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).
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Patent number: 8588615Abstract: 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: GrantFiled: January 10, 2011Date of Patent: November 19, 2013Assignee: Hitachi, Ltd.Inventors: Masafumi Kamakura, Koji Takatori, Yasuyuki Fukashiro, Tetsuya Uda, Hidemasa Narita
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Patent number: 8520196Abstract: 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: GrantFiled: February 1, 2012Date of Patent: August 27, 2013Assignee: Hitachi, Ltd.Inventors: Riu Hirai, Nobuhiko Kikuchi, Tetsuya Uda, Shinya Sasaki
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Publication number: 20120224168Abstract: 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: ApplicationFiled: February 1, 2012Publication date: September 6, 2012Applicant: HITACHI, LTD.Inventors: Riu HIRAI, Nobuhiko KIKUCHI, Tetsuya UDA, Shinya SASAKI
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Patent number: 8209169Abstract: 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: GrantFiled: October 24, 2011Date of Patent: June 26, 2012Assignee: Nuance Communications, Inc.Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
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Publication number: 20120099871Abstract: 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: ApplicationFiled: September 23, 2011Publication date: April 26, 2012Inventors: Masafumi KAMAKURA, Koji TAKATORI, Yasuyuki FUKASHIRO, Tetsuya UDA, Hidemasa NARITA
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Patent number: 8121486Abstract: 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: GrantFiled: February 7, 2008Date of Patent: February 21, 2012Assignee: Hitachi, Ltd.Inventors: Tetsuya Uda, Hiroshi Takeuchi
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Publication number: 20120041758Abstract: 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: ApplicationFiled: October 24, 2011Publication date: February 16, 2012Applicant: Nuance Communications, Inc.Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
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Patent number: 8065142Abstract: 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: GrantFiled: June 25, 2008Date of Patent: November 22, 2011Assignee: Nuance Communications, Inc.Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
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Publication number: 20110243558Abstract: 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: ApplicationFiled: March 28, 2011Publication date: October 6, 2011Inventors: Kento Iizawa, Tetsuya Uda
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Publication number: 20110176812Abstract: 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: ApplicationFiled: January 10, 2011Publication date: July 21, 2011Inventors: Masafumi KAMAKURA, Koji TAKATORI, Yasuyuki FUKASHIRO, Tetsuya UDA, Hidemasa NARITA
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Patent number: 7809263Abstract: 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: GrantFiled: November 25, 2008Date of Patent: October 5, 2010Assignee: Hitachi, Ltd.Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano
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Patent number: 7725034Abstract: 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: GrantFiled: May 14, 2009Date of Patent: May 25, 2010Assignee: Hitachi Communication Technologies, Inc.Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano
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Publication number: 20090324229Abstract: 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: ApplicationFiled: May 14, 2009Publication date: December 31, 2009Applicant: Hitachi Communication Technologies , Inc.Inventors: Tetsuya UDA, Kenta NODA, Yasuhiro UCHIYAMA, Hiroshi MASUDA, Hiroyuki NAKANO
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Publication number: 20090317078Abstract: 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: ApplicationFiled: June 19, 2009Publication date: December 24, 2009Applicant: HITACHI COMMUNICATION TECHNOLOGIES, LTD.Inventors: Tetsuya UDA, Hiroyuki NAKANO, Yasuyuki FUKASHIRO
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Patent number: 7554717Abstract: 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: GrantFiled: June 23, 2006Date of Patent: June 30, 2009Assignee: Hitachi Communication Technologies, Ltd.Inventors: Hiroyuki Nakano, Tetsuya Uda, Yasuhiro Uchiyama
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Patent number: 7536110Abstract: 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: GrantFiled: May 10, 2007Date of Patent: May 19, 2009Assignee: Hitachi, Ltd.Inventors: Tetsuya Uda, Hiroshi Masuda, Hirofumi Nakano, Eita Miyasaka, Satoshi Asamizu
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Publication number: 20090087185Abstract: 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: ApplicationFiled: November 25, 2008Publication date: April 2, 2009Applicant: HITACHI COMMUNICATION TECHNOLOGIES, LTD.Inventors: Tetsuya UDA, Kenta NODA, Yasuhiro UCHIYAMA, Hiroshi MASUDA, Hiroyuki NAKANO
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Publication number: 20090061274Abstract: 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: ApplicationFiled: September 5, 2008Publication date: March 5, 2009Applicant: California Institute of TechnologyInventors: Sossina M. Haile, Tetsuya Uda
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Publication number: 20090006087Abstract: 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: ApplicationFiled: June 25, 2008Publication date: January 1, 2009Inventors: Noriko Imoto, Tetsuya Uda, Takatoshi Watanabe
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Patent number: 7463829Abstract: 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: GrantFiled: December 23, 2004Date of Patent: December 9, 2008Assignee: Hitachi Communication Technologies, Ltd.Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano