PATENT DOCUMENT

Publication Number: US-11637153-B2
Application Number: US-202016940192-A
Country: US
Kind Code: B2

Title: Displays with optical edge sensors

Abstract:
A display may have an array of light-emitting pixels that display an image in an active area of the display. These light-emitting pixels may be visible light pixels such as red, green, and blue thin-film organic light-emitting diode pixels. The display may also have a border region that runs along a peripheral edge of the active area. The border region may be free of pixels that display image light, whereas the active area may be free of light detectors. A non-optical touch sensor such as a capacitive touch sensor may overlap the active area to gather touch input from the active area. The non-optical touch sensor may not overlap any portion of the border region. In the border region, an optical sensor formed from infrared light-emitting pixels and infrared light-sensing pixels or other optical sensing circuitry may serve as an optical touch sensor.

Claims:
What is claimed is: 
     
       1. A display having an active area and a border region that runs along a peripheral edge of the active area, comprising:
 a substrate; and 
 an array of pixels formed in rows and columns on the substrate, wherein:
 a first portion of the array of pixels comprises an array of light-emitting pixels on the substrate and in the active area, 
 the array of light-emitting pixels is configured to display an image in the active area, 
 the active area does not contain light detectors, 
 a second portion of the array of pixels comprises light-sensing pixels on the substrate, in the border region, and configured to measure light indicative of user input over the border region, the light-sensing pixels at least partly forming an optical sensor. 
 
 
     
     
       2. The display defined in  claim 1  further comprising a capacitive touch sensor that overlaps the active area. 
     
     
       3. The display defined in  claim 1  wherein the optical sensor comprises an infrared optical sensor. 
     
     
       4. The display defined in  claim 1  wherein the light-sensing pixels comprise infrared light-sensing pixels. 
     
     
       5. The display defined in  claim 1  wherein the light-sensing pixels comprise infrared light-sensing pixels and wherein the optical sensor further comprises infrared light-emitting pixels in the array of pixels. 
     
     
       6. The display defined in  claim 5  wherein the infrared light-sensing pixels and the infrared light-emitting pixels are arranged in two parallel lines in the array of pixels extending along the border region. 
     
     
       7. The display defined in  claim 5  wherein the infrared light-sensing pixels and the infrared light-emitting pixels alternate with each other along the border region. 
     
     
       8. The display defined in  claim 1  wherein the border region is free of light-emitting pixels and the array of light-emitting pixels contains only visible light-emitting pixels. 
     
     
       9. The display defined in  claim 1  wherein the optical sensor forms an optical touch sensor configured to detect touch input over the border region and wherein the display further comprises a non-optical two-dimensional touch sensor in the active area that is configured to detect touch input over the active area. 
     
     
       10. The display defined in  claim 9  wherein the light-sensing pixels comprise infrared light-sensing pixels and wherein the non-optical two-dimensional touch sensor comprises a two-dimensional capacitive touch sensor that overlaps the active area and that does not overlap the border region. 
     
     
       11. A display, comprising:
 a substrate layer; 
 active area pixels on the substrate layer configured to display an image in an active area that is free of light sensing circuitry; 
 a capacitive touch sensor overlapping the active area configured to gather touch input over the active area; 
 an optical sensor that has infrared light-emitting pixels on the substrate layer and infrared light-sensing pixels on the substrate layer, wherein the optical sensor is in a border region that runs along a peripheral edge of the active area and is configured to gather touch input over the border region; and 
 display control circuitry formed along an edge of the substrate layer and coupled to the active area pixels, the infrared light-emitting pixels, and the infrared light-sensing pixels via corresponding parallel signal lines. 
 
     
     
       12. The display defined in  claim 11 
 wherein the active area pixels comprise thin-film visible-light-emitting pixels on the substrate layer in the active area. 
 
     
     
       13. The display defined in  claim 12  wherein the infrared light-sensing pixels comprise thin-film infrared light-sensing pixels on the substrate layer in the border region. 
     
     
       14. The display defined in  claim 13  wherein the infrared light-emitting pixels comprise thin-film infrared light-emitting pixels on the substrate layer in the border region. 
     
     
       15. The display defined in  claim 14  further comprising capacitive touch sensor electrodes that overlap the active area, wherein no capacitive touch sensor electrodes overlap the border region. 
     
