Patent application number | Description | Published |
20110248949 | EQUALIZING PARASITIC CAPACITANCE EFFECTS IN TOUCH SCREENS - Reduction of the effects of differences in parasitic capacitances in touch screens is provided. A touch screen can include multiple display pixels with stackups that each include a first element and a second element. For example, the first element can be a common electrode, and the second element can be a data line. The display pixels can include a first display pixel including a third element connected to the first element, and the third element can contribute to a first parasitic capacitance between the first and second elements of the first display pixel, for example, by overlapping with the second element. The touch screen can also include a second display pixel lacking the third element. The second display pixel can include a second parasitic capacitance between the first and second elements of the second display pixel. The first and second parasitic capacitances can be substantially equal, for example. | 10-13-2011 |
20110267283 | Kickback Voltage Equalization - Scanning gate lines in a gate driver system of a touch screen is provided. The gate driver system can include gate lines connected to display pixel transistors, a display driver that can generate first and second gate clock signals including first and second voltage transitions, respectively, and a gate drivers that can receive the first and second gate clock signals via gate clock lines and that can apply gate line signals, based on the gate clock signals, to the gate lines. A first voltage change generated in a common electrode line of the touch screen by the first voltage transition can be reduced by a second voltage change generated in the common electrode by the second voltage transition. | 11-03-2011 |
20120154699 | DISPLAYS WITH MINIMIZED CROSSTALK - Display ground plane structures may contain slits. Image pixel electrodes in the display may be arranged in rows and columns. Image pixels in the display may be controlled using gate lines that are associated with the rows and data lines that are associated with the columns. An electric field may be produced by each image pixel electrode that extends through a liquid crystal layer to an associated portion of the ground plane. The slits in the ground plane may have a slit width. Data lines may be located sufficiently below the ground plane and sufficiently out of alignment with the slits to minimize crosstalk from parasitic electric fields. A three-column inversion scheme may be used when driving data line signals into the display, so that pairs of pixels that straddle the slits are each driven with a common polarity. Gate line scanning patterns may be used that enhance display uniformity. | 06-21-2012 |
20120162121 | SLEW RATE AND SHUNTING CONTROL SEPARATION - Setting a slew rate, e.g., a rising time or a falling time, of a scanning signal can be performed with a first operation, and a shunting resistance of the scanning line can be set with a second operation. A scanning system that scans a display screen, a touch screen, etc., can set a desired slew rate during a first period of time and can set a desired shunting resistance during a second period of time. A gate line system can sequentially scan gate lines to display an image during a display phase of a touch screen. The gate line system can, for example, increase the falling times of gate line signals. After the falling gate line signal has stabilized, for example, the gate line system can decrease the shunting resistance of the gate line. | 06-28-2012 |
20120280957 | DISPLAY EDGE SEAL IMPROVEMENT - Embodiments of the present disclosure relate to liquid crystal displays (LCDs) and electronic devices incorporating LCDs having an organic passivation layer positioned between edge-sealed two substrates. Specifically, embodiments of the present disclosure employ lithographic techniques (e.g., a half-tone mask, diffractive exposure mask, etc.) to remove or not deposit a portion of the organic passivation layer near the edges of the substrates prior to sealing the substrates along these edges. As described herein, this reduction in the thickness of the organic layer near the edges of the device may improve the strength of the edge seal due to reduced strain in the organic layer. | 11-08-2012 |
20120293485 | GATE SIGNAL ADJUSTMENT CIRCUIT - A gate signal adjustment circuit for a display is disclosed. The gate signal adjustment circuit can adjust a transition time of a gate signal used to drive data displaying. The adjustment can be to either speed up or slow down the transition time according to the requirements of the display. In an example, the gate signal adjustment circuit can include multiple transistors, where a first set of the transistors outputs the gate signal and a second set of the transistors outputs an adjustment to the gate signal. The second set of transistors can be the same or different sizes depending on the desirable number of adjustment options. The circuit can also include a control line coupled to the second set of transistors to control the adjustment output. Gate signal adjustment can reduce crosstalk in the display. | 11-22-2012 |
