Optical connector and ferrule

Abstract

This optical connector is provided with: a plurality of optical fibers; the insertion core is provided with a plurality of optical fiber holes into which a plurality of optical fibers are inserted, two positioning holes and a connecting end surface for opening the plurality of optical fiber holes and the two positioning holes; and a housing that holds the ferrule, the connection end surface being inclined with respect to an imaginary plane perpendicular to the longitudinal direction of the plurality of fiber holes when viewed from the arrangement direction in which the two positioning holes are arranged, the housing having a housing-side contact surface, and the ferrule having a ferrule-side contact surface. And a ferrule-side contact surface that restricts the amount of protrusion of the ferrule from the housing by contacting with the housing-side contact surface, the ferrule being capable of swinging about a swinging center axis with respect to the housing in a state where the housing-side contact surface and the ferrule-side contact surface are in contact, the swinging center axis being located at a position where the housing-side contact surface and the ferrule-side contact surface are in contact with each other, and the swinging center axis being located at a position where the housing-side contact surface and the ferrule-side contact surface are in contact with each other. And extending in an orthogonal direction orthogonal to both the longitudinal direction and the arrangement direction.

Description

Technical Field

[0001] This invention relates to optical connectors and ferrules.

[0002] This application claims priority based on Japanese Patent Application No. 2023-114788, filed in Japan on July 12, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] Patent Document 1 discloses an optical connector having a ferrule with an inclined connection end face. By tilting the connection end face of the optical fiber, the amount of light reflection at the connection point can be reduced. Furthermore, because the connection end face is tilted, when a pair of optical connectors are connected, the ferrule moves in a sliding manner relative to the connection end face on the target side. This displacement is estimated, and the position of the optical fiber on the connection end face is pre-biased relative to the positioning pin.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-101232

[0005] In optical connectors where the connection end faces are tilted, there are cases where the actual displacement is smaller than the designed displacement. In this case, axial misalignment occurs between the optical fibers of a pair of connectors, increasing optical connection loss. Summary of the Invention

[0006] This invention was made with this situation in mind, and its purpose is to reduce optical connection loss in ferrules and optical connectors with tilted connection end faces.

[0007] The optical connector according to Embodiment 1 of the present invention comprises: a plurality of optical fibers; a ferrule having a plurality of fiber holes through which the plurality of optical fibers are inserted, two positioning holes, and a connection end face for opening the plurality of fiber holes and the two positioning holes; and a housing holding the ferrule, wherein, when viewed from the arrangement direction of the two positioning holes, the connection end face is inclined relative to an imaginary plane perpendicular to the length direction of the plurality of optical fibers, the housing has a housing-side contact surface, and the ferrule has a ferrule-side contact surface, the ferrule-side contact surface restricting the amount of protrusion of the ferrule from the housing by contacting the housing-side contact surface, and the ferrule being able to swing relative to the housing about a swing center axis, the swing center axis being located at the position where the housing-side contact surface and the ferrule-side contact surface are in contact, and extending along an orthogonal direction orthogonal to both the length direction and the arrangement direction.

[0008] Method 2 of the present invention is based on the optical connector involved in Method 1, wherein the contact surface on the housing side is curved.

[0009] The ferrule involved in Embodiment 3 of the present invention is a ferrule partially housed inside the housing of an optical connector, comprising: a plurality of fiber optic holes for inserting a plurality of optical fibers; two positioning holes; a connecting end face for opening the two positioning holes and the plurality of fiber optic holes; and a ferrule-side contact surface that limits the amount of protrusion of the ferrule from the housing by contacting the housing. When viewed from the arrangement direction of the two positioning holes, the connecting end face is inclined relative to an imaginary plane perpendicular to the length direction of the plurality of fiber optic holes, and the ferrule-side contact surface is curved.

[0010] The fourth embodiment of the present invention is based on the ferrule involved in the third embodiment, and has two clearance portions. The two clearance portions are configured to sandwich the ferrule-side contact surface in the middle in the above-mentioned arrangement direction. The two clearance portions are recessed relative to the ferrule-side contact surface toward the side opposite to the above-mentioned connection end face in the above-mentioned length direction.

