PATENT DOCUMENT

Publication Number: US-9658479-B2
Application Number: US-201314104298-A
Country: US
Kind Code: B2

Title: Electronic device with display backlight unit and display assembly

Abstract:
An electronic device may be provided with electrical components mounted in an electronic device housing. A display module may be attached to a display cover layer with a layer of adhesive to form a display module assembly. The display module assembly may include a display module assembly chassis. The display module assembly chassis may include a plastic display module assembly chassis molded over a metal display module assembly chassis. The display module assembly and a backlight unit may be assembled to form a display module that is installed within the electronic device housing or display module assembly layers and backlight unit structures may be assembled into the electronic device housing. The backlight unit may include a backlight unit chassis. A metal housing midplate may serve as part of the backlight unit chassis.

Claims:
What is claimed is: 
     
       1. A method of forming an electronic device, comprising:
 forming a display module assembly by attaching a glass display cover layer to a liquid crystal display module; 
 forming a backlight unit having a backlight unit chassis, wherein the backlight unit chassis comprises plastic chassis structures molded over a metal midplate member; 
 attaching the backlight unit to the display module assembly to form a display assembly; and 
 mounting the display assembly in an electronic device housing. 
 
     
     
       2. The method defined in  claim 1  wherein forming the backlight unit comprises forming the backlight unit at least partly from the metal midplate member. 
     
     
       3. The method defined in  claim 2  wherein attaching the liquid crystal display module to the glass display cover layer comprises attaching the liquid crystal display module to the glass display cover layer with a layer of adhesive. 
     
     
       4. The method defined in  claim 3  wherein the display module assembly includes a display module assembly chassis and wherein assembling the backlight unit and the display module assembly comprises using screws to attach the metal midplate member in the backlight unit and the display module assembly chassis. 
     
     
       5. The method defined in  claim 1  wherein forming the display module assembly comprises incorporating a display module assembly chassis into the display module assembly. 
     
     
       6. The method defined in  claim 5  wherein assembling the backlight unit and the display module assembly to form the display assembly comprises attaching the display module assembly chassis to the backlight unit chassis. 
     
     
       7. The method defined in  claim 6  wherein mounting the display assembly in the electronic device housing comprises attaching the backlight unit chassis to walls in the electronic device housing. 
     
     
       8. The method defined in  claim 7  wherein attaching the backlight unit chassis to the walls in the electronic device housing comprises attaching the metal midplate member to the walls in the electronic device housing. 
     
     
       9. A method of forming an electronic device, comprising:
 forming a display backlight unit chassis by molding plastic chassis structures over a metal midplate member; 
 forming a display backlight unit from the display backlight unit chassis; 
 attaching the metal midplate member to walls in an electronic device housing; 
 placing a foam gasket on the display backlight unit so that the display backlight unit is interposed between the metal midplate member and the foam gasket; and 
 mounting a display module in the electronic device housing such that the foam gasket is interposed between the display module and the display backlight unit, wherein the foam gasket surrounds an air gap that separates the display backlight unit and the display module. 
 
     
     
       10. The method defined in  claim 9  wherein forming the display backlight unit comprises:
 mounting a reflector in the display backlight unit chassis; 
 placing a light guide plate on top of the reflector without flipping over the display backlight unit chassis; and 
 placing optical films on top of the light guide plate without flipping over the display backlight unit chassis. 
 
     
     
       11. The method defined in  claim 10  wherein mounting the display module comprises mounting a liquid crystal display module in the electronic device housing. 
     
     
       12. Apparatus, comprising:
 a backlight unit; 
 a display module assembly having an active area and an inactive area, wherein the display module assembly is formed from a display cover layer that is attached to a display module and overlaps the active area and the inactive area; 
 a foam gasket interposed between the backlight unit and the display module assembly, wherein the foam gasket surrounds an air gap that separates the backlight unit and the display module assembly; and 
 a housing in which the backlight unit, the foam gasket, and the display module assembly are mounted. 
 
     
     
       13. The apparatus defined in  claim 12  wherein backlight unit comprises a metal midplate that provides structural support for the housing. 
     
