NZ623457B2

NZ623457B2 - Optical fiber ribbon and optical fiber cable housing optical fiber ribbon

Info

Publication number: NZ623457B2
Application number: NZ623457A
Authority: NZ
Inventors: Shinya Hamaguchi; Daisuke Kakuta; Hisaaki Nakane; Akira Namazue; Naoki Okada; Ken Osato; Yusuke Yamada
Original assignee: Fujikura Ltd; Nippon Telegraph And Telephone Corporation
Priority date: 2011-10-18
Filing date: 2012-10-15
Publication date: 2015-06-30

Abstract

Provided is an optical fibre tape core wire with which it is possible to implement higher density and narrower gauges, and to mount an optical fibre in a V-shaped groove of a fusion machine without falling away. An optical fibre tape core wire (1) has three or more optical fibre cores (2) which are positioned in parallel, with two adjacent optical fibre cores (2) being coupled with coupling parts (3), and the coupling parts (3) being respectively disposed intermittently in the tape core wire longitudinal and latitudinal directions. The adjacent fibres are spaced apart and connected at discrete points by concave resin connections. positioned in parallel, with two adjacent optical fibre cores (2) being coupled with coupling parts (3), and the coupling parts (3) being respectively disposed intermittently in the tape core wire longitudinal and latitudinal directions. The adjacent fibres are spaced apart and connected at discrete points by concave resin connections.

Description

DESCRIPTION OPTICAL FIBER RIBBON AND OPTICAL FIBER CABLE HOUSING OPTICAL FIBER RIBBON TECHNICAL FIELD The present invention relates to an optical fiber ribbon having an intermittent fixing structure in which adjacent optical fibers are intermittently connected together via ting portions, and relates to an optical fiber cable g the optical ﬁber ribbon.

BACKGROUND ART There has been an increased demand for higher density and reduction in er in the technical field of optical fiber cables. As an example of a method for achieving higher y and reduction in er, there is proposed a method for reducing the outer diameter of optical fibers from 250 um, which is a presently-used size, to 200 am or smaller (for example, described in Patent Literature 1). An optical fiber ribbon using this method has a ure in which a ity of optical fibers each having the outer diameter of 200 um or smaller are arranged in parallel, and the entire circumference of the optical fibers is covered with ultraviolet curable resin.

With the optical fiber ribbon described in Patent ture 1, however, an intermediate branching ion is difficult when laying optical fibers into residences of subscribers. In order to lay the optical fibers into the residences of subscribers, a cover layer entirely covered with the ultraviolet curable resin is required to be removed in the middle of the cable so that particular optical fibers are only ted from the plurality of optical fibers. Since the entire circumference of the plural optical fibers is covered with the ultraviolet curable resin, the removal of the ultraviolet curable resin is difficult and the particular optical fibers are not easily d from the other optical fibers. Further, in the optical fiber ribbon described in Patent Literature 1, the entirely-covered cover layer increases the thickness of the optical fiber ribbon by the thickness of the cover layer, which decreases the packaging density thereof.

Patent Literature 2 teaches an l ﬁber ribbon capable of solving these problems. This optical ﬁber ribbon does not have a structure in which optical ﬁbers are entirely covered with resin, but has an intermittent ﬁxing structure in which nt two optical ﬁbers of three or more of optical ﬁbers arranged in parallel are connected together with resin. The intermittent ﬁxing structure of the optical ﬁber ribbon described in Patent Literature 2 butes to easy intermediate ing operation and has the advantage of higher density since the number of connecting portions is smaller than that in the structure of Patent Literature 1.

CITATION LIST PATENT LITERATURE Patent Literature 1: Japanese Patent No. 3058203 Patent ture 2: Japanese Patent No. 4143651 SUMMARY OF INVENTION However, when the optical ﬁber ribbon described in Patent Literature 1 is fused and connected with another optical ﬁber ribbon, bare optical ﬁbers (glass optical ﬁbers) from which the cover layer made of resin is d may be hard to be set in a fusion machine having plural V—shaped grooves formed at a predetermined pitch to be independently placed in the V—shaped grooves. Failure in placing the l ﬁbers in the V—shaped grooves in the fusion machine requires extra work to forcibly place the optical ﬁbers in the V—shaped grooves.

