JP2013109120A - Optical fiber fusion splicing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber fusion splicing method which allows for inspecting entire end faces of optical fibers for cracks and hackles and removing detected cracks and hackles before fusing the end faces of the optical fibers together.SOLUTION: An optical fiber fusion splicing method for fusing end faces of a pair of optical fibers 1, 3 is provided. Images of the end faces 1a, 3a of the optical fibers 1, 3 are acquired from the front thereof by image capturing means 23, 25, 27 which are positioned to face the end faces 1a, 3a. Electrical discharge processing is applied on to the end faces on which cracks and hackles have been detected by detection means, after which the end faces of the optical fibers are fused together.

Description

  The present invention relates to an optical fiber fusion splicing method, and more particularly, to a technique for detecting an end of an optical fiber and a hackle.

  For example, in Patent Document 1, the luminance distribution obtained by imaging the end face of the optical fiber with the optical system from the side rather than from the front is made to be substantially flat, and a chip is detected from the shaded portion of the luminance distribution. I have to.

JP 2000-146751 A

  However, in the technique described in Patent Document 1, since the end face state of the optical fiber is detected from an observation image obtained by capturing the end face of the optical fiber from the side with an optical system, it is not possible to detect a chip or a hackle at a blind spot. .

  Accordingly, the present invention provides a fusion of optical fibers capable of observing the entire end face of the optical fiber so that the chips and hackles can be detected and the end faces of the optical fibers can be fused and connected by removing the chips and hackles. An object is to provide a connection method.

  The first aspect of the present invention is an optical fiber fusion splicing method in which the end faces of a pair of optical fibers are fused and connected, and imaging means arranged to face the end faces of the optical fibers, and the end faces of the optical fibers are imaged from the front. In addition, after the discharge means discharges to the end face of the optical fiber having the chipped and hackles detected by the detection means, the end faces of both optical fibers are fusion-connected.

  According to a second invention, in the first invention, the image of the end face of the optical fiber obtained by the imaging means is displayed by the image means, the luminance information is missing from the image, and the part of the hackle is clearly indicated on the image means. The discharge means is discharged to the end face of the optical fiber until the detected chipping and hackles are reduced or eliminated in the end face observation image.

  According to a third aspect of the present invention, in the second aspect of the present invention, the chip or hackle part is clearly indicated on the image means by indicating the chip or hackle part on the end face observation image of the optical fiber with a mark such as a box or a line. It is characterized by specifying.

  A fourth invention is characterized in that, in the third invention, luminance information in an arbitrary axial direction crossing the chipped and hackled portion is digitized and displayed in a graph.

  According to the optical fiber fusion splicing method of the present invention, since the end face of the optical fiber is picked up from the front by the imaging means arranged opposite to the end face of the optical fiber, luminance information is obtained from the image of the entire end face of the optical fiber. And lacking as luminance information, the part of the hackle can be clearly shown on the image means. Then, after discharging to the end face of the optical fiber having the detected chipping and hackles by the discharge means, the end faces of both optical fibers can be fused and connected, so that a low-loss connection can be made.

