JP2019128466A - Ferrule with fixed component, optical connector receptacle, and method for manufacturing ferrule with fixed component - Google Patents

Abstract

To secure the space for containing the part with an extra length of an optical fiber in the housing of an optical module by reducing the size of the ferrule with a fixed component forming an optical receptacle.SOLUTION: The drawing 3B shows the ferrule with a fixed component, including: a ferrule 23 holding an end part of an optical fiber 10; a ferrule holding unit 25 holding the ferrule; and tube 26 through which the optical fiber is inserted. The ferrule also includes a retaining part 39 into which an end part of the tube is inserted, the retaining part retaining the tube.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a ferrule with a fixed component, an optical connector receptacle, and a method for manufacturing a ferrule with a fixed component.

  In an optical module such as an optical transceiver, an optical connector receptacle (hereinafter simply referred to as an "optical receptacle") so that an optical connector plug (hereinafter sometimes simply referred to as an "optical plug") can be attached to or detached from the optical module. May be provided). In such an optical module, an optical device component including a transmitting and receiving module and the like and an optical receptacle are connected via an optical fiber.

  As an optical module having such an optical receptacle, for example, Patent Document 1 discloses an optical module in which a space for accommodating an extra length portion of an optical fiber is secured in a housing of the optical module.

JP2015-55834A

  In recent years, in an optical module as described in Patent Document 1, further downsizing of a housing is required. With the miniaturization of the casing of such an optical module, the space for accommodating the extra length portion of the optical fiber in the casing becomes smaller. If the space for accommodating the extra length portion becomes smaller, the bending radius of the optical fiber becomes smaller, and as a result, the bending loss of the optical fiber in the housing increases.

  An object of the present invention is to secure a space for accommodating an extra length portion of an optical fiber in a housing of an optical module by miniaturizing a ferrule with a fixed part that constitutes the optical receptacle.

  Some embodiments of the present invention include a ferrule that holds an end portion of an optical fiber, a ferrule holding portion that holds the ferrule, and a fixed component that includes a tube through which the optical fiber is inserted. The ferrule according to claim 1, wherein the ferrule is a ferrule with a fixed part, into which an end portion of the tube is inserted and provided with a detent portion for detaining the tube.

  Other characteristics of the present invention will be made clear by the description and drawings described later.

  According to some embodiments of the present invention, by reducing the size of the ferrule with a fixing component constituting the optical receptacle, it is possible to secure a space for accommodating the extra length portion of the optical fiber in the housing of the optical module. .

FIG. 1 is a view showing an optical module 1 provided with the optical receptacle 20 of the first embodiment. FIG. 2 is an exploded perspective view of the optical receptacle 20 of the first embodiment. FIG. 3A is a cross-sectional view of the optical receptacle 20 of the comparative example. FIG. 3B is a cross-sectional view of the optical receptacle 20 of the first embodiment. FIG. 4 is a flowchart of a method of manufacturing the ferrule 22 with a fixed part of the first embodiment. FIG. 5A is a cross-sectional view showing a portion of the ferrule 23 into which the end of the tube 26 is inserted. FIG. 5B is a cross-sectional view showing the uneven portion 43 of the tube 26. As shown in FIG. FIG. 6A is a cross-sectional view of the optical receptacle 20 of the comparative example. FIG. 6B is a cross-sectional view of the optical receptacle 20 of the second embodiment.

  At least the following matters will be clear from the description of the specification and drawings to be described later.

  A ferrule with a fixed part having a ferrule that holds an end of an optical fiber, a ferrule holding part that holds the ferrule, and a tube through which the optical fiber is inserted, wherein the ferrule is A ferrule with a fixed part is revealed, characterized in that the end of the tube is inserted and provided with a detent to detain the tube. According to such a ferrule with a stationary part, by miniaturizing the ferrule with the stationary part that constitutes the optical receptacle, it is possible to secure a space for accommodating the extra length portion of the optical fiber in the housing of the optical module.

