JP4408589B2 - Optical fiber and laser apparatus including the same - Google Patents

Description

【００３２】
【発明の効果】
以上説明したように本発明によれば、光ファイバ本体の破断の有無あるいは位置等を容易にかつ安価に検出することができる。
【図面の簡単な説明】
【図１】本発明による光ファイバの一実施の形態を示す図。
【図２】本発明による光ファイバの他の実施の形態を示す図。
【図３】本発明による光ファイバのさらに他の実施の形態を示す図。
【図４】図３に示す光ファイバの変形例を示す図。
【図５】本発明による光ファイバのさらに他の実施の形態を示す図。
【図６】本発明による光ファイバが組み込まれて用いられるレーザ装置の一実施の形態を示す図。
【符号の説明】
１０ 光ファイバ
１１ 光ファイバ本体
１２，１４，１６，１８ 導電性被覆層
１３，１５，１７，１９ 絶縁性被覆層
２１ レーザ出力装置
２２，２３ コネクタ
２４ 入射機構
２５ 出射機構
２６ 検出装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber that transmits laser light, and more particularly, to an optical fiber that can easily and inexpensively detect the presence or absence of breakage and the position thereof, and a laser apparatus including the same.
[0002]
[Prior art]
In recent years, optical fibers have been widely used as transmission paths for transmitting laser light output from laser output devices. Such an optical fiber is often laid over a long distance as a transmission line for optical communication or the like. In that case, the optical fiber is mechanically broken by some external force at a position in the middle of the optical fiber. The possibility increases.
[0003]
[Problems to be solved by the invention]
However, the conventional optical fiber described above has a problem that when the optical fiber is broken, it is difficult to detect the presence or absence of the break, and it is difficult to estimate the position of the break.
[0004]
Japanese Patent Laid-Open No. 9-66384 proposes a method for attaching a breakage detection wire, a protective tube, and the like together with an optical fiber in a laser processing apparatus provided with the optical fiber. However, it is difficult to apply to an optical fiber having a long length, although it can be applied to an optical fiber having a short length as used in a laser processing apparatus. . Further, there is a problem that although the presence or absence of breakage can be detected, the position of breakage cannot be detected.
[0005]
The present invention has been made in consideration of such points, and an object of the present invention is to provide an optical fiber that can easily and inexpensively detect the presence / absence or position of breakage, and a laser device including the same. To do.
[0006]
[Means for Solving the Problems]
As a first solution, the present invention includes an optical fiber body that transmits laser light, and a conductive coating layer provided so as to cover the outer peripheral surface of the optical fiber body. Provide fiber.
[0007]
In addition, in the 1st solution means mentioned above, it is preferable to further provide the insulating coating layer provided so that the outer peripheral surface of the said conductive coating layer might be covered.
[0008]
As a second solution, the present invention includes an optical fiber main body for transmitting laser light, and a plurality of conductive coating layers provided so as to cover an outer peripheral surface of the optical fiber main body. The conductive coating layer is laminated via an insulating coating layer, and each of the conductive coating layers is electrically short-circuited with the other conductive coating layer on one end portion side of the optical fiber body and the other end Provided is an optical fiber characterized in that it is electrically open to another conductive coating layer on the part side.
[0009]
In the second solution described above, at least three conductive coating layers are provided as the plurality of conductive coating layers, and any set of adjacent conductive coatings among the at least three conductive coating layers. The electrical connection positions between the layers are preferably different from each other with respect to the length direction of the optical fiber body. Moreover, it is preferable to further comprise an insulating coating layer provided so as to cover the outer peripheral surface of the outermost conductive coating layer of the plurality of conductive coating layers.
[0010]
In the first and second solving means described above, the conductive coating layer is preferably formed of a material that melts by heat or a material whose physical characteristics change by heat. In addition, the conductive coating layer changes its physical characteristics by absorbing a material that melts by absorbing laser light transmitted through the optical fiber body or by absorbing laser light transmitted through the optical fiber body. It is preferably formed from a material. Furthermore, it is preferable that the conductive coating layer and / or the insulating coating layer be formed by applying a strip or applying a paint. Furthermore, it is preferable to further include an exposure member provided in the middle of the optical fiber body and exposing the conductive coating layer to the outside. Furthermore, it is preferable that the conductive coating layer and / or the insulating coating layer have elasticity that can cope with the bending of the optical fiber body.
