Optical fiber ribbon

Abstract

An optical fiber ribbon (1) comprises five or more optical fibers (20) and a plurality of connecting parts (10) which connect two adjacent optical fibers. The plurality of connecting parts (10) are disposed intermittently in the longitudinal direction (X direction) and in an arrangement direction (Y direction). The optical fiber ribbon has a first high density region (D1), a first low density region (S1), a second high density region (D2), and a second low density region (S2). The number density of the connecting parts (10) in the first low density region (S1) is lower than the number density of the connecting parts (10) in the first high density region (D1). The number density of the connecting parts (10) in the second low density region (S2) is lower than the number density of the connecting parts (10) in the second high density region (D2). The first low density region (S1) and the second low density region (S2) are offset in the longitudinal direction (X direction).

Description

[Technical field]

[0001] The present invention relates to an optical fiber ribbon. This application claims priority based on Japanese Patent Application No. 2021-115536, filed on July 13, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] Patent Document 1 discloses an optical fiber ribbon including a plurality of optical fibers arranged in an arrangement direction perpendicular to the longitudinal direction and a plurality of connecting parts. The connecting parts are formed between two optical fibers adjacent to each other in the arrangement direction and connect the two optical fibers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2021-43363 Summary of the Invention [Problem to be solved by the invention]

[0004] The optical fiber ribbon of Patent Document 1 has a plurality of high-density regions (connected regions) and a plurality of low-density regions (non-connected regions) alternately arranged in the longitudinal direction. At least two connecting parts are arranged in each of the plurality of high-density regions. In each of the plurality of low-density regions, a connecting part for fixing the arrangement pitch between two adjacent optical fibers is not arranged. On the other hand, the optical fiber ribbon may be wrapped in, for example, a pressure winding or a sheath and used as an optical fiber cable. In manufacturing such an optical fiber cable, a method is often adopted in which the optical fiber ribbon is moved along the longitudinal direction while merging the optical fiber ribbon with other components (pressure winding, sheath, etc.).

[0005] Incidentally, the portion of the optical fiber ribbon where the joint portion is formed has a higher rigidity than the other portions. Therefore, the rigidity of the optical fiber ribbon in each low-density region is likely to be smaller than the rigidity of the optical fiber ribbon in each high-density region. For example, in the optical fiber ribbon of Patent Document 1, high-density regions with high rigidity and low-density regions with low rigidity are arranged alternately in the longitudinal direction. When the optical fiber ribbon is moved during the manufacture of the optical fiber cable, the optical fiber ribbon may ripple or twist in the portion with low rigidity. Such ripples or undulations of the optical fiber ribbon may hinder the smooth manufacture of the optical fiber cable.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an optical fiber ribbon having improved rigidity. [Means for solving the problem]

[0007] In order to solve the above problems, an optical fiber ribbon according to one aspect of the present invention is an optical fiber ribbon comprising five or more optical fibers arranged in an arrangement direction perpendicular to a longitudinal direction, and a plurality of connecting portions formed between two of the optical fibers adjacent to each other in the arrangement direction and connecting the two optical fibers, the plurality of connecting portions being arranged intermittently in the longitudinal direction and the arrangement direction, the optical fiber ribbon having at least one first high density region and at least one first low density region arranged at different positions in the longitudinal direction, and at least one second high density region and at least one second low density region arranged at different positions in the longitudinal direction, and the first high density region includes at least one of the plurality of connecting portions. At least two connecting portions are arranged at different positions in the longitudinal direction and the arrangement direction, and at least two connecting portions among the multiple connecting portions are arranged in the second high density region, the number density of the connecting portions in the first low density region is lower than the number density of the connecting portions in the first high density region, the number density of the connecting portions in the second low density region is lower than the number density of the connecting portions in the second high density region, and a dimension L9 in the longitudinal direction of a portion where the first low density region and the second low density region overlap in the arrangement direction is smaller than a dimension L6 in the longitudinal direction of the first low density region and a dimension L8 in the longitudinal direction of the second low density region. Effect of the Invention

[0008] According to the above-described aspects of the present invention, an optical fiber ribbon having improved rigidity can be provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a plan view showing an optical fiber ribbon according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a plan view showing an optical fiber ribbon according to a second embodiment of the present invention. [Diagram 3]FIG. 11 is a plan view showing an optical fiber ribbon according to a third embodiment of the present invention. [Figure 4] FIG. 11 is a plan view showing an optical fiber ribbon according to a fourth embodiment of the present invention. [Diagram 5] FIG. 11 is a plan view showing an optical fiber ribbon according to a fifth embodiment of the present invention. [Figure 6] FIG. 13 is a plan view showing an optical fiber ribbon according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (First embodiment) Hereinafter, the optical fiber ribbon according to the first embodiment will be described with reference to the drawings. 1, the optical fiber ribbon 1 includes a plurality of optical fibers 20. The plurality of optical fibers 20 are arranged in a direction perpendicular to the longitudinal direction of each optical fiber 20. The optical fiber ribbon 1 further includes a plurality of connecting portions 10 that connect two adjacent optical fibers 20 among the plurality of optical fibers 20. 1, the number of optical fibers 20 included in the optical fiber ribbon 1 is 25. However, the number of optical fibers 20 can be changed as appropriate, and is not limited to any number as long as it is 5 or more.

[0011] (direction definition) In this embodiment, the longitudinal direction of the optical fiber ribbon is simply referred to as the longitudinal direction X. One direction in the longitudinal direction X is referred to as the +X direction or rightward. The direction opposite to the +X direction is referred to as the -X direction or leftward. The direction in which the multiple optical fibers 20 are arranged is referred to as the arrangement direction Y. The arrangement direction Y is perpendicular to the longitudinal direction X. One direction in the arrangement direction Y is referred to as the +Y direction or upward. The direction opposite to the +Y direction is referred to as the -Y direction or downward. The direction perpendicular to the longitudinal direction X and the arrangement direction Y is referred to as the perpendicular direction Z.

[0012] Each optical fiber 20 has a waveguide and a coating portion (not shown). The waveguide is made of, for example, glass. The waveguide has a core and a clad. The coating portion is made of, for example, resin, and covers the glass portion. Specific examples of the material of the coating portion include UV-curable resin.

