Optical fiber ribbon and sub-tape type optical fiber ribbon

Abstract

This intermittently-connected-type optical fiber ribbon (1A) has a plurality of optical fiber core wires (10) disposed in parallel and intermittently has connection units (20) formed by connecting portions between adjacent optical fiber core wires (10) by means of a resin, wherein, in the connection units (20), the resin is provided to one side surface and the other side surface of the optical fiber ribbon (1A), and D / 4≤TFave≤D / 2 when the average maximum value of the thicknesses TF of the connection units (20) on the one side surface is TFave, and the outer diameter of the optical fiber core wire (10) is D, and TBave<TFave when the average maximum value of the thicknesses TB of the connection units (20) on the other side surface is TBave.

Description

[Technical Field]

[0001] The present disclosure relates to an optical fiber ribbon and a sub-tape type optical fiber ribbon.

[0002] This application claims priority to Japanese Application No. 2020-155584, filed on September 16, 2020, and incorporates by reference all of the contents of said Japanese application. [Background technology]

[0003] Patent document 1 describes an optical fiber ribbon in which an adhesive material is intermittently applied to both the upper and lower surfaces of adjacent optical fiber cores, and where the thickness of the adhesive material is T and the diameter of the optical fiber cores is D, the relationship T<(√3-1) / 2×D is satisfied.

[0004] Patent document 2 describes an optical fiber ribbon in which, when multiple optical fiber core wires are arranged in parallel, markings for identifying the number of the optical fiber ribbon core wire are provided on only one side, and adhesive resin is applied only to the other side.

[0005] Patent document 3 describes an optical fiber ribbon in which adjacent optical fiber core wires are intermittently bonded together via a connecting portion, and the breaking elongation of the adhesive resin that makes up the connecting portion is set to be greater than 250% and less than 500%.

[0006] Patent document 4 describes an optical fiber ribbon comprising two or more sub-tapes formed by intermittently bonding adjacent optical fiber cores together with a first adhesive portion, the sub-tapes being intermittently bonded together with a second adhesive portion to form an integrated unit, the thickness of the first adhesive portion being set to a thickness that does not protrude from a tangent line passing through the surface of each optical fiber core, and the thickness of the second adhesive portion being set to a thickness that protrudes beyond the tangent line. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2016-133607 [Patent Document 2] Japanese Patent Application Publication No. 2019-49617 [Patent Document 3] Japanese Patent Application Publication No. 2017-62431 [Patent Document 4] Japanese Patent Application Publication No. 2016-146003 Summary of the Invention

[0008] An optical fiber ribbon according to one aspect of the present disclosure includes: An intermittently connected optical fiber ribbon having a plurality of optical fiber core wires arranged in parallel and having intermittent connection portions formed by connecting parts of adjacent optical fiber core wires with resin, the resin is provided on one surface and the other surface of the optical fiber ribbon in the connecting portion; The average of the maximum thickness TF of the connecting portion on the surface on one side is TF ave When the outer diameter of the optical fiber is D, D / 4≦TF ave ≦D / 2, The average of the maximum thicknesses TB of the connecting portions on the surface on the other side is TB ave When this is done, TB ave <TF ave is.

[0009] Furthermore, a sub-tape type optical fiber ribbon according to an aspect of the present disclosure includes: A sub-tape type optical fiber ribbon includes at least two sub-tapes, each having a plurality of optical fiber core wires arranged in parallel and a first connecting portion formed by connecting adjacent optical fiber core wires with a resin, The tape has second connecting portions formed by connecting a portion of each adjacent sub-tape with a resin, In the second connecting portion, the resin is provided on one surface and the other surface of the sub-tape type optical fiber ribbon, The average of the maximum values ​​of the thickness TF1 of the second connecting portion on the surface on one side is TF1 ave When the outer diameter of the optical fiber core is D, D / 4≦TF1 ave ≦D / 2, The average of the maximum values ​​of the thickness TB1 of the second connecting portion on the surface on the other side is TB1 ave When this is done, TB1 ave <TF1 ave is. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing an optical fiber ribbon according to the first embodiment. [Figure 2] FIG. 2 is a perspective view of the optical fiber ribbon shown in FIG. [Figure 3] FIG. 3 is a diagram illustrating a method for manufacturing an optical fiber ribbon. [Figure 4] FIG. 4 is a diagram illustrating the resin application process. [Figure 5] FIG. 5 is a diagram showing how resin is applied to the optical fiber core. [Figure 6] FIG. 6 is a cross-sectional view showing an optical fiber ribbon according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Problem to be solved by this disclosure] Optical fiber ribbons are sometimes housed in optical fiber cables. When housed in an optical fiber cable, a bending force is applied to the optical fiber ribbon in an attempt to roll it up in a cross-sectional direction perpendicular to the longitudinal direction. Therefore, when the optical fiber ribbon is rolled up, there is a possibility that the adhesive joints connecting the optical fibers may break.

