Patents by Inventor Kouki Yamamoto

Kouki Yamamoto 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: 8674647
    Abstract: Provided is a drive device for an alternating current motor which performs vector control on sensorless driving of the alternating current motor in an extremely low speed region without applying a harmonic voltage intentionally while maintaining an ideal PWM waveform. A current and a current change rate of the alternating current motor are detected, and a magnetic flux position inside of the alternating current motor is estimated and calculated in consideration of an output voltage of an inverter which causes this current change. The current change rate is generated on the basis of a pulse waveform of the inverter, and hence the magnetic flux position inside of the alternating current motor can be estimated and calculated without applying a harmonic wave intentionally.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: March 18, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Iwaji, Daigo Kaneko, Kouki Yamamoto
  • Patent number: 8040186
    Abstract: A bias circuit 12 includes: a transistor Q5 operable to supply, to an amplifier 11, a bias current in accordance with a base current supplied thereto; a transistor Q3 operable to pass a current in accordance with a reference voltage Vref; a transistor Q2 operable to correct, in accordance with the current passed by the transistor Q3, the base current to be supplied to the transistor Q5, so as to compensate a temperature characteristic represented by the transistor Q5; and a bias changing section (of a transistor Q4, and resistances R5, R6, and R7), connected to a base of the transistor Q5, operable to change, in accordance with a control voltage VSW, an amount of the base current to be supplied to the transistor Q5. The amplifier 11 amplifies, by using the bias current supplied by the bias circuit 12, a radio frequency signal having been inputted thereto.
    Type: Grant
    Filed: November 25, 2009
    Date of Patent: October 18, 2011
    Assignee: Panasonic Corporation
    Inventors: Masao Nakayama, Hiroshi Sugiyama, Kazuhiko Oohashi, Kouki Yamamoto, Kaname Motoyoshi
  • Publication number: 20110204831
    Abstract: Provided is a drive device for an alternating current motor which performs vector control on sensorless driving of the alternating current motor in an extremely low speed region without applying a harmonic voltage intentionally while maintaining an ideal PWM waveform. A current and a current change rate of the alternating current motor are detected, and a magnetic flux position inside of the alternating current motor is estimated and calculated in consideration of an output voltage of an inverter which causes this current change. The current change rate is generated on the basis of a pulse waveform of the inverter, and hence the magnetic flux position inside of the alternating current motor can be estimated and calculated without applying a harmonic wave intentionally.
    Type: Application
    Filed: February 18, 2011
    Publication date: August 25, 2011
    Inventors: Yoshitaka Iwaji, Daigo Kaneko, Kouki Yamamoto
  • Publication number: 20110175681
    Abstract: To provide a radio frequency power amplifier that realizes a favorable high-frequency characteristic without using an isolator and also achieves low power consumption. The radio frequency power amplifier includes: a power amplifier which amplifies a radio frequency signal; a voltage supplying unit which supplies a collector voltage to the power amplifier; a current supplying unit which supplies a bias current to the power amplifier; and a bias current detecting unit which detects the bias current. The voltage supplying unit has a control unit which sets the power supply voltage at: a first voltage when the detected bias current is lower than a bias-current reference value; and a second voltage lower than the first voltage when the detected bias current is higher than the bias-current reference value.
    Type: Application
    Filed: December 17, 2010
    Publication date: July 21, 2011
    Applicant: PANASONIC CORPORATION
    Inventors: Masahiko INAMORI, Kaname MOTOYOSHI, Masao NAKAYAMA, Kouki YAMAMOTO, Tsunehiro TAKAGI, Hiroshi SUGIYAMA, Junji KAIDO
  • Publication number: 20100134189
    Abstract: A bias circuit 12 includes: a transistor Q5 operable to supply, to an amplifier 11, a bias current in accordance with a base current supplied thereto; a transistor Q3 operable to pass a current in accordance with a reference voltage Vref; a transistor Q2 operable to correct, in accordance with the current passed by the transistor Q3, the base current to be supplied to the transistor Q5, so as to compensate a temperature characteristic represented by the transistor Q5; and a bias changing section (of a transistor Q4, and resistances R5, R6, and R7), connected to a base of the transistor Q5, operable to change, in accordance with a control voltage VSW, an amount of the base current to be supplied to the transistor Q5. The amplifier 11 amplifies, by using the bias current supplied by the bias circuit 12, a radio frequency signal having been inputted thereto.
