Fusion splicer and method for connecting optical fibers

Abstract

A fusion splicer (1) for fusion splicing a plurality of optical fibers (3L) arranged along the direction orthogonal to the longitudinal direction thereof respectively to other optical fibers (3R) comprises a base member (11L) having a groove portion (17L) in which are formed a plurality of V-grooves in which the plurality of optical fibers (3L) are mounted, and a pair of guide walls (12FL, 12BL) for guiding mounting of the plurality of optical fibers (3L) in the plurality of V-grooves, the pair of guide walls (12FL, 12BL) being disposed at intervals in the width direction of the groove portion (17L), one (12FL) of the pair of guide walls having a guide face (GF1) capable of contacting one of the plurality of optical fibers (3L), the other (12BL) of the pair of guide walls having a guide face (GF2) capable of contacting one other of the plurality of optical fibers (3L), and the guide faces (GF1, GF2) each including a portion that is inclined toward the groove portion (17L) when viewed along the extension direction of the plurality of V-grooves.

Description

Technical Field

[0001] The present disclosure relates to a fusion splicer and a method for connecting optical fibers.

[0002] This application claims priority based on Japanese Application No. 2021-101985 filed on June 18, 2021, and incorporates all the descriptions set forth in the above Japanese application.

Background Art

[0003] Conventionally, a fusion splicer for fusion-splicing a plurality of optical fibers arranged in parallel along a width direction that intersects the longitudinal direction is known (see Patent Document 1). This fusion splicer includes a fiber mounting table having a groove portion in which a plurality of V-grooves for installing a plurality of optical fibers are formed.

[0004] In the case of fusion splicing, the coating material at the tip of a plurality of optical fibers is removed. Among the optical fibers, the portion where the coating material is removed and the glass fiber is exposed is referred to as a bare fiber portion, and the portion in the state of being covered with the coating material is referred to as an optical fiber strand or an optical fiber core wire. A plurality of optical fibers tend to spread in the width direction in the bare fiber portion not covered with the coating material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0006] A fusion splicer according to an embodiment of the present disclosure is a fusion splicer for fusion splicing each of a plurality of parallel optical fibers arranged in a direction intersecting the longitudinal direction with other optical fibers, comprising: a base member having a groove portion in which a plurality of V-grooves are formed for the installation of the plurality of optical fibers; and a pair of guide walls for guiding the installation of the plurality of optical fibers into the plurality of V-grooves, wherein the pair of guide walls are spaced apart in the width direction of the groove portion, one of the pair of guide walls has a guide surface that can contact one of the plurality of optical fibers, and the other of the pair of guide walls has a guide surface that can contact another of the plurality of optical fibers, and the guide surface includes a portion that is inclined toward the groove portion when viewed along the extending direction of the plurality of V-grooves. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view of a part of the fusion splicer and the optical fibers to be spliced. [Figure 2A] Figure 2A is a top view of a part of a fusion splicer. [Figure 2B] Figure 2B is a top view of a part of the fusion splicer and the optical fiber to be spliced ​​during the installation process. [Figure 2C] Figure 2C is a top view of a part of the fusion splicer and the optical fibers to be spliced. [Figure 3] Figure 3 is a cross-sectional view of a part of the fusion splicer and the optical fibers to be spliced. [Figure 4] Figure 4 is a block diagram showing the control system for controlling a fusion splicer. [Figure 5] Figure 5 is a perspective view of the optical fiber and base member. [Figure 6] Figure 6 is a cross-sectional view of the optical fiber and base member. [Figure 7] Figure 7 is a partial cross-sectional view of the right base member. [Figure 8] Figure 8 is a partial cross-sectional view of the right base member. [Figure 9] Figure 9 is a partial cross-sectional view of the right base member. [Figure 10A]FIG. 10A is a top view of an example of a right base member. [Figure 10B] FIG. 10B is a top view of another example of a right base member. [Figure 10C] FIG. 10C is a top view of another example of a right base member. [Figure 10D] FIG. 10D is a top view of another example of a right base member. [Figure 10E] FIG. 10E is a top view of another example of a right base member. [Figure 10F] FIG. 10F is a top view of another example of a right base member. [Figure 10G] FIG. 10G is a top view of another example of a right base member. [Figure 10H] FIG. 10H is a top view of another example of a right base member. [Figure 10I] FIG. 10I is a top view of another example of a right base member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] [PROBLEMS TO BE SOLVED BY THE PRESENT DISCLOSURE] The groove portion of the fiber installation table is configured such that the bare fiber portions of a plurality of optical fibers, that is, a plurality of V-grooves in which glass fibers are installed, are parallel to each other. Therefore, there is a possibility that the direction of the outermost glass fiber among the plurality of glass fibers extending in the width direction may deviate from the direction of the corresponding V-groove. And some of the bare fiber portions of the plurality of optical fibers extending in the width direction may not be properly accommodated in the corresponding V-grooves and may protrude from the corresponding V-grooves.

[0009] Therefore, it is desirable to suppress the bare fiber portion of the optical fiber from protruding from the V-groove.

[0010] [EFFECTS OF THE PRESENT DISCLOSURE] According to the present disclosure, it is possible to suppress the bare fiber portion of the optical fiber from protruding from the V-groove.

[0011] [DESCRIPTION OF EMBODIMENTS OF THE PRESENT DISCLOSURE] First, embodiments of the present disclosure will be listed and described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description thereof will not be repeated.

[0012] (1) A fusion splicing machine according to an aspect of the present disclosure is a fusion splicing machine that fuses and connects each of a plurality of optical fibers arranged in parallel along a direction intersecting the longitudinal direction to another optical fiber, and includes a base member having a groove portion in which a plurality of V-grooves for installing the plurality of optical fibers are formed, and a pair of guide walls for guiding the installation of the plurality of optical fibers into the plurality of V-grooves. The pair of guide walls are arranged at intervals in the width direction of the groove portion. One of the pair of guide walls has a guide surface that can contact one of the plurality of optical fibers, and the other of the pair of guide walls has a guide surface that can contact another one of the plurality of optical fibers. The guide surface includes a portion that inclines toward the groove portion when viewed along the extending direction of the plurality of V-grooves. This configuration can narrow the spread of the bare fiber portion in the width direction when the bare fiber portions of the plurality of optical fibers are installed in the plurality of V-grooves by having a pair of guide walls. This is because when the bare fiber portion that has spread outward in the width direction approaches the V-groove, it contacts the guide surface of the guide wall and is pushed back inward in the width direction. As a result, this configuration has the effect of suppressing the bare fiber portion from protruding from the V-groove when the bare fiber portions of the plurality of optical fibers are installed in the plurality of V-grooves.

[0013] (2) The guide surface may be arranged to be continuous with the surface of one of the V grooves when viewed along the extending direction of the V grooves. Continuity between the guide surface and the groove surface means, for example, that at the point where the guide surface and the groove surface are connected when viewed along the extending direction of the V grooves, the inclination angle of the guide surface and the inclination angle of the groove surface are equal. Note that the guide surface and the groove surface do not need to be physically connected, as the guide surface and the groove surface may be spaced apart from each other in the extending direction of the V grooves. The inclination angle of the guide surface is the angle formed between the guide surface and a virtual vertical plane, and the inclination angle of the groove surface is the angle formed between the groove surface and a virtual vertical plane. The equality of the inclination angle of the guide surface and the inclination angle of the groove surface may include the angular difference between the inclination angle of the guide surface and the inclination angle of the groove surface being less than or equal to a predetermined small angle. This configuration has the effect of making it easier for a bare fiber portion moving along the guide surface while being pushed back by the guide surface to enter the V groove.

[0014] (3) The pair of guide walls may be formed as separate members from the base member. This configuration has the effect of allowing guide walls to be retrofitted to an existing fusion splicer without removing or replacing the existing base member from the existing fusion splicer. This configuration also allows the guide walls and the base member to be formed from different materials. Therefore, this configuration has the effect of reducing the manufacturing cost of the fusion splicer compared to, for example, the case where the guide walls and the base member are integrally formed from the same material and the material of the base member is expensive.

[0015] (4) The pair of guide walls may be integrated with the base member. This configuration has the effect of improving the positioning accuracy of the guide walls relative to the V groove compared to, for example, the case in which the guide walls are formed as separate members from the base member.

[0016] (5) At least one of the pair of guide walls may be configured to be movable relative to the groove portion in the width direction. This configuration has the effect of allowing the guide wall to accommodate optical fibers with various numbers of cores. For example, this configuration has the effect of allowing the guide wall configured to correct the widthwise spreading of a tape fiber with fewer cores (e.g., a 16-core tape fiber or an 8-core tape fiber) to correct the widthwise spreading of the bare fiber portion of a 24-core tape fiber.

