KR20160092667A - Ribbon-Tube Type Optical Cable - Google Patents

Abstract

The present invention relates to a ribbon-tube type optical cable and, more specifically, to a ribbon-tube type optical cable which can minimize light loss due to stress of an optical fiber ribbon accommodated in a loose tube and simultaneously minimize an outer diameter and a weight. The ribbon-tube type optical cable comprises: a central tensile line arranged in a central portion; a plurality of optical units; and an external jacket configured to surround external portions of the optical units.

Description

Ribbon tube optical cable {Ribbon-Tube Type Optical Cable}

The present invention relates to a ribbon-tube optical cable. More particularly, the present invention relates to a ribbon tube optical cable capable of minimizing light loss due to the stress of an optical fiber ribbon housed in a loose tube, while minimizing the outer diameter and weight.

Optical cable is suitable for transmitting large amount of multimedia information such as voice data or moving picture at a rate of 15,000 to 16,000 times that of the conventional copper wire, and has a broadband capability to accommodate a transmission speed of more than gigabit per second Since the amount of reduction of light is small, it can be transmitted farther than the copper wire even when the amplifier is not installed in the middle, and is advantageous against external noise, and is widely used as a communication cable.

Such an optical cable is roughly divided into a loose tube type, a ribbon tube type, and a tight buffer type depending on the structure of the optical unit constituting the optical fiber.

FIG. 1 is a schematic cross-sectional view of a conventional optical unit 900 constituting a ribbon-shaped optical cable.

As shown in FIG. 1, the optical unit 900 constituting the ribbon-shaped optical cable includes an optical fiber ribbon laminate body 910 in which a plurality of ribboned optical fiber ribbons 911, which are composed of a plurality of optical fibers, And is loosely accommodated and has a structure that can move freely to some extent.

When the space in which the optical fiber ribbon stack body 910 can move is narrow in the tube 920 of the optical unit 900, the optical fiber ribbon stack body 910 and the inner wall of the tube 920 collide with each other There is a problem that stress is applied to the optical fiber ribbon laminate 910 and the optical fiber included therein, resulting in optical signal loss.

On the other hand, in order to suppress optical signal loss due to collision between the optical fiber ribbon laminate 910 and the inner wall of the tube 920, a space in which the optical fiber ribbon laminate 910 can move is widened in the tube 920 Jelly or the like is filled in the interior of the optical unit 900, and as a result, the outer diameter and weight of the optical unit 900 are increased.

Accordingly, it is required to minimize the optical signal loss, minimize the increase of the outer diameter and the weight, and to provide a ribbon cable optical cable of a new structure having various capacities and configurations according to the demand of the user. In particular, guidelines for optimized design according to the inner diameter of the tube and the size of the ribbon laminate are required.

An object of the present invention is to provide a ribbon-shaped optical cable capable of minimizing optical loss due to stress of an optical fiber ribbon accommodated in a loose tube, while minimizing the outer diameter and weight.

According to an aspect of the present invention, there is provided an optical fiber ribbon laminate in which a plurality of layers of ribboned optical fiber ribbons, each of which is composed of a plurality of optical fibers, is arranged around a center tension line disposed at a central portion, (L) of the diagonal length (L) of the optical fiber ribbon laminate to the inner diameter (Di) of the tube constituting the optical unit, wherein the ratio / Di) of 0.7 to 0.85 can be provided.

The outside diameter of the optical cable may be 16 to 19 millimeters (mm).

Here, the weight per unit length of the optical cable may be 200 to 260 kg / km.

The outer diameter of the optical fiber may be 240 to 260 탆.

In this case, the number of optical fibers constituting the optical fiber ribbon may be eight.

The number of the optical units may be six.

The difference between the inner diameter Di of the tube constituting the optical unit and the diagonal length L of the optical fiber ribbon laminate may be 0.5 to 1.0 millimeter (mm).

Here, the loss value of the optical signal loss test at a wavelength of 1550 nm at room temperature can be 0.35 dB / km or less.

And, the ratio of the area of the optical fiber tube laminate to the inside area of the tube may be 0.34 to 0.45.

Further, the outside of the optical unit may be taped with a waterproof tape.

In this case, a waterproof yarn may be provided between a pair of adjacent optical units of the optical unit or between the optical unit and the center tensile line.

Also, at least one rib cord may be provided inside the outer jacket.

Further, the center tension line may be taped with a waterproof tape.

The optical fiber ribbon has a width of 1.9 to 2.3 mm and a length L of the diagonal of the optical fiber ribbon laminate is 2.7 to 2.8 mm mm), and the outer diameter of the optical cable may be 16 to 19 millimeters (mm).

