Patents by Inventor Kentaro Oi

Kentaro Oi 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).

  • FORWARD RAMAN AMPLIFIER, BIDIRECTIONAL RAMAN AMPLIFICATION SYSTEM, AND FORWARD RAMAN AMPLIFICATION SYSTEM
    Publication number: 20240129034
    Abstract: A forward Raman amplifier includes a plurality of pumping light sources with different wavelengths and the forward Raman amplifier, according to a fiber type or a zero-dispersion wavelength of the fiber, changes the number of pumping light sources to be emitted, changes a power ratio between the plurality of pumping light sources with the different wavelengths or changes wavelength characteristics of a gain, according to a fiber type.
    Type: Application
    Filed: July 12, 2023
    Publication date: April 18, 2024
    Applicant: Fujitsu Limited
    Inventors: Hiroshi NAKAMOTO, GOJI NAKAGAWA, Kentaro KAWANISHI, Hiroki OI, Tomohiro YAMAUCHI, Takafumi TERAHARA, Teppei OHATA
  • Speed controller of magnetic motor
    Patent number: 8344671
    Abstract: The invention relates to a speed control method of a magnetic motor and is capable of providing a speed controller of the magnetic motor realizing highly stable, highly efficient and highly responsive control characteristics even around critical torque of the motor. When an excessive torque command value (or a q-axis commanded current value) greater than a torque maximum value (or a q-axis current) that can be outputted by the motor is required, an input of speed control is limited so that the q-axis commanded current value does not increase up to a limit value.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: January 1, 2013
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kazuaki Tobari, Yasuo Notohara, Wataru Hatsuse, Dongsheng Li, Kentaro Oi, Yuuji Funayama
  • Torque controller for permanent magnet synchronous motor
    Patent number: 8305019
    Abstract: When output voltage V1 of an electric power converter reaches a prescribed voltage V1*ref, a difference between V1 and V1*ref is integrated to correct a commanded torque to ?o* (?*=?o*+??).
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: November 6, 2012
    Assignee: Hitachi Car Engineering Co., Ltd.
    Inventors: Kazuaki Tobari, Shigehisa Aoyagi, Kentaro Oi
  • Field weakening control apparatus for permanent magnet motor and electric power steering using same
    Patent number: 7791295
    Abstract: A motor control apparatus which controls an output voltage reference for an inverter driving a permanent magnet synchronous motor based on d-axis and q-axis current references, d-axis and q-axis current detected values, and a computed frequency value. When a torque reference specifying torque greater than maximum torque that the motor can output is input, a limit value for a phase angle that is a deviation between a rotation phase reference of control and a rotation phase value of the motor is varied depending on a quantity of the predetermined state.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: September 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kentaro Oi, Kazuaki Tobari, Yoshitaka Iwaji, Mitsuo Sasaki, Tatsuo Matsumura
  • SPEED CONTROLLER OF MAGNETIC MOTOR
    Publication number: 20100148707
    Abstract: The invention relates to a speed control method of a magnetic motor and is capable of providing a speed controller of the magnetic motor realizing highly stable, highly efficient and highly responsive control characteristics even around critical torque of the motor. When an excessive torque command value (or a q-axis commanded current value) greater than a torque maximum value (or a q-axis current) that can be outputted by the motor is required, an input of speed control is limited so that the q-axis commanded current value does not increase up to a limit value.
    Type: Application
    Filed: December 11, 2009
    Publication date: June 17, 2010
    Inventors: Kazuaki TOBARI, Yasuo Notohara, Wataru Hatsuse, Dongsheng Li, Kentaro Oi, Yuuji Funayama