Patents by Inventor Kiyohisa Fujita

Kiyohisa Fujita 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: 6900883
    Abstract: A swept-wavelength loss measuring system is provided with an arrangement including a tunable laser source that outputs light to a DUT with the wavelength being continuously varied, and outputs measuring trigger signals at arbitrary intervals, at least one optical power meter for measuring an intensity of light transmitted through the DUT in response to reception of each of the measuring trigger signals, a wavelength measuring unit for measuring a wavelength of the outputted light from the tunable laser source in response to reception of each of the measuring trigger signals, and an arithmetic operation unit carrying out an arithmetic operation of the outputs from the optical power meter and the wavelength measuring unit to output a light intensity value relative to each wavelength. The arrangement assures accuracy of the measured wavelength.
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: May 31, 2005
    Assignee: Ando Electric Co., Ltd.
    Inventors: Kiyohisa Fujita, Nobuaki Ema
  • Patent number: 6798510
    Abstract: Wavelength dependent measurement is made by launching light into an object 8 to be measured and receiving transmitted light from the object 8 while continuously changing wavelengths of output light. Next, peak wavelength detection processing for detecting a wavelength at the time when loss or gain of the transmitted light from the object 8 becomes maximum based on a wavelength dependent measurement result is performed. Then, polarization dependent loss measurement processing for measuring polarization dependent loss of the object 8 is performed by measuring the transmitted light from the object 8 while launching light of a measurement wavelength detected into the object 8 and randomly changing a polarization state of the light. Further, a control circuit processes associating a wavelength dependent analysis result with a PDL measurement result, and displays its result on a display part 2.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: September 28, 2004
    Assignee: Ando Electric Co., Ltd.
    Inventor: Kiyohisa Fujita
  • Patent number: 6686578
    Abstract: Optical wavelength sensitivities in an optical meter used for a sweep synchronization measurement are corrected by a method comprising the steps of measuring a plurality of reference values when no device under test is connected to the optical meter, computing a series of corrective values for the reference values for a plurality of selected reference wavelengths, respectively, such that the reference value at one of the selected reference wavelengths is zero, correcting a plurality of actual measured values using the series of corrective values when an device under test is connected to the optical meter, and displaying the actual measured values corrected.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: February 3, 2004
    Assignee: Ando Electric Co., Ltd.
    Inventor: Kiyohisa Fujita
  • Patent number: 6646428
    Abstract: Techniques for use in sweep synchronization test equipment include receiving a simulation setting and displaying a simulated result based on the simulation setting and previously-measured data. The equipment is switched to a measurement mode in response to user activity, and the simulation setting is used as a control setting. A new measurement is performed based on the control setting. The displayed simulated result is updated based on data obtained from the new measurement.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: November 11, 2003
    Assignee: Ando Electric Co., Ltd.
    Inventor: Kiyohisa Fujita
  • Publication number: 20030164940
    Abstract: A swept-wavelength loss measuring system is provided with an arrangement including a tunable laser source that outputs light to a DUT with the wavelength being continuously varied, and outputs measuring trigger signals at arbitrary intervals, at least one optical power meter for measuring an intensity of light transmitted through the DUT in response to reception of each of the measuring trigger signals, a wavelength measuring unit for measuring a wavelength of the outputted light from the tunable laser source in response to reception of each of the measuring trigger signals, and an arithmetic operation unit carrying out an arithmetic operation of the outputs from the optical power meter and the wavelength measuring unit to output a light intensity value relative to each wavelength. The arrangement assures accuracy of the measured wavelength.
    Type: Application
    Filed: March 3, 2003
    Publication date: September 4, 2003
    Inventors: Kiyohisa Fujita, Nobuaki Ema
  • Publication number: 20030117625
    Abstract: Wavelength dependent measurement is made by launching light into an object 8 to be measured and receiving transmitted light from the object 8 while continuously changing wavelengths of output light. Next, peak wavelength detection processing for detecting a wavelength at the time when loss or gain of the transmitted light from the object 8 becomes maximum based on a wavelength dependent measurement result is performed. Then, polarization dependent loss measurement processing for measuring polarization dependent loss of the object 8 is performed by measuring the transmitted light from the object 8 while launching light of a measurement wavelength detected into the object 8 and randomly changing a polarization state of the light. Further, a control circuit processes associating a wavelength dependent analysis result with a PDL measurement result, and displays its result on a display part 2.
    Type: Application
    Filed: December 18, 2002
    Publication date: June 26, 2003
    Applicant: Ando Electric Co., Ltd.
    Inventor: Kiyohisa Fujita
  • Publication number: 20020008194
    Abstract: Optical wavelength sensitivities in an optical meter used for a sweep synchronization measurement is corrected by a method comprising the steps of measuring a plurality of reference values when no device under test is connected to the optical meter; computing a series of corrective values for the reference values for a plurality of selected reference wavelengths, respectively, such that the reference value at one of the selected reference wavelengths is zero; correcting a plurality of actual measured values using the series of corrective values when an device under test is connected to the optical meter; and displaying the actual measured values corrected.
    Type: Application
    Filed: June 29, 2001
    Publication date: January 24, 2002
    Inventor: Kiyohisa Fujita
  • Publication number: 20020000799
    Abstract: Techniques for use in sweep synchronization test equipment include receiving a simulation setting and displaying a simulated result based on the simulation setting and previously-measured data. The equipment is switched to a measurement mode in response to user activity, and the simulation setting is used as a control setting. A new measurement is performed based on the control setting. The displayed simulated result is updated based on data obtained from the new measurement.
    Type: Application
    Filed: June 6, 2001
    Publication date: January 3, 2002
    Inventor: Kiyohisa Fujita