JP2011145546A - Hot-line detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot-line detector in which a light quantity leaked from an optical fiber is easily controlled to a necessary level of a quantity for the purpose of determining whether an optical path is in a hot-line state or not. <P>SOLUTION: The hot-line detector detects whether the optical path formed of the optical fibers 11, 12 is in the hot-line state or not. The cut face 11a of the optical fiber 11 which is cut diagonally with respect to the optical axis receives transmitted light P1 between the cut faces 11a, 12a of the two optical fibers 11, 12, respectively, an optical signal P0 is not totally reflected on the cut face 11a, leaked light P2 passing through the cut face 11a is generated and a light detection part 2 detects the leaked light P2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a live line detection device that detects whether or not an optical line formed by an optical fiber is in a live line state (a state in which light is normally transmitted through the optical line).

  2. Description of the Related Art Conventionally, there has been provided a live line detector that detects whether or not an optical line formed by an optical fiber is in a live line state (see, for example, Patent Document 1). This hot-line detector includes a modulation mechanism that modulates an optical signal by applying bending deformation to an optical fiber, and first and second detection mechanisms that are each provided with a light receiving element and are arranged on both sides of the modulation mechanism. In the state where the optical fiber is bent and deformed by the modulation mechanism, a part of the optical signal propagating in the optical fiber leaks from the bent portion, so that the leaked light is received by the light receiving element. The presence or absence of a signal can be detected. Then, when the leak light can be received by the light receiving element, the optical line is in a live line state, and when it is not received, it is determined that it is not in a live line state.

JP-A-10-246818 (paragraph [0016] and FIG. 1)

  In the live line detector shown in the above-mentioned Patent Document 1, it is determined whether or not the optical line is in the live line state based on the optical signal leaking from the bent portion of the optical fiber. When bent, the amount of light leaking from the bent portion increases, which may increase the effect on the optical signal. Further, if the bending of the optical fiber is too small, the amount of light leaking from the bent portion is reduced, and the detection accuracy of the live line state of the optical line may be lowered.

  However, it is difficult to control the amount of light leaking from the optical fiber by adjusting the bending condition of one optical fiber, and it is possible to easily control the amount of light leaking from the optical fiber. A device was sought.

  The present invention has been made in view of the above reasons, and its purpose is to easily control the amount of light leaked from an optical fiber to a necessary amount in order to determine whether or not the optical line is in a live state. An object of the present invention is to provide a possible hot-line detection device.

  The invention of claim 1 is a hot-wire detection device that detects whether or not an optical line formed by an optical fiber is in a live-wire state, and transmits and receives light between the cut surfaces of the two optical fibers. In addition, it is characterized by comprising a light branching means for branching a part of the light transmitted and received between the cut surfaces of the two optical fibers, and a light detection unit for detecting the light branched by the light branching means.

  According to the present invention, the optical branching means can be configured without bending one optical fiber, and the amount of light leaked from the optical fiber is easily required to determine whether or not the optical line is in a live state. The amount can be controlled.

  According to a second aspect of the present invention, in the first aspect, the optical branching unit is configured by a cut surface of one optical fiber formed obliquely with respect to the optical axis, and reflection of the cut surface of the one optical fiber. The light is transmitted and received between the cut surfaces of the two optical fibers, and light is leaked from the cut surface of one of the optical fibers. It is characterized by detecting.

  According to this invention, since the cut surface of the optical fiber constitutes the optical branching means, it is not necessary to provide the optical branching means as a separate member, and the configuration is simplified.

  According to a third aspect of the present invention, in the first aspect, the optical branching unit is an optical unit that includes at least one of a lens and a light reflecting member and is configured separately from the optical fiber. To do.

  According to this invention, since the optical means separate from the optical fiber constitutes the light branching means, the amount of light leaked from the optical fiber can be controlled with higher accuracy.

  As described above, the present invention has an effect that the amount of light leaked from the optical fiber can be easily controlled to a necessary amount in order to determine whether or not the optical line is in a live line state.

1 is a diagram illustrating a configuration of a first embodiment. 6 is a diagram illustrating a configuration of a second embodiment. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a live line detection apparatus according to Embodiment 1, and this live line detection apparatus detects whether or not an optical line formed by an optical fiber is in a live line state.

