JPH11295565A - Coated optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably cover and hold a bar code sheet after mounting and to relatively easily perform the work of opening a vertical cut and forcibly putting it on a coated optical fiber further by turning the tension yield elongation and flexural rigidity of a transparent plastic tube to the ones within a specified range. SOLUTION: The tension yield elongation of the plastic tube (t) is turned to the one within the range of 30-300% and the flexural rigidity is turned to the one within the range of 5.0-10.0 kilogram f.square millimeter. When an extension yield elongation rate is low, the bar code sheet S can not be stably held. On the other hand, when the extension yield elongation rate is high, the coating of the bar code sheet S becomes incomplete and the possibility of exposing a part of both ends of the bar code sheet S becomes large. Also, wrinkles are locally generated on the bar code sheet S when the flexural rigidity is less than 5.0 kilogram f.square millimeter and opening from the vertical cut Y becomes difficult when the flexural rigidity exceeds the 10.0 kilogram f.square millimeter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the addition of a core identification code to an optical fiber core.
The present invention relates to the addition of an identification code for managing the connection status of a core in a telephone exchange, and the use of a barcode as the identification code makes it possible to clearly and easily use a barcode on an extremely thin optical fiber cable. In addition, the protection and holding of the barcode display by the transparent plastic tube can be easily added, and the protection and holding of the barcode display by the transparent plastic tube can be ensured, and the durability can be improved. This makes it possible to easily and quickly mount the transparent plastic tube on the optical fiber.

[0002]

