JPH09197142A - Light branching unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive light branching unit capable of being simply replaced without exerting influence upon optical communication. SOLUTION: This light branching unit 10 is used for an optical line access device for leading test light into an optical line and many units 10 are arrayed on a wiring frame at a prescribed pitch so as to be optionally attached/detached to connect a terminated out-of-station cable to an intra-station cable. Each unit 10 is provided with a coupler 11 for connecting at least one of an optical fiber 13 for the out-of-station cable and a test fiber 14 for leading test light into the unit 10 to one end of an intra-station side fiber 15 and an adaptor 12 fixed to the other end of the fiber 15 and connected to the intra-station cable so as to be optionally attached/detached.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical branching unit used in an optical line access device for introducing test light into an optical line.

[0002]

2. Description of the Related Art An optical branching unit used in an optical line access device for the purpose of testing or monitoring an optical line in an optical line system is disclosed in, for example, Japanese Patent Laid-Open No. 6-18774.
The one disclosed in FIG. 15 of the publication is known. This optical branching unit is a flat box with a thickness of about 12 mm.
For example, as shown in FIG. 4, a large number of optical branch units 1 are slidably arranged at a pitch of 16 mm and used in a wiring rack having a plurality of stages. Then, as shown in FIG. 3, the optical branching unit 1 is attached to an end portion of each station inner fiber 3 which extends from the optical branching unit 1 and is branched into a plurality of connecting portions 2 provided on the back surface of the wiring rack. Connector 3
a is connected to the corresponding optical fiber 4 of the intra-station cable. Here, the arrow shown in FIG. 3 is the pulling direction of the optical branching unit 1.

[0003]

By the way, the optical branch unit is pulled out from the wiring rack to the front side as shown in FIG. Need to be inserted and removed. However, since a large number of optical branching units are arranged on the wiring rack as described above, the space from which one of the optical branching units has been pulled out must be used to replace the optical branching unit by inserting / removing the connector. become.

Therefore, when the optical branching unit is replaced, bending or lateral pressure is applied to the optical fibers of the adjacent optical branching units, and the connection loss at the connecting portion of the optical fibers fluctuates or the optical signal level becomes unstable. There is a possibility that it will adversely affect optical communication. In addition, the optical branching unit has a problem that the manufacturing cost increases because the extending fiber inside the branch is branched into a plurality of fibers.

The present invention has been made in view of the above points, and can be easily replaced without adversely affecting optical communication.
Moreover, it is an object to provide an inexpensive optical branching unit.

[0006]

According to the present invention, in order to achieve the above object, it is used in an optical line access device for introducing a test light into an optical line and is arranged in a wiring rack at a predetermined pitch so that it can be freely inserted and removed. In the optical branching unit for connecting the terminated out-of-station cable and the in-station cable, a coupler connecting at least one of the optical fiber of the out-of-station cable and the test fiber for introducing test light to one end of the in-station fiber, and The other end of the office inside fiber is attached and an adapter for detachably connecting to the inside office cable is provided.

[0007] Preferably, a connector which is detachable from the adapter is attached to the other end of the office inner fiber.
The optical branching unit can be attached / detached to / from the intra-station cable by simply inserting and removing it from the wiring rack, or by simply inserting and removing the connector attached to the end of each optical fiber in the intra-station cable from the adapter on the back surface of the wiring rack.

At this time, if an adapter and a detachable connector are attached to the other end of the station inner fiber, the optical branching unit can be easily assembled.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
This will be described in detail with reference to FIG. Optical branching unit 1
As shown in FIG. 1, reference numeral 0 denotes a flat box having a coupler 11 and an adapter 12 and a lid (not shown). Subunits 20 are arranged adjacent to each other by a slider 10a provided above. It is removably attached to the wiring rack described in the conventional art.

The coupler 11 is a waveguide type coupler that multiplexes and demultiplexes communication light and test light.
Also, one end of the test fiber 14 for introducing the test light is connected to one end of the office inner fiber 15. Here, the optical fiber 1
3, the test fiber 14 and the intra-station fiber 15 are each composed of, for example, an 8-core tape fiber, and are fixed to the optical branching unit 10 by a pulling member 16.

