JP5901933B2 - Optical fiber ribbon, optical fiber core, optical fiber cable, and intermediate post branching method of optical fiber cable - Google Patents

Description

  The present invention relates to an optical fiber tape core wire having an intermittently fixed structure in which adjacent optical fibers are intermittently connected at a connecting portion, an optical fiber cable, and an intermediate post-branching method of the optical fiber cable.

  In recent years, FTTH network construction has progressed, and in order to draw an optical fiber into a subscriber's house, a specific optical fiber tape core is taken out from a plurality of optical fiber cable sheaths by tearing the sheath of the optical fiber cable, and another optical fiber tape. An intermediate post-branch operation is performed to connect the core wire.

  At the time of intermediate post-branching work, the distinction between the optical fiber ribbon to be taken out from the cable and other optical fiber ribbons, and the other optical fiber ribbon as far as possible from the optical fiber ribbon to be taken out Handleability that can be taken out without touching the wire is required.

  In the field of optical fiber cables, due to the recent demand for high density and small diameter, optical fiber tape cores having an intermittently fixed structure in which each optical fiber is intermittently fixed at a connecting portion have been used. (For example, described in Patent Document 1).

Japanese Patent No. 4143651

  However, although the optical fiber ribbon described in Patent Document 1 has an intermittently fixed structure, it is flexible and suitable for high density. It is difficult to find an optical fiber ribbon.

  In addition, the optical fiber tape core of the intermittently fixed structure is mostly a portion where the optical fiber is not connected to the adjacent optical fiber in the longitudinal direction, such a place has low rigidity, and bending due to handling enters greatly, May increase transmission loss. In addition, when a specific optical fiber ribbon is taken out from the cable, there is a possibility that the connecting portion may be broken by grabbing an arbitrary one from a plurality of optical fibers.

  Therefore, an object of the present invention is to provide an optical fiber ribbon, an optical fiber cable, and an intermediate post-branching method for an optical fiber cable, which are excellent in distinguishability and handling properties.

  According to the first aspect of the present invention, three or more optical fibers are arranged in parallel and two adjacent optical fibers are connected by a connecting portion, and the connecting portion is connected to the longitudinal direction of the tape core wire and It is an optical fiber tape core of an intermittently fixed structure provided with a plurality of intermittently in the tape core width direction, respectively, at a position where an arbitrary connecting portion is provided among the plurality of connecting portions or at the positions of all connecting portions, A marking for identifying the optical fiber ribbon is provided on each optical fiber.

  The invention according to claim 2 is the optical fiber ribbon according to claim 1, wherein each of the plurality of optical fiber ribbons is provided in the optical fiber constituting each optical fiber ribbon. The type of the marking is different.

  The invention described in claim 3 is an optical fiber cable in which a plurality of optical fiber ribbons according to claim 1 or 2 are covered with a sheath.

  The invention according to claim 4 is the intermediate post-branching method of the optical fiber cable according to claim 3, wherein when the part of the sheath is cut off in the middle of the cable and the intermediate post-branch is branched, the connecting portion and the marking are The sheath is peeled off so as to enter at least one period.

  According to the optical fiber ribbon of the present invention, markings for identifying the optical fiber ribbon are provided at positions where an arbitrary coupling portion is provided or positions of all coupling portions among a plurality of coupling portions. Since it is provided in each of the fibers, the optical fiber ribbon can be easily identified from other optical fiber ribbons by identifying this marking. Further, according to the optical fiber ribbon of the present invention, since the marking is provided at the position of the connecting portion, the connecting portion always exists at the portion where the marking is provided, and the marking is provided. By grasping the part, it becomes possible to securely grasp the connecting portion, and the handling property is naturally improved.