[0011]
As a third solution, the present invention provides an optical fiber according to the first and second solutions described above, a laser output device that outputs laser light to the optical fiber, and the conductivity of the optical fiber. A detecting device for detecting the state of the optical fiber by detecting a conductive state of the conductive coating layer, and when the detecting device detects that the optical fiber is in an abnormal state, the laser by the laser output device Provided is a laser device characterized in that output of light is stopped.
[0012]
According to the first and second solving means of the present invention, since the conductive coating layer is provided so as to cover the outer peripheral surface of the optical fiber body, it is possible to easily detect the presence / absence or position of breakage. Possible optical fibers can be manufactured easily and inexpensively.
[0013]
Further, according to the third solving means of the present invention, the state of the optical fiber is detected by providing a conductive coating layer so as to cover the outer peripheral surface of the optical fiber body and detecting the conductive state of the conductive coating layer. Therefore, it is possible to easily and inexpensively detect the presence / absence or position of the optical fiber body.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
FIGS. 1A and 1B are diagrams showing an embodiment of an optical fiber according to the present invention.
[0016]
First, referring to FIG. 6, a laser apparatus in which the optical fiber shown in FIGS. As shown in FIG. 6, insulating connectors 22 and 23 are attached to both ends of the optical fiber 10. Among these, the laser output device 21 is connected to one connector 22 via an incident mechanism 24, and the laser beam transmitted via the optical fiber 10 is used for the other connector 23 for various applications. The emission mechanism 25 such as a lens is connected. Instead of the emission mechanism 25, an optical fiber relay mechanism or the like for connecting other optical fibers may be connected.
[0017]
Here, the detection device 26 is connected to both ends of the optical fiber 10, and in the detection device 26, the conductive state of the conductive coating layer of the optical fiber 10 (see reference numeral 12 in FIGS. 1A and 1B). By detecting this, the state of the optical fiber 10 is detected, and when it is detected that the optical fiber 10 is in an abnormal state, the output of the laser beam by the laser output device 21 can be stopped.
[0018]
As shown in FIGS. 1A and 1B, an optical fiber 10 includes an optical fiber main body 11 that transmits laser light and a conductive coating layer 12 that is provided so as to cover the outer peripheral surface of the optical fiber main body 11. I have. Among these, the optical fiber main body 11 is composed of a single optical fiber strand composed of a core and a clad, or an assembly of a plurality of optical fiber strands. The conductive coating layer 12 is formed by applying a conductive paint made of a metal fine powder-containing paint, a conductive polymer-containing paint, or the like to the outer peripheral surface of the optical fiber body 11. In addition, it is preferable that the conductive coating layer 12 has a stretchability that can correspond to the bending of the optical fiber body 11 and is made of a material that melts by heat.
[0019]
The optical fiber 10 shown in FIGS. 1 (a) and 1 (b) is provided with only a conductive coating layer on the outer peripheral surface of the optical fiber main body 11. However, depending on the installation location of the optical fiber 10, an intermediate portion of the optical fiber 10 is provided. May be electrically short-circuited by a holding mechanism or the like. Therefore, as shown in FIGS. 2A and 2B, an insulating coating layer 13 may be further provided so as to cover the outer peripheral surface of the conductive coating layer 12. Here, the insulating coating layer 13 is formed by applying an insulating coating material such as an acrylic coating material or a urethane coating to the outer peripheral surface of the conductive coating layer 12. The insulating coating layer 13 preferably has stretchability that can cope with the bending of the optical fiber body 11.
[0020]
Next, the operation of the present embodiment having such a configuration will be described.
[0021]
In the detection device 26 to which both ends of the optical fiber 10 are connected, the conduction state of the conductive coating layer 12 of the optical fiber 10 is detected. The detection device 26 is used when the optical fiber body 11 is mechanically broken and the conductive coating layer 12 is not conductive, or when the conductive coating layer 12 is melted by the heat generation of the optical fiber main body 11 and is not conductive. Detecting that the optical fiber 10 is in an abnormal state, and safely outputting the laser beam by the laser output device 21 via a safety device (not shown) mounted on the laser output device 21 based on the detection result Stop.
[0022]
As described above, according to the present embodiment, the conductive coating layer 12 is provided so as to cover the outer peripheral surface of the optical fiber body 11, and the state of the optical fiber 10 is detected by detecting the conductive state of the conductive coating layer 12. Therefore, it is possible to easily detect whether or not the optical fiber body 11 is broken.
[0023]
Moreover, according to this Embodiment, since the electroconductive coating layer 12 provided in the outer peripheral surface of the optical fiber main body 11 is formed by apply | coating a coating material, it can detect the presence or absence of a fracture | rupture easily. A simple optical fiber 10 can be manufactured very simply and inexpensively.
