Patents by Inventor Sunao Kakizaki

Sunao Kakizaki 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: 7542672
    Abstract: A method is provided for detecting an optical reflection position in an optical switching unit by using a measuring system. Multiple switching commands are provided in order to direct a test light to an input port and an output port of the optical switching unit. Status information regarding the internal path of the test light is stored in a memory, along with flags corresponding to the magnitude of reflected light generated when the test light is reflected from an abnormal position along the internal path selected. The status information is stored in the form of a reflection alarm information table where the flags are stored in association with each of the internal paths. A rearmost connection among the optical interconnections in the optical switching unit is detected as an abnormal position based on the reflection alarm information table and the interconnection control table.
    Type: Grant
    Filed: May 23, 2007
    Date of Patent: June 2, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Sunao Kakizaki, Hideaki Tushima, Sigeki Kitajima, Yasuyuki Fukashiro
  • Patent number: 7356257
    Abstract: An optical communication network system is disclosed, which includes an optical switching apparatus. The optical switching apparatus includes an optical switch for switching and setting routes of an optical signal without being converted, a control unit for instructing the optical switch to execute a route switching operation, and a performance monitor for detecting performance of the optical signal having a route set by the optical switch. The performance monitor issues an alarm when the performance detected is deteriorated from predetermined performance. The control unit includes an alarm masking unit for masking the alarm issued from the performance monitor at least for a predetermined masking period from a starting time of a switching operation by the optical switch, and thus preventing the alarm from being issued.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: April 8, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Shigeki Kitajima, Sunao Kakizaki, Hideaki Tsushima, Yasuyuki Fukashiro
  • Publication number: 20070223918
    Abstract: Practical utilization of an optical signal processor configured by combining a plurality of optical components requires configurations and methods by which reflected light arising in the processor during assembly, installation, or operation thereof can be detected reliably and immediately to enable switching of optical signal paths and recovery actions (maintenance) such as replacement and repair of components, thereby improving the reliability, availability, and serviceability of the processor. The present invention provides an optical switching system configured as a combination of optical components, including multistage-connected optical switching devices each having a plurality of optical reflection monitoring functions. These functions enable reliable and immediate detection and notification of reflected light arising in the optical switching system. The invention also provides a method of monitoring and reporting reflection.
    Type: Application
    Filed: May 23, 2007
    Publication date: September 27, 2007
    Inventors: Sunao Kakizaki, Hideaki Tushima, Sigeki Kitajima, Yasuyuki Fukashiro
  • Patent number: 7206475
    Abstract: In an optical switching apparatus having redundantly-arranged optical switches, a route switching operation mode, an autonomic redundant switching operation mode and a compulsory redundant switching operation mode are discriminated from one another so that these operation modes are prevented from being executed at the same time, and also proper mask processing is performed at every switching operation mode. Therefore, emission of an undesired alarm and thus occurrence of malfunction when each switching operation is carried out can be prevented.
    Type: Grant
    Filed: September 20, 2004
    Date of Patent: April 17, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Shigeki Kitajima, Yasuyuki Fukashiro, Takashi Mori
  • Publication number: 20050281556
    Abstract: An optical communication network system is disclosed, which includes an optical switching apparatus. The optical switching apparatus includes an optical switch for switching and setting routes of an optical signal without being converted, a control unit for instructing the optical switch to execute a route switching operation, and a performance monitor for detecting performance of the optical signal having a route set by the optical switch. The performance monitor issues an alarm when the performance detected is deteriorated from predetermined performance. The control unit includes an alarm masking unit for masking the alarm issued from the performance monitor at least for a predetermined masking period from a starting time of a switching operation by the optical switch, and thus preventing the alarm from being issued.
    Type: Application
    Filed: July 28, 2005
    Publication date: December 22, 2005
    Applicant: HITACHI, LTD.
    Inventors: Shigeki Kitajima, Sunao Kakizaki, Hideaki Tsushima, Yasuyuki Fukashiro
  • Patent number: 6975811
    Abstract: An optical one-to-one protection switching apparatus exchanges signals between a transmit node and a receive node. If a fault is detected in the first transmission line (down-stream), a controller in the node controls a drive circuit so as to shut off a gate. Then, the controller in the transmit node upon receiving a switching request from the receive node, controls the drive circuit so as to shut off the gate. Thereby, the optical switch is switched. The transmitter of the client terminal is thus connected to the second transmission line (down-stream). Upon receiving the switching request from the transmit node, the optical switch in the receive node is switched. Thereby the receiver in the client terminal is connected to the second transmission line (down-stream).
