JPS61252508A - Formation of multicore optical fiber core terminal and forming part of multicore optical fiber core terminal - Google Patents

Abstract

PURPOSE:To form a connecting part which has a high strength and is small in size, by covering a covering removed part with a heat treatment tube, forming a single core by bringing it to heating contraction, collecting plural pieces of tip parts of this single core and forming them as one body. CONSTITUTION:A heat contraction tube 5 is inserted to a covering removed end of an optical fiber which has removed a covering 1 of a single core I, and subsequently, by a heat contraction tube heating heater 6, the heat contraction tube 5 is brought to heating contraction. The single cores I of the same number as that of optical fibers 2' of a tape core II are collected, contained in a substrate 8, centering around the covering removed end 7 of the single core I, and thereafter, a substrate 8' is fitted and stuck by an adhesive agent 9. In this case, a groove of a width which can contain plural pieces of single cores I is formed on the substrate 8, and the adhesive agent layer 9 is stuck to the upper face of the groove. By containing in terminal forming tools 10, 10', a pitch of the optical fiber 2 is matched to a pitch P' of the optical fiber 2' of the tape core II. In this way, a welding connection of the single core and the tape core can be executed easily by using a multicore batch welding connecting device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method for forming a single fiber end and a terminal forming unit for connecting a tape core wire and a single fiber wire at once. .

(Prior Art and its Problems) Up until now, the common method for connecting tape core wires and single core wires has been to use connectors. First, a method for processing the ends of core wires in connectors will be briefly described. As shown in Fig. 1, when five single fibers I are arranged in parallel, the pitch p of the optical fiber 2 of the single fiber I is 0.9 l, and the optical fiber in the tape fiber 2' pinch p' is different from 0.3 m. Therefore, the coating 1 of the single fiber wires I was removed, and the five single fiber wires I with the optical fibers 2 exposed were placed in a V-groove for pitch conversion provided on the upper surface of the substrate 3 shown in FIG. accommodated within
By fixing, the pitch p of the optical fiber 2 on the single fiber ■ side is reduced to the pinch p of the optical fiber 2' in the tape fiber ■.
’. However, since the optical fiber 2 is accommodated in the curved V-groove 4, the surface of the optical fiber 2 may be seriously damaged, leading to breakage, and the length of the optical fiber 2 in the axial direction may be approximately 10 mm. Since the pitch is converted from p to p', it is necessary to bend the optical fiber 2 considerably, and this bending may cause problems such as breakage of the optical fiber 2 and increase in transmission loss. In addition, connectors have the advantage of being removable, but they require a large number of parts and take time to assemble.
It has the disadvantage of high cost.

In addition, for fusion splicing of tape core wire ■ and single fiber wire I, after terminal treatment is applied to tape core wire ■, a pair of optical fibers 2,
Since there is a method of fusion splicing 2', this terminal processing method will be briefly explained. The method for processing the end of the tape core (■) is to remove the coating over a distance of 20 to 30 cm from the end of the tape core (■), separate a plurality of optical fibers 2' within the tape core (■), and then separate these multiple optical fibers 2' from each other. The optical fibers 2' are individually coated to make the end portion of the tape core wire (I) into a single fiber I. In this terminal processing method, the coating at the end of the tape core wire (2) is removed for a long time, and each optical fiber 2' is further coated for a long length, so that the optical fiber 2'
It is easy to break and requires advanced terminal processing technology. Moreover, since the coating is discontinuous at the end where the coating is removed from the tape cable (2), stress tends to concentrate, and the optical fiber 2' often breaks. Moreover, since the optical fiber 2 of the tape core wire (■) which has been subjected to the terminal treatment as described above and the single fiber i%II are fusion spliced pair by pair, the workability is extremely poor.
The area that needs to be fixed to prevent external force from being applied is the tape core ■
Since the coating ranges from 1 to 2 single-core wires, there is a problem in that the area for accommodating the connection part becomes large.

(Object of the Invention) The object of the present invention is to solve these problems and to enable fusion splicing that can form a high-strength, compact joint by using a multi-fiber batch fusion splicing device. An object of the present invention is to provide a method for forming a multi-core optical fiber end and a multi-core optical fiber end forming unit.

