PATENT DOCUMENT

Publication Number: US-10739882-B2
Application Number: US-201414453574-A
Country: US
Kind Code: B2

Title: Electronic device display with array of discrete light-emitting diodes

Abstract:
An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The substrate may be a silicon substrate. Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the silicon substrate and may be coupled to the array of light-emitting diodes using through-silicon vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within the silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. The substrate may be formed from a transparent material that allows image light to reach a lens and image sensor mounted below the substrate.

Claims:
What is claimed is: 
     
       1. A display, comprising:
 a semiconductor substrate having opposing first and second surfaces; 
 circuitry formed at least partially within the semiconductor substrate; 
 an array of light-emitting diodes mounted on the first surface of the semiconductor substrate; and 
 a touch sensor formed from capacitive touch sensor electrodes that are located in spaces between the light-emitting diodes. 
 
     
     
       2. The display defined in  claim 1  wherein the semiconductor substrate comprises a silicon substrate, the display further comprising:
 through-silicon vias that pass through the silicon substrate. 
 
     
     
       3. The display defined in  claim 2  further comprising display control circuitry on the second surface that controls the array of light-emitting diodes using signals that pass through the through-silicon vias. 
     
     
       4. The display defined in  claim 1  wherein the semiconductor substrate is non-transparent.

Description:
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 a liquid crystal display in which an array of liquid crystal display pixels is used to display images for a user. Liquid crystal displays often include light-emitting diode backlight units for providing backlight illumination. Display efficiency can be adversely affected by inefficiencies in producing backlight illumination and in transmitting backlight illumination through liquid crystal display structures. Liquid crystal display structures also exhibit limited contrast ratios. Organic light-emitting diode displays have been developed that exhibit high contrast ratios, but these devices may consume more power than desired due to the inefficiencies in their organic light-emitting diodes. 
     It would therefore be desirable to be able to provide electronic devices with improved displays. 
     SUMMARY 
     An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The light-emitting diodes may be discrete crystalline semiconductor light-emitting diodes. The substrate may be a semiconductor substrate such as a silicon substrate or may be a transparent substrate such as a layer of clear glass or plastic. 
     Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the substrate and may be coupled to the array of light-emitting diodes using vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within a silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. 
     In configurations in which the substrate is formed from a transparent material, an image sensor and lens may be placed below the substrate. This allows the image sensor to capture images using image light that passes through the transparent substrate and the lens. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device having a display in accordance with an embodiment. 
         FIG. 2  is a schematic diagram of an illustrative electronic device having a display in accordance with an embodiment. 
         FIG. 3  is a diagram of an illustrative display in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of a portion of a display having discrete light-emitting diodes attached to a substrate in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of a display having an array of discrete light-emitting diodes in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of a display having an array of discrete light-emitting diodes covered with a transparent display cover layer in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of an illustrative discrete light-emitting diode mounted on a substrate with bonding material in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of a portion of a substrate for a display in accordance with an embodiment. 
         FIG. 9  is a top view of an illustrative touch sensor array within which an array of discrete light-emitting diodes for a display has been formed in accordance with an embodiment. 
         FIG. 10  is a top view of an illustrative touch sensor electrode pattern that may be used to accommodate an array of discrete light-emitting diodes in accordance with an embodiment. 
         FIG. 11  is a top view of an illustrative display including an array of light-emitting diodes and other circuitry in spaces between the light-emitting diodes in accordance with an embodiment. 
         FIG. 12  is a cross-sectional side view of an illustrative light-emitting diode mounted on a silicon display substrate having through-silicon vias in accordance with an embodiment. 
         FIG. 13  is a cross-sectional side view of a display system having a substrate with an array of light-emitting diodes and an image sensor that captures images through the substrate in accordance with an embodiment. 
         FIG. 14  is a cross-sectional side view of an illustrative display having an array of light-emitting diodes and interspersed microlenses and light detectors in accordance with an embodiment. 
         FIG. 15  is a top view of an illustrative display showing how circuits may receive digital display data on one or more global data paths and may control an associated local set of light-emitting diodes using local control paths in accordance with an embodiment. 
         FIG. 16  is a cross-sectional side view of an illustrative display having a transparent substrate and an array of components mounted on the underside of the transparent substrate in accordance with an embodiment. 
