PATENT DOCUMENT

Publication Number: US-9400349-B2
Application Number: US-201213673808-A
Country: US
Kind Code: B2

Title: Electronic device with display chassis structures

Abstract:
Electronic devices may include displays. A display may include backlight components that provide backlight illumination for the display. Backlight components may include a light guide plate that distributes light from a light source across the display. Display chassis structures may be used to support display layers and backlight components. A metal chassis may include a portion that partially surrounds the light source. Openings or perforations in the metal chassis may allow the portion that surrounds the light source to flex about a flex axis. A portion of a display layer may be mounted to a plastic chassis. The plastic chassis may be insert molded over a light source, may form part of a package for a light source, may be adhered to a light source, or may wrap around the light source. An encapsulant may be formed over the light source to protect the light source from vibrations and contaminants.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a display; 
 a light source configured to provide light; 
 a light guide plate configured to receive the light and to provide the light to the display as backlight illumination; 
 a metal display chassis that has a curved portion that flexes about a flex axis and that at least partly surrounds the light source, wherein the metal display chassis includes at least one flex promotion feature in the curved portion that helps the curved portion of the metal display chassis to flex about the flex axis, wherein the curved portion has a first surface and a second surface interposed between the first surface and the light source and wherein the flex promotion feature comprises a plurality of openings that extend through the first and second surfaces; and 
 an opaque film on the first surface that covers the plurality of openings, wherein the first surface is interposed between the opaque film and the second surface. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the at least one flex promotion feature comprises at least one opening in the metal display chassis. 
     
     
       3. The electronic device defined in  claim 2  wherein the curved portion that flexes about the flex axis comprises a bend and wherein the at least one opening is formed in the bend. 
     
     
       4. The electronic device defined in  claim 2 , further comprising a layer of opaque film formed over the at least one opening that prevents light from passing through the at least one opening. 
     
     
       5. The electronic device defined in  claim 1  wherein the at least one flex promotion feature comprises a plurality of perforations formed in the metal display chassis. 
     
     
       6. The electronic device defined in  claim 1  wherein the display comprises at least one display layer, wherein the plastic display chassis is molded over the curved portion of the metal display chassis that flexes about a flex axis, and wherein a portion of the at least one display layer is mounted to the plastic display chassis. 
     
     
       7. An electronic device, comprising:
 a display; 
 a light source configured to provide light; 
 a light guide plate configured to receive the light and to provide the light to the display as backlight illumination; 
 a metal display chassis having a bent portion that at least partly surrounds the light source, wherein the bent portion of the metal display chassis comprises a plurality of slits; and 
 an opaque film formed over the plurality of slits that reduces a transmission of light through the plurality of slits, wherein the bent portion of the metal display chassis is interposed between the light source and the opaque film. 
 
     
     
       8. The electronic device defined in  claim 7  wherein the bent portion bends around a bend axis and wherein the slits partially surround the bend axis. 
     
     
       9. The electronic device defined in  claim 7  wherein the opaque film comprises black polyester film. 
     
     
       10. The electronic device defined in  claim 7  wherein the opaque film comprises a plurality of discrete portions each covering a respective one of the slits in the metal display chassis. 
     
     
       11. The electronic device defined in  claim 7  wherein the opaque film comprises a continuous layer of opaque film that covers all of the slits in the metal display chassis. 
     
     
       12. The electronic device defined in  claim 7  further comprising:
 a plastic display chassis molded over the bent portion of the metal display chassis. 
 
     
     
       13. The electronic device defined in  claim 12  wherein the display comprises a display layer that is mounted to the plastic display chassis. 
     
     
       14. The electronic device defined in  claim 13  wherein the display layer comprises a thin-film transistor layer. 
     
     
       15. The electronic device defined in  claim 12  wherein the plastic display chassis has a protruding portion that is attached to the light guide plate with adhesive. 
     
     
       16. The electronic device defined in  claim 7  wherein the bent portion of the metal display chassis curves around the light source. 
     
     
       17. The electronic device defined in  claim 1  wherein the curved portion of the metal display chassis curves around the light source.

