Patents by Inventor Ken Takei

Ken Takei 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: 11081811
    Abstract: A controller of a transmitter outputs cyclically different digital data to equivalent transmission circuits, that is, RF circuits to generate a rotation polarized wave.
    Type: Grant
    Filed: August 2, 2019
    Date of Patent: August 3, 2021
    Assignee: HITACHI, LTD.
    Inventor: Ken Takei
  • Patent number: 10749273
    Abstract: A wireless communication system that communicates by an electromagnetic wave includes a first wireless device that includes a transmission rotationally polarized wave frequency generator for giving a rotation period to a polarized wave of the electromagnetic wave to be transmitted, transmits a synchronization code by the electromagnetic wave of the polarized wave rotated using the transmission rotationally polarized wave frequency generator, and transmits data by the electromagnetic wave, and a second wireless device that includes a reception rotationally polarized wave frequency generator for giving a rotation period to the polarized wave received in a reception of the electromagnetic wave, calculates transmission timing of the synchronization code included in the received electromagnetic wave of the polarized wave rotated using the reception rotationally polarized wave frequency generator, and sets a signal included in the received electromagnetic wave, as data based on the calculated transmission timing.
    Type: Grant
    Filed: November 30, 2018
    Date of Patent: August 18, 2020
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10630370
    Abstract: A transmitter includes: a first transmission block that generates a first radio wave having an information signal modulated thereon and having a plane of polarization that rotates; and a second transmission block that generates a second radio wave having the information signal modulated thereon and having a plane of polarization that is fixed. A receiver includes: a first receive section that demodulates a first radio wave having an information signal modulated thereon and having a plane of polarization that rotates; and a second receive section that demodulates a second radio wave having the information signal modulated thereon and having a plane of polarization that is fixed. The receiver restores the information signal on the basis of the result of reception by the first receive section and the second receive section.
    Type: Grant
    Filed: May 9, 2017
    Date of Patent: April 21, 2020
    Assignee: HITACHI, LTD.
    Inventor: Ken Takei
  • Publication number: 20200067204
    Abstract: A controller of a transmitter outputs cyclically different digital data to equivalent transmission circuits, that is, RF circuits to generate a rotation polarized wave.
    Type: Application
    Filed: August 2, 2019
    Publication date: February 27, 2020
    Applicant: Hitachi, Ltd.
    Inventor: Ken TAKEI
  • Patent number: 10574332
    Abstract: There is provided a radio communication system configured to communicate with the electromagnetic wave. The radio communication system includes a plurality of slave stations, each configured to transmit and receive the electromagnetic wave using the fixed polarized wave, and a master station including an antenna and a base band circuit, the master station configured to identify a polarization direction of the electromagnetic wave reaching the antenna and a slave station transmitting the electromagnetic wave and notify the identified slave station of a communication timing based on an identified polarized direction. The plurality of slave stations include a plurality of slave stations arranged such that electromagnetic waves transmitted from a plurality of slave stations among the plurality of slave stations reach the antenna of the master station in a plurality of different fixed polarization directions.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: February 25, 2020
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10470039
    Abstract: A highly-secure wireless communication system has a transmitter for transmitting the same information at predetermined polarized wave angles having different rotation-polarized waves for rotating the polarized waves of a carrier wave, and a receiver for restoring the reception information at the aforementioned predetermined polarization wave angles and for comparing the restoration results of the predetermined polarization wave angles with one another.