[0017] (6) A method for connecting optical fibers according to one aspect of the present disclosure is a method for connecting optical fibers using a fusion splicer that includes a base member having a groove portion in which a plurality of V-grooves are formed for installing a plurality of optical fibers, and a pair of guide walls that guide the installation of the plurality of optical fibers into the plurality of V-grooves, wherein each of the plurality of optical fibers is fusion spliced ​​with another optical fiber, the method comprising the steps of: installing the plurality of optical fibers into the plurality of V-grooves while contacting one of the plurality of optical fibers with the guide surface of one of the pair of guide walls which are spaced apart in the width direction of the groove portion; and fusion splicing each of the plurality of optical fibers with another optical fiber. By having the step of installing the plurality of optical fibers into the plurality of V-grooves while contacting one of the plurality of optical fibers with the guide surface of one of the pair of guide walls, the spread of the bare fiber portion in the width direction can be narrowed when the bare fiber portion of the plurality of optical fibers is installed in the plurality of V-grooves. This is because the bare fiber portion that has spread outward in the width direction comes into contact with the guide surface of the guide wall as it approaches the V-groove and is pushed back inward in the width direction. As a result, this method has the effect of preventing the bare fiber portions of multiple optical fibers from protruding from the V-grooves when multiple bare fiber portions of multiple optical fibers are placed in multiple V-grooves. [Details of the embodiments of this disclosure] In the following, with reference to the attached drawings, a specific example of a fusion splicer 1 and a method for connecting optical fibers according to the embodiment of this disclosure will be described.

[0018] Figure 1 is a perspective view showing a part of the fusion splicer 1. In Figure 1, X1 represents one direction of the X axis in a three-dimensional Cartesian coordinate system, and X2 represents the other direction of the X axis. Similarly, Y1 represents one direction of the Y axis in a three-dimensional Cartesian coordinate system, and Y2 represents the other direction of the Y axis. Likewise, Z1 represents one direction of the Z axis in a three-dimensional Cartesian coordinate system, and Z2 represents the other direction of the Z axis. In this embodiment, the X1 side of the fusion splicer 1 corresponds to the front side of the fusion splicer 1, and the X2 side of the fusion splicer 1 corresponds to the rear side of the fusion splicer 1. The Y1 side of the fusion splicer 1 corresponds to the left side of the fusion splicer 1, and the Y2 side of the fusion splicer 1 corresponds to the right side of the fusion splicer 1. The Z1 side of the fusion splicer 1 corresponds to the top side of the fusion splicer 1, and the Z2 side of the fusion splicer 1 corresponds to the bottom side of the fusion splicer 1. The same applies to the other figures.

[0019] The fusion splicer 1 is a device configured to fusion splice multiple pairs of optical fibers, which are arranged with their end faces facing each other, together by arc discharge. In the illustrated example, the fusion splicer 1 is configured to fusion splice four pairs of optical fibers. Specifically, the fusion splicer 1 includes a pair of electrode rods 5 (rear electrode rod 5B and front electrode rod 5F), a pair of base members 11 (left base member 11L and right base member 11R), a pair of clamps 21 (left clamp 21L and right clamp 21R), and a pair of fiber holders 31 (left fiber holder 31L and right fiber holder 31R).

[0020] The pair of electrode rods 5 includes a rear electrode rod 5B and a front electrode rod 5F, which are spaced apart from each other in the X-axis direction. The pair of electrode rods 5 are positioned so that the tip 5Ba of the rear electrode rod 5B and the tip 5Fa of the front electrode rod 5F face each other. In the illustrated example, the rear electrode rod 5B includes a substantially conical portion whose diameter decreases towards the tip 5Ba. The same applies to the front electrode rod 5F.

[0021] The multiple pairs of optical fibers arranged on the pair of base members 11 are glass fibers and are positioned between the rear electrode rod 5B and the front electrode rod 5F for generating an arc discharge. Of the multiple pairs of optical fibers, the portion placed on the pair of base members 11 is a bare fiber portion in which the coating material has been removed and the glass is exposed.

[0022] Specifically, the multiple pairs of bare fiber sections include the bare fiber sections of the left optical fiber group 3L that constitute the left ribbon fiber 4L, and the bare fiber sections of the right optical fiber group 3R that constitute the right ribbon fiber 4R. For the sake of clarity, the left optical fiber group 3L and the right optical fiber group 3R may be referred to as optical fiber group 3 below.

[0023] A ribbon cable consists of multiple optical fibers (optical fiber strands) arranged in parallel and coated together with, for example, an ultraviolet-curing resin (coating material). In the illustrated example, the left ribbon cable 4L and the right ribbon cable 4R are each 4-core ribbon cables, each consisting of four optical fibers (optical fiber strands) arranged in parallel and coated together with an ultraviolet-curing resin (coating material).

[0024] The pair of base members 11 are members for supporting multiple pairs of optical fibers and include a left base member 11L and a right base member 11R that are arranged to sandwich a pair of electrode rods 5. That is, the pair of electrode rods 5 are arranged between the left base member 11L and the right base member 11R, which are spaced apart from each other in the Y-axis direction. In the illustrated example, the right base member 11R has a right V-groove group 17R, also referred to as the right optical fiber arrangement portion or right groove portion, and the left base member 11L has a left V-groove group 17L, also referred to as the left optical fiber arrangement portion or left groove portion. In the following, for convenience of explanation, the left V-groove group 17L and the right V-groove group 17R may be referred to as the V-groove group 17.

[0025] The left V-groove group 17L has multiple V-grooves for arranging multiple optical fibers (left optical fiber group 3L), and the right V-groove group 17R has multiple V-grooves for arranging multiple optical fibers (right optical fiber group 3R). In the illustrated example, the left V-groove group 17L has four V-grooves for arranging four optical fibers. The four V-grooves are arranged at equal intervals in the X-axis direction and are formed to extend linearly along the Y-axis direction. Similarly, the right V-groove group 17R has four V-grooves for arranging four optical fibers. The four V-grooves are arranged at equal intervals in the X-axis direction and are formed to extend linearly along the Y-axis direction.

[0026] The multiple V-grooves in the right V-groove group 17R and the multiple V-grooves in the left V-groove group 17L are configured to allow for the simultaneous positioning of multiple optical fiber pairs. In the illustrated example, the four V-grooves in the right V-groove group 17R and the four V-grooves in the left V-groove group 17L are arranged to face each other in the extending direction (Y-axis direction), and are configured to allow for the simultaneous positioning of four optical fiber pairs.

[0027] As a result, the four optical fibers positioned by the four V-grooves in the right V-groove group 17R and the four optical fibers positioned by the four V-grooves in the left V-groove group 17L are brought into contact with each other in the region between the right base member 11R (right V-groove group 17R) and the left base member 11L (left V-groove group 17L).

[0028] Here, with reference to Figures 2A to 2C, the details of the V-groove group 17 in which the four optical fiber pairs are positioned will be explained. Figures 2A to 2C are top views showing a part of the fusion splicer 1. Specifically, Figures 2A to 2C are top views of the electrode rod 5, the base member 11, and the guide wall 12. More specifically, Figure 2A shows the state before the optical fiber group 3 is positioned above the V-groove group 17, Figure 2B shows the state when the optical fiber group 3 is positioned above the V-groove group 17 (the state before the optical fiber group 3 is installed in the V-groove group 17), and Figure 2C shows the state after the optical fiber group 3 is installed in the V-groove group 17. In Figures 2A to 2C, for clarity, a coarse dot pattern is applied to the groove surface of the V-groove group 17, and a fine dot pattern is applied to the guide surface GF (described later) of the guide wall 12. Also, the bottom of each V-groove is represented by a dashed line.

[0029] As shown in Figure 2A, the left V-groove group 17L includes the first left V-groove 17AL, the second left V-groove 17BL, the third left V-groove 17CL, and the fourth left V-groove 17DL, while the right V-groove group 17R includes the first right V-groove 17AR, the second right V-groove 17BR, the third right V-groove 17CR, and the fourth right V-groove 17DR. The first left V-groove 17AL and the first right V-groove 17AR constitute the first V-groove pair 17A, the second left V-groove 17BL and the second right V-groove 17BR constitute the second V-groove pair 17B, the third left V-groove 17CL and the third right V-groove 17CR constitute the third V-groove pair 17C, and the fourth left V-groove 17DL and the fourth right V-groove 17DR constitute the fourth V-groove pair 17D.

[0030] Furthermore, as shown in Figure 2B, the left optical fiber group 3L includes the first left optical fiber 3AL, the second left optical fiber 3BL, the third left optical fiber 3CL, and the fourth left optical fiber 3DL as bare fiber portions, and the right optical fiber group 3R includes the first right optical fiber 3AR, the second right optical fiber 3BR, the third right optical fiber 3CR, and the fourth right optical fiber 3DR as bare fiber portions. The first left optical fiber 3AL and the first right optical fiber 3AR constitute the first optical fiber pair 3A, the second left optical fiber 3BL and the second right optical fiber 3BR constitute the second optical fiber pair 3B, the third left optical fiber 3CL and the third right optical fiber 3CR constitute the third optical fiber pair 3C, and the fourth left optical fiber 3DL and the fourth right optical fiber 3DR constitute the fourth optical fiber pair 3D.

[0031] The guide wall 12 is configured to guide the placement of the optical fiber group 3 into the V-groove group 17. In the illustrated example, the guide wall 12 includes a left guide wall 12L and a right guide wall 12R, as shown in Figure 2A. The left guide wall 12L includes a left rear guide wall 12BL and a left front guide wall 12FL, and the right guide wall 12R includes a right rear guide wall 12BR and a right front guide wall 12FR.

[0032] Specifically, the guide wall 12 includes a left guide wall 12L that guides the placement of the left optical fiber group 3L into the left V-groove group 17L, and a right guide wall 12R that guides the placement of the right optical fiber group 3R into the right V-groove group 17R.