FIG. 1 is a plan view of the optical fiber ribbon of the present embodiment. FIG. 2 is an enlarged cross-sectional view at a position where the connecting portion of the optical fiber ribbon of the present embodiment is provided. FIG. 3 is a plan view of one optical fiber constituting the optical fiber ribbon of the present embodiment. FIG. 4 is an enlarged cross-sectional view of the optical fiber of FIG. FIG. 5 is a diagram showing the types of markings used in the examples. FIG. 6 is a cross-sectional view of the optical fiber cable of the present embodiment. FIG. 7 is a process diagram showing the evaluation workability performed in order of the workability evaluation and transmission loss evaluation of the intermediate post-branch work performed in the embodiment.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  1 is a plan view of the optical fiber ribbon of the present embodiment, FIG. 2 is an enlarged cross-sectional view at a position where the connecting portion of the optical fiber ribbon of FIG. 1 is provided, and FIG. 3 is an optical fiber ribbon. FIG. 4 is an enlarged cross-sectional view of an optical fiber.

  As shown in FIG. 1, the optical fiber ribbon 1 has three or more optical fibers 2 arranged in parallel and connects two adjacent optical fibers 2 with a connecting portion 3. The part 3 has an intermittent fixing structure in which a plurality of portions 3 are intermittently provided in the longitudinal direction of the tape core (in the direction of arrow X in FIG. 1) and in the width direction of the tape (in the direction of arrow Y in FIG. 1).

  In FIG. 1, a total of four optical fibers 2 (2 </ b> A to 2 </ b> D) are formed, and two optical fibers 2 adjacent to each other among these four optical fibers 2 are connected to the longitudinal direction X of the tape core wire and the tape by the connecting portion 3. They are connected intermittently in the core width direction Y. A plurality of connecting portions 3 that connect two adjacent optical fibers 2 are formed at a predetermined pitch P1 in the longitudinal direction X of the tape core wire. For example, the connecting portions 3 that connect the first optical fiber 2A and the second optical fiber 2B are formed at a pitch P1 with a period of 120 mm in the longitudinal direction X of the tape core wire. Similarly, the connecting portion 3 for connecting the second optical fiber 2B and the third optical fiber 2C and the connecting portion 3 for connecting the third optical fiber 2C and the fourth optical fiber 2D are also tapes. It is formed at a pitch P1 with a period of 120 mm in the longitudinal direction X of the core wire.

  Further, there is only one connecting portion 3 for connecting the adjacent two optical fibers 2 at the same position in the tape core width direction Y, and connecting the other adjacent two optical fibers 2. The position is not in the same line as the portion 3 but is shifted in the longitudinal direction Y of the tape core wire. Therefore, the connection part 3 formed in the optical fiber ribbon 1 is arranged in a zigzag as a whole. In addition, arrangement | positioning of the connection part 3 is not limited to the arrangement | positioning shown in FIG. 1, Other arrangement | positioning structures may be sufficient. The arrangement of FIG. 1 is merely an example.

  For example, as shown in FIG. 2, the connecting portion 3 is filled with resin (for example, ultraviolet curable resin) in a gap between two adjacent optical fibers 2 and cured, so that both optical fibers 2 (2A, 2B) are connected to each other. Are connected. The connecting portion 3 travels four optical fibers 2 arranged in parallel in the longitudinal direction, intermittently supplies ultraviolet curable resin to the gap between the two optical fibers 2, and then shines light with an ultraviolet lamp. It is hardened and formed.

  As shown in FIGS. 3 and 4, the optical fiber 2 includes a glass optical fiber 4 provided at the center, a fiber coating layer 5 covering the outer periphery of the glass optical fiber 4, and an outer periphery of the fiber coating layer 5. The marking 6 is provided on the surface, and a translucent colored layer 7 that forms an outermost layer coated thereon.

  The diameter of the glass optical fiber 4 is, for example, 125 μm. The fiber coating layer 5 is made of a resin layer provided to buffer the side pressure applied to the glass and prevent external damage. The marking 6 is a mark for identifying a specific optical fiber ribbon 1 from other optical fiber ribbons when, for example, a specific optical fiber ribbon 1 is taken out from a plurality of markings.

