PATENT DOCUMENT

Publication Number: US-9214507-B2
Application Number: US-201213588831-A
Country: US
Kind Code: B2

Title: Narrow border organic light-emitting diode display

Abstract:
An electronic device may be provided having an organic light-emitting diode display and control circuitry for operating the display. The display may include one or more display layers interposed between the control circuitry and a display layer having thin-film transistors. The electronic device may include a coupling structure interposed between the layer of thin-film transistors and the control circuitry that electrically couples the layer of thin-film transistors to the control circuitry. The coupling structure may include a dielectric member having a conductive via, a flexible printed circuit having a bent portion, or a conductive via formed in an encapsulation layer of the display. The display may include a layer of opaque masking material. The layer of opaque masking material may be formed on an encapsulation layer, an organic emissive layer, a thin-film transistor layer, or a glass layer of the organic light-emitting diode display.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 an organic light-emitting diode display that includes an array of thin-film transistors; 
 control circuitry configured to generate control signals for operating the organic light-emitting diode display, wherein the organic light-emitting diode display includes at least one display layer interposed between the array of thin-film transistors and the control circuitry; and 
 at least one coupling structure that couples the array of thin-film transistors to the control circuitry, wherein the at least one coupling structure includes a conductive via coupled between the array of thin-film transistors and the control circuitry. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the at least one coupling structure comprises a dielectric member interposed between a portion of the array of thin-film transistors and the control circuitry. 
     
     
       3. The electronic device defined in  claim 2  wherein the conductive via is coupled to the array of thin-film transistors using an anisotropic conductive adhesive. 
     
     
       4. The electronic device defined in  claim 2  wherein the control circuitry comprises a printed circuit board and a flexible printed circuit attached to the printed circuit board. 
     
     
       5. The electronic device defined in  claim 4  wherein the at least one coupling structure is attached to the flexible printed circuit using an anisotropic conductive adhesive. 
     
     
       6. The electronic device defined in  claim 5  wherein the at least one display layer comprises a layer of organic emissive material. 
     
     
       7. The electronic device defined in  claim 6  wherein the at least one display layer further comprises an encapsulation layer that covers the layer of organic emissive material. 
     
     
       8. The electronic device defined in  claim 1  wherein the at least one display layer comprises a layer of organic emissive material. 
     
     
       9. The electronic device defined in  claim 8  wherein the at least one display layer further comprises an encapsulation layer that covers the layer of organic emissive material. 
     
     
       10. The electronic device defined in  claim 9  wherein the at least one coupling structure comprises a conductive via in the encapsulation layer that extends from a first surface of the encapsulation layer to a second surface of the encapsulation layer. 
     
     
       11. The electronic device defined in  claim 10  wherein the control circuitry comprises a flexible printed circuit and wherein the conductive via is attached to the flexible printed circuit using anisotropic conductive adhesive. 
     
     
       12. An electronic device, comprising:
 an organic light-emitting diode display that includes an array of thin-film transistors; 
 control circuitry configured to generate control signals for operating the organic light-emitting diode display, wherein the organic light-emitting diode display includes at least one display layer interposed between the array of thin-film transistors and the control circuitry; and 
 at least one coupling structure that couples the array of thin-film transistors to the control circuitry, wherein the at least one coupling structure comprises a flexible printed circuit having a bent portion that extends around the at least one display layer. 
 
     
     
       13. The electronic device defined in  claim 12  wherein the control circuitry comprises a printed circuit board and wherein the flexible printed circuit couples the array of thin-film transistors to the printed circuit board. 
     
     
       14. The electronic device defined in  claim 12  wherein the at least one display layer is transparent. 
     
     
       15. A display, comprising:
 an organic light-emitting diode layer having opposing first and second surfaces; 
 an encapsulation layer formed on the first surface; 
 a substrate layer formed on the second surface; and 
 a conductive via formed in the substrate layer that couples the organic light-emitting diode layer to control circuitry for the display. 
 
     
     
       16. The display defined in  claim 15  wherein the display includes an active area for displaying images and an inactive area, the display further comprising a layer of opaque masking material formed on a display layer in the inactive area. 
     