     
       14. The apparatus defined in  claim 13  wherein the backlight unit comprises:
 a backlight unit chassis that includes the metal midplate; and 
 a light guide plate in the backlight unit chassis. 
 
     
     
       15. The apparatus defined in  claim 14  wherein the backlight unit chassis comprises plastic chassis structures that are molded over portions of the metal midplate. 
     
     
       16. The apparatus defined in  claim 15  wherein the housing comprises metal walls, the apparatus further comprising welds that attach the metal midplate to the metal walls. 
     
     
       17. The apparatus defined in  claim 16  wherein the foam gasket comprises a polymer foam. 
     
     
       18. The apparatus defined in  claim 17  wherein the display module comprises a liquid crystal display layer. 
     
     
       19. The apparatus defined in  claim 18  wherein the display module assembly further comprises a display module assembly chassis wherein at least part of the display module assembly chassis is interposed between the display cover layer and the display module.

Description:
This application claims priority to U.S. provisional patent application No. 61/759,153 filed Jan. 31, 2013, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with displays. 
     Electronic devices often have displays. Displays may be protected using cover glass layers. For example, a cover glass layer may be attached to the front of a liquid crystal display module to prevent layers in the liquid crystal display module from becoming damaged. A backlight unit that provides the liquid crystal display module with backlight is attached to the liquid crystal display module with a strip of adhesive. During assembly, the liquid crystal display module and the attached display cover layer and backlight unit may be mounted within a device housing. The housing may be strengthened using a metal midplate that is separated from the backlight unit by an air gap. 
     Challenges arise when mounting components such as display components in an electronic device. If care is not taken, the display components may be overly bulky or may be characterized by excessively wide inactive border regions. 
     It would therefore be desirable to be able to provide electronic devices with improved display arrangements. 
     SUMMARY 
     An electronic device may be provided with electrical components mounted in an electronic device housing. The electronic device may have a display such as a liquid crystal display. The liquid crystal display may be formed from a liquid crystal display module having polarizers, a thin-film transistor layer, a color filter layer, and a layer of liquid crystal material. 
     The display module may be attached to a display cover layer with a layer of adhesive to form a display module assembly. The display module assembly may include a display module assembly chassis. The display module assembly chassis may include a plastic display module assembly chassis molded over a metal display module assembly chassis. 
     The display module assembly and a separate backlight unit may be assembled to form a display module. The display module may be installed within the electronic device housing attachment mechanisms such as welds or fasteners. Display module assembly layers and backlight unit structures may also be assembled directly into the electronic device housing without forming the display module. 
     The backlight unit may include a backlight unit chassis. The backlight unit chassis may have plastic portions molded over metal portions. The metal portions may be used in forming structural elements for the electronic device housing. For example, the metal backlight unit chassis portions may be formed from a metal housing midplate that serves both as part of the backlight unit chassis and as a structural portion of the electronic device housing that resists twisting of the electronic device housing during use. 
     Further features, their 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 of the type that may be provided with display structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a cross-sectional side view of a portion of an electronic device with a display in accordance with an embodiment of the present invention. 
         FIG. 3  is a flow chart of illustrative steps involved in forming electronic devices with backlit displays in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device that may be provided with a display is shown in  FIG. 1 . Electronic devices such as device  10  of  FIG. 1  may be cellular telephones, media players, other handheld portable devices, somewhat smaller portable devices such as wrist-watch devices, pendant devices, or other wearable or miniature devices, gaming equipment, tablet computers, notebook computers, desktop computers, televisions, computer monitors, computers integrated into computer displays, or other electronic equipment. 
     In the example of  FIG. 1 , device  10  includes a display such as display  14 . Display  14  has been mounted in 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.). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     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 electrowetting display pixels, or display pixels based on other display technologies. The brightness of display  14  may be adjustable. For example, display  14  may include backlight structures formed from a light source such as a lamp or light-emitting diodes that can be used to increase or decrease display backlight levels and thereby adjust display brightness. 
