JP2005249977A - Fiber optic cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber optic cable out of which a single-unit optical fiber or a ribbon of coated optical fibers with a clad can excellently be taken. <P>SOLUTION: The fiber optic cable 1 is formed by covering coated optical fibers 10 of a ribbon having a recessed part 16 in ribbon resin 12 with a clad 3, which is provided with a couple of notches 4 formed opposite the coated optical fibers 10 of the ribbon in the center along the short side of a section of an element part 9 and three notches 5 and 5a formed opposite the coated optical fibers 10 of the ribbon in the center along the long side of the section of the element part 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical fiber cable in which an optical fiber or an optical fiber tape core is covered with a jacket.

  In recent years, as the demand for optical communication systems increases, an optical fiber cable as an optical transmission line is often used. As an optical fiber cable used for applications such as FTTH (Fiber To The Home), it is distributed to each one or a plurality of optical fibers from a multi-core optical fiber cable laid over a utility pole etc. A drop cable (see, for example, Non-Patent Document 1) pulled down to a person's house can be cited.

  An example of an optical fiber cable used as the drop cable is shown in FIG. As shown in FIG. 15, the conventional optical fiber cable 100 has a configuration in which a main body portion 107 and a messenger wire portion 108 are connected by a neck portion 105.

  The main body 107 is formed by coating a single optical fiber 101 disposed substantially at the center and two strength members 102 with a jacket 103 of a thermoplastic resin. The two strength members 102 are juxtaposed in the same plane as the optical fiber 101, and the optical fiber 101 is disposed between the two strength members 102. As the optical fiber 101 used here, an optical fiber 101 having a structure in which an outer periphery of a double-structured glass body composed of a core and a clad is coated with an ultraviolet curable resin and having an outer diameter of 0.25 mm can be exemplified. .

  As the strength member 102, steel, glass fiber reinforced plastic (glass FRP), or the like is used. Since the optical fiber 101 and the tensile body 102 are collectively covered, the tensile body 102 receives an external force such as a tensile force applied to the optical fiber cable 100 and protects the optical fiber 101 from the external force.

  Further, two notches 104 cut out toward the optical fiber 101 are provided on the outer periphery of the main body 107. This notch 104 is for facilitating the removal of the optical fiber 101. The removal is performed by making a cut in the outer cover 103 between the notches 104 using two notches 104 and tearing the outer cover 103. Done.

The messenger wire portion 108 is for securing strength for supporting the optical fiber cable 100 in an aerial manner, and a steel support wire 106 is covered with an outer sheath 103.
The neck 105 is made of the same resin material as that of the main body 107 and the messenger wire 108. For example, the main body 107 and the messenger wire 108 are integrally formed of thermoplastic resin.

  Here, the optical fiber cable 100 having one optical fiber 101 is illustrated here, but a conventional drop cable has a plurality of optical fibers or a plurality of optical fibers arranged in parallel to form a tape integrally. Some have an optical fiber ribbon.

  Further, when the optical fiber cable 100 shown in FIG. 15 is drawn into the building from an aerial space, the messenger wire portion 108 for supporting the aerial space becomes unnecessary, so the neck portion 105 is torn and the main body portion 107 and the messenger wire portion are removed. 108 is divided. And as shown in FIG. 16, the indoor type optical fiber cable 100a comprised only by the main-body part 107 is wired in a building.

Optical cable network wiring system general catalog, Sumitomo Electric Industries, Ltd., August 2002, p10, p13

  By the way, the optical fiber cable 100 shown in FIG. 15 and the optical fiber cable 100a shown in FIG. 16 are obtained by taking out the optical fiber 101 and connecting it to other optical fibers in the termination box of the subscriber's house or in the house. There is. In that case, first, the notch 104 of the optical fiber cables 100, 100 a is used to cut the outer cover 103 between the notches 104 and tear the outer cover 103 to take out the optical fiber 101. Then, the extracted optical fiber 101 is connected to another optical fiber.

