Nippon Telegraph and Telephone Corporation

Naotsugu Ambe

Hidenobu Hirota

Hiroyuki Iida

Takui Uematsu

Yasuhiro Maehara

Jun Onishi

Sachi Tsujimura

An object of the present invention is to provide, in a local-light coupling technique for improving efficiency of work, an optical fiber local-light coupling apparatus configured to hardly affect communication between an OLT and an ONU while causing light to leak from a coated optical fiber in such an amount that makes it possible to confirm a communication state. The optical fiber local-light coupling apparatus according to the present invention includes a first jig including a concave portion curved in a longitudinal direction with respect to a coated optical fiber, and a probe configured to receive leakage light leaking from the coated optical fiber being bent; a second jig including a convex portion curved in the longitudinal direction with respect to the coated optical fiber, the convex portion being configured to sandwich the coated optical fiber between the convex portion and the concave portion of the first jig; a pressing unit configured to apply pressing force in a direction in which the concave portion of the first jig and the convex portion of the second jig approach each other to form a bend in the coated optical fiber; and a reflective film configured to cover a surface of the concave portion of the first jig except for a leakage light passage portion through which, among the leakage light, reception leakage light to be received by the probe passes, and reflect and return the leakage light other than the reception leakage light to the coated optical fiber.

Optical fiber lateral input/output device

An object is to provide a determination device that determines a state of a terminal end portion of a coated optical fiber at any location of the coated optical fiber. Reflection of test light varies in a reflection amount at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. In other words, if the magnitude of the reflection amount at each wavelength can be known, the situation of the terminal end portion of the coated optical fiber can be estimated. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a light intensity ratio of each reflected light beams reflected at the terminal end. In addition, reflection of test light varies in return loss at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. If Rayleigh backscattered light can also be measured when measuring a reflection amount, the return loss can be known for each wavelength, and the situation of the terminal end portion of the coated optical fiber can be estimated from the result. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a return loss at the terminal end.

Judgment device and judgment method

It is intended to provide a cable pulling machine that can avoid, even when installed at a high place, a stop of pulling and a cable installation method. A cable pulling machine according to the present invention includes two roller portions c having outer peripheries between which a cable a is to be held and a guide f that introduces the cable a between the roller portions c. The guide f adjusts an angle θ formed between a straight line connecting respective centers o of the roller portions c and the cable a introduced between the roller portions c to a value of not less than 45° and not more than 90°.

Cable towing machine and cable laying method

The purpose of the present invention is to provide a hazard prediction method that can perform hazard prediction activities so as to prevent accidents, regardless of skills and personalities of workers. A hazard prediction method according to the present invention includes: photographing an outdoor facility along with environment to capture an image; collating the image with accident data including photos of outdoor facilities along with environment and accidents occurred at open-air facilities in the photos to detect, when a photo similar to the image is found, an accident occurred at an open-air facility in the photo from the accident data; extracting, from a safety measure list describing accidents, hazardous spots related to the accidents, and safety measures for prevention of the accidents, hazard information on a hazardous spot and a safety measure corresponding to the detected accident; receiving input information that is a safety measure devised by a worker for the hazardous spot; and comparing the input information with the hazard information to check that the input information and the hazard information match each other.

Danger prediction method and danger prediction device

An object of the present invention is to provide a versatile optical fiber lateral output device that can deal with various types of optical fiber core wires. An optical fiber input-output device according to the present invention includes: a first jigincluding a recess portionand an optical input-output means; a second jigincluding a projection portionand a guide groove; and a pressing unitconfigured to apply a pressing force in a direction in which the recess portionof the first jigand the projection portionof the second jigapproach each other so as to bend an optical fiber core wire. Letting R1 be a curvature radius of the recess portionof the first jig, θ1 be a central angle of the recess portion, R2 be a curvature radius of the projection portionof the second jig, and θ2 be a central angle of the projection portion, R2≤R1 and θ2≤θ1 are satisfied.

An object is to provide a highly versatile local-light detection apparatus for an optical fiber capable of supporting various types of coated optical fibers. A local-light detection apparatus for an optical fiber according to the present invention includes a first jig including a recess curved in a longitudinal direction of a coated optical fiber and an optical input and output device configured to make light incident on the coated optical fiber in which a bend is formed and to receive light leaking from the coated optical fiber, a second jig including a protrusion curved in the longitudinal direction of the coated optical fiber, the protrusion being configured to sandwich the coated optical fiber between the recess of the first jig and the protrusion, a presser configured to apply a pressing force in a direction in which the recess of the first jig and the protrusion of the second jig approach each other and to form the bend in the coated optical fiber, and fiber guides disposed at both ends of the recess of the first jig in the longitudinal direction of the coated optical fiber, and to arrange the coated optical fiber on a predetermined path on the recess of the first jig regardless of a diameter of the coated optical fiber when the presser forms the bend in the coated optical fiber.

Optical fiber side input and output device

There are provided an optical fiber display system and an optical fiber changeover method each enabling an efficient optical fiber changeover work. The optical fiber display system according to the present invention includes a plurality of core wire identification terminals. Each of the core wire identification terminalsincludes: bent part formation unitsconfigured to form a bent part at an optional position of an optical fiberand to leak optical signals propagating through the optical fiberfrom the bent part; analysis unitsconfigured to acquire identification numbers of communication apparatuses (and) included in the leaked optical signals, the communication apparatuses (and) being connected to respective ends of the optical fiber; a communication unitconfigured to inquire of a databasestoring relationship between the optical fiber and the communication apparatuses about the acquired identification numbers of the communication apparatuses, and to receive an identification number of the optical fibercorresponding to the acquired identification numbers of the communication apparatuses, from the database; and a display unitconfigured to display the acquired identification numbers of the communication.

Optical fiber display system and optical fiber switching method

The present disclosure has an object to provide a technique for enabling a communication state to be confirmed not in a communication building but in a work site, and to provide a technique for enabling correct splicing between optical cables to be confirmed before fusion splicing. The present disclosure is a communication apparatus identification deviceincluding an optical fiber bent portionobtained by, when a portion of optical fibers to which communication apparatuses (the OLT-and the ONU) for which appropriateness of connection is to be determined are connected on opposite ends is bent, bending a portion of the optical fibers in a vicinity of a clearance provided between the optical fibers, the clearance having a range in which the communication apparatuses for which appropriateness of connection is to be determined can communicate with each other, and a MAC address analysis unitthat analyzes communication light leaked out of the bent portion of the optical fibers in the vicinity of the clearance to acquire identification numbers (MAC addresses) of the communication apparatuses for which appropriateness of connection is to be determined.

Communication apparatus identification device, optical fiber connection system, communication apparatus identification method, and optical fiber connection method

Provided are a communication monitoring method and a communication monitoring apparatus capable of an operation of identifying a coated optical fiber regardless of a propagation direction of an optical signal even before communication between an OLT and an ONU is opened. The communication monitoring apparatus according to the present invention includes: an optical signal detection unitconfigured to receive, as a received signal, at least one of a downlink optical signal transmitted from an OLTor an uplink optical signal transmitted from an ONU; and a signal analysis unitconfigured to detect a signal type and unique information of a transmission source from information included in the received signal, determine whether the received signal is the downlink optical signal or the uplink optical signal on the basis of the signal type, and determine that the unique information of the transmission source is unique information of the OLT when the received signal is the downlink optical signal and that the unique information of the transmission source is unique information of the ONU when the received signal is the uplink optical signal.

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Tokyo, Japan

Naotsugu Ambe