PATENT DOCUMENT

Publication Number: US-9829397-B2
Application Number: US-201615090831-A
Country: US
Kind Code: B2

Title: Compression seal for force sensing device

Abstract:
An electronic device includes a seal compressed between a moveable structure and a support. A retainer maintains seal compression in a first direction absent force exerted on the moveable structure. However, the retainer allows increased seal compression by moving in a second, opposing direction when force is exerted on the moveable structure. A force sensor (positioned internal to the seal) is influenced by movement of the moveable structure in response to the force and a signal received from the force sensor indicates an amount of the force. By maintaining the seal in compression but allowing further compression, the seal can hermetically seal the electronic device against contaminant entry without adversely impacting detection of the amount of force.

Claims:
What is claimed is: 
     
       1. A force sensing device, comprising:
 a housing; 
 a cover; 
 a gasket compressed between the housing and the cover; 
 a retainer that binds the gasket to maintain compression of the gasket absent a force exerted on the cover and is operable to allow increased compression of the gasket when the force is exerted on the cover; and 
 a force sensor disposed between the housing and the cover that produces a signal indicative of an amount of the force; 
 wherein the gasket is positioned between the force sensor and an exterior environment. 
 
     
     
       2. The force sensing device of  claim 1 , wherein the gasket forms a hermetic seal. 
     
     
       3. The force sensing device of  claim 1 , wherein the force sensor comprises a pair of capacitive plates separated by a deformable spacer material. 
     
     
       4. The force sensing device of  claim 3 , wherein the deformable spacer material is softer than the gasket. 
     
     
       5. The force sensing device of  claim 3 , wherein the deformable spacer material comprises a foam. 
     
     
       6. The force sensing device of  claim 1 , wherein the force sensor comprises a piezoelectric material. 
     
     
       7. The force sensing device of  claim 1 , wherein:
 the housing includes a shelf; 
 the retainer includes a lip; 
 the lip is operable to engage the shelf absent the force to restrict expansion of the gasket. 
 
     
     
       8. A force sensing electronic device, comprising:
 a support; 
 an input surface; 
 an o-ring preloaded in compression between the support and the input surface; 
 a clamp that:
 resists expansion of the o-ring in a first direction absent a force exerted on the input surface; and 
 moves in a second direction opposite to the first direction when the force is exerted on the input surface; and 
 a force sensor disposed between the support and the input surface that produces a signal indicative of an amount of displacement between the input surface and the support caused by the force, the force sensor positioned proximate to the o-ring in a third direction perpendicular to the first direction. 
 
 
     
     
       9. The force sensing electronic device of  claim 8 , wherein a dimension of the o-ring between the support and the input surface is different than a dimension of the force sensor between the support and the input surface. 
     
     
       10. The force sensing electronic device of  claim 8 , wherein the amount of displacement between the input surface and the support caused by the force depends on a resistance of the o-ring and the force sensor. 
     
     
       11. The force sensing electronic device of  claim 8 , wherein the clamp is fixed to the input surface and moves with respect to the support in the second direction. 
     
     
       12. The force sensing electronic device of  claim 8 , wherein the clamp is fixed to the support and moves with respect to the input surface in the second direction. 
     
     
       13. The force sensing electronic device of  claim 8 , wherein:
 the o-ring is formed of a first type of silicone; and 
 the force sensor includes a second type of silicone having a lower durometer than the first type of silicone. 
 
     
     
       14. The force sensing electronic device of  claim 8 , wherein the clamp is positioned between the o-ring and the input surface and between the force sensor and the input surface. 
     
     
       15. An electronic device, comprising:
 a base; 
 a moveable structure; 
 a compressed seal positioned between the base and the moveable structure; 
 a restraint that restricts the seal to maintain compression of the seal absent a force exerted on the moveable structure and allow movement of the moveable structure relative to the base in response to the force; 
 a strain gauge that experiences a strain related to the movement; 
 a processing unit that receives a signal indicative of an amount of the force from the strain gauge; and 
 wherein the strain for the amount of the force is dependent upon a resistance of the compressed seal to the movement. 
 
