PATENT DOCUMENT

Publication Number: US-11609650-B2
Application Number: US-202117475113-A
Country: US
Kind Code: B2

Title: Force sensor and coplanar display

Abstract:
Embodiments described herein generally take the form of an electronic device including a primary and secondary display; at least the secondary display is force-sensitive and further has its force-sensing circuitry in-plane with the display. The secondary display and force-sensing circuitry may be encapsulated between two glass layers that are bonded to one another by a frit. In some embodiments the force-sensing circuitry is formed from, or constitutes part of, the frit.

Claims:
What is claimed is: 
     
       1. A computing device, comprising:
 an enclosure defining an exterior of the computing device; 
 a display positioned at least partially within the enclosure and comprising:
 a display layer; 
 a top encapsulant above the display layer; and 
 a bottom encapsulant below the display layer; 
 
 a sidewall connecting the top encapsulant to the bottom encapsulant and extending about the display layer; 
 force-sensing circuitry positioned either within the sidewall or between the display and the sidewall; and
 a circuit extending from the force-sensing circuitry through a portion of the sidewall, wherein: 
 the force-sensing circuitry is configured to measure a change in capacitance with respect to the enclosure; and 
 the force-sensing circuitry is configured to determine an amount of force applied to the display using the measured change in capacitance. 
 
 
     
     
       2. The computing device of  claim 1 , wherein:
 the enclosure comprises:
 a top portion; 
 a bottom portion comprising:
 a top case; 
 a bottom case connected to the top case; and 
 a hinge connecting the top portion to the bottom portion; 
 
 the display is a secondary display; 
 the secondary display is visible through the top case; 
 the top encapsulant is glass; 
 the bottom encapsulant is glass; 
 the force-sensing circuitry is at least partially encapsulated by the sidewall; and 
 the computing device further comprises:
 a primary display at least partially within the top portion of the enclosure; and 
 a keyboard at least partially extending through the top case. 
 
 
 
     
     
       3. The computing device of  claim 1 , wherein the force-sensing circuitry is positioned at least partially about the display layer. 
     
     
       4. The computing device of  claim 1 , wherein:
 the enclosure comprises:
 a top case; and 
 a bottom case attached to the top case, thereby defining at least a portion of the enclosure. 
 
 
     
     
       5. The computing device of  claim 4 , wherein the force-sensing circuitry measures the change in capacitance with respect to the bottom case. 
     
     
       6. The computing device of  claim 1 , wherein the top encapsulant is formed from glass. 
     
     
       7. The computing device of  claim 6 , wherein:
 the bottom encapsulant is a substrate on which the display layer is formed; and 
 the top encapsulant, the bottom encapsulant, and the sidewall cooperate to surround the display layer and the force-sensing circuitry. 
 
     
     
       8. The computing device of  claim 1 , wherein the force-sensing circuitry comprises a frit metal. 
     
     
       9. A portable computing device, comprising:
 an enclosure defining an exterior surface of the portable computing device; 
 a display at least partially within the enclosure; 
 a force sensor configured to measure a change in capacitance in response to an input force exerted on the display; and 
 an encapsulant surrounding the force sensor and within the enclosure; wherein:
 the force sensor measures the change in capacitance with respect to the exterior surface of the portable computing device; and 
 the force sensor comprises force sensing circuitry that determines an amount of force applied to the display using the measured change in capacitance. 
 
 
     
     
       10. The portable computing device of  claim 9 , wherein:
 the force sensor is coplanar with a portion of the display and within the enclosure; 
 the display comprises a display layer; 
 the encapsulant is part of the display; and 
 the encapsulant surrounds the display layer. 
 
     
     
       11. The portable computing device of  claim 10 , wherein:
 the encapsulant is formed from glass; 
 the display layer is visible through the encapsulant; and 
 the force sensor is not visible through the encapsulant. 
 
     
     
       12. The portable computing device of  claim 10 , wherein the display layer comprises low-temperature polysilicon. 
     
     
       13. The portable computing device of  claim 10 , wherein:
 the display further comprises a touch sensor; and 
 the display layer is visible through the touch sensor. 
 