         FIG. 17  is a cross-sectional side view of a curved display having an array of light-emitting diodes mounted on the underside of a flexible substrate in accordance with an embodiment. 
         FIG. 18  is a cross-sectional side view of a curved display having an array of light-emitting diodes mounted on the upper surface of a flexible substrate 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 . An electronic device such as electronic device  10  of  FIG. 1  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, or other wearable or miniature device, a display for video, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. The configuration of device  10  that is shown in  FIG. 1  (e.g., a portable device configuration in which device  10  is a cellular telephone, media player, wrist device, tablet computer, or other portable computing device) is shown as an example. Other configurations may be used for device  10  if desired. 
     Device  10  may have one or more displays such as display  14  mounted in housing structures such as housing  12 . Housing  12  of device  10 , which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device  10  may be formed using a unibody construction in which most or all of housing  12  is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal frame elements or other internal housing structures). 
     Display  14  may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display  14  may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components. Touch sensor electrodes may be used to capture touch input from a user&#39;s finger or a stylus and/or may be used to gather fingerprint data. 
     Display  14  may include an array of display pixels that emit light such as an array of light-emitting diode display pixels. In general, display  14  may use liquid crystal display technology, light-emitting diode display technology such as organic light-emitting diode display technology, plasma display technology, electrophoretic display technology, electrowetting display technology, or other types of display technology. Configurations in which display  14  is based on an array of light-emitting diodes are sometimes described herein as an example. This is, however, merely illustrative. Other types of display technology may be incorporated into device  10  if desired. 
     A schematic diagram of an electronic device such as electronic device  10  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , electronic device  10  may have control circuitry  16 . Control circuitry  16  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry 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 codec chips, application specific integrated circuits, etc. 
     Input-output circuitry in device  10  such as input-output devices  17  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  17  may include buttons, joysticks, click wheels, scrolling wheels, touch pads, fingerprint sensors, 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-output devices  17  and may receive status information and other output from device  10  using the output resources of input-output devices  17 . Input-output devices  17  may include one or more displays such as display  14 . 
     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  in input-output devices. 
     As shown in the illustrative diagram of  FIG. 3 , display  14  may include layers such as substrate layer  24 . Layers such as substrate  24  may be formed from layers of material such as glass layers, polymer layers, composite films that include polymer and inorganic materials, metallic foils, semiconductors such as silicon or other semiconductor materials, layers of material such as sapphire (e.g., crystalline transparent layers, ceramics, etc.), or other material. Substrate  24  may be planar or may have other shapes (e.g., concave shapes, convex shapes, shapes with planar and curved surface regions, etc.). The outline of substrate  24  may be circular, oval, rectangular, square, may have a combination of straight and curved edges, or may have other suitable shapes. As shown in the rectangular substrate example of  FIG. 3 , substrate  24  may have left and right vertical edges and upper and lower horizontal edges. 
     Display  14  may have an array of display pixels  22  for displaying images for a user. The array of display pixels  22  may be formed from rows and columns of display pixel structures (e.g., display pixels formed from structures on display layers such as substrate  24 ). The array may have a rectangular outline or may have an outline of other suitable shapes. There may be any suitable number of rows and columns in the array of display pixels  22  (e.g., ten or more, one hundred or more, or one thousand or more). Each display pixel may be formed from a light-emitting component such as a light-emitting diode. 
     Display driver circuitry such as display driver circuitry  28  may be coupled to conductive paths such as metal traces on substrate  24  using solder or conductive adhesive. Display driver circuitry may contain communications circuitry for communicating with system control circuitry over path  26 . Path  26  may be formed from traces on a flexible printed circuit or other cable or may be formed using other signal path structures in device  10 . The control circuitry may be located on a main logic board in an electronic device in which display  14  is being used. During operation, the control circuitry on the logic board (e.g., control circuitry  16  of  FIG. 1 ) may supply control circuitry such as display driver circuitry  28  with information on images to be displayed on display  14 . 
     To display the images on display pixels  22 , display driver integrated circuit  28  may supply corresponding image data to data lines D (sometimes referred to as source lines) while issuing clock signals and other control signals to supporting display driver circuitry such as gate driver circuitry  18  and demultiplexing circuitry  20 . 
