KR20140013563A - Optical fiber cable - Google Patents

Abstract

The present invention relates to an optical fiber cable. According to one embodiment of the present invention, the optical fiber cable includes optical fibers; at least one fiber reinforced plastic (FRP) arranged in the inner or outer side of the optical fibers; a first coating surrounding the optical fibers and the FRP; and a second coating surrounding the first coating.

Description

Fiber Optic Cable {OPTICAL FIBER CABLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable, and more particularly, to an optical fiber cable including a lead wire and a tensile wire.

Optical communication that exchanges information using an optical signal instead of an electrical signal uses an optical fiber made of glass fiber as an intermediary of signal transmission and has an advantage that a transmission speed is high and a transmission capacity is large compared with a communication method using an existing electric signal .

Fiber optic cables are fabricated in various forms to protect the optical fiber, which is a transmission path for transmitting an optical signal, from moisture and the external environment depending on the use environment and use. Such an optical fiber cable constitutes a plurality of communication networks and, depending on the installation location, an optical fiber cable for a duct, an outdoor optical fiber cable installed outdoors, an indoor optical fiber cable installed indoors, And optical fiber cables for incoming calls.

A loose tube optical fiber cable, which is a typical type of optical fiber cable, includes a tensile wire providing tensile strength, a plurality of loose tubes gathered around a tensile wire and mounted with a plurality of optical fibers, and a plurality of loose tubes As shown in Fig.

The incoming fiber-optic cable has an 8-shape, a concentric, and a flat structure depending on its structure, and it is directly or processed through a wall, a window, an existing duct, etc. between a photon, a pole and a subscriber.

These optical fiber cables must maintain the optical transmission medium function by maintaining the optical loss within the specification even under the circumstances of external environment change, tensile, impact, compression, etc. during installation and use.

However, the conventional optical fiber cable has a complicated internal structure, has a large cost and time to manufacture, has a large outer diameter and weight, and is difficult to install and handle.

It is an object of certain embodiments of the present invention to at least partially solve, alleviate or eliminate at least one of the problems and / or disadvantages associated with the prior art.

It is an object of the present invention to provide an optical fiber cable which has proper mechanical / environmental characteristics in a situation where a fiber-optic cable is required to be installed due to the new installation and expansion of a communication network and which does not increase optical loss even at a small radius of curvature, Fiber optic cable. The present invention also provides an optical fiber cable which is simple in structure, small in size, easy to handle and install, does not have any additional components and thus shortens manufacturing cost and time, and has a circular structure and low surface resistance.

An optical fiber cable according to an aspect of the present invention includes: optical fibers; At least one aperture disposed inside or outside the optical fibers; A primary coating surrounding said optical fibers and said aperture; And a secondary coating surrounding the primary coating.

INDUSTRIAL APPLICABILITY According to the present invention, an optical fiber cable is provided which is simple in internal structure, has minimum cost and time to manufacture, is small in outer diameter and weight, and is easy to install and handle.

1 is a cross-sectional view showing an optical fiber cable according to a first preferred embodiment of the present invention,
2 is a cross-sectional view showing an optical fiber cable according to a second preferred embodiment of the present invention,
3 is a cross-sectional view showing an optical fiber cable according to a third preferred embodiment of the present invention,
4 is a cross-sectional view showing an optical fiber cable according to a fourth preferred embodiment of the present invention,
5 is a cross-sectional view illustrating an optical fiber cable according to a fifth preferred embodiment of the present invention.
6 is a cross-sectional view showing an optical fiber cable according to a sixth preferred embodiment of the present invention.

The present invention can be variously modified and may have various embodiments, and specific embodiments will be described in detail with reference to the drawings. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

1 is a cross-sectional view showing an optical fiber cable according to a first preferred embodiment of the present invention. The optical fiber cable 100 extends along its longitudinal direction, and FIG. 1 is a cross-sectional view showing the optical fiber cable 100 cut in a direction perpendicular to the longitudinal direction.

