Patents by Inventor Yoshiyasu Nakashima

Yoshiyasu 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).

  • Patent number: 9318972
    Abstract: A power circuit includes: a rectifying circuit configured to rectify an AC voltage; a capacitor configured to integrate an output current of the rectifying circuit; a field effect transistor connected between the rectifying circuit and the capacitor; and a control circuit configured to supply a first gate voltage to a gate of the field effect transistor when a voltage of the capacitor is lower than a threshold value and supply a second gate voltage to the gate of the field effect transistor when the voltage of the capacitor is higher than the threshold value, wherein a resistance of the field effect transistor when the first gate voltage is supplied is higher than a resistance of the field effect transistor when the second gate voltage is supplied.
    Type: Grant
    Filed: February 23, 2015
    Date of Patent: April 19, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Yu Yonezawa, Yoshiyasu Nakashima
  • Publication number: 20150381065
    Abstract: A double-ended forward converter includes: a first switching element and a second switching element that are coupled to a primary side of a transformer; a pulse generation circuit that generates a pulse signal for controlling the first and second switching elements; an isolation transformer that converts the pulse signal into an alternating-current signal; a rectifier circuit that rectifies the alternating-current signal and generate gate voltages of the first and second switching elements; a driver circuit that includes a third switching element which drives gates of the first and second switching elements, a voltage generated on a secondary side of the isolation transformer being input to a gate of the third switching element; and a minus bias generation circuit that generates a source voltage of the third switching, based on a change in the voltage generated on the secondary side of the isolation transformer.
    Type: Application
    Filed: September 3, 2015
    Publication date: December 31, 2015
    Inventors: Yu Yonezawa, Yoshiyasu Nakashima
  • Publication number: 20150346788
    Abstract: A control device includes a processor that executes a process including generating a driving signal that drives a switching device, so that an output voltage of a converter circuit that performs a step-down conversion on input power by driving the switching device matches a target value, and modifying the target value so that as an output current of the converter circuit becomes lower the output voltage becomes closer to an upper limit value of the output voltage.
    Type: Application
    Filed: May 12, 2015
    Publication date: December 3, 2015
    Inventors: Tomotake Sasaki, Yu Yonezawa, Junji Kaneko, YOSHIYASU NAKASHIMA
  • Publication number: 20150302972
    Abstract: A planar type transformer includes: a multilayer substrate including a primary main winding pattern and a secondary main winding pattern that perform first power transmission, the primary main winding pattern and the secondary main winding pattern being stacked with an insulating layer interposed between the primary main winding pattern and the secondary main winding pattern; and an auxiliary winding that is disposed outside the multilayer substrate and performs second power transmission between the auxiliary winding and the primary main winding pattern or the secondary main winding pattern.
    Type: Application
    Filed: March 18, 2015
    Publication date: October 22, 2015
    Inventors: Yu YONEZAWA, Hiroshi NAKAO, Yoshiyasu NAKASHIMA
  • Patent number: 9166480
    Abstract: This is an insulation-type power factor correction circuit including a resonance unit configured to accumulate energy of a surge occurring when the first switching element is turned off and to transmit a resonance current generated by resonating the first capacitor and the primary winding of the second transformer from the primary winding of the second transformer to the secondary winding, a rectifier unit configured to rectify a resonance current output from the resonance unit, a smoothing unit configured to regenerate power output from the rectifier unit to an output of the insulation-type power factor correction circuit, and a control unit configured to control a first switching element for each cycle.
    Type: Grant
    Filed: August 7, 2013
    Date of Patent: October 20, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yu Yonezawa, Yoshiyasu Nakashima
  • Patent number: 9152472
    Abstract: A load distribution system for allocating a job to one of a plurality of arithmetic devices includes a temperature data acquirer, a candidate selector, and a job allocator. The temperature data acquirer acquires temperature data indicating temperature of each of the plurality of arithmetic devices. The candidate selector selects at least one of the plurality of arithmetic devices as a candidate for a device to which the job is to be allocated. The job allocator allocates the job to the selected candidate.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: October 6, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Satoshi Kazama, Yoshiyasu Nakashima
  • Publication number: 20150256101
    Abstract: A power circuit includes: a rectifying circuit configured to rectify an AC voltage; a capacitor configured to integrate an output current of the rectifying circuit; a field effect transistor connected between the rectifying circuit and the capacitor; and a control circuit configured to supply a first gate voltage to a gate of the field effect transistor when a voltage of the capacitor is lower than a threshold value and supply a second gate voltage to the gate of the field effect transistor when the voltage of the capacitor is higher than the threshold value, wherein a resistance of the field effect transistor when the first gate voltage is supplied is higher than a resistance of the field effect transistor when the second gate voltage is supplied.
