Fusion splicer

Abstract

To prevent generation of a situation in which abnormal substances on a fiber clamp cause the fiber clamp to be unable to appropriately press an optical fiber down.SOLUTION: A fusion splicer 1 for fusion-connecting an optical fiber includes: a base member 11 having a V-shaped groove group 17 in which an optical fiber group 3 is set; and a fiber clamp 21B having a flat lower surface 26 facing the upper surface of the base member 11. A recessed part 25 is formed in a part of the region which faces the region in which the V-shaped groove group 17 is formed in the upper surface of the base member 11 of the lower surface 26 of the fiber clamp 21B.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a fusion splicer. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a fusion splicer that positions optical fibers to be spliced ​​within a V-groove and presses them down with a fiber clamp to perform fusion splicing (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 162044 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses the operation of a fusion splicer for removing foreign matter adhering to an optical fiber. However, this fusion splicer needs to perform an operation for actively removing foreign matter in addition to the operation for normal fusion splicing. Therefore, it is desirable to minimize the additional operation for removing foreign matter. [Means for solving the problem]

[0005] A fusion splicer according to an embodiment of the present invention is a fusion splicer for fusion splicing optical fibers, and comprises a base member having a V-groove in which the optical fiber is installed, and a fiber clamp having a flat lower surface facing the upper surface of the base member, and a recess is formed in a portion of the lower surface of the fiber clamp that faces the area on the upper surface of the base member in which the V-groove is formed. Effect of the Invention

[0006] The above-described fusion splicer can suppress a situation in which the fiber clamp is unable to properly press down on the optical fiber due to foreign matter adhering to the fiber clamp. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a portion of a fusion splicer. [Figure 2A] FIG. 2A is a top view of a portion of a fusion splicer. [Figure 2B] FIG. 2B is a top view of a portion of the fusion splicer. [Diagram 3] FIG. 3 is a cross-sectional view of a portion of a fusion splicer. [Figure 4] FIG. 4 is a block diagram showing a control system for controlling the fusion splicer. [Figure 5A] FIG. 5A is a cross-sectional view of a portion of a fusion splicer. [Figure 5B] FIG. 5B is a cross-sectional view of a portion of a fusion splicer. [Figure 6A] FIG. 6A is a perspective view of a fiber clamp. [Figure 6B] FIG. 6B is a perspective view of the fiber clamp. [Figure 7] FIG. 7A is a cross-sectional view of a portion of a fusion splicer. [Figure 8A] FIG. 8A is a bottom view of the fiber clamp. [Figure 8B] FIG. 8B is a bottom view of the fiber clamp. [Figure 8C] FIG. 8C is a bottom view of the fiber clamp. [Figure 8D] FIG. 8D is a bottom view of the fiber clamp. [Figure 8E] FIG. 8E is a bottom view of the fiber clamp. [Figure 8F] FIG. 8F is a bottom view of the fiber clamp. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Description of the embodiment of the present invention] First, embodiments of the present invention will be listed and described.

[0009] (1) A fusion splicer according to one aspect of the present invention is a fusion splicer for fusion splicing optical fibers, comprising a base member having a V-groove in which the optical fiber is placed, and a fiber clamp having a flat lower surface facing the upper surface of the base member, and a recess may be formed in a part of the lower surface of the fiber clamp that faces the area in the upper surface of the base member where the V-groove is formed. This configuration can reduce the probability that a foreign object will be caught between the lower surface of the fiber clamp and the upper surface of the base member or the optical fiber placed in the V-groove by forming a recess in the lower surface of the fiber clamp. This is because the probability that the foreign object will be contained in the recess increases. Therefore, this configuration has the effect of being able to appropriately contact the optical fiber placed in the V-groove with the fiber clamp. In other words, this configuration has the effect of being able to suppress the occurrence of a situation in which the optical fiber placed in the V-groove and the fiber clamp do not contact each other at all. As a result, this configuration has the effect of being able to suppress the occurrence of a malfunction in which the position of the optical fiber is shifted from a predetermined position because the optical fiber is not appropriately pressed by the fiber clamp. The portion of the optical fiber that is placed in the V-groove is the portion where the coating material is removed to expose the glass fiber, and is also called the bare fiber portion. The portion coated with the coating material is also called the optical fiber strand or optical fiber core.

[0010] (2) The recess may be formed to extend in a direction non-parallel to the extension direction of the V-groove formed in the base member. This configuration has the effect of ensuring that the optical fiber is pressed against the base member 11 by a part of the lower surface of the fiber clamp (a part where the recess is not formed). Therefore, this configuration has the effect of ensuring that the optical fiber placed in the V-groove and the fiber clamp can be in appropriate contact with each other, and thus the optical fiber can be accurately positioned within the V-groove.

[0011] (3) The recess may be configured such that at least one end opens to a side surface of the fiber clamp. This configuration provides the effect that an operator who cleans the recess can easily use a cotton swab or the like to remove foreign matter adhering to the inside of the recess to the outside along the extension direction of the recess. Therefore, this configuration provides the effect that, for example, the number of foreign matter that may adhere to the optical fiber when the optical fiber is placed in the V-groove can be reduced, and thus foreign matter can be prevented from being pinched between the optical fiber placed in the V-groove and the lower surface of the fiber clamp. As a result, this configuration provides the effect that the optical fiber can be accurately positioned in the V-groove.

