Optical connector

Abstract

A housing (20) has a positioning part (20A, 20B) that defines the storage position of a ferrule assembly (100), the positioning part (20A, 20B) has an inclined surface with which a portion of the ferrule assembly (100) is brought into contact, and the ferrule assembly (100) includes a ferrule (110), a sleeve (120), and a flange (130). The sleeve (120) has a protruding part (121), and the flange (130) is provided between the positioning part (20A, 20B) and the protruding part (121) of the sleeve (120), and has a flange front surface (130a) including an edge (135) that is brought into contact with the inclined surface of the positioning part (20A, 20B), and a flange back surface (130b) that is brought into contact with or brought close to the protruding part (121) of the sleeve (120).

Description

Technical Field

[0001] The present disclosure relates to an optical connector. The present application claims priority based on Japanese Patent Application No. 2021-112954 filed on July 7, 2021, relies on the content thereof, and is incorporated herein by reference in its entirety.

Background Art

[0002] A single-core optical connector attached to the distal end of an optical fiber such as a multi-core optical fiber (hereinafter referred to as "MCF") or a polarization-maintaining optical fiber (hereinafter referred to as "PMF") is provided with a structure for maintaining the alignment state of the optical fiber with respect to the optical connector. For example, according to the push-pull optical connector disclosed in the following Patent Document 1 and Non-Patent Document 1, a ferrule assembly fixed to the distal end of an optical fiber with the distal end inserted therein is housed in a housing, and a structure is adopted in which a flange constituting a part of the ferrule assembly is pressed against a positioning portion provided on the inner wall surface of the housing using a spring material. In the push-pull optical connector having such a structure, the fluctuation of the housing position of the ferrule assembly housed in the housing in the housing is suppressed by the elastic force (restoring force) of the spring material, and the azimuth fluctuation around the fiber axis (the central axis of the optical fiber to which the ferrule assembly is fixed) is suppressed (maintenance of the aligned state).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

[0005] The optical connector disclosed herein comprises an optical fiber, a ferrule assembly attached to the tip of the optical fiber, and a housing. The housing has an inner wall surface that defines a space for housing the ferrule assembly, and a positioning portion provided on the inner wall surface. This positioning portion defines the housing position of the ferrule assembly and has an inclined surface that is inclined with respect to the central axis of the tip of the optical fiber and against which a part of the ferrule assembly abuts. The ferrule assembly also includes a ferrule, a sleeve, and a flange. The ferrule is attached to the tip of the optical fiber, including the end face. The sleeve has a front end face and a rear end face that face each other, a sleeve through-hole, and a projection. The sleeve through-hole connects the front end face and the rear end face, and a part of the ferrule is inserted from the front end face side with the optical fiber passing through it. The projection of the sleeve extends from the central axis of the sleeve through-hole toward the inner wall surface of the housing and has a projection front face located on the front end face side and a projection rear face located on the rear end face side. The flange is positioned between the positioning portion of the housing and the projection of the sleeve, and has a flange through-hole through which the sleeve is inserted, a front flange surface, and a rear flange surface. The front flange surface includes a rim that abuts against the inclined surface of the positioning portion of the housing. The rear flange surface abuts against or is close to the front surface of the projection. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 shows the structure of the main components of the optical connector in this disclosure. [Figure 2] Figure 2 is a diagram illustrating the various assembly processes (including alignment) of a ferrule assembly. [Figure 3] Figure 3 shows the internal structure of the optical connector in the present disclosure. [Figure 4] Figure 4 shows a modified example of the internal structure of the optical connector in the present disclosure. [Figure 5] Figure 5 is a diagram illustrating the technical effects of the optical connector of this disclosure, along with comparative examples. [Modes for carrying out the invention]

[0007] [Issues this disclosure aims to address] The inventors, after examining the above-mentioned prior art, discovered the following problems. For example, the ferrule assembly disclosed in Patent Document 1 comprises a ferrule fixed to the tip of an optical fiber, a sleeve into which the ferrule is inserted at an opening on the front end face, and a flange attached to the sleeve. Patent Document 1 discloses a structure in which a projection is provided on the outer surface of the sleeve to prevent the flange from moving toward the ferrule. In a push-pull type optical connector, the flange of the ferrule assembly having the above-described structure is pressed against a positioning portion provided on the inner wall of the housing by a spring material housed in the rear of the housing. Therefore, with a push-pull type optical connector, the ferrule assembly is positioned in a predetermined position relative to the housing, and at the same time, the alignment of the optical fiber is fixed relative to the optical connector.

