Ferrule and ferrule structure

Abstract

In order to suppress deformation of the ferrule, the ferrule (10) involved in the present disclosure comprises: a main body (10); an inner wall (14) having a plurality of openings of optical fiber holes (12) arranged in the main body; an adhesive filling portion (13) for adhesive filling; an upper opening (131) connected to the adhesive filling portion; and a lower opening (132) arranged on the side opposite to the upper opening (131). The inner wall (14) comprises a first surface (14A) and a second surface (14B) protruding from the first surface (14A) toward the adhesive filling portion (13). The upper opening (131) is arranged at a position along the first surface, and the lower opening (132) is arranged at a position along the second surface.

Description

Technical Field

[0001] The present disclosure relates to a ferrule and a ferrule structure.

[0002] This application claims priority based on Japanese Patent Application No. 2021-008664 filed in Japan on January 22, 2021, and the contents are incorporated herein by reference. Background Art

[0003] As a ferrule for connecting multiple optical fibers together, a so-called MT ferrule is known. Such a ferrule is provided with an adhesive filling portion. The optical fiber is fixed to the ferrule by filling the adhesive into the adhesive filling portion. For example, Patent Document 1 describes a ferrule that can be filled with adhesive from an adhesive injection port.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2003-131069

[0005] There is a concern that the ferrule may be deformed due to the shrinkage of the adhesive filled in the ferrule. In contrast, Patent Document 1 describes molding the optical fiber hole, guide pin hole, etc. of the ferrule by insert molding the resin in the metal frame. However, the structure of the ferrule described in Patent Document 1 is complicated and the manufacturing cost is high. Summary of the invention

[0006] The present invention provides a new structure capable of suppressing deformation of a ferrule.

[0007] The first embodiment of the present invention involves a ferrule comprising: a main body, having an outer wall and a connecting end face for configuring the front end portion of the optical fiber; an inner wall, having an opening of a plurality of optical fiber holes capable of inserting optical fibers toward the connecting end face, and configured in the main body; an adhesive filling portion, which is configured in the main body on the side opposite to the connecting end face relative to the inner wall and is filled with adhesive; an upper opening, which leads from the outer wall to the adhesive filling portion; and a lower opening, which leads from the outer wall to the adhesive filling portion and is configured on the side opposite to the upper opening, the inner wall having a first surface and a second surface protruding from the first surface toward the adhesive filling portion side, the upper opening being configured at a position along the first surface, and the lower opening being configured at a position along the second surface.

[0008] In addition, the ferrule involved in the second embodiment of the present invention comprises: a main body, having an outer wall and a connecting end face for configuring the front end portion of the optical fiber; an inner wall, having an opening of a plurality of optical fiber holes capable of inserting optical fibers toward the above-mentioned connecting end face, and configured in the above-mentioned main body; an adhesive filling portion, which is configured in the above-mentioned main body on the side opposite to the above-mentioned connecting end face relative to the above-mentioned inner wall, for adhesive filling; an upper opening, which leads from the above-mentioned outer wall to the above-mentioned adhesive filling portion; and a lower opening, which leads from the above-mentioned outer wall to the above-mentioned adhesive filling portion, and is configured on the side opposite to the above-mentioned upper opening, and the above-mentioned inner wall comprises: a first surface, which is along the above-mentioned connecting end face side in the above-mentioned upper opening; a second surface, which protrudes from the above-mentioned first surface to the above-mentioned adhesive filling portion side; and a third surface, which is configured on the side opposite to the above-mentioned upper opening relative to the above-mentioned second surface, and is configured on the above-mentioned connecting end face side than the above-mentioned second surface.

[0009] Other features of the present invention will become apparent from the following description and drawings.

[0010] According to the present invention, deformation of the ferrule can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A and Figure 1B It is a perspective view of the ferrule 10 .

[0012] Figure 2 It is a cross-sectional perspective view of the ferrule 10 .

[0013] Figure 3A It is a cross-sectional view of the ferrule structure 100 . Figure 3B It is a diagram showing a first comparative example. Figure 3C It is a diagram showing a second comparative example.

[0014] Figure 4A and Figure 4B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the first embodiment.

[0015] Figure 5A and Figure 5B It is an explanatory diagram of the simulation result of the ferrule 10 of a modification example.

[0016] Figure 6 It is a cross-sectional view of the ferrule structure 100 according to the second embodiment.

[0017] Fig. 7A and Figure 7B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the second embodiment.

[0018] Fig. 8A It is a perspective view of the ferrule structure 100 according to the third embodiment. Figure 8B It is an exploded explanatory diagram of the ferrule structure 100 according to the third embodiment.

[0019] Fig. 9 It is a cross-sectional perspective view of a ferrule structure 100 according to the third embodiment.

[0020] Fig. 10A It is a top view of the ferrule structure 100 of the third embodiment. Fig. 10B It is a cross-sectional view of the ferrule structure 100 according to the third embodiment.

[0021] Fig.11 It is an orthographic projection diagram of the shield 20 in each direction according to the third embodiment.

[0022] Fig. 12A and Fig. 12B It is a perspective view of the shield 20 alone.

[0023] Fig.13A It is an enlarged cross-sectional view of the vicinity of a gap between an end surface 231A of the protrusion 231 and the first surface 14A of the ferrule 10 . Fig. 13B It is an explanatory diagram of the protrusion 231 of a modified example.

[0024] Fig.14A It is an enlarged view of the vicinity of the front end of the optical fiber insertion hole 21 . Fig. 14B It is an enlarged view of the vicinity of the front end of the optical fiber insertion hole 21 in a state where the optical fiber 1 is inserted therethrough.

[0025] Fig.15A and Fig. 15B It is an explanatory diagram of the exposed portion 232 .

[0026] FIG. 16A to FIG. 16D This is a diagram for explaining a method for manufacturing an optical fiber with a ferrule.

[0027] Fig.17A and Fig. 17B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the first comparative example.

[0028] Fig.18A and Fig.18B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the second comparative example. DETAILED DESCRIPTION

[0029] An embodiment that is an example of the invention of the present application will be described based on the description of the specification and drawings given below.

[0030] ===First Embodiment===

[0031] Figure 1A and Figure 1B It is a perspective view of the ferrule 10 . Figure 2 It is a cross-sectional perspective view of the ferrule 10 . Figure 3Ais a cross-sectional view of the insert structure 100. Figure 3B is a diagram showing a first comparative example, Figure 3C It is a diagram showing a second comparative example.