  The marking 6 is provided so as to substantially go around the peripheral surface of the optical fiber 2 and is, for example, a belt-like ring mark. The marking 6 is provided at a position where an arbitrary connecting portion 3 is provided or a position of all connecting portions 3 among the plurality of connecting portions 3. In the present embodiment, the marking 6 is arranged at the same position as the connecting portion 3 that connects the first optical fiber 2A and the second optical fiber 2B. In the present embodiment, the pitch P1 of the connecting portion 3 and the pitch P2 of the marking 6 are the same. The pitch P1 of the connecting portion 3 and the pitch P2 of the marking 6 must be within the branch length of the cut off sheath when an optical fiber cable formed by covering a plurality of optical fiber ribbons with a sheath is branched after the middle. The pitch is such that both the connecting portion 3 and the marking 6 enter at least one cycle. The range of these pitches will be described in the examples described later.

  The marking 6 is provided in each of the optical fibers 2A to 2D, and the marking 6 is in the same position in the longitudinal direction X of the tape core in all the optical fibers 2A to 2D, and is aligned in the longitudinal direction Y of the tape core. It is arranged. From another viewpoint, four optical fibers 2 having a plurality of markings 6 provided at a predetermined pitch P2 in the longitudinal direction X of the tape core are arranged at the same position in the longitudinal direction X of the tape and in the width direction Y of the tape core. The connecting portions 3 are formed at positions where the four markings 6 are arranged in parallel so as to be arranged in a line. In addition, although the marking 6 is provided in the same position as the said connection part 3, if the marking 6 has overlapped with the connection part 3 in the tape core wire longitudinal direction X, it will be assumed that it was arranged in the same position. In other words, the marking 6 and the connecting portion 3 may have a relationship that includes not only a complete match but also a partial match.

  The colored layer 7 is for identifying each of the optical fibers 2A to 2D, and is colored translucent. Therefore, the marking 6 can be seen through the colored layer 7. For example, the first optical fiber 2 </ b> A is a blue colored layer 7. The second optical fiber 2B is a yellow colored layer 7. The third optical fiber 2 </ b> C is a green colored layer 7. The fourth optical fiber 2D is a red colored layer. In this embodiment, since all four are colored layers 7 of different colors, the optical fibers 2A to 2D can be identified by the color of the colored layer 7.

  The optical fiber ribbon 1 configured in this way is identified by the difference in the type of the marking 6. For example, when there are five optical fiber ribbons 1 (1A to 1E) shown in FIG. 5, the number of markings 6 is one in FIG. 5A, and the number of markings 6 in FIG. 5B. In FIG. 5C, the number of the markings 6 is three, in FIG. 5D, the number of the markings 6 is four, and in FIG. 5E, the number of the markings 6 is one. However, the entire mark length is increased. The optical fiber ribbons 1A to 1E can be identified by the difference in the number or shape of the markings 6 as described above. In FIG. 5, the connecting portion 3 is omitted for easy understanding of the type of the marking 6.

  Based on the following conditions, an optical fiber cable is created, and after the middle branch, the discriminating ability to take out a specific optical fiber ribbon from a plurality of optical fiber ribbons, fluctuations in transmission loss during removal, and take-out workability The connection workability of connecting the taken optical fiber ribbon to another optical fiber ribbon was evaluated.

Four optical fibers having a diameter of 250 μm were juxtaposed, and an optical fiber ribbon in which the optical fibers were intermittently fixed was manufactured. The pitch P1 of the connecting portion was 120 mm. Moreover, the pitch P2 of the marking 6 was set to 120 mm, similarly to the pitch P1 of the connecting portion. The marking 6 is provided at the same position as the connecting portion that connects the first optical fiber 2A and the second optical fiber 2B. Twenty-five optical fiber ribbons (tape numbers 1 to 25) were prepared as shown in Table 1. The colors of the optical fibers are as shown in Table 1 for the first (# 1), second (# 2), third (# 3), and fourth (# 4). As shown in FIGS. 5A to 5E, the types of the markings 6 are one, two, three, four, and one long in length.

