Patents by Inventor Eiji Fujiwara

Eiji Fujiwara 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: 10276339
    Abstract: The purpose is to make it possible to autonomously suppress a reduction in an electron beam without providing a means for supervising the electron beam intensity of a monitor or the like. An electron gun, provided with: a heater (12) in which one terminal serves as a heater terminal (H) and the other terminal serves as a shared terminal (HK), and in which a low-voltage power supply (21) is connected between the terminals, the heater (12) generating heat due to a current being supplied from the low-voltage power supply (21); and a cathode electrode (11) connected to the shared terminal (HK) and heated by the heater (12) to discharge thermal electrons. A cathode current (Ik) due to the thermal electrons discharged from the cathode electrode (11), and a current (Ih) due to the low-voltage power supply, flow in opposite directions through the heater (12).
    Type: Grant
    Filed: September 16, 2016
    Date of Patent: April 30, 2019
    Assignee: NEC NETWORK AND SENSOR SYSTEMS, LTD.
    Inventors: Yukihira Nakazato, Eiji Fujiwara
  • Publication number: 20180286622
    Abstract: The purpose is to make it possible to autonomously suppress a reduction in an electron beam without providing a means for supervising the electron beam intensity of a monitor or the like. An electron gun, provided with: a heater (12) in which one terminal serves as a heater terminal (H) and the other terminal serves as a shared terminal (HK), and in which a low-voltage power supply (21) is connected between the terminals, the heater (12) generating heat due to a current being supplied from the low-voltage power supply (21); and a cathode electrode (11) connected to the shared terminal (HK) and heated by the heater (12) to discharge thermal electrons. A cathode current (Ik) due to the thermal electrons discharged from the cathode electrode (11), and a current (Ih) due to the low-voltage power supply, flow in opposite directions through the heater (12).
    Type: Application
    Filed: September 16, 2016
    Publication date: October 4, 2018
    Applicant: NEC NETWORK AND SENSOR SYSTEMS, LTD.
    Inventors: Yukihira NAKAZATO, Eiji FUJIWARA
  • Patent number: 8230292
    Abstract: An apparatus for correcting and detecting multiple spotty-byte errors within a byte occurred in a limited number of bytes and which has a function capable of controlling multiple spotty-byte errors within a byte occurred in the limited number of bytes, is provided. The apparatus for correcting and detecting multiple spotty-byte errors within a byte occurred in a limited number of bytes, comprises an encoding means for generating a transmitted word based on input information data; and a decoding means for inputting the transmitted word where errors occurred in an information transmission channel as a received word and correcting and detecting the errors. The encoding means generates the transmitted word by adding check information generated based on a parity check matrix expressing a spotty-byte error control code and the input information data to the input information data.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: July 24, 2012
    Assignees: Tokyo Institute of Technology, Japan Aerospace Exploration Agency
    Inventors: Eiji Fujiwara, Kazuyoshi Suzuki, Toshihiko Kashiyama, Satoshi Ichikawa
  • Publication number: 20090106633
    Abstract: An apparatus for correcting and detecting multiple spotty-byte errors within a byte occurred in a limited number of bytes and which has a function capable of controlling multiple spotty-byte errors within a byte occurred in the limited number of bytes, is provided. The apparatus for correcting and detecting multiple spotty-byte errors within a byte occurred in a limited number of bytes, comprises an encoding means for generating a transmitted word based on input information data; and a decoding means for inputting the transmitted word where errors occurred in an information transmission channel as a received word and correcting and detecting the errors. The encoding means generates the transmitted word by adding check information generated based on a parity check matrix expressing a spotty-byte error control code and the input information data to the input information data.
