Patents by Inventor Taku Takeishi

Taku Takeishi 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: 20010015619
    Abstract: The invention provides an EL device having a structure in which a first electrode 12 formed according to a predetermined pattern, a first insulator layer 13, an electroluminescence-producing light emitting layer 14, a second insulator layer 15 and a second electrode layer 16 are successively stacked on an electrical insulating substrate 11. At least one of the first insulator layer 13 and the second insulator layer 15 contains as a main component barium titanate and as subordinate components magnesium oxide, manganese oxide, yttrium oxide, at least one oxide selected from barium oxide and calcium oxide and silicon oxide. The ratios of magnesium oxide, manganese oxide, yttrium oxide, barium oxide, calcium oxide and silicon oxide with respect to 100 moles of barium titanate are: 1 MgO: 0.1 to 3 moles, MnO: 0.05 to 1.
    Type: Application
    Filed: December 8, 2000
    Publication date: August 23, 2001
    Applicant: TDK CORPORATION
    Inventors: Katsuto Nagano, Takeshi Nomura, Taku Takeishi, Suguru Takayama
  • Publication number: 20010003614
    Abstract: A composite substrate in which the surface of the insulating layer is not influenced by the electrode layer and which requires neither a grinding process nor a sol-gel process, is easy to produce and can provide a thin-film EL device having a high display quality when used therein; a thin-film EL device using the substrate; and a production process for the device. The thin-film EL device is produced by forming a luminescent layer, other insulating layer and other electrode layer successively on a composite substrate comprising a substrate; an electrode layer embedded in the substrate in such a manner that the electrode layer and the substrate are in one plane; and an insulating layer formed on the surface of a composite comprising the substrate and the electrode layer.
    Type: Application
    Filed: December 7, 2000
    Publication date: June 14, 2001
    Applicant: TDK CORPORATION
    Inventors: Katsuto Nagano, Taku Takeishi, Suguru Takayama, Takeshi Nomura, Yukie Nakano, Daisuke Iwanaga
  • Patent number: 6132635
    Abstract: ferrite magnet raw material particles and a non-aqueous solvent is compacted wet in a magnetic field, while said non-aqueous solvent is removed therefrom, to obtain a compact, and the compact is sintered to obtain an anisotropic ferrite magnet. In this case, a surface active agent is allowed to exist in the slurry during the wet compaction. Alternatively, in addition to or in place of this, the raw material particles are pulverized to apply strains thereto, thereby reducing the iHc values to preferably 3.5 kOe or less. This makes some considerable improvement in the degree of orientation of the compact, thus achieving much more improved magnet properties.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: October 17, 2000
    Assignee: TDK Corporation
    Inventors: Hitoshi Taguchi, Fumihiko Hirata, Taku Takeishi, Teruo Mori
  • Patent number: 5945028
    Abstract: A slurry containing ferrite magnet raw material particles and a non-aqueous solvent is compacted wet in a magnetic field, while said non-aqueous solvent is removed therefrom, to obtain a compact, and the compact is sintered to obtain an anisotropic ferrite magnet. In this case, a surface active agent is allowed to exist in the slurry during the wet compaction. Alternatively, in addition to or in place of this, the raw material particles are pulverized to apply strains thereto, thereby reducing the iHc values to preferably 3.5 kOe or less. This makes some considerable improvement in the degree of orientation of the compact, thus achieving much more improved magnet properties.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: August 31, 1999
    Assignee: TDK Corporation
    Inventors: Hitoshi Taguchi, Fumihiko Hirata, Taku Takeishi, Teruo Mori
  • Patent number: 5846449
    Abstract: A magnet powder has a primary phase of hexagonal magnetoplumbite ferrite of the formula: A.sub.1-x R.sub.x (Fe.sub.12-y M.sub.y).sub.z O.sub.19 wherein A is Sr, Ba, Ca or Pb; R is Y, rare earth element or Bi (R essentially containing La); M is Zn or Cd; x, y, and z representative of a molar ratio are 0.04.ltoreq.x.ltoreq.0.45, 0.04.ltoreq.y.ltoreq.0.45, and 0.7.ltoreq.z.ltoreq.1.2. This ferrite is increased in saturation magnetization, offering a magnet having high remanence and maximum energy product. The magnet powder may be fired into a sintered magnet or bound into a bonded magnet. A magnetic recording medium comprising the magnet powder as a coating layer is provided as well as a magnetic recording medium comprising a thin film magnetic layer of the hexagonal magnetoplumbite ferrite.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: December 8, 1998
    Assignee: TDK Corporation
    Inventors: Hitoshi Taguchi, Kenichiro Suwa, Taku Takeishi
  • Patent number: 5811024
    Abstract: An anisotropic hexagonal barium ferrite sintered magnet is prepared by molding a powder barium ferrite raw material in a magnetic field into a compact and sintering the compact; or by molding a powder barium ferrite raw material in a magnetic field into a compact, disintegrating the compact into particles, compacting the particles in a magnetic field into a second compact, and sintering the second compact. In either case, the raw material contains calcined hexagonal barium ferrite, a silicon component, and a barium component. The resulting anisotropic hexagonal barium ferrite sintered magnet has improved sintered density and coercivity while the method minimizes deformation during sintering which is otherwise caused by the difference between the shrinkage factors in axis c and a directions, and simplifies or omits post-treatment like polishing.
    Type: Grant
    Filed: June 25, 1996
    Date of Patent: September 22, 1998
    Assignee: TDK Corporation
    Inventors: Hitoshi Taguchi, Fumihiko Hirata, Taku Takeishi, Teruo Mori
  • Patent number: 5648039
    Abstract: A slurry containing ferrite magnet raw material particles and a non-aqueous solvent is compacted wet in a magnetic field, while said non-aqueous solvent is removed therefrom, to obtain a compact, and the compact is sintered to obtain an anisotropic ferrite magnet. In this case, a surface active agent is allowed to exist in the slurry during the wet compaction. Alternatively, in addition to or in place of this, the raw material particles are pulverized to apply strains thereto, thereby reducing the iHc values to preferably 3.5 kOe or less. This makes some considerable improvement in the degree of orientation of the compact, thus achieving much more improved magnet properties.
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: July 15, 1997
    Assignee: TDK Corporation
    Inventors: Hitoshi Taguchi, Fumihiko Hirata, Taku Takeishi, Teruo Mori
  • Patent number: 5607615
    Abstract: In a method for preparing a magnet by pulverizing a calcined powder of hexagonal barium ferrite, compacting the thus pulverized ferrite magnet source particles in a magnetic field, and sintering the compact, a structure comprising barium ferrite as a primary phase and containing strontium and silicon as grain boundary components is obtained when a silicon component such as SiO.sub.2 and a strontium component such as SrCO.sub.3 are contained in the compact. This results in a hexagonal barium ferrite sintered magnet which has minimal anisotropy of shrinkage factor and minimal deformation during sintering, requires only simple or no post-polishing, and has improved sintered density and coercivity.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: March 4, 1997
    Assignee: TDK Corporation
    Inventors: Hitoshi Taguchi, Fumihiko Hirata, Taku Takeishi, Teruo Mori