PATENT DOCUMENT

Publication Number: US-9753195-B2
Application Number: US-201514751000-A
Country: US
Kind Code: B2

Title: Border structures for displays

Abstract:
An organic light-emitting diode display may have an active area that contains pixels and an inactive area. The inactive area of the display may be provided with opaque masking layer structures having an appearance that matches the active area of the display when the pixels are off and are not displaying images. The opaque masking layer structures may include a polymer layer coated with a layer of metal. The display may have pixels with anodes and a cathode layer. The anodes may be formed from metal pads. Dummy structures such as a dummy cathode and dummy anodes may be formed in the inactive area. A circular polarizer in the display may overlap the active area and the inactive area or may overlap the active area without overlapping some or all of the inactive area.

Claims:
What is claimed is: 
     
       1. An organic light-emitting diode display having an active area in which images are displayed and having an inactive area in which no images are displayed, comprising:
 a display cover layer that overlaps the active area and the inactive area; 
 a circular polarizer that overlaps the active area and the inactive area; 
 an organic light-emitting diode layer having an array of pixels that overlaps the active area, wherein the organic light-emitting diode layer comprises an anode layer and a cathode layer that form the array of pixels in the active area; and 
 opaque masking layer structures that overlap the inactive area, wherein the opaque masking layer structures include a polymer layer and a portion of the cathode layer that extends into the inactive area, and wherein the portion of the cathode layer does not overlap the anode layer in the inactive area. 
 
     
     
       2. The organic light-emitting diode display defined in  claim 1  further comprising a layer of adhesive that overlaps the active area and the inactive area and that is interposed between the circular polarizer and the display cover layer to attach the circular polarizer to the display cover layer. 
     
     
       3. The organic light-emitting diode display defined in  claim 2  wherein the portion of the cathode layer comprises a planar metal layer on the polymer layer. 
     
     
       4. The organic light-emitting diode display defined in  claim 3  wherein the portion of the cathode layer is interposed between the layer of adhesive and the polymer layer. 
     
     
       5. The organic light-emitting diode display defined in  claim 4  further comprising a conductive path that shorts the portion of the cathode layer to ground. 
     
     
       6. The organic light-emitting diode display defined in  claim 2  wherein the polymer layer comprises a pixel definition layer. 
     
     
       7. The organic light-emitting diode display defined in  claim 6  wherein the pixel definition layer is formed in the active area and in the inactive area. 
     
     
       8. A display having an active area in which images are displayed and having an inactive area in which no images are displayed, comprising:
 a display layer having an array of pixels that overlaps the active area and having an edge portion that overlaps the inactive area, wherein the inactive area includes a first inactive area portion in which the edge portion includes thin-film transistor display driver circuitry that supplies signals to the array of pixels and includes a second inactive area portion in which a metal layer forms an opaque masking structure that matches the array of pixels in the active area in appearance when the pixels are off, wherein the first inactive area portion is interposed between the second inactive area portion and the active area. 
 
     
     
       9. The display defined in  claim 8  wherein the display layer comprises an organic light-emitting diode layer and wherein the array of pixels comprises an array of organic light-emitting diodes. 
     
     
       10. The display defined in  claim 9  further comprising a transparent layer that overlaps the active area and the inactive area. 
     
     
       11. The display defined in  claim 10  further comprising a circular polarizer that overlaps the active area and the inactive area. 
     
     
       12. The display defined in  claim 11  wherein the transparent layer comprises a display cover layer that protects the organic light-emitting diode layer and wherein the circular polarizer is interposed between the display cover layer and the organic light-emitting diode layer in the active area, the first inactive area portion, and the second inactive area portion. 
     
     
       13. The display defined in  claim 12  wherein the pixels include a cathode layer and wherein the metal layer of the opaque masking structure is formed from a part of the cathode layer. 
     
     
       14. The display defined in  claim 12  wherein the pixels include anodes formed from a patterned metal layer and wherein the metal layer of the opaque masking structure is formed from part of the patterned metal layer. 
     
