JP3445223B2 - Optical connector and method of assembling the same - Google Patents

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 tubular plug frame and an assembling method thereof.

[0002]

2. Description of the Related Art FIG. 5 shows an SC type optical connector (Single fiber Coupling optical) established in JIS C 5973.
fiber connector). This optical connector 10
In this case, the ferrule 2 housed in the cylindrical plug frame 1 has a key groove 4 (see FIG. 6) formed in a flange portion 3 projecting in a ring shape on its outer peripheral portion, and a plug frame. Key 5 protruding inside 1 (FIGS. 7A to 7C)
(See reference) allows the sliding movement in the axial direction and restricts the rotation around the axis. Also,
The ferrule 2 is urged forward (in the left side in FIG. 5) in the connecting direction by a spring 6 built in the plug frame 1, but a stopper wall 8 protruding in the ferrule housing hole 7 inside the plug frame 1 is provided. When the flange portion 3 comes into contact with the above, further protrusion to the front in the connecting direction is prevented. The ferrule 2 is adapted to be 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 so as to be connector connectable.
Is connected to the optical line of the optical connector on the other side. Further, the ferrule 2 can be slightly pushed rearward in the connecting direction within the elastic deformation range of the spring 6 when the ferrule 2 is abutted against the ferrule of the mating optical connector, so that damage due to extreme stress concentration is caused. Etc., and the biasing force of the spring 6 acts as a butting force between the ferrules, so that the desired connection loss can be stably obtained.

[0003]

By the way, the optical connector 10 having the above-described structure has a complaint that the mounting angle around the axis of the ferrule 2 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 of 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 evenly formed at two or four locations in the circumferential direction of the flange portion 3 (four locations in FIG. 6). That is, since the ferrule 2 is formed in units of 180 units or 90 ° around the axis of the ferrule 2, these key grooves 4 are formed.
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 the engagement of the key 5 and the key 5, fine adjustment is impossible because the adjustment can be made only in units of 180 or 90 degrees.

That is, a slight misalignment may occur when the optical fiber (bare fiber exposed at the tip) inserted into the fine hole formed through the ferrule 2 is accommodated in the fine hole. This misalignment may cause an increase in connection loss. Therefore, it is conceivable to reduce the connection loss by aligning the ferrule 2 around the axis to an optimum mounting state and storing and fixing the ferrule 2 in the plug frame 1, but the optical connector 1 having the above-mentioned configuration is considered.
At 0, it is not possible to finely adjust the mounting angle, so that alignment cannot be sufficiently performed.

In addition, the so-called PANDA (Polarization
In a butt connection between ferrules in which a polarization-maintaining optical fiber such as a fiber is inserted and fixed, the distribution of the optical transmission area between the polarization-maintaining optical fibers depends on the relative positional relationship between the ferrules. By matching or differentiating (polarization plane), desired characteristics can be obtained at the time of connection. Positioning the distribution of the optical transmission region between the polarization-maintaining optical fibers requires precision, and therefore, in the ferrule 2 in which the polarization-maintaining optical fibers are inserted and fixed, the key groove 4 of the flange 3 and the plug frame are provided. There is a demand not only to adjust the mounting angle around the axis by the engagement position with the key 5 on the 1st side, but also to finely adjust the mounting angle by rotating around the axis, and development of an optical connector that can realize this fine adjustment has been developed. It was wanted.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an optical connector and a method of assembling the optical connector, which enables fine adjustment of the mounting angle of the ferrule around its axis.

[0007]

