JP7552621B2 - Fiber optic cable - Google Patents

Description

The present disclosure relates to fiber optic cables.
This application claims priority based on Japanese application "Patent Application No. 2020-16254" filed on February 3, 2020, and incorporates all of the contents of the above-mentioned Japanese application by reference.

2. Description of the Related Art Conventionally, optical fiber cables are known that include optical fiber units each having a plurality of optical fiber ribbons in which a plurality of optical fiber core wires are arranged in parallel.
In such optical fiber cables, it is necessary to identify the optical fiber core when connecting cables together, and therefore it is required to identify the optical fiber unit. For example, optical fiber units wound with an identification bundle thread are known (see, for example, Patent Document 1).

JP 2013-190641 A

According to one aspect of the present disclosure,
A plurality of optical fiber units are provided,
Each of the optical fiber units includes a plurality of optical fiber ribbons,
The optical fiber ribbons each have a mark that can be distinguished from the optical fiber units,
the mark has both distinguishability among the plurality of optical fiber units and distinguishability among the plurality of optical fiber ribbons within one optical fiber unit,
the marks of the optical fiber ribbons in the one optical fiber unit have common characteristics among the optical fiber ribbons as distinguishing characteristics among the optical fiber units;
An optical fiber cable is provided in which at least a portion of the marker is exposed on an outer peripheral surface of the optical fiber unit.

FIG. 1 is a cross-sectional view of an optical fiber cable according to an embodiment. FIG. 2A is a side view of an optical fiber unit according to a first example of the embodiment. FIG. 2B is a side view of the optical fiber unit according to the second embodiment. FIG. 3A is a plan view of an optical fiber ribbon according to an embodiment. FIG. 3B is an enlarged view of a main portion of FIG. 3A. FIG. 4 is a table summarizing the specifications of the identification band and the pattern formation pitch.

[Problem to be solved by this disclosure]
In the optical fiber cable described in Patent Document 1, in order to wind the bundle yarn around the optical fiber unit, it is necessary to prepare a bundle yarn and a winding device for the bundle yarn, which makes the structure of the optical fiber cable complicated and the manufacturing process of the optical fiber cable cumbersome.

This disclosure has been made in light of the above-mentioned circumstances, and aims to provide an optical fiber cable that has a simple structure and is capable of identifying optical fiber units.

[Effects of the present disclosure]
According to the above, it is possible to provide an optical fiber cable capable of identifying optical fiber units with a simple structure.

[Description of the embodiments of the present disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described.

[1] An optical fiber cable according to one embodiment of the present disclosure,
A plurality of optical fiber units are provided,
Each of the optical fiber units includes a plurality of optical fiber ribbons,
The optical fiber ribbons each have a mark that can be distinguished from the optical fiber units,
the mark has both distinguishability among the plurality of optical fiber units and distinguishability among the plurality of optical fiber ribbons within one optical fiber unit,
the marks of the optical fiber ribbons in the one optical fiber unit have common characteristics among the optical fiber ribbons as distinguishing characteristics among the optical fiber units;
At least a portion of the marker is exposed on the outer circumferential surface of the optical fiber unit.
According to this configuration, it is possible to identify the optical fiber unit with a simple structure without providing an identification member such as a bundle thread.

[ 2 ] The optical fiber cable according to the above [1] ,
The marker has a different color for each of the optical fiber units.
According to this configuration, the optical fiber unit can be easily identified.

[ 3 ] In the optical fiber cable according to the above [1] or [2] ,
The mark has a different shape for each of the optical fiber units.
According to this configuration, the optical fiber unit can be easily identified.

[ 4 ] The optical fiber cable according to any one of [1] to [ 3 ] above,
The label has one or more discrimination zones ;
Each of the multiple optical fiber tape core wires has at least one identification band whose longitudinal identification band length is 1 mm or more and whose lateral identification band width is equal to or more than half the lateral width of the optical fiber tape core wire itself.
According to this configuration, the pattern can be reliably seen from the outer peripheral surface of the optical fiber unit, making it even easier to distinguish between the optical fiber units.