[0008] However, in the push-pull type optical connector disclosed in Patent Document 1, the elastic force of the spring material is applied directly to the flange that contacts the positioning portion of the housing, and the sleeve into which the ferrule is inserted is held only by the flange. Therefore, if the optical connector is repeatedly attached and detached, the relative positional relationship between the flange and the sleeve may change.

[0009] This disclosure was made to solve the problems described above, and aims to provide an optical connector equipped with a structure for suppressing changes in the relative positional relationship between the sleeve and flange caused by the attachment and detachment of the optical connector.

[0010] [Effects of this disclosure] According to the optical connector disclosed herein, fluctuations in the relative position and relative angle between the sleeve and flange caused by attaching and detaching the optical connector can be suppressed.

[0011] [Description of Embodiments in this Disclosure] First, the contents of each embodiment of this disclosure will be listed and described individually.

[0012] (1) In one embodiment, an optical connector of the present disclosure comprises an optical fiber, a ferrule assembly attached to the tip portion of the optical fiber, and a housing. The housing has an inner wall surface that defines a space for housing the ferrule assembly, and a positioning portion provided on the inner wall surface. This positioning portion is a portion that defines the housing position of the ferrule assembly and has an inclined surface that is inclined with respect to the central axis of the tip portion of the optical fiber and against which a part of the ferrule assembly abuts. The ferrule assembly also includes a ferrule, a sleeve, and a flange. The ferrule is attached to the tip portion including the end face of the optical fiber. The sleeve has a front end face and a rear end face that face each other, a sleeve through hole, and a projection. The sleeve through hole connects the front end face and the rear end face, and a part of the ferrule is inserted from the side of the front end face. There are no particular structural restrictions on the timing of attaching the ferrule to the tip portion of the optical fiber. For example, the ferrule may be attached to the tip portion including the end face of the optical fiber introduced into the sleeve through hole with a part of it inserted into the sleeve through hole. Alternatively, the ferrule may be pre-attached to the tip of the optical fiber (which has already passed through the sleeve through-hole), with a portion of it inserted into the sleeve through-hole. The projection of the sleeve extends from the central axis of the sleeve through-hole toward the inner wall surface of the housing and has a front projection surface located on the front end face side and a rear projection surface located on the rear end face side. The flange is installed between the positioning portion of the housing and the projection of the sleeve and has a flange through-hole through which the sleeve is inserted, a flange front surface, and a flange rear surface. The flange front surface includes a rim that abuts against the inclined surface of the positioning portion of the housing. The flange rear surface abuts against or is close to the projection front surface. In this specification, the state in which the flange rear surface is "close to" the projection front surface means a non-contact state between the flange rear surface and the projection front surface, as defined when the sleeve is inserted through the flange through-hole, in which case the flange rear surface and the projection front surface face each other directly without any obstruction.

[0013] In conventional optical connectors, fluctuations in the relative positional relationship between the flange and the sleeve occurred. However, in the optical connector of the present disclosure, a flange is disposed between the positioning portion of the housing and the protruding portion of the sleeve. In such a structure, the protruding portion of the sleeve directly receives the elastic force of an elastic body such as a spring material or a rubber material, and functions to press the flange against the positioning portion of the housing. In this case, since the protruding portion of the sleeve functions to press the flange against the positioning portion of the housing, fluctuations in the relative positional relationship between the flange and the sleeve are less likely to occur.

[0014] (2) As one aspect of the present disclosure, the optical connector may further include an elastic body that abuts against the rear surface of the protruding portion and presses the edge of the front surface of the flange against the inclined surface of the positioning portion via the protruding portion. In this case, the elastic body is preferably made of a material having elastic force such as a spring material or a rubber material. This enables implementation of a push-pull type optical connector that stably fixes the installation position of the ferrule assembly in the housing using the elastic body.

[0015] (3) As one aspect of the present disclosure, the optical fiber preferably includes a multi-core optical fiber or a polarization-maintaining optical fiber as an optical fiber that requires alignment with respect to an orientation centered on its central axis (fiber axis). As described above, the configuration of the ferrule assembly and the positioning portion in the optical connector of the present disclosure can maintain a favorable alignment state of the optical fiber.

