JP2001147347A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small optical connector having high performance which is excellent in attachability/detachability and satisfactory in optical characteristics capable of being used in an in-line filter. SOLUTION: An adapter 13 of the optical connector is a tubular shell member 13 extending so as to have first and second end parts 15-1 and 15-2. A first plug 23 and a first optical fiber are inserted from the inserting part of a first facing end part of the first adapter end part 15-1. A second plug 33 and a second optical fiber are inserted from the nearly rectangular inserting part of a second facing end part of the second adapter end part 15-2. When the optical connector is fitted, first engaging projected parts 27-1 and 27-2 of a first inner body 29 of the first plug 23 are fitted into a small groove and are fixed, after being inserted temporarily into a large groove of first engaging grooves 16-1a and 16-1b. Likewise, the second plug 33 is inserted from the insertion port of the second facing end part of the second end part 15-2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector for connecting optical fibers, and more particularly, to a type (JIS F) in which an adapter is interposed between two identical plugs.
04 etc.).

[0002]

2. Description of the Related Art Japanese Patent Application No. 60-218932 and Japanese Patent Application Laid-Open No. 6-51165 are examples of conventional optical connectors of the JIS F04 type.

An optical fiber used for an optical connector has a waveguide portion of about 10 μm, which is very small (single mode fiber: 10 μm, multimode fiber: 50 μm). Therefore, even if a small amount of dust adheres to the ferrule end face of the optical connector, the performance is degraded.

[0004]

Problems to be Solved by the Invention
In the optical connector described above, the plug frame locking groove needs to be formed considerably long in the longitudinal direction. For this reason, the structure of this conventional example has a drawback that it hinders miniaturization.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-performance, compact optical connector having good operability for attachment and detachment without using a dedicated jig, and having excellent optical characteristics and usable for an in-line filter. It is in.

[0006]

The present invention employs the following means to solve the above-mentioned problems.

(1) An optical connector having an adapter interposed between a first plug and a second plug for connecting the first and second optical fibers, wherein the adapter extends in a longitudinal direction. A tubular outer shell member extending to have first and second ends, wherein said first and second adapter ends are:
First and second opposed ends having first and second insertion openings along the longitudinal direction for accommodating the first and second plugs, respectively, and a first having a first and second locking groove. A first outer peripheral end portion, wherein the first plug has a first insertion hole into which the first optical fiber is inserted and a first engagement projection fitted into the first locking groove; An inner body, and a first ferrule for housing, mounting and holding the first optical fiber, wherein the second plug has a second insertion hole for inserting the second optical fiber and the second locking member. A second inner body having a second engagement protrusion fitted into the groove, and a second ferrule for mounting and holding the second optical fiber;
The ferrule and the second ferrule each have a ferrule main body having ferrule end faces joined to each other, and first and second ferrule flange portions having a rectangular shape, and the second plug is formed by the first and second ferrules. It has a cylindrical alignment member that is positioned when joined to each other, and the first and second adapter ends are rectangular for accommodating the first and second inner bodies and the first and second ferrule flanges. Each square hole of the shape is formed,
The optical connector according to claim 1, wherein the first and second ferrules are sandwiched between the first and second inner bodies, locked and held.

(2) In the optical connector according to (1), the second plug further includes a collar disposed on an outer peripheral end of the alignment member, and an elastic member for urging the second ferrule. Thereby, the alignment member is positioned at the intermediate portion between the first and second ferrule joining points (contact positions) by the collar, and the first and second ferrules are
An optical connector which is pressed against each other.

(3) In the optical connector described in (1), the first and second opposed ends of the outer shell member have a rectangular opening, and the first and second ends are formed from both corners on a diagonal line thereof. (2) An optical connector, wherein escape recesses are formed along the longitudinal direction up to the vicinity of the first and second locking grooves at the outer peripheral end.

(4) In the optical connector described in (1), the first locking groove has a T-shape including a large groove for provisional insertion on the ferrule connection position side and a small groove for fixing on the outer peripheral end side. An optical connector characterized by being perforated to exhibit.

(5) The optical connector according to (4), wherein the small groove of the first locking groove has a tapered portion.

[0012]

The adapter of the optical connector according to the present invention is a tubular outer shell member extending along the longitudinal direction so as to have first and second adapter ends. The first plug and the first optical fiber are inserted through the insertion port at the first opposing end of the first adapter end, while the second plug and the second optical fiber are inserted through the insertion port at the second opposing end of the second end. Inserted from.

