JP5075562B2 - Multi-fiber optical connector and assembly method thereof - Google Patents

Description

  The present invention relates to a multi-fiber optical connector including a ferrule having a plurality of optical fiber holes, and more particularly, to a multi-fiber optical connector including ferrules in which optical fiber holes are arranged in a plurality of rows and opened to a joining end surface, and an assembling method thereof About.

For example, a plurality of optical fiber holes are formed in the ferrule as in the MT type multi-fiber optical connector (MT: Mechanically Transferable) defined in JIS C 5981 and the like, and by fixing the optical fiber to these optical fiber holes, There is a multi-fiber optical connector in which a plurality of optical fibers can be optically connected together.
As this type of multi-fiber optical connector, there is a multi-fiber optical connector having a multi-fiber structure by forming a plurality of rows of optical fiber holes. As the optical fiber, a single-core optical fiber or a taped multi-core optical fiber is used.
In an optical connector in which optical fiber holes are formed in a plurality of rows, it is difficult to insert optical fibers into fine optical fiber holes when assembling.
As an optical connector that can solve this problem, there is known an optical connector in which a base portion having a guide groove for introducing an optical fiber is formed in multiple stages in a ferrule (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-84177

However, the multi-fiber optical connector having the above-described structure has a problem that as the number of fibers is increased, the structure inside the ferrule becomes more complicated and it becomes difficult to form the ferrule.
When a taped multi-core optical fiber is used, insertion into the optical fiber hole is relatively easy, but there is a limit to increasing the density (multi-core).
The present invention has been made in view of the above-mentioned problems, and in an optical connector in which optical fiber holes are formed in a plurality of rows on the joining end face, the optical fiber can be efficiently inserted into the optical fiber holes, In addition, an object of the present invention is to provide a multi-fiber optical connector capable of increasing the density and an assembling method thereof.

The present invention comprises a ferrule having a plurality of optical fiber holes in which N rows (N is an integer of 2 or more) and N-1 rows arranged in the width direction are alternately arranged and opened at the joint end face, In each of the plurality of optical fiber holes , a leading end portion of a single-core coated optical fiber can be inserted, and the ferrule has a bonding wall portion whose one surface is the bonding end surface, and a rectangular cross section of the peripheral wall portion and the joining end face from the peripheral edge extending in the opposite direction, said plurality of optical fiber hole has a close-packed arrangement to each other coating is in contact at a plurality of the sheathed optical fiber in the ferrule The plurality of optical fiber holes are coated at both ends in the width direction and at the bottom end of the plurality of coated optical fibers inserted therethrough. Each of the attached optical fibers Provided but both sides in the width direction of the peripheral wall (2d, 2d), and the side wall portion of the bottom side multi-fiber optical connector that is formed at a position corresponding to the distal portion when in contact with the respective inner surfaces of the (2c) .
In the multi- fiber optical connector of the present invention, the coated optical fiber located at the top end of the plurality of coated optical fibers through which the plurality of optical fiber holes are inserted is provided on the inner surface of the side wall portion on the top side. It is preferable that it is formed at a position corresponding to the tip portion when it contacts .
In the multi-fiber optical connector according to the present invention, the coated optical fiber includes a bare optical fiber forming the tip and a coating layer formed on an outer periphery thereof, and the tip of the coating layer is formed on the bonding wall. It is preferable that they are formed at close positions.
In the multi-fiber optical connector of the present invention, it is preferable that the coated optical fiber is an optical fiber core or an optical fiber, and the tip is an optical fiber bare wire.

