Patents by Inventor Chikao Yamasaki

Chikao Yamasaki 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).

  • Patent number: 9029861
    Abstract: Thin film transistors having a high current drive capability and a suitable threshold voltage are provided. The thin film transistor includes a gate electrode, an insulating layer formed on the gate electrode, a semiconductor layer formed on the insulating layer, and source/drain electrodes formed on the semiconductor layer. The semiconductor layer includes a plurality of regions separated from each other in a longitudinal direction of the source/drain electrodes.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: May 12, 2015
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsuo Kikuchi, Yoshiharu Kataoka, Shinya Tanaka, Junya Shimada, Chikao Yamasaki
  • Publication number: 20140306225
    Abstract: Thin film transistors having a high current drive capability and a suitable threshold voltage are provided. The thin film transistor includes a gate electrode, an insulating layer formed on the gate electrode, a semiconductor layer formed on the insulating layer, and source/drain electrodes formed on the semiconductor layer. The semiconductor layer includes a plurality of regions separated from each other in a longitudinal direction of the source/drain electrodes.
    Type: Application
    Filed: May 20, 2011
    Publication date: October 16, 2014
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Tetsuo Kikuchi, Yoshiharu Kataoka, Shinya Tanaka, Junya Shimada, Chikao Yamasaki
  • Patent number: 8786582
    Abstract: The present invention is to provide a display panel and a display apparatus which can reduce the picture-frame area while sufficiently preventing the delay of signals by allowing a required amount of current to flow. The display panel of the present invention is a display panel which includes a circuit substrate, and an opposed substrate facing the circuit substrate, and which is featured in that the circuit section is arranged in the picture-frame area of the display panel, in that the circuit section includes trunk wiring, and branch wiring connected to the gate electrode or the source electrode of a transistor in the circuit section, and in that all or a part of the trunk wiring is provided on the opposed substrate, and the branch wiring is provided on the circuit substrate so as to be electrically connected to the trunk wiring via a conductor.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: July 22, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Junya Shimada, Shinya Tanaka, Tetsuo Kikuchi, Chikao Yamasaki
  • Patent number: 8781059
    Abstract: A shift register is formed by connecting unit circuits 11 in multi-stage. One electrode of a capacitor Cap2 in the unit circuit 11 is connected to the gate terminal (node N1) of a transistor T2, and the other connected to a node N2. A compensation circuit composed of transistors T3 to T5 provides a clock signal CKB to the node N2 when the node N1 potential is at low level, and applies a low-level potential to the node N2 when the node N1 potential is at high level. Accordingly, even when the gate potential of the transistor T2 changes with a change in a clock signal CK, a signal that cancels out the change is provided through the capacitor Cap2, stabilizing the gate potential of the transistor T2. Thus, a change in the control terminal potential of an output transistor associated with a change in a clock signal is prevented.
    Type: Grant
    Filed: January 6, 2011
    Date of Patent: July 15, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Junya Shimada, Chikao Yamasaki
  • Patent number: 8742424
    Abstract: The present invention provides a shift register and a display device, each of which operates stably. The present invention relate to a shift register, comprising a thin-film transistor which includes a source electrode, a drain electrode, and a gate electrode, the thin-film transistor being a bottom gate thin-film transistor which includes a comb-shaped source/drain structure, the gate electrode being provided with at least one of a cut and an opening in at least one of a region overlapping with the source electrode and a region overlapping with the drain electrode.
    Type: Grant
    Filed: July 9, 2010
    Date of Patent: June 3, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Chikao Yamasaki, Tetsuo Kikuchi, Shinya Tanaka, Junya Shimada
  • Patent number: 8586987
    Abstract: A second stem wires (17c), formed by a reflective pixel electrode layer formed as a different layer from first stem wires (17a), is provided in such a way as to extend along a long side of its adjacent one of the first stem wires (17a). This makes it possible to achieve a TFT array substrate (1) on which a gate drive circuit (15) and its wires (17a, 17b, 17c, 18) have been monolithically formed, wherein the width of a frame part in which the a gate drive circuit (15) and its wires (17a, 17b, 17c, 18) are formed can be reduced.