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: December 13, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Takashi Mori, Masahiro Takatori, Yukio Hayashi, Shinichi Kuwano
  • Patent number: 6933852
    Abstract: An optical communication network system is disclosed, which includes an optical switching apparatus. The optical switching apparatus includes an optical switch for switching and setting routes of an optical signal without being converted, a control unit for instructing the optical switch to execute a route switching operation, and a performance monitor for detecting performance of the optical signal having a route set by the optical switch. The performance monitor issues an alarm when the performance detected is deteriorated from predetermined performance. The control unit includes an alarm masking unit for masking the alarm issued from the performance monitor at least for a predetermined masking period from a starting time of a switching operation by the optical switch, and thus preventing the alarm from being issued.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: August 23, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Shigeki Kitajima, Sunao Kakizaki, Hideaki Tsushima, Yasuyuki Fukashiro
  • Publication number: 20050031346
    Abstract: In an optical switching apparatus having redundantly-arranged optical switches, a route switching operation mode, an autonomic redundant switching operation mode and a compulsory redundant switching operation mode are discriminated from one another so that these operation modes are prevented from being executed at the same time, and also proper mask processing is performed at every switching operation mode. Therefore, emission of an undesired alarm and thus occurrence of malfunction when each switching operation is carried out can be prevented.
    Type: Application
    Filed: September 20, 2004
    Publication date: February 10, 2005
    Applicant: Hitachi, Ltd.
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Shigeki Kitajima, Yasuyuki Fukashiro, Takashi Mori
  • Patent number: 6839480
    Abstract: In an optical switching apparatus having redundantly-arranged optical switches, a route switching operation mode, an autonomic redundant switching operation mode and a compulsory redundant switching operation mode are discriminated from one another so that these operation modes are prevented from being executed at the same time, and also proper mask processing is performed at every switching operation mode. Therefore, emission of an undesired alarm and thus occurrence of malfunction when each switching operation is carried out can be prevented.
    Type: Grant
    Filed: October 15, 2003
    Date of Patent: January 4, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Shigeki Kitajima, Yasuyuki Fukashiro, Takashi Mori
  • Patent number: 6778725
    Abstract: In an optical switching apparatus having redundantly-arranged optical switches, a route switching operation mode, an autonomic redundant switching operation mode and a compulsory redundant switching operation mode are discriminated from one another so that these operation modes are prevented from being executed at the same time, and also proper mask processing is performed at every switching operation mode. Therefore, emission of an undesired alarm and thus occurrence of malfunction when each switching operation is carried out can be prevented.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: August 17, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Shigeki Kitajima, Yasuyuki Fukashiro, Takashi Mori
  • Publication number: 20040131366
    Abstract: A wavelength tunable optical transmitter is used in a protection system of a WDM network, and its conventional wavelength tuning process has to perform steps of tuning intermediate wavelengths which are used by other optical transmission equipment in the network. Thus the conventional system interferes with normal communications in the other optical transmission equipment. To prevent the interference, wavelength tunable optical transmission equipment is provided with an optical gate for selectively on and off an optical signal output. A controller closes the optical gate while wavelength tunable optical transmission equipment and opens the optical gage to pass the signal through the optical gate once the target wavelength is attained and virtually stabilized.
    Type: Application
    Filed: December 16, 2003
    Publication date: July 8, 2004
    Inventors: Hideaki Tsushima, Yukio Hayashi, Sunao Kakizaki
  • Publication number: 20040081460
    Abstract: In an optical switching apparatus having redundantly-arranged optical switches, a route switching operation mode, an autonomic redundant switching operation mode and a compulsory redundant switching operation mode are discriminated from one another so that these operation modes are prevented from being executed at the same time, and also proper mask processing is performed at every switching operation mode. Therefore, emission of an undesired alarm and thus occurrence of malfunction when each switching operation is carried out can be prevented.
    Type: Application
    Filed: October 15, 2003
    Publication date: April 29, 2004
    Applicant: HITACHI, LTD.
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Shigeki Kitajima, Yasuyuki Fukashiro, Takashi Mori
  • Publication number: 20030128979
    Abstract: An optical communication network system is disclosed, which includes an optical switching apparatus. The optical switching apparatus includes an optical switch for switching and setting routes of an optical signal without being converted, a control unit for instructing the optical switch to execute a route switching operation, and a performance monitor for detecting performance of the optical signal having a route set by the optical switch. The performance monitor issues an alarm when the performance detected is deteriorated from predetermined performance. The control unit includes an alarm masking unit for masking the alarm issued from the performance monitor at least for a predetermined masking period from a starting time of a switching operation by the optical switch, and thus preventing the alarm from being issued.