[0012] (4) The fiber clamp may be configured to be swingable around an axis parallel to the extension direction of the V-groove formed in the base member. This configuration is for maintaining parallelism between the upper surface of the base member and the lower surface of the fiber clamp even when the dimensional tolerance of members such as the fiber clamp and the base member is large. The recess formed on the lower surface of the fiber clamp can reduce the probability that a foreign object is caught between the lower surface of the fiber clamp and the upper surface of the base member or the optical fiber placed in the V-groove, even when the fiber clamp is configured to be swingable in this way. This is because the probability that the foreign object will fit in the recess increases. Therefore, the recess formed on the lower surface of the fiber clamp has the effect of allowing the optical fiber placed in the V-groove to be in proper contact with the fiber clamp. As a result, the recess formed on the lower surface of the fiber clamp has the effect of suppressing the occurrence of a defect in which the position of the optical fiber is shifted from a predetermined position because the optical fiber is not properly pressed by the fiber clamp.

[0013] [Details of the embodiment of the present invention] Hereinafter, specific examples of the fusion splicer 1 and the optical fiber splicing method according to the embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] FIG. 1 is a perspective view showing a part of a fusion splicer 1. In FIG. 1, X1 represents one direction of the X axis constituting a three-dimensional orthogonal coordinate system, and X2 represents the other direction of the X axis. Furthermore, Y1 represents one direction of the Y axis constituting the three-dimensional orthogonal coordinate system, and Y2 represents the other direction of the Y axis. Similarly, Z1 represents one direction of the Z axis constituting the three-dimensional orthogonal 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 (front side) of the fusion splicer 1, and the X2 side of the fusion splicer 1 corresponds to the rear side (rear side) of the fusion splicer 1. Furthermore, 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. Furthermore, the Z1 side of the fusion splicer 1 corresponds to the upper side of the fusion splicer 1, and the Z2 side of the fusion splicer 1 corresponds to the lower side of the fusion splicer 1. The same applies to the other figures.

[0015] The fusion splicer 1 is a device configured to be able to fusion-splice a plurality of pairs of optical fibers arranged with their end faces butted against each other by arc discharge. In the illustrated example, the fusion splicer 1 is configured to be able to fusion-splice four pairs of optical fibers. Specifically, the fusion splicer 1 includes a pair of electrode rods 5 (a rear electrode rod 5B and a front electrode rod 5F), a pair of base members 11 (a left base member 11L and a right base member 11R), a pair of fiber clamp assemblies 21 (a left fiber clamp assembly 21L and a right fiber clamp assembly 21R), and a pair of fiber holders 31 (a left fiber holder 31L and a right fiber holder 31R). The pair of base members 11 (a left base member 11L and a right base member 11R) may be integrally formed as one part.

[0016] The pair of electrode bars 5 includes a rear electrode bar 5B and a front electrode bar 5F that are spaced apart from each other in the X-axis direction. The pair of electrode bars 5 are arranged such that a tip 5Ba of the rear electrode bar 5B and a tip 5Fa of the front electrode bar 5F face each other. In the illustrated example, the rear electrode bar 5B includes a cone-shaped portion whose diameter decreases toward the tip 5Ba. The same is true for the front electrode bar 5F.

[0017] The optical fibers arranged on the pair of base members 11 are glass fibers, and are arranged between the rear electrode rod 5B and the front electrode rod 5F for generating an arc discharge. Of the optical fibers, the portions arranged on the pair of base members 11 are bare fiber portions where the coating material has been removed to expose the glass fibers.

[0018] Specifically, the pairs of bare fiber portions include bare fiber portions of the left optical fiber group 3L constituting the left ribbon core wire 4L and bare fiber portions of the right optical fiber group 3R constituting the right ribbon core wire 4R. In the following, the left optical fiber group 3L and the right optical fiber group 3R may be referred to as the optical fiber group 3 for convenience of explanation.

[0019] A ribbon core wire is a core wire in which a plurality of optical fibers (optical fiber strands) are arranged in parallel and collectively coated with, for example, an ultraviolet-curable resin (coating material). Each of the left ribbon core wire 4L and the right ribbon core wire 4R in the illustrated example is a four-core ribbon core wire in which four optical fibers (optical fiber strands) are arranged in parallel and collectively coated with an ultraviolet-curable resin (coating material).

[0020] The pair of base members 11 are members for supporting a plurality of pairs of optical fibers, and include a left base member 11L and a right base member 11R arranged to sandwich a pair of electrode bars 5. That is, the pair of electrode bars 5 are arranged between the left base member 11L and the right base member 11R arranged to be spaced apart from each other in the Y-axis direction. The right base member 11R in the illustrated example has a right V-groove group 17R also referred to as a right optical fiber arrangement portion or a right groove portion, and the left base member 11L has a left V-groove group 17L also referred to as a left optical fiber arrangement portion or a left groove portion. In the following, the left V-groove group 17L and the right V-groove group 17R may be referred to as a V-groove group 17 for convenience of explanation.

[0021] The left V groove group 17L has a plurality of V grooves for arranging a plurality of optical fibers (left optical fiber group 3L), and the right V groove group 17R has a plurality of V grooves for arranging a plurality of 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.

[0022] 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 simultaneously position 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 extension direction (Y-axis direction), and are configured to simultaneously position the four optical fiber pairs.

[0023] 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 butted against each other in the area between the right base member 11R (right V groove group 17R) and the left base member 11L (left V groove group 17L).

[0024] Here, with reference to Fig. 2A and Fig. 2B, the details of the V-groove group 17 in which the four optical fiber pairs are positioned will be described. Fig. 2A and Fig. 2B are top views showing a part of the fusion splicer 1. Specifically, Fig. 2A and Fig. 2B are top views of the electrode rod 5 and the base member 11. More specifically, Fig. 2A shows the state before the optical fiber group 3 is placed in the V-groove group 17, and Fig. 2B shows the state after the optical fiber group 3 is placed in the V-groove group 17. Note that in Fig. 2A and Fig. 2B, for clarity, a dot pattern is applied to the groove surface of the V-groove group 17. Also, in Fig. 2A, the bottom of each V-groove is represented by a dashed line.