     
     
       14. The portable computing device of  claim 9 , wherein the force sensor comprises:
 first force-sensing circuitry positioned along a first side of the display; and 
 second force-sensing circuitry position along a second side of the display. 
 
     
     
       15. The portable computing device of  claim 9 , wherein:
 the first force-sensing circuitry and the second force-sensing circuitry are each at least partially within the encapsulant; and 
 an electrical circuit extends from the first force-sensing circuitry through the encapsulant. 
 
     
     
       16. The portable computing device of  claim 9 , wherein the encapsulant flexes in response to the input force on the display. 
     
     
       17. A computing device, comprising:
 a touch-sensitive display comprising a display layer and configured to accept an input; 
 force-sensing circuitry configured to detect a force of the input; 
 a processing unit operably connected to the force-sensing circuitry and configured to estimate an amount of the force based on an output of the force-sensing circuitry; 
 an encapsulant forming a portion of the touch-sensitive display and encapsulating the force-sensing circuitry; and 
 an enclosure enclosing the force-sensing circuitry, the processing unit, and at least a portion of the touch-sensitive display; wherein:
 the force sensing circuitry is configured to measure a change in capacitance with respect to an exterior surface of the computing device; and 
 the force sensing circuitry is configured to determine an amount of force applied to the touch-sensitive display using the measured change in capacitance. 
 
 
     
     
       18. The computing device of  claim 17 , wherein:
 the computing device further comprises a frit metal within the encapsulant; 
 the force-sensing circuitry surrounds at least a portion of the touch-sensitive display; and 
 the force-sensing circuitry is coplanar with the display layer. 
 
     
     
       19. The computing device of  claim 18 , wherein at least a portion of the force-sensing circuitry is formed from the frit metal. 
     
     
       20. The computing device of  claim 19 , wherein:
 the portion of the force-sensing circuitry formed from the frit metal is capacitively coupled to the exterior surface of the computing device; and 
 a capacitance between the force-sensing circuitry and the exterior surface of the computing device varies as the force varies.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 16/422,727, filed May 24, 2019, the contents of which are incorporated herein by reference as if fully disclosed herein. 
    
    
     FIELD 
     Embodiments described herein generally relate to electronic devices having a display with a force sensor about, and coplanar with, the display. 
     BACKGROUND 
     Electronic devices typically include a display to provide visual information to a user. In many cases these displays are touch-sensitive. Touch sensing, while useful, is limited. Touch-sensitive displays can detect where a user touches, but not an amount of force exerted on the touch-sensitive surface. 
     Further, electronic devices have become increasingly thinner and lighter over time, thereby enhancing portability. This drive towards compact devices reduces the amount of space available for components of electronic devices, especially with respect to components layered or positioned atop one another (e.g., along a thickness or “Z-axis” of a device). 
     SUMMARY 
     Embodiments described herein generally relate to electronic devices, and particularly electronic devices having a display with a force sensor positioned at least partially around, and coplanar with, the display. 
     One embodiment described herein takes the form of a computing device, comprising: an enclosure; a display positioned at least partially within the enclosure and comprising: a display layer; a top encapsulant above the display layer; a bottom encapsulant below the display layer; and a sidewall connecting the top encapsulant to the bottom encapsulant and extending about the display layer; force-sensing circuitry positioned at least partially about the display layer; and a circuit extending from the force-sensing circuitry through a portion of the sidewall; wherein: the force-sensing circuitry is positioned either within the sidewall or between the display and the sidewall. 
     Another embodiment takes the form of a portable computing device, comprising: an enclosure; a display at least partially within the enclosure; a force sensor coplanar with a portion of the display and within the enclosure; an encapsulant surrounding the force sensor and within the enclosure; wherein: the force sensor is configured to measure a change in capacitance in response to an input force exerted on the display; and the force sensor is configured to measure the change in capacitance with respect to the enclosure. 
     Still another embodiment takes the form of a computing device, comprising: a touch-sensitive display comprising a display layer and configured to accept an input; force-sensing circuitry configured to detect a force of the input; a processing unit operably connected to the force-sensing circuitry and configured to estimate an amount of the force based on an output of the force-sensing circuitry; an encapsulant forming a portion of the display and encapsulating the force-sensing circuitry; an enclosure enclosing the force-sensing circuitry, processing unit, and at least a portion of the touch-sensitive display; wherein: the force-sensing circuitry surrounds at least a portion of the display; and the force-sensing circuitry is coplanar with the display layer. 
     In addition to the aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following description. 
    