  At that time, as shown in FIG. 17, the tear 104 a may not be directed to the optical fiber 101 and may be formed obliquely. In that case, as shown in the figure, it was difficult to take out the optical fiber 101 even if the outer cover 103 was torn into two.

  Further, even when the tear is formed straight toward the optical fiber 101, an optical fiber cable having a plurality of single optical fibers and an optical fiber cable having an optical fiber ribbon are shown in FIGS. As described above, even when the outer cover 103 is torn, the optical fiber 101 or the optical fiber ribbon 101a is buried in the outer cover 103, which may be difficult to take out.

  An object of the present invention is to provide an optical fiber cable having a good take-out property of a single-core optical fiber or an optical fiber tape core covered with a jacket.

  An optical fiber cable according to the present invention that can achieve the above object is an optical fiber or an optical fiber in which a plurality of optical fibers integrated with a resin are covered with a jacket. The cable is characterized in that notches are formed in at least two different directions on the jacket.

  In the optical fiber cable of the present invention, the two different directions are preferably directions orthogonal to each other.

  In the optical fiber cable of the present invention, it is preferable that a plurality of the optical fibers are arranged in parallel, and at least one of the notches is formed in the parallel direction of the optical fibers.

  Moreover, the optical fiber cable of this invention WHEREIN: It is preferable that the recessed part according to the hollow between the said adjacent optical fibers is formed in the said resin of the said optical fiber ribbon.

  According to the optical fiber cable of the present invention, it is possible to reliably take out a single optical fiber or an optical fiber ribbon covered with a jacket.

Hereinafter, an example of an embodiment of an optical fiber cable according to the present invention will be described with reference to FIGS.
An optical fiber cable 1 shown in FIG. 1 is used as a drop cable. The optical fiber cable 1 has a configuration in which an element portion 9 and a messenger wire portion 8 are connected by a neck portion 6.

  In the element portion 9, an optical fiber tape core wire 10 disposed substantially at the center and two strength members 2 are covered and integrated with a jacket 3 of a thermoplastic resin. The optical fiber ribbon 10 and the two strength members 2 are covered with almost no gap so as to be in close contact with the outer jacket 3. As the thermoplastic resin of the jacket 3, flame retardant polyethylene or PVC can be suitably used.

The two strength members 2 are juxtaposed on the same plane as the optical fiber ribbon 10, and the optical fiber ribbon 10 is disposed between the two strength members 2. As the strength member 2, glass FRP or steel wire is used. An adhesive layer (not shown) may be provided on the outer periphery of the strength member 2. In that case, the strength member 2 and the jacket 3 are strongly bonded. Polyethylene is preferably used as the material for the adhesive layer.
As described above, since the optical fiber ribbon 10 and the tensile body 2 are collectively covered, the tensile body 2 receives an external force such as a tension applied to the element portion 9, and the optical fiber ribbon 10. Can be protected from external force.

  The messenger wire portion 8 is configured to have strength to support the optical fiber cable 1 in aerial space, and a support wire 7 such as steel or FRP is covered with a jacket 3 of a thermoplastic resin. In addition, an adhesive layer (not shown) may be provided on the outer periphery of the support wire 7.

  The neck portion 6 is formed integrally with the element portion 9 and the messenger wire portion 8 by the same resin as the outer cover 3 of the element portion 9 and the messenger wire portion 8. The neck portion 6 can be easily torn with fingers or the like when the element portion 9 and the messenger wire portion 8 are divided.

  In addition, a pair of notches 4 formed in the cross-sectional short direction (vertical direction in the figure) of the element portion 9 so as to face the outer cover 3 of the element portion 9 with the optical fiber tape core wire 10 as the center, and Three notches 5 and 5a formed in the longitudinal direction of the cross section of the element portion 9 (left and right in the drawing) are provided so as to face each other with the optical fiber ribbon 10 as the center. In addition, the direction of a notch refers to the direction orthogonal to the outer peripheral surface of a jacket when the notch is not formed. These notches 4, 5, and 5a facilitate the removal of the optical fiber ribbon 10. When taking out, the notches 4 are cut from the two notches 4 into the outer cover 3 in the cross-sectional direction. It may be torn in the longitudinal direction, or cut in the longitudinal direction of the cross section from the notches 5 and 5a into the outer cover 3 and torn in the lateral direction of the cross section. Usually, the direction to tear the outer jacket 3 is a direction orthogonal to the direction of the notch. Also, if the optical fiber tape core wire 10 is buried in the outer cover 3 and is difficult to remove even if the notch 4 or the notches 5 and 5a are first cut and the outer cover 3 is torn, the other remaining one is then removed. The outer cover 3 may be further torn by making a notch from the notches 5, 5a or the notch 4.