[0012] In the case of the optical fiber ribbon described in Patent Document 1, the adhesive material is applied in equal amounts on both the top and bottom sides, so there is a high possibility that the adhesive material will break or the adhesive material will peel off from the optical fiber ribbon on the outside where it is bent, causing the optical fiber ribbon to come apart.

[0013] In the case of the optical fiber ribbon described in Patent Documents 2 and 3, the adhesive resin is applied to only one side, so when the ribbon is bent, the adhesive resin may break or the adhesive resin may peel off from the optical fiber ribbon, which may result in the optical fiber ribbon coming apart.

[0014] In the case of the optical fiber ribbon described in Patent Document 4, the second adhesive portion is provided protruding from the tangent line passing through the surface of the optical fiber ribbon, which increases the cross-sectional area of ​​the optical fiber ribbon and makes it impossible to pack the optical fiber ribbon into an optical fiber cable at a high density.

[0015] The present disclosure aims to provide an optical fiber ribbon and a sub-tape type optical fiber ribbon that can suppress damage to the adhesive resin that connects the optical fiber core wires together and can be accommodated at high density within an optical fiber cable.

[0016] [Effects of this disclosure] According to the present disclosure, it is possible to provide an optical fiber ribbon and a sub-tape type optical fiber ribbon that can suppress damage to the resin that connects the optical fiber core wires and can be accommodated at high density within an optical fiber cable.

[0017] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. An optical fiber ribbon according to one aspect of the present disclosure includes: (1) An intermittently connected optical fiber ribbon having a plurality of optical fiber core wires arranged in parallel and having intermittent connection portions formed by connecting a part of the adjacent optical fiber core wires with a resin, the resin is provided on one surface and the other surface of the optical fiber ribbon in the connecting portion; The average of the maximum thickness TF of the connecting portion on the surface on one side is TF ave When the outer diameter of the optical fiber is D, D / 4≦TF ave ≦D / 2, The average of the maximum thicknesses TB of the connecting portions on the surface on the other side is TB ave When this is done, TB ave <TF ave is. According to this configuration, when a bending force is applied to roll the optical fiber ribbon in a cross-sectional direction perpendicular to the longitudinal direction during storage in an optical fiber cable, the difference in the amount of resin between the first surface and the second surface makes it less likely that the resin will break or that the resin will peel off from the optical fiber. This reduces the risk of the optical fiber ribbon coming apart, making it easier to roll the optical fiber ribbon and store it in an optical fiber cable. Furthermore, because the resin does not protrude beyond the tangent line passing through the surface of the optical fiber, an increase in the ribbon cross-sectional area can be prevented, allowing optical fiber ribbons to be stored in an optical fiber cable at a high density.

[0018] Furthermore, a sub-tape type optical fiber ribbon according to an aspect of the present disclosure includes: (2) A sub-tape type optical fiber ribbon including at least two sub-tapes each having a plurality of optical fiber core wires arranged in parallel and a first connecting portion formed by connecting adjacent optical fiber core wires with resin, The tape has second connecting portions formed by connecting a portion of each adjacent sub-tape with a resin, In the second connecting portion, the resin is provided on one surface and the other surface of the sub-tape type optical fiber ribbon, The average of the maximum values ​​of the thickness TF1 of the second connecting portion on the surface on one side is TF1 ave When the outer diameter of the optical fiber core is D, D / 4≦TF1 ave ≦D / 2, The average of the maximum values ​​of the thickness TB1 of the second connecting portion on the surface on the other side is TB1 ave When this is done, TB1 ave <TF1 ave is. According to this configuration, even when connecting sub-tapes together, when a force is applied to bend the optical fiber ribbon in the cross-sectional direction to roll it up during storage in the optical fiber cable, the difference in the amount of resin on both sides makes it less likely that the resin will break or that the resin will peel off from the sub-tape. This reduces the risk of the optical fiber ribbon coming apart, making it easier to roll the optical fiber ribbon and store it in the optical fiber cable. Furthermore, because the resin does not protrude beyond the tangent line passing through the surface of the optical fiber, the ribbon cross-sectional area can be prevented from increasing, which is advantageous for increasing the density of the optical fiber cable.