     
       15. The display defined in  claim 12  wherein the pixels include a cathode layer and anodes, wherein the organic light-emitting diode layer in the second inactive area portion includes a dummy cathode formed from the metal layer and an additional metal layer that forms dummy anodes, wherein the cathode layer is formed from a portion of the metal layer that forms the dummy cathode, and wherein the anodes are formed from a portion of the additional metal layer that forms the dummy anodes. 
     
     
       16. The display defined in  claim 15  further comprising a polymer layer interposed between the dummy cathode and the dummy anodes in the second inactive area portion. 
     
     
       17. The display defined in  claim 16  wherein a portion of the polymer layer is interposed between the cathode layer and the anodes. 
     
     
       18. The display defined in  claim 17  further comprising emissive material that is interposed between the dummy cathode and the dummy anodes, wherein the emissive material does not emit light during operation of the display to display images with the array of pixels. 
     
     
       19. The display defined in  claim 15  wherein the organic light-emitting diode layer in the first inactive area portion includes a dummy cathode and dummy anodes. 
     
     
       20. The display defined in  claim 8  further comprising a conductive path that shorts the metal layer to ground. 
     
     
       21. An organic light-emitting diode display having an active area in which images are displayed and having an inactive area in which no images are displayed, comprising:
 an organic light-emitting diode layer having an array of pixels that display the images in the active area; 
 a circular polarizer that overlaps the active area and the inactive area; and 
 opaque masking layer structures that are separate from the organic light-emitting diode layer and that overlap the inactive area without extending into the active area, wherein the opaque masking layer structures include a polymer substrate layer and a metal layer formed on the polymer substrate layer, wherein the metal layer is interposed between the polymer substrate layer and the circular polarizer. 
 
     
     
       22. The organic light-emitting diode display defined in  claim 21  wherein the metal layer comprises a planar metal coating layer on the polymer layer. 
     
     
       23. The organic light-emitting diode display defined in  claim 21  wherein the opaque masking layer structures include metal pads. 
     
     
       24. The organic light-emitting diode display defined in  claim 21  wherein the opaque masking layer structures comprise an additional polymer layer, wherein the metal layer is a coating on the polymer layer and wherein the opaque masking layer further comprises metal pads that are interposed between the additional polymer layer and the polymer layer. 
     
     
       25. The organic light-emitting diode display defined in  claim 21  further comprising a display cover layer that overlaps the active area and the inactive area.

