Optical connector and optical connection structure

Abstract

An optical connector (A) comprises a plurality of optical fibers (4), a ferrule (1) that holds front ends of the plurality of optical fibers (4), a gripping part (20) that is provided behind the ferrule (1), and a linking part (30) that links the ferrule (1) and the gripping part (20). The ferrule (1) has a front end surface (17), a rear end surface (10), a first side surface (13) and a second side surface (15), and a first principal surface (14) and a second principal surface (16). The first side surface (13) and the second side surface (15) intersect a second direction that is the width direction of the ferrule (1), face away from each other with the plurality of optical fibers (4) therebetween, and connect the front end surface (17) and the rear end surface (10). The first principal surface (14) and the second principal surface (16) intersect a third direction that is the thickness direction of the ferrule (1), face away from each other with the plurality of optical fibers (4) therebetween, and connect the front end surface (17) and the rear end surface (10). The linking part (30) has a first engagement part (31) that engages the ferrule (1) at the first principal surface (14) and a second engagement part (32) that engages the ferrule (1) at the second principal surface (16). The entireties of the first side surface (13) and the second side surface (15) are exposed.

Description

Optical connector and optical connection structure

[0001] This application claims priority to Japanese Patent Application No. 2023-116795, filed on July 18, 2023, and incorporates by reference the entire contents of said Japanese application.

[0002] Patent Document 1 discloses a technology relating to an interconnection system including a plurality of fiber cables for optical connection and a wiring method for the fiber cables. This system includes a connector housing that accommodates an optical connector in an optical adapter, and a ferrule provided in the optical connector. The ferrule is provided at the end of one or more optical fibers. The connector housing forms the optical connector, and the optical connector is attached to the inside of the optical adapter.

[0003] US Patent No. 1,147,4307 US Patent Application Publication No. 2019-0187383 US Patent Application Publication No. 2023-0003949

[0004] An optical connector according to an embodiment of the present disclosure includes a plurality of optical fibers extending rearward in a first direction, a ferrule for holding front ends of the plurality of optical fibers, a gripping portion disposed around the plurality of optical fibers and rearward of the ferrule, and a coupling portion disposed between the ferrule and the gripping portion and coupling the ferrule to the gripping portion. The ferrule has a front end face facing a mating ferrule in the first direction, a rear end face facing away from the front end face, first and second side faces connecting the front and rear end faces and intersecting a second direction that is the width direction of the ferrule and facing opposite to each other with the plurality of optical fibers therebetween, and first and second main faces connecting the front and rear end faces and intersecting a third direction that is the thickness direction of the ferrule and facing opposite to each other with the plurality of optical fibers therebetween. The connecting portion has a first engaging portion that engages with the ferrule on the first main surface and a second engaging portion that engages with the ferrule on the second main surface, and the ferrule is fixed to the connecting portion by the first engaging portion and the second engaging portion. The first side surface and the second side surface are entirely exposed.

[0005] FIG. 1 is a perspective view showing a configuration of an optical connection structure according to an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the optical connection structure. FIG. 3 is a perspective view showing a state in which a sub-adapter is fitted into an opening of an optical adapter. FIG. 4 is a perspective view showing a state in which the optical connector together with the sub-adapter is pulled out from the optical adapter. FIG. 5 is a perspective view showing the appearance of an optical connector according to an embodiment. FIG. 6 is an exploded perspective view of the optical connector. FIG. 7 is a side view of the optical connector. FIG. 8 is a perspective view showing a state in which a coupling portion is attached to a ferrule. FIG. 9 is a side view showing a cylindrical protective tube attached to the tip of an optical cable. FIG. 10 is a front view of the optical connector as seen from the x direction. FIG. 11 is a perspective view showing an optical connector according to a first modified example, showing a state before a grip portion is attached to the coupling portion. FIG. 12 is a perspective view of an optical connector according to a second modified example. FIG. 13 is a perspective view showing the appearance of a cap.

[0006] [Problem to be Solved by the Present Disclosure] An optical connector equipped with a ferrule that holds multiple optical fibers may be housed in a cylindrical protective tube that is attached to the tip of an optical cable, for example. In recent years, the inner diameter of protective tubes has become smaller in order to reduce size. If the width of the optical connector is too small for the inner diameter of the protective tube, it is difficult to house the optical connector in the protective tube. The challenge is to reduce the width of the optical connector and make the optical connector more compact.