(Structure of the Invention) The present invention provides a single heat-shrinkable tube or a heat-shrinkable tube that is fixed in advance to the end optical fiber from which the coating of the single-filament wire is removed, so that the outer diameter after shrinkage is equivalent to the pitch of the optical fiber of the tape core wire. The arrayed heat-shrinkable tubes are inserted and heated to form a single fiber end portion or a multi-core optical fiber end forming portion, and for the single fiber end portion, the optical fibers are arranged to form a tape-core optical fiber. The most important feature is that a plurality of optical fibers are assembled using terminal forming sections so as to face each other to form a multi-core optical fiber coated wire terminal forming section. Conventionally, there is no such type of terminal processing method for fusion splicing, and there is no technology for assembling multiple optical fibers after attaching a heat shrink tube to the optical fiber.
This is different from the formation technology of multi-fiber connector terminals.

Examples of the present invention will be described below.

(Embodiment 1) FIG. 3 is a diagram explaining the first embodiment of the present invention, in which l is a coating of a single-fiber wire ■, 2 is an optical fiber of a single-fiber wire ■, and 5
9 is a heat-shrinkable tube whose outer diameter after shrinking is equivalent to the pitch p' of the optical fiber 2' of tape core wire ■, 6 is a heater for heating the heat-shrinkable tube, 8°8' is a substrate for reinforcing the removed end of the coating, 9
1 is a hot-melt adhesive, and 10 is a terminal forming tool. To carry out this method, the covering 1 of the single-core wire I is shown in (a).
The heat shrink tube 5 is inserted into the optical fiber 2 from which the coating has been removed, up to the end where the coating is removed. Here, the length of the optical fiber 2 (L-l), which is obtained by subtracting the length l of the heat shrink tube 5 from the length of the optical fiber 2, must be secured to the length required for cutting the optical fibers 2 all at once. No. Next, as shown in (b), the heat shrink tube 5 is heated by the heat shrink tube heating heater 6.
Heat and shrink. Thereafter, as shown in (C), the same number of single fibers I as the optical fibers 2' of the tape core wire (■) are assembled and housed in the substrate 8 with the coated removed end 7 of the single fibers I as the center. The substrate 8' is fitted and bonded with adhesive 9. Here, the board 8 has a plurality of single-core wires as shown in the figure.
A groove with a width that can accommodate the
An adhesive layer 9 is pasted. This adhesive layer 9 is
A hot-melt adhesive may also be used.

On the other hand, as shown in the figure, the substrate 8' may have a flat surface with a size that can fit into the groove, and may have a structure in which an adhesive layer 9 is attached to one side, but the structure is not limited to this. As shown in (d), the end portion formed in this way is accommodated in the end forming tool 10.10', so that the pitch of the optical fiber 2 is adjusted to the pitch p' of the optical fiber 2' (of the ribbon core ■). let

Here, the terminal forming tool 10 is provided with a groove capable of accommodating the substrate 8.8' and a plurality of single fiber wires I, and (d)
As shown in the AA' cross section (d-1), grooves are formed such that the optical fibers 2 covered with the heat-shrinkable tubes 5 are arranged adjacently and in parallel. Also, terminal forming tool 10.1
0' may be bonded to each other, but if they have a removable structure, they can be removed after fusion splicing to be integrally reinforced with the fused portion, and the connecting portion can be made even more compact. (e) shows the completed multi-core optical fiber terminal section.

In this manner, in this embodiment, the optical fiber 2 at the end of the single-fiber wire is covered with the heat shrink tube 5 in advance, so that the optical fiber 2 is not damaged. In addition, the outer diameter of the heat-shrinkable tube 5 after shrinkage is determined by the pitch p of the optical fiber 2' of the tape core wire ■.
Since the pitches p and p' are aligned with each other, the pitches p and p' can be matched simply by arranging the single fiber wires adjacent to each other, which is very simple.

Furthermore, since multi-fiber batch fusion splicing for tape core wires can be applied during connection, workability is excellent, the connection portion can be made smaller, and a new connection device is not required.

(Embodiment 2) FIG. 4 shows a second embodiment of the present invention. 11 is the pitch p' of the optical fiber 2' whose outer diameter after shrinkage is tape core wire ■.
This is a heat-shrinkable tube similar to the above, and has a structure in which multiple tubes are integrated in parallel in advance. Here, a case of five lines will be explained.

First, as shown in (a), 5
Insert the book's single-fiber wire (■) and heat-shrink it to form a single-fiber wire assembly. At this time, the uncoated end 7 of the single-filament wire (2) is positioned inside the heat-shrinkable tube 11. Next, the single fiber assembly section is accommodated in the groove 12 of the terminal fixture 10 as shown in (bl), and the terminal fixtures 10 and 10' are bonded together using the adhesive layer 9, as shown in (C). A multi-core optical fiber terminal part is formed. Note that (b-1), (b-2
) is a cross-sectional view taken along lines BB' and CC' in (b), respectively, and (b-4) is a cross-sectional view taken along line D-D' in (b-3).