Thus, since the optical fiber cable 1 of the present embodiment has notches formed in two different directions in the cross section, the optical fiber ribbon 10 can be reliably taken out. In addition, the direction in which the notch is formed maximizes the ease of taking out the optical fiber ribbon 10 by the second tearing by making the two directions orthogonal, such as a combination of the longitudinal direction and the short direction of the cross section. Can get to.
In one direction in which the notch is formed, it is not always necessary to provide the notch on both sides of the jacket, and only one location may be provided in that direction. For example, only the notch 5 may be provided in the longitudinal direction of the cross section of the element portion 9 without providing the notch 5a.

Here, the aspect of the optical fiber ribbon 10 accommodated in the optical fiber cable according to the present invention will be described.
FIG. 2 is a sectional view showing the optical fiber ribbon 10. The optical fiber ribbon 10 has a plurality of optical fibers 11 (four used here as an example) arranged in parallel, and the entire outer periphery of the optical fibers 11 arranged in parallel is integrally formed with a tape resin 12. It's covered.

  2 shows the optical fiber ribbon in which all the adjacent optical fibers are in contact with each other, the optical fibers may not be in contact with each other and may be separated from each other. Here, “not in contact” means that at least two optical fibers included in the optical fiber ribbon are not in contact. Comparing the case where the optical fibers included in the optical fiber ribbon are in contact with the case where they are not in contact, it is easier to branch the optical fiber ribbon when they are in contact. When the optical fibers are in contact with each other, the tape resin between the optical fibers can be broken only by rubbing the tape resin with a brush, for example, by using the location where the tape resin between the optical fibers is not continuous as a trigger. The tape resin integrating the optical fiber can be removed from the optical fiber.

  When the optical fiber cores are not in contact with each other, the interval between the optical fiber cores is preferably 10 μm or less. If the distance is 10 μm or less, the amount of the tape resin entering between the optical fibers is not large, so the tape resin is likely to be broken, and the tape resin is almost the same as when the tape resin is not continuous between the optical fibers. The removability is easy and branching is easy.

The optical fiber 11 is a so-called glass fiber 13 composed of a core 13a and a clad 13b, the outer periphery of the glass fiber 13 covered with a primary protective coating 14, and the outer periphery of the protective coating 14 covered with a secondary protective coating 15. It has a configuration of an optical fiber core wire. A colored layer having a thickness of about 1 μm to 10 μm may be formed on the outer periphery of the secondary protective coating 15. Further, a thin film carbon layer may be coated around the glass fiber 13. The optical fiber 11 preferably conforms to G652 defined by ITU-T (International Telecommunication Union-Telecommunication standardization sector).
As the glass fiber 13 applicable to the present invention, a glass fiber having any refractive index distribution, such as a glass fiber composed of a core and a clad having a plurality of layers, can be applied.

Moreover, as the glass fiber 13, it is preferable that the mode field diameter (MFD: Mode Field Diameter) by the definition of Petermann-I in wavelength 1.55 micrometer is 10 micrometers or less. Furthermore, the mode field diameter is more preferably 8 μm or less.
When the mode field diameter is reduced, microbend loss and bending loss (macrobend loss) can be reduced. Therefore, an increase in transmission loss due to an external force received by the optical fiber ribbon 10 in the cable can be suppressed. Further, even if the optical fiber 11 is bent with a small bending radius, the increase in transmission loss is small, so that the hot line is easily branched.