[0019] (3) The outer diameter D may be 210 μm or less. According to this configuration, by using an optical fiber core wire with a small diameter of 210 μm or less, it is possible to achieve even higher density of the optical fiber cable.

[0020] [Details of the embodiments of the present disclosure] Specific examples of optical fiber ribbons and sub-tape type optical fiber ribbons according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0021] (First embodiment) Fig. 1 is a cross-sectional view of an optical fiber ribbon 1A according to a first embodiment, Fig. 2 is a perspective view of the optical fiber ribbon 1A, Fig. 1 is a cross-sectional view taken along line AA in Fig. 2. 1 and 2, the optical fiber ribbon 1A includes a plurality of optical fibers 10 (10A to 10H in this example) and a plurality of connecting portions 20 (20a to 20i in this example) that connect the optical fibers 10. In this example, the optical fiber ribbon 1A includes eight optical fibers 10A to 10H and nine connecting portions 20a to 20i that connect the optical fibers 10 together.

[0022] The eight optical fibers 10A-10H are arranged side by side in a direction intersecting the longitudinal direction of the optical fibers. The nine connecting portions 20a-20i are provided intermittently in the longitudinal and width directions of the parallel optical fibers 10A-10H. In other words, the optical fiber ribbon 1A is an intermittently connected optical fiber ribbon having connecting portions 20a-20i that intermittently connect some of the optical fibers together in the longitudinal and width directions of the optical fibers 10A-10H.

[0023] The optical fiber 10 includes, for example, a glass fiber 11 composed of a core and a cladding, and two coating layers 12, 13 that surround the glass fiber 11. The inner coating layer 12 of the two coating layers is formed of a cured product of a primary resin. The outer coating layer 13 of the two coating layers is formed of a cured product of a secondary resin. The outer diameter of the coating layer 13 made of the secondary resin, i.e., the outer diameter D of the optical fiber 10, is, for example, 210 μm or less. The optical fiber 10 may have a colored layer on its outermost periphery.

[0024] The primary resin constituting the inner coating layer 12 in contact with the glass fiber 11 is a soft resin with a relatively low Young's modulus, which acts as a buffer layer. The secondary resin constituting the outer coating layer 13 is a hard resin with a relatively high Young's modulus, which acts as a protective layer. The Young's modulus of the cured secondary resin is 900 M at room temperature (e.g., 23°C). P a or more, preferably 1000 MPa or more, and more preferably 1500 MPa or more.

[0025] The coupling portions 20a to 20i are provided on both the front side (upper side in FIG. 1) and the back side (lower side in FIG. 1) of the ribbon surface formed by the parallelly arranged optical fibers 10A to 10H. The coupling portions 20a to 20i have front coupling portions 21a to 21i provided on the front side and back coupling portions 22a to 22i provided on the back side. The front coupling portions 21a to 21i and back coupling portions 22a to 22i are each provided in pairs at the same positions on the front and back sides between the optical fibers.

[0026] The connecting portions 20a-20i are arranged in a line in the width direction of the optical fiber ribbon 1A, i.e., in the parallel direction of the optical fibers 10A-10H. For example, in the splicing region 31 shown in Fig. 2, the connecting portion 20a between the optical fibers 10A and 10B, the connecting portion 20b between the optical fibers 10C and 10D, the connecting portion 20c between the optical fibers 10E and 10F, and the connecting portion 20d between the optical fibers 10G and 10H are arranged in a line in the width direction. Similarly, in the splicing region 32, the connecting portion 20e between the optical fibers 10B and 10C, the connecting portion 20f between the optical fibers 10D and 10E, and the connecting portion 20g between the optical fibers 10F and 10G are arranged in a line in the width direction. Similarly, in the splicing region 33, a connecting portion 20h between the optical fibers 10C and 10D and a connecting portion 20i between the optical fibers 10E and 10F are arranged in a line in the width direction.

[0027] The connecting portion 20 is made of a resin material such as an acrylic ultraviolet curable resin or an epoxy ultraviolet curable resin. The Young's modulus of the cured resin constituting the connecting portion 20 is 0.5 MPa or more and 200 MPa or less at room temperature (e.g., 23°C). The connecting portion 20 may be made of a resin containing a silicone lubricant, for example.

[0028] In this way, in the optical fiber ribbon core wire 1A, the parts where resin is applied form connecting portions 20 where the optical fiber core wires are connected to each other, and the parts where resin is not applied form non-connecting portions where the optical fiber core wires are not connected to each other.

