JP2002006174A - Optical connector and assembling method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize fine adjustment of attaching angle around the axis of a ferrule, related to an SC type optical connector. SOLUTION: The optical connector is provided with a cylindrical plug frame, the ferrule housed in a ferrule housing hole inside the plug frame, and a flange engagement ring which, housed and fixed in the ferrule housing hole, is engaged with a ring-flange part protruding above the outer peripheral part of the ferrule so that movement of the ferrule in the axial direction of the ferrule housing hole is tolerated while rotation of the ferrule around the axis of the ferrule housing hole is regulated. The flange engagement ring is so housed as to be freely rotatable around the axis of the ferrule housing hole and fixed to the plug frame at a desired attaching angle around the axis of the ferrule housing hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector in which a ferrule is housed in a cylindrical plug frame and a method for assembling the same.

[0002]

2. Description of the Related Art FIG. 5 shows an SC type optical connector (Single fiber Coupling optical connector) specified in JIS C5973.
fiber connector). This optical connector 10
The ferrule 2 housed in the cylindrical plug frame 1 has a key groove 4 (see FIG. 6) formed in a flange 3 projecting in a ring shape on the outer periphery thereof, and a plug frame. Key 5 protruding inside 1 (FIGS. 7A to 7C)
), The slide movement in the axial direction is allowed and the rotation around the axis is restricted. Also,
The ferrule 2 is urged forward (to the left in FIG. 5) in the connection direction by a spring 6 built in the plug frame 1, but a stopper wall 8 protruding into a ferrule housing hole 7 inside the plug frame 1. The flange portion 3 abuts on the contact portion, thereby preventing further forward projection in the connection direction. The ferrule 2 is butt-connected to the ferrule of another optical connector with the joint end face 2a, whereby the optical fiber 9 terminated by the ferrule 2 to be connectable to the connector is provided.
Is connected to the optical line of the optical connector on the other side. Further, the ferrule 2 can be pushed slightly backward in the connection direction within the elastic deformation range of the spring 6 when the ferrule 2 is brought into contact with the ferrule of the mating optical connector. And the like, and the biasing force of the spring 6 acts as a butting force between the ferrules, so that a desired connection loss can be stably obtained.

[0003]

However, in the optical connector 10 having the above-mentioned structure, there is a complaint that the mounting angle of the ferrule 2 around the axis in the plug frame 1 cannot be finely adjusted. That is, the optical connector 10
Then, the mounting angle of the ferrule 2 around the axis in the plug frame 1 is determined by the engagement between the key groove 4 of the flange portion 3 of the ferrule 2 and the key 5 on the plug frame 1 side. The key grooves 4 are uniformly formed at two or four positions in the circumferential direction of the flange portion 3 (four positions in FIG. 6). In other words, these key grooves 4 are formed in units of 180 or 90 degrees around the axis of the ferrule 2.
Even if an attempt is made to adjust the mounting angle of the ferrule 2 with respect to the plug frame 1 around the axis by engagement of the key 5 with the key 5, the fine adjustment is impossible because the adjustment can only be made in units of 180 or 90 degrees.

That is, when the optical fiber (bare fiber exposed at the tip) inserted into the fine hole formed through the ferrule 2 is housed in the fine hole, a slight misalignment may occur. This misalignment may cause an increase in connection loss. Therefore, it is conceivable to reduce the connection loss by centering the ferrule 2 in an optimum mounting state by rotation about an axis and storing and fixing the ferrule 2 in the plug frame 1.
At 0, fine adjustment of the mounting angle is impossible, so that alignment cannot be performed sufficiently.

A so-called PANDA (Polarization)
In a butt connection between ferrules into which polarization-maintaining optical fibers such as fibers are inserted and fixed, the distribution of the optical transmission area between the polarization-maintaining optical fibers depends on the relative positional relationship around the axis of both ferrules. By making the (polarization planes) the same or different, desired characteristics can be obtained at the time of connection. Since positioning of the distribution of the optical transmission region between the polarization-maintaining optical fibers is an operation requiring precision, therefore, in the ferrule 2 into which the polarization-maintaining optical fiber is inserted and fixed, the key groove 4 of the flange portion 3 and the plug frame There is a demand not only for adjustment of the mounting angle around the axis by the engagement position with the key 5 on one side, but also for fine adjustment of the mounting angle by rotation around the axis. Development of an optical connector that can realize this fine adjustment has been demanded. Was sought.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide an optical connector and a method of assembling the optical connector, which can realize fine adjustment of a mounting angle of a ferrule around an axis.