     
       17. The display defined in  claim 16  wherein the opaque masking material is interposed between a portion of the encapsulation layer and a portion of the organic light-emitting diode layer. 
     
     
       18. The display defined in  claim 16 , further comprising:
 a light-polarizing layer formed on the encapsulation layer, wherein the opaque masking material is interposed between the light-polarizing layer and the encapsulation layer. 
 
     
     
       19. The display defined in  claim 16  wherein the organic light-emitting diode layer comprises a layer of thin-film transistor circuitry and a layer of organic light-emitting material. 
     
     
       20. The display defined in  claim 19  wherein opaque masking material is formed on the layer of thin-film transistor circuitry. 
     
     
       21. A display, comprising:
 a transparent substrate layer having opposing first and second surfaces; 
 an organic light-emitting diode layer on the first surface; and 
 a light-polarizing layer formed on the second surface; and 
 opaque masking material interposed between a portion of the transparent substrate layer and a portion of the light-polarizing layer. 
 
     
     
       22. The display defined in  claim 21  wherein the transparent substrate layer comprises glass. 
     
     
       23. The display defined in  claim 22  wherein the opaque masking material comprises a polymer material infused with an opaque dye. 
     
     
       24. The display defined in  claim 22  wherein the opaque masking material comprises chrome oxide.

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 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 ways to provide displays for electronic devices. 
     SUMMARY 
     An electronic device may be provided with an organic light-emitting diode display. The display may include an organic light-emitting diode layer that includes an array of thin-film transistors and a layer of organic light-emitting material. 
     The electronic device may include control circuitry that generates control signals for operating the organic light-emitting diode display. The display may include at least one display layer interposed between the array of thin-film transistors and the control circuitry. The electronic device may include one or more coupling structures that electrically couple the array of thin-film transistors to the control circuitry. 
     The coupling structures may include a dielectric member that includes a conductive via interposed between a portion of the array of thin-film transistors and the control circuitry. 
     The control circuitry may include a flexible printed circuit attached to a printed circuit board and, if desired, a display driver integrated circuit attached to the printed circuit board. 
     The layer of organic light-emitting material and an encapsulation layer that covers the layer of organic light-emitting material may be interposed between the array of thin-film transistors and the control circuitry. 
     The coupling member may include a flexible printed circuit having a bent portion or may include a conductive via in the encapsulation layer that extends from a first surface of the encapsulation layer to a second surface of the encapsulation layer. 
     The display may include an organic light-emitting diode layer having opposing first and second surfaces, an encapsulation layer formed on the first surface, and a substrate layer such as a polyimide layer formed on the second surface. A conductive via may be provided in the substrate layer that couples the organic light-emitting diode layer to the control circuitry. 
     The display may include an active area for displaying images and an inactive area and layer of opaque masking material formed on a display layer in the inactive area. The opaque masking material may be interposed between a portion of the encapsulation layer and a portion of the organic light-emitting diode layer, may be formed between a light-polarizing layer for the and the encapsulation layer, or may be formed on the layer of thin-film transistor circuitry. 
     The display may include a transparent substrate layer such as a glass layer having opposing first and second surfaces, the organic light-emitting diode layer may be formed on the on the first surface, a light-polarizing layer may be formed on the second surface, and the opaque masking material may be interposed between a portion of the transparent substrate layer and a portion of the light-polarizing layer. 
     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. 5A  is a cross-sectional side view of an illustrative bottom emission organic light-emitting diode display in accordance with an embodiment of the present invention. 
         FIG. 5B  is a cross-sectional side view of a top emission organic light-emitting diode display accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional side view of a portion of an illustrative display having an organic light-emitting diode array and a gap-filling member in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional side view of a portion of an illustrative display having an organic light-emitting diode array and a bent flexible circuit substrate in accordance with an embodiment of the present invention. 