[0032] In the following description, each direction is defined as follows. Figure 3A ) is defined as the “optical fiber insertion direction” or the “front-to-back direction”, and the front end side of the optical fiber 1 is defined as the “front” and the opposite side is defined as the “rear” with reference to the optical fiber 1 inserted into the ferrule 10. In addition, the optical axis direction (the direction of the longitudinal axis) of the optical fiber 1 inserted into the ferrule 10 is defined as the optical fiber insertion direction (or the front-to-back direction). In addition, the direction in which the plurality of optical fibers 1 inserted into the ferrule 10 are arranged side by side, that is, the direction orthogonal to the optical axis direction (the direction of the longitudinal axis), is defined as the “width direction” or the “left-to-right direction”, and the right side when the front side is viewed from the rear side is defined as the “right”, and the opposite side is defined as the “left”. In addition, the direction perpendicular to the optical fiber insertion direction (front-to-back direction) and the width direction (left-to-right direction), that is, the direction orthogonal to the plane formed by the optical axis direction (the direction of the longitudinal axis) and the width direction is defined as the “upper-lower direction”, and the side of the opening (upper opening 131) for filling the adhesive into the adhesive filling portion 13 is defined as the “upper”, and the opposite side is defined as the “lower”. In addition, the upper side may be referred to as the “filling window side” and the lower side may be referred to as the “bottom side”.

[0033] Insert structure 100 (see Figure 3A ) has a ferrule 10 and a cover 20. In addition, a component in which the optical fiber 1 is fixed to the ferrule structure 100 may be referred to as an optical fiber with a ferrule.

[0034] The ferrule 10 is a component that holds the ends of a plurality of optical fibers 1. The ferrule 10 of the present embodiment is an MT connector (MT ferrule) specified in JIS C 5981 and IEC 61754-5. The main body of the ferrule 10 has a connection end face 10A and an outer wall. The connection end face 10A is the end face on the front side of the ferrule 10, and is the end face connected to the counterpart ferrule (not shown here). The outer wall constitutes the outer surface connected to the connection end face 10A (mainly the upper and lower and left and right outer surfaces of the main body of the ferrule 10). A flange portion 10B (flange portion) protruding outward from the side of the main body of the ferrule 10 is provided at the rear of the ferrule 10. In addition, a pair of guide holes 11 are provided on the left and right of the ferrule 10.

[0035] The ferrule 10 of the present embodiment includes a plurality of optical fiber holes 12 , an adhesive-filled portion 13 , an inner wall 14 , a step portion 15 , and a boot insertion port 17 .

[0036] The optical fiber hole 12 is a hole for inserting the end of the optical fiber 1. The end of the optical fiber 1 is fixed to each optical fiber hole 12. A plurality of optical fiber holes 12 are arranged side by side in the width direction (arranged side by side in one direction). Here, 24 optical fiber holes 12 are arranged side by side in one row in the width direction. However, the number of optical fiber holes 12 is not limited to 24. In addition, the row of optical fiber holes 12 can be either one row or two or more rows. One end (rear end) of the optical fiber hole 12 opens at the inner wall 14 (more specifically, the first surface 14A) of the adhesive filling portion 13. The other end (front end) of the optical fiber hole 12 opens at the connecting end surface 10A of the ferrule 10. In addition, the optical fiber hole 12 is connected to the guide groove 15A described later.

[0037] The adhesive filling portion 13 is a portion (space) filled with adhesive. An upper opening 131 (adhesive filling window) is provided on the upper surface of the ferrule 10. The upper opening 131 is an opening that leads from the outer wall of the ferrule 10 to the adhesive filling portion 13. The adhesive is filled into the adhesive filling portion 13 from the upper opening 131. In addition, a lower opening 132 is provided on the lower surface of the ferrule 10. The lower opening 132 is an opening that leads from the outer wall of the ferrule 10 to the adhesive filling portion 13. The lower opening 132 is arranged on the side opposite to the upper opening 131. As described later, by providing openings on the upper and lower surfaces of the ferrule 10, deformation of the ferrule 10 caused by shrinkage accompanying the curing of the adhesive can be suppressed.

[0038] The inner wall 14 has a plurality of openings of the optical fiber holes 12, and is arranged in the body of the ferrule 10. The space arranged on the side opposite to the connection end face 10A with respect to the inner wall 14 is the adhesive filling portion 13. That is, the inner wall 14 is a wall surface on the connection end face 10A side (the front side of the adhesive filling portion 13; the side where the optical fiber hole 12 opens) among the wall surfaces constituting the adhesive filling portion 13. In the present embodiment, the inner wall 14 has a first surface 14A and a second surface 14B. The first surface 14A is a surface along the edge of the connection end face 10A side (front side) in the upper opening 131. The upper opening 131 opens at a position along the first surface 14A. The second surface 14B is a surface protruding further toward the adhesive filling portion 13 side (rear side) than the first surface 14A, and is the rear end surface of the step portion 15. In the first embodiment, the second surface 14B is a surface along the edge of the connection end face 10A side (front side) in the lower opening 132. The lower opening 132 opens at a position along the second surface 14B.

[0039] The step portion 15 is a step provided inside the adhesive filling portion 13, and guides the optical fiber 1 to the optical fiber hole 12. A plurality of guide grooves 15A are provided on the upper surface of the step portion 15. The guide groove 15A is a groove for guiding the optical fiber 1 to the optical fiber hole 12. The guide groove 15A is a groove along the optical fiber insertion direction (front-rear direction). The plurality of guide grooves 15A are arranged side by side in the width direction. Here, the guide groove 15A is composed of a circular groove with a semicircular cross section. However, the guide groove 15A may be other shapes such as a V-groove, a circular groove with a semicircular cross section, a U-groove, or a square groove. In addition, the guide groove 15A may not be provided on the upper surface of the step portion 15. The front end of the guide groove 15A reaches the inner wall 14 (more specifically, the first surface 14A) on the front side of the adhesive filling portion 13. The front end of the guide groove 15A is connected to the opening of the optical fiber hole 12. The rear end of the guide groove 15A reaches the second surface 14B which becomes the rear end surface of the step portion 15. The rear end surface (second surface 14B) of the step portion 15 is formed of a surface perpendicular to the optical fiber insertion direction.

[0040] The shield insertion port 17 is an opening for inserting the shield 20. The shield insertion port 17 is provided at the rear end of the ferrule 10. The shield insertion port 17 is communicated with the adhesive filling portion 13. The shield insertion port 17 allows a plurality of optical fibers 1 to be inserted therethrough. The optical fibers 1 inserted from the shield insertion port 17 traverse the adhesive filling portion 13 and are inserted into the optical fiber hole 12.

[0041] like Figure 3A As shown, the shield 20 is installed in the shield insertion port 17. The shield 20 is configured to block the rear portion of the adhesive filling portion 13. Thus, the adhesive is prevented from leaking from the rear end of the ferrule 10. On the other hand, the ferrule 10 is deformed due to the shrinkage of the adhesive filled in the adhesive filling portion 13. The following is a simulation result of the deformation amount of the ferrule 10.

[0042] Figure 3B It is an explanatory diagram of the first comparative example. Fig.17A and Fig. 17B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the first comparative example. Fig.17A and Fig. 17B The numerical value shown on the right side of represents the deformation amount (displacement amount) in the upward direction. Fig.17A The simulation result of the cross section of the ferrule 10 viewed from the left side is shown. Fig. 17B The simulation result of the right half of the ferrule 10 viewed from the front is shown.