An optical connector according to claim 1, wherein a tubular plug frame, a ferrule housed in a ferrule housing hole inside the plug frame, and a connection of the plug frame in the ferrule housing hole. After direction
It was stored from the side and it was projected inside the ferrule storage hole.
Push the plug wall against the stopper wall from the rear side in the connecting direction.
It is fixed to the frame, by being engaged against the ring-shaped flange portion projecting from the outer peripheral portion of the ferrule, allowing the movement of the ferrule in the axial direction of the ferrule receiving hole and said ferrule accommodating A flange engaging ring for restricting rotation of the ferrule around the axis of the hole, the flange engaging ring facing the stopper wall.
It is to rotate the shaft around the ferrule receiving hole while maintaining the abutting state, being adapted to be secured to the plug frame after adjusting the desired mounting angle of the axis of the ferrule receiving hole , The plug frame
The ferrule from the rear side to the front side
The flange portion of the ferrule inserted into the storage hole,
The flange engagement previously fixed in the plug frame
It is characterized in that it can be assembled in a procedure of engaging with the combination ring . According to this optical connector, the flange engaging ring, which is separate from the plug frame,
By engaging with the flange portion of the ferrule, the ferrule is allowed to move in the axial direction of the ferrule housing hole, and the rotation around the axis is restricted. By rotating the flange engaging ring around the axis of the ferrule housing hole, the mounting angle around the axis of the ferrule with respect to the plug frame can be finely adjusted, and the centering of the ferrule can be realized.

According to a second aspect of the present invention, in this optical connector, the plug frame is formed with a window penetrating a side wall portion of the plug frame and communicating with a storage position of the flange engaging ring. More preferable. Workability can be improved by utilizing the window for operations such as rotation, positioning, and fixing of the flange engaging ring housed in the ferrule housing hole of the plug frame.

The invention according to claim 3 is the invention according to claim 1 or 2.
The method for assembling the optical connector as described above, wherein the flange engaging ring is housed in the ferrule housing hole from the rear side in the connection direction of the plug frame to face the stopper wall.
After fixing to the plug frame is positioned by rotating about the axis of the ferrule receiving hole while maintaining the abutting state of the connection direction the rear side of the connection direction rear side of the plug frame to the ferrule receiving hole From front
Inserted toward the flange portion of the housing and the ferrule by engaging the flange engaging ring, said furan
With the engagement ring in the axial direction of the ferrule hole
Permit the ferrule to move and collect the ferrule.
To restrict rotation about the axis of the ferrule Osameana characterized Rukoto. According to this invention, by finely adjusting the mounting angle of the ferrule around the axis of the ferrule housing hole by rotating and positioning the flange engaging ring in the ferrule housing hole, the ferrule can be easily centered for positioning.

According to a fourth aspect of the present invention, there is provided an optical connector in which a ferrule having a fine hole into which an optical fiber is inserted and fixed is penetrated is housed in a ferrule housing hole inside a cylindrical plug frame. Connection direction
From the rear side, it is inserted rotatably around the axis of the ferrule housing hole, and the stopper which is projected in the ferrule housing hole is provided.
Said plug frame and abuts against the path wall from the connecting direction rear side at a desired mounting angle of the axis of the said ferrule accommodating hole
Comprising a fixed flange engaging ring beam, the hula
The engagement ring and the ring-shaped flange portion provided on the outer peripheral portion of the ferrule restrict the rotation of the ferrule around the axis of the ferrule housing hole, and in the axial direction of the ferrule housing hole. Of the ferrule is allowed to move, and the plug frame is
From the rear side to the front side, in the ferrule storage hole
The flange portion of the inserted ferrule is previously
The flange engaging phosphorus fixed in the plug frame
It is characterized in that it can be assembled in the procedure of engaging with the plug . This optical connector is constructed by assembling the optical connectors of claims 1 and 2.

[0011]

DETAILED DESCRIPTION OF THE INVENTION 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.
2A and 2B are views showing a plug frame 21 applied to a No. 0, wherein (a) is a sectional view, (b) is a side view, and (c) is A of (b).
It is a sectional view taken along line A-A. 3A and 3B are views showing the flange engaging ring 22, where FIG. 3A is a front view and FIG. 3B is a bottom view. In the figure, the same components as those in FIGS. 5 and 6 are designated by the same reference numerals to simplify the description.

In FIG. 1, an optical connector 20 includes a tubular 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. And an engagement ring 22. The provision of the knob 11 and the boot 12 is the same as that of the optical connector 10 shown in FIG. Further, hereinafter, the side of the ferrule 2 to which the joining end surface 2a is directed, that is, the left side in FIG. 1 is the front side in the connecting direction (or “front side in the connecting direction”), and the opposite side, that is, the right side in FIG. 1 is the rear side in the connecting direction (or It may be referred to as "rear direction rear side").

