PATENT DOCUMENT

Publication Number: US-11626578-B2
Application Number: US-202117481751-A
Country: US
Kind Code: B2

Title: Borderless display with light-bending structures

Abstract:
An electronic device may be provided with a display mounted in a housing. The display may have an array of display pixels that provide image light to a user. The array of display pixels may form an active display structure with a rectangular shape. The rectangular active display structure may be surrounded by an inactive border region. Optical structures such as a sheet of glass or another optical member may have portions that are configured to bend light from the display pixels along the periphery of the active display structure. The optical member may have an area that is larger than the area of the active display structure, so that the presence of the optical member may serve to enlarge the apparent size of the display. Solidified liquid polymer may be used to support the optical structures and may be interposed between the optical structures and the active display structures.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 an organic light-emitting diode display layer having an active area that emits light and that is surrounded by an inactive border region; 
 a housing having a back surface opposite the organic light-emitting diode display layer, wherein the housing comprises sidewall portions; 
 a transparent display cover layer that has first and second opposing surfaces, wherein the first surface has a flat portion that defines a plane and overlaps the active area, wherein the first surface has a curved portion that curves out of the plane and overlaps the inactive border region, and wherein the transparent display cover layer redirects at least some of the light emitted by the active area to the curved portion over the inactive border region; and 
 a transparent layer interposed between the active area and the transparent display cover layer, wherein the inactive border region of the organic light-emitting diode display layer, at least one of the sidewall portions of the housing, the curved portion of the transparent display cover layer, and the transparent layer all overlap. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the first surface is an inner surface that faces the organic light-emitting diode display layer, and the second surface is an outer surface. 
     
     
       3. The electronic device defined in  claim 2  wherein the inactive border region of the organic light-emitting diode display layer overlaps the curved portion of the first surface of the transparent display cover layer, the transparent layer, and the sidewall portions of the housing. 
     
     
       4. The electronic device defined in  claim 3  wherein the transparent display cover layer has a first width and wherein the organic light-emitting diode display layer has a second width that is smaller than the first width. 
     
     
       5. The electronic device defined in  claim 4  wherein the curved portion of the transparent display cover layer is convex to guide at least some of the light emitted by the organic light-emitting diode display layer to have a viewable width that is greater than the second width. 
     
     
       6. The electronic device defined in  claim 2  wherein the curved portion of the inner surface is convex, and a part of the convex curved portion overlaps the organic light-emitting diode display layer. 
     
     
       7. The electronic device defined in  claim 6  wherein the transparent layer is a layer of optically clear adhesive that adheres the organic light-emitting diode display layer to the inner surface of the transparent display cover layer. 
     
     
       8. The electronic device defined in  claim 7  wherein the optically clear adhesive extends from a first one of the housing sidewall portions to a second one of the housing sidewall portions. 
     
     
       9. The electronic device defined in  claim 7  wherein the transparent display cover layer has a first index of refraction, and wherein the layer of optically clear adhesive has a second index of refraction that is less than the first index of refraction. 
     
     
       10. The electronic device defined in  claim 1  wherein the second surface is an inner surface that faces the organic light-emitting diode display layer, and the first surface is an outer surface. 
     
     
       11. The electronic device defined in  claim 10  wherein the curved portion of the outer surface is convex, and wherein a portion of the convex curved portion overlaps the organic light-emitting diode display layer.

Description:
This application is a continuation of U.S. patent application Ser. No. 16/806,224, filed Mar. 2, 2020, which is a continuation of U.S. patent application Ser. No. 15/234,955, filed Aug. 11, 2016, now U.S. Pat. No. 10,600,997, which is a continuation of U.S. patent application Ser. No. 13/631,024, filed Sep. 28, 2012, which are hereby incorporated by reference herein in their entireties. 
    
