KR100559646B1 - Small-sized high-count optical fiber drop cable - Google Patents

Abstract

Disclosed is an optical fiber for entry having a structure capable of accommodating multicore optical fibers. The optical cable of the present invention includes a cable body and a support portion connected to the cable body to support the cable body, wherein the cable body comprises at least two or more optical fibers arranged parallel to each other without intentional twisting, waterproof powder, waterproof powder and talc. A tube (optical fiber unit) mounted with a mixture of (Talc) or waterproof yarn (Yarn), a tensile line symmetrically disposed on both sides of the tube, and an outer shell surrounding the tube and the tensile line. In addition, the support portion includes a support line disposed at the center thereof, and an outer shell surrounding the support line, wherein the outer shell of the support portion is connected to the outer shell of the cable main body on which one of the tensile lines is disposed. According to the present invention, by using a waterproof powder, a mixture of a waterproof powder and talc, or a waterproof yarn without using a jelly compound, the handleability is remarkably improved, and multicore optical fibers can be accommodated. In addition, despite being multiplied, miniaturization and light weight are possible.

Optical cable, incoming cable, multicore, waterproof powder

Description

Multi-Conductor Small Entry Fiber Cable {SMALL-SIZED HIGH-COUNT OPTICAL FIBER DROP CABLE}

The following drawings attached to the present specification are intended to assist in understanding the technical idea of the present invention together with the following detailed description of the invention, and the present invention should not be construed as being limited to only the matters shown in the following drawings.

1 is a cross-sectional view showing an example of the configuration of an optical cable for entry according to the prior art.

2 is a cross-sectional view showing another example of the configuration of the optical cable for entry according to the prior art.

Figure 3 is a cross-sectional view showing the configuration of the optical cable for entry according to a preferred embodiment of the present invention.

<Description of main reference numerals in the drawings>

1.Cable body 2.Supporting part 3.Outer shell

4 ... optical fiber 5 ... tension line 6 ... notch

7 ... Support 8 ... Outer 9 ... Bridge

13 ... waterproof powder 14 ... tube 15 ... fiber optic unit

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an optical fiber drop cable (FTTH) for indoor entry, and more particularly, to an optical cable for incorporation having a small outer diameter while mounting multi-core optical fibers.

Optical cables, also called fiber optic cables, are used to carry optical signals. Optical cables are classified into various types according to their structure and usage environment. An optical fiber for pulling in (hereinafter, simply referred to as a cable) is a cable which is introduced into a building such as each home or office from an optical cable installed in the air.

Fig. 1 shows a configuration example of a lead cable according to the prior art. The entry cable of FIG. 1 disclosed in Unexamined-Japanese-Patent No. 2001-337255 consists largely of the cable main body 1 and the support part 2 for supporting a cable main body. The cable main body 1 includes a sheath 3 made of polyolefin-based thermoplastic resin such as polyethylene, an optical fiber 4 of one core basically disposed at the center of the sheath 3, and an optical fiber 4 as a tension line. It consists of a copper wire 5 arranged symmetrically with respect to On the other hand, notches 6 are formed in the sheath 3 so as to easily peel off at both sides of the portion where the optical fiber 4 is disposed.

The support part 2 consists of the steel wire 7 and the coating layer 8 which coat | covered this steel wire 7 with the polyolefin thermoplastic resin, and is connected with the cable main body 1 by the bridge 9. The bridge 9 is formed in a narrow shape to facilitate the separation of the cable body 1 and the support 2. The sheath 3 of the cable main body 1 and the covering layer 8 of the support part 2 are formed of the same material, so that the sheath 3 and the covering layer 8 can be integrally formed including the bridge 9. .

However, the incoming cable shown in Fig. 1 is basically a structure that employs a single fiber and is not suitable for transmitting a large amount of information to a building such as a multi-family house or a building. Furthermore, since the optical fiber of one core extends in a straight line, it is vulnerable to stress caused by the optical fiber due to the bending of the optical cable during the laying of the optical cable or the winding of the drum.

On the other hand, U.S. Patent Application Publication No. 2003/0012529 A1 discloses an entry cable having a structure in which a transmission amount can be increased compared to the one-core structure by employing a two-core optical fiber ribbon. However, the incoming cable disclosed in this U.S. Patent Publication still has the disadvantage of being vulnerable to the above stress by extending the optical fiber in a straight line, and it is also difficult to manufacture an optical cable that accommodates more multi-core optical fibers with this structure.

