JP2021026139A - Optical fiber cutter and method for cutting optical fiber - Google Patents

Abstract

To suppress a clearance formed between a core and a core of optical fibers when the optical fibers having an inclined end face are butted against each other.SOLUTION: An optical fiber cutter comprises a blade body 47 forming an initial flaw on an optical fiber 1 and a bending part imparting bending stress to the optical fiber. In a state where, by the bending stress, tensile stress is formed on a side coming into contact with the blade body and compressive stress is also formed on an opposite side to the side coming into contact with the blade body, the initial flaw is formed on the optical fiber by the blade body.SELECTED DRAWING: Figure 6

Description

The present invention relates to an optical fiber cutter and an optical fiber cutting method.

In general, an optical fiber cutter that cuts an optical fiber cuts an optical fiber by forming an initial scratch on the optical fiber with a blade and growing the initial scratch to cleave the optical fiber (for example, Patent Documents 1 to 3). reference).

Japanese Unexamined Patent Publication No. 62-194204 Japanese Unexamined Patent Publication No. 2014-238574 JP-A-2018-194598

By forming initial scratches on the optical fiber while applying torsional stress or bending stress to the optical fiber, the cut surface (cleavage surface) of the optical fiber may be inclined. When the optical fibers whose end faces are inclined in this way are butted against each other, the edge of the inclined end face of one optical fiber on the protruding side and the edge of the inclined end face of the other optical fiber on the retracted side come into contact with each other. As a result, if a large gap is formed between the cores of the optical fiber, the loss of the optical signal (connection loss) at the connection portion of the optical fiber may increase (see FIG. 18B).

An object of the present invention is to suppress a gap formed between the cores of an optical fiber when the optical fibers having inclined end faces are butted against each other.

The main invention for achieving the above object includes a blade body that forms an initial scratch on the optical fiber and a bending portion that applies bending stress to the optical fiber, and the side that comes into contact with the blade body due to the bending stress. An optical fiber cutter characterized in that an initial scratch is formed on an optical fiber by the blade in a state where a tensile stress is formed on the optical fiber and a compressive stress is formed on a side opposite to the side in contact with the blade. Is.

Other features of the present invention will be clarified by the description of the specification and drawings described later.

According to the present invention, when optical fibers having inclined end faces are butted against each other, it is possible to suppress a gap formed between the cores of the optical fibers.

FIG. 1 is a perspective view of the fiber cutter 100. FIG. 2 is an exploded perspective view of the fiber cutter 100. 3A to 3C are operation explanatory views of the fiber cutter 100. 4A to 4C are schematic explanatory views of the fiber cutter 100. 5A and 5B are explanatory views of the bent portion 48. FIG. 6A is an explanatory diagram of the stress distribution of the optical fiber 1 after the latch is released in the first embodiment. FIG. 6B is an explanatory diagram of the growth of the initial wound in the first embodiment. FIG. 6C is an explanatory view of the cut surface 11 of the optical fiber 1 in the first embodiment. FIG. 7 is a photograph of the cut surface 11 of the optical fiber 1 cut by using the optical fiber cutter of the present embodiment. FIG. 8A is an explanatory diagram of a state at the time of cutting the optical fiber 1 of the reference example. FIG. 8B is an explanatory view of a cut surface 11 of the optical fiber 1 of the reference example. FIG. 8C is a graph of compressive stress of this embodiment and a reference example. FIG. 9A is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the first embodiment are butted against each other. FIG. 9B is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the first embodiment are butted against each other. FIG. 10A is an explanatory diagram of the cutting method of the second embodiment. FIG. 10B is an explanatory view of the cut surface 11 of the optical fiber 1 in the second embodiment. FIG. 11A is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the second embodiment are butted against each other. FIG. 11B is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the second embodiment are butted against each other. 12A and 12B are explanatory views of the blade body 47 of the second embodiment. 13A and 13B are explanatory views of another blade body 47 of the second embodiment. 14A and 14B are explanatory views of a modified example of the second embodiment. 15A and 15B are explanatory views of a method of forming an initial scratch in a modified example. 16A and 16B are schematic explanatory views in the vicinity of the bent portion 48 of another embodiment. FIG. 17A is an explanatory diagram of the stress distribution of the optical fiber 1 before the latch is released. FIG. 17B is an explanatory diagram of the stress distribution of the optical fiber 1 after the latch is released in the comparative example. FIG. 17C is an explanatory view of a cut surface 11 of the optical fiber 1 in the comparative example. FIG. 18A is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the comparative example are butted against each other. FIG. 18B is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the comparative example are butted against each other.

At least the following matters will be clarified from the description of the specification and drawings described later.

A blade body that forms an initial scratch on the optical fiber and a bending portion that applies bending stress to the optical fiber are provided, and the bending stress forms a tensile stress on the side in contact with the blade body and the blade body. An optical fiber cutter characterized in that an initial scratch is formed on the optical fiber by the blade in a state where a compressive stress is formed on the side opposite to the side in contact with the optical fiber becomes clear. According to such an optical fiber cutter, it is possible to suppress a gap formed between the cores of an optical fiber when the optical fibers having inclined end faces are butted against each other.

A tension applying portion that applies tension to the optical fiber is provided, and when the initial scratch is formed on the optical fiber by the blade, the tension applying portion applies tensile stress to the core region of the optical fiber. It is desirable to form. This makes it possible to form a good cut surface in the core region.

It is desirable that the bent portion applies the bending stress to the optical fiber so that the compressive stress becomes larger toward the proximal end side on the side opposite to the side in contact with the blade. As a result, on the side opposite to the side that comes into contact with the blade, the cut surface and the outer peripheral surface of the optical fiber have a shape in which the corners are removed.

A grip portion for gripping the optical fiber on a mounting surface on which the optical fiber is placed is provided on the tip side of the optical fiber with respect to the blade body, and the bent portion is the optical fiber rather than the blade body. It is desirable that the base end side of the above-mentioned surface protrudes upward from the above-mentioned mounting surface. As a result, when the optical fiber mounted on the mounting surface is gripped, bending stress can be applied to the optical fiber by the bending portion.

It is desirable that the blade forms at least two of the initial scratches at different positions in the longitudinal direction of the optical fiber and combines at least two scratches progressing from the initial scratches to cleave the optical fiber. As a result, the shape of the cut surface of the optical fiber is rounded on the side in contact with the blade.

By applying bending stress to the optical fiber, tensile stress is formed on the side in contact with the blade, compressive stress is formed on the side opposite to the side in contact with the blade, and the tensile stress is formed. The blade body is brought into contact with the stressed portion to form an initial scratch on the optical fiber, and the opening surface inclined with respect to the plane perpendicular to the optical axis of the optical fiber and the opening of the optical fiber are stopped. After that, by forming a cut surface having a cracked surface formed by cracking the optical fiber, an optical fiber cutting method characterized by cutting the optical fiber becomes clear. According to such an optical fiber cutting method, the gap formed between the cores of the optical fiber can be suppressed.