[0043] The ferrule 10 of the first comparative example is different from the ferrule 10 of the present embodiment in that the lower surface is not provided with the lower opening 132. Fig.17A As shown in FIG. 1 , if the adhesive filled in the adhesive filling portion 13 of the ferrule 10 of the first comparative example shrinks as it cures, the ferrule 10 deforms so as to bend into a U-shape. Fig. 17BAs shown, if the right end of the connecting end surface 10A is focused on, it is shown that the area with large deformation is distributed toward the upper edge, and the ferrule 10 is also easily deformed in a U-shape in the connecting end surface 10A (it is shown that when the ferrule 10 is observed from the front side, the ferrule 10 is also easily deformed in a U-shape).

[0044] Figure 3C It is an explanatory diagram of the second comparative example. Fig.18A and Fig.18B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the second comparative example.

[0045] The ferrule 10 of the second comparative example is provided with a lower opening 132 on the lower surface. However, in the second comparative example, unlike the ferrule 10 of the present embodiment, the lower opening 132 is not opened along the second surface 14B (the rear end surface of the step portion 15), but is opened at a position behind the second surface 14B. Fig.18A As shown in FIG. 1 , in the second comparative example, if the adhesive filled in the adhesive filling portion 13 of the ferrule 10 shrinks, the ferrule 10 also deforms in a U-shaped warp (however, the deformation of the second comparative example is suppressed compared to the deformation of the first comparative example). Fig.18B As shown, focusing on the right end of the connection end surface 10A, it is shown that in the second comparative example, the region with a large deformation amount is also distributed toward the upper edge, and the ferrule 10 is also easily deformed so as to be warped into a U-shape in the connection end surface 10A.

[0046] like Fig. 17B and Fig.18B As shown in FIG. 1 , when the ferrule 10 is easily deformed in a U-shape at the connection end surface 10A, the difference in the vertical position of the plurality of optical fibers 1 (the optical fibers 1 inserted into the optical fiber holes 12 opened at the connection end surface 10A) is likely to increase. As a result, there is a concern that the connection loss of the optical signal (specifically, the maximum connection loss among the plurality of optical fibers 1) will increase.

[0047] Figure 4A and Figure 4B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the first embodiment.

[0048] As already described, the ferrule 10 of the first embodiment is provided with a lower opening 132 on the lower surface. In addition, the upper opening 131 is arranged at a position along the first surface 14A of the inner wall 14 (the upper opening 131 opens at a position along the first surface 14A), and the lower opening 132 is arranged at a position along the second surface 14B (the rear end surface of the step portion 15) (the lower opening 132 opens at a position along the second surface 14B). Figure 4AAs shown, in the first embodiment, when the adhesive filled in the adhesive filling portion 13 of the ferrule 10 shrinks, the ferrule 10 can be prevented from warping into a U-shaped deformation compared to the first comparative example and the second comparative example. Figure 4B As shown, focusing on the right end of the connection end surface 10A, it is shown that the region with a large deformation amount is distributed almost evenly in the upper and lower parts compared with the first and second comparative examples, and deformation of warping into a U shape is easily suppressed even in the connection end surface 10A.

[0049] Figure 5A and Figure 5B 1 is an explanatory diagram of simulation results of the ferrule 10 of the modified example. Figure 3A , Figure 4A Compared with the ferrule 10 of the first embodiment shown in FIG. 1 , the dimension of the lower opening 132 of the ferrule 10 of the modified example in the front-rear direction is smaller. Figure 3A , Figure 4A Compared with the ferrule 10 of the first embodiment shown in FIG. 1 , the rear edge of the lower opening 132 of the ferrule 10 of the modified example is located at the front side. Figure 5A The dimension of the lower opening 132 of the ferrule 10 in the front-to-back direction is Fig.18A The dimensions of the lower opening 132 in the front-rear direction of the ferrule 10 of the second comparative example are substantially the same.

[0050] like Figure 5A As shown, in the modified example, the upper opening 131 is also opened at a position along the first surface 14A of the inner wall 14. In addition, the lower opening 132 is opened at a position along the second surface 14B (the rear end surface of the step portion 15). Figure 5A As shown, in the modified example, when the adhesive filled in the adhesive filling portion 13 of the ferrule 10 shrinks, the ferrule 10 can also be prevented from warping into a U-shaped deformation compared to the first comparative example and the second comparative example. Figure 5B As shown, focusing on the right end of the connection end surface 10A, it is shown that the region with a large deformation amount is distributed almost evenly in the upper and lower parts compared with the first and second comparative examples, and deformation of warping into a U shape is easily suppressed even in the connection end surface 10A.

[0051] like Figure 4B (First Embodiment) and Figure 5B As shown in (Variation of the First Embodiment), when the connection end face 10A of the ferrule 10 can be prevented from warping and deforming in a U-shape, the difference in the vertical position of the plurality of optical fibers 1 (the optical fibers 1 inserted into the optical fiber holes 12 opened in the connection end face 10A) is reduced. As a result, the connection loss of the optical signal (specifically, the maximum connection loss among the plurality of optical fibers 1) can be suppressed.

[0052] That is, usually, the arrangement of the multiple optical fibers 1 is deformed due to the deformation of the ferrule caused by the shrinkage accompanying the curing of the adhesive. However, if the invention of the present application is applied, the deformation generated in the ferrule can be made linearly symmetrical with respect to the arrangement of the optical fibers 1, so that the arrangement of the multiple optical fibers 1 will not be deformed.

[0053] In addition, in the first embodiment and the modified example, the dimensions of the lower opening 132 in the front-rear direction are different, but as shown in FIG. Figure 4B as well as Figure 5B As shown, both the first embodiment and the modified example can suppress the deformation of the connection end surface 10A from warping into a U shape. On the other hand, in the modified example and the second comparative example, the dimensions of the lower opening 132 in the front-rear direction are the same, but Fig.18B As shown in the second comparative example, the ferrule 10 is easily warped into a U-shape at the connection end surface 10A. Figure 5B As shown, in the modified example, the deformation of the connection end face 10A being warped into a U-shape can be suppressed. Therefore, in order to suppress the deformation of the connection end face 10A being warped into a U-shape, as shown in the first embodiment and the modified example, it is effective that the inner wall 14 of the ferrule 10 has a first surface 14A and a second surface 14B protruding from the first surface 14A toward the adhesive filling portion 13, the upper opening 131 is opened at a position along the first surface 14A of the inner wall 14, and the lower opening 132 is opened at a position along the second surface 14B (the rear end surface of the step portion 15).

[0054] ===Second Embodiment===

[0055] Figure 6 It is a cross-sectional view of the ferrule structure 100 according to the second embodiment.