The difference between the inner diameter Di of the tube and the diagonal length of the optical fiber ribbon laminate may be 0.5 to 1.0 millimeter (mm).

Further, the tube of the optical unit may be filled with a low-density jelly compound having a density of 0.2 to 0.5 g / cm < 3 >.

In this case, the low-density jelly compound may include base oil, a gelling agent, and a microsphere having a specific gravity of 0.023 to 0.028, and may contain 0.1 to 1.6 parts by weight of a pour point depressant based on 100 parts by weight of the base oil.

Further, the thickness of the tube of the optical unit may be 0.53 to 0.62 millimeters (mm).

In addition, the thickness of the outer jacket may be 1.3 to 1.7 millimeters (mm).

In order to solve the above-mentioned problems, the present invention also provides an optical fiber ribbon having six layers of ribboned optical fiber ribbons arranged around a center tension line disposed at a central portion, an optical fiber having eight 250 탆 outer diameter, Wherein the laminated optical fiber ribbon laminate includes six optical units accommodated in a tube and an outer jacket surrounding the optical unit, wherein a diagonal length of the optical fiber ribbon laminate to the inner diameter Di of the tube constituting the optical unit L is 0.7 to 0.85, the loss value of the optical signal loss test at a wavelength of 1550 nm at room temperature is 0.35 dB / km or less, and the total optical cable has an outer diameter of 16 to 19 millimeters (mm) A ribbon-shaped optical cable can be provided.

In this case, the width of the optical fiber ribbon may be 1.9 to 2.3 millimeters (mm), and the length L of the diagonal line of the optical fiber ribbon laminate may be 2.7 to 2.8 millimeters (mm).

Further, the inner diameter of the tube of the optical unit may be 3.1 to 3.9 millimeters (mm).

Further, the thickness of the tube of the optical unit may be 0.53 to 0.70 millimeters (mm).

Here, the ratio of the area of the optical fiber tube laminate to the inside area of the tube may be 0.34 to 0.45.

The difference between the inner diameter Di of the tube and the diagonal length of the optical fiber ribbon laminate may be 0.5 to 1.0 millimeter (mm).

The ribbon-shaped optical cable according to the present invention minimizes the optical signal loss and minimizes the outer diameter and weight of the cable by adjusting the ratio between the inner diameter of the tube constituting the optical unit and the size of the optical fiber ribbon laminate accommodated in the tube.

Further, according to the ribbon-type optical cable of the present invention, by providing the optimized ratio of the inner diameter of the tube constituting the optical unit and the size of the optical fiber ribbon laminate accommodated in the tube, .

Further, according to the ribbon-shaped optical cable of the present invention, it is possible to provide an optimized ratio of the inner diameter of the tube constituting the optical unit and the size of the optical fiber ribbon laminate accommodated in the tube, Good results can also be obtained in temperature tests in which a positive judgment is made by measuring a change value.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view of a conventional optical unit constituting a ribbon-shaped optical cable.
FIG. 2 illustrates a cross-sectional structure according to one embodiment of a ribbon-tube optical cable according to the present invention.
3 illustrates a cross-sectional structure according to another embodiment of the ribbon-shaped optical cable according to the present invention.
4 is a cross-sectional view illustrating another embodiment of the ribbon-shaped optical cable according to the present invention.
5 is a cross-sectional view illustrating another embodiment of the ribbon-shaped optical cable according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals designate like elements throughout the specification.

FIG. 2 illustrates a cross-sectional structure according to one embodiment of a ribbon-tube optical cable according to the present invention. 2 (a) shows a cross-sectional structure according to one embodiment of the ribbon-shaped optical cable, and Fig. 2 (b) shows an enlarged view of the optical unit shown in region A of Fig. 2 .

2, the ribbon-shaped optical cable according to the present invention includes a central tensile line 100, a plurality of ribboned optical fiber ribbons 211 disposed around the center tensile line 100 and composed of a plurality of optical fibers, Layered optical fiber ribbon laminate 210 may include a plurality of optical units 200 accommodated in the tube 220 and an outer jacket 300 surrounding the optical unit. In particular, it may be a '1 + 6' structure having six optical units 200 disposed around one central tensile line 100.

The center tensile line 100 functions to suppress deformation of the entire optical cable and improve the tensile strength of the optical cable. The material of the center tension line 100 is not particularly limited as long as it can perform the function of the center tension line 100. For example, the center tension line 100 may be made of a highly rigid fiber such as aramid fiber, have.