    
     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 and weight are often important considerations in designing electronic devices. If care is not taken, displays may be bulky or may be surrounded by overly large borders. 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 displays for electronic devices. 
     SUMMARY 
     An electronic device may be provided with a display. The display may be mounted in a housing. The display may have an array of display pixels that provide image light to a user. Display pixels may be organic light-emitting diode pixels, may be backlit liquid crystal display pixels, or may be display pixels of other types. 
     The array of display pixels may form an active display structure with a rectangular shape. The rectangular active display structure may be surrounded by an inactive display structure border region. Optical structures such as a sheet of glass or other optical member may have portions that are configured to bend light from the display pixels that are located along the periphery of the active display structure. 
     The optical member may have an area that is larger than area of the active display structure. The presence of the optical member and the portions of the optical member that are configured to bend the light may serve to enlarge the apparent size of the display. Solidified liquid polymer may be used to support the optical structures and may be interposed between the optical structures and the active display structures. A display cover layer may overlap the optical member. A touch sensor and coating layers may be included in the display. 
     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 top view of illustrative display layers in a display having an active region with an array of display pixels and an inactive border region in accordance with an embodiment of the present invention. 
         FIG.  7    is a diagram showing how a mold may be used to form display structures such as glass structures with curved surfaces in accordance with an embodiment of the present invention. 
         FIG.  8    is a diagram showing how a slumping process may be used to form display structures such as glass structures with curved surfaces in accordance with an embodiment of the present invention. 
         FIG.  9    is a diagram showing how a machining process may be used to form display structures such as glass structures with curved surfaces in accordance with an embodiment of the present invention. 
         FIG.  10    is a cross-sectional side view of an illustrative display with a glass layer having a curved portion along the edge of a lower surface for bending light produced by an array of display pixels and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  11    is a cross-sectional side view of an illustrative display with a glass layer having curved upper and lower surfaces along the edge of the glass layer for bending light produced by an array of display pixels and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  12    is a cross-sectional side view of an illustrative display with a glass layer having a convex curved upper surface for bending light produced by an array of display pixels and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  13    is a cross-sectional side view of an illustrative display with a glass layer having edges with curved upper surfaces for bending light produced by an array of display pixels and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  14    is a cross-sectional side view of an illustrative display with a glass layer having edges with curved upper surfaces for bending light produced by an array of display pixels that is separated from the glass layer by a gap and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  15    is a cross-sectional side view of an illustrative display with a glass layer having a convex curved upper surface for bending light produced by an array of display pixels that is separated from the glass layer by a gap and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  16    is a cross-sectional side view of an illustrative display with a display cover layer and optical structures with angled surfaces for bending light produced by an array of display pixels and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  17    is a cross-sectional side view of an illustrative display with a glass layer that is covered with one or more coating layers and that has an upper surface with curved edge regions for bending light produced by an array of display pixels and thereby creating a borderless appearance for the display in accordance with an embodiment of the present invention. 
         FIG.  18    is a cross-sectional side view of an illustrative display having a glass layer with a curved upper surface for bending light produced by an array of display pixels and having a layer of clear material such as solidified liquid polymer interposed between the glass layer and array of display pixels in accordance with an embodiment of the present invention. 
         FIG.  19    is a cross-sectional side view of an illustrative display having a glass layer with a curved lower surface for bending light produced by an array of display pixels and having a layer of clear material such as solidified liquid polymer interposed between the glass layer and array of display pixels in accordance with an embodiment of the present invention. 
         FIG.  20    is a cross-sectional side view of an illustrative display having a glass layer with a curved surface for bending light produced by an array of display pixels and having a planar display cover layer in accordance with an embodiment of the present invention. 