=== 1st Embodiment ===
<Basic configuration of optical fiber cutter>
FIG. 1 is a perspective view of the fiber cutter 100. FIG. 2 is an exploded perspective view of the fiber cutter 100. 3A to 3C are operation explanatory views of the fiber cutter 100. 4A to 4C are schematic explanatory views of the fiber cutter 100.

In the following description, each direction is defined as shown in FIG. That is, the direction parallel to the moving direction of the moving member 40 is defined as "X-axis direction" or "front-back direction", and the moving side of the moving member 40 immediately after cutting the optical fiber 1 is defined as "+ X direction" or "front". The opposite side (the side of the holder 3 as viewed from the moving member 40) is defined as "-X direction" or "rear". Further, the direction perpendicular to the mounting surface 41B on which the end portion of the optical fiber 1 is placed is defined as the "Z-axis direction" or the "vertical direction", and the side on which the optical fiber 1 is mounted as viewed from the mounting surface 41B is ". "+ Z direction" or "up", and the opposite side is "-Z direction" or "down". Further, the direction perpendicular to the X-axis direction (front-back direction) and the Z-axis direction (vertical direction) is defined as the Y-axis direction, and the side of the rotating portion 45A as viewed from the optical fiber 1 is defined as "+ Y direction" or "back". The opposite side is "-Y direction" or "front".

Further, in the following description, the end side of the optical fiber 1 may be referred to as the "tip side", and the opposite side may be referred to as the "base end side". Here, the front side (+ X side) of the optical fiber 1 is the front end side, and the rear side (−X side) of the optical fiber 1 is the base end side.

The fiber cutter 100 is a cutting device (optical fiber cutter; optical fiber cutting device) that cuts the optical fiber 1. The fiber cutter 100 is a device that cuts the optical fiber 1 by forming an initial scratch on the optical fiber 1 with a blade body 47 (blade) and growing the initial scratch to cleavage the optical fiber 1. The fiber cutter 100 of the present embodiment includes a blade body 47 and a bending portion 48, and the blade body 47 causes an initial scratch on the optical fiber 1 while the bending portion 48 applies bending stress to the optical fiber 1. By forming, the cut surface of the optical fiber 1 can be inclined (inclined with respect to the surface perpendicular to the optical axis of the optical fiber 1).

The fiber cutter 100 has a base member 20 and a moving member 40. Further, the fiber cutter 100 has a latch portion 50 and a tension applying spring 60.

The base member 20 has a holder mounting portion 21, a guide portion 23, and an operation portion 25.
The holder mounting portion 21 is a portion on which the holder 3 for holding the optical fiber 1 is mounted. The holder mounting portion 21 is arranged on the rear side of the base member 20.
The guide portion 23 is a portion that guides the moving member 40 so as to be movable in the front-rear direction. The guide portion 23 is formed on the front side of the base member 20.

The operation unit 25 is a portion operated by the operator. The operation unit 25 is configured to be openable / closable (rotatable) with respect to the main body of the base member 20. When the operator operates the operation unit 25, the blade body 47 is brought close to the optical fiber 1 to form an initial scratch on the optical fiber 1.

The operating unit 25 has a rotating unit 25A, an accommodating unit 25B, and a latch releasing unit 25C.
The rotating portion 25A is a connecting portion that rotatably connects the operating portion 25 to the base member 20. The accommodating portion 25B is a portion for accommodating the wound forming portion 46 inside. The accommodating portion 25B accommodates the scratch forming portion 46 so as to be movable in the front-rear direction with respect to the operating portion 25. The inner wall surface of the accommodating portion 25B (the surface facing the upper surface of the scratch forming portion 46) serves as a portion for pressing the scratch forming portion 46.
The latch release portion 25C is a portion for releasing the latch state of the latch portion 50. When the operator rotates the operation unit 25 in the closing direction, the latch release unit 25C releases the latch state of the latch unit 50.

The moving member 40 is a member that can move with respect to the base member 20. The moving member 40 moves to the front side immediately after cutting the optical fiber 1 (see FIGS. 3C and 4C). The moving member 40 has a moving body 41, a gripping member 45, a scratch forming portion 46, and a bending portion 48.

The moving body 41 is a portion constituting the main body of the moving member 40. The moving body 41 can move in the front-rear direction while being guided by the guide portion 23 of the base member 20. The end of the tension applying spring 60 is connected to the moving body 41, and the moving body 41 moves with respect to the base member 20 by the force of the tension applying spring 60. Further, the gripping member 45 and the scratch forming portion 46 are independently rotatably provided on the moving body 41.

The moving body 41 has a case accommodating portion 41A, a mounting surface 41B, and an engaging hole 41C.
The case accommodating portion 41A is a portion for accommodating a waste material case (not shown). The waste material case is a case for storing the end portion of the cut optical fiber 1.
The mounting surface 41B is a surface on which the end portion of the optical fiber 1 is mounted. A V-groove may be formed on the mounting surface 41B, or a flat surface may be formed without the V-groove being formed. The optical fiber 1 is gripped by being sandwiched between the mounting surface 41B and the gripping member 45 (specifically, the clamp portion 45B). Here, the mounting surface 41B is a surface parallel to the XY plane (a surface perpendicular to the Z-axis direction).
The engaging hole 41C is a portion for locking the locking portion 45C of the gripping member 45. By locking the locking portion 45C to the engaging hole 41C, the gripping member 45 is fixed in a closed state, and the optical fiber 1 is held between the mounting surface 41B and the clamp portion 45B.

The gripping member 45 is a member that grips the end portion of the optical fiber 1. The gripping member 45 is configured to be openable / closable (rotatable) with respect to the moving body 41. The gripping member 45 is arranged on the front side of the blade body 47. Therefore, the gripping member 45 grips the end portion of the optical fiber 1 (a portion that becomes waste material after cutting) on the front side of the cutting position of the optical fiber 1. The gripping member 45 has a rotating portion 45A, a clamp portion 45B, and a locking portion 45C.
The rotating portion 45A is a connecting portion that rotatably connects the gripping member 45 to the moving body 41. The clamp portion 45B is a portion that comes into contact with the end portion of the optical fiber 1 mounted on the mounting surface 41B and presses the optical fiber 1 against the mounting surface 41B. That is, the optical fiber 1 is sandwiched between the mounting surface 41B and the clamp portion 45B from the vertical direction. The locking portion 45C is a portion that locks into the engaging hole 41C of the moving body 41, and is a portion that fixes the gripping member 45 in a closed state. The optical fiber 1 is held between the mounting surface 41B and the clamp portion 45B by locking the locking portion 45C to the engaging hole 41C of the moving body 41 and fixing the gripping member 45 in a closed state. It will be.

