Optical connector

Abstract

This optical connector comprises: a ferrule having a plurality of fiber holes arranged in a first direction and having a connection end face in which the plurality of fiber holes open; a support member disposed on the side opposite the connection end face with respect to the ferrule; a spring for impelling the support member towards the connection end face side; and a housing that accommodates a section of the ferrule, the support member, and the spring. When viewed from the longitudinal direction of the fiber holes, the length of the spring in the first direction is longer than the length of the spring in a second direction orthogonal to the first direction. The housing includes an accommodation hole that accommodates the spring, and the inner dimension of the accommodating hole in the second direction gradually increases towards the distal end side.

Description

Optical Connector

[0001] This application claims priority to Japanese Patent Application No. 2023-211642, filed on December 15, 2023, the contents of which are incorporated herein by reference.

[0002] In recent years, optical connectors have become increasingly miniaturized. Patent Document 1 discloses an optical connector that accommodates multiple optical fibers. Such optical connectors generally include a ferrule having multiple fiber holes into which multiple optical fibers are inserted in the longitudinal direction, a spring that biases the ferrule toward a connection target such as another connector, and a housing that accommodates a portion of the ferrule and the spring. In the optical connector disclosed in Patent Document 1, a recess is formed in the ferrule and a positioning protrusion is formed in the housing. The positioning protrusion of the housing enters the recess of the ferrule, thereby determining the position of the ferrule within the housing.

[0003] US Patent Application Publication No. 2023 / 0161116

[0004] In order to reduce optical connection loss when connecting an optical connector to a connection target, it is desirable to adjust the posture of the ferrule. As optical connectors become smaller, more precise adjustment of the posture of the ferrule is required. For example, it is conceivable to adjust the posture of the ferrule by providing a gap between the housing and the ferrule and allowing the ferrule to swing relative to the housing within the range of this gap. However, in this case, depending on the size of the gap between the housing and the spring, it may be difficult to adjust the posture of the ferrule.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an optical connector in which a ferrule can be connected in an appropriate position to a connection target.

[0006] An optical connector according to aspect 1 of the present invention comprises a ferrule having a plurality of fiber holes arranged in a first direction and a connection end face into which the plurality of fiber holes open, a support member arranged on the opposite side of the ferrule from the connection end face, a spring that biases the support member toward the connection end face, and a housing that accommodates a portion of the ferrule, the support member, and the spring, wherein, when viewed from the longitudinal direction of the fiber holes, the length of the spring in the first direction is longer than the length of the spring in a second direction perpendicular to the first direction, and the housing has an accommodating hole that accommodates the spring, and when the connection end face side in the longitudinal direction is the tip side, the inner dimension of the accommodating hole in the second direction increases toward the tip side.

[0007] In addition, aspect 2 of the present invention is an optical connector of aspect 1, wherein the ferrule has a recess, the housing has a positioning protrusion that enters the recess, and the size of the gap between the tip of the spring and the inner surface of the accommodating hole in the second direction is larger than the size of the gap between the positioning protrusion and the recess in the second direction.

[0008] Furthermore, in aspect 3 of the present invention, in the optical connector of aspect 1 or 2, the accommodating hole has a pair of side surfaces facing the second direction, and the pair of side surfaces are inclined so that the inner dimensions of the accommodating hole in the second direction increase toward the tip side.

[0009] A fourth aspect of the present invention is the optical connector of the third aspect, wherein the inner surface of the accommodation hole is inclined over the entire circumference so that the inner dimension of the accommodation hole increases toward the tip side.

[0010] According to the above aspects of the present invention, it is possible to provide an optical connector in which a ferrule can be connected in an appropriate position to a connection target.

[0011] Fig. 3 is a perspective view of an optical connector according to an embodiment. Fig. 4 is a cross-sectional view of the tip of the optical connector according to an embodiment, taken along a direction perpendicular to the first direction. Fig. 5 is a cross-sectional view of the tip of the optical connector according to an embodiment, taken along a direction perpendicular to the second direction. Fig. 6 is a cross-sectional view taken along line IV-IV shown in Fig. 2. Fig. 7 is a view of the optical connector according to an embodiment, seen from the tip side.

