PATENT DOCUMENT

Publication Number: US-9759937-B2
Application Number: US-201514863260-A
Country: US
Kind Code: B2

Title: Display with integrated backlight

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 and a backlight unit assembly may together form a display that is mounted within an electronic device housing. A support structure that supports the display cover layer may be integrated with the backlight unit assembly. The support structure may have an upper surface to which the display cover layer is attached and a lower portion that is molded to a metal chassis that supports the backlight unit. The lower portion of the support structure may form a plastic chassis that surrounds the backlight unit. In this way, an integrated support structure may be used to support both the display module and the backlight unit.

Claims:
What is claimed is: 
     
       1. An electronic device having a display, wherein the display comprises:
 a backlight unit including backlight structures supported by a metal chassis; 
 a display module assembly including a display module attached to a display cover layer; and 
 a support structure having an upper surface that supports the display cover layer and a lower portion that is molded over the metal chassis, wherein the metal chassis has opposing upper and lower surfaces that are parallel to the upper surface of the support structure, and wherein the support structure contacts the upper and lower surfaces of the metal chassis. 
 
     
     
       2. The electronic device defined in  claim 1  further comprising:
 an electronic device housing in which the display is mounted, wherein a portion of the support structure is interposed between the display cover layer and the electronic device housing. 
 
     
     
       3. The electronic device defined in  claim 1  further comprising an adhesive that attaches a lower surface of the display cover layer to the upper surface of the support structure. 
     
     
       4. The electronic device defined in  claim 1  wherein the support structure surrounds the display cover layer. 
     
     
       5. The electronic device defined in  claim 1  wherein the metal chassis has a first portion that lies in a plane and a second portion that is bent out of the plane, wherein the support structure is molded over the first and second portions of the metal chassis. 
     
     
       6. The electronic device defined in  claim 1  wherein the display module comprises:
 a color filter layer; 
 a thin-film transistor layer; and 
 a liquid crystal layer interposed between the color filter layer and the thin-film transistor layer. 
 
     
     
       7. The electronic device defined in  claim 1  further comprising a metal electronic device housing in which the display is mounted, wherein the metal chassis is welded to the metal electronic device housing. 
     
     
       8. The electronic device defined in  claim 1  wherein the backlight unit comprises:
 a plurality of optical films; 
 a reflector; and 
 a light guide plate interposed between the plurality of optical films and the reflector. 
 
     
     
       9. The electronic device defined in  claim 1  wherein the support structure comprises a plastic support structure. 
     
     
       10. The electronic device defined in  claim 1  wherein the backlight unit and the display module are separated by a gap and wherein a size of the support structure determines a size of the gap. 
     
     
       11. A method for forming an electronic device, comprising:
 forming a display backlight unit having a metal chassis and a plastic chassis, wherein forming the display backlight unit comprises injection molding the plastic chassis over the metal chassis; and 
 mounting a display module assembly to the display backlight unit by attaching a display cover layer in the display module assembly to an upper surface of the plastic chassis. 
 
     
     
       12. The method defined in  claim 11  wherein forming the display backlight unit comprises mounting a light guide plate within a recess defined by the metal chassis and the plastic chassis. 
     
     
       13. The method defined in  claim 11  further comprising mounting the display backlight unit and the display module assembly in an electronic device housing such that a portion of the plastic chassis is interposed between the display cover layer and the electronic device housing. 
     
     
       14. The method defined in  claim 13  wherein the electronic device housing comprises a metal electronic device housing and wherein mounting the display backlight unit in the electronic device housing comprises welding the metal chassis to the metal electronic device housing. 
     
     
       15. Apparatus, comprising:
 a backlight unit; 
 a support structure that supports the backlight unit, wherein the support structure comprises a plastic frame molded to a metal support member, wherein the plastic frame has first and second surfaces, and wherein the metal support member passes through the plastic frame from the first surface to the second surface; 
 a display module having a transparent cover layer; and 
 an adhesive that attaches a lower surface of the transparent cover layer to an upper surface of the plastic frame. 
 
     
     
       16. The apparatus defined in  claim 15  wherein the display module comprises a liquid crystal display module that is attached to the lower surface of the transparent cover layer with adhesive. 
     
     
       17. The apparatus defined in  claim 15  wherein the backlight unit comprises a light guide plate and wherein the metal support member extends under the light guide plate. 
     