At the time of mating of the optical connector, the first engagement projection of the first inner body of the first plug is loosely inserted into the clearance recess at the corner at the first facing end of the first adapter end. It is temporarily inserted into the large groove of the first locking groove. Then the first
The engaging projection is fitted in the small groove, hooked and fixed.

[0014] Similarly, the second plug is inserted from the insertion port at the second opposing end of the second adapter end.

The inside of the optical connector will be described in detail. In the outer shell member, the end faces of the ferrules in the centering member are in contact with each other, and the centering member is joined by a collar at the joining point (contact portion) of the first and second ferrules. ) Is positioned at the middle part.

At the same time, the first and second ferrules are pressed against each other by the elastic member. For this reason, the ferrules are sandwiched between the inner bodies, which facilitates assembly. Therefore, the optical connector of the present invention can be easily attached and detached without using a dedicated jig, thereby improving operability.

As described above, the engaging projection is fitted into the small groove of the locking groove and hooked, and the locking groove requires only a small space in the longitudinal direction, so that the optical connector can be downsized.

Further, as a result of fitting the rectangular ferrule flanges into the square holes at the adapter end of the outer shell member, the ferrules are held between the rectangular ferrule flanges without rotating. Therefore, the end faces of the ferrules are arranged at desired positions of the round holes in the intermediate portion of the outer shell member, and are joined together and held (locked).

As described above, as a result of fitting the optical connector, rotation of the ferrule is prevented, and the performance does not vary.

Moreover, if a desired filter is formed on the end face of the ferrule, the optical connector of the present invention can be used as an in-line filter and becomes a high-performance optical connector.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical connector 11 according to one embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 1 to FIG.
Is a device in which an adapter 13 is interposed between a first plug 23 and a second plug 33 to connect the first and second optical fibers 10-1 and 10-2 to each other. It consists of.

The adapter 13 of the optical connector 11 shown in FIGS. 1 and 2 is a rectangular tubular outer shell member (outer body) extending in the longitudinal direction. As shown in FIG. 3, the first and second adapter ends 15-1, 15-2 of the adapter 13 are provided.
Has first and second opposed ends having first and second square holes, respectively, and first and second outer peripheral ends.

Incidentally, the two square holes are rounded holes 17-1 described later.
Are insertion ports for receiving the components of the first plug 23 and the second plug 33 from the front and rear, respectively.

On the other hand, an intermediate portion 17 extending from the center in the longitudinal direction of the adapter 13 to one-fourth the front thereof has a round hole 17-1 for holding a connection position between ferrule end faces to be joined to each other, which will be described later. Have been. This round hole 1
At the front edge of 7-1, the tapered portion (boss 17-2) acts as an insertion guide, and the end surface portion A (see FIG. 3) acts as a stopper.

Referring to FIGS. 2, 3 and 4, first adapter end 15- of outer shell member (outer body) 13 will be described.
The first locking groove 16 is formed on the upper and lower surfaces of the first outer peripheral end of the first locking groove 16.
-1a and 16-1b are respectively provided on the upper and lower surfaces of the second outer peripheral end of the second adapter end 15-2.
a, 16-2b are respectively formed. First locking groove 16-1a, 16-1b and second locking groove 16-2
a, 16-2b are formed in a T shape with a large groove on the ferrule connection position side and a small groove on the outer peripheral end side.

As shown in FIG. 5, the first locking groove 16-
1a, 16-1b and second locking grooves 16-2a, 16-
The small groove 2b may have a tapered portion (trapezoidal shape). In this modification, the first locking grooves 16-1a and 16-1b and the second locking grooves 16-2a and 16-2b are formed as two-step grooves having trapezoidal small grooves, and as a result, the first and second locking grooves are formed. 2 The convex portions (first engaging convex portions) 27-1 of the inner bodies 29, 39,
27-2, 37 (there are two convex portions like 27)
It is harder to come off than in the embodiment.

Referring to FIGS. 14 and 15, outer shell member (outer body) 13 has rectangular opposite ends perpendicular to the longitudinal direction, and is formed with square holes.
The first and second locking grooves 16-1a, 16-1b, 16-2 at the first and second outer peripheral ends from both corners on the diagonal line of each opposing end.
The escape recesses 28-1 and 28-2 are formed along the longitudinal direction up to the vicinity of the large grooves a and 16-2b.