    
     
       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    illustrates a sample electronic device; 
         FIG.  2    is a cross-section of a display and a lower housing of the sample electronic device, taken along line  2 - 2 ; 
         FIG.  3    shows a top cross-sectional view of the display of  FIG.  2   , illustrating force-sensing circuitry surrounding part of the display; 
         FIG.  4 A  shows a schematic view of one sample configuration of example force-sensing circuitry; and 
         FIG.  4 B  shows a second schematic view of a second sample configuration of example force-sensing circuitry. 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented therebetween, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following description is 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. 
     Embodiments described herein generally take the form of an electronic device including a primary and a secondary display; at least the secondary display is both touch- and force-sensitive and further has its force-sensing circuitry in-plane with the display. The secondary display and force-sensing circuitry may be encapsulated between two glass layers that are bonded to one another by a frit. The frit may at least partially encircle the display and force-sensing circuitry, or may fully encircle it. In embodiments where the secondary display and the force-sensing circuitry are fully encircled by the frit, one or more electrical lines, circuits, or the like may extend through the frit (or, in some embodiments, through one of the glass layers) to provide electrical communication and/or power between the display and/or force-sensing circuitry and other components of the electronic device. In some embodiments the force-sensing circuitry is formed from, or constitutes part of, the frit. 
     Certain embodiments may have a primary input mechanism, such as a keyboard, trackpad, or the like, positioned next to or near the secondary display. The secondary display may function as an additional or ancillary input mechanism and may, in some embodiments, extend a functionality of the primary input mechanism. The secondary display may further change one or more elements, icons, graphics, or the like shown on the display as a context of the user&#39;s interaction changes in order to provide content-sensitive inputs to the user. For example, as the user changes focus to, or otherwise selects or initiates, a program, application, or the like, the secondary display may change one or more user-selectable graphics, buttons, icons, soft keys, and so on to ones that are specific to the program, application, or other context. 
     In some embodiments, the electronic device is a laptop computer with a secondary display positioned near or next to a keyboard. The laptop computer may have an upper and lower portion connected to one another with a hinge; the keyboard and secondary display may be positioned in the lower portion. The primary display may be located in another part of the laptop computer, such as in the top portion. The lower portion may include a top case through which the keyboard and/or secondary display is accessed for user input and a bottom case connected to the top case such that the combination of the two form the (or a majority of, or a part of) exterior of the lower portion. 
     The secondary display may include circuitry for measuring an amount and/or location of a force exerted on its surface, thereby permitting force to be used as an input through the secondary display. Force-sensing circuitry may extend along one or more edges of the secondary display, or along portions of one or more edges of the secondary display. The force-sensing circuitry may sense force through changes in capacitance, resistance, optical properties, thermal properties, or the like resulting from a user (or object) exerting force on the display. 
     The display and force-sensing circuitry may be fully or partially encapsulated between a top glass layer and a bottom glass layer, where the top glass layer is positioned nearer the top case than the bottom glass layer. Likewise, the bottom glass layer is positioned nearer the bottom case than the top glass layer. A frit may bond the top glass layer to the bottom glass layer and fully or partially encircle the force-sensing circuitry and the secondary display. Power and/or signal lines may extend through the frit, the top glass, or the bottom glass and connect the display and/or the force-sensing circuitry to a power source, processing unit, or other elements of the electronic device. 
     The force-sensing circuitry may be coplanar with at least a portion of the display. For example, the force-sensing circuitry may be formed, deposited, or otherwise positioned on a common substrate with part of the display, such as the substrate on which the pixel circuitry is formed, deposited, or otherwise positioned. 