An object of the present ion is to provide an optical ﬁber ribbon capable of achieving higher density and reduction in diameter and accurately placing optical ﬁbers in V—shape grooves in a fusion machine without e, and provide an optical ﬁber cable housing the optical ﬁber ribbon, and/or to at least provide the public with a useful choice. [0007a] In accordance with a ﬁrst aspect of the invention, there is provided an optical ﬁber ribbon sing three or more of optical ﬁbers arranged in parallel and connecting portions connecting adjacent two optical ﬁbers together, the connecting ns being intermittently provided in each of a ribbon longitudinal direction and a ribbon width direction, wherein a gap is formed between adjacent two optical ﬁbers, the connecting portions are each formed in such a manner as to ﬁll resin into the gap, and top and bottom surfaces of the respective connecting portions in a state where the l ﬁbers are placed on a horizontal e are each formed into a recess having a concave shape curved toward a center of the gap to separate from lines each connecting top ends or bottom ends of the optical ﬁbers when being placed on the horizontal surface. [0007b] In accordance with a second aspect of the invention, there is provided an optical ﬁber cable housing the optical ﬁber ribbon of the ﬁrst aspect.

There is provided an l ﬁber ribbon comprising three or more of optical ﬁbers arranged in parallel and connecting portions connecting nt two optical ﬁbers together, the connecting portions being intermittently provided in each of a ribbon longitudinal direction and a ribbon width direction, wherein an outer diameter dimension of the optical ﬁbers is set to smaller than or equal to 220 pm, and a distance between centers of the nt two optical ﬁbers is set to 250 um with a margin of plus or minus 30 pm.

In an embodiment, the connecting portions are each formed in such a manner as to ﬁll resin into a gap between adjacent two optical ﬁbers, and both surfaces of the respective connecting portions are each formed into a recess curved toward a center of the gap to separate from lines each connecting contact points of the optical ﬁbers when being placed on a horizontal surface.

In an embodiment, the ting ns are each formed in such a manner as to ﬁll resin into a gap between adjacent two optical ﬁbers and cover a periphery of the respective optical ﬁbers with the resin, and a resin thickness of the periphery covered with the resin is set to smaller than or equal to 15 ptm. [001 1] In an ment of the disclosure, an outermost layer of the respective optical ﬁbers is colored. (followed by page 4a) There is ed an optical ﬁber cable g any one of the optical ﬁber ribbons disclosed above.

According to at least embodiments of the present invention, a reduction in diameter of the optical ﬁbers is achieved and the optical ﬁber ribbon is easily bent due to the intermittent ﬁxing ure thereof in which the connecting portions for ting adjacent two optical ﬁbers are intermittently provided in each of the ribbon longitudinal direction and the ribbon width direction and due to the reduced outer diameter dimension of the optical ﬁbers which is set to smaller than or equal to 220 tun.

As a result, a larger number of the optical ﬁber ribbons can be housed in the cable so as to improve the packaging densityl.

According to ments of the present invention, the distance between the centers of adjacent two optical ﬁbers is set to 250i30 nm, which is equal to a distance between the centers of adjacent two optical ﬁbers of an optical ﬁber ribbon commonly distributed, so as to accurately place the respective l ﬁbers in the corresponding V—shape grooves in the fusion machine t falling out of the V-shaped grooves. [0014a] The term ‘comprising’ as used in this speciﬁcation and claims means ‘consisting at least in part of’. When reting statements in this speciﬁcation and claims which include the term ‘comprising’, other features s the features prefaced by this term in each statement can also be present. Related terms such as ‘comprise’ and ‘comprised’ are to be interpreted in a r manner.