The scratch forming portion 46 is a portion where an initial scratch is formed on the optical fiber 1. The scratch forming portion 46 is configured to be openable / closable (rotatable) with respect to the moving body 41. The scratch forming portion 46 has a rotating portion 46A and a blade body 47. The rotating portion 46A is a connecting portion that rotatably connects the scratch forming portion 46 to the moving body 41. The blade body 47 is a portion (blade) that forms an initial scratch on the optical fiber 1. The upper surface of the scratch forming portion 46 is a portion pressed by the inner wall surface of the accommodating portion 25B of the operating portion 25. When the operator rotates the operating portion 25 in the closing direction, the inner wall surface of the accommodating portion 25B presses the scratch forming portion 46 in the closing direction, and the scratch forming portion 46 also rotates in the closing direction. As a result, the blade body 47 of the scratch forming portion 46 forms an initial scratch on the optical fiber 1.

5A and 5B are explanatory views of the bent portion 48.

The bent portion 48 is a portion that applies bending stress to the optical fiber 1. By forming an initial scratch on the optical fiber 1 while applying bending stress to the optical fiber 1, the cut surface of the optical fiber 1 can be inclined (inclined with respect to a surface perpendicular to the optical axis of the optical fiber 1). .. As shown in FIG. 5A, the bent portion 48 is arranged above the mounting surface 41B, and supports the optical fiber 1 above the mounting surface 41B. As a result, as shown in FIG. 5B, when the optical fiber 1 is gripped by the gripping member 45 (clamp portion 45B), the bent portion 48 and the clamp portion are arranged so that the optical fiber 1 is on the upper side as it is closer to the bent portion 48. It will be bent in an S shape with 45B (that is, in the present embodiment, the optical fiber 1 is on the upper side toward the proximal end side (the side closer to the bent portion 48) when viewed from the cutting portion. , Bent).

A gap 49 is formed between the bent portion 48 and the mounting surface 41B. When the scratch forming portion 46 is rotated in the closing direction, the blade body 47 is inserted into the gap 49 as shown in FIG. 5B. Therefore, in the present embodiment, the blade body 47 forms an initial scratch on the portion of the optical fiber bent by the bent portion 48. That is, in the present embodiment, the initial scratch is formed at the portion to which the bending stress is applied by the bending portion 48.

The latch portion 50 is a portion for latching the base member 20 and the moving member 40. The latch portion 50 has a base-side latch portion 51 and a moving-side latch portion 54. The base-side latch portion 51 is a cantilever-shaped portion provided on the base member 20. The base-side latch portion 51 comes into contact with the latch release portion 25C of the operation portion 25 and elastically deforms. As a result, the base-side latch portion 51 is disengaged from the moving-side latch portion 54, and the latch state is released. The moving side latch portion 54 is a portion provided on the moving member 40, and is a portion for hooking the end portion of the base side latch portion 51.

The tension applying spring 60 is a member (tension applying portion) that applies a force between the base member 20 and the moving member 40. The tension applying spring 60 is arranged between the base member 20 and the moving member 40. One end (front end) of the tension applying spring 60 is connected to the base member 20, and the other end is connected to the moving member 40. When the latch portion 50 is in the latch state (when the base side latch portion 51 and the moving side latch portion 54 are in the latch state; see FIG. 4A), a tensile force is applied to the tension applying spring 60. When the latch state of the latch portion 50 is released (see FIG. 4B), tension is applied to the optical fiber 1 by the tension applying spring 60.

Next, the basic operation of the fiber cutter 100 when cutting the optical fiber 1 will be described.

If the latch portion 50 is in the released state, the operator moves the moving member 40 to the rear side (the side of the holder 3) to bring it into the latch state. In the latched state, the base member 20 and the moving member 40 are fixed in a state where a tensile force is applied to the tension applying spring 60. Further, in the latch state, the scratch forming portion 46 is accommodated inside the accommodating portion 25B of the operating portion 25 (the inner wall surface of the accommodating portion 25B and the upper surface of the scratch forming portion 46 are opposed to each other). ..

The operator sets the holder 3 on the holder mounting portion 21 of the base member 20. The optical fiber 1 to be cut is held in the holder 3. The optical fiber 1 extends from the front side of the holder 3, and the coating on the end portion of the optical fiber 1 is removed in advance. When the operator sets the holder 3 on the holder mounting portion 21, the operator puts the optical fiber 1 on the mounting surface 41B.

Next, as shown in FIGS. 3A and 4A, the operator closes the gripping member 45 and sandwiches the optical fiber 1 between the mounting surface 41B and the gripping member 45 (specifically, the clamp portion 45B). , The optical fiber 1 is gripped. As a result, the optical fiber 1 is laid between the holder 3 and the gripping member 45 (or the mounting surface 41B). At this time, in the present embodiment, bending stress is applied to the optical fiber 1 by the bending portion 48 (see FIG. 5B).

After gripping the optical fiber 1 by the gripping member 45, the operator closes the operating portion 25 (and the scratch forming portion 46) as shown in FIGS. 3B and 4B. When the operating portion 25 is rotated in the closing direction, the scratch forming portion 46 is also rotated in the closing direction together with the operating portion 25, and the blade body 47 of the scratch forming portion 46 moves in the direction approaching the optical fiber 1.

As shown in FIG. 4B, when the operation portion 25 is rotated in the closing direction, the latch release portion 25C of the operation portion 25 comes into contact with the base side latch portion 51. Further, when the operation unit 25 is rotated in the closing direction, the base side latch portion 51 is disengaged from the moving side latch portion 54, and the latch state is released. When the latch state is released, the force of the tension applying spring 60 is applied between the base member 20 and the moving member 40, so that the optical fiber 1 is tensioned. Since tension acts on the optical fiber 1 before cutting the optical fiber 1, the moving member 40 does not move at this stage.

Further, when the operation portion 25 is further rotated in the closing direction after the latch state is released, the blade body 47 of the scratch forming portion 46 comes into contact with the optical fiber 1, and an initial scratch is formed on the optical fiber 1. When an initial scratch is formed on the optical fiber 1 in a tensioned state, the initial scratch grows and the optical fiber 1 is cleaved, whereby the optical fiber 1 is cut. When the optical fiber 1 is cut, as shown in FIGS. 3C and 4C, the moving member 40 moves forward by the force of the tension applying spring 60. The blade body 47 moves to the front side together with the moving member 40 and the end portion of the optical fiber 1 which is a waste material. As a result, it is possible to prevent the cut surface of the optical fiber 1 (the optical fiber on the side held by the holder 3) from being soiled or damaged by the blade body 47. In this embodiment, since the optical fiber 1 is subjected to bending stress, the cut surface (cleavage surface) of the optical fiber 1 is inclined with respect to the surface perpendicular to the optical axis of the optical fiber 1. ..

<Comparison example>
FIG. 17A is an explanatory diagram of the stress distribution of the optical fiber 1 before the latch is released. FIG. 17B is an explanatory diagram of the stress distribution of the optical fiber 1 after the latch is released in the comparative example. FIG. 17C is an explanatory view of a cut surface 11 of the optical fiber 1 in the comparative example.