     
       16. A display, comprising:
 a substrate; and 
 an array of pixels formed in rows and columns on the substrate, each pixel in the array comprising thin-film circuitry on the substrate, wherein the array of pixels comprises: 
 active area pixels on the substrate that are configured to display an image in an active area that is free of light sensing circuitry; and 
 light-sensing pixels on the substrate that extend along a border region running along a peripheral edge of the active area and that sense light indicative of user input outside of the active area, wherein the light-sensing pixels at least partly form an optical sensor in the border region and wherein the border region does not have pixels that display images. 
 
     
     
       17. The display defined in  claim 16  further comprising capacitive touch sensor circuitry overlapping the active area, wherein the border region is not overlapped by any capacitive touch sensor circuitry. 
     
     
       18. The display defined in  claim 17  wherein the light-sensing pixels comprise infrared light-sensing pixels and wherein the optical sensor comprises infrared light-emitting pixels in the array of pixels. 
     
     
       19. The display defined in  claim 18  wherein the border region contains a signal line that is configured to supply signals to the infrared light-emitting pixels and that is configured to carry signals from the infrared light-sensing pixels. 
     
     
       20. The display defined in  claim 18  wherein the border region contains a first signal line that is configured to supply signals to the infrared light-emitting pixels and a second signal line that is configured to carry signals from the infrared light-sensing pixels. 
     
     
       21. The display defined in  claim 16  further comprising a transparent display cover layer that overlaps the active area and the border region, the optical sensor further comprising a light-emitting device that is configured to emit light into an edge of the transparent display cover layer that is guided by total internal reflection along the border region until the total internal reflection is locally defeated by an external object on a surface of the transparent display cover layer, thereby scattering light through the transparent display cover layer towards the light-sensing pixels, wherein the optical sensor is configured to measure a location of the external object on the surface using output from the light-sensing pixels that extend along the border region. 
     
     
       22. The display defined in  claim 21  wherein the light-emitting device is an infrared light-emitting device. 
     
     
       23. The display defined in  claim 1 , wherein each of the light-emitting pixels and the light-sensing pixels in the array of pixels comprises thin-film circuitry on the substrate.