FIG. 2 is a cross-sectional view of an inlet cable having a structure capable of mounting a multi-core optical fiber by applying a loose tube to the cable body 1. The cable main body 1 of the lead-in cable shown in FIG. 2 mounts the number of optical fibers 4 core wires required in the buffer tube 10 together with the jelly compound 11 for preventing water penetration, and the tube 10 In the outer circumference of the) is placed a tension member 12 for minimizing the various stresses applied to the drum winding or indoor installation of the cable, the outer structure is to surround the outer shell (8) for protecting them.

The incoming cable of FIG. 2 can accommodate a multi-core optical fiber, but due to the application of a loose tube, the outer diameter becomes large and the jelly compound is filled, so handling is poor, and it is not suitable for indoor use. In addition, unlike the inlet cable shown in Figure 1 there is no notch, and since the tension member 12 is disposed on the outer periphery of the tube 10, there is a problem that the coating stripping is not easy.

The present invention has been made in view of the above-described problems, and an object thereof is to provide an optical cable that is capable of multiplexing and has a small outer diameter and suitable for use indoors or outdoors.

In addition, an object of the present invention is to provide an optical cable that can be diversified and has good handleability.

In order to achieve the above object, an optical cable according to the present invention includes a cable body and a support part connected to the cable body to support the cable body, wherein the cable body comprises at least two optical fibers arranged in parallel with each other without intentional twisting. , A tube (optical fiber unit) mounted with a waterproof powder, a mixture of waterproof powder and talc, or a waterproof yarn, an extension line symmetrically disposed on both sides of the tube, and the tube and the tension line It includes an enclosing envelope. The support portion includes a support line disposed at its center and an outer shell surrounding the support line, and the outer shell of the support portion is connected to the outer shell of the cable main body on the side on which one of the tensile lines is disposed.

According to an embodiment of the present invention, it is preferable that the cross section of the cable main body has a long rectangular or oval shape in which the tensile line is disposed, and the size of the optical cable cross section including the supporting portion is 3 mm x 6 mm or less.

In addition, according to an embodiment of the present invention, the outer diameter of the tube (optical fiber unit) is preferably 1.4mm or less.

Moreover, it is preferable that the notch is formed in the outer part of the said cable main body in the part in which the said tube is arrange | positioned so that peeling may be easy.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the terms used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

3 is a cross-sectional view showing the configuration of a lead cable according to a preferred embodiment of the present invention.

Referring to FIG. 3, the incoming cable according to the present embodiment includes a cable main body 1 and a support 2 extending parallel to the cable main body 1 and supporting the cable main body. The cable main body 1 includes an optical fiber unit 15 and a tensile line 5 symmetrically arranged on both sides (up and down in the figure) of the optical fiber unit 15, and the optical fiber unit 15 and the tensile line 5 ) Is wrapped by the sheath 3.

The optical fiber unit 15 is arranged in parallel without deliberately twisting the number of colored optical fiber 4 core wires required in the tube 14, so that the waterproof powder 13, a mixture of the waterproof powder and talc, Or by mounting waterproof yarns together. The number of optical fibers 4 is not particularly limited here, but about 2 to 12 cores are suitable so that the outer diameter of the entire cable is not too large.

As the waterproof powder 13, various kinds of known powders having a waterproof function may be employed, and preferably, a polymer (Super Absorbent Polymer; SAP) having excellent hygroscopicity may be employed. In particular, by using the waterproof powder 13, a mixture of the waterproof powder and talc, or waterproof yarn (Yarn), the present invention significantly improves the handleability compared to the case of using a conventional jelly compound.

In addition, the tube 14 is polyvinyle chloride (PVC), polybutylene terephthalate (PBT), polyethylene (PE), Hytrel (registered trademark of DuPont as a polyester-based elastomer) It is made of a plastic-based material such as. The optical fiber unit 15 may be manufactured by applying a waterproof powder to the required number of optical fiber 4 core wires and extruding the tube material to surround the optical fibers. In the tube 14 of the optical fiber unit 15 thus formed, the optical fiber 4 core wire may flow to some extent with the waterproof powder to absorb shock from the outside.

