PATENT DOCUMENT

Publication Number: US-11068089-B1
Application Number: US-201715675566-A
Country: US
Kind Code: B1

Title: Electronic device with display apertures

Abstract:
An electronic device may have a display such as an organic light-emitting diode display. The display may have an active area formed from an array of pixels with light-emitting diodes. The light-emitting diodes may be formed from an organic layer containing emissive material between an anode layer and a cathode layer. Apertures may be formed in the active area of the display. The apertures may allow light to pass to light-sensitive components under the display. A polarizer may overlap the display and may have a bleached area that forms part of a camera aperture. Light may pass through the camera aperture to a camera under the display. The display may have an array of apertures that allow light to pass to a light-sensitive fingerprint sensor under the display.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a light-sensitive component; and 
 a display having:
 a substrate; 
 thin-film layers on the substrate that form pixel circuits with light-emitting diodes; 
 a polarizer layer on the thin-film layers, wherein the polarizer layer has a transparent bleached region that forms part of an aperture in the display through which light passes to the light-sensitive component; 
 a planarization layer that overlaps the pixel circuits and that has an opening that forms part of the aperture, wherein the planarization layer has opposing first and second surfaces, the opening extends from the first surface to the second surface, and the light passes through the opening in the planarization layer; and 
 a patterned photoimageable polymer layer interposed between the polarizer layer and the thin-film layers and having first openings that overlap the light-emitting diodes and second openings aligned with the aperture. 
 
 
     
     
       2. The electronic device defined in  claim 1  wherein the light-sensitive component comprises a camera. 
     
     
       3. The electronic device defined in  claim 2  wherein the thin-film layers include a thin-film encapsulation layer, wherein the thin-film encapsulation layer overlaps the aperture, and wherein the light passes through the thin-film encapsulation layer overlapping the aperture. 
     
     
       4. The electronic device defined in  claim 3  wherein the thin-film layers include an organic layer containing emissive material for the light-emitting diodes and wherein the organic layer has an organic layer opening that forms part of the aperture, wherein the light passes through the organic layer opening. 
     
     
       5. The electronic device defined in  claim 4  wherein the thin-film layers include a cathode layer, wherein the cathode layer has a cathode layer opening that forms part of the aperture, and wherein the light passes through the cathode layer opening. 
     
     
       6. The electronic device defined in  claim 1  wherein the thin-film layers include a layer of emissive material for the light-emitting diodes and wherein the layer of emissive material does not overlap the aperture. 
     
     
       7. The electronic device defined in  claim 1  wherein the thin-film layers include a cathode layer that forms cathodes for the light-emitting diodes and wherein the cathode layer does overlap the aperture. 
     
     
       8. The electronic device defined in  claim 1  wherein the light-sensitive component comprises a camera, wherein the light-emitting diodes form an array of pixels for an active area of the display, wherein the aperture is formed within the active area, wherein the thin-film layers include a thin-film encapsulation layer, wherein the thin-film encapsulation layer overlaps the aperture, and wherein the light passes through the thin-film encapsulation layer overlapping the aperture. 
     
     
       9. The electronic device defined in claim  8  further comprising a display cover layer, wherein the display is between the light-sensitive component and the display cover layer. 
     
     
       10. An electronic device, comprising:
 a light-sensitive component; 
 a display having an array of pixels that form an active area, each pixel including a respective light-emitting diode, wherein light passes to the light-sensitive component through the display and wherein the display includes:
 a substrate; 
 thin-film layers on the substrate that include an anode layer that forms anodes for the light-emitting diodes, a cathode layer that forms cathodes for the light-emitting diodes, and an organic layer including emissive material between the anodes and the cathodes; 
 an array of apertures through which the light passes to the light-sensitive component, wherein the organic layer has organic layer openings that form parts of the apertures and wherein the light passes through the organic layer openings to the light-sensitive component; and 
 a patterned opaque photoimageable polymer layer interposed between the anode layer and the cathode layer and having first openings that overlap the light-emitting diodes and second openings aligned with the apertures. 
 
 
     
     
       11. The electronic device defined in  claim 10  wherein the cathode layer has cathode layer openings that form parts of the apertures and wherein the light passes through the cathode layer openings to the light-sensitive component. 
     