Description:
This application claims the benefit of provisional patent application No. 62/906,590, filed Sep. 26, 2019, 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, cellular telephones have displays for presenting information to users. Displays are often provided with capacitive touch sensors for gathering touch input. The incorporation of a capacitive touch sensor into a display allows a user to control device operation using touch input, but may present integration challenges for some cellular telephones. 
     SUMMARY 
     A display may have an array of light-emitting pixels that display an image in an active area of the display. These light-emitting pixels may be visible light pixels such as red, green, and blue thin-film organic light-emitting diode pixels. During operation of an electronic device that contains the display, the display may be used in presenting visual content for the user in the active area. 
     The display may also have a border region that runs along a peripheral edge of the active area. The border region is free of pixels that display image light. A non-optical touch sensor such as a capacitive touch sensor may overlap the active area to gather touch input from the active area. The non-optical touch sensor may not overlap any portion of the border region. 
     To gather touch input or other user input in the border region, the border region may have an optical sensor. For example, an optical sensor in the border region may be formed from infrared light-emitting pixels and infrared light-sensing pixels. The optical sensing circuitry of the border region may serve as an optical touch sensor. By gathering touch input in the border region using the optical sensor in the border region and by gathering touch input in the active area using the non-optical touch sensor, most or all of the area covering the display may be responsive to user touch input. 
     The optical sensor may have light-sensing pixels and light-emitting pixels that share common signal lines or the light-sensing pixels may use a first signal line while the light-emitting pixels use a second signal line. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram of an illustrative display in accordance with an embodiment. 
         FIG.  2    is a diagram of an illustrative pixel circuit for a display having pixels with light-emitting diodes in accordance with an embodiment. 
         FIG.  3    is an illustrative light sensor circuit in accordance with an embodiment. 
         FIG.  4    is a timing diagram showing illustrative signals involved in operating the circuitry of  FIG.  3    in accordance with an embodiment. 
         FIG.  5    is a circuit diagram of another illustrative light sensor circuit in accordance with an embodiment. 
         FIG.  6    is a timing diagram showing illustrative signals involved in operating the circuitry of  FIG.  5    in accordance with an embodiment. 
         FIGS.  7 ,  8 , and  9    are diagrams of illustrative layouts for light-emitting pixels and light sensing pixels in a display in accordance with an embodiment. 
         FIG.  10    is a diagram showing how interleaved light emitters and light detectors may be provided in a border region of a display using separate signal lines for sensing and driving in accordance with an embodiment. 
         FIG.  11    is a diagram showing how interleaved light emitters and light detectors may be provided in a border region of a display using a shared signal line for sensing and driving in accordance with an embodiment. 
         FIG.  12    is a timing diagram illustrating signals involved in operating the circuitry of  FIG.  11    in accordance with an embodiment. 
         FIG.  13    is a diagram showing how a border region of a display in an electronic device may have an optical sensor that detects local frustration of total internal reflection using an array of border region light-sensing pixels in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as a cellular telephone, tablet computer, wristwatch, laptop computer, desktop computer, or other electronic device may have a display such as illustrative display  14  of  FIG.  1   . In some configurations, display  14  may cover some or all of the front surface of the electronic device. 
     As shown in  FIG.  1   , display  14  may have one or more layers such as substrate  24 . Layers such as substrate  24  may be formed from insulating materials such as glass, plastic, ceramic, and/or other dielectrics. Substrate  24  may be rectangular or may have other shapes. Rigid substrate material (e.g., glass) or flexible substrate material (e.g., a flexible sheet of polymer such as a layer of polyimide or other materials) may be used in forming substrate  24 . 
     Display  14  may have an array of pixels  22 . Pixels  22  may, as an example, be formed from thin-film circuitry such as organic light-emitting diode thin-film circuitry. 
     Some of pixels  22  emit visible light that creates an image for viewing by a user of display  14  and the device containing display  14 . These pixels may be located, for example, in a central active area (AA) of display  14 . Other pixels  22  may be used for optical sensing and do not emit image light. Pixels  22  that are used in optical sensing may, in an illustrative configuration, be located along one or more edges of display  14  (e.g., in a border region that covers some or all of the peripheral edge area of display  14  along left edge L, right edge R, top edge T, and/or lower edge B). Configurations in which optical sensing circuitry is provided along the left edge (and, if desired, the right edge) of display  14  may sometimes be described herein as an example. 
     The optical sensing circuitry of display  14  may have light-sensing pixels for sensing light (e.g., for sensing the magnitude and location of incoming light). The light-sensing pixels may sense visible light, infrared light, and/or ultraviolet light. Some light-emitting pixels in display  14  and/or other light sources in an electronic device may include lasers or light-emitting diodes that emit visible, infrared, and/or ultraviolet light that is used in illuminating a user&#39;s fingers or other external objects. Emitted light that has illuminated the user&#39;s fingers and that has reflected and/or scattered back towards the light-sensing pixels may provide information about the location of the user&#39;s fingers and/or other information (e.g., health information such as heart rate information, fingerprint information, handprint information, and/or other biometric information). 
