Patents by Inventor Hitoshi Oaku

Hitoshi Oaku 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: 8115388
    Abstract: There is provided a plasma display panel device using phosphors to improve reliability and color reproductivity or color performance. A plasma display panel includes: a discharge gas for generating ultraviolet light as a result of electric discharge, and a phosphor layer containing a phosphor for emitting light as a result of excitation by the ultraviolet light, in which the phosphor contains an Eu activated silicate phosphor added with at least one element selected from Al, Ga, Y and Gd, represented by the following General Formula (1): M13-yM2Si2O8:Euy??(1) wherein M1 is at least one element selected from the group consisting of Ba, Ca, and Sr; M2 is at least one element selected from the group consisting of Mg and Zn; and y satisfies the condition of 0.001?y?0.2.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: February 14, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hirotaka Sakuma, Hitoshi Oaku, Choichiro Okazaki, Shin Imamura, Masaaki Komatsu
  • Patent number: 8059245
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: November 15, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Publication number: 20110019116
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Application
    Filed: September 28, 2010
    Publication date: January 27, 2011
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Patent number: 7826022
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Grant
    Filed: April 20, 2009
    Date of Patent: November 2, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Patent number: 7786659
    Abstract: Using Eu2+ as the luminescence center for a green-emitting phosphor, a plasma display panel and a PDP device using it are configured by using an Eu2+-activated silicate green-emitting phosphate (Ca1-xM1x)2-e.M2.Si2O7:Eue with improved decay characteristics. In the formula, M1 is at least one element selected from the group containing Sr and Ba; M2 is at least one element selected from the group containing Mg and Zn; and x indicates the mole fraction of the component M1 and e indicates the mole fraction of Eu respectively satisfy the following conditions: 0<x<1 and 0.001?e?0.2.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: August 31, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Hitoshi Oaku, Hirotaka Sakuma, Choichiro Okazaki
  • Publication number: 20090224668
    Abstract: There is provided a plasma display panel device using phosphors to improve reliability and color reproductivity or color performance. A plasma display panel includes: a discharge gas for generating ultraviolet light as a result of electric discharge, and a phosphor layer containing a phosphor for emitting light as a result of excitation by the ultraviolet light, in which the phosphor contains an Eu activated silicate phosphor added with at least one element selected from Al, Ga, Y and Gd, represented by the following General Formula (1): M13-yM2Si2O8:Euy (1) wherein M1 is at least one element selected from the group consisting of Ba, Ca, and Sr; M2 is at least one element selected from the group consisting of Mg and Zn; and y satisfies the condition of 0.001?y?0.2.
    Type: Application
    Filed: October 8, 2008
    Publication date: September 10, 2009
    Inventors: Hirotaka Sakuma, Hitoshi Oaku, Choichiro Okazaki, Shin Imamura, Masaaki Komatsu
  • Publication number: 20090207361
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Application
    Filed: April 20, 2009
    Publication date: August 20, 2009
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Patent number: 7538829
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: May 26, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Publication number: 20090115332
    Abstract: A problem of the present invention is to reduce discharge delay and discharge voltage in an image display device such as a PDP using ultraviolet rays emission generated by the discharge, thereby improving image quality and reducing cost. In order to solve the above problem, according to the present invention, the image display device using the ultraviolet rays emission generated by discharge includes, within a discharge space, a phosphor where a 1/10 afterglow time is 1 ms or more and a light emitting wavelength is in a range of 200 to 460 nm in which light emitting intensity is at the maximum. Under the same condition, the effect of the invention can be improved by making the 1/10 afterglow time 8 ms or more. Further, the effect of the present invention is further effective by making the 1/10 afterglow time 100 ms or more.
    Type: Application
    Filed: October 30, 2008
    Publication date: May 7, 2009
    Inventors: Shin Imamura, Hitoshi Oaku, Tatsuya Miyake, Masaaki Komatsu, Shunsuke Mori, Masatoshi Shiiki
  • Publication number: 20090058255
    Abstract: Using Eu2+ as the luminescence center for a green-emitting phosphor, a plasma display panel and a PDP device using it are configured by using an Eu2+-activated silicate green-emitting phosphate (Ca1-xM1x)2-e.M2.Si2O7:Eue with improved decay characteristics. In the formula, M1 is at least one element selected from the group containing Sr and Ba; M2 is at least one element selected from the group containing Mg and Zn; and x indicates the mole fraction of the component M1 and e indicates the mole fraction of Eu respectively satisfy the following conditions: 0<x<1 and 0.001?e?0.2.
    Type: Application
    Filed: June 17, 2008
    Publication date: March 5, 2009
    Inventors: Hitoshi OAKU, Hirotaka Sakuma, Choichiro Okazaki
  • Publication number: 20080048547
    Abstract: A plasma display panel including a discharge gas for generating ultraviolet light as a result of electric discharge, and a phosphor layer containing a phosphor for emitting light upon excitation by ultraviolet light is provided. The phosphor contains a novel Eu-activated silicate phosphor represented by (CaxM11-x)3-e.M2.Si2O8: Eue. In the formula, M1 is at least one element selected from the group consisting of Sr and Ba; M2 is at least one element selected from the group consisting of Mg and Zn; x is the mole fraction of the component Ca satisfying the condition of 0<x?0.2, and e is the mole fraction of Eu satisfying the condition of 0.001?e?0.2.
