PATENT DOCUMENT

Publication Number: US-9713295-B2
Application Number: US-201213529635-A
Country: US
Kind Code: B2

Title: Tape-based grounding structures

Abstract:
An electronic device housing may have conductive walls and planar metal internal housing structures. A display in the electronic device may have a touch sensor layer such as an array of capacitive touch sensor electrodes. The display may have display layers in a plastic chassis structure and a metal chassis structure. A display layer may have a conductive surface. Conductive tape may be used to couple the touch sensor to the metal chassis structure and a metal radio-frequency shielding structure. Conductive tape may also be used to short the conductive surface of the display layer to the internal metal housing structure. Segments of conductive tape may run along each of the four edges of a display and may overlap at display corners. Conductive foam structures may be used to short the segments to adjacent portions of the conductive housing walls.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a display having a rectangular perimeter with four edges and four corners and having a conductive layer; 
 a metal internal electronic device housing structure; 
 conductive tape that has first and second opposing surfaces and that exhibits three-dimensional conductivity such that the tape comprises an electrical pathway that extends from the first surface to the second surface and that electrically connects the conductive layer to the metal internal electronic device housing structure, wherein the conductive tape extends along a first edge of the display; and 
 additional conductive tape that extends along a second edge of the display that is substantially orthogonal to the first edge, wherein the conductive tape overlaps and is electrically shorted to the additional conductive tape. 
 
     
     
       2. The apparatus defined in  claim 1  wherein the conductive tape has opposing inner and outer surfaces, wherein the inner surface is attached to the conductive layer and wherein the outer surface is coupled to the metal internal electronic device housing structure. 
     
     
       3. The apparatus defined in  claim 2  wherein the metal internal electronic device housing structure comprises a sheet metal structure. 
     
     
       4. The apparatus defined in  claim 2  wherein the metal internal electronic device housing structure comprises a planar housing member formed of at least one sheet metal structure and wherein the outer surface is electrically connected to the planar housing member. 
     
     
       5. The apparatus defined in  claim 1  wherein the display comprises a plastic chassis structure and wherein the conductive tape is wrapped around the plastic chassis structure. 
     
     
       6. The apparatus defined in  claim 1  wherein the display comprises a metal chassis structure, the apparatus further comprising:
 a display cover layer; and 
 a touch sensor layer on the display cover layer, wherein the additional conductive tape exhibits three-dimensional conductivity and electrically connects the touch sensor layer to the metal chassis structure. 
 
     
     
       7. The apparatus defined in  claim 6  further comprising a metal shielding can, wherein the additional conductive tape has an outer surface that faces the touch sensor layer and that is coupled to the touch sensor layer and has an inner surface that faces the metal shielding can and that is coupled to the metal shielding can. 
     
     
       8. The apparatus defined in  claim 7  further comprising conductive foam that electrically connects the touch sensor layer to the outer surface of the additional conductive tape. 
     
     
       9. The apparatus defined in  claim 6  wherein the display comprises a color filter layer and a thin-film transistor layer, wherein the conductive layer is formed on the color filter layer such that the color filter layer is interposed between the conductive layer and the thin-film transistor layer, and wherein the conductive layer is interposed between the touch sensor layer and the color filter layer. 
     
     
       10. The apparatus defined in  claim 1  wherein the conductive layer comprises a layer of indium tin oxide. 
     
     
       11. The apparatus defined in  claim 1  wherein conductive tape segments cover each of the four edges of the display, wherein the conductive tape segments include the conductive tape and the additional conductive tape, and wherein each of the conductive tape segments is formed from conductive tape material that exhibits three-dimensional conductivity. 
     
     
       12. The apparatus defined in  claim 11  wherein the conductive tape-overlaps the additional conductive tape at one of the four corners of the display. 
     
     
       13. The apparatus defined in  claim 11  further comprising:
 a metal electronic device housing wall; and 
 at least one strip of conductive foam that extends between at least one of the conductive tape segments along at least one of the edges and the metal electronic device housing wall. 
 