     The user&#39;s fingers can be detected using this type of optical sensing arrangement when the user&#39;s fingers touch display  14  (e.g., optical sensing may be used to implement an optical touch sensor for a fixed-position edge button, an edge button with a movable slider, other touch sensitive icons and buttons on the edge of display  14 , etc.) and/or when the user&#39;s fingers are in close proximity to display  14  (e.g., optical sensing may be used to implement an optical proximity sensor, an air gesture sensor, a proximity-sensitive edge button, etc.). Configurations in which optical sensing is used to form an optical touch sensor in one or more border regions of display  14  that are free of pixels that emit image light are sometimes described herein as an example. Other portions of display  14  (e.g., the central active area of display  14  that does not include optical sensing circuitry) may be provided with capacitive touch sensing (e.g., a two-dimensional capacitive touch sensor) or other non-optical touch sensor circuitry. 
     In some configurations, a two-dimensional capacitive touch sensor has electrodes that overlap the active area and that do not overlap any portion of the border region. In the border region, touch input can be gathered using the optical sensor (which, in some embodiments, does not overlap any portion of the active area). Accordingly, the active area can use the capacitive touch sensor to gather touch input, whereas the border region can use the optical sensor to gather touch input. In this way, most or all of the area of display  14  can be touch sensitive, even in arrangements in which it may be challenging to provide capacitive touch sensing along the borders of display  14 . 
     The pixels  22  in display  14  (e.g., the light-emitting pixels and light-sensing pixels) may be formed in rows and columns on substrate  24 . There may be any suitable number of rows and columns in the array of pixels  22  (e.g., ten or more, one hundred or more, or one thousand or more). 
     Display  14  may include display control circuitry  20 . The display control circuitry may include display driver circuitry for controlling the light-emitting pixels (e.g., so that the light-emitting pixels in the active area display a desired image). The display control circuitry may also include optical sensor control circuitry for operating the optical sensing circuitry of display  14  (e.g., light-sensing pixels and optional light-emitting pixels in the sensing circuitry). Control circuitry  20  may include on or more integrated circuits and, if desired, may include thin-film circuitry on substrate  24 . Control circuitry  20  may be located at one or both ends of display  14  (see, e.g., illustrative circuitry  16  along the top edge T of display  14 ) and/or may be located along one or both of edges L and R (see, e.g., circuitry  18 ). 
     Signal lines on display  14  may be used for distributing power supply signals, data, control signals, and/or other signals for the operation of display  14 . Some signal paths may convey signals globally to most or all of pixels  22 . For example, display  14  may have a global ground path and other global power supply paths. Other signal paths may be associated with particular rows and may be associated with particular columns of pixels  22 . The signal paths for display  14  may, for example, include signal lines that extend vertically (see, e.g., paths  26 , each of which is associated with a respective column of pixels  22  and may contain one or more vertically extending lines for that column of pixels  22 ) and horizontally (see, e.g., paths  28 , each of which extends orthogonally to paths  26  and each of which may contain one or more horizontally extending lines associated with a respective row of pixels). 
     Circuitry  20  may be coupled to control circuitry in an electronic device in which display  14  is mounted using paths such as path  25 . Path  25  may be formed from traces on a flexible printed circuit or other signal lines. The control circuitry may be located on a main logic board in an electronic device such as a cellular telephone, wristwatch, computer, or other electronic equipment in which display  14  is being used. During operation, the control circuitry of the electronic device may supply display control circuitry  20  with information on images to be displayed on display  14  and may use display control circuitry gather sensor readings from the optical sensor circuitry in display  14 . To display the images on pixels  22 , display driver circuitry in circuitry  20  may supply image data to data lines (e.g., data lines in paths  26 ) while issuing clock signals and other control signals (sometimes referred to as horizontal control signals, emission control signals, scan signal, gate line signals, etc.) that are conveyed to display  14  over paths  28 . 
     The light-emitting pixels of display  14  (whether active area pixels that display images or border pixels that are used to generating infrared light or other light for use in an optical sensor), may include light-emitting devices such as light-emitting diodes or lasers. The light-emitting diodes may be crystalline semiconductor light-emitting dies or thin-film light-emitting diodes. Configurations in which the light-emitting pixels of display  14  are thin-film organic light-emitting diodes are described herein as an example. 
