Patents by Inventor Naoki Tokuda

Naoki Tokuda 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: 8368311
    Abstract: The present invention overcomes image defects such as the brightness inclination or smears by reducing the line resistance of a power source bus line which supplies electricity to organic EL elements. A plurality of pixels which are arranged in a matrix array is connected to power source lines, and the plurality of power source lines are connected to a power source bus line. Both ends of the power source bus line are connected to a power source part via a FPC. By supplying electricity to both ends of the power source bus line from the power source part, the line resistance of the power source bus line can be reduced.
    Type: Grant
    Filed: July 5, 2012
    Date of Patent: February 5, 2013
    Assignees: Hitachi, Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Naoki Tokuda, Hiroshi Kageyama, Masamitsu Furuie
  • Publication number: 20120274223
    Abstract: The present invention overcomes image defects such as the brightness inclination or smears by reducing the line resistance of a power source bus line which supplies electricity to organic EL elements. A plurality of pixels which are arranged in a matrix array is connected to power source lines, and the plurality of power source lines are connected to a power source bus line. Both ends of the power source bus line are connected to a power source part via a FPC. By supplying electricity to both ends of the power source bus line from the power source part, the line resistance of the power source bus line can be reduced.
    Type: Application
    Filed: July 5, 2012
    Publication date: November 1, 2012
    Applicants: Panasonic Liquid Crystal Display Co., Ltd., Hitachi Displays, Ltd.
    Inventors: Naoki Tokuda, Hiroshi Kageyama, Masamitsu Furuie
  • Publication number: 20120248476
    Abstract: A color light emitting display includes light-emitting devices constituting a plurality of red, green and blue pixels disposed in a matrix form on a substrate, said light-emitting display takes out light from a side of said light-emitting devices opposite to said substrate on which said light-emitting devices are formed, and wherein when a wavelength of the light having an interference intensity of which with respect to the light emitted from an emissive layer constituting said light-emitting device becomes a maximum value at 0 degree of a viewing angle is ?imax, and a wavelength of the light becomes a maximum in a light intensity of the light emitted from said emissive layer is ?emax, a relationship of ?emax?50 nm??imax<?emax is satisfied.
    Type: Application
    Filed: May 16, 2012
    Publication date: October 4, 2012
    Inventors: Masaya ADACHI, Toshihiro Sato, Naoki Tokuda
  • Patent number: 8279203
    Abstract: An image display device capable of controlling in a differentiated manner the signal-brightness characteristics of natural pictures and those of different image sources, such as texts, in the screen frame is to be provided. The image display device is provided with a display area in which are arrayed a plurality of pixels each having a light-emitting device whose brightness is controlled with an image signal output voltage supplied from a signal voltage output circuit. The display area comprises first and second pixel groups of pixels connected to different drive voltage lines. The display area has a display characteristic that the first pixel group and the second pixel group are substantially equal in emission spectrum and differ in light emission brightness relative to the same image signal voltage supplied from the signal voltage output circuit.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: October 2, 2012
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Hajime Akimoto, Toshihiro Sato, Naoki Tokuda
  • Patent number: 8274218
    Abstract: A color light emitting display includes light-emitting devices constituting a plurality of red, green and blue pixels disposed in a matrix form on a substrate, said light-emitting display takes out light from a side of said light-emitting devices opposite to said substrate on which said light-emitting devices are formed, and wherein when a wavelength of the light having an interference intensity of which with respect to the light emitted from an emissive layer constituting said light-emitting device becomes a maximum value at 0 degree of a viewing angle is ?imax, and a wavelength of the light becomes a maximum in a light intensity of the light emitted from said emissive layer is ?emax, a relationship of ?emax?50 nm??imax<?emax is satisfied.
