PATENT DOCUMENT

Publication Number: US-9472360-B2
Application Number: US-201314038806-A
Country: US
Kind Code: B2

Title: Curable foam shims for buttons of electronic devices

Abstract:
Button assemblies using curable foam shims are disclosed. A button assembly may include a housing, a button positioned within the housing, and a curable foam shim positioned within the housing, the foam shim transformable between a compressible state having a first thickness, to a rigid state having a second thickness smaller than the first thickness. In this manner, the foam shim can be used to adaptively fill the interior of a button assembly by adapting to the dimensions of various components within the button assembly. In another example, a button assembly is formed using a foam shim by curing from a first state having a first thickness to a second state having a second thickness greater than the first thickness. In this manner, the foam shim can be used to adaptively fill the interior of a button assembly by adapting to the dimensions of various components within the button assembly.

Claims:
I claim: 
     
       1. A button assembly for an electronic device, comprising:
 a housing; 
 a button positioned within the housing; 
 a tactile switch positioned within the housing; and 
 a foam shim positioned within the housing, the foam shim having been transformed from a compressible state to a rigid state by curing the foam shim. 
 
     
     
       2. The button assembly of  claim 1 , further comprising:
 a button bracket positioned within the housing; and 
 a flexible circuit positioned within the housing. 
 
     
     
       3. The button assembly of  claim 1 , wherein:
 the foam shim has been compressed to a thickness prior to being transformed from the compressible state; and 
 the foam shim in the rigid state has substantially the same thickness as the compressed foam shim. 
 
     
     
       4. The button assembly of  claim 1 , wherein the curing comprises ultraviolet curing. 
     
     
       5. The button assembly of  claim 1 , wherein the curing comprises heat curing. 
     
     
       6. The button assembly of  claim 2 , wherein the foam shim is positioned between the button bracket and the flexible circuit. 
     
     
       7. The button assembly of  claim 2 , wherein the foam shim is positioned between the flexible circuit and the tactile switch. 
     
     
       8. The button assembly of  claim 1 , wherein the foam shim is positioned between the tactile switch and an interior surface of the button. 
     
     
       9. The button assembly of  claim 1 , wherein the electronic device is a mobile phone. 
     
     
       10. A button assembly for an electronic device, comprising:
 a housing; 
 a button positioned within the housing; 
 a tactile switch positioned within the housing; and 
 a foam shim positioned within the housing, the foam shim having been transformed from a first state having a first thickness, to a rigid second state having a second thickness greater than the first thickness. 
 
     
     
       11. The button assembly of  claim 10 , further comprising:
 a button bracket positioned within the housing; and 
 a flexible circuit positioned within the housing. 
 
     
     
       12. The button assembly of  claim 10 , wherein the foam shim transforms from the first state to the second state in response ultraviolet curing. 
     
     
       13. The button assembly of  claim 10 , wherein the foam shim transforms from the first state to the second state in response heat curing. 
     
     
       14. The button assembly of  claim 10 , wherein when in the second state, the foam shim becomes rigid. 
     
     
       15. The button assembly of  claim 11 , wherein the foam shim is positioned between the button bracket and the flexible circuit. 
     
     
       16. The button assembly of  claim 10 , wherein the foam shim is positioned between the tactile switch and an interior surface of the button. 
     
     
       17. A button stack for an electronic device, comprising:
 a tactile switch; 
 a button member configured to actuate the tactile switch; and 
 a foam shim filling a gap in the button stack, the foam shim having been transformed from an at least partially compressed state to a rigid state in which the foam shim has substantially a same thickness as the foam shim in the at least partially compressed state. 
 
     
     
       18. The button stack of  claim 17 , wherein the foam shim has been transformed from the at least partially compressed state to the rigid state by heat curing, ultraviolet curing, or both. 
     
     
       19. The button stack of  claim 17 , further comprising a button bracket, wherein the foam shim is disposed between the tactile switch and the button bracket. 
     
     
       20. The button stack of  claim 17 , wherein the foam shim is configured to resist deformation in response to force applied to the button member.