(Example 3) FIG. 5 shows a third example of the present invention. 13 is a reinforcing plate; 14 is a housing for housing the heat shrink tube 11 and the reinforcing plate 13;
After shrinking, the heat shrink tube is structured so that it will come into close contact with these. To do this, (a) and its cross-sectional view (
As shown in a-1), five single-core wires are inserted into the heat-shrinkable tube 11 so that their sheath-removed ends 7 are located inside the heat-shrinkable tube 11, and heated together with the heat-shrinkable tube 14. - Shrink it to form the multi-core optical fiber terminal part shown in (b). Here, the reinforcement plate 13 prevents external forces from concentrating on the uncoated end 7 of the single-filament wire, and furthermore, the pitch of the optical fibers of the single-filament wire matches the pitch of the optical fibers of the tape core wire. Therefore, it is possible to connect with conventional multi-fiber batch fusion splicing equipment for tape core wires.
Moreover, since this multi-core optical fiber terminal part is very small in size, it is also possible to integrally reinforce the multi-core optical fiber together with the fusion splicing part 16 in a small size by means of reinforcing bases vi, 15, as shown in FIG.

(Effects of the Invention) As explained above, according to the present invention, by using a method of using a heat-shrinkable tube whose outer diameter after shrinking is equivalent to the pitch of an optical fiber for a tape core, and by using an end forming part, While easily assembling single fibers, the pinch of the optical fibers can be matched to the pitch of the optical fibers in the tape fibers, making it possible to perform multi-fiber fusion splicing of single fibers and tape fibers, which was previously difficult. The effect is that it can be easily performed using a batch fusion splicing device.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional single-fiber wire and tape-fiber wire;
Fig. 2 is a perspective view of a groove board used in the single-fiber wire gathering portion of a multi-fiber connector, Fig. 3 is a perspective view and a cross-sectional view of the first embodiment that best represents the features of the present invention, and Fig. 4 is a perspective view of the first embodiment. The figure is a perspective view of a second embodiment of the invention, and FIG. 5 is a perspective view and a sectional view of a third embodiment of the invention. ■...Single-core wire, ■...Tape core wire, 1...Single-core wire coating, 1'...Tape core wire coating, 2...Single-core optical fiber, 2' ...Tape optical fiber, 3...V-groove substrate, 4...V-groove, 5...heat-shrinkable tube, 6...heater, 8...for reinforcing the coated removed end. Substrate, 8'... Substrate for reinforcing the coating removed end, 9... Adhesive layer, IO... Terminal forming tool, 1
0'...Terminal forming tool, 11...Integrated heat shrink tube, I2...Groove portion, 13...Reinforcement plate, 14
... Heat shrink tube, 15 ... Fusion splicing part reinforcement board.

Claims (6)

[Claims] (1) A process of removing the coating from the end of each coated single optical fiber, and a process of covering the removed part with a heat shrink tube and heating the heat shrink tube to shrink it. . A method for forming a multi-core optical fiber end, including the step of assembling and aligning and integrating the tips of a plurality of the single fibers covered with the heat-shrinkable tube. (2) A patent characterized in that the optical fibers at the tips covered with heat-shrinkable tubes are aligned so that they have the same pitch and the same number as each optical fiber of a tape core wire in which a plurality of optical fibers are collectively coated. A method for forming a multi-core optical fiber end according to claim 1. (3) A step of removing the coating at the end of each coated single optical fiber, and heat-shrinking the coated ends of the plurality of single fibers beforehand. A method for forming an end of a multi-core optical fiber, including the steps of inserting it into a tube, heating and shrinking the heat-shrinkable tube, and aligning the tips of the heat-shrinkable tube. (4) A patent characterized in that the optical fibers at the tips covered with heat-shrinkable tubes are aligned so that they have the same pitch and the same number as each optical fiber of a tape core wire in which a plurality of optical fibers are collectively coated. A method for forming a multi-core optical fiber end according to claim 3. (5) A multi-core fiber in which the distal end portion of a single coated single optical fiber from which the coating has been removed is assembled across a portion where the coating is present and a portion from which the coating has been removed. In the optical fiber coated wire terminal forming section, each optical fiber is covered and aligned with a heat shrink tube at the tip, and the pitch of the optical fibers at the tip is narrower than the pitch in the portion where the coating is present. A multi-core optical fiber end forming section characterized by the following. (6) The optical fibers at the tip portion are arranged so as to have the same pitch and the same number as a tape core wire in which a plurality of optical fibers are collectively coated. Multi-core optical fiber end forming section.