  The optical fiber 1 includes a core 1a and a clad 1b that covers the periphery of the core 1a, and uses a silica glass fiber that is excellent in environmental resistance such as propagation loss, transmission bandwidth, and mechanical strength. In particular, the present embodiment employs a single mode fiber. The optical fiber 1 may be a plastic fiber other than a quartz glass fiber, and may further employ a multimode fiber. Further, as light propagating through the optical fiber 1, it is preferable to use light having a wavelength in the ultraviolet region in consideration of transmission speed, bandwidth, etc. However, if the transmission speed or bandwidth is not a problem, this wavelength is not affected. The light is not limited to light, and may be light in the infrared region or visible region.

  One end of one optical fiber 11 is constituted by a cut surface 11a cut obliquely with respect to the optical axis, and one end of the other optical fiber 12 is a cut surface cut substantially perpendicular to the optical axis. 12a. Then, at one end of the optical fiber 11, the cut surface 12a of the optical fiber 12 is connected to the clad 1b facing the cut surface 11a cut obliquely with respect to the optical axis by adhesion, fusion, or abutment. The optical axes of the optical fibers 11 and 12 are configured to be substantially orthogonal to each other.

  Then, the optical signal P 0 propagated from the other end of the optical fiber 11 to one end is reflected by the cut surface 11 a of the optical fiber 11 toward one end of the optical fiber 12. The light P1 reflected by the cut surface 11a (hereinafter referred to as propagating light P1) is incident substantially perpendicularly to the core 1a and the cladding 1b of the optical fiber 11 (incident angle is equal to or less than the critical angle), so that it is totally reflected. Instead, the light passes through the core 1a and the cladding 1b, enters the optical fiber 12 from the cut surface 12a, and propagates from one end of the optical fiber 12 to the other end.

  Here, the cut surface 11a of the optical fiber 11 is not a mirror surface but a rough surface, and the optical signal P0 propagated from the other end of the optical fiber 11 to one end is reflected by the cut surface 11a of the optical fiber 11. In addition, leakage light P2 leaks out of the optical fiber from the cut surface 11a. In this case, the leakage light P2 becomes scattered light that passes through the cut surface 11a formed on the rough surface. Alternatively, the cut surface 11a is formed into a periodic pattern (for example, a plurality of coaxial annular shapes, etc.), and the leaked light P2 transmitted through the cut surface 11a is generated without totally reflecting the optical signal P0 by the cut surface 11a. You may let them. Alternatively, the cut surface 11a may be a curved surface, and the leakage light P2 that passes through the cut surface 11a may be generated without totally reflecting the optical signal P0 by the cut surface 11a. That is, the cut surface 11a of the optical fiber 11 constitutes an optical branching unit that branches part of the light transmitted and received between the cut surfaces of the optical fibers 11 and 12, and the branched light becomes the leaked light P2. .

  As described above, the leakage light P2 is generated by the surface roughness, the periodic pattern shape, the curved surface shape, and the like of the cut surface 11a cut obliquely with respect to the optical axis, and thus the surface roughness and period of the cut surface 11a. By arbitrarily setting a specific pattern shape, curved surface shape, etc., the amount of leaked light P2 can be easily controlled to a required amount.

  The cut surface 11a of the optical fiber 11 is provided with a light detection unit 2 that detects leaked light P2 leaking from the cut surface 11a to the outside of the optical fiber 11. As shown in FIG. 1, the light detection unit 2 includes a photodiode 22 fixed to the cut surface 11a via a transparent adhesive layer 21 made of a transparent adhesive (for example, an acrylic resin or an epoxy resin). The photodiode 22 outputs a signal corresponding to the amount of received light. Since the light detection unit 2 is fixed to the cut surface 11a via the transparent adhesive layer 21, the adhesion between the cut surface 11a and the light detection unit 2 is enhanced, and the light receiving efficiency of the light detection unit 2 can be increased. The transparent adhesive layer 21 may form an air layer inside.