  It is desirable that the ferrule is inserted through the ferrule holding part. As a result, by miniaturizing the ferrule with the fixed part that constitutes the optical receptacle, it is possible to secure a space for accommodating the extra length portion of the optical fiber in the housing of the optical module.

  It is desirable that the ferrule be fixed to the ferrule holding portion by press fitting. This makes it possible to further miniaturize the fixed part-equipped ferrule that constitutes the optical receptacle.

  It is desirable that an undulation is provided on the outer periphery of the end of the tube. This can increase the clamping force that the ferrule holds on to the tube.

  It is desirable that the undulations be provided in a band shape along the circumferential direction of the tube, and the surface of the undulations be positioned closer to the center of the tube than the surface of the outer circumferential portion. This can increase the clamping force that the ferrule holds on to the tube.

  An optical connector receptacle comprising: a ferrule that holds an end of an optical fiber; a ferrule holding part that holds the ferrule; a tube through which the optical fiber is inserted; and a housing that houses the ferrule holding part. The optical connector receptacle is characterized in that the end portion of the tube is inserted and a retaining portion for retaining the tube is provided. According to such an optical connector receptacle, it is possible to secure a space for housing the extra length portion of the optical fiber in the housing of the optical module.

  A method for manufacturing a ferrule with a fixed part, comprising: a ferrule for holding an end of an optical fiber, a ferrule holding part for holding the ferrule, and a tube through which the optical fiber is inserted. A manufacturing method of a ferrule with a fixed part is characterized in that the ferrule is attached to a holding portion, the ferrule includes a holding portion for holding the tube, and an end portion of the tube is inserted into the holding portion and bonded. It becomes. According to the manufacturing method of such a fixed part-equipped ferrule, by making the fixed part-equipped ferrule that constitutes the optical receptacle compact, it is possible to secure a space for accommodating the extra length portion of the optical fiber in the housing of the optical module. Can.

=== First Embodiment ===
<Overall Configuration of Optical Module 1>
FIG. 1 is a view showing an optical module 1 provided with the optical receptacle 20 of the first embodiment. FIG. 2 is an exploded perspective view of the optical receptacle 20 of the first embodiment.

  In the following description, each direction is defined as shown in the figure. That is, the longitudinal direction of the optical fiber 10 attached to the optical receptacle 20 is referred to as "longitudinal direction", and in the ferrule 23 in which the optical fiber 10 is held, the ferrule end face 36 is referred to as "front" and the opposite side (light from the ferrule 23 The side from which the fiber 10 extends is referred to as “rear” (see FIG. 2). The front-rear direction also refers to the mounting and demounting direction of the optical plug that is mounted to and demounted from the optical receptacle 20.

  The optical module 1 is an optical component to which an optical plug can be attached and detached. The optical module 1 in the present embodiment is, for example, an optical transceiver. However, the optical module 1 is not limited to the optical transceiver, and may be an optical component to which the optical plug can be attached and detached.

  The optical module 1 has a housing 2, an optical device component 6, an optical fiber 10, and an optical receptacle 20 (see FIG. 1).

  The housing 2 is a member that accommodates the optical device component 6, the optical fiber 10, and the optical receptacle 20. In order to connect the optical plug to the optical receptacle 20, the housing 2 may be formed with an opening (not shown) into which the optical plug is inserted. In addition, in order to prevent the optical plug connected to the optical receptacle 20 from falling off, the housing 2 may be formed with a latch portion (not shown) in which the optical plug is latched.

  The optical device component 6 in the present embodiment is, for example, an optical transmission / reception module (optical transmission module and optical reception module). However, the optical device component 6 is not limited to the optical transmission / reception module, and may be another optical device component. As shown in FIG. 1, a plurality of optical fibers 10 respectively connected to the pair of optical receptacles 20 (optical receptacles 20A and 20B) at one end are connected to the optical device component 6 at the other end. Of the plurality of optical fibers 10, one optical fiber 10 is connected to the optical device component 6 for transmitting an optical signal, and the other optical fiber 10 is connected to the optical device component 6 for receiving an optical signal. There is.

