Patents by Inventor Tetsuya Uda

Tetsuya Uda 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: 8588615
    Abstract: Multiplexing-technology based large-capacity transmission requires the installation of many types of interface card. In addition, supporting a redundant configuration for preventing data communication from being interrupted requires the devices and cards more than double those required for the production system. An optical communication card includes multiple optical signal transmission/reception units, main signal processing units corresponding to the optical signal transmission/reception units and required for a multiplexed system, and a connection selection unit that can switch among multiple optical transmission lines, and each of the main signal processing units includes multiple function units and a function selection unit.
    Type: Grant
    Filed: January 10, 2011
    Date of Patent: November 19, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Masafumi Kamakura, Koji Takatori, Yasuyuki Fukashiro, Tetsuya Uda, Hidemasa Narita
  • Patent number: 8520196
    Abstract: Bending of an optical fiber where a heat may be generated by a high output power can be detected without using a dedicated light source. An optical communication module that outputs a continuous wave light generated by at least one light source to an optical fiber transmission line, includes: (1) a loss measurement unit that measures a loss of an amplified spontaneous emission generated by allowing the continuous wave light output from the light source to create stimulated Raman scattering in the optical fiber transmission line; (2) a fiber abnormality analyzer that detects the abnormal state of the optical fiber transmission line on the basis of loss information on the ASE measured by the loss measurement unit; and (3) a light source controller that controls a supply state of the continuous wave light from the light source on the basis of the detection of the fiber abnormality analyzer.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: August 27, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Riu Hirai, Nobuhiko Kikuchi, Tetsuya Uda, Shinya Sasaki
  • Publication number: 20120224168
    Abstract: Bending of an optical fiber where a heat may be generated by a high output power can be detected without using a dedicated light source. An optical communication module that outputs a continuous wave light generated by at least one light source to an optical fiber transmission line, includes: (1) a loss measurement unit that measures a loss of an amplified spontaneous emission generated by allowing the continuous wave light output from the light source to create stimulated Raman scattering in the optical fiber transmission line; (2) a fiber abnormality analyzer that detects the abnormal state of the optical fiber transmission line on the basis of loss information on the ASE measured by the loss measurement unit; and (3) a light source controller that controls a supply state of the continuous wave light from the light source on the basis of the detection of the fiber abnormality analyzer.
    Type: Application
    Filed: February 1, 2012
    Publication date: September 6, 2012
    Applicant: HITACHI, LTD.
    Inventors: Riu HIRAI, Nobuhiko KIKUCHI, Tetsuya UDA, Shinya SASAKI
  • Patent number: 8209169
    Abstract: A method and system for synchronizing words in an input text of a speech with a continuous recording of the speech. A received input text includes previously recorded content of the speech to be reproduced. A synthetic speech corresponding to the received input text is generated. Ratio data including a ratio between the respective pronunciation times of words included in the received text in the generated synthetic speech is computed. The ratio data is used to determine an association between erroneously recognized words of the received text and a time to reproduce each erroneously recognized word. The association is outputted in a recording medium and/or displayed on a display device.
    Type: Grant
    Filed: October 24, 2011
    Date of Patent: June 26, 2012
    Assignee: Nuance Communications, Inc.
    Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
  • Publication number: 20120099871
    Abstract: There arises a problem that power consumption increases along with an increasing throughout of an FEC function effective in speeding up of a transmission speed. FEC function information necessary for a system is prepared, and multiple FEC functions are properly used according to a selected transmission line, etc.