[ 5 ] In the optical fiber cable according to any one of [1] to [ 4 ] above,
the markers are provided repeatedly at predetermined intervals in the longitudinal direction of the optical fiber ribbon,
The repeat spacing of the markers is 500 mm or less.
When optical fiber ribbons are spliced, they are usually connected to terminals with a length of about 500 mm. Therefore, if the pattern interval is 500 mm or less, the pattern is reliably exposed. The configuration of [ 5 ] makes it possible to reliably view the pattern from the outer peripheral surface of the optical fiber unit, and to easily distinguish between optical fiber units. It also makes it possible to easily distinguish between optical fiber ribbons.

[Details of the embodiment of the present disclosure]
Hereinafter, an optical fiber cable 100 according to one embodiment of the present disclosure will be described with reference to FIGS. 1 to 4. FIG.
FIG. 1 is a cross-sectional view of an optical fiber cable according to an embodiment, FIG. 2A is a side view of an optical fiber unit according to a first example of the embodiment, FIG. 2B is a side view of an optical fiber unit according to a second example of the embodiment, FIG. 3A is a plan view of an optical fiber ribbon according to an embodiment, FIG. 3B is an enlarged view of a main portion of FIG. 3A, and FIG. 4 is a table summarizing the specifications of the identification band and the pattern formation pitch.
In the following description, configurations denoted with the same reference numerals in different drawings are assumed to be similar, and descriptions thereof may be omitted.
Furthermore, the present disclosure is not limited to these examples, but is intended to include all modifications within the meaning and scope of the claims, as defined by the claims.

In this disclosure, the term "longitudinal direction" refers to the direction in which the length of an elongated body or elongated shape is long, and can be rephrased as "axial direction" in linear bodies such as the optical fiber cable 100, the optical fiber unit 120, and the optical fiber ribbon 121. The term "short-side direction" refers to the direction in which the length of an elongated body or elongated shape is short, and can refer to a direction perpendicular to the longitudinal direction. Note that the "short-side direction" in linear bodies with a circular cross section such as the optical fiber cable 100 can be rephrased as the "radial direction." Also, the "short-side direction" in the optical fiber ribbon 121 can be rephrased as the "width direction." Also, the term "outer peripheral surface" refers to the surface facing radially outward in linear bodies such as the optical fiber cable 100.

[Optical fiber cable]
First, the optical fiber cable 100 will be described with reference to FIG.
As shown in FIG. 1 , the optical fiber cable 100 includes, for example, a plurality of optical fiber units 120 .

Specifically, the optical fiber cable 100 includes, for example, a slot rod 110 having a plurality of ribs 111 and slot grooves 112 formed between the plurality of ribs 111, an optical fiber unit 120 disposed in the slot groove 112, a cable jacket 130 that covers these, and a tension member 140 embedded in the center of the slot rod 110.

The ribs 111 of the slotted rod 110 protrude in the radial direction from the center of the slotted rod 110. For example, eight ribs 111 are formed at equal intervals in the circumferential direction.

The slot groove 112 is provided between a pair of slot rods 110. For example, one optical fiber unit 120 is accommodated in one slot groove 112.

In this embodiment, since eight ribs 111 are provided, eight slot grooves 112 are formed in the slot rod 110. The slot grooves 112 are formed along the longitudinal direction of the optical fiber cable 100, for example, in a spiral shape, or in an SZ shape in which the twisting direction is periodically reversed.

The tension member 140 is composed of a wire having resistance to tension and compression, such as a steel wire or FRP (Fiber Reinforced Plastics).

The cable sheath 130 is arranged to surround the outer periphery of the slot rod 110 and houses multiple optical fiber units 120 inside.