The optical fiber cable 100 includes a plurality of optical fibers 110 positioned at the center of the optical fiber cable 100 for transmitting an optical signal and a plurality of optical fibers 110 disposed inside or outside the optical fibers 110 A primary covering 130 surrounding the optical fibers 110 and the opening 120, a reinforcing member 140 surrounding the primary covering 130, Or a secondary coating 160 surrounding the reinforcing member 140. The reinforcing member 140 may be formed of a plurality of rib cords 150 disposed between the secondary coating 160 and the secondary coating 160, The optical fiber cable 100 is a twelfth optical fiber cable having twelve optical fibers 110.

Each of the optical fibers 110 may be any kind of optical fiber that is a transmission medium for an optical signal. Examples of such an optical fiber include a core in which an optical signal propagates in the longitudinal direction along its length and a clad for holding the optical signal in the core or a resin layer on the outside of the core Optical fibers, and tight buffer optical fibers. That is, the optical fiber 110 may be a glass or plastic bare optical fiber made of a high refractive index core and a low refractive index clad, a bare optical fiber coated with a resin (this type is usually referred to as an optical fiber ), Colored fiber optics to facilitate identification, or extrusion coated bare optical fiber with plastic (referred to as tight buffer optical fiber), and the like. In the tight buffer optical fiber, as the material of the tight coating layer, a material containing or consisting only of one of polyvinyl chloride, Hytrel, nylon, polyethylene (PE) and polyester can be used .

Each of the optical fibers 110, the aperture stop 120, the primary sheath 130, the pair of lip cords 150 and the secondary sheath 160 has a cross section (Including an elliptical shape, a roughly circular shape such as a circular shape having concavo-convex shape, and the like). The optical fiber 110 preferably has a diameter of 250 mu m or less.

The canal 120 can withstand high compressive and tensile loads and can be absorbent. The openings 120 may be made of fiber reinforced plastic (FRP) yarns, aramid reinforced plastic yarns, flame retarded or non-flammable polypropylene yarns, polyester yarns, aramid yarns, a single filament made of a nonconductive material such as a glass yarn, or a combination of filaments (made by twisting them or integrating them by coating them). Alternatively, the opening 120 may be formed by coating a super absorbent powder on the outer circumferential surface of a non-conductive filament, or a combination of a non-absorbent filament and a water-swellable yarn. The opening 120 is disposed in contact with the primary sheath 130 to assist in the molting of the primary sheath 130. Preferably, the aperture stop 120 may have a diameter ranging from 0.5 to 1.5 times the diameter of the optical fiber 110.

The primary sheath 130 protects the optical fibers 110 disposed therein from the external environment and can be integrally formed of a single material through an extrusion process. The primary coating 130 preferably has high tensile strength and high hardness in order to prevent the optical fiber cable 100 from being damaged by roadside trees or other obstacles when the optical fiber cable 100 is installed. As the material of the primary coating 130, a polyolefin-based material can be used, and a flame-retardant polyolefin having a tensile strength of 12 Mpa or more and a hardness (Shore D) of 52 or more can be used. Alternatively, a material containing or consisting only of one of polyvinyl chloride (PVC), polyethylene (PE), hytrel and nylon may be used as the material of the primary coating 130 . In addition, the primary coating 130 preferably has an oxygen index of 28% or more to ensure sufficient flame retardant properties. The oxygen index is a non-dimensional value of the critical oxygen concentration that can be ignited by a combustible solid, which is also referred to as a limit oxygen index (LOI). The primary coating 130 may contain a halogen compound, aluminum hydroxide or magnesium hydroxide to increase the oxygen index. Alternatively, the primary coating 130 may be made of a low smoke zero halogen (LSZH) material having an ultraviolet protection function.

The open end 120 is provided to improve the tensile force and the compressive strength of the optical fiber cable 100 and to assist in peeling off (i.e., peeling, removing or separating) the primary cover 130. That is, the operator strips off the secondary coating 160 and the primary coating 130 of the optical fiber cable 100 and then pulls the primary inspection cap 120 to pull the primary coating 130 to the optical fiber cable (100) along the longitudinal direction. At this time, since the opening depth 120 has high tensile force and compressive strength, the primary cover 130 can be continuously peeled by 1 m or more without cutting the opening depth 120.