    Type: Application
    Filed: September 23, 2011
    Publication date: April 26, 2012
    Inventors: Masafumi KAMAKURA, Koji TAKATORI, Yasuyuki FUKASHIRO, Tetsuya UDA, Hidemasa NARITA
  • Patent number: 8121486
    Abstract: An optical transmission apparatus is arranged by: means for demultiplexing monitoring light for received wavelength-multiplexed signal light so as to detect optical intensity of the monitoring light; means for detecting optical intensity of wavelength-multiplexed signal light after the monitoring light has been demultiplexed therefrom; a gain controlling type optical amplifier for amplifying the wavelength-multiplexed signal light; an optical attenuating unit for adjusting optical intensity of the amplified wavelength-multiplexed signal light; and a monitoring control unit for controlling the gain controlling type optical amplifier in such a manner that the gain of the optical amplifier becomes constant, and for controlling an attenuating amount of the optical attenuating unit in such a manner that the optical intensity of the wavelength-multiplexed signal light becomes a predetermined target value.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: February 21, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuya Uda, Hiroshi Takeuchi
  • Publication number: 20120041758
    Abstract: A method and system for synchronizing words in an input text of a speech with a continuous recording of the speech. A received input text includes previously recorded content of the speech to be reproduced. A synthetic speech corresponding to the received input text is generated. Ratio data including a ratio between the respective pronunciation times of words included in the received text in the generated synthetic speech is computed. The ratio data is used to determine an association between erroneously recognized words of the received text and a time to reproduce each erroneously recognized word. The association is outputted in a recording medium and/or displayed on a display device.
    Type: Application
    Filed: October 24, 2011
    Publication date: February 16, 2012
    Applicant: Nuance Communications, Inc.
    Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
  • Patent number: 8065142
    Abstract: A method and system for synchronizing words in an input text of a speech with a continuous recording of the speech. A received input text includes previously recorded content of the speech to be reproduced. A synthetic speech corresponding to the received input text is generated. Ratio data including a ratio between the respective pronunciation times of words included in the received text in the generated synthetic speech is computed. The ratio data is used to determine an association between erroneously recognized words of the received text and a time to reproduce each erroneously recognized word. The association is outputted in a recording medium and/or displayed on a display device.
    Type: Grant
    Filed: June 25, 2008
    Date of Patent: November 22, 2011
    Assignee: Nuance Communications, Inc.
    Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
  • Publication number: 20110243558
    Abstract: An OADM device without a transponder unit does not mount the transponder in charge of separating a fault between the OADM device and an external device and is difficult to perform fault separation and to identify a fault interval. To solve this problem, for the OADM device without the transponder unit, the optical loop back function is provided by using such a switch as, for example, 2×2 optical switch. By identifying a fault developing interval by the use of the optical loop back function, fault separation at the time of occurrence of a fault can be facilitated.
    Type: Application
    Filed: March 28, 2011
    Publication date: October 6, 2011
    Inventors: Kento Iizawa, Tetsuya Uda
  • Publication number: 20110176812
    Abstract: Multiplexing-technology based large-capacity transmission requires the installation of many types of interface card. In addition, supporting a redundant configuration for preventing data communication from being interrupted requires the devices and cards more than double those required for the production system. An optical communication card includes multiple optical signal transmission/reception units, main signal processing units corresponding to the optical signal transmission/reception units and required for a multiplexed system, and a connection selection unit that can switch among multiple optical transmission lines, and each of the main signal processing units includes multiple function units and a function selection unit.
    Type: Application
    Filed: January 10, 2011
    Publication date: July 21, 2011
    Inventors: Masafumi KAMAKURA, Koji TAKATORI, Yasuyuki FUKASHIRO, Tetsuya UDA, Hidemasa NARITA
  • Patent number: 7809263
    Abstract: An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: October 5, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano
  • Patent number: 7725034
    Abstract: An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: May 25, 2010
    Assignee: Hitachi Communication Technologies, Inc.
    Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano
  • Publication number: 20090324229
    Abstract: An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.
    Type: Application
    Filed: May 14, 2009
    Publication date: December 31, 2009
    Applicant: Hitachi Communication Technologies , Inc.
    Inventors: Tetsuya UDA, Kenta NODA, Yasuhiro UCHIYAMA, Hiroshi MASUDA, Hiroyuki NAKANO
  • Publication number: 20090317078
    Abstract: The signal quality of ultra high-speed signals such as 40 Gbit/s and 100 Gbit/s are significantly degraded due to wavelength dispersion and nonlinear effects in an optical fiber. Thus, there is provided a transponder unit in which a light source is polarization multiplexed in a direction mutually orthogonal to a signal direction, in order to reduce the nonlinear effects in the optical fiber and improve the signal quality. At the same time, it is possible to monitor an amount of the wavelength dispersion in the optical fiber, allowing for more precise dispersion compensation design.