[Optical fiber unit]
Next, the optical fiber unit 120 will be described with reference to FIGS. 2A, 2B, and 3A.

The optical fiber unit 120 has, for example, a plurality of optical fiber ribbon core wires 121 as shown in FIG. 3A. Each of the optical fiber ribbon core wires 121 has, for example, a plurality of optical fiber core wires 121a arranged in parallel and has a flat shape. The connection mode of the optical fiber ribbon core wires 121 will be described later.

2A and 2B, the optical fiber unit 120 is formed, for example, by twisting together a plurality of optical fiber ribbon core wires 121. In this embodiment, the optical fiber unit 120 is formed by twisting together, for example, 12 optical fiber ribbon core wires 121. In addition, the optical fiber unit 120 is twisted, for example, in an S twist (right twist).

Furthermore, the outer peripheral surface of the optical fiber unit 120 is not covered with a tube, bundle thread, etc. Therefore, when the cable jacket 130 is stripped off, the optical fiber ribbon core wire 121 (i.e., the optical fiber core wire 121a) is exposed on the outer peripheral surface of the optical fiber unit 120 over the entire length of the optical fiber unit 120.

[Optical fiber ribbon]
Next, the optical fiber ribbon 121 will be described with reference to FIG. 3A.

3A, the optical fiber ribbon core wire 121 is configured as, for example, a so-called intermittent ribbon core wire. That is, the optical fiber ribbon core wire 121 has a connection region 121b that connects adjacent optical fiber core wires 121a in the short direction, and a non-connection region 121c that separates adjacent optical fiber core wires 121a in the short direction. In this embodiment, the optical fiber ribbon core wire 121 has, for example, 12 optical fiber core wires 121a.

[Sign]
Next, the marker 122 will be described with reference to FIGS. 2A to 3B.

As shown in Figures 2A to 3B, in this embodiment, at least one of the multiple optical fiber ribbons 121 has, for example, a mark 122 that can be distinguished among the multiple optical fiber units 120. At least a portion of the mark 122 is exposed on the outer peripheral surface of the optical fiber unit 120. This makes it possible to identify the optical fiber unit 120 with a simple structure.

In this embodiment, the marker 122 is configured as a pattern, such as a design, printed, painted or attached on the flat surface of the optical fiber ribbon 121. Note that the "flat surface" here refers to the surface of the flat optical fiber ribbon 121 when viewed from above, and may have irregularities following the external shape of the optical fiber 121a.

In addition, in this embodiment, the mark 122 has, for example, both distinguishability between multiple optical fiber units 120 and distinguishability between multiple optical fiber ribbons 121 within one optical fiber unit 120. "Distinguishing ability" here means a characteristic that allows differences between objects to be grasped from appearance. By configuring the mark 122 as described above, it is possible to simultaneously identify the optical fiber unit 120 and the optical fiber ribbon 121 while maintaining a simple structure.

2A and 2B, in this embodiment, the markers 122 have, for example, different colors for each optical fiber unit 120. This makes it easy to identify the optical fiber units.

Note that "different colors" here may refer to, for example, different chromaticities or different color intensities.

As a specific configuration that satisfies the above-mentioned requirements, for example, each of the multiple optical fiber ribbon core wires 121 has a marker 122. The marker 122 has a different pattern shape for each optical fiber ribbon core wire 121. In other words, the pattern shape of the marker 122 of each optical fiber ribbon core wire 121 indicates the distinguishability between the optical fiber ribbon core wires 121.

3A, for example, in each optical fiber ribbon 121, the markers 122 are provided repeatedly at a predetermined interval in the longitudinal direction of the optical fiber ribbon 121. In one optical fiber ribbon 121, the pattern shape of each of the repeated markers 122 is common.

