Patents by Inventor Hisao Yokokura

Hisao Yokokura 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: 7790248
    Abstract: An active matrix type liquid crystal display apparatus has a pair of substrates, at least one of the substrates being transparent; a liquid crystal layer arranged between the pair of substrates; and electrode structure for generating an electric field having a dominant component parallel to a surface of the substrate and passing through the liquid crystal layer, the electrode structure being formed on one of the pair of substrates; a pair of alignment layers formed on respective surfaces in contact with the liquid crystal layer of the pair of substrates; and a pair of polarizing plates arranged so as to sandwich the pair of substrates, wherein the glass transition temperature Tg of a boundary surface between said liquid crystal layer and the alignment layer is higher than the nematic-isotropic phase transition temperature T(N?I) of a liquid crystal composite forming the liquid crystal layer.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: September 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Tomioka, Takao Miwa, Katsumi Kondo, Hisao Yokokura
  • Patent number: 7615260
    Abstract: An active-matrix liquid crystal display device includes a pair of substrates, a liquid crystal layer disposed between the pair of substrates, a group of electrodes for applying to the liquid crystal layer an electric field substantially parallel to the substrate plane and a plural number of active elements being formed on one of the pair of substrates, and an alignment layer disposed between the liquid crystal layer and at least one of the pair of substrates. The alignment layer is made from polyamic acid obtained by reacting a diamine with an acid anhydride, and the acid anhydride is at least one member selected from the group consisting of 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: November 10, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoneya, Kishiro Iwasaki, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Yoshiharu Nagae
  • Publication number: 20070178250
    Abstract: An active matrix type liquid crystal display apparatus has a pair of substrates, at least one of the substrates being transparent; a liquid crystal layer arranged between the pair of substrates; and electrode structure for generating an electric field having a dominant component parallel to a surface of the substrate and passing through the liquid crystal layer, the electrode structure being formed on one of the pair of substrates; a pair of alignment layers formed on respective surfaces in contact with the liquid crystal layer of the pair of substrates; and a pair of polarizing plates arranged so as to sandwich the pair of substrates, wherein the glass transition temperature Tg of a boundary surface between said liquid crystal layer and the alignment layer is higher than the nematic-isotropic phase transition temperature T(N-I) of a liquid crystal composite forming the liquid crystal layer.
    Type: Application
    Filed: February 21, 2007
    Publication date: August 2, 2007
    Inventors: Yasushi Tomioka, Takao Miwa, Katsumi Kondo, Hisao Yokokura
  • Patent number: 7189439
    Abstract: An active matrix type liquid crystal display apparatus has a pair of substrates, at least one of the substrates being transparent; a liquid crystal layer arranged between the pair of substrates; and electrode structure for generating an electric field having a dominant component parallel to a surface of the substrate and passing through the liquid crystal layer, the electrode structure being formed on one of the pair of substrates; a pair of alignment layers formed on respective surfaces in contact with the liquid crystal layer of the pair of substrates; and a pair of polarizing plates arranged so as to sandwich the pair of substrates, wherein the glass transition temperature Tg of a boundary surface between said liquid crystal layer and the alignment layer is higher than the nematic-isotropic phase transition temperature T(N-I) of a liquid crystal composite forming the liquid crystal layer.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: March 13, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Tomioka, Takao Miwa, Katsumi Kondo, Hisao Yokokura
  • Publication number: 20050012884
    Abstract: An in-plane switching active-matrix liquid crystal display device includes an alignment layer which is a photo-reactive material layer disposed between a liquid crystal layer and at least one of a pair of substrates of the display device. The display device includes at least one of (a) a tilt angle of 3° or less, (b) an extrapolation length of at least 10% of a gap between the pair of substrates, (c) a torsional anchoring coefficient A2 of an alignment layer surface for liquid crystal molecules at an inner face of the liquid crystal layer and the alignment layer which is not greater than 20 ?N/m, and (d) the alignment layer is obtained by using as an acid moiety an acid hydride except for benzophenone tetracarboxylic dianhydride.
    Type: Application
    Filed: June 24, 2004
    Publication date: January 20, 2005
    Inventors: Makoto Yoneya, Kishiro Iwasaki, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Yoshiharu Nagae
  • Patent number: 6833898
    Abstract: A liquid crystal display apparatus having a pair of substrates and a liquid crystal layer interposed between the pair of substrates. One of the pair of substrates has an electrode structure including a plurality of pixel electrodes and a plurality of common electrodes, an inorganic film is formed on a surface of at least one of the plurality of pixel electrodes and the plurality of common electrodes, an organic polymer film is formed on the inorganic film and the liquid crystal layer is in direct contact with the organic polymer film.
