JP4030800B2 - Optical fiber sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber sheet, and more particularly, to an optical fiber sheet in which an optical fiber cord is formed by protecting an extension portion of an optical fiber wired inside the sheet with a tensile fiber and a protective tube.
[0002]
[Prior art]
As shown in FIG. 4, in the optical fiber sheet 3 in which the optical fiber 2 is wired between the two upper and lower sheets 1 and 1 bonded together, the portion where the optical fiber 2 extends outside the sheet 1 (hereinafter, “ In the case where the optical fiber cord 5 in which the optical fiber 2 is coated with the protective tube 4 is used as the optical fiber cord 5, the distal end portion 4 a of the protective tube 4 is accommodated inside the sheet 1 and is retained. ing.
When the optical connector 6 is attached to the optical fiber 2, the optical connector 6 is required to have the same tensile strength as that of the optical connector attached to the optical fiber cord with a tensile fiber such as aramid yarn. is there. In such a case, the tensile strength required for the optical connector 6 cannot be obtained with the optical fiber cord 5 simply covered with the protective tube 4 as shown in FIG.
[0003]
Therefore, in order to increase the tensile strength of the optical fiber cord, as shown in FIG. 5, an optical fiber cord 8 in which the optical fiber 2 is accommodated in a protective tube 4 together with a tensile strength fiber 7 such as an aramid yarn is used.
When such an optical fiber cord 8 in which the tensile strength fiber 7 is attached to the optical fiber 2 is used, the structure as shown in FIGS. 6 and 7 is used as a structure for securing the tip 4 a of the protective tube 4 to the sheet 1. Can be mentioned.
In this optical fiber sheet 9, the distal end portion 4 a of the protective tube 4 is accommodated inside the sheet 1, and the tensile fiber 7 exposed from the protective tube 4 is disposed on the lower sheet 1 together with the optical fiber 2. The upper sheet 1 is bonded on top.
[0004]
[Problems to be solved by the invention]
In the optical fiber sheet 9, although the tensile strength of the optical fiber cord 8 itself can be secured, the upper and lower sheets are formed by combining the tensile fiber 7 composed of a very thin number of fibers and the optical fiber 2 thicker than the tensile fiber 7 together. There is a problem that even if the sheets 1 and 1 are bonded together, a sufficiently strong adhesive force cannot be obtained between the upper and lower sheets 1 and 1.
In addition, when the tensile strength fiber 7 and the optical fiber 2 are mixed, the tensile strength fiber 7 is in direct contact with the optical fiber 2 or due to a gap that is slightly generated between the optical fiber 2 and the sheet 1 due to the presence of the optical fiber 2. In some cases, the tensile strength fiber 7 is not sufficiently firmly adhered and fixed between the upper and lower sheets 1 and 1. Therefore, there is also a problem that the tensile strength fiber 7 is not sufficiently fastened to the sheet 1, that is, the optical fiber cord 8 is not sufficiently strong.
Further, if the tensile strength fibers 7 are bundled and enter under the optical fiber 2 when the optical fiber 2 is wired, the optical fiber 2 may be bent due to the influence, and the bending loss of the optical fiber 2 may increase.
[0005]
The present invention has been made in view of the above circumstances, and an optical fiber cord in which an optical fiber is inserted into a protective tube together with a tensile fiber is used as an extension portion of the optical fiber wired between two sheets. In such a case, there is no risk that the adhesive strength of the two sheets will be insufficient, and the optical fiber cord can be firmly held on the sheet by firmly holding the tensile fiber inside the sheet. An object of the present invention is to provide an optical fiber sheet that does not cause problems such as bending of an optical fiber wired inside.
[0006]
[Means for Solving the Problems]
According to the present invention, an optical fiber cord tip in which an optical fiber is housed in a protective tube together with a tensile fiber and an optical fiber exposed from the optical fiber cord tip are sandwiched between a pair of lower sheet and upper sheet. An auxiliary sheet is affixed on the optical fiber wired to the lower sheet, and the tensile fiber exposed from the protective tube is disposed on the auxiliary sheet. the upper sheet is pasted on the tensile strength fibers, the distal end portion of the protective tube, the are arranged to ensure a distance L between the outer end portion of the auxiliary sheet, so as to fill the tensile strength fiber The provided adhesive layer also extends between the end of the auxiliary sheet and the tip of the protective tube disposed away from the auxiliary sheet. Serial the optical fiber which is located between the auxiliary sheet and the protective tube is embedded, to provide an optical fiber sheet being fixed.
The separation distance L is preferably 5 mm or more.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
1 is a partially cutaway plan view showing an embodiment of the optical fiber sheet of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG.
In the figure, reference numeral 11 is an optical fiber sheet of this embodiment, 1 is a sheet, 2 is an optical fiber, 7 is a tensile fiber, 8 is an optical fiber cord, 12 is an auxiliary sheet, and the optical fiber sheet 11 is an optical fiber cord. 8 end portions (specifically, the front end portion 4a of the protective tube 4 of the optical fiber cord 8), the optical fiber 2 and the tensile fiber 7 exposed from the front end of the optical fiber cord 8, two sheets 1, 1, It has a schematic structure that is sandwiched and fixed by an auxiliary sheet 12 disposed between the two sheets 1 and 1.
In this embodiment, in FIGS. 2 and 3, the lower side is described as “lower” and the upper side is described as “upper”.
[0008]
The optical fiber cord 8 is an optical fiber cord in which the optical fiber 2 is housed in a protective tube 4 together with a tensile fiber 7 such as an aramid yarn. However, in this embodiment, the optical fiber 2 accommodated in the protective tube 4 is used that is accommodated in a thin protective tube 2a.
The optical fiber 2 accommodated in the optical fiber cord 8 is not particularly limited. For example, a bare fiber coated with an ultraviolet curable resin, a so-called 250 μm outer UV strand, and silicon coated silicon Wire is used. Furthermore, if necessary, an optical fiber core, an optical fiber cord further strengthened with this protective coating, an optical fiber tape core, a carbon coated fiber further strengthened with this protective coating, and the like can be used.
As the material of the protective tubes 2a and 4 of the optical fiber cord 8, nylon, Hytrel (trademark of Toray DuPont) or the like can be used.
[0009]
The two sheets 1, 1 are upper and lower layers of the outermost layer of the optical fiber sheet 11, and are flexible resin sheets having flexibility in which an adhesive is applied on one side. The material and thickness of the sheet 1 are appropriately selected in consideration of Young's modulus according to required workability, scratch resistance, bending rigidity, tensile strength, and the like. Examples of the material of the sheet 1 include polyimide, polyethylene terephthalate, low density polyethylene, high density polyethylene, polypropylene, polyester, nylon 6, nylon 66, ethylene-tetrafluoroethylene copolymer, poly-4-methylterpene, and polyvinylidene chloride. , Plasticized polyvinyl chloride, polyetherester copolymer, ethylene-vinyl acetate copolymer, flexible polyurethane, and the like.
Furthermore, the combination of the material of the sheet | seat 1 is arbitrary, For example, the upper and lower sheets 1 and 1 can also be made into the same kind of material, or can also be made into the combination of a different kind of material.
The sheet 1 is coated with a rubber-based or acrylic room-temperature pressure-sensitive adhesive (adhesive) on one side in order to bond the upper sheet and the lower sheet when the optical fiber sheet 11 is manufactured. Yes.
[0010]
Here, as the auxiliary sheet 12, a sheet in which a pressure-sensitive adhesive is formed in a sheet shape is used. Alternatively, a flexible soft resin sheet in which a pressure sensitive adhesive is applied to both surfaces of a base material made of the same material as the sheet 1 can be used. However, it is desirable that the auxiliary sheet 12 is thinner than the upper and lower sheets 1 and 1.
[0011]
The distal end portion 4 a of the protective tube 4 of the optical fiber cord 8 is inserted into the sheet 1, and the tensile fiber 7 in the optical fiber cord 8 is exposed from the protective tube 4 by an appropriate length. Then, in the portion where the tensile strength fiber 7 is exposed, an auxiliary sheet 12 having an appropriate width is stuck on the lower sheet 1 from the optical fiber 2 disposed on the lower sheet 1. The tensile strength fibers 7 are arranged on the auxiliary sheet 12 so as not to be bundled, and the upper sheet 1 is attached to the auxiliary sheet 12 and the lower sheet 1 from above.
[0012]
In the distal end portion 4a of the protective tube 4, the upper and lower sheets 1 and 1 extend outward from the outer end portion 12a of the auxiliary sheet 12 (referring to the end portion on the side facing the distal end portion 4a of the protective tube 4). It is fixed so as to be sandwiched between the extended portions 13 which are the formed portions. However, the distal end portion 4 a of the protective tube 4 is disposed with a separation distance L between the outer end portion 12 a of the auxiliary sheet 12 and does not overlap the auxiliary sheet 12. In addition, the optical fiber 2 leaves the protective tube 2a from the tip part 4a of the protective tube 4 to the part arranged below the outer end part 12a of the auxiliary sheet 12, and removes the protective tube 2a in other parts. . The optical fiber 2 is fixed between the upper and lower sheets 1 and 1 so as to be sandwiched between the sheets 1 and 1.