BRIEF DESCRIPTION OF GS [FIG 1] is a top perspective view showing an example of an optical ﬁber ribbon having an intermittent ﬁxing structure according to the present embodiment.

[FIG 2] is an enlarged cross—sectional view of a connecting portion of the optical ﬁber ribbon of A) is a structural example of the connecting portion, and B) is another structural example of the connecting portion. 1 This advantage and other stated advantages are advantages of at least preferred embodiments of the invention It is not necessary for every embodiment of the invention to meet each stated advantage. wed by page 5) [FIG 3] is an ed cross-sectional View of a connecting portion of the optical ﬁber ribbon having another structure of A) is a structural example of the connecting portion, and B) is another structural example of the connecting portion.

[FIG 4] is a View showing a state where glass optical ﬁbers in the optical ﬁber ribbon according to the present embodiment from which covering is removed, are placed in V—shaped grooves of a fusion machine.

[FIG 5] is a cross—sectional view of a center tube—type optical ﬁber cable housing the l ﬁber ribbon according to the present embodiment therein.

[FIG 6] is a cross-sectional view of an SZ—slotted optical ﬁber cable housing the optical ﬁber ribbon according to the present embodiment therein.

[FIG 7] is a cross—sectional View of a C—slotted optical ﬁber cable g the optical ﬁber ribbon according to the present ment therein.

PTION OF EMBODIMENTS Hereinafter, a speciﬁc embodiment of the present invention will be explained in detail with reference to the drawings. shows an example of an optical ﬁber ribbon having an ittent ﬁxing structure according to the present embodiment, and shows an enlarged cross section of a connecting portion of the optical ﬁber ribbon of As shown in FIG 1, the optical ﬁber ribbon 1 ing to the present embodiment has a structure in which three or more of optical ﬁbers 2 are arranged in el, the adjacent two optical fibers 2 are connected together via connecting portions 3, and the connecting portions 3 are intermittently located in each of a ribbon udinal direction (in the X-arrow direction in and a ribbon width direction (in the Y—arrow direction in .

As shown in the l ﬁber ribbon 1 is composed of the n optical fibers 2 in total, and the adjacent two optical fibers 2 of the n optical fibers 2 are intermittently connected together Via the connecting portions 3 in each of the ribbon udinal direction and the ribbon width direction. The connecting portions 3 connecting the adjacent two l fibers 2 together are formed in the ribbon longitudinal direction at a fixed pitch Pl, and have a shorter length than unconnected portions each located therebetween. Namely, the length of each connecting portion 3 is shorter than that of each unconnected portion in the ribbon longitudinal direction.

Further, only one connecting portion 3 is formed in the ribbon width ion to connect the adjacent two optical fibers 2. The connecting portion 3 is not located on the same line in the ribbon width direction as the other connecting portion 3 connecting other adjacent two optical fibers 2 but located in the offset position from the other connecting portion 3 in the ribbon longitudinal direction. Therefore, the connecting ns 3 formed in the optical fiber ribbon l are arranged in a zigzag manner as a whole. Note that the arrangement of the ting portions 3 is not limited to that shown in and may be other configurations. The arrangement shown in is merely an example. Here, in addition to the arrangement in which only one connecting portion 3 is provided in the ribbon width direction, two or more ting portions 3 may be formed in the ribbon width ion in a manner such that at least one unconnected portion is located between the connecting portions 3 As shown in A), the connecting portion 3 connects the adjacent two optical ﬁbers 2 er in such a manner as to fill the gap S between the adjacent two optical fibers 2 with resin (for example, ultraviolet e resin) and then cure it.

Both surfaces 3a and 3b of the connecting portion 3 are respectively positioned on the same lines as lines 4 and 5 each ting the contact points of the respective optical fibers 2 when being placed on the horizontal surface. Therefore, the inner half circumferences of the optical fibers 2 facing the gap S are covered with the resin composing the connecting portion 3, but the outer half circumferences on the opposite side of the gap S are not covered with the resin.