[0029] The front coupling portions 21a to 21i provided on the front (upper) side of the optical fiber ribbon 1A are arranged so as not to protrude upward from the imaginary line Pf passing through the front surfaces of the optical fibers 10A to 10H. In addition, the back coupling portions 22a to 22i provided on the back (lower) side of the optical fiber ribbon 1A are arranged so as not to protrude downward from the imaginary line Pb passing through the back surfaces of the optical fibers 10A to 10H.

[0030] Specifically, the four front connecting portions 21a to 21d included in the connection region 31 have a thickness TF from the imaginary plane H formed by connecting the centers of the parallel optical fibers 10A to 10H to the top of the front connecting portions 21a to 21d. max The average value of TF av e Then, TF ave where D / 4≦TF is the outer diameter D of the optical fiber core 10. ave The three front connecting portions 21e to 21g included in the connection region 32 are also formed so that the thickness TF from the imaginary plane H to the top point of the front connecting portions 21e to 21g is ≦D / 2. max Average value of TF ave However, D / 4≦TF ave The two front connecting portions 21h and 21i included in the connection region 33 are also formed so that the thickness TF from the imaginary plane H to the top point of the front connecting portions 21h and 21i is ≦D / 2. max Average value of TF ave However, D / 4≦TF ave 2. In this way, the thickness TF of each of the front connecting portions 21a to 21i is set to be equal to or less than D / 2. max Average value of TF ave However, D / 4≦TF ave The front connecting portions 21a to 21i are formed so as to satisfy the condition ≦D / 2.

[0031] Furthermore, the four back connecting portions 22a to 22d included in the connection region 31 have a thickness TB max The average value of TB ave Then, TB aveis the average thickness TF of the front connection parts 21a to 21d of the connection area 31 ave with respect to TB ave < TF ave is formed to be so. For the three back connection parts 22e to 22g included in the connection area 32, the thickness TB from the virtual plane H to the lowest points of the back connection parts 22e to 22g max average value of TB ave is the average thickness TF of the front connection parts 21e to 21g of the connection area 32 ave with respect to TB ave < TF ave is formed to be so. For the two back connection parts 22h, 22i included in the connection area 33, the thickness TB from the virtual plane H to the lowest points of the back connection parts 22h, 22i max average value of TB ave is the average thickness TF of the front connection parts 21h, 21i of the connection area 33 ave with respect to TB ave < TF ave is formed to be so.

[0032] In addition, based on the average value of the maximum thicknesses of the front connection parts for each of the connection areas 31, 32, 33, the average value of the maximum thicknesses of the thicknesses TF of all the front connection parts 21a to 21i can be calculated as TF ave Similarly, based on the average value of the maximum thicknesses of the back connection parts for each of the connection areas 31, 32, 33, the average value of the maximum thicknesses of the thicknesses TB of all the back connection parts 22a to 22i can be calculated as TB ave Also, for the average maximum TF of the thicknesses TF of the front connection parts 21a to 21i ave it is sufficient if D / 4 ≤ TF ave ≤ D / 2 is satisfied, and even if the individual thicknesses TF of some of the front connection parts 21a to 21i do not satisfy D / 4 ≤ TF ≤ D / 2, it is okay. Similarly, for the average maximum TB of the thicknesses TB of the back connection parts 22a to 22i ave with respect to TB a ve < TF​​​​ Next, a method for manufacturing the optical fiber ribbon 1A will be described with reference to FIGS. As shown in Fig. 3, the optical fibers 10A to 10H are closely arranged in a vertical line in the up-down direction. The optical fibers 10A to 10H are unwound from the unwinding bobbin at predetermined intervals so that the number of cores arranged in the vertical line is 2, 3, 4, ... 8, and the timing of their arrangement is staggered.

[0034] The optical fiber 10A unwound from the payout bobbin 51a and the optical fiber 10B unwound from the payout bobbin 51b are vertically aligned so as to be in close contact with each other at bonding position P1. Next, the optical fiber 10C unwound from the payout bobbin 51c is vertically aligned so as to be in close contact with the optical fiber 10B directly above it at bonding position P2. Next, the optical fiber 10D unwound from the payout bobbin 51d is vertically aligned so as to be in close contact with the optical fiber 10C directly above it at bonding position P3. Although not shown in the figures, the optical fibers 10E to 10H are similarly vertically aligned so as to be in close contact with the adjacent optical fibers 10D to 10G directly above them at bonding positions P4 to P7.

[0035] At each of the bonding positions P1, P2, and P3, there is provided a bonding means for bonding the optical fibers that are closely adjacent in the vertical direction with a resin that forms the connecting portion 20. As the bonding means, for example, there are provided resin supply devices 54a to 54c each including a pair of syringes 52a to 52c that supply the resin for forming the connecting portion 20 and dispensers 53a to 53c that control the amount of resin supplied. In addition, ultraviolet light irradiation devices 55a to 55c that harden the resin are provided downstream of the resin supply devices 54a to 54c.