    Type: Application
    Filed: June 19, 2009
    Publication date: December 24, 2009
    Applicant: HITACHI COMMUNICATION TECHNOLOGIES, LTD.
    Inventors: Tetsuya UDA, Hiroyuki NAKANO, Yasuyuki FUKASHIRO
  • Patent number: 7554717
    Abstract: Disclosed is an optical transmission device with a simple configuration that can attenuate an input optical power only when it is necessary so that it falls within a predetermined range, and can suppress insertion loss when it is unnecessary. A variable optical attenuator is configured pluggable. A pluggable variable optical attenuator is equipped with an optical connector that is an interface of an optical signal and an electrical signal connector for receiving an electrical signal that specifies the amount of control used for feedback-controlling the attenuation, and controls the attenuation depending on the input optical power of the optical transmission board. Moreover, an optical through that has the same shape as the variable optical attenuator being configured pluggable and that is configured pluggable is prepared.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: June 30, 2009
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Hiroyuki Nakano, Tetsuya Uda, Yasuhiro Uchiyama
  • Patent number: 7536110
    Abstract: In the WDM systems, the OSNR and the signal loss among the optical signals are substantially minimized at the receiving terminal to combat the SRS effects. An equal amount of the signal loss is expected for every span in the transmission path so that the optical amplifier gain tilt is not affected among a number of wavelength frequencies in the optical signal. This is accomplished by controlling the amplification process according to a feedback from the monitoring units for monitoring the optical signal.
    Type: Grant
    Filed: May 10, 2007
    Date of Patent: May 19, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuya Uda, Hiroshi Masuda, Hirofumi Nakano, Eita Miyasaka, Satoshi Asamizu
  • Publication number: 20090087185
    Abstract: An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.
    Type: Application
    Filed: November 25, 2008
    Publication date: April 2, 2009
    Applicant: HITACHI COMMUNICATION TECHNOLOGIES, LTD.
    Inventors: Tetsuya UDA, Kenta NODA, Yasuhiro UCHIYAMA, Hiroshi MASUDA, Hiroyuki NAKANO
  • Publication number: 20090061274
    Abstract: Direct alcohol fuel cells using solid acid electrolytes and internal reforming catalysts are disclosed. The fuel cell generally comprises an anode, a cathode, a solid acid electrolyte and an internal reforming catalyst. The internal reforming catalyst may comprise any suitable reformer and is positioned adjacent the anode. In this configuration the heat generated by the exothermic fuel cell catalyst reactions and ohmic heating of the fuel cell electrolyte drives the endothermic fuel reforming reaction, reforming the alcohol fuel into hydrogen. Any alcohol fuel may be used, e.g. methanol or ethanol. The fuel cells according to this invention show increased power density and cell voltage relative to direct alcohol fuel cells not using an internal reformer.
    Type: Application
    Filed: September 5, 2008
    Publication date: March 5, 2009
    Applicant: California Institute of Technology
    Inventors: Sossina M. Haile, Tetsuya Uda
  • Publication number: 20090006087
    Abstract: A method and system for synchronizing words in an input text of a speech with a continuous recording of the speech. A received input text includes previously recorded content of the speech to be reproduced. A synthetic speech corresponding to the received input text is generated. Ratio data including a ratio between the respective pronunciation times of words included in the received text in the generated synthetic speech is computed. The ratio data is used to determine an association between erroneously recognized words of the received text and a time to reproduce each erroneously recognized word. The association is outputted in a recording medium and/or displayed on a display device.
    Type: Application
    Filed: June 25, 2008
    Publication date: January 1, 2009
    Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
  • Patent number: 7463829
    Abstract: An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: December 9, 2008
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano