Optical fiber structure for road surface installation and method for installing the same

Abstract

An optical fiber structure 10 for road surface installation includes: a protective member 11 that extends in the longitudinal direction and has a bottom surface 11a, a top surface 11c that is a predetermined height from the bottom surface 11a, and a cavity 22f that is formed in the longitudinal direction between the bottom surface 11a and the top surface 11c; an adhesive layer 12 that is formed from an adhesive on the bottom surface 11a; and an optical fiber 13 accommodated in the cavity 11f. The cavity 11f has an opening 11e in the top surface and the optical fiber 11 accommodated in the cavity 11f can be extracted via the opening 11e.

Description

Technical Field

[0001] The present disclosure relates to a fiber optic structure for road surface laying and a laying method thereof.

Background Art

[0002] An optical fiber cable that connects between a user and equipment of a receiving station to provide services to the user is installed on the ground or on a utility pole. Many of the optical fiber cables installed on the ground are laid by being buried underground. To lay an optical fiber cable underground, it is necessary to deeply dig the ground, install the optical fiber cable in the dug trench, and then refill the trench with soil after installing the optical fiber cable. Patent Document 1 discloses a technique for laying an optical fiber cable by burying it underground.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in order to lay an optical fiber cable underground, much of the work is spent on the process of digging a trench on the ground and the process of refilling the trench after installing the optical fiber cable in the trench. The work burden is large, and the cost for laying the optical fiber cable is also high.

[0005] The present disclosure is proposed in view of the above circumstances, and an object thereof is to provide a fiber optic structure for road surface laying and a laying method thereof that can reduce the work burden of laying an optical fiber cable on the ground and also reduce the cost.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, the optical fiber structure for road surface installation according to this disclosure includes a protective member that extends in the longitudinal direction and has a bottom surface, a top surface having a predetermined height from the bottom surface, and a cavity formed in the longitudinal direction between the bottom surface and the top surface, an adhesive layer formed on the bottom surface with adhesive, and an optical fiber housed in the cavity.

[0007] The method for laying a road surface optical fiber structure involves fixing the bottom surface of the road surface optical fiber structure, which includes a protective member extending in the longitudinal direction and having a bottom surface, a top surface at a predetermined height from the bottom surface, and a cavity formed in the longitudinal direction between the bottom surface and the top surface, an adhesive layer formed by adhesive on the bottom surface of the protective member, and optical fibers housed in the cavity, to the road surface with the adhesive layer. [Effects of the Invention]

[0008] According to this disclosure, the burden of laying fiber optic cables on the ground can be reduced, and costs can also be lowered. [Brief explanation of the drawing]

[0009] [Figure 1] This is an overhead view of a fiber optic cable structure for road surface installation. [Figure 2] This is a cross-sectional view of a fiber optic structure for road surface installation. [Figure 3] This is a cross-sectional view showing a road surface-mounted optical fiber structure. [Figure 4] This is an overhead view of a modified example of a road surface optical fiber structure. [Figure 5] This is a cross-sectional view of a key part of a modified optical fiber structure for road surface installation, showing the area near the tearing cord. [Modes for carrying out the invention]

[0010] The embodiments of the optical fiber structure for road surface installation and the method for installing the same will be described in detail below with reference to the drawings. In this embodiment, the road surface is assumed to be a paved outdoor surface such as a road, but it is not limited to this and may be an unpaved outdoor surface, or even an indoor floor surface.

[0011] Figure 1 is an overhead view of the road surface optical fiber structure 10. Figure 2 is a cross-sectional view of the road surface optical fiber structure 10. The cross-sectional view in Figure 2 shows section II-II, which is perpendicular to the longitudinal direction in which the road surface optical fiber structure 10 extends in the overhead view of Figure 1.

[0012] The road surface laying optical fiber structure 10 comprises a protective member 11, an adhesive layer 12 formed on the bottom surface 11a of the protective member 11, and an optical fiber 13 housed in a cavity 11f formed in the protective member 11. The protective member 11 extends in the longitudinal direction and has a bottom surface 11a, a top surface 11c having a predetermined height from the bottom surface, and a side surface 11b formed between the bottom surface 11a and the top surface 11c. The front side of Figure 1 shows the end surface 11g of the road surface laying optical fiber structure 10. As shown in Figure 2, the cross-sectional shape of the protective member 11 forms an isosceles trapezoid with the bottom surface 11a as the lower base, the top surface 11c as the upper base, and the side surface 11b as the hypotenuse, with the lower base being longer than the upper base. However, the cross-sectional shape of the protective member 11 is not limited to an isosceles trapezoid.