On the other hand, as shown in Figures 2A and 2B, for example, the markers 122 of all of the multiple optical fiber ribbon cores 121 in one optical fiber unit 120 have a common color. As described above, the markers 122 have different colors for each optical fiber unit 120 (for example, the difference in color density of the markers 122 as shown in Figures 2A and 2B). In other words, the color of the markers 122 of each optical fiber unit 120 indicates the distinguishability between the optical fiber units 120.

With the above-described configuration, it is possible to easily identify both the optical fiber unit 120 and the optical fiber ribbon core 121.

3A and 3B, the sign 122 of this embodiment has, for example, one or more identification bands 122a. The identification band 122a is configured, for example, as a rectangular (band-shaped) pattern. For example, a first side (not shown) of the identification band 122a is arranged along the longitudinal direction of the optical fiber ribbon 121, and a second side (not shown) perpendicular to the first side of the identification band 122a is arranged along the transverse direction of the optical fiber ribbon 121. The identification band 122a has, for example, a length B in the longitudinal direction of the optical fiber ribbon 121 and a width A in the transverse direction perpendicular to the longitudinal direction.

Furthermore, the marker 122 has, for example, a number of identification bands 122a with different lengths B. The multiple identification bands 122a are spaced apart at an identification band forming pitch L. The identification band forming pitch L is, for example, about 3 mm.

For example, the length B of the identification bands 122a can be set to indicate identification numbers 1, 5, 10, etc., in ascending order from shortest to longest. By combining multiple identification bands 122a with different lengths B, it is possible to assign a unique identification number to each optical fiber ribbon 121. For example, in the case of Figure 3A, there is a combination of one identification band 122a with the longest length B, one identification band 122a with an intermediate length B, and one identification band 122a with a short length B, so the identification number of this optical fiber ribbon 121 is 16.

As shown in Figure 3A, the optical fiber ribbon core 121 is marked with markers 122 at a predetermined repetition interval (pattern forming pitch) P.

The pattern formation pitch P may be larger than the discrimination band formation pitch L, for example, 50 mm or more apart. This makes it possible to prevent confusion between repeated marks 122.

On the other hand, it is preferable that the pattern formation pitch P is 500 mm or less. This allows the pattern to be reliably viewed from the outer peripheral surface of the optical fiber unit 120, making it easy to distinguish between optical fiber units 120. It also allows the optical fiber ribbon core wires 121 to be easily distinguished from each other.

Because the optical fiber unit 120 is not covered with a tube or bundle thread, the optical fiber core 121a is exposed on its outer surface over the entire length of the optical fiber unit 120. As a result, as shown in Figures 2A and 2B, at least a portion of the marker 122 is exposed on the outer surface of the optical fiber unit 120.

Here, the specifications of the discrimination band 122a and the optimum value of the pattern formation pitch P will be considered.
In this study, the variables were the optical fiber ribbon width W, the identification band width A, the identification band length B, and the pattern formation pitch P. Using these variables, the identifiability of the optical fiber unit (whether it is possible to identify one optical fiber unit at a glance from among multiple optical fiber units arranged in one slot groove) and the identifiability of the optical fiber ribbon (whether it is possible to identify one optical fiber ribbon from among one optical fiber unit) were evaluated.
There were three optical fiber units in the slot groove, and each optical fiber unit contained 12 optical fiber ribbons as described above.

As shown in FIG. 3B , the above-mentioned "optical fiber tape core width W" is the length in the short direction X perpendicular to the longitudinal direction Y of the optical fiber tape core 121, the "identification band width A" is the length of the identification band 122a in the same direction as the short direction X, which is the width direction of the optical fiber tape core 121, and the "identification band length B" is the length of the identification band 122a in the direction Y perpendicular to the width direction of the identification band 122a.
Moreover, the pattern formation pitch P was set to be the longest within one optical fiber unit 120 .