  Of the optical signal P 0 propagating through the core 1 a of the optical fiber 11, the leaked light P 2 leaking from the cut surface 11 a to the outside of the optical fiber 11 passes through the transparent adhesive layer 21 and enters the photodiode 22. Outputs a signal corresponding to the amount of received light to a discrimination circuit (not shown). This determination circuit is configured by using, for example, a comparator, and outputs a predetermined drive signal when the signal input from the photodiode 22 exceeds a predetermined reference value. Then, a light-emitting diode (not shown) is turned on by this drive signal to indicate that the optical line is in a live line state.

  On the other hand, when there is no leakage light P2 from the cut surface 11a to the outside of the optical fiber 11, the leakage light P2 does not enter the photodiode 22, so the photodiode 22 does not output the signal, and the discrimination circuit Since the signal is not input from the photodiode 22, the drive signal is not output. As a result, the light emitting diode is not turned on, and it can be seen that the optical line is not in a live state. Therefore, the operator can determine whether or not the optical line is in a live line state by confirming the state of the light emitting diode (lighted or turned off).

  In the above description, the case where light is propagated from the optical fiber 11 to the optical fiber 12 is illustrated. It is possible to determine whether or not the optical line is in a live line state as described above.

  Thus, according to the present embodiment, the optical branching means is configured without bending one optical fiber, and the surface roughness, periodic pattern shape, curved surface shape, etc. of the cut surface 11a are arbitrarily set. Therefore, it is possible to easily control the amount of the leaked light P2 to a necessary amount, so that it is possible to prevent the propagation light P1 from being greatly influenced by the excessive leaked light P2, and the live line of the optical line is prevented by the insufficient leaked light P2. The state detection accuracy is prevented from being lowered. That is, the live line detection device can easily control the amount of light leaked from the optical fiber 1 to a necessary amount in order to determine whether or not the optical line is in a live line state.

  Further, since the cut surface 11a of the optical fiber 11 constitutes the light branching means, it is not necessary to provide the light branching means as a separate member, and the configuration becomes simple.

  In the above example, the transparent adhesive layer 21 is interposed between the light detection unit 2 and the cut surface 11 a of the optical fiber 11, but a liquid transparent layer such as matching oil is interposed instead of the transparent adhesive layer 21. May be. In this case, the light detection unit 2 is attached to the cut surface 11a by a fixing means (not shown).

(Embodiment 2)
FIG. 2 is a schematic configuration diagram of the hot-wire detection device according to the second embodiment. The hot-wire detection device is a hot-wire detection unit 3 that detects whether or not an optical line formed by an optical fiber is in a hot-wire state. It is configured. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, and description is abbreviate | omitted.

  One end of each of the optical fibers 11 and 12 is constituted by cut surfaces 11a and 12a cut substantially perpendicular to the optical axis, and is inserted through the inlet ports 31 and 32 of the live line detection unit 3, respectively. The inlets 31 and 32 are formed in a cylindrical shape in which the incoming lines are orthogonal to each other, and the bottom surfaces of the incoming outlets 31 and 32 are optically continuous by the lens body 33. The bottom surface includes lens surfaces 33 a and 33 b of the lens body 33.

  The optical signal P0 propagated from the other end of the optical fiber 11 to the one end enters the lens surface 33a from the cut surface 11a of the optical fiber 11, and the propagation direction is changed by the reflecting member 33c in the lens body 33. Later (in FIG. 2, the propagation direction changes from the optical axis direction of the optical fiber 11 to the optical axis direction of the optical fiber 12), the light is condensed on the lens surface 33 b and emitted toward one end of the optical fiber 12. Light P11 condensed on the lens surface 33b (hereinafter referred to as propagation light P11) enters the optical fiber 12 from the cut surface 12a and propagates from one end of the optical fiber 12 to the other.

  Further, a part of the optical signal P0 that has entered from the lens surface 33a is diffused and is not incident on the reflecting member 33c, but is changed in the propagation direction by another reflecting member 33d in the lens body 33, and then the lens body. The light is collected by 33 lens surfaces 33e. That is, the lens body 33 constitutes an optical branching unit that branches a part of the light transmitted and received between the cut surfaces of the optical fibers 11 and 12, and the branched light becomes the leakage light P2.