[0013] The protective member 11 has a cavity 11f extending in the longitudinal direction and having a predetermined diameter between its bottom surface 11a and top surface 11c. The cavity 11f has an opening 11e on the top surface 11c. As shown in Figure 2, in a cross-section perpendicular to the longitudinal direction of the road surface laying optical fiber structure 10, the cavity 11f may be located directly below the center of the top surface 11c, and the opening 11e may be formed in the center of the top surface 11c.

[0014] An adhesive layer 12 of a predetermined thickness is formed on the bottom surface 11a of the protective member 11. The adhesive layer 12 may be formed by applying adhesive or by attaching an adhesive film.

[0015] An optical fiber 13 is housed in the cavity 11f of the protective member 11. The optical fiber 13 extends longitudinally through the cavity 11f and is composed of, for example, a core 13a, cladding 13b, primary sheathing 13c, and secondary sheathing 13d. The optical fiber 13 shown is merely housed in the cavity 11f and is not fixed to the cavity 11f. The optical fiber 13 has only a single core 13a, but may have multiple cores. Furthermore, the sheathing of the core 13a and cladding 13b is not limited to two layers such as primary sheathing 13c and secondary sheathing 13d, but may be one layer or three or more layers.

[0016] The protective member 11 is made of a resin such as polyvinyl chloride or high-density polyethylene so that it can withstand contact and stepping by people or vehicles when installed on the road surface and protect the optical fiber 13 housed in the cavity 11f. The protective member 11 is not limited to resin; it may also be made of a metal such as iron or stainless steel.

[0017] Figure 3 is a cross-sectional view showing the road surface optical fiber structure 10 laid on the road surface. The road surface optical fiber structure 10 can be laid by adhering an adhesive layer 12 to the road surface 100 and fixing the bottom surface 11a of the protective member 11 to the road surface 100. When the road surface optical fiber structure 10 is laid on the road surface 100, the optical fiber 13 housed in the cavity 11f of the protective member 11 can be taken out of the protective member 11 through the opening 11e.

[0018] According to this embodiment, laying optical fibers on the road surface 100 only requires adhering the adhesive layer 12 of the road surface laying optical fiber structure 10 to the road surface 100 and fixing the protective member 11 to the road surface 100, thus reducing the burden of laying work. Furthermore, since no labor is required for laying, costs can also be reduced. In the road surface laying optical fiber structure 10, the optical fiber 13 is housed in the cavity 11f inside the protective member 11, so even if the road surface laying optical fiber structure 10 is touched or stepped on by people or vehicles, the optical fiber 13 will not bend or twist.

[0019] FIG. 4 is a plan view of a fiber optic structure for road surface laying according to a modified example. The fiber optic structure 20 for road surface laying according to the modified example is different from the fiber optic structure 10 for road surface laying according to the present embodiment shown in FIGS. 1 and 2 in that, instead of the cavity 11f opening to the top surface 11c, a slit string 11j for forming an opening by splitting the protection member 11 is embedded in a portion between the top surface 11c of the protection member 11 and the cavity 11f.

[0020] Specifically, the cavity 11f of the fiber optic structure 20 for road surface laying according to the modified example has a regular hexagon in which the cross-sectional contour has at least a predetermined diameter, and one pair of opposing surfaces within the surface forming the cavity 11f is parallel to the bottom surface 11a and the top surface 11c. Referring to the cross-sectional view of the main part of FIG. 5 showing the vicinity of the slit string 11j, a pair of slit strings 11j extending longitudinally to a predetermined depth from the top surface 11c are embedded at a predetermined interval in a portion between the top surface 11c of the protection member 11 and the cavity 11f. Further, perforations 11k are formed from the top surface 11c toward the slit string 11j. Other structures of the modified example are the same as those of the fiber optic structure 10 for road surface laying according to the present embodiment, and corresponding reference numerals are assigned to corresponding components to clarify the correspondence.