         FIG.  21    is a cross-sectional side view of an illustrative display having a glass layer with a curved surface for bending light produced by an array of display pixels and having a touch sensor located on a lower surface of the glass layer in accordance with an embodiment of the present invention. 
         FIG.  22    is a cross-sectional side view of an illustrative display having a glass layer with a curved surface for bending light produced by an array of display pixels and having a touch sensor located on an upper surface of the array of display pixels in accordance with an embodiment of the present invention. 
         FIG.  23    is a cross-sectional side view of an illustrative display having a glass layer with a curved surface for bending light produced by an array of display pixels and having a touch sensor located on an upper surface of the glass layer in accordance with an embodiment of the present invention. 
         FIG.  24    is a cross-sectional side view of an illustrative display having a glass layer with a curved surface for bending light produced by an array of display pixels and having a touch sensor located on an upper surface of the glass layer under an associated display cover layer in accordance with an embodiment of the present invention. 
         FIG.  25    is a cross-sectional side view of an illustrative display having a glass layer with a curved surface for bending light produced by an array of display pixels and having a touch sensor located on a lower surface of an associated display cover layer 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 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 structures. 
     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 . Display  14  may contain an array of display pixels (e.g., liquid crystal display pixels) that are organized in rows and columns. Control circuitry  29  may be used to display content for a user of device  10  on the array of display pixels in 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  (e.g., the array of display pixels in 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 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  14  may, if desired, have one or more optical structures that are located above display layers  46 . For example, display  14  may have a display cover layer such as display cover layer  84 . Display cover layer  84  may be formed from a layer of clear glass, a transparent sheet of plastic, or other transparent structure. Display cover layer  84  may be mounted in housing  12  (e.g., using housing sidewalls). During operation, light  44  may pass through the array of display pixels formed from display layers  46  and display cover layer  84  for viewing by user  48 . 
     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 sometimes be referred to as a display module, a display, or an array of display pixels. The image light (light  44 ) that passes through the array of display pixels is used in displaying content on display  14  for user  48 . 
     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 . 
     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.  5   ) 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 control circuitry such as 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 . During operation of display  14 , display driver circuitry  62  and/or other display control circuitry such as gate driver circuitry formed on substrate  58  or coupled to substrate  58  may be used in controlling the array of display pixels in layers  46  (e.g., using a grid of vertical data lines and horizontal gate lines). 
     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). 
     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. 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.  5   , optical films  70  and reflector  80  may have a matching rectangular footprint. Display layers  46  and the other display structures of  FIG.  5    typically have rectangular shapes with four peripheral edges, but display configurations with other shapes may be used in forming display  14  if desired. 
     As shown in  FIG.  6   , display structures  46  of display  14  may include a plurality of display pixels  86 . Display pixels  86  may be organized in rows and columns. Display control circuitry may be used in controlling the operation of display pixels  86  using signal lines such as data lines  88  and gate lines  90 . In liquid crystal displays, display pixels  86  may each contain an electrode for applying an electric field to an associated portion of liquid crystal layer  52  ( FIG.  5   ) and a thin-film (amorphous silicon or polysilicon) transistor for controlling the magnitude of the signal applied to the electrode and therefore the magnitude of the electric field. In other types of displays, display pixels  86  may be formed from other types of structures (e.g., organic light-emitting diodes, etc.). 
     Lines  90  may be coupled to the gates of the thin-film transistors and may sometimes be referred to as gate lines. Lines  88  may be coupled to the sources of the thin-film transistors and may sometimes be referred to as source lines or data lines. Gate driver circuitry (e.g., thin-film transistor gate driver circuitry) may be coupled to gate lines  90 . Display driver circuitry that produces data signals for lines  88  (e.g., a display driver integrated circuit) may be coupled to data lines  88 . 