  The optical fiber 10 is an optical fiber that optically connects the optical device component 6 and the optical receptacle 20. The optical fiber 10 in the present embodiment is, for example, a single mode fiber. Furthermore, the optical fiber 10 in the present embodiment may be a polarization maintaining fiber. However, the optical fiber 10 is not limited to a single mode fiber (polarization maintaining fiber), and may be another optical fiber. As described above, the plurality of optical fibers 10 are accommodated inside the housing 2 of the optical module 1. Each of the optical fibers 10 among the plurality of optical fibers 10 is connected to the optical receptacle 20 (optical receptacle 20A or optical receptacle 20B) at one end. Further, among the plurality of optical fibers 10, each optical fiber 10 is connected to the optical device component 6 (optical transmission module or optical reception module) at the other end.

  As shown in FIG. 1, each of the plurality of optical fibers 10 has an extra length portion. The extra length of the optical fiber 10 is accommodated in the housing 2 of the optical module 1 so as to be routed around the optical device component 6. Specifically, the extra length portion of the optical fiber 10 connected to the optical receptacle 20A shown in FIG. 1 is connected to the optical device part 6 around the optical device part 6 approximately twice clockwise. . On the other hand, the extra length portion of the optical fiber 10 connected to the optical receptacle 20 B is connected to the optical device part 6 around the optical device part 6 almost twice in a counterclockwise direction. In the excess length accommodation area 3 shown in FIG. 1, the bent portion of the optical fiber 10 is accommodated.

  The optical receptacle 20 is an optical connector on the receptacle side to which an optical plug can be attached and detached. As shown in FIG. 1, the optical module 1 in the present embodiment is provided with a pair of optical receptacles 20 (optical receptacles 20A and optical receptacles 20B). Of the pair of optical receptacles 20, one optical receptacle 20 is an optical receptacle to which an optical fiber 10 for optical transmission is connected, and the other optical receptacle 20 is an optical receptacle to which an optical fiber 10 for optical reception is connected is there. However, the optical module 1 is not limited to being provided with a pair of optical receptacles 20, and only one optical receptacle 20 may be provided. Further, three or more optical receptacles 20 may be provided in the optical module 1.

<Configuration of Optical Receptacle 20>
As shown in FIG. 2, the optical receptacle 20 has a housing 21, a sleeve 27, a ferrule 23, and a fixed component 24 composed of a ferrule holding portion 25 and a tube 26. The ferrule 23 to which the fixing component 24 is attached may be referred to as a ferrule 22 with a fixing component.

  The housing 21 is a member that holds the ferrule holding part 25. As described later, the ferrule holding portion 25 holds the ferrule 23, and the tube 26 is held by the ferrule 23. Therefore, the housing 21 is also a member for holding the ferrule 22 with a fixed part. The housing 21 is also a member fixed to the housing 2 of the optical module 1. The optical receptacle 20 and the optical plug are optically connected by fitting a plug housing (not shown) of the optical plug with the housing 21 of the optical receptacle 20 fixed to the housing 2 of the optical module 1. The housing 21 has a plug insertion portion 31, a flange portion 32 and a fixing component holding portion 33.

  The plug insertion part 31 is a part inserted into a plug housing (not shown) of the optical plug. The plug insertion portion 31 is a portion located on the front side of the housing 21. By inserting the plug insertion portion 31 into the plug housing (not shown) of the optical plug, the plug insertion portion 31 is fitted to the inner wall surface of the plug housing (not shown). As a result, the optical plug is aligned with the optical receptacle 20 in the direction (vertical direction and horizontal direction) perpendicular to the front-rear direction. Accordingly, the end face of the plug side ferrule can be made to accurately face the ferrule end face 36 of the ferrule 23 of the optical receptacle 20. In the inside of the plug insertion portion 31, a sleeve 27 is accommodated.