[0013] Each optical fiber 20 extends along the longitudinal direction X. The optical fibers 20 are arranged in the arrangement direction Y. A gap may be provided between two adjacent optical fibers 20 in the arrangement direction Y, or the two optical fibers 20 may be in contact with each other. In the optical fiber ribbon 1 according to this embodiment, the optical fibers 20 are arranged at approximately constant intervals (arrangement pitch P5) in the arrangement direction Y. Hereinafter, the gap or contact surface between two adjacent optical fibers 20 in the arrangement direction Y is referred to as an inter-fiber region B. In the example of FIG. 1, 25 optical fibers 20 and 24 inter-fiber regions B are arranged alternately in the arrangement direction Y.

[0014] Each of the multiple connecting parts 10 is formed in the inter-fiber region B. The multiple connecting parts 10 are intermittently arranged in the longitudinal direction X and the arrangement direction Y. In this specification, the multiple connecting parts 10 being "intermittently arranged" includes both cases where the intervals between the connecting parts 10 are constant and cases where they are not constant. Each connecting part 10 connects two optical fibers 20 adjacent to the inter-fiber region B in which the connecting part 10 is arranged. More specifically, each connecting part 10 connects the coating parts of two optical fibers 20 adjacent to the inter-fiber region B in which the connecting part 10 is arranged. That is, in the optical fiber ribbon 1 according to this embodiment, two optical fibers 20 adjacent in the arrangement direction Y are intermittently connected to each other in the longitudinal direction X by the multiple connecting parts 10. The optical fiber ribbon 1 is also referred to as an intermittently fixed ribbon 1. Any material capable of connecting the coating parts of adjacent optical fibers 20 can be used as the connecting part 10. For example, a UV-curable resin may be used as the connecting part 10.

[0015] The optical fiber ribbon 1 according to this embodiment has a plurality of first high density regions D1, a plurality of first low density regions S1, a plurality of second high density regions D2, and a plurality of second low density regions S2. The plurality of first high density regions D1 and the plurality of first low density regions S1 are alternately arranged in the longitudinal direction X. The plurality of second high density regions D2 and the plurality of second low density regions S2 are alternately arranged in the longitudinal direction X. In this embodiment, the first high density region D1 and the second high density region D2 are arranged at different positions in the arrangement direction Y.

[0016] In this embodiment, the dimension L1 of each first high density region D1 in the arrangement direction Y and the dimension L2 of each first low density region S1 in the arrangement direction Y are approximately equal to each other. The dimension L3 of each second high density region D2 in the arrangement direction Y and the dimension L4 of each second low density region S2 in the arrangement direction Y are approximately equal to each other. The dimensions L1 and L3 may be approximately equal to each other. In this embodiment, the dimension of each first high density region D1 in the longitudinal direction X is approximately constant at dimension L5. The dimension of each first low density region S1 in the longitudinal direction X is approximately constant at dimension L6. The dimension of each second high density region D2 in the longitudinal direction X is approximately constant at dimension L7. The dimension of each second low density region S2 in the longitudinal direction X is approximately constant at dimension L8. However, each of the dimensions L5 to L8 may not be approximately constant. The dimensions L5 and L7 may be approximately equal to each other. The dimensions L6 and L8 may be approximately equal to each other. In this embodiment, each of the regions D1, D2, S1, and S2 includes 13 optical fibers 20 and 12 inter-fiber regions B.

[0017] The region consisting of the plurality of first high-density regions D1 and the plurality of first low-density regions S1 is referred to as the first region A1. The region consisting of the plurality of second high-density regions D2 and the plurality of second low-density regions S2 is referred to as the second region A2. In this embodiment, the first region A1 and the second region A2 are adjacent to each other in the arrangement direction Y. Note that the first region A1 and the second region A2 do not have to be adjacent to each other in the arrangement direction Y.

[0018] In this embodiment, each of the first high-density regions D1, each of the first low-density regions S1, each of the second high-density regions D2, and each of the second low-density regions S2 are formed in a substantially rectangular shape. Hereinafter, the right edge of each of the first high-density regions D1 may be referred to as the first right edge D1RE, and the left edge of each of the first high-density regions D1 may be referred to as the first left edge D1LE. Similarly, the right edge of each of the second high-density regions D2 may be referred to as the second right edge D2RE, and the left edge of each of the second high-density regions D2 may be referred to as the second left edge D2LE. In this embodiment, each of the edges D1RE, D1LE, D2RE, and D2LE is a line segment parallel to the arrangement direction Y. At least one connecting portion 10 is arranged to be in contact with each of the edges D1RE, D1LE, D2RE, and D2LE.

[0019] In this embodiment, the first right edge D1RE of each first high-density region D1 is also the left edge of the first low-density region S1 adjacent to the right of the first high-density region D1. Similarly, the first left edge D1LE of each first high-density region D1 is also the right edge of the first low-density region S1 adjacent to the left of the first high-density region D1. That is, each first high-density region D1 and each first low-density region S1 are partitioned by each first right edge D1RE and each first left edge D1LE. In this embodiment, the second right edge D2RE of each second high-density region D2 is also the left edge of the second low-density region S2 adjacent to the right of the second high-density region D2. Similarly, the second left edge D2LE of each second high-density region D2 is also the right edge of the second low-density region S2 adjacent to the left of the second high-density region D2. That is, the second high-density regions D2 and the second low-density regions S2 are partitioned by the second right edges D2RE and the second left edges D2LE.

[0020] The configuration of each of the first high-density regions D1 and each of the first low-density regions S1 will be described below.

[0021] In each first high-density region D1, at least two of the multiple connecting parts 10 are arranged at different positions in the longitudinal direction X and the arrangement direction Y. In the example of FIG. 1, twelve connecting parts 10 are arranged in each first high-density region D1. In the example of FIG. 1, the arrangement pattern of the twelve connecting parts 10 included in each first high-density region D1 is substantially the same between the first high-density regions D1. More specifically, three connecting part groups G are arranged in each first high-density region D1, and the three connecting part groups G are arranged in the arrangement direction Y. In each connecting part group G, four connecting parts 10 are arranged in a linear manner. In other words, in each first high-density region D1, the twelve connecting parts 10 are arranged periodically in the arrangement direction Y, with four connecting parts 10 (connecting part group G) as one unit. The number of connecting parts 10 included in each connecting part group G can be changed as appropriate, and the number of connecting parts 10 is not limited as long as it is two or more. In each connecting portion group G, a plurality of connecting portions may be arranged in a curved line. The number of connecting portion groups G included in each first high-density region D1 can be changed as appropriate. The number of connecting portions 10 included in each first high-density region D1 can be changed as appropriate, and the number of connecting portions 10 is not limited as long as it is two or more.