     Gate driver circuitry, one or more display driver integrated circuits, traces for distributing gate and data signals and other display control signals, and other display control circuitry may be formed in inactive region  461  of display  14  and display structures  46 . As an example, a display driver integrated circuit may be mounted along the upper segment of inactive region  461 , whereas gate driver thin-film circuitry may be formed along the left and right segments of inactive region  461 . During operation of display  14 , display pixels  86  may display images for a user, so the portion of display structures  46  containing display pixels  86  may sometimes be referred to as active display structures or the active area of display  14 . The metal traces and other display control circuit structures in inactive region  461  do not display any images, so this portion of structures  46  may sometimes be referred to as inactive display structures. 
     Inactive region  461  may form a border that surrounds some or all of active area  46 A. For example, inactive region  461  may have a rectangular ring shape of the type shown in  FIG.  6    having opposing upper and lower border segments and left and right border segments. To provide display  14  with a borderless appearance, display  14  may be provided with optical structures such as glass layers with curved or angled surfaces. The optical structures may be configured to bend and therefore guide light that is emitted from the array of display pixels  86  in active area  46 A into a portion of display  14  that overlaps inactive area  461 . By using optical structures to bend light from active area  46 A, content may be displayed in portions of display  14  that overlap inactive regions  461 , providing display  14  with a borderless or near borderless appearance. 
     The optical structures that are used to enhance the apparent size of display  14  may be formed from transparent materials such as clear glass or plastic structures. As an example, the optical structures may be formed from sheets of clear glass or plastic material or from glass, plastic, or other transparent material of other shapes. Optical structures with curved surfaces for bending light may be formed using molding equipment, slumping equipment, machining equipment, or other tools for shaping clear material. 
       FIG.  7    is a diagram showing how a mold may be used to form optical structures with curved surfaces for bending light in display  14 . As shown in  FIG.  7   , molding equipment  92  may include mold structures such as upper mold structures  94  and lower mold structures  98 . Structures such as mold structures  94  and  98  may be heated. Optical material  102  (e.g., glass, plastic, ceramic, etc.) may be molded between the opposing surfaces of mold structures  94  and  98  (e.g., when upper mold structure  94  is moved in direction  96  and/or when lower mold structures  98  is moved in direction  100 ). If desired, molding operations may also involve injection molding techniques. By molding material  102  with molding equipment  92 , optical structures  104  that have curved or angle surfaces may be formed. 
     As shown in the illustrative configuration of  FIG.  8   , a slumping process may be used in forming optical structures with curved surfaces for bending light in display  14 . Slumping equipment  106  may include a heated metal structure or other equipment with exposed curved surfaces such as curved surface  110 . Optical material  108  (e.g., glass, plastic, ceramic, etc.) may be placed on top of surface  110  while slumping equipment  106  is heated. When equipment  106  reaches a sufficiently high temperature, optical material  108  will slump under its own weight, thereby creating optical structures with curved surfaces such as optical structures  112 . Following cooling, structures  112  may be removed from slumping equipment  106 . As shown on the right-hand side of  FIG.  8   , the resulting shape for optical structures  112  may have curved surfaces such as curved upper surface  114  and curved lower surface  116 . 
       FIG.  9    is a diagram showing how a machining process may be used to form display structures such as glass structures with curved surfaces. As shown in  FIG.  9   , optical material  130  may be processed using machining equipment  118 . Machining equipment  118  may have a machining head such as head  124  (e.g., a drill bit, milling cutter, or other machining tool). Actuator  120  may use shaft  122  to rotate head  124  in direction  126  about rotational axis  128 . Actuator  120  may include a motor for rotating shaft  122  and computer-controlled positioners for adjusting the location of shaft  122  and head  124  relative to optical material  130 . Following machining of the edges or other portions of optical structures  130 , optical structures  130  may have curved surfaces such as curved surfaces  132 , as shown on the right-hand side of  FIG.  9   . 
     By providing optical structures in display  14  with curved edges or other curved or angled surfaces, the optical structures may bend light that is emitted from display pixels  86  in a way that allows the light to extend laterally outward over the otherwise inactive portions of the display. As a result, it will appear to a user of the display as if the display is borderless or nearly borderless. 
