Display with embedded components and subpixel windows

A display may have an array of pixels. Each pixel may have a light-emitting diode such as an organic light-emitting diode. The organic light-emitting diodes may each have an anode that is coupled to a thin-film transistor pixel circuit for controlling the anode. Transparent windows may be formed in the display. The windows may be formed by replacing subpixels in some of the pixels with transparent windows. When subpixels are replaced by transparent windows, adjacent subpixels may be overdriven to compensate for lost light from the replaced subpixels. Adjacent subpixels may also be enlarged to help compensate for lost light. An array of electrical components such as an array of light sensors may be aligned with the transparent windows and may be used to measure light passing through the transparent windows.

BACKGROUND

Electronic devices often include displays. Displays such as organic light-emitting diode displays have pixels with light-emitting diodes. The light emitting diodes each have electrodes (i.e., an anode and a cathode). Emissive material is interposed between the electrodes. During operation, current passes through the emissive material between the electrodes, generating light.

The electrodes in an organic light-emitting diode display are formed from a photolithographically patterned layer of conductive material. Electrodes are organized in a regularly spaced array. This type of arrangement simplifies the layout of thin-film transistor circuits for the display.

It may be desirable to incorporate electrical components into a display. If care is not taken, the electrodes and other circuitry in a display may interfere with these components.

It would therefore be desirable to be able to provide improved display arrangements for accommodating the addition of electrical components.

SUMMARY

A display may have an array of pixels. Each pixel may have a light-emitting diode such as an organic light-emitting diode. The organic light-emitting diodes may each have an anode that is coupled to an associated pixel circuit. The pixel circuit may include thin-film transistor circuitry for controlling the anode.

Transparent windows may be formed by replacing subpixels in some of the pixels with transparent windows. When subpixels are replaced by transparent windows, adjacent subpixels may be overdriven to compensate for lost light from the replaced subpixels. Adjacent subpixels may also be enlarged to help compensate for lost light.

Further features will be more apparent from the accompanying drawings and the following detailed description.

DETAILED DESCRIPTION

Input-output circuitry in device10such as input-output devices12may be used to allow data to be supplied to device10and to allow data to be provided from device10to external devices. Input-output devices12may 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, and other electrical components. A user can control the operation of device10by supplying commands through input-output devices12and may receive status information and other output from device10using the output resources of input-output devices12.

Input-output devices12may include one or more displays such as display14. Display14may be a touch screen display that includes a touch sensor for gathering touch input from a user or display14may be insensitive to touch. A touch sensor for display14may 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.

Control circuitry16may be used to run software on device10such as operating system code and applications. During operation of device10, the software running on control circuitry16may display images on display14using an array of pixels in display14.

Device10may be a tablet computer, laptop computer, a desktop computer, a display, a cellular telephone, a media player, a wristwatch device or other wearable electronic equipment, or other suitable electronic device.

Display14may be an organic light-emitting diode display or may be a display based on other types of display technology. Configurations in which display14is 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.

Display14may have a rectangular shape (i.e., display14may have a rectangular footprint and a rectangular peripheral edge that runs around the rectangular footprint) or may have other suitable shapes. Display14may be planar or may have a curved profile.

A top view of a portion of display14is shown inFIG. 2. As shown inFIG. 2, display14may have an array of pixels22formed on substrate36. Substrate36may be formed from glass, metal, plastic, ceramic, or other substrate materials. Pixels22may 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 pixels22in display14(e.g., tens or more, hundreds or more, or thousands or more). Each pixel22may have a light-emitting diode26that emits light24under the control of a pixel circuit formed from thin-film transistor circuitry such as thin-film transistors28and thin-film capacitors). Thin-film transistors28may be polysilicon thin-film transistors, semiconducting-oxide thin-film transistors such as indium gallium zinc oxide transistors, or thin-film transistors formed from other semiconductors. Pixels22may contain light-emitting diodes of different colors (e.g., red, green, and blue diodes for red, green, and blue pixels, respectively) to provide display14with the ability to display color images.

