PATENT DOCUMENT

Publication Number: US-12185616-B1
Application Number: US-202217840472-A
Country: US
Kind Code: B1

Title: Devices with displays having transparent openings and transition regions

Abstract:
An electronic device may include a display and an optical sensor formed underneath the display. The display may have both a full pixel density region and a pixel removal region with a plurality of high-transmittance areas that overlap the optical sensor. To mitigate reflectance mismatch between the full pixel density region and the pixel removal region, the pixel removal region may include a transition region at one or more edges. In the transition region, one or more components may have a gradual density change between the full pixel density region and a central portion of the pixel removal region. Components that may have a changing density in the transition region include dummy thin-film transistor sub-pixels, dummy anodes, a cathode layer, and a touch sensor metal layer. The transition region may also include anodes that gradually change shape and/or size.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 an input-output component; and 
 a display having an array of pixels, wherein the display has:
 a first portion having a first pixel density; 
 a second portion having a second pixel density that is lower than the first pixel density, wherein the second portion overlaps the input-output component; and 
 a transition portion between the first and second portions, wherein, in the transition portion, at least one component has a density that gradually changes across the transition portion. 
 
 
     
     
       2. The electronic device defined in  claim 1 , wherein the array of pixels includes emissive sub-pixels that emit light and thin-film transistor sub-pixels that control the emissive sub-pixels and wherein the at least one component comprises dummy thin-film transistor sub-pixels. 
     
     
       3. The electronic device defined in  claim 2 , wherein each one of the dummy thin-film transistor sub-pixels does not control a respective emissive sub-pixel. 
     
     
       4. The electronic device defined in  claim 2 , wherein each one of the dummy thin-film transistor sub-pixels has a matching size and shape to the thin-film transistor sub-pixels. 
     
     
       5. The electronic device defined in  claim 1 , wherein the array of pixels includes emissive sub-pixels that emit light and thin-film transistor sub-pixels that control the emissive sub-pixels, wherein each emissive sub-pixel includes a respective anode, and wherein the at least one component comprises dummy anodes. 
     
     
       6. The electronic device defined in  claim 5 , wherein each one of the dummy anodes has a matching size and shape to at least some of the anodes. 
     
     
       7. The electronic device defined in  claim 1 , wherein the at least one component comprises a cathode for the array of pixels. 
     
     
       8. The electronic device defined in  claim 7 , wherein the transition portion has first and second opposing sides, wherein the first side is adjacent the first portion, wherein the second side is adjacent the second portion, and wherein the cathode has openings that gradually increase in density from the first side to the second side. 
     
     
       9. The electronic device defined in  claim 1 , wherein the at least one component comprises a touch sensor metal layer. 
     
     
       10. The electronic device defined in  claim 1 , wherein the transition portion has first and second opposing sides, wherein the first side is adjacent the first portion, wherein the second side is adjacent the second portion, and wherein the density of the at least one component gradually decreases from the first side to the second side. 
     
     
       11. The electronic device defined in  claim 1 , wherein the transition portion has first and second opposing sides, wherein the first side is adjacent the first portion, wherein the second side is adjacent the second portion, and wherein the density of the at least one component gradually increases from the first side to the second side. 
     
     
       12. An electronic device, comprising:
 an input-output component; and 
 a display having an array of pixels, wherein the display has a first portion having a first pixel density and a second portion having a second pixel density that is lower than the first pixel density, wherein the second portion overlaps the input-output component, wherein the second portion has first and second opposing sides, and wherein a coverage percentage per unit area of at least one component gradually changes from the first side towards the second side. 
 
     
     
       13. The electronic device defined in  claim 12 , wherein the array of pixels includes emissive sub-pixels that emit light and thin-film transistor sub-pixels that control the emissive sub-pixels and wherein the at least one component comprises dummy thin-film transistor sub-pixels. 
     
     
       14. The electronic device defined in  claim 13 , wherein the second portion includes a quarter of the thin-film transistor sub-pixels per unit area of the first portion. 
     
     
       15. The electronic device defined in  claim 14 , wherein the thin-film transistor sub-pixels in the second portion are grouped at one or more edges of the second portion. 
     
     
       16. The electronic device defined in  claim 14 , wherein the second portion includes half of the emissive sub-pixels per unit area of the first portion. 
     
     
       17. The electronic device defined in  claim 13 , wherein the second portion includes half of the thin-film transistor sub-pixels per unit area of the first portion and half of the emissive sub-pixels per unit area of the first portion. 
     
     
       18. The electronic device defined in  claim 12 , wherein the array of pixels includes emissive sub-pixels that emit light and thin-film transistor sub-pixels that control the emissive sub-pixels and wherein the at least one component comprises dummy emissive sub-pixels. 
     
     
       19. An electronic device, comprising:
 an input-output component; and 
 a display having an array of pixels, wherein each pixel in the array of pixels has a respective emissive sub-pixel and wherein the display has:
 a first portion having a first pixel density, wherein first emissive sub-pixels in the first portion have a first shape; 
 a second portion having a second pixel density that is lower than the first pixel density, wherein the second portion overlaps the input-output component and wherein second emissive sub-pixels in the second portion have a second shape that is different than the first shape; and 
 a transition portion between the first and second portions, wherein third emissive sub-pixels in the transition portion gradually change shape from the first shape to the second shape. 
 
 
     
     
       20. The electronic device defined in  claim 19 , wherein the second shape has more curvature at its perimeter than the first shape. 
     
     
       21. An electronic device, comprising:
 an input-output component; and 
 a display having an array of pixels, wherein each pixel in the array of pixels has a respective emissive sub-pixel and wherein the display has:
 a first portion having a first pixel density, wherein first emissive sub-pixels in the first portion have a first size; 
 a second portion having a second pixel density that is lower than the first pixel density, wherein the second portion overlaps the input-output component and wherein second emissive sub-pixels in the second portion have a second size that is smaller than the first size; and 
 a transition portion between the first and second portions, wherein third emissive sub-pixels in the transition portion gradually change size from the first size to the second size.