2. Description of the Related Art Many optical fiber cores (including single cores, multiple cores, and cords) are gathered together and formed into cables, and each optical fiber core is numbered at its connection end. Is performed, and the core connection state management of the intra-office wiring is performed by this numbering. By the way, the cord diameter has been further reduced in order to improve the aggregation density of the optical fiber core cord, and the cord diameter has been 1.7 to 2.0 mm, but has recently become 1 mm. This makes it very difficult to directly print a clear numbering that can be visually identified on the outer surface of the optical fiber core, and the aggregation density of the optical fiber core is significantly increased, and the number of numbering is reduced. Has become a very difficult issue as to how to number them for identification. This is the current state of the art for identifying optical fibers in office wiring. On the other hand, the former problem is a limitation problem by directly printing the numbering on the thin optical fiber, and the latter problem is a problem of how to use the numbering identification method in order to cope with an increase in the number to be identified. It is. Both problems can be solved at once if a barcode is printed on a sheet and can be used as an identification symbol of the optical fiber. This is because the bar code is printed on the sheet, so it is not related to the reduction in the diameter of the optical fiber core, and if this is read by a contact bar code reader, it is sufficiently identified even if the optical fiber core is thin. The number that can be identified by the barcode is infinite. By the way, the following two problems exist when a barcode is printed on a sheet and an identification method using the barcode is adopted. The first is how to efficiently and accurately fix the sheet on which the barcode is printed to the surface of the ultrafine optical fiber, and the second is how to read the barcode by a contact type barcode reader (bar). How to prevent the display surface from being damaged due to repeated rubbing of the code printing surface).
Damage to the bar code display can result in erroneous readings and serious consequences of misconnection. About adopting the identification method based on the barcode printed on the above sheet,
It is necessary to devise a mounting method so that the barcode-printed sheet can be easily, easily and accurately fixed to the optical fiber core wire, and the barcode display surface can be effectively prevented from being scratched. There is something that has been an issue. This is covered with the barcode printed sheet vertically attached to the optical fiber core, the back surface is adhered to the optical fiber core and wound once, and the transparent plastic tube is overlaid on the barcode printed surface. This is fitted and covered. The above-mentioned transparent plastic tube is fitted to and fixed to the optical fiber core wire by making the transparent plastic tube into a C-shaped cross section and forcibly fitting it into the optical fiber core wire. Hereinafter, this prior art is shown in FIGS.
This will be described with reference to FIG. The sheet S on which the barcode is printed (hereinafter, referred to as a “barcode sheet”) may be paper, synthetic paper, or a polymer film, but has a width b of 15 mm, a length L of 82 mm, and a length of The barcode M of 63 mm is displayed. In order to facilitate handling such as winding around the optical fiber core and cutting off the extra length, it is desirable that the material be relatively strong. The barcode sheet S has a barcode printing layer 2 on the surface of a sheet body 1, an adhesive layer 3 on the back surface, and a release paper 4 laminated on the adhesive layer 3. For example, each optical fiber core wire f is separated from the end of the optical fiber tape cord, the release paper 4 is removed, and a barcode sheet S is vertically attached and wound once. In this state, the barcode sheet S is temporarily fixed to the optical fiber core wire f by the adhesive layer 3.
In a state where the barcode sheet S is wound once and temporarily fixed, a transparent plastic tube t having a diameter smaller than the optical fiber core wire f is formed into a plastic tube having a C-shaped cross section, and a longitudinal cut Y is formed. It is opened and forcibly fitted to the optical fiber core f. Fix optical fiber core wire to jig V
In this state, the cut Y at one end of the C-shaped tube is widened, and the optical fiber core f is pushed in from the cut Y so that the tube can be relatively easily forcibly fitted. Can be done. The diameter of the optical fiber core wire f is 1 mm, and the thickness of the barcode sheet S is 0.1 mm.
mm, the outer diameter in a state where this is wound once is about 1.2 mm. The plastic tube t is a transparent body made of polyolefin, and has an inner diameter of 1.0 mm and a thickness of 0.5 mm. The plastic tube t is
This is for firmly fixing the barcode sheet S to the optical fiber core wire with its own elasticity and protecting the barcode display surface. In response to this functional requirement,
In order to improve the handleability for forcibly fitting, it is desirable to have the above-mentioned thickness. When the barcode sheet S is wound around the optical fiber core f and the plastic tube t is forcibly fitted thereon, the plastic tube t is fixed to the optical fiber core by the elastic contraction force. After fixing the plastic tube t, a connector is connected to the end of each optical fiber core wire f. By reading the bar code display on the bar code sheet S wound around the optical fiber core f with a contact bar code reader, the identification symbol of each optical fiber core can be reliably determined. The above is an example of the prerequisite technology of the present invention, but the above-mentioned transparent plastic tube, that is, the transparent covering tube, must be capable of stably covering the barcode sheet S after being mounted and not being able to securely hold the barcode sheet S. In addition, it is desired that the operation of enlarging the vertical cut Y and forcibly fitting the optical fiber core f with the optical fiber core f can be performed easily and easily.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention is to provide a cover tube for a bar code sheet according to the prior art described above, which is capable of stably covering and holding the bar code sheet S after the tube is attached, with its elasticity and rigidity. It is still another object of the present invention to make it possible to relatively easily perform the operation of enlarging the vertical cut Y and forcibly fitting the optical fiber core f.

[0004]

A first measure taken to solve the above-mentioned problem is that the tensile yield elongation of the plastic tube is in the range of 30 to 300%. A second solution is that the bending rigidity of the plastic tube is within a range of 5.0 to 10.0 kgf · square millimeter.

[0005]

[Operation] If the tensile yield elongation is small, the plastic deformation that occurs when the plastic tube is expanded is large,
Therefore, the holding force of the plastic tube on the barcode sheet S is small. Therefore, the barcode sheet S cannot be stably held. On the other hand,
When the tensile yield elongation is large, the plastic deformation generated when the plastic tube is expanded is small (or zero). Therefore, there is no problem of a decrease in the holding power to the barcode sheet S, but the tensile yield elongation is large. Plastic has a greater tendency to shrink over time, which can lead to shrinking length and incomplete coating of the barcode sheet, exposing parts of both ends of the barcode sheet. Becomes larger. Above is the large tensile yield elongation,
This is a general tendency due to small. When the tensile yield elongation of the plastic tube is less than 30%, the former problem is remarkable and therefore a practical problem, and when it exceeds 300%, the latter problem is remarkable and therefore a practical problem. On the other hand, when it is within the range of 30 to 300%, both of the above problems remain within a range that does not hinder practical use. The above results are shown in Tables 1 and 2.