The ferrule 2 is a precise capillary shape having a fine hole 2b (see FIG. 4) into which the exposed optical fiber 9a (bare fiber or the like, see FIG. 4) is inserted at the tip of the optical fiber 9, and is a plug frame. The ferrule housing hole 23 inside the housing 21 and the center axes of the ferrule housing holes 21 are substantially aligned with each other.

As shown in FIGS. 3A and 3B, the flange engaging ring 22 is a ring-shaped main body ring portion 22a.
And a protrusion-shaped key 22c projectingly provided at two diametrically opposite surfaces on the surface opposite to the stopper abutment surface 22b on one axial side of the main body ring portion 22a. . The flange engaging ring 22 is fixed in the plug frame 21 at the rear side in the connection direction of the stopper wall 21a protruding in 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 abutted against the stopper wall 21a, and the key 22c is fixed with the key 22c facing the rear side in the connection direction.

As shown in FIG. 4, the flange portion 3 of the ferrule 2 has the key 2 of the flange engaging ring 22.
2c is housed in the key groove 4, and is engaged with the flange engaging ring 22. That is, the ferrule 2 restricts the rotation of the ferrule housing hole 23 around its axis by the engagement of the key groove 4 of the flange portion 3 and the key 22c of the flange engaging ring 22, and the front and rear in the connecting direction with respect to the plug frame 21. To move to
It is stored in the ferrule storage hole 23.

As shown in FIGS. 1 and 2A, the ferrule 2 includes a spring 6 built in a plug frame 21.
Is urged forward by the flange portion 3 of the ferrule 2 by the flange portion 3 of the ferrule 2.
Also, the flange engaging ring 22 abuts against the stopper wall 21a of the plug frame 21 to prevent further movement in the connecting direction. When the flange engaging ring 22 hits 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. The ferrule 2 is within the elastic deformation range of the spring 6 at the time of butting with the ferrule of the optical connector on the other side,
It is possible to push it slightly backward in the connection direction.
This is the same as the conventional general SC type optical connector (for example, the optical connector 10 shown in FIG. 5 and the like), which prevents damage to the ferrule 2 due to extreme stress concentration, and the spring 6.
Similarly, the biasing force of (2) 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 engaging ring 22 engaged with the flange portion 3 is inserted into the ferrule accommodation hole 23 from the rear side in the connection direction and accommodated.

Next, while confirming the position of the fine hole 2b of the ferrule 2, the ferrule 2 and the flange engaging ring 22 are integrally rotated around the axis of the ferrule housing hole 23. Thereby, precise alignment of the ferrule 2 can be realized. Ferrule housing hole 2 near the stopper wall 21a
3 The inner surface 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 in a curved surface (cylindrical surface) that substantially matches 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 engaging ring 22, the flange engaging ring 22 is
It can be smoothly rotated around the axis of the ferrule housing hole 23. Before the rotating work of the ferrule 2, if a spring pusher 24 is assembled on the rear side in the connection direction of the plug frame 21 so that the urging force of the spring 6 acts on the ferrule 2, the urging force of the spring 6 causes the flange to move. The abutting state of the engagement ring 22 against the stopper wall 21a is maintained, and the flange engagement ring 22 can be stably rotated without inclining.

Ferrule 2 and flange engagement ring 22
As a method of integrally rotating and, for example, it is possible to employ a method of rotating the ferrule 2 using a portion of the ferrule 2 protruding to the rear end portion (rear end portion in the connection direction) of the plug frame 21. In the present embodiment, FIG.
As shown in (b), the side wall portion 21 of the plug frame 21
The plug frame 21 having a window 21c penetrating through b and communicating with the storage position of the flange engaging ring 22 in the plug frame 21 is adopted, and the flange is opened by a thin tool or the like inserted from the window 21c. It is possible to rotate the engagement ring 22 directly. This window 21
The c may be formed on the plug frame 21 after the ferrule 2 and the flange engaging ring 22 are inserted into the ferrule housing holes 23 of the plug frame 21, but the ferrule 2 and the flange engaging ring housed inside the plug frame 21. It goes without saying that a forming method that does not damage 22 is adopted.