20120299983 | WRITING DATA TO SUB-PIXELS USING DIFFERENT WRITE SEQUENCES - With respect to liquid crystal display inversion schemes, a large change in voltage on a data line can affect the voltages on adjacent data lines due to capacitive coupling between data lines. The resulting change in voltage on these adjacent data lines can give rise to visual artifacts in the data lines' corresponding sub-pixels. Various embodiments of the present disclosure serve to prevent or reduce persisting visual artifacts by offsetting their effects or by distributing their presence among different colored sub-pixels. In some embodiments, this may be accomplished by using different write sequences during the update of a row of pixels. | 11-29-2012 |
20120313881 | DISPLAY SCREEN SHIELD LINE SYSTEM - Electrical shield line systems are provided for openings in common electrodes near data lines of display and touch screens. Some displays, including touch screens, can include multiple common electrodes (Vcom) that can have openings between individual Vcoms. Some display screens can have an open slit between two adjacent edges of Vcom. Openings in Vcom can allow an electric field to extend from a data line through the Vcom layer. A shield can be disposed over the Vcom opening to help reduce or eliminate an electric field from affecting a pixel material, such as liquid crystal. The shield can be connected to a potential such that electric field is generated substantially between the shield and the data line to reduce or eliminate electric fields reaching the liquid crystal. | 12-13-2012 |
20130052971 | INTERFERENCE REDUCTION SYSTEMS AND METHODS - The antenna on hand held devices, such as the iPhone or iPad, can be subject to interference from other circuitry on the device. Such interference may come from high frequency switching of nearby display circuitry, such as de-multiplexors or other circuits. To address this issue, the switching rates may be slowed in certain circuits by adding resistance and/or capacitance, thus raising the RC time constant and slowing the switching times to reduce the high frequency components. Alternatively or in addition to, an EMI shield can be placed over some or all of the display driving circuitry to shield the antenna from high frequency interference. | 02-28-2013 |
20130141343 | COMMON ELECTRODE CONNECTIONS IN INTEGRATED TOUCH SCREENS - Common electrodes (Vcom) of integrated touch screens can be segmented into electrically isolated Vcom portions that can be operated as drive lines and/or sense lines of a touch sensing system. The touch screen can include high-resistivity connections between Vcom portions. The resistivity of the high-resistivity connections can be high enough so that touch sensing and image display can be performed by the touch screen, and the high-resistivity connections can provide an added functionality by allowing a charge build up on one of the Vcom portions to be spread to other Vcom portions and/or discharged from system by allowing charge to leak through the high-resistivity connections. In this way, for example, visual artifacts that result from charge build up on a Vcom portion can be reduced or eliminated. | 06-06-2013 |
20130147774 | DISPLAYS WITH MINIMIZED CROSSTALK - Display ground plane structures may contain slits. Image pixel electrodes in the display may be arranged in rows and columns. Image pixels in the display may be controlled using gate lines that are associated with the rows and data lines that are associated with the columns. An electric field may be produced by each image pixel electrode that extends through a liquid crystal layer to an associated portion of the ground plane. The slits in the ground plane may have a slit width. Data lines may be located sufficiently below the ground plane and sufficiently out of alignment with the slits to minimize crosstalk from parasitic electric fields. A three-column inversion scheme may be used when driving data line signals into the display, so that pairs of pixels that straddle the slits are each driven with a common polarity. Gate line scanning patterns may be used that enhance display uniformity. | 06-13-2013 |
20130271684 | DEVICES AND METHODS FOR REDUCING THE SIZE OF DISPLAY PANEL ROUTINGS - Disclosed embodiments relate to signal routings for use in a display device. The display device may include a liquid crystal display (LCD) panel having multiple pixels arranged in rows and columns. Each of the pixels includes a pixel electrode and a thin-film transistor (TFT). The LCD may include a conductive signal routing portion having a first metallic layer, a second metallic layer formed directly on the first metallic layer, and a third metallic layer formed directly on the second metallic layer. The first metallic layer may include a contact terminal. The second metallic layer when combined with the third metallic layers may decrease the resistance of the third metallic layer. | 10-17-2013 |