     Gate driver circuitry  18  (sometimes referred to as scan line driver circuitry) may be formed on substrate  24  (e.g., on the left and right edges of display  14 , on only a single edge of display  14 , or elsewhere in display  14 ). Demultiplexer circuitry  20  may be used to demultiplex data signals from display driver integrated circuit  16  onto a plurality of corresponding data lines D. 
     Display control circuitry such as circuitry  18 ,  20 , and  28  may be implemented using one or more integrated circuits (e.g., display driver integrated circuits such as timing controller integrated circuits and associated source driver circuits and/or gate driver circuits), may be implemented using thin-film transistor circuitry implemented on substrate  24 , and/or may be implemented using circuitry formed within substrate  24  (e.g., in a configuration in which substrate  24  is formed from a semiconductor substrate such as a silicon substrate). 
     With the illustrative arrangement of  FIG. 3 , data lines (source lines) D run vertically through display  14 . Data lines D are associated with respective columns of display pixels  22 . Display pixels  22  may include light-emitting diodes of different colors (e.g., red, green, blue). Corresponding data lines D may be used to carry red, green, and blue data. 
     Gate lines G (sometimes referred to as scan lines) run horizontally through display  14 . Each gate line G is associated with a respective row of display pixels  22 . If desired, there may be multiple horizontal control lines such as gate lines G associated with each row of display pixels. Gate driver circuitry  18  may be located on the left side of display  14 , on the right side of display  14 , or on both the right and left sides of display  14 , as shown in  FIG. 2 . Gate driver circuitry  18  and the other display control circuitry for display  14  may also be placed elsewhere in display  14 , if desired. 
     Gate driver circuitry  18  may assert horizontal control signals (sometimes referred to as scan signals or gate signals) on the gate lines G in display  14 . For example, gate driver circuitry  18  may receive clock signals and other control signals from display driver circuitry  28  and may, in response to the received signals, assert a gate signal on gate lines G in sequence, starting with the gate line signal G in the first row of display pixels  22 . As each gate line is asserted, data from data lines D is located into the corresponding row of display pixels. In this way, circuitry  28 ,  20 , and  18  may provide display pixels  22  with signals that direct display pixels  22  to generate light for displaying a desired image on display  14 . More complex control schemes may be used to control display pixels with multiple associated control transistors (e.g., to implement threshold voltage compensation schemes) if desired. 
     Display pixels  22  may be formed from individual (discrete) light-emitting diode structures (i.e., small crystalline semiconductor die). For example, each display pixel  22  may be formed from a respective red, blue, or green light-emitting diode. If desired, phosphorescent materials may be incorporated into pixels  22  (e.g., to convert blue light from a diode into red or green light, etc.). Each light-emitting diode may be formed from a separate crystalline semiconductor device. Examples of semiconductors that may be used in forming discrete light-emitting diodes for display pixels  22  include III-V compounds such as GaN or GaP, II-VI compounds such as ZnSe, and other compounds such as AlGaInP. The discrete light-emitting diodes may include quantum well structures, quantum wires, or quantum dots. The active layer(s) of the diodes may have thicknesses of 0.5-5 microns (as an example). Display pixel diodes may be oriented vertically or horizontally. For example, diodes for display pixels  22  may have cathodes and anodes that are aligned above each other (i.e., the cathode may be formed on top of a display pixel light-emitting diode and the anode may be formed on the bottom of the display pixel light-emitting diode or vice versa). Configurations in which the terminals for the diodes are spaced laterally (parallel to the surface of the substrate) may also be used. 
     A cross-sectional side view of an illustrative display pixel  22  that is based on a light-emitting diode is shown in  FIG. 4 . As shown in  FIG. 4 , display pixel  22  may include light-emitting diode  30  for emitting light  32  upwards out of display  14 . A viewer such as viewer  34  who is viewing display  14  in direction  36  may view images on display  14  that are formed from light  32  from an array of display pixels  22 . The array may include display pixels  22  of different colors (i.e., light-emitting diodes of different colors such as red, blue, and green light-emitting diodes that respectively emit red, blue, and green light). 