Description:
BACKGROUND 
     This relates generally to electronic devices, and more particularly, to electronic devices with displays. 
     Electronic devices often include displays. For example, cellular telephones and portable computers often include displays for presenting information to a user. An electronic device may have a housing such as a housing formed from plastic or metal. Components for the electronic device such as display components may be mounted in the housing. 
     It can be challenging to incorporate a display into the housing of an electronic device. Size, weight, electrical grounding, robustness, ease of assembly, and light-tightness are often important considerations in designing electronic devices. If care is not taken, displays may be bulky, may exhibit undesired light reflections, or may be prone to damage during a drop event. The housing of an electronic device can be adjusted to accommodate a bulky display with large borders, but this can lead to undesirable enlargement of the size and weight of the housing and unappealing device aesthetics. 
     It would therefore be desirable to be able to provide improved ways to provide displays for electronic devices. 
     SUMMARY 
     An electronic device may be provided with a display. The display may have display layers for displaying images. Backlight structures may be included in the display. The backlight structures may provide backlight that illuminates the display layers in the display that are displaying an image for a user. 
     Display chassis structures may be used to support display layers and backlight structures. The display chassis structures may include a metal display chassis and a plastic display chassis. 
     The metal display chassis may include a planar portion and a bent portion. The bent portion may partially surround a light source. Flex promotion features may be formed in the bent portion to allow the bent portion of the metal display chassis to flex around one or more flex axes. The flex promotion features may include openings or perforations. An opaque film may be used to cover the openings so that light is prevented from passing through the openings. 
     A light source may emit light into the edge of a light guide plate in a display. The light source may include a semiconductor device mounted on a lead frame structure. A wire bond may electrically couple the semiconductor device to the lead frame structure. The lead frame structure may be mounted on a flexible printed circuit substrate using solder. A plastic package may be molded over the semiconductor device and lead frame structure. 
     A plastic display chassis on which a portion of a display layer is mounted may be insert molded over the light source. An encapsulant may be formed over the light source to protect the light source from vibrations and contaminants. The encapsulant may include potting material. 
     A plastic display chassis on which a portion of a display layer is mounted may form part of a package for a light source. The plastic display chassis may be injection molded over at least some of the light-emitting diode and lead frame structure that form the light source. 
     A light source may be mounted on a printed circuit substrate. The printed circuit substrate may be attached to a metal display chassis using adhesive. 
     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 such as a laptop computer with a display in accordance with an embodiment of the present invention. 
         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 of the present invention. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer with a display in accordance with an embodiment of the present invention. 
         FIG. 4  is a schematic diagram of an illustrative electronic device with a display in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative display in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of illustrative display layers and backlight structures in accordance with an embodiment of the present invention. 
         FIG. 7  is a perspective view of a light guide plate and corresponding chassis structure in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of illustrative display layers, backlight structures, and chassis structures in accordance with an embodiment of the present invention. 
         FIG. 9  is a perspective view of a metal display chassis having flex promotion features such as openings in accordance with an embodiment of the present invention. 
         FIG. 10  is a perspective view of a metal display chassis having flex promotion features such as perforations in accordance with an embodiment of the present invention. 
         FIG. 11  is a perspective view of a metal display chassis that has been partially covered with an opaque layer of film in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional side view of an illustrative display in which a plastic display chassis has been insert molded over a light-emitting diode package in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional side view of an illustrative display in which a plastic display chassis has been insert molded over a light-emitting diode package and in which an encapsulant has been formed over the light-emitting diode package in accordance with an embodiment of the present invention. 
         FIG. 14  is a cross-sectional side view of an illustrative display in which a plastic display chassis wraps around a light source and attaches to a metal display chassis in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross-sectional side view of an illustrative display in which a plastic display chassis forms at least part of a package for a light-emitting diode in accordance with an embodiment of the present invention. 
         FIG. 16  is a cross-sectional side view of an illustrative display in which a plastic display chassis is adhered to a light-emitting diode package using adhesive in accordance with an embodiment of the present invention. 
     
