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).
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Patent number: 9318972Abstract: 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: GrantFiled: February 23, 2015Date of Patent: April 19, 2016Assignee: FUJITSU LIMITEDInventors: Yu Yonezawa, Yoshiyasu Nakashima
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Publication number: 20150381065Abstract: 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: ApplicationFiled: September 3, 2015Publication date: December 31, 2015Inventors: Yu Yonezawa, Yoshiyasu Nakashima
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Publication number: 20150346788Abstract: 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: ApplicationFiled: May 12, 2015Publication date: December 3, 2015Inventors: Tomotake Sasaki, Yu Yonezawa, Junji Kaneko, YOSHIYASU NAKASHIMA
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Publication number: 20150302972Abstract: 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: ApplicationFiled: March 18, 2015Publication date: October 22, 2015Inventors: Yu YONEZAWA, Hiroshi NAKAO, Yoshiyasu NAKASHIMA
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Patent number: 9166480Abstract: 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: GrantFiled: August 7, 2013Date of Patent: October 20, 2015Assignee: FUJITSU LIMITEDInventors: Yu Yonezawa, Yoshiyasu Nakashima
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Patent number: 9152472Abstract: 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: GrantFiled: March 7, 2011Date of Patent: October 6, 2015Assignee: FUJITSU LIMITEDInventors: Satoshi Kazama, Yoshiyasu Nakashima
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Publication number: 20150256101Abstract: 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: ApplicationFiled: February 23, 2015Publication date: September 10, 2015Inventors: Yu YONEZAWA, Yoshiyasu NAKASHIMA
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Publication number: 20150236590Abstract: 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: ApplicationFiled: December 31, 2014Publication date: August 20, 2015Inventors: Yu YONEZAWA, Yoshiyasu Nakashima
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Publication number: 20150200050Abstract: 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: ApplicationFiled: November 13, 2014Publication date: July 16, 2015Inventors: Hiroshi NAKAO, Yu YONEZAWA, Takahiko SUGAWARA, Yoshiyasu NAKASHIMA, Yoshikatsu ISHIZUKI, Shinya SASAKI, Shinya IIJIMA
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Patent number: 9075606Abstract: 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: GrantFiled: February 28, 2013Date of Patent: July 7, 2015Assignee: FUJITSU LIMITEDInventors: Satoshi Kazama, Yoshiyasu Nakashima
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Publication number: 20150188534Abstract: 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: ApplicationFiled: December 1, 2014Publication date: July 2, 2015Inventors: Yu Yonezawa, YOSHIYASU NAKASHIMA
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Publication number: 20150155792Abstract: 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: ApplicationFiled: February 10, 2015Publication date: June 4, 2015Inventors: Yu YONEZAWA, Yoshiyasu NAKASHIMA
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Publication number: 20150138851Abstract: 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: ApplicationFiled: November 4, 2014Publication date: May 21, 2015Inventors: Yu Yonezawa, Tomotake Sasaki, Yoshinobu Matsui, YOSHIYASU NAKASHIMA
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Publication number: 20150084607Abstract: 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: ApplicationFiled: July 30, 2014Publication date: March 26, 2015Inventors: Kazunori Hayami, Yoshiyasu Nakashima, Yu Yonezawa
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Patent number: 8954761Abstract: 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: GrantFiled: October 28, 2009Date of Patent: February 10, 2015Assignee: Fujitsu LimitedInventors: Yoshiyasu Nakashima, Satoshi Kazama
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Patent number: 8901906Abstract: 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: GrantFiled: October 2, 2012Date of Patent: December 2, 2014Assignee: Fujitsu LimitedInventors: Yu Yonezawa, Yoshiyasu Nakashima
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Patent number: 8850234Abstract: 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: GrantFiled: June 21, 2010Date of Patent: September 30, 2014Assignee: Fujitsu LimitedInventors: Satoshi Kazama, Yoshiyasu Nakashima, Isamu Yamada, Masatomo Yasaki
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Publication number: 20140232365Abstract: 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: ApplicationFiled: December 3, 2013Publication date: August 21, 2014Applicant: Fujitsu LimitedInventors: Tomotake SASAKI, Tsugito MARUYAMA, Yu YONEZAWA, Yoshiyasu NAKASHIMA
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Patent number: 8786134Abstract: 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: GrantFiled: March 30, 2010Date of Patent: July 22, 2014Assignee: Fujitsu LimitedInventors: Satoshi Kazama, Yoshiyasu Nakashima, Seiki Shibata, Yuki Tamura
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Patent number: 8773103Abstract: 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: GrantFiled: June 7, 2012Date of Patent: July 8, 2014Assignee: Fujitsu LimitedInventors: Yu Yonezawa, Yoshiyasu Nakashima