[0007]

According to a first aspect of the present invention, there is provided an optical connector comprising: a cylindrical plug frame; a ferrule stored in a ferrule storage hole inside the plug frame; and a ferrule stored and fixed in the ferrule storage hole. The ferrule is allowed to move in the axial direction of the ferrule storage hole by being engaged with a ring-shaped flange portion protruding from an outer peripheral portion of the ferrule, and the ferrule can be moved around the axis of the ferrule storage hole. A flange engagement ring for restricting rotation of the ferrule, wherein the flange engagement ring is rotatably housed around the axis of the ferrule housing hole, and has a desired mounting angle around the axis of the ferrule housing hole. The plug frame is fixed to the plug frame. According to this optical connector, the flange engagement ring, which is separate from the plug frame, allows the ferrule to move in the axial direction of the ferrule housing hole by engaging with the flange portion of the ferrule, and the rotation around the axis. Performs the function of regulating the rotation of By rotating the flange engagement ring about the axis of the ferrule housing hole, fine adjustment of the mounting angle of the ferrule with respect to the plug frame around the axis can be performed, and centering of the ferrule can be realized.

In this optical connector, a window is formed in the plug frame so as to penetrate a side wall of the plug frame and communicate with a storage position of the flange engagement ring. More preferred. By using the window for operations such as rotation, positioning, and fixing of the flange engagement ring housed in the ferrule housing hole of the plug frame, workability can be improved.

The invention described in claim 3 is the first or second invention.
The method for assembling an optical connector according to claim 1, wherein the flange engagement ring is housed in the ferrule housing hole, and is positioned and fixed by rotating about an axis of the ferrule housing hole. The ferrule is inserted and stored, and the flange portion of the ferrule is engaged with the flange engaging ring. According to the present invention, fine adjustment of the mounting angle of the ferrule around the axis of the ferrule storage hole can be realized by rotation and positioning of the flange engagement ring in the ferrule storage hole, and the alignment of the ferrule can be easily performed.

According to a fourth aspect of the present invention, there is provided an optical connector in which a ferrule having a fine hole through which an optical fiber is inserted and fixed is housed in a ferrule housing hole inside a cylindrical plug frame. A flange engagement ring rotatably inserted around the axis of the hole and fixed at a desired mounting angle around the axis of the ferrule storage hole, and a ring-shaped flange provided on an outer peripheral portion of the ferrule. In some cases, the rotation of the ferrule around the axis of the ferrule storage hole is regulated, and the ferrule is allowed to move in the axial direction of the ferrule storage hole. This optical connector
It is constituted by assembling the optical connector of the first and second aspects. However, the assembling of the optical connector is not limited to the assembling method according to the third aspect of the present invention. For example, a ferrule and a flange engaging ring engaged with a flange portion of the ferrule may include a ferrule housing of a plug frame. It is also possible by inserting and storing in a hole, positioning by rotating the ferrule housing hole around an axis, or the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view showing an optical connector 20 according to the present invention, and FIG.
FIGS. 3A and 3B are diagrams showing a plug frame 21 applied to the plug 0, wherein FIG. 3A is a sectional view, FIG. 3B is a side view, and FIG.
FIG. 4 is a cross-sectional view taken along line -A. 3A and 3B are views showing the flange engagement ring 22, wherein FIG. 3A is a front view and FIG. 3B is a bottom view. In the drawings, the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof will be simplified.

In FIG. 1, an optical connector 20 includes a cylindrical plug frame 21, a ferrule 2 housed in the plug frame 21, and a flange housed and fixed in a ferrule housing hole 24 of the plug frame 21. An engagement ring 22 is provided. The provision of the knob 11 and the boot 12 is the same as that of the optical connector 10 shown in FIG. Also, hereinafter, the side of the ferrule 2 on which the joint end face 2a is directed, that is, the left side in FIG. 1 is forward in the connection direction (or “front side in connection direction”), and the opposite side, ie, the right side in FIG. "Connection direction rear side").

The ferrule 2 is a precise capillary having a fine hole 2b (see FIG. 4) into which an optical fiber 9a (bare fiber or the like; see FIG. 4) exposed at the tip of the optical fiber 9 is inserted. The ferrule storage hole 23 on the inside 21 and the center axis of the ferrule storage hole 23 are substantially aligned with each other.