  The flange portion 32 is a part that is fixed to the housing 2 of the optical module 1. The flange portion 32 is a portion that protrudes outward from the outer peripheral surface of the main body (the plug insertion portion 31 and the fixing component holding portion 33) of the housing 21. Further, the flange portion 32 is a portion provided in the housing 21 between the plug insertion portion 31 and the fixed component holding portion 33. The flange portion 32 is fixed to the housing 2 of the optical module 1 by fitting the flange portion 32 to a receptacle holding portion provided in the housing 2 of the optical module 1, for example.

  The fixed component holding part 33 is a part for holding the ferrule holding part 25 (ferrule 22 with fixed parts). The fixed component holding portion 33 is a portion located on the rear side of the housing 21. As described above, the ferrule holding portion 25 holds the ferrule 23, and the tube 26 is held by the ferrule 23. Therefore, the fixed component holding portion 33 is also a portion for holding the fixed component equipped ferrule 22. As shown in FIG. 2, the fixed component holding portion 33 is formed in a hexagonal column shape. However, the shape of the fixed component holder 33 is not limited to this.

  The sleeve 27 is a member that guides an optical plug-side ferrule (not shown) that is butt-connected to the ferrule 23. As shown in FIG. 2, the sleeve 27 is formed in a cylindrical shape in which a slit 28 is provided in the front-rear direction. The sleeve 27 is accommodated in the housing 21 as shown in FIG. 3B described later. Further, the ferrule 23 is inserted into the rear side portion of the sleeve 27. Then, the optical plug side ferrule (not shown) is inserted into the front portion of the sleeve 27, and the end faces of the ferrules (optical plug side ferrule and ferrule 23 (not shown)) abut on each other.

  The ferrule 23 is a member that holds the end of the optical fiber 10. Further, in the present embodiment, the ferrule 23 is also a member for retaining the end of the tube 26. The detailed configuration of the ferrule 23 will be described later.

  The ferrule holding unit 25 is a member that holds the ferrule 23. As shown in FIG. 3B described later, the ferrule holding portion 25 holds the ferrule 23 by inserting the ferrule 23. Also, the ferrule holding portion 25 is held by the housing 21. The ferrule holding portion 25 and the housing 21 may be integrally formed.

  The tube 26 is a member that protects a portion where the optical fiber 10 extends from the optical receptacle 20. The optical fiber 10 is inserted into the inside of the tube 26 and fixed by an adhesive. In the present embodiment, as shown in FIG. 3B described later, the front end of the tube 26 is inserted into the ferrule 23 and held against the ferrule 23 with an adhesive.

Optical Receptacle 20 of Comparative Example
FIG. 3A is a cross-sectional view of the optical receptacle 20 of the comparative example. In the optical receptacle 20 of this comparative example, the ferrule holding portion 25 holds both the ferrule 23 and the tube 26. That is, as shown in FIG. 3A, the ferrule 23 is held by the front side portion of the ferrule holding portion 25 and the tube 26 is held by the rear side portion of the ferrule holding portion 25. In other words, the ferrules 23 and the tubes 26 are respectively inserted into the same insertion holes of the ferrule holding portion 25 from both sides and held. That is, the ferrule holding portion 25 holds the ferrule 23 and the tube 26 in series in the front-rear direction.

  Further, in the present comparative example, in order to prevent the ferrule 23 and the tube 26 from coming off with respect to the ferrule holding portion 25, the ferrule 23 and the tube 26 are held against the ferrule holding portion 25. That is, in the present comparative example, the ferrule 23 and the tube 26 are fixed to the ferrule holding portion 25 by, for example, bonding with an adhesive. Alternatively, the ferrule 23 and the tube 26 are inserted into the insertion hole of the ferrule holding portion 25 by press fitting, and the frictional force between the ferrule 23 and the tube 26 and the ferrule holding portion 25 causes the ferrule 23 and the tube 26 to It is fixed against.