[0011] The fifth embodiment of the present invention is based on the ferrule involved in the third or fourth embodiment, and has two ferrule side contact surfaces, including the ferrule side contact surface mentioned above. The two ferrule side contact surfaces are arranged at different positions in an orthogonal direction that is orthogonal to both the length direction and the arrangement direction.

[0012] The present invention, embodiment 6, is based on the insert involved in any one of embodiments 3 to 5, and includes: a protrusion protruding in an orthogonal direction orthogonal to both the length direction and the arrangement direction, the protrusion having the insert-side contact surface.

[0013] According to the above-described manner of the present invention, in ferrules and optical connectors with tilted connection end faces, optical connection loss can be reduced. Attached Figure Description

[0014] Figure 1 This is a perspective view of the optical connector involved in this embodiment.

[0015] Figure 2 yes Figure 1 View in direction II.

[0016] Figure 3 Viewed from the front end Figure 1 A diagram of an optical connector.

[0017] Figure 4 yes Figure 1 A 3D diagram of the ferrule.

[0018] Figure 5 yes Figure 1 The VV section view.

[0019] Figure 6AThis is a simplified diagram illustrating the connection of the two optical connectors involved in this embodiment.

[0020] Figure 6B This is a simplified diagram illustrating the connection of the two optical connectors involved in this embodiment.

[0021] Figure 7A This diagram illustrates the position of the locating pins of the male optical connector, inside the locating hole of the female optical connector.

[0022] Figure 7B This diagram illustrates the position of the locating pins of the male optical connector, inside the locating hole of the female optical connector.

[0023] Figure 8 This is a simplified diagram illustrating the situation where the ferrule swings relative to the housing in the optical connector of this embodiment.

[0024] Figure 9 This is a simplified diagram of the optical connector involved in the first variation.

[0025] Figure 10 This is a simplified diagram of the optical connector involved in the second variation.

[0026] Figure 11 This is a simplified diagram of the optical connector involved in the third variation.

[0027] Figure 12 This is a simplified diagram of the optical connector involved in the fourth variation. Detailed Implementation

[0028] The optical connector and ferrule of this embodiment will be described below based on the accompanying drawings.

[0029] like Figure 1 As shown, the optical connector 1 includes a ferrule 10, a housing 20, a protective cover 30, and multiple optical fibers F. The ferrule 10 has multiple fiber optic holes 12 and two positioning holes 13. An optical fiber F is inserted into each fiber optic hole 12. However, it is also possible that some fiber optic holes 12 are not inserted with an optical fiber F. That is, the number of optical fibers F can be less than the number of fiber optic holes 12. The ferrule 10 has a connection end face 11. The fiber optic holes 12 and positioning holes 13 open at the connection end face 11. The housing 20 has an opening 21. A portion of the ferrule 10 protrudes outward from the housing 20 through the opening 21.

[0030] (Direction definition)

[0031] In this specification, the direction in which the multiple fiber optic holes 12 extend is referred to as the length direction Z. The side of the connecting end face 11 (+Z side) in the length direction Z is referred to as the front end side. The opposite side (-Z side) is referred to as the base end side. The direction in which the two positioning holes 13 are arranged is referred to as the arrangement direction X. The direction orthogonal to both the length direction Z and the arrangement direction X is referred to as the orthogonal direction Y.

[0032] The housing 20 holds a portion of the insert 10 internally. The front end (the end on the +Z side) of the insert 10 protrudes from the housing 20. Inside the housing 20 are a pin clamping member 40 and a force-applying member 50 (see reference). Figure 5 The insert 10 is subjected to force by the force-applying member 50 towards its front end, i.e., the connecting end face 11. For example, a coil spring can be used as the force-applying member 50. A pin clamping member 40 is disposed between the force-applying member 50 and the insert 10. The force exerted by the force-applying member 50 is transmitted to the insert 10 via the pin clamping member 40. However, the force-applying member 50 may directly contact the insert 10 without the pin clamping member 40.