[0025] 2A, the left V groove group 17L includes a first left V groove 17AL, a second left V groove 17BL, a third left V groove 17CL, and a fourth left V groove 17DL, and the right V groove group 17R includes a first right V groove 17AR, a second right V groove 17BR, a third right V groove 17CR, and a fourth right V groove 17DR. The first left V groove 17AL and the first right V groove 17AR form a first V groove pair 17A, the second left V groove 17BL and the second right V groove 17BR form a second V groove pair 17B, the third left V groove 17CL and the third right V groove 17CR form a third V groove pair 17C, and the fourth left V groove 17DL and the fourth right V groove 17DR form a fourth V groove pair 17D.

[0026] 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 form the first optical fiber pair 3A, the second left optical fiber 3BL and the second right optical fiber 3BR form the second optical fiber pair 3B, the third left optical fiber 3CL and the third right optical fiber 3CR form the third optical fiber pair 3C, and the fourth left optical fiber 3DL and the fourth right optical fiber 3DR form the fourth optical fiber pair 3D.

[0027] Next, the movement of the pair of fiber clamp assemblies 21 (the left fiber clamp assembly 21L and the right fiber clamp assembly 21R) will be described with reference to Fig. 1 and Fig. 3. Fig. 3 is a cross-sectional view showing a part of the fusion splicer 1. Specifically, Fig. 3 is a cross-sectional view of the cross-section including the section line III-III in Fig. 2B as viewed from the X1 side as indicated by the arrow. Note that the cross-section in Fig. 2B includes a cross-section of the base member 11.

[0028] As shown in FIG. 1, the fiber clamp assembly 21 is configured to be able to press the optical fiber group 3 placed in the V-groove group 17 against the V-groove group 17. In the illustrated example, the fiber clamp assembly 21 includes an arm portion 21A, a fiber clamp 21B, a connecting pin 21C, and a clamp block 21D. The fiber clamp assembly 21 is disposed above the V-groove group 17 and is configured to be able to move in the vertical direction. The fiber clamp 21B is attached to the lower end of the arm portion 21A via the connecting pin 21C. In the illustrated example, the fiber clamp 21B is made of heat-resistant ceramics such as zirconia. The arm portion 21A is attached to the lower end of the clamp block 21D via an elastic body (not shown) such as a spring.

[0029] Specifically, the left fiber clamp assembly 21L is configured to be able to press the left optical fiber group 3L installed in the left V groove group 17L against the left V groove group 17L. Similarly, the right fiber clamp assembly 21R is configured to be able to press the right optical fiber group 3R installed in the right V groove group 17R against the right V groove group 17R. In the illustrated example, the left fiber clamp assembly 21L includes a left arm portion 21AL, a left fiber clamp 21BL, a left connecting pin 21CL (see FIG. 3), and a left clamp block 21DL, and the right fiber clamp assembly 21R includes a right arm portion 21AR, a right fiber clamp 21BR, a right connecting pin 21CR, and a right clamp block 21DR. The left fiber clamp assembly 21L is disposed above the left V groove group 17L, and the right fiber clamp assembly 21R is disposed above the right V groove group 17R. In addition, the left fiber clamp assembly 21L and the right fiber clamp assembly 21R are configured to be able to move in the up and down directions. The left fiber clamp 21BL is attached to the lower end of the left arm section 21AL via the left connecting pin 21CL, and the right fiber clamp 21BR is attached to the lower end of the right arm section 21AR via the right connecting pin 21CR. In the illustrated example, the left fiber clamp 21BL is movable in the up-down direction (Z direction) together with the left arm section 21AL, and the right fiber clamp 21BR is movable in the up-down direction (Z direction) together with the right arm section 21AR. In the state shown in FIG. 3, the left fiber clamp 21BL is separated from the left optical fiber group 3L installed in the left V-groove group 17L, but by moving the left fiber clamp assembly 21L downward, the left fiber clamp 21BL comes into contact with the left optical fiber group 3L and can press the left optical fiber group 3L toward the left V-groove group 17L. The same is true for the right fiber clamp 21BR.

[0030] The left fiber clamp assembly 21L may be configured to be able to change the fiber clamp pressure. The fiber clamp pressure is the pressure that the left optical fiber group 3L placed in the left V-groove group 17L receives from the left fiber clamp 21BL of the left fiber clamp assembly 21L. Specifically, an elastic body such as a spring that urges the left arm portion 21AL downward may be disposed between the left arm portion 21AL and the left clamp block 21DL. In this case, the left fiber clamp assembly 21L can control the fiber clamp pressure by controlling the position of the left clamp block 21DL in the up-down direction. The same applies to the right fiber clamp assembly 21R.

[0031] As shown in FIG. 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 core wire 4L including the left optical fiber group 3L, and the right fiber holder 31R is configured to hold the right ribbon core wire 4R including the right optical fiber group 3R. More specifically, the left fiber holder 31L has a left fiber holder main body 31La having a recess (not shown) for accommodating the left ribbon core wire 4L, and a left cover body 31Lb attached to the left fiber holder main body 31La. Similarly, the right fiber holder 31R has a right fiber holder main body 31Ra having a recess (not shown) for accommodating the right ribbon core wire 4R, and a right cover body 31Rb attached to the right fiber holder main body 31Ra.