     Light-emitting diodes  30  may be mounted on surface  40  of substrate  24 . Bonding materials such as conductive bonding materials (e.g., bonding materials formed from solder, semiconductors, metals, polymers, other materials and/or combinations of these materials) may be used in attaching each discrete light-emitting diode  30  to substrate  24 . Light-emitting diodes  30  may be partially or completely free of polymer packaging so that the overall size of light-emitting diodes  30  is minimized. The lateral size W of light-emitting diodes  30  may be about 1-500 microns, 2-50 microns, 5-30 microns, less than 30 microns, 3-7 microns, more than 2 microns, or other suitable size. The height H of light-emitting diodes  30  may be less than 100 microns, less than 10 microns, less than 2 microns, less than 1 micron, or more than 1 micron (as examples). Light-emitting diodes  30  may be spaced apart from each other by a spacing of about 5-100 microns, 10-75 microns, a distance of 20-50 microns, a distance of greater than 10 microns, or a distance of less than 100 microns (as examples). 
     Substrate  24  may contain interconnects (metal traces) formed from patterned metal lines, metal vias, and other conductive signal paths. As shown schematically in  FIG. 4 , signal paths  38  supported by substrate  24  may be coupled to light-emitting diodes  30  so that current can be driven through light-emitting diodes  30  to cause diodes  30  to emit light  32 . 
     Substrate  24  may be formed from a dielectric material such as plastic, glass, ceramic, or other materials (e.g., clear plastic, clear glass, clear ceramic, etc.), may be formed from conductive materials (e.g., metal), may be formed from a semiconductor (e.g., silicon or a compound semiconductor), may be formed from other materials, or a combination of these materials. 
     If desired, filler material may be formed in the gaps between adjacent light-emitting diodes  30 , as illustrated by filler material  42  of  FIG. 5 . Filler material  42  may be formed from a dielectric such as a polymer or other suitable material.  FIG. 6  shows how additional layers may be attached to display  14  such as display cover layer  44 . Display cover layer  44  may be a clear layer of plastic or glass (as examples). Filler material  42  (e.g., a polymer such as an adhesive) may be used in attaching display cover layer  44  to substrate  24  and/or additional layers of material such as illustrative adhesive layer  46  may be used in attaching display cover layer  44  to substrate  24 . 
       FIG. 7  is a cross-sectional side view of an illustrative light-emitting diode  30  that has been mounted to substrate  24  using bonding material  48  (e.g., conductive bonding material). Light-emitting diode  30  may have a cathode and anode (see, e.g., upper terminal  52  and lower terminal  50 ). Bonding material  48  may form an electrical path that shorts terminal  50  to signal path  38 A of substrate  24 . Upper signal path  38 B may be formed from metal that overlaps upper terminal  52 . Metal  38 B and metal in signal line  38 A may be isolated from each other using dielectric spacers  54  (as an example). 
       FIG. 8  is a cross-sectional side view of substrate  24  in an illustrative configuration in which substrate  24  has a dielectric stack with interconnects (signal paths). As shown in  FIG. 8 , dielectric stack  56  may be formed from multiple dielectric layers  58  on the surface of substrate  24 . Dielectric layers  58  may include metal interconnects (metal traces) such as contacts (e.g., pad  60 ), vias  62 , and metal lines  64 . The metal interconnects of dielectric stack  56  may form terminals for transistors and other circuitry  66  in substrate  24  (e.g., in a configuration in which substrate  24  is formed from a semiconductor such as silicon). Circuitry  66  may include metal-oxide-semiconductor transistors, diodes, photodetectors, and other circuitry. If desired, integrated circuits, other circuits, and other electronic components may be mounted on pads such as pad  60 . For example, an integrated circuit or a discrete component may be soldered to pads  60  using solder. 
     If desired, light-emitting diodes  30  may be interspersed among touch sensor structures. As shown in  FIG. 9 , for example, a capacitive touch sensor may be formed from capacitive touch sensor electrodes on substrate  24  such as horizontal electrodes  70  and vertical electrodes  68 . Using touch sensor circuitry  72 , drive signals D may be applied to horizontal electrodes  70  and corresponding sense signals S may be detected on electrodes  68 . Touch sensor circuitry  72  may perform touch sensor signal processing operations that allow the touch sensor of  FIG. 9  to determine the location of external objects touching the touch sensor (i.e., to locate an external object such as user finger  74  or a stylus). Electrodes  70  and  68  may be formed on the same surface of substrate  24  or may be formed on opposite sides of substrate  24 . Touch sensor electrodes  68  and  70  may be used to gather touch input from one or more fingers or other external objects (e.g., gestures). The display pixel array formed from light-emitting diodes  30  may be used to display images for a user. 