[0016] As described above, each aspect listed in the section [Description of Embodiments of the Present Disclosure] is applicable to each of all the remaining aspects, or to any combination of all these remaining aspects.

[0017] [Detailed Description of Embodiments of the Present Disclosure] Hereinafter, a specific structure of the optical connector according to the present disclosure will be described in detail with reference to the accompanying drawings. The present invention is not limited to these exemplifications, but is defined by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

[0018] FIG. 1 is a diagram showing the structure of a main part of the optical connector of the present disclosure (in FIG. 1, the description "Connector appearance and stored components" is given). Specifically, in the topmost row (in FIG. 1, the description "Single-core connector" is given), an example of the appearance of a push-pull type optical connector 10 is shown as an example of the optical connector of the present disclosure. In the second row (in FIG. 1, the description "Ferrule assembly" is given), the structure of a ferrule assembly 100 installed inside the optical connector 10 is shown. In the third row (in FIG. 1, the description "Front of connector (MCF application example)" is given), a front view of the optical connector 10 including an end face of an MCF 50A (multi-core optical fiber) is shown as an example of an optical fiber 50 (an optical fiber requiring alignment) to which a ferrule 110 is attached. In the bottommost row (in FIG. 1, the description "Front of connector (PMF application example)" is given), a front view of the optical connector 10 including an end face of a PMF 50B (polarization-maintaining optical fiber) is shown as another example of the optical fiber 50 to which a ferrule 110 is attached.

[0019] The housing of the optical connector 10 shown in the topmost row of FIG. 1 is composed of a front housing 20 and a rear housing 30. A ferrule assembly 100 including a ferrule 110 and a spring member for stably maintaining the storage position of the ferrule assembly 100 are stored in the housing. A ferrule 110 is attached to a tip portion including an end face (glass fiber 51 from which a resin coating has been removed) of the optical fiber 50, and a boot 40 is attached to the rear housing 30 to protect the optical fiber 50 extending from the rear housing 30.

[0020] The ferrule assembly 100 shown in the second row of Figure 1 is housed in a housing composed of a front housing 20 and a rear housing 30, and includes a ferrule 110, a sleeve 120, and a flange 130. The optical fiber 50 comprises a glass fiber 51 and a resin coating provided on the outer surface of the glass fiber 51, with the resin coating covering the tip portion, including the end face, of the optical fiber 50 removed. The ferrule 110 is attached to the tip portion of the optical fiber 50 from which the resin coating has been removed via an adhesive (e.g., thermosetting resin or UV-curing resin). The sleeve 120 has a front end face 120a and a rear end face 120b facing each other, a through hole (sleeve through hole), and a projection 121 extending from the central axis of the sleeve through hole toward the inner wall surface of the housing. The through hole of the sleeve 120 connects the front end face 120a and the rear end face 120b, and a portion of the ferrule 110 is inserted from the front end face side with the optical fiber 50 passing through it. The optical fiber 50 may be inserted into the ferrule 110 after the rear portion of the ferrule 110 has been press-fitted into the front end face of the through-hole of the sleeve 120. The projection 121 of the sleeve 120 has a front surface 121a (front surface of the projection) and a rear surface 121b (rear surface of the projection). The front surface 121a of the projection 121 is located on the side of the front end face 120a of the sleeve 120. The rear surface 121b of the projection 121 is located on the side of the rear end face 120b. The flange 130 is installed between the positioning portion of the housing and the projection 121 of the sleeve 120 and has a through-hole 131 (flange through-hole), a front surface 130a (flange front surface), a rear surface 130b (flange rear surface), and an outer peripheral surface. The front surface 130a of the flange 130 includes a rim 135 that abuts against the inclined surface of the positioning portion of the housing. If the boundary between the front surface 130a and the outer surface is chamfered, the "edge" includes the chamfered portion, and a part of the "edge" including the chamfered portion abuts against the inclined surface of the positioning portion of the housing. The rear surface 130b of the flange 130 abuts against or is close to the front surface 121a of the projection 121.The state in which the rear surface 130b of the flange 130 is close to the front surface 121a of the projection 121 is defined as a non-contact state between the rear surface 130b of the flange 130 and the front surface 121a of the projection 121, when the sleeve 120 is inserted through the through hole 131 of the flange 130.