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to buttons of electronic devices, and more particularly relates to shims used in buttons of electronic devices. 
     BACKGROUND 
     Electronic devices—such as mobile devices, mobile phones, tablet computers, music and multi-media players, watches, gaming devices, and other handheld, wearable or portable devices—have one or more buttons such as home buttons, power buttons, or buttons that perform other functions. 
     These buttons typically are formed of multiple components arranged in a button assembly that may include button portion which is depressed by the finger or thumb of a user, and one or more components beneath the button portion.  FIG. 1A  illustrate an example of a typical button assembly  10  within a housing  12 , wherein the button assembly  10  includes a button portion  14 . One the opposing end of the button housing  12 , a tactile switch  16  may be provided that can contact a flexible circuit portion  20  that can be affixed through a pressure sensitive adhesive (PSA)  21  to a button bracket  22 , in this example. 
     In this example in  FIG. 1A , a metal or plastic shim  18  is attached to the interior side of the button portion  14  using a pressure sensitive adhesive. 
     The shims  18  shown in  FIGS. 1A-1C  can play an important role in proper tactile feel of a button assembly  10  as experienced by a user—although some buttons can be formed without shims. Typical button click lengths/travel ranges can span from 0.12 mm to 0.28 mm, and shim thicknesses can have tolerances of approximately 0.01 mm in one example. 
     As recognized by the present inventor, proper tactile feel of a button assembly  10  for user is achieved when, as shown in  FIG. 1A , the shim  18  is precisely sized in the gap between the tactile switch  16  and the interior surface of button portion  14 —so that there is not excessive play for instance when shim  18  is too thin as shown in  FIG. 1B  such that the button assembly  10  rattles or feels loose to the user because there is a small gap present between the tactile switch  16  and button portion  14 . Conversely, if the shim  18  is too thick as shown in  FIG. 1C , then the tactile switch  16  becomes preloaded and the button  14  travel is too short which also is problematic for tactile feel. 
     As recognized by the present inventor, there are variations in the manufactured thicknesses of each part  12 ,  14 ,  16 ,  20 ,  22  within a button assembly  10 , including variations in the thickness of a conventional plastic shim  18 , and these variations can result in either a small gap in the button assembly  10  such as shown in  FIG. 1B , or a button tactile switch preload condition in the button assembly  10  such as shown in  FIG. 1C . 
     Accordingly, as recognized by the present inventor, what is needed are improved button shims for buttons of electronic devices. 
     SUMMARY 
     According to one broad aspect of one embodiment of the present disclosure, disclosed herein is a button assembly for an electronic device. In one example, the button assembly may include a housing for encasing the button assembly, a button positioned within the housing, and a curable foam shim positioned within the housing, the foam shim transformable between a compressible state to a rigid state. In one example, the foam shim in the compressible state has a first thickness, and when transformed by curing into the rigid state, the foam shim shrinks to a second thickness which is smaller than the first thickness. In this manner, the foam shim can be used to adaptively fill the interior of a button assembly by adapting to the dimensions of various components within the button assembly. 
     In one example, the foam shim transforms from the compressible state to the rigid state in response ultraviolet curing or curing by heat exposure. 
     In one example, the position of a curable foam shim may vary. For example, in one embodiment of the present disclosure, a button assembly also includes a button bracket positioned within the housing, a flexible circuit positioned within the housing, and a tactile switch positioned within the housing. The foam shim may be positioned between the button bracket and the flexible circuit; between the flexible circuit and the tactile switch; or between the tactile switch and an interior surface of the button, by way of example. 
     The button assemblies disclosed herein may be used within a variety of electronic devices, such as mobile devices, mobile phones, tablet computers, music and multi-media players, watches, gaming devices, and other handheld, wearable or portable devices. The button assemblies disclosed herein may be used for numerous purposes, such as but not limited to buttons for power, volume, camera functions, controls, home function, multi-functions, configurable button functions, or any other functions of an electronic device. 
     According to another broad aspect of another embodiment of the present invention, disclosed herein is a button assembly for an electronic device including a housing for encasing the button assembly; a button positioned within the housing; and a foam shim positioned within the housing, the foam shim transformable by curing from a first state having a first thickness to a second state having a second thickness greater than the first thickness. In this manner, the foam shim can be used to adaptively fill the interior of a button assembly by adapting to the dimensions of various components within the button assembly. 