In addition, moisture penetrated through the distal end of the optical fiber cable for the connection with the connection box flows along the central tensile line 100 made of aramid fibers and then diffused out of the central tensile line 100, A waterproof layer 110 may be further included on the surface of the center tensile line 100 in order to prevent penetration of the center tensile wire 100 into the core 200. Here, the waterproof layer 110 may be formed by laying a waterproof tape having elasticity or by coating a waterproof polymer.

The optical unit 200 includes an optical fiber ribbon laminate 210 in which a plurality of optical fiber ribbons 211 are stacked in a ribbon form, that is, a plurality of optical fibers arranged in a line are coated with UV curable resin or the like, 220, respectively.

Here, the optical fiber constituting the optical fiber ribbon 211 has a double cylindrical structure in which a portion called a core in the center is surrounded by a portion called cladding around the core, A glass optical fiber made of silica having a high refractive index is used and the cladding is made of silica glass or synthetic resin having a refractive index relatively lower than that of the core so that light passing through the center is totally reflected And transmits the signal.

A multimode optical fiber having a diameter of several micrometers of the core of the optical fiber is classified as a single mode optical fiber and a multimode optical fiber having a diameter of several tens of micrometers is classified as a stepped or a hill type optical fiber according to a refractive index distribution of the core. The outer diameter of the optical fiber may be, for example, 200 占 퐉 or 250 占 퐉.

The number of optical fibers included in one optical fiber ribbon 211 may vary depending on the data transmission efficiency and the flexibility of the cable per unit time of the optical cable. For example, the number of the optical fibers may be 4 to 24, 8 < / RTI > The width and height of the optical fiber ribbon and the outer diameter of the optical fiber may differ depending on the number of the optical fibers. For example, the width of the optical fiber ribbon may be 2.0 mm to 2.2 mm.

 In addition, from the viewpoint of increasing the optical density of the optical cable, the height and width of the optical fiber ribbon 211 are advantageously small. However, when designing the optical fiber ribbon 211, the mechanical characteristics of the optical fiber and the problem of handling during connection must be taken into account. Therefore, the size of the optical fiber ribbon 211 must be determined.

The optical fiber ribbon laminate 210 may be formed by laminating the above-described optical fiber ribbons 211 in a plurality of layers. The number of layers of the optical fiber ribbon forming the optical fiber ribbon laminate 210 may vary depending on the data transmission efficiency of the optical cable per unit time, the flexibility of the cable, etc. For example, If the number of optical fibers included is eight, the number of layers of the optical fiber ribbon forming the optical fiber ribbon laminate 210 may be 4 to 8, preferably 6.

The tube 220 forming the optical unit 200 is usually made of a plastic resin such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), polyamide (PA) And may be a polypropylene (PP) tube in consideration of compatibility with a jelly compound, which will be described later, as a waterproof material that can be filled in an empty space in the tube 220.

The tube 220 is generally cylindrical in shape and has a through hole, which is a space in which the optical fiber ribbon laminate 210 can be received. Preferably, the tube 220 is formed with a color coating layer colored in different colors from the outside, so that the tube 220 can be easily classified according to functions and actions of the optical units 200, And can be configured to facilitate discrimination.

The outer diameter / inner diameter and the thickness of the tube 220 are determined according to the dimensions of the optical fiber ribbon laminate 210 accommodated in the tube 220, the mechanical strength and the bending property required in the optical cable, For example, the thickness of the tube 220 may preferably be 0.53 to 0.62 millimeters (mm).

The hollow space inside the tube 220 in which the optical fiber ribbon laminate 210 is accommodated may be filled with a waterproofing material. The waterproofing material may include, for example, a jelly compound, a waterproof powder, a waterproofing yarn, and the like.

The waterproofing material functions to prevent moisture permeating the inside of the optical cable from penetrating into the optical fiber ribbon laminate 210 in the tube 220 and further to prevent the water from penetrating into the optical fiber ribbon laminate 210 are stably flowed so as to suppress the stress applied to the optical fiber ribbon laminate 210 due to the friction between the inner wall of the fragrance tube 220 and the optical fiber ribbon laminate 210, Function.

The jelly compound that can be used as the waterproof material may be a polymer resin having excellent thermal stability, water resistance, electrical insulation, etc., a mixture of a base oil and a gelling agent, and in particular, a jelly compound composed of a mixture of a base oil and a gelling agent Since the viscosity is low and the removal is easy, the workability for connection with the connection box is excellent. In particular, since the density is about 0.2 to 0.5 g / cm 3, preferably about 0.4 to 0.5 g / cm 3, The weight can be reduced by 10 to 15%, which is advantageous for reducing the weight of the optical cable.