[0033] The left guide wall 12L includes a left rear guide wall 12BL and a left front guide wall 12FL, which are formed at positions corresponding to the left end of the left V-groove group 17L, located on the side closer to the left fiber holder 31L. Similarly, the right guide wall 12R includes a right rear guide wall 12BR and a right front guide wall 12FR, which are formed at positions corresponding to the right end of the right V-groove group 17R, located on the side closer to the right fiber holder 31R.

[0034] Furthermore, the guide wall 12 has a guide surface GF. In Figures 2A to 2C, a fine dot pattern is applied to the guide surface GF for clarity. Specifically, as shown in Figure 2B, the left front guide wall 12FL has a first guide surface GF1 that contacts the first left optical fiber 3AL, which is located at the very front (X1 side) of the left optical fiber group 3L, and the left rear guide wall 12BL has a second guide surface GF2 that contacts the fourth left optical fiber 3DL, which is located at the very rear (X2 side) of the left optical fiber group 3L. Similarly, the right front guide wall 12FR has a third guide surface GF3 that contacts the first right optical fiber 3AR, which is located at the very front (X1 side) of the right optical fiber group 3R, and the right rear guide wall 12BR has a fourth guide surface GF4 that contacts the fourth right optical fiber 3DR, which is located at the very rear (X2 side) of the right optical fiber group 3R.

[0035] In the illustrated example, the first guide surface GF1 of the left front guide wall 12FL is formed to be continuous with the first left V-groove 17AL, which is located furthest forward in the left V-groove group 17L, and the second guide surface GF2 of the left rear guide wall 12BL is formed to be continuous with the fourth left V-groove 17DL, which is located furthest rear in the left V-groove group 17L. Similarly, the third guide surface GF3 of the right front guide wall 12FR is formed to be continuous with the first right V-groove 17AR, which is located furthest forward in the right V-groove group 17R, and the fourth guide surface GF4 of the right rear guide wall 12BR is formed to be continuous with the fourth right V-groove 17DR, which is located furthest rear in the right V-groove group 17R.

[0036] Here, we will explain the procedure for installing optical fiber group 3 into V-groove group 17. The following explanation pertains to the procedure for installing the left optical fiber group 3L into the left V-groove group 17L, but it also applies to the procedure for installing the right optical fiber group 3R into the right V-groove group 17R.

[0037] When installing the left optical fiber group 3L into the left V-groove group 17L, the worker positions the left optical fiber group 3L, which is spread in the width direction (X-axis direction) of the left tape core 4L, directly above the left V-groove group 17L, as shown in Figure 2B. Then, the worker moves the left optical fiber group 3L downwards (in the direction in which the left V-groove group 17L is located).

[0038] When the left optical fiber group 3L is moved downward (in the direction in which the left V-groove group 17L is located), the first left optical fiber 3AL, located at the frontmost end (X1 side) of the left optical fiber group 3L, comes into contact with the first guide surface GF1 of the left front guide wall 12FL, and the fourth left optical fiber 3DL, located at the rearmost end (X2 side) of the left optical fiber group 3L, comes into contact with the second guide surface GF2 of the left rear guide wall 12BL.

[0039] Subsequently, the first left optical fiber 3AL, the foremost of the four optical fibers constituting the left optical fiber group 3L, is guided by the first guide surface GF1 of the left front guide wall 12FL, which is inclined toward the first left V-groove 17AL, and as shown by arrow AR1 in Figure 2B, it is moved backward (in the X2 direction) as it moves downward (in the Z2 direction). In other words, the first guide surface GF1 of the left front guide wall 12FL can move the first left optical fiber 3AL, which is spreading in the width direction (forward (X1 direction)), backward (in the X2 direction) so that as the first left optical fiber 3AL moves downward (in the Z2 direction), it approaches the center in the width direction of the left ribbon fiber 4L. In other words, the first guide surface GF1 can straighten the first left optical fiber 3AL, which is curved in the width direction (forward (X1 direction)), so that its longitudinal direction (axial direction) coincides with the extending direction of the first left V-groove 17AL.

[0040] In the example shown in Figure 2B, the second left optical fiber 3BL extends straight along the second left V-groove 17BL. However, like the first left optical fiber 3AL, it may also be curved in the width direction (forward (X1 direction)), i.e., curved in the width direction (forward (X1 direction)).

[0041] In this case, the second left optical fiber 3BL is pushed backward by the first left optical fiber 3AL, which has been moved backward by the left front guide wall 12FL. As a result, the second left optical fiber 3BL extends straight along the second left V-groove 17BL.

[0042] Similarly, the fourth left optical fiber 3DL, located furthest to the rear of the four optical fibers constituting the left optical fiber group 3L, is guided by the second guide surface GF2 of the left rear guide wall 12BL, which slopes toward the fourth left V-groove 17DL, and as shown by arrow AR2 in Figure 2B, it is moved forward (in the X1 direction) as it moves downward (in the Z2 direction). In other words, the second guide surface GF2 of the left rear guide wall 12BL can move the fourth left optical fiber 3DL, which is curved in the width direction (rearward (X2 direction)), forward (in the X1 direction) so that as the fourth left optical fiber 3DL moves downward (in the Z2 direction), it moves closer to the center in the width direction of the left ribbon fiber 4L. In other words, the second guide surface GF2 can straighten the fourth left optical fiber 3DL, which is curved in the width direction (rearward (X2 direction)), so that its longitudinal direction (axial direction) coincides with the extending direction of the fourth left V-groove 17DL.

[0043] In the example shown in Figure 2B, the third left optical fiber 3CL extends straight along the third left V-groove 17CL. However, like the fourth left optical fiber 3DL, it may also be curved in the width direction (rearward (X2 direction)).

[0044] In this case, the third left optical fiber 3CL is pushed forward by the fourth left optical fiber 3DL, which has been moved forward by the left rear guide wall 12BL. As a result, the third left optical fiber 3CL extends straight along the third left V-groove 17CL.

[0045] Subsequently, as shown in Figure 2C, the left optical fiber group 3L is moved downward to the extent that it contacts the left V-groove group 17L, and its spread in the width direction is narrowed by the left rear guide wall 12BL and the left front guide wall 12FL. That is, the spread in the width direction of the left optical fiber group 3L is narrowed so that the axes of the first left optical fiber 3AL to the fourth left optical fiber 3DL are parallel to each other. As a result, the first left optical fiber 3AL is installed in the first left V-groove 17AL with its longitudinal direction parallel to the extending direction of the first left V-groove 17AL. The same applies to the second left optical fiber 3BL to the fourth left optical fiber 3DL.

[0046] Next, with reference to Figure 3, the movement of the pair of clamps 21 (left clamp 21L and right clamp 21R) will be described. Figure 3 is a cross-sectional view showing a part of the fusion splicer 1. Specifically, Figure 3 is a view from the X1 side, as indicated by the arrows, of the cross section including the cutting line III-III in Figure 2C. Note that the cross section in Figure 2C includes the cross section of the base member 11.

[0047] The left clamp 21L is configured to relatively press the left optical fiber group 3L, which is installed in the left V-groove group 17L, against the left V-groove group 17L. Similarly, the right clamp 21R is configured to relatively press the right optical fiber group 3R, which is installed in the right V-groove group 17R, against the right V-groove group 17R. In the illustrated example, the left clamp 21L includes a left arm portion 21La and a left pressing portion 21Lb, and the right clamp 21R includes a right arm portion 21Ra and a right pressing portion 21Rb. The left arm portion 21La is positioned above the left V-groove group 17L, and the right arm portion 21Ra is positioned above the right V-groove group 17R. The left arm portion 21La and the right arm portion 21Ra are configured to move in the vertical direction. The left arm portion 21La and the right arm portion 21Ra may have, for example, a substantially rectangular columnar shape as shown in Figure 1. Furthermore, the left pressing portion 21Lb may be attached to the lower end of the left arm portion 21La, and the right pressing portion 21Rb may be attached to the lower end of the right arm portion 21Ra. In the illustrated example, the left pressing portion 21Lb is movable in the vertical direction (Z direction) at the lower end of the left arm portion 21La, and the right pressing portion 21Rb is movable in the vertical direction (Z direction) at the lower end of the right arm portion 21Ra. In the state shown in Figure 3, the left pressing portion 21Lb is separated from the left optical fiber group 3L installed in the left V-groove group 17L, but by moving the left arm portion 21La downward, the left pressing portion 21Lb can come into contact with the left optical fiber group 3L and press the left optical fiber group 3L toward the left V-groove group 17L. The same applies to the right pressing portion 21Rb.

[0048] In the illustrated example, the left clamp 21L may be configured to allow the clamping pressure to be varied. The clamping pressure is the pressure that the left optical fiber group 3L, installed in the left V-groove group 17L, receives from the left pressing portion 21Lb of the left clamp 21L. An elastic body such as a spring that biases the left pressing portion 21Lb downward may be placed between the left arm portion 21La and the left pressing portion 21Lb. In this case, the clamping pressure of the left clamp 21L can be controlled by controlling the position of the left arm portion 21La in the vertical direction. The same applies to the right clamp 21R.