  At this time, the larger the surface area of the region of the outer peripheral portion of the ferrule 23 and the tube 26 (hereinafter, may be referred to as "retaining region") inserted into the insertion hole of the ferrule holding portion 25, The adhesion between the ferrule 26 and the ferrule holder 25 is increased. Therefore, in order to apply a predetermined adhesion between the ferrule 23 and the tube 26 and the ferrule holding portion 25, it is necessary to secure a predetermined amount of surface area of the retaining region. In particular, by sufficiently securing the longitudinal length (L1 and L2 shown in FIG. 3A) of the retaining region, the ferrules 23 and the tubes 26 inserted from both sides in the longitudinal direction with respect to the insertion hole of the ferrule holding portion 25 are , Can be held with a predetermined adhesion. That is, in order to secure predetermined amounts of L1 and L2, the ferrule 23 and the tube 26 can be held at a predetermined adhesion force by sufficiently increasing the length of the ferrule holding portion 25 in the front-rear direction.

However, when the length of the ferrule holding portion 25 in the front-rear direction is increased, there is a possibility that the ferrule holding portion 25 interferes with the above-described remaining length accommodation area 3 (see FIG. 1) of the optical module 1. On the other hand, also with regard to the extra length accommodation area 3, in order to suppress an increase in the bending loss of the optical fiber 10, it is necessary to sufficiently secure the size of the extra length accommodation area 3 in the front-rear direction. For this reason, there is a possibility that the ferrule holding portion 25 may interfere with the extra-length portion accommodation area 3, so that the case 2 of the optical module 1 can not be miniaturized, and as a result, the miniaturization of the optical module 1 is limited. It had brought.
<Optical receptacle 20 having a special ferrule>

  FIG. 3B is a cross-sectional view of the optical receptacle 20 of the first embodiment. As described above, in the present embodiment, the front end of the tube 26 is inserted into the ferrule 23 and held against the ferrule 23 by the adhesive. The ferrule 23 in the present embodiment has a fiber insertion portion 37, a tapered portion 38 and a retaining portion 39. The fiber insertion portion 37, the tapered portion 38, and the retaining portion 39 are insertion holes formed inside the ferrule 23.

  The fiber insertion portion 37 is a portion through which the optical fiber 10 whose coating has been removed is to be inserted. The end face of the optical fiber 10 is positioned at the front end of the fiber insertion portion 37, and the end faces of the ferrules (optical plug side ferrule and ferrule 23 not shown) butts, so that the end faces of the optical fibers physically At the end, the optical fibers are connected to each other.

  The tapered portion 38 is a portion that facilitates the insertion of the optical fiber 10 into the fiber insertion portion 37. As shown in FIG. 3B, the tapered portion 38 is located between the fiber insertion portion 37 and the detent portion 39. Further, the tapered portion 38 is formed in a tapered shape in which the inner diameter is reduced from the rear side to the front side. That is, it is formed in a tapered shape in which the inner diameter decreases from the side of the detent portion 39 into which the tube 26 into which the optical fiber 10 is inserted is inserted into the side of the fiber insertion portion 37 into which the optical fiber 10 is inserted. Therefore, when inserting the optical fiber 10 from the side of the retaining portion 39 and inserting the optical fiber 10 into the fiber insertion portion 37 having a smaller inner diameter with respect to the retaining portion 39, the end of the optical fiber 10 is formed by the wall surface of the tapered portion 38 Can be guided.