[0013]
The separation distance L is appropriately set according to the number of cores and the size (outer diameter) of the optical fiber cord 8. For example, when the optical fiber cord 8 is a normal single-core cord, the separation distance L can be set in any way, but is preferably 5 mm or more. When the separation distance L is less than 5 mm, it is difficult for the adhesive to enter between the distal end portion 4 a of the protective tube 4 and the outer end portion 12 a of the auxiliary sheet 12. On the other hand, if the separation distance L is too long, the length of the tensile strength fiber 7 fixed by the adhesive between the upper sheet 1 and the auxiliary sheet 12 becomes longer, and the tensile strength fiber between the upper sheet 1 and the auxiliary sheet 12 becomes longer. 7 is not preferable because it takes time and effort for the arrangement process 7. Therefore, the separation distance L is set to an appropriate length so that these problems do not occur.
[0014]
The tensile strength fiber 7 is fixed in an embedded state in an adhesive layer 14 provided between the upper sheet 1 and the auxiliary sheet 12. The adhesive layer 14 is the optical fiber 2 positioned between the distal end 4a of the protective tube 4 of the optical fiber cord 8 and the distal end 4a of the protective tube 4 and the auxiliary sheet 12 (hereinafter also referred to as an embedded portion 2b). The tensile strength fiber 7, the distal end portion 4 a of the protective tube 4, and the embedded portion 2 b of the optical fiber 2 are integrally fixed to the sheets 1, 1 and the auxiliary sheet 12. As a result, the optical fiber cord 8 is adhesively fixed to the sheet 1 sufficiently firmly. In addition, a part of the adhesive layer 14 extends so as to slightly enter between the lower sheet 1 and the auxiliary sheet 12. That is, in the optical fiber sheet 11, the tensile fiber is formed by the adhesive layer 14 that extends from the region between the upper sheet 1 and the auxiliary sheet 12 to the region between the auxiliary sheet 12 and the lower sheet 1. 7, the optical fiber 2, and the tip 4 a of the protective tube 4 are integrally bonded and fixed to the upper and lower sheets 1, 1 and the auxiliary sheet 12. Yield) can be improved. In this embodiment, the portion of the optical fiber 2 embedded and fixed by the adhesive layer 14 is where the protective tube 2a is present, and therefore the adhesive layer 14 adversely affects the optical characteristics of the optical fiber 2. There is an advantage that can be prevented. Further, since the optical fiber 2 (embedded portion 2b) from which the protective tube 4 is removed is present between the auxiliary sheet 12 and the distal end portion 4a of the protective tube 4 in the length of the aforementioned separation distance L, the vicinity of the auxiliary sheet 12 Thus, when the optical fiber sheet 11 is bent, the embedded portion 2b is gently bent, so that local abrupt bending is hardly applied between the auxiliary sheet 12 and the distal end portion 4a of the protective tube 4. There are also advantages.
[0015]
Any adhesive can be used as the adhesive for forming the adhesive layer 14 as long as it is flexible even after curing. For example, an adhesive having a silyl group-containing special polymer as a main component (super X: trademark of Cemedine Co., Ltd.).
[0016]
Further, the optical fiber sheet 11 has a structure in which the optical fiber cord 8 has a structure in which the tensile fiber 7 is attached to the optical fiber 2 accommodated in the protective tube 4, and thus has a sufficient tensile strength.
Furthermore, since the tensile strength fiber 7 and the optical fiber 2 exist in different layers, a large number of extremely thin tensile strength fibers (for example, about 12 μm outer diameter in the case of aramid yarn) 7 and an optical fiber sufficiently thicker than this ( For example, in the case of a nylon core wire, there is no problem that the upper and lower sheets 1 and 1 are not sufficiently firmly adhered by mixing with an outer diameter of 0.9 mm.
Further, since the tensile strength fiber 7 is adhesively fixed between the auxiliary sheet 12 and the upper sheet 1 separately from the optical fiber 2, the tensile strength fiber 7 is in direct contact with the optical fiber 2 or the presence of the optical fiber 2. Therefore, the problem that the tensile strength fiber 7 is not sufficiently firmly adhered and fixed between the upper and lower sheets 1 and 1 does not occur. Therefore, the tensile strength fiber 7 is firmly and firmly fixed. As a result, the optical fiber cord 8 is firmly attached to the sheet 1.
