Patents by Inventor Tomokazu Sakashita

Tomokazu Sakashita 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).

  • Publication number: 20240074017
    Abstract: At least one light source unit includes light sources which are series connected, switches which are each connected in parallel with each of the light sources, a light source drive circuit which supplies a current to a structure including the light sources and the switches, and switch control means which carries out on and off control of the switches. Based on light source control information, the light source unit carries out light dimming control of the light sources by performing on and off of the switches, according to a light turned on duty ratio. In addition, each of the light sources is sequentially light turned on from the one with a larger light on duty ratio, and in addition, each of the light sources is sequentially light turned off from the one with a smaller light on duty ratio source.
    Type: Application
    Filed: January 22, 2021
    Publication date: February 29, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroyuki YOSHINO, Tomokazu SAKASHITA
  • Publication number: 20240055898
    Abstract: A power receiving device and a wireless power transfer system including the same for non-contact power transfer to a plurality of mobile bodies are obtained, which allow stable power transfer even when the number of power transfer targets varies. In the wireless power transfer system, electric power is transmitted from a power transmitting source in a power transmitting device to generate a high frequency voltage and a power-transmitting resonant circuit with a power transmitting coil to generate an AC magnetic flux by resonance when receiving the high frequency voltage. A power-receiving resonant circuit receives the AC magnetic flux transmitted from the power-transmitting resonant circuit and converts the AC magnetic flux into AC power. At least one compensation element cancels out a variation of an inductance of the power transmitting coil attributable to the movement of the power-receiving resonant circuit to a position where electric power can be received.
    Type: Application
    Filed: February 5, 2021
    Publication date: February 15, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hidehito YOSHIDA, Tomokazu SAKASHITA
  • Publication number: 20230294957
    Abstract: A power transmission unit includes a plurality of power transmission coils provided along a hoistway and at least one power transmission device that supplies power to each of a plurality of power transmission coils. A power reception unit includes a plurality of power reception coils provided on a surface of a car opposite to the power transmission coil and at least one power reception device that receives the power from each of power reception coils. The plurality of power transmission coils include at least a first power transmission coil and a second power transmission coil. A length of the second power transmission coil in a traveling direction of the car is longer than a length of the first power transmission coil.
    Type: Application
    Filed: September 4, 2020
    Publication date: September 21, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Mariko NAKAGAWA, Tomokazu SAKASHITA, Takuya MIURA
  • Publication number: 20230188151
    Abstract: N (n is a natural number) power converters operate in accordance with a drive signal to generate a power to be supplied to a load. Multi-redundant A/D converters convert an analog detection value from the power converters into digital values. First and second controllers operate in parallel and each generate a drive signal of the power converters using the digital values from the A/D converters. A system selector selects one controller in accordance with an abnormality detection result of the first and second controllers. Each of n output selectors receives the drive signals from both of the first and second controllers and outputs the drive signal from the one controller selected by the system selector to the power converters.
    Type: Application
    Filed: June 30, 2020
    Publication date: June 15, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Atsushi MATSUDA, Satoshi OJIKA, Tomokazu SAKASHITA, Shinichiro OIKAWA
  • Publication number: 20220413450
    Abstract: A main circuit includes a switching element, and converts electric power input to the main circuit and supplies a result of the conversion to a load. The controller switches a control scheme of the main circuit from a first control scheme to a second control scheme at a first time point when the output value starts to vary and switches the control scheme of the main circuit from the second control scheme to the first control scheme at a second time point when a determination is made that switching of a variation direction of the output value will occur on the basis of a detection value of the detector.
    Type: Application
    Filed: January 7, 2020
    Publication date: December 29, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shota WATANABE, Tomokazu SAKASHITA
  • Publication number: 20220416563
    Abstract: An elevator includes: a car moving in a hoistway; a load provided to the car; a first power storage unit, composed of one battery capable of charging and discharging, connected to the load, and supplying power to the load; a second power storage unit, composed of one or more batteries capable of charging and discharging, and connected to the load; a power transmission circuit and capable of transmitting power between the first power storage unit and the second power storage unit; and a control unit controlling the power transmission circuit to supply power from the second power storage unit to the first power storage unit, when it is determined that a remaining stored power amount of the battery constituting the first power storage unit is less than an amount of power required for driving the load for a certain period of time.
    Type: Application
    Filed: March 30, 2020
    Publication date: December 29, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Mariko NAKAGAWA, Tomokazu SAKASHITA, Miyuki TAKESHITA, Hidehito YOSHIDA, Hirohisa KUWANO, Takuya MIURA
  • Patent number: 11527947
    Abstract: An output terminal of a contact type charger connected to an AC power supply 1 and being for boosting or stepping down an input voltage, and an output terminal of a non-contact type charger for receiving power in a non-contact manner are connected to an input terminal of a DC/DC converter via an integrated bus, a DC link capacitor is connected between an AC/DC converter and an isolated DC/DC converter included in the contact type charger, an integrated capacitor is connected to the integrated bus, and a control circuit adjusts a DC voltage of the DC link capacitor or the integrated capacitor such that at least one of power losses or a total power loss of the contact type charger, the non-contact type charger, and the DC/DC converter is reduced.