     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 . 
     Display  14  may contain an array of active display pixels within rectangular region  20 . This region may sometimes be referred to as the active area of the display. As shown in  FIG. 1 , active area AA may be surrounded by inactive display areas IA that do not contain any active display pixels. Inactive areas IA may be formed on the upper and lower edges of display  14  and/or on the right and left sides of display  14 . In the  FIG. 1  example, inactive areas IA form a rectangular ring-shaped region that surrounds the periphery of active display region AA. The display cover layer and/or other display layers in display  14  may be provided with opaque masking structures in the inactive region to hide internal components from view by a user. For example, the underside of a display cover layer in inactive region IA may be coated with a layer of black or white ink. 
     A cross-sectional side view of device  10  and display  14  is shown in  FIG. 2 . As shown in  FIG. 2 , display  14  and additional components such as components  72  may be mounted in electronic device housing  12 . 
     Electronic device housing  12  may be formed from plastic, metal, glass, ceramic, fiber-based composites, other materials, and combinations of these materials. As an example, housing  12  may include metal sidewall structures such as vertical metal walls or other suitable housing structures. The metal walls may run around the periphery of electronic device housing  12  and may sometimes be referred to as a peripheral metal band or peripheral conductive housing structures. 
     Components  72  may be electrical components such as integrated circuits, connectors, batteries, discrete devices such as resistors, capacitors, and inductors, switches, and other electronic devices. Components  72  may be mounted to one or more substrates such as substrate  74 . Substrate  74  may be coupled to additional substrates in device  10  using connectors, cables, flexible printed circuit paths, and other interconnect pathways. Substrates such as substrate  74  may be formed from molded plastic, ceramic, glass, or printed circuits (as examples). For example, substrates such as substrate  74  may be formed from rigid printed circuit boards (e.g., printed circuits formed from rigid layers of material such as fiberglass-filled epoxy) or flexible printed circuits (e.g., flexible sheets of polyimide or other flexible layers of polymer). 
     Electrical components such as components  72  may be electrically connected to conductive paths in substrates such as substrate  74 . The conductive paths in substrates such as substrate  74  may sometimes be referred to as lines, traces, or interconnects and may be formed from conductive materials such as metal (e.g., copper, gold, aluminum, etc.). Using these printed circuit paths, components  72  may be interconnected with each other and may be interconnected with other components in device  10  such as display  14 . 
     Display  14  may include active display pixels in active area AA and may be devoid of active display pixels in inactive area IA. Display  14  may include layers such as display cover layer  30 . Display cover layer  30  may be formed from a clear layer of glass, a transparent plastic layer, or other transparent material. Display cover layer  30  may have the shape of a planar rectangular member or may have other shapes such as shapes with a curved cross-sectional profile and/or a footprint with curved edges. 
     Display module  26  may be attached to the underside of display cover layer  30  using adhesive layer  32  (e.g., a layer of optically clear adhesive or other suitable adhesive). In inactive area IA, opaque masking material  56  may be formed on the underside of display cover layer  30 . Opaque masking material  56  may be formed from an opaque material such as black ink, white ink, substances with colors other than black or white, metal, opaque metal oxides, combinations of these substances, or other opaque material. The layers of display module  26  may also be provided with a peripheral strip of opaque masking material such as opaque masking material  70 . 
     Display module  26  may be a liquid crystal display module or may be a display module based on other display technologies. Touch screen functionality may be incorporated into display module  26  if desired (e.g., by providing display module  26  with an array of transparent capacitive touch sensor electrodes such as electrodes formed from indium tin oxide). In the  FIG. 2  example, display module  26  is a liquid crystal display module having a layer of liquid crystal material such as liquid crystal layer  40 . Liquid crystal layer  40  is sandwiched between an upper display layer such as color filter layer  36  and a corresponding lower display layer such as thin-film transistor layer  38 . 