     In some embodiments using capacitive elements to measure force, the force-sensing circuitry may be mutually capacitive, while in others it may be self-capacitive. Self-capacitive force-sensing circuitry may measure a capacitance (or changes thereto) relative to a ground, such as the bottom case or top case, in order to determine a magnitude of an input force on the display. 
     The term “attached,” as used herein, refers to two elements, structures, objects, parts, or the like that are physically affixed to one another. The term “coupled,” as used herein, refers to two elements, structures, objects, parts, or the like that are physically attached to one another, operate with one another, communicate with one another, are in electrical connection with one another, or otherwise interact with one another. Accordingly, while two elements attached to one another are coupled to one another, the reverse is not required. 
     Turning now to  FIG.  1   , the electronic device  100  may be a laptop computer having a top portion  120  joined to a bottom portion  110  by a hinge  160 . The laptop computer may include a primary display  150 , which may be an OLED, LCD, LED, CCFL, LTPS, or other suitable display and may be positioned at least partially within the top portion  120 . The primary display  150  may be touch- and/or force-sensitive in certain embodiments. 
     Continuing the example, a secondary display  130  of the laptop computer  100  may be any suitable display type as listed above, and may be the same type of display as the primary display  150  or may be different. Generally, although not necessarily, the secondary display  130  is touch-sensitive and force-sensitive; in some embodiments the secondary display may be force-sensitive but not touch-sensitive (or vice versa). The secondary display  130  may be positioned fully or partially within the bottom portion  110  and may provide a first input to the electronic device  100 , such as a touch or force. 
     Additionally, an input mechanism, such as the keyboard  140 , may be used to provide a second input, such as a key selection, to the laptop computer  100 . The first and second inputs may be of the same type (e.g., force, touch, or the like) or may be of different types. The laptop computer  100  (or other electronic device) may have additional input mechanisms, as well. Sample additional input mechanisms include buttons, switches, keys, trackpads, mice, styluses, and so on. 
     As discussed above, the secondary display  130  may be force-sensitive. A cross-section the display and related force-sensing circuitry are shown in  FIG.  2   ; this cross-section is taken along line  2 - 2  of  FIG.  1   . The sample embodiment of the secondary display  130 , as shown, includes a cover  200 , a polarizer  220 , an optically clear adhesive  210  attaching the cover  200  to the polarizer  220 , a top encapsulant  230 , an optional shield layer  240 , force-sensing circuitry  250 , a display layer  260 , which may implement any of the display technologies mentioned herein or any other suitable technology, a bottom encapsulant  265  (which, in some embodiments, may be a substrate on which the display layer  260  is formed, or that is otherwise a support or substrate of the display layer, or may be a separate element from the display layer), a compliant layer  270 , and an enclosure attached to the bottom encapsulant  265  by the adhesive  210 . 
     Generally the cover  200  is formed from glass, plastic, carborundum, or another suitable transparent material. A top or upper surface of the cover  200  (e.g., the surface at the top of  FIG.  2   ) may be flush with an enclosure of the electronic device, such as the top case of the laptop computer shown in  FIG.  1   , or may protrude therefrom. The cover  200  typically flexes or otherwise deforms when an input force is exerted on it, although the amount the cover  200  flexes maybe visually and/or tactilely imperceptible to a user. By flexing, the cover  200  may transmit some or all of the input force through the display  130 , thereby permitting the force-sensing circuitry  250  to operate as described below. 
     The optically clear adhesive  210  attaches the cover  200  to the rest of the display  130 . In the embodiment shown in  FIG.  2   , the optically clear adhesive  210  attaches the cover  200  to the polarizer  220 . Typically, the optically clear adhesive is transparent or near-transparent so that it does not inhibit, block, or otherwise degrade the quality of the display layer  260 . Thus, in many embodiments the optically clear adhesive  210  is imperceptible (or near-imperceptible) to a viewer. 
     The polarizer  220  is optional and may be omitted in some embodiments. The polarizer typically enhances visibility of the display layer, for example by preventing internal and/or external reflections from degrading visibility of the display layer  260 . The polarizer  220  may increase the display layer&#39;s contrast, as one example. 