     
     
       16. The electronic device of  claim 15 , wherein:
 the strain gauge is coupled to a portion of the restraint that deflects absent the force; and 
 the strain decreases as the amount of the force increases. 
 
     
     
       17. The electronic device of  claim 15 , further comprising a strut positioned between the base and the moveable structure that flexes in response to the movement wherein:
 the strain gauge is coupled to the strut. 
 
     
     
       18. The electronic device of  claim 15 , wherein the restraint blocks entry of contaminants that breach the compressed seal. 
     
     
       19. The electronic device of  claim 15 , wherein:
 the compressed seal forms a continuous outer perimeter around the strain gauge; and 
 the strain gauge does not form a continuous inner perimeter within the outer perimeter. 
 
     
     
       20. The electronic device of  claim 15 , wherein the compressed seal does not stiffen in response to the movement.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/233,961, filed Sep. 28, 2015, and entitled “Compression Seal for Force Sensing Device,” the contents of which are incorporated by reference as if fully disclosed herein. 
    
    
     FIELD 
     The described embodiments relate generally to force sensing. More particularly, the present embodiments relate to a compression sealed interface for a force sensing device. 
     BACKGROUND 
     There are many different kinds of electronic devices such as desktop computing devices, laptop computing devices, tablet computing devices, mobile computing devices, smart phones, wearable electronic devices, digital media players, displays, and so on. Many electronic devices include mechanisms that are operable to receive input from a user. Operation of the electronic device may be controlled or changed based on received input. 
     For example, some electronic devices include touch surfaces such as touch screens, buttons, and so on. Sensors included in the electronic device may be operable to detect when a user touches the touch surface. This touch, or various characteristics thereof, may be interpreted by the electronic device as input. 
     Many touch surfaces may be separate components from a housing of the electronic device. As such, contaminants such as water or other liquids, dust, dirt, and so on may be able to enter into an internal volume of the electronic device from an exterior environment in areas between touch surfaces and the housing. Various components of the electronic device may be vulnerable to such contaminants. In some electronic device, various components may be positioned in such areas to seal the electronic device against contaminant entry. 
     SUMMARY 
     The present disclosure relates to a compression seal for a force sensing device. An electronic device includes a force sensor disposed between a housing or other support and a cover glass or other moveable structure. The force sensor is operable to detect deflection of the cover glass caused by force exerted on the cover glass. The electronic device also includes a gasket or other seal compressed between the cover glass and the force sensor. A retainer maintains compression of the gasket while allowing additional compression related to the deflection of the cover glass. In this way, the gasket may hermetically seal the electronic device without adversely impacting operation of the force sensor. 
     In various embodiments, a force sensing device includes a housing, a cover, a gasket compressed between the housing and the cover, a retainer that maintains compression of the gasket absent a force exerted on the cover and that is operable to allow increased compression of the gasket when the force is exerted on the cover, and a force sensor disposed between the housing and the cover that produces a signal indicative of an amount of the force. The gasket is positioned between the force sensor and an exterior environment. The gasket may form a hermetic seal. 
     In some examples, the force sensor includes a pair of capacitive plates separated by a deformable spacer material. The deformable spacer material may be softer than the gasket. The deformable spacer material may be a foam. In other examples, the force sensor includes a piezoelectric material. 
     In various examples, the housing includes a shelf and the retainer includes a lip. In such examples, the lip is operable to engage the shelf absent the force to restrict expansion of the gasket. 
     In numerous embodiments, a force sensing electronic device includes a support, an input surface, an o-ring preloaded in compression between the support and the input surface, a clamp, and a force sensor disposed between the support and the input surface. The clamp resists expansion of the o-ring in a first direction absent a force exerted on the input surface and moves in a second direction opposite to the first direction when the force is exerted on the input surface. The force sensor is disposed between the support and the input surface that produces a signal indicative of an amount of displacement between the input surface and the support caused by the force. The force sensor is positioned proximate to the o-ring in a third direction perpendicular to the first direction. 