     Color filter layer  36  may be used to provide display  14  with the ability to display color images. Color filter layer  36  may have a substrate formed from clear glass, transparent plastic, or other clear substrate material. An array of color filter elements such as red, green, and blue polymer color filter elements may be formed on the underside of color filter layer  36 . 
     Thin-film transistor layer  38  may have a substrate formed from a layer of clear glass, a sheet of transparent plastic, or other clear substrate layer. The upper surface of thin-film transistor layer  38  may have a layer of thin-film transistor circuitry that includes thin-film transistors and electrodes. Using the thin-film transistors, the electrodes may be used to adjust the strength of electric fields applied to the array of display pixels in active area AA. 
     Backlight unit  22  may be used to provide backlight  76  that travels upwards through display module  26  in direction Z to viewer  78 . The layers of display module  26  such as color filter layer  36 , thin-film transistor layer  38 , and interposed liquid crystal layer  40  may be sandwiched between polarizer layers such as upper polarizer  34  and lower polarizer  42 . During operation of display  14 , adjustments to the electric fields supplied by the electrodes in thin-film transistor layer  38  can be used to create changes to liquid crystal layer  40  that rotate the polarization of light  76  by corresponding amounts. The rotation of the polarization of light  76  in combination with the presence of upper and lower polarizers  34  and  42  adjusts the amount of light  76  that is transmitted to viewer  78 . This allows display  14  to be used to display images to viewer  78 . 
     If desired, opaque masking material  70  may be provided between the substrates associated with color filter layer  36  and thin-film transistor layer  38 . For example, opaque masking material may be provided on the underside of color filter layer  36 . 
     Display module  26  may be attached to display cover layer  30  to form display module assembly  24 . Display module assembly chassis structures  80  may be attached to display structures such as display cover layer  30  and/or display module  26  in display module assembly  24 . For example, display module chassis structures  80  may be attached to display cover layer  30  and/or display module  26  using adhesive, fasteners, or other mounting structures and/or by configuring display module assembly chassis structures. Display module assembly chassis structures  80  may be formed from plastic, glass, ceramic, metal, fiber-based materials, other materials, or combinations of these materials. As an example, display module assembly chassis  80  may be formed by molding plastic ring  58  over metal legs  60 . There may be any suitable number of legs  60  around the rectangular periphery of display  14 . For example, there may be two, three, or more than three chassis legs  60  on each edge of display  14 . Holes may be provided in legs  60  to accommodate screws or other fastening structures. 
     Display structures such as display cover layer  30 , display module chassis  80 , and display module  26 , which form display module assembly  24 , may sometimes be collectively referred to as a cover glass frame. During assembly operations, the structures of display module assembly  24  and the structures of backlight structures  22  may be assembled directly into device housing  12  without prior coupling of these components to form an assembly. If desired, display module assembly  24  and backlight unit  22  may also be assembled together to form a unitary structure such as display assembly  82  of  FIG. 2  that is then mounted within housing  12 . 
     Backlight structures  22 , which may sometimes be referred to as a backlight unit, may include reflector  52  and light guide plate  50 . Light guide plate  50  may be formed from a clear sheet of material such as a layer of transparent plastic. Light-emitting diodes or other light sources may be used to launch light into one or more of the peripheral edges of light guide plate  50 . The light that is launched into light guide plate  50  in this way propagates laterally throughout light guide plate  50  due to the principal of total internal reflection. Light guide plate  50  may include pits, bumps, or other light scattering features to enhance light scattering in direction Z. Reflector  52 , which may be formed from a sheet of white plastic or other reflective material may be used to increase backlight efficiency by reflecting rays of light that have escaped from light guide plate  50  in a downwards direction back upwards in direction Z. 
     Optical films  28  may be incorporated into backlight unit  22  to help improve the quality of the backlight produced by light guide plate  50  and reflector  52 . Optical films  28  may, as an example, include one or more, two or more, or three or more layers such as layers  48  and  46  for improving the homogeneity and directionality of emitted backlight  76 . Examples of optical films  28  include diffuser films and brightness enhancement films (sometimes referred to as turning films or prism films). 
