Patents by Inventor Keitaro Yamashita

Keitaro Yamashita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170365213
    Abstract: An organic light-emitting diode display may contain an array of display pixels. Each display pixel may have a respective organic light-emitting diode that is controlled by a drive transistor. At low temperatures, it may be necessary to increase the amount of current through an organic light-emitting diode to achieve a desired luminance level. In order to increase the current through the light-emitting diode, the ground voltage level may be lowered. However, this may lead to thin-film transistors within the pixel leaking, which may result in undesirable display artifacts such as bright dots being displayed in a dark image. In order to prevent leakage in the transistors, the transistors may be coupled to separate reference voltage supplies or separate control lines. Additionally, the transistors may be positioned to minimize leakage even at low ground voltage levels.
    Type: Application
    Filed: August 24, 2016
    Publication date: December 21, 2017
    Inventors: Warren S. Rieutort-Louis, Keitaro Yamashita, Tsung-Ting Tsai, Yun Wang, Ting-Kuo Chang, Cheng-Ho Yu, Shinya Ono
  • Patent number: 9842551
    Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The display may be provided with intra-frame pausing (IFP) capabilities, where touch or other operations may be performed during one or more intra-frame blanking intervals. In one suitable arrangement, a gate driver circuit may include multiple gate line driver segments each of which is activated by a separate gate start pulse is that received through a demultiplexing circuit. In another suitable embodiment, the gate driver circuit may include analog or digital gate driver units that include control circuits for selectively (dis)charging internal nodes in the gate driver circuit so as to balance the amount of stress that is experienced by a drive transistor in gate driver units at or near an IFP row and the amount of stress that is experienced by the remaining gate driver units.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: December 12, 2017
    Assignee: Apple Inc.
    Inventors: Keitaro Yamashita, Ting-Kuo Chang
  • Publication number: 20170351379
    Abstract: Thin-film transistor circuitry for a display may include conductive layers such as transparent conductive layers and metal layers and may include dielectric layers. The dielectric layers may include buffer layers, interlayer dielectric, gate insulator, and organic planarization layers. The organic planarization layers may be patterned photolithographically to form vias, trenches, and other structures. Trenches may be formed by removing the planarization layer in a strip. When planarization material is removed for forming a trench or other structure, a step is formed in the planarization material. Metal lines such as data lines and other signal lines may cross steps in the planarization material. To prevent shorts between lines, a step may have protrusions that help eliminate metal etch residue. Vias may be reduced in depth by forming metal bumps and dielectric bumps under the vias and by forming other via structures.
    Type: Application
    Filed: September 8, 2016
    Publication date: December 7, 2017
    Inventors: Yu Cheng Chen, Keitaro Yamashita, Abbas Jamshidi Roudbari, Hirokazu Yamagata, Ting-Kuo Chang
  • Patent number: 9734783
    Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The display may be provided with intra-frame pausing (IFP) capabilities, where touch or other operations may be performed during one or more intra-frame blanking intervals. In one suitable arrangement, a gate driver may be operable in a high impedance mode, where the output of the gate driver is left floating during touch or IFP intervals. In another suitable arrangement, the gate driver may be operable in an IFP reduced stress mode, where a digital pass gate in the gate driver is deactivated during IFP intervals. In yet another suitable arrangement, the gate driver may be operable in an all-gate-high (AGH) power-down mode, where the output of each gate driver in the driver circuitry is driven high in parallel when the displayed is being powered off. These arrangements may be implemented in any suitable combination.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: August 15, 2017
    Assignee: Apple Inc.
    Inventors: Cheng-Ho Yu, Keitaro Yamashita, Ting-Kuo Chang, Yun Wang, Hopil Bae, Kingsuk Brahma
  • Publication number: 20170090631
    Abstract: Methods and devices useful in discharging an aberrant charge on a touch sensitive display of an electronic device are provided. By way of example, a an electronic device includes a power management and control circuitry configured to receive a first voltage signal and a second voltage signal from a display subsystem of a display of the electronic device, receive a third voltage signal from a touch subsystem of the display, provide a power signal to the display subsystem to activate the display subsystem when the display is determined to be in a temporarily inactive state. Providing the power signal to the display subsystem comprises discharging an aberrant charge based on the third voltage signal.