     
       18. The apparatus defined in  claim 15  further comprising:
 a metal housing in which the backlight unit and the display module are mounted, wherein a portion of the plastic frame is interposed between the transparent cover layer and the metal housing. 
 
     
     
       19. The apparatus defined in  claim 18  wherein the metal support member is attached to the metal housing. 
     
     
       20. The electronic device defined in  claim 1  wherein the support structure forms an outermost surface of the electronic device.

Description:
This application claims the benefit of provisional patent application No. 62/154,624 filed on Apr. 29, 2015, 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 and a separate backlight unit may be assembled to form a display module. The display module and backlight unit may be installed within the electronic device housing using 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. 
     A support structure that supports the display module assembly when the display module assembly is mounted in the electronic device housing may be integrated with the backlight assembly. For example, the support structure may have an upper portion that forms a display module chassis and a lower portion that forms a backlight chassis. An adhesive may be used to attach the display cover layer to the upper portion of the support structure. The lower portion of the support structure may be injection molded over a metal chassis that supports the backlight unit. 
     During assembly operations, the display module assembly may be formed by attaching a display module to a display cover layer. The backlight unit may be formed by molding a plastic chassis over a metal chassis and by subsequently mounting backlight structures within a recess defined by the plastic chassis and metal chassis. The plastic backlight chassis may be molded to include an upper shelf portion for receiving the display cover layer. 
     After the display module assembly and the backlight unit have been separately assembled, the display module assembly may be mounted to the backlight unit by attaching the display cover layer to an upper surface of the plastic chassis. This display assembly may then be mounted in the electronic device housing. If desired, the plastic chassis may be designed such that an upper portion of the plastic chassis is interposed between the display cover layer and the electronic device housing. 
     Alternatively, the backlight unit and display module assembly may be mounted in the electronic device housing prior to being coupled to one another. Once mounted in the electronic device housing, the display cover layer may be fixed to the upper surface of the plastic chassis structure. 
     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 such as a laptop computer with a display in accordance with an embodiment. 
         FIG. 2  is a perspective view of an illustrative electronic device such as a handheld electronic device with a display in accordance with an embodiment. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer with a display in accordance with an embodiment. 
         FIG. 4  is a perspective view of an illustrative electronic device such as a computer display with a display in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative display in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative display that has been mounted in an electronic device using a support structure that is integral with a backlight in accordance with an embodiment. 
         FIG. 7  is a flow chart of illustrative steps involved in forming electronic devices with backlit displays of the type shown in  FIG. 6  in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative display that has been mounted in an electronic device using a multiple-part support structure that is integral with a backlight in accordance with an embodiment. 
         FIG. 9  is a flow chart of illustrative steps involved in forming electronic devices with backlit displays of the type shown in  FIG. 8  in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may include displays. The displays may be used to display images to a user. Illustrative electronic devices that may be provided with displays are shown in  FIGS. 1, 2, 3, and 4 . 
       FIG. 1  shows how electronic device  10  may have the shape of a laptop computer having upper housing  12 A and lower housing  12 B with components such as keyboard  16  and touchpad  18 . Device  10  may have hinge structures  20  that allow upper housing  12 A to rotate in directions  22  about rotational axis  24  relative to lower housing  12 B. Display  14  may be mounted in upper housing  12 A. Upper housing  12 A, which may sometimes referred to as a display housing or lid, may be placed in a closed position by rotating upper housing  12 A towards lower housing  12 B about rotational axis  24 . 
       FIG. 2  shows how electronic device  10  may be a handheld device such as a cellular telephone, music player, gaming device, navigation unit, or other compact device. In this type of configuration for device  10 , housing  12  may have opposing front and rear surfaces. Display  14  may be mounted on a front face of housing  12 . Display  14  may, if desired, have openings for components such as button  26 . Openings may also be formed in display  14  to accommodate a speaker port (see, e.g., speaker port  28  of  FIG. 2 ). 