  The live line detection unit 3 includes a light detection unit 2 that faces the lens surface 33e and detects leakage light P2 emitted from the lens surface 33e. As shown in FIG. 2, the light detection unit 2 includes a photodiode 22 fixed to a lens surface 33e through a transparent adhesive layer 21 made of a transparent adhesive (for example, acrylic resin or epoxy resin). The photodiode 22 outputs a signal corresponding to the amount of received light. Since the light detection unit 2 is fixed to the lens surface 33e via the transparent adhesive layer 21, the adhesion between the lens surface 33e and the light detection unit 2 can be improved, and the light receiving efficiency of the light detection unit 2 can be increased. The transparent adhesive layer 21 may form an air layer inside.

  Of the optical signal P0 propagating in the core 1a of the optical fiber 11, the leaked light P2 leaked from the lens surface 33e passes through the transparent adhesive layer 21 and enters the photodiode 22, and the photodiode 22 receives the received light amount. Is output to a determination circuit (not shown). This determination circuit is configured by using, for example, a comparator, and outputs a predetermined drive signal when the signal input from the photodiode 22 exceeds a predetermined reference value. Then, a light-emitting diode (not shown) is turned on by this drive signal to indicate that the optical line is in a live line state.

  On the other hand, when there is no leaked light P2 from the lens surface 33e, the leaked light P2 does not enter the photodiode 22, so the photodiode 22 does not output the signal, and the discriminating circuit receives the signal from the photodiode 22. Since no signal is input, the drive signal is not output. As a result, the light emitting diode is not turned on, and it can be seen that the optical line is not in a live line state. Therefore, the operator can determine whether or not the optical line is in a live line state by confirming the state of the light emitting diode (lighted or turned off).

  In the above description, the case where light is propagated from the optical fiber 11 to the optical fiber 12 is exemplified. However, even when light is propagated from the optical fiber 12 to the optical fiber 11, the leakage light P2 is generated from the lens surface 33e. Then, it is possible to determine whether or not the optical line is in a live line state as described above.

  Thus, according to the present embodiment, the amount of the leaked light P2 can be easily controlled to the required amount by arbitrarily configuring the lens surface of the lens body 33 and the reflecting member, and therefore propagated by the excessive leaked light P2. A large influence on the light P1 is prevented, and the detection accuracy of the live line state of the optical line is prevented from being lowered due to the excessive leakage light P2. That is, the live line detection device can easily control the amount of light leaked from the optical fiber 1 to a necessary amount in order to determine whether or not the optical line is in a live line state. Further, since the lens body 33 separate from the optical fiber 1 constitutes the light branching means, the amount of leaked light P2 can be controlled with higher accuracy. The lens body 3 may be configured to include only one of a lens surface (lens) and a reflecting member (light reflecting member) as necessary.

  In the above example, the transparent adhesive layer 21 is interposed between the light detection unit 2 and the lens surface 33e of the lens body 33, but a liquid transparent layer such as matching oil is interposed instead of the transparent adhesive layer 21. May be. In this case, the light detection unit 2 is attached to the lens surface 33e by a fixing means (not shown).

1 (11, 12) Optical fiber 11a, 12a Cut surface 2 Photodetector 21 Transparent adhesive layer 22 Photodiode P0 Optical signal P1 Propagation light P2 Leakage light

Claims (3)

  A hot-line detection device that detects whether or not an optical line formed by an optical fiber is in a live-line state, and transmits and receives light between the cut surfaces of two optical fibers and two optical fibers A hot-line detection apparatus comprising: a light branching unit that branches a part of light transmitted and received between the cut surfaces; and a light detection unit that detects light branched by the light branching unit.   The optical branching means is constituted by a cut surface of one optical fiber formed obliquely with respect to the optical axis, and is reflected between the cut surfaces of the two optical fibers by reflection of the cut surface of the one optical fiber. 2. The light according to claim 1, wherein light is transmitted and received, light is leaked from a cut surface of one optical fiber, and the light detecting unit detects light leaked from the cut surface of one optical fiber. Live line detector.   2. The live line detection apparatus according to claim 1, wherein the light branching means is an optical means that includes at least one of a lens and a light reflecting member and is configured separately from the optical fiber.

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