[0032] When the left cover 31Lb is closed with the left ribbon core fiber 4L accommodated in the left fiber holder main body 31La, the left ribbon core fiber 4L is held in the left fiber holder 31L. The left fiber holder 31L is fixed to a movable stage (not shown) and is movable in a direction along the axial direction of the held left optical fiber group 3L. That is, the left fiber holder 31L is movable along the extension 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.

[0033] Similarly, when the right cover 31Rb is closed with the right ribbon core wire 4R housed in the right fiber holder main body 31Ra, the right ribbon core wire 4R is held in the right fiber holder 31R. The right fiber holder 31R is fixed to a movable stage (not shown) and 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 extension 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.

[0034] Next, a control system for controlling the fusion splicer 1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the control system for controlling the fusion splicer 1.

[0035] 4, the fusion splicer 1 includes an imaging device 51, a fusion device 52, a fiber clamp driving device 53, a fiber holder (stage) driving device 54, a display device 55, and a control device 60. In this embodiment, the imaging device 51, the fusion device 52, the fiber clamp driving device 53, the fiber holder (stage) driving device 54, and the display device 55 are controlled by the control device 60.

[0036] The imaging device 51 is configured to include, for example, a pair of cameras (X camera and Y camera). Both the X camera and the Y camera are arranged so as to simultaneously capture images of 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. The imaging direction of the X camera and the imaging direction of the Y camera are perpendicular 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 identify the position of the optical fiber group 3.

[0037] The fusion device 52 is a device that fusion-splices an end portion of the left optical fiber group 3L and an end portion of the right optical fiber group 3R. In this embodiment, the pair of electrode rods 5 are included in the fusion device 52.

[0038] The fiber clamp driving device 53 is a device for pressing the optical fiber group 3 against the V-groove group 17. In this embodiment, the fiber clamp driving device 53 includes an actuator for vertically moving each of the left clamp block 21DL constituting the left fiber clamp assembly 21L and the right clamp block 21DR constituting the right fiber clamp assembly 21R.

[0039] The fiber holder (stage) driving 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 (stage) driving device 54 includes an actuator for moving the left fiber holder 31L fixed to the stage 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 fixed to the stage in a direction along the axial direction (Y-axis direction) of the right optical fiber group 3R.

[0040] The display device 55 is a device for displaying various types of information. In this embodiment, the display device 55 is configured to display an image captured by the imaging device 51. In this embodiment, the display device 55 is a liquid crystal display.

[0041] The control device 60 is a device for controlling each of the imaging device 51, the fusion device 52, the fiber clamp driving device 53, the fiber holder (stage) driving device 54, and the display device 55. In this embodiment, the control device 60 is a computer including, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a communication module, and an external storage device.

[0042] Specifically, the control device 60 controls the imaging device 51 to obtain an image captured by the imaging device 51. The control device 60 can display the obtained image on the display device 55, for example. The control device 60 can also determine the state of one or more pairs of optical fibers by performing image processing on the obtained image. 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 device 52. The control device 60 can also move the left clamp block 21DL of the left fiber clamp assembly 21L and the right clamp block 21DR of the right fiber clamp assembly 21R in the up and down directions by controlling the fiber clamp driver 53. Under the control of the control device 60, the left fiber clamp assembly 21L can change the pressing state of the left optical fiber group 3L arranged in the left V-groove group 17L, and the right fiber clamp assembly 21R can change the pressing state of the right optical fiber group 3R arranged in the right V-groove group 17R. Moreover, 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 (stage) driving device 54. Specifically, 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) by moving the stage (not shown) to which the left fiber holder 31L is fixed in the left-right direction (Y-axis direction), and can move the right optical fiber group 3R held by the right fiber holder 31R in the left-right direction (Y-axis direction) by moving the stage (not shown) to which the right fiber holder 31R is fixed in the left-right direction (Y-axis direction).

[0043] As described above, the fiber clamp 21B is used to press the optical fiber group 3 to be fusion spliced ​​against the V-groove group 17, but if any foreign matter is attached to the lower surface (the surface on the Z2 side) of the fiber clamp 21B, it may not be possible to properly press the optical fiber group 3 against the V-groove group 17. Note that foreign matter may be, for example, dust in the surrounding atmosphere, glass or coating material residue that is attached to the optical fiber group 3 to be fusion spliced ​​or residue from the previous fusion splicing, etc.

[0044] Here, referring to Fig. 5A and Fig. 5B, a problem caused by a fiber clamp (left fiber clamp 21BLX) as a comparative example will be described. The left fiber clamp 21BLX as a comparative example has a flat lower surface (surface on the Z2 side). Fig. 5A and Fig. 5B are cross-sectional views of a part of a fusion splicer including the left fiber clamp 21BLX as a comparative example. Specifically, Fig. 5A and Fig. 5B are cross-sectional views of the left base member 11L in which the left V-groove group 17L is formed, the left optical fiber group 3L, and the left fiber clamp 21BLX, and correspond to the cross section including the cutting line VV in Fig. 3 as viewed from the Y2 side as indicated by the arrow. Note that the following description referring to Fig. 5A and Fig. 5B relates to the left fiber clamp 21BLX, but is also applicable to a right fiber clamp (not shown) having a flat lower surface (surface on the Z2 side) in the same manner.

[0045] More specifically, Figure 5A shows an example of the state of the left optical fiber group 3L installed in the left V-groove group 17L when no foreign matter is attached to the lower surface (Z2 side surface) of the left fiber clamp 21BLX, and Figure 5B shows an example of the state of the left optical fiber group 3L installed in the left V-groove group 17L when a foreign matter G is attached to the lower surface (Z2 side surface) of the left fiber clamp 21BLX.