[0021] The front view of the optical connector 10 shown in the third row of Figure 1 (connector front view (MCF application example)) shows the end face of the MCF50A as the optical fiber 50 that requires alignment, a ferrule 110 attached to the tip portion (glass fiber 51A) of the MCF50A, a sleeve 120 into which the ferrule 110 is inserted, and a flange 130. The MCF50A comprises a plurality of cores 52A each extending along the fiber axis AX (central axis of the MCF50A), and a common cladding 53A surrounding each of these plurality of cores 52A. A This indicates the reference direction (direction with a rotation angle of 0°) for the rotational alignment of the MCF50A, and line L R L is the reference line for the installation of the ferrule assembly 100, along the edge 135 of the flange 130. In the ferrule assembly 100, including the MCF50A after alignment, the reference direction line L is indicated. A and the installation reference line L R They are parallel.

[0022] The front view of the optical connector 10 shown at the bottom of Figure 1 (connector front view (PMF application example)) shows the end face of the PMF50B as the optical fiber 50 that requires alignment, the ferrule 110 attached to the tip portion (glass fiber 51B) of the PMF50B, the sleeve 120 into which the ferrule 110 is inserted, and the flange 130. The PMF50B is aligned along the fiber axis AX (the central axis of the PMF50B) stretch The ferrule assembly 100 includes a core 52B, stress-applying sections 54 positioned to sandwich the core 52B, and a common cladding 53B surrounding the core 52B and the stress-applying sections 54, respectively. In the ferrule assembly 100 including the PMF 50B after alignment, a line L indicates the reference orientation. A and the installation reference line L R They are parallel.

[0023] Figure 2 is a diagram illustrating various assembly processes (including alignment) of a ferrule assembly (indicated as "Ferrule Assembly Assembly Process" in Figure 2). Specifically, the upper diagram (indicated as "Type 1" in Figure 2) illustrates a method for aligning the optical fiber 50 with a pre-assembled ferrule assembly 100. The middle diagram (indicated as "Type 2" in Figure 2) illustrates a method for assembling the ferrule assembly 100 by aligning the optical fiber 50, with a ferrule 110 attached to its tip, with a flange 130 integrated with a sleeve 120. The lower diagram (indicated as "Type 3" in Figure 2) illustrates a method for assembling the ferrule assembly 100 by aligning the optical fiber 50, with a ferrule 110 and sleeve 120 attached to its tip, with the flange 130.

[0024] In "Type 1" shown in the upper part of Figure 2, a structure that will become the ferrule assembly 100 is assembled before it is attached to the tip portion (glass fiber 51) of the optical fiber 50. As described above, the ferrule assembly 100 consists of a ferrule 110, a sleeve 120 having a front end face 120a, a rear end face 120b and a projection 121, and a flange 130 having a front face 130a and a rear face 130b. The front portion of the sleeve 120 (the section between the front end face 120a and the projection 121) passes through the through hole 131 of the flange 130, and the projection 121 of the sleeve 120 has a front face 121a and a rear face 121b. The front face 121a of the projection 121 abuts against or is close to the rear face 130b of the flange 130, and the rear face 121b of the projection 121 abuts against a spring material. The alignment of the optical fiber 50 is performed by rotating the optical fiber 50 by a predetermined angle in the direction indicated by arrow S1 relative to the ferrule assembly 100. Once the alignment of the optical fiber 50 is complete, the ferrule 110 of the already assembled ferrule assembly 100 is attached to the tip of the aligned optical fiber 50. The front view of the ferrule assembly 100 attached to the aligned optical fiber 50 matches the front view shown in the third and bottom rows of Figure 1.

[0025] In "Type 2," shown in the middle section of Figure 2, the optical fiber 50 is aligned with a structure (sleeve member) consisting of an already assembled sleeve 120 and flange 130, with the ferrule 110 attached to the tip portion (glass fiber 51) of the optical fiber 50. During alignment, the optical fiber 50 remains in a state where it has passed through the through-hole of the sleeve member. Once the alignment is complete, one end of the ferrule 110 attached to the tip portion of the optical fiber 50 is inserted into the through-hole of the sleeve 120 from the side of the front end face 120a of the sleeve 120. The front view of the ferrule assembly 100 attached to the optical fiber 50 after alignment matches the front view shown in the third and bottom sections of Figure 1.

