Patents by Inventor Kenji Kokuda

Kenji Kokuda 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: 20220114961
    Abstract: A pixel circuit driving method is a method for driving a pixel circuit that includes a drive transistor that supplies a current corresponding to a signal voltage supplied via a signal line, a write transistor connected between the signal line and a gate electrode of the drive transistor, and an organic EL element that emits light in accordance with the current. The pixel circuit driving method includes supplying a reference potential to the gate electrode of the drive transistor before a threshold correction preparation operation of making a gate-source voltage of the drive transistor higher than a threshold voltage of the drive transistor.
    Type: Application
    Filed: October 6, 2021
    Publication date: April 14, 2022
    Applicant: JOLED INC.
    Inventors: Tetsuro YAMAMOTO, Kenji KOKUDA, Hitoshi TSUGE, Teppei TANAKA
  • Publication number: 20200243613
    Abstract: Disclosed are an organic EL display panel and a method of manufacturing an organic EL display panel including a display element array having a plurality of pixels arranged in a form of a matrix. An organic EL display panel includes: a substrate; a planarizing layer; an organic electro luminescence element array; an electrode plate; a plurality of sealing members; and a sealing layer. The method of manufacturing an organic EL display panel includes: preparing a substrate; forming a planarizing layer; forming a plurality of pixel electrodes, and forming an electrode plate; forming sealing members; forming functional layers; forming a common electrode; and forming a sealing layer on the common electrode.
    Type: Application
    Filed: January 23, 2020
    Publication date: July 30, 2020
    Applicant: JOLED Inc.
    Inventors: Kenichi NENDAI, Takashi OSAKO, Kenji KOKUDA
  • Patent number: 10644092
    Abstract: A display panel includes a contact area which includes an upper conductive layer forming first electrodes of the organic EL elements, a lower conductive layer disposed below the upper conductive layer, a middle layer between the upper conductive layer and the lower conductive layer, and an insulating layer between the lower conductive layer and the middle layer. The middle layer includes a first area and a second area which are conductive and electrically connected to the upper conductive layer, and an insulating separating area which separates the first area and the second area. The lower conductive layer includes a first line which is electrically connected to the first area via a first contact hole, and a second line which is electrically connected to the second area via a second contact hole.
    Type: Grant
    Filed: August 2, 2018
    Date of Patent: May 5, 2020
    Assignee: JOLED INC.
    Inventors: Kenji Kokuda, Masafumi Matsui, Hitoshi Tsuge, Takashi Osako, Shigeo Homura, Ryoichi Yasuda
  • Patent number: 10367051
    Abstract: An active-matrix display device includes: a pixel matrix that includes a plurality of pixel cells arranged in rows and columns; a first global power supply wire that is disposed for each of the columns in the pixel matrix and connected to each of the plurality of pixel cells in the column; and a second global power supply wire that is disposed for each of the columns in the pixel matrix and connected to each of the plurality of pixel cells in the column. Each of the plurality of pixel cells includes a local power supply wire that is connected to the first global power supply wire, and the local power supply wire does not overlap the second global power supply wire in a plan view of the pixel matrix.
    Type: Grant
    Filed: June 19, 2018
    Date of Patent: July 30, 2019
    Assignee: JOLED INC.
    Inventor: Kenji Kokuda
  • Publication number: 20190115413
    Abstract: A display panel includes a contact area which includes an upper conductive layer forming first electrodes of the organic EL elements, a lower conductive layer disposed below the upper conductive layer, a middle layer between the upper conductive layer and the lower conductive layer, and an insulating layer between the lower conductive layer and the middle layer. The middle layer includes a first area and a second area which are conductive and electrically connected to the upper conductive layer, and an insulating separating area which separates the first area and the second area. The lower conductive layer includes a first line which is electrically connected to the first area via a first contact hole, and a second line which is electrically connected to the second area via a second contact hole.
    Type: Application
    Filed: August 2, 2018
    Publication date: April 18, 2019
    Applicant: JOLED INC.
    Inventors: Kenji KOKUDA, Masafumi MATSUI, Hitoshi TSUGE, Takashi OSAKO, Shigeo HOMURA, Ryoichi YASUDA
  • Publication number: 20190051717
    Abstract: An active-matrix display device includes: a pixel matrix that includes a plurality of pixel cells arranged in rows and columns; a first global power supply wire that is disposed for each of the columns in the pixel matrix and connected to each of the plurality of pixel cells in the column; and a second global power supply wire that is disposed for each of the columns in the pixel matrix and connected to each of the plurality of pixel cells in the column. Each of the plurality of pixel cells includes a local power supply wire that is connected to the first global power supply wire, and the local power supply wire does not overlap the second global power supply wire in a plan view of the pixel matrix.