[0036] 4 and 5, the resin 57 can be applied by dropping it using a pair of syringe needles 56 (56a to 56c), and it is desirable that the resin adheres between the optical fibers 10 by surface tension and does not easily drip down. For example, a viscosity of 1 to 10 Pa·S at 25°C is preferable for the resin 57. The pair of syringe needles 56a to 56c are arranged on both sides of the two optical fibers 10 that are closely spaced one above the other, so that the resin 57 can be applied toward the close-contact portion between the two fibers.

[0037] The optical fiber ribbon 1A thus produced is wound around a take-up bobbin 58.

[0038] As explained above, the optical fiber ribbon 1A is an intermittently connected optical fiber ribbon having a plurality of optical fibers 10A-10H arranged in parallel, and having intermittent connection portions 20a-20i formed by connecting a part of adjacent optical fibers with resin. In the connection portions 20a-20i, resin is provided on both the front surface (an example of one surface) and the back surface (an example of the other surface) of the optical fiber ribbon 1A, and the average of the maximum values ​​of the thicknesses TF of the front connection portions 21a-21i is TF ave When the outer diameter of the optical fiber core wires 10A to 10H is D, D / 4≦TF ave ≦D / 2, and the average of the maximum values ​​of the thicknesses TB of the back connecting portions 22a to 22i is TB ave When this is done, TB ave <TF a veAccording to this configuration, when the optical fiber ribbon 1A is accommodated in the optical fiber cable, if a bending force is applied to roll the optical fiber ribbon 1A in a cross-sectional direction perpendicular to the longitudinal direction, the resin amounts (thicknesses TF and TB) of the coupling portions 20 provided on both the front and back sides of the optical fiber ribbon 1A are different. Therefore, by, for example, positioning the front coupling portions 21a-21i with the larger thickness on the outside of the bend, it is possible to reduce the risk of resin damage or peeling between the resin and the optical fiber. This makes it easier to roll the optical fiber ribbon 1A without the optical fiber ribbon 1A coming apart, improving the ease of accommodating the optical fiber ribbon 1A in the optical fiber cable. Furthermore, because the resin constituting both the front coupling portions 21a-21i and the back coupling portions 22a-22i does not protrude beyond the tangent line passing through the surfaces of the optical fibers 10A-10H, it is possible to prevent the cross-sectional area of ​​the optical fiber ribbon 1A from increasing, thereby enabling the optical fiber ribbon 1A to be accommodated at a high density in the optical fiber cable.

[0039] Furthermore, according to the optical fiber ribbon 1A, by using the small-diameter optical fibers 10A to 10H having an outer diameter D of 210 μm or less, it is possible to achieve even higher density of the optical fiber cable.

[0040] In the above embodiment, an optical fiber ribbon consisting of eight optical fibers is used as an example, but the present invention is not limited to this. For example, the optical fiber ribbon may be an optical fiber ribbon consisting of optical fibers that are a multiple of four, such as 12 or 24 optical fibers.

[0041] (Example) Next, an example of the optical fiber ribbon 1A configured as described above will be described with reference to Table 1. As shown in Table 1, the maximum thickness TF of the front connecting portions 21a to 21i is max TF is the average of ave and the maximum thickness TB of the rear connecting portions 22a to 22i max The average TB aveVarious optical fiber ribbons 1A shown as No. 1 to No. 11 were produced by changing the above, and the resistance to separation when stored in an optical fiber cable, cable storage ability, and high density were evaluated for each of the optical fiber ribbons 1A No. 1 to No. 11.

[0042] [Table 1]

[0043] As shown in Table 1, the thickness of the front joint part of the No. 1 optical fiber ribbon is TF ave and the thickness of the back joint TB ave was set to the same thickness of 40 μm. For the optical fiber ribbons No. 2 to No. 4, the thickness of the front joint TF ave are all 50 μm, and the thickness of the back joint TB ave No. 2 was 50 μm, No. 3 was 40 μm, and No. 4 was 0 μm. For the optical fiber ribbons No. 5 to No. 7, the thickness of the front joint TF ave The thickness of the back joint part is TB ave No. 5 was 75 μm, No. 6 was 50 μm, and No. 7 was 0 μm. For the optical fiber ribbons No. 8 to No. 10, the thickness of the front joint TF ave are all 100 μm, and the thickness of the back joint TB ave No. 8 was 100 μm, No. 9 was 75 μm, and No. 10 was 0 μm. In the case of No. 11 optical fiber ribbon, the thickness of the front joint TF ave and the thickness of the back joint TB ave was set to the same thickness of 120 μm. The outer diameter D of the optical fiber core wires constituting each optical fiber ribbon was set to 200 μm, so D / 4=50 μm and D / 2=100 μm.