[0049] Furthermore, as shown in Figure 1, the left fiber holder 31L is configured to hold the left optical fiber group 3L, and the right fiber holder 31R is configured to hold the right optical fiber group 3R. Specifically, the left fiber holder 31L is configured to hold the left ribbon fiber 4L including the left optical fiber group 3L, and the right fiber holder 31R is configured to hold the right ribbon fiber 4R including the right optical fiber group 3R. More specifically, the left fiber holder 31L has a left fiber holder body 31La having a recess (not shown) for accommodating the left ribbon fiber 4L, and a left cover 31Lb attached to the left fiber holder body 31La. Similarly, the right fiber holder 31R has a right fiber holder body 31Ra having a recess (not shown) for accommodating the right ribbon fiber 4R, and a right cover 31Rb attached to the right fiber holder body 31Ra.

[0050] When the left tape fiber core 4L is housed in the left fiber holder body 31La and the left cover 31Lb is closed, the left tape fiber core 4L is held in the left fiber holder 31L. The left fiber holder 31L is movable in a direction along the axial direction of the left optical fiber group 3L that it holds. That is, the left fiber holder 31L is movable along the extending direction (Y-axis direction) of the left V-groove group 17L. When the left fiber holder 31L holding the left optical fiber group 3L moves, the held left optical fiber group 3L can move along the left V-groove group 17L.

[0051] Similarly, when the right tape core 4R is housed in the right fiber holder body 31Ra and the right cover 31Rb is closed, the right tape core 4R is held in the right fiber holder 31R. The right fiber holder 31R is movable in a direction along the axial direction of the right optical fiber group 3R it holds. That is, the right fiber holder 31R is movable along the extending direction (Y-axis direction) of the right V-groove group 17R. When the right fiber holder 31R holding the right optical fiber group 3R moves, the held right optical fiber group 3R can move along the right V-groove group 17R.

[0052] Next, with reference to Figure 4, the control system for controlling the fusion splicer 1 will be described. Figure 4 is a block diagram showing the control system for controlling the fusion splicer 1.

[0053] As shown in Figure 4, the fusion splicer 1 includes an imaging device 51, a fusion splicer 52, a clamp drive device 53, a fiber holder drive device 54, a display device 55, and a control device 60. In this embodiment, the imaging device 51, the fusion splicer 52, the clamp drive device 53, the fiber holder drive device 54, and the display device 55 are controlled by the control device 60.

[0054] The control device 60 includes, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), a communication module, and an external storage device. It is a computer equipped with the following features.

[0055] The imaging device 51 is configured, for example, to include a pair of cameras (X camera and Y camera). Both the X camera and the Y camera are positioned to simultaneously image the end of the left optical fiber group 3L installed in the left V-groove group 17L and the end of the right optical fiber group 3R installed in the right V-groove group 17R. Furthermore, the imaging direction of the X camera and the imaging direction of the Y camera are orthogonal to each other. Based on the images of the optical fiber group 3 captured from two different directions by the pair of cameras, the control device 60 can determine the position of the optical fiber group 3.

[0056] The fusion splicer 52 is a device that fusion splices the end of the left optical fiber group 3L and the end of the right optical fiber group 3R. In this embodiment, a pair of electrode rods 5 are included in the fusion splicer 52.

[0057] The clamp drive device 53 is a device for pressing the optical fiber group 3 relative to the V-groove group 17. In this embodiment, the clamp drive device 53 includes actuators that move the left arm portion 21La, which constitutes the left clamp 21L, and the right arm portion 21Ra, which constitutes the right clamp 21R, in the vertical direction.

[0058] The fiber holder drive device 54 is a device for moving the optical fiber group 3 in a direction along the axial direction (Y-axis direction). In this embodiment, the fiber holder drive device 54 includes an actuator for moving the left fiber holder 31L in a direction along the axial direction (Y-axis direction) of the left optical fiber group 3L, and an actuator for moving the right fiber holder 31R in a direction along the axial direction (Y-axis direction) of the right optical fiber group 3R.

[0059] The display device 55 is a device for displaying various types of information. In this embodiment, the display device 55 is configured to display images captured by the imaging device 51. In this embodiment, the display device 55 is a liquid crystal display.

[0060] The control device 60 is a device for controlling the imaging device 51, the fusion splicer 52, the clamp drive device 53, the fiber holder drive device 54, and the display device 55, respectively. In this embodiment, the control device 60 acquires images captured by the imaging device 51 by controlling the imaging device 51. The control device 60 can, for example, display the acquired images on the display device 55. The control device 60 can also determine the state of one or more pairs of optical fibers by applying image processing to the acquired images. The control device 60 can also generate an arc discharge between the rear electrode rod 5B and the front electrode rod 5F by controlling the fusion splicer 52. Furthermore, the control device 60 can move the left arm portion 21La of the left clamp 21L and the right arm portion 21Ra of the right clamp 21R in the vertical direction by controlling the clamp drive device 53. The control device 60 can control the left clamp 21L to change the pressing state of the left optical fiber group 3L located in the left V-groove group 17L, and the right clamp 21R can change the pressing state of the right optical fiber group 3R located in the right V-groove group 17R. Furthermore, the control device 60 can control the positions of the left fiber holder 31L and the right fiber holder 31R in the Y-axis direction by controlling the fiber holder drive device 54. Specifically, by moving the left fiber holder 31L in the left-right direction (Y-axis direction), the control device 60 can move the left optical fiber group 3L held by the left fiber holder 31L in the left-right direction (Y-axis direction), and by moving the right fiber holder 31R in the left-right direction (Y-axis direction), the control device 60 can move the right optical fiber group 3R held by the right fiber holder 31R in the left-right direction (Y-axis direction).

[0061] Next, the details of the guide wall 12 will be described with reference to Figures 5 and 6. Figure 5 is a top perspective view of the base member 11 having a group of V-grooves 17 in which each of the 16 optical fibers of the ribbon cable can be installed. Figure 6 is a view from the Y2 side, as indicated by the arrows, of the cross section including the cutting line VI-VI in Figure 5. Note that the cross section in Figure 5 includes the cross section of the right base member 11R in which 16 V-grooves (first right V-groove 17R1 to 16th right V-groove 17R16) are formed, and the cross sections of the bare fiber portions (first right optical fiber 3R1 to 16th right optical fiber 3R16) of the 16 optical fibers that constitute the 16-core right ribbon cable 4R.

[0062] In recent years, not only 16-core ribbon cables as shown in Figure 5, but also ultra-multi-core ribbon cables and intermittent ribbon cables (pliable ribbon cables) with even more optical fibers have been put into practical use. A characteristic of these ribbon cables is that the bare fiber portion after the coating is removed tends to spread out more easily in the width direction (X-axis direction) compared to a 4-core ribbon cable as shown in Figure 1. In the case of ultra-multi-core ribbon cables, one reason for this is thought to be that when the coating is removed, the edges of the coating are crushed, and the spacing between adjacent optical fibers gradually widens. Furthermore, in intermittent ribbon cables, where two or four optical fibers (optical fiber strands) are paired and loosely engaged in a mesh-like manner to form the ribbon cable, one reason for this is thought to be that when the intermittent ribbon cable is installed in the fiber holder, these optical fibers tend to point in various directions, and as a result, tend to point towards the outside of the tape where there are no obstructions.

[0063] Therefore, in the examples shown in Figures 5 and 6, the bare fiber portions of the 16 optical fibers constituting the 16-core ribbon cable are more likely to spread out in the width direction (X-axis direction) than the bare fiber portions of the 4 optical fibers constituting the 4-core ribbon cable shown in Figure 1.

[0064] Furthermore, when the bare fiber portion extending in the width direction is installed in the V-groove group 17 engraved on the flat surface, as shown in Figures 5 and 6, the orientation of the outermost core of the tape core is not restricted in a configuration that does not include the guide wall 12. Note that "orientation of the outermost core of the tape core" refers to the orientation of the bare fiber portion of the outermost optical fiber in the width direction among the multiple optical fibers that make up the tape core. In the example shown in Figures 5 and 6, the orientation of the outermost core of the right tape core 4R refers to the orientation of the first right optical fiber 3R1 and the orientation of the 16th right optical fiber 3R16.

[0065] Therefore, in a configuration that does not include the guide wall 12, the discrepancy between the orientation of the V-groove group 17, which is processed to be straight, and the orientation of the outermost core of the tape fiber becomes large, resulting in a situation where the optical fiber group 3 does not fit within the V-groove group 17 and protrudes from the V-groove group 17. Such a situation leads to failure and rework of the fusion splicing. Furthermore, reworking the fusion splicing requires redoing the cutting of the tape fiber and the removal of the coating material, which adds to the time spent. The guide wall 12 can suppress the occurrence of such a situation.

[0066] The following explanation, referring to Figures 5 and 6, pertains to the right guide wall 12R that contacts the right optical fiber group 3R, but it also applies similarly to the left guide wall 12L that contacts the left optical fiber group 3L.

[0067] The bare fiber portions of the 16 optical fibers constituting the right ribbon core 4R (the first right optical fiber 3R1 to the 16th right optical fiber 3R16) are spread out in the width direction (X-axis direction) when they are positioned above the right V-groove group 17R as shown in Figures 5 and 6, that is, before they come into contact with the right guide wall 12R.

