Abstract:
A display may have a thin-film transistor (TFT) layer and a color filter layer. The TFT layer may have a first substrate, a first black masking layer, a planarization layer, and a layer of TFT circuitry on the planarization layer. The color filter layer may have a second substrate and a second black masking layer on the second substrate. A portion of the inactive area may serve as a logo area for displaying desired information to the user. A reflective structure may be formed on the bottom surface of the planarization layer, on the bottom surface of the first substrate, on the bottom surface of the second substrate, or on the upper surface of the first substrate in the logo area. In another embodiment, the logo area may be backlit by transmitting light through one or more openings in the first and second black masking layers in the logo area.
Abstract:
A display may have upper and lower display layers. A layer of liquid crystal material may be interposed between the upper and lower display layers. The display layers may have substrates. The display layers may include a color filter layer having an array of color filter elements on a glass substrate and a thin-film transistor layer having a layer of thin-film transistor circuitry on a glass substrate. Dielectric layers within the display layers such as dielectric layers within the thin-film transistor layer may have differing indices of refraction. Reflections and color shifts due to index of refraction discontinuities may be minimized by interposing graded index dielectric layers between adjacent layers with different indices. The graded index layers may be formed from structures with a continuously varying index of refraction or structures with a step-wise varying index of refraction.
Abstract:
A touch screen. In some examples, the touch screen can comprise a first element coupled to a first sense connection, and a second element coupled to a second sense connection. In some examples, the first and second sense connections can be configured such that a load presented by the first sense connection and the first element is substantially equal to a load presented by the second sense connection and the second element. In some examples, the first and second sense connections can comprise detour routing configured such that a resistance of the first sense connection is substantially equal to a resistance of the second sense connection. In some examples, the first and second sense connections can be coupled to dummy routing configured such that a first capacitance presented by the first sense connection is substantially equal to a second capacitance presented by the second sense connection.
Abstract:
A touch screen including display pixels with capacitive elements is provided. The touch screen includes first common voltage lines connecting capacitive elements in adjacent display pixels, and a second common voltage line connecting first common voltage lines. Groups of pixels can be formed as electrically separated regions by including breaks in the common voltage lines. The regions can include a drive region that is stimulated by stimulation signals, a sense region that receives sense signals corresponding to the stimulation signals. A grounded region can also be included, for example, between a sense region and a drive region. A shield layer can be formed of a substantially high resistance material and disposed to shield a sense region. A black mask line and conductive line under the black mask line can be included, for example, to provide low-resistance paths between a region of pixels and touch circuitry outside the touch screen borders.
Abstract:
An electronic display system has a light transmissive panel, a region of display elements on the panel, and source lines coupled to the display elements. A demultiplexer circuit has multiple groups of pass gates. Each pass gate has a pair of complimentary on-panel transistors, and the signal outputs of each group are connected to a respective group of the source lines. A display driver integrated circuit (IC) receives video data and timing control signals. A signal input of each group of pass gates is connected to a respective output pin of the driver IC. The display driver IC provides digital timing control signals to control the pass gates of the demultiplexer circuit. Other embodiments are also described.
Abstract:
A display may have a thin-film-transistor layer with a substrate layer. A layer of dielectric may be formed on the substrate layer and may have an upper surface and a lower surface. The thin-film-transistor layer may include an array of display pixels. Data lines and gate lines may provide signals to the display pixels. Gate driver circuitry in an inactive peripheral portion of the display may include a gate driver circuit for each gate line. The gate driver circuits may include thin-film transistors that are formed on the upper surface of the layer of dielectric. Signal lines such as a gate low line, a gate routing line coupled between the gate driver circuits, and a common electrode line may be formed from two or more layers of metal to reduce their widths or may be embedded within the dielectric layer between the upper and lower surfaces under the thin-film transistors.
Abstract:
A display may have an array of organic light-emitting diode display pixels. Each display pixel may have a light-emitting diode that emits light under control of a drive transistor. Each display pixel may also have control transistors for compensation and programming operations. Each display pixel may have five p-type transistor and two capacitors. One of the five p-type transistors may serve as the drive transistor and may be compensated using the remaining four of the p-type transistors and the two capacitors. A first of the capacitors may be coupled between the gate and source of the drive transistor. A second of the capacitors may have a terminal coupled to the source. Alternatively, each display pixel may have six p-type transistors and a single capacitor. The six p-type transistors may include a drive transistor having a gate coupled to the capacitor.
Abstract:
Integrated touch screens are provided including drive lines formed of grouped-together circuit elements of a thin film transistor layer and sense lines formed between a color filter layer and a material layer that modifies or generates light. The common electrodes (Vcom) in the TFT layer can be grouped together during a touch sensing operation to form drive lines. Sense lines can be formed on an underside of a color filter glass, and a liquid crystal region can be disposed between the color filter glass and the TFT layer. Placing the sense lines on the underside of the color filter glass, i.e., within the display pixel cell, can provide a benefit of allowing the color filter glass to be thinned after the pixel cells have been assembled, for example.
Abstract:
A display may have an active area surrounded by an inactive border area. The inactive border area may be provided with an opaque masking material. The display may be a liquid crystal display having a liquid crystal layer sandwiched between a color filter layer and a thin-film transistor layer. Upper and lower polarizers may be provided above and below the color filter and thin-film transistor layers. The upper polarizer may have a polarized central region that overlaps the active area of the display. The upper polarizer may also have an unpolarized portion in the inactive border area overlapping the opaque masking material. The opaque masking material may alternatively be formed on the underside of a clear polymer substrate that is attached to the display above the upper polarizer or may be incorporated within the layers that make up the upper polarizer.
Abstract:
An electronic device may include a display having an array of display pixels on a substrate. The display pixels may be organic light-emitting diode display pixels or display pixels in a liquid crystal display. In an organic light-emitting diode display, hybrid thin-film transistor structures may be formed that include semiconducting oxide thin-film transistors, silicon thin-film transistors, and capacitor structures. The capacitor structures may overlap the semiconducting oxide thin-film transistors. Organic light-emitting diode display pixels may have combinations of oxide and silicon transistors. In a liquid crystal display, display driver circuitry may include silicon thin-film transistor circuitry and display pixels may be based on oxide thin-film transistors. A single layer or two different layers of gate metal may be used in forming silicon transistor gates and oxide transistor gates. A silicon transistor may have a gate that overlaps a floating gate structure.