     The illustrative touch sensor configuration of  FIG. 9  includes horizontal and vertical capacitive touch sensor electrodes formed in the spaces between light-emitting diodes  30 . If desired, other touch sensor electrode patterns may be used (see, e.g., the diagonally coupled square pads of  FIG. 10 ). 
       FIG. 11  is a top view of a portion of an illustrative display having an array of display pixels formed from light-emitting diodes  30  on substrate  24 . As shown in the example of  FIG. 11 , one or more components may be interspersed in the spaces between respective light-emitting diodes  30 . The components that are formed within the spaces between light-emitting diodes  30  may include components such as component  76 , component  78 , components  80  and conductive lines (signal paths)  82 . 
     Components such as component  76  may be elongated component that are located in the channel-shaped spaces formed between respective rows or columns of light-emitting diodes. A component such as component  78  may have a smaller footprint that allows component  78  to fit within the space between light-emitting diodes without extending past multiple rows or columns of light-emitting diodes. Components such as components  80  may be formed in an array (e.g., a one-dimensional array such as a row or column, or a two-dimensional array that covers some or all of display  14 ). 
     Components such as components  76 ,  78 , and  80  may be integrated circuits, discrete components such as capacitors, resistors, or inductors, light-emitting components (e.g., infrared light-emitting diodes, lasers, etc.), light detectors (e.g., photodetectors sensitive to visible and/or infrared light for forming an ambient light sensor or other detector), light-based proximity sensors (e.g., a light detector and photodetector for transmitting light and gathering reflected light), capacitive proximity sensors, electrodes and control circuitry for a touch sensor, force sensors (e.g., piezoelectric sensors, resistive force sensors, capacitive force sensors, etc.), Peltier effect heating and cooling elements, temperature sensors, resistance sensors, moisture detectors, strain gauges, pressure sensors, accelerometers and other microelectromechanical systems (MEMs) devices, switches, audio components such as microphones or sound producing structures, an array of light-emitting components that work with an array of light detectors for use in capturing three-dimensional scans of external objects, miniature integrated circuits (e.g., circuit die such as illustrative components  80  that have sizes comparable to light-emitting diodes  30  and that are optionally protected by one or more overlapping moisture barrier layers), miniature integrated circuits or other integrated circuit that have support communications using a one wire interface or other suitable communications interface, display driver circuitry (e.g., circuitry for performing signal demultiplexing and display pixel control operations), circuitry for touch sensing (e.g., drive and sense circuitry), circuitry for capturing capacitance signals from capacitive touch sensor electrodes to implement a fingerprint sensor (e.g., a capacitive fingerprint sensor), circuitry for capacitance sensing, force sensors and other circuitry for force sensing, etc. As an example, there may be numerous circuits  76  interspersed among an array of light-emitting diodes  30 . Each circuit  76  may contain digital data communications circuitry for receiving display data from other display circuitry (see, e.g., circuitry  28  of  FIG. 3 ). Each circuit  76  may also include display driver circuitry (e.g., pixel circuits) for controlling a subset of diodes  30  (e.g., 2-40 diodes  30 , as an example) in the vicinity of that circuit  76 . Circuits such as circuit  76  may also be located on the rear surface of substrate  24 . 
     Signal paths such as lines  82  may be formed in one or more layers of dielectric stack  56  and may, if desired, be organized to form busses such as bus  84 . Signal paths on substrate  24  may be coupled to solder pads on the upper surface of substrate  24  and/or on the opposing lower surface of substrate  24 . Integrated circuits, discrete components, and other circuit components may be soldered to the solder pads using solder. To enhance the signal carrying capacity of bus  84 , signals may be multiplexed using time division multiplexing and/or frequency multiplexing. 
     It may be desirable to form interconnects and/or other circuitry on the lower surface of substrate  24 . As shown in  FIG. 12 , for example, substrate  24  may have circuitry such as upper surface circuitry  66 A and lower surface circuitry  66 B. Through-silicon vias  38 D may be used in coupling light-emitting diode  30  for display pixel  22  to circuitry  66 B. Light-emitting diode  30  and, if desired, circuitry  66 B, may also be coupled to circuitry  66 A (e.g., using traces on the upper and/or lower surfaces of substrate  24  and using through-silicon vias  38 D). 