    Type: Application
    Filed: July 26, 2007
    Publication date: February 28, 2008
    Inventors: Hitoshi Oaku, Hirotaka Sakuma, Choichiro Okazaki
  • Patent number: 7256843
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Grant
    Filed: August 11, 2003
    Date of Patent: August 14, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Patent number: 7221083
    Abstract: A blue-emitting phosphor is optimized by controlling mole fractions typically of Mg and Si in Sr3-eMgbSi2cO8d:Eue or by further including an optimal amount of at least one additional component such as Ba or Ca. The resulting phosphor exhibits a higher brightness and a higher color purity upon excitation by ultraviolet light emitted as a result of discharge of xenon gas. The optimized phosphor is incorporated into light emitting devices such as lamps and PDPs, and further into display devices.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: May 22, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Hitoshi Oaku, Choichiro Okazaki, Masatoshi Shiiki
  • Publication number: 20070035686
    Abstract: An active matrix liquid crystal display device is provided, in which an after image remaining after removing an application of a direct current voltage is suppressed. The active matrix liquid crystal display device has a liquid crystal layer containing a liquid crystal molecule having negative dielectric anisotropy and a dopant having a dissociative group.
    Type: Application
    Filed: October 24, 2006
    Publication date: February 15, 2007
    Inventors: Yasushi Iwakabe, Masuyuki Ohta, Shigeru Matsuyama, Hitoshi Oaku, Katsumi Kondo
  • Patent number: 7027023
    Abstract: To provide a high-quality liquid crystal display device that does not produce image sticking and that can realize high response speed, a third electrode is provided that is different from a common electrode or a pixel electrode, and a voltage applied to the third electrode is varied within one frame period to drive a liquid crystal using a strong electric field and a uniform horizontal electric field in an initial stage within one frame period, while driving the liquid crystal only with the uniform horizontal electric field in a latter stage within one frame period.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: April 11, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Okishiro, Hitoshi Oaku, Ikuo Hiyama, Katsumi Kondou
  • Publication number: 20050264161
    Abstract: A blue-emitting phosphor is optimized by controlling mole fractions typically of Mg and Si in Sr3-eMgbSi2cO8d:Eue or by further including an optimal amount of at least one additional component such as Ba or Ca. The resulting phosphor exhibits a higher brightness and a higher color purity upon excitation by ultraviolet light emitted as a result of discharge of xenon gas. The optimized phosphor is incorporated into light emitting devices such as lamps and PDPs, and further into display devices.
    Type: Application
    Filed: May 24, 2005
    Publication date: December 1, 2005
    Inventors: Hitoshi Oaku, Choichiro Okazaki, Masatoshi Shiiki
  • Patent number: 6943861
    Abstract: A liquid crystal display device having a pair of substrates, at least one of the substrates being transparent, a liquid crystal layer interposed between the pair of substrates, and pixel electrodes and common electrodes and active elements being arranged on at least one substrate between the pair of substrates. The liquid crystal of the liquid crystal layer is controlled to perform display by applying a voltage between the pixel electrode and the common electrode. An alignment layer is disposed on a surface in contact with the liquid crystal layer of each of the pair of substrates, and the alignment layer is made of an organic polymer selected from the group consisting of polyamic acid group polymers and polyimide ester group polymers having a relative imidization ratio above 60%.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: September 13, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Tomioka, Kenji Okishiro, Yoshiyuki Umeda, Hitoshi Oaku, Katsumi Kondo
  • Publication number: 20040165132
    Abstract: A liquid crystal display device having a pair of substrates, at least one of the substrates being transparent, a liquid crystal layer interposed between the pair of substrates, and pixel electrodes and common electrodes and active elements being arranged on at least one substrate between the pair of substrates. The liquid crystal of the liquid crystal layer is controlled to perform display by applying a voltage between the pixel electrode and the common electrode. An alignment layer is disposed on a surface in contact with the liquid crystal layer of each of the pair of substrates, and the alignment layer is made of an organic polymer selected from the group consisting of polyamic acid group polymers and polyimide ester group polymers having a relative imidization ratio above 60%.
    Type: Application
    Filed: March 2, 2004
    Publication date: August 26, 2004
    Inventors: Yasushi Tomioka, Kenji Okishiro, Yoshiyuki Umeda, Hitoshi Oaku, Katsumi Kondo
  • Publication number: 20040080676
    Abstract: A display device substrate which meets requirements for weight reduction, thickness reduction, high reliability, good heat resistance, and good impact resistance all at once. The display device substrate is composed of a pair of glass sheets facing each other and a layer of plastics material interposed between said paired glass sheets in such a way that said glass sheets have an internal compressive strain ascribed to the plastic sheet. Thus, the very thin glass sheets are hardly liable to breakage. This makes light weight and reduced thickness compatible with reliability.
    Type: Application
    Filed: October 21, 2003
    Publication date: April 29, 2004
    Inventors: Hitoshi Oaku, Yasuo Hanawa, Shigeo Amagi, Tomoji Oishi, Katsumi Kondou
  • Patent number: 6704082
    Abstract: A liquid crystal display device has a pair of substrates, at least one of the substrates being transparent; a liquid crystal layer interposed between the pair of substrates; and pixel electrodes and common electrodes and active elements arranged on at least one substrate between the pair of substrates, wherein a pair of alignment layers are made of an organic polymer of polyamic acid group of polyamide ester group having a relative imidization ration above 60%; or at least one layer of an insulation film is interposed between the alignment layer in a side of the substrate having the group of electrodes formed thereon, and the pixel electrode and the common electrode disposed under the alignment layer to prevent occurrence of the sticking image and the after image by flattening the electrode portions to moderate the electric field concentration.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: March 9, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Tomioka, Kenji Okishiro, Yoshiyuki Umeda, Hitoshi Oaku, Katsumi Kondo