[0033] Figure 2 This is a diagram showing the front end of the optical connector 1 as viewed from the X-direction. Figure 2 The imaginary plane P shown is orthogonal to the length direction Z. Viewed from the alignment direction X, the connecting end face 11 is inclined relative to the imaginary plane P. The angle between the connecting end face 11 and the imaginary plane P is, for example, 8°. However, this angle can be changed. In this way, by inclining the connecting end face 11 of the ferrule 10, the generation of Fresnel reflections can be suppressed when connecting two optical connectors 1.

[0034] After the ferrule 10 has been injection molded, part or all of the connection end face 11 may not be tilted relative to the imaginary plane P. Alternatively, after molding, the connection end face 11 may be tilted relative to the imaginary plane P by grinding. During grinding, the optical fiber F may protrude from the optical fiber hole 12, and the connection end face 11 and the optical fiber F may be ground together.

[0035] like Figure 3 As shown, the ferrule 10 in this embodiment has a total of 12 fiber optic holes 12. These fiber optic holes 12 are arranged in a row. That is, a row (hereinafter referred to as a fiber optic row) is arranged including 12 fiber optic holes 12. The fiber optic holes 12 included in the fiber optic row are arranged in the arrangement direction X. In addition, there may be two or more fiber optic rows formed in the ferrule 10. The number of fiber optic holes 12 included in a fiber optic row may also be changed.

[0036] like Figure 3As shown, the housing 20 has a first limiting portion 22 and a second limiting portion 23. The first limiting portion 22 and the second limiting portion 23 protrude toward the inside of the opening 21. The first limiting portion 22 and the second limiting portion 23 are configured to clamp the insert 10 in the middle. The first limiting portion 22 and the second limiting portion 23 prevent the insert 10 from dislodging toward the front end relative to the housing 20.

[0037] like Figure 4 As shown, the ferrule 10 has a first end face 14 and a second end face 15 facing the orthogonal direction Y. A first recess 14a is formed on the first end face 14, and a second recess 15a is formed on the second end face 15. A ferrule-side contact surface 14b and two clearance portions 14c are formed on the inner wall of the first recess 14a. The ferrule-side contact surface 14b faces the front end side (+Z side). Figure 5 As shown, the first limiting part 22 enters the inner side of the first recess 14a. The first limiting part 22 has a housing-side contact surface 22a that contacts the insert-side contact surface 14b.

[0038] like Figure 5 As shown, the ferrule-side contact surface 14b is pressed against the housing-side contact surface 22a by the force applied by the force-applying component 50. In this way, the amount of protrusion of the ferrule 10 relative to the housing 20 is determined by the contact between the ferrule-side contact surface 14b and the housing-side contact surface 22a. In this embodiment, the ferrule-side contact surface 14b is a curved surface that protrudes towards the front end side (+Z side). Therefore, with the ferrule-side contact surface 14b in contact with the housing-side contact surface 22a, the ferrule 10 can swing relative to the housing 20. The central axis of this swing (hereinafter referred to as the swing center axis C) is located at the position where the ferrule-side contact surface 14b contacts the housing-side contact surface 22a. The swing center axis C extends along the orthogonal direction Y. If the ferrule 10 swings, the angle of the connecting end face 11 relative to the arrangement direction X changes. The mechanism that causes the ferrule 10 to swing in this way is called a "swing mechanism".

[0039] Two clearance portions 14c are connected to both ends of the ferrule-side contact surface 14b in the X-direction alignment. The two clearance portions 14c are recessed towards the base end side (-Z side) relative to the ferrule-side contact surface 14b. By forming the clearance portions 14c, the ferrule 10 relative to the housing 20 is made easier to swing. As a result, the connection loss is stabilized during repeated connection of the optical connectors 1 with each other.

[0040] like Figure 3As shown, the second limiting part 23 enters the second recess 15a. Although not shown in the figure, the second limiting part 23 has a second housing-side contact surface, and the second recess 15a has a second ferrule-side contact surface. In other words, the ferrule 10 has two ferrule-side contact surfaces, and the housing 20 has two housing-side contact surfaces. The two ferrule-side contact surfaces are arranged at different positions in an orthogonal direction. Similarly to the first recess 14a, the second recess 15a may also have two clearance portions.

[0041] Next, the function of the optical connector 1 and the ferrule 10 configured as described above will be explained.