     Through-silicon vias  38 D may have diameters of 20-30 microns, 5-40 microns, more than 15 microns, or less than 50 microns (as examples). As shown in  FIG. 12 , paths  38 A and  38 B may be used in coupling the terminals of light-emitting diode  30  to respective vias  38 D and corresponding signal paths  38 C on the lower surface of substrate  24 . With one suitable arrangement, a first of vias  38 D is a source line (data line) via carrying data signals D and a second of vias  38 D is a gate line carrying gate line signals G. Circuitry  66 A and/or circuitry  66 B may be used in forming display driver circuitry such as circuitry  18 ,  20 , and  28  of  FIG. 3 . Borderless configurations or nearly borderless configuration may be formed for display  14  by placing display driver circuitry on the backside of substrate  24  or otherwise reducing display driver circuitry in inactive border regions of substrate  24 . Circuitry  66 A and/or circuitry  66 B may also be used in forming touch sensor circuitry  72  ( FIG. 9 ), circuitry such as circuitry  76 ,  78 , and  80  of  FIG. 11 , circuitry  16  of  FIG. 2 , and circuitry for devices  17  of  FIG. 2  (as examples). 
       FIG. 13  is a cross-sectional side view of display  14  in a configuration in which substrate  24  has been formed from a transparent material such as clear glass, clear plastic, or other clear dielectric. Display cover layer  44  may serve as a protective outer layer for display  14 . During operation, an array of display pixels formed from light-emitting diodes  30  may be used to emit light  32  to form images for a user of device  10 . Image sensor  90  and lens  88  may be mounted within device  10  in alignment with display substrate  24 . Display cover layer  44  and display substrate  24  are clear (in the example of  FIG. 13 ), which allows image light  86  from an external object on the exterior of device  10  to pass through layer  44  and substrate  24 . Light  86  that has passed through layer  44  and substrate  24  may then be focused onto image sensor  90  by lens  88 . Image sensor  90  may convert the incoming light  86  into a digital image for processing by the control circuitry of device  10 . If desired, a circular polarizer may be incorporated into display  14  to suppress reflections from light-emitting diodes  30  and other circuit components on the surface of substrate  24 . 
       FIG. 14  is a cross-sectional side view of display  14  in a configuration in which a light sensor array is formed on the upper surface of substrate  24  (e.g., a silicon substrate). The light detectors may be located in the spaces between respective light-emitting diodes  30  and may be formed from discrete components mounted to the upper surface of substrate  24  (see, e.g., light detectors  94 A) or may be formed from light sensor circuitry embedded within substrate  24  (see, e.g., light detectors  94 B). Microlenses  96  (e.g., polymer microlenses or microlenses formed from other clear material) may be used to direct incoming image light  86  onto respective light detectors  94 A or  94 B. To avoid interference between the display pixels formed from light-emitting diodes  30  and the array of light detectors, light  32  may be emitted from light-emitting diodes  30  during time periods when light detectors  94 A or  94 B are not actively acquiring light and light detectors  94 A and  94 B may be used to gather light readings when light-emitting diodes  30  are not actively emitting light. The array of light detectors of  FIG. 14  may be used in gathering touch data, may form part of a camera, may be used to gather ambient light sensor readings, may be used as part of a proximity sensor, or may be used for other operations within device  10 . 
     In configurations for display  14  that include an array of light detectors for gathering images, the light detectors may be used to form a front-facing camera in device  10 . Light detectors such as an image sensor or an array of detectors such as detectors  94 A and  94 B may also be used to implement a three-dimensional scanning system in which light from light-emitting diodes  30  and/or other light-emitting diodes in display  14  is emitted in a known pattern (e.g., a pattern of scan lines or other suitable pattern) and is subsequently reflected from an object. The reflected light may be captured using the image sensor or array of light detectors to acquire three-dimensional scans of people or other external objects. Light-emitting diodes  30  may also be used as light emitters in a light-based proximity sensor where light detectors  94  are used to detect reflected emitted light or in other light-based components for device  10 . If desired, light detectors  94 A or  94 B may be used as ambient light sensors or as detectors in an optical fingerprint sensor device (e.g., a device in which light-emitting diodes  30  or other light emitters emit light that is reflected from a finger). 