     A schematic diagram of an illustrative pixel circuit for a thin-film organic light-emitting diode pixel is shown in  FIG.  2   . As shown in  FIG.  2   , light-emitting pixel  22 E may include light-emitting diode  38 . A positive power supply voltage may be supplied to positive power supply terminal  34  through p-type field-effect transistor (PFET)  32   a  and a ground power supply voltage may be supplied to ground power supply terminal  36 . PFET  32   a  is conducting when signal PEN is LOW. Diode  38  has an anode (terminal AN) and a cathode (terminal CD). Transistor  32  forms a constant current source with capacitor Cst, which sets the gate-to-source voltage VGS of transistor  32 . The voltage across Cst controls the amount of current through transistor  32  and thus diode  38  and therefore the amount of emitted light  40  from light-emitting pixel  22 E. The wavelength of emitted light  40  is determined by the structure of diode  38  and may be, as an example, visible light (e.g., red light, green light, blue light, etc.), infrared light, or ultraviolet light. For example, in the active area of display  14  that displays images, pixels such as pixel  22 E may be configured to emit visible light (e.g., red pixels may emit red light, green pixels may emit green light, and blue pixels may emit blue light). In the border region of display  14 , pixels  22 E may be used to emit infrared light (as an example). Infrared light is not visible to the human eye and therefore will not disturb users of display  14  during optical sensing operations (e.g., the emitted infrared light will not interfere with the visible-light image presented in the active area of display  14 ). Configurations in which pixels  22 E emit visible light in optical sensing regions of display  14  may also be used. For example, the border region of display  14  may include visible light-emitting pixels that help illuminate a user&#39;s finger or other external object for optical sensing, but that do not emit visible light that forms part of an image. In some arrangements, ambient light and/or stray light from the active area of display  14  may help illuminate a user&#39;s fingers or other external objects that are sensed by light-sensing pixels in display  14 . 
     In light-emitting pixel  22 E of  FIG.  2   , cathode CD of diode  38  is coupled to ground terminal  36 , so cathode terminal CD of diode  38  may sometimes be referred to as the ground terminal for diode  38 . Cathode CD may be shared among multiple diodes (i.e., the cathodes CD of multiple diodes may be tied to a shared voltage). The voltage on the anode AN of each diode is independently controlled to control the amount of light the diode produces for the pixel associated with that diode. 
     To ensure that transistor  32  is held in a desired state between successive frames of data, pixel  22 E may include a storage capacitor such as storage capacitor Cst. The voltage on storage capacitor Cst is applied to the gate of transistor  32  at node A relative to the source of transistor  32  at node AN to control the amount of current through transistor  32 . Data can be loaded into storage capacitor Cst using one or more switching transistors such as switching transistor  30  and transistor  30   a . When switching transistors  30  and  30   a  are off, paths  26   a  and  26  are isolated from storage capacitor Cst and the difference in voltage between gate line  26   a  and source line  26  is equal to the voltage stored across storage capacitor Cst (i.e., the data value from the previous frame of display data being displayed on display  14 ). When signal PEN is LOW, transistor  32   a  turns on, causing the current source formed from transistor  32  and capacitor Cst to turn on and inject current into light-emitting diode  38 , which emits light  40  at a level related to the amount of voltage stored in Cst. 
     When a control signal on path  28  in the row associated with pixel  22 E is asserted, switching transistors  30  and  30   a  will be turned on and a new data signal on paths  26  and  26   a  will be loaded into storage capacitor Cst. The new signal on capacitor Cst is applied to the gate of transistor  32  at node A relative to the source of transistor  32  at node AN, thereby adjusting the current through transistor  32  and adjusting the corresponding amount of light  40  that is emitted by light-emitting diode  38 . If desired, the circuitry for controlling the operation of light-emitting diodes for pixels in display  14  (e.g., thin-film transistors, capacitors, etc. in pixel circuits such as the pixel circuit of  FIG.  2   ) may be formed using other configurations (e.g., configurations that include circuitry for compensating for threshold voltage variations in drive transistor  32 , configurations in which pixel  22 E has emission control transistors, reset transistors, two or more capacitors, three or more transistors, and/or other circuitry). The pixel circuit of  FIG.  2    is merely an illustrative example of a light-emitting pixel for display  14 . 
       FIG.  3    is a circuit diagram of an illustrative light-sensing pixel  22 D. Pixel  22 D has a photodetector such as photodiode  52  for detecting light  50  during optical sensing. Light  50  may, for example, be infrared light, visible light, or ultraviolet light that has reflected/scattered from a user&#39;s finger or other external object. This light may be ambient light that has reflected/scattered towards pixel  22 D from a user&#39;s finger or other object and/or may be light that was emitted from nearby (e.g., adjacent) light-emitting pixels  22 E before being reflected/scattered towards pixel  22 D from a user&#39;s finger or other object. 
     Photodiode  52  may have an anode coupled to ground  54  and a cathode (which may be shared with cathode CD of pixels  22 E) coupled to node N. Capacitor Cpix may be coupled between ground  54  and node N. Row selection switch RS may be controlled by control signals (e.g., a gate line signal) on path  28 . The optical sensor in the border region of display  14  may have multiple rows of pixels  22 D that extend in a column along the length of the border region. Pixels  22 D may be coupled to path  26 , which is used in carrying measured light signals to control circuitry  20 . Control circuitry  20  may have sensing circuitry  60  (e.g., correlated double sampling sample-and-hold circuitry) for receiving and processing signals from the photodiodes in pixels  22 D. 