    Type: Application
    Filed: December 16, 2005
    Publication date: April 23, 2009
    Applicants: TOKYO INSTITUTE OF TECHNOLOGY, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Eiji Fujiwara, Kazuyoshi Suzuki, Toshihiko Kashiyama, Satoshi Ichikawa
  • Patent number: 7489084
    Abstract: A power supply apparatus for supplying predetermined supply voltages respectively to an anode electrode, a cathode electrode, a collector electrode, and a helix of an electron tube. The power supply apparatus comprises an anode switch for turning on/off the anode voltage output, and an anode switch control circuit for controlling the on/off operation of the anode switch such that a pulsed anode voltage is repeatedly applied to the anode electrode a plurality of times at a predetermined period when operation of a helix power supply and a collector power supply is stopped.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: February 10, 2009
    Assignee: NEC Microwave Tube, Ltd.
    Inventors: Junichi Kobayashi, Eiji Fujiwara
  • Publication number: 20070176689
    Abstract: A power supply apparatus for supplying predetermined supply voltages respectively to an anode electrode, a cathode electrode, a collector electrode, and a helix of an electron tube. The power supply apparatus comprises an anode switch for turning on/off the anode voltage output, and an anode switch control circuit for controlling the on/off operation of the anode switch such that a pulsed anode voltage is repeatedly applied to the anode electrode a plurality of times at a predetermined period when operation of a helix power supply and a collector power supply is stopped.
    Type: Application
    Filed: January 30, 2007
    Publication date: August 2, 2007
    Applicant: NEC MICROWAVE TUBE, LTD.
    Inventors: Junichi Kobayashi, Eiji Fujiwara
  • Patent number: 7034472
    Abstract: A power supply apparatus for a traveling-wave tube disclosed herein eliminates the need for isolation through a vacuum relay or the like, and is therefore fabricated in small size and at low cost. An oscillator circuit generates an oscillating signal at a frequency optionally selected from a plurality of frequencies. An inverter is applied with the oscillating signal from the oscillator circuit to generate an AC voltage signal at the frequency of the oscillating signal. A transformer transforms the AC voltage signal generated by the inverter disposed on the primary side and supplies the resulting signal to the secondary side. A rectifier circuit, which is disposed on the secondary side, rectifies the AC voltage signal transformed by the transformer for application to the traveling-wave tube. A frequency detector circuit detects the frequency of the AC voltage signal applied from the transformer to the rectifier circuit to generate a device control signal in accordance with the frequency.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: April 25, 2006
    Assignee: NEC Microwave Tube, Ltd.
    Inventors: Junichi Kobayashi, Eiji Fujiwara
  • Patent number: 7034462
    Abstract: A power supply circuit for a traveling-wave tube disclosed herein eliminates a large relay and a relay driving power supply to reduce the size and cost and to make itself tolerable to vibrations and impacts. A first control device turns on, when a potential on a helix electrode rises to a predetermined threshold determined by the ratio of the resistance of a first resistor to the resistance of a second resistor with respect to a potential on a positive heater electrode or a negative heater electrode, to conduct from a first terminal to a second terminal of the first control device. A second control device turns on when the first control device is off to maintain an anode electrode and a cathode electrode at the same potential. The second control device turns off when the first control device turns on to generate a potential difference between the anode electrode and cathode electrode, thereby applying a voltage to the anode electrode.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: April 25, 2006
    Assignee: NEC Microwave Tube, Ltd.
    Inventors: Shuji Abiko, Eiji Fujiwara
  • Patent number: 6990625
    Abstract: A syndrome S is found from a received information D and a parity check matrix for correcting burst errors up to b bits. The syndrome S is inputted to p sets of burst error pattern generation circuits that correspond to information frames overlapping each other by (b?1) bits and each having a length of 2b bits. If a burst error is included entirely in any one of the p sets of burst error pattern generation circuits, then the burst error pattern is outputted. An error pattern calculation circuit executes OR respectively on overlapping bits output from the error pattern generation circuits. By executing exclusive OR on an output of the error pattern calculation circuit and received information D, corrected information Ds is obtained. As a result, a burst error in the received information can be detected and corrected.