[0022] In the example of FIG. 1, in each connecting portion group G, the four connecting portions 10 are arranged at a substantially constant pitch P1 in the longitudinal direction X. The four connecting portions 10 are arranged at a substantially constant interval P2 in the longitudinal direction X. The four connecting portions 10 may be arranged without the interval P2 in the longitudinal direction X. That is, the connecting portions 10 may overlap each other in the arrangement direction Y. In each connecting portion group G, the inter-fiber region B in which a certain connecting portion 10 is arranged and the inter-fiber region B in which the connecting portion 10 closest to the certain connecting portion 10 is arranged are adjacent to each other in the arrangement direction Y. Here, in each connecting portion group G, the connecting portion 10 located at the top of the four connecting portions 10 included in the connecting portion group G is referred to as the upper end connecting portion. In each connecting portion group G, the connecting portion 10 located at the bottom of the four connecting portions 10 included in the connecting portion group G is referred to as the lower end connecting portion. In this embodiment, the three connecting portion groups G are adjacent to each other in the arrangement direction Y. For example, the inter-fiber region B in which the upper end connection part of the central connection part group G among the three connection part groups G is arranged is adjacent to the inter-fiber region B in which the lower end connection part of the upper connection part group G among the three connection part groups G is arranged. Similarly, the inter-fiber region B in which the lower end connection part of the central connection part group G among the three connection part groups G is arranged is adjacent to the inter-fiber region B in which the upper end connection part of the lower connection part group G among the three connection part groups G is arranged. Since the connection part groups G are adjacent to each other in the arrangement direction Y, one connection part 10 is arranged in each inter-fiber region B included in each first high density region D1. Note that the connection part groups G do not have to be adjacent to each other in the arrangement direction Y.

[0023] In the example of FIG. 1, the three rightmost connecting portions 10 among the four connecting portions 10 included in each connecting portion group G in each first high-density region D1 are arranged at approximately the same position as one another in the longitudinal direction X. These three connecting portions 10 are in contact with the first right edge D1RE. Similarly, the three leftmost connecting portions 10 among the four connecting portions 10 included in each connecting portion group G are arranged at approximately the same position as one another in the longitudinal direction X. These three connecting portions 10 are in contact with the first left edge D1LE.

[0024] 1, each second high-density region D2 also has a connecting portion group G similar to that of the first high-density region D1 (details will be described later). The connecting portion group G is included in any one of the multiple first high-density regions D1 and the multiple second high-density regions D2. Note that the first high-density region D1 and the second high-density region D2 may include a connecting portion 10 that does not belong to the connecting portion group G.

[0025] The number density of the connecting parts 10 in each first low-density region S1 is lower than the number density of the connecting parts 10 in each first high-density region D1. Similarly, the number density of the connecting parts 10 in each second low-density region S2 is lower than the number density of the connecting parts 10 in each second high-density region D2. The "number density of the connecting parts 10 in the first low-density region S1" is a value obtained by dividing the number of the connecting parts 10 included in the first low-density region S1 by the area of ​​the first low-density region S1. The "number density of the connecting parts 10 in the first high-density region D1" is a value obtained by dividing the number of the connecting parts 10 included in the first high-density region D1 by the area of ​​the first high-density region D1. The number density of the second low-density region S2 and the second high-density region D2 is defined in the same manner. In the example of FIG. 1, the low-density regions S1 and S2 do not include the connecting parts 10. That is, the number density of the connecting parts 10 in the low-density regions S1 and S2 is zero. However, the low-density regions S1 and S2 may include the connecting parts 10.

[0026] The configurations of the second high-density regions D2 and the second low-density regions S2 will be described below. In this embodiment, the configurations of the second high-density regions D2 are substantially the same as the configurations of the first high-density regions D1. Similarly, the configurations of the second low-density regions S2 are substantially the same as the configurations of the first low-density regions S1.

[0027] In each second high-density region D2, at least two of the multiple connecting parts 10 are arranged at different positions in the longitudinal direction X and the arrangement direction Y. In the example of FIG. 1, twelve connecting parts 10 are arranged in each second high-density region D2. In the example of FIG. 1, the arrangement pattern of the twelve connecting parts 10 included in each second high-density region D2 is substantially the same between the second high-density regions D2. More specifically, three connecting part groups G are arranged in each second high-density region D2, and the three connecting part groups G are arranged in the arrangement direction Y. In each connecting part group G, four connecting parts 10 are arranged in a linear manner. In other words, in each second high-density region D2, the twelve connecting parts 10 are arranged periodically in the arrangement direction Y, with four connecting parts 10 (connecting part group G) as one unit. The number of connecting parts 10 included in each connecting part group G can be changed as appropriate, and the number of connecting parts 10 is not limited as long as it is two or more. In each connecting portion group G, a plurality of connecting portions may be arranged in a curved line. The number of connecting portion groups G included in each second high-density region D2 may be changed as appropriate. The number of connecting portions 10 included in each second high-density region D2 may be changed as appropriate, and the number of connecting portions 10 is not limited as long as it is two or more.

[0028] In the example of FIG. 1, in each connecting portion group G, the four connecting portions 10 are arranged at a substantially constant pitch P3 in the longitudinal direction X. The four connecting portions 10 are arranged at a substantially constant interval P4 in the longitudinal direction X. The four connecting portions 10 may be arranged without the interval P4 in the longitudinal direction X. That is, the connecting portions 10 may overlap each other in the arrangement direction Y. In each connecting portion group G, the inter-fiber region B in which a certain connecting portion 10 is arranged is adjacent to the inter-fiber region B in which a connecting portion 10 adjacent to the certain connecting portion 10 is arranged in the arrangement direction Y. The three connecting portion groups G are adjacent to each other in the arrangement direction Y. For example, the inter-fiber region B in which the upper end connecting portion of the connecting portion group G located at the center among the three connecting portion groups G is arranged is adjacent to the inter-fiber region B in which the lower end connecting portion of the connecting portion group G located at the upper side among the three connecting portion groups G is arranged. Similarly, the inter-fiber region B in which the lower end coupling portion of the central coupling portion group G among the three coupling portion groups G is disposed is adjacent to the inter-fiber region B in which the upper end coupling portion of the lower coupling portion group G among the three coupling portion groups G is disposed. Since the coupling portion groups G are adjacent to each other in the arrangement direction Y, one coupling portion 10 is disposed in each inter-fiber region B included in each second high density region D2. Note that the coupling portion groups G do not have to be adjacent to each other in the arrangement direction Y.