[0012] An optical connector according to one embodiment will now be described with reference to the drawings. As shown in Figures 1 and 2, the optical connector 1 includes a ferrule 10, a pin clamp 20 (support member), a spring 30, a housing 40, a boot 50, and a plurality of optical fibers F. The ferrule 10 has two rows (hereinafter referred to as fiber rows) in which a plurality of fiber holes 11 are arranged. The plurality of fiber holes 11 may be arranged in a single row, or in three or more rows.

[0013] The ferrule 10 has a connection end face 10a. Fiber holes 11 are opened in the connection end face 10a. An optical fiber F is inserted into each of the fiber holes 11. However, it is not necessary for an optical fiber F to be inserted into some of the fiber holes 11. In other words, the number of optical fibers F may be less than the number of fiber holes 11. The optical fibers F are exposed at the connection end face 10a. The connection end face of another connector to be connected can be abutted against the connection end face 10a, thereby optically connecting the optical connector 1 to the other connector.

[0014] (Directional Definition) In this specification, the direction in which the multiple fiber holes 11 extend is referred to as the longitudinal direction Z. The side of the connection end face 10a in the longitudinal direction Z (+Z side) is referred to as the front or tip side. The opposite side (-Z side) is referred to as the rear or base side. The direction in which the multiple fiber holes 11 are arranged in the fiber row is referred to as the first direction X. The first direction X is orthogonal to the longitudinal direction Z. One side in the first direction X is referred to as the +X side, and the other side is referred to as the -X side. The direction orthogonal to both the first direction X and the longitudinal direction Z is referred to as the second direction Y. One side in the second direction Y is referred to as the +Y side, and the other side is referred to as the -Y side. Figure 2 is a cross-sectional view of the tip of the optical connector 1 taken along a direction orthogonal to the first direction X, and Figure 3 is a cross-sectional view of the tip of the optical connector 1 taken along a direction orthogonal to the second direction Y. Note that the optical fiber F is not shown in Figure 3.

[0015] The ferrule 10 has a connecting end face 10a, a plurality of fiber holes 11, and two positioning holes 12. The positioning holes 12 open to the connecting end face 10a and penetrate the ferrule 10 in the longitudinal direction Z. The two positioning holes 12 are spaced apart in the first direction X. The two positioning holes 12 are arranged so as to sandwich the plurality of fiber holes 11 between them in the first direction X. As shown in FIG. 3 , a guide pin 21 of a pin clamp 20 is inserted into the positioning hole 12 from the base end side. The optical connector 1 of this embodiment is a female connector, and the relative positions of the optical connector 1 and the other connector are determined by inserting a positioning pin of the other connector into the positioning hole 12. However, the optical connector 1 may be a male connector. In other words, the optical connector 1 may have a positioning pin.

[0016] The optical fibers F are inserted through the fiber holes 11 and extend from the ferrule 10 toward the base end. As shown in Fig. 2, the optical fibers F are inserted inside the spring 30. The optical fibers F are also inserted inside the boot 50.

[0017] The pin clamp 20 is disposed between the spring 30 and the ferrule 10 in the longitudinal direction Z. The pin clamp 20 is disposed on the opposite side of the ferrule 10 from the connection end face 10a. The pin clamp 20 contacts the base end of the ferrule 10 and holds the ferrule 10. The pin clamp 20 serves to transmit the biasing force of the spring 30 to the ferrule 10.

[0018] The housing 40 has a distal end member 41 and a proximal end member 42. These two members 41, 42 are combined to form the housing 40. However, the housing 40 may be a single member. A portion of the ferrule 10, the pin clamp 20, and the spring 30 are housed inside the housing 40. The distal end (the end on the +Z side) of the ferrule 10 protrudes from the housing 40.