         FIG. 8  is a cross-sectional side view of a portion of an illustrative display having an organic light-emitting diode array and an extended encapsulation layer with a conductive via in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional side view of a portion of an illustrative display having an organic light-emitting diode array and an opaque mask showing various display layers on which the opaque mask may be formed in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional side view of a portion of an illustrative display having an organic light-emitting diode array and an opaque mask formed on a glass layer of the display 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). 
     Peripheral portions of display  14  may be provided with an opaque masking layer. As shown in  FIGS. 1 ,  2 , and  3 , display  14  may be characterized by a central active region such as active region AA in which an array of display pixels is used in displaying information for a user. Active region AA may be surrounded by an inactive region such as inactive border region IA. Active region AA may have a rectangular shape bordered by rectangular line  21 . Inactive region IA may have a rectangular ring shape that surrounds active region AA (as an example). Portions of display  14  in inactive region IA may be covered with an opaque masking material such as a layer of black ink (e.g., a polymer filled with carbon black) or a layer of opaque metal. The opaque masking layer may help hide components in the interior of device  10  in inactive region IA from view by a user. 
     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 OLED components to form display  14 , so configurations for display  14  in which display  14  is an organic light-emitting diode display are sometimes described herein as an example. Other types of display technology may be used in device  10  if desired. 
     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 OLED 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. 
     Cross-sectional side views of configurations 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  FIGS. 5A and 5B .  FIG. 5A  is a cross-sectional side view of an illustrative bottom emission organic light-emitting diode display.  FIG. 5B  is a cross-sectional side view of an illustrative top emission organic light-emitting diode display. 
     In a configuration for display  14  of the type shown in  FIG. 5A , display  14  may have a transparent substrate layer such as glass layer  52 . A layer of organic light-emitting diode structures such as organic light-emitting diode layer  54  may be formed on the underside of glass layer  52 . An encapsulation layer such as encapsulation layer  56  may be used to encapsulate organic light-emitting diode layer  54 . Encapsulation layer  56  may be formed from a layer of metal foil, metal foil covered with plastic, other metal structures, a glass layer, a thin-film encapsulation layer formed from a material such as silicon nitride, a layered stack of alternating polymer and ceramic materials, or other suitable material for encapsulating organic light-emitting diode layer  54 . Encapsulation layer  56  may be used to protect organic light-emitting diode layer  54  from environmental exposure by preventing water and oxygen from reaching organic emissive materials within organic light-emitting diode layer  54 . 
     Organic light-emitting diode layer  54  may contain an array of thin-film transistors. The thin-film transistors may be formed from semiconductors such as amorphous silicon, polysilicon, or compound semiconductors (as examples). Signal lines (e.g., a grid of horizontal and vertical metal lines) may be used in applying control signals to the array of thin-film transistors. During operation, signals may be applied to the organic light-emitting diodes in layer  54  using the signal lines so that an image may be created on display  14 . Image light  60  from the organic light-emitting diode pixels in layer  54  may be emitted upwards through transparent glass layer  52  for viewing in direction  64  by viewer  62 . Circular polarizer  50  may suppress reflections from the metal signal lines in layer  54  that might otherwise be visible to viewer  62 . 
     In a configuration for display  14  of the type shown in  FIG. 5B , display  14  may have a substrate layer such as substrate layer  58 . Substrate layer  58  may be a polyimide layer that is temporarily carried on a glass carrier during manufacturing or may be a layer formed from glass or other suitable substrate materials. 
     Organic light-emitting diode layer  54  may be formed on the upper surface of substrate  58 . An encapsulation layer such as encapsulation layer  56  may be used to encapsulate organic light-emitting diode layer  54 . During operation, individually controlled pixels in organic light-emitting diode layer  54  may be used to generate image light  60  for viewing in direction  64  by viewer  62 . Circular polarizer  50  may suppress reflections from metal signal lines in layer  54 . If desired an array of color filter elements may be included in polarizer layer  50 . 