     
     
       14. An electronic device, comprising:
 a display having a touch sensor layer and having a metal chassis structure; and 
 conductive tape that exhibits three-dimensional conductivity and that has opposing outer and inner surfaces, wherein the outer surface of the conductive tape faces the touch sensor layer and is electrically coupled to the touch sensor layer, wherein the inner surface of the conductive tape faces the metal chassis structure and is electrically coupled to the metal chassis structure such that the touch sensor layer is shorted to the metal chassis structure through the conductive tape, and wherein the conductive tape has a substantially C-shaped cross-sectional profile. 
 
     
     
       15. The electronic device defined in  claim 14  further comprising a housing having at least one internal planar metal structure, the electronic device further comprising:
 additional conductive tape that exhibits three-dimensional conductivity, wherein the additional conductive tape has an outer surface that faces the internal planar metal structure and that is electrically coupled to the internal sheet metal structure. 
 
     
     
       16. The electronic device defined in  claim 15  wherein the display comprises display layers including at least one layer with an indium tin oxide surface and wherein the additional conductive tape has an inner layer that is connected to the indium tin oxide layer. 
     
     
       17. The electronic device defined in  claim 16  wherein the at least one layer comprises a color filter layer and the display layers include a thin-film transistor layer interposed between the color filter layer and the metal chassis structure, and wherein the indium tin oxide surface is interposed between the touch sensor layer and the color filter layer. 
     
     
       18. The electronic device defined in  claim 14  further comprising a printed circuit to which a metal radio-frequency shielding structure is mounted, wherein the inner surface of the conductive tape faces the metal radio-frequency shielding structure and is connected to the metal radio-frequency shielding structure. 
     
     
       19. An electronic device, comprising:
 a metal housing including at least one internal planar metal structure; 
 a display having first and second opposing surfaces, wherein the display comprises a layer with a conductive surface; and 
 conductive tape that exhibits three-dimensional conductivity and that has a first portion with an inner surface that faces and is connected to the conductive surface and that has a second portion with an opposing outer surface that faces and is coupled to the internal planar metal structure, wherein the conductive tape wraps around the display from the first surface to the second surface such that the first and second portions of the conductive tape overlap and the second portion is interposed between the first portion and the internal planar metal structure, and wherein the first and second opposing surfaces are substantially parallel. 
 
     
     
       20. The electronic device defined in  claim 19  wherein the display includes metal chassis structures, the electronic device further comprising:
 a touch sensor layer; and 
 a conductive tape structure that electrically grounds the touch sensor layer to the metal chassis structures. 
 
     
     
       21. The electronic device defined in  claim 20  wherein the display comprises:
 a thin-film transistor layer on the metal chassis structures; and 
 a display driver integrated circuit mounted to the thin-film transistor layer, wherein the layer with the conductive surface comprises a color filter layer. 
 
     
     