[0044] For "separation resistance," the optical fiber ribbon core was expanded widthwise at the non-connected portion where resin was not applied, and when the optical fiber core was expanded by 60% of the length of the non-connected portion (the distance between adjacent connected portions), it was given an "A" rating if it did not peel off from the connected portion, and a "C" rating if it did peel off. "Cable storage" is the thickness of the front connection part TF ave and the thickness of the back joint TB ave When the ease of rolling was compared with that of optical fiber ribbons with the same properties, the case where it was easy to roll was given an "A" rating, and the case where it was about the same was given an "B" rating. For "high density," the cross-sectional area of ​​the optical fiber ribbon was compared. Optical fiber ribbons with a thickness of 100 μm or less at each connection point were judged to have a small cross-sectional area and be suitable for high density, and were given an "A" rating. Optical fiber ribbons with a thickness of more than 100 μm were judged to be unsuitable for high density, and were given a "C" rating.

[0045] (Evaluation results of resistance to scattering) In the case of No. 1 optical fiber ribbon, which has a connecting part with a thickness of less than 50 μm on both the front and back sides, the adhesive area between the connecting part and the optical fiber is small, and the adhesive strength between the two is not sufficient, so the unraveling resistance was rated as "C". In addition, No. 4, No. 7, and No. 8, which do not have a back connecting part (no resin applied to the back side), . In the case of the optical fiber ribbon No. 10, the front joint alone did not provide sufficient adhesion between the optical fiber core and the joint, so the unraveling resistance was rated "C". ave is 50 μm or more, and the thickness of the back joint part TB ave N with a diameter of 40 μm or more o In the case of optical fiber ribbon core wires No. 2, No. 3, No. 5, No. 6, No. 8, No. 9, and No. 11, the adhesive area between the connection part and the optical fiber core wire was sufficiently secured and the adhesion strength between the two was fully exerted, so the resistance to separation was rated "A".

[0046] (Evaluation results for cable storage) Thickness of front joint TF ave and the thickness of the back joint TB aveThe optical fiber ribbons No. 3, No. 4, No. 6, No. 7, No. 9, and No. 10, which have different thicknesses at the front and back sides, are easier to roll up than the optical fiber ribbons with the same thickness at the joints on the front and back sides, and were rated "A" for cable storage. In the case of the optical fiber ribbons No. 1, No. 2, No. 5, No. 8, and No. 11, the thickness TF at the front joint ave and the thickness of the back joint TB ave Since the thickness is the same as the thickness of the front joint, TF ave and the thickness of the back joint TB ave It is slightly more difficult to roll up than the optical fiber ribbon, which has a different thickness, and the cable storage ability was rated "B".

[0047] (Evaluation results for high density) For optical fiber ribbons No. 1 to No. 10, the thickness of the front joint TF ave and the thickness of the back joint TB ave In the case of No. 11 optical fiber ribbon, the thickness of the front joint TF is 100 μm or less, i.e., the outer diameter D of the optical fiber core wire is less than 100 μm. Therefore, the cross-sectional area is small and suitable for high density. Therefore, the high density was evaluated as "A". ave and the thickness of the back joint TB ave In other words, the connecting parts protruded from the surface of the optical fiber core, which resulted in a large cross-sectional area that was not suitable for high density, and the high density rating was "C."

[0048] From the above evaluation results, it was confirmed that the optical fiber ribbons No. 3, No. 6, and No. 9 were rated "A" in the three evaluation items of "unraveling resistance," "cable storage," and "high density." Furthermore, as for their configuration, the connecting parts on the front side and the back side of the optical fiber ribbon were D / 4≦TF ave ≦D / 2, TB ave <TF ave It was confirmed that the above conditions must be met.