Description:
BACKGROUND 
     This relates generally to electronic devices, and, more particularly, to displays for electronic devices. 
     Electronic devices such as cellular telephones, computers, and other electronic devices often contain displays. Organic light-emitting diode displays are thin displays that can be used to display color images for a user. The pixels in an organic light-emitting diode display each include a light-emitting diode having an anode and cathode. A circular polarizer layer may overlap that pixels to help suppress ambient light reflections from diodes. 
     Organic light-emitting diode displays have inactive border regions that contain display driver circuitry but do not contain any pixels. To block display driver circuitry in the inactive border regions and internal components in an electronic device from view, a display may be provided with a bezel that overlaps the border of the display. In some devices, the front surface of the display is covered with a protective cover glass layer. 
     The use of a bezel can be avoided by forming an opaque masking layer such as a layer of black ink on the underside of the cover glass layer along the edge of the display. When the display is off, the display will have a dark color. Although the black ink border also has a dark color, there can be a noticeable mismatch between the appearance of the black ink border and the dark color of the display. This mismatch may be aesthetically undesirable and distracting to the user. 
     It would therefore be desirable to be able to provide improved border structures for electronic device displays. 
     SUMMARY 
     A display such as an organic light-emitting diode display may have an active area that contains pixels that display images for a user. The display may also have an inactive area that does not contain any pixels and that does not display images for the user. The display may be mounted in a housing of an electronic device. A transparent display cover layer may be used as an outer layer of the display. 
     The inactive area of the display may be provided with opaque masking layer structures having an appearance that matches the active area of the display when the pixels are off and are not displaying images. The display may have an organic light-emitting diode display layer containing an array of the pixels. Opaque masking structures may be formed as part of the organic light-emitting diode display layer or may be formed as the structures that are attached to the display cover layer along the edge of the organic light-emitting diode display layer. 
     The opaque masking layer structures may include a polymer layer coated with a layer of metal. The organic light-emitting diode display may have pixels with anodes and a cathode layer. The anodes may be formed from metal pads. The anodes may be separated from the cathode layer by a polymer layer. A circular polarizer in the display may overlap display cover layer. The circular polarizer may overlap the active area and the inactive area or may overlap the active area without overlapping some or all of the inactive area. Dummy structures may be formed in the inactive area to ensure that the inactive area has an appearance matching that of the active area. The dummy structures may include a dummy cathode and dummy anodes that are formed respectively from portions of the cathode layer and the metal layer that forms the anodes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device in accordance with an embodiment. 
         FIG. 2  is a top view of an illustrative electronic device display in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative organic light-emitting diode pixel in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative electronic device in accordance with an embodiment. 
         FIGS. 5, 6, and 7  are cross-sectional side views of illustrative opaque border structures in accordance with embodiments. 
         FIG. 8  is a cross-sectional side view of an illustrative electronic device having a display with a border in accordance with an embodiment. 
         FIGS. 9 and 10  are cross-sectional side views of displays having borders in accordance with an embodiment. 
         FIG. 11  is a cross-sectional side view of an illustrative display with a border in accordance with an embodiment. 
         FIG. 12  is a cross-sectional side view of a display having an opaque border layer that overlaps an edge of an organic light-emitting diode display layer in accordance with an embodiment. 
         FIG. 13  is a cross-sectional side view of an illustrative device with a housing structure that helps retain a display in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may contain a display such as display  14 . The display may have pixels organized in an array. The pixels may form an active area AA of the display that displays images for a user. Active area AA may have a rectangular shape or other shapes (e.g., area AA may be circular, rectangular with rounded corners, elliptical, etc.). An inactive border area IA in which no pixels are present may run along one or more of the edges of the active area. For example, in a configuration in which active area AA has a rectangular shape, inactive area IA may have a rectangular ring shape that surrounds active area AA. Inactive border area IA may contain circuits, signal lines, and other structures that do not emit light for forming images. 