[0029] In the example of FIG. 1, the three rightmost connecting portions 10 among the four connecting portions 10 included in each connecting portion group G in each second high-density region D2 are arranged at substantially the same position as one another in the longitudinal direction X. These three connecting portions 10 are in contact with the second right edge D2RE. Similarly, the three leftmost connecting portions 10 among the four connecting portions 10 included in each connecting portion group G are arranged at substantially the same position as one another in the longitudinal direction X. These three connecting portions 10 are in contact with the second left edge D2LE.

[0030] Hereinafter, the positional relationship between each of the first high-density regions D1, each of the first low-density regions S1, each of the second high-density regions D2, and each of the second low-density regions S2 will be described.

[0031] In each first low-density region S1 according to this embodiment, there is at least one second low-density region S2 that overlaps in the arrangement direction Y. In other words, each first low-density region S1 and each second low-density region S2 overlap each other in the arrangement direction Y. The dimension in the longitudinal direction X of each overlapping portion is substantially constant at dimension L9.

[0032] In this embodiment, dimension L9 is smaller than dimension L6 in the longitudinal direction X of each first low-density region S1 and dimension L8 in the longitudinal direction X of each second low-density region S2. That is, it satisfies L9 < L6 and L9 < L8. Also, dimension L9 is smaller than dimension L5 in the longitudinal direction X of each first high-density region D1 and dimension L7 in the longitudinal direction X of each second high-density region D2. That is, it satisfies L9 < L5 and L9 < L7. That is, the dimension L9 in the longitudinal direction X of the portion where the rigidity is the lowest in the longitudinal direction X of the optical fiber ribbon core wire 1 (that is, the portion where the first low-density region S1 and the second low-density region S2 overlap in the arrangement direction Y) is shorter than L5 to L8. Thereby, the area of the portion where the rigidity is the lowest in the longitudinal direction X of the optical fiber ribbon core wire 1 (that is, the portion of dimension L9) can be reduced, and the overall rigidity of the optical fiber ribbon core wire 1 can be increased.

[0033] Hereinafter, in each inter-fiber region B included in each first high density region D1, the rightmost connecting portion 10 is referred to as the first right end connecting portion 11R. In each inter-fiber region B included in each first high density region D1, the leftmost connecting portion 10 is referred to as the first left end connecting portion 11L. In each inter-fiber region B included in each second high density region D2, the rightmost connecting portion 10 is referred to as the second right end connecting portion 12R. In each inter-fiber region B included in each second high density region D2, the leftmost connecting portion 10 is referred to as the second left end connecting portion 12L. In the example of FIG. 1, for all inter-fiber regions B included in each inter-fiber region B included in each first high density region D1, there is only one connecting portion 10 arranged in the inter-fiber region B. Therefore, all connecting portions 10 included in each first high density region D1 correspond to both the first right end connecting portion 11R and the first left end connecting portion 11L. Similarly, in the example of FIG. 1, all of the connecting portions 10 included in each second high-density region D2 correspond to both the second right end connecting portion 12R and the second left end connecting portion 12L.

[0034] In each first high-density region D1, the straight line connecting the right ends of the two first right-end connecting parts 11R located on the right side is called the first right-side straight line D1R. If there are multiple points (points) corresponding to the right ends of each first right-end connecting part 11R, the first right-side straight line D1R is defined to connect the midpoint between two points located at both ends in the arrangement direction Y among the multiple points. The same applies to the first left-side straight line D1L, the second right-side straight line D2R, and the second left-side straight line D2L defined below. In each first high-density region D1, the straight line connecting the left ends of the two first left-end connecting parts 11L located on the left side is called the first left-side straight line D1L. In each second high-density region D2, the straight line connecting the right ends of the two second right-end connecting parts 12R located on the right side is called the second right-side straight line D2R. In each second high-density region D2, a straight line connecting the left ends of the two second left-end connecting portions 12L located at the leftmost position is referred to as a second left straight line D2L. In the example of Fig. 1, each of the first right straight lines D1R overlaps with each of the first right edges D1RE, and each of the first left straight lines D1L overlaps with each of the first left edges D1LE. Similarly, each of the second right straight lines D2R overlaps with each of the second right edges D2RE.

[0035] In this embodiment, among the multiple connecting parts 10 included in each first high-density region D1, all of the connecting parts 10 that overlap with the first right straight line D1R (in the example of FIG. 1, three connecting parts 10 that contact the first right edge D1RE) do not overlap with each of the multiple second right straight lines D2R. Similarly, among the multiple connecting parts 10 included in each first high-density region D1, all of the connecting parts 10 that overlap with the first left straight line D1L (in the example of FIG. 1, three connecting parts 10 that contact the first left edge D1LE) do not overlap with each of the multiple second left straight lines D2L. Among the multiple connecting parts 10 included in each second high-density region D2, all of the connecting parts 10 that overlap with the second right straight line D2R (in the example of FIG. 1, three connecting parts 10 that contact the second right edge D2RE) do not overlap with each of the multiple first right straight lines D1R. Of the multiple connecting portions 10 included in each second high-density region D2, all of the connecting portions 10 that overlap with the second left straight line D2L (in the example of Figure 1, the three connecting portions 10 that are in contact with the second left edge D2LE) do not overlap with each of the multiple first left straight lines D1L.

[0036] Next, the operation of the optical fiber ribbon 1 configured as above will be described.

[0037] The optical fiber ribbon 1 according to this embodiment has a plurality of first high density regions D1 and a plurality of second high density regions D2 in which many connecting portions 10 are arranged, and a plurality of first low density regions S1 and a plurality of second low density regions S2 in which few connecting portions 10 are arranged (particularly in the example of FIG. 1, no connecting portions 10 are arranged). Here, in each of the first high density regions D1 and each of the second high density regions D2, the plurality of optical fibers 20 are connected to each other and integrated. The connecting portions 10 also serve to fix the arrangement pitch P5 between two adjacent optical fibers 20. Therefore, the arrangement pitch P5 can be stabilized in each of the first high density regions D1 and each of the second high density regions D2.

[0038] Incidentally, a fusion splicer is generally used when fusion splicing an optical fiber ribbon to another optical fiber ribbon. The fusion splicer has a plurality of grooves extending along the longitudinal direction X. Inside the fusion splicer, the optical fibers 20 included in the optical fiber ribbon are inserted one by one into the plurality of grooves for alignment. Here, the arrangement pitch P5 is fixed by the connecting part 10. For this reason, when performing a fusion operation on a certain optical fiber ribbon, a fusion splicer having grooves arranged at the arrangement pitch P5 of the optical fibers in the optical fiber ribbon has been used in the past.