     According to another broad aspect of another embodiment of the present invention, disclosed herein is a method of forming a button assembly for use in an electronic device. In one example, the method may include providing a housing for encasing the button assembly; positioning a button within the housing; positioning a curable foam shim within the housing, the foam shim having a first thickness; curing the foam shim, thereby transforming the foam shim from a first state into a rigid second state wherein the foam shim has a second thickness. 
     In one example, in the first state the foam shim is compressible, and upon curing, the foam shim becomes rigid wherein the second thickness is smaller than the first thickness. 
     In another example, upon the curing operation, the foam shim expands such that the second thickness is greater than the first thickness. 
     The curing operation may be ultraviolet curing or curing by heat exposure, in one example. 
     Other embodiments of the disclosure are described herein. The features, utilities and advantages of various embodiments of this disclosure will be apparent from the following more particular description of embodiments as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIGS. 1A-C  illustrate examples of a typical button assembly. 
         FIG. 2  illustrates an example of a process for forming a button of electronic device using a compressible foam shim, in accordance with one embodiment of the present disclosure. 
         FIGS. 3A-C  illustrate an example of a button of electronic device using a compressible foam shim, in accordance with one embodiment of the present disclosure. 
         FIG. 4  illustrates an example of a process for forming a button of electronic device using an expandable foam shim, in accordance with one embodiment of the present disclosure. 
         FIGS. 5A-C  illustrate an example of a button of electronic device using an expandable foam shim, in accordance with one embodiment of the present disclosure. 
         FIG. 6  illustrates an example of an electronic device, having a plurality of buttons which may be formed using foam shims, in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein are various embodiments of foam shims that may be in button assemblies of electronic devices. These foam shims may be used in place of or in combination with conventional shims within any type of button assemblies for electronic devices, such as but not limited to buttons for power, volume, camera functions, controls, home function, multi-functions, configurable button functions, or any other functions of an electronic device. 
     As described herein, in one example of the disclosure, a button assembly includes a compressible oversized curable foam shim that is positioned within and compressed within the button assembly, which upon curing such as through heat or ultraviolet light, the foam shim becomes rigid with a fixed thickness. In this manner, the foam shim adapts to the precise thickness needed within the button assembly, which aids in providing desired tactile feel of the button for a user. 
     In another example of the disclosure, a button assembly may include an expandable curable foam shim positioned within the button assembly, which upon curing such as through heat or ultraviolet light while within the button assembly, the foam shim expands and becomes rigid with a fixed thickness. In this manner, the foam shim adapts to the precise thickness needed within a button assembly, which aids in providing desired tactile feel for the button assembly. 
     Various embodiments of foam shims for use in button assemblies of electronic devices, and related methods, are disclosed herein. The following detailed description refers to the accompanying drawings that depict various details of examples selected to show how particular embodiments may be implemented. The discussion herein addresses various examples of the inventive subject matter at least partially in reference to these drawings and describes the depicted embodiments in sufficient detail to enable those skilled in the art to practice the embodiments. Many other embodiments may be utilized for practicing the subject matter other than the illustrative examples discussed herein, and many structural and operational changes in addition to the alternatives specifically discussed herein may be made without departing from the scope of the disclosed subject matter. 
     In this description, references to “one embodiment” or “an embodiment,” or to “one example” or “an example” mean that the feature being referred to is, or may be, included in at least one embodiment or example of the disclosure. Separate references to “an embodiment” or “one embodiment” or to “one example” or “an example” in this description are not intended to necessarily refer to the same embodiment or example; however, neither are such embodiments mutually exclusive, unless so stated or as will be readily apparent to those of ordinary skill in the art having the benefit of this disclosure. Thus, the present disclosure includes a variety of combinations and/or integrations of the embodiments and examples described herein, as well as further embodiments and examples as defined within the scope of all claims based on this disclosure, as well as all legal equivalents of such claims. 
     Referring to  FIG. 2  and  FIGS. 3A-C , an example of a process for forming a button assembly of electronic device (such as device  38  in  FIG. 6 ) using a compressible foam shim is illustrated in accordance with one embodiment of the present disclosure.  FIGS. 3A-C  illustrate an example of a button assembly of electronic device (such as device  38  in  FIG. 6 ) using a compressible foam shim, in accordance with one embodiment of the present disclosure. 