     Sensing circuitry  60  may have a sense amplifier formed from amplifier  56  and associated feedback capacitor CFB. Reset switch INTRST may be coupled between the output of amplifier  56  and its negative input. Amplifier  56  may receive bias voltage Vbias at its positive input. The output of each light-sensing pixel  22 D may be received via row selection switch RS at the negative input of amplifier  56 . The sample-and-hold circuitry for capturing and digitizing the output Vout of amplifier  56  may include first sample-and-hold switch CDS 1  and second sample-and-hold switch CDS 2 . When switch CDS 1  is closed, Vout may be sampled to sample-and-hold capacitor C 1 . When switch CDS 2  is closed, Vout may be sampled to sample-and-hold capacitor C 2 . Switching circuitry and analog-to-digital control circuitry (ADC) may be used to digitize the voltages gathered using the sample-and-hold circuits. Signal measurements (e.g., light measurements gathered using sensing circuitry  60 ) may be processed by control circuitry to detect finger touch input and other user input. 
     During sensing with light-sensing pixel  22 D, sensing circuitry  60  samples the voltage from pixel  22 D before and after capacitor Cpix of pixel  22 D gathers charge associated with incoming light  50 . The amount of charge gathered on capacitor Cpix is proportional to the amount of light  50  that is received in a given measurement interval, so by measuring the output of pixels  22 D (e.g., the charge on capacitor Cpix), the amount of detected light  50  during each measurement interval can be measured. 
       FIG.  4    is a timing diagram of signals involved in operating a display with pixels such as light-sensing pixels  22 D of  FIG.  3   . During time period TI, row selection switch RS is open, light  50  is being received by pixel  22 D, and this received light is creating current through diode  52  that is stored in capacitor Cpix. This amount of stored charge is measured using sensing circuitry  60  by opening and closing the switches of  FIG.  3    in accordance with the timing diagram of  FIG.  4   . During time period T 1 , sense amplifier reset switch INTRST is closed while row select switch RS is open. The sense amplifier tries to equilibrate its inputs, so that voltage Vbias is driven onto node N. During period T 2 , switch CDS 1  is closed to gather a first sample of output voltage Vout. Switch CDS 1  remains closed until a certain time after INTRST is opened to ensure that the KT/C noise from CFB is captured. During period T 3 , row select switch RS is closed to transfer the stored charge from capacitor Cpix to sensing circuitry  60 . This causes Vout to rise. The rise in Vout due to the closing of switch RS is proportional to the change in voltage at node N (ΔVpix, which is proportional to the amount of received light  50  during period TI) times Cpix divided by CFB. During period T 4 , switch CDS 2  is closed to sample Vout after this change in voltage has occurred. Control circuitry can then process the measured difference between the two sampled values of Vout to determine the magnitude of light  50  and thereby determine if a finger is present on the optical sensor, whether a finger is in close proximity to the optical sensor, etc. 
     Another illustrative light-sensing pixel circuit is shown in  FIG.  5   . Illustrative control signals for operating light-sensing pixel  22 D of  FIG.  5    are shown in  FIG.  6   . This type of circuit may provide complete isolation of sense node N from the input to the sensing circuitry (coupled to the end of path  26 ) and can be used to perform double sampling. Low assertion of signal RST causes photodiode  52  and CPIX to be reset to VBIAS. Integration of photocurrent through photodiode  52  into CPIX commences after RST signal is deasserted. Transistor  51  is a source follower buffering the pixel voltage Vpix across Cpix. Upon assertion of signal RS, the buffered pixel voltage is connected to the sense node. The voltage mode buffer of  FIG.  5    buffers the voltage and this buffered voltage is passed on to a sample-and-hold circuit (see CDS 1  and CDS 2  of  FIG.  3   ). The integration time is the time between deassertion of signal RST and the assertion of signal RS. Other type of circuits can be used for light-sensing pixels  22 D, if desired. The examples of  FIGS.  3  and  5    are illustrative. 
       FIGS.  7 ,  8 , and  9    show illustrative layouts for light-emitting pixels  22 E and light sensing pixels  22 D in display  14 . Light-emitting pixels  22 E in active area AA may include colored pixels (e.g., visible light pixels such as red, green, and blue pixels) for displaying colored images in active area AA. Images are not displayed in border region B. Border region B runs along the peripheral edge of display  14  and may contain one or more rows and/or columns of light-sensing and/or light-emitting pixels. In the example of  FIG.  7   , border region B has light-emitting pixels  22 E (which may, if desired, emit visible, infrared, and/or ultraviolet light) and light-sensing pixels  22 D (which may detect the emitted light after the emitted light has reflected and/or scattered from a user&#39;s fingers or other external objects). Using the optical sensor formed from pixels  22 D and pixels  22 E in border region B, display  14  may gather touch input (e.g., finger input) in border region B. To gather touch input seamlessly across display  14 , display  14  may also have a two-dimensional touch sensor in active area AA. As an example, display  14  may have a two-dimensional capacitive touch sensor that overlaps active area AA, but that does not overlap any of border region B (see, e.g., the illustrative two-dimensional array of capacitive touch sensor electrodes  70  overlapping pixels  22 E in active area AA and corresponding capacitive touch sensor processing circuitry  72 ). 
     In the example of  FIG.  7   , the optical sensing circuitry in border region B contains light-emitting pixels  22 E and light-sensing pixels  22 D that alternate along the length of elongated border region B (e.g., infrared light-emitting pixels and infrared light-sensing pixels are present in alternating rows of display  14 ). In the example of  FIG.  8   , border region B contains only a column of light-sensing pixels  22 D (e.g., for detecting infrared light and/or visible light or ultraviolet light). Ambient light and/or light from nearby active area visible-light pixels  22 E may be used to illuminate a user&#39;s fingers or other external objects during optical sensing with pixels  22 D. In the example of  FIG.  9   , border region B contains a single column of light-emitting pixels  22 E (e.g., infrared light-emitting pixels) and a single corresponding column of light-sensing pixels (e.g., infrared light-sensing pixels)  22 D. 