Display driver circuitry may be used to control the operation of pixels22. The display driver circuitry may be formed from integrated circuits, thin-film transistor circuits, or other suitable circuitry. Display driver circuitry30ofFIG. 2may contain communications circuitry for communicating with system control circuitry such as control circuitry16ofFIG. 1over path32. Path32may be formed from traces on a flexible printed circuit or other cable. During operation, the control circuitry (e.g., control circuitry16ofFIG. 1) may supply circuitry30with information on images to be displayed on display14.

To display the images on display pixels22, display driver circuitry30may supply image data to data lines D while issuing clock signals and other control signals to supporting display driver circuitry such as gate driver circuitry34over path38. If desired, circuitry30may also supply clock signals and other control signals to gate driver circuitry on an opposing edge of display14.

Gate driver circuitry34(sometimes referred to as horizontal control line 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 display14may carry gate line signals (scan line signals), emission enable control signals, and other horizontal control signals for controlling the pixels of each row. There may be any suitable number of horizontal control signals per row of pixels22(e.g., one or more, two or more, three or more, four or more, etc.).

A cross-sectional side view of a portion of an illustrative organic light-emitting diode display that includes a light-emitting diode (diode26) and thin-film transistor circuitry for an associated pixel circuit (pixel circuit48) is shown inFIG. 3. As shown inFIG. 3, display14may include a substrate layer such as substrate layer36. Substrate36may be a planar layer or a non-planar layer and may be formed from plastic, glass, ceramic, sapphire, metal, or other suitable materials. The surface of substrate36may, if desired, be covered with one or more buffer layers (e.g., inorganic buffer layers such as layers of silicon oxide, silicon nitride, etc.).

Thin-film transistor circuitry for pixel circuit48may be formed on substrate36. The thin film transistor circuitry may include transistors, capacitors, and other thin-film structures. As shown inFIG. 3, a transistor such as thin-film transistor28may be formed from thin-film semiconductor layer60. Semiconductor layer60may be a polysilicon layer, a semiconducting-oxide layer such as a layer of indium gallium zinc oxide, or other semiconductor layer. Gate layer56may be a conductive layer such as a metal layer that is separated from semiconductor layer60by an intervening layer of dielectric such as dielectric58(e.g., an inorganic gate insulator layer such as a layer of silicon oxide). Dielectric62may also be used to separate semiconductor layer60from underlying structures such as shield layer64(e.g., a shield layer that helps shield the transistor formed from semiconductor layer60from charge in buffer layers on substrate36).

Semiconductor layer60of transistor28may be contacted by source and drain terminals formed from source-drain metal layer52. Dielectric layer54(e.g., an inorganic dielectric layer) may separate gate metal layer56from source-drain metal layer52. Pixel circuit48(e.g., source-drain metal layer52) may be shorted to anode42of light-emitting diode26using a metal via such as via53that passes through dielectric planarization layer50. Planarization layer50may be formed from an organic dielectric material such as a polymer.

Light-emitting diode26is formed from light-emitting diode layers40on the thin-film transistor layers of pixel circuit48. Each light-emitting diode has a lower electrode and an upper electrode. In a top emission display, the lower electrode may be formed from a reflective conductive material such as patterned metal to help reflect light that is produced by the light-emitting diode in the upwards direction out of the display. The upper electrode (sometimes referred to as the counter electrode) may be formed from a transparent or semi-transparent conductive layer (e.g., a thin layer of transparent or semitransparent metal and/or a layer of indium tin oxide or other transparent conductive material). This allows the upper electrode to transmit light outwards that has been produced by emissive material in the diode. In a bottom emission display, the lower electrode may be transparent (or semi-transparent) and the upper electrode may be reflective.

In configurations in which the anode is the lower electrode, layers such as a hole injection layer, hole transport layer, emissive material layer, and electron transport layer may be formed above the anode and below the upper electrode, which serves as the cathode for the diode. In inverted configurations in which the cathode is the lower electrode, layers such as an electron transport layer, emissive material layer, hole transport layer, and hole injection layer may be stacked on top of the cathode and may be covered with an upper layer that serves as the anode for the diode. Both electrodes may reflect light.