[0007] Effect of the Present Disclosure According to the present disclosure, it is possible to provide an optical connector that can be made smaller by reducing its width, and an optical connection structure that is suitable for the optical connector.

[0008] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0009] [1] An optical connector according to an embodiment of the present disclosure includes a plurality of optical fibers extending rearward in a first direction, a ferrule for holding front ends of the plurality of optical fibers, a gripping portion disposed around the plurality of optical fibers and rearward of the ferrule, and a connecting portion disposed between the ferrule and the gripping portion and connecting the ferrule to the gripping portion. The ferrule has a front end face facing a mating ferrule in the first direction, a rear end face facing away from the front end face, first and second side faces connecting the front and rear end faces and intersecting a second direction that is the width direction of the ferrule and facing opposite to each other with the plurality of optical fibers therebetween, and first and second main faces connecting the front and rear end faces and intersecting a third direction that is the thickness direction of the ferrule and facing opposite to each other with the plurality of optical fibers therebetween. The connecting portion has a first engaging portion that engages with the ferrule on the first main surface and a second engaging portion that engages with the ferrule on the second main surface, and the ferrule is fixed to the connecting portion by the first engaging portion and the second engaging portion. The first side surface and the second side surface are entirely exposed.

[0010] The distance between the first and second side surfaces determines the maximum width of the ferrule. In a typical optical connector, at least a portion of each of the first and second side surfaces of the ferrule is covered by a housing. Therefore, the portions of the housing provided on the first and second side surfaces determine the maximum width of the optical connector, and this maximum width is greater than the maximum width of the ferrule. In contrast, in the above-described optical connector, the first engaging portion engages with the ferrule on the first main surface of the ferrule, and the second engaging portion engages with the ferrule on the second main surface of the ferrule, thereby fixing the ferrule to the gripping portion via the connecting portion. The entire first and second side surfaces are exposed. As a result, the first and second side surfaces are not covered by a housing or the like, and the distance between the first and second side surfaces, i.e., the maximum width of the ferrule, can be the maximum width of the optical connector. This allows the width of the optical connector to be reduced, thereby enabling the optical connector to be miniaturized.

[0011] [2] The optical connector of [1] above may further include a guide pin, the ferrule further having first guide pin holes aligned in the second direction and penetrating the ferrule along the first direction, the gripping portion having a second guide pin hole communicating with the first guide pin hole, and the guide pin may be inserted from the first guide pin hole to the second guide pin hole. In this case, the connection between the ferrule and the gripping portion is further strengthened via the guide pin.

[0012] [3] The optical connector of [1] above may further include guide pins, and the ferrule may further have first guide pin holes aligned in the second direction and penetrating the ferrule along the first direction, the guide pins being inserted into the first guide pin holes, and the connecting portion may hold the guide pins. In this way, the connecting portion may also serve as a portion that holds the guide pins, i.e., a guide pin keeper. In this case, the number of parts can be reduced compared to when a guide pin keeper is provided separately.

[0013] [4] The optical connectors of [1] to [3] above may further include guide pins and a cap covering the front end surface of the ferrule. The ferrule may further have first guide pin holes aligned in the second direction on the front end surface, and the guide pins may be inserted into the first guide pin holes. The cap may have third guide pin holes communicating with the first guide pin holes and through which the guide pins are inserted, and the cap may be fixed to the ferrule by inserting the guide pins into the third guide pin holes. In this case, since the cap is supported by the guide pins, the portions covering the first side surface, second side surface, first main surface, and second main surface of the ferrule can be made thinner than when the cap is supported only by the first side surface, second side surface, first main surface, and second main surface of the ferrule. Therefore, even when the cap is attached, the width of the optical connector can be reduced, thereby making the optical connector more compact.

[0014] [5] The optical connector of any one of [1] to [4] above may be configured so that the gripping portion and the coupling portion fit within the circumscribing circle of the ferrule when viewed from the first direction. This ensures that the width of the optical connector in all directions within a plane perpendicular to the first direction is equal to or less than the maximum width of the ferrule. This makes it easier to accommodate the optical connector in a cylindrical protective tube.