       FIG. 3  shows how electronic device  10  may be a tablet computer. In electronic device  10  of  FIG. 3 , housing  12  may have opposing planar front and rear surfaces. Display  14  may be mounted on the front surface of housing  12 . As shown in  FIG. 3 , display  14  may have an opening to accommodate button  26  (as an example). 
       FIG. 4  shows how electronic device  10  may be a display such as a computer display or may be a computer that has been integrated into a computer display. With this type of arrangement, housing  12  for device  10  may be mounted on a support structure such as stand  27  or stand  27  may be omitted (e.g., to mount device  10  on a wall). Display  14  may be mounted on a front face of housing  12 . 
     The illustrative configurations for device  10  that are shown in  FIGS. 1, 2, 3, and 4  are merely illustrative. In general, electronic device  10  may be a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, or other wearable or miniature device, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. 
     Housing  12  of device  10 , which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device  10  may be formed using a unibody construction in which most or all of housing  12  is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal frame elements or other internal housing structures). 
     Display  14  may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display  14  may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components. 
     Display  14  for device  10  may include pixels formed from liquid crystal display (LCD) components. A display cover layer may cover the surface of display  14  or a display layer such as a color filter layer or other portion of a display may be used as the outermost (or nearly outermost) layer in display  14 . The outermost display layer may be formed from a transparent glass sheet, a clear plastic layer, or other transparent member. 
     Display  14  may contain an array of active display pixels within rectangular region  30 . This region may sometimes be referred to as the active area of the display. As shown in  FIGS. 1, 2, 3, and 4 , active area AA may be surrounded by inactive display areas IA that do not contain 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 some arrangements, inactive areas IA may 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 an illustrative configuration for display  14  of device  10  (e.g., for display  14  of the devices of  FIG. 1 ,  FIG. 2 ,  FIG. 3 ,  FIG. 4  or other suitable electronic devices) is shown in  FIG. 5 . As shown in  FIG. 5 , display  14  may include backlight structures such as backlight unit  42  for producing backlight  44 . During operation, backlight  44  travels outwards (vertically upwards in dimension Z in the orientation of  FIG. 5 ) and passes through display pixel structures in display layers  46 . This illuminates any images that are being produced by the display pixels for viewing by a user. For example, backlight  44  may illuminate images on display layers  46  that are being viewed by viewer  48  in direction  50 . 
     Display layers  46  may be mounted in chassis structures such as a plastic chassis structure and/or a metal chassis structure to form a display module for mounting in housing  12  or display layers  46  may be mounted directly in housing  12  (e.g., by stacking display layers  46  into a recessed portion in housing  12 ). Display layers  46  may form a liquid crystal display or may be used in forming displays of other types. 
     Display layers  46  may include a liquid crystal layer such a liquid crystal layer  52 . Liquid crystal layer  52  may be sandwiched between display layers such as display layers  58  and  56 . Layers  56  and  58  may be interposed between lower polarizer layer  60  and upper polarizer layer  54 . 
     Layers  58  and  56  may be formed from transparent substrate layers such as clear layers of glass or plastic. Layers  58  and  56  may be layers such as a thin-film transistor layer and/or a color filter layer. Conductive traces, color filter elements, transistors, and other circuits and structures may be formed on the substrates of layers  58  and  56  (e.g., to form a thin-film transistor layer and/or a color filter layer). Touch sensor electrodes may also be incorporated into layers such as layers  58  and  56  and/or touch sensor electrodes may be formed on other substrates. 
     With one illustrative configuration, layer  58  may be a thin-film transistor layer that includes an array of pixel circuits based on thin-film transistors and associated electrodes (pixel electrodes) for applying electric fields to liquid crystal layer  52  and thereby displaying images on display  14 . Layer  56  may be a color filter layer that includes an array of color filter elements for providing display  14  with the ability to display color images. If desired, layer  58  may be a color filter layer and layer  56  may be a thin-film transistor layer. Configurations in which color filter elements are combined with thin-film transistor structures on a common substrate layer in the upper or lower portion of display  14  may also be used. 
     During operation of display  14  in device  10 , control circuitry (e.g., one or more integrated circuits on a printed circuit) may be used to generate information to be displayed on display  14  (e.g., display data). The information to be displayed may be conveyed to a display driver integrated circuit such as circuit  62 A or  62 B using a signal path such as a signal path formed from conductive metal traces in a rigid or flexible printed circuit such as printed circuit  64  (as an example). 