[0068] Figures 5 and 6 show the state in which the first right optical fiber 3R1 to the 16th right optical fiber 3R16 are positioned higher than the height H1 of the right guide wall 12R. The height H1 of the right guide wall 12R refers to the distance between the upper surface TF1 of the right base member 11R (right optical fiber arrangement section) and the upper surface TF2 of the right guide wall 12R in the Z-axis direction.

[0069] Figure 6 shows the movement paths of the right optical fiber group 3R as it is moved downward from a height H1, indicated by dotted arrows. Figure 6 also shows the right optical fiber group 3R moved downward to a height H2, indicated by a dashed line, and the right optical fiber group 3R installed within the right V-groove group 17R, indicated by a thick dotted line. Note that height H2 refers to the height relative to the upper surface TF1 (see Figure 5) of the right base member 11R (right optical fiber arrangement section).

[0070] As shown by the dashed line in Figure 6, when the first right optical fiber 3R1 is moved downward to a height H2, it comes into contact with the third guide surface GF3 of the right front guide wall 12FR. Then, when the first right optical fiber 3R1 is moved further downward, it moves inward (in the X2 direction) along the third guide surface GF3 and is finally placed in the first right V groove 17R1 as shown by the thick dotted line in Figure 6. This is because the third guide surface GF3 is formed to be inclined toward the right V groove group 17R when viewed from the right side (X2 side) along the extending direction (Y axis direction) of the right V groove group 17R. In other words, the third guide surface GF3 is inclined to approach the right V groove group 17R when viewed from the right side, and is formed to be continuous with the first groove surface GS1 of the first right V groove 17R1.

[0071] Similarly, when the 16th right optical fiber 3R16 is moved downward to a height H2, as shown by the dashed line in Figure 6, it comes into contact with the fourth guide surface GF4 of the right rear guide wall 12BR. Then, when the 16th right optical fiber 3R16 is moved further downward, it moves inward (in the X1 direction) along the fourth guide surface GF4 and is finally placed in the 16th right V groove 17R16, as shown by the thick dotted line in Figure 6. This is because the fourth guide surface GF4 is inclined to approach the right V groove group 17R in a right side view and is formed to be continuous with the 16th groove surface GS16 of the 16th right V groove 17R16.

[0072] As shown by the dotted arrow in Figure 6, the second right optical fiber 3R2 moves inward (in the X2 direction) when it is below the height H2, pushed by the first right optical fiber 3R1 which moves inward (in the X2 direction) along the third guide surface GF3. Then, as shown by the thick dotted line in Figure 6, the second right optical fiber 3R2 is finally installed in the second right V groove 17R2. Similarly, as shown by the dotted arrow in Figure 6, the third right optical fiber 3R3 moves inward (in the X2 direction) when it is below the height H2, pushed by the second right optical fiber 3R2 which moves inward (in the X2 direction) pushed by the first right optical fiber 3R1. Then, as shown by the thick dotted line in Figure 6, the third right optical fiber 3R3 is finally installed in the third right V groove 17R3.

[0073] Similarly, as indicated by the dotted arrow in Figure 6, the 15th right optical fiber 3R15 moves inward (in the X1 direction) when it is below the height H2, pushed by the 16th right optical fiber 3R16 which moves inward (in the X1 direction) along the 4th guide surface GF4. Then, as indicated by the thick dotted line in Figure 6, the 15th right optical fiber 3R15 is finally installed in the 15th right V groove 17R15. Also, as indicated by the dotted arrow in Figure 6, the 14th right optical fiber 3R14 moves inward (in the X1 direction) when it is below the height H2, pushed by the 15th right optical fiber 3R15 which moves inward (in the X1 direction) pushed by the 16th right optical fiber 3R16. Then, as indicated by the thick dotted line in Figure 6, the 14th right optical fiber 3R14 is finally installed in the 14th right V groove 17R14.

[0074] In the examples shown in Figures 5 and 6, the fourth right optical fiber 3R4 to the thirteenth right optical fiber 3R13 are not spread out in the width direction even at a height H1. Therefore, as shown by the dotted arrows in Figure 6, each of the fourth right optical fiber 3R4 to the thirteenth right optical fiber 3R13 is moved downward without contacting adjacent optical fibers and is installed within the fourth right V-groove 17R4 to the thirteenth right V-groove 17R13, respectively.

[0075] This configuration allows the operator to position the bare fiber portions of the right optical fiber group 3R (the first right optical fiber 3R1 to the 16th right optical fiber 3R16) within the right V-groove group 17R, even if they are spread out in the width direction (X-axis direction), so as not to protrude from the right V-groove group 17R.

[0076] Furthermore, in the examples shown in Figures 5 and 6, the right guide wall 12R is configured such that its height H1 is significantly greater than the depth of the right V-groove group 17R. The depth of the right V-groove group 17R refers to the distance in the Z-axis direction between the upper surface TF1 of the right base member 11R (right optical fiber placement section) and the bottom of the right V-groove group 17R. The right guide wall 12R is configured such that the inclination angle of the third guide surface GF3 is the same as the inclination angle of the first groove surface GS1, and the inclination angle of the fourth guide surface GF4 is the same as the inclination angle of the sixteenth groove surface GS16. The depth of the right V-groove group 17R and the inclination angles of each groove surface are appropriately determined so that when the bare fiber portion of the right optical fiber group 3R is placed in the V-groove, the bare fiber portion protrudes above the upper surface TF1 of the right base member 11R.

[0077] However, the height H1 of the right guide wall 12R and the inclination angle of its guide surface GF can be set to any value, as long as the right guide wall 12R is formed in such a way that the spread of the bare fiber portion can be converged simply by moving the right optical fiber group 3R, which is spread in the width direction (X-axis direction), vertically downward. In other words, the height H1 of the right guide wall 12R and the inclination angle of its guide surface GF can be set to any value, as long as the right guide wall 12R is formed in such a way that the bare fiber portion can be extended straight. For example, the height H1 of the right guide wall 12R may be approximately the same value (slightly larger) as the depth of the right V-groove group 17R. Also, the inclination angle of the guide surface GF is approximately 25 degrees in the illustrated example, but it may be a larger or smaller value.

[0078] Furthermore, in the illustrated example, the right guide wall 12R is configured such that, at the same level (height) as the upper surface TF1 of the right base member 11R, the distance between the right front guide wall 12FR and the right rear guide wall 12BR is the same as the width of the right V-groove group 17R. In addition, the right guide wall 12R is configured such that the distance widens upwards. However, the right guide wall 12R may also be configured such that, at the same level (height) as the upper surface TF1 of the right base member 11R, the distance between the right front guide wall 12FR and the right rear guide wall 12BR is greater than the width of the right V-groove group 17R.

[0079] Furthermore, in the illustrated example, the guide surface GF is a flat surface and is configured such that, in a top view, the direction of its normal vector is perpendicular to the direction of extension (Y-axis direction) of the right V-groove group 17R. However, the guide surface GF may be configured such that, in a top view, the direction of its normal vector intersects diagonally with the direction of extension (Y-axis direction) of the right V-groove group 17R.

[0080] Next, with reference to Figures 7 to 9, another example of the guide wall 12 configuration will be described. Figures 7 to 9 are partial cross-sectional views of the right base member 11R including the right V-groove group 17R, and correspond to Figure 6. Note that the following explanation with reference to Figures 7 to 9 pertains to the right guide wall 12R which cooperates with the right V-groove group 17R, but the left guide wall 12L which cooperates with the left V-groove group 17L (not visible in Figures 7 to 9) will also be discussed. ) The same applies.

[0081] The right guide wall 12R shown in Figure 7 differs from the right guide wall 12R shown in Figure 6 in that the third guide surface GF3 and the fourth guide surface GF4 each include a vertical plane (central vertical plane VS), but is otherwise the same as the right guide wall 12R shown in Figure 6. Therefore, the explanation of the common parts will be omitted below, and the differences will be explained in detail.

[0082] In the example shown in Figure 7, the third guide surface GF3 of the right front guide wall 12FR includes an upper inclined surface US, a central vertical surface VS, and a lower inclined surface LS. Both the upper inclined surface US and the lower inclined surface LS are formed to be inclined toward the right V groove group 17R. The same applies to the fourth guide surface GF4 of the right rear guide wall 12BR.

[0083] In the third guide surface GF3, the inclination angle of the upper inclined surface US and the inclination angle of the lower inclined surface LS are the same. However, the inclination angle of the upper inclined surface US and the inclination angle of the lower inclined surface LS may be different. In this book, the inclination angle of the upper inclined surface US refers to the angle formed between the upper inclined surface US and the vertical plane. The same applies to the inclination angle of the lower inclined surface LS.

[0084] The larger the inclination angle of the upper inclined surface US and the lower inclined surface LS, the greater the inward (X2 direction) movement distance of the first right optical fiber 3R1 when the right optical fiber group 3R is moved downward. This has the effect of quickly converging the spread of the first right optical fiber 3R1 in the width direction.

[0085] Conversely, the smaller the inclination angle of the upper inclined surface US and the lower inclined surface LS, the smaller the inward (X2 direction) movement distance of the first right optical fiber 3R1 when the right optical fiber group 3R is moved downward. This has the effect of gradually converging the spread of the right optical fiber group 3R in the width direction.

[0086] Therefore, the inclination angles of the upper inclined surface US and the lower inclined surface LS are set appropriately according to the operating environment of the fusion splicer 1.