     Backlight unit layers such as optical films  28 , light guide plate  50 , and reflector  52  may be mounted within a chassis such as backlight unit chassis  84 . Backlight unit chassis  84  may be formed from plastic, metal, fiber-based composites, glass, ceramic, or other suitable material. As an example, backlight unit chassis  84  may be formed from one or more metal structures such as metal plate  54  and one or more plastic structures such as plastic chassis structure  64 . Plastic chassis structures  64  may be attached to metal plate  54  using adhesive, screws or other fasteners, or other attachment mechanisms. As an example, plastic chassis structures  64  may be molded to metal plate  54  using plastic molding equipment such as plastic injection molding equipment. 
     After forming backlight unit chassis  84 , the layers of backlight unit  22  may be assembled into backlight unit chassis  84 . As an example, backlight unit chassis  84  may be configured to form a recessed rectangular support structure (e.g., a rectangular recess) into which display backlight unit layers such as reflector  52 , light guide plate  50 , and optical films may be placed in succession. During backlight unit assembly operations, backlight unit chassis  84  may be maintained in an upright position (as shown in  FIG. 2 ) without flipping over backlight unit chassis  84 . 
     Device  10  may be provided with structural strength and rigidity using internal sheet metal structures. These internal sheet metal structures may individually or collectively span the width (and, if desired, the length) of housing  12 . The internal sheet metal structures may, as an example, be formed from one or more thin metal plate structures (e.g., a metal sheet with a thickness of less than 1 mm, less than 0.5 mm, or less than 0.3 mm) that run across device  10  in a position that is vertically roughly midway between the outer surface of display cover layer  30  and the rear surface of housing  12 . Because of this illustrative position in the middle of device  10 , the internal sheet metal structures that are used in providing device  10  with structural support may sometimes be referred to as midplate structures, a housing midplate, or a housing midplate member. If desired, the housing midplate may be formed from multiple stamped metal structures that are attached to each other through overmolded plastic structures, provided that the resulting midplate is able to provide device  10  with structural support. Once the midplate has been properly attached to housing structures such as the left and right housing walls of housing  12 , the tendency of housing  12  to twist during use will be minimized. 
     To avoid incorporation of excessively bulky structures into device  10 , device  10  may be provided with a midplate that is also used as part of backlight unit  22 . In particular, metal plate  54  may serve as both a housing midplate that stabilizes device  10  and housing  12  against undesirable twisting and as the lower support surface for the layers of display backlight unit  22  in display backlight unit chassis  84 . By using metal plate  54  both as a housing midplate and as a part of backlight unit chassis  84 , the thickness of device  10  can be reduced and/or additional components  72  can be incorporated into the interior of device  10  without need to adjust the overall thickness of device  10 . 
     As shown in  FIG. 2 , display module chassis  80  and the other portions of display module assembly  24  may be attached to midplate  54  of display backlight unit  22  and to housing  12  using attachment structures  66 . Attachment structures  66  may be welds, solder, screws, clips, rivets, or other fasteners, overmolded plastic, or other connection mechanisms. Attachment structures  66  such as welds, solder, screws, clips, rivets, or other fasteners, overmolded plastic, or other connection mechanisms may also be used in mounting display unit structures such as midplate  54  in chassis  84  of backlight unit  22  to housing  12 . For example, portions  68  of the bend edges of midplate  54  may be attached to housing  12  using attachment structures  66 . If desired, one or more screws or other attachment structures  66  may be used to attach metal legs  60  of chassis  80  to downwardly bent peripheral edge portions of midplate  54  and welds or other attachment structures  66  may be used to attach portions  68  of midplate  54  to vertical metal housing sidewalls walls in housing  12  or other metal housing structures. These are merely illustrative arrangements for attaching assembly  24  and separate display backlight unit  22  into electronic device housing  12 . Other mounting arrangements may be used, if desired. 
     A flow chart of illustrative steps involved in assembling display module and backlight unit structures to form an electronic device such as device  10  of  FIG. 2  is shown in  FIG. 3 . At step  92 , backlight chassis  84  may be formed by attaching chassis structures such as chassis structures  64  to chassis structures such as planar support structure  54 . For example, plastic chassis structures  64  may be injection molded over portions of metal midplate  52 . Midplate  54  may serve both as a planar support structure for the layers of material mounted in the rectangular recess in backlight unit  22  and as a planar structural housing member that spans the width of housing  12  from sidewall to sidewall. 