    
    
     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, and 3 . 
       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 a display cover layer or other exterior layer that includes openings for components such as button  26 . Openings may also be formed in a display cover layer or other display layer 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 a cover layer or other external layer with an opening to accommodate button  26  (as an example). 
     The illustrative configurations for device  10  that are shown in  FIGS. 1, 2, and 3  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 television, 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 or cast 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. 
     Displays for device  10  may, in general, include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. In some situations, it may be desirable to use LCD components to form display  14 , so configurations for display  14  in which display  14  is a liquid crystal display are sometimes described herein as an example. It may also be desirable to provide displays such as display  14  with backlight structures, so configurations for display  14  that include a backlight unit may sometimes be described herein as an example. Other types of display technology may be used in device  10  if desired. The use of liquid crystal display structures and backlight structures in device  10  is merely illustrative. 
     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 . A display cover layer or other outer display layer may be formed from a transparent glass sheet, a clear plastic layer, or other transparent member. 
     Touch sensor components such as an array of capacitive touch sensor electrodes formed from transparent materials such as indium tin oxide may be formed on the underside of a display cover layer, may be formed on a separate display layer such as a glass or polymer touch sensor substrate, or may be integrated into other display layers (e.g., substrate layers such as a thin-film transistor layer). 
     A schematic diagram of an illustrative configuration that may be used for electronic device  10  is shown in  FIG. 4 . As shown in  FIG. 4 , electronic device  10  may include control circuitry  29 . Control circuitry  29  may include storage and processing circuitry for controlling the operation of device  10 . Control circuitry  29  may, for example, include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Control circuitry  29  may include processing circuitry based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc. 
     Control circuitry  29  may be used to run software on device  10 , such as operating system software and application software. Using this software, control circuitry  29  may present information to a user of electronic device  10  on display  14 . When presenting information to a user on display  14 , sensor signals and other information may be used by control circuitry  29  in making adjustments to the strength of backlight illumination that is used for display  14 . 
     Input-output circuitry  30  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output circuitry  30  may include communications circuitry  32 . Communications circuitry  32  may include wired communications circuitry for supporting communications using data ports in device  10 . Communications circuitry  32  may also include wireless communications circuits (e.g., circuitry for transmitting and receiving wireless radio-frequency signals using antennas). 
     Input-output circuitry  30  may also include input-output devices  34 . A user can control the operation of device  10  by supplying commands through input-output devices  34  and may receive status information and other output from device  10  using the output resources of input-output devices  34 . 
     Input-output devices  34  may include sensors and status indicators  36  such as an ambient light sensor, a proximity sensor, a temperature sensor, a pressure sensor, a magnetic sensor, an accelerometer, and light-emitting diodes and other components for gathering information about the environment in which device  10  is operating and providing information to a user of device  10  about the status of device  10 . 
     Audio components  38  may include speakers and tone generators for presenting sound to a user of device  10  and microphones for gathering user audio input. 
     Display  14  may be used to present images for a user such as text, video, and still images. Sensors  36  may include a touch sensor array that is formed as one of the layers in display  14 . 
     User input may be gathered using buttons and other input-output components  40  such as touch pad sensors, buttons, joysticks, click wheels, scrolling wheels, touch sensors such as sensors  36  in display  14 , key pads, keyboards, vibrators, cameras, and other input-output components. 
     A cross-sectional side view of an illustrative configuration that may be used for display  14  of device  10  (e.g., for display  14  of the devices of  FIG. 1 ,  FIG. 2 , or  FIG. 3  or other suitable electronic devices) is shown in  FIG. 5 . As shown in  FIG. 5 , display  14  may include one or more layers of touch sensitive components such as touch-sensitive layers  47  that are attached to a cover layer such as cover layer  49 . Cover layer  49  may be formed from a sheet of rigid or flexible transparent material such as glass or plastic. 