[0087] Furthermore, in the example shown in Figure 7, the fourth guide surface GF4 of the right rear guide wall 12BR includes an upper inclined surface US, a central vertical surface VS, and a lower inclined surface LS, similar to the third guide surface GF3 of the right front guide wall 12FR. Both the upper inclined surface US and the lower inclined surface LS are formed to incline toward the right V groove group 17R. In the fourth guide surface GF4, unlike the third guide surface GF3, the upper inclined surface US is formed such that its inclination angle is greater than that of the lower inclined surface LS. However, the upper inclined surface US may be formed such that its inclination angle is smaller than that of the lower inclined surface LS, or its inclination angle may be the same as that of the lower inclined surface LS.

[0088] Furthermore, in the example shown in Figure 7, the right guide wall 12R is formed such that the shape of the third guide surface GF3 of the right front guide wall 12FR and the shape of the fourth guide surface GF4 of the right rear guide wall 12BR are asymmetrical with respect to the YZ plane. However, the right guide wall 12R may also be formed such that the shape of the third guide surface GF3 of the right front guide wall 12FR and the shape of the fourth guide surface GF4 of the right rear guide wall 12BR are symmetrical with respect to the YZ plane, similar to the example shown in Figure 6.

[0089] The right guide wall 12R shown in Figure 8 differs from the right guide wall 12R shown in Figure 7 in that the third guide surface GF3 and the fourth guide surface GF4 each include a curved surface (upper curved surface WS) and a horizontal surface (lower horizontal surface HS), but are otherwise the same as the right guide wall 12R shown in Figure 7. Therefore, the explanation of the common parts will be omitted below, and the differences will be explained in detail.

[0090] In the example shown in Figure 8, the third guide surface GF3 of the right front guide wall 12FR includes an upper curved surface WS, a central vertical surface VS, and a lower horizontal surface HS. The upper curved surface WS is formed to be inclined toward the right V-groove group 17R. The same applies to the fourth guide surface GF4 of the right rear guide wall 12BR. Furthermore, the right guide wall 12R is formed such that the shape of the third guide surface GF3 of the right front guide wall 12FR and the shape of the fourth guide surface GF4 of the right rear guide wall 12BR are symmetrical with respect to the YZ plane. However, the right guide wall 12R may be formed such that the shape of the third guide surface GF3 of the right front guide wall 12FR and the shape of the fourth guide surface GF4 of the right rear guide wall 12BR are asymmetrical with respect to the YZ plane.

[0091] The upper curved surface WS is formed such that the angle of inclination gradually decreases, but it may include a portion where the angle of inclination gradually increases.

[0092] The configuration of the third guide surface GF3, including the lower horizontal surface HS, is intended to clarify that the vertical or inclined surface constituting the third guide surface GF3 does not necessarily have to be continuous with the first groove surface GS1 of the first right V groove 17R1.

[0093] In this case, the lower horizontal plane HS is formed such that its length (width) in the width direction (X-axis direction) is smaller than the diameter of the first right optical fiber 3R1. This is to prevent the first right optical fiber 3R1 from remaining on the lower horizontal plane HS when the right optical fiber group 3R is installed in the right V-groove group 17R. Preferably, the lower horizontal plane HS is formed such that its length (width) in the width direction (X-axis direction) is smaller than the radius of the first right optical fiber 3R1. However, at least one of the central vertical plane VS and the lower horizontal plane HS may be omitted. That is, the third guide plane GF3 may consist only of the upper curved plane WS, or it may consist of a combination of the upper curved plane WS and the central vertical plane VS, or it may consist of a combination of the upper curved plane WS and the lower horizontal plane HS.

[0094] The right guide wall 12R shown in Figure 9 differs from the right guide wall 12R shown in Figure 6 in that the third guide surface GF3 and the fourth guide surface GF4 each include multiple inclined surfaces, but is otherwise the same as the right guide wall 12R shown in Figure 6. Therefore, the explanation of the common parts will be omitted below, and the differences will be explained in detail.

[0095] In the example shown in Figure 9, the third guide surface GF3 of the right front guide wall 12FR includes an upper inclined surface US, a central inclined surface MS, and a lower inclined surface LS. The upper inclined surface US, the central inclined surface MS, and the lower inclined surface LS are all formed to be inclined toward the right V-groove group 17R. The same applies to the fourth guide surface GF4 of the right rear guide wall 12BR. Furthermore, the right guide wall 12R is formed such that the shape of the third guide surface GF3 of the right front guide wall 12FR and the shape of the fourth guide surface GF4 of the right rear guide wall 12BR are symmetrical with respect to the YZ plane. However, the right guide wall 12R may be formed such that the shape of the third guide surface GF3 of the right front guide wall 12FR and the shape of the fourth guide surface GF4 of the right rear guide wall 12BR are asymmetrical with respect to the YZ plane.

[0096] In the third guide surface GF3, the upper inclined surface US is formed such that its inclination angle is greater than that of the central inclined surface MS, and the central inclined surface MS is formed such that its inclination angle is greater than that of the lower inclined surface LS. However, the relative magnitudes of the inclination angles of the upper inclined surface US, the central inclined surface MS, and the lower inclined surface LS may be set arbitrarily. For example, the upper inclined surface US may be formed such that its inclination angle is smaller than that of the central inclined surface MS, and the central inclined surface MS may be formed such that its inclination angle is smaller than that of the lower inclined surface LS.

[0097] Next, with reference to Figures 10A to 10I, yet another example of the guide wall 12 configuration will be described. Each of Figures 10A to 10I is a top view of the right base member 11R including the right V-groove group 17R. Note that the following explanation with reference to Figures 10A to 10I pertains to the right guide wall 12R which cooperates with the right V-groove group 17R, but the left guide wall 12L which cooperates with the left V-groove group 17L (not visible in Figures 10A to 10I) will also be discussed. ) The same applies.

[0098] The right guide wall 12R shown in Figure 10A differs from the right guide wall 12R shown in Figure 5, which is located at the right end (Y2 side end) of the right base member 11R in the left-right direction (Y axis direction), in that it is located in the center of the right base member 11R in the left-right direction (Y axis direction).

[0099] The right guide wall 12R shown in Figure 10B differs from the right guide wall 12R shown in Figure 5, which is located at the right end (Y2 end) of the right base member 11R in the left-right direction (Y-axis direction), in that it is located at the left end (Y1 end) of the right base member 11R in the left-right direction (Y-axis direction).

[0100] The right guide wall 12R shown in Figure 10C differs from the right guide wall 12R shown in Figure 5, which is positioned only at the right end (the Y2 side end) of the right base member 11R in the left-right direction (Y axis direction), in that it is positioned at both the left and right ends of the right base member 11R in the left-right direction (Y axis direction).

[0101] Furthermore, the right guide wall 12R shown in Figure 10C differs from the right guide wall 12R in Figure 5, which is composed of two parts (right front guide wall 12FR and right rear guide wall 12BR), in that it is composed of four parts (first right front guide wall 12FR1, second right front guide wall 12FR2, first right rear guide wall 12BR1, and second right rear guide wall 12BR2).

[0102] Furthermore, in the example shown in Figure 10C, the right guide wall 12R may be configured such that the inclination angles of the guide surfaces of the first right front guide wall 12FR1 and the first right rear guide wall 12BR1 are different from the inclination angles of the guide surfaces of the second right front guide wall 12FR2 and the second right rear guide wall 12BR2. This is because the degree of widthwise spread of the bare fiber portion at the left end (Y1 side end) of the right base member 11R is greater than the degree of widthwise spread of the bare fiber portion at the right end (Y2 side end) of the right base member 11R. For similar reasons, the right guide wall 12R may be configured such that the distance between the guide surface of the first right front guide wall 12FR1 and the guide surface of the first right rear guide wall 12BR1 is smaller at the same height than the distance between the guide surface of the second right front guide wall 12FR2 and the guide surface of the second right rear guide wall 12BR2.

[0103] As shown in Figure 10D, the right guide wall 12R is such that in the left-right direction (Y-axis direction), the right front guide wall 12FR is relative to the right base member 11R. right Unlike the right guide wall 12R in Figure 5, where both the right front guide wall 12FR and the right rear guide wall 12BR are positioned at the right end (Y2 side end) of the right base member 11R, the right guide wall 12R is positioned at the end, and the right rear guide wall 12BR is positioned in the central part of the right base member 11R.

[0104] Furthermore, the right guide wall 12R shown in Figure 10D differs from the right guide wall 12R in Figure 5, in that the right front guide wall 12FR and the right rear guide wall 12BR are not facing each other in the front-rear direction (X-axis direction).

[0105] In the examples shown in Figures 10A to 10D, the right guide wall 12R is configured such that its thickness (length in the Y-axis direction) is significantly smaller than the total length (length in the Y-axis direction) of the right V-groove group 17R. However, the right guide wall 12R may be configured to have any thickness. For example, the thickness of the right guide wall 12R may be the same as the total length of the right V-groove group 17R, or it may be configured to be about half or one-third of the total length of the right V-groove group 17R.

[0106] The right guide wall 12R shown in Figures 10E and 10F differs from the right guide wall 12R in Figure 5, which is arranged to be adjacent to the right V-groove group 17R in the front-to-back direction (X-axis direction), in that it is not adjacent to the right V-groove group 17R in the front-to-back direction (X-axis direction).