The present invention includes a ferrule having a plurality of optical fiber holes in which N rows (N is an integer of 2 or more) arranged in the width direction and N-1 rows are alternately arranged and opened in the joint end face. a method of assembling a multiple-core optical connectors, to each of the plurality of optical fiber hole is yarn end finding are tip of the sheathed optical fiber of single core is insertable, said ferrule, one surface the a joining wall portion which is the joining end face, and a peripheral wall portion having a rectangular cross section extending in a direction opposite to the joining end face of its periphery, the plurality of optical fiber holes, the plurality of the sheathed optical fiber The ferrule is formed at a position corresponding to the tip when the coating is in close-packed arrangement where the coatings are in contact with each other , and the plurality of optical fiber holes are among the plurality of coated optical fibers inserted through them. Both ends in the width direction, and Each of the coated optical fibers located at the bottom end is in a position corresponding to the tip when contacting the inner surfaces of the peripheral wall portions (2d, 2d) on both sides in the width direction and the side wall portion (2c) on the bottom side. In the state where the coated optical fibers are formed and closely arranged in a line along the inner surface of the ferrule, their tip portions are inserted into the optical fiber holes, and a plurality of the coated optical fibers are placed on the coated optical fibers. Provided is a method of assembling a multi-fiber optical connector in which the tip end portions are inserted into the optical fiber holes in a state where the coated optical fibers are arranged in a close-packed arrangement.

According to the present invention, since the optical fiber hole is formed at a position corresponding to the tip portion of the coated optical fiber when it is in the close-packed arrangement, the coated optical fibers are arranged so as to be in the close-packed arrangement. The tip portion is disposed at a position corresponding to the optical fiber hole. For this reason, a front-end | tip part can be easily inserted in an optical fiber hole.
Moreover, when the coated optical fiber is placed so as to be the most densely arranged on the densely arranged coated optical fiber, the coated optical fiber is not covered with the already arranged coated fibers when the tip portion is inserted into the optical fiber hole. Since it is guided by the attached optical fiber, the tip can be easily inserted into the optical fiber hole.
For this reason, the front-end | tip part of a coated optical fiber can be efficiently inserted in an optical fiber hole.
In addition, since the coated optical fiber is arranged in a close-packed manner, high-density mounting is possible.
Furthermore, since the structure for guiding the optical fiber in the ferrule is not required, the structure of the ferrule can be simplified and the manufacturing cost can be reduced.

The best mode for carrying out the present invention will be described below with reference to the drawings.
1A and 1B are diagrams showing an example of a multi-fiber optical connector according to the present invention. FIG. 1A is a front view, and FIG. 1B is an enlarged view of a joining end surface. 2 and 3 are perspective views of the multi-fiber optical connector shown in FIG. FIG. 4 is an enlarged view of a main part of the multi-fiber optical connector.

As shown in FIGS. 1-4, the multi-fiber optical connector 12A which is an example of the multi-fiber optical connector of this invention is assembled at the front-end | tip of the optical fiber core wire 1 (refer FIG. 3).
The multi-fiber optical connector 12 </ b> A has a ferrule 12. The illustrated multi-fiber optical connector 12A is an MT type multi-fiber optical connector (MT: Mechanically Transferable) defined in JIS C 5981 or the like.
In the following description, the front side (connection direction) in FIG. 1 may be referred to as the front, and the opposite direction may be referred to as the rear. In addition, the direction corresponding to the short side of the joining end face 4 of the ferrule 12 (the vertical direction in FIG. 1A) is referred to as the thickness direction, and the direction corresponding to the long side (the horizontal direction in FIG. 1A) is the width. It is called direction.

As shown in FIG. 3, the optical fiber core wire 1 is a single-core coated optical fiber composed of a bare optical fiber 8 and a resin coating layer 9 formed on the outer periphery thereof, and has a circular cross section in the illustrated example. .
As the bare optical fiber 8, an all-quartz single mode optical fiber, an all-quartz multimode optical fiber, or the like can be used.
The resin coating layer 9 is composed of a single layer or multiple layers, and examples of the constituent material include UV curable resins such as urethane acrylate, epoxy acrylate, and butadiene acrylate, polyimide resins, and the like.
As for the optical fiber core wire 1, the bare optical fiber 8 is lead out in the front-end | tip part 1a.
Instead of the optical fiber core 1, another coated optical fiber, for example, an optical fiber can be used.
Here, as an optical fiber core wire, a structure in which a bare layer made of glass is covered with a buffer layer, a nylon coating layer is covered thereon, and an outer diameter is 0.9 mm can be suitably used. As the optical fiber, one having a structure in which a bare wire made of glass is covered with a coating made of an ultraviolet curable resin and an outer diameter is 0.25 mm can be suitably used. These have a clad diameter of, for example, 125 μm. In addition, a primary coating layer (outer diameter 110 μm) made of a urethane acrylate-based ultraviolet curable resin is provided on the outer periphery of a cladding layer (core diameter 50 μm) having an outer diameter of 80 μm, and a colored coating layer (outer diameter 125 μm) is provided on the outer periphery. It is also possible to use a provided thin optical fiber core wire.