     
       12. The electronic device defined in  claim 11  wherein the light-sensitive component comprises a fingerprint sensor. 
     
     
       13. The electronic device defined in  claim 10  wherein the cathode layer comprises a lift-off patterned cathode layer and wherein the light-sensitive component comprises a fingerprint sensor. 
     
     
       14. The electronic device defined in  claim 13  wherein the light-emitting diodes are configured to emit the light that passes through the organic layer openings. 
     
     
       15. The electronic device defined in  claim 14  wherein the lift-off patterned cathode layer has cathode layer openings that form parts of the apertures and wherein the light passes through the cathode layer openings to the fingerprint sensor. 
     
     
       16. The electronic device defined in  claim 10  wherein the thin-film layers include a thin-film encapsulation layer that overlaps the apertures. 
     
     
       17. An electronic device, comprising:
 a light-sensitive fingerprint sensor; and 
 a display having an array of pixels that form an active area, each pixel including a respective light-emitting diode, wherein light passes to the light-sensitive fingerprint sensor through the display and wherein the display includes:
 a substrate; 
 thin-film layers on the substrate that include an anode layer that forms anodes for the light-emitting diodes, a cathode layer that forms cathodes for the light-emitting diodes, and an organic layer including emissive material between the anodes and the cathodes; 
 an array of apertures through which the light passes to the light-sensitive fingerprint sensor, wherein portions of the anode layer and the organic layer overlap the apertures and wherein the light passes through the portions of the anode layer and the organic layer; 
 a transparent photoimageable polymer layer having openings aligned with the apertures; and 
 a lift-off patterned opaque polymer layer having openings aligned with the anodes and having openings aligned with the apertures. 
 
 
     
     
       18. The display defined in  claim 17  wherein the thin-film layers include a thin-film encapsulation layer that overlaps the apertures. 
     
     
       19. The display defined in  claim 18  wherein the cathode layer overlaps the apertures.

Description:
This application claims the benefit of provisional patent application 62/378,440, filed on Aug. 23, 2016, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates generally to electronic devices and, more particularly, to electronic devices with displays. 
     Electronic devices often include displays. For example, devices such as cellular telephones, tablet computers, laptop computers, wristwatch devices, and other devices may have displays. 
     It can be challenging to incorporate components such as fingerprint sensors, cameras, and other components into an electronic device with a display. These components may be located within inactive border regions of a display, but enlarging the widths of the border regions to accommodate the components can make a device bulky and unsightly. 
     SUMMARY 
     An electronic device may have a display such as an organic light-emitting diode display. The display may have an active area formed from an array of pixels with light-emitting diodes. The light-emitting diodes may be formed from an organic layer containing emissive material located between an anode layer and a cathode layer. Apertures may be formed in the active area of the display. The apertures may allow light to pass to light-sensitive components under the display. 
     A polarizer may overlap the display and may have a transparent bleached area that forms part of a camera aperture. Light may pass through the camera aperture to a camera under the display. The cathode layer and the organic layer may be omitted from the camera aperture to enhance light transmission. A thin-film encapsulation layer may have a portion that overlaps the camera aperture. 
     The display may have an array of apertures that allow light to pass to a light-sensitive fingerprint sensor under the display. A thin-film encapsulation layer may overlap the array of apertures. A lift-off patterned opaque layer may have openings that form portions of the apertures in the array of apertures. Portions of thin-film layers in the display may be removed from the apertures to enhance transmission. These thin-film layers may include the cathode layer, which may be patterned to form an array of cathode layer openings for the apertures and the organic layer, which may be patterned to form an array of organic layer openings for the apertures. 
    
    
     