     Touch-sensitive layers  47  may be attached to cover layer  49  using an adhesive material such as optically clear adhesive (OCA)  43 . Adhesive  43  may be liquid adhesive, light-cured adhesive, pressure-sensitive adhesive or other suitable adhesive. Touch-sensitive layers  47  may include touch sensor components such as an array of capacitive touch sensor electrodes formed from transparent materials such as indium tin oxide. 
     Display  14  may include display layers such as layers  46  for generating images to be displayed on display  14 . Display layers  46  may include polarizer layers, color filter layers, transistor layers, adhesive layers, layers of liquid crystal material, or other layers for generating display images. Display layers  46  may be attached to touch-sensitive layers  43  using adhesive such as optically clear adhesive  45 . Adhesive  45  may be liquid adhesive, light-cured adhesive, pressure-sensitive adhesive or other suitable adhesive. 
     Display layers  46  may use light generated by light-generating structures such as backlight structures  42  to form images to be viewed by a user of device  10 . Backlight structures  42  may include light-generating components such as light-emitting diodes, light guiding structures, reflective structures, optical films, etc. Backlight structures  42  may be attached to display layers  46  or may be mounted adjacent to layers  46  by attaching backlight structures  42  to one or more structural members. 
     A cross-sectional side view of an illustrative configuration that may be used for display layers  46  and backlight structures  42  of display  14  (e.g., for display layers  46  and backlight structures  42  of the display of  FIG. 5 , or other suitable display) is shown in  FIG. 6 . As shown in  FIG. 6 , 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. 6 ) 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. 
     In a configuration in which display layers  46  are used in forming a liquid crystal display, 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 . If desired, upper polarizer layer  54  may be attached to an outer cover layer such as cover layer  49  ( FIG. 5 ). 
     Layers  58  and  56  may be formed from transparent substrate layers such as clear layers of glass or plastic. Layers  56  and  58  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 thin-film transistors and associated electrodes (display 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. 
     During operation of display  14  in device  10 , control circuitry  29  (e.g., one or more integrated circuits such as components  68  on printed circuit  66  of  FIG. 6 ) may be used to generate information to be displayed on display  14  (e.g., display data). The information to be displayed may be conveyed from circuitry  68  to display driver integrated circuit  62  using a signal path such as a signal path formed from conductive metal traces in flexible printed circuit  64  (as an example). 
     Display driver integrated circuit  62  may be mounted on thin-film transistor layer driver ledge  82  or elsewhere in device  10 . A flexible printed circuit cable such as flexible printed circuit  64  may be used in routing signals between printed circuit  66  and thin-film transistor layer  58 . If desired, display driver integrated circuit  62  may be mounted on printed circuit  66  or flexible printed circuit  64 . 
     Printed circuit  66  may be formed from a rigid printed circuit board (e.g., a layer of fiberglass-filled epoxy) or a flexible printed circuit (e.g., a flexible sheet of polyimide or other flexible polymer layer). However, these examples are merely illustrative. If desired printed circuits  64  and  66  may be formed from a combination of rigid and flexible printed circuit layers (e.g., printed circuit  66  may be formed from a rigid printed circuit board with a layer of flexible printed circuitry that extends from an edge of printed circuit  66  to form flexible printed circuitry  64  that attaches to thin-film transistor layer  58 ). 
     Backlight structures  42  may include a backlight 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 laterally 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  74  that scatters upwards in direction Z 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 white plastic or other shiny materials. 
     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. 6 , optical films  70  and reflector  80  may have a matching rectangular footprint. 
     Display structures such as light guide plate  78  may be mounted in a support structure such as display chassis  90  of  FIG. 7 . Display chassis  90  may include plastic chassis structures and metal chassis structures. Display chassis  90  may serve as an interface between the structures of display  14  and surrounding portions of housing  12 . If desired, display chassis  90  may include a ring of plastic (e.g., a plastic ring with a thickness of about 0.2 to 1.5 mm, as an example) or may be formed from a plate of material that includes a rectangular recess to accommodate display structures such as light guide plate  78 . Chassis structure  90  may be formed from housing structures (e.g., as part of a housing frame, part of a unibody housing such as a metal housing, etc.). 
