JP2007316404A - Optical fiber cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cord which can improve bending tolerance of the optical fiber cord and which can be applied to a bending part with a smaller bending radius than required in securing an optical fiber strength. <P>SOLUTION: The optical fiber cord 11 is characterized in that the a part or the entirety of the optical fiber cord is provided with a two-dimensional spread and that optical fibers 12 are disposed in a two-dimensional surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides an optical fiber cord that can be installed even in a place where it is required to bend the optical fiber cord with a small bending radius when laying the optical fiber cord in a narrow area. The present invention relates to an optical fiber cord corresponding to a small bending diameter.

Conventional optical fiber cords are mainly concentrically coated around an optical fiber. At present, optical fiber strands used for communication are mainly made of glass material, so if bent with a small radius, the mechanical strength deteriorates with time, and eventually breaks with a certain probability (for example, Non-patent document 1).
Therefore, in order not to bend the optical fiber at a radius less than a certain value, the thickness of the coating is increased, for example, the thickness of the coating is set to a predetermined radius or more, and the bending radius is constant. I have devised it to be more than the value. As another method, there is a method in which a curve guide member in which the bending radius of the optical fiber cord is a certain value or more is arranged in a portion where the optical fiber cord is curved.

Kenichi Nishimura and Hidetoshi Shirakawa “Easy Fiber Optic Communication (Revised 3rd Edition)” The Telecommunications Association, May 17, 1999 p. 69-70

  In the conventional method, the thickness of the coating is increased or the bending radius is secured by a guide member as a means for ensuring a bending radius of a certain value or more. An optical fiber cord could not be installed in a narrow place where a radius is required.

  The present invention has been made in view of the above-described circumstances. A part or all of an optical fiber cord has a two-dimensional extension, and an optical fiber is disposed in a two-dimensional plane. An object of the present invention is to provide an optical fiber cord that can improve the bending tolerance of the fiber cord and can be applied to a bending portion smaller than a bending radius required for securing the strength of the optical fiber.

  In order to achieve the above object, an optical fiber cord of the present invention is characterized in that a part or all of an optical fiber cord has a two-dimensional extension, and an optical fiber is arranged in a two-dimensional plane. It is what.

  In the optical fiber cord of the present invention, part or all of the optical fiber cord is formed in a polygonal plate shape, and an optical fiber strand is disposed on a diagonal line of the polygonal plate shape or a line substantially parallel to the diagonal line. It is characterized by that.

  According to the present invention, another optical fiber cord is connected to one end or both ends of the optical fiber cord.

  Further, the present invention is characterized in that an optical fiber cord connector is attached to one end or both ends of the optical fiber cord.

  The optical fiber cord of the present invention has a two-dimensional extension in a part or all of the optical fiber cord, and the optical fiber strand is arranged in a two-dimensional plane so that the substantial length of the optical fiber strand is reduced. Increase the length of the optical fiber cord so that the bending per unit length of the optical fiber is smaller than when the optical fiber is connected at the shortest distance even when the optical fiber cord is bent. Therefore, an optical fiber cord having a small bending radius can be realized to improve the bending tolerance of the optical fiber cord, and an optical fiber cord applicable to a bending portion smaller than the bending radius required for securing the optical fiber strength can be obtained. Can be provided.

  Therefore, optical fiber cords can be installed in confined spaces such as places where large bends are required and places where small bend radii are necessary. Can be spread.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1A is a side view showing an optical fiber cord according to the first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line WW ′ of FIG. As shown in FIGS. 1A and 1B, the optical fiber cord 11 is entirely formed in a rectangular plate shape, and an optical fiber strand is placed on a line substantially parallel to the diagonal line of the rectangular plate-like optical fiber cord 11. 12 is embedded and disposed.

  That is, the entire optical fiber cord 11 is spread two-dimensionally, the optical fiber 12 is disposed in a two-dimensional plane, and the substantial length of the optical fiber 12 is increased. Even when the surface of the cord 11 is bent, the bending radius per unit length of the optical fiber 12 can be made smaller than the state where the optical fiber is connected at the shortest distance. An optical fiber cord 11 that can improve the bending tolerance of the optical fiber cord 11 by realizing a small optical fiber cord 11 and can be applied to a bending portion smaller than a bending radius required for ensuring the strength of the optical fiber is provided. can do.

  It should be noted that the optical fiber cord is not limited to a rectangular plate shape, but can be implemented in the same manner even if it is formed in a polygonal plate shape. Further, the optical fiber strand may be disposed on a diagonal line of the optical fiber cord.

  Next, when the wide optical fiber cord 11 having a rectangular plate shape is bent in the thickness direction, the optical fiber strand 12 incorporated in the optical fiber cord 11 is bent in a spiral shape, thereby the optical fiber strand. It will be described below that the bending radius applied to 12 is smaller than the bending radius applied in the thickness direction of the optical fiber cord 11.

FIG. 2A is a configuration diagram for explaining the function and effect of the optical fiber cord according to the first embodiment of the present invention, and FIG. 2B shows the function and effect of the optical fiber cord according to the comparative example. It is a block diagram for doing. As shown in FIG. 2B, the bending radius is a considering that the optical fiber 22 is wound around a cylinder 21 having a radius a along the periphery of the cross section perpendicular to the central axis. However, as shown in FIG. 2A, when the optical fiber 24 is spirally wound around a cylinder 23 having a radius a, the angle of winding on the central axis of the cylinder 23 is φ, and the length on the central axis. Is b, the bending radius r applied to the optical fiber 24 is given by the following equation.
r = a (1+ (b / aφ) ² ) …………………… (1)

  Therefore, the bending radius r applied to the optical fiber 24 increases as the length b on the central axis increases with respect to the winding angle φ. When the surface of the cylinder 23 is flattened, the optical fiber 24 is disposed on a line substantially parallel to the diagonal line with the winding start end and the winding end of the optical fiber 24 being in the vicinity of the diagonal. Become. By converting this state into an optical fiber cord, an optical fiber cord in which the built-in optical fiber 24 is bent with a bending radius larger than the bending radius in the thickness direction of the optical fiber cord can be realized.