     In various examples, a dimension of the o-ring between the support and the input surface is different than a dimension of the force sensor between the support and the input surface. In numerous examples, the amount of displacement between the input surface and the support caused by the force depends on a resistance of the o-ring and the force sensor. 
     In some examples, the clamp is fixed to the input surface and moves with respect to the support in the second direction. In other examples, the clamp is fixed to the support and moves with respect to the input surface in the second direction. The clamp may be positioned between the o-ring and the input surface and between the force sensor and the input surface. 
     In various examples, the o-ring is formed of a first type of silicone and the force sensor includes a second type of silicone. The second type of silicone may have a lower durometer than the first type of silicone. 
     In various embodiments, an electronic device includes a base, a moveable structure, a compressed seal positioned between the base and the moveable structure, a restraint that maintains compression of the seal absent a force exerted on the moveable structure and allows movement of the moveable structure relative to the base in response to the force, a strain gauge that experiences a strain related to the movement, and a processing unit that receives a signal indicative of an amount of the force from the strain gauge. The strain for the amount of the force is dependent upon a resistance of the compressed seal to the movement. 
     In some examples, the strain gauge is coupled to a portion of the restraint that deflects absent the force and the strain decreases as the amount of the force increases. In other examples, the electronic device further includes a strut positioned between the base and the moveable structure that flexes in response to the movement. In such examples, the strain gauge is coupled to the strut. 
     In various examples, the restraint blocks entry of contaminants that breach the compressed seal. In some examples, the compressed seal forms a continuous outer perimeter around the strain gauge and the strain gauge does not form a continuous inner perimeter within the outer perimeter. In numerous examples, the compressed seal does not stiffen in response to the movement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  depicts an electronic device including a compression seal for a force sensing device; 
         FIG. 2A  depicts first example partial cross-sectional view of the electronic device of  FIG. 1 , taken along line A-A of  FIG. 1 . 
         FIG. 2B  depicts the view of  FIG. 2A  when a force is exerted on the cover glass; 
         FIG. 2C  depicts a simplified mechanical schematic illustrating the displacement of the cover glass shown in  FIGS. 2A-2B  in relation to compression of the gasket and the force sensor; 
         FIG. 3  depicts a second example partial cross-sectional view of the electronic device of  FIG. 1  in accordance with further embodiments; 
         FIG. 4  depicts a third example partial cross-sectional view of the electronic device of  FIG. 1  in accordance with further embodiments; 
         FIG. 5  depicts a fourth example partial cross-sectional view of the electronic device of  FIG. 1  in accordance with further embodiments; and 
         FIG. 6  is a flow chart illustrating a method for constructing a compression seal for a force sensing device. This method may be performed as part of manufacturing one or more of the electronic devices of  FIGS. 1-5 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The description that follows includes sample systems, methods, and apparatuses that embody various elements of the present disclosure. However, it should be understood that the described disclosure may be practiced in a variety of forms in addition to those described herein. 
     The following disclosure relates to a compression seal for a force sensing device. An electronic device includes a seal compressed between a moveable structure and a support. A retainer maintains seal compression in a first direction absent force exerted on the moveable structure. However, the retainer allows increased seal compression by moving in a second, opposing direction when force is exerted on the moveable structure. A force sensor (positioned internal to the seal) is influenced by movement of the moveable structure in response to the force and a signal received from the force sensor indicates an amount of the force. By maintaining the seal in compression but allowing further compression, the seal can hermetically seal the electronic device against contaminant entry without adversely impacting detection of the amount of force. 