    Type: Grant
    Filed: May 16, 2012
    Date of Patent: September 25, 2012
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Masaya Adachi, Toshihiro Sato, Naoki Tokuda
  • Patent number: 8242698
    Abstract: The present invention overcomes image defects such as the brightness inclination or smears by reducing the line resistance of a power source bus line which supplies electricity to organic EL elements. A plurality of pixels which are arranged in a matrix array is connected to power source lines, and the plurality of power source lines are connected to a power source bus line. Both ends of the power source bus line are connected to a power source part via a FPC. By supplying electricity to both ends of the power source bus line from the power source part, the line resistance of the power source bus line can be reduced.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: August 14, 2012
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Naoki Tokuda, Hiroshi Kageyama, Masamitsu Furuie
  • Publication number: 20120127221
    Abstract: An organic EL displaying apparatus which suppresses a defective display caused by a leak current at a time when an emission period controlling transistor is off is provided. The organic EL displaying apparatus comprises a plurality of pixels each of which includes an organic EL element, a power supply line, a driving transistor and the emission period controlling transistor, a data line, and a control line. In this apparatus, in a certain one of the pixels, a resistance Roff—ILM between source and drain electrodes of the emission period controlling transistor in an off state of the emission period controlling transistor, and a resistance Rbk—Dr between source and drain electrodes of the driving transistor in a state that a minimum gradation displaying data voltage has been applied to a gate electrode of the driving transistor satisfy Roff—ILM?Rbk—Dr.
    Type: Application
    Filed: November 15, 2011
    Publication date: May 24, 2012
    Applicants: Hitachi Displays, Ltd., CANON KABUSHIKI KAISHA
    Inventors: Junya Tamaki, Nobuhiko Sato, Masami Iseki, Kouji Ikeda, Masahiro Tamura, Takeshi Izumida, Naoki Tokuda
  • Patent number: 8183770
    Abstract: A color light emitting display includes light-emitting devices of a plurality of red, green and blue pixels disposed in a matrix form. The light-emitting display takes out light from a side opposite to a substrate on which the light-emitting devices are formed. A wavelength of the light, of which an interference intensity to the light emitted from an emissive layer constituting a part of one of said light-emitting devices becomes a maximum value at 0 degree of a viewing angle, is ?imax, a wavelength of the light becomes a minimum value in the interference intensity is ?imin, a wavelength of the light becomes a maximum in a light intensity in relation to the light emitted from said emissive layer is ?emax, and a relationship of ?imax<?emax and ?imin??emax+70 nm, is satisfied for at least one color among red, green and blue.
    Type: Grant
    Filed: July 6, 2011
    Date of Patent: May 22, 2012
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Masaya Adachi, Toshihiro Sato, Naoki Tokuda
  • Patent number: 8148896
    Abstract: The present invention provides an organic electroluminescent display device and a method of repairing a defective pixel of an organic electroluminescent display device which can realize the repairing a defective pixel to a light emitting pixel by electrically separating a leak portion which generates a defective pixel. To be more specific, a peeling suppression layer is formed between an anode and an organic light emitting layer formed on a main substrate, and a cavity is formed between the main substrate and the peeling suppression layer due to the evaporation generated by an absorption of laser beams thus electrically separating a defective portion so as to repair a black-dot defective pixel to form a light emitting pixel.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: April 3, 2012
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystals Display Co., Ltd.
    Inventors: Kenta Kajiyama, Toshihiro Sato, Naoki Tokuda
  • Publication number: 20110310137
    Abstract: The present invention provides an image display device comprising data lines each supplying a data signal, and a plurality of pixel circuits. Each of the pixel circuits includes a light-emitting element, a capacitor which stores a difference in potential caused by the data signal therein, a drive transistor which has a gate electrode connected to the data line via the capacitor and controls light emission of the light-emitting element based on a difference in potential between the gate electrode and a source electrode thereof, which is generated by a potential supplied by the data line and the potential difference stored in the capacitor, and a variation control switch which causes the difference in potential between the gate and source electrodes of the drive transistor to vary based on the data signal at the turning on thereof and prevents the difference in potential from varying at the turning off thereof.