     Backlight structures  42  may include a light guide plate such as light guide plate  78 . Light guide plate  78  may be formed from a transparent material such as clear glass or plastic. During operation of backlight structures  42 , a light source such as light source  72  may generate light  74 . Light source  72  may be, for example, an array of light-emitting diodes. 
     Light  74  from light source  72  may be coupled into edge surface  76  of light guide plate  78  and may be distributed in dimensions X and Y throughout light guide plate  78  due to the principal of total internal reflection. Light guide plate  78  may include light-scattering features such as pits or bumps or other light-scattering structures. The light-scattering features may be located on an upper surface and/or on an opposing lower surface of light guide plate  78 . Light source  72  may be located at the left of light guide plate  78  as shown in  FIG. 5  or may be located along the right edge of plate  78  and/or other edges of plate  78 . 
     Light  74  that scatters upwards in direction from light guide plate  78  may serve as backlight  44  for display  14 . Light  74  that scatters downwards may be reflected back in the upwards direction by reflector  80 . Reflector  80  may be formed from a reflective material such as a layer of plastic covered with a dielectric minor thin-film coating. Reflective tape (e.g., white plastic tape or tape formed from other reflective materials) may be incorporated into the backlight reflector for display  14 . For example, backlight structures  42  may include a strip of tape that runs along the edge of reflector  80  that is adjacent to light-emitting diodes  72 . 
     To enhance backlight performance for backlight structures  42 , backlight structures  42  may include optical films  70 . Optical films  70  may include diffuser layers for helping to homogenize backlight  44  and thereby reduce hotspots, compensation films for enhancing off-axis viewing, and brightness enhancement films (also sometimes referred to as turning films) for collimating backlight  44 . Optical films  70  may overlap the other structures in backlight unit  42  such as light guide plate  78  and reflector  80 . For example, if light guide plate  78  has a rectangular footprint in the X-Y plane of  FIG. 5 , optical films  70  and reflector  80  may have a matching rectangular footprint. If desired, films such as compensation films may be incorporated into other layers of display  14  (e.g., polarizer layers). 
     A cross-sectional side view of display  14  mounted in device  10  is shown in  FIG. 6 . As shown in  FIG. 6 , display  14  and additional components such as components  96  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. The example of  FIG. 6  in which the sides of device housing  12  are planar is merely illustrative. If desired, the sides of device housing  12  may be curved. For example, the outer surface of device housing  12  may have a curve that matches the curved surface of cover layer  84 . 
     Components  96  may be electrical components such as integrated circuits, connectors, batteries, discrete devices such as resistors, capacitors, and inductors, switches, and other electronic devices. Components  96  may be mounted to one or more substrates such as substrate  94 . Substrate  94  may be coupled to additional substrates in device  10  using connectors, cables, flexible printed circuit paths, and other interconnect pathways. Substrates such as substrate  94  may be formed from molded plastic, ceramic, glass, or printed circuits (as examples). For example, substrates such as substrate  94  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  96  may be electrically connected to conductive paths in substrates such as substrate  94 . The conductive paths in substrates such as substrate  94  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  96  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  84 . Display cover layer  84  may be formed from a clear layer of glass, a transparent plastic layer, or other transparent material. Display cover layer  84  may have the shape of a rectangular member or may have other shapes such as shapes with a curved cross-sectional profile and/or a footprint with curved edges. In the example of  FIG. 6 , the upper surface of cover layer  84  is flat in the central portion of display  14  and curved at the edges. 
     Display module  46  may be attached to the underside of display cover layer  84  using adhesive layer  86  (e.g., a layer of optically clear adhesive or other suitable adhesive). In inactive area IA, opaque masking material  98  may be formed on the underside of display cover layer  30 . Opaque masking material  98  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  46  may also be provided with a peripheral strip of opaque masking material such as opaque masking material  102 . 
     Display module  46  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  46  if desired (e.g., by providing display module  46  with an array of transparent capacitive touch sensor electrodes such as electrodes formed from indium tin oxide). In the  FIG. 6  example, display module  46  is a liquid crystal display module having a layer of liquid crystal material  52  sandwiched between an upper display layer such as color filter layer  56  and a corresponding lower display layer such as thin-film transistor layer  58 . 