The number and size of identification bands in one tag differ for each optical fiber ribbon 121. For this reason, in this study, Min (A _Max ) was evaluated as the identification band width, and Min (B _Max ) was evaluated as the identification band length.
however,
A _Max is the widest identification band width A in each of the optical fiber ribbons.
Min(A _Max ) is the minimum value of A _Max when comparing A _Max between optical fiber ribbons in one optical fiber unit.
B _Max is the longest identification band length B in each of the optical fiber ribbons.
Min(B _Max ) is the minimum value of B _Max when comparing B _Max between optical fiber ribbons in one optical fiber unit.

Furthermore, regarding the identifiability of the optical fiber units described above, a rating of "A (best)" was given when one optical fiber unit could be clearly identified from multiple optical fiber units at a glance, and a rating of "B (good)" was given when one optical fiber unit could be clearly identified from multiple optical fiber units but with a rating slightly inferior to A.
Furthermore, with regard to the identifiability of the optical fiber ribbon core wire, a case where one optical fiber ribbon core wire could be clearly identified from one optical fiber unit was rated as "A (best)," and a case where one optical fiber ribbon core wire could be clearly identified from one optical fiber unit but with a slightly inferior level to A was rated as "B (good)."

The results of investigating the optimal values for the identification band specifications and pattern formation pitch are shown in Figure 4.

For samples B1, B3 and B4, which had Min(A _Max )<W/2 or Min(B _Max )<1 mm, the unit discrimination was rated "B".

In contrast, in samples A1 to A4 in which Min(A _Max )≧W/2 and Min(B _Max )≧1 mm, the unit identification was rated "A."

From this, it is clear that the most preferable specifications of the discrimination band are Min(A _Max )≧W/2 and Min(B _Max )≧1 mm.

In sample B2, in which the pattern forming pitch P was greater than 500 mm, the tape core identifiability was "B."

In contrast, samples A1 to A4, B1 and B4, in which the pattern formation pitch P was 500 mm or less, had a ribbon fiber identifiability of "A."

From this, it can be seen that it is most preferable for the pattern formation pitch P to be 500 mm or less.

Based on the above considerations, it is preferable that a mark 122 that satisfies the optimal range of specifications of the identification band 122a and the optimal pattern formation pitch is marked on each optical fiber ribbon core 121.

[Effects of this embodiment]
According to this embodiment, one or more of the following advantages are achieved.

(a) In this embodiment, at least one of the multiple optical fiber ribbon core wires 121 has a mark 122 that can be distinguished among the multiple optical fiber units 120. At least a portion of the mark 122 is exposed on the outer peripheral surface of the optical fiber unit 120. This allows the mark 122 to be easily seen from the outer peripheral surface of the optical fiber unit 120. As a result, the optical fiber unit 120 can be identified with a simple structure without providing an identification member such as a bundle thread.

(b) In this embodiment, the marker 122 has both distinguishability between multiple optical fiber units 120 and distinguishability between multiple optical fiber ribbon cores 121 within one optical fiber unit 120. This eliminates the need to identify the optical fiber unit 120 using a bundle thread or the like. As a result, it is possible to both identify the optical fiber unit 120 and the optical fiber ribbon core 121 while maintaining the simple structure of the optical fiber cable 100.

In addition, the process of providing identification members such as bundle threads is no longer necessary. This makes it possible to shorten the manufacturing process of the optical fiber cable 100.

(c) In this embodiment, the markers 122 have, for example, different colors for each optical fiber unit 120. This makes it easy to identify the optical fiber units.

For example, if the mark 122 has both distinguishability between optical fiber units 120 and distinguishability between optical fiber tape cores 121, each distinguishability can be easily distinguished such that the pattern shape of the mark 122 indicates the distinguishability between optical fiber tape cores 121 and the color of the mark 122 indicates the distinguishability between optical fiber units 120.