[0021] Also in the modified example, the method of laying the fiber optic structure 20 for road surface laying on the road surface is the same as the method of laying the fiber optic structure 10 for road surface laying according to the present embodiment shown in FIG. 3. That is, the adhesive layer 12 of the fiber optic structure 20 for road surface laying according to the modified example is adhered to the road surface 100, and the bottom surface 11a of the protection member 11 is fixed to the road surface 100.

[0022] In a modified example, to remove the optical fiber from the road surface-laying optical fiber structure 20, the protective member 11 is removed by scraping along the perforations 11k formed from the top surface 11c of the protective member 11 toward the tear string 11j until the tear string 11j is reached. Once the protective member 11 is removed down to the tear string 11j, the protective member 11 is torn by pulling the tear string 11j, forming an opening of a cavity 11f in the top surface 11c. In a modified example, the protective member 11 is made of a resin such as polyvinyl chloride or high-density polyethylene so that it can be removed from the top surface 11c down to the tear string 11j and then torn by the tear string 11j. Through the opening 11e thus formed, the optical fiber 13 stored in the cavity 11f of the protective member 11 can be removed from the cavity 11f.

[0023] In the modified example, as in this embodiment, laying the optical fiber on the road surface only requires adhering the adhesive layer 12 of the modified road surface laying optical fiber structure 20 to the road surface 100 and fixing the protective member 11 to the road surface 100, thus reducing the burden of laying work. Furthermore, since no labor is required for laying, costs can also be reduced.

[0024] In the modified road surface optical fiber structure 20, the optical fiber 13 is housed in the cavity 11f inside the protective member 11. Therefore, even if people or vehicles come into contact with or step on the road surface optical fiber structure 20, the optical fiber 13 will not bend or twist. Furthermore, in the modified version, the optical fiber is formed in a closed cavity 11f without an opening formed in the protective member 11. Therefore, even when installed on an outdoor road surface, soil, sand, rainwater, etc., will not flow into the cavity and affect the optical fiber. [Explanation of Symbols]

[0025] 10. Optical fiber structure for road surface installation 11 Protective member 11a Bottom 11c top surface 11e aperture 11f hollow 12 Adhesive layer 13 Optical Fiber

Claims

1. A protective member extending in the longitudinal direction, having a bottom surface, a top surface having a predetermined height from the bottom surface, and a cavity formed in the longitudinal direction between the bottom surface and the top surface, The bottom surface has an adhesive layer formed by an adhesive, The optical fiber stored in the cavity and Includes, The top surface has an opening formed in the longitudinal direction at the upper end of the cavity, The cavity has a shape that is substantially circular in a cross-section perpendicular to the longitudinal direction, and whose upper part connects to the top surface. The optical fiber can be removed from the opening to the outside of the protective member. The protective member further includes a tearing string embedded between the cavity and the top surface so as to tear the portion between the cavity and the top surface, allowing the cavity to open to the top surface. Optical fiber structure for road surface installation.

2. The protective member is perforated from the top surface toward the tearing string, as described in claim 1, for the road surface laying optical fiber structure.

3. A road surface laying optical fiber structure includes a protective member extending in the longitudinal direction and having a bottom surface, a top surface having a predetermined height from the bottom surface, and a cavity formed in the longitudinal direction between the bottom surface and the top surface, an adhesive layer formed by adhesive on the bottom surface of the protective member, and an optical fiber housed in the cavity, which is fixed to the road surface by the adhesive layer. The top surface has an opening formed in the longitudinal direction, The cavity has a shape that is substantially circular in a cross-section perpendicular to the longitudinal direction, and whose upper part connects to the top surface. The optical fiber can be removed from the opening to the outside of the protective member. The protective member further includes a tear-off string embedded in the portion between the top surface and the cavity, The protective member is cut with the aforementioned tearing string to open the cavity on the top surface. The optical fiber is removed from the aforementioned open cavity. Method for laying optical fiber on road surfaces.

4. The method for laying optical fiber on a road surface according to claim 3, wherein the protective member is perforated from the top surface toward the tearing string, and the protective member is removed along the perforations until the tearing string is reached.

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