[0049] Second Embodiment FIG. 6 is a cross-sectional view of an optical fiber ribbon 1B according to the second embodiment. As shown in FIG. 6, the optical fiber ribbon 1B includes a plurality of (four in this example) sub-tapes 100 (100A to 100D in this example) and a plurality of connecting portions 120 (120a to 120d in this example) that connect the sub-tapes 100 together. 1 20b) and

[0050] Each sub-tape 100 is composed of two optical fibers 110. For example, the sub-tape 100A is composed of optical fibers 110A and 110B. The optical fibers 110A and 110B are coated on their outer peripheries with a coating resin 115a (an example of a first connecting portion). The sub-tape 100B is composed of optical fibers 110C and 110D. The optical fibers 110C and 110D are coated on their outer peripheries with a coating resin 115b (an example of a first connecting portion). The sub-tape 100C is composed of optical fibers 110E and 110F. The optical fibers 110E and 110F are coated on their outer peripheries with a coating resin 115c (an example of a first connecting portion). The sub-tape 100D is composed of optical fibers 110G and 110H. The outer peripheries of the coated optical fibers 110G and 110H are coated with a coating resin 115d (an example of a first connecting portion).The outer diameter D of the coated optical fibers 110A to 110H is, for example, 210 μm or less.

[0051] The connecting portion 120a (an example of a second connecting portion) is provided between the sub-core fibers 100A and 100B. The connecting portion 120b (an example of a second connecting portion) is provided between the sub-core fibers 100C and 100D. The connecting portions 120a and 120b are arranged side by side in the width direction of the optical fiber ribbon 1B. The connecting portions 120a and 120b are composed of front connecting portions 121a and 121b provided on the front side of the optical fiber ribbon 1B and back connecting portions 122a and 122b provided on the back side. The front connecting portions 121a and 121b and the back connecting portions 122a and 122b are each provided in pairs at the same positions on the front and back sides between the optical fibers.

[0052] 6 shows two connecting portions 120a, 120b, but in the optical fiber ribbon 1B, the connecting portions 120 are provided intermittently in the longitudinal and width directions of the parallel sub-tapes 100A-100D, similar to the optical fiber ribbon 1A shown in Fig. 2. The optical fiber ribbon 1B is an intermittently connected sub-tape optical fiber ribbon having connecting portions 120 that connect some of the sub-tapes together in the longitudinal and width directions of the sub-tapes 100A-100D.

[0053] Optical fiber ribbon 1 The front coupling portions 121a and 121b of the optical fiber ribbon 1B are arranged so as not to protrude upward from a straight line Pf passing through the front surfaces (upper surfaces in FIG. 6) of the optical fibers 110A to 110H. The back coupling portions 122a and 122b of the optical fiber ribbon 1B are arranged so as not to protrude downward from a straight line Pb passing through the back surfaces (lower surfaces in FIG. 6) of the optical fibers 110A to 110H.

[0054] For example, the imaginary plane H formed by connecting the centers of the parallel optical fibers 110A to 110H is set as the reference position, and the thickness TF1 from the imaginary plane H to the top point of the front connecting portions 121a and 121b is max The average value of TF1 ave Then, TF1 ave is the outer diameter D of the optical fiber core 110, D / 4≦TF1 ave ≦D / 2. In addition, the thickness TB1 from the virtual plane H to the lowest point of the back connecting portions 122a and 122b is max The average value of TB1 ave Then, TB1 ave is TF1 ave On the other hand, TB1 ave <TF1 a ve It is formed so that: The average value TF1 ave and average TB1 ave As in the first embodiment, may be an average value for each splice region aligned in the width direction of the optical fiber ribbon 1B.

[0055] As explained above, the optical fiber ribbon 1B according to the second embodiment is a sub-tape type optical fiber ribbon including sub-tape fibers 100A-100D, each having a plurality of parallel-arranged optical fibers 110A-110H and coating resins 115a-115d (an example of a first connecting portion) formed by connecting adjacent optical fibers with resin. The optical fiber ribbon 1B has intermittent connecting portions 120a, 120b (an example of a second connecting portion) formed by connecting a portion between adjacent sub-tapes with resin, and resin is provided on both the front surface (an example of one surface) and the back surface (an example of the other surface) of the optical fiber ribbon 1B in the connecting portions 120a, 120b. The average of the maximum values ​​of the thicknesses TF1 of the front connecting portions 121a, 121b is TF1. ave When the outer diameter of the optical fiber core wires 110A to 110H is D, D / 4≦TF1 ave ≦D / 2, and the average of the maximum values ​​of the thicknesses TB1 of the back connecting portions 122a and 122b is TB1 ave When this is done, TB1 a ve <TF1 ave By configuring a sub-tape type optical fiber ribbon formed by connecting the sub-tape fibers together in this way, it is possible to obtain the same effects as in the optical fiber ribbon 1A of the first embodiment.

[0056] In the second embodiment, the sub-tape core wire is made up of two optical fibers, but the number of optical fibers constituting the sub-tape core wire may be a predetermined number equal to or greater than 2. The sub-tape core wire may also be an intermittently connected type sub-tape core wire that has connected portions and non-connected portions intermittently in the longitudinal or width direction of the optical fiber.

