JPH01219805A - Ferrule for optical fiber connector - Google Patents

Abstract

PURPOSE:To eliminate the influence of dispersion in the external diameter of an optical fiber in use by forming the fiber guide groove of a fiber array plate held on the inner periphery of an elastic member at one end according to a reference fiber which has the smallest clad diameter and core diameter. CONSTITUTION:The fiber guide groove 14 of the fiber array plate 15 held on the inner periphery of the elastic member 13 at one end side is formed according to the reference fiber 20 which has the smallest core diameter, so even if the optical fiber in use has dispersion in its external diameter, its influence is eliminated. Consequently, the external diameter of the optical fiber need not be confirmed one by one to select a ferrule. Further, a metallic sleeve 18 and a sleeve 19 are clamped to screw parts 13c and 13d of the outer periphery of the elastic member 13 on both end sides to easily fix the optical fiber, so characteristic confirmation is easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ferrule used in an optical fiber connector.

[Conventional technology]

Generally, a ferrule is used in an optical fiber connector as an important member for holding an optical fiber therein, polishing its end face, and positioning and connecting the optical fiber with high precision.

As a conventional ferrule for optical fiber connectors, the fifth
The structure shown in the figure is known. This ferrule
is composed of a metal sleeve 2, and a ceramic member 3 and a glass member 4 inserted into the sleeve 2. This ceramic member 3 is connected to an optical fiber 5.
It has a pore 6 for guiding, and is adhesively fixed within the metal sleeve 2. Further, the outer periphery of the metal sleeve 2 is machined with the pore 6 at its center, so that the pore 6 is located at the center of the sleeve 2.

When assembling the optical fiber 5 to this ferrule 1,
First, the hole 7 of the ferrule 1 is filled with an adhesive, the optical fiber 5 that has undergone end treatment is inserted into the ferrule 1, the adhesive is cured, and then the end surface 8 of the ferrule 1 is polished. This completes the assembly work described above.

[Problem to be solved by the invention]

By the way, in the conventional ferrule configured as described above, the ferrule l is selected according to the cladding outer diameter of the optical fiber 5, so it is necessary to measure and confirm the cladding diameter of the optical fiber 5 to be used in advance. There was a drawback that it had to be done. Also, optical fiber 5
Even when it is desired to connect the optical fiber 5 and check the characteristics m, it is necessary to adhesively fix the optical fiber 5 to the ferrule 1 and polish the end face 8 of the ferrule 1, which is a disadvantage in that it is very time-consuming.

SUMMARY OF THE INVENTION An object of the present invention was to provide a ferrule for an optical fiber connector that does not require measuring and confirming the outer diameter of an optical fiber when selecting a ferrule, and in which characteristics can be easily confirmed. be.

[Means to solve the problem]

The ferrule for an optical fiber connector according to the present invention includes an elastic member having threaded portions on the outer periphery of both ends and an inner fiber guide groove, and a fiber of the elastic member that is held on the inner periphery of one end of the elastic member. A fiber alignment plate is connected to the guide groove and has a fiber guide groove provided in accordance with the reference fiber with the smallest clad diameter and core diameter, and is screwed and fixed to the outer periphery of one end of the above-mentioned elastic member, and in this fixed state, the elastic The metal sleeve is provided with a metal sleeve that pressurizes and compresses the member, and a sleeve that is screwed and fixed to the outer periphery of the other end of the elastic member and pressurizes and compresses the elastic member in this fixed state. The outer periphery is cut so that the optical fiber fixed therein is located at the center.

[Effect]

In this way, in the present invention, the fiber guide groove of the fiber alignment plate held on the inner periphery of one end of the elastic member is formed to match the reference fiber with the smallest Crabt diameter and the smallest core diameter. Even if the outer diameter of the optical fiber varies, it is not affected by this, so there is no need to measure and confirm the outer diameter of the optical fiber each time to select a ferrule. Further, since the optical fiber can be easily fixed by tightening the metal sleeve to the threaded portions on the outer periphery of both ends of the elastic member, characteristics can be easily confirmed.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the seven ferrule for an optical fiber connector according to the present invention, FIG. 2 is a longitudinal sectional view of the ferrule for the optical fiber connector, and FIG. 3 is a perspective view of one elastic member. FIGS. 4(a) and 4(b) are explanatory diagrams for assembling the ferrule for the same optical fiber connector.