The tension line 5 is for preventing the transmission loss from increasing due to the deformation of the outer skin 3 due to the use environment temperature of the optical cable and the deformation of the optical fiber 4, and Fiber Reinforced Plastic (FRP) ), Glass yarns, aramid yarns and the like. On the other hand, at least one of the tension line 5 may be made of a conductive metal such as copper, aluminum, in this case, the tension line 5 may serve as a feeder for supplying power.

PE, PVC, etc. may be used for the outer shell 3 as flame-retardant plastic. On the other hand, the notch 6 is formed in the outer part 3 in the part in which the optical fiber unit 15 is arrange | positioned, and the outer skin can be easily peeled off by hand.

The support part 2 consists of the support line 7 and the outer shell 8 which surrounds this support line 7, and the cable main body 1 and any tension line 5 are arrange | positioned by the bridge 9 It is connected to one side. The bridge 9 is formed to be narrow in order to facilitate the separation of the cable body 1 and the support 2.

On the other hand, the outer shell 3 of the cable main body 1 and the outer shell 9 of the support part 2 are formed of the same material, so that the outer shell 3 and the support part 2 of the cable main body 1 including the bridge 9 are formed. The outer shell 9 of) can be integrally formed.

On the other hand, the drawn cable of the embodiment described above was actually created and its size and performance were tested, and the result is described.

First, a 12-core fiber core (0.25 mm in diameter) was mounted in a tube made of PVC or Hytrel with a mixture of waterproof powder and talc, where the outer diameter of the tube was made less than 1.4 mm. It was possible.

In addition, a hygroscopic polymer was used as the waterproof powder, but there was no problem in waterproofing. In other words, the tube manufactured as described above was tested by IEC 60794-1-2 Method F5, and water did not leak for 24 hours.

Tensile lines were positioned symmetrically up and down the tube (optical fiber unit) using a 0.4 mm diameter FRP. In addition, the support wire was manufactured using a steel wire with a diameter of 1.2mm, and black LSZH, a flame retardant, was used as the cable jacket.

Tensile testing of the finished cable (IEC 60794-1-2 Method E1) resulted in properties beyond the tensile strength required by the product, even with tensions above 1200 N. On the other hand, in the optical loss measurement, 0.25 dB or less for light of 1550 nm wavelength, and light for 1310 nm wavelength Good results of less than 0.36 dB were obtained.

In addition, the cross-sectional size of the optical cable including the support is 3mm x 6mm or less, even though it accommodates multi-core optical fibers, it was possible to manufacture a very small cable. Therefore, it is suitable for drawing into a building.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

According to the optical fiber for incoming according to the present invention can accommodate a multi-core optical fiber, and further downsizing and weight can be reduced in spite of the multi-core, solving the problems of using indoors and the problem of stripping the coating.

In addition, according to the optical fiber structure for the introduction of the present invention, the handleability is remarkably improved by using waterproof powder, a mixture of waterproof powder and talc, or waterproof yarn (Yarn) without using a jelly compound.

Claims (10)

Tubes incorporating at least two or more optical fiber cores arranged in parallel with each other in a non-ribbon type with no intentional twist, together with a waterproof powder, a mixture of waterproof powder and talc, or a waterproof yarn, and both sides of the tube A cable body including a tensile line symmetrically disposed in the outer shell and the outer shell surrounding the tube and the tensile line; And And a support including a support line disposed at the center thereof and an envelope surrounding the support line. The outer sheath of the support portion is an indoor cable for entering the fiber which is connected to the sheath of the cable main body of the side on which one of the tension line is disposed. The indoor cable according to claim 1, wherein the cross section of the cable main body has a long rectangular or oval shape in which the tension line is disposed, and the size of the cross section including the support portion is 3 mm x 6 mm or less. The indoor cable of claim 1, wherein an outer diameter of the tube is 1.4 mm or less. The indoor cable according to claim 1, wherein the at least two optical fiber core wires are colored in different colors. The indoor cable according to claim 1, wherein the tensile line is made of a nonmetallic material. The indoor cable of claim 1, wherein at least one of the tension lines is made of a conductive metal. delete The indoor cable according to claim 1, wherein a notch is formed in a portion of the cable main body in which the tube is disposed. The indoor cable of claim 1, wherein an outer shell of the cable body and an outer shell of the support part are integrally formed of the same material. The indoor cable of claim 1 or 9, wherein the outer shell of the cable body and / or the outer shell of the support portion are made of flame-retardant plastic.

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