     In these illustrative arrangements, border region B contains optical sensing circuitry that with a line of pixels (e.g., a column of pixels) that can serve as a one-dimensional (linear) optical sensor (e.g., a one-dimensional optical touch sensor or one-dimensional optical proximity sensor). Configurations in which border region B contains multiple lines (e.g., columns) of light-sensing pixels, contains multiple lines (e.g., columns) of alternating light-sensing and light-emitting pixels, and/or contains multiple lines (e.g., columns) of light-sensing pixels and multiple lines (e.g., columns) of light emitting pixels to create a two-dimensional optical sensor in border region B may also be used. 
       FIG.  10    is a diagram showing how row-interleaved light-emitting pixels and light-sensing pixels in border region B may each have a respective vertical signal line in path  26 . Pixels  22 D extend along a first line (e.g., column) that runs along the length of border region B and pixels  22 E extend along a parallel second line (e.g., column) that runs along the length of border region B. For example, each column of pixels  22 E/ 22 D such as the illustrative column of pixels in border region B of  FIG.  10    may have a first line that is used as a data line for loading data into pixels  22 E or for otherwise driving pixels  22 E and a second line that is separate from the first line that is used as a sense line for gathering photodiode signals (sensed light signals) from pixels  22 D. 
       FIG.  11    is a diagram showing how row-interleaved light-emitting pixels and light-sensing pixels in border region B may share a common vertical signal line in path  26 . For example, each column of pixels  22 E/ 22 D such as the illustrative column of pixels in border region B of  FIG.  11    may have signal line that is partly used for loading data into pixels  22 E or for otherwise driving pixels  22 E and that is partly used as a sense line for gathering photodiode signals (sensed light signals) from pixels  22 D. 
     In the example of  FIG.  11   , switches Φ 1  and Φ 2  control whether driver  82  is used in driving signals to light-emitting pixels  22 E (when switch Φ 1  is closed to couple pixel driver circuit  82  to path  26  and switch Φ 2  is open to isolate sensing circuitry  84  from path  26 ) or whether sense amplifier  84  is receiving light measurements carried over path  26  from light-sensing pixels  22 D (when switch Φ 1  is opened to isolate pixel driver circuit  82  from path  26  and switch Φ 2  is closed to couple the input of sensing circuitry  84  to path  26 ). As shown in the timing diagram of  FIG.  12   , during operations  86 , when switch Φ 1  is closed, switches Φ 11 , Φ 12 , Φ 13 , etc. are closed in sequence to select successive rows of light-emitting pixels  22 E to drive with driver  82 . During operations  88 , when switch Φ 2  is closed, switches Φ 21 , Φ 22 , Φ 23 , etc. are closed in sequence to select successive rows of light-sensing pixels  22 D to couple to the input of sensing circuitry  84 . Other timing sequences for switches Φ 1 , Φ 11 , Φ 12 , Φ 13 , Φ 2 , Φ 21 , Φ 22  and Φ 23  are possible. For example, switches Φ 21 , Φ 11 , Φ 22 , Φ 12 , Φ 23  and Φ 13  may be engaged one at a time and in sequence, with appropriate assertion of switches Φ 1  and Φ 2  (e.g. Φ 2 , Φ 1 , Φ 2 , Φ 1 , Φ 2 , Φ 1 , respectively). 
     In the example of  FIG.  12   , the optical sensing circuitry in elongated border region B contains light-sensing pixels  22 D arranged along the length of border region B (e.g., infrared light-detecting pixels formed from infrared photodiodes or other infrared photodetectors and/or visible light-detecting pixels that are formed from visible photodiodes or other visible photodetectors. Light-emitting device  100  (e.g., a light-emitting diode or laser diode configured to emit light at an infrared and/or visible light wavelength) may emit light  102  into an adjacent edge  104  of a transparent member such as display cover layer  106 . Display cover layer  106  may be formed from a transparent material such as glass, clear polymer, sapphire or other crystalline material, other transparent materials, and/or combinations of these materials and may overlap all of the pixels in display  14 . Display cover layer  106  may, as an example, have a rectangular shape or other shape that overlap the pixels in active area AA and that extends over border areas such as border region B of  FIG.  13   . 
     Light  102  that is emitted from light-emitting device  100  may be guided between the upper and lower surface of display cover layer  106  along the length of border region B in accordance with the principal of total internal reflection. In the absence of external objects such as user finger  108 , light  102  does not penetrate into the interior of the electronic device in which display  14  is mounted (e.g., light  102  does not reach any of the overlapped light-sensing pixels  22 D). At a location of the display cover layer  106  where the surface of layer  106  is touched by finger  108  or external object, total internal reflection will be locally defeated. This will cause light  102  to exit outwardly from display cover layer  106 , where light  102  will strike finger  108  and be scattered back downwards by finger  108  as scattered light  102 ′. The location where scattered light  102 ′ is present may be detected by analyzing the output of light-sensing pixels  22 D (e.g., by detecting the elevated output of the light-sensing pixel  22 D at the location where finger  108  scattered light  102 ′ inwardly). In this way, the location of finger  108  along dimension Y (e.g., along the length of the border region B of display  14 ) may be measured. With configurations of the type shown in  FIG.  13   , there may be one or more parallel columns of light-sensing pixels  22 D running along the length of border region B. Additional columns of pixels  22 D may, as an example, be included to provide additional location information (e.g., location along dimension X in the example of  FIG.  13    in addition to location along dimension Y). 
     Display  14  may be operated in a system that uses personally identifiable information. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     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. 
     