[0046] 5A, when no foreign matter is attached to the bottom surface of the left fiber clamp 21BLX, each of the four optical fibers (the first left optical fiber 3AL to the fourth left optical fiber 3DL) placed in the left V-groove group 17L comes into contact with the bottom surface of the left fiber clamp 21BLX. That is, the left fiber clamp 21BLX can appropriately press all of the four optical fibers (the first left optical fiber 3AL to the fourth left optical fiber 3DL) placed in the left V-groove group 17L.

[0047] On the other hand, when a foreign object G is attached to the lower surface of the left fiber clamp 21BLX as shown in FIG. 5B, the left fiber clamp 21BLX tilts (swings) around the left connecting pin 21CL as indicated by the arrow AR1. This is because the left fiber clamp 21BLX is configured to tilt (swing) around the left connecting pin 21CL so as to maintain the parallelism between the upper surface of the left base member 11L and the lower surface of the left fiber clamp 21BLX. In this case, one of the four optical fibers (the fourth left optical fiber 3DL) contacts the lower surface of the left fiber clamp 21BLX, but the remaining three (the first left optical fiber 3AL to the third left optical fiber 3CL) do not contact the lower surface of the left fiber clamp 21BLX. That is, the fusion splicer 1 cannot properly press the left optical fiber group 3L into the left V-groove group 17L. As a result, the optical fiber that is not in contact with the lower surface of the left fiber clamp 21BLX is not properly pressed by the left fiber clamp 21BLX, and may deviate from the V-groove. For example, if the first left optical fiber 3AL deviates from the first left V-groove 17AL, a misalignment occurs between the axial direction of the first left optical fiber 3AL and the axial direction of the first right optical fiber 3AR, and the fusion splicer 1 may not be able to properly fusion-splice the first left optical fiber 3AL and the first right optical fiber 3AR. Note that the typical size of an actual foreign object that adheres to the V-groove is smaller than the size of the foreign object G shown in FIG. 5B. However, even if the foreign object is of such a small size, it still hinders the realization of proper fusion splicing. In addition, such a problem may occur in a configuration in which the left fiber clamp 21BLX does not tilt (swing).

[0048] Therefore, as shown in FIGS. 6A and 6B, a recess 25 is formed in the lower surface 26 of each of the fiber clamps 21B in the fusion splicer 1 according to this embodiment.

[0049] Figures 6A and 6B are diagrams showing an example of the configuration of the fiber clamp 21B constituting the fusion splicer 1 according to this embodiment. Specifically, Figure 6A is a perspective view of the left fiber clamp 21BL when viewed obliquely from below, and Figure 6B is a perspective view of the right fiber clamp 21BR when viewed obliquely from above. In the illustrated example, the left fiber clamp 21BL and the right fiber clamp 21BR have the same shape and size.

[0050] The recess 25 is a portion (structure) formed on the lower surface 26 of the fiber clamp 21B. In this embodiment, the recess 25 is a structure formed so as to prevent the foreign matter G from coming into contact with the lower surface 26 of the fiber clamp 21B at a position higher than the optical fiber group 3 installed in the V-groove group 17.

[0051] Specifically, the recess 25 includes a left recess 25L formed in the left fiber clamp 21BL and a right recess 25R formed in the right fiber clamp 21BR.

[0052] 6A, the left recess 25L includes three grooves (first left groove 25AL, second left groove 25BL, and third left groove 25CL) extending in a direction (X-axis direction) perpendicular to the extension direction (Y-axis direction) of the left V-groove group 17L. The lower surface (left lower surface 26L) of the left fiber clamp 21BL is a rectangular flat surface surrounded by four inclined surfaces (rear inclined surface CB, front inclined surface CF, left inclined surface CL, and right inclined surface CR). Specifically, the left lower surface 26L is configured such that the length in the X-axis direction is length L1 and the length (width) in the Y-axis direction is width W1, and is divided into four parts. The four portions include a first left portion 26AL bounded by the left slope CL and the first left groove 25AL, a second left portion 26BL bounded by the first left groove 25AL and the second left groove 25BL, a third left portion 26CL bounded by the second left groove 25BL and the third left groove 25CL, and a fourth left portion 26DL bounded by the third left groove 25CL and the right slope CR.

[0053] Similarly, as shown in Fig. 6B, the right recess 25R includes three grooves (first right groove 25AR, second right groove 25BR, and third right groove 25CR) extending in a direction (X-axis direction) perpendicular to the extension direction (Y-axis direction) of the right V-groove group 17R. The lower surface (right lower surface 26R) of the right fiber clamp 21BR is a rectangular flat surface surrounded by four inclined surfaces (rear inclined surface CB, front inclined surface CF, left inclined surface CL, and right inclined surface CR). Specifically, the right lower surface 26R is configured so that the length in the X-axis direction is length L1 and the length (width) in the Y-axis direction is width W1, and is divided into four parts. The four portions include a first right portion 26AR bounded by the left slope CL and the first right groove 25AR, a second right portion 26BR bounded by the first right groove 25AR and the second right groove 25BR, a third right portion 26CR bounded by the second right groove 25BR and the third right groove 25CR, and a fourth right portion 26DR bounded by the third right groove 25CR and the right slope CR.

[0054] Both the left fiber clamp 21BL and the right fiber clamp 21BR are configured to have a substantially U-shaped cross section in front view. Specifically, as shown in Fig. 6A, the left fiber clamp 21BL has a base BS, a left wall WL, and a right wall WR. A recess RS for receiving the protruding portion of the left arm portion 21AL is formed between the left wall WL and the right wall WR, and a through hole TH through which the left connecting pin 21CL is inserted is formed along the Y-axis direction in each of the left wall WL and the right wall WR. The same is true for the right fiber clamp 21BR shown in Fig. 6B.