The two surfaces 3a and 3b of the connecting portion 3 shown in B) are each formed into a recess having a concave shape curved toward the center of the gap S to separate from the lines 4 and 5 each connecting the contact points of the respective optical fibers 2 when being placed on the horizontal surface. In B), the amount of the resin composing the connecting portion 3 is smaller than that in A), and the resin is y concentrated in the central portion of the gap S between the two optical fibers 2. The optical fiber ribbon ted with the connecting portions 3 having such a configuration is more easily bent since the amount of the resin used is smaller than that of the connecting n 3 shown in A), so that the number of the optical fiber ribbons to be housed in a cable further increases.

Each of the optical fibers 2 includes a bare glass optical fiber 6 provided in the center thereof, a first cover layer 7 covering the periphery of the glass optical fiber 6, and a second cover layer 8 further covering the periphery of the first cover layer 7.

The glass optical fiber 6 has a diameter of 125 pm. The first cover layer 7 is a relatively soft resin layer to absorb lateral pressure applied to the glass. The second cover layer 8 is a relatively hard resin layer to protect t external damage. The second cover layer 8 may be further covered with a colored layer so that the respective optical ﬁbers 2 can be discriminated etween. The colored layer is formed as an outermost layer so as to easily differentiate the tive optical fibers 2 Visually.

According to the present embodiment, the outer diameter dimension of the optical fibers 2 (the entire diameter including the outermost layer) H is set to smaller than or equal to 220 am, and the distance L n the centers of the adjacent two optical fibers 2 is set to 250i30 urn. The optical fiber 2 of the present embodiment is a size r than the optical fiber 2 conventionally used which has the outer diameter dimension H of 250 pm. In addition, the distance L between the centers of the nt two optical fibers in the optical fiber ribbon conventionally used is 250 pm.

The present embodiment sets the distance L to 250 pm with a margin of plus or minus mm.

The connecting portion 3 shown in A) has a thickness which is the same as the outer er dimension H of the l fibers 2. The connecting portion 3 shown in B) has a thickness which is smaller than the outer diameter dimension H of the optical fibers 2.

The optical fiber ribbon 1 has an intermittent fixing structure in which the connecting portions 3 are ittently provided in each of the ribbon longitudinal direction and the ribbon width ion to connect the adjacent two optical fibers 2 together, and has a configuration in which the optical fibers 2 have the outer diameter dimension H of smaller than or equal to 220 pm which is smaller than that of the conventionally—used optical fibers, which contributes to decreasing the diameter of the optical fibers 2 and easily bending the . As a result, a larger number of the optical fiber ribbons 1 can be housed in a cable compared with optical fiber s having a tional structure so as to increase the packaging density thereof.

Further, since the optical fiber ribbon according to the present ment has a conﬁguration in which the Optical fibers 2 have the outer diameter dimension H of smaller than or equal to 220 nm which is smaller than that of the conventionally-used optical fibers, the volume of the optical fibers can be reduced by 20% or greater compared with the optical fibers having a conventional configuration. Accordingly, the entire diameter of the optical fiber ribbon can be decreased so as to further increase the packaging density f.

It should be noted that the connecting portions 3 are not limited to the configurations shown in A) and B) in which the connecting portions 3 are formed only in the gap S between the adjacent two optical ﬁbers 2, but may have the configurations shown in A) and B). The connecting portions 3 shown in are formed in such a manner as to fill resin into the gap S between the adjacent two optical fibers 2 and cover the eries of the optical fibers 2 with the resin. The resin thickness T on the outer half ference of each optical fiber 2 covered with the connecting portion 3 is set to smaller than or equal to 15 am.

The example shown in in which the outer half circumference of each optical fiber 2 having the outer diameter dimension of 220 um is covered with the resin, has no inﬂuence on the bending mance of the optical fiber ribbon 1 since the resin thickness T of the resin covering the outer half circumference is as thin as 15 pm or smaller. Therefore, such a configuration does not prevent from improving the packaging density in the cable.

