Patents by Inventor Kouichiro Maekawa

Kouichiro Maekawa 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).

  • Ceramic discharge vessel for a high-pressure discharge lamp, having a filling bore sealed with a plug, and method of its manufacture
    Patent number: 5637960
    Abstract: To provide a tight seal for a fill bore in the wall or an end plug of a dharge vessel for high-pressure discharge lamps, a fill bore is provided either through the wall--in the region of the plug--or through a plug, and the fill bore is then closed by a stopper in combination with a melt sealing material, which is so chosen that the sealing material and plug-like member combination provide a minimum of sealing material exposed to the fill in the discharge volume. The fill in the discharge volume of the discharge vessel is ionizable and, for example containing halides, is highly corrosive to the sealing material. The lamp can be made by inserting a stopper into the filling bore, applying, with the stopper in place in the filling bore, sealing material to the outer end of the filling bore, and heating the portion of the discharge vessel to liquefying temperature of the sealing material to liquefy the sealing material and hence close off the fill bore.
    Type: Grant
    Filed: July 11, 1995
    Date of Patent: June 10, 1997
    Assignees: Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH, NGK Insulators Ltd.
    Inventors: Stefan Juengst, Roland Huettinger, Jens Clark, Osamu Asano, Kouichiro Maekawa
  • High-pressure discharge lamp and method of manufacture
    Patent number: 5404078
    Abstract: A high pressure discharge lamp has a ceramic discharge vessel (8), whose s are closed with plugs (11). The metallic feedthrough, or a main part of it, has a thermal coefficient of expansion which is smaller than the coefficient of the ceramic. The current feedthrough is gas-tightly sintered directly into the plug.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: April 4, 1995
    Assignees: Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH, NGK Insulators Ltd.
    Inventors: Axel Bunk, Stefan Jungst, Kouichiro Maekawa, Joachim Werner
  • Method of making ceramic arc tube for high-pressure metal-vapor discharge lamp
    Patent number: 4765820
    Abstract: A process of producing a ceramic arc tube for a high-pressure metal-vapor discharge lamp, including a translucent ceramic tube, and at least one end cap which closes corresponding at least one end of the ceramic tube and which supports a discharge electrode. A green ceramic tubular body which gives the ceramic tube is formed of a first ceramic material, whereas at least one green end cap which gives the at least one end cap is formed of a second ceramic material of a same kind as the first ceramic material. Each green end cap has a cylindrical portion, and a flange portion which extends radially outwardly from one of opposite axial ends of an outer circumferential surface of the cylindrical portion. The cylindrical portion of each green end cap is inserted and positioned in a corresponding end portion of the green ceramic tubular body, such that the flange portion abuts on an end face of the corresponding end portion of the green ceramic tubular body.
    Type: Grant
    Filed: January 20, 1987
    Date of Patent: August 23, 1988
    Assignee: NGK Insulators Ltd.
    Inventors: Hitoshi Naganawa, Kouichiro Maekawa