     An illustrative display of the type that may use curved optical structures to achieve a borderless or near borderless appearance to a viewer is shown in  FIG.  10   . As shown in the cross-sectional side view of display  14  in  FIG.  10   , display  14  may include active area display layers such as active display structures  46 A. Inactive display structures such as inactive display structures  461  of  FIG.  6    are not shown. Active area display structures  46 A may contain a rectangular array of display pixels such as display pixels  86  with a rectangular peripheral edge. Light rays  44  associated with display pixels may be produced by a backlight unit (e.g., a backlight unit in a display such as a backlit liquid crystal display), may be produced by light reflected off of a reflector such as reflector  80  of  FIG.  5   , or may be emitted by light-emitting diode structures or other light sources within display pixels  86 . 
     Optical structures  134  (e.g., optical structures of the type formed using the equipment of  FIGS.  7 ,  8 , and  9    or other equipment) may be formed from transparent optical members. For example, a display may be provided with an optical structure such as a transparent member formed from glass, plastic, ceramic, or other clear material. An optical member such as optical member  134  of  FIG.  10    may have planar surfaces such as upper surface  136  (in the example of  FIG.  10   ) and may have curved surfaces such as curved surfaces  138 . Curved surfaces may be located on the upper and/or lower side of optical member  134 . As shown in  FIG.  10   , for example, curved surfaces  138  may be located in peripheral edge portions of optical member  134  (e.g., the left and right edges of member  134  and, if desired, the upper and lower edges of member  134 , as viewed from above in direction  50  by viewer  48 ). 
     Curved surfaces  138  may allow optical structures such as member  134  to serve as light bending structures to bend light  44  from active display structures  46 A so that the entire lateral expanse of display  14  appears to be filled with active image content. Display  14  may, for example, appear to have no left and right borders (when viewed in direction  50 ) and/or may additionally have no upper and lower borders (when viewed in direction  50 ). The lateral dimensions (in X and Y) for active display structures  46 A are less than the respective lateral dimensions X and Y of optical member  134 , so the apparent image size for display  14  is enlarged. By enlarging the apparent size of the display, the display may be made to appear borderless or nearly borderless, even if active display structures  46 A are surrounded by a border of inactive structures such as structures  46 B. 
     Rays of light from active display structures  46 A such as light ray  44 M are produced by display pixels  86  that are near to the center of display  14 . In this portion of display  14 , light may travel vertically upwards to viewer  48  without significant bending. Near to the peripheral edges of active display structures  46 A, light rays such as light rays  44 E are emitted that are bent by the curved nature of the edges of optical structures  134  (i.e., curved surfaces  138 ). 
     As shown by the bent trajectory of light rays  44 E, light rays  44 E that are emitted by display pixels  86  along the edges of active display structures  46 A may, upon passing through optical structures  134 , appear to viewer  48  as if they were emitted by display pixels located in inactive border region IA. The lateral extent (e.g., width W in  FIG.  10   ) of display  14  over which light rays  44  are emitted and therefore the effective size of display  14  for displaying content to viewer  48  is enhanced by the presence of curved portions  138  of optical member  134 , so it appears as if display  14  has an active area of lateral dimension W, rather than the more limited size of active area AA that is associated with the physical size of the array of display pixels  86  in structures  46 A. In this way, surface  136  can be entirely covered with active display pixel content (e.g., graphics, text, video, etc.), providing display  14  with a borderless or nearly borderless appearance, despite the presence of display control circuitry and other inactive structures in inactive region  461  of display structures  46  ( FIG.  6   ). 
     In the illustrative example of  FIG.  10   , optical structures  134  have curved surfaces  138  that are located on the lower side of structures  134  near the peripheral edge of structures  134 . Structures  134  may have a rectangular shape when viewed in direction  50  (i.e., structures  134  may be formed from a rectangular sheet of optical material or other planar member with curved edge surfaces). One or more, two or more, three or more, or four of the edges of rectangular optical structures  134  may be provided with curved surfaces such as surfaces  138 . 
     If desired, both the upper and lower sides of optical structures  134  may be provided with curved surfaces such as curved surfaces  138 , as shown in  FIG.  11   . Curved surfaces  138  may cover some or all of the upper and lower surfaces of structures  134 . In the example of  FIG.  11   , curved surfaces  138  are formed in peripheral portions of optical structures  134 , but not in the central portions of structures  134 . The center portions of the upper and lower surface of optical structures  134  may be planar. 
       FIG.  12    shows how the upper surface of optical structures  134  may be provided with a curved (convex) shape using upper curved surface  138 . The lower surface of optical structures  134  in this type of configuration may be planar (as an example). 