[0017]
From the above, when the optical connector is attached to one end of the optical fiber cord 8 of the optical fiber sheet 11 of this embodiment, as in the optical fiber sheet 3 shown in FIG. The tensile strength required for the optical connector attached to the cord 8 can be sufficiently satisfied.
Further, since the tensile fiber 7 is arranged on the auxiliary sheet 12 after the optical fiber 2 is wired, there is a problem that the optical fiber 2 is bent due to the influence of the tensile fiber 7 when the optical fiber 2 is wired. Absent.
[0018]
In the above-described embodiment, the optical fiber 2 in the protective tube 4 is exemplified by a single-core optical fiber. However, in the optical fiber sheet of the present invention, a plurality of optical fibers are used. A multi-core optical fiber cord in which the fiber is inserted into the protective tube 4 together with the tensile strength fiber 7 can also be applied.
In the case of using a plurality of optical fibers, similarly to the case of using a single-core optical fiber, the plurality of optical fibers are wired on the lower sheet 1, and the auxiliary sheet 12 is pasted thereon, and this auxiliary fiber is attached. The tensile strength fiber 7 is disposed on the sheet 12, and then the upper sheet 1 is bonded.
[0019]
【The invention's effect】
As described above, in the optical fiber sheet of the present invention, the adhesive layer provided so as to embed the tensile strength fiber extends between the auxiliary sheet and the tip of the protective tube disposed away from the auxiliary sheet. In this adhesive layer, the optical fiber located between the auxiliary sheet and the protective tube is embedded and fixed, so that it adheres between the upper and lower sheets, between the upper sheet and the auxiliary sheet, and in the extension part. The agent layer is formed, and the tensile fibers and the optical fibers in the end portion and the extension portion of the protective tube are firmly and firmly fixed to the sheet. Therefore, the optical fiber cord is firmly attached to the sheet.
In addition, since the tensile strength fiber and the optical fiber are in different layers, there is no problem that the upper and lower sheets are not sufficiently firmly adhered by mixing the tensile strength fiber and the optical fiber.
In addition, since the tensile strength fiber is adhesively fixed between the auxiliary sheet and the upper sheet separately from the optical fiber, sufficiently strong adhesive fixing inside the tensile strength fiber sheet is possible, and the optical fiber cord is attached to the sheet. Detention is a strong source.
Furthermore, since the tensile strength fiber is held in a layer different from that of the optical fiber, there is no possibility of problems such as bending of the optical fiber due to the influence of the tensile strength fiber during wiring of the optical fiber.
Then, the protective tube is effectively prevented from coming off, and the optical fiber cord is firmly secured to the sheet together with the tensile strength fiber.
[Brief description of the drawings]
FIG. 1 is a partially cutaway plan view showing an embodiment of an optical fiber sheet of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
3 is a cross-sectional view taken along the line BB in FIG.
FIG. 4 is a schematic plan view showing an optical fiber sheet having a structure in which an extension portion of the optical fiber sheet is protected by a protective tube.
FIG. 5 is a schematic view showing a structure of an optical fiber cord in which a tensile strength fiber such as an aramid yarn is inserted into a protective tube together with an optical fiber.
FIG. 6 is a partially cutaway plan view showing a conventional optical fiber sheet.
7 is a cross-sectional view taken along the line CC of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sheet, 2 ... Optical fiber, 2b ... Buried part, 4 ... Protection tube, 4a ... Tip part, 7 ... Tensile fiber, 8 ... Optical fiber cord, 11 ... Optical fiber sheet, 12 ... Auxiliary sheet, 13 ... Extension part, 14 ... Adhesive layer

Claims (2)

An optical fiber cord tip in which an optical fiber is housed in a protective tube together with a tensile fiber and an optical fiber exposed from the optical fiber cord tip are fixed so as to be sandwiched between a pair of lower sheet and upper sheet . An optical fiber sheet,
An auxiliary sheet is affixed on the optical fiber wired to the lower sheet, the tensile fiber exposed from the protective tube is disposed on the auxiliary sheet, and the upper sheet is adhered on the tensile fiber, The tip portion of the protective tube is arranged with a separation distance L between the outer end portion of the auxiliary sheet and an adhesive layer provided so as to embed the tensile strength fibers is provided in the auxiliary sheet. And the optical fiber located between the auxiliary sheet and the protective tube is embedded in the adhesive layer. An optical fiber sheet characterized by being fixed. The optical fiber sheet according to claim 1, wherein the separation distance L is 5 mm or more.

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