[0055] Next, the effect of the fiber clamp 21B according to the embodiment of the present invention will be described with reference to FIG. 7. FIG. 7 is a cross-sectional view of a part of the fusion splicer 1 including the fiber clamp 21B according to the embodiment of the present invention. Specifically, FIG. 7 is a cross-sectional view of the left base member 11L in which the left V-groove group 17L is formed, the left optical fiber group 3L, and the left fiber clamp 21BL. More specifically, the upper view of FIG. 7 corresponds to a view of the cross section including the cutting line VV in FIG. 3 as viewed from the Y2 side as indicated by the arrow, and corresponds to FIG. 5A. The lower view of FIG. 7 corresponds to a view of the cross section including the cutting line VII-VII in the upper view of FIG. 7 as viewed from the X2 side as indicated by the arrow. Note that the following description with reference to FIG. 7 relates to the left fiber clamp 21BL, but is similarly applicable to the right fiber clamp 21BR.

[0056] In the illustrated example, the left V groove group 17L is configured to have a length L2 in the X-axis direction as shown in the upper diagram of Fig. 7. Each of the four V grooves (first left V groove 17AL, second left V groove 17BL, third left V groove 17CL, and fourth left V groove 17DL) has the same width WD, and the length L2 of the left V groove group 17L in the X-axis direction corresponds to the sum of the widths of the four V grooves.

[0057] In the illustrated example, the left recess 25L is configured so that the length L1 in the X-axis direction is greater than the length L2 of the left V-groove group 17L. Specifically, the left recess 25L is configured so that it protrudes forward (in the X1 direction) from the front edge (the edge on the X1 side) of the left V-groove group 17L by a length L11, and protrudes rearward (in the X2 direction) from the rear edge (the edge on the X2 side) of the left V-groove group 17L by a length L12. In the illustrated example, the length L11 and the length L12 are the same. However, the length L11 and the length L12 may be different from each other. In addition, the left recess 25L may be configured so that the length L1 in the X-axis direction is the same as the length L2 of the left V-groove group 17L, or may be configured so that it is smaller than the length L2.

[0058] Each of the three grooves (first left groove 25AL, second left groove 25BL, and third left groove 25CL) constituting the left recess 25L is configured to form a substantially rectangular parallelepiped space with a width WC, a length L1, and a height (depth D1) inside the left fiber clamp 21BL, as shown in FIG. 7. That is, each of the three grooves includes a flat ceiling surface extending along the X-axis direction and two wall surfaces extending along the Z-axis direction. The two wall surfaces are flat vertical surfaces and include a left side surface (wall surface on the Y1 side) and a right side surface (wall surface on the Y2 side). However, the three grooves constituting the left recess 25L may be grooves having other shapes such as V-grooves or U-grooves.

[0059] In the illustrated example, each of the three grooves is configured so that its depth D1 is smaller than the depth D2 of the left V-groove group 17L. However, each of the three grooves may be configured so that its depth D1 is greater than or equal to the depth D2 of the left V-groove group 17L.

[0060] Each of the three grooves is configured so that the width of the opening and the width of the ceiling surface are both width WC, but the width of the opening and the width of the ceiling surface may be configured so that they are different from each other. For example, each of the three grooves may be configured so that the width of the opening is larger than the width of the ceiling surface. Each of the three grooves is configured so that one end opens to the front slope CF and the other end opens to the rear slope CB. However, each of the three grooves may be configured so that one end does not open to the front slope CF. That is, each of the three grooves may be configured so that it has a front side surface (wall surface on the X1 side). Alternatively, each of the three grooves may be configured so that the other end does not open to the rear slope CB. That is, each of the three grooves may be configured so that it has a rear side surface (wall surface on the X2 side). In this case, each of the three grooves may be configured so that the length of the opening in the X-axis direction is longer than the length of the ceiling surface in the X-axis direction. Alternatively, each of the three grooves may be configured so that the ceiling surface is a curved surface that is convex upward. This is to allow any foreign matter adhering to the inside of the groove to be easily scraped out with a cotton swab or the like.

[0061] Next, another configuration example of the recess 25 will be described with reference to Figs. 8A to 8F. Each of Figs. 8A to 8F is a bottom view of the left fiber clamp 21BL in which the left recess 25L is formed. Specifically, Fig. 8A is a bottom view of the left fiber clamp 21BL shown in Fig. 7. Figs. 8B to 8F are bottom views of the left fiber clamp 21BL in which left recesses (left recesses 25L1 to 25L5) having a different shape from the left recess 25L shown in Fig. 7 are formed. Note that in each of Figs. 8A to 8F, a dot pattern is applied to the ceiling surface of the left recess 25L for clarity. Also, the following description with reference to each of Figs. 8A to 8F relates to the left fiber clamp 21BL, but is similarly applied to the right fiber clamp 21BR having a flat right lower surface 26R (surface on the Z2 side).

