JP3342849B2 - Assembling method of protective cap and optical fiber connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention protects a ferrule end face and an optical fiber end face of an optical fiber connector, and reduces the heat efficiency when a thermosetting adhesive used for assembling the optical fiber and the optical fiber connector is cured by heating. The present invention relates to a protective cap for stabilizing and an assembling method of an optical fiber connector.

[0002]

2. Description of the Related Art Conventionally, when an optical fiber is fixed to a ferrule to be assembled to an optical fiber connector, a thermosetting adhesive is injected into the optical fiber connector, and then an optical fiber having a predetermined coating removed is inserted. The adhesive is heated and cured by a heater, and the optical fiber is bonded and fixed to the optical fiber connector. The optical fiber connector is used after the optical fiber is bonded and fixed, and the end face of the ferrule and the end face of the optical fiber are polished smoothly and finished to a mirror surface. If the polished ferrule and the polished surface of the optical fiber are damaged, when the ferrules are connected to each other, the precision of the facing position is deteriorated and the loss is increased. Therefore, in order to protect the ferrule end face and the optical fiber end face after polishing, a rubber fitting to the tip of the optical fiber connector,
2. Description of the Related Art A protective cap formed of plastic or the like is known.

[0003]

However, since this conventional protective cap is used only after the end faces of the ferrule and the optical fiber are polished, the optical fiber connector is formed by using a heat-curable adhesive for the optical fiber connector. At the time of assembling, or until the ferrule end face and the optical fiber end face are polished, the ferrule end face and the optical fiber end face are not protected, so that there is a problem in safety during operation.

When the thermosetting adhesive is heated and cured by a heater, the adhesive is directly heated from the outside of the optical fiber connector. However, since the optical fiber connector is not exposed, heat is not uniformly transmitted to the ferrule and its surroundings. There was a problem that thermal efficiency was poor. Therefore, in view of such circumstances, the present invention protects the ferrule end surface and the optical fiber end surface even when assembling the optical fiber connector and the optical fiber, or thereafter, and heat-curs the thermosetting adhesive. An object of the present invention is to provide a protective cap and a method for assembling an optical fiber connector, which improve the thermal efficiency at the time of performing the operation.

[0005]

According to a first aspect of the present invention, there is provided a ferrule for inserting and holding an optical fiber and an optical fiber connector assembly having a holding member for holding the ferrule. A protective cap used for bonding and holding a fiber, wherein the protective cap has a shape fitted to the holding member to cover at least the ferrule, and is formed of a heat-resistant resin in which the inside is visible. In the protective cap.

According to a second aspect of the present invention, in the first aspect, the optical fiber connector assembly comprises the ferrule, a spring for biasing the ferrule in an axial direction, and a rear end of the ferrule inserted. And a stop ring having a through hole to be formed. The third aspect of the present invention is directed to the first aspect.
In the aspect, the optical fiber connector assembly comprises:
The protective cap is an assembly for any one of FC type, SC type and ST type optical fiber connectors.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a rear end portion of the protective cap has a first insertion hole fitted with the holding member, and a first insertion hole. And a second insertion hole smaller than the first insertion hole,
When the holding member is inserted up to the locking portion due to the step between the first insertion hole and the second insertion hole, there is a sufficient gap between the bottom of the second insertion hole and the ferrule. The protective cap is characterized in that:

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, at least the thickness of the heat-resistant resin fitted to the optical fiber connector assembly is formed to be substantially uniform. A protective cap is characterized in that: A sixth aspect of the present invention is a method for assembling an optical fiber connector for bonding and fixing the optical fiber to an optical fiber connector assembly including a ferrule for inserting and holding an optical fiber and a holding member for holding the ferrule, Fitting a protective cap having a shape covering the ferrule and formed of a heat-resistant resin in which the inside can be visually recognized, to the tip end side of the optical fiber connector assembly; and A step of injecting a heat-curable adhesive into the rear end of the three-dimensional body and inserting the optical fiber, and a step of heat-curing the heat-curable adhesive while leaving the optical fiber connector assembly as it is. The feature lies in a method of assembling an optical fiber connector.

