JP2000019347A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connector which facilitates the handling of short-length optical fibers in assembling work of the optical connector and allows the easy cleaning of polishing dust, etc. SOLUTION: This optical connector has a ferrule 1 which is provided with optical fiber insertion holes 1c, a positioning member 4 which has optical fiber fixing grooves 4b aligned to these optical fiber insertion holes 1c, a retaining member 5 which retains and fixes the optical fibers to the optical fiber fixing grooves 4b of the positioning member 4 and a clamping member 6 which holds the positioning member 4 and the retaining member 5. The short-length optical fibers 2 are previously built in from the optical fiber insertion holes of the ferrule 1 to a portion in the longitudinal direction of the optical fiber fixing grooves 4b of the positioning member 4. The intermediate parts of the short- length optical fibers 2 are coated by coating parts 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector used for connecting optical fiber cores or optical fiber cores to optical equipment.

[0002]

2. Description of the Related Art With the spread of optical communication, when connecting optical fiber cores constituting optical cables, optical cords, or the like, or optical fiber cores to optical equipment, terminals of the optical fiber cores are installed at the installation site. There is a need for an optical connector that can be easily mounted on a computer. When an optical connector is attached to a terminal of an optical fiber core and an optical connector or an optical connector and an optical device are to be connected to each other, it is necessary to accurately adjust the axial center position of the optical fiber.

For this reason, a ferrule that has been precisely machined is disposed at the tip of the optical connector, and the axis of the optical fiber is accurately determined by the ferrule. Also, in order to facilitate the coupling of the ferrules, the optical fiber insertion hole of the ferrule is inserted into the optical fiber insertion hole of the ferrule. Polish with the surface. At this time, an operation for polishing the optical fiber requires a polishing machine or the like, and the operation is difficult at a laying site or the like.

[0004] Therefore, the polishing step at the installation site is eliminated,
The necessary polishing has been devised in advance so that it can be performed in the factory. The method is to prepare a short bare glass optical fiber having a length of several centimeters (hereinafter referred to as “short optical fiber”), and insert the optical fiber insertion hole of a ferrule provided with an optical fiber insertion hole in a factory beforehand. The short end of the bare optical fiber is inserted into and fixed to the end face of the ferrule, and the end face of the optical fiber and the end face of the ferrule are polished in the factory. Bring the ferrule containing the fiber to the installation site, and connect the rear end face of the short optical fiber to the front end face of the optical fiber exposed by removing the coating at the end of the long optical fiber core. The method described in
No. 127371.

FIG. 4 shows such an example.
4A is a longitudinal sectional view of the optical connector containing the short optical fiber before being attached to the optical fiber core, and FIG. 4B is a longitudinal sectional view after the optical connector is attached to the optical fiber core. .
21 is a ferrule, 21a is a holding member insertion groove, 2
1b is a rear optical fiber insertion hole, 21c is a front optical fiber insertion hole, 22 is a flange, 23 is a short optical fiber, 23a is a distal end surface of a short optical fiber, 23b is a rear end surface of a short optical fiber, 24 is a pressing member, 25 is a clamp member, 26 is an optical fiber core wire, 27 is an optical fiber, 27a is a distal end face of the optical fiber, and 28 is a joint.

The short optical fiber 23 is inserted in advance in a portion from the front optical fiber insertion hole 21c of the ferrule to the vicinity of the center of the holding member insertion groove 21a and is fixed with an adhesive. The tip surface 23a is polished together with the tip surface of the ferrule 21. In the holding member insertion groove 21a of the ferrule, an optical fiber fixing groove is formed in the longitudinal direction so as to be aligned with the front optical fiber insertion hole 21c. The rear end surface 23b of the short optical fiber 23 is mirror-cut, and the rear end portion of the short optical fiber is inserted and mounted in the optical fiber fixing groove. The collar 22 is a member used when fixing the ferrule to an adapter (not shown) or the like, and is fixed to the ferrule 21.

[0007] In such a state, the optical connector is delivered to the installation site, and the optical connector is attached to the terminal of the optical fiber to be attached at the installation site. When mounting,
The coating on the end of the optical fiber 26 is removed to expose the optical fiber 27, and the tip of the optical fiber 27 is cut into a mirror surface to form a tip surface 27a. And optical fiber 2
7 through the rear optical fiber insertion hole 21b of the optical connector, and the rear end face 23b of the short optical fiber 23 and the optical fiber 2
7 with the tip end surface 27a via a matching oil.