    Type: Application
    Filed: December 31, 2015
    Publication date: March 30, 2017
    Inventors: Keitaro Yamashita, Majid Gharghi, Ting-Kuo Chang, Abbas Jamshidi Roudbari
  • Publication number: 20170084243
    Abstract: Methods and devices useful in discharging an aberrant charge on the VCOM of an electronic display and harvesting energy from the VCOM of the electronic display are provided. By way of example, a method may include supplying an activation signal to an active switching device of an electronic display. The active switching device is configured to discharge an aberrant charge on a common electrode of the electronic display. The method further includes discharging the aberrant charge by way of the active switching device. Discharging the aberrant charge comprises preventing a possible occurrence of image artifacts from becoming apparent on the electronic display.
    Type: Application
    Filed: January 26, 2016
    Publication date: March 23, 2017
    Inventors: Kasra M. Ohmid Zohoor, Hyunwoo Nho, Keitaro Yamashita, Majid Gharghi, Sarath Chandrasekhar Venkatesh Kumar, Ting-Kuo Chang, Abbas Jamshidi Roudbari
  • Publication number: 20170031477
    Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The gate driver circuitry may include gate drivers connected in a chain. A given one of the gate drivers may include a set-reset latch. The set-reset latch may have a set input and a reset input. A logic gating circuit such as a logic NOR gate may have an output directly connected to the set input. The NOR gate may have a first input coupled to an output of a preceding gate driver in the chain and a second input coupled to an output of a succeeding gate driver. The reset input may be coupled to the output of the preceding gate driver. Gate line output signals may be simultaneously asserted for each of the drivers without generating unstable scenarios where logic high signals are provided to the set and reset inputs.
    Type: Application
    Filed: January 5, 2016
    Publication date: February 2, 2017
    Inventors: Abbas Jamshidi Roudbari, Keitaro Yamashita
  • Patent number: 9466252
    Abstract: An embodiment of the invention provides a liquid crystal display (LCD) device including a pixel array, a timing controller to output a clock signal and a gate driver. The gate driver receives the clock signal to control rows of the pixel array to be turned on or turned off. The gate driver includes a first shift register coupled to a first row of the pixel array, and a second shift register coupled to a second row of the pixel array. When the first row is determined to be skipped, the first shift register outputs a first voltage level to the first row, and when the second row is to be scanned, the second shift register outputs a second voltage level, wherein the first voltage level is between the second voltage level and a third voltage level which maintains a previously written display data.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: October 11, 2016
    Assignee: INNOLUX CORPORATION
    Inventor: Keitaro Yamashita
  • Publication number: 20160275889
    Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The display may be provided with intra-frame pausing (IFP) capabilities, where touch or other operations may be performed during one or more intra-frame blanking intervals. In one suitable arrangement, a gate driver may be operable in a high impedance mode, where the output of the gate driver is left floating during touch or IFP intervals. In another suitable arrangement, the gate driver may be operable in an IFP reduced stress mode, where a digital pass gate in the gate driver is deactivated during IFP intervals. In yet another suitable arrangement, the gate driver may be operable in an all-gate-high (AGH) power-down mode, where the output of each gate driver in the driver circuitry is driven high in parallel when the displayed is being powered off. These arrangements may be implemented in any suitable combination.
    Type: Application
    Filed: September 24, 2015
    Publication date: September 22, 2016
    Inventors: Cheng-Ho Yu, Keitaro Yamashita, Ting-Kuo Chang, Yun Wang, Hopil Bae, Kingsuk Brahma
  • Publication number: 20160266693
    Abstract: Improvement of visual uniformity of an integrated touch screen display is provided. A touch screen can include common electrodes separated by gaps in a Vcom layer. To improve visual non-uniformity in the display resulting from the gaps, a first set of semi-transparent dummy features (primary-dummy features) can be formed on a second layer at the locations of the gaps, and a second set of dummy features (supplementary-dummy features) can also be formed on the second layer or another layer to mitigate low spatial resolution of the primary-dummy features and/or non-uniform spacing of the primary-dummy features. In some examples, holes or slits can be formed in the Vcom layer at areas of the supplementary-dummy features to further improve visual uniformity.