FIG. 1 is a perspective view of a fusion splicing device according to an embodiment of the present invention. FIG. 2 is a side view showing a portion for holding the optical fiber of the fusion splicing apparatus of FIG. FIG. 3 shows a state in which the end face of one optical fiber is imaged by the fusion splicing apparatus of FIG. 1, (a) is a plan view thereof, and (b) is a right side view of (a). 4A and 4B show a state in which the end face of the other optical fiber is imaged by the fusion splicer of FIG. 1, FIG. 4A is a plan view thereof, and FIG. 4B is a right side view of FIG. 5 shows a state in which the mirror shaft is at the rising end position in the fusion splicing device of FIG. 1, (a) is a side view seen from the side perpendicular to the optical fiber of FIG. 1, and (b) is a diagram. It is the front view seen from the length direction to 1 optical fiber. 6 shows a state where the mirror shaft is in the lowered end position in the fusion splicing apparatus of FIG. 1, (a) is a side view seen from the side perpendicular to the optical fiber of FIG. 1, and (b) is a diagram. It is the front view seen from the length direction to 1 optical fiber. FIG. 7 is a control block diagram of the fusion splicer of FIG. FIG. 8 is a view corresponding to FIG. 3 in the fusion splicing device according to another embodiment of the present invention, in which (a) is a plan view and (b) is a right side view of (a). FIG. 9 is a view corresponding to FIG. 4 in the fusion splicing device according to another embodiment of the present invention, in which (a) is a plan view and (b) is a right side view of (a). FIG. 10 is a flowchart showing the process of fusion splicing the end faces of the optical fibers by the method of the present invention. FIG. 11A shows an observation image of the end face of the optical fiber obtained by the method of the present invention, FIG. 11B shows a luminance line in the Y-axis direction, and FIG. 11C shows a luminance line in the X-axis direction. FIG. 12A shows an observation image of the end face of the optical fiber after discharge, FIG. 12B shows a luminance line in the Y-axis direction, and FIG. 12C shows a luminance line in the X-axis direction.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  First, a fusion splicing device that fuses and connects the end faces of a pair of optical fibers will be described. As shown in FIG. 1, the pair of optical fibers 1 and 3 correspond to the optical fibers 1 and 3 in a state where the optical fibers 1 and 3 face each other in the axial direction and the end surfaces 1a and 3a are separated from each other. It is gripped by the provided fiber holder 5 shown in FIG. The fiber holder 5 is pressed with a pressing plate 11 that can be opened and closed from above while the optical fibers 1 and 3 are housed in the recesses of the holder main body 9 that is detachably mounted on the holder base 7. Fix it. In FIG. 1, the axial direction of the optical fibers 1 and 3 is defined as the X-axis direction, the direction orthogonal thereto is defined as the Y-axis direction, and the direction perpendicular to the longitudinal direction of the optical fibers 1 and 3 is defined as the Z-axis direction. Hereinafter, a plane parallel to the X axis is a horizontal plane, and a plane parallel to the Z axis is a vertical plane.

  As shown in FIG. 2, the optical fibers 1 and 3 are provided with coating resins 1B and 3B covering the outer circumferences of the quartz glass fibers 1A and 3A, and the portions provided with the coating resins 1B and 3B are connected to the fiber holder. 5 grips.

  Further, the end faces 1a and 3a of the optical fibers 1 and 3 are positioned and held by the V-groove bases 13 and 15 on the side of the optical fibers 1 and 3 with respect to the fiber holder 5 described above. Similarly to the fiber holder 5, the V-groove bases 13 and 15 are positioned and fixed to the portions provided with the coating resins 1B and 3B, but the glass fibers 1A and 3A may be positioned and fixed.

  The V-groove bases 13 and 15 are provided with clamps (not shown) that partially enter the V-grooves 13 a and 15 a and press the optical fibers 1 and 3 between the V-groove bases 13 and 15.

  As shown in FIG. 1, LED lamps 17 and 19 that project light into the optical fibers 1 and 3 from the side are disposed at appropriate positions of the pair of optical fibers 1 and 3. Light projected into the optical fibers 1 and 3 by the LED lamps 17 and 19 is radiated from the end faces 1 a and 3 a of the optical fibers 1 and 3.

  Between the end faces 1a and 3a of the pair of optical fibers 1 and 3, a mirror shaft 21 as a reflecting member extending in the vertical direction perpendicular to the axial direction of the optical fibers 1 and 3 can be moved up and down and rotated. It is arranged. A concave portion 21a is formed in one side portion near the tip (upper end) of the mirror shaft 21, and a mirror 23 constituting a reflecting surface is attached to the concave portion 21a.

  The mirror 23 reflects either one of the end faces 1a and 3a of the optical fibers 1 and 3 in a state where the mirror shaft 21 is positioned at the rising end as shown in FIG. The reflected light of the mirror 23 is directed to either one of the first television camera 25 as the first imaging means and the second television camera 27 as the second imaging means arranged on the side. The optical axes of the optical systems of the first and second television cameras 25 and 27 are arranged in an inclined state with respect to the horizontal plane, and are provided with first and second lenses 25a and 27a, respectively, on the front end side. .