     In the configuration of  FIG.  13   , display  14  has been provide with optical structures  134  that have an upper surface with a planar central region and curved peripheral edge portions  138 . The lower surface of optical structures  134  may be planar. 
     Optical structures  134  may be mounted against active display structures  46 A or may be mounted so that an air gap or a gap filled with materials other than air is formed between optical structures  134  and active display structures  46 A.  FIG.  14    is a cross-sectional side view of display  14  in a configuration in which optical structures  134  have been mounted so that there is an air gap G between optical structures  134  and display structures  46 A. In  FIG.  14   , the center of the upper surface of optical structures  134  is planar.  FIG.  15    is a cross-sectional side view of display  14  in a configuration in which optical structures  134  with a curved upper surface (surface  138 ) have been separated from display structures  46 A by an air gap of size G. 
     Optical structures  134  (e.g., glass, plastic, or ceramic optical members of the types described in connection  FIGS.  10 - 15   ) may be mounted on the exterior of device  10  or in the interior of device  10 . When mounted as the outermost structural display layer in device  10 , optical structures  134  may sometimes be referred to as a display cover layer or display cover layer structures. When mounted in the interior of device  10 , optical structures  134  may be covered by one or more additional layers of transparent material such as a display cover layer and/or other layers of clear material. 
       FIG.  16    is a cross-sectional side view of display  14  in an illustrative configuration in which optical structures  134  have been covered by additional optical structures such as display cover layer  140 . Display cover layer  140  may be a layer of transparent material such as a clear layer of plastic, glass or ceramic (as examples). Light bending optical structures  134  of  FIG.  16    have been formed from glass, plastic, or other clear material with a shape that exhibits a triangular cross-section (i.e. a shape with sloped surfaces  138 ). Sloped surfaces  138  may form planar or non-planar curved surfaces for bending light. Air gap G may separate the lower surface of display cover layer  140  and the upper surface of display structures  46 A. Optical structures  134  of  FIG.  16    may run along the right and left edges of display  14  (e.g., make display  14  appear borderless along its right and left edges), may run around the entire periphery of display  14  (e.g., structures  134  may have a rectangular ring shape with a central opening that makes display  14  appear borderless along all four of its edges), or may be configured to cover other portions of the edges of display  14 . 
     As shown in  FIG.  17   , optical structures  134  may be provided with optical coating layers such as layers  142 . Layers  142  may be formed from dielectrics such as sputtered oxides, from clear materials deposited using physical vapor deposition, chemical vapor deposition, or other deposition techniques (e.g., coatings of glass, polymer, ceramic, or other materials), or may be formed from other transparent coating layers on optical structures  134 . There may be one or more layers  142 , two or more layers  142 , three or more layers  142 , or four or more layers  142 . Layers  142  may include layers such as antireflection layers, antismudge layers, antiscratch layers, or other layers to modify the properties of the upper and/or lower surface of optical structures  134 . 
     It may be desirable to use optically clear support structures such as layers of cured clear adhesive (transparent solidified liquid polymer) to support optical structures  134 . As shown in  FIG.  18   , for example, device  10  may have a clear polymer layer such as polymer structure  144  for supporting optical structures  134 . Components  146  may be mounted within housing  12 . Display structures  46  may be mounted on support structures such as portions of housing  12  or other structures. To provide display  14  with a borderless or nearly borderless appearance, optical structures  134  may have curved surfaces such as curved surfaces  138 . Polymer material  144  may be formed from a cured optical adhesive (e.g., optically clear adhesive). Initially, when in an uncured liquid state, polymer  144  may be placed on top of display structures  46  (e.g., by dripping, screen printing, spraying, etc.) Optical structures  134  may then be placed on top of the liquid polymer. Ultraviolet light curing or thermal curing techniques may then be used to cure the polymer material to form solid polymer support structures such as structures  144  of  FIG.  18   . 
     Structures  144  of  FIG.  18    may support optical structures  134  and may hold structures  134  at a desired distance from display structures  46  such as active display structures  46 A and may help attach optical structures  134  to device  10 . Polymer material  144  may, if desired, have a relatively low index of refraction compared to the index of refraction of optical structures  134 . For example, optical structures  134  may be formed from a material such as glass with an index of refraction of 1.4 or above (e.g., 1.4 to 1.8), whereas polymer material  144  may have an index of refraction of less than 1.4, less than 1.3, less than 1.2, or less than 1.1 (e.g., 1.0 to 1.2). In this way, polymer material  144  may behave optically as an air gap, allowing light  44  to be bent effectively by curved surfaces  138  of optical structures  134 . 