After the ferrule is positioned or aligned to the desired mounting angle by rotation, the flange engaging ring 22 is fixed to the plug frame 21. As a method of fixing the flange engaging ring 22 to the plug frame 21, 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. Further, a resin flange engagement ring can be fixed to the plug frame 21 by heat fusion or the like. In this case, the positioning accuracy of the ferrule 2 by the key 22c is not affected by locally heat-melting a predetermined fixing portion provided on the flange engaging ring.

When the flange engaging ring 22 is fixed to the plug frame 21, the flange portion 3 of the ferrule 2 is used.
Are 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 are engaged with each other to allow the ferrule to move. Reference numeral 2 restricts the rotation of the ferrule housing hole 23 about its axis and is supported so as to be movable in the axial direction of the ferrule housing hole 23.

As shown in FIG. 1, does the flange portion 3 of the ferrule 2 contact the inner surface of the ferrule housing hole 23?
Alternatively, the main body ring portion 2 of the flange engaging ring 22
The outer peripheral surface 22d of 2a is preferably flush with the outer peripheral surface 22d, so that stable rotation and positioning accuracy of the flange engaging ring 22 in the ferrule housing hole 23 can be secured. That is, if the flange portion 3 of the ferrule 2 has a configuration in which the outer peripheral surface 22d of the flange engaging ring 22 does not project, the ferrule 2 around the axis of the ferrule housing hole 23 is provided.
The fine adjustment of the attachment angle and the accuracy of positioning and alignment are determined by the adjustment of the attachment angle around the axis of the ferrule accommodation hole 23 by the rotation of the flange engagement ring 22 in the ferrule accommodation hole 23. As long as the positioning accuracy of the ring 22 around the axis of the ferrule housing hole 23 is ensured, the ferrule 2 can be accurately positioned at the desired mounting angle around the axis of the ferrule housing hole 23. Therefore, if the formation accuracy is ensured in the portion of the flange engaging ring 22 that contacts the inner surface of the ferrule housing hole 23, etc.
It is possible to realize smooth rotation of the flange engagement ring 22 inside, to efficiently perform fine adjustment of the mounting angle around the axis of the ferrule housing hole 23 and alignment, and to ensure accuracy. Further, it suffices that the flange engaging ring 22 has a high forming accuracy, and the flange portion 3 of the ferrule 2 does not need to have a forming accuracy for stable rotation in the ferrule housing hole 23.

(Another Assembly Method) Flange Engaging Ring 2
2 is first stored in the ferrule housing hole 23 and positioned and fixed, then the ferrule 2 is inserted and housed in the ferrule housing hole 23, and the flange portion 3 of the ferrule 2 is engaged with the flange engaging 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. In addition, operations other than the engagement of the flange portion 3 with the flange engagement ring 22,
For example, the positioning and fixing of the flange engaging ring 22 in the ferrule housing hole 23 may be the same as the above-described assembling method. According to this assembling method, the flange engagement ring 22 positioned is fixed to the plug frame 21 before the ferrule 2 is accommodated in the ferrule accommodation hole 23. Therefore, the work for fixing the flange engagement ring 22 to the plug frame 21 is performed. The ferrule 2 can be prevented from interfering with each other, and the fixing work can be efficiently performed. Further, when the flange engaging 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 adhering to the flange portion 3 and the like of the ferrule 2.

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 within the ferrule housing hole 23. Can be finely adjusted, and the ferrule 2 can be positioned and aligned with the ferrule of the optical connector on the other side to be connected. Therefore, it is possible to reduce the connection loss during the butt connection of the ferrules. 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, the ferrule of the mating optical connector to be connected is finely adjusted by finely adjusting the mounting angle around the axis of the ferrule housing hole 23. 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 that is stored and fixed. This gives P
The desired optical characteristics can be stably and reliably obtained when the ferrules containing the ANDA fibers are butt-connected to each other.

The present invention is not limited to the above embodiment, and various changes can be made. For example, the specific shapes of the flange engaging 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 engaging ring, which is separate from the plug frame, inside the ferrule housing hole inside the plug frame, the flange portion is engaged with this flange engaging ring, and rotation around the axis is restricted. The mounting angle around the axis of the ferrule housing hole can be finely adjusted. As a result, the ferrule can be positioned and aligned, so that the connection loss at the time of butt connection of the ferrules can be reduced. Also, for example, PA
With a ferrule that stores and fixes a polarization-maintaining (conserving) type optical fiber such as NDA fiber, by finely adjusting the mounting angle of the ferrule around the axis of the ferrule housing hole described above,
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 stabilize the desired optical characteristics when the ferrules containing the PANDA fiber are butt-connected. It also has an excellent effect that it can be reliably obtained.

