JPS6078409A - Connector for optical fiber - Google Patents

Abstract

PURPOSE:To obtain a connector contg. an optical fiber in the exact central position by using a ferrule in which three rods are inscribed with each other, fixing the optical fiber into the central gap among the rods and treating the outside circumference thereof with a radiation curing type resin. CONSTITUTION:An optical fiber 2 is fixed with pressure into the central gap formed of three rods 1, each of which consists of a rigid body and which contact with each other. The fiber and the rods are bundled and the bundled rods 1, 1, 1 are tightened from the outside by a spiral body 3 and further the rods 1, 1, 1 are covered and tightened by an elastic material tube 4. A radiation curing type resin 6 is thereafter cast to the inside gap of the tube 4 and is cured by irradiation. The tube 4 is then removed.

Description

[Detailed Description of the Invention] The present invention provides a highly accurate ferrule! This invention relates to optical fiber connectors.

Is the optical fiber connection the center of the optical fiber core that connects oppositely, what is called a plug-in? Matching is said to be the most effective way to reduce the total connection loss. Conventionally, the most general and reliable method is
This is a method of aligning the centers of the optical fiber cores with the centers of the outer diameters of the 7 ferrules, and then butting and welding these ferrules together in a sleeve whose inner surface is smooth and precisely finished. . Then, as a means for fixing the center of the optical fiber core to the center of this ferrule, the optical fiber is inserted into the fine hole in the ceramic sleeve or the elliptical molded ferrule and fixed with a cold-curing or heat-curing adhesive. This results in heavy reliance on manual labor. This method can only be applied to optical fibers that match the diameter of the micropores, so it lacks versatility.
The work is extremely complicated, and the original fiber is easily damaged when inserted into the microhole, and there are major problems in workability, such as difficulty in on-site work. Another method is to use a method in which the outer diameter of the optical fiber is made of ceramic. Prepare in advance ceramic spheres or ceramic rods having a diameter that is the same as the temporary inscribed circle diameter of the central gap formed when three spheres or ceramic rods are brought into contact with each other, and After preliminarily storing the three fibers in a mold with the original fiber sandwiched in the central gap, the curable resin is fully injected into the mold and cured.
There are ways to fix the fiber, but especially when the outer diameter of the ferrule, that is, the inner diameter of the joining sleeve, and the diameter of the circumscribed circle formed by the three ceramic balls or rods are different, it is necessary to In order to match the center of the circumscribed circle of the ferrule with the center of the ferrule, the manufacturing precision of the stepped mold for ferrule molding was extremely high, and during molding, three ceramic It is necessary to insert and fix the rod or ball together with the optical fiber. This has the disadvantage that fixing the position of the ceramic rod or sphere within a minute mold is complicated and time consuming, difficult to handle, and often causes breakage of the optical fiber.

The present invention eliminates the above-mentioned drawbacks of the conventional manufacturing method for optical fiber connectors.The present invention uses a ferrule with three rods inscribed in each other, fixes the optical fiber in the center gap between the rods, and hardens it by irradiation on the outer periphery. The purpose is to provide a connector with an accurate center position of the optical fiber by applying mold resin treatment.

That is, in the present invention, the optical fibers 2 are clamped and fixed in a central gap formed by three rigid rods υ in contact with each other and bundled, and the bundled rods 1° 1.1 are pressed from the outside with a spiral body 3. □After tightening, and further covering these rods 1, 1.1 with the elastic tube 4 and tightening, the radiation-curable resin 6 is injected into the internal gap of the elastic tube 4, solidified by radiation curing, and then This is an optical fiber connector formed by removing the elastic tube 4.

The rod 1 used in the present invention may be made of any one of ceramic, glass 2, and synthetic resin that transmits radiation. In particular, if an ultraviolet-transparent material is used, and if an ultraviolet-curable resin is used as the radiation-curable resin, the resin can be cured easily and in a short time by allowing ultraviolet rays to penetrate into the interior. Furthermore, in the case of electron beam irradiation, even if the material is non-transparent, if it is reflective or scattering, the entire curable resin can be irradiated by reflection and scattering of the electron beam, so it can be used as the material for the rod 1. Can be done. Next, the radius rr of the rod 1 used is determined by the formula (
There is a relationship expressed as r+r)μ530=ri, and f parallelism, roundness, and outer diameter accuracy are preferably ±1μ.

The shape of the rod 1 may be any shape as long as it satisfies the above-mentioned parallelism, roundness, and outer diameter accuracy, such as one with a smooth outer surface (see Fig. 2 (1)), one with an uneven outer surface, For example, those with minute protrusions of a certain height on the surface (see same@)), those with spiral grooves in one direction (see (3) in the same figure), those with spiral grooves in both directions (see (4) in the same figure), Those with spiral protrusions in one direction (see (5) in the same figure) and those with spiral protrusions in both directions (see (6) in the same figure) can be suitably used.In particular, these have the advantage that the injected resin can easily flow into them. has.

The number of rods 1 used in the present invention may be arbitrarily determined to be three or more, but preferably three.

7 and 13 (Figure 4 (1), (2),
(See (3)).