     The top encapsulant  230  is positioned between, and attached to, the polarizer  220  and the display layer  260 . The top encapsulant  230  may be attached to a sidewall (not shown) that attaches the top encapsulant  230  to a bottom encapsulant  265  such that the combination of top encapsulant  230 , sidewall, and bottom encapsulant  265  fully, substantially or partially surrounds the display layer  260 . The top encapsulant  230  is formed from glass in many embodiments, but may be made from crystal, plastic or another polymer, or other suitable materials in other embodiments. Generally, the top encapsulant  230  is fully or nearly transparent so that it does not obscure the display layer  260 . 
     As mentioned, the top encapsulant  230 , sidewall, and bottom encapsulant  265  may cooperate to surround the display layer  260 . Further, in some embodiments the display layer, or a portion thereof, may abut any or all of the top encapsulant, sidewall, and bottom encapsulant. 
     In some embodiments there is no intervening layer or gap between the bottom of the top encapsulant  230  and the top of the display layer  260 , or at least no designed intervening layer or gap. For example, although the shield layer  240  and force-sensing circuitry  250  (as discussed below) are shown as positioned between the top encapsulant  230  and the display layer  260 , in many embodiments one or both of these are co-planar with the display layer. As used herein, a first layer or element is “co-planar” with a second layer or element if a surface of the first layer or element is planar with a surface of the second layer or element. Typically, such surfaces are either the top surface, bottom surface, or both top and bottom surfaces of the first and second layers/elements. Parallel surfaces of two elements or layers are not co-planar unless the surfaces lie in the same plane as one another; the fact that a plane intersects and passes through two such surfaces does not render the corresponding layers co-planar. 
     By contrast, a first layer or element is “co-located” with a second layer or element if the first element&#39;s or layer&#39;s upper and lower surfaces do not extend above or below the upper and lower surfaces of the second element, respectively. Put another way, the first layer/element is co-located with the second layer or element if: 1) the second layer/element is at least as thick as the first layer/element; and 2) top and bottom surfaces of the second layer/element are co-planar or extend further than top and bottom surfaces of the first layer/element. Thus, it is possible for one layer to be co-located with a second layer while the reverse is not true. As one example, this can happen where a second layer is thicker than a first layer; the first layer would then be co-located with the second layer, while the second layer is not co-located with the first layer. As another example, in an embodiment where the second layer&#39;s top surface extends beyond the top surface of the first layer, but the bottom surfaces of the first and second layers are co-planar, then the first and second layers are co-planar, the first layer is co-located with the second layer, and the second layer is not co-located with the first layer. 
     It should be appreciated that references to “top,” “bottom,” “upper,” and “lower” are intended to be with reference to a device in a rest and/or operating position. Thus, where the device is a laptop computer, a “top surface” is a surface nearest a top case and a bottom surface is one nearest a bottom case, as one example. Where the electronic device is a tablet, phone, watch, or the like, a “top surface” may be the surface nearest a display or a cover of the device while a “bottom surface” may be one nearest a part of the device&#39;s enclosure on an opposite side of the device from the display and/or cover. 
     Still with respect to  FIG.  2    and bearing in mind the above, it should be appreciated that the shield layer  240  and force-sensing circuitry  250  are shown as non-co-planar with the display layer  260  for ease of illustration, although in many embodiments one or both such layers are co-planar with the display layer. For example, a bottom surface of the display layer  260  may be on the same plane as a bottom surface of the force-sensing circuitry  250 , while a top surface of the display layer  260  may be on the same plane as a top surface of the shield layer  240 . Thus, in some embodiments, the display layer  260  is co-planar with both the shield layer  240  and the force-sensing circuitry  250 . In other embodiments, the display layer may not be co-planar with either or both of the shield layer and force-sensing circuitry. 