According to a seventh aspect of the present invention, in the sixth aspect, the optical fiber connector assembly further comprises a ferrule, a spring for urging the ferrule in an axial direction, and a rear end of the ferrule. A stop ring having a through hole to be inserted is pre-assembled with an optical fiber connector assembling method. According to an eighth aspect of the present invention, in the sixth aspect, the assembly for an optical fiber connector is an assembly for any one of FC type, SC type, and ST type optical fiber connectors. The method is for assembling an optical fiber connector.

According to the present invention, the end face of the ferrule and the end face of the optical fiber are more reliably protected, the safety during the operation of assembling the optical fiber connector is high, and the work efficiency is improved by stabilizing the thermal efficiency during the heating. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a protective cap according to one embodiment of the present invention, FIG. 2 is a sectional view of a protective cap and a basic plug of a universal type optical fiber connector, and FIG. 3 shows a method of assembling an optical fiber connector using the protective cap. FIG.

First, a universal type optical fiber connector will be described. As shown in FIG. 2, in the basic plug 10 of the universal type optical fiber connector according to the present embodiment, a ferrule 11 to which an optical fiber is fixed includes a ferrule cylindrical body 12 having an optical fiber insertion hole 12a, and a ferrule cylindrical body. And a flange member 13 fixed to the rear end of the body 12. A compression spring 14 is mounted on the outer peripheral portion of the flange member 13 of the ferrule 11, and a stop ring 15 is fitted outside the compression spring 14 so as to cover the compression spring 14. That is, the compression spring 14 urges and holds the ferrule 11 forward with respect to the stop ring 15.
1 can be retracted by a predetermined amount. The basic plug 10 is fitted into a plug housing (not shown),
It becomes an optical fiber connector.

As shown in FIGS. 1 and 2, the protective cap 20 according to this embodiment is formed in a cylindrical shape having a small outer diameter at the front end and a basic plug at the rear end. 10 has an inner diameter on the rear end side to fit into the stop ring 15 of the basic plug 10 and at least a stop ring from the distal end of the flange member 13 of the ferrule 11. A large-diameter insertion hole 21 longer than the distal end portion 15 is formed. Also,
Continuing from the large-diameter insertion hole 21, a small-diameter insertion hole 22 having an inner diameter that fits into the ferrule 11 of the basic plug and longer than the ferrule cylindrical body 12 of the basic plug 10.
Is formed. In addition, a step 23 formed by a difference in inner diameter is provided between the large-diameter insertion hole 21 and the small-diameter insertion hole 22.

The thickness of the protective cap 20 is substantially uniform along the large-diameter insertion hole 21 and the small-diameter insertion hole 22, and the large-diameter cylindrical portion 24 and the small-diameter cylindrical portion 25 are formed respectively. A disc-shaped flange 26 is formed on the rear end side of 24. An arbitrary number of ribs 27 are formed on the outer periphery of the small-diameter cylindrical portion 25 on the large-diameter cylindrical portion 24 side. As a material of the protective cap 20, a transparent material having heat resistance and visible inside can be used, for example, polycarbonate, polyethylene terephthalate, polyetherimide and the like.

A procedure for assembling an optical fiber connector using the protective cap 20 according to the present embodiment will be described. First, when the protection cap 20 is fitted to the distal end of the basic plug 10, the step 23 of the protection cap 20 is locked to the flange member 13 of the ferrule 11. Next, FIG.
As shown in (a), the adhesive injector 30 is inserted from the base end side of the adhesive injection jig 40, and the adhesive injection jig 40 is inserted.
Is inserted into the rear end of the basic plug 10.
Thereafter, as shown in FIG. 3B, the heat-curable adhesive 5
0 is injected into the optical fiber insertion hole 12a of the ferrule 11, and the inside of the ferrule 11 is filled with the heat-curable adhesive 50.
The heat-curable adhesive 50 is filled from the tip of the optical fiber insertion hole 12 a of the ferrule 11.
It can be confirmed by visually confirming that a has come out. After the filling of the heat-curable adhesive 50 has been completed, FIG.
As shown in (d), the adhesive injector 30 and the adhesive injection jig 40 are removed from the basic plug 10.