    Type: Grant
    Filed: November 5, 2002
    Date of Patent: December 21, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Setsuo Kobayashi
  • Publication number: 20040170777
    Abstract: An active matrix type liquid crystal display apparatus has a pair of substrates, at least one of the substrates being transparent; a liquid crystal layer arranged between the pair of substrates; and electrode structure for generating an electric field having a dominant component parallel to a surface of the substrate and passing through the liquid crystal layer, the electrode structure being formed on one of the pair of substrates; a pair of alignment layers formed on respective surfaces in contact with the liquid crystal layer of the pair of substrates; and a pair of polarizing plates arranged so as to sandwich the pair of substrates, wherein the glass transition temperature Tg of a boundary surface between said liquid crystal layer and the alignment layer is higher than the nematic-isotropic phase transition temperature T(N-I) of a liquid crystal composite forming the liquid crystal layer.
    Type: Application
    Filed: December 11, 2003
    Publication date: September 2, 2004
    Inventors: Yasushi Tomioke, Takao Miwa, Katsumi Kondo, Hisao Yokokura
  • Patent number: 6756089
    Abstract: An active-matrix liquid crystal display device having a pair of substrates at least one of which is transparent, a liquid crystal layer disposed between the pair of substrates, a group of electrodes for applying to the liquid crystal layer an electric field substantially parallel to the substrate plane and a plural number of active elements being formed on one of the pair of substrates and an alignment layer disposed between the liquid crystal layer and at least one of the pair of substrates. The alignment layer is a photo-reactive material layer, and the photo-reactive material layer is a photo-reactive alignment layer which has been subjected to linearly polarized light irradiation to selectively derive a photochemical reaction and a tilt angle of liquid crystal molecules on the alignment layer surface of the substrate is 3° or less.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: June 29, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoneya, Kishiro Iwasaki, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Yoshiharu Nagae
  • Patent number: 6682783
    Abstract: An active matrix type liquid crystal display apparatus has a pair of substrates, at least one of the substrates being transparent; a liquid crystal layer arranged between the pair of substrates; an electrode structure for generating an electric field having a dominant component parallel to a surface of the substrate and passing through the liquid crystal layer, the electrode structure being formed on one of the pair of substrates; a pair of alignment layers formed on respective surfaces in contact with the liquid crystal layer of the pair of substrates; and a pair of polarizing plates arranged so as to sandwich the pair of substrates, wherein the glass transition temperature Tg of a boundary surface between said liquid crystal layer and the alignment layer is higher than the nematic-isotropic phase transition temperature T(N-I) of a liquid crystal composite forming the liquid crystal layer.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: January 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Yasushi Tomioka, Takao Miwa, Katsumi Kondo, Hisao Yokokura
  • Publication number: 20030058397
    Abstract: A liquid crystal display apparatus having a pair of substrates and a liquid crystal layer interposed between the pair of substrates. One of the pair of substrates has an electrode structure including a plurality of pixel electrodes and a plurality of common electrodes, an inorganic film is formed on a surface of at least one of the plurality of pixel electrodes and the plurality of common electrodes, an organic polymer film is formed on the inorganic film and the liquid crystal layer is in direct contact with the organic polymer film.
    Type: Application
    Filed: November 5, 2002
    Publication date: March 27, 2003
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Setsuo Kobayashi
  • Patent number: 6483564
    Abstract: A liquid crystal display apparatus having a pair of substrates and a liquid crystal layer interposed between the pair of substrates. One of the pair of substrates has an electrode structure including a plurality of pixel electrodes and a plurality of common electrodes, an organic polymer film is formed on at least one of the pixel electrodes and the common electrodes, and the liquid crystal layer is in direct contact with the organic polymer film.
    Type: Grant
    Filed: October 24, 2001
    Date of Patent: November 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Setsuo Kobayashi
  • Publication number: 20020027632
    Abstract: A liquid crystal display apparatus having a pair of substrates and a liquid crystal layer interposed between the pair of substrates. One of the pair of substrates has an electrode structure including a plurality of pixel electrodes and a plurality of common electrodes, an organic polymer film is formed on at least one of the pixel electrodes and the common electrodes, and the liquid crystal layer is in direct contact with the organic polymer film.
    Type: Application
    Filed: October 24, 2001
    Publication date: March 7, 2002
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Setsuo Kobayashi
  • Publication number: 20010046569
    Abstract: An active-matrix liquid crystal display device having a pair of substrates at least one of which is transparent, a liquid crystal layer disposed between the pair of substrates, a group of electrodes for applying to the liquid crystal layer an electric field substantially parallel to the substrate plane and a plural number of active elements being formed on one of the pair of substrates and an alignment layer disposed between the liquid crystal layer and at least one of the pair of substrates. The alignment layer is a photo-reactive material layer, and the photo-reactive material layer is a photo-reactive alignment layer which has been subjected to linearly polarized light irradiation to selectively derive a photochemical reaction and a tilt angle of liquid crystal molecules on the alignment layer surface of the substrate is 3° or less.