     Typically, neither the shield layer  240  nor the force-sensing circuitry  250  extends over the portions of the display layer  260  that are visible through the cover  200 , so that they do not block the display layer from being visible outside the electronic device  100 . The shield layer  240  may be positioned above or below the force-sensing circuitry  250 , in order to shield the circuitry from parasitic capacitances (or other undesired electrical phenomena) that may interfere with the operation of the force-sensing circuitry. For example, in embodiments that include touch-sensing circuitry (e.g., a touch sensor), the shield layer  240  may be positioned between the touch-sensing circuitry and the force-sensing circuitry  250 . Likewise, in some embodiments the shield layer  240  may be positioned between the display layer  260  and the force-sensing circuitry  250 , or between a battery and the force-sensing circuitry. 
     The display layer  260  may be an LTPS (e.g., low-temperature polysilicon) layer configured to emit light from light-emitting elements, such as pixels to form images, graphics, words, icons, and so forth. In other embodiments, the display layer  260  may be implemented with a different display technology, as described herein. The display layer  260  may be flexible such that it bends, deforms, or otherwise moves (at least locally) when an input force is exerted on the cover  200 . 
     In some embodiments a touch sensor (not shown) may be positioned between the cover  200  and the display layer  260  and configured to detect a location of a touch and/or input force on the cover. (Typically, although not necessarily, the touch exerts the input force on the cover  200 .) The touch sensor may be a capacitive sensor, a resistive sensor, an optical sensor, or the like. 
     The display layer  260  may rest on, be formed on, or otherwise be supported by a bottom encapsulant  265 . In some embodiments the bottom encapsulant  265  may be a substrate of the display layer  260 , such as a flex, metal, glass, or plastic material. The light-emitting elements of the display layer  260  may be formed on the bottom encapsulant  265 . In other embodiments, the bottom encapsulant may be positioned below the substrate of the display layer  260 . The bottom encapsulant  265  may function as a mirror to reflect light emitted from the display layer in order to increase brightness of the display  130 , although this is not necessary nor is it the case in all embodiments. Some embodiments may employ a separate mirror between the bottom encapsulant  265  and display layer  260 , one positioned below the bottom encapsulant, or may omit a mirror entirely. 
     As mentioned above, the top encapsulant  230  is generally attached to the bottom encapsulant  265  by a sidewall. This is discussed in more detail below with respect to  FIG.  3   . Generally, however, the encapsulating structure formed by the top encapsulant  230 , sidewall, and bottom encapsulant  265  flexes, bends, or otherwise deforms in response to an input force exerted on the cover. 
     A compliant layer  270  may be positioned between the bottom encapsulant  265  and the bottom portion  110 ; in the example shown in  FIG.  2   , the bottom portion  110  is the bottom case of the bottom portion of the laptop computing device  100  shown in  FIG.  1   . In some embodiments an internal metal (or other electrically conductive) support or structure may be substituted for the bottom portion  110 . As one example, a midplate of a smart phone, tablet, or other electronic device may be positioned below the compliant layer  270 . An adhesive, such as a Mylar adhesive or other heat-sensitive or pressure-sensitive adhesive, may attach the compliant layer to the bottom portion  110 . 
     The compliant layer  270  may be formed from polysilicon, rubber, a gel, a polymer, and so on. In some embodiments holes, voids, gaps, or the like may be present in the compliant layer  270  to permit the layer to compress or otherwise deform. 
     Generally, the compliant layer  270  deforms, compresses, or otherwise permits the force-sensing circuitry  250  to move toward the bottom portion  110  (or other support or structure) in response to an input force exerted on the cover  200 . In certain embodiments, the input force deflects the cover  200 , optically clear adhesive  210 , polarizer  220 , the encapsulating structure formed by the top encapsulant  230 , bottom encapsulant  265  and sidewall, the display layer  260  positioned within the encapsulating structure, and the force-sensing circuitry  250  positioned within the encapsulating structure, thereby compressing or otherwise deforming the compliant layer  270 . Typically, the bottom portion  110  does not deflect or bend in response to the input force, or deflects or bends less than the compliant layer  270  and other layers or elements. 
     Accordingly, when an input force is exerted on the cover  200 , the force-sensing circuitry  250  moves closer to the bottom portion  110  (or closer to a midplate or other structural element used in place of the enclosure). The force-sensing circuitry  250  is configured to measure an electrical property with respect to the bottom portion  110 ; this electrical property changes as the distance between the force-sensing circuitry  250  and the bottom portion changes. 
