Patents by Inventor Atsuo Koyama

Atsuo Koyama 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: 5034655
    Abstract: A fluorescent lamp has at least a pair of electrodes, at least two circular discharge tubes connected to said electrodes and enclosing rare gas and mercury therein, and a phosphor coating provided on an inside wall of each of said discharge tubes, the two circular discharge tubes being arranged coaxially circularly on one and the same plane, the diameter of each of the discharge tubes being selected to have a value within a range of from 5 mm to 25 mm both inclusive, the luminance on surface of each of the discharge tubes being selected to have a value within a range of from 2.times.10.sup.4 Cd/m.sup.2 to 6.times.10.sup.4 Cd/m.sup.2.
    Type: Grant
    Filed: August 24, 1989
    Date of Patent: July 23, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Seiichi Murayama, Hiromitsu Matsuno, Tetsuo Ono, Yasusuke Seki, Atsuo Koyama, Churyo Kodama, Tsuyoshi Kobayashi
  • Patent number: 4694224
    Abstract: A lighting apparatus for an electric discharge lamp includes a lighting ballast capacitor connected in series to an electric dicharge lamp for stabilizing a lighting current to the lamp; a preheating ballast capacitor connected in parallel to the lamp for supplying a preheating electric power to the lamp; electric power supply including an output transformer for supplying an electric power to the lighting ballast capacitor; a control electric power supply circuit for obtaining a control electric power through the lighting ballast capacitor and discharge lamp or the preheating ballast capacitor without adding a stepdown transformer or a resistive element for voltage drop; and an oscillator which receives the control electric power from the control power supply circuit and controls the electric power supply. With this lighting apparatus, the electric power loss is made small and the miniaturization of the apparatus can be realized.
    Type: Grant
    Filed: October 19, 1984
    Date of Patent: September 15, 1987
    Assignee: Hitachi Lighting, Ltd.
    Inventors: Hisato Nakagawa, Hideo Kuwahara, Atsuo Koyama, Mitsuo Akatsuka