     This configuration of the seal and the force sensor decouples sealing of the electronic device from the force sensor. By having the seal separate, and in some implementations providing at least a portion of the resistance to applied force utilized in force sensor operation, a wider variety of materials that may be used in the force sensor over electronic device that use a force sensor as a seal. Further, this may allow a wider variety of other force sensor parameters, such as force sensor dimensions. 
     These and other embodiments are discussed below with reference to  FIGS. 1-6 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  depicts an electronic device  100  including a compression seal for a force sensing device, which is described in detail with respect to  FIG. 2A  below. The electronic device  100  may include a housing  101 , base, or support and a cover glass  102 , input surface, or moveable structure. The electronic device  100  may be operable to receive input via a user exerting force on the cover glass  102 . 
       FIG. 2A  depicts first example partial cross-sectional view of the electronic device  100  of  FIG. 1 , taken along line A-A of  FIG. 1 . A gasket  210  (also encompassing a seal or an o-ring) and a force sensor  213  may be disposed within an internal volume  222  of the electronic device  100 . The gasket  210  and the force sensor  213  or force sensing device may be positioned between a shelf  211  of the housing  101  and the cover glass  102 . The gasket  210  may be positioned between the force sensor  213  and an exterior environment around the electronic device  100 . A retainer  219  (also encompassing a clamp, a restraint, or a retaining element) may be positioned between the gasket  210  and the cover glass  102 , as well as between the force sensor  213  and the cover glass  102 . 
     As shown in  FIG. 2A , the gasket  210  may be compressed absent force exerted on the cover glass  102 . Compression of the gasket  210  may energize the gasket  210  and allow the gasket  210  to provide a better seal than if uncompressed. The seal may be a hermetic seal, protecting the force sensor  213  and/or other components of the electronic device  100  in extreme environments such as submersion at high pressures, exposure to chemicals, and so on. The gasket  210  may be preloaded in compression between the shelf  211  and the cover glass  102  by the retainer  219 . The retainer  219  may maintain compression of the compressed gasket  210  absent force exerted on the cover glass  102 . 
     The retainer  219  may maintain compression of the gasket  210  via an L-shaped structure  220  (also encompassing a lip) or other engagement mechanism. The L-shaped structure  220  may extend through an aperture  212  in the shelf  211  and engage the shelf  211  to restrict and/or not allow the gasket  210  to expand or uncompress. The L-shaped structure  220  may not allow the gasket  210  to uncompress by engaging the shelf  211  to resist movement in a first direction  223 . However, the retainer  219  may allow further compression of the gasket  210  in a second direction  224 , opposite the first direction  223 . 
       FIG. 2B  depicts the view of  FIG. 2A  when a force  225  is exerted on the cover glass  102 . In response to the force  225 , the cover glass  102  may deflect with respect to the shelf  211  in the second direction  224 . The retainer  219  may more or translate (by the L-shaped portion moving in the aperture  212 ) to transfer the force  225  to the gasket  210 . This may further compress the gasket  210 . The retainer  219  may also transfer the force  225  to the force sensor  213 . 
     The force sensor  213  may be coupled to a processing unit  218  via a flex circuit  217  and/or other electrical connection. The processing unit  218  may receive one or more signals produced by and/or from the force sensor  213  indicating an amount of displacement (and thus the force  225 ) between the cover glass  102  and the shelf  211  caused by the force  225 . The processing unit  218  may correlate the signal to determine the force  225 . The processing unit  218  may determine the force  225  to be an amount of force within a range as opposed to whether or not the force  225  is exerted on the cover glass  102 , though in various implementations the processing unit  218  may determine whether or not the force  225  is exerted rather than an amount of the force  225 . 
     For example, in this implementation, the force sensor  213  may include first and second capacitive plates  214  and  216  separated by a deformable spacer material  215 . The first and second capacitive plates  214  and  216  may form a capacitor. The capacitance of a capacitor formed by the first and second capacitive plates  214  and  216  may vary based on the deflection of the first and second capacitive plates  214  and  216  with respect to each other, which in turn varies based on the deflection of the cover glass  102  and thus the force  225 . The signals received by the processing unit  218  may indicate a capacitance of that capacitor. The capacitance may be correlated by the processing unit  218  (such as by comparison to values in a lookup table stored in a non-transitory storage media of the electronic device  100 ) to determine an amount of the force  225 . 