[0039] However, in recent years, research and development aimed at reducing the diameter of the optical fibers 20 has been actively conducted, and accordingly, the arrangement pitch P5 of the optical fibers 20 has been reduced accordingly. Therefore, when attempting to fusion splice optical fiber ribbons manufactured at different times, a problem has arisen in that it becomes difficult to fusion splice both optical fiber ribbons using a fusion splicer because the arrangement pitches P5 of both optical fiber ribbons are different from each other.

[0040] In contrast, the optical fiber ribbon 1 according to the present embodiment has a plurality of first low-density regions S1 and a plurality of second low-density regions S2. In each of the first low-density regions S1 and the second low-density regions S2, no or few connecting portions 10 for fixing the arrangement pitch P5 between two adjacent optical fibers 20 are arranged. Therefore, a user can change the arrangement pitch P5 by pulling or compressing the optical fiber ribbon 1 in the arrangement direction Y in the first low-density region S1 or the second low-density region S2. This makes it possible to use a fusion splicer having an arrangement pitch P5 different from that of the optical fiber ribbon 1 when fusion splicing the optical fiber ribbon 1. In addition, it becomes possible to fusion splice the optical fiber ribbon 1 to an optical fiber ribbon having an arrangement pitch P5 different from that of the optical fiber ribbon 1.

[0041] On the other hand, the optical fiber ribbon 1 may be used as an optical fiber cable by, for example, wrapping it in a pressure winding or a sheath. In manufacturing such an optical fiber cable, a method is often adopted in which the optical fiber ribbon 1 is moved along the longitudinal direction X while merging the optical fiber ribbon 1 with other components (pressure winding, sheath, etc.).

[0042] Here, the portion where the connection portion 10 is formed between the optical fibers 20 has a higher rigidity than the portion where the connection portion 10 is not formed. Therefore, the rigidity of the optical fiber ribbon 1 in each of the low-density regions S1, S2 is likely to be smaller than the rigidity of the optical fiber ribbon 1 in each of the high-density regions D1, D2. For example, in the case of an optical fiber ribbon in which a plurality of high-density regions and a plurality of low-density regions are simply arranged alternately in the longitudinal direction (in the case of an optical fiber ribbon having only one of the first region A1 and the second region A2 in this embodiment), there are portions (each low-density region) in which the rigidity is extremely low in the longitudinal direction of the optical fiber ribbon. In the case of an optical fiber ribbon in which such a portion with extremely low rigidity exists, there is a possibility that the optical fiber ribbon may wavy or twist in the portion with extremely low rigidity when the optical fiber ribbon is moved. Such waving or undulation of the optical fiber ribbon impedes smooth manufacturing of optical fiber cables.

[0043] In contrast, the optical fiber ribbon 1 according to the present embodiment has both the first region A1 and the second region A2, and the first region A1 and the second region A2 are offset from each other in the longitudinal direction X. More specifically, the first high-density regions D1 and the second high-density regions D2 are offset from each other in the longitudinal direction X, and the first low-density regions S1 and the second low-density regions S2 are offset from each other in the longitudinal direction X. This shortens the dimension L9 in the longitudinal direction X of the portion of the optical fiber ribbon 1 that has the lowest rigidity in the longitudinal direction X (i.e., the portion where the first low-density region S1 and the second low-density region S2 overlap in the arrangement direction Y). In other words, the dimension L9 in the longitudinal direction X of the portion of the optical fiber ribbon 1 that has particularly low rigidity can be shortened. Therefore, the rigidity of the optical fiber ribbon 1 as a whole can be increased, and waving and twisting of the optical fiber ribbon 1 when the optical fiber ribbon 1 is moved can be suppressed.

[0044] As described above, the optical fiber ribbon 1 according to the present embodiment includes five or more optical fibers 20 arranged in the arrangement direction Y, and a plurality of connecting portions 10 formed between two adjacent optical fibers 20 in the arrangement direction Y and connecting the two optical fibers 20, the plurality of connecting portions 10 being intermittently arranged in the longitudinal direction X and the arrangement direction Y, the optical fiber ribbon 1 having a plurality of first high density regions D1 and a plurality of first low density regions S1 alternately arranged in the longitudinal direction X, and a plurality of second high density regions D2 and a plurality of second low density regions S2 alternately arranged in the longitudinal direction X, and each of the plurality of first high density regions D1 includes at least two of the plurality of connecting portions 10 that are located at different positions in the longitudinal direction X and the arrangement direction Y. connecting portions 10 are arranged, and in each of the plurality of second high-density regions D2, at least two of the plurality of connecting portions 10 are arranged, the positions of which in the longitudinal direction X and the arrangement direction Y are different from each other, the number density of the connecting portions 10 in each of the plurality of first low-density regions S1 is lower than the number density of the connecting portions 10 in each of the plurality of first high-density regions D1, the number density of the connecting portions 10 in each of the plurality of second low-density regions S2 is lower than the number density of the connecting portions 10 in each of the plurality of second high-density regions D2, and a dimension L9 in the longitudinal direction X of each portion where each of the plurality of first low-density regions S1 and each of the plurality of second low-density regions S2 overlap in the arrangement direction Y is smaller than a dimension L6 in the longitudinal direction X of each of the plurality of first low-density regions S1 and a dimension L8 in the longitudinal direction X of each of the second low-density regions S2.

[0045] With this configuration, the first low-density region S1, which has a lower rigidity than the first high-density region D1, and the second low-density region S2, which has a lower rigidity than the second high-density region D2, are arranged to be shifted in the longitudinal direction X. As a result, compared to a case where the first low-density region S1 and the second low-density region S2 are not shifted in the longitudinal direction X, for example, the dimension L9 in the longitudinal direction X of the portion of the optical fiber ribbon 1 where the rigidity is lowest in the longitudinal direction X (i.e., the portion where the first low-density region S1 and the second low-density region S2 overlap in the arrangement direction Y) is shorter. Therefore, the rigidity of the optical fiber ribbon 1 as a whole can be increased, and waving and twisting of the optical fiber ribbon 1 when the optical fiber ribbon 1 is moved can be suppressed.