  Here, as shown in FIG. 3 corresponding to the state of FIG. 1, as the first state, the image 1a ′ of the end face 1a of one optical fiber 1 is reflected by the mirror 23 and incident on the first lens 25a. Let In the state where the mirror shaft 21 is rotated 180 degrees from the state of FIGS. 1 and 3, as shown in FIG. 4, the image 3a ′ of the end face 3a of the other optical fiber 3 is mirrored as the second state. The light is reflected by 23 and is incident on the second lens 27a. Since the reflecting surface of the mirror 23 is positioned so as to include the rotation axis of the mirror shaft 21, the position of the reflecting surface does not change even if the mirror shaft 21 rotates 180 degrees.

  Next, a rotation mechanism that rotates about the rotation axis of the mirror shaft 21 orthogonal to the axis of the optical fibers 1 and 3 will be described. 5 shows a state in which the mirror shaft 21 is located at the rising end as in FIG. 1, FIG. 6 shows a state in which the mirror shaft 21 is located at the falling end, and the state of FIG. With respect to the state, the mirror shaft 21 is rotated 90 degrees clockwise around the rotation axis as viewed from above in FIG.

  The mirror shaft 21 can move up and down with respect to the fixed bracket 29, and the fixed bracket 29 includes a guide tube 31 having a lower portion attached so as to protrude upward from the upper plate portion 29 a. The mirror shaft 21 in the state of being inserted into the vertical movement moves up and down. A stopper flange 32 is attached to the mirror 23 on the tip side of the guide tube 31 of the mirror shaft 21, and when the mirror shaft 21 is lowered as shown in FIG. 6, the upper end of the guide tube 31 is connected to the stopper flange 32. It abuts and restricts further lowering of the mirror shaft 21.

  A cylindrical member 33 is provided at the lower end of the mirror shaft 21 so as to be integrated, and a groove 35 illustrated as a front view in FIG. 6A is formed in one of the semicircular arc portions of the outer peripheral portion of the cylindrical member 33. doing. The groove 35 includes a first inclined groove 35a that spirals from the vicinity of the end of the mirror shaft 21 opposite to the mirror 23 in the axial direction to the vicinity of the end of the mirror 23, and the upper end of the first inclined groove 35a. A second inclined groove 35b having a spiral shape downward from the mirror 23 is provided.

  Here, the surface on the mirror 23 side of the first inclined groove 35 a becomes the guide inclined surface 37. On the other hand, in the second inclined groove 35 b, the surface opposite to the mirror 23 becomes the guide inclined surface 39. Each of these guide inclined surfaces 37, 39 constitutes at least a pair of cam surfaces having different inclination directions and facing each other.

  Further, as shown in FIG. 5B, the guide inclined surfaces 37 and 39 are formed close to each other along the rotation direction, and the adjacent portions of the pair of guide inclined surfaces 37 and 39 are circumferential. Are overlapping each other. That is, as shown in FIG. 5B, the upper end 37a of the guide inclined surface 37 and the upper end 39a of the guide inclined surface 39 overlap each other in the rotational direction.

  Further, as shown in FIG. 5A, a lower axial groove 41 extending in the vertical direction is formed in the lower portion in the axial direction facing the guide inclined surface 37 in the cylindrical member 33, as shown in FIG. 5B. As described above, an upper axial groove 43 extending in the vertical direction is formed on the upper portion in the axial direction of the cylindrical member 33 facing the guide inclined surface 39. These axial grooves 41 and 43 are set at positions separated by an angle of 90 degrees in the circumferential direction.

  The fixed bracket 29 is provided with a protrusion 45 as a guided portion that moves relatively along the spiral groove 35 and the axial grooves 41 and 43. The projecting portion 45 protrudes inward at the tip of an arm portion 29b extending downward from one side portion of the upper plate portion 29a of the fixing bracket 29 so as to enter the groove 35 and the axial grooves 41 and 43. Forming. The protrusion 45 is located in the lower axial groove 41 in FIG. 5, and is located in the upper axial groove 43 in FIG. The rotation of 23 is restricted.