     Electronic device  10  may be a computing device such as 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, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, 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. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     In the example of  FIG. 1 , display  14  of device  10  is mounted in housing  12 . Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Display  14  may be a touch screen display that incorporates a layer of conductive capacitive touch sensor electrodes or other touch sensor components (e.g., resistive touch sensor components, acoustic touch sensor components, force-based touch sensor components, light-based touch sensor components, etc.) or may be a display that is not touch-sensitive. Capacitive touch screen electrodes may be formed from an array of indium tin oxide pads or other transparent conductive structures. 
     Display  14  may be protected using a display cover layer such as a layer of transparent glass or clear plastic. Openings may be formed in the display cover layer. For example, an opening may be formed in the display cover layer to accommodate a button such as button  16 . An opening may also be formed in the display cover layer to accommodate ports such as speaker port  18 . Openings may be formed in housing  12  to form communications ports (e.g., an audio jack port, a digital data port, etc.), to form openings for buttons, etc. 
     Display  14  may include an array of display pixels formed from liquid crystal display (LCD) components, an array of electrophoretic pixels, an array of plasma pixels, an array of organic light-emitting diode pixels or other light-emitting diodes, an array of electrowetting pixels, or pixels based on other display technologies. Illustrative configurations for display  14  that are based on organic light-emitting diode displays are sometimes described herein as an example. 
     As shown in  FIG. 2 , display  14  may have rows and columns of pixels  22  that form active area AA. Active area AA is used to display images for a user of device  10 . Pixels  22  may be formed using one or more layers of material such as substrate layer  36 . Layers such a layer  36  may be formed from flexible polymers or other flexible materials (as examples). Substrate  36  may have left and right vertical edges and upper and lower horizontal edges. If desired, substrates such as substrate  36  may have non-rectangular shapes (e.g., shapes with curved edges, rectangular shapes and other shapes with protrusions that form flexible tails, etc.). 
     Each pixel  22  may have a light-emitting diode (e.g., an organic light-emitting diode). The light-emitting diode may have an anode (e.g., a metal pad), a cathode (e.g., a blanket transparent film formed from a transparent conductive material such as indium tin oxide and/or layers of metal that are sufficiently thin to be transparent), and organic emissive material interposed between the anode and cathode. Each of pixels  22  may also include thin-film circuitry (e.g., one or more thin-film transistors formed from polysilicon, indium gallium zinc oxide or other semiconducting oxides, or other semiconductors, thin-film capacitors, signal routing lines, etc.). The thin-film transistor circuitry and other circuits of display  14  may be used to apply control signals to the light-emitting diodes of pixels  22 , thereby creating desired images on display  14 . 
     Pixels  22  may receive data signals over signal paths such as data lines D and may receive one or more control signals over control signal paths such as horizontal control lines G (sometimes referred to as gate lines, scan lines, emission control lines, etc.). There may be any suitable number of rows and columns of pixels  22  in display  14  (e.g., tens or more, hundreds or more, or thousands or more). In organic light-emitting diode displays, pixels  22  contain pixel circuits that control the application of current to the light-emitting diodes of pixels  22 . The pixel circuits in pixels  22  may contain thin-film transistors having gates that are controlled by signals on horizontal control lines such as lines G. 
     Display driver circuitry  20  may be used to control the operation of pixels  22 . Display driver circuitry  20  may be formed from integrated circuits, thin-film transistor circuits, or other suitable circuitry. Thin-film transistor circuitry may be formed from polysilicon thin-film transistors, semiconducting-oxide thin-film transistors such as indium gallium zinc oxide transistors, or thin-film transistors formed from other semiconductors. Pixels  22  may have color filter elements of different colors (e.g., red, green, and blue) to provide display  14  with the ability to display color images. 
     Display driver circuitry  20  may include display driver circuits such as display driver circuit  20 A and gate driver circuitry  20 B. Display driver circuit  20 A may be formed from one or more integrated circuits and/or thin-film transistor circuitry. Gate driver circuitry  20 B may be formed from integrated circuits or may be thin-film circuitry. Display driver circuit  20 A of  FIG. 2  may contain communications circuitry for communicating with system control circuitry over path  32 . Path  32  may be formed from traces on a flexible printed circuit such as flexible printed circuit  40  or other conductive lines. During operation, control circuitry in device  10  may supply circuit  20 A with information on images to be displayed on display  14 . 