As shown in FIGS. 3 (a) and 3 (b), the flange engagement ring 22 has a ring-shaped main body ring portion 22a.
And two protruding keys 22c projecting diametrically on a surface opposite to the one stopper contact surface 22b in the axial direction of the main body ring portion 22a. . The flange engagement ring 22 is fixed in the plug frame 21 on the rear side in the connection direction of a stopper wall 21 a protruding into the ferrule housing hole 23 inside the plug frame 21. Specifically, as shown in FIGS. 1 and 2A, the stopper contact surface 22b of the main body ring portion 22a is provided.
To the stopper wall 21a, and the key 22c is fixed with the key 22c facing rearward in the connection direction.

As shown in FIG. 4, the flange portion 3 of the ferrule 2 is connected to the key 2 of the flange engaging ring 22.
2c is engaged with the flange engagement ring 22 so as to be stored in the key groove 4. That is, the ferrule 2 regulates the rotation of the ferrule housing hole 23 around the axis by the engagement between the key groove 4 of the flange portion 3 and the key 22 c of the flange engagement ring 22, and the connection direction with respect to the plug frame 21. Allow movement to
It is stored in the ferrule storage hole 23.

As shown in FIGS. 1 and 2A, the ferrule 2 is provided with a spring 6 built in a plug frame 21.
And the flange portion 3 of the ferrule 2 causes the flange engagement ring 22
Is also urged forward in the connection direction, but the flange engagement ring 22 abuts against the stopper wall 21a of the plug frame 21 to further restrict the forward movement in the connection direction. When the flange engagement ring 22 abuts against the stopper wall 21a of the plug frame 21 by the urging force of the spring 6, the ferrule 2
The flange engaging ring 22 is sandwiched between the flange portion 3 and the stopper wall 21a. When the ferrule 2 is brought into contact with the ferrule of the mating optical connector, the ferrule 2 falls within the elastic deformation range of the spring 6.
It is possible to push it slightly backward in the connection direction,
This is the same as a conventional general SC type optical connector (for example, the optical connector 10 shown in FIG. 5), thereby preventing damage to the ferrule 2 due to excessive stress concentration,
The same applies to the fact that the urging force gives a butting force between the ferrules to stably obtain the desired low connection loss.

Next, an example of a method of assembling the optical connector 20 will be described. First, ferrule 2 and this ferrule 2
The flange engagement ring 22 engaged with the flange portion 3 is inserted and stored in the ferrule storage hole 23 from the rear side in the connection direction.

Next, the ferrule 2 and the flange engaging ring 22 are integrally rotated about the axis of the ferrule housing hole 23 while confirming the position of the fine hole 2b of the ferrule 2. Thereby, precise alignment of the ferrule 2 can be realized. Ferrule storage hole 2 near stopper wall 21a
The inner surface 3 is formed in a precise circular cross section, and the outer peripheral surface of the main body ring portion 22a of the flange engaging ring 22 is also formed as a curved surface (cylindrical surface) substantially matching the inner surface of the ferrule housing hole 23. By rotating the ferrule 2 while maintaining the contact state between the stopper wall 21a and the flange engagement ring 22, the flange engagement ring 22 is
It can be smoothly rotated around the axis of the ferrule storage hole 23. Before the rotation of the ferrule 2, a spring press 24 or the like is assembled on the rear side of the plug frame 21 in the connection direction so that the urging force of the spring 6 acts on the ferrule 2. The state in which the engagement ring 22 abuts against the stopper wall 21a is maintained, and the flange engagement ring 22 can be rotated stably without inclining or the like.

Ferrule 2 and flange engaging ring 22
As a method of rotating the ferrule 2 integrally, for example, it is possible to employ a method of rotating the ferrule 2 using a portion of the ferrule 2 protruding from the rear end of the plug frame 21 (the rear end in the connection direction). In the present embodiment, FIG.
As shown in (b), the side wall 21 of the plug frame 21 is formed.
b, a plug frame 21 having an open window 21c communicating with the storage position of the flange engaging ring 22 in the plug frame 21 is employed. It is possible to rotate the engagement ring 22 directly. This window 21
c may be formed in the plug frame 21 after the ferrule 2 or the flange engaging ring 22 is inserted into the ferrule housing hole 23 of the plug frame 21, but the ferrule 2 or the flange engaging ring housed inside the plug frame 21 may be used. Needless to say, a forming method that does not damage the substrate 22 is adopted.