     As illustrated, the gasket  210  and the force sensor  213  may be positioned between the shelf  211  and the cover glass  102  such that neither is positioned between the other and either the shelf  211  or the cover glass  102 . Thus, the implementation illustrated in  FIGS. 2A-2B  decouples sealing and force sensing. Further, as displacement of the cover glass  102  by the force  225  causes compression of both the gasket  210  and the force sensor  213  (or the deformable spacer material  215 ), the amount of displacement may be dependent on the resistance of the gasket  210  and the force sensor  213 . 
     For example,  FIG. 2C  depicts a simplified mechanical schematic illustrating the displacement of the cover glass  102  shown in  FIGS. 2A-2B  in relation to compression of the gasket  210  and the force sensor  213 . The displacement is represented by D, the mechanical compression of the gasket  210  is represented by Ks, and the mechanical compression of the force sensor  213  is represented by Kn. Thus, the amount of the force  225  is D times the sum of Ks and Kn. 
     Returning to  FIGS. 2A-2B , the dependence of the amount of displacement of the cover glass  102  on the resistance of the gasket  210  and the force sensor  213  may allow a wider variety of materials to be used for the deformable spacer material  215  without adversely impacting performance of the force sensor  213 . For example, a harder (or harder durometer) material may be used for the gasket  210  and a softer (or lower durometer) material may be used for the deformable spacer material  215 . In some implementations, different materials may be used for the gasket  210  and the deformable spacer material  215 . However, in other implementations, harder and softer forms of a same or similar material may be used. 
     For example, in various implementations, the gasket  210  and the deformable spacer material  215  may both be formed of silicone. In other words, the gasket  210  may be formed of a first type of silicone and the deformable spacer material  215  may be formed of a second type of silicone. In such an implementation, the gasket  210  may be formed of a harder silicone and the deformable spacer material  215  may be formed of a softer silicone. In some cases, the gasket  210  may be formed of a solid silicone and the deformable spacer material  215  may be formed of a silicone foam. 
     Regardless of the particular materials used for the gasket  210  and/or the deformable spacer material  215 , the gasket  210  may be formed of a material that does not significantly stiffen or compression set significantly beyond the preload absent the force  225 . Forming the gasket  210  of a material that significantly stiffens or compression sets significantly beyond the preload could affect the amount of the displacement of the cover glass  102  in response to the force  225 , making the force curve uneven and/or making measurements based on the force sensor  213  inaccurate. Forming the gasket  210  of a material that does not significantly stiffen or compression set significantly beyond the preload prevents these potential issues. 
     The retainer  219  is shown as fixed to the cover glass  102  (such as by adhesive, by being integrally formed with the cover glass  102 , and so on) and operable to move or translate in the second direction  224  with respect to the shelf  211  and/or housing  101 . However, it is understood that this is an example. In other implementations, the retainer  219  may be fixed to the shelf  211  and/or housing  101  and may be operable to move or translate in the second direction  224  with respect to the cover glass  102  without departing from the scope of the present disclosure. 
     As shown, portions of the retainer  219  (such as the L-shaped structure  220 ) may be positioned between the force sensor  213  or other components of the electronic device  100  and the external environment  221 . As such, the retainer  219  may also function as a seal and block entry of contaminants into the internal volume  222 , particularly if the contaminants breach the gasket  210 . 
     The gasket  210  may form a continuous perimeter around the internal volume  222 . The force sensor  213  may be positioned within the perimeter formed by the gasket  210 . In some implementations, the force sensor  213  may form a continuous inner perimeter within a continuous outer perimeter formed by the gasket  210 . However, in other implementations, the force sensor  213  may not be continuous within an inner perimeter of a gasket  210  outer perimeter. In some examples, multiple discontinuous force sensors  213  may be positioned within a continuous perimeter formed by the gasket  210 . 
     Although the force sensor  213  is illustrated and described above with respect to  FIGS. 2A-2B  as having a particular configuration of components, it is understood that this is an example. In various implementations, a variety of different force sensors may be used without departing from the scope of the present disclosure. For example,  FIG. 3  depicts a second example partial cross-sectional view of the electronic device  100  of  FIG. 1  in accordance with further embodiments. 