       22. The electronic device defined in  claim 21  wherein the conductive surface comprises a layer of transparent conductive material coated on a surface of the color filter layer, and wherein the layer of transparent conductive material is interposed between the touch sensor layer and the color filter layer.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to tape-based grounding structures in electronic devices. 
     Electronic devices such as computers and cellular telephones have displays, conductive housings, and other conductive structures. It may sometimes be desirable short together conductive electronic device structures. For example, it may be desirable to ground a display to a conductive housing wall to reduce electromagnetic interference. 
     Conventional grounding structures may consume more volume than desired and may require the use of screws and complex metal structures. 
     It would therefore be desirable to be able to provide improved conductive structures for electrically coupling structures in an electronic device. 
     SUMMARY 
     An electronic device may have a display mounted in a housing. The housing may have conductive walls and internal housing structures such as planar metal structures. Planar internal housing structures may form a mid-plate member having one or more sheet metal structures. 
     The display may have a conductive touch sensor layer such as an array of capacitive touch sensor electrodes. The display may have display layers such as a color filter layer, a thin-film transistor layer, and polarizer layers. Display layers may be mounted in a display chassis that includes a plastic chassis structure and a metal chassis structure. A display layer may have a conductive surface such as an indium tin oxide surface. 
     The electronic device may include conductive tape having opposing inner and outer surfaces. The conductive tape may include conductive fibers embedded in adhesive or other structures for providing the conductive tape with three-dimensional conductivity. Conductive tape with three-dimensional conductivity may be used to short the touch sensor to the metal chassis structure and to a metal shielding can associated with an integrated circuit. Conductive tape may also be used to short the conductive surface of the display layer to the internal metal housing structure or other conductive structures within an electronic device. 
     Segments of conductive tape may run along each of the four edges of a display and may overlap at corners of the display. Foam may be used to short the segments of conductive tape to adjacent portions of the conductive housing walls. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with tape-based grounding structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a cross-sectional side view of illustrative electronic device display structures in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of conductive tape that includes adhesive and conductive fibers embedded in the adhesive and that exhibits three-dimensional conductivity in accordance with an embodiment of the present invention. 
         FIG. 4  is a cross-sectional side view of illustrative conductive tape that include layers of conductive fibers embedded in adhesive on opposing sides of a conductive layer such as a metal layer and that exhibits three-dimensional conductivity in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an electronic device structure that has been wrapped with an L-shaped tape-based grounding structure in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of an electronic device structure that has been wrapped with a C-shaped tape-based grounding structure in accordance with an embodiment of the present invention. 
         FIG. 7  is a perspective view of an illustrative device structure such as a display that has been wrapped on four peripheral edges with C-shaped and L-shaped tape-based grounding structures in accordance with an embodiment of the present invention. 
         FIG. 8  is a top view of an interior portion of an electronic device in which tape-based grounding structures have been used to ground display structures to a conductive housing in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional side view of an edge portion of illustrative electronic device with display structures and tape-based grounding structures in accordance with the present invention. 
         FIG. 10  is a cross-sectional side view of another edge portion of an illustrative electronic device with display structures and tape-based grounding structures in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Conductive tape-based grounding structures may be formed from conductive tape that exhibits substantial conductivity in three dimensions. This type of conductive tape may be formed, for example, from conductive fibers embedded in adhesive or from layers of fiber-based conductive structures on the surfaces of a sheet of metal or other carrier (as examples). Conductive tape that exhibits conductivity in three dimensions (i.e., orthogonal dimensions X, Y, and Z) may, if desired, exhibit substantially equal conductivity in each of these three dimensions and may sometimes be referred to as three-dimensionally conductive tape or XYZ-axis electrically conductive tape. 