When the positioning or alignment of the ferrule to the desired mounting angle by rotation is completed, the flange engagement ring 22 is fixed to the plug frame 21. As a method of fixing the flange engaging ring 22 to the plug frame 21, an adhesive fixing with an adhesive or the like can be adopted. In the case of fixing with an adhesive, the flange engaging ring 22 can be easily fixed to the plug frame 21 by injecting the adhesive using the window 21c or the like. In addition, a resin-made flange engagement ring can be fixed to the plug frame 21 by heat fusion or the like. In this case, the positioning of the ferrule 2 by the key 22c is not affected by locally melting the predetermined fixing portion provided on the flange engaging ring.

When fixing the flange engaging ring 22 to the plug frame 21, the flange portion 3 of the ferrule 2 is used.
Is not fixed to the plug frame 21. When the fixing of the flange engaging ring 22 to the plug frame 21 is completed, the key 22c of the positioned flange engaging ring 22 and the key groove 4 (FIG. 4) of the flange portion 3 of the ferrule 2 engage with the ferrule. Reference numeral 2 restricts the rotation of the ferrule storage hole 23 around the axis, and is supported so as to be movable in the axial direction of the ferrule storage hole 23.

As shown in FIG. 1, the flange portion 3 of the ferrule 2 does not contact the inner surface of the ferrule housing hole 23,
Alternatively, the main body ring portion 2 of the flange engagement ring 22
It is preferably flush with the outer peripheral surface 22d of 2a, so that the rotation of the flange engaging ring 22 in the ferrule housing hole 23 and the positioning accuracy can be secured. That is, if the flange portion 3 of the ferrule 2 does not project from the outer peripheral surface 22 d of the flange engaging ring 22, the ferrule 2 around the axis of the ferrule housing hole 23.
Of the mounting angle around the axis of the ferrule storage hole 23 by rotation of the flange engagement ring 22 in the ferrule storage hole 23. As long as the positioning accuracy of the ring 22 around the axis of the ferrule storage hole 23 is ensured, the ferrule 2 can be accurately positioned at a desired mounting angle around the axis of the ferrule storage hole 23. Therefore, if the formation accuracy is ensured at a portion or the like of the flange engagement ring 22 that contacts the inner surface of the ferrule storage hole 23, the ferrule storage hole 23
The smooth rotation of the flange engagement ring 22 can be realized in the inside, the fine adjustment of the mounting angle around the axis of the ferrule housing hole 23, the alignment can be performed efficiently, and the accuracy can be secured. Further, it is only necessary to ensure high forming accuracy in the flange engagement ring 22, and it is not necessary for the flange portion 3 of the ferrule 2 to ensure forming accuracy for stable rotation in the ferrule housing hole 23.

(Alternative Assembly Method) Ring 2 for Flange Engagement
After the ferrule 2 is stored and positioned and fixed in the ferrule storage hole 23 in advance, the ferrule 2 is inserted and stored in the ferrule storage hole 23, and the flange portion 3 of the ferrule 2 is engaged with the flange engagement ring 22. The engagement of the flange portion 3 of the ferrule 2 with the flange engagement ring 22 is performed by inserting the key groove 4 of the flange portion 3 into the key 22c of the flange engagement ring 22. Operations other than the engagement of the flange portion 3 with the flange engagement ring 22,
For example, the positioning, fixing, and the like of the flange engagement ring 22 in the ferrule storage hole 23 may be the same as the above-described assembling method. According to this assembling method, since the positioned flange engagement ring 22 is fixed to the plug frame 21 before the ferrule 2 is stored in the ferrule storage hole 23, the operation of fixing the flange engagement ring 22 to the plug frame 21 is performed. The ferrule 2 can be prevented from interfering with the work, and the fixing work can be performed efficiently. Further, when the flange engagement ring 22 and the plug frame 21 are bonded and fixed with an adhesive, there is an advantage that the adhesive can be prevented from being attached to the flange portion 3 of the ferrule 2 and the like.

According to this optical connector 20, the mounting angle of the ferrule 2 around the axis of the ferrule housing hole 23 is determined by the rotational positioning of the flange engaging ring 22 separate from the plug frame 21 in the ferrule housing hole 23. Can be finely adjusted, and the ferrule 2 can be positioned and aligned with respect to the ferrule of the optical connector to be connected. Therefore, a reduction in connection loss when the ferrules are butt-connected can be realized. Also, for example, P
ANDA (Polarization maintaining and absorption)
In the ferrule 2 in which a polarization maintaining (conserving) type optical fiber such as a fiber is housed and fixed, fine adjustment of the mounting angle of the ferrule housing hole 23 around the axis allows the ferrule of the mating optical connector to be connected. It is easy to position the polarization plane of the polarization-maintaining optical fiber at a desired angle around the axis of the polarization-maintaining optical fiber with respect to the optical fiber housed and fixed. This allows P
Desired optical characteristics can be stably and reliably obtained at the time of butt connection of ferrules containing ANDA fibers.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the specific shapes of the flange engagement ring and the flange portion of the ferrule are not limited to those described in the above embodiment, and the design can be changed as appropriate.