[0024]
In the above-described embodiment, the conductive coating layer 12 and the insulating coating layer 13 are formed by applying a conductive paint or an insulating paint. However, the present invention is not limited to this, and is made of metal or resin. You may make it form by affixing the conductive tape (band-like material) of this, and resin-made insulating tapes (band-like material).
[0025]
In the above-described embodiment, the conductive coating layer 12 is formed from a material that melts by heat. However, the present invention is not limited to this, and the laser that transmits the conductive coating layer 12 through the optical fiber body 11. You may form from the material which fuse | melts by absorbing light. Note that as such a material, a conductive resin to which carbon is added can be used.
[0026]
Furthermore, in the above-described embodiment, the conductive coating layer 12 is formed from a material that melts by absorption of heat or laser light, and the conductive coating layer 12 is emitted by laser light that leaks when the optical fiber body 11 breaks. However, the present invention is not limited to this, and the conductive coating layer 12 or the insulating coating layer 13 may have a physical property (for example, a temperature change caused by heat or a chemical change caused by absorption of laser light). It is made of a material whose electrical resistance and electrostatic capacity (capacitance between a plurality of conductive coating layers 12 and 14 as shown in FIGS. 3 (a) and 3 (b)) change, and changes in the state are detected. Thus, the state of the optical fiber 10 may be detected. Further, the conductive coating layer 12 and the insulating coating layer 13 are formed from a material whose physical properties (for example, electrical resistance) are changed by melting and mixing with each other by absorption of heat or laser light, and the change in the state thereof. The state of the optical fiber 10 may be detected by detecting.
[0027]
Further, in the above-described embodiment, when the continuity is lost, it is detected that the optical fiber is in an abnormal state. However, in the normal state, there is no continuity, and the continuity is detected when the abnormal state occurs. You may comprise so that it may be in a state. For example, an insulating coating layer is formed of a hot-melt material, and at least two conductive coating layers having a melting temperature higher than that of the insulating coating layer are illustrated with the insulating coating layer interposed therebetween. It is formed as shown in the sectional view of 3 (b) and detects the conduction state between the two conductive coating layers, and there is no conduction between the conductive coating layers when the optical fiber is in a normal state. The insulating coating layer that was in an abnormal state and insulated the conductive coating layer was lost due to heat melting, etc., resulting in conduction between the conductive coating layers that had been insulated until then. The state of the optical fiber can be detected by detecting this change in state.
[0028]
Furthermore, in the above-described embodiment, the conductive state of the conductive coating layer 12 is detected at both ends of the optical fiber 10, but as shown in FIGS. If the optical fiber 10 has the conductive coating layer 12 on the outer peripheral surface, it is possible to detect the conductive state of the conductive coating layer 12 between any part of the optical fiber 10, thereby breaking. Can be easily and inexpensively detected. 2 (a) and 2 (b), even in the optical fiber 10 in which the outer peripheral surface of the outermost layer is the insulating coating layer 13, the conductive coating layer 12 is exposed to the outside in the middle of the optical fiber body 11. By further providing a connector (exposed member), it is possible to detect the conductive state of the conductive coating layer 12 between any part of the optical fiber 10, thereby making the break position easy and inexpensive. Can be detected.
[0029]
In the above-described embodiment, the conductive state of the conductive coating layer 12 is detected at both ends of the optical fiber 10. However, as shown in FIGS. The conductive coating layers 12 and 14 are laminated via the insulating coating layer 13, and the conductive coating layers 12 and 14 are electrically short-circuited on one terminal side of the optical fiber body 11 and are electrically connected on the other terminal side. Therefore, the conductive state of the conductive coating layers 12 and 14 can be detected only on one end side of the optical fiber main body 11. In the optical fiber 10 shown in FIGS. 3A and 3B, the conductive coating layers 12 and 14 are disposed concentrically with the insulating coating layer 13 interposed therebetween. As shown in a) and (b), the conductive coating layers 12 and 14 may be arranged at the same radial position via the insulating coating layer 13.