       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 cross-sectional side view of an illustrative display with an aperture to accommodate a camera in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative display with an array of apertures to accommodate a fingerprint sensor in accordance with an embodiment. 
         FIG. 4  is a diagram showing how display structures may be patterned using a lift-off technique in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative display having a bleached polarizer that forms part of a display aperture to accommodate a camera in accordance with an embodiment. 
         FIGS. 6 and 7  are cross-sectional side views of illustrative displays having arrays of apertures to accommodate fingerprint sensors in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as electronic device  10  of  FIG. 1  may have a display with apertures. The apertures may allow light to pass through the display for use by components mounted behind (under) the display. 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. 
     Device  10  may include a display such as display  14 . Display  14  may be mounted in a housing such as 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 include an array of pixels  22 . Pixels  22  may be arranged in rows and columns in an array that covers most or all of the front face of device  10  (as an example). The array of pixels  22  in device  10  may display images for a user and may therefore sometimes be referred to the active area of display  14 . The active area of display  14  may have a rectangular shape or other suitable shape and may, if desired, be bordered along one or more edges by an inactive border region (e.g., a portion of display  14  that is free of pixels  22  and that does not emit light). 
     It may be desirable to maximize the lateral extent of the active area of display  14  while minimizing the size of any inactive border areas. In this type of configuration, it may be desirable to mount components under display  14  that can operate through display  14 . For example, a light-sensitive fingerprint sensor or other light-sensitive component may be mounted in region  16  within the active area of display  14 . During operation, light from pixels  22  or other light source can illuminate a user&#39;s fingerprint associated with a finger placed on region  16 . The fingerprint sensor can use an array of light sensors that are each located under a respective aperture in an array of fingerprint sensor apertures in region  16  to capture a user&#39;s fingerprint. As another example, region  20  in the active area of display  14  may be provided with a camera aperture. Light associated with external objects can be gathered and images captured using a camera (image sensor) mounted under the camera aperture. 
       FIG. 2  is a diagram of device  10  in an illustrative configuration in which display  14  has an aperture to accommodate a light-sensitive component such as a camera. As shown in  FIG. 2 , device  14  may be covered with a protective display cover layer such as display cover layer  30 . Display cover layer  30  may be formed from a transparent material such as clear plastic, glass, sapphire or other transparent crystalline material, or other transparent covering material. 
     Cover layer  30  may cover and protect pixel array  38 . Pixel array  38 , which may sometimes be referred to as a display, display module, or pixel array layer, may include an array of pixels for displaying images for a user of device  10 . Pixel array  38  may be, for example, an organic light-emitting diode display. 
     One or more functional layers such as polarizer and touch sensor layer  34  may be interposed between cover layer  30  and pixel array  38 . Layer  34  may include a polarizer such as a circular polarizer to reduce reflections from pixel array  38  and may include an array of capacitive touch sensor electrodes (e.g., indium tin oxide electrodes, etc.) to form a touch sensor for display  14  (e.g., so that display  14  is touch sensitive). Adhesive layer  32  (e.g., a layer of optically clear adhesive) may be used to attach layer  34  to layer  30 . Adhesive layer  36  (e.g., a layer of optically clear adhesive) may be used to attach layer  36  to pixel array  38 . 
     A light-transparent aperture may be formed in pixel array  38  such as aperture (opening)  40 . Aperture  40  may be sufficiently free of metal traces, thin-film transistors, and/or other light blocking structures to allow light  46  from external object  44  to be captured by light-based component  42  (e.g., a camera). Polarizer layer  34  may have a bleached polarizer area or a removed area such as area  34 B that is transparent (e.g., has a light transmission of 80% or more, 90% or more, or other suitable amount) and therefore allows light  46  to pass through layer  34 . Transparent bleached  34 B may form a part of aperture  40 . If desired, other structures in display (e.g., opaque thin-film layers) may be patterned to form openings for aperture  40  (e.g., a camera opening). 