  For example, if an optical fiber strand is arranged diagonally on a wide rectangular plate-shaped optical fiber cord having an aspect ratio of 1: 1, and the optical fiber cord is bent at a radius R in the thickness direction, the optical fiber strand is actually The bending radius applied to is 2R from the equation (1). Conversely, if the allowable radius of the optical fiber is AR, the rectangular plate-shaped optical fiber cord having an aspect ratio of 1 can be bent to a radius of AR / 2 with respect to the thickness direction. Application to a place where a smaller bending radius is required becomes possible.

  FIG. 3 is a side view showing an optical fiber cord according to the second embodiment of the present invention. As shown in FIG. 3, the optical fiber cord 11 is formed in a rectangular plate shape, and an optical fiber strand 12 is embedded and disposed on a line substantially parallel to the diagonal line of the rectangular plate-like optical fiber cord 11. . The other ends of the optical fiber cord 11 are connected to other optical fiber cords 13 not corresponding to the small bending diameter. That is, the optical fiber cord 11 which is a part of the optical fiber cords 11 and 13 has a two-dimensional extent, and the optical fiber 12 is disposed in a two-dimensional plane.

  In addition, you may make it connect the other optical fiber cord which does not respond | correspond to a small bending diameter only to the one end of a polygonal plate-shaped optical fiber cord.

  FIG. 4 is a side view showing an optical fiber cord according to the third embodiment of the present invention. As shown in FIG. 4, the optical fiber cord 11 is formed in a rectangular plate shape, and an optical fiber strand 12 is embedded and disposed on a line substantially parallel to the diagonal line of the rectangular plate-like optical fiber cord 11. . The other ends of the optical fiber cord 11 are connected to other optical fiber cords 14 not corresponding to the small bending diameter. The optical fiber cord 14 is formed such that one end is connected to the entire end face of the optical fiber cord 11 and the other end is formed in a cylindrical line shape. The flat shape is gradually deformed from one end to the cylindrical line portion. It is formed in a shape. That is, the optical fiber cord 11 which is a part of the optical fiber cords 11 and 14 has a two-dimensional extent, and the optical fiber 12 is disposed in a two-dimensional plane.

  In addition, you may make it connect the other optical fiber cord which does not respond | correspond to a small bending diameter only to the one end of a polygonal plate-shaped optical fiber cord.

  FIG. 5 is a side view showing an optical fiber cord according to the fourth embodiment of the present invention. As shown in FIG. 5, the optical fiber cord 11 is formed in a rectangular plate shape, and an optical fiber strand 12 is embedded and disposed on a line substantially parallel to the diagonal line of the rectangular plate-like optical fiber cord 11. . The other ends of the optical fiber cord 11 are connected to other optical fiber cords 14 not corresponding to the small bending diameter. An optical fiber cord connector 15 is attached to each of the optical fiber cords 14. By attaching the optical fiber cord connector 15 to both ends of the optical fiber cords 11 and 14 in advance, the connection work with other optical fiber cords can be simplified.

  The optical fiber cord connector 15 may be attached only to one end of the optical fiber cords 11 and 14. It is also possible to attach optical fiber cord connectors directly to one or both ends of the wide optical fiber cord 11. Further, the optical fiber 12 does not need to be fixed in the wide optical fiber cord 11, and the optical fiber 12 has the same length as the length between the diagonal points of the wide optical fiber cord 11. It is possible to obtain the effect. Moreover, in FIGS. 1-5, a dotted line shows an optical fiber strand.

  As described above, since an optical fiber cord with a small bending radius can be realized, for example, when it is necessary to lay an optical fiber cord across a room, when a hole cannot be made in a wall, a gap in a door or window is used. However, it is possible to use such a narrow space with the optical fiber cord of the present invention.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

(A) is a side view which shows the optical fiber cord concerning the 1st Embodiment of this invention, (b) is the WW 'sectional view taken on the line of (a). (A) is a block diagram for demonstrating the effect of the optical fiber cord which concerns on the 1st Embodiment of this invention, (b) is the structure for demonstrating the effect of the optical fiber cord which concerns on a comparative example. FIG. It is a side view which shows the optical fiber cord which concerns on the 2nd Embodiment of this invention. It is a side view which shows the optical fiber cord which concerns on the 3rd Embodiment of this invention. It is a side view which shows the optical fiber cord which concerns on the 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Optical fiber cord, 12 ... Optical fiber strand, 13 ... Optical fiber cord, 14 ... Optical fiber cord, 15 ... Optical fiber cord connector, 21 ... Cylinder, 22 ... Optical fiber strand, 23 ... Cylinder, 24 ... Optical fiber strand.

Claims (4)

  An optical fiber cord characterized in that a part or all of the optical fiber cord has a two-dimensional extent and an optical fiber is disposed in a two-dimensional plane.   A part or all of an optical fiber cord is formed in a polygonal plate shape, and an optical fiber strand is disposed on a diagonal line of the polygonal plate shape or a line substantially parallel to the diagonal line. .   An optical fiber cord, wherein another optical fiber cord is connected to one or both ends of the optical fiber cord according to claim 1 or 2.   An optical fiber cord, wherein an optical fiber cord connector is attached to one end or both ends of the optical fiber cord according to any one of claims 1 to 3.

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