     Color filter layer  56  may be used to provide display  14  with the ability to display color images. Color filter layer  56  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  56 . 
     Thin-film transistor layer  58  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  58  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  42  may be used to provide backlight  44  that travels upwards through display module  46  in direction to viewer  48 . The layers of display module  46  such as color filter layer  56 , thin-film transistor layer  58 , and liquid crystal layer  52  may be sandwiched between polarizer layers such as upper polarizer  54  and lower polarizer  60 . During operation of display  14 , adjustments to the electric fields supplied by the electrodes in thin-film transistor layer  58  can be used to create changes to liquid crystal layer  52  that rotate the polarization of light  44  by corresponding amounts. The rotation of the polarization of light  44  in combination with the presence of upper and lower polarizers  54  and  60  adjusts the amount of light  44  that is transmitted to viewer  48 . This allows display  14  to be used to display images to viewer  48 . 
     If desired, opaque masking material  102  may be provided between the substrates associated with color filter layer  56  and thin-film transistor layer  58 . For example, opaque masking material may be provided on the underside of color filter layer  56 . 
     Display module  46  may be attached to display cover layer  84  using adhesive  86  to form display module assembly  106 . Display module assembly  106  may be mounted in housing  12  using portion  88 A of support structure  88 . Cover layer  84  and/or other display layers in assembly  106  may be mounted to portion  88 A of support structure  88  using attachment members such as attachment member  92 . Attachment member  92  may be an adhesive (e.g., heat-cured adhesive, light-cured adhesive, pressure-sensitive adhesive, or other adhesive), a fastener, or other mounting structure. 
     Support structure  88  (sometimes referred to as cover layer support structure  88 ) may be one of multiple structures that together form a chassis for display module assembly  106 . Support structure  88  may formed from plastic, glass, ceramic, metal, fiber-based materials, other materials, or combinations of these materials. 
     Backlight assembly  108  may include backlight structures  42  (sometimes be referred to as a backlight unit) and backlight chassis  110  within which backlight structures  42  are mounted. Backlight structures  42  may include reflector  80  and light guide plate  78 . Light guide plate  78  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  78 . 
     Optical films  70  may be incorporated into backlight unit  42  to help improve the quality of the backlight produced by light guide plate  78  and reflector  80 . Optical films  70  may, as an example, include one or more, two or more, or three or more layers for improving the homogeneity and directionality of emitted backlight  44 . Examples of optical films  70  include diffuser films and brightness enhancement films (sometimes referred to as turning films or prism films). 
     Backlight unit chassis  110  may be formed from plastic, metal, fiber-based composites, glass, ceramic, or other suitable material. As an example, backlight unit chassis  110  may be formed from one or more metal structures such as metal chassis  90  (sometimes referred to as an m-chassis, metal plate, or metal frame) and one or more plastic structures such as plastic chassis structure  88 B (e.g., a lower portion of cover layer support structure  88 ). Plastic chassis structure  88 B may be attached to metal plate  90  using adhesive, screws or other fasteners, or other attachment mechanisms. As an example, plastic chassis structures  88 B may be molded to metal plate  90  using plastic molding equipment such as plastic injection molding equipment (e.g., plastic chassis structures  88 B may be insert molded around portions of metal plate  90 ). 
     After forming backlight unit chassis  110 , the layers of backlight unit  42  may be assembled into backlight unit chassis  110 . As an example, backlight unit chassis  110  may be configured to form a recessed rectangular support structure (e.g., a rectangular recess) into which display backlight unit layers such as reflector  80 , light guide plate  78 , and optical films  70  may be placed in succession. During backlight unit assembly operations, backlight unit chassis  110  may be maintained in an upright position (as shown in  FIG. 6 ) without flipping over backlight unit chassis  110 . 
     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  84  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. 
     If desired, device  10  may be provided with a midplate that is also used as part of backlight unit  42 . In particular, metal plate  90  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  42  in display backlight unit chassis  110 . By using metal plate  90  both as a housing midplate and as a part of backlight unit chassis  110 , the thickness of device  10  can be reduced and/or additional components  96  can be incorporated into the interior of device  10  without need to adjust the overall thickness of device  10 . This is, however, merely illustrative. If desired, metal plate  90  may be separate from a metal midplate member in device  10  or device  10  may not include a metal midplate member. 