Description:
This application claims priority to U.S. provisional patent application No. 63/236,593, filed Aug. 24, 2021, 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, an electronic device may have an organic light-emitting diode (OLED) display based on organic light-emitting diode pixels. In this type of display, each pixel includes a light-emitting diode and thin-film transistors for controlling application of a signal to the light-emitting diode to produce light. The light-emitting diodes may include OLED layers positioned between an anode and a cathode. 
     There is a trend towards borderless electronic devices with a full-face display. These devices, however, may still need to include sensors such as cameras, ambient light sensors, and proximity sensors to provide other device capabilities. Since the display now covers the entire front face of the electronic device, the sensors will have to be placed under the display stack. In practice, however, the amount of light transmission through the display stack is very low (i.e., the transmission might be less than 20% in the visible spectrum), which severely limits the sensing performance under the display. 
     It is within this context that the embodiments herein arise. 
     SUMMARY 
     An electronic device may include a display and an optical sensor formed underneath the display. The display may have both a full pixel density region and a partial pixel density region or pixel removal region. The pixel removal region includes a plurality of high-transmittance areas that overlap the optical sensor. Each high-transmittance area may be devoid of thin-film transistors and other display components. The plurality of high-transmittance areas regions is configured to increase the transmittance of light through the display to the sensor. The high-transmittance areas may therefore be referred to as transparent windows in the display. 
     To mitigate reflectance mismatch between the full pixel density region and the pixel removal region, the pixel removal region may include a transition region at one or more edges. In the transition region, one or more components may have a gradual density change between the full pixel density region and a central portion of the pixel removal region. 
     Dummy thin-film transistor sub-pixels may be included to mitigate the reflectance mismatch. The dummy thin-film transistor sub-pixels may have a gradually decreasing density from an edge of the pixel removal region towards a center of the pixel removal region. Dummy anodes may be included to mitigate the reflectance mismatch. The dummy anodes may have a gradually decreasing density from an edge of the pixel removal region towards a center of the pixel removal region. A cathode layer may have a gradually decreasing density from an edge of the pixel removal region towards a center of the pixel removal region. A touch sensor metal layer may have a gradually decreasing density from an edge of the pixel removal region towards a center of the pixel removal region. 
     Anodes in the pixel removal region may have a different size and/or shape than anodes in the full pixel density region. Accordingly, in a transition region between the pixel removal region and the full pixel density region, the anodes may gradually change size and/or shape from a first shape (used in the full pixel density region) to a second shape (used in the central portion of the pixel removal region). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an illustrative electronic device having a display and one or more sensors in accordance with an embodiment. 
         FIG.  2    is a schematic diagram of an illustrative display with light-emitting elements in accordance with an embodiment. 
         FIG.  3    is a cross-sectional side view of an illustrative display stack that at least partially covers a sensor in accordance with an embodiment. 
         FIG.  4    is a cross-sectional side view of an illustrative display stack with a high-transmittance area that overlaps a sensor in accordance with an embodiment. 
         FIG.  5    is a top view of an illustrative display with transparent openings that overlap a sensor in accordance with an embodiment. 
         FIGS.  6 A- 6 F  are top views of illustrative displays showing possible positions for pixel removal regions in accordance with an embodiment. 
         FIG.  7    is a top view of an illustrative pixel removal region in a display that has one thin-film transistor sub-pixel for each emissive sub-pixel in accordance with an embodiment. 
         FIG.  8    is a top view of an illustrative pixel removal region in a display that has one thin-film transistor sub-pixel for every two emissive sub-pixels in accordance with an embodiment. 
         FIG.  9    is a top view of an illustrative pixel removal region in a display with thin-film transistor sub-pixels that are grouped vertically at the edges of the pixel removal region in accordance with an embodiment. 
         FIG.  10    is a top view of an illustrative pixel removal region that includes first and second transition regions in accordance with an embodiment. 
         FIG.  11    is a top view of an illustrative transition region that includes dummy thin-film transistor sub-pixels in accordance with an embodiment. 
         FIG.  12 A  is a graph of the density of the dummy thin-film transistor sub-pixels as a function of position across the transition region in accordance with an embodiment. 
         FIG.  12 B  is a graph of the density of all of the thin-film transistor sub-pixels as a function of position in accordance with an embodiment. 
         FIG.  13    is a top view of an illustrative transition region that includes dummy anodes in accordance with an embodiment. 
         FIG.  14 A  is a graph of the density of the dummy anodes as a function of position across the transition region in accordance with an embodiment. 
         FIG.  14 B  is a graph of the density of all of the emissive sub-pixels as a function of position in accordance with an embodiment. 
         FIG.  15    is a top view of an illustrative transition region that includes a cathode layer with progressively decreasing density in accordance with an embodiment. 
         FIG.  16    is a graph of the density of the cathode as a function of position in accordance with an embodiment. 
         FIG.  17    is a top view of an illustrative transition region that includes a touch sensor metal layer with progressively decreasing density in accordance with an embodiment. 
         FIG.  18    is a graph of the density of the touch sensor metal layer as a function of position in accordance with an embodiment. 
         FIG.  19    is a top view of an illustrative transition region that includes anodes that gradually change shape in accordance with an embodiment. 
         FIG.  20    is a top view of an illustrative transition region that includes anodes that gradually change size in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative electronic device of the type that may be provided with a display is shown in  FIG.  1   . 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 display, a computer display that contains an embedded computer, 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, or other electronic equipment. Electronic device  10  may have the shape of a pair of eyeglasses (e.g., supporting frames), may form a housing having a helmet shape, or may have other configurations to help in mounting and securing the components of one or more displays on the head or near the eye of a user. 
     As shown in  FIG.  1   , electronic device  10  may include control circuitry  16  for supporting the operation of device  10 . Control circuitry  16  may 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. Processing circuitry in control circuitry  16  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application-specific integrated circuits, etc. 
     Input-output circuitry in device  10  such as input-output devices  12  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 devices  12  may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input resources of input-output devices  12  and may receive status information and other output from device  10  using the output resources of input-output devices  12 . 
     Input-output devices  12  may include one or more displays such as display  14 . Display  14  may be a touch screen display that includes a touch sensor for gathering touch input from a user or display  14  may be insensitive to touch. A touch sensor for display  14  may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. A touch sensor for display  14  may be formed from electrodes formed on a common display substrate with the display pixels of display  14  or may be formed from a separate touch sensor panel that overlaps the pixels of display  14 . If desired, display  14  may be insensitive to touch (i.e., the touch sensor may be omitted). Display  14  in electronic device  10  may be a head-up display that can be viewed without requiring users to look away from a typical viewpoint or may be a head-mounted display that is incorporated into a device that is worn on a user&#39;s head. If desired, display  14  may also be a holographic display used to display holograms. 
     Control circuitry  16  may be used to run software on device  10  such as operating system code and applications. During operation of device  10 , the software running on control circuitry  16  may display images on display  14 . 