     An illustrative electronic device of the type that may be provided with a conductive tape structures is shown in  FIG. 1 . Electronic device  10  may be a computer such as a computer that is integrated into a display such as a computer monitor, a laptop computer, a tablet computer, a somewhat smaller portable device such as a wrist-watch device, pendant device, or other wearable or miniature device, a cellular telephone, a media player, a tablet computer, a gaming device, a navigation device, a computer monitor, a television, or other electronic equipment. 
     As shown in  FIG. 1 , device  10  may include a display such as display  14 . Display  14  may be a touch screen that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components or may be a display that is not touch-sensitive. Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic display pixels, an array of plasma display pixels, an array of organic light-emitting diode display pixels, an array of electrowetting display pixels, or display pixels based on other display technologies. Configurations in which display  14  includes liquid crystal display (LCD) components may sometimes be described herein as an example. This is, however, merely illustrative. Display  14  may include display pixels formed using any suitable type of display technology. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass or clear plastic. Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button such as button  16 . An opening may also be formed in the display cover layer to accommodate ports such as speaker port  18 . 
     Device  10  may have a housing such as housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. 
     Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). The periphery of housing  12  may, if desired, include conductive walls. For example, housing  12  may have a peripheral conductive member such as a metal housing sidewall member that runs around some or all of the periphery of device  10  or a display bezel that surrounds display  14 . One or more openings may be formed in housing  12  to accommodate connector ports, buttons, and other components. 
     A cross-sectional side view of electronic device structures associated with display  14  is shown in  FIG. 2 . As shown in  FIG. 2 , display  14  may include display backlight structures  20 , display structures  38 , and optional touch sensor layer  40 . Touch sensor layer  40  may be formed from an array of transparent conductive capacitive touch sensor electrodes such as indium tin oxide electrodes. A display cover layer such as a layer of glass or plastic may be used to cover the surface of display  14  (e.g., the front face of device  10  of  FIG. 1 ). The conductive structures of touch sensor layer  40  may be formed on the cover layer, may be formed on a touch sensor substrate such as a layer of glass or plastic, or may be formed on other layers of display  14 . 
     Display backlight structures  20  may include a light guide plate, a reflector, and optical films. The light guide plate may be formed from a rectangular planar layer of plastic. Light  24  that is emitted from light-emitting diode array  22  may be coupled into the light guide plate through the edge of the light guide plate. Light  24  may be distributed laterally throughout display  14  due to the principal of total internal reflection. Light such as light  26  that scatters vertically upwards through backlight structures  20  may pass through display layer  38  (and touch sensor array layer  40 ) and may serve as backlight that helps a user such as user  380  to view images on display  14 . The reflector in backlight structures  20  may be located below the light guide plate and may be used to direct light that has escaped from the light guide plate in the downwards direction back up in upwards direction  26 , thereby enhancing backlight efficiency. Optical films such as brightness enhancing films, diffusing films, and other films may be included in backlight structures  20  (e.g., above the light guide plate), if desired. 
     Display structures  38  may include liquid crystal display structures or structures associated with other suitable types of display. In an illustrative liquid crystal display configuration, a layer of liquid crystal material may be sandwiched between color filter layer  32  and thin-film transistor layer  34 . Layer  32  may contain an array of color filter elements for providing display  14  with the ability to display color images for viewer  38 . Layer  34  may contain an array of display pixels electrodes. The display pixel electrodes may be used to impose electric fields on portions of the liquid crystal layer, thereby creating an image on display  14 . Thin-film transistor circuitry on layer  34  may be used to route control signals from a display driver circuit (e.g., a display driver integrated circuit) to display pixel thin-film transistors and electrodes on layer  34 . Layers  32  and  34  may be sandwiched between upper polarizer layer  30  and lower polarizer layer  36 . 
     One or more chassis structures such as chassis structures  42  may be used in forming display  14 . Chassis structures  42  may include a plastic chassis structure (sometimes referred to as a p-chassis) and/or a metal chassis structure (sometimes referred to as an m-chassis). These chassis structures may be used in supporting the structures of display  14  such as backlight light source  22 , backlight structures  20 , and other display layers such as display layers  38 . 