  Then, as shown in FIG. 6, the core 8 including the 25 optical fiber ribbons is covered with the holding tape 9 and then covered with the sheath 12 by extrusion molding together with the tear string 10 and the strength member 11. Thus, the optical fiber cable 13 was manufactured. Then, the manufactured optical fiber cable 13 was branched after the middle, and the workability, the distinguishability, the connection workability, and the loss variation at the time of the middle branching were verified.

  In order to obtain the loss variation, as shown in FIG. 7A, a light source 14 is connected to the optical fiber ribbon 1 led out from one end of the optical fiber cable 13, and light is emitted from the light source 14 to illuminate the inside of the cable. The return light that reciprocated was monitored by the power meter 15.

  In the intermediate post branching operation, as shown in FIG. 7B, first, a part of the sheath 12 is peeled off by a predetermined length L1 (for example, about 500 mm) in the middle of the optical fiber cable 13. At this time, the tear string 10 and the strength member 11 are also removed. Then, as shown in FIG. 7C, one specific optical fiber ribbon 1 is taken out from the core 8 exposed at the site where the sheath 12 is peeled off. Next, as shown in FIG. 7D, the optical fiber tape core wire 1 that has been taken out is cut from one end of the sheath 12 at a position of length L2 (for example, 250 mm). Then, as shown in FIG. 7E, another optical fiber ribbon 16 branched to the cut optical fiber ribbon 1 is fused and connected.

  In order to compare with the optical fiber ribbon and the optical fiber cable according to the present embodiment, samples of comparisons 1 to 25 shown in Table 2 are manufactured, and the intermediate branch is similarly performed on these samples. Workability, identification, connection workability (fusion splicing workability), and loss fluctuation at the time were verified. Judgment criteria were as follows. The target loss fluctuation amount was such that the loss fluctuation amount until an arbitrary (specific) optical fiber ribbon was taken out of 25 optical fiber ribbons was less than 0.01 dB. The target workability is that any optical fiber ribbon can be easily identified visually from 25 optical fiber ribbons, and can be taken out without damaging the optical fiber ribbon. The target connection workability was that four optical fiber ribbons could be connected together.

These verification results are shown in Table 2. The verification results were evaluated as ◎ or ○ when the workability, discriminability, connection workability (fusion splicing workability), and loss fluctuation were all good, ▲ when it was possible, and × when it was impossible .

  As can be seen from the results in Table 2, regarding the loss fluctuation, the relationship between the marking and the connecting part is that the marking pitch is an integral multiple of the connecting part pitch, and the marking is applied at the same place as the arbitrary connecting part. Furthermore, the amount of fluctuation in loss when the optical fiber ribbon was removed was less than the target value of 0.01 dB. This is due to the fact that if the optical fiber tape core wire is taken out by pinching the position where the marking is provided, a highly rigid connecting portion will be grasped.

  With regard to discriminating and picking up the optional tape, it is better that the marking pitch is short. Especially at 250 mm or less, which is half of the sheath removal length of 500 mm, two or more markings can always be confirmed, and the discriminating property is good. It was. When the marking pitch is 300 mm or 500 mm, at least one marking can be confirmed, and when the marking pitch is 500 mm, the marking does not always come to the center of the sheath removal portion, and the visibility decreases as the marking pitch increases. It was confirmed. Also, if the marking pitch is longer than the sheath removal length, the marking cannot be confirmed at the sheath removal portion and cannot be identified.

  As for the removal workability of the optional tape, the results were good when the marking and the connecting portion were applied at the same place as in the loss fluctuation. In other cases, it is inevitably increased to work on single-core parts (parts without connecting parts) even if marking is used as a reference. There was a thing.

  Regarding the connection workability (fusion connection workability), the work was possible when the connecting portion pitch was equal to or shorter than the length handled at the time of fusion connection. In the case where the connecting portion pitch is longer than that, there is a case where no connection exists over the entire length of the working length, and it is impossible to work on four pieces collectively. From this result, in the optical fiber ribbon of the present embodiment, it is desirable that the marking pitch is 500 mm or less and the connecting portion pitch is 250 mm or less.