[0015] [6] In the optical connector of any one of [1] to [5] above, the member constituting the gripping portion may be made of resin, and the member constituting the connecting portion may be made of metal. By using a member constituting the gripping portion made of resin, it is possible to reduce the weight of the optical connector. In addition, by using a member constituting the connecting portion made of metal, it is possible to improve the strength of the connecting portion.

[0016] [7] In the optical connector of any one of [1] to [6] above, the gripping portion may have a third side surface and a fourth side surface that face opposite each other and intersect with the second direction, sandwiching the plurality of optical fibers therebetween, and the connecting portion may have a third engaging portion that engages with the gripping portion on the third side surface and a fourth engaging portion that engages with the gripping portion on the fourth side surface, and the gripping portion may be fixed to the connecting portion by the third engaging portion and the fourth engaging portion. In this case, the arrangement direction of the first engaging portion and the second engaging portion (the third direction) and the arrangement direction of the third engaging portion and the fourth engaging portion (the second direction) in the connecting portion may be different from each other. This makes it possible to easily form the connecting portion, for example, by forming the connecting portion from a single metal plate by sheet metal processing.

[0017] [8] An optical connection structure according to an embodiment of the present disclosure includes the optical connector according to any one of [1] to [7] above and a sub-adapter. The sub-adapter has a latch portion that engages with the optical adapter to detachably secure the sub-adapter to the optical adapter, and a fitting hole into which the optical connector fits. The optical connector is held in the sub-adapter by fitting into the fitting hole of the sub-adapter. In this optical connection structure, when fitting the optical connector into the sub-adapter, the optical connector is removed from the protective tube. After fitting the optical connector into the sub-adapter, the optical connector becomes one with the sub-adapter, and when the optical connector is removed from the optical adapter, the latch portion of the sub-adapter is released. With this optical connection structure, the optical connector can be detachably secured to the optical adapter.

[0018] [Details of the embodiments of the present disclosure] Specific examples of the optical connector and optical connection structure of the present disclosure will be described below with reference to the drawings. The present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, the same elements in the description of the drawings will be given the same reference numerals, and redundant explanations will be omitted. An x-y-z Cartesian coordinate system is shown in each figure as necessary. The x-direction corresponds to the first direction. The positive x-direction is the forward direction, and the negative x-direction is the backward direction. The y-direction corresponds to the second direction. The z-direction corresponds to the third direction.

[0019] FIG. 1 is a perspective view illustrating a configuration of an optical connection structure 100 according to an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the optical connection structure 100. As shown in FIGS. 1 and 2 , the optical connection structure 100 according to this embodiment includes an optical connector A, an optical adapter B, an optical connector C, and a sub-adapter D. The optical connector A has a ferrule 1 and two guide pins 12. The ferrule 1 holds the front end of an optical fiber group 5. The optical fiber group 5 is composed of a plurality of optical fibers 4 extending rearward in the same direction (x direction). The sub-adapter D has, for example, a rectangular cylindrical shape extending in the x direction and includes a pair of latch portions 91 and a mating hole 92. Each of the latch portions 91 is a latch lever provided on each side of the sub-adapter D in the y direction. The latch portions 91 are latch levers provided on both sides of the sub-adapter D in the y direction, and engage with the optical adapter B to detachably fix the sub-adapter D to the optical adapter B. The mating hole 92 penetrates the sub-adapter D in the x direction and mates with the optical connector A. The optical connector A is held in the sub-adapter D by fitting into a fitting hole 92 of the sub-adapter D.

[0020] The optical connector C is a mating optical connector and is a conventional optical connector, such as an MPO connector. The optical connector C has a mating ferrule 1C. The mating ferrule 1C holds the front end of an optical fiber group 7. The optical fiber group 7 is made up of a plurality of optical fibers 6 that extend forward along the same direction (x direction), i.e., backward as viewed from the optical connector C.

[0021] The optical adapter B receives the sub-adapter D from one end in the x direction and the optical connector C from the other end in the x direction. That is, the optical adapter B has an opening 101 that mates with the sub-adapter D and an opening (not shown) that mates with the optical connector C. Inside the optical adapter B, the ferrule 1 of the optical connector A faces a mating ferrule 1C of the optical connector C. In one example, the ferrule 1 abuts against the mating ferrule 1C. At this time, two guide pins 12 are inserted into two guide pin holes formed in the mating ferrule 1C, thereby positioning the ferrule 1 and the mating ferrule 1C relative to each other. As a result, each of the multiple optical fibers 4 is optically coupled to each of the multiple optical fibers 6.