       FIG. 3  is a diagram of device  10  in an illustrative configuration in which display  14  has an array of apertures (openings) such as aperture  40 A to accommodate a light-based component with an array of light sensors  48 ′ (e.g., photodiodes or other photodetectors) such as component  48 . Component  48  may be, for example, a light-based fingerprint sensor that gathers reflected light  50  from the fingerprint of a user&#39;s finger  52 . Light  50  may be generated by pixels  22  in pixel array  38  or other light sources. 
     It may be desirable to use fabrication techniques such as lift-off techniques to fabricate portions of display  14 . A lift-off process is illustrated in  FIG. 4 . Initially, a substrate such as substrate  52  is provided. Substrate  52  may be, for example, one or more layers in pixel array  38 . As shown in  FIG. 4 , substrate  52  may be covered with a photolithographically patterned layer of photoresist such as photoresist  54 . Metal, polymer, inorganic dielectric, or other material may be deposited in a layer on photoresist  54 , as shown by layer  56 . Layer  56  may be patterned by removing photoresist layer  54  using a solvent that removes photoresist layer  54  without significantly removing any of layer  56 . This leaves patterned portion  56 P of layer  56  on substrate  52  as desired. 
     As described in connection with  FIG. 2 , display  14  may have an aperture such as aperture  40  in the active area of display  14  that allows light to pass to camera  42  or other light sensing component (e.g., an ambient light sensor, proximity sensor, etc.). As shown in IG.  5 , display  14  may have a substrate formed from one or more supporting layers such as polyethylene terephthalate layer  90  and polyimide layer  88  or other suitable polymer layers (as an example). Thin-film layers  74  may be patterned using photolithography and other techniques on substrate layers  88  and  90  and may be used to form light-emitting diodes such as light-emitting diode  96  and associated thin-film transistors and other components for pixel circuits (e.g., pixel control circuitry including thin-film transistors such as transistor  22 T for controlling light-emitting diode  96  in pixel  22 ). 
     Layers  74  may include dielectric layers (e.g., silicon oxide, silicon nitride, and/or other inorganic dielectric layers) such as buffer layers  86  and  82 , gate insulator layer  80 , interlayer dielectric layers  78  and  76 , and passivation layer  70 . Shielding layer  84  may be formed under the transistor circuitry of pixel  22  between layers  86  and  82 . Active layer material  92  (e.g., polysilicon, semiconducting-oxide material, and/or other material for forming transistors) may be formed on layer  82 . Interlayer dielectric layers  78  and  76  may be formed under source-drain terminals  72 . Gate metal  94  may be patterned above gate insulator layer  80 . 
     Anode layer material  68  may contact the source-drain metal of layer  72 . In light-emitting diode  96 , the anode layer material may form anode  68 A for light-emitting diode  96 . Organic layers such as organic layer  64  (e.g., emissive layer material and other organic layers) may be formed above anode  68 A and may be used in generating light as current is passed between anode  68 A and an overlapping cathode layer  62 , which forms cathodes in display  14  for diodes such as light-emitting diode  96 . 
     Thin-film encapsulation layer  60  may be formed over cathode layer  62  to protect underlying thin-film structures from moisture. Thin-film encapsulation layer  60  may be formed from a stack of thin-film inorganic layers (e.g., silicon oxide, silicon nitride, etc.) and/or other encapsulation layer materials. Pixel definition layer  66  may be formed from a photoimageable polymer or other suitable polymer. Using photolithography, pixel definition layer  66  may be patterned to form openings for light-emitting diodes such as light-emitting diode  96  of  FIG. 5 . 
     Polarizer  34  may be interposed between display cover layer  30  and thin-film layers  74 . In opening  40 , polarizer  34  may be bleached to enhance transparency (e.g., to a transmission level of 90% or more or other suitable amount), as shown by bleached polarizer portion  34 B. Bleached polarizer portion  34 B may be formed by exposing polarizer  34  to ultraviolet light, to bleaching chemicals (e.g., KOH), or using other suitable polarizer bleaching techniques. Bleaching may be performed, for example, after polarizer lamination. If desired, the portion of polarizer  34  in portion  34 B may be removed (e.g., using laser ablation, etc.). These arrangements may be used to ensure that region  34 B is transparent and allows light to pass through opening  40  to camera  42  or other light-based component that are aligned with opening  40 . 
     Thin-film layers  98  are transparent and therefore allow light to pass to camera  42  within aperture  40 . Materials that may block light such as cathode layer  62 , organic layer  64 , anode layer  68 , and other opaque thin-film layers in layers  74  may be omitted from opening  40 . 
     Planarization layer  100  may be formed from a photoimageable polymer (e.g., polyimide, acrylic, etc.). To reduce light losses, planarization layer  100  may patterned to form an opening for aperture  40  (e.g., during the patterning of layer  100  to form vias to allow anode layer  68  to contact source-drain layer  72 ). By preventing planarization layer  100  from overlapping camera  42 , the transparency of opening  40  may be enhanced. Transparency may also be enhanced by ensuring that substrates  90  and  88  are formed from transparent polymers or other non-opaque materials. Thin-film encapsulation layer  60  may be retained in opening  40  to help prevent lateral moisture ingress. 