(d) In this embodiment, each of the multiple optical fiber ribbon core wires 121 has at least one identification band 122a in which the identification band length B in the longitudinal direction of the optical fiber ribbon core wire 121 is 1 mm or more, and the identification band width A in the lateral direction of the optical fiber ribbon core wire 121 is at least half the lateral width W of the optical fiber ribbon core wire 121 itself. This allows the marker 122 to be reliably visible from the optical fiber unit 120, making it even easier to distinguish between the optical fiber units 120.

Here, the multiple optical fiber ribbon core wires 121 in the optical fiber unit 120 are twisted together in a spiral shape as described above. For this reason, it may be impossible to know which of the multiple optical fiber ribbon core wires 121 has a mark 122 exposed on the outer circumferential surface of the optical fiber unit 120. Alternatively, it may be impossible to know at what position on the outer circumferential surface of the optical fiber unit 120 a specific mark 122 will appear.

In contrast, by each of the multiple optical fiber ribbon core wires 121 having at least one or more identification bands 122a that satisfy the above-mentioned requirements, the mark 122 of any optical fiber ribbon core wire 121 can be reliably visually recognized no matter which mark 122 is exposed on the outer peripheral surface of the optical fiber unit 120, or no matter where a specific mark 122 appears on the outer peripheral surface of the optical fiber unit 120. As a result, it is possible to stably ensure the identification between the optical fiber units 120 described above.

(e) In this embodiment, the markers 122 are repeatedly provided at a predetermined interval in the longitudinal direction of the optical fiber ribbon 121, and the repetition interval of the markers 122 (pattern formation pitch P) is 500 mm or less. This allows the markers 122 to be reliably visible from the outer peripheral surface of the optical fiber unit 120, making it possible to easily distinguish between optical fiber units 120. It also makes it possible to easily distinguish between optical fiber ribbons 121.

[Modification]
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above.
Furthermore, the elements of the above-described embodiments can be combined as far as technically possible, and combinations of these are also included within the scope of the present disclosure as long as they include the features of the present disclosure.

For example, in this embodiment, the optical fiber cable has a structure having a slot rod, but it may have a so-called "slotless" structure in which only the optical fiber unit is housed inside the cable sheath without using a slot rod.

For example, in this embodiment, the number of slot grooves in the slot rod is eight, but the present invention is not limited to this.
Furthermore, in this embodiment, the position of the tension member in the slot rod is the center of the slot rod, but this is not limited to this.
The number of tension members may be more than one.

For example, in this embodiment, the optical fiber unit is formed from 12 optical fiber ribbon core wires, but the number of optical fiber ribbon core wires is not limited to this and may be any number as long as there is a plurality of pieces.
Furthermore, in this embodiment, the optical fiber unit is S-twisted, but this is not limited thereto, and it may be, for example, Z-twisted (left-handed) or SZ-twisted.
Furthermore, in this embodiment, the optical fiber ribbon is formed from 12 optical fiber core wires, but the number of optical fiber core wires is not limited to this, and any number of optical fiber core wires may be used as long as it is more than one.

For example, in this embodiment, the optical fiber tape core wire 121 is a so-called "intermittent tape core wire" having a connected region 121b and a non-connected region 121c, but the optical fiber tape core wire is not limited to an intermittent tape core wire as long as it is composed of multiple optical fiber core wires.

For example, the method of marking the indicator 122 on the optical fiber ribbon core 121 may be any method capable of coloring the optical fiber ribbon core, such as coloring by inkjet or coloring by hot stamping.

For example, in this embodiment, a case has been described in which the markers 122 have different colors for each optical fiber unit 120, but this is not limited to this case.

As a modified example, the mark 122 may have a different shape for each optical fiber unit 120. For example, the pattern shape of the mark 122 may indicate the distinguishability between the optical fiber units 120, and the color of the mark 122 may indicate the distinguishability between the optical fiber ribbon core wires 121. In this case, the shape of the mark 122 that differs for each optical fiber unit 120 may be a square, a circle, a star, a line, a V-shaped line, a W-shaped line, an S-shaped line, a Z-shaped line, or various patterns. Alternatively, the thickness or number of these patterns may be different.