    Type: Application
    Filed: March 9, 2016
    Publication date: September 15, 2016
    Inventors: Yu Cheng CHEN, Abbas JAMSHIDI-ROUDBARI, Hiroshi OSAWA, Shang-Chih LIN, Shih-Chang CHANG, Shin-Hung YEH, Ting-Kuo CHANG, Majid GHARGHI, Keitaro YAMASHITA
  • Patent number: 9299452
    Abstract: A shift register is provided. In the shift register, each of successively cascaded shift register units includes first and second switches and first and second capacitors. For the first switch, a control terminal is coupled to a first node, an input terminal receives a first clock signal, and an output terminal is coupled to an output node. The first capacitor is coupled between the first node and the output node. The second capacitor is coupled between the output node and a ground terminal. For the second switch, an input terminal receives a second clock signal, and an output terminal is coupled to the first node. A carry signal is generated at the first node. For the N-th shift register unit, a control terminal of the second switch receives the carry signal generated at the first node of the previous shift register unit.
    Type: Grant
    Filed: August 9, 2012
    Date of Patent: March 29, 2016
    Assignees: Innocom Technology (SHENZHEN) Co., Ltd., Innolux Corporation
    Inventor: Keitaro Yamashita
  • Publication number: 20150356934
    Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The display may be provided with intra-frame pausing (IFP) capabilities, where touch or other operations may be performed during one or more intra-frame blanking intervals. In one suitable arrangement, a gate driver circuit may include multiple gate line driver segments each of which is activated by a separate gate start pulse is that received through a demultiplexing circuit. In another suitable embodiment, the gate driver circuit may include analog or digital gate driver units that include control circuits for selectively (dis)charging internal nodes in the gate driver circuit so as to balance the amount of stress that is experienced by a drive transistor in gate driver units at or near an IFP row and the amount of stress that is experienced by the remaining gate driver units.
    Type: Application
    Filed: November 20, 2014
    Publication date: December 10, 2015
    Inventors: Keitaro Yamashita, Ting-Kuo Chang
  • Patent number: 9208714
    Abstract: A display panel is provided, including an image data storage capacitor, a capacitive element, and four switches. The image data storage capacitor stores an image data. The sample unit has a control terminal for receiving a sample control signal. The capacitive element has a first terminal coupled to a pixel electrode of the image data storage capacitor via the sample unit. The first refresh unit has a control terminal coupled to the first terminal. The second refresh unit has a control terminal for receiving a refresh control signal. The third and first refresh units are serially coupled with each other between a corresponding source line and the image data storage capacitor for receiving a data signal. The shunt unit has a control terminal coupled to the pixel electrode, a data terminal coupled to the first terminal, and another data terminal for receiving a shunt control signal.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: December 8, 2015
    Assignee: INNOLUX CORPORATION
    Inventor: Keitaro Yamashita
  • Patent number: 9159283
    Abstract: A switch circuit, a pixel element and a display panel are provided. The switch circuit is for the pixel element, and includes switches. A switch is turned on to perform a sample operation on the pixel element. Another switch has a control terminal coupled to an image data storage capacitor of the pixel element via the switch, a data terminal to a corresponding source line, and another data terminal to the image data storage capacitor. During the sample operation, the second switch stores an image data of the image data storage capacitor in a parasitic gate capacitor existing on its control terminal. The parasitic gate capacitor maintains its stored data from the sample operation to a refresh operation in which the pixel element is refreshed. The second switch selectively electrically connects its two data terminals with each other according to stored image data in the parasitic gate capacitor.