    Type: Application
    Filed: June 17, 2011
    Publication date: December 22, 2011
    Inventors: Kenta Kajiyama, Takeshi Izumida, Naoki Tokuda, Hajime Akimoto
  • Publication number: 20110260605
    Abstract: A color light emitting display includes light-emitting devices of a plurality of red, green and blue pixels disposed in a matrix form. The light-emitting display takes out light from a side opposite to a substrate on which the light-emitting devices are formed. A wavelength of the light, of which an interference intensity to the light emitted from an emissive layer constituting a part of one of said light-emitting devices becomes a maximum value at 0 degree of a viewing angle, is ?imax, a wavelength of the light becomes a minimum value in the interference intensity is ?imin, a wavelength of the light becomes a maximum in a light intensity in relation to the light emitted from said emissive layer is ?emax, and a relationship of ?imax<?emax and ?imin??emax+70 nm, is satisfied for at least one color among red, green and blue.
    Type: Application
    Filed: July 6, 2011
    Publication date: October 27, 2011
    Inventors: Masaya Adachi, Toshihiro Sato, Naoki Tokuda
  • Publication number: 20110234568
    Abstract: A display device includes: scanning lines for selecting a group of pixels out of pixels; control lines to which a pulse signal is supplied to control selection of at least one of the plurality of scanning lines to which a scanning signal is input; a scanning circuit which includes transistors controlled with the pulse signal, the scanning circuit being connected to the plurality of scanning lines and being disposed outside a display area; and a conductive mesh including conductive wires running in intersecting directions. The conductive mesh is placed above the transistors and the plurality of scanning lines except the display area. Above the plurality of scanning lines, the plurality of conductive wires constituting the conductive mesh intersect each other three-dimensionally in a manner that does not make the plurality of conductive wires parallel to the plurality of scanning lines.
    Type: Application
    Filed: March 18, 2011
    Publication date: September 29, 2011
    Inventors: Takeshi IZUMIDA, Kenta Kajiyama, Naoki Tokuda, Yasuharu Yatsu, Noriyuki Shikina
  • Publication number: 20110221791
    Abstract: An image display device includes pixel circuits, a power supply line, and a data line for supplying a data signal to the pixel circuits. The pixel circuits each include a light emitting element, a drive transistor for controlling light emission of the light emitting element, a storage capacitor provided between the data line and a gate electrode of the drive transistor, a both-end connection switch for connecting both ends of the storage capacitor to each other, and a current interruption switch for interrupting a path of a current flowing from the power supply line through the both-end connection switch. Before the data signal is supplied to each of the pixel circuits, the both-end connection switch connects the both ends of the storage capacitor to each other, and the current interruption switch is disconnected.
    Type: Application
    Filed: March 8, 2011
    Publication date: September 15, 2011
    Inventors: Kenta KAJIYAMA, Takeshi Izumida, Naoki Tokuda, Hajime Akimoto, Hiroshi Kageyama, Norihiro Nakamura, Masami Iseki
  • Publication number: 20110210988
    Abstract: In a liquid crystal display device, both of the brightness characteristic and the chromaticity characteristic are set to optimum values. In the liquid crystal display device which includes a liquid crystal display panel, a data driver, a scanning driver and a display control circuit, the display control circuit includes a first circuit which generates insertion display data which differs from the image display data and inserts the display data into the data driver, and a second circuit which sets a first time at which the scanning signal for displaying the display data and a second time at which the scanning signal for displaying the insertion display data are outputted. The first circuit generates display data of one chromatic color and, at the same time, sets gradations of chromatic color for every frame period.
    Type: Application
    Filed: May 6, 2011
    Publication date: September 1, 2011
    Inventors: Chikae Kubo, Naoki Tokuda
  • Patent number: 7977875
    Abstract: A light emitting display includes light-emitting devices in which unnecessary layers for the emission operation of the light-emitting device are removed in an emission region, and in a case where a wavelength of a light, of which an interference intensity to the light emitted from an emissive layer constituting the light-emitting device becomes a maximum value at 0 degree of a viewing angle, is ?imax and a wavelength of the light becoming a maximum in a light intensity in relation to the light emitted from the emissive layer is ?emax, a relationship of ?imax<?emax is satisfied, obtaining a light emitting display with a little variation in color over a wide range of viewing angles.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: July 12, 2011
    Assignee: Hitachi Displays, Ltd.