     Input-output devices  12  may also include one or more sensors  13  such as force sensors (e.g., strain gauges, capacitive force sensors, resistive force sensors, etc.), audio sensors such as microphones, touch and/or proximity sensors such as capacitive sensors (e.g., a two-dimensional capacitive touch sensor associated with a display and/or a touch sensor that forms a button, trackpad, or other input device not associated with a display), and other sensors. In accordance with some embodiments, sensors  13  may include optical sensors such as optical sensors that emit and detect light (e.g., optical proximity sensors such as transreflective optical proximity structures), ultrasonic sensors, and/or other touch and/or proximity sensors, monochromatic and color ambient light sensors, image sensors, fingerprint sensors, temperature sensors, proximity sensors and other sensors for measuring three-dimensional non-contact gestures (“air gestures”), pressure sensors, sensors for detecting position, orientation, and/or motion (e.g., accelerometers, magnetic sensors such as compass sensors, gyroscopes, and/or inertial measurement units that contain some or all of these sensors), health sensors, radio-frequency sensors, depth sensors (e.g., structured light sensors and/or depth sensors based on stereo imaging devices), optical sensors such as self-mixing sensors and light detection and ranging (lidar) sensors that gather time-of-flight measurements, humidity sensors, moisture sensors, gaze tracking sensors, and/or other sensors. In some arrangements, device  10  may use sensors  13  and/or other input-output devices to gather user input (e.g., buttons may be used to gather button press input, touch sensors overlapping displays can be used for gathering user touch screen input, touch pads may be used in gathering touch input, microphones may be used for gathering audio input, accelerometers may be used in monitoring when a finger contacts an input surface and may therefore be used to gather finger press input, etc.). 
     Display  14  may be an organic light-emitting diode display or may be a display based on other types of display technology (e.g., liquid crystal displays). Device configurations in which display  14  is an organic light-emitting diode display are sometimes described herein as an example. This is, however, merely illustrative. Any suitable type of display may be used, if desired. In general, display  14  may have a rectangular shape (i.e., display  14  may have a rectangular footprint and a rectangular peripheral edge that runs around the rectangular footprint) or may have other suitable shapes. Display  14  may be planar or may have a curved profile. 
     A top view of a portion of display  14  is shown in  FIG.  2   . As shown in  FIG.  2   , display  14  may have an array of pixels  22  formed on a substrate. 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). Each pixel  22  may include a light-emitting diode  26  that emits light  24  under the control of a pixel control circuit formed from thin-film transistor circuitry such as thin-film transistors  28  and thin-film capacitors. Thin-film transistors  28  may be polysilicon thin-film transistors, semiconducting-oxide thin-film transistors such as indium zinc gallium oxide (IGZO) transistors, or thin-film transistors formed from other semiconductors. Pixels  22  may contain light-emitting diodes of different colors (e.g., red, green, and blue) to provide display  14  with the ability to display color images or may be monochromatic pixels. 
     Display driver circuitry may be used to control the operation of pixels  22 . The display driver circuitry may be formed from integrated circuits, thin-film transistor circuits, or other suitable circuitry. Display driver circuitry  30  of  FIG.  2    may contain communications circuitry for communicating with system control circuitry such as control circuitry  16  of  FIG.  1    over path  32 . Path  32  may be formed from traces on a flexible printed circuit or other cable. During operation, the control circuitry (e.g., control circuitry  16  of  FIG.  1   ) may supply display driver circuitry  30  with information on images to be displayed on display  14 . 
     To display the images on display pixels  22 , display driver circuitry  30  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  34  over path  38 . If desired, display driver circuitry  30  may also supply clock signals and other control signals to gate driver circuitry  34  on an opposing edge of display  14 . 
     Gate driver circuitry  34  (sometimes referred to as row control circuitry) may be implemented as part of an integrated circuit and/or may be implemented using thin-film transistor circuitry. Horizontal control lines G in display  14  may carry gate line signals such as scan line signals, emission enable control signals, and other horizontal control signals for controlling the display pixels  22  of each row. There may be any suitable number of horizontal control signals per row of pixels  22  (e.g., one or more row control signals, two or more row control signals, three or more row control signals, four or more row control signals, etc.). 
     The region on display  14  where the display pixels  22  are formed may sometimes be referred to herein as the active area. Electronic device  10  has an external housing with a peripheral edge. The region surrounding the active area and within the peripheral edge of device  10  is the border region. Images can only be displayed to a user of the device in the active region. It is generally desirable to minimize the border region of device  10 . For example, device  10  may be provided with a full-face display  14  that extends across the entire front face of the device. If desired, display  14  may also wrap around over the edge of the front face so that at least part of the lateral edges or at least part of the back surface of device  10  is used for display purposes. 
     Device  10  may include a sensor  13  mounted behind display  14  (e.g., behind the active area of the display).  FIG.  3    is a cross-sectional side view of an illustrative display stack of display  14  that at least partially covers a sensor in accordance with an embodiment. As shown in  FIG.  3   , the display stack may include a substrate such as substrate  300 . Substrate  300  may be formed from glass, metal, plastic, ceramic, sapphire, or other suitable substrate materials. In some arrangements, substrate  300  may be an organic substrate formed from polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) (as examples). One or more polyimide (PI) layers  302  may be formed over substrate  300 . The polyimide layers may sometimes be referred to as an organic substrate (e.g., substrate  300  is a first substrate layer and substrate  302  is a second substrate layer). The surface of substrate  302  may optionally be covered with one or more buffer layers  303  (e.g., inorganic buffer layers such as layers of silicon oxide, silicon nitride, amorphous silicon, etc.). 
     Thin-film transistor (TFT) layers  304  may be formed over inorganic buffer layers  303  and organic substrates  302  and  300 . The TFT layers  304  may include thin-film transistor circuitry such as thin-film transistors, thin-film capacitors, associated routing circuitry, and other thin-film structures formed within multiple metal routing layers and dielectric layers. Organic light-emitting diode (OLED) layers  306  may be formed over the TFT layers  304 . The OLED layers  306  may include a diode cathode layer, a diode anode layer, and emissive material interposed between the cathode and anode layers. The OLED layers may include a pixel definition layer that defines the light-emitting area of each pixel. The TFT circuitry in layer  304  may be used to control an array of display pixels formed by the OLED layers  306 . 
     Circuitry formed in the TFT layers  304  and the OLED layers  306  may be protected by encapsulation layers  308 . As an example, encapsulation layers  308  may include a first inorganic encapsulation layer, an organic encapsulation layer formed on the first inorganic encapsulation layer, and a second inorganic encapsulation layer formed on the organic encapsulation layer. Encapsulation layers  308  formed in this way can help prevent moisture and other potential contaminants from damaging the conductive circuitry that is covered by layers  308 . Substrate  300 , polyimide layers  302 , buffer layers  303 , TFT layers  304 , OLED layers  306 , and encapsulation layers  308  may be collectively referred to as a display panel. 
     One or more polarizer films  312  may be formed over the encapsulation layers  308  using adhesive  310 . Adhesive  310  may be implemented using optically clear adhesive (OCA) material that offer high light transmittance. One or more touch layers  316  that implement the touch sensor functions of touch-screen display  14  may be formed over polarizer films  312  using adhesive  314  (e.g., OCA material). For example, touch layers  316  may include horizontal touch sensor electrodes and vertical touch sensor electrodes collectively forming an array of capacitive touch sensor electrodes. Lastly, the display stack may be topped off with a cover glass layer  320  (sometimes referred to as a display cover layer  320 ) that is formed over the touch layers  316  using additional adhesive  318  (e.g., OCA material). display cover layer  320  may be a transparent layer (e.g., transparent plastic or glass) that serves as an outer protective layer for display  14 . The outer surface of display cover layer  320  may form an exterior surface of the display and the electronic device that includes the display. 
     Still referring to  FIG.  3   , sensor  13  may be formed under the display stack within the electronic device  10 . As described above in connection with  FIG.  1   , sensor  13  may be an optical sensor such as a camera, proximity sensor, ambient light sensor, fingerprint sensor, or other light-based sensor. In some cases, sensor  13  may include a light-emitting component that emits light through the display. Sensor  13  may therefore sometimes be referred to as input-output component  13 . Input-output component  13  may be a sensor or a light-emitting component (e.g., that is part of a sensor). The performance of input-output component  13  depends on the transmission of light traversing through the display stack, as indicated by arrow  350 . A typical display stack, however, has fairly limited transmission properties. For instance, more than 80% of light in the visible and infrared light spectrum might be lost when traveling through the display stack, which makes sensing under display  14  challenging. 