     The arrangement of  FIG. 7  in which chassis structure  90  surrounds light guide plate  78  and is formed from a single contiguous structure is merely illustrative. If desired, chassis structure  90  may only partially surround light guide plate  78 , may be formed from multiple structures, and/or may be formed from different materials. 
     An illustrative arrangement in which display  14  is mounted in a chassis structure that includes multiple parts formed from different materials is shown in  FIG. 8 . As shown in  FIG. 8 , chassis structure  90  may include a plastic display chassis such as plastic chassis member  90 P (sometimes referred to as a p-chassis) and a metal display chassis such as metal chassis member  90 M (sometimes referred to as an m-chassis). Plastic chassis member  90 P and metal chassis member  90 M may each be formed from a single structure or may each include multiple parts. 
     Display structures such as display layers  46  may be mounted on a planar portion such as portion  91  of plastic chassis  90 P. An adhesive such as adhesive  92  may be used in attaching an interior layer of display layers  46  such as lower polarizer  60  to planar surface  91  of plastic chassis  90 P. Adhesive  92  may be liquid adhesive, light-cured adhesive, pressure-sensitive adhesive, or other suitable adhesive. If desired, adhesive  92  may be optically clear adhesive. 
     Plastic chassis  90 P may have a protruding portion such as protruding portion  93  that extends between some of display layers  46  and light guide plate  78 . Adhesive such as adhesive  84  may be used in attaching light guide plate  78  to the underside of protruding portion  93  of plastic chassis  90 P. A display layer such as display layer  58  may be attached to plastic chassis  90 P using an adhesive such as adhesive  51 . Adhesives  51  and  84  may be liquid adhesives, light-cured adhesives, pressure-sensitive adhesives, or other suitable adhesives. If desired, adhesives  51  and  84  may be optically clear adhesives. 
     Plastic chassis  90 P may be formed from materials such as polycarbonate, polycarbonate acrylonitrile butadiene styrene (PC-ABS), nylon, glass-filled polycarbonate, glass-filled nylon, silicone, or other suitable materials. Using a glass-reinforced plastic may lower the thermal expansion coefficient of chassis  90 P. Chassis  90 P may include any suitable amount of glass fibers (e.g., 10%, 20%, 30%, 40%, or other suitable amount of glass). If desired, chassis  90  may contain a sufficient amount of glass to lower the thermal expansion coefficient to a desired level without causing chassis  90 P to be excessively rigid. If desired, chassis  90 P may be free of glass fibers. The example in which chassis  90 P is formed from glass-filled polycarbonate (e.g., a low-glass-filled polycarbonate) is merely illustrative. 
     Features such as low coefficient of thermal expansion and low rigidity may ensure that chassis  90 P provides structural support for display  14  without inducing undesired stress on display  14 . For example, the thermal expansion coefficient of chassis  90 P may be matched to that of other structures in device  10  such as device housing structures (e.g., housing  12  of  FIGS. 1, 2, and 3 ). This may ensure that chassis  90 P and the surrounding structures such as housing  12  expand at similar rates when device  10  heats up. 
     Chassis  90 P may be provided with other features that may help minimize mechanical stress on display  14 . For example, chassis  90 P may have a minimized footprint in the X-Y plane. Wall sections such as wall section  95  of chassis  90 P may, for example, have a width W of about 0.1 mm, 0.2 mm, 0.3 mm, less than 0.3 mm, more than 0.3 mm, etc. 
     Chassis structure  90 P may be molded (e.g., using an injection molding process or other suitable molding process), machined, thermoformed, or may be formed using any other suitable fabrication process. Plastic chassis  90 P may, for example, be injection molded over metal chassis  90 M (e.g., at the corners of device  10  or at other suitable locations in device  10 ). In the example of  FIG. 8 , plastic chassis  90 P is attached to metal chassis  90 M at location  89 . 
     Metal chassis  90 M may be formed from stainless steel sheet metal or other suitable materials. Chassis  90 M may have a planar portion such as portion  97  that overlaps light guide plate  78  and a bent portion such as portion  99  that wraps around an edge portion of light guide plate  78  (e.g., using a C-shaped wrap). As shown in  FIG. 8 , backlight structures may be mounted in c-shaped portion  99  of chassis  90 M. For example, light-emitting diodes  72  may be mounted on a substrate such as substrate  88 . Light-emitting diodes  72  and substrate  88  may be mounted within c-shaped portion  99  of chassis  90 M (e.g., light-emitting diodes  72  and substrate  88  may be interposed between upper and lower layers of metal chassis  90 M). Substrate  88  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  88  may be mounted on planar portion  97  of chassis  90 M. 