Then, the short optical fiber 23 and the optical fiber 27 on the side of the optical fiber 26 near the butted joint 28 are pressed and fixed by the clamp member 25 with the pressing member 24 applied thereto from above. The optical fiber core 26 is bonded and fixed, or a so-called rubber boot or the like is placed on the optical fiber core 26 so that an unreasonable force is not applied to the optical fiber core 26 near the boundary between the optical connector and the optical fiber core 26. May be covered.

[0009]

In the above-described optical connector containing a short optical fiber, a bare optical fiber made of quartz glass or the like is inserted and fixed in the optical fiber insertion hole of the ferrule, and the optical fiber and the ferrule are connected to each other. Is polished. The operation of inserting an optical fiber into the optical fiber insertion hole of a ferrule is usually performed by hand, but since bare optical fiber is handled, great care must be taken not to damage the optical fiber.

In polishing the ferrule and the tip end surface of the optical fiber, fine polishing dust is generated. Since the polishing debris is easily scattered, the polishing debris may adhere to the inside of the holding member insertion groove. The upper surface of the holding member insertion groove is open and can be cleaned for the time being.However, since the short optical fiber is already inserted in the optical fiber fixing groove formed in the holding member insertion groove, It takes utmost care and effort to remove the abrasive debris that has entered by cleaning. In some cases, a dustproof cover is attached to the holding member insertion groove to perform the work. In that case, however, it takes time to attach the dustproof cover.

An object of the present invention is to provide an optical connector which can easily handle short optical fibers in such an optical connector assembling operation, and can easily clean off polishing dust and the like.

[0012]

An optical connector according to the present invention comprises:
A ferrule having an optical fiber insertion hole, a positioning member having an optical fiber fixing groove axially aligned with the optical fiber insertion hole, a pressing member for pressing and fixing an optical fiber in the optical fiber fixing groove of the positioning member; A short optical fiber is provided in advance from the optical fiber insertion hole of the ferrule to a part of the longitudinal direction of the optical fiber fixing groove of the positioning member. Is coated with

Further, the ferrule, the positioning member and the pressing member are separable, and the pressing member is pressed against the positioning member by one clamp member, and the positioning member and the pressing member are fixedly held on the ferrule. If it is, it is easy to clean the polishing debris when polishing the tip surface of the ferrule and the short optical fiber, and with one clamp member,
The pressing and fixing of the pressing member to the positioning member can be performed, and the ferrule can be connected and held to the positioning member and the pressing member.

[0014]

FIG. 1 is a view showing one embodiment of a multi-core optical connector according to the present invention. FIG. 1A is a perspective view of each member, and FIG. 1) is an assembled perspective view of the optical connector, and FIG. 1C is a sectional view in the X direction. In FIG. 1, 1 is a ferrule, 1a is a flange, 1b is a guide pin hole, 1c is an optical fiber insertion hole, 2 is a plurality of short optical fibers, 3 is a coating portion, 4 is a positioning member, 4a is a wedge member insertion groove. 4b is an optical fiber fixing groove, 5 is a pressing member, 5
a is a clamp groove, 6 is a clamp member, 6a is a positioning clamp part, and 6b is a ferrule fixing part.

At the rear end of the ferrule 1, a flange 1a is integrally formed. In the manufacture of the optical connector, first, a coated tape-shaped optical fiber core is prepared for the short optical fiber 2, and the end of the coating is removed to expose the bare glass optical fiber. prepare.

Then, the exposed optical fiber portion is inserted from behind into the optical fiber insertion hole 1c of the ferrule 1, and the ferrule 1 and the optical fiber or the ferrule 1 and the coated portion of the optical fiber core are fixed with an adhesive. . Then, the optical fiber protruding from the tip of the ferrule 1 is cut, and the tip surfaces of the ferrule 1 and the optical fiber are polished.

Next, the tape-shaped optical fiber core having the terminal inserted and fixed in the ferrule 1 is reduced to a predetermined length (the length of the ferrule + 1/2 the length of the positioning member) required as the short optical fiber 2. Cut with a margin of several cm. Then, the coating on the side opposite to the ferrule 1 is removed while leaving the coating portion 3 of about 1 cm at the time of the ferrule to expose the optical fiber. Next, the rear end portion of the coated optical fiber that is not on the ferrule side is mirror-cut to a predetermined length to obtain a short optical fiber 2.

Since the positioning member 4 is provided with an optical fiber fixing groove 4b in the longitudinal direction, the rear end of the short optical fiber 2 fixed to the ferrule 1 is inserted and mounted in the optical fiber fixing groove 4b. The holding member 5 is pressed, and the rear end of the short optical fiber 2 is pressed and fixed together with the holding member 5 by the positioning clamp portion 6 a of the clamp member 6. At this time, the rear end face of the short optical fiber is located substantially at the center of the optical fiber fixing groove 4b in the longitudinal direction.