       FIG. 6  is a cross-sectional side view of a bottom-emissive organic light-emitting diode display of the type shown in  FIG. 5A  showing how the size of inactive area IA may be minimized by forming control circuitry such as control circuitry  28  ( FIG. 4 ) for the display behind a portion of the display. As shown in  FIG. 6 , control circuitry  28  may include component  82  and printed circuit  74  that are coupled to display  14 . Printed circuit  74  may, for example, be a printed circuit board. Printed circuit  74  may be a dedicated printed circuit for controlling operation of display  14  or may be a printed circuit board such as a mother board that is used in controlling multiple components within device  10 . 
     As shown in  FIG. 6 , control circuitry for display  14  (e.g., printed circuit  74  and component  82 ) may be formed behind display  14  so that the control circuitry is not visible to a viewer such as viewer  62  viewing display  14  in direction  64  and without extending beyond edge  71  of display  14 . In this way, the size of inactive area IA may be reduced in comparison with conventional displays in which a display driver integrated circuit is formed along the edge of the display. 
     Component  82  may, for example, be a display driver integrated circuit that is used to generate control signals to be conveyed to thin-film transistors in thin-film-transistor layer  70  of OLED layer  54 . Printed circuit  74  and/or component  82  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 control circuitry such as printed circuit  74  to thin-film-transistors in layer  70  using a signal path such as a signal path  88  formed from conductive metal traces in printed circuit  76  (as an example). 
     Printed circuit  76  may, for example be a flexible printed circuit (e.g., a flexible printed circuit cable). Printed circuit  76  may be used in routing signals between printed circuit  74  and thin-film-transistor layer  70 . If desired, display driver integrated circuit  82  may be mounted on printed circuit  74  or flexible printed circuit  76 . Printed circuit  74  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). Printed circuit  76  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). In one suitable example that is sometimes described herein, printed circuit  76  is implemented as a flexible printed circuit. 
     Signal path  88  may be coupled to signal path  84  in printed circuit board  74  using conductive contact  86 . Conductive contact  86  may be formed from a conductive adhesive, solder, or other suitable conductive structures or materials. 
     Organic-light-emitting diode layer  54  may include thin-film transistor (TFT) layer  70  and a layer of organic light-emitting material such as emissive layer  72 . TFT layer  70  may include an array of thin-film transistors. The thin-film transistors may be formed from semiconductors such as amorphous silicon, polysilicon, or compound semiconductors (as examples). Organic emissive layer  72  may be formed from organic plastics such as polyfluorene or other organic emissive materials. Encapsulation layer  56  may cover emissive layer  72  and, if desired, some or all of TFT layer  70 . 
     Signal lines  94  (e.g., a grid of horizontal and vertical metal lines) may be used in applying control signals to the array of thin-film transistors in TFT layer  70 . Signals applied to the thin-film transistors in TFT layer  70  may selectively cause portions of emissive layer  72  to emit display light such as light  66 . In this way, images may be created on display  14 . 
     Thin-film transistors in TFT layer  70  may be formed in active area AA. Signal lines  94  may be used to route signals received from printed circuit  74  in inactive area IA to the thin-film transistors in TFT layer  70 . However, in some situations, emissive layer  72  and encapsulation layer  56  may form a gap between flexible printed circuit  76  and TFT layer  70 . In order to couple signal lines  94  in TFT layer  70  to signal lines  88  in printed circuit  76 , a dielectric spacer such as gap-filling member  78  may be provided that has a conductive via such as via  80 . 
     Conductive via  80  in spacer  78  may be used to route signals to TFT layer  70  from printed circuit  76  (or from other components such as integrated circuit  82 ). Conductive contacts  90  (e.g., contacts formed from conductive adhesive, anisotropic conductive adhesive, solder, etc.) may be used to couple via  80  to conductive contacts on flexible printed circuit  76  and TFT layer  70 . 
     Gap-filling member  78  may be formed from a polymer material or other dielectric material in which a conductive via can be formed. Via  80  may be formed in member  78  by forming a opening (e.g., by mechanical drilling or laser drilling) in member  78  and forming a conductive coating or a conductive filler material (e.g., conductive paste, conductive adhesive, conductive foam, or other suitable conductive material) within the opening. However, this is merely illustrative. If desired, member  78  may be formed from additional layers of flexible printed circuit material (e.g., polyimide) or additional layers of rigid printed circuit material (e.g., glass infused epoxy). 