     During assembly operations, the structures of display module assembly  106  and the structures of backlight assembly  108  may be assembled separately to form two unitary structures. The two assemblies may each be mounted directly into device housing  12  prior to being coupled to one another or the two assemblies may be coupled together to form a single unitary structure and then mounted within housing  12 . 
     Care should be taken to ensure that abrasive contact between backlight unit  42  and display module  46  does not occur. In some arrangements, it may be desirable to maintain a gap such as air gap between the lowermost layer of display module  46  (e.g., polarizer  60 ) and the uppermost layers of backlight unit  42  (e.g., optical films  70 ). 
     To maintain a desired tolerance between display module  46  and backlight unit  42 , support structures that support display module  46  may be integrated with support structures that support backlight unite  42 . In the example of  FIG. 6 , cover layer support member  88 A and backlight plastic chassis  88 B are formed from a unitary support structure  88 . Upper portion  88 A of support structure  88  forms a display module chassis that surrounds display module  46  and supports cover layer  84 . Lower portion  88 B of support structure  88  is overmolded onto metal backlight chassis  90  and forms a plastic frame (sometimes referred to as a p-chassis) that surrounds or partially surrounds backlight module  42 . 
     If desired, support structure  88  may be insert molded or overmolded onto other metal structures such as one or more metal legs around the rectangular periphery of display  14 . For example, there may be one, two, three, or more than three chassis legs on each side of display  14 . The legs may include holes for accommodating screws or other fastening structures. 
     As shown in  FIG. 6 , support structure  88  and the other portions of display module assembly  106  and/or backlight assembly  108  may be attached to midplate  90  of display backlight unit  42  and to housing  12  using attachment structures  104 . Attachment structures  104  such as welds, solder, screws, clips, rivets, or other fasteners, adhesive, overmolded plastic, or other connection mechanisms may also be used in mounting display unit structures such as midplate  90  in chassis  110  of backlight unit  42  to housing  12 . For example, portions  112  of the bent edges of metal plate  90  may be attached to housing  12  using attachment structures  104 . If desired, one or more screws or other attachment structures  104  may be used to attach metal legs of chassis  88  to downwardly bent peripheral edge portions of metal plate  90  and welds or other attachment structures  104  may be used to attach portions  112  of metal plate  90  to metal housing walls in housing  12  or other metal housing structures. These are merely illustrative arrangements for attaching assembly  106  and backlight assembly  108  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. 6  is shown in  FIG. 7 . 
     At step  200 , display module assembly  106  may be formed by attaching display module  46  to cover layer  84  using an adhesive such as adhesive layer  86 . 
     At step  202 , backlight chassis  110  may be formed by attaching chassis structures such as cover layer support structures  88  to chassis structures such as planar support structure  90 . For example, plastic chassis structures  88  may be injection molded over portions of metal midplate  90 . Support structure  88  may, for example, be molded to have an upper shelf portion  88 A configured to support display layers (e.g., cover layer  84  of  FIG. 6  or other suitable display layer) and a lower frame portion  88 B configured to support and at least partially surround backlight layers. Lower frame portion  88 B may be insert molded or overmolded onto metal frame  90 . If desired, metal frame  90  of chassis  110  may serve both as a planar support structure for the layers of material mounted in the rectangular recess in chassis  110  and as a planar structural housing member that spans the width of housing  12  from sidewall to sidewall. 
     Metal plate  90  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  90  within housing  12  and attachment of backlight unit  42  to display module assembly  46 . Chassis structures  110  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  110  may have a rectangular opening into which rectangular backlight unit layers may be placed such as a rectangular reflector  80 , a rectangular light guide plate  78 , and rectangular optical films  70 . The lateral dimensions of the backlight unit layers need not all be the same. For example, reflector  80  and light guide plate  78  may have a smaller rectangular footprint than optical films  70 , if desired. 
     After forming backlight unit chassis  110 , backlight unit layers such as layers  80 ,  78 , and  70  may be mounted within the rectangular recess formed by chassis structures  110  (at step  204 ), thereby forming backlight assembly  108 . 