    Type: Application
    Filed: November 25, 2009
    Publication date: June 3, 2010
    Applicant: PANASONIC CORPORATION
    Inventors: Masao NAKAYAMA, Hiroshi SUGIYAMA, Kazuhiko OOHASHI, Kouki YAMAMOTO, Kaname MOTOYOSHI
  • Patent number: 7671558
    Abstract: The present invention provides an induction motor controller which includes: a circuit for generating a d-axis current reference signal from a d-axis current command value and a periodically varying periodic signal; a d-axis current controller for controlling a d-axis motor current flowing through an induction motor to be controlled to match the d-axis current reference signal; parameter determining means for calculating and determining a motor parameter of the induction motor based on a deviation of the d-axis motor current from the d-axis current reference signal, and controlling a voltage applied to the induction motor using a compensation voltage calculated from the calculated and determined motor parameter, in which a control parameter for controlling the induction motor is set based on the calculated and determined motor parameter.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: March 2, 2010
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kouki Yamamoto, Toshiaki Okuyama, Hiroyuki Tomita, Yoshitaka Iwaji, Koichiro Nagata
  • Patent number: 7639080
    Abstract: A bias circuit 12 includes: a transistor Q5 operable to supply, to an amplifier 11, a bias current in accordance with a base current supplied thereto; a transistor Q3 operable to pass a current in accordance with a reference voltage Vref; a transistor Q2 operable to correct, in accordance with the current passed by the transistor Q3, the base current to be supplied to the transistor Q5, so as to compensate a temperature characteristic represented by the transistor Q5; and a bias changing section (of a transistor Q4, and resistances R5, R6, and R7), connected to a base of the transistor Q5, operable to change, in accordance with a control voltage VSW, an amount of the base current to be supplied to the transistor Q5. The amplifier 11 amplifies, by using the bias current supplied by the bias circuit 12, a radio frequency signal having been inputted thereto.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: December 29, 2009
    Assignee: Panasonic Corporation
    Inventors: Masao Nakayama, Hiroshi Sugiyama, Kazuhiko Oohashi, Kouki Yamamoto, Kaname Motoyoshi
  • Patent number: 7545116
    Abstract: An object of the present invention is to provide a driver for an induction motor which performs an operation at an acceleration suitable for the magnitude of a load and is excellent in efficiency, without an acceleration failure. The driver for an induction motor includes a slip frequency estimate value arithmetic operation section 15 for arithmetically operating a slip frequency ?s^ of an induction motor 12, and a maximum torque generation slip arithmetic operation section 16 for arithmetically operating a slip frequency ?smax at which a maximum torque is generated. When the slip frequency ?s^ exceeds a predetermined value ?smaxTH (=0.9 ?smax, etc.) corresponding to the slip frequency ?smax at which the maximum torque is generated, a speed change rate arithmetic operation section 17 and a speed change rate correcting section 18 reduce a rate of increase in a speed command ?r*.
    Type: Grant
    Filed: January 25, 2007
    Date of Patent: June 9, 2009
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Koichiro Nagata, Toshiaki Okuyama, Kouki Yamamoto, Hiroyuki Tomita
  • Patent number: 7425873
    Abstract: An intermodulation distortion which is output from a final-stage amplifier 15 is fed back to an inter-stage matching circuit 14 via a first control circuit 16 and a second control circuit 17. The first control circuit 16 and the second control circuit 17 control an amplitude and a phase of an intermodulation distortion to be fed back from the final-stage amplifier 15 to the inter-stage matching circuit 14, such that a synthesized scalar of an intermodulation distortion input from a first-stage amplifier 13 to the final-stage amplifier 15 and amplified by the final-stage amplifier 15 and an intermodulation distortion newly generated by the final-stage amplifier 15 is reduced.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: September 16, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Kouki Yamamoto
  • Publication number: 20080169783
    Abstract: The present invention provides an induction motor controller which includes: a circuit for generating a d-axis current reference signal from a d-axis current command value and a periodically varying periodic signal; a d-axis current controller for controlling a d-axis motor current flowing through an induction motor to be controlled to match the d-axis current reference signal; parameter determining means for calculating and determining a motor parameter of the induction motor based on a deviation of the d-axis motor current from the d-axis current reference signal, and controlling a voltage applied to the induction motor using a compensation voltage calculated from the calculated and determined motor parameter, in which a control parameter for controlling the induction motor is set based on the calculated and determined motor parameter.