    Type: Grant
    Filed: May 14, 2019
    Date of Patent: December 13, 2022
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hiroyasu Iwabuki, Tomokazu Sakashita, Ryota Kondo, Takaaki Takahara, Hiroto Mizutani, Takuya Nakanishi, Yusuke Higaki
  • Publication number: 20220376553
    Abstract: A power receiving device of a wireless power transfer system receives power from a power transmitting circuit connected to a power source and having a power transmitting coil. The power receiving device includes a power receiving circuit, a power converter, an LC filter, and switches which are controlled by a control device on the basis of voltage detected by voltage detection means for detecting output voltage of the power receiving circuit, so that conduction between the power receiving circuit and the power converter is interrupted during a non-power-transfer period.
    Type: Application
    Filed: December 26, 2019
    Publication date: November 24, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hidehito YOSHIDA, Tomokazu SAKASHITA, Takuya NAKANISHI
  • Publication number: 20220329159
    Abstract: A DC/DC converter includes N converters connected in parallel and each having an inductor, a switching element, and a reverse-flow preventing element. Each converter is controlled at phases different from each other and such that a sum of switching frequencies F is out of a first non-selected frequency band. The inductor has an inductance that decreases as the switching frequency F increases. The switching element is controlled using the switching frequency F higher than a second non-selected frequency band of which upper and lower limit frequencies are 1/N of upper and lower limit frequencies of the first non-selected frequency band, and has a total gate charge such that a total loss is smaller than that in a case where the switching frequency F is set to be lower than the second non-selected frequency band.
    Type: Application
    Filed: November 21, 2019
    Publication date: October 13, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroyuki YOSHINO, Tomokazu SAKASHITA
  • Patent number: 11462946
    Abstract: A first converter performs power conversion and outputs AC power. The AC power outputted from the first converter is supplied to a first coil. The first coil is magnetically coupled with a second coil, and the AC power is transmitted from the first coil to the second coil. A second converter is connected to the second coil, and converts the AC power transmitted to the second coil to DC power and supplies the DC power to a load. A first control unit controls the first converter so as to alternately switch between a first state of outputting rectangular wave voltage which cyclically changes and a second state of outputting constant reference voltage, on the basis of required power of the load.
    Type: Grant
    Filed: July 5, 2019
    Date of Patent: October 4, 2022
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takuya Nakanishi, Tomokazu Sakashita
  • Publication number: 20220259008
    Abstract: A wireless power supply system for elevators includes a power transmitting device, first and second power receiving devices provided in the first and second elevator cars respectively, and a control device. The power transmitting device includes power transmitting units each having an inverter and two power transmitter coils. The first power receiving device includes first power receiving units each having a rectifier circuit and a power receiver coil that can be coupled with one of the two power transmitter coils. The second power receiving device includes second power receiving units each having a rectifier circuit and a power receiver coil that can be coupled with the other of the two power transmitter coils. The power transmitting device, or the first and second power receiving devices include switches to disconnect the inverter and the first load device as well as the inverter and the second load device.
    Type: Application
    Filed: July 19, 2019
    Publication date: August 18, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Mariko NAKAGAWA, Tomokazu SAKASHITA, Miyuki TAKESHITA, Hidehito YOSHIDA, Hirohisa KUWANO, Takuya MIURA
  • Publication number: 20220158500
    Abstract: An elevator includes a plurality of power transmission/reception devices each including: a power transmission coil connected to a main power supply; a power reception coil for receiving power transmitted from the power transmission coil and supplying power to a load; and an inverter which is provided between the main power supply and the power transmission coil, and which converts power supplied from the main power supply, to power having a predetermined frequency, and supplies the power to the power transmission coil, wherein the plurality of power transmission/reception devices are connected in parallel between the main power supply and the load. Since the inverters are individually connected to the power transmission coils, it is possible to efficiently supply power to the load even when using some of the power transmission coils.
    Type: Application
    Filed: April 26, 2019
    Publication date: May 19, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hirohisa KUWANO, Tomokazu SAKASHITA, Miyuki TAKESHITA, Hidehito YOSHIDA, Mariko SHIOZAKI, Takuya MIURA
  • Patent number: 11171574
    Abstract: To provide a power conversion device capable of estimating a load voltage with high accuracy without directly detecting the load voltage to be applied to a load, a control circuit includes an estimator for estimating the load voltage to be applied to the load based on an electric current of a resonant circuit, an AC frequency of an inverter and an electrostatic capacitance of the load, or an estimator for estimating the load voltage based on the electric current of the resonant circuit, the AC frequency of the inverter, an inductance of a resonant coil and a correction coefficient previously set from a relationship between a voltage of the resonant coil and the load voltage, and which controls an output to a target load voltage based on the estimated load voltage.