As shown in FIGS. 1 to 3, the ferrule 12 includes a substantially rectangular parallelepiped ferrule main body 2 into which the optical fiber core wire 1 is introduced, and a flange having a width wider than the ferrule main body 2 formed at the rear end thereof. 3.
As shown in FIG. 2, the ferrule body 2 includes a rectangular joining wall portion 2 a and a peripheral wall portion 2 h extending rearward from the peripheral edge thereof.
The peripheral wall portion 2h includes side wall portions 2b and 2c extending from the long side of the joining wall portion 2a and end wall portions 2d and 2d extending from the short side.

As shown in FIGS. 1 and 2, the front end face of the joining wall portion 2 a is a joining end face 4 on which the tip of the optical fiber core wire 1 is positioned and fixed so that it can be abutted and connected.
A plurality of optical fiber holes 6 into which the distal end portion 1a of the optical fiber core wire 1 is inserted and guide pin holes 7 (positioning member insertion holes) are formed in the bonding wall portion 2a.
The guide pin hole 7 is for inserting and fitting a guide pin for positioning with another optical connector to be butt-connected to the optical connector 20.
On the side wall 2b, a window 2f used for injecting an adhesive into the internal space 2e of the ferrule 12 is formed.
As shown in FIG. 3, an opening 2 g for introducing the optical fiber core wire 1 into the ferrule 12 is formed on the rear surface side of the ferrule 12.

As shown in FIGS. 1 and 2, the optical fiber hole 6 is formed so as to penetrate the joining wall 2a. The inner surface of the end portion of the optical fiber hole 6 on the inner space 2e side is a tapered surface whose diameter gradually increases toward the inner space 2e side, and the position of the tip end portion 1a is slightly shifted from the center of the optical fiber hole 6. The tip portion 1a can be easily inserted.
The optical fiber core wire 1 is introduced into the ferrule 12 from the opening 2g on the rear surface side, and the exposed optical fiber bare wire 8 (tip portion 1a) is inserted into the optical fiber hole 6, and the inner surface of the optical fiber hole 6 is inserted. Adhered and fixed to.
The internal space 2e in the ferrule 12 is free from protrusions such as positioning shelves and stepped bases, and a sufficient space is secured to allow the optical fiber cores 1 and 1 to contact each other.

As shown in FIG. 1A, the optical fiber holes 6 are formed in a plurality of rows on the joint end surface 4.
In the illustrated example, the openings 6a of the plurality of optical fiber holes 6 that are arranged in the width direction are arranged in a plurality of rows. Specifically, a row of 11 openings 6a and a row of 12 openings 6a are alternately formed in a total of 9 stages (9 rows). Each row is parallel to each other.
The plurality of rows of optical fiber holes 6 are shifted in the width direction for each row, and are arranged in a staggered manner as a whole.

As shown in FIG. 1B, the optical fiber holes 6 in the row closest to the side wall 2c (hereinafter referred to as the first row 10a) are formed at regular intervals in the width direction, and the pitch L1 is the optical fiber core wire 1. Is approximately equal to the outer diameter of the. The pitch is the distance between the centers of the adjacent optical fiber holes 6 and 6.
The position in the thickness direction (height direction) of the optical fiber holes 6 in the first row 10a is set so that the height difference L2 from the inner surface of the side wall 2c is substantially equal to the thickness of the resin coating layer 9. Yes. For this reason, the outer surface of the optical fiber core wire 1 in which the distal end portion 1a is inserted into the optical fiber hole 6 of the first row 10a is in contact with the inner surface of the side wall portion 2c.
Of the optical fiber holes 6 in the first row 10a, the distance L3 between the optical fiber holes 6b and 6c located at one end and the other end in the width direction and the inner surfaces of the end wall portions 2d and 2d is the thickness of the resin coating layer 9. Is almost equal. For this reason, the outer surface of the optical fiber core wire 1 in which the distal end portion 1a is inserted into the optical fiber holes 6b and 6c is in contact with the inner surface of the end wall portion 2d.