The jelly compound composed of a mixture of the base oil and the gelling agent may further include a microsphere having a specific gravity of 0.023 to 0.028 in order to achieve a low viscosity and a low density, 0.1 to 1.6 parts by weight of a pour point depressant.

Stress is applied to the optical fiber ribbon laminate 210 of the optical units 200 included in the optical cable due to various load conditions that may occur in the manufacturing process of the optical cable and the installation environment such as elongation, bending, twist, etc., Disconnection, degradation of characteristics, and the like may be caused.

Therefore, in order to allow the length of the optical unit 200 and the optical fiber ribbon laminate 210 included therein to compensate for the strain of the optical cable due to the stress generated by bending of the optical cable, (200) can be gathered about the center tensile strength (100) by SZ twist, helical twist, and the like.

In this case, the optical units 200 can maintain a twisted state at a predetermined pitch. The pitch of the optical unit 200, which is twisted at such a pitch, is expanded by bending of the optical cable, , The outer diameter of the optical cable, the bending radius, and the like.

In addition, since the individual optical fibers are independent of the routed tube optical cable in which the single optical fiber core wire is mounted, the ribbon-shaped optical cable does not receive much influence of bending, while the optical fiber ribbon 211 in which several optical fibers are arranged in a row is mounted Upon bending, each optical fiber has a different strain rate, which has an adverse effect on optical loss.

In other words, the optical fiber is tensioned on the upper side with respect to the neutral axis inside the tube 220, and the lower side is compressed. Therefore, the optical fiber must remain uniformly within a pitch of the tube 220 in which the tensioned portion and the compressed portion are collected, The strain of the optical fiber ribbon laminate 210 can be reduced and optical signal loss occurring due to the impact of the optical fiber ribbon laminate 210 on the inner wall of the tube 220 can be prevented.

Accordingly, not only the tube 220 constituting the optical unit 200 but also the optical fiber ribbon laminate 210 accommodated therein can be maintained in a twisted state at a constant pitch, and the optical fiber ribbon laminate 210, The twist pitch of the tube 220 may be appropriately selected in consideration of the twist pitch of the tube 220, the inner diameter of the tube 220, the dimensions of the optical fiber ribbon laminate 210, and the like.

Particularly, the ribbon-shaped optical cable according to the present invention has a ratio (L / Di) of the diagonal length L of the optical fiber ribbon laminate 210 to the inner diameter Di of the tube 220 in the optical unit 200 ) To a predetermined range, thereby suppressing the stress applied to the optical fiber ribbon laminate 210 and optical signal loss caused thereby, and at the same time, it is possible to minimize the increase of the outer diameter (Dc) and the weight of the optical cable . A detailed description thereof will be described later with reference to Table 1.

The outer jacket 300 may be made of a polyethylene resin having excellent water resistance, electrical insulation, acid resistance, alkali resistance and thermal stability, and having excellent moldability, particularly a midium density polyethylene (MDPE) Polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), ethylenetetrafluoroethylene (ETFE), or the like, or combinations thereof.

The thickness of the outer jacket 300 may be appropriately selected depending on the use of the optical cable, specifically, the total outer diameter of the optical cable, the required flexibility, the bending property, and the like, and may be, for example, 1.3 to 1.7 millimeters 1, an embodiment according to the present invention to be described later is an example in which the thickness of the outer jacket 300 is 1.5 millimeters (mm).

In addition, the outer jacket 300 may include a stripe 700 of a specific color on the surface thereof, and the stripe 700 may perform a function of identifying the manufacturer of the optical cable.

The ribbon-shaped optical cable according to the present invention may further include a waterproof layer 400 inside the outer jacket 300. The waterproof layer 400 contacting the optical unit 200 of the two waterproofing layers 400 may be formed by horizontally laying a metal tape such as aluminum foil on the outside of the optical fiber unit 210 or formed by a transparent film or a non- And a function of suppressing penetration of moisture penetrated through the damaged portion of the outer jacket 300 into the optical cable, as well as a function of covering the outside of the optical unit 200, So that the outer jacket 300 can be formed.

The waterproof layer 400 contacting the outer jacket 300 of the two waterproof layers 400 may be formed by attaching a water swellable tape made of a material such as a nonwoven fabric to the optical unit 200, And it is possible to achieve not only a function of suppressing penetration of moisture penetrated through the damaged portion of the outer jacket 300 into the optical cable but also a function of achieving close adhesion with the polymer resin constituting the outer jacket 300 have.

In the ribbon-shaped optical cable according to the present invention, a bedding material made of a waterproof material such as a jelly compound, a waterproof powder, and a waterproof yarn 500 is filled in an empty space between the outer jacket 300 and the optical unit 200 .

