 . 
     Anti-roll bar  7892  may be formed from metal. Housing structure  5612  and button bracket  7844  may also be formed from metal. If desired, anti-roll bar  7892  may be provided with a core  7896  formed from metal and a lubricating coating  7894 . Coating  7894  may a polymer or plastic material such as silicone that reduces friction between anti-roll bar  7892 , housing  5612 , and bracket  7844  (e.g., in groove  78104 ). Coating  7894  may be applied to bar  7892  using techniques such as dip coating, pad printing, painting, electrostatic painting, powder coating, sputtering, or heat shrinking. Anti-roll bar  7892  may also be formed from a coated wire. 
       FIG. 43  is a diagram of button member  7850  and anti-roll bar  7892  when viewed in direction  78100  of FIG.  42 . Anti-roll bar  7892  may be substantially U-shaped with three sides. Anti-roll bar  7892  may have tips  78108  that are inserted into openings  78106  in button member  7850 . Bar tips  78108  in openings  78106  may form a pin-in-hole joints or “revolute joints”. Bar  7892  may have a coating such as coating  7894  over a core  7896 . Core  7896  may be formed from metal. Coating  7894  may be formed from a polymer to prevent undesired metal-on-metal friction when bar tips  78108  pivots within openings  78106 . 
     If desired, a spring such as a bias spring may be used to minimize rattle in button assemblies.  FIG. 44  is a side view of a button assembly that has bias spring  78110 . Button member  7850  may be attached to button plate  7834 . Button member  7850  may be inserted through an opening such as opening  7852  in housing structure  5612 . Button member  7850  and button plate  7834  may press against dome switch  7846  on button bracket  7844 . If desired, button bracket  7844  may have a flex circuit such as flex circuit  78114  that may be used for dome switch electronics. A spring such as spring  78110  may be attached to button plate  7834 . Spring  78110  may be welded to button plate  7834  at location  78112 . Spring  78110  may be known as a bias spring or a clip. Spring  78110  may bias button plate  7834  against button bracket  7844 . If bracket  7844  has a flex circuit such as flex circuit  78114 , spring  78110  may rest against or adjacent to flex circuit  78114 . Spring  78110  may help reduce rattle in button assembly  7848 . Spring  78110  may also help secure button plate  7834  against housing structure  5612 . Spring  78110  may also guide button member  7850  as it reciprocates within opening  7852  of housing structure  5612 . 
       FIG. 45  is a bottom view of button plate  7834  of  FIG. 44 . Button plate  7834  may have springs  78110  located on either side of button member  7850 . Springs  78110  may press on button bracket  7844  on either side of dome switch  7846  (see, e.g.,  FIG. 44 ). 
     When button member  7850  is pressed by a user, spring  78110  may compress, as shown in the example of  FIG. 46 . In  FIG. 46 , button member  7850  has been pressed by a user in the direction of arrow  78116 . Button member  7850  is therefore in a depressed position. Spring  78110  may aid in guiding button member  7850  so that button member  7850  presses squarely onto dome switch  7846 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20100604
Publication Date: 20150224
Grant Date: 20150224
Priority Date: 20100419
Inventors: WEBER TRENT
WITTENBERG MICHAEL B.
YU MICHELLE A.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H2215/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/236", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H9/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H9/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/236", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2221/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H13/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/236", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2215/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H13/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01H2215/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/14", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 44788056