[0019] The spring 30 serves to bias the ferrule 10 toward the distal end. The spring 30 is, for example, a coil spring. The proximal member 42 has a support surface 42a (see FIG. 3 ) facing forward. The proximal end of the spring 30 contacts the support surface 42a. The distal end of the spring 30 contacts the pin clamp 20. The spring 30 is compressed between the pin clamp 20 and the support surface 42a of the proximal member 42.

[0020] 4, the spring 30 of this embodiment is substantially elliptical when viewed in the longitudinal direction Z. Specifically, when viewed in the longitudinal direction Z, the length L1 of the spring 30 in the first direction X is longer than the length L2 of the spring 30 in the second direction Y. The term "substantially elliptical" does not necessarily mean that the shape of the spring 30 is elliptical, but also includes, for example, a case in which the shape of the spring 30 is composed of a pair of straight portions and curved portions connecting the ends of the pair of straight portions, such as a track in a sports stadium, as in the example shown in the figure.

[0021] 2 to 4, an accommodation hole 43 for accommodating the spring 30 is formed inside the housing 40. The accommodation hole 43 is provided across the distal end side member 41 and the proximal end side member .

[0022] As shown in FIG. 2 , the accommodation hole 43 has a pair of first side surfaces 43a (side surfaces) facing the second direction Y. The pair of first side surfaces 43a are part of the inner surface of the accommodation hole 43. The pair of first side surfaces 43a are inclined so as to move away from each other toward the tip side. In this embodiment, the angle formed by the pair of first side surfaces 43a is, for example, 2°. However, this angle may be changed as appropriate. In other words, the inner dimension of the accommodation hole 43 in the second direction Y increases toward the tip side.

[0023] With the above configuration, the size G1 (see FIG. 4 ) of the gap between the tip end of the spring 30 and the first side surface 43 a in the second direction Y is larger than the size of the gap between the base end of the spring 30 and the first side surface 43 a in the second direction Y. Because the gap between the housing 40 and the spring 30 is small at the base end of the spring 30, the position of the spring 30 relative to the housing 40 is determined with greater precision. In contrast, because the gap between the housing 40 and the spring 30 is large at the tip end of the spring 30, the tip end of the spring 30 can move relative to the housing 40 in the second direction Y. Therefore, the spring 30 can be tilted with respect to the longitudinal direction Z.

[0024] In this embodiment, the inner surface of the accommodating hole 43 is inclined around the entire circumference so that the inner dimension of the accommodating hole 43 increases toward the tip side. For example, as shown in Fig. 3, the accommodating hole 43 has a pair of second side surfaces 43b facing the first direction X as the inner surface of the accommodating hole 43. The pair of second side surfaces 43b are inclined so as to move away from each other toward the tip side. In other words, the inner dimension of the accommodating hole 43 in the first direction X increases toward the tip side.

[0025] 5, the ferrule 10 has a first end face 14 and a second end face 15 facing the second direction Y. A first recess 14a (recess) is formed in the first end face 14, and a second recess 15a is formed in the second end face 15. The first recess 14a and the second recess 15a are recessed inward in the second direction Y from the first end face 14 and the second end face 15, respectively.

[0026] A first protrusion 44 (positioning protrusion) and a second protrusion 45 are formed on the tip of the tip side member 41. The first protrusion 44 and the second protrusion 45 each protrude inward in the second direction Y from the pair of second side surfaces 43b.

[0027] The first protrusion 44 extends into the first recess 14a, and the second protrusion 45 extends into the second recess 15a. This structure defines the positional relationship of the ferrule 10 in the first direction X and the second direction Y within the housing 40. Furthermore, in the second direction Y, a gap exists between the first protrusion 44 and the first recess 14a, or between the second protrusion 45 and the second recess 15a. The ferrule 10 can swing in the second direction Y relative to the housing 40 within the range of this gap. That is, the ferrule 10 is held in a floating state so as to be swingable in the second direction Y relative to the housing 40. Note that, in the present embodiment, a gap also exists in the first direction X between the first protrusion 44 and the first recess 14a, and between the second protrusion 45 and the second recess 15a. The ferrule 10 can swing in the first direction X relative to the housing 40 within the range of this gap.