  In this optical fiber ribbon 10, an ultraviolet curable resin is used as a tape resin 12 on the outer periphery of four parallel optical fibers 11. As the tape resin 12 other than the ultraviolet curable resin, a thermoplastic resin, a thermosetting resin, or the like can also be used.

  The optical fiber ribbon 10 is set so that T ≦ d + 40 (μm), where T (μm) is the maximum thickness and d (μm) is the outer diameter of the optical fiber 11. That is, the thickness t of the tape resin 12 determined by t = (T−d) / 2 is 20 μm or less, and the tape resin 12 is formed thinner than the conventionally used optical fiber ribbon.

  Since the thickness t of the optical fiber ribbon 10 is thin, the tape resin 12 is cracked or peeled off by manual operation by an operator or by a branching tool such as a brush. Can be easily peeled off. Thus, the optical fiber ribbon 10 has a structure that facilitates the intermediate post-branching operation, and the optical fiber cable 1 can also take out the optical fiber from the optical fiber ribbon after tearing the jacket 3. Very easy.

  The optical fiber ribbon 10 has a recess 16 formed in the tape resin 12 covering the optical fiber 11 in accordance with the depression formed between the adjacent optical fibers 11 and 11. As for this recessed part 16, the bottom part 17 is formed as a part with the largest hollow. The concave portion 16 of the tape resin 12 is effective when the optical fiber 11 is branched by peeling the tape resin 12 from the optical fiber ribbon 10. The more the tape resin 12 is thinner, the easier the tape resin 12 breaks, and the branching operation becomes easier. Further, since the branching work is facilitated, the external force applied to the optical fiber during the branching work can be reduced. Therefore, the increase in the loss of the hot line branch can be suppressed small.

  Thus, the thickness t of the tape resin 12 formed around the optical fiber 11 is preferably thinner from the viewpoint of branching workability, and may be about 0.5 μm. However, in order to prevent the resin from running out when manufacturing the optical fiber ribbon, it is desirable to form the tape resin 12 with a thickness of 2.5 μm or more with respect to the optical fiber 11. In that case, in order to reduce the amount of resin in the thickness direction of the optical fiber ribbon while maintaining the desired thickness of the tape resin, the tape resin formed in the recess between the adjacent optical fibers may be reduced. The portion where the resin breakage is likely to occur is the portion where the outer diameter of the optical fiber is the largest in the thickness direction of the optical fiber ribbon, so reducing the amount of tape resin between adjacent optical fibers It does not prevent the application of. Therefore, forming the recess 16 as shown in FIG. 2 can improve the branching workability while preventing the resin from being cut.

  The optical fiber ribbon 10 is formed so that the depth Y of the recess 16 is shorter than the distance between the common tangent S1 of the tape resin 12 and the common tangent S2 of each optical fiber 11. That is, the concave portion 16 is formed so that the position of the bottom portion 17 is located outside the common tangent line S <b> 2 of each optical fiber 11.

Moreover, as an optical fiber tape core wire provided in the optical fiber cable of the present invention, the optical fiber tape shown in FIG. 3, which is another embodiment in which the configuration of the optical fiber tape core wire 10 shown in FIG. The core wire 10a is mentioned. The basic configuration of the optical fiber ribbon 10a is the same as that of the optical fiber ribbon 10 shown in FIG. 2, and the description of the common configuration is omitted.
The tape resin 12a covering the outer periphery of the optical fiber 11 has a concave shape in accordance with the depression formed between the adjacent optical fibers 11 and 11. The concave portion 16a of the tape resin 12a has a deeper concave shape than in the case of FIG. The optical fiber ribbon 10 c is formed so that the bottom 17 a of the recess 16 a is positioned inside the common tangent S <b> 2 c of the optical fiber 11. In consideration of the branching property, the recess is preferably formed so as not to exceed the common tangent formed by the adjacent optical fibers, in other words, to enter the inside of the common tangent.

