Abstract: A distributed position detection rope includes: basic optical elements each including an optical fiber, tensile strength bodies, and a sheath material and the tensile strength bodies; a cylindrical inner sheath layer having a first optical element formed by arranging a plurality of the basic optical elements which are arranged at positions on the same circle and are helically wound at a predetermined pitch along the axial direction of the axis; and a cylindrical outer sheath layer on the outer side of the inner sheath layer and having a second optical element which are arranged at positions on the same circle and are helically wound along the axial direction so as to have a placement angle different from that of the basic optical elements of the first optical element.

Abstract: A DPTSS fiber optic cable includes an optical fiber sheathing cylindrical metal tube accommodating a pressure sensor optical fiber and having a plurality of through holes formed therein; and pressure blocking sections formed at intervals in the axial direction of the cable.

Abstract: Initial data and target data are frequency-analyzed to obtain an initial Rayleigh-scattering spectrum (RSS) and a target RSS, respectively. A distance correction is performed for the target RSS by comparing the target RSS with the initial RSS, and a Rayleigh spectrum shift is determined on the basis of a correlation coefficient between the initial RSS and the target RSS after distance-corrected.

Abstract: A distributed pressure, temperature, strain (DPTS) sensing cable includes at least two slotted fiber optic metal wires each having a slot groove extended along in an outer circumference of the wires to encapsulate optical fibers in the slot grooves. The two slotted fiber optic metal wires have characteristics different from each other.

Abstract: A DPTSS fiber optic cable includes an optical fiber sheathing cylindrical metal tube accommodating a pressure sensor optical fiber and having a plurality of through holes formed therein; and pressure blocking sections formed at intervals in the axial direction of the cable.

Abstract: A distributed pressure, temperature, strain (DPTS) sensing cable includes at least two slotted fiber optic metal wires each having a slot groove extended along in an outer circumference of the wires to encapsulate optical fibers in the slot grooves. The two slotted fiber optic metal wires have characteristics different from each other.

Abstract: A fiber optic biodiagnostic sensor system includes a blood vessel insertable pressure distribution measurement device to be inserted in vivo into a blood vessel to measure distributions of temperature and pressure of an object to be measured along a predetermined site, the device having an SM optical fiber deformable by temperature and strain, a structural member being in contact with a portion of the optical fiber to convert pressure of the to-be-measured object to strain of the optical fiber; and an outer layer converting the optical fiber and the structural member. The sensor system further includes a measurement unit emitting laser light into the SM optical fiber, detecting a frequency shift produced in the scattered light, and calculating a blood pressure at a given position of the optical fiber from a pressure change and a strain change of the SM optical fiber that are calculated from the frequency shift.

Abstract: Distributions of a Brillouin frequency shift and a Rayleigh frequency shift in optical fibers set up in a material are measured from scattered waves of pulse laser light entered into the optical fibers, and distributions of pressure, temperature, and strain of the material along the optical fibers at a measurement time point are analyzed using coefficients that are inherent to the set up optical fibers and correlate pressure, temperature, and strain of material with the Brillouin frequency shift and the Rayleigh frequency shift.

Abstract: In an optical fiber cable that includes an optical fiber core for measuring pressure and a multilayer armor cable for measuring temperature, an annular clearance space having a desired thickness is formed between the optical fiber core and the multilayer armor cable and fixing members for fixing the optical fiber core and the multilayer armor cable are provided at predetermined intervals in the axial direction of the optical fiber cable.

Abstract: A fiber optic biodiagnostic sensor system includes a blood vessel insertable pressure distribution measurement device to be inserted in vivo into a blood vessel to measure distributions of temperature and pressure of an object to be measured along a predetermined site, the device having an SM optical fiber deformable by temperature and strain, a structural member being in contact with a portion of the optical fiber to convert pressure of the to-be-measured object to strain of the optical fiber; and an outer layer converting the optical fiber and the structural member. The sensor system further includes a measurement unit emitting laser light into the SM optical fiber, detecting a frequency shift produced in the scattered light, and calculating a blood pressure at a given position of the optical fiber from a pressure change and a strain change of the SM optical fiber that are calculated from the frequency shift.

Abstract: A plurality of optical fibers is helically embedded in tubular installation layers on the outer circumferential surface of a shaped body having a circular cross section. A three-dimensional position of the shaped body after deformed produced by bend, torsion, or stretch due to external force is measured by utilizing frequency change or phase change of pulse laser light emitted into the optical fibers caused by Brillouin scattering and/or Rayleigh scattering occurring in the optical fiber deformed in accordance with the shaped body deformation.