  The spiral groove 35 and the axial grooves 41 and 43 are similarly formed on the other semicircular arc portion of the outer peripheral portion of the cylindrical member 33, that is, on the back side of the paper surface in FIG.

  A spring 47 as an elastic means is provided between the upper end surface of the cylindrical member 33 provided with the groove 35 and the axial grooves 41 and 43 and the upper plate portion 29a of the fixing bracket 29. Therefore, the mirror shaft 21 is always pressed downward.

  As shown in FIGS. 5B and 6B, a mirror shaft drive mechanism mounting portion 49 is formed on the opposite side of the arm portion 29b with the mirror shaft 21 of the fixed bracket 29 interposed therebetween. Yes. The mirror shaft drive mechanism mounting portion 49 includes a motor mounting arm 51 that bends upward on the outer side opposite to the mirror shaft 21 and a rotation link mounting arm 53 that bends downward on the outer side opposite to the mirror shaft 21. ing.

  A motor 55 as drive means is attached to the upper part of the motor attachment arm 51, and a rotation link 59 is rotatably attached to the tip of the rotation link attachment arm 53 via a rotation support pin 57. The rotation drive shaft 61 of the motor 55 is connected to a screw shaft 63 of a ball screw. The rotation of the screw shaft 63 accompanying the rotation of the rotation drive shaft 61 causes the screw shaft 63 to rotate while rotating relative to a nut (not shown). Move in the direction.

  The tip of the screw shaft 63 is in contact with one end 59 a of the rotation link 59, and the other end 59 b of the rotation link 59 is in contact with the lower end surface of the cylindrical member 33.

  In the state where the mirror shaft 21 is located at the rising end as shown in FIGS. 1 and 5, the screw shaft 63 is moving forward, and at this time, the other end portion 59 b of the rotation link 59 is located on the lower end surface of the cylindrical member 33. By pressing upward, the spring 47 is in a compressed state. From this state, when the motor 55 is driven to move the screw shaft 63 backward, the rotation link 59 rotates counterclockwise in FIG. 5B, and the spring 47 is extended accordingly. Due to the elastic force of the spring 47, the cylindrical member 33 is lowered together with the mirror shaft 21 as shown in FIG.

  When the cylindrical member 33 moves downward from the state of FIG. 5, the projection 45 moves relatively upward from the lower axial groove 41 and comes into contact with the guide inclined surface 37 immediately above the protrusion 45. Will move relative to the guide inclined surface 37 while being pressed against it. Here, since the protrusion 45 is provided on the fixing bracket 29 and is fixed, the cylindrical member 33 is rotated clockwise as viewed from above in FIG. Is rotated 90 degrees to the state shown in FIG. That is, the mirror shaft 21 is located at the lower end, and at this time, the protrusion 45 is in a state of entering the upper axial groove 43 and the spring 47 is in an extended state.

  Subsequently, from the state of FIG. 6, when the motor 55 is rotationally driven in the opposite direction to move the screw shaft 63 to advance, the rotation link 59 rotates clockwise in FIG. The cylindrical member 33 is raised against the spring 47. When the cylindrical member 33 is lifted, the projection 45 located in the upper axial groove 43 as shown in FIG. 6A comes into contact with and is pressed against the guide inclined surface 39 immediately below the cylindrical member 33. The shape member 33 further rotates 90 degrees in the same direction as described above.

  As described above, the mirror shaft 21 is lowered from the state where the mirror shaft 21 is located at the rising end position of FIGS. 1 and 5 by rotating the screw shaft 63 by driving the motor 55 and moving backward by 90 degrees. Moves forward by 90 degrees in the same direction. Thus, by repeating the backward movement and forward movement of the screw shaft 63 once, the mirror shaft 21 can be in a state in which the direction of the mirror 23 is rotated 180 degrees at the rising end position.