  In the optical fiber ribbon 10a shown in FIG. 3, for example, the thickness T is 260 μm, and the outer diameter d of the optical fiber 11 is 250 μm. Further, the thickness t of the tape resin 12 is 5 μm, the depth Y of the concave portion is 30 μm, and the thickness g of the optical fiber ribbon at the concave portion is 200 μm.

  As shown in FIG. 2 and FIG. 3, in the optical fiber ribbon having a recess formed therein, the recess preferably has a smooth curved shape R. For example, if the concave portion has a shape in which the bottom portion is sharp along the shape of the optical fiber core wire, stress concentrates on the bottom portion, and cracks, cracks, and the like are likely to occur.

In the optical fiber cable of the present invention, an optical fiber ribbon having no recess formed in the jacket may be used.
In the optical fiber ribbon 10b shown in FIG. 4, the thickness of the tape resin 12b is set so that T ≦ d + 40 (μm), that is, the thickness t of the tape resin 12 is 20 μm or less. . Since the thickness t of the tape resin 12 is thin, the tape resin 12 can be easily peeled off by causing the tape resin 12b to crack or peel off by a manual operation by an operator or a branching tool such as a brush. . Therefore, the tape resin 12b is peeled off from the optical fiber ribbon 10 so that the optical fiber 11 can be easily branched, and the intermediate post-branching operation is facilitated.

Further, the thickness t of the outer jacket can be made zero. An optical fiber ribbon having a thickness t = 0.0 of the jacket is one in which the tape resin does not cover the entire optical fiber. An example of such an optical fiber ribbon is shown in FIG.
In the optical fiber ribbon 10c shown in FIG. 5, adjacent optical fibers 11 are integrated with a tape resin 12c. The tape resin 12c is formed so as to fill in the recesses between the optical fibers 11, and bonds the adjacent optical fibers 11 together. Further, the thickness of the optical fiber ribbon 10 a is designed not to be larger than the outer diameter d of the optical fiber 11. Therefore, the thickness T of the optical fiber ribbon 10a in this case is equal to the outer diameter d of the optical fiber 11. The optical fiber ribbon 10c is integrated only by the adhesive force between the tape resin 12c and the optical fiber 11 because the tape resin 12c does not cover the entirety of each optical fiber 11. For example, as shown in FIG. Such a tape resin is more likely to be branched than an optical fiber ribbon that covers the whole of all optical fibers.
Moreover, the recessed part may be formed in the tape resin 12c.

  Further, in the optical fiber ribbon used in the optical fiber cable of the present invention as shown in FIGS. 2 to 5, the adhesive force between the optical fiber and the tape resin is the activity after tearing out the outer cover. There are cases where transmission loss at the time of line branching increases and branching work efficiency is affected. The adhesive strength between the optical fiber and the tape resin is within the range of 0.025 (gf) to 0.25 (gf) in terms of the adhesive strength per optical fiber in consideration of prevention of increase in transmission loss and branching workability. It is desirable to be. If the adhesion force is smaller than the above range, the tape resin may be involuntarily broken when the cable jacket is torn from the notch, and the optical fibers may be separated. Moreover, when the said adhesive force is larger than the said range, branching property will worsen.

  Moreover, in the optical fiber ribbon used in the present invention, when the main purpose is to maintain the integrity without losing the optical fiber, the thickness of the tape resin is preferably 0.5 μm or more. The maximum thickness T of the optical fiber ribbon is T ≧ optical fiber outer diameter d + 1 (μm).

  In the optical fiber cable of the present invention, the optical fiber tape core covered with the jacket may be a thick one of the conventional tape resin, but when a thin tape resin as described above is used. As described above, the intermediate post-branching property is good. Further, particularly when the concave portion is formed in the tape resin as in the optical fiber ribbons 10 and 10a described above, it is possible to select a form of taking out the optical fiber when the outer jacket is torn.