[0042] Figure 6A and Figure 6B This is a schematic diagram of two optical connectors 1 connected. One of the two optical connectors 1 is the male side, and the other is the female side. The male optical connector 1 has two positioning pins 13p. Each positioning pin 13p passes through two positioning holes 13 in the male side's ferrule 10 and is held by a pin clamping member 40. The male side's positioning pins 13p are inserted into the female side's positioning holes 13, thereby positioning the two optical connectors 1.

[0043] Here, the connection end face 11 in this embodiment is inclined. Therefore, if the connection end faces 11 of the two optical connectors 1 are brought into contact with each other, a result is generated. Figure 6B The force f is indicated by the arrow. Force f acts in the direction that moves the insert 10 along the orthogonal direction Y. Here, the outer diameter of the locating pin 13p is smaller than the inner diameter of the locating hole 13. In other words, there is a gap between the locating pin 13p and the locating hole 13. This gap is provided to facilitate the insertion of the locating pin 13p into the locating hole 13.

[0044] Figure 7A and Figure 7B An example showing the position of the male-side locating pin 13p inside the female-side locating hole 13. Figure 7A That is the ideal state. Figure 7B This is a less than ideal state. Furthermore, for ease of understanding, in Figure 7A and Figure 7B The size of the gap between the locating pin 13p and the locating hole 13 is exaggerated in the text. For example... Figure 7A As shown, in an ideal state, the center of the positioning pin 13p and the center of the positioning hole 13 on the female side are aligned in the X-direction. The distance between the center of the positioning pin 13p and the center of the positioning hole 13 in this state is called the design displacement dY. The dimensions of the ferrule 10 are determined by considering the design displacement dY, ensuring that the fiber optic holes 12 of the two optical connectors 1 are properly positioned relative to each other. A specific example of "dimensions" is the distance of each fiber optic hole 12 relative to the orthogonal direction Y of the positioning hole 13.

[0045] However, when connecting the two optical connectors 1, sometimes the optical connectors 1 are tilted relative to each other. At this time, as... Figure 7B As shown, there is a possibility that the center of the male-side positioning pin 13p may be offset in the alignment direction X relative to the center of the female-side positioning hole 13. The magnitude of the offset in the orthogonal direction Y between the center of the positioning pin 13p and the center of the positioning hole 13 in this state is called the actual displacement ΔY. When the actual displacement ΔY differs from the designed displacement dY, the fiber optic holes 12 of the two optical connectors 1 are offset from each other. This results in an increase in optical connection loss.

[0046] Therefore, the optical connector 1 of this embodiment is configured such that the ferrule 10 can swing relative to the housing 20 while the ferrule-side contact surface 14b is in contact with the housing-side contact surface 22a. Specifically, as Figure 8 As shown, the ferrule 10 swings around the pivot axis C. Figure 8 The position of the ferrule 10 after swinging is shown by reference numeral 10'. Figure 8 The pin clamping element 40 is omitted, but the ferrule 10 can swing regardless of its presence or absence. This swinging capability of the ferrule allows for connection of the two optical connectors 1, even when temporarily separated. Figure 7B The state shown can also prevent the ferrule 10 from being fixed in this state. That is, it is possible to prevent the ferrule 10 from being fixed in this state. Figure 7B The state transition shown Figure 7A The state.

[0047] The mechanism of the above-described transfer will be explained in more detail. When at least one of the ferrule-side contact surface 14b and the housing-side contact surface 22a is a curved surface, it is possible to achieve… Figure 8 The ferrule 10 swings as shown. Conversely, when both the ferrule-side contact surface 14b and the housing-side contact surface 22a are planar, the posture of the ferrule 10 is constrained due to the contact between the two planes. More specifically, because the force applied in the alignment direction X cannot be released, the ferrule 10 cannot deflect in the orthogonal direction Y of the inclined connection end face 11. Under such constrained state, once the posture of the ferrule 10 becomes... Figure 7B If the state is such that the position of the ferrule 10 is difficult to change further.