     As shown in  FIG. 8 , reflector  80  may be interposed between metal chassis  90 M and light guide plate  78 . Reflector  80  may be attached to plastic chassis  90 P using an adhesive such as adhesive  86  (e.g., a pressure sensitive or other suitable adhesive). 
     Metal chassis  90 M may be provided with features that may help minimize mechanical stress on display  14 . For example, as shown in  FIG. 9 , chassis  90 M may include flex promotion features such as flex promotion features  100 . Flex promotion features  100  may include holes, openings, notches, or perforations in curved portion  99  of chassis  90 M. Flex promotion features  100  may allow chassis  90  to flex slightly around flex axes  102  and  104 . Flex promotion features  100  may be formed using any suitable metalworking process (e.g., chemical etching, perforating, coining, stamping, other suitable methods, etc.). 
     As shown in  FIG. 9 , flex promotion features  100  may be formed along c-shaped portion  99 . Flex promotion features  100  may be formed locally at the bend in chassis  99 . If desired, flex promotion features  100  may extend into planar portion  97 , as shown by portion  106  of opening  100 . 
     In the example of  FIG. 9 , flex promotion features  100  are each formed as an elongated opening that is contiguous throughout the c-shape. This is, however, merely illustrative. If desired, flex promotion features  100  may have an arrangement of the type shown in  FIG. 10 . As shown in  FIG. 10 , flex promotion features  100  may each be formed as multiple openings in chassis  90 M. For example, flex promotion features  100  may include perforations formed along curved portion  99  of chassis  90 M. 
     The examples of  FIGS. 9 and 10  in which openings  100  have rounded shapes are merely illustrative. In general, openings  100  may have any suitable shape (triangular, rectangular, rectilinear, circular, thin lines, etc.). 
     If desired, a blackout layer may be used to prevent light from escaping through openings  100 .  FIG. 11  shows an illustrative arrangement in which a blackout layer such as blackout layer  85  is formed over openings  100  (e.g., on an exterior surface of chassis  90 M). Blackout layer  85  may be formed from an optically opaque film or adhesive (e.g., Mylar® film, other polyester film, other optically opaque adhesives or tapes, etc.). Blackout layer  85  may, for example, be formed from a layer of black polyester film having a thickness T of 20-30 microns. If desired, opaque layer  85  may be laminated to the exterior surface of chassis  90 M. 
     In the example of  FIG. 11 , blackout layer  85  is formed as a contiguous layer that covers openings  100  in chassis  90 M. This is, however, merely illustrative. If desired, optically opaque layer  85  may include separate portions that are localized to cover individual openings  100  in chassis  90 M. 
     Flex promotion features  100  of  FIGS. 9 and 10  may help reduce the rigidity of chassis  90 M while still allowing chassis  90 M to provide structural support for display  14 . If desired, bent portion  99  of metal chassis  90 M may be omitted. An illustrative arrangement in which metal chassis  90 M does not include c-shaped portion  99  is shown in  FIG. 12 . 
     As shown in  FIG. 12 , metal chassis  90 M includes planar portion  97  which overlaps light guide plate  78 . In the example of  FIG. 12 , metal chassis  90 M does not include a c-shaped portion that wraps around light-emitting diodes  72 . 
     Substrate  88  and light-emitting diodes  72  (sometimes collectively referred to as a “light bar”) may be mounted on planar surface  97  of metal chassis  90 M. If desired, an adhesive such as adhesive  108  may be used in attaching substrate  88  to sheet metal  90 M. Adhesive  108  may be pressure-sensitive adhesive or other suitable adhesive. If desired, other mounting mechanisms may be used to mount substrate  88  to sheet metal  90 M. Using an adhesive such as adhesive  108  is merely illustrative. 
     Light-emitting diodes  72  may each contain a semiconductor device that emits light. The semiconductor device in each diode may be mounted on lead frame structures in a molded plastic package such as molded plastic package  72 P. In order to provide planar surface  91  on which display layers  46  are mounted, plastic chassis  90 P may be insert molded (e.g., injection molded) over light-emitting diode packaging  72 P. This type of configuration may help minimize mechanical stress on display  14 . 
     Another suitable embodiment in which metal chassis  90 M does not include a bent portion that wraps around light-emitting diodes  72  is shown in  FIG. 13 . The arrangement shown in  FIG. 13  is similar to the arrangement of  FIG. 12  in that plastic chassis  90 P is molded over light-emitting diodes  72 . 