The reinforcing member 140 provides stiffness and tensile strength to the optical fiber cable 100 and is disposed outside the primary sheath 130 to surround the primary sheath 130. The reinforcing member 140 can withstand high compressive and tensile loads, and can have flame retardancy. The reinforcing member 140 is composed of a plurality of yarns, each of which is made of a fiber reinforced plastic (FRP) yarn, an aramid reinforced plastic yarn, a flame retardant or non-burning polypropylene yarn, a polyester yarn , Aramid yarn or glass yarn. The reinforcing member 140 may be linearly disposed around the primary sheath 130, or wound in a spiral or S-Z fashion.

The S-Z method is Heinrich. Since the S-Z STRANDED OPTICAL CABLE disclosed in US Patent No. 4,828,352 (Heinrich A. Kraft) was invented and patented, the description of the S-Z scheme will be omitted.

The secondary cover 160 is located at the outermost portion of the optical fiber cable 100 and protects the optical fibers 110 disposed therein from the external environment and can be integrally formed of a single material through an extrusion process . It is preferable that the secondary coating 160 has high tensile strength and high hardness in order to prevent the optical fiber cable 100 from being damaged by roadside trees or other obstacles when the optical fiber cable 100 is installed. As the material of the secondary coating 160, a polyolefin-based material can be used, and a flame-retardant polyolefin having a tensile strength of 12 Mpa or more and a hardness (Shore D) of 52 or more can be used. Alternatively, a material containing or consisting only of one of polyvinyl chloride (PVC), polyethylene (PE), hytrel and nylon may be used as the material of the secondary coating 160 . In addition, the secondary coating 160 preferably has an oxygen index of 28% or more to ensure sufficient flame retardant properties. The oxygen index is a non-dimensional value of the critical oxygen concentration that can be ignited by a combustible solid, which is also referred to as a limit oxygen index (LOI). The secondary coating 160 may contain a halogen compound, aluminum hydroxide or magnesium hydroxide to increase the oxygen index. Alternatively, the secondary coating 160 may be made of a low smoke zero halogen (LSZH) material having an ultraviolet protection function. The primary sheath 130, the reinforcing member 140 and the secondary sheath 160 are laminated in a concentric structure.

The rib cords 150 are provided on both sides of the primary cover 130 to assist in peeling off (i.e., peeling, removing or separating) the secondary cover 160. The rib cord 150 may be disposed between the reinforcement member 140 and the secondary sheath 160 or between the primary sheath 130 and the reinforcement member 140. That is, the operator strips the secondary cover 160 of the optical fiber cable 100 and pulls the rib cord 150 to pull the secondary cover 160 in the longitudinal direction of the optical fiber cable 100 Follow along. At this time, since the rib cord 150 has a high tensile force and a compressive strength, the secondary sheath 160 can be continuously peeled for at least 1 m without cutting the rib cord 150.

Since the primary sheath 130 is formed by an extrusion process, the primary sheath 130 is in intimate contact with the optical fibers 110 and the sheath core 120, and the primary sheath 130 and one The adhesion between the optical fibers 110, that is, the adhesion per se of the optical fiber is 100 g / 10 cm or more. For example, in the method of measuring the adhesion, only the primary sheath 130 and the secondary sheath 160 are peeled off with a predetermined length along the outer circumference of the optical fiber cable 100 at a position 10 cm away from the end of the optical fiber cable 100 A load at which the primary coating 130 slips is measured while applying a gradually increasing load to the primary coating 130 and the load at the instant when the primary coating 130 slides is measured in g / Indicating adhesion. For example, when the adhesion between the primary sheath 130 and one optical fiber 110 is 100 g / 10 cm, the adhesion of the 12-core optical fiber cable 100 becomes 1.2 kg or more. For another example, the adhesion of a two-core optical fiber cable is 0.2 kg or more.

When the optical fiber cable 100 is once wound around a cylinder having a radius of 20 mm, the optical loss at a wavelength of 1550 nm for each optical fiber 110 is 0.1 dB or less.