[0048] In contrast, the ferrule 10 can swing relative to the housing 20, thereby alleviating the constraint on the posture of the ferrule 10. When connecting the two optical connectors 1, the component force f generated due to the tilt of the connection end face 11 (refer to...) Figure 6B The function is to make the ferrule 10 become Figure 7AThe state is such that, due to the presence of the "oscillating mechanism," the component force f is more reliably utilized, enabling the actual displacement ΔY to approach the design displacement dY. Therefore, the offset between the fiber optic holes 12 of the pair of optical connectors 1 is reduced. The result is a reduction in optical connection loss.

[0049] In this embodiment, the ferrule-side contact surface 14b is curved. However, the ferrule-side contact surface 14b can also be flat. In this case, if the housing-side contact surface 22a is curved, the ferrule 10 can swing relative to the housing 20. If the housing 20 can swing, the effect of reducing optical connection loss can be achieved.

[0050] As described above, the optical connector 1 of this embodiment includes a plurality of optical fibers F, ferrules 10, and a housing 20 for holding the ferrules 10. The housing 20 has a housing-side contact surface 22a. The ferrule 10 has a ferrule-side contact surface 14b, which limits the amount of protrusion of the ferrule 10 from the housing 20 by contacting the housing-side contact surface 22a. When the housing-side contact surface 22a and the ferrule-side contact surface 14b are in contact, the ferrule 10 can swing relative to the housing 20 about a swing center axis C. The swing center axis C is located at the position where the housing-side contact surface 22a contacts the ferrule-side contact surface 14b, and extends along an orthogonal direction Y that is orthogonal to both the length direction Z and the arrangement direction X.

[0051] Furthermore, a portion of the ferrule 10 in this embodiment is housed inside the housing 20 of the optical connector 1. The ferrule 10 includes: a plurality of fiber optic holes 12 for inserting a plurality of optical fibers F; two positioning holes 13; a connecting end face 11 for opening the two positioning holes 13 and the plurality of fiber optic holes 12; and a ferrule-side contact surface 14b, which limits the amount of protrusion of the ferrule 10 from the housing 20 by contacting it. Viewed from the arrangement direction X of the two positioning holes 13, the connecting end face 11 is perpendicular to an imaginary plane P (refer to...) perpendicular to the longitudinal direction Z of the plurality of fiber optic holes 12. Figure 2 The ferrule side contact surface 14b is curved.

[0052] The optical connector 1 or ferrule 10 with the above structure can reduce optical connection loss.

[0053] Alternatively, the ferrule 10 may have two clearance portions 14c, which are configured to sandwich the ferrule-side contact surface 14b in the alignment direction X. The two clearance portions 14c may also be recessed relative to the ferrule-side contact surface 14b towards the opposite side (-Z side) of the connection end face 11 in the length direction Z. In this case, when the ferrule 10 swings relative to the housing 20, a portion of the housing-side contact surface 22a can enter the clearance portion 14c. Therefore, the ferrule 10 swings more easily relative to the housing 20.

[0054] Alternatively, the ferrule 10 may also have two ferrule-side contact surfaces, including the ferrule-side contact surface 14b. The two ferrule-side contact surfaces may also be positioned at different locations in the orthogonal direction Y. In this way, by having the two ferrule-side contact surfaces abut against the housing 20 at different positions in the orthogonal direction Y, the posture of the ferrule 10 can be stabilized.

[0055] Furthermore, the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0056] use Figures 9-12 Modifications to this embodiment will be described. Figures 9-12 In this version, the pin clamping element 40 is omitted. Alternatively, the pin clamping element 40 may also be omitted.

[0057] exist Figure 9 In this example, the ferrule-side contact surface 14b is a plane, and the housing-side contact surface 22a is a curved surface. In this case, the ferrule 10 can also swing relative to the housing 20. That is, as long as either the ferrule-side contact surface 14b or the housing-side contact surface 22a is a curved surface, the ferrule 10 can swing.

[0058] exist Figure 10 In the example, a recess is formed in the first limiting portion 22 that is recessed toward the front end side (+Z side). The inner side of this recess becomes the housing side contact surface 22a.

[0059] exist Figure 11 In this example, a recess is formed in the ferrule 10 that is recessed toward the base end side (-Z side). The inner side of this recess becomes the ferrule-side contact surface 14b.