Also in the second row 10b and the subsequent rows 10c, 10d,..., The pitch of the optical fiber holes 6 in that row is substantially equal to the outer diameter of the optical fiber core wire 1.
The position in the width direction of the optical fiber holes 6 in the second row 10b is shifted from the position in the width direction of the optical fiber holes 6 in the first row 10a by half the outer diameter of the optical fiber core wire 1. The same applies to the even columns after the fourth column 10d. For odd rows after the third row 10c, the position of the optical fiber hole 6 in the width direction is the same as that of the first row 10a.

The position in the thickness direction (height direction) of the optical fiber holes 6 in the second row 10b is such that the distance between the centers of the optical fiber holes 6 and the adjacent optical fiber holes 6 in the first row 10a is light. It is set to be approximately equal to the outer diameter of the fiber core wire 1.
In the illustrated example, the optical fiber hole 6d located at one end in the width direction of the second row 10b is adjacent to the optical fiber hole 6b at one end of the first row 10a and the optical fiber hole 6e adjacent thereto. The center-to-center distance L4 of the optical fiber holes 6d and 6b and the center-to-center distance L5 of the optical fiber holes 6d and 6e are substantially equal to the outer diameter of the optical fiber core wire 1, respectively.
For this reason, the outer surface of the optical fiber core wire 1 in which the tip portion 1a is inserted into the optical fiber hole 6d is the outer surface of the optical fiber core wires 1c and 1d in which the tip portions 1a and 1a are inserted into the optical fiber holes 6b and 6e. Will be in touch. The same applies to the other columns 10c, 10d,.

That is, since the distance between the centers of the optical fiber hole 6 and the optical fiber hole 6 adjacent to the optical fiber hole 6 is almost equal to the outer diameter of the optical fiber core wire 1, the distal end portion 1 a is inserted into the optical fiber hole 6. The outer surface of the optical fiber core wire 1 is an optical fiber core wire in which the tip end portion 1a is inserted into the optical fiber holes 6, 6,. 1 and 1 are in contact with the outer surface.
In other words, the optical fiber core wire 1 in which the tip end portion 1a is inserted into the optical fiber hole 6 takes a close-packed arrangement (hereinafter referred to as a close-packed arrangement). The close-packed arrangement is an arrangement in which the gap between the optical fiber core wire 1 and the optical fiber core wire 1 adjacent thereto is minimized, and the optical fiber core wire 1 is in contact with a maximum of six optical fiber core wires 1.

A guide groove (not shown) in which the optical fiber core wire 1 is fitted may be formed on the inner surface of the side wall portion 2c at a position corresponding to the optical fiber core wire 1 constituting the first row 5a. Thereby, the operation of inserting the distal end portion 1a into the optical fiber hole 6 becomes easier.
Alternatively, a guide member (not shown) in which a guide groove (not shown) into which the optical fiber core wire 1 is fitted may be prepared separately and disposed in the ferrule 12.

  As shown in FIGS. 3 and 4, the position in the front-rear direction of the tip 9 a of the resin coating layer 9 is not particularly limited, but is desirably a position close to the bonding wall portion 2 a. The optical fiber cores 1 are preferably in contact with each other at a portion including the tip 9a of the resin coating layer 9.

Next, assembly of the multi-fiber optical connector 12A to the optical fiber core wire 1 will be described.
As shown in FIGS. 3 and 4, the plurality of optical fiber core wires 1 from which the bare optical fibers 8 are led out are arranged densely in a line and introduced into the ferrule 12 from the opening 2 g on the rear surface side.
In the illustrated example, twelve optical fiber cores 1 are inserted into the ferrule 12 in a line on the side wall 2c, and each tip 1a is inserted into the optical fiber hole 6 in the first row 10a. Adjacent optical fiber cores 1 and 1 are in contact with each other.