2 is a cross-sectional view showing an optical fiber cable according to a second preferred embodiment of the present invention. FIG. 2 is a cross-sectional view of the optical fiber cable 200 taken along a direction perpendicular to the longitudinal direction of the optical fiber cable 200. As shown in FIG. The optical fiber cable 200 has a structure similar to that of the optical fiber cable 100 shown in FIG. 1 and differs only in that it further includes a pair of tensile wires 270, .

The optical fiber cable 200 includes a plurality of optical fibers 210 positioned at the center of the optical fiber cable 200 for transmitting optical signals and a plurality of optical fibers 210 disposed inside or outside the optical fibers 210 A primary covering 230 surrounding the optical fibers 210 and the opening core 230; a reinforcing member 240 surrounding the primary covering 230; A secondary coating 260 surrounding the reinforcing member 240 and a second coating 260 surrounding the secondary coating 260 between the secondary coating 260 and the secondary coating 260. [ Or only a pair of tensile lines 270 that are formed.

Each of the tension lines 270 is buried in the secondary sheath 260 to provide stiffness and tensile strength, can withstand high compressive and tensile loads, and can have flame retardancy. The tensile line 270 may be a fiber reinforced plastic (FRP) yarn, an aramid reinforced plastic yarn, a flame retarded or non-flame retardant polypropylene yarn, a polyester yarn, an aramid yarn, a single filament made of a nonconductive or conductive material such as a glass yarn or a steel wire or a combination of filaments formed by twisting or integrating them. Alternatively, the tensile wire 270 may be formed of polyvinyl chloride (PVC), polyethylene (PE), low smoke zero halogen (LSZH), ethylene acrylic acid, or the like on the outer surface of the combination of the filaments or filaments. EAA) or the like. That is, the tensile line 270 may be composed of a core formed of a combination of filaments or filaments, or a coating layer laminated on the outer periphery of the core and the core in a concentric structure.

Preferably, the tensile line 270 has a diameter ranging from 1.5 to 4 times the diameter of the optical fiber 210, more preferably a diameter ranging from 2 to 4 times the diameter of the optical fiber 210 Lt; / RTI >

The tensile line 270 has an outer periphery of a generally circular shape (including an elliptical shape, a roughly circular shape such as a convexo-concave shape and a roughly circular shape) at its cross-section (cross section perpendicular to the longitudinal direction thereof).

3 is a cross-sectional view showing an optical fiber cable according to a third preferred embodiment of the present invention. 3 is a cross-sectional view showing the optical fiber cable 300 cut in a direction perpendicular to the longitudinal direction. The optical fiber cable 300 shown in FIG. The optical fiber cable 300 has a structure similar to that of the optical fiber cable 100 shown in FIG. 1, and differs only in that it includes only six optical fibers 310, so that redundant description will be omitted.

The optical fiber cable 300 includes a plurality of optical fibers 310 disposed at the center of the optical fiber cable 300 for transmitting an optical signal and a plurality of optical fibers 310 disposed inside or outside the optical fibers 310 A primary coating 330 surrounding the optical fibers 310 and the aperture 320 and a reinforcing member 340 surrounding the primary coating 330 and a primary coating Or a secondary coating 360 surrounding the reinforcing member 340. The pair of rib cords 350 may be disposed on both sides of the reinforcing member 340. The pair of rib cords 350 may be disposed on both sides of the reinforcing member 340, The optical fiber cable 300 is a six-core optical fiber cable having six optical fibers 310.

4 is a cross-sectional view showing an optical fiber cable according to a fourth preferred embodiment of the present invention. FIG. 4 is a cross-sectional view showing the optical fiber cable 200 cut in a direction perpendicular to the longitudinal direction. The optical fiber cable 400 has a structure similar to that of the optical fiber cable 200 shown in FIG. 2, and differs only in that it includes only six optical fibers 410, so that redundant description will be omitted.