Next, as shown in FIG. 3E, the optical fiber 60 from which a predetermined coating has been removed is inserted into the rear end of the basic plug 10. Also at this time, the optical fiber 60 can be reliably inserted by visually recognizing that the distal end portion 60a of the optical fiber 60 has come out from the distal end portion of the optical fiber insertion hole 12a of the ferrule 11. Thereafter, by heating from the outside with a heater (not shown) or the like, the thermosetting adhesive 50 is cured, and the optical fiber 60 and the basic plug 10 are bonded.

Therefore, according to this embodiment, the end face of the ferrule and the end face of the optical fiber are more reliably protected, and the safety during and after the assembling work of the optical fiber connector is high. Further, the thermal efficiency at the time of heating is increased by the protective cap, and the reliability and workability of bonding and fixing the optical fiber and the optical fiber connector are improved. (Other Embodiments) In the above-described embodiments of the present invention, a universal type optical fiber connector has been described as an example. However, the present invention is not limited to this, and it is needless to say that the present invention is applicable to other optical fiber connectors. Below, SC type,
Description will be made by taking an example of an FC type or ST type optical fiber connector.

FIG. 4 is a partial sectional view of a protective cap and an SC type optical fiber connector according to another embodiment. Note that members having the same functions as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted. The SC type optical fiber connector 70 is a ferrule 11
And an optical fiber connector for inserting and holding an optical fiber after all the urging holding members are assembled to the plug housing 71. Therefore, in the above-described embodiment, the large-diameter insertion hole 21 of the protection cap 20 is fitted to the stop ring 15, but in the present embodiment, the large-diameter insertion hole 21A of the protection cap 20A is fitted to the plug housing 71. , Step 23
A engages with the tip of the plug housing 71.

The method of assembling the optical fiber connector is as follows.
The steps of fitting A, injecting the adhesive, inserting the optical fiber, and heating and curing the adhesive are the same as those in the above-described embodiment. FIG. 5A shows a protective cap 20 </ b> B for the FC type optical fiber connector 80. The large-diameter insertion hole 21B of the protection cap 20B fits into the plug frame 81 of the FC-type optical fiber connector 80, and the step 23B engages with the tip of the plug frame 81.

FIG. 5B shows a protective cap 20C for the ST type optical fiber connector 90. The large-diameter insertion hole 21C of the protection cap 20C fits into the ST plug housing 91 of the ST-type optical fiber connector 90, and the step 23C engages with the tip of the ST plug housing 91. As described above, by forming the protective cap so as to be fitted to the distal end portions of various optical fiber connectors, the same effect as in the above-described embodiment can be obtained.

[0021]

As described above, by assembling an optical fiber connector using the protective cap according to the present invention,
The end face of the ferrule and the end face of the optical fiber can be more reliably protected, and the safety during and after the assembly work of the optical fiber connector can be improved. Further, the thermal efficiency at the time of heating is enhanced by the protective cap, and the reliability and workability of bonding and fixing the optical fiber and the optical fiber connector are improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a protective cap according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a protective cap and a basic plug of a universal optical fiber connector.

FIG. 3 is an explanatory diagram of a method of assembling an optical fiber connector using a protective cap.

FIG. 4 is a partial cross-sectional view of a protective cap and an SC-type optical fiber connector according to another embodiment of the present invention.