20130300681 | LOW COMPLEXITY GATE LINE DRIVER CIRCUITRY - Gate driver circuitry that controls an array of display elements is described. The gate driver circuitry has gate drivers that apply a control pulse to each of a number of gate lines in sequence, from a previous gate line to a current gate line, during a frame interval in which the array of display elements is filled with pixel values. Each gate driver has a latch stage followed by an output stage. The output stage is coupled to drive a current gate line, and the latch stage is coupled to drive a) a first hold circuit that holds the current gate line at a predetermined voltage, and b) a second hold circuit that holds a previous gate line at a predetermined voltage. Other embodiments are also described and claimed. | 11-14-2013 |
20130328053 | Thin Film Transistor with Increased Doping Regions - A transistor that may be used in electronic displays to selectively activate one or more pixels. The transistor includes a metal layer, a silicon layer deposited on at least a portion of the metal layer, the silicon layer includes an extension portion that extends a distance past the metal layer, and at least three lightly doped regions positioned in the silicon layer. The at least three lightly doped regions have a lower concentration of doping atoms than other portions of the silicon layer forming the transistor. | 12-12-2013 |
20130329171 | DEVICES AND METHODS FOR SHIELDING DISPLAYS FROM ELECTROSTATIC DISCHARGE - Methods and devices for shielding displays from electrostatic discharge (ESD) are provided. In one example, a display of an electronic device may include a high resistivity shielding layer configured to protect electrical components from static charges. The display may also include a conductive layer electrically coupled to the high resistivity shielding layer and configured to decrease a discharge time of static charges from the high resistivity shielding layer. The display may include a grounding layer and a conductor electrically coupled between the conductive layer and the grounding layer to direct static charges from the conductive layer to the grounding layer. | 12-12-2013 |
20140043552 | Display with Multilayer and Embedded Signal Lines - 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. | 02-13-2014 |
20140061656 | Two Doping Regions in Lightly Doped Drain for Thin Film Transistors and Associated Doping Processes - A method is provided for fabricating thin-film transistors (TFTs) for an LCD having an array of pixels. The method includes depositing a first photoresist layer over a portion of a TFT stack that includes a conductive gate layer, and a semiconductor layer. The method also includes doping the exposed semiconductor layer with a first doping dose. The method further includes etching a portion of the conductive gate layer to expose a portion of the semiconductor layer, and doping the exposed portion of the semiconductor layer with a second doping dose. The method also includes depositing a second photoresist layer over a first portion of the doped semiconductor layer in an active area of the pixels to expose a second portion of the doped semiconductor layer in an area surrounding the active area, and doping the second portion of the doped semiconductor layer with a third doping dose. | 03-06-2014 |
20140070225 | Hydrogenation and Crystallization of Polycrystalline Silicon - A TFT stack for a liquid crystal display is provided. The TFT stack includes a silicon layer that includes a heavily doped region, a non-doped region, and a lightly doped region between the heavily doped region and the non-doped region. The heavily doped region is hydrogenated. The TFT stack also includes an insulation layer that includes a first portion formed over the lightly doped region and a second portion disposed over the non-doped region and a gate metal electrode layer formed over the second portion of the non-doped region. The TFT stack also includes a first dielectric layer disposed over the gate metal electrode and over the first portion of the insulation layer. The heavily doped region is hydrogenated to reduce the dependence of the capacitance between the gate metal electrode and the conductive layer C | 03-13-2014 |
20140103349 | DIFFERENT LIGHTLY DOPED DRAIN LENGTH CONTROL FOR SELF-ALIGN LIGHT DRAIN DOPING PROCESS - A method is provided for fabricating thin-film transistors (TFTs) for an LCD having an array of pixels. The method includes depositing a first photoresist layer over a portion of a TFT stack. The TFT stack includes a conductive gate layer, and a semiconductor layer. The method also includes doping the exposed semiconductor layer with a first doping dose. The method further includes etching a portion of the conductive gate layer to expose a portion of the semiconductor layer, and doping the exposed portion of the semiconductor layer with a second doping dose. The method also includes removing the first photoresist layer, and depositing a second photoresist layer over a first portion of the doped semiconductor layer in an active area of the pixels to expose a second portion of the doped semiconductor layer in an area surrounding the active area. The method further includes doping the second portion of the doped semiconductor layer with a third doping dose, the first dose being higher than the second dose and the third dose. | 04-17-2014 |