     To display the images on display pixels  22 , display driver circuitry  20 A may supply image data to data lines D while issuing clock signals and other control signals to supporting display driver circuitry such as gate driver circuitry  20 B over path  38 . Circuitry  20 A may supply signals to gate driver circuitry  20 B on one or both edges of display  14  (see, e.g., path  38 ′ and gate driver circuitry  20 B′ on the right-hand side of display  14  in the example of  FIG. 2 ). 
     Gate driver circuitry  20 B (sometimes referred to as horizontal control line control circuitry) may control horizontal control lines (gate lines) G. Gate lines G in display  14  may carry signals for controlling rows of pixels  22  (e.g., signals such as scan signals, emission control signals, etc.). The control signals in each row can be used to turn on transistors in pixels  22  in that row when loading data from the data lines into pixel storage capacitors in those pixels from data lines D). During operation, frames of image data may be displayed by asserting a signals on the rows of display  14  in sequence. 
     The portion of substrate  36  that contains the array of pixels  22  (i.e., active area AA) is used in displaying images for a user of device  10 . The portion of substrate  36  that contains routing lines and supporting circuitry such as display driver circuitry  20  (i.e., the portion of substrate  36  in inactive area IA) does not contain any pixels  22  and therefore does not display images for device  10 . 
     A cross-sectional side view of a pixel  22  in active area AA in an illustrative organic light-emitting diode display is shown in  FIG. 3 . As shown in  FIG. 3 , display  14  may include a substrate layer such as substrate layer  30 . Substrate  30  may be a planar layer or a non-planar layer and may be formed from plastic, glass, ceramic, sapphire, or other suitable materials. Configurations for display  14  in which substrate  30  is formed from a material such as plastic are sometimes described herein as an example. 
     Thin-film transistor circuitry  44  may be formed on substrate  30 . Thin film transistor circuitry  44  may include anode structures such as anode  56  on thin-film layers  52 . Layers  52  may include semiconductor layers, metal layers, and dielectric layers that form circuitry  44 . Circuitry  44  may include transistors and capacitors that form pixel circuits for controlling light-emitting diodes such as light emitting diode  64  of  FIG. 3 . During operation, light-emitting diode  64  may emit light  24  for pixel  22 . 
     Light-emitting diode  64  may be formed within an opening in pixel definition layer  60 . Pixel definition layer  60  may be formed from a patterned photoimageable polymer. In each light-emitting diode, organic emissive material  62  is interposed between a respective anode  56  and cathode  42 . Anodes  56  may be patterned from a layer of metal on circuitry  44 . Cathode  42  may be formed from a common conductive layer that is deposited on top of pixel definition layer  40 . Cathode  42  may be formed from a transparent conductive material such as indium tin oxide, one or more metal layers that are sufficiently thin to be transparent, or other conductive material that is transparent so that light  24  may exit light emitting diode  64 . In some configurations, anode  56  may be formed above cathode  42  (i.e., the conductive layers for the terminals of the diodes  64  may be reversed). The configuration of  FIG. 3  in which cathode layer  42  is located above anodes  56  is merely illustrative. 
     Display  14  may have a protective outer display layer such as display cover layer  50 . The outer display layer maybe formed from a material such as sapphire, glass, plastic, clear ceramic, or other transparent material. Configurations in which the outermost layer of display  14  is formed from a clear layer of glass are sometimes described herein as an example. This is merely illustrative. In general, the outermost layer of display  14  may be formed from any suitable material and may be formed with a thickness sufficient to provide display  14  with damage from scratches, etc. For example, display cover layer  50  may have a thickness of 0.05 to 2 mm, 0.1 to 0.5 mm, etc. 
     If desired, display  14  may include functional layers  48 . Functional layers  48  may include a touch sensor layer, a circular polarizer layer, and other layers. A circular polarizer layer may help reduce light reflections from metal in thin-film transistor circuitry  44  such as cathode  42  and anodes  56 . 
     Layer  46  may include one or more moisture barrier layers, polymer layers, adhesive layers, buffer layers, and other structures. Layer  46  may help planarize circuitry  44  and may sometimes be referred to as a planarization layer. 
     Layers of optically clear adhesive may be used to attach cover glass layer  50  and functional layers  48  to underlying display layers such as planarization layer  46 , thin-film transistor circuitry  44 , and substrate  30 . 