  That is, in the state of FIG. 1 and FIG. 5, the image 1 a ′ of the end face 1 a of one optical fiber 1 is reflected by the mirror 23 and incident on the first lens 25 a and captured by the first television camera 25. Can do. From this state, by rotating the mirror shaft 21 by 180 degrees by driving the motor 55 as described above, the image 3a ′ of the end face 3a of the other optical fiber 3 is reflected by the mirror 23 and is reflected on the second lens 27a. Incident light can be picked up by the second television camera 27.

  After the mirror shaft 21 is rotated 180 degrees, the screw 55 is further driven backward and forward once by driving the motor 55 so that the orientation of the mirror 23 is the original state, that is, one of the optical fibers 1 in FIG. The state returns to the state of reflecting the image 1a ′ of the end face 1a.

  As shown in FIG. 7, the images taken by the first and second television cameras 25 and 27 are individually image-processed by the image processing circuit of the control unit 65 to obtain different data, and based on these data. Then, the entire fiber holder 5 shown in FIG. 2 is rotated around the axis of the optical fibers 1 and 3 to perform alignment work. Alternatively, only the V-groove bases 13 and 15 are moved in the radial direction to perform axial alignment. Separate image data of the optical fibers 1 and 3 are individually displayed on the first display unit 69 and the second display unit 70.

  After the alignment operation and the axial alignment, the end faces 1a and 3a of the optical fibers 1 and 3 are brought into contact with each other and fusion-bonded using a discharge electrode (not shown). At the time of fusion splicing, the mirror shaft 21 is positioned at the lower end as shown in FIG. 6 so that the mirror shaft 21 does not get in the way. When the end faces 1a and 3a are brought into contact with each other, the fiber holder 5 is moved in the axial direction.

  As described above, in the present embodiment, when imaging the end faces 1a and 3a of the pair of optical fibers 1 and 3 to be fusion-spliced, the single mirror 23 provided on the mirror shaft 21 rotated by 180 degrees is used. Images are individually acquired from the front of the end faces 1a and 3a of the optical fibers 1 and 3, respectively. For this reason, it is possible to acquire a high-accuracy image by imaging the end faces 1a and 3a from the front as compared with the case where the optical fiber is taken from the side, and to each end face 1a and 3a of the pair of optical fibers 1 and 3 High-accuracy images can be acquired by individually capturing images with the corresponding first TV camera 25 and second TV camera 27.

  At this time, since the first television camera 25 captures the image 1a ′ of the end face 1a of the one optical fiber 1, the image 1a ′ can be received at the center of the first lens 25a. 27 is picking up an image 3a ′ of the end face 3a of the other optical fiber 3, so that the image 3a ′ can be received at the center of the second lens 27a. As a result, even when the fiber diameter is large, it is easy to fit within the imaging range of the TV camera, resulting in an incomplete image as if both of the pair of optical fibers were simultaneously imaged by one TV camera. This can be avoided and a highly accurate image can be obtained.

  In addition, by imaging and observing the end faces 1a and 3a of the optical fibers 1 and 3, it is possible to find damaged parts such as chips on the end faces 1a and 3a. You can also

  Moreover, in this embodiment, the mirror axis | shaft 21 is equipped with one mirror 23, and it is 180 degree | times centering on the rotating axis orthogonal to the axis line of the optical fibers 1 and 3 between a 1st state and a 2nd state. A first television camera 25 that can rotate and captures an image 1a ′ of one end face 1a reflected in the first state, and an image 3a ′ of the other end face 3a reflected in the second state. And a second television camera 27.

  As a result, the images 1a ′ and 3a ′ of the end faces 1a and 3a can be individually reflected toward the first and second television cameras 25 and 27 using the single mirror 23. The image captured by the second television cameras 25 and 27 can be easily specified as one of the pair of optical fibers 1 and 3.

  In the present embodiment, the guide inclined surfaces 37 and 39 are provided on the mirror shaft 21 and are inclined in a spiral shape facing the axial direction of the rotation axis and turning around the rotation axis, A projection 45 that moves relative to the inclined surfaces 37 and 39 while being guided with respect to the surface 39 and moves the mirror shaft 21 in the axial direction of the rotational axis, and at the same time, rotates about the axis of the rotational axis. , Respectively. The guide inclined surfaces 37 and 39 are formed such that at least a pair of guide inclined surfaces 37 and 39 having different shapes and facing each other are adjacent to each other along the rotation direction. , 39 are adjacent to each other in the circumferential direction.