     As examples, member  78  may be formed from a portion of printed circuit board  74  that extends beyond encapsulation layer  56  under TFT layer  70  and includes additional layers of printed circuit board material, member  78  may be a portion of flexible printed circuit  76  having additional layers of flexible printed circuit material or member  78  and flexible printed circuit  76  may be formed from a common printed circuit having rigid and flexible portions (e.g., flexible circuit  76  may be a flex tail that extends from a layer of flexible printed circuit material in a rigid printed circuit that forms member  78 ). 
     If desired, printed circuit  74  may be coupled to via  80  of member  78  without using an interposed flexible printed circuit. Printed circuit  74  may extend under member  78  so that conductive contact  90  couples via  80  to a conductive contact on a surface of printed circuit  74 . 
       FIG. 7  is a cross-sectional side view of a bottom-emissive organic light-emitting diode display of the type shown in  FIG. 5A  showing how the size of inactive area IA may be minimized by forming control circuitry for the display behind a portion of the display without using a gap-filling member. As shown in  FIG. 7 , flexible printed circuit  76  may be used as a coupling structure by providing flexible printed circuit  76  with a bent portion such as curved portion  77  that carries traces  88  in flexible circuit  76  from contact  86  to contact  90 . Flexible printed circuit  76  may be coupled to traces  94  using conductive material  90 . 
       FIG. 8  is a cross-sectional side view of a bottom-emissive organic light-emitting diode display of the type shown in  FIG. 5A  showing how the size of inactive area IA may be minimized by forming control circuitry for the display behind a portion of the display using a conductive via formed in the encapsulation layer. As shown in  FIG. 8 , encapsulation layer  56  may extend substantially to edge  71  of display  14  and may include a conductive via such as via  98  formed through the encapsulation layer. Conductive via  98  may be connected between traces  94  of TFT layer  70  and traces  88  of flexible printed circuit  76  using, for example, conductive coupling material  90  (e.g., anisotropic conductive adhesive, solder or other suitable conductive material). 
     Via  98  may be formed in encapsulation layer  56  by forming a opening (e.g., by mechanical drilling, laser drilling, wet or dry etching, or other suitable processes) in encapsulation layer  56  and forming a conductive coating or a conductive filler material such as conductive paste within the opening. 
     Providing an organic light-emitting diode display such as display  14  with control circuitry that is formed behind the display so that one or more display layers (e.g., encapsulation layer  56  and/or emissive layer  72 ) is interposed between the thin-film transistors and the control circuitry as described above in connection with  FIGS. 6 ,  7 , and  8  (as examples) may help reduce or eliminate inactive area IA along one or more peripheral portions of the display. 
     In configurations in which organic light-emitting diode display  14  includes an inactive area IA, portions of the display in the inactive area may be provided with an opaque masking material in the inactive area. The opaque masking material may be configured to block portions of the device in the inactive region of the display from being seen by a viewer such as viewer  62  viewing display  14  in direction  64  as shown in  FIG. 9 .  FIG. 9  is a cross-sectional side view of a top-emissive organic light-emitting diode display of the type shown in  FIG. 5B  showing various locations within an OLED display where opaque masking material  104  may be formed. 
     Opaque masking material  104  may be formed from an opaque metal such as chrome oxide (sometimes referred to as black chrome), a polymer material infused with an opaque dye or pigment (e.g., carbon black), opaque photo-patternable material (i.e., material that can be formed over glass  52  and selectively patterned using light), other suitably opaque or mostly opaque materials, or any combination of these materials. 
     As shown in  FIG. 9 , opaque masking material  104  may be formed on a portion of TFT layer  70 . Opaque masking material that is formed on top of TFT layer  70  may be uncovered by other display materials or a portion of the opaque masking material may be covered by organic emissive layer  72  and/or encapsulation layer  56 . However, this is merely illustrative. If desired, opaque masking material  104  may be formed between OLED layer  54  and encapsulation layer  56  or opaque masking material  104  may be formed between encapsulation layer  56  and upper polarizer layer  50 . If desired, opaque masking material  104  may be formed at any or all of the locations shown in  FIG. 9 . 
     In configurations of the type shown in  FIG. 9 , opaque masking material  104  may be used to hide a conductive via such as via  100  formed in substrate  58  of display  14 . As shown in  FIG. 9 , via  100  may be connected between signal paths  94  in TFT layer  70  and signal paths  88  in flexible printed circuit  76 . 