    Inventors: Masaya Adachi, Toshihiro Sato, Naoki Tokuda
  • Patent number: 7961162
    Abstract: In a liquid crystal display device, both of the brightness characteristic and the chromaticity characteristic are set to optimum values. In the liquid crystal display device which includes a liquid crystal display panel, a data driver, a scanning driver and a display control circuit, the display control circuit includes a first circuit which generates insertion display data which differs from the image display data and inserts the display data into the data driver, and a second circuit which sets a first time at which the scanning signal for displaying the display data and a second time at which the scanning signal for displaying the insertion display data are outputted. The first circuit generates display data of one chromatic color and, at the same time, sets gradations of chromatic color for every frame period.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: June 14, 2011
    Assignee: Hitachi Displays, Ltd.
    Inventors: Chikae Kubo, Naoki Tokuda
  • Patent number: 7880753
    Abstract: The present invention provides a driving method for a display device which includes a display part having pixels of M columns×N rows and a memory, wherein each pixel includes a light emitting element and a driving transistor for driving the light emitting element. At times other than a usual light emitting time, a driving voltage is applied to the driving transistor of each pixel so as to turn on the light emitting element of each pixel, a value of current which flows in the light emitting element of each pixel is detected, correction data for each pixel is calculated based on the detected value of current, and the calculated correction data for each pixel is stored in the memory. At the usual light emitting time, a driving voltage which is based on data which is obtained by adding the correction data stored in the memory to video signal data is applied to the driving transistor of each pixel.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: February 1, 2011
    Assignee: Hitachi Displays, Ltd.
    Inventors: Akira Shingai, Naoki Tokuda
  • Publication number: 20100259563
    Abstract: An inexpensive organic electroluminescent display device is realized by using a data driver IC for liquid crystal that is used in a liquid crystal display device, as a driver of the organic electroluminescent display device. In an active-matrix organic electroluminescent display device that has a pixel circuit capable of controlling light emitting luminance per time in accordance with magnitude of a grey scale voltage, a control signal is supplied from a timing control IC to the data driver so that the polarity is reversed twice consecutively, or a control signal is supplied from the timing control IC to the data driver so that a mode of not reversing the polarity is selected. This control signal need not necessarily be provided in the timing control IC and may be formed in a circuit on a substrate that is not an IC.
    Type: Application
    Filed: November 29, 2006
    Publication date: October 14, 2010
    Inventors: Naoki Tokuda, Hiroshi Kageyama, Naruhiro Kasai, Toshihito Sato, Masamitsu Furuie
  • Publication number: 20100231615
    Abstract: Provided is an image display device for displaying an image by causing a light emitting element to emit light, the light emitting element being disposed in each of a plurality of pixel areas which are defined by dividing a display area into a grid pattern, the image display device including a pixel circuit for controlling light emission of the light emitting element disposed in each of the plurality of pixel areas, the pixel circuit being formed in an area having a portion that protrudes from the pixel area of the pixel circuit toward an adjacent pixel area and a portion where an adjacent pixel area protrudes into the pixel area.
    Type: Application
    Filed: March 5, 2010
    Publication date: September 16, 2010
    Inventors: Naoki TOKUDA, Atsushi Hasegawa
  • Patent number: 7773080
    Abstract: A plurality of organic EL elements which are arranged on a display panel lowers the brightness along with a lapse of light emitting time and hence, the power consumption is increased to maintain the brightness. However, the increase of the power consumption shortens a lifetime of the organic EL elements. To overcome this drawback, a power supply circuit which drives the display panel has a function of controlling an electric power supplied to the display panel to a fixed value or less in response to a detection signal from a detection part which detects a cathode current of the organic EL elements.
    Type: Grant
    Filed: September 14, 2005
    Date of Patent: August 10, 2010
    Assignee: Hitachi Displays, Ltd.
    Inventors: Toshihiro Sato, Hajime Akimoto, Naruhiko Kasai, Naoki Tokuda