17A and 17B show the stress distribution of the optical fiber 1 at the site where the initial scratch is formed. That is, FIGS. 17A and 17B show the stress distribution of the optical fiber 1 at the portion (contact portion) in contact with the blade body 47. The right-pointing arrow in the figure indicates that tensile stress is acting. The left-pointing arrow in the figure indicates that compressive stress is acting. The length of the arrow indicates the magnitude of stress.

As shown in FIG. 17A, the optical fiber 1 before the latch is released has a tensile stress formed on the side in contact with the blade 47 (upper side in the drawing of the optical fiber 1) due to the bending stress applied by the bending portion 48. , The compressive stress is formed on the side opposite to the side in contact with the blade body 47 (lower side in the drawing of the optical fiber 1).

In order to grow the initial scratches in order to cleave the optical fiber 1, it is desirable to apply a tensile stress to the inside of the optical fiber 1. For this reason, the force of the tension applying spring 60 is applied to the optical fiber 1 by releasing the latch state, and a tensile stress is applied to the inside of the optical fiber 1. The stress distribution of the optical fiber 1 after the latch is released is a stress distribution in which the stress distribution shown in FIG. 17A and the tensile stress by the tension applying spring 60 are superimposed. In the comparative example, as shown in FIG. 17B, a tensile stress is applied to the entire inside of the optical fiber 1.

In the comparative example, tensile stress acts not only on the side in contact with the blade 47 (upper side in the drawing of the optical fiber 1) but also on the entire area up to the opposite side (lower side in the drawing of the optical fiber 1). ing. Therefore, in the comparative example, when an initial scratch is formed on the optical fiber 1 by the blade body 47, the initial scratch grows at a stretch to the opposite side of the optical fiber 1 and the optical fiber 1 is cleaved. As a result, in the comparative example, as shown in FIG. 17C, the cut surface 11 of the optical fiber 1 becomes a flat surface close to a mirror surface, and is formed at the edge of the cut surface 11 (the angle between the cut surface 11 and the outer periphery of the optical fiber 1). Is formed with angular corners. Since the optical fiber 1 is subjected to bending stress, the cut surface 11 of the optical fiber 1 is an inclined end surface inclined with respect to the surface perpendicular to the optical axis of the optical fiber 1.

FIG. 18A is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the comparative example are butted against each other. FIG. 18B is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the comparative example are butted against each other.

As shown in FIG. 18A, the cut surface 11 of one optical fiber 1 and the cut surface 11 of the other optical fiber 1 may not be parallel to each other. Even if the inclined end faces of the two optical fibers 1 can be formed so that the inclination angles of the cut surfaces 11 with respect to the optical axis of the optical fiber 1 are the same, the rotation of the optical fiber 1 around the optical axis If the position is not adjusted accurately, as shown in FIG. 18A, the cut surface 11 (inclined end surface) of one optical fiber 1 and the cut surface 11 (inclined end surface) of the other optical fiber 1 are not parallel to each other. ..

As shown in FIG. 18A, when the inclined end faces of the optical fibers 1 are not parallel to each other and the optical fibers having the inclined end faces are butted against each other, as shown in FIG. 18B, the inclined end faces of one of the optical fibers 1 protrude. The side edge (the angle between the cut surface 11 and the outer periphery of the optical fiber 1) and the recessed side edge of the inclined end surface of the other optical fiber 1 come into contact with each other. As a result, as shown in FIG. 18B, a large gap is formed between the cores of the optical fiber 1, and there is a possibility that the loss of the optical signal (connection loss) at the connection portion of the optical fiber 1 becomes large. In order to suppress the loss of the optical signal at the connection portion of the optical fiber 1, it is desirable to narrow the gap between the cores of the butted optical fibers 1.

<About the cutting method of the first embodiment>
FIG. 6A is an explanatory diagram of the stress distribution of the optical fiber 1 after the latch is released in the first embodiment. In other words, FIG. 6A is an explanatory diagram of the stress distribution of the optical fiber 1 at the time of initial scratch formation in the first embodiment. A cross-sectional view of the optical fiber 1 is shown on the left side of FIG. 6A. FIG. 6B is an explanatory diagram of the growth of the initial wound in the first embodiment. FIG. 6C is an explanatory view of the cut surface 11 of the optical fiber 1 in the first embodiment.

FIG. 6A shows the stress distribution of the optical fiber 1 at the site where the initial scratch is formed. The right-pointing arrow in the figure indicates that tensile stress is acting. The left-pointing arrow in the figure indicates that compressive stress is acting. The length of the arrow indicates the magnitude of stress.

As described above, the force of the tension applying spring 60 is applied to the optical fiber 1 by releasing the latch state, and a tensile stress is applied to the inside of the optical fiber 1. Therefore, the stress distribution of the optical fiber 1 after the latch release shown in FIG. 6A is a stress distribution in which the stress distribution of the optical fiber 1 before the latch release (see FIG. 17A) and the tensile stress by the tension applying spring 60 are superimposed. become. However, the tensile stress due to the tension applying spring 60 of the present embodiment is set to be weaker than the tensile stress due to the tension applying spring 60 in the above-mentioned comparative example. Specifically, the tension of the tension applying spring 60 is such that when the latch state is released, a compressive stress is formed on the side opposite to the side in contact with the blade 47 (lower side in the drawing of the optical fiber 1). Is set.

In this embodiment, as shown in FIG. 6A, a tensile stress is formed on the side in contact with the blade 47 (upper side in the drawing of the optical fiber 1). Therefore, when an initial scratch is formed in this portion, the initial scratch grows due to the action of the tensile stress (the cleavage of the optical fiber 1 progresses). Further, since the optical fiber 1 is subjected to bending stress, the initial scratches grow in a direction inclined with respect to the plane perpendicular to the optical axis. In FIG. 6B, the wound progressed by cleavage is shown by a solid line.

On the other hand, in the present embodiment, as shown in FIG. 6A, a compressive stress is formed on the side opposite to the side in contact with the blade body 47 (lower side in the figure of the optical fiber 1). That is, in the cross section of the optical fiber 1 at the portion in contact with the blade body 47, a region where tensile stress is not applied is formed. Therefore, when the scratch grown from the initial scratch due to the tensile stress reaches the region where the tensile stress does not act, the progress of the scratch stops there. That is, as shown by the solid line in FIG. 6B, the cleavage of the optical fiber 1 stops in the region where the tensile stress does not act.

In the present embodiment, not only the bending stress is applied to the optical fiber 1 by the bending portion 48, but also the tension is applied to the optical fiber 1 by the tension applying spring 60, so that the optical fiber 1 is as shown in FIG. 6A. A tensile stress is formed in the area of the core. As a result, in the present embodiment, the cleavage of the optical fiber 1 is stopped after the scratches grown from the initial scratches have passed through the core region. If the blade 47 is brought into contact with the optical fiber 1 to which the bending stress is applied by the bending portion 48 without applying the tensile stress to the optical fiber 1 by the tension applying spring 60, an initial scratch is formed, as shown in FIG. 17A. Since the region where the tensile stress is not applied is located in the central portion of the optical fiber 1, the opening of the optical fiber 1 may stop in the region of the core of the optical fiber 1. When the cleavage of the optical fiber 1 is stopped in the region of the core of the optical fiber 1, the opening of the core on the cut surface may not be mirror-like (as a result, the loss of the optical signal (connection loss) may increase). .. On the other hand, in the present embodiment, the optical fiber 1 can be cleaved up to at least the core region (as a result, the opening of the core on the cut surface becomes mirror-like, and the loss of the optical signal can be suppressed).