    Type: Grant
    Filed: May 21, 2010
    Date of Patent: November 19, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Junya Shimada, Chikao Yamasaki
  • Patent number: 8575620
    Abstract: The present invention provides a circuit board with a reduced circuit area, and a display device comprising the circuit board and a narrower picture frame. The circuit board of the present invention comprises: a bottom gate thin film transistor comprising a first semiconductor layer, a first gate electrode, a first source electrode, and a first drain electrode; and a top gate thin film transistor comprising a second semiconductor layer, a second gate electrode, a second source electrode, and a second drain electrode, wherein the first semiconductor layer and the second semiconductor layer are formed from the same material, and the first drain electrode or the first source electrode and the second gate electrode are connected without interposing any other thin film transistor therebetween, and have the same electric potential.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: November 5, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Chikao Yamasaki, Shinya Tanaka, Tetsuo Kikuchi, Junya Shimada
  • Patent number: 8559588
    Abstract: Provided is a shift register configured by cascade connecting unit circuits each including a bootstrap circuit. In at least one example embodiment, for the unit circuits, a time period during which a transistor is in an ON state and a clock signal is high level corresponds to a clock passing period. Among transistors whose one conduction terminal is connected to a gate of the transistor, channel lengths of transistors configured such that a low-level potential is fed to gates of the transistors to turn the transistors to an OFF state in the clock passing period and that a low-level potential is applied to the conduction terminal of the transistors in the clock passing period are made longer than the channel length of the transistor. With this, it is possible to reduce a leakage current in the clock passing period, and to prevent the fluctuation of a gate potential of the transistor and dullness in an output signal from occurring.
    Type: Grant
    Filed: December 25, 2009
    Date of Patent: October 15, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Chikao Yamasaki, Junya Shimada
  • Patent number: 8531224
    Abstract: An object is shortening a clock fall-rise period while suppressing an increase in a circuit area, an increase in current consumption, and a cost increase, without generating an abnormal operation, in a shift register within a monolithic gate driver. In a shift register (410) that operates based on four-phase clock signals, including two-phase clock signals (GCK1, GCK3) that are provided to odd-order stages and two-phase clock signals (GCK2, GCK4) that are provided to even-order stages, of which phases are shifted by 90 degrees from each other, a potential of a first clock (CKA) appears as a potential of a scanning signal (GOUT), when a potential of a first node is at a high level, in each stage. In this configuration, the potential of the first node included in each stage is set to a high level based on a pulse of a scanning signal outputted from a pre-stage, and is set to a low level based on a pulse of a scanning signal outputted from a third stage after a stage concerned.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: September 10, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Akihisa Iwamoto, Hideki Morii, Takayuki Mizunaga, Shinya Tanaka, Tetsuo Kikuchi, Takaharu Yamada, Satoshi Horiuchi, Chikao Yamasaki, Kei Ikuta
  • Publication number: 20130201610
    Abstract: The present invention provides a circuit board with a reduced circuit area, and a display device comprising the circuit board and a narrower picture frame. The circuit board of the present invention comprises: a bottom gate thin film transistor comprising a first semiconductor layer, a first gate electrode, a first source electrode, and a first drain electrode; and a top gate thin film transistor comprising a second semiconductor layer, a second gate electrode, a second source electrode, and a second drain electrode, wherein the first semiconductor layer and the second semiconductor layer are formed from the same material, and the first drain electrode or the first source electrode and the second gate electrode are connected without interposing any other thin film transistor therebetween, and have the same electric potential.
    Type: Application
    Filed: January 25, 2011
    Publication date: August 8, 2013
    Inventors: Chikao Yamasaki, Shinya Tanaka, Tetsuo Kikuchi, Junya Shimada
  • Publication number: 20130038583
    Abstract: Provided is a shift register circuit which includes: first through N-th circuit sections (1a, 1b) (N is an integer equal to or larger than 2) in each of which a plurality of shift register stages (SR1, SR2, . . . , SRn) are connected in cascade; and supply wires (10b, 10c, 10e, 10f). Each of the first through N-th circuit sections (1a, 1b) receives drive signals (CKA1, CKA2, CKB1, CKB2) for driving the shift register stages (SR1, SR2, . . . , SRn) via supply wires (10b, 10c, 10e, 10f) exclusive for the each of the first through N-th circuit sections (1a, 1b).
    Type: Application
    Filed: January 28, 2011
    Publication date: February 14, 2013
    Inventors: Junya Shimada, Shinya Tanaka, Tetsuo Kikuchi, Chikao Yamasaki, Masahiro Yoshida, Satoshi Horiuchi, Isao Ogasawara
  • Publication number: 20130028370
    Abstract: A shift register is formed by connecting unit circuits 11 in multi-stage. One electrode of a capacitor Cap2 in the unit circuit 11 is connected to the gate terminal (node N1) of a transistor T2, and the other connected to a node N2. A compensation circuit composed of transistors T3 to T5 provides a clock signal CKB to the node N2 when the node N1 potential is at low level, and applies a low-level potential to the node N2 when the node N1 potential is at high level. Accordingly, even when the gate potential of the transistor T2 changes with a change in a clock signal CK, a signal that cancels out the change is provided through the capacitor Cap2, stabilizing the gate potential of the transistor T2. Thus, a change in the control terminal potential of an output transistor associated with a change in a clock signal is prevented.