     At step  206 , display module assembly  106  may be mounted to backlight assembly  108  using support structure  88 . For example, support structure  88  may have an upper shelf portion  88 A on which cover layer  84  rests, as shown in  FIG. 6 . An attachment member such as adhesive layer  92  may be used to attach cover layer  84  to shelf portion  88 A of support structure  88 . Step  206  may include, for example, applying light or heat to cure adhesive  92  and thereby bond cover layer  84  to support structure  88 . Because support structure  88  is integral with backlight chassis  110 , mounting cover layer  84  to support structure  88  may define a distance between display module  46  and backlight unit  42  (e.g., a desired air gap between lower polarizer  60  of display module  46  and optical films  70  of backlight  42 ). Display module assembly  106  and backlight assembly  108  may sometimes be referred to as a display assembly when the two assemblies are attached to one another. 
     At step  208 , the display assembly formed in step  206  may be mounted in housing  12  to form device  10 . For example, attachment mechanisms  104  such as welds or other attachment mechanisms may be used in attaching bent metal edge portions  112  of metal frame  90  to metal walls in housing  12 . 
     If desired, backlight assembly  108  formed in steps  202  and  204  may be mounted in housing  12  prior to being attached to display module assembly  106 . For example, prior to attaching backlight assembly  108  to display module assembly  106 , assembly operations may proceed to step  210 . At step  210 , backlight assembly  108  including backlight unit  42  and backlight chassis  110  may be mounted within housing  12 . When mounting backlight assembly  108  within housing  12 , attachment structures  104  such as welds, screws, or other structures may be used in attaching metal chassis  90  of backlight assembly  108  to the inner surface of a metal electronic device housing wall or other portion of housing  12 . 
     At step  212 , display module assembly  106  may be mounted in housing  12 . For example, support structure  88  of backlight assembly  108  may have an upper shelf portion  88 A on which cover layer  84  rests, as shown in  FIG. 6 . An attachment member such as adhesive layer  92  may be used to attach cover layer  84  to shelf portion  88 A of support structure  88 . Light or heat may be applied to cure adhesive  92  and thereby bond cover layer  84  to support structure  88 . Because support structure  88  is integral with backlight chassis  110 , mounting cover layer  84  to support structure  88  may define a distance between display module  46  of assembly  106  and backlight unit  42  of assembly  108 . 
     In some scenarios, it may be desirable to attach cover layer  84  to support structure  88  prior to assembling display module assembly  106  with backlight unit  108  and/or prior to attaching display layers  46  to cover layer  84 . For example, bonding cover layer  84  to support structure  88  may, in some arrangements, involve adhesive attachment processes that could potentially damage other components in the display. To accommodate these types of attachment processes while maintaining the benefits of integrating cover layer support structures with backlight support structures, an arrangement of the type shown in  FIG. 8  may be used. 
     As shown in  FIG. 8 , cover layer support structure  88  may include multiple parts such as first portion  88 A and second portion  88 B. Similar to the arrangement of  FIG. 6 , support structure  88  forms both a mounting surface for cover layer  84  as well as a backlight chassis to support backlight unit  42 . In the example of  FIG. 8 , however, upper portion  88 A of support structure  88  that is attached to cover layer  84  is separate from portion  88 B that forms part of backlight chassis  110 . If desired, a layer of adhesive such as adhesive  120  may be used to attach upper portion  88 A to lower portion  88 B to form support structure  88 . This is, however, merely illustrative. If desired, other attachment structures such as welds, solder, screws, clips, rivets, or other fasteners, adhesive, overmolded plastic, or other connection mechanisms may be used to attach portion  88 A to portion  88 B. 
     By forming support structure  88  from multiple pieces, attachment operations that may otherwise damage certain parts of display  14  may be performed without risking harm to those parts of the display. For example, adhesive  92  may be applied and cured to attach cover layer  84  to upper support structure  88 A prior to attaching upper support structure  88 A to lower support structure  88 B with adhesive  120 . This ensures that the operations associated with curing adhesive  92  (e.g., application of heat, force, light, etc.) do not damage backlight unit components  42  that are mounted in support structure  88 B of backlight chassis  110 . If desired, there may be two, three, four, or more than four parts that make up support structure  88 . The two-piece example of  FIG. 8  is merely illustrative. 
     The examples of  FIGS. 6 and 8  in which support structure  88  and backlight chassis  110  include multiple discrete parts (e.g., a plastic support structure such as support structure  88  and a metal support structure such as metal frame  90 ) is merely illustrative. If desired, cover layer support structure  88  and metal chassis  90  may be formed from one piece of material (e.g., a single piece of plastic, metal, or other suitable material). 
     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. 8  is shown in  FIG. 9 . 
     At step  300 , display module assembly  106  may be formed by attaching display module  46  to cover layer  84  using an adhesive such as adhesive layer  86 . 