[0107] Specifically, the right guide wall 12R shown in Figure 10E differs from the right guide wall 12R in Figure 5, which is positioned adjacent to the right V-groove group 17R in the front-to-back direction (X-axis direction), in that it is positioned to protrude to the right (Y2 direction) from the right end of the right base member 11R.

[0108] Furthermore, the right guide wall 12R shown in Figure 10F differs from the right guide wall 12R in Figure 5, which is positioned adjacent to the right V-groove group 17R in the front-to-back direction (X-axis direction), in that it is positioned to protrude to the left (Y1 direction) from the left end of the right base member 11R.

[0109] Thus, the right guide wall 12R does not need to be formed adjacent to the right V-groove group 17R in the front-to-back direction (X-axis direction), and may be arranged to protrude to the left (Y1 direction) from the left end of the right base member 11R, or to the right (Y2 direction) from the right end of the right base member 11R.

[0110] The right guide wall 12R shown in Figures 10G and 10H differs from the right guide wall 12R in Figure 5, which is formed as part of the right base member 11R, in that it is formed as a separate member from the right base member 11R.

[0111] Specifically, the right guide wall 12R shown in Figure 10G differs from the right guide wall 12R in Figure 5, which is integrally formed as part of the right base member 11R, in that it is positioned spaced apart to the right (in the Y2 direction) from the right end of the right base member 11R.

[0112] Furthermore, the right guide wall 12R shown in Figure 10H differs from the right guide wall 12R in Figure 5, which is integrally formed as part of the right base member 11R, in that it is positioned spaced apart to the left (in the Y1 direction) from the left end of the right base member 11R.

[0113] Thus, the right guide wall 12R may be positioned at a distance from the right base member 11R. Furthermore, the right guide wall 12R may be made of a different material than the right base member 11R.

[0114] In the example shown in Figure 10G, the right base member 11R is made of a heat-resistant ceramic such as zirconia. This is because it is exposed to the high temperature caused by the arc discharge generated by the electrode rod 5. On the other hand, the right guide wall 12R is made of a metal such as stainless steel because it is positioned so as not to be exposed to the high temperature caused by the arc discharge and so as not to have an electromagnetic effect on the arc discharge. The right guide wall 12R may also be made of a synthetic resin material.

[0115] The right guide wall 12R shown in Figure 10I differs from the right guide wall 12R shown in Figure 10E, which is formed in a way that it is not movable in the front-to-back direction (X-axis direction), in that it is formed to be movable in the front-to-back direction (X-axis direction).

[0116] Figure 10I shows the state of the right guide wall 12R when the distance between the right front guide wall 12FR and the right rear guide wall 12BR is at its minimum. The dashed line in Figure 10I shows the state of the right guide wall 12R when the distance between the right front guide wall 12FR and the right rear guide wall 12BR is at its maximum. The bidirectional arrows in Figure 10I indicate the direction of movement of the right front guide wall 12FR and the right rear guide wall 12BR, respectively.

[0117] This configuration is particularly suitable for achieving fusion splicing of tape cores with fewer than 16 cores (e.g., 4, 8, or 12 cores) than a 16-core tape core by utilizing fewer than 16 V-grooves (e.g., 4, 8, or 12 V-grooves).

[0118] Specifically, when performing fusion splicing of a 4-core tape fiber, the worker moves the right front guide wall 12FR and the right rear guide wall 12BR so that the distance between them is the same as the width of the four V-grooves. More specifically, the worker moves the right front guide wall 12FR backward (in the X2 direction) and the right rear guide wall 12BR forward (in the X1 direction). The right guide wall 12R, represented by the solid line in Figure 10I, is in a state suitable for fusion splicing of a 4-core tape fiber.

[0119] Furthermore, when performing fusion splicing of 16 core ribbon fiber wires, the worker moves the right front guide wall 12FR and the right rear guide wall 12BR so that the distance between them is the same as the width of the 16 V-grooves. More specifically, the worker moves the right front guide wall 12FR forward (in the X1 direction) and the right rear guide wall 12BR backward (in the X2 direction). The right guide wall 12R, represented by the dashed line in Figure 10I, is in a state suitable for fusion splicing of 16 core ribbon fiber wires.

[0120] In the example shown in Figure 10I, the right guide wall 12R is configured so that both the right front guide wall 12FR and the right rear guide wall 12BR can move in the front-rear direction (X-axis direction). However, the right guide wall 12R may be configured so that either the right front guide wall 12FR or the right rear guide wall 12BR can move in the front-rear direction (X-axis direction). Furthermore, the front-rear movable right guide wall 12R shown in Figure 10I may be applied to the configurations shown in Figures 5 to 9 and Figures 10A to 10H, respectively.

[0121] As described above, the fusion splicer 1 according to the embodiment of this disclosure is configured to fusion splice each of a plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) that are arranged in parallel along a direction (X-axis direction) intersecting the longitudinal direction (Y-axis direction) with other optical fibers (first left optical fiber 3AL to fourth left optical fiber 3DL), as shown in Figures 1 and 2A to 2C. Specifically, the fusion splicer 1 includes a right base member 11R having a groove portion (right V-groove group 17R) in which a plurality of V-grooves (first right V-groove 17AR to fourth right V-groove 17DR) are formed, in which a plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) are installed, and a pair of guide walls (right front guide wall 12FR and right rear guide wall 12BR) that guide the installation of the plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) into the plurality of V-grooves (first right V-groove 17AR to fourth right V-groove 17DR). A pair of guide walls (right front guide wall 12FR and right rear guide wall 12BR) are arranged with a gap in the width direction (X-axis direction) of the right V-groove group 17R. The right front guide wall 12FR has a third guide surface GF3 that contacts the first right optical fiber 3AR, which is one of a plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR), and the right rear guide wall 12BR has a fourth guide surface GF4 that contacts the fourth right optical fiber 3DR, which is another of a plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR). Both the third guide surface GF3 and the fourth guide surface GF4 include a portion that inclins toward the right V-groove group 17R when viewed along the extending direction (Y-axis direction) of the plurality of V-grooves (first right V-groove 17AR to fourth right V-groove 17DR), that is, in a right side view.

[0122] In the examples shown in Figures 1 and 2A to 2C, the multiple optical fibers fused together by the fusion splicer 1 are the bare fiber portions of four optical fibers that make up a four-core ribbon cable, but they may also be the bare fiber portions of multiple optical fibers that make up an intermittent ribbon cable. The number of cores in the ribbon cable may be 8, 12, 16, or 24, etc. In the examples shown in Figures 5 and 6, the number of cores in the ribbon cable is 16.

[0123] In this configuration, the guide wall 12 pushes back the bare fiber portion of the optical fiber group 3 that has spread outward in the width direction (X-axis direction), as shown in Figure 2B, and corrects the bare fiber portion to a straightened state, as shown in Figure 2C. Therefore, this configuration can prevent the bare fiber portion from protruding from the V-groove.

[0124] Furthermore, the guide surface GF may be arranged to be continuous with the surface of one of the V grooves when viewed along the extending direction (Y-axis direction) of the multiple V grooves (first right V groove 17R1 to the 16th right V groove 17R16), as shown in Figure 6, that is, in a right side view as shown in Figure 6. Specifically, as shown in Figure 6, the third guide surface GF3 may be arranged to be continuous with the first groove surface GS1 of the first right V groove 17R1, and the fourth guide surface GF4 may be arranged to be continuous with the 16th groove surface GS16 of the 16th right V groove 17R16.

[0125] In this configuration, where the third guide surface GF3 and the first groove surface GS1 are continuous, the right front guide wall 12FR can guide the first right optical fiber 3R1 into the first right V-groove 17R1 without disturbing the movement of the first right optical fiber 3R1 as it moves along the surface of the third guide surface GF3. Therefore, this configuration can further suppress the bare fiber portion from protruding from the V-groove.

[0126] The pair of guide walls may be formed as separate members from the base member 11, or they may be integrated with the base member 11. For example, the pair of guide walls, the right front guide wall 12FR and the right rear guide wall 12BR, may be integrated with the right base member 11R as shown in Figures 10A to 10F, or they may be formed as separate members from the right base member 11R as shown in Figures 10G to 10I.

[0127] Furthermore, at least one of the pair of guide walls may be configured to be movable relative to the groove portion so as to change the size of the spacing in the width direction of the groove portion. For example, the pair of guide walls, the right front guide wall 12FR and the right rear guide wall 12BR, may be configured to be movable in the X-axis direction relative to the right V groove group 17R so as to change the size of the spacing in the width direction (X-axis direction) of the right V groove group 17R, as shown in Figure 10I.

[0128] Furthermore, the optical fiber connection method according to the embodiment of this disclosure is an optical fiber connection method that uses a fusion splicer 1 which includes a right base member 11R having a groove portion (right V groove group 17R) in which a plurality of V grooves (first right V groove 17AR to fourth right V groove 17DR) are formed in which a plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) are installed, and a pair of guide walls (right front guide wall 12FR and right rear guide wall 12BR) that guide the installation of the plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) into the plurality of V grooves (first right V groove 17AR to fourth right V groove 17DR), as shown in Figures 1 and 2A to 2C, to fusion splice each of the plurality of optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) with other optical fibers (first left optical fiber 3AL to fourth left optical fiber 3DL).