[0022] When the optical connection structure 100 is used, first, the sub-adapter D is fitted into the opening 101 of the optical adapter B, as shown in Fig. 3. Then, as shown in Fig. 1, the optical connector A is fitted into the fitting hole 92 of the sub-adapter D, and the optical connector C is fitted into the opening (not shown) of the optical adapter B. This optically couples the multiple optical fibers 4 with the multiple optical fibers 6. Thereafter, when it becomes necessary to remove the optical connector A from the optical adapter B, the pair of latches 91 is released, and the optical connector A together with the sub-adapter D is pulled out from the optical adapter B, as shown in Fig. 4. Thereafter, the optical connector A can be attached to or detached from the optical adapter B by attaching or detaching the sub-adapter D to or from the optical adapter B.

[0023] Fig. 5 is a perspective view showing the appearance of the optical connector A according to this embodiment. Fig. 6 is an exploded perspective view of the optical connector A. Fig. 7 is a side view of the optical connector A. However, the optical fiber group 5 is not shown in Fig. 6. The structure of the optical connector A will be described in detail with reference to Figs. 5, 6 and 7.

[0024] The optical connector A includes a gripping portion 20 and a connecting portion 30 in addition to a plurality of optical fibers 4 and a ferrule 1. The ferrule 1 is a so-called MT ferrule. The ferrule 1 has a substantially rectangular parallelepiped appearance. When viewed from the x direction, the ferrule 1 has a substantially rectangular shape. The interior of the ferrule 1 is provided with a plurality of fiber holes 19 into which the plurality of optical fibers 4 are respectively inserted. The plurality of fiber holes 19 are formed side by side in the y direction and the z direction (or only in the y direction). Each fiber hole 19 holds the front end of each optical fiber 4. The ferrule 1 is made of a material such as resin.

[0025] The ferrule 1 has a side surface 13 (first side surface), a main surface 14 (first main surface), a side surface 15 (second side surface), a main surface 16 (second main surface), a front end surface 17, a rear end surface 10, and two guide pin holes 11 (first guide pin holes). The ferrule 1 has a width direction in the y direction and a thickness direction in the z direction. That is, the dimension of the ferrule 1 in the y direction is larger than the dimension of the ferrule 1 in the z direction. The side surfaces 13 and 15 intersect the y direction and extend along the z and x directions. The side surfaces 13 and 15 connect the front end surface 17 and the rear end surface 10. The side surfaces 13 and 15 face opposite each other with multiple fiber holes 19 sandwiched between them. The surfaces of the side surfaces 13 and 15 are flat. The entire side surfaces 13 and 15 are exposed to the outside of the optical connector A. In other words, the entire side surfaces 13 and 15 are not covered by any member of the optical connector A. The main surfaces 14 and 16 intersect with the z direction and extend along the x and y directions. The main surfaces 14 and 16 face opposite each other with a plurality of fiber holes 19 sandwiched between them. The main surface 14 has a pair of steps 141 aligned in the y direction. The main surface 16 also has a similar pair of steps 161.

[0026] The front end face 17 is a flat surface facing the mating ferrule 1C in the x direction and intersects with the x direction. In one example, the front end face 17 abuts against the mating ferrule 1C. The rear end face 10 faces away from the front end face 17 and intersects with the x direction. Two guide pin holes 11 are provided at both ends of the front end face 17 in the y direction and are aligned along the y direction. The two guide pin holes 11 penetrate the interior of the ferrule 1 along the x direction from the front end face 17 to the rear end face 10. The two guide pins 12 are aligned along the y direction.

[0027] The two guide pins 12 are held by the two guide pin holes 11, respectively, and protrude forward from the front end surface 17. The two guide pins 12 are cylindrical and extend in the x-direction. The two guide pins 12 are made of, for example, metal.