[Table 1]

[Table 2] If the bending rigidity of the plastic tube is less than 5.0 kilograms f · square millimeter, the tube is relatively soft, and therefore, it is easy to expand the tube and fit it on the optical fiber core. When the optical fiber tube is bent at the portion in the fitted state, the vertical cut Y of the tube is opened, and the tube is bent and buckled locally, causing wrinkles inside the bend. Wrinkles are locally generated in the sheet, and the resilience of the tube is poor, so that the working time until the plastic tube is restored after covering and completely covers the barcode sheet is lengthened, The work of fitting the plastic tube to the barcode sheet becomes slow. On the other hand, if the bending stiffness exceeds 10.0 kilograms f · square millimeter, the plastic tube is so rigid that it is difficult to spread out from the vertical cut Y, so that the tube is fitted to the optical fiber core. When the optical fiber tube is bent with the time taken and also fitted,
The tube is bent and cracked, and the bending of the optical fiber tube becomes large near both ends of the tube (the radius of curvature is reduced), which tends to reduce the transmission efficiency of the optical fiber core. Is generated. The above is the general tendency due to the large and small rigidity of the plastic tube (hereinafter simply referred to as “tube”). When the bending stiffness of the tube is less than 5.0 kgf · square millimeter, the former problem is remarkable and is a practical problem. When it exceeds 10.0 kgf · square millimeter, the latter problem is remarkable and the tube is practically used. It is a problem. However, when the bending stiffness of the tube is in the range of 5.0 to 10.0 kilograms f · square millimeter, both of the above problems remain within a range that does not hinder practical use. Table 3 shows the above results.

[Table 3] In addition, "5.0." And "10.
"0" does not have a critical significance, but defines a range that does not hinder practical use from the qualitative correlation between the above problem and the magnitude of the tensile yield elongation as described above. .

[0006]

Embodiment 1 A thickness of 0.1 mm was applied to an optical fiber having a wire diameter of 1 mm.
mm barcode sheet once and wrap it around
mm, an outer diameter of 2 mm, and a length (A) of 50 mm, a polyethylene tube was fitted and fixed. The tensile yield elongation of the polyethylene tube is about 150% (however, J
The tube was evaluated in place of the test piece of ISK7113, and the tensile speed at that time was 50 mm / m.
in ± 20%). Its bending stiffness is 9.
0 kilogram f · square millimeter. As shown in FIGS. 5 (a) and 5 (b), the test method in this specification is such that a test piece, for example, an optical cord is bent in a U-shape by being sandwiched between upper and lower parallel planes, and its reaction force W is measured. Calculate the bending stiffness from the formula. (Two-point bending method) If (interval between both planes)-(cord outer diameter) is defined as bending interval D, bending rigidity EI can be obtained by the following equation. EI = 0.3483WD ²

[0007]

Embodiment 2 A thickness of 0.1 mm is applied to an optical fiber having a wire diameter of 1 mm.
mm barcode sheet was wound once, and a polyethylene tube having an inner diameter of 1.3 mm, an outer diameter of 2.0 mm, and a length (A) of 50 mm was fitted thereon and fixed. The tensile yield elongation of this tube is about 100% (however, J
The tube was evaluated in place of the test piece of ISK7113, and the tensile speed at that time was 50 mm / m.
in ± 20%). Its bending stiffness is 6.
0 kilogram f · square millimeter.

[0008]

[Comparative Example 1] A thickness of 0.1 mm was applied to an optical fiber having a wire diameter of 1 mm.
A barcode sheet having a diameter of 1.3 mm, an outer diameter of 2.0 mm, and a length (A) of 50 mm was fitted onto the polyamide C-shaped tube and fixed. The tensile yield elongation percentage of the polyamide tube is about (20)% (however, it was evaluated using the tube of this test example instead of the test piece of JIS K7113, and the tensile speed at that time was 50 mm / min ± 20%). Its bending stiffness is 8.0 kilograms f · square millimeter.