In general, display14may use a configuration in which the anode electrode is closer to the display substrate than the cathode electrode or a configuration in which the cathode electrode is closer to the display substrate than the anode electrode. In addition, both bottom emission and top emission arrangements may be used. Top emission display configurations in which the anode is located on the bottom and the cathode is located on the top are sometimes described herein as an example. This is, however, merely illustrative. Any suitable display arrangement may be used, if desired.

In the illustrative configuration ofFIG. 3, display14has a top emission configuration and lower electrode42is an anode and upper electrode46is a cathode. Layers40include a patterned metal layer that forms anodes such as anode42. Anode42is formed within an opening in pixel definition layer66. Pixel definition layer66may be formed from a patterned photoimageable polymer. The photoimageable polymer may be formed from an opaque material and/or a layer of opaque material such as black masking layer66′ may cover other material in layer66(e.g., opaque layer66′ may cover a layer of semitransparent polyimide or other polymer).

In each light-emitting diode, organic emissive material44is interposed between a respective anode42and cathode46. Anodes42may be patterned from a layer of metal on a planarization layer in the thin-film transistor layers of pixel circuit48such as planarization layer50. Cathode46may be formed from a common conductive layer that is deposited on top of pixel definition layer66. Cathode46is transparent so that light24may exit light emitting diode26as current is flowing through emissive material44between anode42and cathode46.

Display14may have an array of pixels22of different colors to provide display14with the ability to display color images. As shown inFIG. 4, each pixel cell22P in display14may contain a red pixel22R, a green pixel22G, and a blue pixel22B (as an example). These pixels, which may sometimes be referred to as subpixels, may have rectangular emissive areas (e.g., rectangular anode shapes) and/or may have emissive areas of other suitable shapes. White pixels, yellow pixels, and pixels of other colors may also be included in display14, if desired.

It may be desirable to incorporate electrical components into display14and/or device10. As shown inFIG. 5, for example, electrical components84may be incorporated into device10under pixels22. Components84may be discrete components or may be formed as part of a common integrated circuit or other shared component. Components84may, as an example, be mounted on a substrate such as substrate82. Substrate82may be, for example, a printed circuit (e.g., a rigid printed circuit board formed from a rigid printed circuit board material such as fiberglass-filled epoxy or a flexible printed circuit formed from a flexible layer of polyimide or other sheet of polymer). Components84and/or substrate82may be integrated into the layers that make up display14and/or may be mounted in alignment with display14.

Electrical components84may be audio components (e.g., microphones, speakers, etc.), radio-frequency components, haptic components (e.g., piezoelectric structures, vibrators, etc.), may be capacitive touch sensor components or other touch sensor structures, may be temperature sensors, pressure sensors, magnetic sensors, or other sensors, or may be any other suitable type of electrical component. With one suitable arrangement, which may sometimes be described herein as an example, electrical components84may be light-based components (e.g., components that emit and/or detect visible light, infrared light, and/or ultraviolet light).

Light-based components84may emit and/or detect light that passes through transparent windows76in display14. Windows76may be formed by selectively removing subpixels from a subset of pixels22in the array of pixels forming display14. Examples of light-based components84that emit light include light-emitting diodes (e.g., organic light-emitting diodes, discrete crystalline light-emitting diode dies, etc.), lasers, and lamps. Examples of light-based components that detect light include light detectors such as photodiodes and phototransistors. Some components may, if desired, include both light emitters and detectors. For example, components84may emit infrared light and may include light detector structures for detecting a portion of the emitted light that has reflected from nearby objects such as object86. Components of this type may be used to implement a proximity detector, a light-based fingerprint sensor (e.g., when object86is the finger of a user), or other light-based sensor. If desired, light-based sensors such as these may be implemented by illuminating object86with light24from one or more of pixels22and/or light78from one or more supplemental light sources such as discrete light-emitting diodes80, while using light-detecting components84to gather reflected light from object86.