[0028] The gripping portion 20 is provided on the outer periphery of the optical fiber group 5 and is disposed rearward of the ferrule 1 facing the rear end face 10. The gripping portion 20 has a shape that is plane-symmetrical with respect to an imaginary plane that includes the center line of the optical connector A and is parallel to the x-y plane. The gripping portion 20 has a substantially elongated cylindrical shape and has a through-hole 24 extending in the x-direction. The optical fiber group 5 is inserted through the through-hole 24. The gripping portion 20 includes a front portion 21 and a rear portion 22. The front portion 21 is provided forward in the x-direction relative to the rear portion 22. The through-hole 24 passes through the front portion 21 and the rear portion 22. The rear portion 22 is slightly constricted so that it can be easily gripped by an operator's fingers.

[0029] The front portion 21 has a side surface 25 (third side surface) and a side surface 26 (fourth side surface). The side surfaces 25 and 26 intersect with the y direction and face opposite each other, sandwiching the plurality of optical fibers 4 therebetween. The side surfaces 25 and 26 are curved to protrude outward from the gripping portion 20. The side surface 25 has a recess 23. The recess 23 houses an engaging portion 33 of the connecting portion 30, which will be described later. The side surface 26 also has a recess (not shown) having a shape similar to the recess 23. The recess of the side surface 26 houses an engaging portion 34 of the connecting portion 30, which will be described later. The gripping portion 20 is formed from a single member. The material of the member forming the gripping portion 20 is, for example, resin.

[0030] The connecting portion 30 is disposed between the ferrule 1 and the gripping portion 20 in the x direction and connects the ferrule 1 and the gripping portion 20. The connecting portion 30 is made of, for example, metal. The connecting portion 30 is formed, for example, by sheet metal processing. The connecting portion 30 includes an engaging portion 31 (first engaging portion), an engaging portion 32 (second engaging portion), an engaging portion 33 (third engaging portion), an engaging portion 34 (fourth engaging portion), and a main body 38. The main body 38 is a plate-shaped portion extending along a plane intersecting the x direction. The main body 38 is disposed on the rear end surface 10 of the ferrule 1. The main body 38 includes a fiber insertion hole 35. The optical fiber group 5 is inserted through the fiber insertion hole 35. The main body 38 further includes guide pin holding holes 36 and 37. FIG. 8 is a perspective view showing the connecting portion 30 attached to the ferrule 1. As shown in FIGS. 6 and 8, the guide pin holding holes 36 and 37 are fitted with the distal ends of the two guide pins 12, respectively, to hold the distal ends.

[0031] The engaging portion 31 protrudes forward in the x direction from the main body 38 and is disposed on the main surface 14 of the ferrule 1. The engaging portion 31 engages with the ferrule 1 at the main surface 14. Specifically, when viewed from the z direction, the engaging portion 31 has a planar shape, such as a T-shape with an axis extending in the x direction. The portion of the T-shape extending in the y direction engages with a pair of steps 141 formed on the main surface 14. The engaging portion 32 protrudes forward in the x direction from the main body 38 and is disposed on the main surface 16 of the ferrule 1. That is, the engaging portion 32 sandwiches the ferrule 1 between itself and the engaging portion 31. The engaging portion 32 engages with the ferrule 1 at the main surface 16. Specifically, when viewed from the z direction, the engaging portion 32 has a planar shape, such as a T-shape with an axis extending in the x direction. The portion of the T-shape extending in the y direction engages with a pair of steps 161 (only one of which is shown in FIG. 6 ) formed on the main surface 16. In this manner, the ferrule 1 is fixed to the connecting portion 30 by the engaging portions 31 and 32 .

[0032] The engaging portion 33 protrudes rearward in the x direction from the main body 38 and is disposed on the side surface 25 of the gripping portion 20. The engaging portion 33 engages with the gripping portion 20 at the side surface 25. Specifically, the engaging portion 33 has a planar shape, such as a T-shape with an axis extending in the x direction, when viewed from the y direction. The engaging portion 33 is accommodated in a recess 23 formed in the side surface 25. The engaging portion 33 engages with the gripping portion 20 by engaging a portion of the T-shape extending in the z direction with the edge of the recess 23. The portion of the engaging portion 33 extending in the z direction may be curved or bent along the curved side surface 25. The engaging portion 34 protrudes rearward in the x direction from the main body 38 and is disposed on the side surface 26 of the gripping portion 20. The engaging portion 34 engages with the gripping portion 20 at the side surface 26. Specifically, the engaging portion 34 has a planar shape, such as a T-shape with an axis extending in the x direction, when viewed from the y direction. The engaging portion 34 is housed in a recess (not shown) formed in the side surface 26. The engaging portion 34 engages with the grip portion 20 by engaging the portion of the T-shape extending in the z direction with the edge of the recess. The portion of the engaging portion 34 extending in the z direction may be curved or bent along the curved side surface 26. In this way, the engaging portions 33, 34 fix the grip portion 20 to the connecting portion 30.