As shown in FIG. 6B, when the cleavage of the optical fiber 1 is stopped in the region where the tensile stress is not applied, the end of the scratch (the end of the solid line in the figure) and the edge of the optical fiber (FIG. 6B) progressed by the cleavage. The optical fiber 1 is connected to the inner optical fiber 1). However, since the thickness of the connected region is small (for example, several μm to 20 μm), the optical fiber 1 is broken after the cleavage of the optical fiber 1 is stopped. In FIG. 6B, the scratches that progress when the optical fiber 1 is broken are shown by dotted lines.

As described above, in the present embodiment, first, the blade body 47 comes into contact with the optical fiber 1 to form an initial scratch on the optical fiber 1. Since a tensile stress acts on the portion where the initial scratch is formed, the optical fiber 1 generated from the initial scratch is cleaved by the action of the tensile stress after the initial scratch is formed, and the scratch progresses from the initial scratch. When the scratches advanced by the cleavage reach the region where the tensile stress is not applied, the cleavage of the optical fiber 1 is stopped. Then, after the cleavage of the optical fiber 1 is stopped, the optical fiber 1 is broken and the optical fiber 1 is cut.

As shown in FIG. 6C, the cut surface 11 of the optical fiber 1 has a cleavage surface 111 and a cracked surface 112.

The cleavage surface 111 is a cut surface shown by the solid line in FIG. 6B, and is a surface (first cut surface) in which the optical fiber 1 is cleaved from the initial scratch by the action of tensile stress. The cleavage surface 111 is an inclined end surface inclined with respect to a surface perpendicular to the optical axis, similarly to the cut surface 11 of the comparative example shown in FIG. 17C.

The cracked surface 112 is a cut surface shown by the dotted line in FIG. 6B, and the surface where the optical fiber 1 is cracked due to the progress of scratches from the end of the cleavage surface 111 without the action of tensile stress (second cut surface). Is. Therefore, the cracked surface 112 shown by the dotted line in FIG. 6B has a different shape from the cleavage surface 111 shown by the solid line in FIG. 6A. Specifically, the cracked surface 112 is located on the proximal end side of the surface on which the cleavage surface 111 is extended. In other words, the cracked surface 112 is shaped so that the outer side of the optical fiber 1 is closer to the proximal end side. In other words, the upper outer peripheral edge of the optical fiber 1 on the cracked surface 112 (the lower edge of the cracked surface 112 in the drawing; the final position of the crack of the optical fiber 1) is the inner side of the optical fiber 1 on the cracked surface 112. The shape is such that it is closer to the base end side than the edge (the upper edge of the crack surface 112 in the drawing; the start position of the crack of the optical fiber 1). That is, in the cut surface 11 of the optical fiber 1, the edge of the inclined end surface on the retracted side is further retracted to the proximal end side. As a result, on the side opposite to the side in contact with the blade 47 (lower side in the drawing of the optical fiber 1), the cut surface 11 of the optical fiber 1 has a shape in which the corners are removed.

FIG. 7 is a photograph of the cut surface 11 of the optical fiber 1 cut by using the optical fiber cutter of the present embodiment. As described above, the cut surface 11 of the optical fiber 1 has a shape in which the recessed side edge of the inclined end surface is further retracted to the base end side. As a result, on the side opposite to the side in contact with the blade body 47, the cut surface 11 and the outer peripheral surface of the optical fiber 1 have a shape in which the angle is removed, and the cut surface 11 and the outer peripheral surface of the optical fiber 1 are formed. It has a rounded corner.

FIG. 8A is an explanatory diagram of a state at the time of cutting the optical fiber 1 of the reference example. FIG. 8B is an explanatory view of a cut surface 11 of the optical fiber 1 of the reference example. In the reference example, the optical fiber 1 is bent so as to be lower toward the proximal end side when viewed from the cutting portion (in contrast, in the present embodiment, the optical fiber 1 is bent from the cutting portion. It is bent so that it is on the upper side toward the base end side). Also in the reference example, due to the bending stress applied to the optical fiber 1, a tensile stress is formed on the side in contact with the blade 47 (upper side in the drawing of the optical fiber 1), and the opposite side (on the optical fiber 1). Compressive stress is formed on the lower side in the figure). However, in the reference example, the upper peripheral edge of the optical fiber 1 on the cracked surface 112 (the lower edge of the cracked surface 112 in the drawing; the final position of the crack of the optical fiber 1) is the optical fiber 1 on the cracked surface 112. The shape is such that it is closer to the tip side than the inner edge (the upper edge of the crack surface 112 in the drawing; the crack start position of the optical fiber 1). That is, in the reference example, the cracked surface 112 of the optical fiber 1 is inclined in the direction opposite to that of the present embodiment.

FIG. 8C is a graph of compressive stress of this embodiment and a reference example. The horizontal axis of the graph indicates the position in the longitudinal direction of the optical fiber centered on the cutting portion, the right side is the position on the tip side, and the left side is the position on the base end side. The vertical axis of the graph shows the magnitude of compressive stress on the side opposite to the side in contact with the blade body 47. That is, the vertical axis of the graph shows the magnitude of the compressive stress on the lower side of the optical fiber 1 of FIG. 5B and the magnitude of the compressive stress on the lower side of the optical fiber 1 of FIG. 8A.

In the present embodiment, as shown by the solid line in FIG. 8C, the compressive stress is larger toward the proximal end side on the side opposite to the side in contact with the blade body 47. On the other hand, in the reference example, as shown by the dotted line in FIG. 8C, the compressive stress on the side opposite to the side in contact with the blade 47 is smaller toward the proximal end side. From this, when the optical fiber 1 is cracked after the cleavage of the optical fiber 1 is stopped, the cracked surface 112 is formed in the direction in which the compressive stress increases on the side opposite to the side in contact with the blade body 47. it is conceivable that. Therefore, it is desirable that the bending portion 48 applies the bending stress to the optical fiber 1 so that the compressive stress becomes larger toward the proximal end side on the side opposite to the side in contact with the blade body 47. As a result, like the cut surface 11 of the optical fiber 1 shown in FIG. 6C (in other words, different from the cut surface 11 of the optical fiber 1 shown in FIG. 8C), the side opposite to the side in contact with the blade 47. Then, the shape is such that the corners between the cut surface 11 and the outer peripheral surface of the optical fiber 1 are removed (the corners between the cut surface 11 and the outer peripheral surface of the optical fiber 1 are rounded).