     Each of the multitude of layers in the display stack contributes to the degraded light transmission to sensor  13 . In particular, the dense thin-film transistors and associated routing structures in TFT layers  304  of the display stack contribute substantially to the low transmission. In accordance with an embodiment, at least some of the display pixels may be selectively removed in regions of the display stack located directly over sensor(s)  13 . Regions of display  14  that at least partially cover or overlap with sensor(s)  13  in which at least a portion of the display pixels have been removed are sometimes referred to as pixel removal regions or low density pixel regions. Removing display pixels (e.g., removing transistors and/or capacitors associated with one or more sub-pixels) in the pixel removal regions can drastically help increase transmission and improve the performance of the under-display sensor  13 . In addition to removing display pixels, portions of additional layers such as polyimide layers  302  and/or substrate  300  may be removed for additional transmission improvement. Polarizer  312  may also be bleached for additional transmission improvement. 
       FIG.  4    is a cross-sectional side view of an illustrative display showing how pixels may be removed in a pixel removal region  332  to increase transmission through the display. As shown in  FIG.  4   , display  14  may include a pixel region  322  and a high-transmittance area  324 . In the pixel region  322 , the display may include a pixel formed from emissive material  306 - 2  that is interposed between an anode  306 - 1  and a cathode  306 - 3 . Signals may be selectively applied to anode  306 - 1  to cause emissive material  306 - 2  to emit light for the pixel. Circuitry in thin-film transistor layer  304  may be used to control the signals applied to anode  306 - 1 . 
     In high-transmittance area  324 , anode  306 - 1  and emissive material  306 - 2  may be omitted. Without the high-transmittance area, an additional pixel may be formed in area  324  adjacent to the pixel in area  322 . However, to increase the transmittance of light to sensor  13  under the display, the pixels in area  324  are removed. The absence of emissive material  306 - 2  and anode  306 - 1  may increase the transmittance through the display stack. Additional circuitry within thin-film transistor layer  304  may also be omitted in high-transmittance area  324  to increase transmittance. 
     Additional transmission improvements through the display stack may be obtained by selectively removing additional components from the display stack in high-transmittance area  324 . As shown in  FIG.  4   , a portion of cathode  306 - 3  may be removed in high-transmittance area  324 . This results in an opening  326  in the cathode  306 - 3 . Said another way, the cathode  306 - 3  may have conductive material that defines an opening  326  in the pixel removal region. Removing the cathode in this way allows for more light to pass through the display stack to sensor  13 . Cathode  306 - 3  may be formed from any desired conductive material. The cathode may be removed via etching (e.g., laser etching or plasma etching). Alternatively, the cathode may be patterned to have an opening in high-transmittance area  324  during the original cathode deposition and formation steps. 
     Polyimide layers  302  may be removed in high-transmittance area  324  in addition to cathode layer  306 - 3 . The removal of the polyimide layers  302  results in an opening  328  in the pixel removal region. Said another way, the polyimide layer may have polyimide material that defines an opening  328  in the high-transmittance region. The polyimide layers may be removed via etching (e.g., laser etching or plasma etching). Alternatively, the polyimide layers may be patterned to have an opening in high-transmittance area  324  during the original polyimide formation steps. Removing the polyimide layer  302  in high-transmittance area  324  may result in additional transmittance of light to sensor  13  in high-transmittance area  324 . 
     Substrate  300  may be removed in high-transmittance area  324  in addition to cathode layer  306 - 3  and polyimide layer  302 . The removal of the substrate  300  results in an opening  330  in the high-transmittance area. Said another way, the substrate  300  may have material (e.g., PET, PEN, etc.) that defines an opening  330  in the pixel removal region. The substrate may be removed via etching (e.g., with a laser). Alternatively, the substrate may be patterned to have an opening in high-transmittance area  324  during the original substrate formation steps. Removing the substrate  300  in high-transmittance area  324  may result in additional transmittance of light in high-transmittance area  324 . The polyimide opening  328  and substrate opening  330  may be considered to form a single unitary opening. When removing portions of polyimide layer  302  and/or substrate  300 , inorganic buffer layers  303  may serve as an etch stop for the etching step. Openings  328  and  330  may be filled with air or another desired transparent filler. 
     In addition to having openings in cathode  306 - 3 , polyimide layers  302 , and/or substrate  300 , the polarizer  312  in the display may be bleached for additional transmittance in the pixel removal region. 
       FIG.  5    is a top view of an illustrative display showing how high-transmittance areas may be incorporated into a pixel removal region  332  of the display. As shown, the display may include a plurality of pixels. In  FIG.  5   , there are a plurality of red pixels (R), a plurality of blue pixels (B), and a plurality of green pixels (G). The red, blue, and green pixels may be arranged in any desired pattern. Different nomenclature may be used to refer to the red, green, and blue pixels in the display. As one option, the red, blue, and green pixels may be referred to simply as pixels. As another option, the red, blue, and green pixels may instead be referred to as red, blue, and green sub-pixels. In this example, a group of sub-pixels of different colors may be referred to as pixel. In high-transmittance areas  324 , no sub-pixels are included in the display (even though sub-pixels would normally be present if the normal sub-pixel pattern was followed). 
     To provide a uniform distribution of sub-pixels across the display surface, an intelligent pixel removal process may be implemented that systematically eliminates the closest sub-pixel of the same color (e.g., the nearest neighbor of the same color may be removed). The pixel removal process may involve, for each color, selecting a given sub-pixel, identifying the closest or nearest neighboring sub-pixels of the same color (in terms of distance from the selected sub-pixel), and then eliminating/omitting those identified sub-pixels in the final pixel removal region. With this type of arrangement, there may be high-transmittance areas in the pixel removal region, allowing a sensor or light-emitting component to operate through the display in the pixel removal region. Additionally, because some of the pixels remain present in the pixel removal region (e.g., 50% of the pixels in the layout of  FIG.  5   ), the pixel removal region may not have a perceptibly different appearance from the rest of the display for a viewer. 
     As shown in  FIG.  5   , display  14  may include an array of high-transmittance areas  324 . Each high-transmittance area  324  may have pixels removed in that area. Each high-transmittance area also has an increased transparency compared to pixel region  322 . The high-transmittance areas  324  may sometimes be referred to as transparent windows  324 , transparent display windows  324 , transparent openings  324 , transparent display openings  324 , etc. The transparent display windows may allow for light to be transmitted through the display to an underlying sensor or for light to be transmitted through the display from a light source underneath the display. The transparency of transparent openings  324  (for visible and/or infrared light) may be greater than 25%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 70%, greater than 80%, greater than 90%, etc. The transparency of transparent openings  324  may be greater than the transparency of pixel region  322 . The transparency of pixel region  322  may be less than 25%, less than 20%, less than 10%, less than 5%, etc. The pixel region  322  may sometimes be referred to as opaque display region  322 , opaque region  322 , opaque footprint  322 , etc. Opaque region  322  includes light emitting pixels R, G, and B, and blocks light from passing through the display. 
     The pattern of pixels ( 322 ) and high-transmittance areas ( 324 ) in  FIG.  5    is merely illustrative. In  FIG.  5   , discrete high-transmittance areas  324  are depicted. However, it should be understood that these high-transmittance areas may form larger, unitary transparent openings if desired. 
     The pattern of sub-pixels and pixel removal regions in  FIG.  5    is merely illustrative. In  FIG.  5   , the display edge may be parallel to the X axis or the Y axis. The front face of the display may be parallel to the XY plane such that a user of the device views the front face of the display in the Z direction. In  FIG.  5   , every other sub-pixel may be removed for each color. The resulting pixel configuration has 50% of the sub-pixels removed. In  FIG.  5   , the remaining pixels follow a zig-zag pattern across the display (with two green sub-pixels for every one red or blue sub-pixel). In  FIG.  5   , the sub-pixels have edges angled relative to the edges of the display (e.g., the edges of the sub-pixels are at non-zero, non-orthogonal angles relative to the X-axis and Y-axis). This example is merely illustrative. If desired, each individual sub-pixel may have edges parallel to the display edge, a different proportion of pixels may be removed for different colors, the remaining pixels may follow a different pattern, etc. 
     In general, the display sub-pixels may be partially removed from any region(s) of display  14 .  FIGS.  6 A- 6 F  are front views showing how display  14  may have one or more localized pixel removal regions in which the sub-pixels are selectively removed. The example of  FIG.  6 A  illustrates various local pixel removal regions  332  (sometimes referred to as low pixel density regions or high-transmittance region  332 ) physically separated from one another (i.e., the various pixel removal regions  332  are non-continuous) by full pixel density region  334 . The full pixel density region  334  (sometimes referred to as full pixel density area  334 ) does not include any transparent windows  324  (e.g., none of the sub-pixels are removed and the display follows the pixel pattern without modifications). The full pixel density region  334  has a higher pixel density (pixels per unit area) than low pixel density regions  332 . The three pixel removal regions  332 - 1 ,  332 - 2 , and  332 - 3  in  FIG.  6 A  might for example correspond to three different sensors formed underneath display  14  (with one sensor per pixel removal region). 