     Device  10  may include radio-frequency transceiver circuitry (e.g., wireless circuitry for transmitting and receiving wireless data), display driver circuitry, processing circuitry, application-specific integrated circuits, clock circuits, and other circuitry. If care is not taken, there is a potential for electromagnetic interference to disrupt the operation of circuits such as these. For example, if a display is not properly grounded, interference from a display driver circuit, display timing circuitry, or other circuitry associated with a display may adversely affect the operation of a sensitive circuit such as a wireless receiver. 
     To ensure that display structures in device  10  are grounded to conductive housing structures and to ensure that other conductive structures in device  10  are properly shorted to each other to mitigate the effects of potentially harmful electromagnetic interference, device  10  may be provided with tape-based conductive structures. The tape-based conductive structures and associated grounding structures such as conductive foam structures may be used in electrically coupling respective conductive structures within electronic device  10 . Tape-based structures such as structures based on three-dimensionally conductive tape may be used, for example, to suppress electromagnetic interference that might otherwise be produced by display structures of the type shown in  FIG. 2 , thereby helping to ensure that wireless circuitry and other sensitive circuitry in device  10  are not adversely affected. 
     As shown in the cross-sectional diagram of  FIG. 3 , conductive tape for tape-based grounding structures in device  10  may be formed from conductive fibers  46  embedded in adhesive  48 . Conductive fibers  46  may include metal fibers, dielectric fibers coated with metal, or other conductive fibers. Adhesive  48  may be, for example, pressure sensitive adhesive. Tape  44  may be characterized by a thickness T and a width (in dimension X) and a length (in dimension Y). The thickness T may be relatively small to help accommodate tape  44  in compact portable electronic devices. For example, thickness T may be less than 0.5 mm, less than 0.2 mm, less than 0.1 mm, or less than 0.05 mm (as examples). The length and width of tape  44  may be, for example, in the range of 0-1 mm or more, 1 cm or more, 10 cm or more, or 100 cm or more (as examples). Tape  44  may exhibit three-dimensional conductivity (i.e., tape  44  may be characterized by substantial conductivity and, if desired, substantially equal conductivity, in the X, Y, and Z dimensions). 
     If desired, tape  44  may include a layer of conductor such as metal layer  50  of  FIG. 4 . In the configuration of  FIG. 4 , tape  44  includes upper fiber-based conductive layer  44 T of thickness T 1 , metal layer  44 M of thickness T 3 , and lower fiber-based conductive layer  44 M of thickness T 2 . The values of T 1 , T 2 , and T 3  may be less than 0.5 mm, less than 0.2 mm, less than 0.1 mm, or less than 0.05 mm (as examples). Layers  44 T and  44 B may include conductive fibers  46  embedded in pressure sensitive adhesive  48 . Layer  44 M may be formed from a sheet of copper, gold, or other metals (as an example). 
     Using tape structures such as the illustrative structures used in forming tape  44  of  FIGS. 3 and 4 , tape  44  may exhibit significant conductivity in three orthogonal dimensions: dimension X, dimension Y, and dimension Z. Because tape  44  such as tape  44  of  FIGS. 3 and 4  is conductive in three dimensions, tape  44  may sometimes be referred to as XYZ tape or as tape that exhibits three-dimensional conductivity. 
     Tape  44  may be wrapped around the edges of display structures and other structures in device  10 . As an example, tape  44  may be used in forming a C-shaped edge wrap about structures  50  of  FIG. 5  or an L-shaped edge wrap about structures  50  of  FIG. 6 . If desired, tape  44  may be wrapped about device structures to form other cross sectional shapes. The illustrative L shape of  FIG. 5  and the illustrative C shape of  FIG. 6  are provided as examples. Structures  50  may include housing structures and internal device components and may include conductive structures in device  10  such as display structures  14 . Examples of conductive structures that may be wrapped with tape  44  and that may be shorted to tape  44  include display structures (e.g., a conductive touch sensor layer, a conductive m-chassis structure, etc.), conductive housing structures, and other conductive structures in device  10 . 
       FIG. 7  is a perspective view of illustrative structures  52  having wrapped tape  44  for forming conductive tape-based electrical shorting structures (e.g., conductive tape-based grounding structures). Structures  52  may be, for example, device structures such as device structures  50  of  FIGS. 5 and 6 . For example, structures  52  may be display structures such as some or all of the structures in display  14  of  FIG. 4  (e.g., a display module). Structures  52  may include conductive layers such as a conductive touch sensor layer, a conductive coating such as an indium tin oxide layer on a color filter layer or other display layer, a conductive m-chassis structure, a p-chassis structure, and other display structures. Conductive materials in structures  52  may be shorted to each other and to other conductive structures in device  10 . For example, conductive tape  44  may be used to ground conductive materials in structures  52  to each other and to conductive housing structures and other conductive device structures to reduce the susceptibility of device  10  to electromagnetic interference. 