       FIG.  19    is a cross-sectional side view of device  10  in a configuration in which curved surfaces  138  of optical structures  134  have been formed on the lower surface of optical structures  134 , adjacent to solidified liquid polymer material  144 . 
     In the illustrative configuration of  FIG.  20   , optical structures  134  have been covered with a layer of transparent material such as display cover layer  140 . Display cover layer  140  may be a planar sheet of glass, plastic, or ceramic. Optical structures  134  may have a planar upper surface such as upper surface  136 . Angled edge surfaces  138  may lie in planes that are not coplanar with upper surface  136  to allow the edges of optical structures  134  to bend light from display structures  46 . Air gaps such as gap G may separate optical structures such as optical structures  134  of  FIG.  20    or other optical structures  134  from display cover layer  140  and/or polymer such as polymer  144  may be interposed between display cover layer  140  and optical structures  134  and/or between optical structures  134  and display structures  46 . 
     If desired, device  10  may be provided with touch sensor functionality. A touch sensor for device  10  may be implemented using an array of capacitive touch sensor electrodes (e.g., transparent conductive electrodes such as indium tin oxide electrodes), may use resistive touch technology, light-based touch sensors, acoustic touch sensor technology, or other touch sensor technology. As an example, a capacitive touch sensor for device  10  may be implemented using a one-sided or two-sided array of indium tin oxide electrodes. The electrodes may be formed on a touch sensor substrate such as a layer of glass or plastic that is separate from other layers in display  14  (e.g., a touch sensor substrate that is mounted within display  14  using adhesive) or may be formed on the surface of optical structures  134 , display cover layer  140 , or other structures in display  14 . 
       FIG.  21    is a cross-sectional side view of display  14  in a configuration in which touch sensor  146  has been formed on the lower surface of optical structures  134 . An air gap or polymer gap may separate touch sensor  146  from display structures  46 A. Touch sensor  146  may include capacitive touch sensor structures such as a one-layer or two-layer array of indium tin oxide electrodes. The indium tin oxide electrodes may be formed directly on the lower surface of optical structures  134  or may be formed on a substrate (e.g., a sheet of glass or polymer) that is attached to the underside of optical structures  134  by adhesive (as examples). An air gap or a gap filled with polymer  144  may separate display structures  46 A from touch sensor  146 . 
     In the illustrative configuration of  FIG.  22   , touch sensor  146  has been formed on the surface of display structures  46 A (e.g., by attaching a touch panel with a thin glass or polymer substrate to display structures  46 A with adhesive). 
       FIG.  23    is a cross-sectional side view of display  14  in a configuration in which touch sensor  146  has been formed on the upper surface of optical structures  134 . Touch sensor  146  may have portions that are bent to conform to the shape of curved surfaces  138  of optical structures  134 . 
       FIG.  24    is a cross-sectional side view of display  14  in a configuration in which touch sensor  146  has been formed on the upper surface of optical structures  134  and in which device  10  has a display cover layer such as cover layer  14 . Cover layer  140  may be separated by an air gap or a gap filled with polymer  144  from touch sensor  146  and optical structures  134 . 
       FIG.  25    is a cross-sectional side view of display  14  in a configuration in which touch sensor  146  has been formed on the underside of display cover layer  140  (either as layers deposited directly on display cover layer  140  or as a touch panel that is attached to display cover layer  140  with adhesive). An air gap or a gap filled with polymer  144  may separate touch sensor  146  of  FIG.  25    from optical structures  134 . 
     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: 20210922
Publication Date: 20230411
Grant Date: 20230411
Priority Date: 20120928
Inventors: YANG, Tseng-mau
PREST, CHRISTOPHER D.
MEMERING, DALE N.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133526", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/8428", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K50/84", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133331", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133526", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133331", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/858", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133331", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133526", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L51/525", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L27/323", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L51/5237", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L51/5275", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133308", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/8723", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/879", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 50384848