    Type: Grant
    Filed: April 2, 2018
    Date of Patent: November 9, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Ryota Asakura, Tomokazu Sakashita, Takahiro Inoue
  • Publication number: 20210313870
    Abstract: An output terminal of a contact type charger connected to an AC power supply 1 and being for boosting or stepping down an input voltage, and an output terminal of a non-contact type charger for receiving power in a non-contact manner are connected to an input terminal of a DC/DC converter via an integrated bus, a DC link capacitor is connected between an AC/DC converter and an isolated DC/DC converter included in the contact type charger, an integrated capacitor is connected to the integrated bus, and a control circuit adjusts a DC voltage of the DC link capacitor or the integrated capacitor such that at least one of power losses or a total power loss of the contact type charger, the non-contact type charger, and the DC/DC converter is reduced.
    Type: Application
    Filed: May 14, 2019
    Publication date: October 7, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroyasu IWABUKI, Tomokazu SAKASHITA, Ryota KONDO, Takaaki TAKAHARA, Hiroto MIZUTANI, Takuya NAKANISHI, Yusuke HIGAKI
  • Patent number: 11092129
    Abstract: A barrier-discharge-type ignition apparatus that can accurately determine the application voltage, of a barrier ignition plug, that causes a non-ignition discharge to occur. In the barrier-discharge-type ignition apparatus, in a combustion assist control, the voltage difference between the one-period-prior application voltage and the present-period application voltage in the AC period is calculated based on an application voltage detected by a voltage detection circuit; then, it is determined whether or not a discharge exists in the barrier ignition plug, based on the comparison between the voltage difference and a preliminarily set discharge determination threshold value.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: August 17, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Ryota Asakura, Tomokazu Sakashita, Takahiro Inoue
  • Patent number: 11095156
    Abstract: A power conversion device comprises an inner coil which can transmit power between an external coil by coupling magnetically with the external coil, an inverter whose AC side is connected to the inner coil and power conversion can be performed between the AC side and a DC side and a bidirectional DC/DC converter which comprises an intermediate capacitor, is connected to the DC side of the inverter and can perform power conversion bidirectionally between a DC power source, which is connected to a side which is opposite to the side of the inverter, and the inverter, wherein in switching operation from power reception to power transmission where power reception operation is switched to power transmission operation, after control of discharging charges which are accumulated in the intermediate capacitor is performed, the power transmission operation is started.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: August 17, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takuya Yabumoto, Tomokazu Sakashita
  • Publication number: 20210249965
    Abstract: The DC/DC converter circuit includes: a primary-side circuit configured to convert DC power from a DC power source into a pulse voltage; an isolation transformer configured to transform the pulse voltage while isolating the pulse voltage; a secondary-side circuit connectable in a switching manner by a switching circuit to one of a rectifier circuit for a high-voltage low-current output mode or a current doubler circuit for a low-voltage high-current output mode; and a control circuit configured to perform connection switching control of the switching circuit so as to establish, depending on target supply power, connection to the rectifier circuit in the high-voltage low-current output mode, and connection to the current doubler circuit in the low-voltage high-current output mode.
    Type: Application
    Filed: June 14, 2018
    Publication date: August 12, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Satoshi OJIKA, Tomokazu SAKASHITA
  • Patent number: 11070054
    Abstract: A power controller includes: a plurality of switching elements provided in one-to-one correspondence with a plurality of power supplies, and each of which switches on or off to switch between supplying and stopping supplying a load with electric power from a corresponding one of the plurality of power supplies; a processing unit which computes an operation amount for adjusting an amount of the electric power supplied to the load; and a signal generator which determines, for each control, a switching-element count indicating a total number of switching elements to be turned on among the plurality of switching elements, and a duty ratio of the switching-element count, based on the operation amount, and generates a drive signal for driving the plurality of switching elements successively, based on the switching-element count and the duty ratio.
    Type: Grant
    Filed: February 26, 2016
    Date of Patent: July 20, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Satoshi Ojika, Tomokazu Sakashita, Toshio Okamura, Shinichiro Oikawa
  • Publication number: 20210143680
    Abstract: A first converter performs power conversion and outputs AC power. The AC power outputted from the first converter is supplied to a first coil. The first coil is magnetically coupled with a second coil, and the AC power is transmitted from the first coil to the second coil. A second converter is connected to the second coil, and converts the AC power transmitted to the second coil to DC power and supplies the DC power to a load. A first control unit controls the first converter so as to alternately switch between a first state of outputting rectangular wave voltage which cyclically changes and a second state of outputting constant reference voltage, on the basis of required power of the load.
    Type: Application
    Filed: July 5, 2019
    Publication date: May 13, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takuya NAKANISHI, Tomokazu SAKASHITA
  • Patent number: 10907606
    Abstract: An ignition device according to the present invention includes: an ignition plug, which includes a first electrode, a second electrode, and a dielectric body arranged between the electrodes; an AC power supply configured to generate an AC voltage to be applied between the electrodes; a thermal plasma detection portion configured to output a thermal plasma occurrence signal when thermal plasma has occurred between the electrodes; and an application time period determination portion configured to determine an application time period for the AC voltage during one cycle of the internal combustion engine in advance before the application, and when the thermal plasma occurrence signal is received while the AC voltage is being applied based on the application time period, change the application time period so as to shorten the application time period.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: February 2, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takahiro Inoue, Taichiro Tamida, Ryota Asakura, Tomokazu Sakashita, Takashi Hashimoto