     Structures  52  may have a rectangular outline with four edges E 1 , E 2 , E 3 , and E 4  (as an example). Tape  44  may be wrapped around structures  52 . As shown in  FIG. 7 , tape  44  may extend along each of the four edges of structures  52 . Wrapped tape on structures  52  may be formed from a single piece of tape  44  or from two or more segments of tape  44 . In the example of  FIG. 7 , a segment of tape  44  having an L-shaped cross section has been formed along edge E 1  and a segment of tape  44  having a C-shaped cross section has been formed along opposing edge E 2 . Edges E 1  and E 2  may be associated with the opposing ends of an elongated rectangular display or other structures  52 . L-shaped segments of tape  44  may be formed along opposing edges E 3  and E 4  (e.g., side edges). Other combinations of L-shaped tape segments, C-shaped tape segments, and tape structures with other configurations may be used. The configuration of  FIG. 7  is merely illustrative. 
     Portions of tape  44  of  FIG. 7  may overlap. For example, portions of tape  44  may overlap in corners such as corners  54 . As an example, portion  56  of tape  44  along edge E 4  may overlap and electrically connect to portion  58  of tape  44  along edge E 2 . Tape  44  may also overlap in corners  60 , as indicated by dashed lines  62  or, if desired, corners  60  may be free of overlapping tape  44 . When tape  44  overlaps in all four corners of rectangular display structures (e.g., structures  52  of  FIG. 7 ), tape  44  may help surround and ground structures  52  without the need for an m-chassis that completely surrounds display structures  52 . The elimination of metal associated with forming a complete rectangular ring-shaped m-chassis for display structures  52  by using four segments of tape  44  may help minimize device size for device  10 . 
       FIG. 8  is a top view of structures  52  along an edge (e.g., edge E 3 ) of structures  52  of  FIG. 7  when installed in device  10 . As shown in  FIG. 8 , conductive foam  64  and tape  44  may be used in electrically connecting structures  52  to housing  12 . Housing  12  may be, for example, a conductive wall of housing  12  of device  10  in  FIG. 1  (e.g., a metal sidewall). Conductive foam  64  may be a gasket formed from foam covered with a conductive fabric or may be other conductive grounding structures. Foam structures such as conductive foam  64  of  FIG. 8  may be used along one or more of the edges of structures  52 . For example, the four edges of a display may be shorted to four corresponding edges of a conductive metal housing such as housing  12  using segments of tape  44  and corresponding foam members  64  or foam members  64  may be used only on the left and right edges of device  10  (as examples). 
       FIG. 9  is a cross-sectional view of a portion of electronic device  10  showing how the structures of display  14  may be wrapped using tape  44 . The cross-sectional side view of  FIG. 9  is taken along lines  66  of  FIG. 7  and is viewed in direction  68 . As shown in  FIG. 9 , housing  12  may include an internal housing structure such as metal member  12 M. Metal member  12 M may be formed from one or more metal structures such as stainless steel sheet metal structures. Member  12 M may have a planar shape and may sometimes be referred to as a mid-plate member. Housing structure  12 M may be shorted to conductive tape  44  using pressure sensitive adhesive  72  (e.g., conductive pressure sensitive adhesive). Pressure sensitive adhesive  72  may be separate from tape  44  or may form part of tape  44  (see, e.g., adhesive  48  of  FIGS. 3 and 4 ). Conductive tape  44  may be wrapped around an edge of display  14  (e.g., using a C-shaped wrap). 
     Display  14  may include a plastic chassis structure such as p-chassis  42 P. Display structures such as display layers  38 - 1  and  38 - 2  may be mounted on p-chassis structure  42 P. Display layers in display  14  such as illustrative layers  38 - 1  and  38 - 2  may include a color filter layer, a thin-film transistor layer, polarizer layers, and a touch sensor layer (as examples). As an example, upper layer  38 - 1  may be a color filter layer having a conductive coating layer such as a blanket layer of indium tin oxide (ITO). The conductive surface of layer  38 - 1  may be shorted to conductive tape  44 . Conductive tape  44  can ground display layer  38 - 1  to conductive housing structure  12 M using conductive pressure sensitive adhesive  72 . Conductive adhesive  72  may be separate from tape  44  or may be part of the adhesive in which conductive tape fibers  46  is embedded such as adhesive  48  of  FIGS. 3 and 4 . 
     Display  14  may include backlight structures  20  such as reflector  20 R. Reflector  20 R may be formed from a metal coating on a sheet of plastic or a reflective plastic coating on a sheet of plastic (as examples). Reflector  29 R may be attached to p-chassis  42 P using pressure sensitive adhesive  70 . 