[0046] Moreover, among the multiple coupling parts 10 included in each of the multiple first high density regions D1, the coupling parts 10 that overlap the first right straight line D1R do not overlap each of the multiple second right straight lines D2R, among the multiple coupling parts 10 included in each of the multiple first high density regions D1, the coupling parts 10 that overlap the first left straight line D1L do not overlap each of the multiple second left straight lines D2L, among the multiple coupling parts 10 included in each of the multiple second high density regions D2, the coupling parts 10 that overlap the second right straight line D2R do not overlap each of the multiple first right straight lines D1R, and among the multiple coupling parts 10 included in each of the multiple second high density regions D2, the coupling parts 10 that overlap the second left straight line D2L do not overlap each of the multiple first left straight lines D1L. With this configuration, the deviation in the longitudinal direction X of the first low density region S1 and the second low density region S2 becomes larger. In other words, the dimension L9 becomes shorter. This makes it possible to further increase the rigidity of the optical fiber ribbon 1.

[0047] Furthermore, a dimension L9 in the longitudinal direction X of each portion where each of the multiple first low-density regions S1 and each of the second low-density regions S2 overlap in the arrangement direction Y is smaller than a dimension L5 in the longitudinal direction X of each of the multiple first high-density regions D1 and a dimension L7 in the longitudinal direction X of each of the multiple second high-density regions D2. With this configuration, the dimensions in the longitudinal direction X of each of the high-density regions D1 and D2, which have high rigidity, are larger than the portions of the optical fiber ribbon 1, which have particularly low rigidity in the longitudinal direction X. Therefore, the rigidity of the optical fiber ribbon 1 as a whole is further improved.

[0048] Furthermore, at least one connecting portion 10 is disposed in each of the inter-fiber regions B included in each of the first high density regions D1, and at least one connecting portion 10 is disposed in each of the inter-fiber regions B included in each of the second high density regions D2. With this configuration, separation of the optical fiber ribbon 1 in the arrangement direction Y in the first high density region D1 or the second high density region D2 is suppressed.

[0049] Also, at least one coupling portion 10 is disposed on each of the first right edge D1RE and each of the first left edge D1LE, and at least one coupling portion 10 is disposed on each of the second right edge D2RE and each of the second left edge D2LE. This makes it possible to improve the rigidity of each first high-density region D1 compared to a case where no coupling portion 10 is disposed on each of the first right edge D1RE and each of the first left edge D1LE. Similarly, it makes it possible to improve the rigidity of each second high-density region D2 compared to a case where no coupling portion 10 is disposed on each of the second right edge D2RE and each of the second left edge D2LE. Therefore, it is possible to increase the rigidity of the optical fiber ribbon 1 as a whole.

[0050] Furthermore, the first region A1, which is a region combining the multiple first high-density regions D1 and the multiple first low-density regions S1, and the second region A2, which is a region combining the multiple second high-density regions D2 and the multiple second low-density regions S2, are adjacent to each other in the arrangement direction Y. With this configuration, bending of the optical fiber ribbon 1 about the longitudinal direction X is suppressed, compared to a case where, for example, the first region A1 and the second region A2 are not adjacent to each other in the arrangement direction Y.

[0051] In addition, in the arrangement direction Y, the dimension L1 of each of the first high density regions D1 is equal to the dimension L2 of each of the first low density regions S1, and the dimension L3 of each of the second high density regions D2 is equal to the dimension L4 of each of the second low density regions S2. This can increase the rigidity of the optical fiber ribbon 1, for example, compared to a case where the dimension L1 is smaller than the dimension L2 and the dimension L3 is smaller than the dimension L4.

[0052] Second embodiment Next, a second embodiment of the present invention will be described, but the basic configuration is similar to that of the first embodiment. Therefore, the same components are given the same reference numerals and the description thereof will be omitted, and only the differences will be described. The optical fiber ribbon 2 according to this embodiment shown in FIG. 2 differs from the first embodiment in the positional relationship between the regions D1, D2, S1, and S2.

[0053] 2, in this embodiment, the first high-density regions D1 and the second high-density regions D2 do not overlap with each other in the arrangement direction Y. Also, each first low-density region S1 and the two second low-density regions S2 closest to the first low-density region S1 are arranged such that their ends in the longitudinal direction X overlap in the arrangement direction Y. Similarly, each second low-density region S2 and the two first low-density regions S1 closest to the second low-density region S2 are arranged such that their ends in the longitudinal direction X overlap in the arrangement direction Y.

[0054] In this case, the entire first high-density region D1 in the longitudinal direction X is adjacent to the second low-density region S2 in the arrangement direction Y. Similarly, the entire second high-density region D2 in the longitudinal direction X is adjacent to the first low-density region S1 in the arrangement direction Y. With this arrangement, the first low-density region S1, which is a portion having a lower rigidity than the first high-density region D1, is reinforced by the second high-density region D2. Similarly, the second low-density region S2, which is a portion having a lower rigidity than the second high-density region D2, is reinforced by the first high-density region D1.

[0055] As described above, in the optical fiber ribbon 2 according to this embodiment, the multiple first high density regions D1 and the multiple second high density regions D2 do not overlap with each other in the arrangement direction Y. This configuration makes it possible for the high density regions D1, D2, which have high rigidity, to reinforce the low density regions S1, S2, which have low rigidity. Therefore, the rigidity of the optical fiber ribbon 2 can be improved overall.

[0056] Third embodiment Next, a third embodiment of the present invention will be described, but the basic configuration is similar to that of the first embodiment. Therefore, the same components are given the same reference numerals and the description thereof will be omitted, and only the differences will be described. The optical fiber ribbon 3 according to this embodiment shown in FIG. 3 differs from the first embodiment in the positional relationship between the regions D1, D2, S1, and S2.

[0057] 3, in this embodiment, the first low-density regions S1 and the second low-density regions S2 do not overlap with each other in the arrangement direction Y. Furthermore, each first high-density region D1 and the two second high-density regions D2 closest to the first high-density region D1 are arranged such that their ends in the longitudinal direction X overlap in the arrangement direction Y. Similarly, each second high-density region D2 and the two first high-density regions D1 closest to the second high-density region D2 are arranged such that their ends in the longitudinal direction X overlap in the arrangement direction Y.

[0058] In this case, the first high density region D1 or the second high density region D2 is disposed at any position in the longitudinal direction X of the optical fiber ribbon 3. Therefore, a high rigidity region is disposed at any position in the longitudinal direction X of the optical fiber ribbon 3.

[0059] As described above, in the optical fiber ribbon 3 according to the present embodiment, the first low-density regions S1 and the second low-density regions S2 do not overlap each other. This configuration can more reliably improve the rigidity of the optical fiber ribbon 3.

[0060] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described, but the basic configuration is similar to that of the first embodiment. Therefore, the same components are given the same reference numerals and the description thereof will be omitted, and only the differences will be described. The optical fiber ribbon 4 according to this embodiment shown in FIG. 4 differs from the first embodiment in the configuration of each of the high density regions D1, D2.