[0009]

[Comparative Example 2] A thickness of 0.1 mm was applied to an optical fiber core wire having a wire diameter of 1 mm.
mm barcode sheet, and the inside diameter is 1.3
A polyethylene C-shaped tube having an outer diameter of 2.0 mm, an outer diameter of 2.0 mm and a length (A) of 50 mm was fitted and fixed. The tensile yield elongation percentage of the polyethylene tube is 100% (however, it was evaluated using the tube of this test example instead of the test piece of JIS K7113, and the tensile speed at that time was 50 mm / min ± 20%). What you did). Its bending stiffness is 12 kgf · square millimeter.

[0010]

[Test Results] The test results for the above Examples and Comparative Examples are as follows. Tube mounting speed Number of tubes mounted per 20 minutes of working time / 1 person Example 1 19 Example 2 20 Comparative Example 1 19 Comparative Example 2 13 Shrinkage of tube after mounting Average of all test pieces Shrinkage rate Example 1 0% Example 2 0% Comparative example 1 0% Comparative example 2 0% Number of tubes that did not hold the sheet well after mounting Example 10 0/10 Example 2 0/10 Comparative example 1 2/10 Comparative example 2 0/10 Bending test result with a radius of curvature of 50 mm over a length of 300 mm (wrinkled tube) (increase in cord loss (0.02 dB or more) Example 1 0/10 0/10 Example 2 0/10/10 0/10 Comparative Example 1 0/10 0/10 Comparative Example 2 0/10 2 pieces / 10 pieces plastic The tensile yield elongation of the resin, the stiffness varies in various ways. With many resins, it is possible to achieve a tensile yield elongation of 30-300% and a bending stiffness of 5.0-10.0 kilograms f · square millimeter. The bending rigidity largely depends on the thickness and diameter of the tube in addition to the rigidity of the plastic resin itself. Any plastic resin can be used as long as it has the transparency required for a barcode reader and the appropriate tensile yield elongation and bending rigidity.

[0011]

[Effect] As described above, a barcode is printed on a sheet in advance, the sheet is wrapped around an optical fiber, and a transparent plastic tube is forcibly fitted and fixed. It is fixed to the optical fiber core and protects the bar code display surface, so the bar code display can be easily and easily added to the optical fiber core, and the bar code display is reliably protected from scratches. In addition, the operation of fitting a thin plastic tube to a thin optical fiber can be easily and quickly performed. In addition, wrinkles and cracks in the tube are eliminated, the protection and holding of the barcode sheet are ensured, and the barcode display can be read accurately and reliably by the contact barcode reader for a long period of time.

[Brief description of the drawings]

FIG. 1 is a plan view of a barcode sheet.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of the prior art.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5A is a side view showing a bending rigidity test method in the present specification, and FIG. 5B is a view showing an attached state of the optical cord in the above item (A).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sheet body 2 ... Printing layer (barcode printing layer) 3 ... Adhesive layer 4 ... Release paper S ... Barcode sheet (sheet which printed barcode) M ... Bar Code display (bar code) Y ... cut f ... optical fiber core wire t ... transparent plastic tube

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiji Ohashi 1440 Mutsuzaki, Sakura City, Chiba Prefecture Inside the Fujikura Sakura Plant (72) Inventor Yoshitaka Enomoto 3-192-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd.

Claims (2)

[Claims] 1. A barcode-printed sheet is covered vertically with an optical fiber core wire, and the back surface is adhered to the optical fiber core wire and wound once, and a transparent plastic tube is superimposed on the barcode printed surface. An optical fiber core wire covered and covered, wherein the tensile yield elongation of the transparent plastic tube is in the range of 30 to 300%. 2. A barcode-printed sheet is vertically covered on an optical fiber core wire, the back surface is adhered to the optical fiber core wire and wound once, and a transparent plastic tube is superimposed on the barcode printed surface. An optical fiber core wire covered and covered with the transparent plastic tube having a bending stiffness within a range of 5.0 to 10.0 kgf · square millimeter.