    Type: Application
    Filed: January 6, 2011
    Publication date: January 31, 2013
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Junya Shimada, Chikao Yamasaki
  • Publication number: 20120241747
    Abstract: The present invention provides a shift register and a display device, each of which operates stably. The present invention relate to a shift register, comprising a thin-film transistor which includes a source electrode, a drain electrode, and a gate electrode, the thin-film transistor being a bottom gate thin-film transistor which includes a comb-shaped source/drain structure, the gate electrode being provided with at least one of a cut and an opening in at least one of a region overlapping with the source electrode and a region overlapping with the drain electrode.
    Type: Application
    Filed: July 9, 2010
    Publication date: September 27, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Chikao Yamasaki, Tetsuo Kikuchi, Shinya Tanaka, Junya Shimada
  • Publication number: 20120218237
    Abstract: The present invention is to provide a display panel and a display apparatus which can reduce the picture-frame area while sufficiently preventing the delay of signals by allowing a required amount of current to flow. The display panel of the present invention is a display panel which includes a circuit substrate, and an opposed substrate facing the circuit substrate, and which is featured in that the circuit section is arranged in the picture-frame area of the display panel, in that the circuit section includes trunk wiring, and branch wiring connected to the gate electrode or the source electrode of a transistor in the circuit section, and in that all or a part of the trunk wiring is provided on the opposed substrate, and the branch wiring is provided on the circuit substrate so as to be electrically connected to the trunk wiring via a conductor.
    Type: Application
    Filed: June 2, 2010
    Publication date: August 30, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Junya Shimada, Shinya Tanaka, Tetsuo Kikuchi, Chikao Yamasaki
  • Publication number: 20120200544
    Abstract: In a shift register that operates based on four-phase clock signals, including two-phase clock signals that are provided to odd-order stages and two-phase clock signals that are provided to even-order stages, of which phases are shifted by 90 degrees from each other, a potential of a first clock appears as a potential of a scanning signal, when a potential of a first node is at a high level, in each stage. In this configuration, the potential of the first node included in each stage is set to a high level based on a pulse of a scanning signal outputted from a pre-stage, and is set to a low level based on a pulse of a scanning signal outputted from a third stage after a stage concerned.
    Type: Application
    Filed: July 15, 2010
    Publication date: August 9, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Akihisa Iwamoto, Hideki Morii, Takayuki Mizunaga, Shinya Tanaka, Tetsuo Kikuchi, Takaharu Yamada, Satoshi Horiuchi, Chikao Yamasaki, Kei Ikuta
  • Publication number: 20120168762
    Abstract: A second stem wires (17c), formed by a reflective pixel electrode layer formed as a different layer from first stem wires (17a), is provided in such a way as to extend along a long side of its adjacent one of the first stem wires (17a). This makes it possible to achieve a TFT array substrate (1) on which a gate drive circuit (15) and its wires (17a, 17b, 17c, 18) have been monolithically formed, wherein the width of a frame part in which the a gate drive circuit (15) and its wires (17a, 17b, 17c, 18) are formed can be reduced.
    Type: Application
    Filed: May 21, 2010
    Publication date: July 5, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Junya Shimada, Chikao Yamasaki
  • Publication number: 20120032615
    Abstract: Provided is a shift register configured by cascade connecting unit circuits each including a bootstrap circuit. In at least one example embodiment, for the unit circuits, a time period during which a transistor is in an ON state and a clock signal is high level corresponds to a clock passing period. Among transistors whose one conduction terminal is connected to a gate of the transistor, channel lengths of transistors configured such that a low-level potential is fed to gates of the transistors to turn the transistors to an OFF state in the clock passing period and that a low-level potential is applied to the conduction terminal of the transistors in the clock passing period are made longer than the channel length of the transistor. With this, it is possible to reduce a leakage current in the clock passing period, and to prevent the fluctuation of a gate potential of the transistor and dullness in an output signal from occurring.
    Type: Application
    Filed: December 25, 2009
    Publication date: February 9, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Chikao Yamasaki, Junya Shimada
  • Publication number: 20110007049
    Abstract: A TFT includes, in at least one embodiment, a capacitor formed: so as to have a region where a first capacitor electrode connected to a source electrode and a second capacitor electrode connected to a gate electrode are arranged to be stacked in a thickness direction and mutually opposed across a first dielectric layer therebetween; and so as to have a region where the first capacitor electrode and a third capacitor electrode connected to the gate electrode are arranged to be stacked in the thickness direction and mutually opposed across a second dielectric layer therebetween with a coupling between the first capacitor electrode and the third capacitor electrode and a coupling between the first capacitor electrode and the second capacitor electrode formed over mutually opposite faces of the first capacitor electrode. This realizes a TFT which can save a footprint of a capacitor connected to a TFT body section.
    Type: Application
    Filed: January 30, 2009
    Publication date: January 13, 2011
    Inventors: Tetsuo Kikuchi, Shinya Tanaka, Hajime Imai, Hideki Kitagawa, Chikao Yamasaki, Yoshiharu Kataoka