[0129] This connection method comprises the steps of: placing multiple optical fibers into multiple V-grooves while bringing one of the multiple optical fibers into contact with the guide surface of one of a pair of guide walls that are spaced apart in the width direction of the groove; and fusion splicing each of the multiple optical fibers with the other optical fibers.

[0130] Specifically, as shown in Figures 2A to 2C, this connection method includes the steps of: installing multiple optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) into multiple V-grooves (first right V-groove 17AR to fourth right V-groove 17DR) while bringing the first right optical fiber 3AR into contact with the third guide surface GF3 of the right front guide wall 12FR, or bringing the fourth right optical fiber 3DR into contact with the fourth guide surface GF4 of the right rear guide wall 12BR; and fusion splicing each of the multiple optical fibers (first right optical fiber 3AR to fourth right optical fiber 3DR) with other optical fibers (first left optical fiber 3AL to fourth left optical fiber 3DL).

[0131] This method pushes the bare fiber portion of optical fiber group 3 (left optical fiber group 3L or right optical fiber group 3R) that has spread outward in the width direction (X-axis direction), as shown in Figure 2B, back inward in the width direction, and straightens the bare fiber portion to a straight state as shown in Figure 2C, after which the left optical fiber group 3L and the right optical fiber group 3R can be fusion spliced ​​together. Therefore, this method can suppress the bare fiber portion from protruding from the V-groove, and consequently, can suppress fusion splicing failures or rework.

[0132] Preferred embodiments of this disclosure have been described in detail above. However, the disclosed embodiments should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended to be included. That is, the invention is not limited to the embodiments described above. Various modifications or substitutions may be applied to the embodiments described above without departing from the scope of the invention. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not conflict technically. [Explanation of Symbols]

[0133] 1. Fusion splicer 3. Optical fiber group 3A...First optical fiber pair 3AL···First left optical fiber 3AR...First right optical fiber 3B...Second optical fiber pair 3BL...Second left optical fiber 3BR...Second right optical fiber 3C...Third optical fiber pair 3CL...Third left optical fiber 3CR...Third right optical fiber 3D...4th optical fiber pair 3DL...4th left optical fiber 3DR...4th right optical fiber 3L...Left optical fiber group 3R...Right optical fiber group 3R1...First right optical fiber 3R2...Second right optical fiber 3R3...Third right optical fiber 3R4...Fourth right optical fiber 3R5...5th right optical fiber 3R6...6th right optical fiber 3R7...7th right optical fiber 3R8...8th right optical fiber 3R9...9th right optical fiber 3R10...10th right optical fiber 3R11...11th right optical fiber 3R12...12th right optical fiber 3R13...13th right optical fiber 3R14...14th right optical fiber 3R15...15th right optical fiber 3R16...16th right optical fiber 4L...Left tape core wire 4R...Right tape core wire 5...electrode rod 5B...Rear electrode rod 5Ba... Tip 5F...Front electrode rod 5Fa... Tip 11. Base component 11L...Left base component 11R...Right base component 12... Guide wall 12BL...Left rear guide wall 12BR...Right rear guide wall 12BR1...First right rear guide wall 12BR2...Second right rear guide wall 12FL...Left front guide wall 12FR...Right front guide wall 12FR1...First right front guide wall 12FR2...Second right front guide wall 12L...Left guide wall 12R...Right guide wall 17···V groove group 17A···1st V-groove pair 17AL...1st left V groove 17AR...1st right V groove 17B...2nd V-groove pair 17BL...2nd left V groove 17BR...2nd right V groove 17C...3rd V groove pair 17CL...3rd left V groove 17CR...3rd right V groove 17D...4th V groove pair 17DL...4th left V groove 17DR...4th right V groove 17L...Left V groove group 17R...Right V groove group 17R1...1st right V groove 17R2...2nd right V groove 17R3...3rd right V groove 17R4...4th right V groove 17R5...5th right V groove 17R6...6th right V groove 17R7...7th right V groove 17R8...8th right V groove 17R9...9th right V groove 17R10...10th right V groove 17R11...11th right V groove 17R12...12th right V groove 17R13...13th right V groove 17R14...14th right V groove 17R15...15th right V groove 17R16...16th right V groove 21... Clamp 21L... Left clamp 21La...Left arm section 21Lb...Left pressing area 21R...Right clamp 21Ra...Right arm section 21Rb...Right pressing area 31. Fiber holder 31L...Left fiber holder 31La···Left Fiber Holder Body 31Lb...Left lid body 31R...Right fiber holder 31Ra...Right fiber holder body 31Rb...Right lid body 51. Imaging device 52...fusion device 53. Clamp drive device 54. Fiber holder drive device 55...Display device 60... Control device GF... Guide surface GF1...First guide surface GF2...Second guide surface GF3...Third guide surface GF4...4th guide surface GS1...1st groove surface GS16...16th groove surface HS...lower horizontal plane LS...Lower slope MS...Central slope TF1, TF2...Top surface US...Upper slope VS...Central vertical plane WS...Upper curved surface

Claims

1. A fusion splicer that fusion splices multiple optical fibers, each running parallel along a direction intersecting the longitudinal direction, with other optical fibers, A base member having groove portions in which multiple V-grooves are formed, in which multiple optical fibers are installed, The system comprises a pair of guide walls that guide the placement of the plurality of optical fibers into the plurality of V-grooves, The pair of guide walls are arranged with a gap between them in the width direction of the groove portion, One of the pair of guide walls has a guide surface that can contact one of the plurality of optical fibers, The other of the pair of guide walls has a guide surface that can contact another of the plurality of optical fibers, The guide surface includes a portion that is inclined toward the groove portion when viewed along the extending direction of the plurality of V grooves. The thickness of the pair of guide walls along the longitudinal direction of the plurality of optical fibers is less than or equal to half the total length of the plurality of V-grooves. The pair of guide walls are It is positioned at a location corresponding to the central part of the base member in the longitudinal direction, or, It is positioned at a location corresponding to one end or the other end of the base member in the longitudinal direction, or They are positioned at positions corresponding to each of the ends of the base member in the longitudinal direction, or It is positioned at a location corresponding to one end or the other end of the base member in the longitudinal direction and at a location corresponding to the central part, or It is arranged to protrude outward from one end of the base member in the longitudinal direction, or, It is arranged to protrude outward from the other end of the base member in the longitudinal direction, or, Displaced outward from one end of the base member in the longitudinal direction, or, Displaced outward from the other end of the base member in the longitudinal direction, or, At least one of them is configured to be movable relative to the groove portion in the width direction, Fusion splicer.

2. The guide surface is arranged to be continuous with the surface of one of the V-grooves when viewed along the extending direction of the plurality of V-grooves. The fusion splicer according to claim 1.

3. The pair of guide walls are formed as separate members from the base member. A fusion splicer according to claim 1 or claim 2.

4. The pair of guide walls are integrated with the base member. A fusion splicer according to claim 1 or claim 2.

5. A fusion splicer for fusion splicing each of a plurality of optical fibers that are parallel to each other along a direction intersecting the longitudinal direction with other optical fibers, A base member having groove portions in which multiple V-grooves are formed, in which multiple optical fibers are installed, The system comprises a pair of guide walls that guide the placement of the plurality of optical fibers into the plurality of V-grooves, The pair of guide walls are arranged with a gap between them in the width direction of the groove portion, One of the pair of guide walls has a guide surface that can contact one of the plurality of optical fibers, The other of the pair of guide walls has a guide surface that can contact another of the plurality of optical fibers, The guide surface includes a portion that is inclined toward the groove portion when viewed along the extending direction of the plurality of V grooves. At least one of the pair of guide walls is configured to be movable relative to the groove portion in the width direction. Fusion splicer.

6. A method for connecting optical fibers, comprising a fusion splicer having a base member having a groove portion with a plurality of V-grooves formed therein for installing a plurality of optical fibers, and a pair of guide walls for guiding the installation of the plurality of optical fibers into the plurality of V-grooves, wherein each of the plurality of optical fibers is fusion spliced ​​with another optical fiber, The process of installing the plurality of optical fibers into the plurality of V-grooves while bringing one of the plurality of optical fibers into contact with the guide surface of one of the pair of guide walls which are arranged at intervals in the width direction of the groove portion, The process includes a step of fusion splicing each of the aforementioned plurality of optical fibers with other optical fibers, The thickness of the pair of guide walls along the longitudinal direction of the plurality of optical fibers is less than or equal to half the total length of the plurality of V-grooves. The pair of guide walls are It is positioned at a location corresponding to the central part of the base member in the longitudinal direction, or, It is positioned at a location corresponding to one end or the other end of the base member in the longitudinal direction, or They are positioned at positions corresponding to each of the ends of the base member in the longitudinal direction, or It is positioned at a location corresponding to one end or the other end of the base member in the longitudinal direction and at a location corresponding to the central part, or It is arranged to protrude outward from one end of the base member in the longitudinal direction, or, It is arranged to protrude outward from the other end of the base member in the longitudinal direction, or, Displaced outward from one end of the base member in the longitudinal direction, or, Displaced outward from the other end of the base member in the longitudinal direction, or, At least one of them is configured to be movable relative to the groove portion in the width direction, How to connect optical fibers.

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