As another variation, the combination of color and pattern shape of the mark 122 may indicate distinguishability between optical fiber units 120.

However, as in the above-described embodiment, it is preferable for only the color of the mark 122 to indicate the distinguishability between the optical fiber units 120, from the viewpoint of making it easier to distinguish the distinguishability.

Also, for example, in this embodiment, the shape of the identification band 122a is rectangular, but the shape of the identification band 122a is not limited to this and may be any shape.

[Basic application form]
Below, one aspect disclosed in the basic application is described.

(Appendix 1)
An optical fiber cable in which a plurality of optical fiber units formed by twisting together a plurality of optical fiber ribbons, each of which has a plurality of optical fiber core wires arranged in parallel, are housed inside a cable jacket,
A pattern for identifying the optical fiber unit is marked on the optical fiber ribbon of the optical fiber unit;
At least a part of the pattern marked on the optical fiber ribbon is exposed on an outer circumferential surface of the optical fiber unit;
An optical fiber cable, wherein the characteristics of a pattern marked on the optical fiber ribbon at the portion exposed to the optical fiber unit differ for each of the optical fiber units.

(Appendix 2)
2. The optical fiber cable of claim 1, wherein the pattern marked on the optical fiber ribbon is characterized by color.

(Appendix 3)
The pattern has at least one discrimination band,
Among the identification bands, the one that is the longest in the optical fiber ribbon and the shortest in the optical fiber unit has a length of 1 mm or more;
An optical fiber cable as described in Appendix 1 or Appendix 2, wherein the width of the identification band that is the widest within the optical fiber ribbon and the narrowest within the optical fiber unit is equal to or greater than half the width of the optical fiber ribbon.

(Appendix 4)
the pattern is different for each of the optical fiber ribbons,
a plurality of the patterns are provided at predetermined intervals on the optical fiber ribbon;
4. The optical fiber cable according to claim 1, wherein the longest predetermined interval within the optical fiber unit is 500 mm or less.

REFERENCE SIGNS LIST 100: Optical fiber cable 110: Slot rod 111: Rib 112: Slot groove 120: Optical fiber unit 121: Optical fiber ribbon 121a: Optical fiber 121b: Connected region 121c: Non-connected region 122: Mark 122a: Identification band 130: Cable jacket 140: Tension member W: Ripple width P: Pattern formation pitch L: Identification band formation pitch A: Identification band width B: Identification band length X: Short direction of optical fiber ribbon Y: Longitudinal direction of optical fiber ribbon

Claims (5)

A plurality of optical fiber units are provided,
Each of the optical fiber units includes a plurality of optical fiber ribbons,
The optical fiber ribbons each have a mark that can be distinguished from the optical fiber units,
the mark has both distinguishability among the plurality of optical fiber units and distinguishability among the plurality of optical fiber ribbons within one optical fiber unit,
the marks of the optical fiber ribbons in the one optical fiber unit have common characteristics among the optical fiber ribbons as distinguishing characteristics among the optical fiber units;
At least a portion of the marker is exposed on the outer peripheral surface of the optical fiber unit. The optical fiber cable according to claim 1 , wherein the indicator has a different color for each of the optical fiber units. 3. The optical fiber cable according to claim 1 , wherein the mark has a different shape for each of the optical fiber units. The label has one or more discrimination zones ;
4. The optical fiber cable according to claim 1, wherein each of the plurality of optical fiber ribbon core wires has at least one identification band whose longitudinal identification band length is 1 mm or more and whose lateral identification band width is at least half the lateral width of the optical fiber ribbon core wire itself. the markers are provided repeatedly at predetermined intervals in the longitudinal direction of the optical fiber ribbon,
5. The optical fiber cable according to claim 1 , wherein the repetition interval of the markers is 500 mm or less.