    Type: Grant
    Filed: June 12, 2002
    Date of Patent: January 24, 2006
    Assignees: Fanuc LTD
    Inventors: Eiji Fujiwara, Jiro Kinoshita
  • Publication number: 20050067966
    Abstract: A power supply apparatus for a traveling-wave tube disclosed herein eliminates the need for isolation through a vacuum relay or the like, and is therefore fabricated in small size and at low cost. An oscillator circuit generates an oscillating signal at a frequency optionally selected from a plurality of frequencies. An inverter is applied with the oscillating signal from the oscillator circuit to generate an AC voltage signal at the frequency of the oscillating signal. A transformer transforms the AC voltage signal generated by the inverter disposed on the primary side and supplies the resulting signal to the secondary side. A rectifier circuit, which is disposed on the secondary side, rectifies the AC voltage signal transformed by the transformer for application to the traveling-wave tube. A frequency detector circuit detects the frequency of the AC voltage signal applied from the transformer to the rectifier circuit to generate a device control signal in accordance with the frequency.
    Type: Application
    Filed: September 27, 2004
    Publication date: March 31, 2005
    Inventors: Junichi Kobayashi, Eiji Fujiwara
  • Publication number: 20050057159
    Abstract: A power supply circuit for a traveling-wave tube disclosed herein eliminates a large relay and a relay driving power supply to reduce the size and cost and to make itself tolerable to vibrations and impacts. A first control device turns on, when a potential on a helix electrode rises to a predetermined threshold determined by the ratio of the resistance of a first resistor to the resistance of a second resistor with respect to a potential on a positive heater electrode or a negative heater electrode, to conduct from a first terminal to a second terminal of the first control device. A second control device turns on when the first control device is off to maintain an anode electrode and a cathode electrode at the same potential. The second control device turns off when the first control device turns on to generate a potential difference between the anode electrode and cathode electrode, thereby applying a voltage to the anode electrode.
    Type: Application
    Filed: September 9, 2004
    Publication date: March 17, 2005
    Inventors: Shuji Abiko, Eiji Fujiwara
  • Publication number: 20030023930
    Abstract: A syndrome S is found from a received information D and a parity check matrix for correcting burst errors up to b bits. The syndrome S is inputted to p sets of burst error pattern generation circuits that correspond to information frames overlapping each other by (b−1) bits and each having a length of 2b bits. If a burst error is included entirely in any one of the p sets of burst error pattern generation circuits, then the burst error pattern is outputted. An error pattern calculation circuit executes OR respectively on overlapping bits output from the error pattern generation circuits. By executing exclusive OR on an output of the error pattern calculation circuit and received information D, corrected information Ds is obtained. As a result, a burst error in the received information can be detected and corrected.
    Type: Application
    Filed: June 12, 2002
    Publication date: January 30, 2003
    Inventors: Eiji Fujiwara, Jiro Kinoshita
  • Patent number: 5563894
    Abstract: An error detecting and correcting apparatus includes a unit for receiving an encoded word including a plurality of b-bit bytes (b is an integer not less than two) and generating syndrome from the encoded word according to a first parity check matrix H.sub.1, and a unit for correcting errors in the received encoded word based on the syndrome.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: October 8, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Fujiwara, Hiroshi Kosuge, Yoshio Kiriu
  • Patent number: 5482544
    Abstract: The disclosure describes a rust-preventive composition comprising a layered phosphate whose active hydrogen is reacted with ammonia in an amount of 20 to 80 mol % based on the total amount of hydrogen of the layered phosphate, and an amphoteric or basic oxide, a ratio by weight of the layered phosphate to the amphoteric or basic oxide being 10:1 to 1:10.
    Type: Grant
    Filed: July 14, 1994
    Date of Patent: January 9, 1996
    Assignee: Tayca Corporation
    Inventors: Masaaki Okuda, Hajime Kondo, Eiji Fujiwara