Patents by Inventor Hidefumi Nakashima

Hidefumi Nakashima 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).

  • Lighting control circuit, lamp, and lighting control method using the lighting control circuit
    Patent number: 9271350
    Abstract: A lighting control circuit includes a rectifier connected to an electric ballast to which a commercial AC power is supplied, and configured to convert an AC to a DC, a series light emitter a plurality of solid-state light-emitting elements is connected in series, a smoothing capacitor provided in parallel with the series light emitter in a current supply line between the rectifier and the series light emitter, and configured to eliminate an AC component included in the DC from an output side of the rectifier, and a switching control circuit configured to generate an output voltage equal to an output voltage from the electric ballast when a fluorescent lamp starts up upon the connection of the fluorescent lamp to the electric ballast as a startup voltage in the startup of the series light emitter.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: February 23, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Masaharu Urano, Hidefumi Nakashima, Shigemi Hagiwara
  • LIGHTING CONTROL CIRCUIT, LAMP, AND LIGHTING CONTROL METHOD USING THE LIGHTING CONTROL CIRCUIT
    Publication number: 20140062320
    Abstract: A lighting control circuit includes a rectifier connected to an electric ballast to which a commercial AC power is supplied, and configured to convert an AC to a DC, a series light emitter a plurality of solid-state light-emitting elements is connected in series, a smoothing capacitor provided in parallel with the series light emitter in a current supply line between the rectifier and the series light emitter, and configured to eliminate an AC component included in the DC from an output side of the rectifier, and a switching control circuit configured to generate an output voltage equal to an output voltage from the electric ballast when a fluorescent lamp starts up upon the connection of the fluorescent lamp to the electric ballast as a startup voltage in the startup of the series light emitter.
    Type: Application
    Filed: August 29, 2013
    Publication date: March 6, 2014
    Applicant: Ricoh Company, Ltd.
    Inventors: Masaharu Urano, Hidefumi Nakashima, Shigemi Hagiwara
  • Direct current arc furnace
    Patent number: 5479433
    Abstract: A DC arc furnace according to the invention has a bottom electrode, which comprises a plurality of contact pins each having an end to be brought into contact with an object and to supply arc-forming current thereto, a current base electrically connected to the other end of each of the contact pins for distributing current from a power supply to the contact pins, and a cooling device for cooling the current base with the use of cooling water.
    Type: Grant
    Filed: December 3, 1993
    Date of Patent: December 26, 1995
    Assignees: NKK Corporation, Tokyo Steel M.F.G. Co., Ltd.
    Inventors: Toshimichi Maki, Hiroyuki Yamashita, Yoshimi Kawazu, Hidefumi Nakashima