[0028] The size of the gap between the first protrusion 44 and the first recess 14a in the second direction Y is referred to as G2. The size G1 of the gap between the tip end of the spring 30 and the first side surface 43a in the second direction Y (see FIG. 4) is larger than the size G2 of the gap between the first protrusion 44 and the first recess 14a in the second direction Y. Note that while FIG. 5 shows a state in which the ferrule 10 is swung in the -Y side, when the ferrule 10 is swung in the +Y side, the size of the gap between the second protrusion 45 and the second recess 15a in the second direction Y is G2. When the difference between the distance in the second direction Y between a pair of first side surfaces 43a at the tip of the spring 30 (the inner dimension of the accommodating hole 43 in the second direction Y) and the length L2 of the spring 30 in the second direction Y is defined as the first difference, and the difference between the distance in the second direction Y between the first protrusion 44 and the second protrusion 45 and the distance in the second direction Y between the first recess 14a and the second recess 15a is defined as the second difference, the first difference is greater than the second difference.

[0029] Here, it is desirable to adjust the posture of the ferrule 10 in order to reduce the optical connection loss when connecting the optical connector 1 to a connection target. In this embodiment, gaps are provided between the protrusions 44, 45 and the recesses 14a, 15a, and the posture of the ferrule 10 can be adjusted by swinging the ferrule 10 relative to the housing 40 within the range of these gaps. Here, in order to swing the ferrule 10, it is necessary to tilt the spring 30 with respect to the longitudinal direction Z. However, for example, if the gap between the spring and the housing receiving hole is small, the tilt of the spring is limited. In this case, the swing of the ferrule is also limited, making it difficult to adjust the posture of the ferrule.

[0030] In this embodiment, the inner dimensions of the accommodation hole 43 in the second direction Y increase toward the tip. Therefore, compared to when the inner dimensions of the accommodation hole in the second direction Y are constant along the longitudinal direction Z, the inclination of the spring 30 can be increased, thereby increasing the amount of swing (floating amount) of the ferrule 10 relative to the housing 40. This allows the orientation of the ferrule 10 to be appropriately adjusted, enabling the ferrule 10 to be connected to a connection target in an appropriate orientation. As a result, optical connection loss can be reduced. In the example shown in FIG. 2 , the spring 30 is inclined toward the +Y side toward the tip, and the ferrule 10 swings toward the -Y side relative to the housing 40. In one example, when the inner dimensions of the accommodation hole are constant along the longitudinal direction Z, the maximum inclination angle of the ferrule relative to the longitudinal direction Z when viewed from the first direction X is, for example, 1.65°. In the present embodiment, when the inner dimensions of the accommodating hole 43 increase toward the tip side, the maximum inclination angle of the ferrule 10 relative to the longitudinal direction Z when viewed from the first direction X can be increased to, for example, 2.57°.

[0031] As described above, the optical connector 1 according to this embodiment includes a ferrule 10 having a plurality of fiber holes 11 aligned in a first direction X and a connecting end face 10a through which the plurality of fiber holes 11 open; a pin clamp 20 disposed on the opposite side of the ferrule 10 from the connecting end face 10a; a spring 30 that biases the pin clamp 20 toward the connecting end face 10a; and a housing 40 that accommodates a portion of the ferrule 10, the pin clamp 20, and the spring 30. When viewed from the longitudinal direction Z, the length L1 of the spring 30 in the first direction X is longer than the length L2 of the spring 30 in the second direction Y. The housing 40 has a receiving hole 43 that accommodates the spring 30. The inner dimension of the receiving hole 43 in the second direction Y increases toward the tip. This configuration allows the orientation of the ferrule 10 to be appropriately adjusted, enabling the ferrule 10 to be connected to a connecting target in an appropriate orientation.