For example, as shown in FIG. 6, when the outer cover 3 is torn from the notch 4 in the cross-sectional short direction, the same light in the tearing direction is applied to the tape resin from the outer cover 3 that has entered the recess of the optical fiber ribbon. The force in the parallel direction of the fibers acts to break the tape resin. Then, the optical fiber 11 is separated into single fibers and taken out.
In addition, as shown in FIG. 7, when the outer cover 3 is torn from the notches 5 and 5a in the longitudinal direction of the cross section, the direction orthogonal to the parallel direction of the optical fibers becomes the tearing direction, and the tape resin is not broken and light is broken. The fiber ribbon 10 is removed while maintaining its shape.

In this way, when the concave portion is formed in the tape resin of the optical fiber ribbon and at least one notch formed in two different directions is formed in the same direction as the parallel direction of the optical fiber, the notch to be used is selected. By doing so, it is possible to select whether to take out the optical fiber ribbon as a single core or as a single optical fiber. Therefore, regardless of whether the optical fiber to be connected is a tape core or a single core, the optical fiber can be taken out from the optical fiber cable according to the form, and the connection work can be performed efficiently.
Further, since the single fiber can be separated without applying an extra external force to the optical fiber 11 simply by tearing the jacket 3 from the notch 4, an increase in transmission loss can be suppressed.

  Next, another embodiment of the optical fiber cable according to the present invention will be described. Each of the optical fiber cables shown below is formed in two directions with different notches as shown in FIG. 1, so that an optical fiber ribbon or a single optical fiber provided inside can be easily taken out. It is the structure which can do. In addition, although the optical fiber tape core wire provided inside has shown the optical fiber tape core wire 10 which has a recessed part similarly to FIG. 1, you may use another optical fiber tape core wire.

  The optical fiber cable 1a shown in FIG. 8 has two optical fiber ribbons 10 provided. The two optical fiber ribbons 10 are laminated in the thickness direction. Note that the two optical fiber ribbons 10 and 10 may be laminated so as to be shifted in the width direction by a distance approximately half the pitch between the optical fibers 11. Since the optical fiber ribbon 10 has an outer shape that has irregularities in the width direction along the outer periphery of the optical fiber 11, the optical fiber ribbons 10 are mutually aligned with the irregularities when they are shifted by a half pitch. Contact to make up. Therefore, the thickness to be stacked is reduced.

Similarly to the optical fiber cable 1 shown in FIG. 1, the jacket 3 has a pair of notches 4 formed in a short cross-sectional direction so as to face each other with the optical fiber ribbon 10 being the center, Three notches 5 and 5a formed in the longitudinal direction of the cross section are provided. Also in the case of this optical fiber cable 1a, the form of taking out the optical fiber can be selected depending on the direction of tearing the jacket 3 as shown in FIGS.
In the optical fiber cable of the present invention, any number of optical fiber ribbons may be provided. In addition, the number of optical fibers constituting one optical fiber ribbon may be any number. For example, in addition to the four forms shown in the present embodiment, 2, 8, 12 Etc.

The optical fiber cable 1b shown in FIG. 9 is provided with eight optical fibers 11 having a single-core optical fiber core configuration. The eight optical fibers 11 are aligned with two, three, and three in the longitudinal direction of the cross section of the element portion 9 and are arranged so as to be in contact with adjacent optical fibers. As in the optical fiber cable 1 shown in FIG. 1, the jacket 3 has a pair of notches 4 formed in a short cross section so as to face each other with the optical fiber 11 in the center, and a longitudinal direction in the cross section. Are provided with three notches 5 and 5a.
When many single-core optical fibers are provided, for example, in the case of a conventional optical fiber cable, if the notch has only one direction, even if the outer shell is torn, some optical fibers are still in the outer jacket. It tends to remain buried. Therefore, as shown in FIG. 9, since the notches are formed in at least two different directions, it is possible to reliably take out all optical fibers by tearing the jacket 3 from different directions.
In the optical fiber cable of the present invention, any number of single-core optical fibers may be provided.

  An optical fiber cable 1c shown in FIG. 10 is in the form of an indoor cable that does not include the messenger wire portion 8 shown in FIG. In the optical fiber cable 1c, one optical fiber tape core wire 10 and two strength members 2 are covered with an outer jacket 3, and the outer jacket 3 has the same structure as the optical fiber cable 1 shown in FIG. A pair of notches 4 formed in the cross-sectional short direction and three notches 5 and 5a formed in the cross-sectional longitudinal direction are provided.