     As one example, a value of a capacitance  280  between the force-sensing circuitry  250  and bottom portion  110  may be defined by a distance between the force-sensing circuitry and enclosure. As this distance decreases, the capacitance  280  increases. Likewise, as this distance increases, the capacitance  280  decreases. The force-sensing circuitry  250  may measure a value (such as a magnitude) of the capacitance  280 . Thus, as the force-sensing circuitry  250  moves toward the bottom portion  110  in response to an input force, the circuitry may detect a corresponding change in capacitance  280 . This change in capacitance may be used by a processing unit of the electronic device  100  to estimate the input force. 
     Generally, at least the cover  200 , the top encapsulant  230 , bottom encapsulant  265 , display layer  260 , and force-sensing circuitry  250  deform locally in response to the input force. Put another way, portions of these layers or elements that are closer to a point at which the input force is exerted deflect or otherwise move more than portions of these layers or elements that are further away from the point. Thus, and as discussed in more detail below with respect to  FIGS.  4 A and  4 B , the force-sensing circuitry  250  (or an associated processing unit) may be able to determine an approximate location at which an input force is exerted as well as the amount of the input force. 
       FIG.  3    generally shows a top view of the force-sensing circuitry  250   a ,  250   b  and display layer  260  as positioned on the bottom encapsulant  265 . In the orientation shown in  FIG.  3   , the top of the laptop computing device  100  shown in  FIG.  1    is toward the viewer, the read of the laptop computing device  100  (e.g., the hinged section of the laptop) is toward the top of the figure, and the front of the laptop computing device (e.g., the edge of the bottom portion that is opposite the hinge) is toward the bottom of the figure. Generally, the cross-section shown in  FIG.  3    is substantially parallel to the top case of the bottom portion  110  shown in  FIG.  1   . 
     The sidewall  300  is illustrated in  FIG.  3   . This sidewall  300  attaches the top encapsulant  230  (shown in  FIG.  2   ) to the bottom encapsulant  265  and cooperates with both top and bottom encapsulants to form the encapsulating structure discussed above. The encapsulating structure typically encloses or encircles the display layer  260  and the force-sensing circuitry  250   a ,  250   b . In the embodiment of  FIG.  3   , the sidewall  300  extends along an entire outer edge or perimeter of the bottom encapsulant  265  such that it forms a barrier between an external environment and the force-sensing circuitry  250   a ,  250   b  and display layer  260 . 
     In some embodiments the force-sensing circuitry  250   a ,  250   b  may be positioned within the sidewall rather than inside a cavity defined by the encapsulating structure. That is, the sidewall may extend over the force-sensing circuitry. This may seal the force-sensing circuitry within the sidewall  300 . The force-sensing circuitry  250   a ,  250   b  may be contained within the sidewall  300  (or within a combination of the sidewall  300  and bottom encapsulant  265 ) in embodiments where the force-sensing circuitry is formed from a frit metal that facilitates bonding the sidewall to the bottom encapsulant, as one example. As another, the force-sensing circuitry may be positioned on the bottom encapsulant, or another substrate, and the sidewall formed over the circuitry. 
       FIG.  3    also illustrates an input/output contact  310  of the force-sensing circuitry  250   a ,  250   b , which may be an electrical circuit. The input/output contact  310  may provide a drive signal to the force-sensing circuitry  250   a ,  250   b  and/or accept an output signal from the force-sensing circuitry (which may be or correspond to a measured change in an electrical property, such as capacitance, resistance, current, voltage, and so on). The input/output contact  310  may be connected to the force-sensing circuitry  250   a ,  250   b  by one or more electrical traces  320  or other electrical circuits. As with the force-sensing circuitry, the input/output contact  310  may be within the sidewall  300  or within the encapsulating structure. In some embodiments the input/output contact  310  extends through the encapsulating structure and permits electrical communication with other parts of the electronic device  100 , such as a processing unit. In some embodiments the input/output contact  310  may be or include a processing unit. 
     As with the force-sensing circuitry  250   a ,  250   b , the input/output contact  310  and/or the traces  320  may be formed from a frit metal or a portion of a frit metal. Generally, the frit metal is used during construction of the encaspulating structure to bond the sidewall to the top encapsulant or bottom encapsulant; in some cases the frit metal may bond the top encapsulant to the bottom encapsulant. The frit metal may be heated by a laser (or other heat source) and distribute that heat to the sidewall or one of the encapsulating layers, thereby promoting melting of the sidewall and/or encapsulating layer to encourage bonding and formation of the encapsulating structure. The frit metal may be deposited to form the force-sensing circuitry  250   a ,  250   b , traces  320 , or input/output contact  310  prior to heating and formation of the encapsulating structure, and may operate accordingly after the encapsulating structure is formed and the electronic device  100  assembled. 