     The example of  FIG.  6 B  illustrates a continuous pixel removal region  332  formed along the top border of display  14 , which might be suitable when there are many optical sensors positioned near the top edge of device  10 . The example of  FIG.  6 C  illustrates a pixel removal region  332  formed at a corner of display  14  (e.g., a rounded corner area of the display). In some arrangements, the corner of display  14  in which pixel removal region  332  is located may be a rounded corner (as in  FIG.  6 C ) or a corner having a substantially 90° corner. The example of  FIG.  6 D  illustrates a pixel removal region  332  formed only in the center portion along the top edge of device  10  (i.e., the pixel removal region covers a recessed notch area in the display).  FIG.  6 E  illustrates another example in which pixel removal regions  332  can have different shapes and sizes.  FIG.  6 F  illustrates yet another suitable example in which the pixel removal region covers the entire display surface. These examples are merely illustrative and are not intended to limit the scope of the present embodiments. If desired, any one or more portions of the display overlapping with optically based sensors or other sub-display electrical components may be designated as a pixel removal region/area. 
       FIG.  5    shows an example of a pixel removal region where some sub-pixels are removed in favor of transparent openings in the display.  FIG.  5    shows a layout for sub-pixels within the pixel removal region. It should be noted that these layouts are for the emissive layer of each sub-pixel. 
     Each display pixel  22  may include both a thin-film transistor layer and an emissive layer. Each emissive layer portion may have associated circuitry on the thin-film transistor layer that controls the magnitude of light emitted from that emissive layer portion. Both the emissive layer and thin-film transistor layer may have corresponding sub-pixels within the pixel. Each sub-pixel may be associated with a different color of light (e.g., red, green, and blue). The emissive layer portion for a given sub-pixel does not necessarily need to have the same footprint as its associated thin-film transistor layer portion. Hereinafter, the term sub-pixel may sometimes be used to refer to the combination of an emissive layer portion and a thin-film transistor layer portion. Additionally, the thin-film transistor layer may be referred to as having thin-film transistor sub-pixels (e.g., a portion of the thin-film transistor layer that controls a respective emissive area, sometimes referred to as thin-film transistor layer pixels, thin-film transistor layer sub-pixels or simply sub-pixels) and the emissive layer may be referred to as having emissive layer sub-pixels (sometimes referred to as emissive pixels, emissive sub-pixels or simply sub-pixels). 
     Different arrangements may be used for the thin-film transistor sub-pixels and the emissive sub-pixels.  FIG.  5    shows an example where the emissive sub-pixels have a horizontal zig-zag arrangement. This emissive sub-pixel arrangement may have multiple possible associated thin-film transistor sub-pixel arrangements, as shown in  FIGS.  7  and  8   . 
     As shown in  FIG.  7   , the pixel removal region  332  may include emissive sub-pixels  62  such as red (R), green (G), and blue (B) emissive sub-pixels  62 . The emissive sub-pixels  62  have the same arrangement as shown in  FIG.  5    (e.g., horizontal zig-zag arrangement). Each emissive sub-pixel has a corresponding thin-film transistor sub-pixel. As shown in  FIG.  6   , red emissive sub-pixel  62 - 1  is controlled by a corresponding thin-film transistor sub-pixel  64 - 1 , green emissive sub-pixel  62 - 2  is controlled by a corresponding thin-film transistor sub-pixel  64 - 2 , blue emissive sub-pixel  62 - 3  is controlled by a corresponding thin-film transistor sub-pixel  64 - 3 , green emissive sub-pixel  62 - 4  is controlled by a corresponding thin-film transistor sub-pixel  64 - 4 , red emissive sub-pixel  62 - 5  is controlled by a corresponding thin-film transistor sub-pixel  64 - 5 , green emissive sub-pixel  62 - 6  is controlled by a corresponding thin-film transistor sub-pixel  64 - 6 , blue emissive sub-pixel  62 - 7  is controlled by a corresponding thin-film transistor sub-pixel  64 - 7 , green emissive sub-pixel  62 - 8  is controlled by a corresponding thin-film transistor sub-pixel  64 - 8 , red emissive sub-pixel  62 - 9  is controlled by a corresponding thin-film transistor sub-pixel  64 - 9 , green emissive sub-pixel  62 - 10  is controlled by a corresponding thin-film transistor sub-pixel  64 - 10 , blue emissive sub-pixel  62 - 11  is controlled by a corresponding thin-film transistor sub-pixel  64 - 11 , green emissive sub-pixel  62 - 12  is controlled by a corresponding thin-film transistor sub-pixel  64 - 12 , red emissive sub-pixel  62 - 13  is controlled by a corresponding thin-film transistor sub-pixel  64 - 13 , green emissive sub-pixel  62 - 14  is controlled by a corresponding thin-film transistor sub-pixel  64 - 14 , blue emissive sub-pixel  62 - 15  is controlled by a corresponding thin-film transistor sub-pixel  64 - 15 , and green emissive sub-pixel  62 - 16  is controlled by a corresponding thin-film transistor sub-pixel  64 - 16 . Each thin-film transistor sub-pixel controls the magnitude of light emitted from its corresponding emissive sub-pixel. 
     Each column of thin-film transistor sub-pixels is coupled to a respective data line. As shown in  FIG.  7   , data line D 1  provides data to thin-film transistor sub-pixels  64 - 1  and  64 - 9 , data line D 2  provides data to thin-film transistor sub-pixels  64 - 2  and  64 - 10 , data line D 3  provides data to thin-film transistor sub-pixels  64 - 3  and  64 - 11 , data line D 4  provides data to thin-film transistor sub-pixels  64 - 4  and  64 - 12 , data line D 5  provides data to thin-film transistor sub-pixels  64 - 5  and  64 - 13 , data line D 6  provides data to thin-film transistor sub-pixels  64 - 6  and  64 - 14 , data line D 7  provides data to thin-film transistor sub-pixels  64 - 7  and  64 - 15 , and data line D 8  provides data to thin-film transistor sub-pixels  64 - 8  and  64 - 16 . 
     In general, thin-film transistor sub-pixels  64  and emissive areas  62  may both have a low transmittance of light through the display stack. The areas between thin-film transistor sub-pixels  64  and emissive areas  62 , however, may have a relatively high transmittance of light through the display stack. With the arrangement of  FIG.  7   , where each emissive sub-pixel has a corresponding thin-film transistor sub-pixel, there may be a high transmittance area  324  between rows of the thin-film transistor sub-pixels. Each row of thin-film transistor sub-pixels may be coupled to one or more corresponding gate lines.  FIG.  7    shows an example where the first row of thin-film transistor sub-pixels (with sub-pixels  64 - 1  through  64 - 8 ) is coupled to gate line G 1  and the second row of thin-film transistor sub-pixels (with sub-pixels  64 - 9  through  64 - 16 ) is coupled to gate line G 2 . Additional gate lines may be included for each row if desired. 
     In the arrangement of  FIG.  7   , pixel removal region  332  includes 50% of the emissive sub-pixels  62  relative to the full density pixel region  334 . Additionally, there are 50% of the thin-film transistor sub-pixels  64  in pixel removal region  332  relative to the full density pixel region  334 . In  FIG.  7   , each emissive sub-pixel  62  has a corresponding dedicated thin-film transistor sub-pixel  64 . This is similar to the full pixel density region  334 , where each thin-film transistor sub-pixel controls only one corresponding emissive sub-pixel. 
     In order to increase the transmission of light through pixel removal region  332  without reducing the light-emitting area of the display in pixel removal region  332 , additional thin-film transistor sub-pixels  64  may be removed from pixel removal region  332 . For example, each thin-film transistor sub-pixel may control the light emitted from two emissive sub-pixels (e.g., that are shorted together). This reduces the number of thin-film transistor sub-pixels by an additional 50% relative to the arrangement of  FIG.  7   . In total, when each thin-film transistor sub-pixel in the pixel removal region controls two emissive sub-pixels, the pixel removal region  332  may have 50% of the emissive sub-pixels and 25% of the thin-film transistor sub-pixels relative to the full pixel density region  334 . 
       FIG.  8    is a top view of a pixel removal region where each thin-film transistor sub-pixel controls two respective emissive sub-pixels. As shown in  FIG.  8   , red emissive sub-pixel  62 - 1  is shorted to red emissive sub-pixel  62 - 5  by shorting path  72 - 1  and thin-film transistor sub-pixel  64 - 1  controls the magnitude of light emitted by both emissive sub-pixels  62 - 1  and  62 - 5 . Green emissive sub-pixel  62 - 2  is shorted to green emissive sub-pixel  62 - 4  by shorting path  72 - 2  and thin-film transistor sub-pixel  64 - 2  controls the magnitude of light emitted by both emissive sub-pixels  62 - 2  and  62 - 4 . Blue emissive sub-pixel  62 - 3  is shorted to blue emissive sub-pixel  62 - 7  by shorting path  72 - 3  and thin-film transistor sub-pixel  64 - 3  controls the magnitude of light emitted by both emissive sub-pixels  62 - 3  and  62 - 7 . Green emissive sub-pixel  62 - 6  is shorted to green emissive sub-pixel  62 - 8  by shorting path  72 - 4  and thin-film transistor sub-pixel  64 - 4  controls the magnitude of light emitted by both emissive sub-pixels  62 - 6  and  62 - 8 . Red emissive sub-pixel  62 - 9  is shorted to red emissive sub-pixel  62 - 13  by shorting path  72 - 5  and thin-film transistor sub-pixel  64 - 5  controls the magnitude of light emitted by both emissive sub-pixels  62 - 9  and  62 - 13 . Green emissive sub-pixel  62 - 10  is shorted to green emissive sub-pixel  62 - 12  by shorting path  72 - 6  and thin-film transistor sub-pixel  64 - 6  controls the magnitude of light emitted by both emissive sub-pixels  62 - 10  and  62 - 12 . Blue emissive sub-pixel  62 - 11  is shorted to blue emissive sub-pixel  62 - 15  by shorting path  72 - 7  and thin-film transistor sub-pixel  64 - 7  controls the magnitude of light emitted by both emissive sub-pixels  62 - 11  and  62 - 15 . Green emissive sub-pixel  62 - 14  is shorted to green emissive sub-pixel  62 - 16  by shorting path  72 - 8  and thin-film transistor sub-pixel  64 - 8  controls the magnitude of light emitted by both emissive sub-pixels  62 - 14  and  62 - 16 . 