Control circuitry16may be used in controlling the emission of light from light sources such as pixels22, components84, and/or light sources80and may be used in processing corresponding detected light from components84(e.g., to generate a proximity sensor signal based on light reflected from object86, to generate a fingerprint reading based on light reflected from object86, to process a captured digital image of a far-field object, that is captured using components84, etc.).

Components84and windows76may be interspersed with pixels22using any suitable arrangement. With one illustrative configuration, windows76and components84are arranged in an array that has a larger pitch than the array of pixels22in display14. There may be, for example, one window76and one corresponding component84for each set of 10-1000 pixels22, for each set of 100-10,000 pixels, for each set of more than 500 pixels, or for each set of less than 5000 pixels (as examples). In configurations such as these, pixels22are arranged on display14with a finer pitch than windows76and components84. Pixels22may, for example, be organized in an array having rows and columns and windows76and components84may be arranged in an array having a smaller number of rows and columns (e.g., in a rectangular patch that consumes less than 20%, less than 10%, less than 5%, more than 1%, or other suitable amount of the total area of display14). Configurations in which windows76and components84are arranged in patterns other than rectangular arrays may also be used. Arrangements in which windows76and components84are arranged in rows and columns may sometimes be described herein as an example.

The pixels of display14may include red, green, and blue subpixels or subpixels of other colors. To create an array of windows76, some of the subpixels in an array of pixels may be selectively replaced with window structures. The human eye is less sensitive to blue and red light than green light, so with one suitable arrangement blue subpixels and/or red subpixels can be selectively replaced with windows76. Surrounding subpixels can then be overdriven to produce light that compensates for the loss of light from the replaced subpixels. If desired, the subpixel of a pixel adjacent to a window can be enlarged to help compensate for the loss of light.

FIGS. 6, 7, and 8show how subpixels can be selectively replaced with windows. Pixel22ofFIG. 6contains all of its subpixels: red subpixel R, green subpixel G, and blue subpixel B. Illustrative pixel NB ofFIG. 7includes red subpixel R and green subpixel G, but blue subpixel B has been replaced with light transmitting window76. Illustrative pixel NR ofFIG. 8includes blue subpixel B and green subpixel G, but red subpixel R has been replaced with light transmitting window76.

FIGS. 9, 10, and 11show illustrative pixel arrays in which some of the pixels have been configured to include windows. In the example ofFIG. 9, pixels22contain red, green, and blue subpixels (see, e.g., pixel22ofFIG. 9), whereas pixels NB contain no blue subpixels but rather include windows76. Each row of pixels NB has the same horizontal position. In the illustrative configuration ofFIG. 10, each row of pixels NB is staggered with respect to the next (i.e., the pixels NB in the second row of the array of pixels NB ofFIG. 10has been horizontally offset with respect to the pixels NB in the first row of the array of pixels NB inFIG. 10).FIG. 11shows how pixels NB and pixels NR may be interspersed with each other when forming an array of pixels containing windows76.

To help suppress visible artifacts on display14, the amount of blue light produced by one or more of the pixels22adjacent to each pixel NB and the amount of red light produced by one or more of the pixels22adjacent to each pixel NR may be increased when displaying images on display14. If desired, the size of the subpixels (i.e., the size of the anodes and overlapping emissive material) that are adjacent to the replaced subpixels may be increased to help compensate for the loss of light from the replaced subpixels. Consider, as an example, the arrangement ofFIG. 12. In theFIG. 12example, subpixel NB has a red subpixel R and a green subpixel G. Blue subpixel B is not present in subpixel NB to make space available for window76. Because blue subpixel B is absent from subpixel NB, the size of adjacent blue subpixel B in adjacent pixel22′ has been increased. The increase in size of subpixel B (and the additional current that is provided to subpixel B) in pixel22′ during image display operations may compensate for the loss of blue light due to the missing blue subpixel in pixel NB. The enlarged subpixel of pixel22′ may therefore help suppress visible artifacts due to the presence of window76in place of the blue subpixel. If desired, a red subpixel in a pixel adjacent to a missing red subpixel may be enlarged in the same way. Subpixels of other colors can also be enlarged and/or multiple adjacent subpixels can be enlarged.