The adapter 12 detachably connects the other end of each of the optical fibers 15a separated from the central fiber of the station inner fiber 15 to the intra-station cable, and has a single-core connector 15b attached to the other end of each optical fiber 15a. Are connected.
When the optical branching unit 10 is inserted into or removed from the wiring rack, the adapter 12 is attached / detached with a similar connector attached to the back surface of the wiring rack. This connector is attached to the corresponding optical fiber of the intra-office cable. Therefore, each optical fiber 15a of the intra-station fiber 15 is detachably connected to the corresponding optical fiber of the intra-station cable.

The connector attached to the corresponding optical fiber of the intra-station cable can be directly connected to the adapter 12 of the optical branching unit 10 without being attached to the back surface of the wiring rack. In this case, before pulling out the optical branching unit 10 from the wiring rack, the connector may be pulled out from the adapter 12 by turning to the rear surface of the wiring rack. As shown by the arrow in FIG. 1, the subunit 20 is slidably attached to the optical branching unit 10 and has an openable / closable lid (not shown). The sub-unit 20 connects the other end of the optical fiber 13 of the out-of-office cable extending from the optical branching unit 10 with an extra length of a predetermined length and the other end of the test fiber 14 introducing the test light to the termination cable 21 and the test apparatus side, respectively. Of the optical fiber 22.

Since the optical branching unit 10 is constructed as described above, it is necessary to replace the optical branching unit 10 with the one shown in FIG.
If the adapter 12 is pulled out to the front side of the wiring rack as indicated by the arrow, the adapter 12 can be easily detached from the corresponding optical fiber connector of the intra-station cable attached to the rear surface of the wiring rack. Then, when a new optical branching unit 10 is inserted, the adapter 12 is easily connected to the connector mounted on the back surface of the wiring rack, and can be replaced very easily. Moreover, the optical branching unit 10 can be replaced by simply inserting and removing it from the wiring rack. Therefore, there is no fear of bending the optical fibers of the adjacent optical branching units, so that the optical communication is not adversely affected, and the structure is simple, so that it can be provided at low cost.

Further, the connection work required after the optical branching unit is assembled is the optical fiber 1 of the outside cable.
Most related to 3. Therefore, for example, like the optical branching unit shown in FIG. 2, only the optical fiber 13 of the out-of-office cable is accommodated in the subunit 20 and connected to the termination cable 21, and the test fiber 14 is accommodated in the subunit 20. Instead, it may be extended along the side surface adjacent to the subunit 20 of the optical branching unit.

In the above embodiment, the case of an 8-fiber optical fiber has been described, but it goes without saying that the number of optical fibers is not limited to this. Further, the connector to be connected to the adapter 12 may be a single-core connector or a multi-core connector.

[0016]

As is apparent from the above description, according to the present invention, it is possible to provide an inexpensive optical branching unit that can be easily replaced without adversely affecting optical communication. At this time, since the adapter and the detachable connector are attached to the other end of the station inner fiber, the optical branching unit can be easily assembled.

[Brief description of drawings]

FIG. 1 is a front view of an optical branching unit of the present invention.

FIG. 2 is a front view showing a modified example of the optical branching unit of FIG.

FIG. 3 is a front view showing a usage example of a conventional optical branching unit.

FIG. 4 is a perspective view showing a state in which conventional optical branching units are arranged on a wiring rack.

[Explanation of symbols]

 10 Optical branching unit 10a Slider 11 Coupler 12 Adapter 13 Optical fiber (outer station cable) 14 Test fiber 15 Station inner fiber 15a Optical fiber 15b Connector 16 Retracting member 20 Sub-unit 21 Termination cable 22 Optical fiber (on test equipment side)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masato Kuroiwa 3-19-3 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Naoki Nakao 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo No. Nippon Telegraph and Telephone Corporation (72) Inventor Takashi Ebihara 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. An optical branch used for an optical line access device for introducing a test light into an optical line and connecting a terminated external cable and an internal cable by arranging a plurality of them at a predetermined pitch on a wiring rack so that they can be freely inserted and removed. In the unit, a coupler that connects at least one of the optical fiber of the outside cable and the test fiber that introduces the test light to one end of the inside fiber of the station, and the other end of the inside fiber of the station is attached, and is detachable from the cable inside the station. An optical branching unit comprising an adapter for connecting to 2. The optical branching unit according to claim 1, wherein the other end of the local fiber is attached with a connector which is detachable from the adapter.