[0062] The left recess 25L1 shown in Fig. 8B is formed so as to diagonally cross the longitudinal direction (X-axis direction) of the left lower surface 26L, which differs from the left recess 25L shown in Fig. 8A which is formed so as to cross perpendicularly to the longitudinal direction (X-axis direction) of the left lower surface 26L. The left recess 25L1 shown in Fig. 8B is also different from the left recess 25L shown in Fig. 8A which includes three grooves (first left groove 25AL to third left groove 25CL) aligned in the Y-axis direction, in that it includes ten grooves (first left groove 25AL to tenth left groove 25JL) aligned in the Y-axis direction. Furthermore, the left recess 25L1 shown in FIG. 8B differs from the left recess 25L shown in FIG. 8A in which one end (front end) of each of the three grooves opens into the front slope CF and the other end (rear end) opens into the rear slope CB, in that one end (front end) of the first left groove 25AL does not open into the front slope CF and the other end (rear end) of the tenth left groove 25JL does not open into the rear slope CB.

[0063] The left recess 25L2 shown in FIG. 8C differs from the left recess 25L shown in FIG. 8A, which includes three grooves (the first left groove 25AL to the third left groove 25CL) aligned in the Y-axis direction, in that the left recess 25L2 shown in FIG. 8C includes ten grooves (the first left groove 25AL to the tenth left groove 25JL) aligned in the Y-axis direction. In addition, the left recess 25L2 shown in Figure 8C differs from the left recess 25L shown in Figure 8A in which one end (front end) of each of the three grooves opens to the front slope CF and the other end (rear end) opens to the rear slope CB in that the other ends (rear ends) of the first left groove 25AL, the third left groove 25CL, the fifth left groove 25EL, the seventh left groove 25GL, and the ninth left groove 25IL do not open to the rear slope CB, and in that one ends (front ends) of the second left groove 25BL, the fourth left groove 25DL, the sixth left groove 25FL, the eighth left groove 25HL, and the tenth left groove 25JL do not open to the front slope CF.

[0064] The left recess 25L3 shown in Fig. 8D is different from the left recess 25L shown in Fig. 8A in which the surface of the left lower surface 26L of the left fiber clamp 21BL is formed in a striped pattern in that the surface of the left lower surface 26L of the left fiber clamp 21BL is formed in a twill pattern. The left recess 25L3 shown in Fig. 8D may be a recess formed by performing surface processing such as flat knurling on the surface of the left lower surface 26L of the left fiber clamp 21BL.

[0065] The left recess 25L4 shown in FIG. 8E is formed as a cross-hatched groove, which differs from the left recess 25L shown in FIG. 8A which is formed as a linear groove extending along the X-axis direction.

[0066] The left recess 25L5 shown in Fig. 8F includes six grooves (first left groove 25AL to sixth left groove 25FL) aligned in the Y-axis direction, which differs from the left recess 25L shown in Fig. 8A including three grooves (first left groove 25AL to third left groove 25CL) aligned in the Y-axis direction. The left recess 25L5 shown in Fig. 8F also differs from the left recess 25L shown in Fig. 8A, in which each of the six grooves is curved, in which each of the three grooves is linear (not curved).

[0067] The left recess 25L, which can have various configurations as shown in each of Fig. 8A to Fig. 8F, can reduce the probability that a foreign object is caught between the left lower surface 26L of the left fiber clamp 21BL and the upper surface of the left base member 11L or the left optical fiber group 3L installed in the left V groove group 17L. Therefore, the left recess 25L can appropriately bring the left lower surface 26L of the left fiber clamp 21BL into contact with each of the left optical fiber groups 3L installed in the left V groove group 17L, and can prevent each of the left optical fiber groups 3L installed in the left V groove group 17L from being shifted from a predetermined position. This is because it can prevent the occurrence of a situation in which at least one optical fiber of the left optical fiber group 3L installed in the left V groove group 17L does not come into contact at all with the left lower surface 26L of the left fiber clamp 21BL.

[0068] 8A to 8F, the plurality of grooves or recesses constituting left recess 25L are formed so that the distances between each of the plurality of grooves or recesses are equal. However, the plurality of grooves or recesses constituting left recess 25L may be formed so that the distances between each of the plurality of grooves or recesses are unequal.

[0069] As described above, the fusion splicer 1 according to the embodiment of the present invention is configured to fusion-splice optical fibers together. Specifically, as shown in Fig. 7, the fusion splicer 1 includes a left base member 11L having a left V-groove group 17L in which a left optical fiber group 3L is placed, and a left fiber clamp 21BL having a flat left lower surface 26L facing the upper surface of the left base member 11L. A left recess 25L is provided in a part of the left lower surface 26L of the left fiber clamp 21BL in an area (area of ​​length L1 and width W1) facing the area (area of ​​length L2 and width W2) in which the left V-groove group 17L is formed on the upper surface of the left base member 11L. The same is true for the right lower surface 26R of the right fiber clamp 21BR.

[0070] This configuration can reduce the probability that a foreign object will be caught between the lower surface 26 of the fiber clamp 21B and the upper surface of the V-groove group 17 or the optical fiber group 3 placed in the V-groove group 17 by forming a recess 25 on the lower surface 26 of the fiber clamp 21B. Therefore, this configuration can appropriately bring the optical fiber group 3 placed in the V-groove group 17 into contact with the fiber clamp 21B. In other words, this configuration can prevent the occurrence of a situation in which one or more optical fibers of the optical fiber group 3 placed in the V-groove group 17 do not come into contact with the fiber clamp 21B at all. As a result, this configuration has the effect of preventing the occurrence of a malfunction in which the position of the optical fiber is shifted from a predetermined position because the optical fiber is not appropriately pressed by the fiber clamp 21B.