The ferrule 10 has a semicircular cross-sectional shape (see Figure 3)
The elastic member 13 is made into a substantially cylindrical shape by overlapping the divided members 11 and 12. As shown in FIGS. 4(a) and 4(b), the divided members 11 and 12 are integrated by joining their contact portions 11a and 12a by ultrasonic welding or the like. Tapered portions 13a and 13b are provided at both ends of the elastic member 13, and the diameters become smaller toward the ends, and male threads 1l13cS and 13d are provided at positions adjacent to the tapered portions 13aS and 13b, respectively. It is screwed. Also,
In the elastic member 13, a mounting hole 13e is provided on the inner peripheral side of the portion where the tapered portion 13a is provided, and a fiber alignment plate 15 having a fiber guide groove 14 is buried and held in the mounting hole 13e. has been done.

That is, this fiber alignment plate 15 has a structure in which it is divided into upper and lower parts, and each divided member 15a of the fiber alignment plate 15 is in a state before the elastic member 13 is assembled.
, 15b are embedded and held in the mounting holes 13e of the dividing members 11.12 of the elastic member 13, respectively, and when the dividing members 11.12 of the elastic member 13 are overlapped, the dividing members 15a, 15b of the fiber alignment plate 15 are also superimposed so that a fiber guide groove 14 is formed at the center thereof.

The fiber guide grooves provided in the divided members 15a and 15b each have a semicircular cross-sectional shape, and the circular fiber guide groove 14 formed when these divided members 15a and 15b are overlapped. The inner diameter of the optical fiber is smaller than the outer diameter of the optical fiber. Further, a fiber guide groove 17 (see FIG. 2) is provided on the inner peripheral side of the elastic member 13 so as to be located on an extension of the fiber guide groove 14.

On the other hand, the elastic member 1 in which the fiber alignment plate 15 is embedded and held
A metal sleeve 18 is fixed to the outer periphery of one end of 3. That is, this metal sleeve 18 has a tapered portion 18a on its inner circumferential side that contacts the tapered portion 13a of the elastic member 13 and pressurizes and compresses the tapered portion 13a, and a female thread 1f (S18b) that is screwed into the male threaded portion 13c. The metal sleeve 18 is fixed to the elastic member 13 by screwing the male threaded portion 13c and the female threaded portion 18b.

Also, on the outer periphery of the other end of the elastic member 13, there is a strip IJ-119.
is fixed. That is, this space IJ-119 has a tapered portion 19 on its inner peripheral side that contacts the tapered portion 13b of the elastic member 13 and pressurizes and compresses the tapered portion 13b.
The sleeve 19 is fixed to the elastic member 13 by screwing the male threaded portion 13d and the female threaded portion 19b.

Now, when manufacturing the ferrule 10 configured as described above, first, the elastic members 13 are superimposed from the separated state of FIG. 4(a) as shown in FIG. 4(b), and then the divided members 11 , 12 contact portions 11a and llb are bonded and fixed by ultrasonic welding or the like. Next, metal sleeves 18 and sleeves 19 are attached to the outer peripheral sides of both ends of the elastic member 13, respectively, and as shown in FIGS. The metal sleeve 18 is screwed and fixed to the elastic member 13, and the tapered part 18a of the metal sleeve 18 pressurizes and compresses the tapered part 13a of the elastic member 13, so that the metal sleeve 18 is inserted into the fiber guide groove 14 of the fiber alignment plate 15. The reference fiber 20 is fixed. On the other hand, the tapered portion 13b of the elastic member 13 is pressurized and compressed by the tapered portion 19a of the sleeve 19, thereby fixing the fiber coating portion 21 within the elastic member 13.

Note that the reference fiber 20 used has the smallest crab diameter and core diameter among the ferrules to which the present ferrule 10 is applied, and the eccentricity of the core with respect to the cladding is small.