[0057] Although the present disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the number, position, shape, etc. that are suitable for implementing the present disclosure. [Explanation of symbols]

[0058] 1A, 1B: Optical fiber ribbon 10 (10A~10H): Optical fiber core 11: Glass fiber 12: Coating layer (primary resin) 13: Coating layer (secondary resin) 20(20a~20i): Connection part 21a~21i: Table connection part 22a~22i: Back connection part 31-33: Connection area 51a~51d: Bobbin 52a-52c: Syringe pair 53a~53c: Dispenser 54a~54c: Resin supply device 55a~55c: Ultraviolet irradiation device 56(56a, 56b): Syringe needle pair 57: Resin 58: Winding bobbin 100 (100A~100D): Sub-tape core wire 110 (110A-110H): Optical fiber core 115a to 115d: coating resin (an example of the first connecting portion) 120 (120a, 120b): connecting portion (an example of a second connecting portion) 121a, 121b: Table connection part 122a, 122b: Back connection part D: Outer diameter of optical fiber core TF, TB: Thickness of the connecting part H: Virtual plane P1~P3: Adhesive position Pf, Pb: Virtual line

Claims

1. An intermittently connected optical fiber ribbon having a plurality of optical fiber core wires arranged in parallel and having intermittent connection portions formed by connecting parts of adjacent optical fiber core wires with resin, the resin is provided on one surface and the other surface of the optical fiber ribbon in the connecting portion; The average of the maximum thickness TF of the connecting portion on the surface on one side is TF ａｖｅ When the outer diameter of the optical fiber core is D, D / 4≦TF ａｖｅ ≦D / 2, The average of the maximum thickness TB of the connecting portion on the surface on the other side is TB ａｖｅ When this is done, TB ａｖｅ <TF ａｖｅ and The outer diameter D is 210 μm or less, (2 / 3) x TF ａｖｅ ≦TB ａｖｅ and The maximum value of the thickness TF of the connecting portion on the one side surface is smaller than the distance between an imaginary line passing through the one side surface of the plurality of optical fiber cores and extending in the direction in which the plurality of optical fiber cores are arranged side by side, and an imaginary plane formed by connecting the centers of the optical fiber cores, An optical fiber ribbon core wire in which the maximum value of the thickness TB of the connecting portion on the other side surface is smaller than the distance between an imaginary straight line passing through the other side surface of the multiple optical fiber core wires and extending in the direction in which the multiple optical fiber core wires are arranged side by side, and an imaginary plane formed by connecting the centers of the multiple optical fiber core wires.

2. An optical fiber tape core wire as described in claim 1, wherein the connecting portion on the one side surface and the connecting portion on the other side surface have a convex shape.

3. A sub-tape type optical fiber ribbon includes at least two sub-tapes, each having a plurality of optical fiber core wires arranged in parallel and a first connecting portion formed by connecting adjacent optical fiber core wires with a resin, The tape has second connecting portions formed by connecting a portion of each adjacent sub-tape with a resin, In the second connecting portion, the resin is provided on one surface and the other surface of the sub-tape type optical fiber ribbon, The average of the maximum values ​​of the thicknesses TF1 of the second connecting portions on the surface on one side is TF1 ａｖｅ When the outer diameter of the optical fiber core is D, D / 4≦TF1 ａｖｅ ≦D / 2, The average of the maximum thickness TB1 of the second connecting portion on the surface on the other side is TB1 ａｖｅ When this is done, TB1 ａｖｅ <TF1 ａｖｅ and The outer diameter D is 210 μm or less, (2 / 3) x TF1 ａｖｅ ≦TB1 ａｖｅ and The maximum value of the thickness TF1 of the second connecting portion on the one side surface is smaller than the distance between an imaginary line passing through the one side surface of the plurality of optical fiber cores and extending in the direction in which the plurality of optical fiber cores are arranged side by side, and an imaginary plane formed by connecting the centers of the optical fiber cores, A sub-tape type optical fiber tape core wire, wherein the maximum value of the thickness TB1 of the second connecting portion on the other side surface is smaller than the distance between an imaginary line passing through the other side surface of the multiple optical fiber core wires and extending in the direction in which the multiple optical fiber core wires are arranged side by side, and an imaginary plane formed by connecting the centers of the multiple optical fiber core wires.

4. A sub-tape type optical fiber tape core wire as described in claim 3, wherein the second connecting portion on the one side surface and the second connecting portion on the other side surface have a convex shape.

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