     In  FIG. 2 , at operation  30 , compressible foam shim (which may be oversized) is provided in a button assembly. One example of this operation  30  is shown in  FIGS. 3A-B , wherein a button assembly  40  is formed having a housing  42 , a button  44 , a tactile switch  46 , and foam shim  48  having an initial thickness. In one example of a button assembly  40 , flexible circuit  50  and a button bracket  52  may also be included in the button assembly, but each are optional depending on the implementation. The foam shim  48 , in one example may be positioned between the tactile switch  46 , flexible circuit  50 , and button bracket  52 , or may be positioned in other locations within the button assembly  40 . The button assembly  40  can be used in or as part of an electronic device  38  ( FIG. 6 ). 
     At operation  32  of  FIG. 2 , the button assembly is positioned within a button housing, thereby compressing the foam shim. One example of this operation  32  is shown in  FIGS. 3A-B , wherein once the subassembly of the tactile switch  46 , optional flexible circuit  50 , the foam shim  48  and optional button bracket  52 , is inserted within button housing  42 , the foam shim  48  is compressed to a second, smaller thickness (when compared to the initial thickness of  FIG. 3A ) when button  24  in its normally open switch position, as shown in  FIG. 3B . The initial thickness of the foam shim  48  may be selected in an oversized dimension such that when the foam shim  48  and the other components (i.e.,  44 ,  46 ,  50 ,  52 ) of the button assembly are positioned within the housing  42 , the foam shim  48  compresses and there is no gap present between the components of the button assembly within the housing  42 . 
     At operation  34  of  FIG. 2 , the foam shim within the button housing is cured, which thereby transforms the foam shim into a rigid state wherein the foam shim has a fixed, static thickness. The curing operation  34  may be achieved using heat curing or ultraviolet light curing, depending upon the implementation. 
     One example of this operation  34  is illustrated in  FIG. 3C , wherein the foam shim  48  is cured into a fixed, static thickness which is the thickness of the foam shim  28  established when the foam shim  48  is compressed by the dimensions of the components  44 ,  46 ,  50 ,  52  when positioned within housing  42 ; this thickness of the foam shim  48  in  FIG. 3B-3C  is smaller than the initial thickness of shim  48  in  FIG. 3A . Once the curing operation  34  is complete, the foam shim  48  does not further compress or otherwise change in thickness and exhibits a rigid, static and fixed thickness for the life of the shim  48  in the button assembly  40 . In this manner, foam shim  48  provides the precise amount of shim thickness to aid in providing a proper tactile feel of the button assembly  40  of  FIG. 3C . 
     Referring to  FIG. 4  and  FIGS. 5A-C , an example of a process for forming a button of electronic device using an expandable foam shim is illustrated in accordance with another embodiment of the present disclosure.  FIGS. 5A-C  illustrate an example of a button assembly  70  of electronic device  38  using an expandable foam shim  78 , in accordance with one embodiment of the present disclosure. 
     In  FIG. 4 , at operation  60 , an expandable foam shim is provided in a button assembly. One example of this operation  60  is shown in  FIGS. 5A-B , wherein a button assembly  70  is formed having a housing  72 , a button  74 , a tactile switch  76 , an expandable foam shim  78  having an initial thickness. A flexible circuit  80  and a button bracket  82  may also be included in the button assembly  70 , but each are optional depending upon the particular implementation. 
     The expandable foam shim  78  may be positioned between the tactile switch  76 , optional flexible circuit  80 , and optional button bracket  82  in one example. The expandable foam shim  78  may have a thickness that increases in response to ultraviolet light curing or heat curing, in one example. 
     At operation  62  of  FIG. 4 , the button assembly is positioned within a button housing, wherein in one example of this operation  42 , a gap may be present within the button assembly. One example of this operation  62  is shown in  FIGS. 5A-B , wherein once the subassembly of the tactile switch  76 , optional flexible circuit  80 , foam shim  78  and optional button bracket  82 , is inserted within button housing  72 , a gap  84  can be present between the button  74  and the tactile switch  76 . In  FIGS. 5A-B , foam shim  78  has an initial thickness. 
     The initial thickness of the foam shim  78  may be selected in an undersized dimension such that when the foam shim  78  and the other components (i.e.,  74 ,  76 ,  80 ,  82 ) of the button assembly  70  are positioned within the housing  72 , there is a gap  84  present between the components of the button assembly within the housing  72 . 
     At operation  64  of  FIG. 4 , the foam shim within the button housing is cured, which thereby expands the thickness of the foam shim to fill the gap established at operation  62  until the foam shim cannot further expand, at which point the foam shim enters a rigid state wherein the foam shim has a fixed, static thickness. The curing operation  64  may be achieved using heat curing or ultraviolet light curing, depending upon the implementation. 