FIG. 5A is a partial cross-sectional view of a protective cap and an FC-type optical fiber connector according to another embodiment,
(B) is a partial cross-sectional view of a protective cap and an ST-type optical fiber connector according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Basic plug 20, 20A, 20B, 20C Protective cap 30 Adhesive injector 40 Adhesive injection jig 50, 50A Heat curing adhesive 60 Optical fiber 70 SC type optical fiber connector 80 FC type optical fiber connector 90 ST type light Fiber connector

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Uchiyama 1-8-8 Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Instruments Inc. (56) References JP-A-2000-9965 (JP, A) JP-A-Heisei 9- 218322 (JP, A) JP-A-9-197187 (JP, A) JP-A-8-327854 (JP, A) JP-A-60-9607 (JP, U) JP-A-4-9906 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 6/36

Claims (12)

(57) [Claims] 1. A ferrule for inserting and holding an optical fiber, a stop ring having a through hole into which a rear end of the ferrule is inserted, and a stop ring abutting on the stop ring.
And a spring for urging the ferrule in the axial direction, the protective cap being used when the optical fiber is adhered and held to the optical fiber connector assembly, wherein at least the ferrule has a shape covering the ferrule and the inner side is formed. A protective cap made of a heat-resistant resin that is visible. 2. The protective cap according to claim 1, wherein
The optical fiber connector assembly, FC type, SC type,
A protective cap, which is an assembly for any of the ST type optical fiber connectors. 3. A protective cap according to any one of claims 1-2, wherein the protective cap, there inner diameter which fits into the ferrule made of ferrule <br/> tubular body and the flange member and a protective cap, characterized in that it has a longer insertion hole than said ferrule tubular body. 4. The protective cap according to claim 1, wherein said protective cap is provided with said ferrule.
Protective cap, characterized in that it comprises a small-diameter insertion hole to be fitted to Le, the large-diameter insertion hole formed continuously with the small-diameter insertion hole is fitted to the stop ring. 5. The protective cap according to claim 1, wherein at least the thickness of the heat-resistant resin fitted to the optical fiber connector assembly is substantially equal. A protective cap, characterized in that: 6. A ferrule for inserting and holding an optical fiber, a stop ring having a through hole into which a rear end of the ferrule is inserted , and a front ring which abuts on the stop ring.
A method of assembling an optical fiber connector assembly for bonding and fixing the optical fiber to an optical fiber connector assembly having a spring for urging the ferrule in the axial direction , comprising: a tip end side of the optical fiber connector assembly; A step of fitting a protective cap having a shape covering the ferrule and formed of a heat-resistant resin in which the inside is visible;
A step of injecting a heat-curable adhesive into the rear end of the optical fiber connector assembly and inserting the optical fiber; and a step of heat-curing the heat-curable adhesive injected into the optical fiber connector assembly. method of assembling an optical fiber connector assembly, characterized by a step for. 7. The method of assembling an optical fiber connector according to claim 6, wherein the assembly for an optical fiber connector is an assembly for any one of FC type, SC type and ST type optical fiber connectors. method of assembling an optical fiber connector assembly according to claim. 8. A ferrule for inserting and holding an optical fiber.
And a protective cap used for bonding and holding the optical fiber to an optical fiber connector having a plug housing or a plug frame , wherein the protective cap has a shape covering at least the ferrule and is formed of a heat-resistant resin in which the inside is visible. A protective cap characterized by being made. 9. The protective cap according to claim 8 , wherein
The optical fiber connector is of FC type, SC type, ST type.
A protective cap, which is any one of the optical fiber connectors . 10. A protective cap according to claim 8 or claim 9.
In the above, the protective cap is fitted to the ferrule.
A small-diameter insertion hole, and formed continuously with the small-diameter insertion hole.
Mates with the plug housing or the plug frame
Protective cap having a large-diameter insertion hole
H. 11. A ferrule for inserting and holding an optical fiber.
And a plug housing or plug frame
Light for bonding and fixing the optical fiber to an optical fiber connector
In the method of assembling the fiber connector, It has a shape that covers the ferrule and the inside is visible
Work to fit a protective cap made of heat-resistant resin
About While injecting a thermosetting adhesive into the ferrule
Inserting the optical fiber, Heating and curing the heat-curable adhesive.
A method for assembling an optical fiber connector, comprising: 12. The optical fiber connector according to claim 11, wherein:
How to assemble Wherein the optical fiber connector comprises:
FC type, SC type, ST type optical fiber connector
Assembling an optical fiber connector characterized by the following:
Method.