  An optical fiber cable 1d shown in FIG. 11 has a configuration in which one strength member 2 is removed from the configuration shown in FIG. In this case, if the outer cover 3 is torn from the notch 5 on the side without the tensile member 2 (right side in the figure), the outer cover 3 can be torn to the optical fiber tape core wire 10 without going through the tensile member 2. The fiber ribbon 10 or the single optical fiber 11 can be easily taken out. In this case, even if the notch 5 on the side having the strength member 2 (left side in the figure) is not provided, the takeout property is good.

  Moreover, the optical fiber cable 1e shown in FIG. 12 is the structure remove | excluding the two strength bodies 2 from the form shown in FIG. In this case, it becomes easier to tear the jacket 3 using the notch 5, and the optical fiber ribbon 10 or the single optical fiber 11 can be easily taken out from either the notch 4 or 5.

  When trying to obtain the same tensile strength as that of the optical fiber cable 1c shown in FIG. 10 with respect to the optical fiber cable 1e shown in FIG. 12, the configuration of the optical fiber cable 1f shown in FIG. Just do it. This optical fiber cable 1f is provided with a strength member 2a having a diameter smaller than that of the strength member 2 at the four corner positions of the jacket 3 while avoiding the space between the notches 4 and 5 and the optical fiber ribbon 10. Is. This optical fiber cable 1f achieves both the take-out property of the optical fiber ribbon 10 or the single optical fiber 11 and the high tensile strength as a cable. Also, the mechanical symmetry in the cross section is good.

  The outer shape of the optical fiber cable of the present invention may be any shape. The optical fiber cable 1g shown in FIG. 14 has a cross-sectional outer shape of the jacket 3 that is substantially circular, and is formed with notches 5b and 5c in two different directions. Further, the strength member 2 can be disposed at a position avoiding the space between the notches 5 b and 5 c and the optical fiber ribbon 10.

It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows an example of the optical fiber tape core wire provided in the optical fiber cable shown in FIG. It is sectional drawing which shows an example of the optical fiber tape core wire provided in the optical fiber cable shown in FIG. It is sectional drawing which shows an example of the optical fiber tape core wire provided in the optical fiber cable shown in FIG. It is sectional drawing which shows an example of the optical fiber tape core wire provided in the optical fiber cable shown in FIG. It is sectional drawing which shows a mode that an optical fiber is taken out from the optical fiber cable shown in FIG. It is sectional drawing which shows a mode that the optical fiber tape core wire is taken out from the optical fiber cable shown in FIG. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is sectional drawing which shows the example of the conventional optical fiber cable. It is sectional drawing which shows the example of the conventional optical fiber cable. It is sectional drawing which shows the example of the state which teared the jacket of the conventional optical fiber cable. It is sectional drawing which shows the example of the state which teared the jacket of the conventional optical fiber cable. It is sectional drawing which shows the example of the state which teared the jacket of the conventional optical fiber cable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a-1g Optical fiber cable 2 Strength body 3 Cover 4,5,5a-5c Notch 6 Neck part 7 Support line 8 Messenger wire part 9 Element part 10 Optical fiber ribbon 11 Optical fiber 12 Cover 13 Glass fiber 16 Recess

Claims (4)

An optical fiber or an optical fiber cable in which a plurality of optical fibers integrated with a resin is covered with a jacket,
An optical fiber cable, wherein the outer cover is formed with notches in at least two different directions. The optical fiber cable according to claim 1,
The two different directions are directions orthogonal to each other. The optical fiber cable according to claim 1 or 2,
A plurality of the optical fibers are juxtaposed,
At least one of the notches is formed in a parallel direction of the optical fibers. The optical fiber cable according to any one of claims 1 to 3,
A concave portion is formed in the resin of the optical fiber ribbon in accordance with a depression between the adjacent optical fibers.