     Each column of thin-film transistor sub-pixels is coupled to a respective data line. As shown in  FIG.  8   , data line D 1  provides data to thin-film transistor sub-pixels  64 - 1  and  64 - 5 , data line D 2  provides data to thin-film transistor sub-pixels  64 - 2  and  64 - 6 , data line D 3  provides data to thin-film transistor sub-pixels  64 - 3  and  64 - 7 , and data line D 4  provides data to thin-film transistor sub-pixels  64 - 4  and  64 - 8 . 
     Pixel removal region  332  in  FIG.  8    therefore has 50% of the emissive sub-pixels, 25% of the thin-film transistor sub-pixels, and 50% of the data lines compared to a full pixel density region. Pixel removal region  332  in  FIG.  8    also has 50% of the thin-film transistor sub-pixels and 50% of the data lines compared to the pixel removal region in  FIG.  7   . These additional omitted components in the pixel removal region allow for increased transmission through the pixel removal region, thereby improving the performance of the pixel removal region. The pixel removal region in  FIG.  8    may have a transmission that is at least 10% greater than the transmission in  FIG.  7   , at least 20% greater than the transmission in  FIG.  7   , at least 30% greater than the transmission in  FIG.  7   , etc. The total transmission of the pixel removal region in  FIG.  8    may be greater than 45%, greater than 50%, greater than 55% greater than 60%, between 50% and 60%, etc. 
     Shorting paths  72  may be formed by conductive routing lines on one or more layers within the display (e.g., within the thin-film transistor circuitry layer in the display). Each shorting path may electrically connect the first anode of a first emissive sub-pixel to the second anode of a second emissive sub-pixel. In this way, when a thin-film transistor sub-pixel applies a drive voltage to the first anode, the drive voltage is also applied to the second anode. Both the first and second emissive sub-pixels therefore emit approximately the same amount of light. This partially reduces the effective resolution of the display in the pixel removal region (since the shorted pixels necessarily emit the same amount of light). However, the display may still have a satisfactory appearance to the viewer in pixel removal region  332  even with the shorted emissive sub-pixels. 
     The arrangements for the pixel removal region  332  in  FIGS.  7  and  8    are merely illustrative. In general, depending on the target transmission through the display, each thin-film transistor sub-pixel may each control one or two of the emissive sub-pixels. Additionally, it should be noted that, regardless of whether the thin-film transistor sub-pixel controls one or two emissive sub-pixels, conductive paths may be used to shift the position of a thin-film transistor sub-pixel relative to an emissive sub-pixel it controls. In other words, the conductive paths allow for the position of the emissive sub-pixel to be decoupled from the position of the thin-film transistor sub-pixel. This allows for the positions of the thin-film transistor sub-pixels and the positions of the emissive sub-pixels to be optimized independently, improving the performance of the display. 
       FIG.  9    is a top view of a pixel removal region where the thin-film transistor sub-pixels are grouped vertically at the edges of the pixel removal region. In this example, there are 24 columns of emissive sub-pixels  62  (e.g., having a horizontal zig-zag layout of the type shown in  FIG.  5   ). The emissive sub-pixels in  FIG.  9    are arranged in 6 horizontal zig-zag rows. Across the entire pixel removal region, there may be one thin-film transistor sub-pixel for two emissive sub-pixels (as previously discussed in connection with  FIG.  8   ). However, the thin-film transistor sub-pixels are consolidated vertically at the edges of the pixel removal region. In other words, continuous rows of thin-film transistor sub-pixels are formed along the upper edge and the lower edge of the pixel removal region  332 . This leaves the central area of the pixel removal region to have a particularly high transmittance. 
     Each column of thin-film transistor sub-pixels has a corresponding data line (e.g., data lines D 1 , D 2 , D 3 , D 4 , etc. in  FIG.  14   ) and each row of thin-film transistor sub-pixels may have one or more corresponding gate lines. 
       FIG.  9    demonstrates how the thin-film transistor sub-pixels may be consolidated to produce larger continuous high transmittance areas in the pixel removal region  332 . The example in  FIG.  9    of grouping the thin-film transistor sub-pixels vertically at the edges of the pixel removal region is merely illustrative. In general, the thin-film transistor sub-pixels may be grouped in any desired manner to produce one or more high-transmittance areas having desired transmittances and shapes/sizes. 
     Care may be taken to ensure that the low pixel density region  332  is not perceptible to the viewer when operating electronic device  10 . As previously discussed, low pixel density region  332  has a lower pixel density (e.g., 50%) than full pixel density region  334 . When the display is on, a software dimming/gain scheme may be applied to the emissive sub-pixels to gradually transition between the full pixel density region  334  and the low pixel density region  332 . This prevents the low pixel density region from being perceptible to the viewer when the display is on. 
     When the display is off, the low pixel density region  332  is still susceptible to being perceptible to the viewer. Due to the reduced number of pixels in region  332 , the reflectance properties of low pixel density region  332  are different than in full pixel density region  334 . To prevent these different properties from causing the low pixel density region  332  to be perceptible to the viewer when the display is off, one or more layers/components in the display may transition between full pixel density region  334  and low pixel density region  332 . 
       FIG.  10    is a top view of an illustrative display that includes transition regions in low pixel density region  332 . As shown, low pixel density region  332  is formed in the display and is laterally surrounded by full pixel density region  334 . A first transition region  336 - 1  is formed adjacent to the full pixel density region  334  on the left side of low pixel density region  332 . A second transition region  336 - 2  is formed adjacent to the full pixel density region  334  on the right side of low pixel density region  332 . Herein, the transition regions  336  may be referred to as a subset of low pixel density region  332 . However, the transition regions  336  may instead sometimes be referred to as separate from low pixel density region  332 . 
     There are many possible arrangements for the sizes and shapes of transition region(s)  336  in the display. In general, any desired arrangement for the transition region(s) may be used. Each transition region may have a density transition of one or more components to improve the off-state cosmetics of the display. In general, one or more components that contribute to reflectance (e.g., the thin-film transistor sub-pixels, the emissive sub-pixels, the cathode layer, and touch sensor metal) may have a density (i.e., coverage percentage per unit area) that transitions across each transition region. This causes the reflectance to undergo a gradual, imperceptible transition between the full pixel density region and the low pixel density region (instead of an abrupt, perceptible transition). 
       FIG.  11    is a top view of an illustrative display that includes a transition region  336  that uses dummy thin-film transistor sub-pixels to approximate a gradual change in density of thin-film transistor sub-pixels.  FIG.  11    shows an array of emissive sub-pixels  62 . There are 50% of the emissive sub-pixels in low pixel density region  332  than in full pixel density region  334 . In  FIG.  11   , the emissive sub-pixels  62  make an abrupt transition at the interface of full pixel density region  334  and low pixel density region  332 . The display also includes thin-film transistor sub-pixels  64 . In full pixel density region  334 , each emissive sub-pixel is controlled by a respective thin-film transistor sub-pixel. In low pixel density region  332 , each thin-film transistor sub-pixel controls two respective emissive sub-pixels. Additionally, the thin-film transistor sub-pixels are consolidated in each row adjacent to the full pixel density region  334 . 
     In the example of  FIG.  11   , there are 32 thin-film transistor sub-pixels on the left edge of low pixel density region  332 . These 32 thin-film transistor sub-pixels may therefore be used to control  64  respective emissive sub-pixels. This example is merely illustrative. In an alternate embodiment, 64 thin-film transistor sub-pixels may be included to control  64  respective emissive sub-pixels. 
     To gradually transition the thin-film transistor sub-pixel density in transition region  336 , the transition region  336  includes dummy thin-film transistor sub-pixels  104  (sometimes referred to as dummy thin-film transistor structures  104 , dummy structures  104 , etc.). The dummy thin-film transistor sub-pixels do not serve an electrical function for the display. In other words, each dummy thin-film transistor sub-pixel is not electrically connected to any emissive sub-pixels. The dummy thin-film transistor sub-pixels  104  may be formed from a metal layer that is also included in the thin-film transistor sub-pixels  64 . The overall reflectance RDUMMY of each dummy thin-film transistor sub-pixel  104  may be similar to the reflectance RTFT of each thin-film transistor sub-pixel  64  (e.g., RDUMMY is within 50% of RTFT, RDUMMY is within 40% of RTFT, RDUMMY is within 30% of RTFT, RDUMMY is within 20% of RTFT, RDUMMY is within 10% of RIFT, RDUMMY is within 5% of RTFT, RDUMMY is within 1% of RTFT, etc.). 