[0056] In the second embodiment, similarly to the first embodiment, the ferrule 10 includes a main body, an inner wall 14, an adhesive filling portion 13, an upper opening 131, and a lower opening 132. In the second embodiment, the main body of the ferrule 10 also includes a connection end face 10A and an outer wall connected to the connection end face 10A. In addition, the inner wall 14 has openings of a plurality of optical fiber holes 12, which are arranged in the main body of the ferrule 10. In addition, the adhesive filling portion 13 is arranged on the side opposite to the connection end face 10A relative to the inner wall 14 in the main body. The adhesive filling portion 13 is filled with adhesive. In addition, the upper opening 131 is an opening from the outer wall to the adhesive filling portion 13. In addition, the lower opening 132 is an opening from the outer wall of the ferrule 10 to the adhesive filling portion 13. The lower opening 132 is arranged on the side opposite to the upper opening 131.

[0057] In the second embodiment, a recess 16 is provided. The recess 16 is a depression provided on the opposite side of the upper surface (the surface provided with the guide groove 15A) of the step portion 15. That is, the recess 16 is a depression provided on the lower side (the lower opening 132 side; the side opposite to the upper opening 131) of the step portion 15. The recess 16 is formed in a shape that makes the rear end surface of the step portion 15, that is, the lower edge of the second surface 14B, concave.

[0058] In the second embodiment, the inner wall 14 of the ferrule 10 (the wall surface on the connection end face 10A side of the wall surface constituting the adhesive filling portion 13) has a first surface, a second surface, and a third surface. The first surface is a surface along the edge of the connection end face 10A side (front side) in the upper opening 131. The upper opening 131 opens at a position along the first surface 14A. The second surface is a surface that protrudes further toward the adhesive filling portion 13 side (rear side) than the first surface 14A, and is the rear end surface of the step portion 15. The third surface 14C is composed of a surface perpendicular to the optical fiber insertion direction, similar to the second surface 14B. Among them, the third surface 14C is composed of a surface on the connection end face 10A side (front side) of the recess 16. Therefore, the third surface 14C is a surface arranged on the side opposite to the upper opening 131 (lower side) relative to the second surface 14B, and is a surface arranged on the connection end face 10A side (front side) than the second surface 14B.

[0059] Fig. 7A and Figure 7B It is an explanatory diagram of the simulation result of the deformation amount of the ferrule 10 of the second embodiment.

[0060] like Fig. 7A As shown, in the second embodiment, when the adhesive filled in the adhesive filling portion 13 of the ferrule 10 shrinks, the ferrule 10 can be prevented from warping into a U-shaped deformation compared to the first comparative example and the second comparative example. Figure 7B As shown, if the right end of the connection end face 10A is focused, it is shown that compared with the first comparative example and the second comparative example, the area with a large deformation amount is distributed almost evenly in the upper and lower parts, and it is easy to suppress the deformation of the connection end face 10A also warping into a U shape. Therefore, in order to suppress the deformation of the connection end face 10A warping into a U shape, as shown in the second embodiment, it is effective that the inner wall 14 of the ferrule 10 has a first surface 14A on the connection end face 10A side (front side) along the upper opening 131, a second surface 14B protruding from the first surface 14A to the adhesive filling portion 13 side, and a third surface 14C arranged on the side opposite to the upper opening 131 (lower side) relative to the second surface 14B and arranged on the connection end face 10A side than the second surface 14B.

[0061] However, when the step portion 15 is provided inside the ferrule 10, the volume of the lower side (the side provided with the step portion 15) of the upper and lower halves is usually larger than the volume of the upper side (the volume difference between the upper and lower halves of the ferrule 10 becomes larger on the front side of the adhesive filling portion 13). As a result, when the adhesive filled in the adhesive filling portion 13 shrinks, the lower side of the upper and lower halves of the ferrule 10 becomes more difficult to displace than the upper side, so the ferrule 10 is easily deformed in a U-shaped warp.

[0062] In contrast, in the second embodiment, since the recess 16 is provided on the lower side of the step portion 15, the volume difference between the upper half and the lower half of the ferrule 10 is reduced compared to the case where the recess 16 is not provided. As a result, in the second embodiment, when the adhesive filled in the adhesive filling portion 13 shrinks, the upper half and the lower half of the ferrule 10 are more likely to deform evenly than in the case where the recess 16 is not provided, and the ferrule 10 can be prevented from warping into a U-shaped deformation. Therefore, as shown in the second embodiment, when the second surface is formed by the rear end surface of the step portion, it is effective that the third surface is formed by the end surface of the recess 16.

[0063] ===Third Embodiment===

[0064] In order to further suppress deformation of the ferrule 10 due to shrinkage of the adhesive, it is preferable to reduce the amount of adhesive filled in the adhesive filling portion 13. On the other hand, simply reducing the amount of adhesive may result in insufficient fixation of the optical fiber 1.

[0065] Therefore, in the third embodiment, a part of the shield 20 is disposed opposite to the upper surface of the step portion 15, thereby reducing the amount of adhesive filled in the adhesive filling portion 13 and applying the adhesive required for fixing the optical fiber 1 around the optical fiber 1. This point will be described below.

[0066] Fig. 8A It is a perspective view of the ferrule structure 100 according to the third embodiment. Figure 8B It is an exploded explanatory diagram of the ferrule structure 100 according to the third embodiment. Fig. 9 It is a cross-sectional perspective view of a ferrule structure 100 according to the third embodiment. Fig. 10A It is a top view of the ferrule structure 100 of the third embodiment. Fig. 10B is a cross-sectional view of the insert structure 100 according to the third embodiment. Fig. 8A In FIG. 1 , an optical fiber ribbon composed of a plurality of optical fibers 1 is shown by dotted lines.

[0067] In the third embodiment, the ferrule structure 100 also includes the ferrule 10 and the shield 20. Figure 1A and Figure 1BThe ferrule 10 of the third embodiment is the same as that of the ferrule 10 of the first embodiment shown in FIG. That is, the ferrule 10 of the third embodiment includes: a body having a connection end face 10A and an outer wall connected to the connection end face 10A, an inner wall 14 disposed in the body, an adhesive filling portion 13, an upper opening 131, and a lower opening 132. The inner wall 14 has a first surface 14A and a second surface 14B, the upper opening 131 is disposed at a position along the first surface 14A (the upper opening 131 opens at a position along the first surface 14A), and the lower opening 132 is disposed at a position along the second surface 14B (the lower opening 132 opens at a position along the second surface 14B). In the third embodiment, the shield insertion port 17 of the ferrule 10 is connected to the adhesive filling portion 13 so that the end of the shield 20 is inserted into the inside of the adhesive filling portion 13. In addition, in the third embodiment, the rear end surface of the step portion 15, that is, the second surface 14B, functions as a positioning surface for positioning the shield 20 in the mounting direction (front-rear direction).

[0068] Fig.11 It is an orthographic projection diagram of the shield 20 in each direction according to the third embodiment. Fig. 12A and Fig. 12B It is a perspective view of the shield 20 alone.