Particularly, the waterproof yarn 500 is formed between the outer jacket 300 and the optical unit 200, in particular, between a pair of adjacent optical units 200 of the optical unit 200, A waterproof yarn that can be inserted between the unit 200 and the center tensile line 100 and is made of a waterproof yarn in which the waterproof powder is attached to the continuous yarn or a waterproof yarn in which the waterproof powder is processed into an actual shape and is made by twisting or bonding the continuous yarn, Available.

The waterproof yarn 500 may have a thickness of 300 to 3,000 denier, a swelling capacity of 20 g / g or more, and a tensile strength of 3 to 150 N in distilled water. If the thickness of the waterproof yarn is less than 300 denier, an excessively large number of waterproof yarns 500 are required to achieve waterproof performance, which is not only difficult to work but also causes an increase in the price of the optical cable. If the waterproof yarn 500 has a blowing capacity of less than 20 g / g, it may be difficult to achieve the desired waterproof performance. If the tensile strength is less than 3 N, It is possible to cause disconnection due to the stress generated at the time of bending.

The ribbon-shaped optical cable according to the present invention may further include at least one rib cord 600 under the outer jacket 300. The rib cord 600 is used for facilitating the peeling of the outer jacket 300, and may also function as an additional tensile cord for improving the tensile strength of the optical cable.

The optical unit shown in Fig. 2 (b) is an embodiment in which the ribbon width (a) (mm) is about 2.1 millimeters (mm) and the height of the ribbon stack (h) (mm) is about 1.8 millimeters (mm). Therefore, the ribbon laminate is arranged in a rectangular shape with a small difference in width and height in the circular tube, and there is a certain amount of free space in order to minimize the physical stress caused by the contact of the optical fiber of each corner area with the inner surface of the tube Can be estimated. This clearance can be determined by the deviation of the diagonal length L of the ribbon tube laminate 210 with respect to the tube inner diameter Di. However, if the car is made larger, the diameter of the tube becomes larger and the amount of jelly or the like to be filled in the tube increases, which may cause a problem that the diameter and the weight of the cable increase. Therefore, as described later, the relationship between the tube inner diameter Di and the diagonal length L of the ribbon tube laminate 210 should be appropriately determined.

The weight per length of the ribbon-shaped optical cable according to the present invention is preferably not more than 260 Kg / Km.

FIGS. 3 and 4 show cross-sectional structures according to another embodiment of the ribbon-shaped optical cable according to the present invention.

As shown in FIG. 3, the ribbon-shaped optical cable according to the present invention includes five optical units 200 disposed around one central tensile line 100, a '1 + 6' structure having one intervening 800 And may be a '1 + 6' structure having four optical units 200 and two interposers 800 disposed around one central tensile line 100, as shown in FIG.

The intervening member 800 shown in FIGS. 3 and 4 can be applied in place of the optical unit 200 according to a predetermined outer diameter at the time of manufacturing the optical cable, can have an outer diameter corresponding to the outer diameter of the optical unit 200, Lightweight and inexpensive polymer resin such as polyethylene, polypropylene and the like in terms of weight reduction of the optical cable and reduction of manufacturing cost.

[Example]

1. Manufacturing Example

Ribbon tubular optical cable specimens according to the examples and comparative examples were produced with the constitutions described in Table 1 below. Although the first, second, and first comparative examples have a "1 + 6" structure in which six optical units 200 are disposed around the center tensile line 100, And can be replaced with the object of reducing the weight of the optical cable and the manufacturing cost in accordance with demands.

2. Property evaluation

1) Evaluation of optical signal loss

Optical signal loss test of a 1550 nm wavelength was performed at room temperature (23 ° C) for ribbon tube type optical cable specimens according to each of the examples and comparative examples, and whether or not the loss value is 0.35 dB / km or less is judged.

2) Temperature test

The ribbon-shaped optical fiber specimen according to each of the examples and the comparative examples was subjected to heat treatment at room temperature (23 占 폚), 24 hours at -40 占 폚, 24 hours at 70 占 폚, 24 hours at -40 占 폚 for 24 hours, ° C), the optical signal loss test was performed at a wavelength of 1550 nm for each temperature change step. The difference between the optical signal loss value at each temperature change step and the optical signal loss value at room temperature (23 ° C) 0.1 dB / km or less, the difference between the optical signal loss value after application of the entire temperature change cycle and the optical signal loss value at room temperature (23 ° C) was 0.2 dB / km or less.