  As a result, the mirror shaft 21 reciprocates in the vertical direction, so that the protrusion 45 is sequentially guided by the guide inclined surfaces 37 and 39, and the mirror shaft 21 is rotated by 90 degrees in the same direction and rotated 180 degrees. Is possible.

  In the present embodiment, the mirror shaft 21 moves in one axial direction of the rotation axis, so that one of the pair of guide inclined surfaces 37 and 39 moves while contacting the protrusion 45 and rotates 90 degrees. Then, by moving to the other axial direction of the rotation axis, the other of the pair of guide inclined surfaces 37 and 39 moves while contacting the protrusion 45 and rotates 90 degrees.

  For this reason, it is possible to rotate the mirror shaft 21 by 90 degrees in the same direction and to rotate 180 degrees simply by moving up and down.

  In the present embodiment, a spring 47 that moves the mirror shaft 21 in one axial direction of the rotation axis, and a motor 55 that moves the mirror shaft 21 in the other axial direction of the rotation axis against the spring 47, It has. Therefore, the mirror shaft 21 moves to one side by driving the motor 55 against the spring 47, and conversely, the mirror 47 is easily driven to the other side by releasing the drive of the motor 55 in the compression direction to the spring 47. Can be moved to. At this time, since only one motor 55 is required, the number of parts can be reduced and the structure can be simplified.

  Further, in the present embodiment, a first display unit 69 and a second display unit 70 that display the respective images captured by the first TV camera 25 and the second TV camera 27 are provided. The respective images are individually displayed by the display units 69 and 70. Thereby, observation of each end face 1a and 3a of a pair of optical fibers 1 and 3 can be performed very easily.

  In the above-described embodiment, the two first and second television cameras 25 and 27 are provided as the imaging unit. However, the mirror shaft 23 is rotated 90 degrees counterclockwise from the state of FIG. Thus, the reflected lights of the images 1a ′ and 3a ′ of the end faces 1a and 3a are set in the same direction (downward in FIG. 3A), and thus it is possible to deal with even one television camera. However, in this case, the mirror shaft 23 needs to have a structure that does not move up and down when rotating, and a drive mechanism that only rotates and a drive mechanism that only moves up and down to retreat downward during fusion are required. It becomes.

  In the above-described embodiment, only one protrusion 45 is provided at the lower end of the arm 29b. However, the protrusion 45 is provided at the lower end of the mirror shaft drive mechanism mounting portion 49 at a position facing the protrusion 45. 5 may be provided symmetrically with the protrusion 45 in FIG. 5B. Similar to the protrusion 45, this other protrusion also moves relative to the groove 35 and performs the same function as the protrusion 45.

  Further, the other protrusion may be provided at a different position in the axial direction with respect to the protrusion 45, and a groove similar to the groove 35 may be provided at a different position in the axial direction.

  In other embodiments shown in FIGS. 8 and 9, two mirrors 23 </ b> A and 23 </ b> B are provided on the mirror shaft 210 in a state of being separated from each other along the axial direction. The mirror shaft 210 is movable in the axial direction orthogonal to the paper surface in FIGS. 8A and 9A, and the two mirrors 23A and 23B are positioned 180 degrees around the axis of the mirror shaft 210. Is different. Therefore, by moving the mirror shaft 210 in the axial direction, one of the two mirrors 23A and 23B can be positioned on the axis of the optical fibers 1 and 3.

  FIG. 8 shows a state in which the mirror shaft 210 is raised. In this state, the mirror 23A located on the base side is located on the axis of the optical fibers 1 and 3, and the mirror 23A is in the first state at this time. The image 1a ′ of the end face 1a of one optical fiber 1 is reflected and incident on the first lens 25a of the first television camera 25.