  According to the optical fiber ribbon of the present embodiment, the optical fiber ribbon 1 is identified at a position where an arbitrary coupling part 3 is provided or a position of all the coupling parts 3 among a plurality of coupling parts 3. Since the marking 6 is provided on each of the optical fibers 2, the connecting portion 3 having high rigidity always exists at the portion where the marking 6 is provided. Therefore, when an optical fiber cable in which a plurality of optical fiber ribbons are covered with a sheath is branched after the middle, if the part provided with the marking 6 is grasped, the highly rigid connecting part 3 is always grasped. The specific optical fiber ribbon can be taken out from the cable while suppressing the loss fluctuation amount without damaging the optical fiber 2.

  Further, according to the optical fiber ribbon of the present embodiment, each of the plurality of optical fiber ribbons 1 has the type of marking 6 provided on the optical fiber 2 constituting each optical fiber ribbon 1. Since they are different from each other, a specific optical fiber ribbon 1 can be easily distinguished from other optical fiber ribbons 1 by visual inspection by looking at the type of the marking 6.

  Further, according to the optical fiber cable 13 in which a plurality of the optical fiber ribbons 1 of the present embodiment are covered with the sheath 12, the workability, the distinguishability, and the connection workability at the time of intermediate post-branching (fusion connection) Workability) and loss fluctuation can both be improved.

  Further, in the intermediate post-branching method of the optical fiber cable 13 according to the present embodiment, since the connecting portion 3 and the marking 6 enter at least one period or more in the sheath removal portion, any optical fiber tape core can be selected from among a plurality. The wire 1 can be easily found, and the optical fiber tape core wire 1 can be taken out by grasping the highly rigid connecting portion 3. Therefore, it is possible to suppress an increase in loss of the optical fiber and prevent damage to the intermittent fixing portion during the intermediate post branching operation.

  INDUSTRIAL APPLICATION This invention can be utilized for the optical fiber tape core wire of the intermittent fixation structure which connected adjacent optical fibers intermittently by the connection part.

DESCRIPTION OF SYMBOLS 1 ... Optical fiber ribbon 2 ... Optical fiber 3 ... Connection part 6 ... Marking 10 ... Tear string 11 ... Strength body 12 ... Sheath 13 ... Optical fiber cable

Claims (4)

Between 3 adjacent with hearts or more optical fibers are arranged in parallel to two-core optical fiber is connected by a connecting portion, the connecting portion, their respective the ribbon longitudinally and ribbon width direction an optical fiber ribbon of setting only intermittent fixed structure,
When three optical fibers are arranged in parallel, a plurality of the connecting portions are intermittently provided in the longitudinal direction of the tape core, and one is provided at the same position in the width direction of the tape.
When four or more optical fibers are arranged in parallel, a plurality of the connecting portions are intermittently provided in the longitudinal direction of the tape core and one or intermittently at the same position in the width direction of the tape. Multiple,
A marking for identifying the optical fiber ribbon is provided in each optical fiber at a position where an arbitrary connecting part is provided or a position of all connecting parts among the plurality of connecting parts. Optical fiber ribbon. An optical fiber core comprising a plurality of optical fiber ribbons according to claim 1,
Each of the plurality of optical fiber ribbons has the same combination of colors of the colored layers of the optical fibers constituting each of the optical fiber ribbons. An optical fiber core , wherein the types of markings provided are different. An optical fiber core of the optical fiber core or claim 2 wherein summarizes the optical fiber ribbon of claim 1, wherein, formed by coating with a sheath
An optical fiber cable characterized by that . An intermediate post-branching method for an optical fiber cable according to claim 3,
An intermediate post-branching method for an optical fiber cable, wherein when the part of the sheath is cut off in the middle of the cable and branched after the middle, the sheath is peeled off so that the connecting portion and the marking enter at least one period.

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