The results of the physical property evaluation are shown in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 rescue 1 + 6 1 + 6 1 + 6 1 + 6 Number of optical units 6 6 6 6 Optical fiber outer diameter (㎛) 250 탆 250 탆 250 탆 250 탆 Number of optical fibers per ribbon 8 8 8 8 Fiber optic strand per ribbon stack 48 48 48 48 Total number of optical fibers 288 288 288 288 Ribbon laminate
Diagonal length (L) (mm) 2.766 2.766 2.766 2.766 Ribbon stack height (h) (mm) 1.8 1.8 1.8 1.8 Ribbon width (a) (mm) 2.1 2.1 2.1 2.1 Ribbon Height (mm) 0.3 0.3 0.3 0.3 Bore size (Di) (mm) 3.7 3.3 4.0 3 Tube OD (Do) (mm) 4.9 4.4 5.3 4.0 Tube thickness (t) (mm) 0.6 0.55 0.65 0.5 Di-L (mm) 0.934 0.534 1.234 0.234 Ribbon laminate
Diagonal length (L) (mm) /
Bore size (Di) (mm) 0.748 0.838 0.691 0.922 Ribbon laminate area (a * h) / tube inner area (S) 0.352 0.442 0.301 0.535 Outer jacket thickness (mm) 1.5 1.5 1.5 1.5 Cable OD (mm) 18.6 16.8 19.8 15.8 Room temperature loss value (1550 nm) (dB / km) 0.27 0.3 0.27 0.47 Weight per cable length (kg / km) 250 205 275 193 Temperature test (-40 to 70 degrees) Good Good Good Bad

In the ribbon-shaped optical cable according to the present invention, when the optical fiber ribbon 211 is composed of eight 250 탆 outer diameter optical fibers, the width of the optical fiber ribbon 211 is 2.0 mm to 2.2 mm, The length L of the diagonal of the optical fiber ribbon laminate 210 may be 2.7 to 2.8 millimeters and the outer diameter of the optical cable may be 16 to 19 millimeters.

According to the evaluation results of the embodiments shown in Table 1, in Examples 1 and 2, conditions such as the signal loss value according to the required physical stress, the temperature test, the cable outer diameter, and the weight per cable length are satisfied, Comparative Example 1 and Comparative Example 2 are examples in which some of the above conditions are satisfied but other conditions are not satisfied or the outer diameter or weight is excessively increased.

The main object of the present invention is to minimize the outer diameter, weight and the like of the cable. The object of the invention is to satisfy the loss value condition and the temperature test condition due to the physical stress of the optical fiber.

Particularly, the conditions related to the loss value are related to the physical stresses that the ribbon laminate receives inside the tube and can be seen to be related to the amount of spatial clearance inside the tube in which the ribbon laminate is disposed.

Specifically, in Comparative Example 1, the loss value in a 1-kilometer (Km) test of an optical signal having a wavelength of 1550 nanometers (nm) satisfies 0.27 (dB / km) with a loss value of 0.35 (dB / The temperature test was also satisfactory, but the weight per 1 Km of the cable was close to 275 kilograms (Kg), which means that one of the objects of the present invention can not be achieved in weight reduction. It can be seen from Example 1 and Example 2 that the weight per 1 Km of a suitable cable satisfying the room temperature loss value condition and the temperature test converges to about 200 kilograms (Kg) to 260 kilograms (Kg).

Comparative Example 2 shows that the light weight of the cable is achieved but the loss value in the 1 Km test of the optical signal of the wavelength of 1550 nanometers is 0.47 dB / / km), the loss value condition was judged to be defective, and the temperature test was also judged to be defective.

This is because the loss value and the temperature test can not be satisfied when the clearance inside the tube is small, that is, when the diagonal length L (mm) / bore (Di) It is understood that the normal use required by the user is impossible.

In order to achieve the object of the present invention, the ratio (L / Di) of the diagonal length L of the optical fiber ribbon laminate 210 to the inner diameter Di of the tube 220, It is possible to suppress the stress applied to the optical fiber ribbon laminate 210 and the optical signal loss caused thereby and to minimize the increase of the outer diameter Dc and the weight of the optical cable Can be predicted.

Specifically, in order to prevent optical signal loss from occurring in the optical unit 200, there is a certain deviation between the inner diameter Di of the tube 220 and the diagonal length L of the optical fiber ribbon laminate 210 , The number of optical fibers constituting the ribbon or ribbon laminate may be variously changed. Therefore, in order not to cause optical signal loss due to each physical stress, the deviation also increases with the size of the ribbon laminate and the outer diameter of the tube .

As shown in Table 1, when the width, the height and the diagonal length of the ribbon laminate are the same, the inner diameter of the tube is 3.0 to 4.0 millimeters (mm) in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 ).