       FIG. 6  is a cross-sectional side view of display  14  in an illustrative configuration in which thin-film layers  74  have been patterned to form an array of openings such as opening  40 A to accommodate an underlying fingerprint sensor or other component such as component  48 . Opening  40 A may include transparent layers of material such as an overlapping portion of thin-film encapsulation layer  60 , an overlapping portion of polymer planarization layer  100 , transparent thin-film dielectric layers  98 ′, and substrates  88  and  90 . Barrier film  102  (e.g., a thin-film layer formed from polymer and/or inorganic layers) may be transparent. Materials that may block light such as cathode layer  62 , organic layer  64 , anode layer  68 , and other opaque thin-film layers in layers  74  may be removed from opening  40 A (e.g., to form cathode layer openings in layer  64  that form parts of openings such as opening  40 A, to form organic layer openings in organic layer  64  that form part of openings such as opening  40 A, etc.). As a result, opening  40 A may allow light from pixel  96  that has reflected from a user&#39;s finger or other external object to be sensed by sensor  48  after passing through opening  40 A. Polarizer  34  may not be bleached over aperture  40 A, but may be sufficiently transparent (e.g., polarizer  34  may exhibit 50% light transmission) to allow sensor  48  to operate satisfactorily. 
     The width of opening  40 A may be about 3-7 microns or other suitable size (e.g., to make openings  40 A invisible to a user and to avoid disrupting the layout of pixels  22  in pixel array  38 ). These dimensions are relatively small, so it may be difficult or impossible to pattern layers such as organic emissive layer  64  by depositing these layers through a shadow mask. Accordingly, layer such as layers  66  and  64  may be patterned using lift-off, as described in connection with the patterning of layer  56 P of  FIG. 4 . Cathode layer  62  may therefore be a lift-off patterned cathode layer and organic layers  62  (including the organic emissive layer for diode  96 ) may be lift-off patterned organic layers. 
     Pixel definition layer  66  of  FIG. 6  may be formed from an opaque material such as a photoimageable polymer containing black pigment (e.g., black negative photoresist). By using opaque material for pixel definition layer  66  of  FIG. 6 , the location and shape of each aperture  40 A in the array of apertures over sensor  48  can be defined. 
     The opacity of pixel definition layer  66  of  FIG. 6  may make it challenging to completely remove the material of layer  66  at the bottom of opening  40 A during photolithographic processing (e.g., because the amount of ultraviolet light that may be applied to layer  66  during photolithography is limited due to the desire to avoid overexposing transistor  22 T to ultraviolet light). 
     To ensure that there is no residual black pixel definition layer material at the bottom of opening  40 A (which could adversely affect the performance of sensor  48 ), an arrangement of the type shown in  FIG. 7  may be used in forming display  14 . In the illustrative configuration of  FIG. 7 , pixel definition layer  66  has been formed from a clear photoimageable polymer that can be completely removed from the bottom of opening  40 A during development. 
     As shown in  FIG. 7 , the thin-film layers of display  14  may be covered with a thin layer of opaque polymer such as layer  66 B. Layer  66 B may be, for example, a polymer layer that contains a sufficient quantity of black pigment to render layer  66 B opaque. The opacity of layer  66 B may reduce the reflectivity of display  14  (e.g., by preventing undesired reflections from cathode layer  62 ). By placing layer  66 B on top of encapsulation layer  60 , outgassing from the pigment in layer  66 B may be prevented from reaching sensitive organic layer  64 . Layer  66 B may be sufficiently opaque to block stray light while being sufficiently thin to allow layer  66 B to be patterned by lift-off. By forming layer  66 B using lift-off, exposure of sensitive underlying layers such as organic layer  64  to ultraviolet light during photolithography may be avoided. Because black layer  66 B is patterned by lift-off, layer  66 B need not be photoimageable (i.e., layer  66 B may be non-photoimagable). 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20170811
Publication Date: 20210720
Grant Date: 20210720
Priority Date: 20160823
Inventors: KIM, KIBEOM
CHEN, CHENG
HO, MENG-HUAN
LIU, RUI
Assignee: APPLE INC
CPC Classifications: [{"code": "G06V40/1318", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/1306", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04103", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F21/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/0338", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F2203/0338", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F21/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06K9/0002", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 76861535