  The retaining portion 39 is a portion that holds the end portion of the tube 26. In addition, the retaining portion 39 is also a site for retaining the tube 26 by being bonded to the tube 26 with an adhesive. In the above-described comparative example, the tube 26 is inserted into the rear portion of the insertion hole of the ferrule holding portion 25 and held therein (see FIG. 3A). On the other hand, in the present embodiment, as shown in FIG. 3B, the tube 26 is inserted into the ferrule 23 (retaining portion 39) and retained. Therefore, the ferrule holding portion 25 does not have to be provided with a portion for holding the tube 26 in place. Then, in the present embodiment, as shown in FIG. 3B, the ferrule holding portion 25 can be shortened in the front-rear direction by a portion (L3 shown in FIG. 3B) of the portion where the tube 26 is held. In other words, in the present comparative example, while the lengths (L1 and L2 shown in FIG. 3A) of the retaining region are provided in series with respect to the insertion hole of the ferrule holding portion 25, the present embodiment In the embodiment, the length in the front-rear direction of the retaining region is provided so as to overlap in the front-rear direction. As a result, the ferrule holding portion 25 (ferrule 22 with fixed part) can be miniaturized in the front-rear direction. As a result, since the extra length accommodation area 3 can be secured in the housing 2 of the optical module 1 by L3 shown in FIG. 3B, the space between the ferrule 22 with the fixed part and the optical device part 6 can be further packed. This makes it possible to miniaturize the entire optical module 1 as well.

  In this comparative example, the ferrule 23 and the tube 26 are respectively held in the same insertion hole of the ferrule holding part 25 (see FIG. 3A), but in this embodiment, the ferrule held in the ferrule holding part 25 The tube 26 is held in the inside of the twenty-three (retaining portion 39) (see FIG. 3B). For this reason, the diameter of the tube 26 of the present embodiment is smaller than that of the tube 26 of the present comparative example. As a result, the ferrule with fixed part 22 can be further miniaturized.

  In this comparative example, the ferrule 23 is inserted in the front part of the ferrule holding unit 25 (see FIG. 3A), but in the present embodiment, as shown in FIG. 3B, the ferrule 23 is a ferrule holding unit 25. The whole of the insertion hole is inserted (see FIG. 3B). Therefore, the length (L4 shown in FIG. 3B) of the retaining region of the ferrule 23 of the present embodiment is the length (L1 shown in FIG. 3A) of the retaining region of the ferrule 23 of the comparative example. Is also getting longer. Thus, the adhesion between the ferrule 23 and the ferrule holding portion 25 can be increased.

<Method of Manufacturing Ferrule 22 with Fixing Part>
FIG. 4 is a flowchart of a method of manufacturing the ferrule 22 with a fixed part of the first embodiment.

  First, the ferrule 23 is attached to the ferrule holding part 25 (S001). At this time, the ferrule 23 is inserted into the insertion hole of the ferrule holding portion 25. In the present embodiment, the ferrule 23 is inserted into the insertion hole of the ferrule holding portion 25 by press-fitting. However, the method of attaching the ferrule 23 to the ferrule holding portion 25 is not limited to the press-fitting. The insertion hole of the ferrule holding portion 25 is formed slightly larger than the outer diameter of the ferrule 23, and the insertion hole of the ferrule holding portion 25 is filled with an adhesive, and after the ferrule 23 is inserted, the adhesive is solidified. The holding portion 25 and the ferrule 23 may be joined.

  Next, the coating of the optical fiber 10 is removed (S002). The optical fiber 10 of the part from which the coating of the optical fiber 10 was removed is an optical fiber strand whose outer diameter is 0.25 mm. Then, the optical fiber 10 is inserted into the tube 26 and bonded and fixed (S003). The insertion hole of the tube 26 is filled with an adhesive, and after the optical fiber 10 is inserted into the tube 26, the adhesive is solidified to bond the optical fiber 10 and the tube 26.