    Type: Grant
    Filed: October 18, 2013
    Date of Patent: November 5, 2019
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10347989
    Abstract: In a thin rotationally polarized antenna which performs highly reliable and highly secure wireless communication, in the case where a feeding point is provided in an integrated plate conductor including a plurality of minute conductor segments and is excited at a first frequency and a second frequency different from the first frequency, matching with a feeding circuit is achieved in both a frequency band including the first frequency and a frequency band including the second frequency. Current distribution formed in orthogonal directions on the plate at the first frequency has the same amplitude and has a phase difference of 90 degrees. Current distribution formed in the same orthogonal directions on the plate at the second frequency has the same amplitude and has a phase difference of 90 degrees, and a phase of the current distribution at the first frequency and a phase of the current distribution at the second frequency have opposite directions.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: July 9, 2019
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Publication number: 20190173199
    Abstract: According to one embodiment, a wireless communication system that communicates by an electromagnetic wave includes a first wireless device that includes a transmission rotationally polarized wave frequency generator for giving a rotation period to a polarized wave of the electromagnetic wave to be transmitted, transmits a synchronization code by the electromagnetic wave of the polarized wave rotated using the transmission rotationally polarized wave frequency generator, and transmits data by the electromagnetic wave of the polarized wave rotated using the transmission rotationally polarized wave frequency generator, and a second wireless device that includes a reception rotationally polarized wave frequency generator for giving a rotation period to the polarized wave received in a reception of the electromagnetic wave, calculates transmission timing of the synchronization code included in the received electromagnetic wave of the polarized wave rotated using the reception rotationally polarized wave frequency
    Type: Application
    Filed: November 30, 2018
    Publication date: June 6, 2019
    Inventor: Ken TAKEI
  • Patent number: 10305200
    Abstract: A wireless communication system includes a plurality of wireless devices that communicate with each other. Each of the wireless devices includes a transmission unit configured to transmit a carrier of a fixed strength with polarization waves thereof rotated to a different one of the wireless devices using two antennae spatially orthogonal to each other, a reception unit configured to receive a carrier transmitted from the transmission unit of the different wireless device, and a timing detection unit configured to detect a timing at which the polarization waves of the carrier received by the reception unit within a period of rotation indicates a maximum strength. The transmission unit performs transmission or reception of a specific information signal using the carrier based on the timing detected by the timing detection unit.
    Type: Grant
    Filed: July 13, 2016
    Date of Patent: May 28, 2019
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Publication number: 20190132041
    Abstract: There is provided a radio communication system configured to communicate with the electromagnetic wave. The radio communication system includes a plurality of slave stations, each configured to transmit and receive the electromagnetic wave using the fixed polarized wave, and a master station including an antenna and a base band circuit, the master station configured to identify a polarization direction of the electromagnetic wave reaching the antenna and a slave station transmitting the electromagnetic wave and notify the identified slave station of a communication timing based on an identified polarized direction. The plurality of slave stations include a plurality of slave stations arranged such that electromagnetic waves transmitted from a plurality of slave stations among the plurality of slave stations reach the antenna of the master station in a plurality of different fixed polarization directions.
    Type: Application
    Filed: March 22, 2018
    Publication date: May 2, 2019
    Inventor: Ken TAKEI
  • Patent number: 10277351
    Abstract: In a wireless communication system, wireless communication devices are disposed, each including two orthogonal antennas, a transmitter, and a receiver using rotating polarized wave having a changeable transmission frequency. Specific codes are assigned to the devices, respectively and are shared. In a first of the devices, information and a first code are superimposed on a first carrier wave. In a second of the devices, the transmitted wave is received to reproduce the information with the codes assigned to the second device and the shared code assigned to the first device. The second device transmits second information through modulation using the code thereof. Each of the first and second devices adjusts the propagation frequency for a maximum ratio in intensity of a signal reproduced with the code assigned to another device to an intensity of a signal reproduced with the code assigned to the own device.
    Type: Grant
    Filed: November 24, 2017
    Date of Patent: April 30, 2019
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10158395
    Abstract: A wireless system allows for selectively using, and communicating through, wireless propagation paths between radio devices in an over-the-horizen communication environment. Also an elevator control system and a substation monitoring system using the same are provided.
    Type: Grant
    Filed: November 20, 2017
    Date of Patent: December 18, 2018
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10153824
    Abstract: Provided is a wireless communication system that achieves high-reliability communication between a transmitter and a receiver.
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: December 11, 2018
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10149180
    Abstract: A radio device includes a transmitter and a receiver. The transmitter transmits rotationally polarized radio waves in a plurality of transmission propagation directions using a plurality of antennas. The receiver receives rotationally polarized radio waves in a plurality of reception propagation directions using a plurality of antennas. The receiver measures changes in rotational loci of polarizations of the radio waves received in the plurality of reception propagation directions corresponding to radio waves transmitted in a plurality of transmission propagation directions. The transmitter performs transmission using a reception propagation direction at which the changes measured by the receiver in the rotational loci of the polarizations of the received radio waves stop.
