JPH06222236A - Optical fiber communication line - Google Patents

Abstract

PURPOSE:To realize an optical fiber communication line capable of easily monitoring the connecting state of lines. CONSTITUTION:An optical cable 3 from a central station 1 is laid in a conduit line embedded in the ground, connected in manholes 4, 5, distributed between poles 6 on the ground, and pulled down to a terminal 2. The optical fibers constituting the optical cable 3 are covered with conductive coats, and connected in connecting points in the manholes 4, 5, and the conductive coats are also electrically connected to each other. In the central station 1, a fine voltage is applied to the conductive thin film of the optical fiber by an applying power source 7. The voltage is detected by a monitor part 8 set on the terminal 2, whereby the cut of the optical fiber can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber communication line, and more particularly to an optical fiber communication line capable of monitoring a coupling state.

[0002]

2. Description of the Related Art When a communication error occurs in a communication line using an optical fiber, it is important to immediately know the cause of the error in order to take countermeasures. Conventionally, there is a method of measuring a line using OTDR as a method of knowing an abnormality of a communication line, particularly a disconnection accident of the communication line.

However, this method requires that each terminal has an OT.
Since it is necessary to always have DR, it is not only a cost issue, but also a problem of complicating equipment, not only for terminals between trunk lines but also for individual terminals using a drop cable such as at home. . Measurement is not easy either.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to realize an optical fiber communication line capable of easily monitoring the coupling state of lines. It is what

[0005]

SUMMARY OF THE INVENTION The present invention is an optical fiber communication line in which optical fibers having a conductive coating are connected, wherein the optical fibers are fusion-spliced at a splicing portion, and the splicing-splicing portion. So that the electrically conductive coatings on both sides can be electrically connected to each other by a local connection to form an electrical circuit by the electrically conductive coating, and the coupling state of the optical fiber communication line can be monitored by the electrical circuit. It is characterized by having done.

A heat shrinkable tube having a metal film formed on the inner surface thereof or a conductive adhesive is used as the local connecting portion.

Further, in an optical fiber communication line in which an optical fiber having a conductive coating is connected, the optical fibers are connected by an optical connector at a connecting portion,
Further, the optical connector has conductivity so as to be electrically connected to a conductive coating, and in the coupled state of the optical connector, an electrical circuit is formed by the conductive coating, and the optical fiber communication line is coupled. It is characterized in that the state can be monitored by the electric circuit.

A metal material is used for the ferrule of the optical connector, or a ferrous material having an insulating material as a base material and a metal film formed on the surface is used, or an insulating material is used as the base material. It is also characterized in that a metal conductor is partially embedded therein.

Further, the present invention is also characterized in that the optical fiber and the conductive portion of the optical connector are fixed with a conductive adhesive, or that the optical connector is coupled with an insulating sleeve or a conductive sleeve. is there.

[0010]

According to the present invention, in an optical fiber communication line, an optical fiber having a conductive coating is used to electrically connect the conductive coatings of the optical fibers on both sides of the connection portion in a coupled state to each other, thereby providing an electrical connection. A circuit can be formed and the electrical circuit can monitor the coupling of the fiber optic communication line.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram of an embodiment of an optical fiber communication line of the present invention. In the figure, 1 is a central station, 2 is a terminal, 3 is an optical cable, 4 and 5 are manholes, 6 is a pole, 7 is an applied power source, and 8 is a monitoring unit. In this figure, the optical communication is performed from the central office 1 to the terminal 2 by the optical cable 3. The central office 1 is assumed to be a central office of a LAN, but it goes without saying that it may be a terminal that communicates with a terminal such as an exchange. Terminal 2
It is an individual terminal, for example, a subscriber's house.

In this example, between the central office 1 and the terminal 2,
They are connected by two optical fibers and perform mutual communication. The optical cable from the central office 1 is laid in a conduit (not shown) buried underground, connected by manholes 4 and 5 at multiple locations, and goes out on the ground, wired between poles 6 and dropped to the terminal 2. Has been. The optical fiber that constitutes the optical cable has a conductive coating,
At the connection points in the manholes 4 and 5, they are joined by fusion splicing or optical connector connection. Since the conductive coatings are also electrically connected to each other at the connection point, the central office 1 and the terminal 2 are also electrically connected.

The conductive coating of the optical fiber can be formed by applying a thin film of a suitable conductive material such as a carbon coating or a metal coating on the surface of the primary coating. Further, a conductive thin film may be applied on the insulating coating formed on the primary coating. The conductive thin film does not necessarily have to be formed over the entire circumference. The point is that conductivity should be imparted in the longitudinal direction of the optical fiber. Needless to say, the coating material itself may have conductivity.