Further, the positioning member 4 and the pressing member 5 constitute a plug-in connecting portion so that the ferrule 1 or the flange 1a can be plugged and connected in a linear state. Further, the ferrule fixing portion 6b of the clamp portion 6 has a function of connecting and holding the positioning member 4 and the pressing member 5 so as not to be detached from the ferrule 1. In addition, since the positioning clamp part 6a of the clamp part 6 and the ferrule fixing part 6b are integrated by the connection part, the insertion connection part is securely connected and held.

The optical connector of the present invention is processed in a factory to the above state and delivered to the installation site. At the installation site,
In attaching the optical connector to the optical fiber core, first, the end of the tape-shaped optical fiber core to which the optical connector is to be attached is removed to expose the optical fiber, and the end is mirror-cut. Then, the pressing state of the clamp member 6 of the optical connector is loosened, and the distal end portion of the optical fiber is inserted into the optical fiber fixing groove 4b of the positioning member 4 from the opposite side of the short optical fiber 2, and the short optical fiber 2
Then, the pressed state of the clamp member 6 is returned to the original state, and the rear end portion of the short optical fiber 2 and the front end portion of the optical fiber are pressed and fixed.

In addition, a refractive index matching agent such as silicone oil is injected into the optical fiber fixing groove 4b at the time of shipment from a factory or before insertion of an optical fiber to which an optical connector is to be attached, so that the short optical fiber 2 and the end face of the optical fiber are inserted. Fill the refractive index matching agent between them. As a method of loosening the pressing state of the clamp member 6, a wedge member insertion groove 4 a is provided between the positioning member 4 and the pressing member 5, and the wedge member 7 is inserted into the groove. The method of slightly widening the interval of 5 is simple and effective.

As the clamp member, a clamp member shown in FIG. 2 can be used in addition to the one shown in FIG. The clamp member 8 has the same positioning clamp portion 8a as the clamp member 6, but the shape of the ferrule fixing portion 8b is different. In the case of the clamp member 8, the ferrule fixing portion 8 b has a leaf spring shape, and has a pressing function of pressing the ferrule 1 toward the positioning member 4 and the pressing member 5. Therefore, the ferrule 1, the positioning member 4 and the pressing member 5 can be more reliably fixed.

FIG. 3 is a longitudinal sectional view showing an embodiment of the optical connector according to the present invention in the case of a single core, where 9 is a ferrule, 9a is a flange, 9b is an optical fiber insertion hole, and 10 is a short optical fiber. Fiber, 11 is a covering portion, 12 is a positioning member,
12a is an optical fiber fixing groove, 13 is a holding member, 14 is a clamp member, 15 is an optical fiber core, and 16 is an optical fiber.

In the case of the single-core optical connector shown in FIG. 3, the short optical fiber 10 is inserted and fixed in the optical connector in advance. The intermediate portion of the short optical fiber 10 is covered with a covering portion 11. In inserting and fixing the short optical fiber 10 to the ferrule 9, first, an optical fiber core having a coating is prepared, the coating of the terminal portion is removed to expose the optical fiber, and the optical fiber is exposed behind the optical fiber insertion hole 9 b of the ferrule 9. The optical fiber portion exposed from the portion is inserted and fixed by bonding.

After that, the optical fiber protruding from the tip of the ferrule 9 is cut, and the ferrule 9 and the tip surface of the optical fiber are polished. Then, the side of the optical fiber core wire which is not on the ferrule fixed side is cut slightly longer than a predetermined length of the short optical fiber 10, and the covering portion 11 is cut by 1 cm at the time of the ferrule.
The coating on the side opposite to the ferrule is removed leaving the optical fiber exposed to some extent. And a short optical fiber 1 having a predetermined length.
The length is determined so that 0 is obtained, and the rear end of the optical fiber is mirror-cut.

Next, the rear end of the short optical fiber 10 is inserted and mounted in the optical fiber fixing groove 12 a of the positioning member 12, pressed by the pressing member 13, and clamped by the clamping member 14 to the positioning member 12. The rear end and the holding member 13 are pressed and fixed. At this time, the rear end face of the short optical fiber 12 is located near the center in the longitudinal direction of the optical fiber fixing groove 12a. The optical connector is processed at the factory to this state and transported to a laying site having an optical fiber core wire to be attached.