    Type: Grant
    Filed: June 26, 2017
    Date of Patent: December 4, 2018
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Patent number: 10148338
    Abstract: A wireless communication system is disclosed by which, in communication that uses rotationally polarized waves, the information transmission amount is increased to perform communication. A transmitter 101 transmits a signal using polarized waves that are different at different timings using a rotationally polarized wave. In a receiver 201, a reception baseband circuit 20 detects different polarized waves received at timings corresponding to the polarized waves used by the transmitter 101 on a time axis using a plurality of signals equivalent to the received signals to obtain a wireless propagation characteristic between the transmitter 101 and the receiver 201. Then, the transmitter 101 propagates different signals in the form of a plurality of polarized waves at the same time using a plurality of rotationally polarized waves having initial polarization rotation phases different from each other. The transmission capacity can be increased by an amount corresponding to the number of different signals.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: December 4, 2018
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei
  • Publication number: 20180262923
    Abstract: A radio device includes a transmitter and a receiver. The transmitter transmits rotationally polarized radio waves in a plurality of transmission propagation directions using a plurality of antennas. The receiver receives rotationally polarized radio waves in a plurality of reception propagation directions using a plurality of antennas. The receiver measures changes in rotational loci of polarizations of the radio waves received in the plurality of reception propagation directions corresponding to radio waves transmitted in a plurality of transmission propagation directions. The transmitter performs transmission using a reception propagation direction at which the changes measured by the receiver in the rotational loci of the polarizations of the received radio waves stop.
    Type: Application
    Filed: June 26, 2017
    Publication date: September 13, 2018
    Inventor: Ken TAKEI
  • Publication number: 20180262260
    Abstract: A transmitter includes: a first transmission block that generates a first radio wave having an information signal modulated thereon and having a plane of polarization that rotates; and a second transmission block that generates a second radio wave having the information signal modulated thereon and having a plane of polarization that is fixed. A receiver includes: a first receive section that demodulates a first radio wave having an information signal modulated thereon and having a plane of polarization that rotates; and a second receive section that demodulates a second radio wave having the information signal modulated thereon and having a plane of polarization that is fixed. The receiver restores the information signal on the basis of the result of reception by the first receive section and the second receive section.
    Type: Application
    Filed: May 9, 2017
    Publication date: September 13, 2018
    Applicant: HITACHI, LTD.
    Inventor: Ken Takei
  • Publication number: 20180152221
    Abstract: A wireless system allows for selectively using, and communicating through, wireless propagation paths between radio devices in an over-the-horizen communication environment. Also an elevator control system and a substation monitoring system using the same are provided.
    Type: Application
    Filed: November 20, 2017
    Publication date: May 31, 2018
    Inventor: Ken TAKEI
  • Publication number: 20180152258
    Abstract: In a wireless communication system, wireless communication devices are disposed, each including two orthogonal antennas, a transmitter, and a receiver using rotating polarized wave having a changeable transmission frequency. Specific codes are assigned to the devices, respectively and are shared. In a first of the devices, information and a first code are superimposed on a first carrier wave. In a second of the devices, the transmitted wave is received to reproduce the information with the codes assigned to the second device and the shared code assigned to the first device. The second device transmits second information through modulation using the code thereof. Each of the first and second devices adjusts the propagation frequency for a maximum ratio in intensity of a signal reproduced with the code assigned to another device to an intensity of a signal reproduced with the code assigned to the own device.
    Type: Application
    Filed: November 24, 2017
    Publication date: May 31, 2018
    Inventor: Ken TAKEI
  • Patent number: 9899875
    Abstract: A radio power transmission apparatus comprises a transmitter 20 having a power transmitting antenna 9 for transmitting electromagnetic waves and a power transmitting circuit and a receiver 40 having a power receiving antenna 29 for receiving electromagnetic waves and a power receiving circuit. In the radio power transmission apparatus, on the basis of power reflected to the power transmitting antenna 9, the power transmitting circuit executes control to change the circuit reactance of the power transmitting circuit in order to control the imaginary part of power of the electromagnetic waves to be transmitted.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: February 20, 2018
    Assignee: Hitachi, Ltd.
    Inventor: Ken Takei