[0071] The recess 25 may include a groove formed to extend in a direction non-parallel to the extension direction (Y-axis direction) of the V groove group 17 formed in the base member 11. For example, in the example shown in FIG. 7 and FIG. 8A, the left recess 25L includes three grooves (first left groove 25AL to third left groove 25CL) formed to extend in a direction (X-axis direction) perpendicular to the extension direction (Y-axis direction) of the left V groove group 17L formed in the left base member 11L. This configuration brings about an effect that the optical fiber group 3 installed in the V groove group 17 can be appropriately contacted with the fiber clamp 21B, and thus the optical fiber group 3 is accurately positioned in the V groove group 17. Note that the recess 25 may include a groove formed to extend parallel to the extension direction (Y-axis direction) of the V groove group 17 formed in the base member 11, as long as the lower surface 26 of the fiber clamp 21B can contact at least a part of each optical fiber installed in each V groove to prevent the positional deviation of each optical fiber. For example, the recess 25 may include a groove formed to extend parallel to the first left V-groove 17AL along a portion of the length of the first left V-groove 17AL.

[0072] Also, the recess 25 may be configured such that one end (front end) opens to a side surface of the fiber clamp 21B as shown in Fig. 7. For example, in the example shown in Fig. 7 and Fig. 8A, the left recess 25L is configured such that one end (front end) opens to a front inclined surface CF constituting a part of the side surface (front surface) of the left fiber clamp 21BL, and the other end (rear end) opens to a rear inclined surface CB constituting a part of another side surface (rear surface) of the left fiber clamp 21BL. This configuration provides the effect that an operator who cleans the left recess 25L can easily discharge foreign matter adhering to the inside of the left recess 25L to the outside along the extension direction (X-axis direction) of the left recess 25L with a cotton swab or the like.

[0073] The fiber clamp 21B may be configured to be swingable around an axis parallel to the extension direction of the V groove formed in the base member 11. For example, in the example shown in the upper diagram of Fig. 7, the left fiber clamp 21BL is configured to be swingable around a left connecting pin 21CL that is an axis parallel to the extension direction (X-axis direction) of the left V groove group 17L formed in the left base member 11L. In this configuration, even when the left fiber clamp 21BL is configured to be swingable in this way, the left recess 25L formed in the left lower surface 26L of the left fiber clamp 21BL can reduce the probability that a foreign object will be caught between the left lower surface 26L of the left fiber clamp 21BL and the left optical fiber group 3L installed on the upper surface of the left base member 11L or the left V groove group 17L.

[0074] Above, the preferred embodiment of the present invention has been described in detail. However, the disclosed embodiment should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not the above-described embodiments, and is intended to include all modifications within the scope of the claims. That is, the present invention is not limited to the above-described embodiments. Various modifications or substitutions can be applied to the above-described embodiments without departing from the scope of the present invention. In addition, each of the features described with reference to the above-described embodiments may be appropriately combined as long as there is no technical contradiction.

[0075] For example, in the above embodiment, the fusion splicer 1 includes a left base member 11L in which a plurality of V grooves are formed and a right base member 11R in which a plurality of V grooves are formed. However, the fusion splicer 1 may include a left base member 11L in which only one V groove is formed and a right base member 11R in which only one V groove is formed. In other words, the fusion splicer 1 may be a device for fusion splicing single-core optical fibers. [Explanation of symbols]

[0076] 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: 3rd 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 4L... Left ribbon core 4R...Right ribbon fiber 5...electrode rod 5B...Rear electrode rod 5Ba···Tip 5F...Front electrode rod 5Fa...Tip 11...Base member 11L: Left base member 11R Right base member 17...V-groove group 17A 1st V-groove pair 17AL...1st left V groove 17AR...1st right V groove 17B...Second 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 21 Fiber clamp assembly 21A···Arm section 21AL···Left arm 21AR···Right arm 21B Fiber clamp 21BL···Left fiber clamp 21BR···Right Fiber Clamp 21C···Connecting pin 21CL···Left connecting pin 21CR···Right connecting pin 21D···Clamp block 21DL···Left clamp block 21DR···Right clamp block 21L···Left fiber clamp assembly 21R···Right Fiber Clamp Assembly 25 Recess 25AL...1st left groove 25AR...1st right groove 25BL...2nd left groove 25BR...2nd right groove 25CL...3rd left groove 25CR...3rd right groove 25DL...4th left groove 25EL...5th left groove 25FL...6th left groove 25GL...7th left groove 25HL...8th left groove 25IL...9th left groove 25JL...10th left groove 25L, 25L1~25L5... Left recess 25R: Right recess 26...Bottom surface 26AL...1st left part 26AR...1st right part 26BL...2nd left part 26BR...2nd right part 26CL...3rd left part 26CR...Third right part 26DL...4th left part 26DR...4th right part 26L...Bottom left surface 26R...Bottom right surface 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 Fiber clamp drive unit 54 Fiber holder drive unit 55...Display device 60...Control device BS...Base CB...Back slope CF...Front slope CL... Left slope CR Right Slope G...Foreign object RS···Recess TH...Through hole WL...Left wall section WR...Right wall section

Claims

1. A fusion splicer for fusion-splicing optical fibers, comprising: a base member having a V-groove in which the optical fiber is placed; a fiber clamp having a flat lower surface opposite to the upper surface of the base member; a recess is formed in a part of the lower surface of the fiber clamp, the part facing the region of the upper surface of the base member where the V-groove is formed; Fusion splicer.

2. The recess is formed so as to extend in a direction non-parallel to an extension direction of the V-groove formed in the base member. The fusion splicer of claim 1.

3. The recess is configured such that at least one end opens to a side surface of the fiber clamp. The fusion splicer according to claim 1 or 2.

4. the fiber clamp is configured to be swingable about an axis parallel to an extension direction of the V-groove formed in the base member; The fusion splicer according to any one of claims 1 to 3.

Images