    Type: Application
    Filed: February 23, 2015
    Publication date: September 10, 2015
    Inventors: Yu YONEZAWA, Yoshiyasu NAKASHIMA
  • Publication number: 20150236590
    Abstract: A synchronous rectification converter includes: a first switching element coupled between a inductor and an input terminal; a second switching element coupled between the inductor and the input terminal; a capacitive element coupled between the other end of the inductor and the other end of the input terminal; a control circuit detects voltages of the inductor and the capacitive element; a current inversion detection circuit detects inversion of a direction in which a current supplied from the second switching element to the inductor flows and outputs an inversion signal; a delay circuit delays the inversion signal and outputs a delay inversion signal; a synchronous rectification reset circuit that changes the control signal; a load detector detects reduction of an output current supplied from a connection node of the inductor and the capacitive element; and a delay control circuit generates a delay control signal.
    Type: Application
    Filed: December 31, 2014
    Publication date: August 20, 2015
    Inventors: Yu YONEZAWA, Yoshiyasu Nakashima
  • Publication number: 20150200050
    Abstract: An inductor apparatus includes: a substrate including an electrical insulation property and a non-magnetic material; and a plurality of inductors disposed in the substrate so as to extend from a first surface of the substrate to a second surface of the substrate, each of the plurality of inductors including: an inductor conductive part that has an electrical conductivity and extends in a thickness direction of the substrate; and a magnetic layer that covers a side of the inductor conductive part and include a relative permeability and a soft magnetic material.
    Type: Application
    Filed: November 13, 2014
    Publication date: July 16, 2015
    Inventors: Hiroshi NAKAO, Yu YONEZAWA, Takahiko SUGAWARA, Yoshiyasu NAKASHIMA, Yoshikatsu ISHIZUKI, Shinya SASAKI, Shinya IIJIMA
  • Patent number: 9075606
    Abstract: In a storage apparatus, a calculation unit calculates first power consumption by adding the power consumption of a first storage device not in use to the total power consumption of a plurality of storage devices in operation, and calculates second power consumption by adding the power consumption of a second storage device not in use to the total power consumption of the plurality of storage devices in operation, and subtracting therefrom the power consumption of one of the plurality of storage devices in operation, from which data is movable to the second storage device. A determination unit determines to activate the first storage device when the second power consumption is not lower than the first power consumption, and determines to activate, the second storage device when the second power consumption is lower than the first power consumption.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: July 7, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Satoshi Kazama, Yoshiyasu Nakashima
  • Publication number: 20150188534
    Abstract: A semiconductor device includes: a first field-effect transistor configured to have a source connected to a reference potential node; a second field-effect transistor configured to have a source connected to a drain of the first field-effect transistor, and a gate connected to the source of the first field-effect transistor; a gate signal node configured to input a gate signal therein; a first resistor configured to be connected between the gate signal node and a gate of the first field-effect transistor; and a first capacitor and a switch circuit configured to be connected between a drain of the second field-effect transistor and the gate of the first field-effect transistor, in which the switch circuit is connected in series with the first capacitor.
    Type: Application
    Filed: December 1, 2014
    Publication date: July 2, 2015
    Inventors: Yu Yonezawa, YOSHIYASU NAKASHIMA
  • Publication number: 20150155792
    Abstract: First FET switches control supply of electricity from an external power supply to a primary winding of a transformer. A condenser is connected, in series, to a secondary winding of the transformer. A second FET switch is connected, in parallel, to the secondary winding and the condenser. The diode is connected, in parallel, to the second FET switch. A switch control unit acquires a value obtained by measuring a current flowing through the first FET switches and the second FET switch and controls, on the basis of the measurement result of the current, conduction of the first FET switches and the second FET switch.
    Type: Application
    Filed: February 10, 2015
    Publication date: June 4, 2015
    Inventors: Yu YONEZAWA, Yoshiyasu NAKASHIMA
  • Publication number: 20150138851
    Abstract: A PFC circuit generates substantially sinusoidal current that is in-phase with AC input voltage to compensate for a power factor. A DC-DC converter converts the voltage of a signal outputted from the PFC circuit to determined voltage. A current change detection section detects an amount of change in current outputted from the DC-DC converter, compares the detected amount of change in current with a threshold set in advance, and if the detected amount of change in current is larger than the threshold, outputs a gain switching signal for raising the gain of voltage outputted from the PFC circuit. The current change detection section outputs a voltage control signal for raising the voltage outputted from the PFC circuit to a determined value. A voltage setting section sets the voltage outputted from the PFC circuit to the determined value on the basis of the voltage control signal.
    Type: Application
    Filed: November 4, 2014
    Publication date: May 21, 2015
    Inventors: Yu Yonezawa, Tomotake Sasaki, Yoshinobu Matsui, YOSHIYASU NAKASHIMA
  • Publication number: 20150084607
    Abstract: A power supply apparatus includes a power supply section and a control section. The power supply section includes a first switch which performs switching of power-supply output, an inductor and a capacitor which form an LC circuit that resonates current flowing through the first switch, and a second switch which changes capacitance of the capacitor. The control section finds in advance a correspondence between a time ratio of a switching pulse of the first switch and a resonance frequency which matches an edge of a switching pulse having each time ratio, and controls switching of the second switch so as to resonate the LC circuit at a resonance frequency corresponding to a time ratio at operation time.
