JPS62127808A - Optical flat cord - Google Patents

Abstract

PURPOSE:To avoid the concentration of a stress to an optical fiber of a separated part by forming an optical flat cord by connecting each tip part of plural wires of optical fiber core wires to an optical connector, and separating plural wires of optical fiber core wires extending over a prescribed length, in the vicinity of the tip part. CONSTITUTION:Plural slits 191-199 are provided by excising, etc., partially a housing 18 of an optical fiber cable 10A, extending over a prescribed length (l) from an outlet of a rubber sheath 25, and as shown by a sectional drawing in a chain line II-II, each fiber core wire 111-1110 is separated from each other. In this way, even when it has been connected to an equipment so that a main plane of an optical connector 20 becomes vertical, each optical fiber 121-1210 is not influenced by each other, in a section where the slits 191-199 have been provided, bent freely so that each stress becomes minimum, and the possibility of a crack and a breakdown in the course of use is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical cladding cord suitable for connecting equipment.

C. Summary of the Invention] The present invention connects each tip of a plurality of optical fiber cores of an optical flat cable to an optical connector to form an optical flat cord, and connects a plurality of optical fiber cores near the tip. The wire is separated over a predetermined length (thereby, stress concentration on the optical fiber at this separated portion is avoided).

[Conventional technology]

Optical fibers are used in long-distance transmission fields such as public communication networks due to their low loss and broadband properties, but their noise resistance also allows them to be used inside transmission equipment frames and transmission terminal stations. It has also become widely used in the field of short-distance transmission.

As shown in FIG. 3, an optical fiber (strand) (2) has a core (3) made of quartz glass with a diameter of 50 μm, for example, and is surrounded by a cladding (4) with a low refractive index of 125 μm in diameter. It consists of This optical fiber (2) is provided with a primary coating (5) made of, for example, nylon for reinforcement, and is further provided with a braided layer (6) of aromatic polyamide fiber. 2 with polyvinyl chloride etc.
A secondary coating (7) is applied to form an optical fiber (11).The outer diameter of the secondary coating (7) is, for example, 3 mm.

This optical fiber core wire (1) is assembled in the same manner as a conventional cable to form an optical fiber cable.

A removable connector connection is used to connect the optical fiber and the transmission equipment as described above.

Generally, an optical connector has optical contacts (8A) and (8B) called ferrules, as shown in FIG. and (8B) is inserted and fixed into a through hole (not shown) provided in the center to match the clad diameter,
The end face is polished. Both filters (8A) and (8B)
The relative position of is maintained, for example, by an adapter (not shown) with a precision sleeve (9).

[Problem that the invention seeks to solve]

By the way, when connecting devices using optical fibers in a transmission terminal station or the like, one device often has a plurality of connection points. In this case, when using multiple optical fiber cores connected to an optical single-core connector, that is, multiple single-core optical fiber cords, it is troublesome to connect and disconnect the optical connector, and it is difficult to connect and disconnect the optical connector between each optical connector seat on the equipment side. A problem arises in that a predetermined space is required for the connection, which increases the space required for the connection.

In addition, when using round optical multicore connectors and optical fiber cables to connect devices, the trouble of connecting and disconnecting connectors is eliminated, but as the optical connectors become larger, the optical fiber cables also become thicker and bendier. Therefore, there was a problem in that the space required for the bending became large.

In order to solve these problems, it is possible to connect devices using flat optical cables and flat optical multi-core connectors.

An optical flat cable is constructed by joining optical fiber cores (1) as shown in FIG. 3 to each other as shown in FIG.

That is, in FIG. 5, a plurality of optical fiber cores (lb), which are optical fibers (12x) and the like coated with a primary coating (151), a braided Fi (16t), a secondary coating (171), etc., are arranged on the same plane. The strips (5 strips in the example shown) are arranged in parallel, and each core wire (llz) to (lls) is joined over its entire length by a common plastic jacket (18),
An optical flat cable aω is constructed.

The optical flat cable aφ as described above is inserted from the rear opening (22) of the outer casing (21) of the flat optical multicore connector (20) as shown in FIG. In this example, there are 10 optical fibers (121).

(122) ... (12to) are arranged on the same plane (231), (232
) ... (231Q: are respectively inserted and fixed. The optical flat cable αψ is appropriately held in the outer casing (21) of the optical connector (20) by the holder (24), and is held in the vicinity of the opening (22). It is inserted into a protective rubber sheath (25).
) and the optical flat cable Ql may be interposed with a heat shrink tube. In addition, the flange (26) of the outer casing (21)
In order to ensure connection with the connector seat on the equipment side,
A pair of screws (27) is provided.