As shown in FIG. 16, escape recesses 28-1, 28-2, 28- are formed at four corners on both diagonal lines of the rectangular end.
3, and 28-4 may be formed.

The first plug 23 is connected to the first optical fiber 10-.
Insertion hole 25 for accommodating the first and first locking grooves 1
Convex part (first engagement convex part) that fits in 6-1a, 16-1b
A first inner body 29 having a first 27 and a first ferrule 31 for mounting and holding the first optical fiber 10-1 are provided. The first ferrule 31 includes a ferrule end surface 31-1.

On the other hand, the second plug 33 is provided with a second engaging projection which fits in the second insertion hole 35 for accommodating the second optical fiber 10-2 and the second locking grooves 16-2a and 16-2b. 37
A second inner body 39 having
And a second ferrule 41 for mounting and holding -2.
The optical fibers 10-1 and 10-2 and the ferrules 31 and 41 may be held and fixed by bonding.

The first ferrule 31 and the second ferrule 31
The ferrule 41 is the same member and is made of zirconia or crystallized glass, and has a φ1.25 mm cylindrical portion, that is, a ferrule main body having ferrule end surfaces 31-1, 41-1 and a rectangular ferrule flange portion formed of stainless steel. 31-2 and 41-2. The rectangular ferrule flange portions 31-2 and 41-2 are disposed in the respective square holes, and clamp the center portion 17, thereby suppressing and preventing rotation of the ferrule end surfaces 31-1 and 41-1 of the ferrule body. Is set to

The second plug 33 has a ferrule end face 31-.
Split sleeve 43 serving as a centering member for positioning joints 1 and 41-1 with each other;
A collar 45 disposed on the outer peripheral end of the split sleeve 43 to keep the ferrule connection position in the inside constant, and a coil spring (elastic member) 4 for pressing the second ferrule 41
7 is further provided. More specifically, the collar 45 is positioned so that the split sleeve 43 in the intermediate portion 17 of the outer shell member (outer body) 13 completely covers the joint between the ferrule end surfaces 31-1 and 41-1.

The procedure for assembling the optical connector 11 will be described with reference to FIGS.

First, as shown in step 1 of FIG.
Upper and lower convex portions (first engaging convex portions) 27 of the inner body 29
-1 and 27-2 are recessed recesses 2 of outer body 13
The first ferrule 31 and the inner body 29 are inserted into the component insertion opening in the front of the outer body 13, that is, the square hole at the first adapter end 15-1 while obliquely matching the position of the corner of 8-1.

Next, in step 2 of FIG. 15, referring also to FIG. 3, the upper and lower convex portions (the first
Engaging projections) 27-1 and 27-2 are connected to the first locking grooves 16-.
1a and the vicinity of the second locking groove 16-1b.

In step 3, the inner body 23 is rotated.

In step 4, the convex portion 27-1 of the inner body 29 is hooked and fixed to a small groove in the first locking groove 16-1a and the second locking groove 16-1b of the outer body 13.

Further, the split sleeve 43, the second ferrule 41, the coil spring (elastic member) 47, the collar 45, and the inner body 29 are inserted from the component insertion opening at the rear of the outer body 13, and similarly fixed. .
In this embodiment, one coil spring (elastic member) 47 is used.

The procedure for assembling the optical connector 11 described above may be reversed. That is, after inserting the split sleeve 43 of the second plug 33, the second ferrule 41, the coil spring (elastic member) 47, the collar 45, and the inner body 29, the first ferrule 31 and the inner body 29 of the first plug 23 are removed. Similarly, insert and fix.

With reference to FIGS. 10 to 13, the polished state of the ferrule end faces 31-1 and 41-1 used in the optical connector 11 of the present invention will be described.

In FIG. 11, the ferrule end face 31-
1 and 41-1 have a convex spherical surface (PC polished surface, AdPC
Polished surfaces) 31-1A and 41-1A are processed and formed.

In FIG. 12, the ferrule end face 31-
Oblique convex spherical surfaces (angle PC polished surfaces) 31-1B and 41-1B are processed and formed on 1 and 41-1.

In FIG. 13, the ferrule end face 31-
Oblique convex spherical surfaces are processed and formed on 1 and 41-1. In this case, one (left) ferrule end face 31-
1, a filter (anti-reflection film) 31-1C is formed by vapor deposition.