[0069] The shield 20 is a component for protecting the optical fiber 1. The shield 20 is made of a flexible material (such as resin) and can be elastically deformed. Therefore, the shield 20 can suppress the load (such as bending stress) applied to the plurality of optical fibers 1. Fig. 9 and Fig. 10B As shown, when the shield 20 is mounted on the ferrule 10, the center portion of the shield 20 in the optical fiber insertion direction (front-rear direction) is arranged to be sandwiched by the upper and lower inner wall surfaces of the ferrule 10. Fig. 9 and Fig. 10B As shown in FIG. 1 , the front portion of the shield 20 (the portion closer to the front side than the portion sandwiched by the upper and lower inner wall surfaces of the ferrule 10) is arranged inside the adhesive filling portion 13. In addition, the portion closer to the rear side than the portion sandwiched by the upper and lower inner wall surfaces of the ferrule 10 protrudes further to the rear side than the ferrule 10, and serves as a portion (strain relief) for suppressing bending stress applied to the optical fiber 1.

[0070] The protective cover 20 has an optical fiber insertion hole 21. The optical fiber insertion hole 21 is a through hole for inserting a plurality of optical fibers 1. Therefore, the optical fiber insertion hole 21 is configured as a through hole along the optical fiber insertion direction (front-back direction; optical axis direction of the optical fiber 1). In addition, the optical fiber insertion hole 21 is configured to be able to insert an optical fiber ribbon composed of a plurality of optical fibers 1. Therefore, the optical fiber insertion hole 21 is configured as a cross-sectional shape extending in the width direction (left-right direction).

[0071] The optical fiber insertion hole 21 is arranged to correspond to the arrangement of the optical fiber hole 12 of the ferrule 10. Therefore, the optical fiber insertion hole 21 is arranged to be at the same height as the optical fiber hole 12 of the ferrule 10 and the upper surface of the step portion 15 (or the guide groove 15A) when the cover 20 is attached to the ferrule 10.

[0072] The shield 20 has a lower portion 22 and an upper portion 23. The shield 20 is formed by connecting two block-shaped lower portions 22 and upper portions 23 at both ends in the width direction. In the following description, the portion connecting the lower portion 22 and the upper portion 23 outside the optical fiber insertion hole 21 in the width direction is sometimes referred to as a connecting portion 24. The space surrounded by the lower portion 22, the upper portion 23, and the pair of connecting portions 24 is the optical fiber insertion hole 21.

[0073] The lower portion 22 is arranged on one side (lower side, bottom side) with the optical fiber insertion hole 21 as a reference. In other words, the lower portion 22 is arranged on the side opposite to the upper opening 131 side of the ferrule 10 when the shield 20 is mounted on the ferrule 10. The lower portion 22 is a block-shaped (plate-shaped) portion constituting the lower side of the shield 20, and is sometimes referred to as a "lower block" or a "first block". The lower portion 22 is arranged at the bottom (lower) of the adhesive filling portion 13 to fill the space on the bottom side of the adhesive filling portion 13.

[0074] The front end surface 22A of the lower portion 22 is formed of a surface perpendicular to the optical fiber insertion direction (the direction in which the shield 20 is installed; the front-back direction). The front end surface 22A of the lower portion 22 is a contact surface that contacts the second surface 14B (the rear end surface of the step portion 15) of the inner wall 14 of the ferrule 10, and functions as an alignment surface for aligning the shield 20 in the installation direction (the front-back direction).

[0075] The upper portion 23 is arranged on the other side (lower side, bottom side; the side opposite to the lower portion 22 side) with the optical fiber insertion hole 21 as a reference. In other words, the upper portion 23 is arranged on the upper opening 131 side of the ferrule 10 when the shield 20 is mounted on the ferrule 10. The upper portion 23 is a block-shaped (plate-shaped) portion constituting the upper side of the shield 20, and is sometimes referred to as an "upper block" or a "second block". The upper portion 23 fills the space on the upper side of the adhesive filling portion 13.

[0076] The upper portion 23 has a protrusion 231. The protrusion 231 protrudes in the direction of the optical fiber insertion than the end face 22A of the lower portion 22. The protrusion 231 is arranged at the end of the front side of the upper portion 23. The optical fiber insertion hole 21 is arranged to correspond to the arrangement of the optical fiber hole 12 of the ferrule 10. In addition, the protrusion 231 protrudes further to the front side than the end face 22A of the lower portion 22 (the portion below the optical fiber insertion hole 21). Thus, in a state where the shield 20 is mounted on the ferrule 10, the protrusion 231 is opposed to the upper surface of the step portion 15 (or the guide groove 15A) inside the adhesive filling portion 13. That is, the lower surface of the protrusion 231 becomes an opposing surface opposed to the upper surface of the step portion 15. Protrusion 231 is disposed inside adhesive-filled portion 13 to face the upper surface of step portion 15 , so that upper portion 23 can fill a space of adhesive-filled portion 13 on the upper opening 131 side (upper side) than step portion 15 .

[0077] Fig.13A 2 is an enlarged cross-sectional view of the gap between the end surface 231A of the protrusion 231 and the first surface 14A of the ferrule 10. Fig.13A yes Fig. 10B An enlarged illustration of area A.

[0078] The end face 231A of the protrusion 231 is arranged opposite to the first face 14A having the opening of the optical fiber hole 12. Since the protrusion 231 protrudes from the lower portion 22, the gap between the end face 231A of the hood 20 (protrusion 231) and the first face 14A can be reduced compared to the case where the protrusion 231 is not provided on the hood 20. The gap between the end face 231A of the protrusion 231 and the first face 14A opens upward at the upper opening 131. The adhesive is filled from this gap. If the adhesive is filled from the gap opened in the upper opening 131 (the gap between the end face 231A of the protrusion 231 and the first face 14A), it penetrates into the interior by capillary phenomenon (described later).

[0079] In this embodiment, the length of the protrusion 231 protruding from the end surface 22A of the lower portion 22 is ( Fig.14A The protruding length L2 shown; the dimension between the end surface 22A of the upper portion 22 and the end surface 231A of the upper portion 23 in the direction of optical fiber insertion) is greater than the length of the step portion 15 in the direction of optical fiber insertion ( Fig.14A The length L1 shown in the figure; the length of the guide groove 15A; the dimension between the first surface 14A and the second surface 14B in the direction of the optical fiber insertion). That is, the protruding length L2 of the protruding portion 231 is smaller than the length L1 of the step portion 15 in the direction of the optical fiber insertion (L2<L1). As a result, when the end surface 22A of the lower portion 22 of the shield 20 is in contact with the second surface 14B of the step portion 15 (refer to Fig. 9 and Fig. 10B ),like Fig.13AAs shown, a gap for filling the adhesive can be formed between the end face 231A of the protrusion 231 and the first surface 14A of the ferrule 10. In the present embodiment, the protrusion length L2 of the protrusion 231 is smaller than the length L1 of the step portion 15 in the optical fiber insertion direction (L2<L1), so that the shroud 20 can be aligned with respect to the installation direction (front-rear direction) of the ferrule 10 by bringing the end face 22A of the lower portion 22 of the shroud 20 into contact with the second surface 14B of the step portion 15.