    Type: Application
    Filed: July 30, 2014
    Publication date: March 26, 2015
    Inventors: Kazunori Hayami, Yoshiyasu Nakashima, Yu Yonezawa
  • Patent number: 8954761
    Abstract: An information processing device is provided. The information processing device which operates upon receipt of power supply from a power unit connected to an alternative current power source or from a battery includes an obtaining unit which obtains load information of parts included in the information processing device itself, a deciding unit which decides a voltage value to be supplied by the power unit which supplies electric power to the information processing device, based on the load information obtained by the obtaining unit, and an output unit which outputs a signal relative to the voltage value decided by the deciding unit to the power unit.
    Type: Grant
    Filed: October 28, 2009
    Date of Patent: February 10, 2015
    Assignee: Fujitsu Limited
    Inventors: Yoshiyasu Nakashima, Satoshi Kazama
  • Patent number: 8901906
    Abstract: A control circuit includes: a first switching device that includes a source, a gate, and a drain; a negative voltage generating circuit that generates, from a pulse width modulation signal that controls the gate of the first switching device, a negative potential voltage which is equal to or smaller than a threshold of the first switching device; a gate control circuit that outputs a signal obtained by shifting a level of the pulse width modulation signal by an amount equal to the negative potential voltage to the gate of the first switching device; a second switching device that is disposed on a side of the drain of the first switching device; and a negative voltage detecting circuit that outputs a signal for turning ON the second switching device upon detecting that the negative potential voltage generated by the negative voltage generating circuit has reached a predetermined negative potential.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: December 2, 2014
    Assignee: Fujitsu Limited
    Inventors: Yu Yonezawa, Yoshiyasu Nakashima
  • Patent number: 8850234
    Abstract: An information processing apparatus and method include measuring power consumptions of devices and outputting power consumption data, receiving operational conditions of the devices for measuring the power consumptions of the devices, setting the operational conditions of the devices according to application-setting conditions, and executing an application program to measure reference power consumptions for executing the application program. The information processing apparatus includes a power consumption data-transmitting section transmitting power consumption data, a normalized power consumption-calculating section receiving normalized reference power consumption calculated from reference power consumptions of information processing apparatuses, and calculating normalized power consumption from the normalized reference power consumption and the reference power consumptions.
    Type: Grant
    Filed: June 21, 2010
    Date of Patent: September 30, 2014
    Assignee: Fujitsu Limited
    Inventors: Satoshi Kazama, Yoshiyasu Nakashima, Isamu Yamada, Masatomo Yasaki
  • Publication number: 20140232365
    Abstract: A control device includes: a power supply circuit that controls output voltage using a switching element; a generation unit that generates a reference signal on the basis of the output voltage from the power supply circuit; a PWM unit that generates a PWM signal that is output to the switching element by comparing the reference signal with a carrier signal; and a switching unit that switches a frequency of the carrier signal by changing amplitude of the carrier signal, wherein the generation unit generates the reference signal on the basis of the frequency.
    Type: Application
    Filed: December 3, 2013
    Publication date: August 21, 2014
    Applicant: Fujitsu Limited
    Inventors: Tomotake SASAKI, Tsugito MARUYAMA, Yu YONEZAWA, Yoshiyasu NAKASHIMA
  • Patent number: 8786134
    Abstract: A wireless power transmitting system that transmits power from a power transmitting station to a power receiving station wirelessly includes the power receiving station. The power receiving station includes a unit receiving power from the power transmitting station, a unit obtaining a level of power received through the antenna, a unit obtaining a level of power consumed by the device operating while being supplied with received power and a unit transmitting the received power level and the power consuming level to the power transmitting station wirelessly. The power transmitting station includes a unit receiving the received power level and the power consuming level from the power receiving station wirelessly, a unit controlling the level of power transmitted through the transmitting antenna based on the difference between the received power level and the received power consuming level, and a unit transmitting power to the power receiving station wirelessly.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: July 22, 2014
    Assignee: Fujitsu Limited
    Inventors: Satoshi Kazama, Yoshiyasu Nakashima, Seiki Shibata, Yuki Tamura
  • Patent number: 8773103
    Abstract: A power supply device includes a step-down unit to step down an input voltage, a switching unit to perform switching on a stepped-down voltage obtained through the stepping down by the step-down unit so as to externally output the voltage, an output variation detection unit to detect a corresponding variation of output from the switching unit, a delay unit to delay the input voltage by a prescribed time period, a delay variation detection unit to detect a corresponding variation of a delayed voltage output from the delay unit, an addition unit to add corresponding variations of the power supply voltage and the delayed voltage respectively detected by the output variation detection unit and the delay variation detection unit, and a control unit to perform feedback control on the basis of the corresponding variations of the power supply voltage and the delayed voltage added by the addition unit.
    Type: Grant
    Filed: June 7, 2012
    Date of Patent: July 8, 2014
    Assignee: Fujitsu Limited
    Inventors: Yu Yonezawa, Yoshiyasu Nakashima