As shown in FIG. 1B, the optical fiber holes 6 in the first row 10a have a pitch L1 substantially equal to the outer diameter of the optical fiber core wire 1 and a difference in height L2 from the inner surface of the side wall portion 2c. Since the thickness of the layer 9 is substantially equal, when the optical fiber cores 1 are arranged and placed on the side wall 2c (hereinafter referred to as the optical fiber cores 1 in the first row 5a), the tip end portion 1a has the optical fiber hole 6 It is arranged at the position according to.
Since the distance L3 between the optical fiber holes 6b, 6c at both ends in the width direction and the inner surfaces of the end wall portions 2d, 2d is substantially equal to the thickness of the resin coating layer 9, the optical fiber cores 1 at both ends in the arrangement direction are Since it is in contact with the end wall 2d, no deviation in the width direction occurs.
Therefore, the tip 1a can be easily inserted into the optical fiber hole 6.

The optical fiber holes 6 in the second row 10b have a pitch substantially equal to the outer diameter of the optical fiber core wire 1, and the distance between the centers of the optical fiber holes 6 adjacent to the optical fiber holes 6 in the first row 10a (for example, distances L4 and L5). Is substantially equal to the outer diameter of the optical fiber core wire 1.
For this reason, when the optical fiber cores 1 in the second row 5b are placed on the optical fiber cores 1 in the first row 5a so as to be in a close-packed arrangement, the tips of the optical fiber cores 1 in the second row 5b The part 1a is arranged at a position corresponding to the optical fiber holes 6 in the second row 10b.
In the close-packed arrangement, the optical fiber cores 1 in the second row 5b are in contact with the two adjacent optical fiber cores 1 and 1 in the first row 5a. In the illustrated example, the optical fiber core wire 1b located at one end in the width direction of the second row 5b is in contact with the optical fiber core wire 1c at one end of the first row 5a and the optical fiber core wire 1d adjacent thereto.
Since the optical fiber core 1b is in contact with the two optical fiber cores 1c and 1d, there is no deviation in the width direction.

Since the distal end portion 1a of the optical fiber cores 1 in the second row 5b is disposed at a position corresponding to the optical fiber hole 6 in the second row 10b, the distal end portion 1a can be easily attached to the optical fiber hole 6 in the second row 10b. Can be inserted into.
At this time, the optical fiber cores 1 in the second row 5b are guided by the optical fiber cores 1 in the first row 5a. In the illustrated example, since the optical fiber core wire 1b is guided by the optical fiber core wires 1c and 1d in the first row 5a, the distal end portion 1a can be smoothly inserted into the optical fiber hole 6.
Similarly, with regard to the third row 5c, the fourth row 5d,..., The tip end portion 1a can be easily inserted into the optical fiber hole 6 in a state where the optical fiber core wire 1 is placed so as to be in the close-packed arrangement. .
Therefore, the tip end portion 1 a of the optical fiber core wire 1 can be efficiently inserted into the optical fiber hole 6.
Moreover, since the optical fiber core wire 1 is arranged in the closest packing, high-density mounting is possible.
Furthermore, since the structure for guiding the optical fiber core wire 1 in the ferrule 12 is not required, the structure of the ferrule 12 can be simplified and the manufacturing cost can be reduced.

5A and 5B are schematic views showing another example of the optical connector of the present invention, in which FIG. 5A is a plan view and FIG. 5B is a side view.
The optical connector 20 is assembled at the tip of the optical fiber cord 16, and includes the ferrule 12 configured as described above, the housing 11 that houses the ferrule 12, the coupling 13 provided outside the housing 11, It has a spring 15 housed inside and a boot 17 provided on the rear end side of the housing 11.
The optical connector 20 in the illustrated example is a push-on type optical connector having the same function as an MPO type optical connector (MPO: Multifiber Push-On) defined in JIS C 5982.
The spring 15 applies a reaction force to the housing 11 and biases the ferrule 12 forward.
The boot 17 prevents sudden bending of the optical fiber cord 16 near the rear end of the optical connector 20.
An optical fiber core wire 1 drawn from the optical fiber cord 16 is introduced into the ferrule 12.