[0026] Furthermore, in "Type 3" shown in the lower part of Figure 2, a structure consisting of a ferrule 110 and a sleeve 120 is attached to the tip portion (glass fiber 51) of the optical fiber 50 and integrated with it, and the optical fiber 50 is aligned with the flange 130 (rotation of the optical fiber 50 along the direction indicated by arrow S1). Once the alignment is complete, the ferrule 110 side (the front portion of the sleeve 120) of the structure (ferrule 110 and sleeve 120) attached to the tip portion of the optical fiber 50 is inserted into the through hole 131 of the flange 130 toward the position of the projection 121. As a result, the rear surface 130b of the flange 130 and the front surface 121a of the projection 121 come into contact or are close to each other. The front view of the ferrule assembly 100 attached to the optical fiber 50 after alignment matches the front view shown in the third and bottom rows of Figure 1.

[0027] Figure 3 shows the internal structure of the optical connector of the present disclosure (referred to as "internal connector structure" in Figure 3). Specifically, the upper section (referred to as "cross-sectional structure" in Figure 3) is a cross-sectional view of the optical connector 10 along line II shown in the uppermost section of Figure 1. The lower section (referred to as "ferrule assembly structure" in Figure 3) is a diagram illustrating the details of the assembly process (Type 3) of the ferrule assembly 100. Figure 4 shows a modified example of the internal structure of the optical connector of the present disclosure (referred to as "modified example of connector internal structure" in Figure 4), with the upper section of Figure 4 (referred to as "upper positioning structure" in Figure 4) and the lower section of Figure 4 (referred to as "lower positioning structure" in Figure 4) corresponding to cross-sectional views of the optical connector 10 along line II shown in the uppermost section of Figure 1.

[0028] As shown in the upper part of Figure 3, the optical connector 10 has a housing for stably housing a ferrule assembly 100 attached to the tip of an optical fiber 50. This housing consists of a front housing 20 and a rear housing 30 fitted into the front housing 20. The tip of a ferrule 110, which constitutes part of the ferrule assembly 100, protrudes from the front opening of the front housing 20. The inner wall surface of the front housing 20 is provided with positioning portions 20A and 20B, which have inclined surfaces against which the edge 135 of the flange 130 of the housed ferrule assembly 100 abuts. Note that the part that functions as a positioning portion may be only the positioning portion 20A (see "upper positioning structure" shown in the upper part of Figure 4) or only the positioning portion 20B (see "lower positioning structure" shown in the lower part of Figure 4). If the part that functions as a positioning part is one of the positioning parts 20A and 20B, the ferrule assembly 100 is positioned by being sandwiched between the positioning part 20A or the positioning part 20B and the inner wall surface of the storage space. Meanwhile, a spring material 140 (elastic body) is housed inside the rear housing 30, and when the rear housing 30 is inserted into the front housing 20 from the rear, the spring material 140 is compressed by being sandwiched between the ferrule assembly 100 housed in the front housing 20 and the rear of the rear housing 30. A through hole for pulling out the optical fiber 50 is provided in the rear of the rear housing 30. Meanwhile, the ferrule assembly 100 receives an elastic force (restoring force of the spring material 140) from the spring material 140, and the edge 135 included in the front surface 130a of the flange 130 is pressed against the positioning parts 20A and 20B of the front housing 20. In the example shown in Figure 3, a pair of positioning parts 20A and 20B are shown, but one or more positioning parts may be provided on the inner wall surface of the front housing 20 so as to correspond to each side that defines the shape of the front surface 130a of the flange 130.

[0029] The structure of the ferrule assembly 100 is shown in the lower part of Figure 3 to show its positional relationship with the spring material 140 as an elastic body. As shown in the lower part of Figure 3, the ferrule assembly 100 includes a ferrule 110, a sleeve 120, and a flange 130. The ferrule 110 is attached to the tip portion (glass fiber 51) of the optical fiber 50 from which the resin coating has been removed. The sleeve 120 has a front end face 120a and a rear end face 120b that face each other, a through hole into which the rear part of the ferrule 110 is fitted, and a projection 121. The optical fiber 50 passes through the through hole of the sleeve 120 when the ferrule 110 is inserted. The projection 121 of the sleeve 120 extends from the central axis of the through hole of the sleeve toward the inner wall surface of the housing. The projection 121 also has a front face 121a and a rear face 121b. The front surface 121a of the projection 121 is located on the side of the front end surface 120a, pushing the flange 130 toward the positioning portions 20A and 20B. The rear surface 121b of the projection 121 is subjected to the elastic force of the spring material 140. The flange 130 has a through hole 131, a front surface 130a, and a rear surface 130b so as to be located between the positioning portions 20A and 20B of the housing and the projection 121 of the sleeve 120. The front surface 130a of the flange 130 includes a rim 135 that abuts against the inclined surface of the positioning portion 20A or 20B of the housing. The rear surface 130b of the flange 130 abuts against or is close to the front surface 121a of the projection 121.