[0030]
Further, in the above-described embodiment, one or two conductive coating layers 12 and 14 are provided so as to cover the outer peripheral surface of the optical fiber main body 11, but as shown in FIG. At least three conductive coating layers 12, 14, 16, and 18 are provided as the coating layers, and an electrical connection between any set of conductive coating layers adjacent to each other among these conductive coating layers 12, 14, 16, and 18 is provided. Different connection positions may be different from each other with respect to the length direction of the optical fiber body 11. As a result, it is possible to detect the conduction state between any pair of conductive coating layers of the conductive coating layers 12, 14, 16, and 18, thereby easily and inexpensively detecting the break position. it can. Specifically, for example, in FIG. 5, assuming a case in which breakage occurs at each of the reference signs A, B, and C, the conductive coating layers 12 and 14, the conductive coating layers 14 and 16, and the conductive properties The conductive state between the coating layers 16 and 18 is as shown in the following table, and the approximate position of the break can be detected from the pattern of the conductive state.
[0031]
[Table 1]

[0032]
【The invention's effect】
As described above, according to the present invention, the presence / absence or position of the optical fiber body can be easily and inexpensively detected.
[Brief description of the drawings]
FIG. 1 shows an embodiment of an optical fiber according to the present invention.
FIG. 2 is a diagram showing another embodiment of an optical fiber according to the present invention.
FIG. 3 is a view showing still another embodiment of the optical fiber according to the present invention.
4 is a view showing a modification of the optical fiber shown in FIG.
FIG. 5 is a view showing still another embodiment of the optical fiber according to the present invention.
FIG. 6 is a diagram showing an embodiment of a laser apparatus in which an optical fiber according to the present invention is incorporated.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Optical fiber 11 Optical fiber main body 12, 14, 16, 18 Conductive coating layer 13, 15, 17, 19 Insulating coating layer 21 Laser output apparatus 22, 23 Connector 24 Incident mechanism 25 Output mechanism 26 Detector

Claims (14)

An optical fiber main body for transmitting laser light;
A plurality of conductive coating layers provided so as to cover the outer peripheral surface of the optical fiber body,
The plurality of conductive coating layers are stacked via an insulating coating layer, and each of the conductive coating layers is electrically short-circuited with another conductive coating layer on one terminal side of the optical fiber body. Together with the other conductive covering layer on the other end side,
Comprising at least three conductive coating layer as the plurality of conductive coating layer, the location of the electrical short at any set of conductive coating layers adjacent one of the at least three conductive coating layer, An optical fiber, wherein the optical fiber bodies are different from each other in the length direction.   2. The optical fiber according to claim 1, further comprising an insulating coating layer provided so as to cover an outer peripheral surface of the outermost conductive coating layer of the plurality of conductive coating layers.   3. The optical fiber according to claim 1, wherein the conductive coating layer is made of a material that melts by heat. 3. The optical fiber according to claim 1, wherein the conductive coating layer is made of a material whose electrical resistance changes due to heat. 2. The conductive coating layer is formed of a material whose capacitance changes with another conductive coating layer adjacent to the conductive coating layer by heat. 2. The optical fiber according to 2. The said insulating coating layer is formed from the material from which the electrostatic capacitance between a pair of conductive coating layers adjacent to the said insulating coating layer changes with heat. The optical fiber described.   3. The optical fiber according to claim 1, wherein the conductive coating layer is made of a material that melts by absorbing laser light transmitted through the optical fiber body. 3. The optical fiber according to claim 1, wherein the conductive coating layer is made of a material whose electrical resistance changes by absorbing laser light transmitted through the optical fiber body. The conductive coating layer is made of a material whose capacitance changes with another conductive coating layer adjacent to the conductive coating layer by absorbing laser light transmitted through the optical fiber body. 3. The optical fiber according to claim 1, wherein the optical fiber is formed. The optical fiber according to any one of claims 1 to 9 , wherein the conductive coating layer and / or the insulating coating layer is formed by attaching a band-like material. The conductive coating layer and / or the insulating cover layer or wherein the optical fiber according to claim 1 to 9, characterized in that it is formed by applying paint. The optical fiber according to claim 2 , further comprising an exposure member provided in the middle of the optical fiber body and exposing the conductive coating layer to the outside. The conductive coating layer and insulation coating layer is any description of the optical fiber according to claim 1 to 12, characterized in that a stretchable capable of corresponding to the bending of the optical fiber body. An optical fiber according to any one of claims 1 to 13 ,
A laser output device for outputting laser light to the optical fiber;
A detection device for detecting a state of the optical fiber by detecting a change in a conductive state of the conductive coating layer of the optical fiber or a state of capacitance between a pair of adjacent conductive coating layers ; With
A laser apparatus, wherein when the detection apparatus detects that the optical fiber is in an abnormal state, the laser output by the laser output apparatus is stopped.

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