Abstract: Under a known pressure is externally applied to a reference member to which an optical fiber is fixed, test light is allowed to enter the optical fiber, and at least one of a reference Brillouin measurement for determining a reference Brillouin frequency shift amount based on the Brillouin scattering phenomenon, and a reference Rayleigh measurement for determining a reference Rayleigh frequency shift amount based on the Rayleigh scattering phenomenon is performed. A Brillouin measurement coefficient or a Rayleigh measurement coefficient is determined from these calculation results. An optical fiber is fixed to a sample member, the volumetric change of which is unknown, and the same sample Brillouin measurement or sample Rayleigh measurement is performed to determine the frequency shift amount. The volumetric change of the sample member is determined from the sample Brillouin or the sample Rayleigh frequency shift amount, and from the Brillouin or the Rayleigh measurement coefficient.

Abstract: In an optical fiber cable that includes an optical fiber core for measuring pressure and a multilayer armor cable for measuring temperature, an annular clearance space having a desired thickness is formed between the optical fiber core and the multilayer armor cable and fixing members for fixing the optical fiber core and the multilayer armor cable are provided at predetermined intervals in the axial direction of the optical fiber cable.

Abstract: The present invention provides a recording device that offers a large displacement control effect. The recording device includes a recording medium 224, a motor 222 that drives the recording medium, and a recording device head M1 that records and reproduces a signal to and from the recording medium. The recording device also has a displacement control mechanism M2. The displacement control mechanism M2 includes a vibrating plate 226 that has two opposing surfaces facing the recording medium, the vibrating plate being displaced in the rotation axis direction of the recording medium; and an oscillator 232 that is positioned away from the two opposing surfaces of the vibrating plate facing the recording medium, the oscillator driving and displacing the vibrating plate.

Abstract: A plurality of optical fibers is helically embedded in tubular installation layers on the outer circumferential surface of a shaped body having a circular cross section. A three-dimensional position of the shaped body after deformed produced by bend, torsion, or stretch due to external force is measured by utilizing frequency change or phase change of pulse laser light emitted into the optical fibers caused by Brillouin scattering and/or Rayleigh scattering occurring in the optical fiber deformed in accordance with the shaped body deformation.

Abstract: The present invention provides a recording device that offers a large displacement control effect. The recording device includes a recording medium 224, a motor 222 that drives the recording medium, and a recording device head M1 that records and reproduces a signal to and from the recording medium. The recording device also has a displacement control mechanism M2. The displacement control mechanism M2 includes a vibrating plate 226 that has two opposing surfaces facing the recording medium, the vibrating plate being displaced in the rotation axis direction of the recording medium; and an oscillator 232 that is positioned away from the two opposing surfaces of the vibrating plate facing the recording medium, the oscillator driving and displacing the vibrating plate.

Abstract: Under a known pressure is externally applied to a reference member to which an optical fiber is fixed, test light is allowed to enter the optical fiber, and at least one of a reference Brillouin measurement for determining a reference Brillouin frequency shift amount based on the Brillouin scattering phenomenon, and a reference Rayleigh measurement for determining a reference Rayleigh frequency shift amount based on the Rayleigh scattering phenomenon is performed. A Brillouin measurement coefficient or a Rayleigh measurement coefficient is determined from these calculation results. An optical fiber is fixed to a sample member, the volumetric change of which is unknown, and the same sample Brillouin measurement or sample Rayleigh measurement is performed to determine the frequency shift amount. The volumetric change of the sample member is determined from the sample Brillouin or the sample Rayleigh frequency shift amount, and from the Brillouin or the Rayleigh measurement coefficient.

Abstract: Distributions of a Brillouin frequency shift and a Rayleigh frequency shift in optical fibers set up in a material are measured from scattered waves of pulse laser light entered into the optical fibers, and distributions of pressure, temperature, and strain of the material along the optical fibers at a measurement time point are analyzed using coefficients that are inherent to the set up optical fibers and correlate pressure, temperature, and strain of material with the Brillouin frequency shift and the Rayleigh frequency shift.

Abstract: In an optical disc drive, a degradation of traveling performance of an optical pickup under hard acceleration or hard deceleration in a random access operation or the like results in a degradation of recording/reproducing performance. Groove structure is provided between two gears of a guide feed provided in an optical pickup, and the groove forms bending structure. Thus, the engagement state between a screw gear and the gears of the guide feed is stabilized. This makes it possible to prevent tooth jumping and step-out from occurring in the gears during the traveling of the optical pickup, achieving stable traveling. In consequence, the recoding/reproducing performance of the optical disc drive can be improved.

Abstract: The present invention provides a distributed optical fiber sensor capable of measuring the strain and temperature of an object to be measured simultaneously and independently with high spatial resolution. A distributed optical fiber sensor FS is a distributed optical fiber sensor which uses an optical fiber 15 as a sensor, and a strain and temperature detector 14 measures a Brillouin frequency shift amount caused by a strain and a temperature generated in the optical fiber 15 by using a Brillouin scattering phenomenon, measures a Rayleigh frequency shift amount caused by the strain and temperature generated in the optical fiber 15 by using a Rayleigh scattering phenomenon, and calculates the strain and temperature generated in the optical fiber 15 from the measured Brillouin frequency shift amount and Rayleigh frequency shift amount.