     During operation of display  14 , current is applied to light-emitting diodes  64  of pixels  22  in active area AA and active area AA displays images for a user of device  10 . When display  14  is off, no current is applied to diodes  64 , so no light  24  is emitted by pixels  22 . Device  10  may be actively used by a user, even when display  14  is off. For example, a user of device  10  may listen to music with device  10 , even though display  14  has been turned off to conserve power. When display  14  is off, ambient light in the vicinity of the user can strike the surface of display  14 . As shown in  FIG. 3 , for example, ambient light  70  may illuminate display  44  and may reflect from display  14  at an angle A with respect to surface normal n to create reflected light  72 . 
     Some conventional displays have display cover glass layers on which a ring of black ink is deposited to form an opaque border mask. The black ink mask in this type of arrangement does not have the same appearance as the display structures in the active area of the display, leading to a mismatch between the appearance of the border and the appearance of the active area. Black ink tends to be darker than the active area of the display and has an appearance that is relatively insensitive to the angle at which the black ink is being illuminated and viewed (see, e.g., angle A of  FIG. 3 ). In contrast, the structures of the active area (e.g., the circular polarizer, planarization layer, cathode, anode, etc.) can lead to reflections and thin-film interference effects that vary from those of a black ink layer. As an example, the metal or other material forming cathode  42  (and anodes  62 ) may reflect non-negligible amounts of ambient light  70  from display  14  and thin-film interference effects may cause the color and intensity of the reflected light to vary significantly as a function of angle A. As a result, the black ink of conventional borders tends to be noticeably different in appearance than the active portion of the display that the conventional borders surround. 
     To reduce the difference in appearance between active area AA and border IA of device  10 , device  10  can be provided with border structures that match the appearance of active area AA. The structures may be formed from extended portions of an organic light-emitting diode display (e.g., edge portions of structures formed on substrate  36  of  FIG. 2 ), and/or may be formed from separate layers of material (e.g., structures formed on the underside of a display cover layer or on a substrate such as a polymer substrate that is attached to the underside of a display cover layer with adhesive). 
     Consider, as an example, the illustrative configuration of  FIG. 4 .  FIG. 4  is a cross-sectional side view of device  10  in an illustrative configuration in which display  14  has been provided with separate opaque masking layer structures in inactive area IA that have an appearance that matches the appearance of active area AA. The cross-sectional view of  FIG. 4  may, as an example, correspond to a cross-section of device  10  of  FIG. 1  taken across the length of device  10 . As shown in  FIG. 4 , device  10  may have a housing such as housing  12  in which components  80  are mounted. Components  80  may include integrated circuits, connectors, sensors, input-output devices, and other circuitry. Components  80  may be mounted on one or more substrates such as illustrative substrate  82 . Substrate  82  may be a printed circuit (e.g., a rigid printed circuit board formed from fiberglass-filled epoxy or other rigid printed circuit board substrate material or a flexible printed circuit formed from a flexible layer of polyimide or a sheet of other polymer material). 
     Display  14  may have an organic light-emitting diode display layer such as display layer (display)  88 . Display  88  may be, for example a flexible organic light-emitting diode display layer formed from a polyimide substrate layer or other suitable substrate (e.g., substrate  30  of  FIG. 3 ) and may have pixels  22  such as pixel  22  of  FIG. 3 . 
     Display layer  88  may have an active area portion with pixels  22  (i.e., portion  88 A in active area AA) and may have an inactive region that contains display driver circuitry  20  but that does not contain pixels  22  (i.e., portion  88 I in inactive area portion IA 1  of inactive area IA). The appearance of inactive portion  88 I may match the appearance of active area portion  88 A. Device  10  may also have opaque masking layer structures  90  with an appearance that matches portions  88 A and  88 I of display layer  88 . Opaque masking layer structures  90  may be formed from one or more layers of material on a plastic substrate or other suitable support layer. Display  14  may be mounted to housing  12  using adhesive  92  or other suitable mounting arrangements. 
     Polarizer layer  48 ′ in layers  48  may be attached to the underside of display cover layer  50  using adhesive layer  84  (e.g., optically clear adhesive). Display layer  88  and opaque masking layer structures  90  may be attached to the underside of polarizer layer  48 ′ using adhesive layer  86  (e.g., an optically clear adhesive). If desired, other layers of material may be interposed within functional layers  48 . The example of  FIG. 4  is merely illustrative. 
