Patents by Inventor Jiro Oouchi

Jiro Oouchi 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).

  • Fixing device using an inverter circuit for induction heating
    Patent number: 6531689
    Abstract: A fixing device for an image forming apparatus includes an inverter circuit for induction heating. In the inverter circuit, a main switch Q1 drives one end of a work coil L1 whose other end is connected to a power source. A serial connection of a capacitor Cs and a subswitch Q2 is connected to opposite ends of the coil L1 in parallel such that one end of the capacitor Cs is connected to the power source E. A second capacitor C1 is connected to the subswitch Q2 in parallel. For a capacitance of 0.1 &mgr;F of the capacitor C1, the factor of the coil L1 and that of the capacitor Cs are selected to be between 70 &mgr;H and 100 &mgr;H and between 1.8 &mgr;F and 5 &mgr;F, respectively. The inverter circuit is operable with optimal efficiency in the event of PWM (Pulse Width Modulation) control using a fixed frequency.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: March 11, 2003
    Assignees: Ricoh Company, Ltd., Tohoku Ricoh Co., Ltd.
    Inventors: Hiroto Ohishi, Jiro Oouchi
  • Fixing device using an inverter circuit for induction heating
    Publication number: 20020003139
    Abstract: A fixing device for an image forming apparatus includes an inverter circuit for induction heating. In the inverter circuit, a main switch Q1 drives one end of a work coil L1 whose other end is connected to a power source. A serial connection of a capacitor Cs and a subswitch Q2 is connected to opposite ends of the coil L1 in parallel such that one end of the capacitor Cs is connected to the power source E. A second capacitor C1 is connected to the subswitch Q2 in parallel. For a capacitance of 0.1 &mgr;F of the capacitor C1, the factor of the coil L1 and that of the capacitor Cs are selected to be between 70 &mgr;H and 100 &mgr;H and between 1.8 &mgr;F and 5 &mgr;F, respectively. The inverter circuit is operable with optimal efficiency in the event of PWM (Pulse Width Modulation) control using a fixed frequency.
    Type: Application
    Filed: May 11, 2001
    Publication date: January 10, 2002
    Applicant: Ricoh Company, Ltd
    Inventors: Hiroto Ohishi, Jiro Oouchi