    Type: Application
    Filed: August 23, 2007
    Publication date: July 17, 2008
    Inventors: KOUKI YAMAMOTO, Toshiaki Okuyama, Hiroyuki Tomita, Yoshitaka Iwaji, Koichiro Nagata
  • Publication number: 20070296503
    Abstract: A bias circuit 12 includes: a transistor Q5 operable to supply, to an amplifier 11, a bias current in accordance with a base current supplied thereto; a transistor Q3 operable to pass a current in accordance with a reference voltage Vref; a transistor Q2 operable to correct, in accordance with the current passed by the transistor Q3, the base current to be supplied to the transistor Q5, so as to compensate a temperature characteristic represented by the transistor Q5; and a bias changing section (of a transistor Q4, and resistances R5, R6, and R7), connected to a base of the transistor Q5, operable to change, in accordance with a control voltage VSW, an amount of the base current to be supplied to the transistor Q5. The amplifier 11 amplifies, by using the bias current supplied by the bias circuit 12, a radio frequency signal having been inputted thereto.
    Type: Application
    Filed: June 7, 2007
    Publication date: December 27, 2007
    Inventors: Masao Nakayama, Hiroshi Sugiyama, Kazuhiko Oohashi, Kouki Yamamoto, Kaname Motoyoshi
  • Patent number: 7312403
    Abstract: A circuit component mounting device includes a resin substrate, vias, a circuit component composed of a main body and electrode portions, a solder, and an insulative sealing resin that covers the circuit component and the solder. The device further includes a base metal pattern which covers parts of the principal face of the resin substrate where the vias are exposed and is composed of a Cu layer and a Ni layer and a copper plated pattern which is provided on the base metal pattern and is composed of a Cu layer, a Ni layer, and an Au layer. The circuit component is provided on the copper plated pattern. The solder allows the copper plated pattern and the circuit component to adhere to each other.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: December 25, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Kouki Yamamoto
  • Publication number: 20070210741
    Abstract: An object of the present invention is to provide a driver for an induction motor which performs an operation at an acceleration suitable for the magnitude of a load and is excellent in efficiency, without an acceleration failure. The driver for an induction motor includes a slip frequency estimate value arithmetic operation section 15 for arithmetically operating a slip frequency ?s? of an induction motor 12, and a maximum torque generation slip arithmetic operation section 16 for arithmetically operating a slip frequency ?smax at which a maximum torque is generated. When the slip frequency ?s? exceeds a predetermined value ?smaxTH(=0.96?smax, etc.) corresponding to the slip frequency ?smax at which the maximum torque is generated, a speed change rate arithmetic operation section 17 and a speed change rate correcting section 18 reduce a rate of increase in a speed command ?r*.
    Type: Application
    Filed: January 25, 2007
    Publication date: September 13, 2007
    Inventors: Koichiro Nagata, Toshiaki Okuyama, Kouki Yamamoto, Hiroyuki Tomita
  • Patent number: 7190982
    Abstract: In the present radio frequency device, a radio frequency circuit part and a transmission line are disposed on the top surface of a circuit board on the surface of which a ground pattern is provided, and a metal shielding cap is fixed to the circuit board so as to cover the radio frequency circuit part and the transmission path. The metal shielding cap includes: a top plate disposed above the radio frequency circuit part and substantially parallel to the circuit board; a grounded side wall being provided so as to hang down from a part of an edge of the top plate, having a spring property and being joined to the ground pattern of the circuit board, and a side wall is open except for the grounded side wall.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: March 13, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kouki Yamamoto, Noriyuki Yoshikawa, Kazuhiko Ohashi
  • Publication number: 20070024375
    Abstract: An intermodulation distortion which is output from a final-stage amplifier 15 is fed back to an inter-stage matching circuit 14 via a first control circuit 16 and a second control circuit 17. The first control circuit 16 and the second control circuit 17 control an amplitude and a phase of an intermodulation distortion to be fed back from the final-stage amplifier 15 to the inter-stage matching circuit 14, such that a synthesized scalar of an intermodulation distortion input from a first-stage amplifier 13 to the final-stage amplifier 15 and amplified by the final-stage amplifier 15 and an intermodulation distortion newly generated by the final-stage amplifier 15 is reduced.