     Polarizer layer  48 ′ may be a circular polarizer to suppress light reflections from reflective structures (e.g., metal structures such as cathode and anode structures) in organic light-emitting diode layer  88 . In the illustrative configuration of  FIG. 4 , polarizer layer  48 ′ has a main rectangular portion in inactive area AA and has an extended edge that covers inactive area portion IA 1  of inactive area IA and inactive area portion IA 2  of active area IA. In portion IA 1  of interactive area IA, polarizer layer  48 ′ may suppress reflections from thin-film transistor structures in display driver circuitry  20  (e.g., metal traces). Polarizer layer  48 ′ also helps ensure that the appearance of inactive area IA will be the same as that of active area AA. For example, the portion of polarizer layer  48 ′ in portion IA 2  of inactive area IA can help ensure that reflections and thin-film interference effects in inactive area IA match those of active area AA. 
       FIGS. 5, 6, and 7  are cross-sectional side views of illustrative embodiments of opaque masking layer structures  90 . In the example of  FIG. 5 , structures  90  have a substrate layer such as layer  94  and one or more layers of material that are supported by layer  94  such as layer  96 . Substrate layer  94  may be a polymer film or other suitable material (e.g., a dielectric layer, etc.). Layer  96  may be a metal coating having a reflectively that helps structure  90  exhibit the same appearance as active area AA of display layer  88 . Layer  96  may be formed from a metal or other reflective material and may be formed from the same material that forms cathode  42  or a different material. Layer  96  may be a planar layer (e.g., a planar metal coating layer on polymer layer  94 ). In scenarios in which layer  90  includes metal such as metal coating layer  96 , it may be desirable to ground metal layer  96  to a ground terminal (see, e.g., ground  100  of  FIG. 5 ). Structures  90  may be formed with grounding paths such a grounding path  98  (e.g., a via) or other grounding paths may be used to ground metal layer  96  (e.g., paths formed from silver paint or other conductive paint, paths formed from conductive adhesive, paths formed from conductive gaskets, paths formed from conductive traces through display  88 , and/or other suitable ground paths). The use of a via structure for forming path  98  is merely illustrative. 
     In the example of  FIG. 6 , structures  102  have been formed on substrate  94  and covered with layer  104 . Layer  96  has been formed on layer  104 . Layer  94  may be a substrate layer formed from a polymer or other material (e.g., a dielectric layer). The patterned structures of layer  102  may be metal structures (e.g., metal pads of the same size and thickness of anodes  56  of  FIG. 3  or having different sizes and/or thicknesses). Layer  104  may be a polymer layer or a layer of other material (e.g., a layer of material with an index of refraction and/or other optical properties similar to that of layer  46  of  FIG. 3  or other suitable layer of material). Layer  96  may be a metal layer or a layer of other material. Layers  94 ,  102 ,  104 , and  96  may be configured so that the reflectivity and thin-film optical interference effects of structures  90  match those of layer  88  in active area AA. Optional vias or other structures may be used to form a grounding path such as path  98  to short layer  96  to ground terminal  100 . 
     In the illustrative configuration of  FIG. 7 , structures  90  have a substrate layer such as layer  94  (e.g., a polymer layer or other layer such as a dielectric layer). Structures  102  such as metal pads may be formed on substrate  94 . Material  110  may be formed on structures  102 . Material  110  may be emissive material such as material  62  of  FIG. 3  or may be material that has an index of refraction and/or other optical properties that match material  62 . The material of layer  108  may have optical properties that match material  60  of  FIG. 3 . Layer  96  may be a metal layer or other layer of material that has optical properties that match those of layer  42  of  FIG. 3 . Layer  106  may serve as a planarization layer and may have optical properties that match those of planarization layer  46  of  FIG. 3 . Layers  94 ,  102 ,  110 ,  108 ,  96 , and  106  are preferably configured so that the reflectivity and thin-film optical interference effects of structures  90  match those of layer  88  in active area AA. If desired, vias or other structures may be used to form a grounding path such as path  98  to short layer  96  to ground  100 . 
       FIG. 8  is a cross-sectional side view of device  10  showing another illustrative arrangement that may be used to ensure that inactive area IA has an appearance that matches that of active area AA. The cross-section of  FIG. 8  is of the type that may be taken across the width of device  10  of  FIG. 1  (as an example). 
     As shown in  FIG. 8 , display  14  may be mounted in housing using adhesive  92  (as an example). Display  14  may have a display cover layer such as display cover layer  50 . Functional layers  48  may be interposed between organic light-emitting diode display layer  88  and display cover layer  50 . Components  80  in the interior of device  10  may be mounted on one or more substrates such as substrate  82  (e.g., printed circuits, etc.). Polarizer layer  48 ′ in layers  48  may overlap active display area AA and inactive display area IA to help ensure that inactive area IA has the same appearance as active area AA. 