  Then, an adhesive is filled into the ferrule 23 (fiber insertion portion 37, taper portion 38, and retaining portion 39) (S004). Further, the tube 26 in which the optical fiber 10 is inserted is inserted into the ferrule 23 and bonded and fixed (S005). At this time, the optical fiber 10 is inserted from the holding portion 39 side and inserted into the fiber insertion portion 37. Since the end of the optical fiber 10 is guided by the wall surface of the tapered portion 38, the optical fiber 10 can be easily inserted into the fiber insertion portion 37. After the optical fiber 10 is inserted into the fiber insertion portion 37, the adhesive is solidified to bond the tube 26 through which the optical fiber 10 is inserted and the ferrule 23.

<Up-and-down portion 43>
FIG. 5A is a cross-sectional view showing a portion of the ferrule 23 into which the end of the tube 26 is inserted. FIG. 5B is a cross-sectional view showing the uneven portion 43 of the tube 26. As shown in FIG.

  As described above, in the present embodiment, the end of the tube 26 is adhesively fixed at the retaining portion 39 of the ferrule 23. Further, as described above, the larger the surface area of the retaining area (the area of the outer peripheral portion of the tube 26 inserted into the ferrule 23), the larger the adhesion between the tube 26 and the ferrule 23. The diameter of the tube 26 of the present embodiment is smaller than that of the tube 26 of the present comparative example. Therefore, as compared with the case where the tube 26 of the present comparative example is used, the retaining region of the tube 26 of the present embodiment may be smaller, and the adhesion between the tube 26 and the ferrule 23 may be smaller.

  Therefore, in the present embodiment, as shown in FIGS. 5A and 5B, the uneven portion 43 roughened on the surface of the tube 26 may be provided. As a result, the adhesive adheres to the undulations 43, so the adhesion between the tube 26 and the ferrule 23 is improved, and the tube 26 and the ferrule 23 can be firmly joined. That is, even if the tube 26 is subjected to an external force such as tension or torsion, the tube 26 can be prevented from coming off the retaining portion 39 of the ferrule 23.

  As shown in FIGS. 5A and 5B, a undulating portion 43 is provided on the surface of the tube 26. The undulating portion 43 is a band-like portion provided along the circumferential direction of the tube 26. The roughened portion 43 is roughened to have minute asperities. The surface roughening can be performed by any one of the laser processing, the plastic processing with a plastic working tool, the cutting with a cutting tool, and the grinding with a grinding tool. As shown in FIG. 5B, the surface of the uneven portion 43 is located inside (the center axis side of the tube 26) from the surface of the outer peripheral portion 42 of the tube 26 when viewed from the center axis of the tube 26. As a result, the filled adhesive 40 solidifies in a bowl shape and functions as an anchor that prevents the tube 26 from coming off the ferrule 23, so the adhesion between the tube 26 and the ferrule 23 is improved. However, it may be located substantially flush with the surface of the outer peripheral portion 42 of the tube 26 as viewed from the central axis of the tube 26.

  As shown in FIG. 5A, a plurality of undulating portions 43 are provided in the front-rear direction of the outer peripheral portion 42 of the tube 26 (two locations in FIG. 5A). However, the undulations 43 may be formed at only one place on the outer peripheral part 42 of the tube 26 or may be formed at three or more places in the front-rear direction. Further, as shown in FIG. 5B, each of the undulating portions 43 is formed in a band shape at a predetermined angle in the circumferential direction of the outer peripheral portion 42 of the tube 26. In addition, although the uneven part 43 is formed shorter than the half circumference of the outer peripheral part of the tube 26, the present invention is not limited to this. The uneven part 43 may be formed over the entire circumference of the outer peripheral part 42 of the tube 26 . In addition, a plurality of band-like undulations 43 having a predetermined angle may be formed in the circumferential direction of the outer circumferential portion 42 of the tube 26.

=== Second Embodiment ===
FIG. 6A is a cross-sectional view of the optical receptacle 20 of the comparative example. FIG. 6B is a cross-sectional view of the optical receptacle 20 of the second embodiment. The cross-sectional view of the optical receptacle 20 of the comparative example shown in FIG. 6A is the same as FIG. 3A.