At the central office 1, a minute voltage is applied to the conductive thin film of the optical fiber by the applied power source 7. As the voltage to be applied, a DC voltage, an AC voltage, or an appropriate voltage such as a pulse voltage or an appropriately modulated signal voltage can be used. The monitoring unit 8 installed in the terminal 2 uses a voltage detection circuit. When an AC voltage, pulse voltage, or appropriately modulated signal voltage is used as the applied power supply, detection of the voltage value may be sufficient, but if the frequency or modulation signal is detected, it will be erroneous. It is easy to avoid detection.

If the optical fibers in the central office 1 and the terminal 2 are connected, the monitoring section 8 can detect the applied voltage from the central office 1. If the monitoring unit 8 can detect the applied voltage from the central office 1 when a communication abnormality occurs, it can be determined that the line is not in failure. If the applied voltage from the central office 1 is not detected, a disconnection accident or the like occurs. I know what I did. The monitoring by the monitoring unit 8 does not always have to be performed. Also,
The applied power supply 7 may be provided on the terminal 2 side and the monitoring unit 8 may be provided on the central office 1 side.

FIG. 2 is a schematic configuration diagram of another embodiment of the optical fiber communication line of the present invention. In the figure, the same parts as those in FIG. In this embodiment, both the applied power supply 7 and the monitoring unit 8 are provided on the central office side. The conductive thin films of the two optical fibers connecting the central office 1 and the terminal 2 are insulated from each other and are connected on the terminal 2 side. Therefore, since the closed loop is formed by the conductive thin films of the two optical fibers, the applied power source 7 is provided on the conductive thin film side of one optical fiber, and the monitoring unit 8 is provided on the conductive thin film of the other optical fiber. By connecting, the optical fiber communication line can be monitored. In this case, the applied power may be applied only during monitoring. Also,
The applied power supply 7 and the monitoring unit 8 may be installed on the terminal 2 side.

An example of the connection structure of the connection points in each of the above-described embodiments will be described. The first and second examples are examples in which fusion splicing is performed, and the third to fifth examples are examples in which connection is performed by an optical connector. In each figure, the conductive part is hatched.

FIG. 3 is a sectional view of the first embodiment. In the figure, 10 is an optical fiber, 11 is a conductive layer, 12 is a coating, 1
3 is a fusion splicing part, 14 is a heat-shrinkable tube, and 15 is a metal film. Before the splicing, the conductive layer 11 of the optical fiber 10 is formed up to the fusion splicing portion 13, but in the fusion splicing, the vicinity of the fusion splicing portion is removed. Therefore, by simply performing fusion splicing, the conductive layers 1 on both sides are
No electrical connection of 1 is made. In this embodiment, the heat shrinkable tube 14 having the metal film 15 formed on the inner surface is used,
Electrical connection of the connection part was performed. Before performing the fusion splicing, the heat shrinkable tube 14 is passed through one of the optical fibers, and after the splicing connection, the heat shrinkable tube 21 is positioned at the fusion splicing portion 13 and heated to heat the heat shrinkable tube 14. Contract. Thereby, the fusion splicing part 13 is protected, and at the same time, the electrical connection of the conductive layer 11 of the optical fiber can be achieved by the metal film 15 on the inner surface of the heat shrinkable tube 14.

FIG. 4 is an explanatory diagram of the second embodiment. In the figure, 10 is an optical fiber, 13 is a fusion splicing part, 16
Is a heat-shrinkable tube, 17 is a conductive adhesive, and 18 is a strength member. The conductive adhesive 1 is provided in the region near the fusion splicing portion 13.
7 is applied, the strength member 18 is added, and the heat-shrinkable tube 16 is heat-shrinked. The conductive layers of the optical fibers on both sides are
It is electrically connected by the conductive adhesive 17. The strength member 18 may be conductive.

FIG. 5 is a sectional view of the third embodiment. In the figure, 10 is an optical fiber, 11 is a conductive layer, 21 is a ferrule, 22 is a coupling member, and 23 is a cap nut. The ferrule 21, the coupling member 22, and the cap nut 23 form an optical connector. The ferrule 21 is made of a conductive material, for example, a metal material, and the optical fiber 10 is inserted into its center hole. The conductive layer 11 of the optical fiber 10 is electrically connected to the ferrule 21. By inserting the ferrule 21 into the coupling member 22 and fixing it with the cap nut 23, the conductive layer 11 is electrically connected via the ferrule while the ferrules on both sides are in contact with each other. In this embodiment, since the coupling member 22 is made of an insulating material, it is possible to detect a state where a gap is created in the coupling of the ferrule 21. When the coupling member 22 is made of a conductive material, it is not possible to detect a state in which a gap is generated in the coupling, but it is possible to detect cutting of the optical fiber. In order to improve the electrical connection between the ferrule 21 and the conductive layer 11, the ferrule 21 and the conductive layer 11 may be fixed with a conductive adhesive.