The optical fiber cable 400 includes a plurality of optical fibers 410 positioned at the center of the optical fiber cable 400 for transmitting an optical signal and a plurality of optical fibers 410 disposed inside or outside the optical fibers 410 A primary cover 430 surrounding the optical fibers 410 and the opening core 420, a reinforcing member 440 surrounding the primary cover 430, A secondary coating 460 surrounding the reinforcing member 440 and a pair of secondary cords 460 disposed between the primary coating 460 and the secondary coating 460. The secondary coating 460 is embedded in the secondary coating 460, Or comprises only a pair of tensile lines 470 that are joined together.

5 is a cross-sectional view showing an optical fiber cable according to a fifth preferred embodiment of the present invention. 5 is a cross-sectional view of the optical fiber cable 500 taken along a direction perpendicular to the longitudinal direction. The optical fiber cable 500 has a structure similar to that of the optical fiber cable 100 shown in FIG. 1 and differs only in that it includes only two optical fibers 510, so that a duplicate description will be omitted.

The optical fiber cable 500 includes a plurality of optical fibers 510 positioned at the center of the optical fiber cable 500 for transmitting an optical signal and a plurality of optical fibers 510 disposed inside or outside the optical fibers 510 520), a primary cover (530) surrounding the optical fibers (510) and the aperture opening (520), a reinforcement member (540) surrounding the primary cover (530) 530 and the secondary coating 560 and a secondary coating 560 surrounding the reinforcing member 540. As shown in FIG. The optical fiber cable 500 is a two-core optical fiber cable having two optical fibers 510.

6 is a cross-sectional view showing an optical fiber cable according to a sixth preferred embodiment of the present invention. FIG. 6 is a cross-sectional view of the optical fiber cable 600 taken along a direction perpendicular to the longitudinal direction of the optical fiber cable 600. FIG. The optical fiber cable 600 has a structure similar to that of the optical fiber cable 200 shown in FIG. 2 and differs only in that it includes only two optical fibers 610, so that a duplicate description will be omitted.

The optical fiber cable 600 includes a plurality of optical fibers 610 disposed at the center of the optical fiber cable 600 for transmitting an optical signal and a plurality of optical fibers 610 disposed inside or outside the optical fibers 610 A primary cover 630 surrounding the optical fibers 610 and the aperture 620, a reinforcing member 640 surrounding the primary cover 630, A secondary coating 660 surrounding the reinforcing member 640 and a secondary coating 660 disposed between the secondary coating 660 and the secondary coating 660. The secondary coating 660 is disposed between the secondary coating 660 and the secondary coating 660, Or consists of only a pair of tension lines 670, as shown in FIG.

In the optical fiber cable according to the present invention, at least one opening may be disposed inside the primary coating. That is, one or a plurality of openings may be disposed inside the primary coating.

The present invention relates to an optical fiber cable and a method of manufacturing the optical fiber cable.

Claims (10)

In an optical fiber cable,
Optical fibers;
At least one aperture disposed inside or outside the optical fibers;
A primary coating surrounding said optical fibers and said aperture;
And a secondary sheath surrounding the primary sheath. The method of claim 1,
And a reinforcing member disposed between the primary sheath and the secondary sheath and surrounding the primary sheath. The method of claim 1,
Further comprising at least one rib cord disposed between the primary jacket and the secondary jacket. The method of claim 1,
Further comprising at least one tensile wire embedded in the secondary sheath. The method of claim 1,
Characterized in that the opening is made of a fiber reinforced plastic yarn, an aramid reinforced plastic yarn, a polypropylene yarn, a polyester yarn, an aramid yarn or a glass yarn. 6. The optical fiber cable according to claim 5, wherein the opening of the optical fiber is absorbent. The optical fiber cable according to claim 1, wherein the optical fiber cable has an adhesive force of 100 g / 10 cm or more per depth of the optical fiber. The optical fiber cable according to claim 1, wherein each of the optical fibers has a diameter of 250 mu m or less. The method of claim 1,
Wherein the optical fiber cable has a light loss of not more than 0.1 dB at a wavelength of 1550 nm for each of the optical fibers when the optical fiber cable is once wound around a cylinder having a radius of 20 mm. The optical fiber cable according to claim 1, wherein the primary and secondary sheaths are made of polyolefin, polyethylene, polyvinyl chloride, hytrel or nylon, respectively.

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