  On the other hand, FIG. 9 shows a state in which the mirror shaft 210 is lowered. In this state, the mirror 23B located on the tip side is located on the axis of the optical fibers 1 and 3, and at this time, the mirror 23B As a state, the image 3a ′ of the end face 3a of the other optical fiber 3 is reflected and incident on the second lens 27a of the second television camera 27.

  As described above, also in the present embodiment, the end faces 1a and 3a of the pair of optical fibers 1 and 3 can be individually imaged and observed from the front, so that it is higher than when the optical fiber is imaged from the side. An accurate image can be acquired, and a high-accuracy image can be acquired by the first television camera 25 and the second television camera 27 corresponding to the end faces 1a and 3a of the pair of optical fibers 1 and 3, respectively.

  In this embodiment, the two mirrors 23A and 23B are used. However, the mirror shaft 210 to which these mirrors 23A and 23B are attached is moved only in the axial direction of the pair of optical fibers 1 and 3. One of the end faces 1a and 3a can be imaged from the front, and the overall structure can be simplified as compared with the above-described embodiment provided with a mechanism for rotating the mirror shaft.

  Also in this embodiment, by providing a mechanism for rotating the mirror shaft 210, for example, from the state of FIG. 8, the mirror shaft 210 is lowered and rotated 90 degrees clockwise in FIG. 8A. In FIG. 8 and FIG. 9, one of the lower television cameras 25 may be used.

  Next, an optical fiber fusion splicing method according to the present invention in which the end faces 1a and 3a of the optical fibers 1 and 3 are fusion-bonded by the above-described fusion splicing apparatus will be described. FIG. 10 shows a process of fusion-bonding the end faces of the optical fibers by the method of the present invention.

  First, in the process of step S1, an optical fiber end face image is captured by the imaging means. Specifically, the mirror 23 is directed toward the end face 1a of one optical fiber 1 and an image of the end face 1a is picked up by the first television camera 25. Similarly, the direction of the mirror 23 is changed to the other optical fiber 3. The second television camera 27 captures an image of the end face 3a toward the end face 3a. Then, the images of both optical fibers 1 and 3 are respectively displayed on the first and second display portions 69 and 70 which are image means. FIG. 11A shows an image (end face observation image) of the optical fiber 1 (3) displayed on the display units 69 and 70. Each of the images is a front image on the end faces 1a and 3a of the optical fiber 1 (3).

  Next, in the process of step S2, the detection means detects the missing image from the image and hackles. Specifically, it lacks as luminance information from the images of the end faces 1a and 3a of the optical fiber 1 (3) obtained by imaging and detects hackles. From the image of FIG. 11 (a), a blackened portion displayed in shading is detected as a chip 100 or a hackle 101 with respect to the portion of the end face observation image of the optical fiber 1 (3) displayed in a circular white color. it can.

  Next, in the process of step S3, missing and hackles are clearly indicated. Specifically, a chipped portion or a hackle portion on the end face observation image of the optical fiber 1 (3) is clearly indicated by a mark such as an enclosure or a line (including an arrow). In FIG. 11 (a), the part of the chip 100 and the hackle 101 is indicated and indicated as a circle. In addition to this, the part of the chip 100 and the hackle 101 may be pointed and indicated as a mark such as an arrow indicating the part. Then, by the processing in step S3, the luminance information in any axial direction (for example, the X-axis direction and the Y-axis direction) that crosses the chipped or hackled portion is digitized, displayed as a graph. Luminance lines 102 and 103 when there is no chipping and hackles have rectangular waveforms. However, when there is a chip or a hackle, portions with low luminance are generated in the luminance lines 102 and 103. For example, a part of the brightness line 103 in the Y-axis direction that has a low brightness appears. This low luminance part is the part of the hackle 101. Similarly, a part of the luminance line 102 in the X-axis direction that has a low luminance appears, and that part is a part with a missing portion 100. In FIG. 11, the X-axis direction and the Y-axis direction are given as examples in the axial direction crossing the chipped and hackled portion, but these XY-axis directions are merely examples, and the present invention is not limited thereto.