When the optical flat cord formed in this way is attached so that the main plane of the flat connector (20) is horizontal, the thickness of the optical flat cable αω is, for example, several meters.
Since it is as small as it+, it can be bent easily and without strain, and in combination with the use of a flat optical multi-core connector (20), the space factor for connection is significantly improved.

However, in small devices, for example, because electrical connectors and other parts are attached to the back panel, it is necessary to attach the optical connector seat so that the main plane of the flat optical multi-core connector (20) as described above is vertical. There are times when you have to.

In this case, since the optical flat cable αω is bent with a small radius of curvature in the vicinity of the optical connector (20), the optical fibers (121) on both sides of the cable are bent.

Stress is concentrated on (122), (12s), (12to), etc., and due to this stress,
The problem of optical fiber cranking and breakage occurs.

In view of the above, an object of the present invention is to provide an optical flat cord that does not require restrictions on the mounting direction of a flat optical multi-core connector.

[Means for solving problems]

The present invention enables the distal end of an optical flat cable in which a plurality of optical fiber core wires are joined to each other to be connected to an optical connector and attached to a device body, etc. This is an optical flat cord in which optical fiber cores are separated from each other over a predetermined length.

[Effect]

With this configuration, concentration of stress on the optical fiber at the separated portion is avoided regardless of the direction in which the optical connector is attached.

〔Example〕

Hereinafter, an embodiment of the optical flat cord according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows the configuration of an embodiment of the present invention. In this FIG. 1, (IOA) is an optical flat cable, which has a plurality of optical fiber cores (lh) as shown in FIG.
), (112)... are joined by a common plastic jacket (18), and multiple optical fibers (121), (122).

... (121o) is the ferrule of the optical connector (20) <231), (232), ...C
231o) are respectively connected to the above-mentioned No. 6
It is similar to the optical flat cable OI shown in the figure.

In this embodiment, as shown in FIG.
is partially removed, etc., and a plurality of slits (191
), (192), . ~(llto) are separated from each other.

Therefore, in this embodiment, even if the optical connector (20) is connected to a device with its main plane vertical,
Each optical fiber (121) to (12to) has a slit (
In the section where 191) to 19s are provided, the crank bends freely without being influenced by each other so that the stress of each is minimized, and there is no risk of the crank breaking during use.

Therefore, the flat optical connector seat can be attached in any direction on the device side, increasing the degree of freedom in designing the device body, and making it possible to further reduce the size of the device.

The above-mentioned optical flat cable (IOA'') is connected by a common jacket (18) over its entire length, and slits (191) to (199) are provided at the ends thereof, but the slits (191) to (199) are provided at predetermined intervals of, for example, 30 cm. Each optical fiber (111) to (llz
o) may be partially joined.

〔Effect of the invention〕

As described in detail above, according to the present invention, a plurality of coated optical fibers are separated from each other over a predetermined length near the tip of the optical flat cable connected to the optical connector. An optical flat cord is obtained that can avoid concentration of stress on each optical fiber in the separated portion, regardless of the direction in which the optical connector is attached.

[Brief explanation of drawings]

1 and 2 are a plan view and an enlarged cross-sectional view of essential parts of an optical flat cord according to an embodiment of the present invention, and FIG.
The figure is a perspective view showing an example of the configuration of a conventional optical fiber.
The figure is a route diagram showing an example of the configuration of the main parts of a conventional optical connector, FIG. 5 is a perspective view showing an example of the configuration of an optical flat cable for explaining the present invention, and FIG. FIG. 3 is a plan view showing an example of the structure of a code. α, (IOA) is an optical flat cable, (llz
) to (11+o) are optical fibers, (121) to (
121o) is an optical fiber, (18) is an outer jacket, (191
) to (19s) are slits, and (20) is an optical connector. 1 7 fibers cm Ishiba pot's special fiber's a hard 1 Fig. 3 Yarai's yokorita's Gakuan p4LA A row Fig. 4! ! 2, 7 U, To γ-A I, 7 Rake, To γ-A Structure A Figure 5

Claims (1)

[Scope of Claims] An optical flat cable in which a plurality of optical fiber core wires are bonded together can be attached to a device body by connecting the tip end to an optical connector, and in the vicinity of the tip end of the optical flat cable. An optical flat cord characterized in that the plurality of coated optical fibers are separated from each other over a predetermined length.