FIG. 9A is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the first embodiment are butted against each other. FIG. 9B is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the first embodiment are butted against each other.

Also in the first embodiment shown in FIG. 9A, similarly to FIG. 18A, the cut surface of one optical fiber 1 (cleavage surface 111 including the opening of the core) and the cut surface of the other optical fiber 1 (opening of the core). It is not parallel to the cleavage plane 111) including it. However, the cut surface 11 of the optical fiber 1 of the first embodiment has a cracked surface 112, and the cracked surface 112 is located on the proximal end side of the surface on which the cleavage surface 111 is extended. Therefore, in the first embodiment, when the optical fibers having the inclined end faces are butted against each other in a situation where the inclined end faces of the optical fibers 1 are not parallel to each other, the opening surfaces of the cores are compared with each other as compared with the comparative example shown in FIG. 18B. Can be brought close to each other, and the gap formed between the cores of the optical fiber can be suppressed. Thereby, in the present embodiment, the loss of the optical signal (connection loss) at the connection portion of the optical fiber can be suppressed.

=== Second embodiment ===
<About the cutting method of the second embodiment>
FIG. 10A is an explanatory diagram of the cutting method of the second embodiment. FIG. 10B is an explanatory view of the cut surface 11 of the optical fiber 1 in the second embodiment.

The fiber cutter 100 of the second embodiment is the same as the basic configuration of the fiber cutter 100 of the first embodiment described above. That is, the fiber cutter 100 of the second embodiment includes a blade body 47 and a bending portion 48, and the blade body 47 initially scratches the optical fiber 1 while the bending portion 48 applies bending stress to the optical fiber 1. To form. Thereby, also in the second embodiment, the cut surface 11 of the optical fiber 1 can be inclined (inclined with respect to the surface perpendicular to the optical axis of the optical fiber 1).

As shown in FIG. 10A, in the second embodiment, the blade body 47 forms two initial scratches at different positions in the longitudinal direction of the optical fiber 1. In other words, as shown in FIG. 10A, in the second embodiment, the optical fiber 1 has two portions (contact portions) that come into contact with the blade body 47. Although FIG. 10A shows how two initial scratches are formed, one or more other initial scratches may be formed between the two initial scratches in the figure. That is, it is sufficient that the blade body 47 forms at least two initial scratches at different positions in the longitudinal direction of the optical fiber.

Also in the second embodiment, tensile stress is formed on the side in contact with the blade body 47. Therefore, when an initial scratch is formed in this portion, the initial scratch grows due to the action of the tensile stress (the cleavage of the optical fiber 1 progresses). In FIG. 10A, the wound progressed from the initial wound by cleavage is shown by a solid line.

In the second embodiment, since the two initial wounds are formed in close proximity to each other, the wounds progressing from the respective initial wounds approach each other and join in the middle of cleavage. It should be noted that the wound that progresses from the initial wound on the proximal end side progresses so as to approach the wound that progresses from the adjacent initial wound until it is combined with the wound that has progressed from the adjacent initial wound. The combined scratches further progress and the optical fiber 1 is cleaved. Since the optical fiber 1 is subjected to bending stress, the coupled scratches also grow in the direction inclined with respect to the plane perpendicular to the optical axis.

Also in the second embodiment, the compressive stress is formed on the side opposite to the side in contact with the blade body 47. Therefore, also in the second embodiment, when the scratch (bonded scratch) advanced by the cleavage reaches the region where the tensile stress does not act, the cleavage of the optical fiber 1 is stopped. Then, after the cleavage of the optical fiber 1 is stopped, the optical fiber 1 is broken and the optical fiber 1 is cut. In FIG. 10A, the scratches that progress when the optical fiber 1 breaks are shown by dotted lines.

As shown in FIG. 10B, also in the second embodiment, the cut surface 11 of the optical fiber 1 has a cleavage surface 111 and a cracked surface 112. In the second embodiment, the cleavage surface 111 is composed of a first cleavage surface 111A and a second cleavage surface 111B. The first cleaved surface 111A is a surface on which the optical fiber 1 is cleaved from the initial scratch on the proximal end side, and is formed by the scratches advanced from the initial scratch on the proximal end side before being combined with the scratches advanced from the adjacent initial scratches. It is a face. The second cleaved surface 111B is a surface on which the optical fiber 1 is cleaved from the coupled scratches. The first cleavage surface 111A has a different shape from the second cleavage surface 111B. Specifically, the first cleavage surface 111A is located on the proximal end side of the extension surface of the second cleavage surface 111B. As a result, in the second embodiment, the cut surface 11 of the optical fiber 1 has a shape in which the corners are removed not only on the side opposite to the side in contact with the blade 47 but also on the side in contact with the blade 47.

FIG. 11A is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the second embodiment are butted against each other. FIG. 11B is an explanatory view of a state in which the optical fibers 1 having the cut surface 11 of the second embodiment are butted against each other.

Also in the second embodiment, the cut surface of one optical fiber 1 (second cleavage surface 111B including the opening of the core) and the cut surface of the other optical fiber 1 (second cleavage surface 111B including the opening of the core). ) Is not parallel. However, as in the first embodiment, the cut surface 11 of the optical fiber 1 of the second embodiment has a cracked surface 112, and the cracked surface 112 is larger than the surface on which the second cleavage surface 111B is extended. It is located on the base end side. Therefore, also in the second embodiment, as in the first embodiment, when the optical fibers having the inclined end faces are butted against each other in a situation where the inclined end faces of the optical fibers 1 are not parallel to each other, the comparative example shown in FIG. 18B is shown. As compared with the above, the opening surfaces of the cores can be brought close to each other, and the gap formed between the cores of the optical fiber can be suppressed.

Further, the cut surface 11 of the optical fiber 1 of the second embodiment has not only the cracked surface 112 but also the first cleavage surface 111A, and the first cleavage surface 111A is an extension of the second cleavage surface 111B. It is located on the base end side. Therefore, in the second embodiment, when the optical fibers having the inclined end faces are butted against each other in a situation where the inclined end faces of the optical fibers 1 are not parallel to each other, the core is further compared with the first embodiment shown in FIG. 9B. The opening surfaces can be brought close to each other, and the gap formed between the cores of the optical fiber can be suppressed.

<About the blade 47 of the second embodiment>
12A and 12B are explanatory views of the blade body 47 of the second embodiment.

The blade body 47 of the second embodiment has two blade edge portions 47A and a recess 47B. The cutting edge portion 47A is a portion having a blade line in contact with the optical fiber 1. The blade line of the cutting edge portion 47A is formed in a direction intersecting the longitudinal direction of the optical fiber 1. Further, the blade line of the blade edge portion 47A is formed in a direction in which the blade body 47 intersects the direction in which the blade body 47 approaches the optical fiber 1 (here, the vertical direction). Here, the blade line of the cutting edge portion 47A is formed along the Y direction. Further, the blade lines of the two blade edge portions 47A are arranged in parallel. The concave portion 47B is a concave (groove-shaped) portion formed between the two cutting edge portions 47A. By forming a groove-shaped recess 47B at the cutting edge of the blade body 47, two cutting edge portions 47A are formed so as to sandwich the recess 47B. As a result, the two positions of the blade body 47 (here, the two blade edge portions 47A) can be brought into contact with the optical fiber 1.