  In the first embodiment described above, the front end of the tube 26 is inserted into the ferrule 23 and held against the ferrule 23 by the adhesive. As a result, by reducing the size of the ferrule holding portion 25 (the ferrule 22 with the fixed part) in the front-rear direction, the extra length accommodation area 3 can be secured in the housing 2 of the optical module 1. However, in the present embodiment, by reducing the thickness of the holding portion of the tube 26 of the ferrule holding portion 25, even if the extra length portion of the optical fiber 10 is accommodated between the ferrule holding portion 25 and the housing 2. Good.

  As shown in FIGS. 6A and 6B, the outer peripheral clearance portion 4 is a clearance provided between the ferrule holding portion 25 and the housing 2. The height T1 of the outer peripheral clearance 4 shown in FIG. 6A is not the height at which the optical fiber 10 can be accommodated. On the other hand, in the present embodiment, as shown in FIG. 6B, the height T2 of the outer peripheral clearance 4 is larger than T1 by reducing the thickness of the holding portion of the tube 26 of the ferrule holding portion 25. (T2> T1). By accommodating the optical fiber 10 in the outer circumferential clearance portion 4, the outer circumferential clearance portion 4 can be made the remaining length accommodation region 3.

=== Other Embodiments ===
The foregoing embodiments are intended to facilitate the understanding of the present invention, and are not intended to limit the present invention. It goes without saying that the present invention can be modified and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

Reference Signs List 1 optical module, 2 housings, 3 extra length accommodation area, 4 outer peripheral clearance 6 optical device parts, 10 optical fibers,
20 optical connector receptacles (optical receptacles), 21 housings,
22 ferrules with fixed parts, 23 ferrules, 24 fixed parts,
25 ferrule holder, 26 tubes, 27 sleeves,
28 slits, 31 plug insertion parts, 32, flange parts,
33 fixed part holding part, 36 ferrule end face, 37 fiber insertion part,
38 Taper, 39 Retainer, 40 Adhesive,
41 insertion hole, 42 outer peripheral portion, 43 uneven portion

Claims (7)

A ferrule for holding the end of the optical fiber;
It is a ferrule with a fixed part which has a fixed part provided with a ferrule holding part holding the above-mentioned ferrule, and a tube by which the above-mentioned optical fiber is inserted,
The ferrule with a fixed part, wherein the ferrule has a detent portion into which an end of the tube is inserted and which detains the tube. It is a ferrule with a fixed part according to claim 1, wherein
The ferrule with a fixed part, wherein the ferrule is inserted into the ferrule holding portion. The ferrule with a fixed part according to claim 2, wherein
The ferrule with a fixed part characterized in that the ferrule is fixed to the ferrule holding portion by press fitting. It is a ferrule with a fixed part according to any one of claims 1 to 3,
A ferrule with a fixed part, wherein an undulating portion is provided on an outer peripheral portion of the end portion of the tube. It is a ferrule with a fixed part according to claim 4,
The ferrule is provided with a band-like shape along the circumferential direction of the tube, and the surface of the relief is located closer to the center of the tube than the surface of the outer periphery. . A ferrule for holding the end of the optical fiber;
A ferrule holding portion for holding the ferrule;
An optical connector receptacle comprising: a tube through which the optical fiber is inserted; and a housing that accommodates the ferrule holder.
An optical connector receptacle characterized in that the ferrule has a detent portion into which the end of the tube is inserted and which detains the tube. A ferrule for holding the end of the optical fiber;
It is a manufacturing method of a ferrule with a fixed part which has a fixed part provided with a ferrule holding part holding the above-mentioned ferrule, and a tube by which the above-mentioned optical fiber is inserted,
Attaching the ferrule to the ferrule holding portion;
The method for manufacturing a ferrule with a fixed part, comprising: a detent for detaining the tube; and inserting and bonding an end of the tube to the detent.

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