     In the implementation illustrated in  FIG. 3 , the force sensor  313  may formed of a piezoelectric material rather than the first and second capacitive plates  214  and  216  separated by the deformable spacer material  215 . Compression of the piezoelectric material by exertion of force on the cover glass  102  may cause the force sensor  313  to transmit signals to the processing unit  318  via the flex circuit  317 . The processing unit  318  may analyze the signals to determine the amount of force exerted on the cover glass  102 . 
     Further, as sealing and force sensing are decoupled, a wider variety of force sensor  313  dimensions may be possible. In this implementation, the force sensor  313  may have a smaller height than the gasket  310 . The retainer  319  may be thinner where it contacts the gasket  310  than where it contacts the force sensor  313  so that the gasket  310  and the force sensor  313  are compressed when the cover glass  102  deflects under the exertion of force. 
     By way of another example, in various implementations, strain gauges may be used.  FIG. 4  depicts a third example partial cross-sectional view of the electronic device  100  of  FIG. 1  in accordance with further embodiments. In the implementation illustrated in  FIG. 4 , the force sensor  413  may include a strain gauge  426  mounted on a strut  425  positioned between the shelf  411  and the cover glass  102 . The strut  425  may flex in response to movement or deflection of the cover glass  102 . This flexing may cause a strain that is experienced by the strain gauge  426 . The processing unit  418  may receive signals from the strain gauge  426  via the flex circuit  417  indicating the experienced strain and may correlate the signals to determine an amount of force exerted on the cover glass  102 . 
     Like the force transferred to the force sensors  213  and  313  of the implementations shown in  FIGS. 2A-2B and 3 , the strain experienced by the strain gauge  426  may be dependent upon the resistance of the gasket  410  to deflection of the cover glass  102  in the direction  424 . The more the gasket  410  resists a particular force, the less the cover glass  102  deflects in the direction  424  and thus the less strain experienced by the strain gauge  426 . 
     However, though  FIG. 4  illustrates the strain gauge  426  mounted on the moveable strut  425  positioned between the shelf  411  and the cover glass  102  where the strain experienced by the strain gauge  426  is proportional to force exerted on the cover glass  102 , it is understood that this is an example. In other implementations, strain gauges may be otherwise disposed without departing from the scope of the present disclosure. 
     For example,  FIG. 5  depicts a fourth example partial cross-sectional view of the electronic device  100  of  FIG. 1  in accordance with further embodiments. In  FIG. 5 , the force sensor  513  may include a strain gauge disposed on a lip portion of the L-shaped structure  520 . Absent force exerted on the cover glass  102 , the lip portion of the L-shaped structure  520  may engage the shelf  511  and may be deflected by the compression of the gasket  510  exerting force on the retainer  519  in the direction  523 . This deflection may cause strain, which may be experienced by the strain gauge of the force sensor  513 . When force is exerted on the cover glass  102 , the retainer  519  may translate or move in the direction  524 , lessening or eliminating the deflection. In other words, the strain decreases as the amount of force increases. As a result, the strain gauge of the force sensor  513  may experience less strain. Thus, the strain experienced by the strain gauge of the force sensor  513  may be inversely proportional to force exerted on the cover glass  102 . 
     The processing unit  518  may receive signals from the strain gauge of the force sensor  513  via the flex circuit  517  indicating the experienced strain. The processing unit  518  may correlate the signals to determine an amount of force exerted on the cover glass  102  based on the strain. The processing unit  518  may correlate lower strains with higher exerted amounts of force and higher strains with lower exerted amounts of force and/or the absence of exerted force. 
     Although  FIGS. 1-5  illustrate the electronic device  100  as a wearable electronic device, it is understood that this is an example. In various implementations, a compression seal for a force sensing device may be used in a variety of different electronic devices (also encompassing a force sensing electronic device) without departing from the scope of the present disclosure. These may include laptop computing devices, desktop computing devices, fitness monitors, mobile computing devices, tablet computing devices, smart phones, displays, digital media players, keyboards, and so on. 