  Next, in the process of step S4, it is determined whether or not there is a chip and a hackle on the end face observation image of the optical fiber 1 (3). If there is chipping or hackles, the process proceeds to the next step S5, and arc discharge is performed on the end faces 1a and 3a of the optical fiber 1 (3) by the discharging means. Specifically, a voltage is applied between discharge electrodes (not shown) to generate an arc, and the arc is applied to the end faces 1a and 3a of the optical fiber 1 (3). The discharge power at this time is set to the same power as when performing a normal fusion splicing operation. The discharge time is 50 ms × 150 times. The discharge position is the center position of the optical fiber 1 (3). In the present embodiment, the processes in steps S1 to S5 are repeated until there is no chipping or hackles due to arc discharge.

  If it is determined in step S4 that the end face observation image of the optical fiber 1 (3) is missing and hackles are absent, the process proceeds to step S6. In step S6, the left and right optical fibers 1, 3 are moved to a predetermined position. Specifically, the left and right optical fibers 1 and 3 are moved closer to each other. Then, the next step S7 is performed. In the process of step S7, arc discharge is generated between the discharge electrodes to start discharge on the end faces 1a and 3a of the optical fibers 1 and 3, and the optical fibers 1 and 3 are advanced so as to approach each other by a predetermined amount.

  Thereafter, the process proceeds to step S8. In the process of step S8, the arc discharge is terminated after a predetermined time has elapsed. By performing the process of step S8, the end faces of the pair of optical fibers 1 and 3 are fusion-connected.

  According to the fusion splicing method of optical fibers of this embodiment, the end faces 1a and 3a of the optical fibers 1 and 3 are picked up by the image pickup means (23, 25 and 27) arranged to face the end faces 1a and 3a of the optical fibers 1 and 3. Since the luminance information can be obtained from the image of the entire end face of the optical fiber, the luminance information is missing and the portion of the hackle can be clearly shown in the image means (69, 70).

  Further, according to the fusion splicing method of the optical fiber of the present embodiment, the unevenness of the optical fiber end surface is eliminated by discharging the optical fiber end surface until the chipped and hackles displayed and detected by the image means disappear. Can do. If the end faces 1a and 3a of the optical fibers 1 and 3 having no chipping and hackles are fusion-spliced, an improvement in mechanical characteristics can be obtained and a low-loss connection can be performed.

  Further, according to the fusion splicing method of the optical fiber of the present embodiment, the chipped and hackled part is clearly shown on the image means (69, 70) on the end face observation image of the optical fiber 1 (3). Is indicated by a mark such as a box or a line, and the luminance information in any axial direction crossing the chipped or hackled part is digitized and displayed as a graph. It can be visually confirmed whether or not exists.

  The present invention can be used for a fusion splicing method of optical fibers.

1, 3 ... Optical fiber 23 ... Mirror (imaging means)
25, 27 ... TV camera (imaging means)
69, 70 ... 1st and 2nd display part (image means)
100 ... chipping 101 ... hackle 102, 103 ... luminance line

Claims (4)

In an optical fiber fusion splicing method in which the end faces of a pair of optical fibers are fusion spliced together,
With the image pickup means arranged facing the end face of the optical fiber, the end face of the optical fiber is picked up from the front, and the discharge means discharges the chipped and hackled optical fiber end face detected by the detection means. An optical fiber fusion splicing method characterized by fusion splicing end faces. In the fusion splicing method of the optical fiber according to claim 1,
An image of the end face of the optical fiber obtained by the imaging unit is displayed on the image unit and is lacked as luminance information from the image, and the part of the hackle is clearly shown on the image unit.
An optical fiber fusion splicing method comprising: discharging the end face of the optical fiber with discharge means until the detected chipping or hackles are reduced or eliminated in the end face observation image. An optical fiber fusion splicing method according to claim 2,
The flaws and hackles are clearly indicated on the image means. The flaws and hackles on the end face observation image of the optical fiber are clearly indicated by surrounding or pointing with a mark such as a line. Connection method. An optical fiber fusion splicing method according to claim 3,
An optical fiber fusion splicing method characterized in that luminance information in an arbitrary axial direction crossing the chipped and hackled portion is digitized and displayed as a graph.

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