At the installation site, the end of the optical fiber core 15 to which the optical connector is attached is removed to expose the optical fiber 16, and the optical fiber 16 is exposed between the positioning member 12 and the holding member 13 of the optical connector. The pressing state by the clamp member 14 is loosened by inserting the wedge, and the optical fiber 16 is inserted into the optical fiber fixing groove 12a from the opposite side of the short optical fiber 10 and the end faces are abutted.

Next, the pressing state of the clamp member 14 is returned to its original state by removing the wedge, and the rear end portion of the short optical fiber 10 and the front end portion of the optical fiber 16 are pressed and fixed to the positioning member 12 together with the pressing member. Since it is necessary to fill a refractive index matching agent between the butted end faces of the short optical fiber 10 and the optical fiber 16, a refractive index matching agent is inserted into the optical fiber fixing groove of the positioning member 12 before inserting the optical fiber. inject. Further, the refractive index matching agent can be injected into the optical fiber fixing groove before the optical connector is shipped from the factory.

[0029]

According to the optical connector of the present invention described above,
In both cases of FIGS. 1 and 3, the short optical fiber 2 or 10 is covered at its intermediate portion with the covering portion 3 or 11. For this reason, since various operations can be performed by holding the part with a finger, it is possible to insert the ferrule into the optical fiber insertion hole of the ferrule without directly touching the bare optical fiber with a hand, thereby reducing damage to the optical fiber. .

Since the ferrule 1 or 9, the positioning members 4, 12 and the holding members 5, 13 are separable, the positioning member and the holding member are kept until the ferrule and the end surface of the short optical fiber are polished. Can be kept separated. For this reason, even if a special protective cover is not provided, polishing dust does not adhere to the optical fiber fixing groove of the positioning member. In addition, it is easy to clean the polishing debris attached around the rear end of the ferrule. In addition, since the portion of the short optical fiber projecting backward from the ferrule can be processed with the coating applied during polishing, there is no accident that the bare optical fiber is damaged during polishing.

Further, as shown in FIG.
A positioning clamp portion for pressing and fixing the holding member and the optical fiber to the positioning member, and a ferrule fixing portion for fixing and holding the positioning member and the holding member to the ferrule, so that the optical fiber can be pressed and fixed with one clamp member. The ferrule and the positioning member can be joined and held. In the case of the single-core optical connector shown in FIG. 3, the clamp member does not have a ferrule fixing portion, but a single-core clamp member having a ferrule fixing portion may be used. It is possible.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a multi-core optical connector according to the present invention, wherein (A) is a perspective view of each member, (B) is an assembled perspective view of the optical connector, and (C). ) Is X
It is a direction sectional view.

FIG. 2 is a perspective view showing another embodiment of a clamp member used for the optical connector of the present invention.

FIG. 3 is a longitudinal sectional view showing one embodiment of a single-core optical connector according to the present invention.

4A and 4B are diagrams illustrating an example of an optical connector according to the related art, wherein FIG. 4A is a longitudinal sectional view before attaching the optical connector to an optical fiber core, and FIG. 4B is a longitudinal sectional view after attaching. .

[Explanation of symbols]

 1, 9: ferrule 1a, 9a: flange 1b: guide pin hole 1c, 9b: optical fiber insertion hole 2, 10: short optical fiber 3, 11: coating portion 4, 12 positioning member 4a: wedge member insertion groove 4b, 12a : Optical fiber fixing groove 5, 13: holding member 5a: clamp groove 6, 14 clamp member 6a: positioning clamp portion 6b: ferrule fixing portion

Continued on the front page (72) Inventor Toshiaki Kakii 1-chome, Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa F-term (reference) in Yokohama Works, Sumitomo Electric Industries, Ltd. 2H036 AA02 DA01 EA01 GA04 GA12

Claims (2)

[Claims] 1. A ferrule having an optical fiber insertion hole, a positioning member having an optical fiber fixing groove axially aligned with the optical fiber insertion hole, and a presser for pressing and fixing an optical fiber in the optical fiber fixing groove of the positioning member. A member and a clamp member for sandwiching the positioning member and the holding member, and a short optical fiber is previously built in from the optical fiber insertion hole of the ferrule to a part of the longitudinal direction of the optical fiber fixing groove of the positioning member. An optical connector, wherein the intermediate portion is covered by a covering portion. 2. The ferrule, the positioning member and the pressing member are separable, and the clamp member presses the pressing member against the positioning member, and holds the positioning member and the pressing member fixed to the ferrule. 2. The optical connector according to claim 1, wherein the means for performing the operation is integrated.