Patents by Inventor Eitetsu IGAWA

Eitetsu IGAWA 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: 10693276
    Abstract: An optical transmitter includes: a semiconductor laser unit that outputs laser light of first output power and outputs a monitor current; a casing of an optical module that holds optical fiber; a monitor current detection unit that generates a monitor voltage; a laser driving unit that controls a laser driving current; a storage unit that stores information based on a result of a measurement of a ratio of second output power with respect to the first output power; a target voltage determination unit that changes the target voltage based on a detected temperature of a temperature sensor and the information based on the result of the measurement; and a power monitor value determination unit that generates a power monitor value indicating the second output power to be transmitted to a host device using the detected temperature and the information based on the result of the measurement.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: June 23, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Eitetsu Igawa, Hiroyuki Ozaki, Satoshi Ishitobi
  • Publication number: 20200136349
    Abstract: An optical transmitter includes: a semiconductor laser unit that outputs laser light of first output power and outputs a monitor current; a casing of an optical module that holds optical fiber; a monitor current detection unit that generates a monitor voltage; a laser driving unit that controls a laser driving current; a storage unit that stores information based on a result of a measurement of a ratio of second output power with respect to the first output power; a target voltage determination unit that changes the target voltage based on a detected temperature of a temperature sensor and the information based on the result of the measurement; and a power monitor value determination unit that generates a power monitor value indicating the second output power to be transmitted to a host device using the detected temperature and the information based on the result of the measurement.
    Type: Application
    Filed: March 31, 2017
    Publication date: April 30, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Eitetsu IGAWA, Hiroyuki OZAKI, Satoshi ISHITOBI
  • Patent number: 10116118
    Abstract: An optical transmitter includes a semiconductor laser, a thermoelement that is connected with the semiconductor laser and that heats or cools the semiconductor laser, a thermistor that detects the temperature of the semiconductor laser via the thermoelement, a laser drive circuit that drives the semiconductor laser, a thermoelement driving circuit that acquires information about the temperature of the semiconductor laser from the thermistor, and that controls a current flowing through the thermoelement in such a way that the temperature detected by the thermistor becomes equal to a set value, and a controller that varies the set value on the basis of monitor current information outputted from the semiconductor laser, the temperature information about the semiconductor laser which is notified from the thermistor, and laser driving current information notified from the laser drive circuit.
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: October 30, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Eitetsu Igawa, Satoshi Ishitobi
  • Publication number: 20170207602
    Abstract: An optical transmitter includes a semiconductor laser, a thermoelement that is connected with the semiconductor laser and that heats or cools the semiconductor laser, a thermistor that detects the temperature of the semiconductor laser via the thermoelement, a laser drive circuit that drives the semiconductor laser, a thermoelement driving circuit that acquires information about the temperature of the semiconductor laser from the thermistor, and that controls a current flowing through the thermoelement in such a way that the temperature detected by the thermistor becomes equal to a set value, and a controller that varies the set value on the basis of monitor current information outputted from the semiconductor laser, the temperature information about the semiconductor laser which is notified from the thermistor, and laser driving current information notified from the laser drive circuit.
    Type: Application
    Filed: February 3, 2015
    Publication date: July 20, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Eitetsu IGAWA, Satoshi ISHITOBI