[0030] Thus, the ferrule assembly 100 applied to the optical connector 10 of this disclosure has a structure that transmits the restoring force of the spring material 140 to the flange 130 not directly to the flange 130, but via a part of the sleeve 120 (projection 121). In other words, the ferrule assembly 100 in this embodiment has a structure in which the spring material 140 (elastic body) does not directly contact the flange 130 (a structure in which it is separated by a predetermined distance via the projection 121 of the sleeve 120). The technical effects of this structure will be explained below with reference to Figure 5.

[0031] Figure 5 is a diagram illustrating the technical effects of the optical connector of the present disclosure together with a comparative example. Specifically, the upper section (labeled "Positioning" in Figure 5) is a schematic diagram showing the state in which the spring material 140 is extended and the ferrule assembly 100 is pressed against the positioning portions 20A and 20B of the front housing 20 for both the comparative example and this embodiment. The middle section (labeled "Floating" in Figure 5) is a schematic diagram showing the state in which the ferrule assembly 100 is pushed from the front and the spring material 140 is compressed for both the comparative example and this embodiment. The lower section (labeled "Repositioning" in Figure 5) is a schematic diagram showing the state in which the spring material 140 is extended again and the ferrule assembly 100 is pressed against the positioning portions 20A and 20B of the front housing 20 for both the comparative example and this embodiment.

[0032] Note that the sleeve structure and the positional relationship between the sleeve and flange differ between the comparative example ferrule assembly shown in Figure 5 and the ferrule assembly of this embodiment. Specifically, in the comparative example ferrule assembly, the rear part of the ferrule 110 is inserted into the opening on the front end face side of the sleeve 200, and a projection 210 is provided on the outer circumferential surface of the sleeve 200 to restrict the movement of the flange 130 toward the front end face side of the ferrule 110. This projection 210 has an outer diameter such that it does not come into contact with the positioning parts 20A and 20B provided on the inner wall of the housing. On the other hand, as described above, in the ferrule assembly 100 of this embodiment, a projection 121 that receives the elastic force of the spring material 140 is provided on the sleeve 120, and the flange 130 is positioned in the section between the projection 121 of the sleeve 120 and the positioning parts 20A and 20B (the front part of the sleeve 120).

[0033] In the "positioning" shown in the upper part of Figure 5, in the case of the comparative example ferrule assembly, when the spring material 140 extends in the direction indicated by arrow S2 (in the configuration shown in the upper part of Figure 3, the rear housing 30 housing the spring material 140 is attached to the front housing 20), the spring material 140 comes into direct contact with the flange 130, and the edge 135 of the flange 130 is pressed against the positioning parts 20A and 20B. At this time, the storage position (orientation around the axis) of the ferrule assembly is positioned, but the sleeve 200 is held by the flange 130 with the projection 210 in contact with the flange 130 without receiving elastic force from the spring material 140.

[0034] On the other hand, in the case of the ferrule assembly of this embodiment, when the spring material 140 extends in the direction indicated by arrow S2, the spring material 140 comes into contact with the projection 121 of the sleeve 120, and the edge 135 of the flange 130 is pressed against the positioning parts 20A and 20B via this projection 121. This positions the ferrule assembly in its storage position.

[0035] Next, in the "floating" position shown in the middle of Figure 5, in both the comparative example and the ferrule assembly of this embodiment, when the ferrule assembly is pushed in the direction indicated by arrow S3, the positioning parts 20A and 20B separate from the flange 130, and the flange 130 and sleeve 120 become movable within the housing. In other words, the comparative example and the ferrule assembly of this embodiment shown in the middle of Figure 5 (hereinafter referred to as the "target ferrule assembly") are pressed together by connecting to another opposing ferrule assembly (in the middle of Figure 5, the tip portion of the ferrule 110 is shown by a dashed line, and hereinafter referred to as the "opposing ferrule assembly"). At this time, friction is generated when the front end faces of the ferrules 110 of both the target ferrule assembly and the opposing ferrule assembly come into contact with each other. In the target ferrule assembly, this friction causes the ferrule 110 to rotate and become fixed. On the other hand, as the spring material 140 compresses simultaneously with the pressing, a rotational force is generated, and the rotational force of the spring material 140 is transmitted to the part that the spring material 140 is in contact with. At this time, the sleeve 120 (sleeve 200) and the ferrule 110 are firmly integrated by press-fitting and bonding.