     Midplate  54  may have a rectangular outline with bent edge portions, leg-shaped tabs with screw hole openings and/or other structures that facilitate attachment of midplate  54  within housing  12  and attachment of backlight unit  22  to display module assembly  24  to form display assembly  82 . Chassis structures  64  may have the shape of a rectangular ring with a rectangular outer periphery that fits within a rectangular housing interior defined by a corresponding rectangular inner sidewall surface of housing  12 . The center of chassis structures  64  may have a rectangular opening into which rectangular backlight unit layers may be placed such as a rectangular reflector  52 , a rectangular light guide plate  50 , and rectangular optical films  28 . The lateral dimensions of the backlight unit layers need not all be the same. For example, reflector  52  and light guide plate  50  may have a smaller rectangular footprint than optical films  28 , as shown in  FIG. 2 . 
     After forming backlight unit chassis  84 , backlight unit layers such as layers  52 ,  50 , and  28  may be mounted within the rectangular recess formed by chassis structures  84 , thereby forming backlight unit  22 . 
     The layers of display  14  such as display cover layer  30  and display module  26  and the structures of backlight unit  22  may be mounted directly into housing  12  to form device  10  (step  100 ). When mounting backlight unit  22  within housing  12 , attachment structures  66  such as welds, screws, or other structures may be used in attaching midplate  52  of backlight unit  22  to the inner surface of a metal electronic device housing wall or other portion of housing  12 . Adhesive layer  32  may be used in attaching display cover layer  30  and display module  26 . 
     If desired, display module assembly  24  may be formed by attaching display module  26  to display cover layer  30  with adhesive  32  and by attaching a separate backlight such as backlight unit  22  to display module assembly  24  to form display module  82  before the structures of display assembly  82  are mounted in housing  12 . As shown in  FIG. 2 , display module assembly  24  may be formed at step  90  by attaching display module  26  to display cover layer  30  with adhesive  32  and by incorporating display module assembly chassis  80  into display module assembly  24  so that display module assembly chassis  80  extends around the periphery of display cover layer  30  and display module  26  of  FIG. 2 . After forming display module assembly  24  at step  90 , backlight unit  22  and display module assembly  24  may be assembled to form display assembly  82  at step  96 . 
     In forming display assembly  82 , backlight unit  22  may be attached to display module assembly  24  using attachment mechanisms  66  (e.g. screws or other features that attach metal portion  60  of display module assembly chassis  80  to the bent edge portion of midplate  54  in backlight unit chassis  84 ). 
     After display assembly  82  has been formed using screws or other fasteners (e.g., screws that pass through holes in downwardly protruding metal chassis structures), display assembly  82  may be mounted within housing  12  to form device  10 . For example, attachment mechanisms  66  such as welds or other attachment mechanisms may be used in attaching bent metal edge portions  68  of midplate  52  to metal walls in housing  12 . 
     During the operations of step  96  (and, if desired, during the assembly operations of step  100  in which the layers of display  14  are formed directly in housing  12 ), a layer of material such as foam gasket  62  may be interposed between display module  26  and backlight unit  22  (e.g., without interposing any adhesive between backlight unit  22  and display module  26 ). Foam gasket  62  may have the shape of a rectangular ring (as an example) and may be formed from a material such as a semi-closed-cell polymer foam. The presence of spacer structures such as foam gasket  62  may create an air gap such as gap  44  that helps prevent undesired contact between layers  28  of backlight unit  22  and the lowermost layer (e.g., polarizer  42 ) of display module  26 . Foam  62  may have a relatively low compressibility, so that the layers of display  14  are not forced apart following assembly. For example, foam  62  may exhibit a restoring force of less than 4 N/cm2 when foam  62  is compressed within display  14  as shown in  FIG. 2 . 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20131212
Publication Date: 20170523
Grant Date: 20170523
Priority Date: 20130131
Inventors: WURZEL JOSHUA G.
DOYLE DAVID A.
GETTEMY SHAWN R.
LIN WEY-JIUN
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F2001/133322", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F2201/54", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F2001/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133322", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F2201/54", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F2201/54", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133322", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 51222557