     Organic light-emitting diode display layer  88  may have a central portion that contains pixels  22  and that forms active area AA of display  14 . Organic light-emitting diode display layer  88  may also have an extended edge portion that is inactive and does not contain any pixels  22 . The inactive edge of organic light-emitting diode display layer  88  may include edge portion  88 ′ in portion IA 1  of inactive area IA and edge portion  88 ″ in portion IA 2  of inactive area IA. Portion  88 ′ of layer  88  may include display driver circuitry  20  (e.g., thin-film transistors for gate driver circuitry  20 B, etc.) Portion  88 ″ of layer  88  may include structures that help ensure that area IA has the same appearance as area AA (and may not contain any display driver circuitry). For example, portion  88 ″ may have structures of the type shown in  FIGS. 5, 6 , and/or  7 . The structures of  FIGS. 5, 6, and 7  (e.g., metal and polymer layers, etc.) that are used in portion  88 ″ may be formed from layers of material that are also present in portion  88 A. 
       FIG. 9  is a cross-sectional side view of organic light-emitting diode display layer  88  in an illustrative configuration in which inactive area IA 2  has dummy pixel structures that help ensure that area IA 2  has the appearance as active area portion  88 A of layer  88 . In portion  88 A of display layer  88 , layer  88  has substrate layer  30 , layers  52 , anode  56 , emissive layer  62 , cathode  42 , and planarization layer  46 . In extended edge portion  88 I″ of layer  88  (i.e., in inactive portion IA 2  of inactive area IA), dummy structures such as dummy anodes  56 ′, dummy emissive layers  62 ′, and dummy cathode layer  42 ′ ensure that the appearance of portion  88 I″ will match that of portion  88 A (i.e., to form an opaque masking layer for the inactive area of display  14  that matches the appearance of the active area). Dummy anodes  56 ′ may be patterned from the same layer of metal (or other material) that is used in forming anodes  56  for diodes  64  in pixels  22  of active area AA or may be formed from different materials. Similarly, dummy layers  62 ′ and  42 ′ may be formed from the same materials as respective layers  62  and  42  in active area AA or may be formed from different materials. Dummy anodes  56 ′ may be formed on a dielectric layer in layers  52  (e.g., an organic or inorganic dielectric layer). 
     Portion IA 1  of inactive area IA may contain circuitry  112  for forming display driver circuitry  20  and may optionally include a dummy cathode layer such as layer  42 ″ (and/or dummy anodes such as dummy anodes  56 ′) or other structures to help ensure that the appearance of region IA 2  matches the appearance of active area AA. Conductive vias or other signal paths may be used to short dummy cathode  42 ′ to ground  100 , as illustrated by via  98 , thereby preventing excess electrostatic charge from developing on dummy cathode  42 ′ when device  10  is exposed to an electrostatic discharge event (e.g., when a user&#39;s finger contacts the edge of device  10  adjacent to dummy cathode  42 ′). Dummy cathode  42 ′ may be formed from part of the same metal layer or other conductive layer that forms cathode  42  and may, if desired, be electrically isolated from cathode  42 ′. 
     If desired, the structures in extended portions  88 I′ and  88 I″ may omit some or all of the dummy structures of  FIG. 9 . As shown in  FIG. 10 , for example, dummy cathode layer  42 ′ may be formed on layer  60  without forming underlying dummy anodes  56 ′. Emissive layer material  62 ′ may also be omitted from the displays of  FIGS. 9 and 10 , if desired. 
     As shown in  FIG. 11 , circular polarizer  48 ′ need not extend to the outermost edge of display  14 . In this type of configuration, structures  90  may be configured to take account of the absence of polarizer  48 ′ above structures  90  while still ensuring that that appearance of structures  90  matches that of layer  88  in active area AA. 
       FIG. 12  is a cross-sectional side view of a portion of an illustrative display for device  10  showing how structures  90  may be deposited as coating layers on the lower surface of display cover layer  50 . Polarizer layer  48 ′ and display layer  88  may extend to the outer edge of display  14  and may therefore be aligned with the outer edge of structures  90  or polarizer  48 ′ and/or display layer  88  may extend only partway to the outer edge of display  14 . 
       FIG. 13  is a cross-sectional side view of an edge portion of device  10  in an illustrative configuration in which display cover layer  50  is held in place by a portion of housing  12 . In the example of  FIG. 13 , display cover layer  50  has protruding portion  50 ′. Adhesive  92  may be used to secure portion  50 ′ to housing  12 . Elastomeric gasket structures such as illustrative gasket  200  may be interposed between display cover layer  50  and housing  12  to help seal display  14  to the front face of housing  12 . Other configurations for securing display  14  within housing  12  may be used, if desired. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20150625
Publication Date: 20170905
Grant Date: 20170905
Priority Date: 20150625
Inventors: DE JONG ERIK G.
GUILLOU JEAN-PIERRE S.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B5/3025", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/223", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B5/223", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B5/3025", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 57602730