20140146026 | Electronic Device with Compact Gate Driver Circuitry - An electronic device display may have an array of display pixels that are controlled using a grid of data lines and gate lines. The display may include compact gate driver circuits that perform gate driver operations to drive corresponding gate lines. Each compact gate driver circuit may include a first driver stage and a second driver stage. The first driver stage may receive a start pulse signal and produce a control signal. The control signal may be stored by a capacitor to identify a control state of the gate driver circuit. The second driver stage may receive the control signal, a clock signal, and a corresponding inverted clock signal and drive the corresponding gate line based on the received signals. The second driver stage may include pass transistor circuitry that passes the clock signal to the corresponding gate line and may include short circuit protection circuitry. | 05-29-2014 |
20140232626 | DISPLAY PANEL SOURCE LINE DRIVING CIRCUITRY - 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 demultiplexor 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 demultiplexor circuit. Other embodiments are also described. | 08-21-2014 |
20140232955 | Display Circuitry with Reduced Pixel Parasitic Capacitor Coupling - A touch screen display may have a color filter layer and a thin-film transistor layer. A layer of liquid crystal material may be located between the color filter layer and the thin-film transistor (TFT) layer. The TFT layer may include thin-film transistors formed on top of a glass substrate. Each display pixel in the TFT layer may include first and second TFTs coupled in series between a data line and a storage capacitor. The first TFT may have a gate that is coupled to a gate line. The second TFT may have a gate that is coupled to a control line that is different than the gate line. A global enable signal may be provided on the control line, where the enable signal is asserted during display intervals and is deasserted during touch intervals. The second TFT may be formed using a top-gate TFT or a bottom-gate TFT arrangement. | 08-21-2014 |
20140247239 | DISPLAY INTEGRATED PRESSURE SENSOR - A touch sensitive device that can detect the amount of pressure being applied to a touch screen from a user or other external object is provided. A spacer of the touch screen can be coated with a layer of conductive material and the change in capacitance between the spacer and various circuit elements of the touch screen can be measured. The change in capacitance can be correlated to the amount of pressure being applied to the touch screen, thus providing a method to determine the pressure being applied. During operation of the device, the system can time multiplex touch, display and pressure sensing operations so as to take advantage of an integrated touch and display architecture. | 09-04-2014 |
20140327632 | Displays with Integrated Touch and Improved Image Pixel Aperture - A display may be provided with integral touch functionality. The display may include a common electrode layer having row electrodes arranged in rows and column electrodes interposed between the row electrodes of each row. The row electrodes may be electrically coupled by conductive paths. The row and column electrodes may be coupled to touch sensor circuitry that uses the row and column electrodes to detect touch events. Each electrode of the common electrode layer may cover a respective portion of an array of pixels. Each pixel of the display may have a respective aperture. The conductive paths that electrically couple row electrodes of the common electrode layer may cover or otherwise block some light from passing through pixels, resulting in reduced apertures. Dummy structures may be provided for other pixels that modify the apertures of the other pixels to match the reduced apertures associated with the conductive paths. | 11-06-2014 |
20150015559 | LIQUID CRYSTAL DISPLAY USING DEPLETION-MODE TRANSISTORS - Methods and devices employing charge removal circuitry are provided to reduce or eliminate artifacts due to a bias voltage remaining on an electronic display after the display is turned off. In one example, a method may include connecting a pixel electrode of a display to ground through charge removal circuitry while the display is off (e.g., using depletion-mode transistors that are active when gates of the depletion-mode transistors are provided a ground voltage). When a corresponding common electrode is also connected to ground, a voltage difference between the pixel electrode and common electrode may be reduced or eliminated, preventing a bias voltage from causing display artifacts in the pixel. | 01-15-2015 |
20150054799 | Display Driver Circuitry For Liquid Crystal Displays With Semiconducting-Oxide Thin-Film Transistors - 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. | 02-26-2015 |
20150055047 | Liquid Crystal Displays with Oxide-Based Thin-Film Transistors - 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. | 02-26-2015 |