[0080] However, if Fig.13A (and Fig. 9 ), a pressing portion 131A is provided on the wall surface on the upper side of the adhesive filling portion 13 of the ferrule 10. The pressing portion 131A presses the protrusion 231 of the shield 20 from the upper side. The pressing portion 131A is provided at both ends in the width direction near the front edge of the upper opening 131. When the shield 20 is mounted on the ferrule 10, the pressing portion 131A is arranged on the upper side of the two edges (two corners) in the width direction of the protrusion 231 of the shield 20. In other words, the protrusion 231 of the shield 20 is configured to be arranged on the lower side of the wall surface (pressing portion 131A) on the upper side of the adhesive filling portion 13 of the ferrule 10. The pressing portion 131A is arranged on the upper side of the protrusion 231 of the shield 20, so that the protrusion 231 of the shield 20 can be suppressed from being displaced upward inside the adhesive filling portion 13, and the protrusion 231 is stably arranged inside the adhesive filling portion 13. In addition, the pressing portion 131A is provided only on the upper sides of both edges in the width direction of the protruding portion 231 of the shield 20, and is not provided on the upper side of the central portion in the width direction of the protruding portion 231. Fig.13A As shown, the upper part of the gap between the end surface 231A of the protrusion 231 and the first surface 14A of the ferrule 10 can be opened, and the adhesive can be filled from the gap. In addition, the ferrule 10 does not need to include the pressing portion 131A.

[0081] Fig. 13B It is an explanatory diagram of the protrusion 231 of a modified example.

[0082] The protrusion 231 of the modified example has an inclined surface 231B between the upper surface of the protrusion 231 (the surface on the upper opening 131 side) and the end surface 231A of the protrusion 231. That is, the protrusion 231 of the modified example has an inclined surface 231B at the upper edge of the end surface 231A. As a result, it is easy to fill the adhesive between the end surface 231A of the protrusion 231 and the first surface 14A of the ferrule 10. In addition, as Fig. 13B As shown, even when the protrusion 231 is provided with the inclined surface 231B, it is preferable that the pressing portion 131A of the ferrule 10 presses the protrusion 231 of the shield 20 from above.

[0083] Fig.14A It is an enlarged view of the vicinity of the front end of the optical fiber insertion hole 21 . Fig. 14B This is an enlarged view of the vicinity of the front end of the optical fiber insertion hole 21 in a state where the optical fiber 1 is inserted. Fig.14A yes Fig. 10B An enlarged illustration of region B.

[0084] like Fig. 14B As shown, the optical fiber insertion hole 21 is formed to be suitable for the diameter of the optical fiber 1 having a cladding. For example, the diameter of the optical fiber 1 (the outer diameter of the cladding) is 250 μm, and the dimension of the optical fiber insertion hole 21 in the vertical direction (the interval between the lower portion 22 and the upper portion 23) is 260 μm. Therefore, the position of the lower surface of the upper portion 23 in the vertical direction becomes almost the same position as the upper edge of the optical fiber 1 (the optical fiber 1 having a cladding) inserted into the optical fiber insertion hole 21. The front end portion (the end on the front side) of the optical fiber 1 is a bare optical fiber from which the cladding has been removed. For example, the diameter of the bare optical fiber is 125 μm. The stripped edge 1A of the cladding (the front end of the cladding of the optical fiber 1) is arranged on the rear side (the side of the shield insertion port 17) of the second surface 14B (or the guide groove 15A) of the step portion 15. Therefore, as Fig. 14B As shown, the stripped edge 1A of the cladding is arranged inside the optical fiber insertion hole 21. In addition, the bare optical fiber is extended toward the front side from the opening of the optical fiber insertion hole 21. In addition, the bare optical fiber is arranged on the upper surface of the step portion 15 (the guide groove 15A).

[0085] like Fig.14A As shown in FIG. 1 , the lower surface of the protrusion 231 becomes an opposing surface to the upper surface of the step portion 15. Fig.14A As shown in FIG. 1 , the lower surface of the protrusion 231 is provided on the extension of the upper edge of the optical fiber insertion hole 21. The optical fiber insertion hole 21 is formed to be suitable for the diameter of the optical fiber 1 having the cladding. Therefore, as in the present embodiment, the lower surface of the protrusion 231 (the opposite surface to the upper surface of the step portion 15) is provided on the extension of the upper edge of the optical fiber insertion hole 21, so that Fig.14A As shown in FIG. 1 , a gap corresponding to the diameter of the clad optical fiber 1 is formed between the lower surface of the protrusion 231 and the upper surface of the step portion 15 (here, the guide groove 15A). Fig. 14B As shown, if a bare fiber is placed between the lower surface of the protrusion 231 and the upper surface (guide groove 15A) of the step portion 15, a narrow gap of the thickness of the cladding is formed around the bare fiber. As a result, the adhesive easily penetrates around the bare fiber by capillary action.

[0086] like Fig. 14B As shown in FIG. 1 , the stripped edge 1A of the cladding is arranged on the rear side (the shield insertion port 17 side) of the second surface 14B (or the guide groove 15A) of the step portion 15, and is therefore located inside the optical fiber insertion hole 21. As a result, Fig. 10BAs shown, when the ferrule structure 100 is viewed from above, the stripped edge 1A of the cladding is hidden by the upper portion 23 of the cover 20, and the position of the stripped edge 1A of the cladding in the optical fiber insertion direction (front-back direction) cannot be confirmed from the upper opening 131. Therefore, as described below, it is preferred that an exposed portion 232 is provided in the cover 20.

[0087] Fig.15A and Fig. 15B It is an explanatory diagram of the exposed portion 232 .

[0088] Fig.15A and Fig. 15B The shield 20 shown has an exposed portion 232. The exposed portion 232 exposes the upper portion of the optical fiber 1 inserted into the optical fiber insertion hole 21. The exposed portion 232 is arranged on the rear side of the end surface 22A on the front side of the lower portion 22. That is, when the shield 20 is mounted on the ferrule 10, the exposed portion 232 is arranged on the rear side of the second surface 14B (or the guide groove 15A) of the step portion 15. In addition, when the shield 20 is mounted on the ferrule 10, the exposed portion 232 is arranged on the front side of the rear edge of the upper opening 131. When the shield 20 is mounted on the ferrule 10, the exposed portion 232 is arranged between the second surface 14B (or the guide groove 15A) of the step portion 15 and the rear edge of the upper opening 131, so that Fig.15A and Fig. 15B As shown, the position of the stripped edge 1A of the cladding in the optical fiber insertion direction (front-rear direction) can be confirmed from the upper opening 131 through the exposed portion 232 .