       FIG. 6  is a flow chart illustrating a method  600  constructing a compression seal for a force sensing device. This method may be performed as part of manufacturing one or more of the electronic devices of  FIGS. 1-5 . 
     At  610 , a force sensor may be configured between a cover or other moveable structure and a housing. The force sensor may be configured to obtain measurements related to force exerted on the cover. The measurements may be analyzed by a processing unit to determine and amount of the exerted force. 
     In  620 , a gasket may be compressed between the cover and the housing. The gasket may be positioned between the force sensor and an external environment. The gasket may form a hermetic seal. The gasket may be disposed proximate (e.g., adjacent and/or other components and/or gaps may be positioned in between) to the force sensor in a direction approximately perpendicular to the direction in which the gasket and force sensor are positioned between the cover and the housing. The gasket may be compressed by a retaining element. Such a retaining element may oppose expansion or release of the gasket compression by engaging the cover, the housing, and/or other such structures. 
     At  630 , the retaining element may be configured to maintain compression of the gasket and allow increased compression. The retaining element may be configured to allow increased compression by being operable to move in a first direction corresponding to increased compression of the gasket. The retaining element may be configured to maintain compression by being restricted from moving in a second direction corresponding to decreased compression of the gasket. 
     Although the example method  600  is illustrated and described as including particular operations performed in a particular order, it is understood that this is an example. In various implementations, various orders of the same, similar, and/or different operations may be performed without departing from the scope of the present disclosure. 
     For example, the method  600  illustrates and describes  620  and  630  as separate, linearly performed operations. However, it is understood that this is an example for the purposes of clarity. In various implementations,  620  and  630  may be performed simultaneously without departing from the scope of the present disclosure. For example, configuring the gasket to maintain compression may also compress the gasket. 
     As described above and illustrated in the accompanying figures, the present disclosure relates to a compression seal for a force sensing device. An electronic device includes a seal compressed between a moveable structure and a support. A retainer maintains seal compression in a first direction absent of force exerted on the moveable structure. However, the retainer allows increased seal compression by moving in a second, opposing direction when force is exerted on the moveable structure. A force sensor (positioned internal to the seal) is influenced by movement of the moveable structure in response to the force and a signal received from the force sensor indicates an amount of the force. By maintaining the seal in compression but allowing further compression, the seal can hermetically seal the electronic device against contaminant entry without adversely impacting detection of the amount of force. This configuration of the seal and the force sensor decouples sealing of the electronic device from the force sensor. By having the seal separate, a wider variety of materials that may be used in the force sensor over electronic device that use a force sensor as a seal. Further, this may allow a wider variety of other force sensor parameters, such as force sensor dimensions. 
     In the present disclosure, the methods disclosed may be implemented as sets of instructions or software readable by a device. Further, it is understood that the specific order or hierarchy of steps in the methods disclosed are examples of sample approaches. In other embodiments, the specific order or hierarchy of steps in the method can be rearranged while remaining within the disclosed subject matter. The accompanying method claims present elements of the various steps in a sample order, and are not necessarily meant to be limited to the specific order or hierarchy presented. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20160405
Publication Date: 20171128
Grant Date: 20171128
Priority Date: 20150928
Inventors: Lukens William C.
BOOZER BRAD
Shuma Richard D.
Assignee: APPLE INC
CPC Classifications: [{"code": "G01L1/142", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01L1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L41/053", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L41/1132", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L1/142", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10N30/88", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01L1/142", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10N30/302", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 58408821