     If desired, display drive circuits such as pixel driver circuits for controlling the operation of light-emitting diodes  30  may incorporated into display  14  (see, e.g., circuits  76  of  FIG. 11 ). An illustrative configuration for display  14  in which driver circuits  76  have been interspersed in gaps between light-emitting diodes  30  is shown in  FIG. 15 . Data paths  84  (e.g., high speed horizontal and/or vertical data paths that carry display data on one or more signal lines) may be used to supply image data to an array of pixel (display) driver circuits  76 . Each driver circuit  76  may supply corresponding control signals to a set of associated light-emitting diodes  30  (e.g., 2 or more 5 or more 10 or more, 2-40, 5-30, or other suitable number of diodes  30 ). Local signal lines  100  may be used in supplying control signals to the set of light-emitting diodes  30  controlled by a given one of driver circuits  76 . Paths  84  and/or local paths  100  may be implemented using metal interconnect lines such as metal lines in dielectric stack  56  of  FIG. 8 . If desired, stack  56  may have five metal layers. The upper two metal layers may be used for implementing touch sensor electrodes  68  and  70  and the lower three metal layers may be used for implementing paths such as paths  84  and  100 . If desired, circuits such as the display driver circuitry of circuits  76  of  FIG. 15  may be mounted on the underside of substrate  24  and through-substrate vias may be used to route signals to an array of light-emitting diodes  30  on the upper surface (i.e., the front side) of substrate  24 . 
     If desired, substrate  24  may be formed from sapphire, clear glass, clear polymer, or other transparent materials. In situations in which substrate  24  is transparent, light-emitting diodes  30  may be mounted on the underside of substrate  24 . As shown in the illustrative cross-sectional side view of  FIG. 16 , an array of light-emitting diodes  30  and optional components  76  (e.g., pixel driver circuits, etc.) may be mounted on the underside of transparent substrate  24 . During operation, light-emitting diodes  30  may produce light  32  that travels outward to user  34  through substrate  24 . Substrate  24  may be formed from a material that is sufficiently durable to resist scratching and damage from contact with external objects (i.e., display cover layer  44  may be omitted as shown in  FIG. 16 ) or display cover layer  44  may be attached over the front of substrate  24  (e.g., using clear adhesive). 
     The cross-sectional side views of display  14  that are shown in  FIGS. 17 and 18  illustrate how substrate  24  may be formed from a flexible material (e.g., polyimide or other flexible polymer, etc.). This allows display  14  to have a concave or convex outer surface. In the example of  FIG. 17 , display cover layer  44  has a convex shape and flexible display substrate  24  has been bent to conform to the curved inner surface of display cover layer  44 . Clear adhesive  102  may be used in attaching flexible substrate layer  24  to display cover layer  44 . Display cover layer  44  may be formed from a material such as sapphire, glass, plastic, or other rigid materials (as examples). 
     In the  FIG. 17  example, light-emitting diodes  30  have been mounted on the underside of substrate  34 . Circuits  76  (e.g., integrated circuits such as pixel driver circuits for controlling associated light-emitting diodes  30 , sensors, other electrical components, etc.) may be mounted to substrate  34  in spaces between light-emitting diodes. With the configuration of  FIG. 17  flexible substrate  24  may be a clear flexible substrate (e.g., a substrate of polyimide or other clear polymer), so that light  32  passes through clear flexible substrate  24  and passes through clear display cover layer  44 . In the  FIG. 18  example, light-emitting diodes  30  have been formed on the upper surface of substrate  24  and clear layer  102  (e.g., a clear layer of adhesive) has been used to mount substrate  24  to the underside of display cover layer  44 . With this configuration, light passes through layer  102  and clear display cover layer  44 , but does not pass through substrate layer  24 . In the configuration of  FIG. 18 , substrate  24  is preferably sufficiently flexible to conform to the curved inner surface of display cover layer  44 , but need not be transparent. 
     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: 20140806
Publication Date: 20200811
Grant Date: 20200811
Priority Date: 20140806
Inventors: CHEN, WEI
HOTELLING, STEVEN P.
ZHONG, JOHN Z.
ATHAS, WILLIAM C.
YAO, WEI H.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06V40/1318", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/1306", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G3/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G3/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04102", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G2360/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04N9/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2360/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G3/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04102", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G09G3/32", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2380/02", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04102", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2360/14", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04N9/30", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 55267414