[0032] The ferrule 10 has a first recess 14a, and the housing 40 has a first protrusion 44 that enters the first recess 14a. The size G1 of the gap between the tip of the spring 30 and the inner surface of the accommodating hole 43 in the second direction Y is larger than the size G2 of the gap between the first protrusion 44 and the first recess 14a in the second direction Y. With this configuration, the first recess 14a and the first protrusion 44 can determine the positional relationship of the ferrule 10 within the housing 40. Furthermore, because the size G1 of the gap between the tip of the spring 30 and the inner surface of the accommodating hole 43 in the second direction Y is larger than the size G2 of the gap between the first protrusion 44 and the first recess 14a in the second direction Y, the ferrule 10 can be more easily swung in the second direction Y, and the posture of the ferrule 10 can be more appropriately adjusted.

[0033] The accommodation hole 43 has a pair of first side surfaces 43a facing the second direction Y, and the pair of first side surfaces 43a are inclined so that the inner dimension of the accommodation hole 43 in the second direction Y increases toward the tip side. This configuration makes it easier to swing the ferrule 10 in the second direction Y, and allows the posture of the ferrule 10 to be more appropriately adjusted.

[0034] The inner surface of the accommodation hole 43 is inclined all around so that the inner dimension of the accommodation hole 43 increases toward the tip side. This configuration makes it easier to swing the ferrule 10 in a direction perpendicular to the longitudinal direction Z, and allows the posture of the ferrule 10 to be more appropriately adjusted.

[0035] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0036] For example, the accommodating hole 43 may be formed so that the inner dimensions of the accommodating hole 43 increase toward the tip side, and for example, the inner surface of the accommodating hole 43 may have a step rather than being inclined.

[0037] Furthermore, the second recess 15a may be omitted from the ferrule 10, and the second protrusion 45 may be omitted from the housing 40 (tip side member 41). That is, the ferrule 10 may have only the first recess 14a, and the housing 40 (tip side member 41) may have only the first protrusion 44. Even in this case, the positional relationship of the ferrule 10 within the housing 40 can be determined by the first recess 14a and the first protrusion 44.

[0038] In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate, without departing from the spirit of the present invention.

[0039] REFERENCE SIGNS LIST 1...optical connector 10...ferrule 10a...connection end face 11...fiber hole 14a...first recess (recess) 15a...second recess 20...pin clamp (support member) 30...spring 40...housing 43...accommodating hole 43a...first side surface (side surface) 43b...second side surface 44...first protrusion (positioning protrusion) 45...second protrusion F...optical fiber X...first direction Y...second direction Z...longitudinal direction

Claims

1. An optical connector comprising: a ferrule having a plurality of fiber holes aligned in a first direction and a connection end face into which the plurality of fiber holes open; a support member arranged on the side of the ferrule opposite the connection end face; a spring that urges the support member toward the connection end face; and a housing that accommodates a part of the ferrule, the support member, and the spring, wherein, when viewed in the longitudinal direction of the fiber holes, the length of the spring in the first direction is longer than the length of the spring in a second direction perpendicular to the first direction, the housing has an accommodating hole that accommodates the spring, and when the connection end face side in the longitudinal direction is the tip side, the inner dimension of the accommodating hole in the second direction becomes larger toward the tip side.

2. An optical connector as described in claim 1, wherein the ferrule has a recess, the housing has a positioning protrusion that enters the recess, and the size of the gap between the tip of the spring and the inner surface of the accommodating hole in the second direction is larger than the size of the gap between the positioning protrusion and the recess in the second direction.

3. An optical connector as described in claim 1 or 2, wherein the accommodating hole has a pair of side surfaces facing the second direction, and the pair of side surfaces are inclined so that the inner dimension of the accommodating hole in the second direction increases toward the tip side.

4. The optical connector according to claim 3, wherein the inner surface of the accommodating hole is inclined all around so that the inner dimension of the accommodating hole increases toward the tip side.

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