    Type: Application
    Filed: March 11, 2002
    Publication date: July 10, 2003
    Inventors: Shigeki Kitajima, Sunao Kakizaki, Hideaki Tsushima, Yasuyuki Fukashiro
  • Publication number: 20030026524
    Abstract: Practical utilization of an optical signal processor configured by combining a plurality of optical components requires configurations and methods by which reflected light arising in the processor during assembly, installation, or operation thereof can be detected reliably and immediately to enable switching of optical signal paths and recovery actions (maintenance) such as replacement and repair of components, thereby improving the reliability, availability, and service ability of the processor. The present invention provides an optical switching system configured as a combination of optical components, including multistage-connected optical switching devices each having a plurality of optical reflection monitoring functions. These functions enable reliable and immediate detection and notification of reflected light arising in the optical switching system. The invention also provides a method of monitoring and reporting reflection.
    Type: Application
    Filed: January 30, 2002
    Publication date: February 6, 2003
    Inventors: Sunao Kakizaki, Hideaki Tushima, Sigeki Kitajima, Yasuyuki Fukashiro
  • Patent number: 6434286
    Abstract: Variable (coupling ratio) optical couplers 3-0 and 6-0 each have ports of two inputs and two outputs, and the coupling ratio of inputted light is variably controlled by drive circuits 4-1 and 7-1. In the optical 1+1 switching structure, the coupling ratio of the variable (coupling ratio) optical coupler 3-0 is controlled to be 50%:50%. The variable (coupling ratio) optical coupler 6-0 is controlled to have the coupling ratio of 100%:0% or 0%:100%. In the optical 1:1 switching structure, the coupling ratios of the variable (coupling ratio) optical couplers 3-0 and 6-0 are controlled to be 100%:0% or 0%:100%. When a performance monitor (0) 9-0 detects signal degradation, signal interruption, and the like, the system controller 1-0 sends an instruction signal and the control circuits 20-0 and 21-0 output control signals for controlling coupling ratios of the variable (coupling ratio) optical couplers 3-0 and 6-0, respectively.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: August 13, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Hayashi, Sunao Kakizaki, Hideaki Tsushima, Shinichi Kuwano
  • Publication number: 20010046074
    Abstract: Upon receiving a check request 300 from a management system 250, a controller 230 sends a switching request 310 to an optical switch driver 165. The optical switch driver 165 sends a drive signal 320, and an optical switch 160 switches from a first transmission line 120 to a second transmission line 130. A receive signal performance monitor 190 sends a sensing result 330 for the second transmission line 130 to the controller 230. The controller 230 sends a switch-back request 340, and the optical switch 160 switches from the second transmission line 130 to the first transmission line 120. Based on information from the receive signal performance monitor 190, a first transmission line optical sensor 210, and a second transmission line optical sensor 220, the controller 230 performs a sensing result save 360 in a memory 240. A management system 250 saves a results report 400 from the controller 230 in a memory device.
    Type: Application
    Filed: May 4, 2001
    Publication date: November 29, 2001
    Inventors: Sunao Kakizaki, Hideaki Tsushima, Takashi Mori, Masahiro Takatori, Yukio Hayashi, Shinichi Kuwano
  • Publication number: 20010046344
    Abstract: Variable (coupling ratio) optical couplers 3-0 and 6-0 each have ports of two inputs and two outputs, and the coupling ratio of inputted light is variably controlled by drive circuits 4-1 and 7-1. In the optical 1+1 switching structure, the coupling ratio of the variable (coupling ratio) optical coupler 3-0 is controlled to be 50%:50%. The variable (coupling ratio) optical coupler 6-0 is controlled to have the coupling ratio of 100%:0% or 0%:100%. In the optical 1:1 switching structure, the coupling ratios of the variable (coupling ratio) optical couplers 3-0 and 6-0 are controlled to be 100%:0% or 0%:100%. When a performance monitor (0) 9-0 detects signal degradation, signal interruption, and the like, the system controller 1-0 sends an instruction signal and the control circuits 20-0 and 21-0 output control signals for controlling coupling ratios of the variable (coupling ratio) optical couplers 3-0 and 6-0, respectively.
    Type: Application
    Filed: January 30, 2001
    Publication date: November 29, 2001
    Inventors: Yuki Hayashi, Sunao Kakizaki, Hideaki Tsushima, Shinichi Kuwano
  • Patent number: 5627923
    Abstract: Optimal winding techniques usable in various information processors are handled. An opto-electric integrated circuit is provided which is excellent in productivity and alignment for free space interconnection.A three-dimensional opto-electric integrated circuit includes an active element substrate having a two-dimensional plane on which a plurality of active elements is disposed, and a passive element formed separately from the two-dimensional plane. The passive element includes a plurality of lenses disposed in correspondence to the plurality of active elements and a plurality of recursive reflectors for performing an optical path separating operation and an optical turning-back reflective operation to allow rays of light from the active elements to sequentially pass through the lenses and to propagate through the active elements, whereby the propagation of rays of light through a free space is used to optically interconnect the active elements one to the other.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: May 6, 1997
    Assignee: Hitachi, Ltd.
    Inventor: Sunao Kakizaki