[0061] As shown in Fig. 4, in the optical fiber ribbon 4 according to this embodiment, a plurality of coupling parts 10 (two in Fig. 4) are arranged in each of a plurality of inter-fiber regions B (12 in Fig. 4) included in each high-density region D1, D2. In the example of Fig. 4, 24 coupling parts 10 are arranged in each high-density region D1, D2. Note that three or more coupling parts 10 may be arranged in each inter-fiber region B. A different number of coupling parts 10 may be arranged in each inter-fiber region B.

[0062] In this way, when each inter-fiber region B in the high-density regions D1, D2 includes multiple connecting portions 10, in each inter-fiber region B, the connecting portion 10 corresponding to the first right end connecting portion 11R and the connecting portion 10 corresponding to the first left end connecting portion 11L are different from each other.

[0063] The optical fiber ribbon 4 according to this embodiment provides the same effects as those of the optical fiber ribbon 1 according to the first embodiment. In addition, by increasing the number of connecting parts 10 arranged in each inter-fiber region B, the rigidity of the optical fiber ribbon 4 in each of the high-density regions D1, D2 can be improved. This allows the rigidity of the optical fiber ribbon 4 to be further improved overall.

[0064] Fifth embodiment Next, a fifth embodiment of the present invention will be described, but the basic configuration is similar to that of the first embodiment. Therefore, the same components are given the same reference numerals and the description thereof will be omitted, and only the differences will be described. The optical fiber ribbon 5 according to this embodiment shown in FIG. 5 differs from the first embodiment in the configuration of each of the high density regions D1, D2.

[0065] As shown in Fig. 5, in the optical fiber ribbon 5 according to this embodiment, one coupling portion group G is arranged in each of the high-density regions D1, D2. In addition, in the coupling portion group G, a plurality of coupling portions 10 (12 in Fig. 5) are arranged in series. In particular, in the example of Fig. 5, the 12 coupling portions are arranged in a curved line. In other words, in the coupling portion groups G included in each of the high-density regions D1, D2, the pitches P1, P3 at which the coupling portions 10 are arranged are not constant.

[0066] In this case, in each first high density region D1, the first right edge D1RE does not overlap with the first right straight line D1R, and the first left edge D1LE does not overlap with the first left straight line D1L. Similarly, in each second high density region D2, the second right edge D2RE does not overlap with the second right straight line D2R, and the second left edge D2LE does not overlap with the second left straight line D2L. Note that, in the optical fiber ribbon 5 according to the present embodiment, among the multiple coupling parts 10 included in each first high density region D1, the coupling parts 10 that overlap with the first right straight line D1R do not overlap with each of the multiple second right straight lines D2R. Similarly, among the multiple coupling parts 10 included in each first high density region D1, the coupling parts 10 that overlap with the first left straight line D1L do not overlap with each of the multiple second left straight lines D2L. Among the multiple connecting portions 10 included in each second high-density region D2, the connecting portions 10 that overlap the second right straight line D2R do not overlap with each of the multiple first right straight lines D1R. Among the multiple connecting portions 10 included in each second high-density region D2, the connecting portions 10 that overlap the second left straight line D2L do not overlap with each of the multiple first left straight lines D1L.

[0067] The optical fiber ribbon 5 according to this embodiment provides the same effects as those of the optical fiber ribbon 1 according to the first embodiment. In addition, since the multiple connection parts 10 included in each of the high-density regions D1, D2 are connected as one connection part group G, it is possible to arrange the multiple connection parts 10 in each of the high-density regions D1, D2 as if they were a traversable figure, a figure written in one stroke. As a result, for example, when manufacturing the optical fiber ribbon 5, if a dispenser that dispenses resin to become the connection parts 10 is moved, the movement distance of the dispenser is shortened, improving manufacturing efficiency.

[0068] Sixth embodiment Next, a sixth embodiment of the present invention will be described, but the basic configuration is similar to that of the first embodiment. Therefore, the same components are given the same reference numerals and the description thereof will be omitted, and only the differences will be described. The optical fiber ribbon 6 according to this embodiment shown in FIG. 6 differs from the first embodiment in the configuration of each of the low-density regions S1, S2.

[0069] 6, in the optical fiber ribbon 6 according to this embodiment, the connection portions 10 are arranged in each of the low-density regions S1, S2. Note that in the optical fiber ribbon 6 according to this embodiment, the number density of the connection portions 10 in each of the first low-density regions S1 is also lower than the number density of the connection portions 10 in each of the first high-density regions D1. Similarly, the number density of the connection portions 10 in each of the second low-density regions S2 is lower than the number density of the connection portions 10 in each of the second high-density regions D2.

[0070] The optical fiber ribbon 6 according to this embodiment provides the same effects as those of the optical fiber ribbon 1 according to the first embodiment. In addition, since the connecting portions 10 are also arranged in each of the low-density regions S1, S2, the rigidity of the optical fiber ribbon 6 in each of the low-density regions S1, S2 can be improved. This can improve the rigidity of the optical fiber ribbon 6 as a whole. In addition, when fusion splicing the optical fiber ribbon 6, the connecting portions 10 included in the low-density regions S1, S2 can be peeled off to change the pitch between the optical fibers 20. Since the number of connecting portions 10 included in the low-density regions S1, S2 is small, peeling is easy.

[0071] In this specification, for example, "approximately equal" includes cases where they can be considered equal if manufacturing errors are removed. The same applies to other expressions using "approximately". In other words, expressions using "approximately" include cases where the meaning indicated by the words following "approximately" can be considered valid if manufacturing errors are removed.

[0072] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0073] For example, in the above embodiment, for each of the plurality of first high-density regions D1, the plurality of first low-density regions S1, the plurality of second high-density regions D2, and the plurality of second low-density regions S2, L9 < L6 and L9 < L8 were satisfied. However, by satisfying L9 < L6 and L9 < L8 for at least one of the first high-density region D1, the first low-density region S1, the second high-density region D2, and the second low-density region S2, the effect of improving the rigidity in that portion can be obtained. The same applies to other dimensional relationships.

[0074] Also, the arrangement pattern of the plurality of connecting portions 10 included in each first high-density region D1 may not be the same among the first high-density regions D1. Similarly, the arrangement pattern of the plurality of connecting portions 10 included in each second high-density region D2 may not be the same among the second high-density regions D2.

[0075] Also, the dimensions of each connecting portion 10 in the longitudinal direction X and the arrangement direction Y may not be the same among the connecting portions 10.