     At step  302 , display module assembly  106  may be mounted to first portion  88 A of support structure  88 . For example, portion  88 A of support structure  88  may have a shelf region on which cover layer  84  rests, as shown in  FIG. 8 . An attachment member such as adhesive layer  92  may be used to attach cover layer  84  to portion  88 A of support structure  88 . Step  302  may include, for example, applying light and/or heat to cure adhesive  92  and thereby bond cover layer  84  to support structure  88 A. 
     At step  304 , backlight chassis  110  may be formed by attaching chassis structures such as portion  88 B of cover layer support structure  88  to chassis structures such as planar support structure  90 . For example, one or more plastic chassis structures  88 B may be injection molded over portions of metal midplate  90  Portion  88 B of support structure  88  may be insert molded or overmolded onto metal frame  90 . If desired, metal frame  90  of chassis  110  may serve both as a planar support structure for the layers of material mounted in the rectangular recess in chassis  110  and as a planar structural housing member that spans the width of housing  12  from sidewall to sidewall. 
     Metal plate  90  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  90  within housing  12  and attachment of backlight unit  42  to display module assembly  46 . Chassis structures  110  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  110  may have a rectangular opening into which rectangular backlight unit layers may be placed such as a rectangular reflector  80 , a rectangular light guide plate  78 , and rectangular optical films  70 . The lateral dimensions of the backlight unit layers need not all be the same. For example, reflector  80  and light guide plate  78  may have a smaller rectangular footprint than optical films  70 , if desired. 
     After forming backlight unit chassis  110 , backlight unit layers such as layers  80 ,  78 , and  70  may be mounted within the rectangular recess formed by chassis structures  110  (at step  306 ), thereby forming backlight assembly  108 . 
     At step  308 , display module assembly  106  may be mounted to backlight assembly  108  using support structure  88 . For example, support structures  88  may include an upper shelf portion  88 A on which cover layer  84  rests and a lower frame portion  88 B supporting backlight unit  42 , as shown in  FIG. 8 . An attachment member such as adhesive layer  120  may be used to attach shelf portion  88 A of support structure  88  to frame portion  88 B of support structure  88 . Because lower support structure  88 B is integral with backlight chassis  110  and upper support structure  88 A supports cover layer  84 , coupling structures  88 A and  88 B together may define a distance between display module  46  and backlight unit  42  (e.g., a desired air gap between lower polarizer  60  of display module  46  and optical films  70  of backlight  42 ). Display module assembly  106  and backlight assembly  108  may sometimes be referred to as a display assembly when the two assemblies are attached to one another. 
     At step  310 , the display assembly formed in step  308  may be mounted in housing  12  to form device  10 . For example, attachment mechanisms  104  such as welds or other attachment mechanisms may be used in attaching bent metal edge portions  112  of metal frame  90  to metal walls in housing  12 . 
     If desired, backlight assembly  108  formed in steps  304  and  306  may be mounted in housing  12  prior to being attached to display module assembly  106 . For example, prior to attaching backlight assembly  108  to display module assembly  106 , assembly operations may proceed to step  312 . At step  312 , backlight assembly  108  including backlight unit  42  and backlight chassis  110  may be mounted within housing  12 . When mounting backlight assembly  108  within housing  12 , attachment structures  104  such as welds, screws, or other structures may be used in attaching metal chassis  90  of backlight assembly  108  to the inner surface of a metal electronic device housing wall or other portion of housing  12 . 
     At step  314 , display module assembly  106  may be mounted in housing  12 . For example, support structure  88 A of display assembly  106  may be attached to support structure  88 B of backlight assembly  108 , as shown in  FIG. 8 . An attachment member such as adhesive layer  120  may be used to attach upper portion  88 A to lower portion  88 B. Because support structure  88  is integral with backlight chassis  110 , mounting cover layer  84  to support structure  88  may define a distance between display module  46  of assembly  106  and backlight unit  42  of assembly  108 . 
     If desired, cover layer  84  may be attached to upper support structure  88 A prior to attaching display layers  46  to cover layer  84  (e.g., step  302  may be performed prior to step  300 ). This may help ensure that display layers  46  are not damaged during the operations associated with curing adhesive  92 . 
     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: 20150923
Publication Date: 20170912
Grant Date: 20170912
Priority Date: 20150429
Inventors: Reightler Seth R.
KAKUDA TYLER R.
HOOTON LEE E.
SCHLAUPITZ ALEXANDER D.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F2001/133325", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F2001/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133325", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133514", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133325", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 57204084