When simultaneously transmitting different wavelengths (for example, 1.3 μm and 1.55 μm), the optical connector 11 of the present invention deposits a filter on one ferrule end face to form a film. It can also be used as a component having a function of transmitting only wavelengths.

The above-described rectangular ferrule flange portion 31
When the ferrule ends are formed into oblique convex spherical surfaces (FIGS. 12 and 13) by the structures of FIGS. 2 and 41-2, the ferrule ends are stably joined and the ferrules are connected. The ferrule end has a convex spherical surface (FIG. 10).
And FIG. 11), if the connection is always made under a constant condition (the first and second members use the same material), the performance becomes more stable.

In the case of connection between ferrules whose ferrule ends are formed into oblique convex spherical surfaces (FIGS. 12 and 13), it is necessary to suppress the rotation of the ferrule at the time of fitting to ± 2 degrees or less. When the rotation of the ferrule occurs, performance and loss are significantly deteriorated. In addition, the ferrule end has a convex spherical surface (FIG. 1).
In the case of the connection between ferrules processed in FIG. 0 and FIG. 11), there is no remarkable performance and loss deterioration due to the rotation of the ferrule.

The optical fiber has a diameter of 125 μm.
is there. However, the core portion of the optical fiber bonded to the ferrule is eccentric although it is 1 μm or less. In the connection between single mode fibers, a loss of about 0.2 dB occurs due to an axis shift of 1 μm in the core portion. The above has been clarified by an evaluation test performed by the inventor, and it is desirable that the ferrule does not rotate during fitting.

Referring to FIG. 17, an optical connector 11 according to a second embodiment of the present invention uses two coil springs 48. In this case, the intermediate portion 17 of the adapter (outer body) 13 is formed substantially at the center in the longitudinal direction.

[0050]

The optical connector of the present invention has a simple structure in which the ferrules are sandwiched between the respective inner bodies, so that the following effects are obtained.

1. Can be assembled without using special jigs. As a result, it is inexpensive because of good operability of attaching and detaching.

2. Highly versatile because it can be connected regardless of the end shape of the ferrule. Therefore, the optical connector can be used for an in-line filter, and a high-performance optical connector having excellent optical characteristics can be obtained.

3. Since the ferrule has a rectangular member structure in which rotation is unlikely to occur at the time of fitting, a high-performance optical connector with little variation in performance can be obtained.

4. The engaging projection fits into and engages with the small groove of the locking groove, so that the locking groove requires only a small space in the longitudinal direction. Moreover, since the holding (locking) mechanism uses a rectangular member having a square hole, the optical connector can be reduced in size.

5. Since the inner bodies for pressing the ferrules are formed separately, the structure is simple and the assembly is easy.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an optical connector 11 according to an embodiment of the present invention.

FIG. 2 is an adapter 13 constituting the optical connector 11 of FIG.
It is a perspective view of.

3 is a partially sectional perspective view of the adapter 13 of FIG. 2 cut diagonally.

4 shows a first adapter end 15- of the adapter 13 of FIG. 2;
In the enlarged perspective view of FIG. 1, a first locking groove 16-1a is formed on the upper surface of the first outer peripheral end.

5 shows a first adapter end 15- of the adapter 13 of FIG. 4;
In the modification of the first embodiment, a first locking groove 16-1A is formed on the upper surface of the first outer peripheral end. First locking groove 16-1A
The small groove has a taper.

FIG. 6 shows an optical connector 11 of FIG.
It is a perspective view of the optical connector 11 after assembling with 1 and 10-2.

FIG. 7 is a partially sectional perspective view showing a fitted state of the optical connector 11 of FIG. 6;

8 is a side view of the optical connector 11 after being assembled together with the optical fibers 10-1 and 10-2 of FIG.

9 is a cross-sectional view of the optical connector 11 assembled with the optical fibers 10-1 and 10-2 of FIG. 6 cut longitudinally along the longitudinal direction.

FIG. 10 is a partial side view of ferrules having ferrule end faces 31A and 41A, and is also a partial cross-sectional view of a first modified example having a different polishing state.

FIG. 11 is an enlarged view of an intermediate portion 17 of FIG.

12 is a partial side view of ferrules having ferrule end faces 31B and 41B of FIG. 10, and is an enlarged view of an intermediate portion 17 of a second modified example having different polishing states.

