Patents by Inventor Kuniichi Ohta

Kuniichi Ohta 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: 5933791
    Abstract: In a concentric cylinder macromolecule represented by a combination of B(2,1)n (n=1, 2, . . . ), each layer thereof has a conductivity of metal and hence there is obtained a concentric cylinder having a high conductivity. In graphite, the layers are bonded with each other by a weak van der Waals force and a two-dimensional band structure can be assumed. In a multi-layer cylinder, since the number of hexagons in the radial direction varies between the layers, the layers are much more independent of each other. There are accordingly implemented a semiconductor having a narrow band gap and a semiconductor having a relatively wide band gap; consequently, the macromolecule can be broadly adopted for various functional devices.
    Type: Grant
    Filed: June 25, 1996
    Date of Patent: August 3, 1999
    Assignee: NEC Corporation
    Inventors: Noriaki Hamada, Kuniichi Ohta
  • Patent number: 5489477
    Abstract: A high-molecular weight carbon material in which cylindrical high-molecular weight carbon materials in the form of a cylindrical tube are bonded through a soccer ball-like spherical high-molecular weight carbon material as a point of junction, the respective cylindrical high-molecular weight carbon materials being formed by rolling a plane network composed of a benzene shell-like hexagonal molecule formed of covalent-bonded carbon atoms, and the soccer ball-like spherical high-molecular weight carbon material being formed of material including five- and six-membered carbon rings. The high-molecular weight carbon material is useful as a material for various functional devices.
    Type: Grant
    Filed: March 16, 1994
    Date of Patent: February 6, 1996
    Assignee: NEC Corporation
    Inventors: Kuniichi Ohta, Noriaki Hamada
  • Patent number: 4737827
    Abstract: A heterojunction-gate field-effect transistor comprises an active layer of semiconductor material having source and drain regions, an intermediate layer of another semiconductor material formed on the active layer between the source and drain regions, the intermediate layer inducing a two-dimensional charge layer in a surface portion of the active layer between the source and drain regions, and a gate electrode of a mixed semiconductor crystal formed on the intermediate layer to control the conductivity of the two-dimensional charge layer by an electrical potential applied thereto. The mixed semiconductor crystal may be GaP-InAs or mixed crystal of GaP-InAs mixed crystal and AlP-GaAs, AlsB-GaP, or GaSb-GaP mixed crystal.
    Type: Grant
    Filed: January 31, 1986
    Date of Patent: April 12, 1988
    Assignee: NEC Corporation
    Inventor: Kuniichi Ohta
  • Patent number: 4670767
    Abstract: The bipolar transistor comprises an emitter of a first semiconductor, a base of a second semiconductor and a collector of a third semiconductor, the first semiconductor having edges of conduction and valence bands positioned outside the energy band gap of the second semiconductor, and the third semiconductor having an edge of conduction band for majority carriers positioned inside the energy band gap of the second semiconductor and an edge of valence band for majority carriers positioned outside the energy band gap of the second semiconductor.
    Type: Grant
    Filed: January 30, 1985
    Date of Patent: June 2, 1987
    Assignee: NEC Corporation
    Inventor: Kuniichi Ohta