[0036] Under the above premise, in the comparative example ferrule assembly, rotational force is transmitted to the flange 130, and the relative angle of the flange 130 may change with respect to the rotatably fixed ferrule 110 (and the firmly integrated sleeve 200). In contrast, in the ferrule assembly of this embodiment, rotational force is transmitted to the projection 121 of the sleeve 120, but no force is transmitted to the flange 130. Therefore, the relative angle between the flange 130 and the ferrule 110 does not change. Furthermore, since the sleeve 120 and the ferrule 110 are firmly integrated, the relative angle does not change even if rotational force is transmitted to the projection 121 of the sleeve 120.

[0037] Furthermore, in the "repositioning" shown in the lower part of Figure 5, in the case of the comparative example ferrule assembly, when the spring material 140 extends again in the direction indicated by arrow S2, the spring material 140 presses the edge 135 of the flange 130 against the positioning parts 20A and 20B. At this time, the spring Material 140 When the flange 130 contracted, the relative positional relationship between the flange 130 and the sleeve 200 changed. As a result, in the comparative example, when the ferrule assembly was repositioned, the end face position of the ferrule 110 shifted along the fiber axis direction of the optical fiber 50.

[0038] In contrast, in the ferrule assembly of this embodiment, when the spring material 140 extends again in the direction indicated by arrow S2, the spring material 140 presses the edge 135 of the flange 130 against the positioning parts 20A and 20B via the projection 121. When the spring material 140 is compressed, the flange 130 and the sleeve 120 Since their relative positions do not change, this ensures that the ferrule assembly remains stably housed. [Explanation of Symbols]

[0039] 10… Optical connector 20…Front housing 20A, 20B... Positioning section 30... Rear housing 40... Boots 50… Fiber optic 50A…MCF (Multicore Optical Fiber) 50B…PMF (Polarization-Maintaining Optical Fiber) 51, 51A, 51B… Glass fiber 52A, 52B... Core 53A, 53B... Common cladding 54... Stress application section 100... Ferrule Assembly 110... Ferrule 120... Sleeves 120a…Front end face 120b…Rear end face 121...Protrusion 121a...Front surface (front surface of protrusion) 121b…Rear surface (rear surface of protrusion) 130…Flange 130a...Front side (front side of flange) 130b...Rear side (rear side of flange) 131…Through hole 135...heli 140... Spring material (elastic body) AX... Fiber axis (central axis) L A ...line (line indicating the reference direction) L R ...Installation reference line S1 to S3... Direction of movement or rotation.

Claims

1. Optical fiber and A ferrule assembly attached to the tip of the optical fiber, A housing for the ferrule assembly, Equipped with, The housing has an inner wall surface that defines a space for housing the ferrule assembly, and a positioning portion provided on the inner wall surface that defines the position for housing the ferrule assembly. The positioning portion has an inclined surface that is tilted with respect to the central axis of the tip portion of the optical fiber and against which a part of the ferrule assembly is in contact. The ferrule assembly is Ferrule and, A sleeve having a sleeve through-hole into which a portion of the ferrule is inserted before or after it is attached to the tip portion of the optical fiber, A flange having a flange through hole through which the sleeve is inserted, Includes, The sleeve has a front end face and a rear end face that face each other, The sleeve through-hole connects the front end face and the rear end face, and a portion of the ferrule is inserted from the front end face side with the optical fiber passing through it. The sleeve has a projection that extends from the central axis of the sleeve through hole toward the inner wall surface of the housing and has a projection having a front surface located on the side of the front end face and a projection having a rear surface located on the side of the rear end face. The flange is installed between the positioning portion of the housing and the projection of the sleeve, and has a front flange surface including a rim that abuts against the inclined surface of the positioning portion of the housing, and a rear flange surface that abuts against or is close to the front surface of the projection. Optical connector.

2. It is in contact with the rear surface of the projection, The system further includes an elastic body for pressing the edge of the front surface of the flange against the inclined surface of the positioning portion via the projection. The optical connector according to claim 1.

3. The optical fiber is a multicore optical fiber or a polarization-maintaining optical fiber. The optical connector according to claim 1 or 2.

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