Also in the second embodiment, when cutting the optical fiber, the operator closes the operation unit 25 (and the scratch forming unit 46) as shown in FIGS. 3B and 4B. When the operating portion 25 is rotated in the closing direction, the scratch forming portion 46 is also rotated in the closing direction together with the operating portion 25, and the blade body 47 of the scratch forming portion 46 moves in the direction approaching the optical fiber 1. Then, after the latch state is released (see FIG. 4B), when the operation unit 25 is further rotated in the closing direction, the blade body 47 of the scratch forming portion 46 comes into contact with the optical fiber 1 and the optical fiber 1 is initially scratched. Is formed. In the second embodiment, when the blade body 47 comes into contact with the optical fiber 1, the two cutting edge portions 47A come into contact with the optical fiber 1, and the two cutting edge portions 47A are placed at different positions in the longitudinal direction of the optical fiber 1. It will form a wound.

The blade body 47 in the drawing has two blade edge portions 47A, but the number of blade edge portions 47A is not limited to two. Further, although the blade body 47 in the drawing is formed with one recess 47B, the number of recesses 47B is not limited to one. For example, the blade body 47 may have three or more blade edge portions 47A by forming two or more recesses 47B at the blade edge of the blade body 47. Even in such a case, by bringing at least two points (here, at least two cutting edge portions 47A) of the blade body 47 into contact with the optical fiber 1, at least two initial scratches are made at different positions in the longitudinal direction of the optical fiber 1. Can be formed.

13A and 13B are explanatory views of another blade body 47 of the second embodiment.

The blade body 47 in the figure has a contact surface 47C that comes into contact with the optical fiber. A plurality of abrasive grains are arranged on the contact surface 47C. For example, by applying a resin (for example, diamond paste) containing abrasive grains to the tip (tip surface) of the base material constituting the blade 47, or by applying the tip of the base material constituting the blade 47 (tip surface). The blade body 47 can be formed by attaching a sheet (for example, sandpaper) to which a large number of abrasive grains are attached to the tip surface). By contacting at least two points (here, at least two abrasive grains) of the blade body 47 with the optical fiber 1, at least two initial scratches can be formed on the optical fiber 1. The blade body 47 shown in FIGS. 13A and 13B is easier to form at least two initial scratches in close proximity to each other as compared with the blade body 47 shown in FIGS. 12A and 12B described above. In other words, the blade body 47 shown in FIGS. 13A and 13B constitutes a blade body 47 capable of forming two initial scratches in close proximity to each other at a lower cost than the blade body 47 shown in FIGS. 12A and 12B described above. be able to.

The contact surface 47C of the blade body 47 is not limited to a flat surface as shown in FIG. 13A. For example, the contact surface 47C may be formed in a curved surface shape. In this case, the contact surface 47C may have a curved surface that follows the curvature of the optical fiber 1 to which bending stress is applied. In other words, the contact surface 47C may have a curved surface that facilitates contact of at least two abrasive grains with the optical fiber 1.

<Modified example of the second embodiment>
In the second embodiment described above, at least two initial scratches are formed on the optical fiber 1 by bringing the blade body 47 into contact with the optical fiber 1. However, even if the blade body 47 comes into contact with the optical fiber 1 at one place, it is possible to form at least two initial scratches on the optical fiber 1.

14A and 14B are explanatory views of a modified example of the second embodiment. 15A and 15B are explanatory views of a method of forming an initial scratch in a modified example of the second embodiment. FIG. 15A is an explanatory view of a state at the time of contact between the blade body 47 and the optical fiber 1. FIG. 15B is an enlarged explanatory view of a contact portion between the blade body 47 and the optical fiber 1.

Also in the modified example of the second embodiment, the fiber cutter 100 is the same as the basic configuration of the first embodiment and the second embodiment described above. That is, also in the modified example of the second embodiment, the fiber cutter 100 includes a blade body 47 and a bending portion 48, and the blade body 47 emits light while the bending portion 48 applies bending stress to the optical fiber 1. Initial scratches are formed on the fiber 1. Thereby, also in the second embodiment, the cut surface 11 of the optical fiber 1 can be inclined (inclined with respect to the surface perpendicular to the optical axis of the optical fiber 1).

In the modified example of the second embodiment, the scratch forming portion 46 has a rotating portion 46A, an arm portion 46B, a deforming portion 46C, a displacement portion 46D, and a blade body 47.

The arm portion 46B is a portion constituting the main body (base) of the scratch forming portion 46, and is a portion extending toward the front side from the rotating portion 46A when the scratch forming portion 46 is in the closed state. A rotating portion 46A is provided at one end (base end) of the arm portion 46B, and the arm portion 46B rotates about the rotating portion 46A. A deformed portion 46C is provided at the other end of the arm portion 46B (the end opposite to the rotating portion 46A). In other words, the rod-shaped (plate-shaped) portion between the rotating portion 46A and the deformed portion 46C is the arm portion 46B.

The deformable portion 46C is a portion that can be elastically deformed. Further, the deformed portion 46C is a portion that elastically deforms when receiving a force. The deformed portion 46C is provided at the end of the arm portion 46B, and is a U-shaped portion here. The deformed portion 46C is elastically deformed by the force received by the blade body 47 from the optical fiber 1. A displacement portion 46D holding the blade body 47 is provided at the tip of the deformed portion 46C. By elastically deforming the deformed portion 46C, the displacement portion 46D and the blade body 47 can be displaced (moved) with respect to the arm portion 46B.

The displacement portion 46D is a portion that is displaced with respect to the arm portion 46B. The displacement portion 46D is displaced with respect to the arm portion 46B (the position with respect to the arm portion 46B changes) due to the elastic deformation of the deformed portion 46C. Here, the displacement portion 46D is configured to be displaceable with respect to the arm portion 46B along the front-rear direction (longitudinal direction of the optical fiber 1). The displacement portion 46D is provided with a blade body 47. When the displacement portion 46D is displaced with respect to the arm portion 46B, the blade body 47 is also displaced with respect to the arm portion 46B.

When the scratch forming portion 46 is rotated in the closing direction, the blade body 47 comes into contact with the optical fiber 1 as shown in FIGS. 14B and 15A. In the present embodiment, the blade body 47 comes into contact with the optical fiber 1 from above. At the portion in contact with the blade body 47, the optical fiber 1 is bent by the bent portion 48 so that the closer to the bent portion 48, the upper side (the side of the blade body 47). That is, the optical fiber 1 is bent so that the base end side (the side closer to the bent portion 48) is on the upper side (the side of the blade body 47) when viewed from the cutting portion.