[Example] Several types of optical fibers having different outer diameter dimensions were used in which the ce between the centers of adjacent optical fibers varied, so as to manufacture l fiber ribbons (4—core ribbons). The manufacture of connecting portions and unconnected portions employed the method disclosed in Japanese Unexamined Patent ation Publication No. 2010-033010 ese Patent Application No. 2009—082778). The pitch adjustment between the optical fibers employed the method disclosed in Japanese ined Patent Application ation No. 08—146239 (Japanese Patent Application No. 06—163292). Note that all optical fibers in one optical ﬁber ribbon have the same outer diameter dimension.

Next, batch fusion splicing performance was evaluated when one optical fiber ribbon thus obtained was entirely fused with the other optical fiber ribbon. The operation process was as follows. First, the optical fiber ribbon was held with a holder, the first cover layers 7 and the second cover layers 8 covering the respective optical fibers were removed by use of Hot Jacket Stripper to obtain the bare glass optical fibers 6, and side surfaces of the bare glass l fibers 6 thus obtained were cut with a fiber . Subsequently, the respective glass optical fibers 6 in the optical fiber ribbon held with the holder were placed on a fusion e 10 having V—shaped grooves 9 formed at a fixed pitch P2 shown in In this state, the evaluation was performed in such a manner as to determine r the respective glass optical fibers 6 were placed in the corresponding V—shaped grooves 9. The case where the glass optical fibers 6 were placed in the V—shaped grooves 9 was defined as OK, and the case where the glass optical ﬁbers 6 deviated from the V—shaped grooves 9 was defined as NG.

Hot Jacket Stripper used was HJS-OZ manufactured by Fujikura Ltd. The fiber cutter used was CT-30 manufactured by Fujikura Ltd. The fusion machine used was FSM—60R also manufactured by Fujikura Ltd. The pitch P2 between the respective V—shaped grooves 9 in the fusion machine 10 is 250 nm. The operation under the conditions described above was ed 10 times and the number of NG was then counted. Table 1 shows the evaluation thereof.

[Table 1] Outer Diameter of Distance between Centers of Number of NG in Batch Optical Fiber Adjacent Optical Fibers Fusion Splicing (um) Performance The results shown in Table 1 revealed that, when the distance L between the centers of the adjacent optical fibers 2 of the optical ﬁber ribbon 1 having an intermittent fixing structure is set to 0 pm (220 um to 280 pm), the glass optical fibers 6 do not deviate from the V—shaped grooves 9 so as to be concurrently fused with the corresponding glass optical fibers of the other optical fiber ribbon. The number of NG increased when the optical fiber ribbon did not meet the above-described ion, and the glass optical fibers 6 could not be placed in the V—shaped grooves 9 ely.

[Optical Fiber Cable] shows an example of a center tube-type optical ﬁber cable g the optical fiber ribbon according to the present embodiment therein. The center tube—type optical fiber cable 11 has a configuration in which the optical fiber ribbon l of the present embodiment is formed into a cable core 12 in a manner such that the optical fibers 2 are rolled in the ribbon width ion and assembled into a bundle as indicated by a dashed and double—dotted line in plastic resin is extruded over the periphery of the cable core 12 thus obtained so as to form a tube 13 thereon, and the tube 13 is further covered with polyethylene so as to form a sheath l4 thereon. shows an example of an tted optical fiber cable housing the optical fiber ribbon according to the present embodiment therein. The SZ-slotted l fiber cable 15 has a configuration in which a plurality of slots 18 having a e in cross section are formed on the outer periphery of a slot core 17 including a tension member 16 in the center thereof extending in the ribbon longitudinal ion, the optical fiber ribbon 1 according to the present embodiment is rolled in the ribbon width direction into a bundle and housed in each of the slots 18, the peripheral surface of the slot core 17 including the openings of the slots 18 is covered with a press winding tape 19, and a sheath 20 is further formed thereon by extrusion. shows an example of a C-slotted optical fiber cable housing the optical fiber ribbon ing to the present embodiment therein. The C—slotted optical fiber cable 21 has a configuration in which the optical fiber ribbon 1 according to the present embodiment is rolled in the ribbon width direction into a bundle and housed in a slot groove 24 of a slot core 23 having a C—shape in cross section including tension members 22 therein, and the entire slot core is covered with a sheath 26 Via a press winding tape interposed therebetween.