[0060] exist Figure 12 In this example, a protrusion 14P is formed on the ferrule 10. The protrusion 14P protrudes outward from the first end face 14 of the ferrule 10 in the orthogonal direction Y. The outer peripheral surface of the protrusion 14P becomes the ferrule-side contact surface 14b.

[0061] exist Figures 9-12 In any of the variations shown, the same effect as the above-described embodiments can be obtained. Figures 9-12 The diagram shows the structure on the first end face 14 side of the insert 10. However, the same structure can also be provided on the second end face 15 side. For example, Figure 12 In the example, the ferrule 10, in addition to having the protrusion 14P, may also have a second protrusion projecting outward from the second end face 15 in the orthogonal direction Y. Moreover, the outer peripheral surface of the second protrusion may also be the ferrule-side contact surface. In other words, the ferrule 10 may also have two protrusions, and the outer peripheral surfaces of the two protrusions are respectively the ferrule-side contact surfaces.

[0062] In addition, without departing from the spirit of the present invention, the constituent elements in the above embodiments can be appropriately replaced with known constituent elements. Furthermore, the above embodiments and variations can be appropriately combined.

[0063] Explanation of reference numerals in the attached figures

[0064] 1… Optical connector; 10… Ferment; 11… Connecting end face; 12… Fiber optic hole; 13… Positioning hole; 14b… Ferment side contact surface; 14c… Clearance part; 14P… Protrusion; 20… Housing; 22a… Housing side contact surface; C… Swing center axis; F… Fiber optic cable; P… Imaginary plane; X… Alignment direction; Y… Orthogonal direction; Z… Length direction.

Claims

1. An optical connector, characterized by, Possessing: a plurality of optical fibers; a ferrule having a plurality of fiber holes into which the plurality of optical fibers are inserted, two positioning holes, and a connection end surface through which the plurality of fiber holes and the two positioning holes are opened; and a housing that holds the ferrule, the connection end surface is inclined with respect to an imaginary plane that is perpendicular to a length direction of the plurality of fiber holes, as viewed from an arrangement direction in which the two positioning holes are arranged, the housing has a housing-side contact surface, the ferrule has a ferrule-side contact surface that restricts an amount by which the ferrule protrudes from the housing by coming into contact with the housing-side contact surface, the ferrule is able to swing with a swing center axis as a center with respect to the housing in a state in which the housing-side contact surface and the ferrule-side contact surface are in abutment, the swing center axis is located at a position at which the housing-side contact surface and the ferrule-side contact surface are in contact, and extends in an orthogonal direction that is orthogonal to both the length direction and the arrangement direction.

2. The optical connector according to claim 1, wherein the housing-side contact surface is a curved surface.

3. An optical ferrule, a part of which is housed inside a housing of an optical connector, characterized by, Possessing: a plurality of fiber holes into which a plurality of optical fibers are able to be inserted; two positioning holes; a connection end surface through which the two positioning holes and the plurality of fiber holes are opened; and a ferrule-side contact surface that restricts an amount by which the ferrule protrudes from the housing by coming into contact with the housing, the connection end surface is inclined with respect to an imaginary plane that is perpendicular to a length direction of the plurality of fiber holes, as viewed from an arrangement direction in which the two positioning holes are arranged, the ferrule-side contact surface is a curved surface.

4. Ferrule according to claim 3, characterized in that Having: two relief portions that are arranged so as to sandwich the ferrule-side contact surface in the arrangement direction, the two relief portions are recessed with respect to the ferrule-side contact surface toward a side opposite the connection end surface in the length direction.

5. The ferrule according to claim 3 or 4, wherein there are two ferrule-side contact surfaces including the ferrule-side contact surface, the two ferrule-side contact surfaces are arranged at mutually different positions in an orthogonal direction that is orthogonal to both the length direction and the arrangement direction.

6. Ferrule according to any of claims 3 to 5, characterized in that Possessing: a protrusion that protrudes in an orthogonal direction that is orthogonal to both the length direction and the arrangement direction, the protrusion has the ferrule-side contact surface.

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