     As shown in  FIG.  11   , the dummy thin-film transistor sub-pixels  104  are included with a gradually decreasing density in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332 . Accordingly, the overall density of thin-film transistor sub-pixels (i.e., including both the functional sub-pixels  64  and dummy sub-pixels  104 ) has a gradually decreasing density in the X-direction from the full pixel density region towards the central portion (e.g., the portion between the transition regions) of the pixel removal region  332 . This results in the display having a gradually decreasing reflectance in the X-direction from the full pixel density region  334  towards the central portion of the pixel removal region  332  while in the off state. 
       FIG.  12 A  is a graph showing the density of the dummy thin-film transistor sub-pixels as a function of position across the display. As shown, at the interface between the full pixel density region and the transition region, the dummy thin-film transistor sub-pixels may have a density of D 1  or near D 1  (e.g., the same density as in the full pixel density region). D 1  may be 100% for example (as in  FIG.  11   ). The density then gradually decreases across the transition region from D 1  to D 2 . D 2  may be equal to the density of the thin-film transistor sub-pixels in a central portion of the pixel removal region (e.g., a minimum thin-film transistor sub-pixel density for the pixel removal region). In  FIG.  11   , D 2  is equal to 0%. However, D 2  may instead be equal to 50% (e.g., if the pixel removal region has the arrangement of  FIG.  7   ). 
       FIG.  12 B  is a graph showing the density of the thin-film transistor sub-pixels (including both dummy structures and functional TFT sub-pixels) as a function of position across the display. Profile  202  shows the density of the functional thin-film transistor sub-pixels alone (in an example where no dummy sub-pixels are included). As shown, there is a first step change (from D 1  to D 3 ) in the TFT sub-pixel density at the interface between the full pixel density region and the pixel removal region. There is then a second step change (from D 3  to D 2 ) in the TFT sub-pixel density. The first step change may correspond, for example, to a change from 100% density in full pixel density region  334  to 50% density in pixel removal region  332  in  FIG.  11   . The second step change may correspond, for example, to a change from 50% density in an edge portion of pixel removal region  332  to 0% density in a central portion of pixel removal region  332 . These step changes in TFT sub-pixel density (without the presence of the dummy structures) may result in perceptible reflectance changes when the display is off. 
     Profile  204  shows the density of the thin-film transistor sub-pixels (including both dummy structures and functional TFT sub-pixels) from  FIG.  11    as a function of position across the display. As shown, with the presence of the dummy thin-film transistor sub-pixels, the overall sub-pixel density gradually decreases from D 1  (at the interface of the pixel removal region/transition region and the full pixel density region) to D 2  (the minimum density at a central portion of the pixel removal region). 
       FIG.  13    is a top view of an illustrative display that includes a transition region  336  that uses dummy anodes to approximate a gradual change in density of emissive sub-pixels.  FIG.  13    shows an array of emissive sub-pixels  62 . There are 50% of the emissive sub-pixels in low pixel density region  332  than in full pixel density region  334 . In  FIG.  11   , the emissive sub-pixels  62  make an abrupt transition at the interface of full pixel density region  334  and low pixel density region  332 . In  FIG.  13   , to gradually transition the emissive sub-pixel density in transition region  336 , the transition region  336  includes dummy emissive sub-pixels  102  (sometimes referred to as dummy emissive structures  102 , dummy structures  102 , dummy anodes  102 , etc.). The dummy anodes do not serve an electrical function for the display. In other words, each dummy anode is not electrically connected to a respective thin-film transistor sub-pixel and/or does not have associated emissive OLED layers. 
     The dummy anodes  102  may be formed from a metal layer that is also included in the emissive sub-pixels  62 . For example, each dummy anode  102  may be formed from the same layer of metal that is patterned to form functioning anodes for the emissive sub-pixels  62 . The overall reflectance RDA of each dummy anode  102  may be similar to the reflectance RA of each emissive sub-pixel  64  (e.g., RDA is within 50% of RA, RDA is within 40% of RA, RDA is within 30% of RA, RDA is within 20% of RA, RDA is within 10% of RA, RDA is within 5% of RA, RDA is within 1% of RA, etc.). 
     As shown in  FIG.  13    the dummy anodes  102  are included with a gradually decreasing density in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332 . Accordingly, the overall density of emissive-sub-pixels (i.e., including both the functional sub-pixels  62  and dummy sub-pixels  102 ) has a gradually decreasing density in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332 . This results in the display having a gradually decreasing reflectance in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332  while in the off state. 
     In  FIG.  13   , the display also includes thin-film transistor sub-pixels  64 . In full pixel density region  334 , each emissive sub-pixel is controlled by a respective thin-film transistor sub-pixel. In low pixel density region  332 , each thin-film transistor sub-pixel controls two respective emissive sub-pixels. Additionally, the thin-film transistor sub-pixels are consolidated in each row adjacent to the full pixel density region  334 . In the example of  FIG.  13   , there are 32 thin-film transistor sub-pixels on the left edge of low pixel density region  332 . These 32 thin-film transistor sub-pixels may therefore be used to control  64  respective emissive sub-pixels. This example is merely illustrative. In an alternate embodiment, 64 thin-film transistor sub-pixels may be included to control  64  respective emissive sub-pixels. 
       FIG.  14 A  is a graph showing the density of the dummy anodes as a function of position across the display. As shown, at the interface between the full pixel density region and the transition region, the dummy anodes may have a density of D 1  or near D 1  (e.g., the same density as in the full pixel density region). The density then gradually decreases across the transition region from D 1  to D 2 . D 2  may be equal to the density of the emissive sub-pixels in a central portion of the pixel removal region (e.g., a minimum emissive sub-pixel density for the pixel removal region). In  FIG.  13   , D 2  is equal to 50% of D 1 . This example is merely illustrative and other D 1  to D 2  ratios may be used if desired. 
       FIG.  14 B  is a graph showing the density of the emissive sub-pixels (including both dummy structures and functional emissive sub-pixels) as a function of position across the display. Profile  206  shows the density of the functional emissive sub-pixels alone (in an example where no dummy anodes are included). As shown, there is a step change from D 1  to D 2  in the emissive sub-pixel density at the interface between the full pixel density region and the pixel removal region. These step changes in emissive sub-pixel density (without the presence of the dummy structures) may result in perceptible reflectance changes when the display is off. Profile  208  shows the density of the emissive sub-pixels (including both dummy anodes and functional emissive sub-pixels) from  FIG.  13    as a function of position across the display. As shown, with the presence of the dummy anodes, the overall emissive sub-pixel density gradually decreases from D 1  (at the interface of the pixel removal region/transition region and the full pixel density region) to D 2  (the minimum density at a central portion of the pixel removal region). 
       FIG.  15    is a top view of an illustrative display that includes a transition region  336  that uses cathode openings to approximate a gradual change in density of cathode layer  306 - 3 . As discussed in connection with  FIG.  4   , cathode layer  306 - 3  may be patterned in the pixel removal region  332  to increase the transmission in the pixel removal region. In the example of  FIG.  15   , a central portion of pixel removal region  332  may have cathode openings  326 . In the full pixel density area, the cathode may have a density (e.g., coverage per unit area) of 100%. In other words, the cathode is formed as a blanket layer across the pixel array without any openings in the full pixel density area. In the central portion of the pixel removal region, the cathode may have a density (e.g., coverage per unit area) of less than 90%, less than 70%, less than 60%, less than 50%, between 40% and 70%, 50%, between 45% and 55%, etc.). 
     To gradually transition between the full pixel density region  334  (where the cathode  306 - 3  has 100% coverage) to the central portion of pixel removal region  332  (where the cathode has a second, lower coverage), additional openings  326  are included in transition region  336 . As shown in  FIG.  15   , the cathode openings  326  are included with a gradually increasing density in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332 . Accordingly, the overall density (coverage) of cathode layer  306 - 3  gradually decreases in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332 . This results in the display having a gradually decreasing reflectance in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332  while in the off state. 