[0089] Furthermore, the exposed portion 232 may be shaped so as to expose the upper part of a portion of the plurality of optical fibers 1 inserted into the optical fiber insertion hole 21. This is because, when removing the cladding of the optical fiber ribbon in such a manner that the positions of the stripped edges 1A of the cladding of the optical fibers 1 are aligned, it is sufficient to confirm the positions of the stripped edges 1A of the cladding of a portion of the optical fibers 1 in the direction of optical fiber insertion. Therefore, the exposed portion 232 does not need to expose the upper parts of all the optical fibers 1.

[0090] like Fig.15A As shown, the exposed portion 232 can be formed by a recessed portion provided at an end portion in the width direction of the shield 20. Fig.15A The exposed portion 232 shown in the figure can confirm the position of the stripped edge 1A of the cladding of the optical fiber 1 located at the end of the width direction of the optical fiber insertion hole 21 in the optical fiber insertion direction. Fig.15A As shown, it is preferable to provide recessed portions at both ends in the width direction. Thus, the position of the stripped edge 1A of the cladding of the optical fiber 1 located at both ends in the width direction in the direction of insertion of the optical fiber can be confirmed, and as a result, it can be inferred that the stripped edge 1A of the other optical fiber 1 (the optical fiber 1 located in the center in the width direction) is located on the line connecting the stripped edges 1A at both ends.

[0091] like Fig. 15B As shown, the exposed portion 232 can be formed by a window (opening) provided in the center portion in the width direction of the shield 20. Fig. 15B The exposed portion 232 shown can confirm the position of the stripped edge 1A of the cladding of the optical fiber 1 located in the center of the width direction of the optical fiber insertion hole 21 in the optical fiber insertion direction. Fig. 15B As shown, by providing the exposed portion 232 at the center of the width direction of the protective cover 20, the stripped edge 1A of the cladding of the optical fiber 1 can be confirmed at the center of the width direction of the upper opening 131, so that the operator can easily perform the confirmation operation. Fig. 15B As shown, by providing the exposed portion 232 at the center portion in the width direction of the shield 20 , it is easy to arrange the protruding portion 231 of the shield 20 under the pressing portion 131A of the ferrule 10 .

[0092] like Fig. 8A and Figure 8B As shown in FIG. 1 , the shield 20 of the third embodiment has a recess 20A. The recess 20A is a depression provided at the rear of the shield 20. Fig. 10A As shown, when the shield 20 is mounted on the ferrule 10, the recess 20A is located on the front side of the rear end face of the ferrule 10. Therefore, when the adhesive filled in the adhesive filling portion 13 penetrates into the inside of the ferrule 10 (described later), even if the adhesive penetrates between the shield insertion port 17 of the ferrule 10 and the shield 20, it is possible to suppress the adhesive from leaking to the rear side of the rear end face of the ferrule 10. However, the shield 20 may not have the recess 20A.

[0093] <Manufacturing method>

[0094] FIG. 16A to FIG. 16D This is a diagram for explaining a method for manufacturing an optical fiber with a ferrule.

[0095] First, the operator prepares the ferrule 10 and the hood 20, respectively. As already described, the ferrule 10 includes a main body having a connection end face 10A and an outer wall connected to the connection end face 10A, an inner wall 14 disposed in the main body, an adhesive filling portion 13, an upper opening 131, and a lower opening 132. The inner wall 14 includes a first surface 14A and a second surface 14B, the upper opening 131 is disposed at a position along the first surface 14A (the upper opening 131 opens at a position along the first surface 14A), and the lower opening 132 is disposed at a position along the second surface 14B (the lower opening 132 opens at a position along the second surface 14B). As already described, the hood 20 includes an optical fiber insertion hole 21, a lower portion 22 disposed at one side of the optical fiber insertion hole 21, and an upper portion 23 disposed at the other side of the optical fiber insertion hole 21. In addition, the upper portion 23 has a protruding portion 231 that protrudes beyond the end surface 22A of the lower portion 22 in the optical fiber insertion direction.

[0096] In addition, the operator pre-processes the plurality of optical fibers 1. For example, as pre-processing of the optical fibers 1, the operator removes the cladding of the optical fiber ribbon (removes the cladding of each of the plurality of optical fibers 1) and cuts the bare optical fibers into a predetermined length.

[0097] Next, if Fig.16A As shown, the operator inserts the plurality of optical fibers 1 (optical fiber ribbon) into the optical fiber insertion holes 21 of the protective cover 20. In addition, the operator inserts the plurality of optical fibers 1 (optical fiber ribbon) into the protective cover 20 in such a manner that the front ends of the optical fibers 1 (bare optical fibers) protrude further forward than the protrusions 231 of the protective cover 20.

[0098] In addition, if Fig.16A As shown in the figure, the operator applies the adhesive to the vicinity of the opening of the optical fiber hole 12 on the side of the adhesive filling portion 13, and applies the adhesive to the optical fiber hole 12. Alternatively, after applying the adhesive to the vicinity of the opening of the optical fiber hole 12 on the side of the adhesive filling portion 13, the operator may suck the adhesive from the connection end surface 10A side of the ferrule 10, thereby applying the adhesive to the inside of the optical fiber hole 12. By applying the adhesive to the optical fiber hole 12 in advance, it is possible to suppress the mixing of bubbles into the inside of the optical fiber hole 12.

[0099] Next, if Fig. 16B As shown, the operator inserts the plurality of optical fibers 1 inserted through the cover 20 into the respective fiber holes 12 of the ferrule 10. At this time, the operator inserts the optical fibers 1 into the fiber holes 12 while guiding the optical fibers 1 using the upper surface of the step portion 15 of the ferrule 10 (here, the guide groove 15A).

[0100] Next, if Fig. 16C As shown, the operator inserts the shield 20 into the shield insertion port 17 of the ferrule 10 and installs the shield 20 on the ferrule 10. Fig. 16C As shown in FIG. 1 , the operator inserts the shield 20 into the ferrule 10 until the end surface 22A of the lower portion 22 of the shield 20 contacts the second surface 14B of the step portion 15 of the ferrule 10. When the end surface 22A of the lower portion 22 of the shield 20 contacts the second surface 14B of the step portion 15 of the ferrule 10, a gap for filling the adhesive is formed between the end surface 231A of the protrusion 231 and the first surface 14A of the ferrule 10. In addition, the lower surface of the protrusion 231 is arranged to face the upper surface of the step portion 15 with a gap of the diameter of the optical fiber 1 (see FIG. 1 ). Fig.14A and Fig. 14B ).

[0101] At this time, the operator arranges the two edges (two corners) of the width direction of the protruding portion 231 of the shield 20 to be located below the upper wall surface (pressing portion 131A) of the adhesive filling portion 13 of the ferrule 10. Fig.15A and Fig. 15B ), after installing the protective cover 20 on the ferrule 10, the operator can confirm the position of the stripped edge 1A of the cladding in the optical fiber insertion direction (front-back direction) from the upper opening 131 through the exposed portion 232.