[0033] The effects obtained by the optical connector A of the present embodiment described above will be described. In the optical connector A, the distance between the side surface 13 and the side surface 15 determines the maximum width of the ferrule 1. In a typical optical connector such as the optical connector C shown in FIGS. 1 to 4, at least a portion of the side surface of the ferrule is covered by a housing. Therefore, the portion of the housing provided on the side surface determines the maximum width of the optical connector, and this maximum width is greater than the maximum width of the ferrule. In contrast, in the optical connector A of the present embodiment, the engaging portion 31 engages with the ferrule 1 on the main surface 14 of the ferrule 1, and the engaging portion 32 engages with the ferrule 1 on the main surface 16 of the ferrule 1, thereby fixing the ferrule 1 to the gripping portion 20 via the connecting portion 30. The side surfaces 13 and 15 are entirely exposed. As a result, the side surfaces 13 and 15 are not covered by a housing or the like, and the distance between the side surfaces 13 and 15, i.e., the maximum width of the ferrule 1, can be the maximum width of the optical connector. This allows the width of the optical connector A to be reduced, thereby making the optical connector A more compact.

[0034] 9 is a side view showing a cylindrical protective tube 40 attached to the tip of an optical cable 41. An optical connector A may be housed in such a protective tube 40, for example. Due to miniaturization, the inner diameter of the protective tube 40 has been decreasing in recent years. If the width of the optical connector A is too small for the inner diameter of the protective tube 40, the optical connector A is difficult to house in the protective tube 40. According to the optical connector A of this embodiment, the width can be reduced, making it easier to house in the protective tube 40.

[0035] 10 is a front view of the optical connector A as viewed from the x direction. In the optical connector A of this embodiment, the gripping portion 20 and the coupling portion 30 are contained within the circumscribing circle R of the ferrule 1 as viewed from the x direction. The diameter of the circumscribing circle R is, for example, 5.4 mm to 7.8 mm, inclusive, and in one example, 6.5 mm. The width L1 of the gripping portion 20 in the z direction, i.e., the maximum width of the optical connector A in the z direction, is, for example, 1.5 mm to 3.5 mm, inclusive, and in one example, 2.8 mm.

[0036] In this way, when viewed from the x direction, the gripping portion 20 and the connecting portion 30 may fit inside the circumscribing circle R of the ferrule 1. In this case, the width of the optical connector A in all directions in a plane perpendicular to the x direction is equal to or less than the maximum width of the ferrule 1. Therefore, the optical connector A can be easily housed in the cylindrical protective tube 40.

[0037] As in this embodiment, the connecting portion 30 may hold two guide pins 12. In this way, the connecting portion 30 may also serve as a portion that holds the guide pins 12, i.e., a guide pin keeper. In this case, the number of parts can be reduced compared to when a separate guide pin keeper is provided.

[0038] As in the present embodiment, the members constituting the gripping portion 20 may be made of resin, and the members constituting the connecting portion 30 may be made of metal. Using resin as the members constituting the gripping portion 20 makes it possible to reduce the weight of the optical connector A. In addition, using metal as the members constituting the connecting portion 30 makes it possible to improve the strength of the connecting portion 30.

[0039] As in the present embodiment, the gripping portion 20 may have side surfaces 25 and 26 that intersect with the y direction and face opposite each other with the plurality of optical fibers 4 sandwiched therebetween. The connecting portion 30 may have an engaging portion 33 that engages with the gripping portion 20 at side surface 25 and an engaging portion 34 that engages with the gripping portion 20 at side surface 26, and the gripping portion 20 may be fixed to the connecting portion 30 by the engaging portions 33 and 34. In this case, the arrangement direction (z direction) of the engaging portions 31 and 32 in the connecting portion 30 can be made different from the arrangement direction (y direction) of the engaging portions 33 and 34 in the connecting portion 30. This makes it possible to easily form the connecting portion 30, for example, by forming the connecting portion 30 from a single metal plate by sheet metal processing.