Instead of using the conductive material as the base material of the ferrule 21, an insulating material may be used as the base material of the ferrule 21 and a metal film may be formed on the surface thereof.

6A and 6B are for explaining the fourth embodiment. FIG. 6A is a sectional view and FIG. 6B is a sectional view of the split sleeve. In the figure, 10 is an optical fiber, 11 is a conductive layer, 21 is a ferrule, 24 is a metal conductor, 25 is a contact for conduction, and 26 is a split sleeve. In this embodiment, an insulating material is used for the ferrule 21 and the metal conductor 2
4 was embedded and this was connected to the conductive layer 11. As described above, the metal conductor 24 may be connected to the conductive layer 11 by using a conductive adhesive. At least one conductive contact was connected from the metal conductor 24 and exposed on the peripheral surface of the ferrule 21. A metallic split sleeve 26 was used to connect the ferrule 21. The ferrules 21 are inserted from both sides of the split sleeve 26 for optical coupling. Since the conductive contacts 25 of the ferrules 21 on both sides are electrically connected by being bridged by the split sleeve, electrical connection between the conductive layers 11 on both sides can be achieved.

FIG. 7 is a sectional view of the fifth embodiment. In the figure, 10 is an optical fiber, 11 is a conductive layer, 21 is a ferrule, 24 is a metal conductor, 27 is a contact for conduction, and 28 is a coupling member. As the connecting member 28, the connecting member as described in FIG. 5 or a split sleeve can be used. When a split sleeve is used, it may be insulating. Also in this embodiment, an insulating material is used for the ferrule 21,
The metal conductor 24 is embedded. A conduction contact 27 is embedded in the tip of the ferrule 21 and connected to the metal conductor 24. Also in this embodiment, the metal conductor 24 may be connected to the conductive layer 11 by using a conductive adhesive. The ferrule 21 is coupled by inserting it into the insertion hole of the coupling member 28. The coupling member may be an insulating material. Also in this embodiment, the ferrule 21
It is also possible to detect a state in which a gap is generated in the coupling of the.

[0024]

As is apparent from the above description, according to the present invention, in an optical fiber communication line, an electric circuit is formed by connecting optical fibers, and the coupling state of the optical fiber communication line is monitored by the electric circuit. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an optical fiber communication line of the present invention.

FIG. 2 is a schematic configuration diagram of another embodiment of the optical fiber communication line of the present invention.

[Figure 3]

FIG. 7 is an explanatory diagram of an embodiment of a connection structure of connection points according to the present invention.

[Explanation of symbols]

 1 Central Office 2 Terminal 3 Optical Cable 4,5 Manhole 6 Pole 7 Applied Power Supply 8 Monitoring Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Fujita 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Hideo Kobayashi 1-6, Uchisaiwai-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp. (72) Inventor Makoto Sato 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (9)

[Claims] 1. In an optical fiber communication line in which optical fibers having a conductive coating are connected, said optical fibers are
It is fusion-bonded at the connection portion, and is connected by a local connection portion that electrically connects the conductive coatings on both sides beyond the fusion-bonded portion, forming an electric circuit by the conductive coating, An optical fiber communication line characterized in that the coupling state of the optical fiber communication line can be monitored by the electric circuit. 2. A heat-shrinkable tube having a metal film formed on its inner surface is used as the local connecting portion.
The optical fiber communication line described in. 3. The optical fiber communication line according to claim 1, wherein a conductive adhesive is used as the local connection portion. 4. An optical fiber communication line connecting optical fibers having a conductive coating, wherein the optical fibers are
The optical connector is connected at the connection portion by an optical connector, and the optical connector is electrically conductive so as to be electrically connected to a conductive coating. In the coupled state of the optical connector, an electric circuit is formed by the conductive coating. And a connection state of the optical fiber communication line can be monitored by the electric circuit. 5. The optical fiber communication line according to claim 4, wherein a metal material is used for the ferrule of the optical connector. 6. The optical fiber communication line according to claim 4, wherein an insulating material is used for the ferrule of the optical connector, and a metal film is formed on the surface thereof. 7. The optical fiber communication line according to claim 4, wherein an insulating material is used for the ferrule of the optical connector, and a metal conductor is embedded in a part of the insulating material. 8. The optical fiber and the conductive portion of the optical connector are fixed by a conductive adhesive.
7. The optical fiber communication line according to any one of items 1 to 7. 9. The optical fiber communication line according to claim 4, wherein the optical connector is coupled with an insulating sleeve or a conductive sleeve.