    Type: Application
    Filed: March 15, 2001
    Publication date: November 29, 2001
    Inventors: Makoto Yoneya, Kishiro Iwasaki, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Yoshiharu Nagae
  • Patent number: 6310676
    Abstract: A liquid crystal display apparatus having a pair of substrates and a liquid crystal layer interposed between the pair of substrates. One of the pair of substrates has an electrode structure including a plurality of pixel electrodes and a plurality of common electrodes, an organic polymer film is formed on at least one of the pixel electrodes and the common electrodes, and the liquid crystal layer is in direct contact with the organic polymer film.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: October 30, 2001
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Setsuo Kobayashi
  • Patent number: 6242060
    Abstract: An active-matrix liquid crystal display device having a pair of substrates at least one of which is transparent, a liquid crystal layer disposed between the pair of substrates, a group of electrodes for applying to the liquid crystal layer an electric field substantially parallel to the substrate plane and a plural number of active elements being formed on one of the pair of substrates, and an alignment layer disposed between the liquid crystal layer and at least one of the pair of substrates. The alignment layer is a photo-reactive material layer, and the photo-reactive material layer is a photo-reactive alignment layer which has been subjected to linearly polarized light irradiation to selectively derive a photochemical reaction.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: June 5, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoneya, Kishiro Iwasaki, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Yoshiharu Nagae
  • Patent number: 6236441
    Abstract: A liquid crystal display apparatus and a method of manufacturing wherein the liquid crystal display apparatus includes a pair of substrates, a liquid crystal layer interposed between the pair of substrates, plural electrodes formed on at least one of the pair of substrates, a passivation layer formed on the plural electrodes and having concave portions, a thin film having low wettability formed on the passivation layer, and an insulating layer formed on the thin film having low wettability. The method includes the steps of irradiating light onto the thin film through a mask, and applying a solution containing organic high polymers so as to form the insulating layer at the concave portions of the passivation layer.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: May 22, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Hiroyuki Kagawa, Hisao Yokokura, Katsumi Kondo, Shigeru Matsuyama, Masahito Oh-e
  • Patent number: 6222602
    Abstract: A liquid crystal display having a wide viewing angle, a large contrast ratio, and little nonuniformity of display, is formed by a pair of substrates, and a liquid crystal layer interposed between the pair of substrates, wherein at least one of the pair of substrates has plural electrodes, a passivation layer formed on the plural electrodes, and an insulating layer formed at concave portions of the passivation layer for making the thickness of the liquid crystal layer uniform.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: April 24, 2001
    Assignee: Hitachi, Ltd
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Hiroyuki Kagawa, Hisao Yokokura, Katsumi Kondo, Shigeru Matsuyama, Masahito Oh-e
  • Patent number: 6130737
    Abstract: A liquid crystal display apparatus has a pair of substrates and a liquid crystal layer interposed between the pair of substrates, one of the pair of substrates having an electrode structure composed of a plurality of electrodes for generating an electric field having a dominant component parallel to the substrate in the liquid crystal layer, a protective film formed on the electrode structure, and an alignment film formed on the protective film, and the thickness of the protective film is greater than the thickness of the electrode in contact with the protective film by more than 0.4 .mu.m.
    Type: Grant
    Filed: January 8, 1998
    Date of Patent: October 10, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Sukekazu Aratani, Yoshiyuki Umeda, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Setsuo Kobayashi
  • Patent number: 6047098
    Abstract: A plastic optical waveguide with a low loss property, a low birefringence and a high temperature endurance constructed with a polyimide obtained from an acid dianhydride based component and a diamine based component, wherein at least one of a core layer and a cladding layer of the optical waveguide is made of an acid dianhydride based component including an alicyclic acid dianhydride or an aliphatic acid dianhydride, the plastic optical waveguide having an optical loss in a 1.3 .mu.m band of 0.5 dB/cm or less, and a refractive index of the core layer being larger than that of the cladding layer.
    Type: Grant
    Filed: February 3, 1998
    Date of Patent: April 4, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Masakazu Sagawa, Takao Miwa, Hisao Yokokura
  • Patent number: 5928733
    Abstract: An active-matrix liquid crystal display device employing the in-plane switching mode in which an electric field substantially parallel to the substrate surface is applied to the liquid crystals, characterized by weak torsional anchoring of the liquid crystal molecules and the alignment layer surface at the liquid crystal/alignment layer interface to an extent that the extrapolation length which expresses the strength of said torsional anchoring will become not less than 10% of the gap between the substrates. For obtaining such weak torsional anchoring, an organic alignment layer comprising a polymer and/or oligomer having long-chain alkylene and/or fluoro groups, or an inorganic alignment layer formed by oblique evaporation technique, or a photo-reactive alignment layer formed by linearly polarized light irradiation is used.
    Type: Grant
    Filed: May 8, 1997
    Date of Patent: July 27, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoneya, Kishiro Iwasaki, Yasushi Tomioka, Hisao Yokokura, Katsumi Kondo, Yoshiharu Nagae