[0102] Next, if Fig.16D As shown, the operator applies adhesive to the gap between the end surface 231A of the protrusion 231 and the first surface 14A of the ferrule 10. The adhesive applied to the gap penetrates into the inside by capillary phenomenon, and the adhesive is applied to the guide groove 15A and the periphery of the optical fiber 1 arranged in the guide groove 15A. After the adhesive is applied, the optical fiber 1 is fixed to the ferrule 10 by curing the adhesive, and the manufacture of the optical fiber with the ferrule is completed.

[0103] In this embodiment, the shield 20 is disposed inside the adhesive filling portion 13 , so that the amount of adhesive filled in the adhesive filling portion 13 can be reduced. As a result, even if the adhesive shrinks when curing, deformation of the ferrule 10 can be suppressed.

[0104] On the other hand, in the present embodiment, the protrusion 231 is provided on the shield 20, so that the gap between the protrusion 231 of the shield 20 and the first surface 14A of the ferrule 10 can be reduced, and the adhesive can easily penetrate into the inside by capillary phenomenon. In addition, in the present embodiment, the gap between the lower surface of the protrusion 231 and the upper surface of the step portion 15 (or the guide groove 15A) can be reduced, and the gap around the optical fiber 1 (bare optical fiber) arranged on the upper surface of the step portion 15 can be reduced, so that the adhesive can easily penetrate into the upper surface of the step portion 15 and the surrounding of the optical fiber 1 arranged on the upper surface of the step portion 15 by capillary phenomenon. As described above, in the present embodiment, even if the amount of adhesive is small, the adhesive can be applied to the upper surface of the step portion 15 and the surrounding of the optical fiber 1, and the optical fiber can be fixed to the ferrule with sufficient strength.

[0105] In addition, the ferrule 10 of the third embodiment may also be Figure 6The ferrule 10 of the second embodiment shown in the figure is substituted for the ferrule 10 of the first embodiment. In this case, the ferrule 10 of the third embodiment includes: a body having a connection end face 10A and an outer wall connected to the connection end face 10A, an inner wall 14 arranged in the body, an adhesive filling part 13, an upper opening 131, and a lower opening 132. The inner wall 14 includes: a first surface 14A along the connection end face 10A side (front side) in the upper opening 131; a second surface 14B protruding from the first surface 14A to the adhesive filling part side (rear side); and a third surface 14C arranged on the side opposite to the upper opening 131 (lower side) with respect to the second surface 14B and arranged on the connection end face 10A side (front side) relative to the second surface 14B. Even in this case, the end of the shield 20 is inserted into the adhesive filling part 13 by connecting the shield insertion port 17 of the ferrule 10 with the adhesive filling part 13. In addition, even in this case, the second surface 14B functions as a positioning surface for positioning the shield 20 in the mounting direction (front-rear direction).

[0106] ===Other Implementation Methods===

[0107] The above-mentioned embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention naturally includes equivalents thereof.

[0108] Description of Reference Numerals

[0109] 1…optical fiber; 1A…stripping edge; 10…insertion core; 10A…connection end face; 10B…flange portion; 11…guide hole; 12…optical fiber hole; 13…adhesive filling portion; 131…upper opening; 131A…pressing portion; 132…lower opening; 14…inner wall; 14A…first surface; 14B…second surface; 14C…third surface; 15…step portion; 15A…guide groove; 16…recess; 17…shield insertion opening; 20…shield; 20A…recess; 21…optical fiber insertion hole; 22…lower portion; 22A…end face; 23…upper portion; 231…protrusion; 231A…end face; 231B…inclined surface; 232…exposed portion; 24…connecting portion; 100…insertion core structure.

Claims

1. A ferrule structure, comprising a ferrule and a shield mounted on the ferrule, characterized in that: The ferrule has: A main body having an outer wall and a connection end surface for the front end of the optical fiber to be disposed; An inner wall having openings of a plurality of optical fiber holes capable of inserting optical fibers toward the connection end surface, and arranged in the main body; An adhesive filling portion, arranged in the main body on a side opposite to the connecting end surface relative to the inner wall, for adhesive filling; an upper opening extending from the outer wall to the adhesive filling portion; as well as a lower opening extending from the outer wall to the adhesive filling portion and arranged on the side opposite to the upper opening; The inner wall has a first surface and a second surface protruding from the first surface toward the adhesive filling portion. The upper opening is arranged along the first surface. The lower opening is arranged along the second surface. The shield has: An optical fiber insertion hole, configured to correspond to the configuration of the plurality of optical fiber holes, for the plurality of optical fibers to be inserted through; a lower portion, arranged on one side with respect to the optical fiber insertion hole; and The upper portion is arranged on the other side with reference to the optical fiber insertion hole, The upper portion has a protrusion that protrudes further than the end surface of the lower portion in the direction in which the optical fiber is inserted. The protruding length of the protruding portion is smaller than the dimension between the first surface and the second surface in the optical fiber insertion direction. The lower portion is in contact with the second surface.

2. A ferrule structure, comprising a ferrule and a shield mounted on the ferrule, characterized in that: The ferrule has: A main body having an outer wall and a connection end surface for the front end of the optical fiber to be disposed; An inner wall having openings of a plurality of optical fiber holes capable of inserting optical fibers toward the connection end surface, and arranged in the main body; An adhesive filling portion, arranged in the main body on a side opposite to the connecting end surface relative to the inner wall, for adhesive filling; an upper opening extending from the outer wall to the adhesive filling portion; as well as a lower opening extending from the outer wall to the adhesive filling portion and arranged on the side opposite to the upper opening; The inner wall has: A first surface, along the connecting end surface side in the upper opening; a second surface protruding from the first surface toward the adhesive filling portion; as well as The third surface is arranged on the side opposite to the upper opening relative to the second surface and is arranged on the connection end surface side relative to the second surface. The shield has: An optical fiber insertion hole, configured to correspond to the configuration of the plurality of optical fiber holes, for the plurality of optical fibers to be inserted through; a lower portion, arranged on one side with respect to the optical fiber insertion hole; and The upper portion is arranged on the other side with reference to the optical fiber insertion hole, The upper portion has a protrusion that protrudes further than the end surface of the lower portion in the direction in which the optical fiber is inserted. The protruding length of the protruding portion is smaller than the dimension between the first surface and the second surface in the optical fiber insertion direction. The lower portion is in contact with the second surface.

3. The insert structure according to claim 2, characterized in that: have: a step portion for guiding the optical fiber toward the optical fiber hole in the main body; and The recessed portion is provided on a side opposite to the upper opening relative to the step portion, The second surface is formed by the end surface of the step portion, The third surface is constituted by an end surface of the recessed portion.

4. The insert structure according to any one of claims 1 to 3, characterized in that: The ferrule has a pressing portion at the upper opening, The protrusion is arranged on the lower side of the pressing portion when the shield is attached to the ferrule.

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