       
         
           
               
             
               
                   
               
               
                 Table of Reference Numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 14 
                 display 
                 16, 18, 20 
                 display control 
               
               
                   
                   
                   
                 circuitry 
               
               
                 25, 26, 26a, 28 
                 paths 
                 24 
                 substrate 
               
               
                 22 
                 pixels 
                 L, R, T, B 
                 edges 
               
               
                 30, 32, 32a, 
                 transistors 
                 Cst 
                 capacitor 
               
               
                 30a, 51 
                   
                   
                   
               
               
                 A, B 
                 nodes 
                 AN 
                 anode 
               
               
                 CD 
                 cathode 
                 38 
                 light-emitting diode 
               
               
                 40 
                 light 
                 34, 36 
                 terminals 
               
               
                 22D 
                 light-sensing 
                 RS, INTRST, 
                 switches 
               
               
                   
                 pixel 
                 CDS1, CDS2 
                   
               
               
                 N 
                 node 
                 52 
                 photodiode 
               
               
                 50 
                 light 
                 60 
                 sensing circuitry 
               
               
                 56 
                 amplifier 
                 CFB 
                 capacitor 
               
               
                 C1, C2 
                 capacitors 
                 Cpix 
                 capacitor 
               
               
                 70 
                 electrodes 
                 72 
                 touch sensor 
               
               
                   
                   
                   
                 processing circuitry 
               
               
                 B 
                 border region 
                 AA 
                 active area 
               
               
                 82 
                 driver 
                 84 
                 sensing circuitry 
               
               
                 86, 88 
                 operations 
                 100 
                 light-emitting device 
               
               
                 102, 102′ 
                 light 
                 108 
                 finger 
               
               
                 106 
                 display cover 
                 104 
                 edge 
               
               
                   
                 layer

Metadata:
Filing Date: 20200727
Publication Date: 20230425
Grant Date: 20230425
Priority Date: 20190926
Inventors: KRAH, CHRISTOPH H.
YEKE YAZDANDOOST, MOHAMMAD
Assignee: APPLE INC
CPC Classifications: [{"code": "H10K59/40", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04106", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04109", "inventive": false, "first": false, "tree": "[]"}, {"code": "H10K59/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10K59/65", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0421", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F2203/04109", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04106", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L27/3234", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L27/323", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/65", "inventive": true, "first": false, "tree": "[]"}, {"code": "H10K59/65", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 75162374