    Type: Application
    Filed: June 19, 2018
    Publication date: February 14, 2019
    Applicant: JOLED INC.
    Inventor: Kenji KOKUDA
  • Publication number: 20100185431
    Abstract: A circuit verification device includes a simulation section and a determination section. The simulation section performs a first simulation using a first net list and a second simulation using a second net list. The first net list includes a size parameter of the pair of transistors and, in the first net list, an instance parameter of a first transistor is specified as +P and an instance parameter of a second transistor is specified as ?P, and the second net list includes the same size parameter as in the first net list and, in the second net list, the instance parameter of the first transistor is specified as ?P and the instance parameter of the second transistor is specified as +P. The value of P is set at ?, which is ½ the control upper limit of mismatch of the threshold voltage between the pair transistors.
    Type: Application
    Filed: January 19, 2010
    Publication date: July 22, 2010
    Inventor: Kenji Kokuda
  • Patent number: 7304632
    Abstract: A driving circuit for an active-matrix liquid-crystal display short-circuits at least two of the signal lines in the matrix at times of transitions of signal-line potentials in the matrix. Charge stored in the parasitic capacitances of the signal lines is thereby recycled from one signal line to another, reducing the current consumption of the driving circuit. When alternating-current driving is employed, current consumption can also be reduced by reducing the frequency with which signal lines are driven from one side of a center potential to the other side.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: December 4, 2007
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Hidetaka Kodama, Kenji Kokuda, Hiroshi Furuya
  • Patent number: 7012587
    Abstract: A display device comprises a plurality of first to fourth switching elements. On the basis of control signals from the drive control circuit, the common line is brought to the selected state when the common line is connected to the low-voltage portion for common lines by turning on the first switching element and turning off the second switching element; the common line is brought to the non-selected state when the common line is brought to the high-impedance state by turning off both the first and second switching elements; the data line is brought to the selected state when the data line is connected to the high-voltage portion for data lines by turning off the third switching element and turning on the fourth switching element; and the data line is brought to the non-selected state when the data line is connected to the low-voltage portion for data lines by turning on the third switching element and turning off the fourth switching element.
    Type: Grant
    Filed: June 18, 2002
    Date of Patent: March 14, 2006
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shinichi Satoh, Shinichi Fukuzako, Junji Kashiwada, Kenji Kokuda
  • Publication number: 20040041763
    Abstract: A driving circuit for an active-matrix liquid-crystal display short-circuits at least two of the signal lines in the matrix at times of transitions of signal-line potentials in the matrix. Charge stored in the parasitic capacitances of the signal lines is thereby recycled from one signal line to another, reducing the current consumption of the driving circuit. When alternating-current driving is employed, current consumption can also be reduced by reducing the frequency with which signal lines are driven from one side of a center potential to the other side.
    Type: Application
    Filed: August 29, 2003
    Publication date: March 4, 2004
    Applicant: Oki Electric Industry Co., Ltd.
    Inventors: Hidetaka Kodama, Kenji Kokuda, Hiroshi Furuya
  • Patent number: 6642916
    Abstract: A driving circuit for an active-matrix liquid-crystal display short-circuits at least two of the signal lines in the matrix at times of transitions of signal-line potentials in the matrix. Charge stored in the parasitic capacitances of the signal lines is thereby recycled from one signal line to another, reducing the current consumption of the driving circuit. When alternating-current driving is employed, current consumption can also be reduced by reducing the frequency with which signal lines are driven from one side of a center potential to the other side.
    Type: Grant
    Filed: November 24, 2000
    Date of Patent: November 4, 2003
    Assignee: Oki Electric Industry Co, Ltd.
    Inventors: Hidetaka Kodama, Kenji Kokuda, Hiroshi Furuya
  • Publication number: 20030043127
    Abstract: A display device comprises a plurality of first to fourth switching elements. On the basis of control signals from the drive control circuit, the common line is brought to the selected state when the common line is connected to the low-voltage portion for common lines by turning on the first switching element and turning off the second switching element; the common line is brought to the non-selected state when the common line is brought to the high-impedance state by turning off both the first and second switching elements; the data line is brought to the selected state when the data line is connected to the high-voltage portion for data lines by turning off the third switching element and turning on the fourth switching element; and the data line is brought to the non-selected state when the data line is connected to the low-voltage portion for data lines by turning on the third switching element and turning off the fourth switching element.
    Type: Application
    Filed: June 18, 2002
    Publication date: March 6, 2003
    Inventors: Shinichi Satoh, Shinichi Fukuzako, Junji Kashiwada, Kenji Kokuda