Although the l fiber ribbon 1 shown in each of and ing to the present embodiment is rolled in the ribbon width direction into a bundle and housed in the cable, the optical fiber ribbon 1 according to the present embodiment may be folded in layers in the vertical direction and housed in the cable.

Alternatively, a plurality of the optical fiber ribbons 1 may be stacked on top of one another to have a stacked structure and then housed in the cable.

The optical fiber cables 11, 15 and 21 according to the present embodiment each use the optical fibers 2 having the d outer diameter dimension of smaller than or equal to 220 um. Therefore, a larger number of the optical ﬁbers 2 can be housed in the cable, compared with the conventionally—used optical fibers 2 having the outer diameter dimension of 250 um, so as to ensure higher density. Further, the optical fiber cables 11, 15 and 21 according to the present embodiment can house the optical fiber ribbon 1 having an ittent fixing structure in any state in a manner such that the optical fiber ribbon l is bent and rolled into a cylindrical shape or folded to be stacked in any direction.

Further, the optical fiber cables 11, 15 and 21 according to the present embodiment can easily separate the respective optical ﬁbers 2 from each other so as to improve single-core separation workability at the time of terminal leading to extract the optical fibers 2 from the terminals of the cable or at the time of connecting operation to connect a connector to the extracted optical fibers 2, since the optical fiber cables 11, 15 and 21 each use the optical fiber ribbon 1 including the connecting portions 3 ittently formed in each of the ribbon longitudinal ion and the ribbon width direction to connect the adjacent two optical fibers 2 together.

INDUSTRIAL APPLICABILITY The present invention is able to the optical fiber ribbon having an intermittent fixing structure to ittently connect the adjacent l fibers together via the connecting portions.

Claims

WHAT WE CLAIM IS:

1. An optical ﬁber ribbon comprising three or more of optical ﬁbers arranged in parallel and connecting portions connecting adjacent two l ﬁbers together, the connecting portions being intermittently provided in each of a ribbon longitudinal direction and a ribbon width direction, wherein a gap is formed between adjacent two optical ﬁbers, the connecting portions are each formed in such a manner as to ﬁll resin into the gap, and top and bottom es of the respective connecting portions in a state where the l ﬁbers are placed on a horizontal surface are each formed into a recess having a concave shape curved toward a center of the gap to separate from lines each connecting top ends or bottom ends of the l ﬁbers when being placed on the horizontal surface.

2. The l ﬁber ribbon ing to claim 1, wherein the connecting portions are each formed in such a manner as to cover a periphery of the respective optical ﬁbers with the resin.

3. The optical ﬁber ribbon according to claim 1 or 2, wherein an outer diameter dimension of the optical ﬁbers is set to smaller than or equal to 220 um, and a distance between centers of the adjacent two optical ﬁbers is set to 250 pm with a margin of plus or minus 30 am.

4. The optical ﬁber ribbon according to claim 2, wherein a resin thickness of the periphery covered with the resin is set to smaller than or equal to 15 pm.

5. The optical ﬁber ribbon according to any one of claims 1 to 4, wherein an outermost layer of the respective optical ﬁbers is d.

6. An optical ﬁber cable housing the optical ﬁber ribbon according to any one of claims 1 to 5 therein.

7. An optical ﬁber ribbon substantially as herein bed with reference to any embodiment shown in the accompanying ﬁgures.

8. The optical ﬁber ribbon according to claim 1, substantially as herein described with reference to any ment sed.

9. An optical ﬁber cable substantially as herein described with reference to any of the accompanying ﬁgures.

10. The optical ﬁber cable according to claim 6, substantially as herein described with reference to any embodiment disclosed.