    Type: Application
    Filed: July 25, 2006
    Publication date: February 1, 2007
    Inventor: Kouki Yamamoto
  • Patent number: 7104363
    Abstract: An elevator having a power feeding apparatus effective for reducing the installation space for the elevator is disclosed. The dimension of the power transmission part disposed at the hoist way and the dimension of the power receiving part mounted on the counter weight, each measured in the direction along which the counter weight moves are made different from each other.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: September 12, 2006
    Inventors: Kazuhisa Mori, Kouki Yamamoto, Hideki Ayano, Ikuo Yamato, Hiromi Inaba, Hirokazu Nagura, Hideki Nihei
  • Publication number: 20060065438
    Abstract: A circuit component mounting device includes a resin substrate, vias, a circuit component composed of a main body and electrode portions, a solder, and an insulative sealing resin that covers the circuit component and the solder. The device further includes a base metal pattern which covers parts of the principal face of the resin substrate where the vias are exposed and is composed of a Cu layer and a Ni layer and a copper plated pattern which is provided on the base metal pattern and is composed of a Cu layer, a Ni layer, and an Au layer. The circuit component is provided on the copper plated pattern. The solder allows the copper plated pattern and the circuit component to adhere to each other.
    Type: Application
    Filed: September 22, 2005
    Publication date: March 30, 2006
    Inventor: Kouki Yamamoto
  • Patent number: 6917133
    Abstract: An air conditioner comprising a compressor including a compression unit and a permanent magnet rotating electric machine, wherein the permanent magnet rotating electric machine includes a stator, into which concentratively wound armature windings are inserted in such a way as to surround a plurality of teeth formed in a stator core, and a rotor having permanent magnets accommodated into a plurality of permanent magnet inserting holes formed in a rotor core. Each pair of adjacent ones of said permanent magnets is arranged generally in one of a convex V-shaped configuration and a convex U-shaped configuration with respect to a rotor axis, and a substantially V-shaped recess portion is formed between adjacent poles in outer circumferential surface portions of the rotor core.
    Type: Grant
    Filed: February 20, 2003
    Date of Patent: July 12, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Koharagi, Masaharu Senoh, Keiji Noma, Kohei Ishii, Kazuo Sato, Satoshi Kikuchi, Miyoshi Takahashi, Kouki Yamamoto
  • Publication number: 20040156178
    Abstract: In the present radio frequency device, a radio frequency circuit part and a transmission line are disposed on the top surface of a circuit board on the surface of which a ground pattern is provided, and a metal shielding cap is fixed to the circuit board so as to cover the radio frequency circuit part and the transmission path. The metal shielding cap includes: a top plate disposed above the radio frequency circuit part and substantially parallel to the circuit board; a grounded side wall being provided so as to hang down from a part of an edge of the top plate, having a spring property and being joined to the ground pattern of the circuit board, and a side wall is open except for the grounded side wall.
    Type: Application
    Filed: January 27, 2004
    Publication date: August 12, 2004
    Inventors: Kouki Yamamoto, Noriyuki Yoshikawa, Kazuhiko Ohashi
  • Patent number: 6735144
    Abstract: A semiconductor intergrated circuit device is comprised a main portion composed of a plurality of memory cells arranged in a plurality of rows and in a plurality of columns, a sub memory portion composed of a plurality of memory cells arranged in a plurality of rows and in a plurality of columns, a bi-directional data transfer circuit for connecting the main memory portion and the sub memory portion through data transfer bus lines, respectively, the sub memory portion being constituted with a plurality of memory cell groups, and a plurality of registers provided such that different data input/output modes are set independently for the plurality of the memory cell groups. Therefore, the semiconductor integrated circuit device of the present invention has a main memory suitable for being accessed from a plurality of data processors.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: May 11, 2004
    Assignee: NEC Corporation
    Inventors: Taketo Maesako, Kouki Yamamoto, Yoshinori Matsui, Kenichi Sakakibara