[Brief description of drawings]

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

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

3A and 3B are diagrams showing a flange engaging ring applied to the optical connector of FIG. 1, in which FIG. 3A is a front view and FIG. 3B is a bottom view.

FIG. 4 is a perspective view showing the flange engaging ring of FIG.

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

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

7 is a diagram showing a plug frame applied to the optical connector of FIG. 5, (a) is a sectional view, (b) is a side view,
(C) is a BB line sectional view taken on the line of (a).

[Explanation of symbols]

2 ... Ferrule, 2b ... Micro hole, 3 ... Flange portion, 9 ...
Optical fiber, 9a ... Bare fiber, 20 ... Optical connector, 2
1 ... Plug frame, 21a ... Stopper wall, 21c ...
Window, 22 ... Flange engaging ring, 23 ... Ferrule housing hole.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Flat 3-20307 (JP, U) Full-blown Sho 62-6706 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/36

Claims (4)

(57) [Claims] 1. A tubular plug frame, a ferrule housed in a ferrule housing hole inside the plug frame, and a contact of the plug frame in the ferrule housing hole.
It is stored from the rear side in the connecting direction and protrudes into the ferrule storage hole.
Abut on the stopper wall provided from the rear side in the connection direction to
It is secured to the plug frame, by being engaged against the ring-shaped flange portion projecting from the outer peripheral portion of the ferrule, allowing the movement of the ferrule in the axial direction of the ferrule receiving hole and said ferrule A flange engagement ring for restricting rotation of the ferrule around the axis of the housing hole, the flange engagement ring projecting from the stopper wall.
By rotating about the axis of the ferrule receiving hole while maintaining the contact state, being adapted to be secured to the plug frame after adjusting the desired mounting angle of the axis of the ferrule receiving hole, wherein Connection direction of plug frame From rear side to front side
The ferrule inserted into the ferrule storage hole
The flange part was previously fixed in the plug frame.
Assembling in the procedure of engaging with the flange engaging ring
An optical connector that is capable of 2. The optical connector according to claim 1, wherein the plug frame is formed with a window penetrating a side wall portion of the plug frame and communicating with a storage position of the flange engaging ring. . 3. The method of assembling the optical connector according to claim 1, wherein the flange engaging ring is provided with the plug.
From the rear side of the connection direction of the frame to the ferrule storage hole from the rear side of the connection direction to the stopper wall.
It said positioning by rotation of the axis of the abutment state the ferrule receiving hole while maintaining Puragufure
The plug into the ferrule hole after fixing
By connecting the flange portion of the ferrule inserted and stored from the rear side to the front side in the connecting direction of the frame with the flange engaging ring, the flange engaging ring can be used.
The ferrule in the axial direction of the ferrule hole.
Movement around the axis of the ferrule housing hole.
Method of assembling an optical connector which is characterized that you restrict the rotation of the ferrule. 4. An optical connector in which a ferrule having a fine hole into which an optical fiber is inserted and fixed is penetrated is accommodated in a ferrule accommodating hole inside a cylindrical plug frame, and from the rear side in the connection direction of the plug frame. is inserted rotatably around the axis of the ferrule receiving hole, said ferrule
From the rear side in the direction of connection to the stopper wall protruding in the hole
Abutment with the said ferrule accommodating desired attachment angle with a fixed flange engaging the ring to the plug frame around the axis of the hole, a ring-shaped flange provided on an outer peripheral portion of the said flange engaging the ring ferrule By engaging with the portion, rotation of the ferrule around the axis of the ferrule housing hole is restricted, and movement of the ferrule in the axial direction of the ferrule housing hole is allowed.
From the rear side to the front side of the plug frame connection direction
The ferrule inserted into the ferrule storage hole
The flange part was previously fixed in the plug frame.
Assembling in the procedure of engaging with the flange engaging ring
An optical connector that is capable of