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: October 13, 2015
    Assignee: INNOLUX CORPORATION
    Inventor: Keitaro Yamashita
  • Patent number: 9129578
    Abstract: The display device according to the present invention comprises a substrate and at least one optical coupler having an optical receiver and an optical transmitter formed on the substrate, wherein the optical transmitter transmits an optical signal to the optical receiver.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: September 8, 2015
    Assignees: Innocom Technology (Shenzhen) Co., Ltd., Innolux Corporation
    Inventors: Keitaro Yamashita, Te-Yu Lee
  • Publication number: 20150070259
    Abstract: An embodiment of the invention provides a liquid crystal display (LCD) device including a pixel array, a timing controller to output a clock signal and a gate driver. The gate driver receives the clock signal to control rows of the pixel array to be turned on or turned off. The gate driver includes a first shift register coupled to a first row of the pixel array, and a second shift register coupled to a second row of the pixel array. When the first row is determined to be skipped, the first shift register outputs a first voltage level to the first row, and when the second row is to be scanned, the second shift register outputs a second voltage level, wherein the first voltage level is between the second voltage level and a third voltage level which maintains a previously written display data.
    Type: Application
    Filed: September 10, 2013
    Publication date: March 12, 2015
    Applicant: Innolux Corporation
    Inventor: Keitaro Yamashita
  • Patent number: 8928829
    Abstract: A display device comprising a first substrate, a second substrate opposite to the first substrate and a pixel array is disclosed. The pixel array is disposed on the first substrate and comprises a plurality of pixels. Each pixel comprises a first conductive layer, a semiconductor layer, an electrode layer and a scan line. The first conductive layer is on the first substrate for receiving pixel data signals to the pixels. The electrode layer is disposed between the first and the second substrates. The semiconductor layer is between the first conductive layer and the electrode layer, and has first and second ends. The first end is directly connected to the first conductive layer, and the second end is electrically connected to the electrode layer. The scan line is on the semiconductor layer for receiving a plurality of scan signals to the pixels.
    Type: Grant
    Filed: May 31, 2013
    Date of Patent: January 6, 2015
    Assignee: Innolux Corporation
    Inventors: Keitaro Yamashita, Minoru Shibazaki
  • Publication number: 20140354911
    Abstract: A display device comprising a first substrate, a second substrate opposite to the first substrate and a pixel array is disclosed. The pixel array is disposed on the first substrate and comprises a plurality of pixels. Each pixel comprises a first conductive layer, a semiconductor layer, an electrode layer and a scan line. The first conductive layer is on the first substrate for receiving pixel data signals to the pixels. The electrode layer is disposed between the first and the second substrates. The semiconductor layer is between the first conductive layer and the electrode layer, and has first and second ends. The first end is directly connected to the first conductive layer, and the second end is electrically connected to the electrode layer. The scan line is on the semiconductor layer for receiving a plurality of scan signals to the pixels.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 4, 2014
    Inventors: Keitaro Yamashita, Minoru Shibazaki
  • Patent number: 8866711
    Abstract: A liquid crystal display device and a driving method thereof capable of reducing flicker are provided. During a predetermined time period, two continuous inversion operations to pixel voltages and common voltages are repeatedly performed with a timing interval in which the liquid crystal component does not react to changes. After the predetermined time period, the pixel voltages and common voltages are performed by a single inversion operation such that they are phase inverted. Then, the pixel voltages and common voltages are repeatedly performed during the predetermined period by two continuous inversion operations with the timing interval in which the liquid crystal component does not react to changes.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: October 21, 2014
    Assignee: Innolux Corporation
    Inventor: Keitaro Yamashita
  • Patent number: 8860652
    Abstract: A shift register is provided. In each of successively cascaded shift register units, for a first switch, control and output terminals are coupled to a first node and an output node respectively, and an input terminal receives a first clock signal. For a second switch, input and output terminals are coupled to the control terminal of the second switch and the first node respectively. For a third switch, a control terminal is coupled to the first node, and an input terminal receives the first clock signal. A first capacitor is coupled between an output terminal of the third switch and the first node. For a fourth switch, an input terminal is coupled to the first node, and an output terminal is coupled to a low voltage terminal. For a current shift register, a control terminal of the second switch receives an output signal generated by previous shift register unit.
    Type: Grant
    Filed: August 23, 2012
    Date of Patent: October 14, 2014
    Assignees: Innocom Technology (Shenzhen) Co., Ltd., Innolux Corporation
    Inventor: Keitaro Yamashita