     In the example of  FIG. 13 , an encapsulant such as encapsulant material  94  may be formed over light-emitting diodes  72  (e.g., encapsulant  94  may be interposed between light-emitting diodes  72  and plastic chassis  90 P). Encapsulant material  94  may be formed from potting material or may be formed from other suitable low pressure molding materials. Examples of materials that may be used for encapsulant  94  include epoxy, silicone, polyurethane, polyamide, other suitable materials, a combination of these materials, etc. Potting or encapsulating light-emitting diodes  72  may provide protection for light-emitting diodes  72  during molding of plastic chassis  90 P over light-emitting diodes  72 . Encapsulant  94  may also provide protection for light-emitting diodes  72  after device  10  has been fully assembled. For example, encapsulant  94  may protect light-emitting diodes  72  from dust, dirt, moisture, and vibration. 
     Another suitable embodiment in which metal chassis  90 M does not include a bent portion that wraps around light-emitting diodes  72  is shown in  FIG. 14 . As shown in  FIG. 14 , plastic chassis  90 P may have a planar portion such as planar portion  91  on which display layers  46  are mounted. Plastic chassis  90 P may also have a bent portion such as bent portion  110  that wraps around light-emitting diodes  72  and attaches to metal chassis  90 M. 
     Plastic chassis  90 P may, for example, be injection molded over metal chassis  90 , thereby forming a tightly sealed mechanical bond at interface  96 . This is, however, merely illustrative. If desired, plastic chassis  90 P may be molded and then subsequently attached at interface  96  using an adhesive (e.g., a pressure-sensitive adhesive or other suitable adhesive). The arrangement of  FIG. 14  may provide structural support for display  14  while minimizing mechanical stress on display  14 . 
     Another suitable embodiment in which metal chassis  90 M does not include a bent portion that wraps around light-emitting diodes  72  is shown in  FIG. 15 . In the example of  FIG. 15 , plastic chassis  90 P forms at least part of a package for light-emitting diodes  72 . Each light-emitting diode may include a semiconductor device such as diode die  114 . Diode die  114  may be mounted on a lead frame structure such as lead frame structure  118 . A wire bond such as wire bond  116  may be used to electrically couple one of the diode&#39;s terminals to lead frame structure  118 . Lead frame structure  118  may extend out from packaging  90 P towards substrate  88  on which light-emitting diode  72  is mounted. Lead frame structure  118  may be mounted to solder pad  124  on substrate  88  using solder  120 . If desired, substrate  88  may be mounted to metal chassis  90 M using an adhesive such as adhesive  126 . 
     Thermoplastic may be molded over diode die  114  and lead frame structures  118  to form a packaging for light-emitting diodes  72  while also forming planar surface  91  on which display layers  46  are mounted. With this type of arrangement, the housing that packages light-emitting diodes  72  may be integral with plastic support structure  90 P that provides support surface  91  for display layers  46 . This type of arrangement may help minimize mechanical stress on display  14 . 
     Another suitable embodiment in which metal chassis  90 M does not include a bent portion that wraps around light-emitting diodes  72  is shown in  FIG. 16 . In the example of  FIG. 16 , plastic chassis  90 P is attached to light-emitting diode package  72 P using an adhesive such as adhesive  98 . Substrate  88  on which light-emitting diodes  72  are mounted may be attached to metal chassis  90 M using adhesive such as adhesive  112 . Adhesives  98  and  112  may be liquid adhesives, light-cured adhesives, pressure-sensitive adhesives or other suitable adhesives. 
     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.

Metadata:
Filing Date: 20121109
Publication Date: 20160726
Grant Date: 20160726
Priority Date: 20121109
Inventors: FRANKLIN JEREMY C.
GIBBS KEVIN D.
QIAN AMY
RAFF JOHN
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133615", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F2001/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0093", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0093", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133615", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0068", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0091", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B6/0088", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133528", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133317", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133615", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133514", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0073", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/1368", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0083", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B6/0088", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B6/0093", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 50681547