     One example of operation  64  is illustrated in  FIG. 5C , wherein the foam shim  78  expands from its initial thickness (shown in  FIGS. 5A-5B ) to a second, enlarged thickness (shown in  FIG. 5C ) which is greater than the initial thickness of  FIGS. 5A-5B  and which fills the gap  84  in  FIG. 5B . In  FIG. 5C , the foam shim  78  has completed its expansion in response to curing operation  64 , and foam shim  78  has a fixed, static thickness which is the thickness of the foam shim  78  as shown in  FIG. 5C . Once the curing operation  64  is complete, the foam shim  78  does not further expand, compress or otherwise change in thickness and exhibits a rigid, static and fixed thickness for the life of the shim  78  in button assembly  50 . In this manner, foam shim  78  provides the precise amount of shim thickness to aid in providing a proper tactile feel of the button assembly  70  of  FIG. 5C . 
     In both  FIGS. 3A-C  and  5 A-C, foam shims  48 ,  78  are shown positioned between the optional button brackets  52 ,  82  and optional flexible circuits  50 ,  80 . In another embodiment, foam shims  48 ,  78  can be positioned within other locations or between other components within the button assemblies  40 ,  70 . For instance, as an example, foam shims  48 ,  78  may be positioned between flex circuits  50 ,  80  and tactile switches  46 ,  76 . As another example, foam shims  48 ,  78  may be positioned between tactile switches  46 ,  76  and the interior surface of buttons  44 ,  74 . 
     In another example of an embodiment of this disclosure, a button can be formed without flexible circuits and without button brackets. For instance, a button could be formed with a button housing, a button, a tactile switch, and a foam shim positioned within the button housing, wherein the foam shim fills any gap that would otherwise exist within the button assembly. In one example, such a button could be mounted to a circuit board or other electronic device or component thereof. 
     In another embodiment, a laser welded bracket could be used in a button assembly instead of an expandable/curable shim. For instance, in one example, two stamped sheet metal parts could have a slight spring between them, and could be positioned within a button assembly to take up or fill any gap that exists within the button assembly. The sheet metal parts could be laser welded together to form a bracket that provides a strong structure inside the button assembly, which can thereby fill gaps between button components within the button assembly to provide desired tactile feel for the button. 
     The buttons  44 ,  74  can be formed using any desired top surface shape or configuration, depending upon the implementation, in order to engage a user&#39;s finger or thumb during use. For instance, the top surface of buttons  44 ,  74  can shaped in configurations such as round, oval, square, rectangular, or any other shape as desired. In the example electronic device  38  of  FIG. 6 , button assemblies  40 ,  70  include round buttons and rectangular buttons, by way of example only. 
       FIG. 6  illustrates an example of an electronic device  38 , having a plurality of buttons which can include button assemblies  40 ,  70  formed using foam shim  48 ,  78 . In this example, the electronic device  38  is in the form of a mobile phone having button assemblies  40 ,  70  having foam shims therein. It is understood that embodiments of the present disclosure can be used within a variety of electronic devices, such as but not limited to mobile devices, mobile phones, tablet computers, music and multi-media players, watches, gaming devices, and other handheld, wearable or portable devices. 
     Accordingly, it can be seen that embodiments of the present disclosure provide for curable foam shims that may be used within button assemblies of electronic devices, in order to aid in providing desired tactile feel of such button assemblies to users of the electronic devices. 
     While the methods disclosed herein have been described and shown with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form equivalent methods without departing from the teachings of the present disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations is not a limitation of the present disclosure. 
     It should be appreciated that in the foregoing description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that an embodiment requires more features than are expressly recited in each claim. Rather, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, and each embodiment described herein may contain more than one inventive feature. 
     It will be understood by those skilled in the art that various changes in the form and details may be made from the embodiments shown and described without departing from the spirit and scope of the disclosure.

Metadata:
Filing Date: 20130927
Publication Date: 20161018
Grant Date: 20161018
Priority Date: 20130927
Inventors: ELY COLIN M.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01H2215/028", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2229/024", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2229/058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/042", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/084", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2229/064", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/084", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2229/058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2229/064", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2215/028", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H13/705", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01H2229/024", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01H2221/042", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 52739012