The ratio L / Di of the diagonal length L of the optical fiber ribbon laminate 210 to the inner diameter Di of the tube 220 is about 0.7 to 0.85 It can be confirmed through various examples including Example 1 and Example 2 that the object can be achieved. It can also be confirmed that the inner diameter of the tube should be in the range of about 3.1 to 3.9 millimeters (mm).

The ratio L / Di of the diagonal length L of the optical fiber ribbon laminate 210 can be also explained by the ratio of the cross sectional area of the optical fiber ribbon laminate 210 to the tube internal area S.

That is, from the viewpoint of the area, it can be confirmed that the ribbon (laminate area (a * h) / inner tube area (S)) should satisfy the range of about 0.37. That is, the area occupied by the optical fiber tube laminate among the tube internal area S should be about 34% to about 45%, and it is about 0.34 (34%) in consideration of the diameter and weight increase of the optical cables according to the embodiments of the present invention. ) To about 0.45 (45%).

That is, when [the laminate area (a * h) / the inner tube area S] is about 34% or less, it means that the free space is increased in the tube part. However, if it is more than 45%, it means that the space in the tube is small. Therefore, the loss value condition or the temperature test is performed by the stress due to the edge of the ribbon laminate and the inner surface of the tube and friction. It can be concluded that it can not be satisfied.

Similarly, when six ribbons of eight optical fibers shown in FIG. 2 are stacked to form a light unit with a ribbon laminate, the inner diameter Di of the tube 220 and the inner diameter Di of the optical fiber ribbon laminate 210 It can be confirmed that the above loss value condition or the temperature test is satisfied when the difference Di-L of the diagonal length L is 0.5 to 1.0 millimeter (mm).

That is, in Comparative Example 1, the difference (Di-L) of the diagonal length (L) relative to the inner diameter Di of the upper tube has a very large value of 1.234 and the ratio of the diagonal length (L) L / Di is decreased to 0.691, a space margin is generated. However, the weight per length of the cable is greatly increased. In the comparative example 2, the difference Di- L is 0.234 and the ratio L / Di of the diagonal length L to the inner diameter Di of the tube is 0.922, which is close to 1. Thus, unlike the first and second embodiments, It means that the space in which the tube stack can not move is very narrow. In this case, when the optical cable is bent or the like, it can be confirmed that the tube can be contacted or compressed with the inner wall surface of the tube to cause loss of the optical signal.

On the other hand, in the case of Embodiments 1 and 2 in which the above conditions are satisfied, the ribbon-shaped optical cable according to the present invention, in which six ribbons composed of eight optical fibers having an outer diameter of 250 탆 are stacked to form a light unit with a ribbon laminate, The maximum loss value of the optical signal loss test at a wavelength of 1550 nm at 23 ° C is measured as 0.27 dB / km or 0.30 dB / km, which is less than 0.35 dB / km, so that the room temperature loss value is satisfied.

In this case, it can be seen that the outside diameter of the optical cable is converged to about 16 to 19 millimeters (mm).

As shown in Table 1, it can be understood that the optical cable according to Comparative Example 2 can reduce the diameter of the cable, but the void space inside the tube is too narrow to satisfy the loss of room temperature of the optical cable due to physical stimulation have.

In summary, the optical cables of Examples 1 and 2 according to the present invention have a ratio (L / Di) of the diagonal length (L) of the optical fiber ribbon laminate to the inner diameter Di of the tube constituting the optical unit, Is an optimized range that satisfies the relationship of 0.7 to 0.85, thereby achieving good room temperature optical signal loss value and temperature test result, while minimizing the outer diameter and weight of the optical cable.

The optical unit shown in Fig. 2 (b) is an embodiment in which the ribbon width (a) (mm) is about 2.1 millimeters (mm) and the height of the ribbon stack (h) (mm) is about 1.8 millimeters (mm). Therefore, the ribbon laminate is arranged in a rectangular shape with a small difference in width and height in the circular tube, and there is a certain amount of free space in order to minimize the physical stress caused by the contact of the optical fiber of each corner area with the inner surface of the tube Can be estimated.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. . It is therefore to be understood that the modified embodiments are included in the technical scope of the present invention if they basically include elements of the claims of the present invention.