[0026]

As described above, according to the present invention,
By rotating a flange engagement ring separate from the plug frame in the ferrule storage hole inside the plug frame, the flange portion is engaged with the flange engagement ring, and rotation around the axis is restricted. The mounting angle of the ferrule housing hole around the axis can be finely adjusted. Accordingly, the alignment of the ferrules can be aligned, so that the connection loss at the time of butt connection of the ferrules can be reduced. Also, for example, PA
In a ferrule in which a polarization-maintaining (conserving) optical fiber such as an NDA fiber is housed and fixed, fine adjustment of the mounting angle of the ferrule around the axis of the above-mentioned ferrule housing hole allows fine adjustment.
It is easy to position the polarization plane of the polarization-maintaining optical fiber at a desired angle around the axis of the polarization-maintaining optical fiber, and the desired optical characteristics are stabilized when the ferrules containing the PANDA fibers are butt-connected. An excellent effect is obtained that it can be obtained reliably.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an optical connector according to an embodiment of the present invention.

FIGS. 2A and 2B are views showing a plug frame applied to the optical connector of FIG. 1, wherein FIG. 2A is a cross-sectional view, FIG.
(C) is a sectional view taken along line AA of (b).

3A and 3B are views showing a flange engagement ring applied to the optical connector of FIG. 1, wherein FIG. 3A is a front view and FIG. 3B is a bottom view.

FIG. 4 is a perspective view showing the flange engagement ring of FIG. 3;

FIG. 5 is a cross-sectional view showing a conventional optical connector.

FIG. 6 is a perspective view showing a ferrule applied to the optical connector of FIG.

7A and 7B are views showing a plug frame applied to the optical connector of FIG. 5, wherein FIG. 7A is a sectional view, FIG.
(C) is a sectional view taken along line BB of (a).

[Explanation of symbols]

2 ... ferrule, 2b ... micro hole, 3 ... flange, 9 ...
Optical fiber, 9a: bare fiber, 20: optical connector, 2
1: Plug frame, 21a: Stopper wall, 21c ...
Window, 22: Flange engagement ring, 23: Ferrule storage hole.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Daisuke Hayasaka 1-10-53 Higashi, Yonezawa City, Yamagata Prefecture Yonezawa Electric Wire Co., Ltd. F-term (reference) 2H036 NA01 QA43 QA45 QA57

Claims (4)

[Claims] 1. A cylindrical plug frame, a ferrule housed in a ferrule housing hole inside the plug frame, and a ring-shaped housing housed and fixed in the ferrule housing hole and protruding from an outer peripheral portion of the ferrule. By being engaged with the flange portion, a flange engaging ring that allows movement of the ferrule in the axial direction of the ferrule storage hole and restricts rotation of the ferrule around the axis of the ferrule storage hole. The flange engaging ring is rotatably housed around the axis of the ferrule housing hole, and is fixed to the plug frame at a desired mounting angle around the axis of the ferrule housing hole. An optical connector, characterized in that: 2. The optical connector according to claim 1, wherein the plug frame has a window penetrating a side wall of the plug frame and communicating with a storage position of the flange engagement ring. . 3. The method for assembling an optical connector according to claim 1, wherein the flange engagement ring is housed in the ferrule housing hole, and is positioned by rotating about the axis of the ferrule housing hole. And inserting and storing a ferrule in the ferrule storage hole, and engaging a flange portion of the ferrule with the flange engagement ring. 4. An optical connector comprising: a ferrule having a fine hole into which an optical fiber is inserted and fixed; the ferrule being housed in a ferrule housing hole inside a cylindrical plug frame, wherein the ferrule is rotated around an axis of the ferrule housing hole. The ferrule housing is formed by the engagement between the flange engagement ring freely inserted and fixed at a desired mounting angle around the axis of the ferrule housing hole and the ring-shaped flange provided on the outer peripheral portion of the ferrule. An optical connector, wherein the rotation of the ferrule around the axis of the hole is restricted, and the movement of the ferrule in the axial direction of the ferrule housing hole is permitted.