FIG. 13 is a partial side view of ferrules having ferrule end surfaces 31C and 41C of FIG. 10, and is an enlarged view of an intermediate portion 17 of a third modified example having different polishing states.

FIG. 14 is a cross-sectional view taken along a facing end of the optical connector 11 for describing a procedure when the inner body 29 is incorporated into the outer body 13 together with the ferrule 31.

FIG. 15 is a diagram illustrating steps 1 to 4 for explaining the procedure of FIG. 14;
4A and 4B are a cross-sectional view taken along the opposite end of the optical connector 11 of FIG.

FIG. 16 is a front view of a modified example of the outer body 13; The first facing end has escape recesses 27-1, 2 at its four corners.
7-2, 27-3, 27-4 are formed along the longitudinal direction.

FIG. 17 shows an optical connector 11 according to a second embodiment of the present invention.
It is sectional drawing cut | disconnected longitudinally along the longitudinal direction of FIG.

[Explanation of symbols]

10-1, 10-2 Optical fiber 11 Optical connector 13 Adapter, rectangular tubular outer shell member (outer body) 15-1 First adapter end (first opposed end and first peripheral end) 15-1A First Adapter end 15-2 Second adapter end (second opposed end and second peripheral end) 16-1a, 16-1b First locking groove 17 Intermediate part 17-1 Round oblong hole 17-2 Boss (Stopper ) 23 first plug 25 first insertion hole 27-1 first engagement projection 27-2 first engagement projection 28-1 first escape recess 28-2 second escape recess 28-3 third escape recess 28 -4 Fourth recessed recess 29 First inner body 31 First ferrule 31-1 Ferrule end face of ferrule main body 31-2 Ferrule flange 33 Second plug 35 Second insertion hole 37 Second engagement projection 39 Second inner Body 41 Second Ferrule 41-1 Ferrule End Surface of Cylindrical Ferrule Main Body 41-2 Rectangular Ferrule Flange 43 Split Sleeve 45 Collar 47 Elastic Member (Coil Spring)

Claims (5)

[Claims] 1. An optical connector having an adapter interposed between a first plug and a second plug for connecting first and second optical fibers, wherein the adapter extends along a longitudinal direction. A tubular outer shell member having first and second ends, wherein the first and second adapter ends are arranged along the longitudinal direction so as to receive the first and second plugs, respectively. The first plug has first and second opposed ends having first and second insertion ports, and first and second outer peripheral ends having first and second locking grooves. A first inner body having a first insertion hole for inserting one optical fiber and a first engagement projection fitted into the first locking groove; and a first inner body for housing, mounting and holding the first optical fiber. A second ferrule, wherein the second plug has a second insertion hole for inserting the second optical fiber and a second insertion hole. A second inner body having a second engagement projection fitted into the second locking groove; and a second ferrule for mounting and holding the second optical fiber, wherein the first ferrule and the second ferrule are provided. Has a ferrule main body having ferrule end faces to be joined to each other, and first and second rectangular ferrule flange portions, and the second plug is positioned when the first and second ferrules are joined to each other. The first and second adapter ends have a rectangular square hole for accommodating the first and second inner bodies and the first and second ferrule flanges. An optical connector characterized by being formed respectively, whereby the first and second ferrules are sandwiched, locked and held between the first and second inner bodies. 2. The optical connector according to claim 1, wherein the second plug further includes a collar disposed on an outer peripheral end of the alignment member, and an elastic member for urging the second ferrule. ,
Thereby, the centering member is moved to the first position by the collar.
An optical connector characterized in that the optical connector is positioned at an intermediate portion of a second ferrule joining point and the first and second ferrules are pressed against each other. 3. The optical connector according to claim 1, wherein the first and second opposed ends of the outer shell member have a rectangular opening, and the first and second opposite ends are formed from both corners on a diagonal thereof. An optical connector, wherein escape recesses are formed along the longitudinal direction up to the vicinity of the first and second locking grooves at the outer peripheral end. 4. The optical connector according to claim 1, wherein the first locking groove has a T shape including a large groove for provisional insertion at a ferrule connection position side and a small fixing groove at an outer peripheral end side. An optical connector characterized by being drilled as follows. 5. The optical connector according to claim 4, wherein the small groove of the first locking groove has a tapered portion.