     As shown in  FIG. 9 , the conductive outer surface of display layer  38 - 1  may be shorted to the inner surface of tape  44  that is facing the conductive outer surface of display layer  38 - 1 , whereas the opposing outer surface of tape  44  that is facing internal metal housing structure  12 M may be shorted to the internal metal housing structure  12 M (e.g., through conductive adhesive structure  72 ). Because tape  44  may exhibit three-dimensional conductivity, tape  44  may form an electrical pathway between display layer  38 - 1  and internal housing structure  12 M that passes through tape  44  from one side to the other (e.g., from the inner surface of tape  44  to the outer surface of tape  44 ). 
       FIG. 10  is a cross-sectional view of display structures  52  of  FIG. 7  taken along lines  74  of  FIG. 7  and viewed in direction  76  and associated portions of device  10 . As shown in  FIG. 10 , display  14  of device  10  may include a cover layer such as display cover layer  78 . Display cover layer  78  may be formed from a layer of clear glass, a transparent plastic sheet, or other clear structure. Display cover layer  78  may be mounted to housing  12  using adhesive  80 . 
     The underside of display cover layer  78  may be covered with a conductive touch sensor layer such as an array of indium tin oxide capacitive touch sensor electrodes (touch sensor array  40 ). Touch sensor layer  40  may be formed from structures that are deposited on cover layer  78  (i.e., that use cover layer  78  as a substrate) and/or separate substrate layers (e.g., a flexible substrate layer such as a sheet of polyimide). Other configurations may be used for implementing touch sensor capabilities in device  10 , if desired. The configuration of  FIG. 10  in which touch sensor layer  40  is mounted adjacent to the underside of display cover layer  98  is merely illustrative. 
     As shown in  FIG. 10 , tape  44  may have an outer surface that faces the underside of cover layer  78  and touch sensor layer  40 . Tape  44  may be attached directly to touch sensor layer  40  or touch sensor layer  40  may be shorted to tape  44  using conductive foam  82  (e.g., a layer of foam covered with conductive fabric). Foam  82  may be attached between tape  44  and touch sensor array layer  40  using adhesive  84  (e.g., conductive adhesive). Adhesive  84  may be separate from tape  44  or may be part of the adhesive in which conductive fibers  46  of tape  44  are embedded (i.e., adhesive  48  of  FIGS. 3 and 4 ). Display driver integrated circuit  86  may be mounted on thin-film transistor layer  34  in display layers  38 . Color filter layer  32  may be mounted above thin-film transistor layer  34 . A layer of liquid crystal material may be interposed between layers  32  and  34 . Layers  32  and  34  may be sandwiched between polarizer layers  30  and  36 . 
     Light-emitting diode array  22  may be used to emit backlight into edge  88  of the light guide plate in backlight structures  20 . Backlight structures  20  may be mounted to m-chassis  42 M. M-chassis  42 M may be attached to p-chassis  42 P of  FIG. 9  (e.g., by injection molding p-chassis  42 P over M-chassis  42 M at the corners of device  10 ). 
     Light-emitting diode array  22  may be mounted on a substrate such as substrate  90 . Substrate  90  may be formed from a rigid printed circuit board material (e.g., fiberglass-filled epoxy material such as FR4) or a flexible printed circuit substrate material such as polyimide or a sheet of other flexible polymer. Substrate  90  may be mounted on m-chassis structures  42 M. 
     Pressure sensitive adhesive  92  may be used to mount printed circuit  94  (e.g., a rigid or flexible printed circuit) to m-chassis  42 M. A display timing integrated circuit for supporting the operation of display  14  may be mounted to printed circuit  94  within conductive radio-frequency shielding structure  96 . Shielding structure  96  may be a rectangular metal shielding can that is grounded to traces on printed circuit  94 . Conductive tape  44  may be used in electrically coupling (grounding) touch sensor layer  40  to ground structures in device  10  (e.g., housing walls  12 , m-chassis  42 M, shielding can  96 , and, if desired, mid-plate  12 M or other metal housing structures). 
     As shown in  FIG. 10 , touch sensor layer  40  may be shorted to the outer surface of tape  44  that faces layer  40  under foam  82 , whereas the inner surface of tape  44  may be shorted to the vertical portion of m-chassis  42 M that is facing the inner surface of tape  44 . The inner surface of tape  44  may also have a portion that faces the lower surface of shielding can  96 , so that tape  44  may be shorted to the lower surface of shielding can  96 . Because tape  44  may exhibit three-dimensional conductivity, tape  44  may form an electrical pathway between touch sensor layer  40  and m-chassis  42 M (and between layer  40  and shielding structure  96 ) that involves signal paths between the opposing inner and outer surfaces of tape  44 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20120621
Publication Date: 20170718
Grant Date: 20170718
Priority Date: 20120621
Inventors: RAPPOPORT BENJAMIN M.
QIAN AMY
AI JIANG
FRANKLIN JEREMY C.
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K9/0054", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K9/0054", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 49774031