Patents by Inventor Kichiya Itagaki

Kichiya Itagaki 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).

  • Magnetic disk storage apparatus
    Publication number: 20050036228
    Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.
    Type: Application
    Filed: September 24, 2004
    Publication date: February 17, 2005
    Inventors: Reiichi Kimura, Yasuhiko Kokami, Kunihiro Kawauchi, Minoru Kurosawa, Kichiya Itagaki
  • Magnetic disk storage apparatus
    Patent number: 6801382
    Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.
    Type: Grant
    Filed: April 17, 2002
    Date of Patent: October 5, 2004
    Assignees: Renesas Technology Corp., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Reiichi Kimura, Yasuhiko Kokami, Kunihiro Kawauchi, Minoru Kurosawa, Kichiya Itagaki
  • Magnetic disk storage apparatus
    Publication number: 20020181137
    Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.
    Type: Application
    Filed: April 17, 2002
    Publication date: December 5, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Reiichi Kimura, Yasuhiko Kokami, Kunihiro Kawauchi, Minoru Kurosawa, Kichiya Itagaki