It is a figure which shows an example of the multi-fiber optical connector of this invention, (a) is a front view, (b) is an enlarged view of a joining end surface. It is a perspective view of the multi-fiber optical connector shown in FIG. It is a perspective view of the multi-fiber optical connector shown in FIG. It is the figure which expanded the principal part of the multi-fiber optical connector shown in FIG. It is a schematic diagram which shows the other example of the optical connector of this invention, (a) is a top view, (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical fiber core wire (coated optical fiber), 1a ... tip part, 2a ... joining wall part, 2h ... peripheral wall part, 2c ... side wall part, 2d ... end wall 4, joint end face, 5 a, optical fiber core wire in the first row, 5 b, optical fiber core wire in the second row, 6, optical fiber hole, 6 a, opening, 8 ... Bare optical fiber, 9 ... Resin coating layer, 10a ... Optical fiber hole in the first row, 10b ... Optical fiber hole in the second row, 12 ... Ferrule, 12A, 20, ..Optical connectors.

Claims (5)

A ferrule having a plurality of optical fiber holes (6) in which N rows (N is an integer of 2 or more) and N-1 rows arranged alternately in the width direction and N-1 rows opened in the joint end face (4) ( 12)
In each of the plurality of optical fiber holes , the leading end portion (1a) of the single-core coated optical fiber (1) can be inserted,
The ferrule includes a joining wall portion (2a) whose one surface is the joining end surface, and a peripheral wall portion (2h) having a rectangular cross section extending from the periphery thereof in a direction opposite to the joining end surface,
Said plurality of optical fiber hole is formed at a position corresponding to the tip portion when a plurality of the coated optical fiber with a close-packed arrangement to each other coating is in contact in said ferrule,
The plurality of optical fiber holes are formed by connecting the coated optical fibers positioned at both ends in the width direction and at the bottom end of the plurality of coated optical fibers inserted through them into the peripheral wall portions (2d, 2d) and a multi-fiber optical connector (12A), characterized in that it is formed at a position corresponding to the tip when contacting the respective inner surfaces of the bottom side wall (2c ). The plurality of optical fiber holes are formed at the tip when the coated optical fiber positioned at the top end of the plurality of coated optical fibers inserted through them is in contact with the inner surface of the side wall (2b) on the top side. The multi-fiber optical connector (12A) according to claim 1, wherein the multi-fiber optical connector (12A) is formed at a position corresponding to the portion . The coated optical fiber comprises an optical fiber bare wire (8) forming the tip, and a coating layer (9) formed on the outer periphery thereof,
The multi-fiber optical connector according to claim 1 or 2 , wherein a tip (9a) of the covering layer is formed at a position close to the joining wall portion. The coated optical fiber is an optical fiber core or an optical fiber,
The multi-fiber optical connector according to claim 1, wherein the tip portion is a bare optical fiber. A ferrule having a plurality of optical fiber holes (6) in which N rows (N is an integer of 2 or more) and N-1 rows arranged alternately in the width direction and N-1 rows opened in the joint end face (4) ( 12) a method of assembling a multi-fiber optical connector comprising:
In each of the plurality of optical fiber holes , the leading end portion (1a) of the single-core coated optical fiber (1) can be inserted,
The ferrule includes a joining wall portion (2a) whose one surface is the joining end surface, and a peripheral wall portion (2h) having a rectangular cross section extending from the periphery thereof in a direction opposite to the joining end surface,
Said plurality of optical fiber hole is formed at a position corresponding to the tip portion when a plurality of the coated optical fiber with a close-packed arrangement to each other coating is in contact in said ferrule,
The plurality of optical fiber holes are formed by connecting the coated optical fibers positioned at both ends in the width direction and at the bottom end of the plurality of coated optical fibers inserted through them into the peripheral wall portions (2d, 2d), and a position corresponding to the tip when contacting the inner surface of the bottom side wall (2c),
In the state where the coated optical fibers are closely arranged in a line along the inner surface of the ferrule, these tip portions are inserted into the optical fiber holes (10a),
A plurality of coated optical fibers (5b) are arranged on top of these coated optical fibers (5a) so as to be in a close-packed arrangement, and the tip portions thereof are inserted into the optical fiber holes (10b). A method for assembling a multi-fiber optical connector.

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