100: center tension line 200: optical unit
300: outer jacket 400: waterproof layer
500: Waterproof yarn 600: Lip cord
700: stripe 800: intervening

Claims (25)

A center tensile line disposed in the center;
A plurality of optical units arranged around the central tensile line and having a plurality of optical fiber ribbon laminates in which a plurality of ribboned optical fiber ribbons composed of a plurality of optical fibers are stacked in a tube; And
And an outer jacket surrounding the outside of the optical unit,
Wherein a ratio (L / Di) of a diagonal length (L) of the optical fiber ribbon laminate to an inner diameter Di of the tube constituting the optical unit is 0.7 to 0.85. The method according to claim 1,
Wherein the outside diameter of the optical cable is 16 to 19 millimeters (mm). 3. The method of claim 2,
Wherein the weight per unit length of the optical cable is 200 to 260 kg / km. 4. The method according to any one of claims 1 to 3,
Wherein the optical fiber has an outer diameter of 240 to 260 占 퐉. 4. The method according to any one of claims 1 to 3,
Wherein the optical fiber ribbon comprises eight optical fibers. 4. The method according to any one of claims 1 to 3,
Wherein the number of the optical units is six. 4. The method according to any one of claims 1 to 3,
Wherein a difference between an inner diameter (Di) of the tube constituting the optical unit and a diagonal length (L) of the optical fiber ribbon laminate is 0.5 to 1.0 millimeter (mm). 4. The method according to any one of claims 1 to 3,
Wherein the loss value of the optical signal loss test at a wavelength of 1550 nm at room temperature is 0.35 dB / km or less. 4. The method according to any one of claims 1 to 3,
Wherein the ratio of the area of the optical fiber tube stack to the inner area of the tube is 0.34 to 0.45. 10. The method of claim 9,
And the outer side of the optical unit is taped with a waterproof tape. 11. The method of claim 10,
Wherein a waterproof yarn is provided between a pair of adjacent optical units of the optical unit or between the optical unit and the center tensile line. 4. The method according to any one of claims 1 to 3,
And at least one rib cord is provided inside the outer jacket. 4. The method according to any one of claims 1 to 3,
Wherein the center tension line is taped with a waterproof tape. 4. The method according to any one of claims 1 to 3,
Wherein the optical fiber ribbon is composed of eight optical fibers and the width of the optical fiber ribbon is 1.9 to 2.3 millimeters and the length L of the diagonal of the optical fiber ribbon stack is 2.7 to 2.8 millimeters, Wherein the outer diameter of the ribbon-shaped optical cable is 16 to 19 millimeters (mm). 4. The method according to any one of claims 1 to 3,
Wherein a difference between an inner diameter (Di) of the tube and a diagonal length of the optical fiber ribbon laminate is 0.5 to 1.0 millimeter (mm). 4. The method according to any one of claims 1 to 3,
Wherein the tube of the optical unit is filled with a low-density jelly compound having a density of 0.2 to 0.5 g / cm < 3 >. 17. The method of claim 16,
The low-density jelly compound includes a base oil, a gelling agent, and a microsphere having a specific gravity of 0.023 to 0.028, and 0.1 to 1.6 parts by weight of a pour point depressant based on 100 parts by weight of the base oil. Optical cable. 4. The method according to any one of claims 1 to 3,
Wherein the tube of the optical unit has a thickness of 0.53 to 0.62 millimeters (mm). 4. The method according to any one of claims 1 to 3,
Wherein the thickness of the outer jacket is 1.3 to 1.7 millimeters (mm). A center tensile line disposed in the center;
Six optical units arranged around the center tensile line and each having an optical fiber ribbon laminate in which six ribbon-shaped optical fiber ribbons composed of eight optical fibers are stacked in a tube; And
And an outer jacket surrounding the outside of the optical unit,
(L / Di) of the diagonal length (L) of the optical fiber ribbon laminate to the inner diameter (Di) of the tube constituting the optical unit is 0.7 to 0.85, and the optical signal loss test Is less than or equal to 0.35 dB / km, and the total optical cable has an outer diameter of 16 to 19 millimeters (mm). 21. The method of claim 20,
Wherein the width of the optical fiber ribbon is 1.9 to 2.3 millimeters and the length L of the diagonal of the optical fiber ribbon laminate is 2.7 to 2.8 millimeters. 22. The method according to claim 20 or 21,
Wherein the inner diameter of the tube of the optical unit is 3.1 to 3.9 millimeters (mm). 22. The method according to claim 20 or 21,
Wherein the tube of the optical unit has a thickness of 0.53 to 0.62 millimeters (mm). 22. The method according to claim 20 or 21,
Wherein the ratio of the area of the optical fiber tube stack to the inner area of the tube is 0.34 to 0.45. 22. The method according to claim 20 or 21,
Wherein a difference between an inner diameter (Di) of the tube and a diagonal length of the optical fiber ribbon laminate is 0.5 to 1.0 millimeter (mm).

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