[0040] In the optical connection structure 100 of this embodiment, when mating the optical connector A with the sub-adapter D, the optical connector A is removed from the protective tube 40. After mating the optical connector A with the sub-adapter D, the optical connector A becomes one with the sub-adapter D, and when the optical connector A is removed from the optical adapter B, the latch portion 91 of the sub-adapter D is released. According to this optical connection structure 100, the optical connector A can be detachably fixed to the optical adapter B. (First Modification)

[0041] FIG. 11 is a perspective view showing an optical connector A1 according to a first modified example, showing the state before the gripping portion 20A is attached to the coupling portion 30. The optical connector A1 of this modified example differs from the optical connector A of the above embodiment in the following respects, but is the same in other respects. As shown in FIG. 11 , the optical connector A1 of this modified example has two guide pins 12A instead of the two guide pins 12 of the above embodiment. The guide pins 12A extend longer in the x-direction than the guide pins 12. The guide pins 12A extend rearward in the x-direction from the rear end face 10. The optical connector A1 has a gripping portion 20A instead of the gripping portion 20. The gripping portion 20A differs from the gripping portion 20 in that it has two guide pin holes 27 (second guide pin holes) that respectively communicate with the two guide pin holes 11 of the ferrule 1, but is the same as the gripping portion 20 in other respects. The two guide pins 12A are inserted from the two guide pin holes 11 of the ferrule 1 to the two guide pin holes 27 of the gripping portion 20A, respectively. According to this modification, the connection between the ferrule 1 and the gripping portion 20A is further strengthened through the two guide pins 12A. (Second Modification)

[0042] 12 is a perspective view showing an optical connector A2 according to a second modification. In addition to the configuration of the optical connector A of the above embodiment, the optical connector A2 further includes a cap 50. The cap 50 covers the front end face 17 of the ferrule 1 when the optical connector A2 is not connected, and is removed from the ferrule 1 when the optical connector A2 is connected.

[0043] FIG. 13 is a perspective view showing the appearance of the cap 50. The cap 50 has a generally rectangular shape when viewed from the x direction, and has an end face 51 that faces or abuts against the front end face 17 of the ferrule 1. The end face 51 extends along a plane intersecting the x direction. The cap 50 has a sidewall 52 that protrudes rearward in the x direction from the peripheral edge of the end face 51 and surrounds the end face 51. The sidewall 52 abuts the side faces 13, 15 and main faces 14, 16 of the ferrule 1, and covers the portions of the side faces 13, 15 and main faces 14, 16 that are closer to the front end face 17. The cap 50 has two guide pin holes 53 (third guide pin holes, only one of which is shown in FIG. 13 ) that extend forward in the x direction from the end face 51. The two guide pin holes 53 communicate with the two guide pin holes 11 of the ferrule 1, respectively, and allow two guide pins 12 (or two guide pins 12A) to be inserted therethrough. Slit-like gaps 54 extending in the x and y directions are formed on both sides of the guide pin hole 53 in the y direction. When the guide pin 12 (or guide pin 12A) is not inserted, the inner diameter of the guide pin hole 53 is slightly smaller than the diameter of the guide pin 12 (or guide pin 12A). As a result, when the guide pin 12 (or guide pin 12A) is inserted into the guide pin hole 53, the guide pin hole 53 elastically expands, and this elastic force securely attaches the cap 50 to the ferrule 1. In this way, the front end face 17 of the ferrule 1 and its vicinity, the front ends of the optical fiber group 5 (plurality of optical fibers 4) exposed at the front end face 17, and the guide pins 12 exposed from the front end face 17 can be protected.

[0044] According to this modification, the cap 50 is supported by two guide pins 12 (or two guide pins 12A), which makes it possible to make the side walls 52 covering the side surfaces 13, 15 and the main surfaces 14, 16 thinner than when the cap 50 is supported only by the side surfaces 13, 15 and the main surfaces 14, 16 of the ferrule 1. Therefore, even when the cap 50 is attached, the width of the optical connector A2 can be reduced, thereby making the optical connector A2 more compact.