       FIG.  16    is a graph showing the density of the cathode (e.g., the coverage per unit area) as a function of position across the display. Profile  210  shows the density of the cathode in an embodiment where the additional openings of the transition region are omitted. As shown, there is a step change from D 1  to D 2  in the cathode density at the interface between the full pixel density region and the pixel removal region. The step change may correspond, for example, to a change from 100% density in full pixel density region  334  to approximately 50% density in pixel removal region  332  in  FIG.  15   . This step change in cathode density may result in perceptible reflectance changes when the display is off. 
     Profile  212  shows the density of the cathode from  FIG.  15    as a function of position across the display. As shown, with the presence of the openings in the transition region, the overall cathode density gradually decreases from D 1  (at the interface of the pixel removal region/transition region and the full pixel density region) to D 2  (the minimum density at a central portion of the pixel removal region). 
       FIG.  17    is a top view of an illustrative display that includes a transition region  336  that has a gradual change in density of touch sensor metal. As discussed in connection with  FIG.  3   , one or more touch layers  316  that implement the touch sensor functions of touch-screen display  14  may be formed over polarizer films  312  using adhesive  314  (e.g., OCA material). For example, touch layers  316  may include horizontal touch sensor electrodes and/or vertical touch sensor electrodes collectively forming an array of capacitive touch sensor electrodes.  FIG.  17    shows touch sensor metal (electrodes) that extends across the display. 
     To increase transmission in pixel removal region  332 , the touch sensor metal may be omitted entirely (or included at a reduced density) in pixel removal region  332 . In the example of  FIG.  17   , a central portion of pixel removal region  332  may have no touch sensor metal  316  (e.g., 0% density). 
     To gradually transition between the full pixel density region  334  (where the touch sensor metal  316  has a maximum coverage) to the central portion of pixel removal region  332  (where the cathode has a minimum coverage), the touch sensor metal  316  may be gradually transitioned between the maximum density and minimum density in transition region  336 . As shown in  FIG.  17   , the touch sensor metal  316  has a gradually decreasing density in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332 . This results in the display having a gradually decreasing reflectance in the X-direction from the full pixel density region towards the central portion of the pixel removal region  332  while in the off state. 
       FIG.  18    is a graph showing the density of the touch sensor metal (e.g., the coverage per unit area) as a function of position across the display. Profile  214  shows the density of the touch sensor metal in an embodiment where there is no transition region. As shown, there is a step change from D 1  to D 2  in the touch sensor metal density at the interface between the full pixel density region and the pixel removal region. The step change may correspond, for example, to a change from a maximum density in full pixel density region  334  to 0% density in pixel removal region  332 . This step change in touch sensor metal density may result in perceptible reflectance changes when the display is off. 
     Profile  216  shows the density of the touch sensor metal from  FIG.  17    as a function of position across the display. As shown, the overall touch sensor metal density gradually decreases from D 1  (at the interface of the pixel removal region/transition region and the full pixel density region) to D 2  (the minimum density at a central portion of the pixel removal region). 
       FIG.  19    is a top view of an illustrative display that includes a transition region  336  that has a gradual change in emissive sub-pixel shape. It may be desirable for the anodes (and corresponding emissive sub-pixels) in pixel removal region  332  to have a different shape than in full pixel density region  334 . For example, the anode shapes in pixel removal region  332  may be selected to mitigate diffraction artifacts for the sensor that operates through the pixel removal region. In the example of  FIG.  19   , the anodes in the central portion of the pixel removal region have circular or oval shapes. In contrast, the anodes in full pixel density region  334  have square or rectangular shapes. 
     Transition region  336  may be included in the display to gradually transition the anode shape between full pixel density region  334  and pixel removal region  332 . In the example of  FIG.  19   , transition region  336  includes a first zone, a second zone, and a third zone. The anode shapes become gradually more curved while moving between zones  1  and  3 . As shown in  FIG.  19   , the anodes in zone  1  have square/rectangular shapes with one rounded corner and three right-angled corners. The anodes in zone  2  have square/rectangular shapes with two rounded corners and two right-angled corners. The anodes in zone  3  have square/rectangular shapes with four rounded corners. In this way, the anodes gradually transition from square/rectangular to circular/oval while moving in the positive X-direction across transition region  336 . In other words, there is at least 1 intermediate shape between the shape of the full pixel density region  334  and the shape of the central portion of the pixel removal region  332 . More intermediate shapes may be included if desired (e.g., at least 2 intermediate shapes, at least 3 intermediate shapes, at least 4 intermediate shapes, at least 8 intermediate shapes, at least 16 intermediate shapes, etc.). 
       FIG.  20    is a top view of an illustrative display that includes a transition region  336  that has a gradual change in emissive sub-pixel size. Instead of removing pixels in high-transmittance region  332 , the emissive sub-pixels may instead be reduced in size. This may reduce the total area occupied by the opaque emissive sub-pixels, increasing transmission in region  332 . In the example of  FIG.  20   , the anodes in the central portion of the high-transmittance region  332  have the same layout, pitches (center-to-center spacing), and aspect ratios as in normal region  334 . However, the anodes in the central portion of the high-transmittance region  332  are smaller than the anodes in normal region  334 . 
     Transition region  336  may be included in the display to gradually transition the anode size between region  334  and region  332 . In the example of  FIG.  20   , transition region  336  includes a first zone and a second zone. The anodes become gradually smaller while moving between zones  1  and  2 . As shown in  FIG.  20   , the anodes in zone  1  have the same shape but a smaller size than the anodes in region  334 . The anodes in zone  2  have the same shape but a smaller size than the anodes in zone  1 . The anodes in a central portion of region  332  have the same shape but a smaller size than the anodes in zone  2 . In this way, the anodes gradually transition in size while moving in the positive X-direction across transition region  336 . In other words, there is at least 1 intermediate anode size between the anode size in region  334  and the anode size in the central portion of the high-transmittance region  332 . More intermediate sizes may be included if desired (e.g., at least 2 intermediate sizes, at least 3 intermediate sizes, at least 4 intermediate sizes, at least 8 intermediate sizes, at least 16 intermediate sizes, etc.). 
     It should be noted that any subset of the aforementioned gradients may be included in a single display. Embodiments have been described where dummy thin-film transistor sub-pixels are included to produce a gradual change in thin-film transistor sub-pixel density (as in  FIG.  11   ), where dummy anodes are included to produce a gradual change in emissive sub-pixel density (as in  FIG.  13   ), where the cathode has a gradually changing density (as in  FIG.  15   ), where the touch sensor metal has a gradually changing density (as in  FIG.  17   ), where the anodes have a gradually changing shape (as in  FIG.  19   ), and where the anodes have a gradually changing size (as in FIG.  20 ). Any subset (or all) of these embodiments may coexist simultaneously in a single display if desired. The width of the transition region for each component may be the same or may be different. The width of each transition region (e.g., the dimension in the direction of the gradient) may be greater than 50 microns, greater than 100 microns, greater than 200 microns, greater than 400 microns, greater than 1000 microns, greater than 3000 microns, less than 400 microns, less than 1000 microns, less than 3000 microns, etc. Each transition region may include (in the direction of the gradient) 1 or more sub-pixels, 4 or more sub-pixels, 10 or more sub-pixels, 20 or more sub-pixels, 50 or more sub-pixels, less than 100 sub-pixels, less than 50 sub-pixels, etc. 
     In the example of  FIG.  10   , the transition regions are included only on the left and right sides of the pixel removal region. This example is merely illustrative. Transition regions may instead be included on the top side, bottoms side, left side, and right side of the pixel removal region (as one example). In general, transition regions of the aforementioned types may be included on one or more sides of a pixel removal region. 
     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: 20220614
Publication Date: 20241231
Grant Date: 20241231
Priority Date: 20210824
Inventors: PETERSON, RICARDO A
CHE, Yuchi
RIEUTORT-LOUIS, Warren S
JAMSHIDI ROUDBARI, ABBAS
QIAO, YI
CUI, Yue
GUILLOU, JEAN-PIERRE S
YANG, SHYUAN
TSAI, TSUNG-TING
Assignee: APPLE INC
CPC Classifications: [{"code": "H10K59/88", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/353", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/352", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K59/353", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/352", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/88", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K59/353", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/352", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/88", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 93933142