     In some embodiments, a glass powder, glass frit, or the like may be used to form the sidewall, optionally in combination with the frit metal described above. The glass may be melted to bond to the top and bottom encapsulants. Heating the frit metal, if present may facilitate melting the glass to form the sidewall and/or attach the top encapsulant to the bottom encapsulant. 
     In some embodiments, the frit metal may form the input/output contact  310  and may pass through the sidewall  300 , the top encapsulant and/or the bottom encapsulant. Further, the frit metal may be segmented to form multiple elements, including multiple instances of force-sensing circuitry  250   a ,  250   b , multiple traces  320 , and/or multiple input/output contacts  310 . Likewise, in some embodiments any or all of the foregoing may be formed from material other than the frit metal. In still further embodiments any of the foregoing elements may be routed through the sidewall  300 , the top encapsulant  230 , or the bottom encapsulant  265 . Further, in many embodiments the drive and/or sense traces  320  may be routed co-planarly with routing for the display layer  260  and may share a substrate with such routing, thereby reducing or eliminating any need for a separate routing layer. 
     The force-sensing circuitry  250   a ,  250   b  may be separately capacitively coupled to the bottom portion  110  (as shown in  FIG.  2   ), such that each instance of the force-sensing circuitry  250   a ,  250   b  has its own capacitance with respect to the bottom portion  110 , moves separately from one another under an input force, and thus experiences its own change in capacitance in response to an input force. In certain embodiments the force-sensing circuitry  250   a ,  250   b  may be mutually capacitive rather than self-capacitive with respect to the bottom portion  110 . 
       FIGS.  4 A and  4 B  illustrate sample layouts of force-sensing circuitry  250   a ,  250   b ,  250   c ,  250   d  on an encapsulant layer  230 . For simplicity of illustration, the display layer  260  and input/output contact  310  are omitted from both  FIG.  4 A  and  FIG.  4 B . It should be appreciated that the examples of  FIGS.  4 A and  4 B  are not exhaustive but instead are illustrative. 
     As shown in  FIG.  4 A , four instances of force-sensing circuitry  250   a ,  250   b ,  250   c ,  250   d  may be positioned such that each is near a different edge of an encapsulant layer  230  and surrounds a display layer  260 . An input force exerted on a cover would cause localized deformation resulting in a unique change in capacitance for each of the instance of force-sensing circuitry, insofar as the change in capacitance for each instance of the force-sensing circuitry varies with the distance of each circuitry from the point of greatest deformation of the encapsulant layer  230  (or other substrate on which the circuitry is positioned). Thus, a processing unit connected to the force sensing circuits  250   a ,  250   b ,  250   c ,  250   d  may use their measured changes in capacitance to determine an approximate location of the cover on which the input force is exerted. 
       FIG.  4 B  shows an embodiment having two force-sensing circuits  250   a ,  250   c . Accordingly, while this embodiment may be able to determine which of the force-sensing circuits is nearer the location of the input force, it may not determine the input force&#39;s location with the same accuracy as the embodiment of  FIG.  4 A , or may be able to determine the input force&#39;s location along one axis of a plane intersecting the force sensing circuits  250   a ,  250   c  rather than both an X and Y coordinate within that plane. 
     The foregoing description, for purposes of explanation, uses 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. What is claimed is:

Metadata:
Filing Date: 20210914
Publication Date: 20230321
Grant Date: 20230321
Priority Date: 20190524
Inventors: LIN, HUNG SHENG
KIM, BYOUNGSUK
QI, JUN
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04142", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0414", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1643", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1643", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0414", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1681", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1616", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1643", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 73456923