FIG. 2 shows a state in which the reference fiber 20 is assembled to the main ferrule 10. In this state, light is input into the core of the reference fiber 20 from the six directions of arrows, and with this core as a reference,
The outer periphery of the metal sleeve 18 is cut to form the metal sleeve 1.
8 so that the core of the reference fiber 20 is located at the center of the fiber.

After alignment, loosen the metal sleeve 18 and sleeve 19,
Take out the reference fiber 20. In this state, the fiber guide groove 14 of the fiber alignment plate 15 is connected to the metal sleeve 18.
Since it is located at the center of the ferrule IO, optical fibers other than the reference fiber 20 actually used in the product are also located at the center of the present ferrule IO.

Moreover, in the case of the present ferrule 10, the size of the fiber guide groove 14 is matched to the reference fiber 20 with the smallest cladding diameter and core diameter, so even if the outer diameter of the optical fiber used varies, it will not be affected. There's no way I'll get it. Note that in order to fix an optical fiber using the present ferrule 10 without adhesive or polishing, the tip of the optical fiber is first cleaved at a right angle.

In addition, if the optical fiber does not need to be removed (and high reliability is required, adhesive may be applied to the optical fiber and the primary coating and then the optical fiber is adhesively fixed to the elastic member 13). good.

In addition, in the embodiment described above, the fiber guide grooves 1 provided in the dividing members 15a and 15b of the fiber alignment plate 15
Although the groove 4 is formed to have a semicircular cross-sectional shape, the groove is not limited to this, and may be a square-shaped groove. In this case as well, the size of the fiber guide groove 14 created by overlapping the dividing members 15a and 15b is formed to be smaller than the outer diameter of the optical fiber.

〔Effect of the invention〕

As explained above, according to the ferrule for an optical fiber connector according to the present invention, the fiber guide groove of the fiber alignment plate held on the inner periphery of one end side of the elastic member can be adjusted according to the cladding diameter.
Since it is formed to match the reference fiber with the smallest core diameter, it is not affected by variations in the outer diameter of the optical fibers used. Therefore, there is no need to measure the outer diameter mti of each optical fiber and select ferrules. In addition, when you want to simply connect optical fibers and check their characteristics, you can easily fix the optical fibers to the fiber alignment plate inside the elastic member by tightening the metal sleeve and the sleeve. Characteristics can be easily confirmed by comparison.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of a ferrule for an optical fiber connector according to the present invention, FIG. 2 is a longitudinal sectional view of the ferrule for an optical fiber connector, and FIG. 3 is a perspective view of one of the elastic members. 4(a) and 4(b) are explanatory diagrams for assembling the ferrule for the same optical fiber connector, and FIG. 5 is a longitudinal sectional view showing an example of a conventional ferrule. 10... Ferrule, 13... Elastic member, 13c, 13d... Male threaded portion, 14.17...
...Fiber guide groove, 15...Fiber alignment plate, 18...Metal sleeve, 19...Sleeve, 20...Reference fiber. Applicant NEC Corporation Representative Patent Attorney Umeo Yamauchi

Claims (1)

[Claims] A ferrule for an optical fiber connector for holding and fixing an optical fiber end and positioning and coupling the optical fibers to each other includes an elastic member provided with threads on the outer periphery of both ends and an inner periphery fiber guide groove. a fiber alignment plate held on the inner periphery of one end of the elastic member and having a fiber guide groove connected to the fiber guide groove of the elastic member and provided in accordance with a reference fiber having the smallest cladding diameter and the smallest core diameter; A metal sleeve is screwed and fixed to the outer periphery of one end of the elastic member, and pressurizes and compresses the elastic member in this fixed state; and a metal sleeve is screwed and fixed to the outer periphery of the other end of the elastic member, and pressurizes the elastic member in this fixed state. A ferrule for an optical fiber connector, comprising: a compressible sleeve, the outer periphery of the metal sleeve being machined so that the optical fiber fixed in the fiber guide groove of the fiber alignment plate is located at the center. .