Bundled rods 1, 1. The helical body 3 to be clamped is the inner diameter of an optical fiber joining sleeve (not shown) and the bundled rods 1, 1. It is made of a wire or an elastic wire or plate having a thickness that is about half the diameter of the temporary circumscribed circle that encloses le. The relationship between the thickness t of the spiral body 3 and the inner diameter of the sleeve for joining optical fibers is 2.
It can be expressed as t=DB-(rf+rr) (in the formula, rr is as in 1f12).

In addition, the processing accuracy of the optical fiber 2 and the spiral body 3 is ±
Good results can be obtained by keeping it within 1μ.

The rods 1, 1, 1, the optical fiber 2, and the coil spring 3 that have been clamped as described above are covered with an elastic tube 4 and clamped, and the elastic tube 4 is preferably made of an elastic material such as rubber or synthetic resin. is made of a material transparent to radiation such as radiation, electron beams, ultraviolet rays, etc., and has a thickness of 0.1 to 1. Orn
It is finished with an outer diameter accuracy of ±1μ at any length between x.

It is preferable that the inner diameter of the elastic tube 4 is smaller than the outer diameter of the spiral body 3 so that the inside can be compressed.

The internal gap pressed by the elastic tube 4 is injected and filled with radiation-curable resin. The most advantageous resin to be used is an ultraviolet curable synthetic resin. The resin is injected by a conventional method. That is, a connector insertion port 5a as shown in FIG.
Rods 1 , 1 , 1 , 1 , 1 , 2 and 4 are clamped with elastic tubes 4 to an injection device 5 provided with a resin injection port 5 b. The resin may be fully press-fitted from the injection port 5a by fitting together the bundles of the resin.

Next, this product is irradiated with radiation to harden the resin, and then the elastic tube 4 is removed to obtain an optical fiber connector of the present invention. When curing the resin, if an ultraviolet curable resin metal is used and the rod material must be ultraviolet transparent, curing can be completed in a short time by irradiating ultraviolet a from the inside as well.

The optical fiber connector of the present invention has the structure as described above, and by using this, the following benefits can be obtained.

+11 A highly accurate connector with minimal eccentricity at the center of the core can be obtained〇(2) Since the three rods touch each other and fix the optical fiber, the center position of the optical fiber can be determined by automatic alignment from three directions. Can be adjusted accurately and easily (3) The work is extremely simple and the resin can be cured in a short time.

(4) Since there is no need to insert the original fiber into a micro hole such as a ferrule, the breakage rate of the original fiber is low.

(5) Since the three rods are fixed in pressure contact with each other, the skeleton of the structure itself is non-shrinkable, and therefore, variations in dimensional accuracy due to shrinkage of the injected resin do not occur.

[Brief explanation of drawings]

A partial longitudinal section of the rod shown in Figure 3 is a perspective view of the present invention.
Figure 5 is a perspective view of the connector, in which 1 is a rod, 2 is an optical fiber, 23 is a spiral body, 4 is an elastic tube, 5 is a resin injection device, and 6 is a radiation-curable resin. Patent applicant Sumitomo Electric Industries Co., Ltd. agent Patent attorney Shibe Mitsuishi (and 1 other person) Figure 3 Procedural amendment dated August 7, 1980 To the Commissioner of the Japan Patent Office 1 Indication of the case 1982 Patent Application No. 185166 Optical Fiber Connector 3 Relationship with the case of the person making the amendment Patent applicant 5-15 Kitahama, Higashi-ku, Osaka-shi, Osaka (21El) Sumitomo Electric Industries, Ltd. 4 Agent postal code 107 6 Subject of the amendment ■ “Detailed Description of the Invention” and “Brief Explanation of Drawings” 1 or 0 Drawing 7 in the Specification, Contents of Amendments■ “Optical fibers to be・Correct ``with the relationship e,'' as follows. ``If the radius of the optical fiber 2 is tvf, the relationship n expressed by the formula (11+rf)coa30−=rl'' is corrected. ・■ Description The description "-...sleeve (omitted in the figure)" on box 6, line 13 is corrected to "・Φ・sleeve 7". ■ The description on page 6, line 19 of the specification (-2j=J)s-
('f0rr) J r 2t = Ds-2(rf +
rr) Correct as J. ■ The statement in the third line from the bottom of the second page of the specification, ``... is shown.'' is corrected to ``..., 7 is a sleeve.'' ■ Correct the attached sheet of Figure 1 of the drawing. 8. List of attached documents ■Corrected drawing l Figure 1

Claims (1)

[Scope of Claims] (1) Optical fibers are clamped and fixed in a central gap formed by at least three rigid rods in contact with each other and bundled, and the bundled rods are compressed by a spiral body; An optical fiber connector characterized in that after a rod is covered with an elastic tube and clamped, an irradiation-curable resin is injected into the internal gap of the elastic tube and solidified, and then the elastic tube is removed. Q) The optical fiber connector according to claim 1, wherein the number of rods is 3, 7, or 13 to form one or more central gaps. (3) The above rod transmits electron beams or ultraviolet rays. 3. A connector for a source fiber according to claim 1 or 2, characterized in that a non-absorbing material that reflects or scatters is made by irradiating and curing a resin through the rod.