Patents by Inventor Tuneyoshi Oohashi

Tuneyoshi Oohashi 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: 5117434
    Abstract: A metal vapor laser has a discharge tube with electrodes at opposite ends. A power source is electronically connected to the electrodes and generates a discharge in a discharge region within the discharge tube. The discharge generates laser light which emerges from the tube via windows. In order to cool the apparatus, the discharge tube is surrounded by a cooling jacket in the form of a hollow cooling vessel. A liquid flows in the cooling vessel and removes heat. The space between the cooling vessel and the discharge tube is evacuated. The cooling vessel is conductive and, since it is connected between one of the electrodes and the power supply, its inner and outer walls provide two potential paths for return current. The fact that the inner and outer walls have different diameters means that the inductance of the return paths is large. Therefore, the outer wall has a gap in it filled with insulating material.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: May 26, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Tuneyoshi Oohashi, Motoo Yamaguchi, Akira Wada, Toshiharu Shirakura, Toshimichi Kichikawa, Hiroyuki Sugawara
  • Patent number: 5054029
    Abstract: In a pulse power supply circuit, first and second charging capacitors are connected in series with a discharge device. First and second gas-filled control switching elements, connected in parallel with each other, are respectively connected in series with the first and second charging capacitors. First and second pulse power sources are respectively connected in parallel with the first and second control switching elements and also respectively connected in series with the first and second charging capacitors so as to charge the capacitors alternately. A control circuit controls the first and second control switching elements so that the switching elements alternately and repeatedly at substantially equal time intervals.
    Type: Grant
    Filed: January 12, 1990
    Date of Patent: October 1, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Sugawara, Tuneyoshi Oohashi
  • Patent number: 4991180
    Abstract: A metallic vapor laser apparatus includes a cylindrical discharge tube (31) having an internal space (2), a heat-insulating material (6) encompassing the periphery of the discharge tube (31), and two electrodes (3a) and (3b) having a cylindrical portion coaxial with the discharge tube (31) and disposed at both ends of the discharge tube (31). The internal space (2) are filled with a gas containing the vapor of copper as a laser medium for effecting laser oscillation by the excitation of the filler gas and the discharge.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: February 5, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Motoo Yamaguchi, Hiroyuki Sugawara, Akira Wada, Toshiharu Shirakura, Tuneyoshi Oohashi, Toshimichi Kichikawa
  • Patent number: 4818892
    Abstract: A laser device equipped with a high-voltage pulse generator wherein the pulse generator supplies an electric energy from a dc power source in an on-off form of a supply voltage to a tank circuit through a transformer, with the switching on and off of the supply voltage being effected in synchronism with the resonance period of the tank circuit. The tank circuit stores the supplied electric energy as a resonance condition so that when the electric energy stored in the tank circuit reaches a predetermined value, a saturable reactor connected between the laser device and the tank circuit becomes saturated and the electric energy in the tank circuit is discharged to the laser device.
    Type: Grant
    Filed: September 25, 1987
    Date of Patent: April 4, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tuneyoshi Oohashi, Satoshi Takemori, Toshimichi Kichikawa, Kouji Kuwabara, Hiroyuki Sugawara