The scratch forming portion 46 (arm portion 46B) rotates slightly in the closing direction from the contact between the blade body 47 and the optical fiber 1 to the completion of cleavage. At this time, when the blade body 47 receives a force from the optical fiber 1, the deformed portion 46C is deformed, the blade body 47 is displaced along the curved outer peripheral surface of the optical fiber 1, and the displaced portion 46D and the blade body 47 are displaced. Displace with respect to the arm 46B. In the present embodiment, since the optical fiber 1 is bent by the bent portion 48 so that the optical fiber 1 is bent toward the base end side (the side closer to the bent portion 48) toward the upper side (the side of the blade 47), the scratch forming portion 46 is closed. When rotated to, the blade body 47 (and the displacement portion 46D) is displaced toward the tip end side of the optical fiber 1 in a state of being in contact with the optical fiber 1. That is, as shown in FIG. 15B, the blade body 47 moves while contacting the outer peripheral surface of the curved optical fiber 1. As a result, the blade body 47 forms a plurality of initial scratches (at least two initial scratches) at different positions in the longitudinal direction of the optical fiber 1.

In the modified examples shown in FIGS. 15A and 15B, the optical fiber 1 is bent by the bending portion 48 so that the optical fiber 1 is bent toward the base end side (the side closer to the bending portion 48) toward the upper side (the side of the blade body 47). The blade 47 is moved toward the tip end side of the optical fiber 1 in a state of being in contact with the optical fiber 1. However, the blade 47 may be moved in contact with the optical fiber 1 without utilizing the curvature of the optical fiber 1.

=== Another embodiment ===
In the above-described embodiment (first embodiment and second embodiment), the bent portion 48 is fixed to the mounting surface 41B. However, the bent portion 48 may be provided so as to be movable with respect to the mounting surface 41B without being fixed to the mounting surface 41B. Further, in the above-described embodiment, the bent portion 48 is arranged above the mounting surface 41B, and a force is applied to the optical fiber 1 from the lower side. However, the direction in which the bent portion 48 applies a force to the optical fiber 1 is not limited to this.

16A and 16B are schematic explanatory views in the vicinity of the bent portion 48 of another embodiment. FIG. 16A is a top view before applying bending stress to the optical fiber 1. FIG. 16B is a top view when bending stress is applied to the optical fiber 1.

In this embodiment, the bent portion 48 is provided in the scratch forming portion 46 described above. Then, when the operating portion 25 is rotated in the closing direction, the scratch forming portion 46 is also rotated in the closing direction, and the bent portion 48 approaches and contacts the optical fiber 1. As described above, the bent portion 48 of this embodiment is provided so as to be movable with respect to the mounting surface 41B.

When the bent portion 48 comes into contact with the optical fiber 1, the bent portion 48 applies a force to the optical fiber 1 from the front side to the back side. When the bent portion 48 comes into contact with the optical fiber 1, the optical fiber 1 is displaced toward the back side by the bent portion 48. On the other hand, the optical fiber 1 on the mounting surface 41B (the optical fiber 1 gripped between the mounting surfaces 41B by the clamp portion 45B) is fixed at a predetermined position in the Y-axis direction on the mounting surface 41B. ing. As a result, as shown in FIG. 16B, the optical fiber 1 is curved in an S shape between the bent portion 48 and the mounting surface 41B (or the clamp portion 45B). Also in this embodiment, the bending portion 48 applies bending stress to the optical fiber 1.

In this embodiment, the blade body 47 is provided in the scratch forming portion 46 so as to form an initial scratch on the optical fiber 1 on the back side (see FIG. 16B). The bent portion 48 is provided on the side opposite to the side on which the blade body 47 forms the initial scratch. Also in this embodiment, the bending portion 48 is formed on the optical fiber 1 so as to form a tensile stress on the side in contact with the blade 47 and a compressive stress on the side opposite to the side in contact with the blade 47. Bending stress can be applied. Further, also in this embodiment, the optical fiber 1 is formed by the blade body 47 in a state where the tensile stress is formed on the side in contact with the blade body 47 and the compressive stress is formed on the side opposite to the side in contact with the blade body 47. Initial wounds can be formed in.

=== Others ===
The above embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. It goes without saying that the present invention can be modified or improved without departing from the spirit thereof, and the present invention includes an equivalent thereof.

1 optical fiber, 11 cut surface, 111 cleavage surface,
111A 1st cleavage plane, 111B 2nd cleavage plane,
112 cracked surface,
3 holder,
20 base member, 21 holder mounting part,
23 Information section, 25 Operation section,
25A rotating part, 25B accommodating part, 25C latch release part,
40 mobile member, 41 mobile body,
41A case housing, 41B mounting surface, 41C engagement hole,
45 gripping member, 45A rotating part,
45B clamp part, 45C locking part,
46 scratch forming part, 46A rotating part,
46B arm, 46C deformed part, 46D displaced part,
47 blade body, 47A blade tip,
47B recess, 47C contact surface,
48 bends, 49 gaps, 50 latches,
51 Base side latch part, 54 Moving side latch part,
60 tensioning springs, 100 fiber cutters

Claims (6)

The blade that forms the initial scratches on the optical fiber and
A bending portion for applying bending stress to the optical fiber is provided.
With the bending stress forming a tensile stress on the side in contact with the blade and compressive stress on the side opposite to the side in contact with the blade, the blade makes the optical fiber the initial stage. An optical fiber cutter characterized by forming scratches. The optical fiber cutter according to claim 1.
It is provided with a tension applying portion that applies tension to the optical fiber.
An optical fiber cutter characterized in that when the initial scratch is formed on the optical fiber by the blade body, a tensile stress is formed in a region of the core of the optical fiber by the tension applying portion. The optical fiber cutter according to claim 1 or 2.
The optical fiber cutter is characterized in that the bent portion applies the bending stress to the optical fiber so that the compressive stress becomes larger toward the proximal end side on the side opposite to the side in contact with the blade. The optical fiber cutter according to claim 3.
A grip portion for gripping the optical fiber on a mounting surface on which the optical fiber is placed is provided on the tip side of the optical fiber with respect to the blade body.
An optical fiber cutter characterized in that the bent portion protrudes upward from the above-mentioned mounting surface on the base end side of the optical fiber with respect to the blade body. The optical fiber cutter according to any one of claims 1 to 4.
The blade forms at least two of the initial scratches at different locations in the longitudinal direction of the optical fiber.
An optical fiber cutter characterized in that at least two scratches progressing from the initial scratches are coupled to cleave the optical fiber. By applying bending stress to the optical fiber, tensile stress is formed on the side in contact with the blade, and compressive stress is formed on the side opposite to the side in contact with the blade.
The blade body is brought into contact with the portion where the tensile stress is formed to form an initial scratch on the optical fiber, and a cleavage surface inclined with respect to a surface perpendicular to the optical axis of the optical fiber and the light. An optical fiber cutting method, characterized in that the optical fiber is cut by forming a cut surface having a cracked surface formed by cracking the optical fiber after the cleavage of the fiber is stopped.