[0076] Also, the plurality of connecting portions 10 included in each high-density region D1, D2 may not form a connecting portion group G. In other words, in each high-density region D1, D2, the plurality of connecting portions 10 may be randomly arranged. Similarly, in each low-density region S1, S2, the plurality of connecting portions 10 may be randomly arranged.

[0077] In addition, when there are a plurality of coupling parts 10 included in the first high density region D1 and overlapping with the first right straight line D1R, some of the coupling parts 10 may overlap with the second right straight line D2R. However, it is preferable that all of the coupling parts 10 do not overlap with the second right straight line D2R, because the deviation in the longitudinal direction X of the first low density region S1 and the second low density region S2 becomes larger, and the rigidity of the optical fiber ribbon 1 can be more reliably increased. The same applies when there are a plurality of coupling parts 10 included in the first high density region D1 and overlapping with the first left straight line D1L. The same applies when there are a plurality of coupling parts 10 included in the second high density region and overlapping with the second right straight line D2R. The same applies when there are a plurality of coupling parts 10 included in the second high density region and overlapping with the second left straight line D2L.

[0078] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate. [Explanation of symbols]

[0079] 1-6...Optical fiber ribbon 10...Connection portion 11R...First right end connection portion 11L...First left end connection portion 12R...Second right end connection portion 12L...Second left end connection portion 20...Optical fiber D1...First high density region D1R...First right straight line D1RE...First right edge (edge ​​in the longitudinal direction of the first high density region) D1L...First left straight line D1LE...First left edge (edge ​​in the longitudinal direction of the first high density region) D2...Second high density region D2R...Second right straight line D2RE...Second right edge (edge ​​in the longitudinal direction of the second high density region) D2L...Second left straight line D2LE...Second left edge (edge ​​in the longitudinal direction of the second high density region) S1...First low density region S2...Second low density region A1...First region A2...Second region X...Longitudinal direction Y...Arrangement direction

Claims

1. Five or more optical fibers arranged in an arrangement direction perpendicular to the longitudinal direction; a plurality of connecting portions formed between two adjacent optical fibers in the arrangement direction and connecting the two optical fibers; The optical fiber ribbon has a plurality of connecting portions arranged intermittently in the longitudinal direction and the arrangement direction, the optical fiber ribbon has a plurality of first high density regions and at least one first low density region arranged at different positions in the longitudinal direction, and a plurality of second high density regions and at least one second low density region arranged at different positions in the longitudinal direction, At least two of the plurality of connecting portions are arranged in the first high-density region, the connecting portions being located at different positions in the longitudinal direction and the arrangement direction; At least two of the plurality of connecting portions are arranged in the second high-density region, the connecting portions being located at different positions in the longitudinal direction and the arrangement direction, a number density of the connecting portions in the first low-density region is lower than a number density of the connecting portions in the first high-density region, a number density of the connecting portions in the second low-density region is lower than a number density of the connecting portions in the second high-density region, a dimension L9 in the longitudinal direction of a portion where the first low-density region and the second low-density region overlap in the arrangement direction is smaller than a dimension L6 in the longitudinal direction of the first low-density region and a dimension L8 in the longitudinal direction of the second low-density region; One direction in the longitudinal direction is referred to as the right side, and the opposite direction to the right side is referred to as the left side. The area between two adjacent optical fibers is called an inter-fiber area, In each of the plurality of inter-fiber regions included in the first high density region, a coupling portion located at the rightmost position is referred to as a first right end coupling portion, In each of the plurality of inter-fiber regions included in the first high density region, a coupling portion located at the leftmost position is referred to as a first left end coupling portion, In each of the plurality of inter-fiber regions included in the second high density region, a coupling portion located at the rightmost position is referred to as a second right end coupling portion, In each of the plurality of inter-fiber regions included in the second high density region, a coupling portion located at the leftmost position is referred to as a second left end coupling portion, a straight line connecting the right ends of two rightmost first right end connecting portions among the plurality of first right end connecting portions included in the first high-density region is referred to as a first right side straight line; a straight line connecting the left ends of two first left end connecting parts located at the leftmost position among the plurality of first left end connecting parts included in the first high-density region is referred to as a first left straight line; a straight line connecting the right ends of two second right end connecting parts located at the rightmost position among the plurality of second right end connecting parts included in the second high-density region is referred to as a second right side straight line, When a straight line connecting the left ends of two second left end connecting parts located at the leftmost position among the plurality of second left end connecting parts included in the second high-density region is referred to as a second left straight line, a connecting portion included in the first high density region and overlapping the first right straight line does not overlap the second right straight line; a connecting portion included in the first high density region and overlapping the first left straight line does not overlap the second left straight line; a connecting portion included in the second high density region and overlapping with the second right straight line does not overlap with the first right straight line; a connecting portion included in the second high density region and overlapping with the second left straight line does not overlap with the first left straight line; The first low-density region does not include the connecting portion, The optical fiber ribbon, wherein the second low-density region does not include the connection portion.

2. 2. The optical fiber ribbon according to claim 1, wherein a dimension L9 in the longitudinal direction of a portion where the first low-density region and the second low-density region overlap in the arrangement direction is smaller than a dimension L5 in the longitudinal direction of the first high-density region and a dimension L7 in the longitudinal direction of the second high-density region.

3. When the area between two adjacent optical fibers is referred to as an inter-fiber area, At least one of the coupling portions is disposed in each of the plurality of inter-fiber regions included in the first high density region, 3 . The optical fiber ribbon according to claim 1 , wherein at least one of the coupling portions is disposed in each of the plurality of inter-fiber regions included in the second high density region.

4. At least one connecting portion is disposed on each of both end edges in the longitudinal direction of the first high-density region, 3 . The optical fiber ribbon according to claim 1 , wherein at least one of the coupling portions is disposed on each of both longitudinal ends of the second high density region.

5. 3. The optical fiber ribbon according to claim 1, wherein a first region, which is a region combining the first high density region and the first low density region, and a second region, which is a region combining the second high density region and the second low density region, are adjacent to each other in the arrangement direction.

6. 3. The optical fiber ribbon according to claim 1, wherein in the arrangement direction, a dimension L1 of the first high density region and a dimension L2 of the first low density region are equal to each other, and a dimension L3 of the second high density region and a dimension L4 of the second low density region are equal to each other.

7. 3. The optical fiber ribbon according to claim 1, wherein the first high density region and the second high density region do not overlap with each other in the arrangement direction.

8. 3. The optical fiber ribbon according to claim 1, wherein the first low-density region and the second low-density region do not overlap with each other in the arrangement direction.

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