[0045] The optical connector and optical connection structure according to the present disclosure are not limited to the above-described embodiment, and various other modifications are possible. For example, the above-described embodiment and each modification may be combined with each other depending on the required purpose and effect. In the above-described embodiment, the connecting portion 30 holds two guide pins 12, but the optical connector may further include a member separate from the connecting portion 30 for holding the guide pins 12. In the above-described embodiment, the member constituting the gripping portion 20 is made of resin, and the member constituting the connecting portion 30 is made of metal, but the constituent materials of the gripping portion 20 and the connecting portion 30 are not limited to these.

[0046] DESCRIPTION OF SYMBOLS 1...Ferrule 1C...Mating ferrule 4, 6...Optical fiber 5, 7...Optical fiber group 10...Rear end face 11, 27...Guide pin hole 12, 12A...Guide pin 13, 15...Side face 14, 16...Main face 17...Front end face 19...Fiber hole 20, 20A...Gripping portion 21...Front portion 22...Rear portion 23...Recess 24...Through hole 25, 26...Side face 30...Coupling portion 31, 32, 33, 34...Engagement portion 35...Fiber insertion hole 36, 37...Guide pin holding hole 38...Main body portion 40...Protective tube 41...Optical cable 50...Cap 51...End face 52...Side wall 53...Guide pin hole 54...Gap 91...Latch portion 92...Fitting hole 100...Optical connection structure 101...Opening 141, 161...Step A, A1, A2, C...Optical connector B...Optical adapter D...Sub-adapter L1...Width R...Circumscribed circle

Claims

1. A ferrule for holding front ends of the optical fibers extending rearward in a first direction, a gripping portion provided around the optical fibers and positioned rearward of the ferrule, and a connecting portion positioned between the ferrule and the gripping portion and connecting the ferrule and the gripping portion, wherein the ferrule has a front end face facing a mating ferrule in the first direction, a rear end face facing away from the front end face, first and second side faces connecting the front end face and the rear end face, intersecting a second direction which is the width direction of the ferrule and facing opposite to each other with the optical fibers therebetween, and first and second main faces connecting the front end face and the rear end face, intersecting a third direction which is the thickness direction of the ferrule and facing opposite to each other with the optical fibers therebetween, an optical connector, wherein the connecting portion has a first engaging portion that engages with the ferrule on the first main surface and a second engaging portion that engages with the ferrule on the second main surface, the ferrule is fixed to the connecting portion by the first engaging portion and the second engaging portion, and the first side surface and the second side surface are entirely exposed.

2. An optical connector as described in claim 1, further comprising a guide pin, the ferrule further having a first guide pin hole penetrating the ferrule along the first direction, the gripping portion having a second guide pin hole communicating with the first guide pin hole, and the guide pin being inserted from the first guide pin hole to the second guide pin hole.

3. An optical connector as described in claim 1, further comprising a guide pin, the ferrule further having a first guide pin hole penetrating the ferrule along the first direction, the guide pin being inserted into the first guide pin hole, and the connecting portion holding the guide pin.

4. An optical connector as described in any one of claims 1 to 3, further comprising: a guide pin; and a cap covering the front end face of the ferrule, wherein the ferrule further has a first guide pin hole at the front end face, the guide pin being inserted into the first guide pin hole, and the cap has a third guide pin hole communicating with the first guide pin hole and allowing the guide pin to be inserted therethrough, and the cap is fixed to the ferrule by inserting the guide pin into the third guide pin hole.

5. An optical connector as described in any one of claims 1 to 4, configured so that the gripping portion and the connecting portion are contained within a circumscribing circle of the ferrule when viewed from the first direction.

6. An optical connector according to any one of claims 1 to 5, wherein the member constituting the gripping portion is made of resin, and the member constituting the connecting portion is made of metal.

7. An optical connector as described in any one of claims 1 to 6, wherein the gripping portion has a third side and a fourth side that intersect with the second direction and face opposite each other with the multiple optical fibers therebetween, and the connecting portion has a third engagement portion that engages with the gripping portion on the third side and a fourth engagement portion that engages with the gripping portion on the fourth side, and the gripping portion is fixed to the connecting portion by the third engagement portion and the fourth engagement portion.

8. An optical connection structure comprising: an optical connector according to any one of claims 1 to 7; and a sub-adapter, wherein the sub-adapter has a latch portion which engages with the optical adapter to removably secure the sub-adapter to the optical adapter; and a mating hole which engages with the optical connector, and wherein the optical connector is held in the sub-adapter by mating with the mating hole of the sub-adapter.

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