     Via  100  may be formed in substrate  58  by drilling (e.g., laser drilling) an opening in substrate  58  and lining or filling the opening with conductive material. Conductive material  90  may be used to electrically couple signal lines in TFT layer  70  to signal lines in flexible printed circuit  76  through via  100 . TFT layer  70  and via  100  may be formed on substrate  58  by forming thin-film transistors on a first surface of substrate  58 , laser drilling an opening in substrate  58  and plating, lining, or filling the opening with conductive material. 
     If desired, display  14  of  FIG. 9  may be coupled to printed circuit  74  without the use of flexible printed circuit  76  by forming signal lines (e.g., patterned conductive metal traces) along a back surface of substrate (i.e., a surface opposite to the surface on which TFT layer  70  is formed). These types of back-surface traces may be used to couple via  100  to printed circuit  74 . 
     If desired, a layer of touch-sensitive circuitry (e.g., an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, force-based touch technologies, or other suitable touch sensor components) may be formed on an upper surface of encapsulation layer  56  (e.g., between encapsulation layer  56  and polarization layer  50 ). However, this is merely illustrative. If desired, touch-sensitive circuitry for display  14  may be formed on polarizer layer  50  or may be formed separately from display layers  50 ,  56 ,  54 , and  58 . As an example, touch-sensitive circuitry for display  14  may be formed on an outer cover layer as shown in  FIG. 10 . 
       FIG. 10  is a cross-sectional side view of a bottom-emissive organic light-emitting diode display of the type shown in  FIG. 5A  having a layer of opaque masking material. As shown in  FIG. 10 , display  14  may be optionally provided with a cover layer such as cover layer  110 . Cover layer  110  may be formed from glass, plastic, or other suitable transparent material. Cover layer  110  may be rigid or flexible and may sometimes be referred to as a cover glass (CG) layer. Touch-sensor circuitry  112  may be formed on an inner layer of cover layer  112 . However, this is merely illustrative. If desired, touch-sensor circuitry  112  may be formed on polarizer layer  50 , between polarizer layer  50  and glass layer  52  or may be formed as a separate layer of display  14 . 
     Opaque masking material  104  may be formed between a portion of glass layer  52  and a corresponding portion of upper (circular) polarizer  50  in inactive region IA of display  14 . During manufacturing of display  14 , opaque masking material  104  may be applied to a top (outer) surface of glass  52  and patterned (e.g., photo-patterned) or may be painted or otherwise applied to glass  52 . 
     In some configurations, opaque masking material  104  may be formed from a material (e.g., black chrome) that can withstand relatively high temperatures associated with display assembly processes such as thin-film-transistor polysilicon deposition processes that may be used in formatting of OLED array  54  on glass  52 . In configurations which opaque masking material  104  is formed from this type of high temperature material, opaque masking material may be formed on a bottom side of glass layer  52  (i.e., interposed between a portion of OLED array  54  and glass layer  52 ). 
     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: 20120817
Publication Date: 20151215
Grant Date: 20151215
Priority Date: 20120817
Inventors: MATHEW DINESH C.
GARELLI ADAM T.
DRZAIC PAUL S.
CHEN WEI
DEGNER BRETT W.
POSNER BRYAN W.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/041", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K2217/96031", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05B45/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K2217/96031", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03K2217/96031", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05B33/0896", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/041", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L51/5281", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L27/3276", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K59/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/868", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/86", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05B45/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/131", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K2217/96031", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/131", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05B45/60", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K77/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/131", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K50/86", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/868", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K77/111", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/865", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K50/841", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/40", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02E10/549", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02B20/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/871", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/8791", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/8793", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 50084557