The present invention relates to an optical fiber ferrule assembly including an optical fiber and a ferrule integrated with an end of the optical fiber, an optical connector with the optical fiber ferrule assembly, and a method for producing an optical fiber ferrule assembly.
Conventionally, an optical connector is known which includes an optical fiber, a ferrule attached to an end of the optical fiber, a housing for the ferrule, and a holder incorporated in the housing, the holder being configured to prevent the ferrule from removal (see e.g. Patent Document 1). In the present specification, the term “optical fiber ferrule assembly” shall refer to an optical fiber with a ferrule integrated with an end of the optical fiber.
The optical fiber 304 is formed from a bare fiber 341 made of quartz, plastics etc. which is covered with a coating 342 made of resin, wherein the coating 342 is removed in advance from the optical fiber 304 at an end which is to be inserted into the ferrule 305.
Patent Document 1: JP 2014-44335 A
For the optical fiber ferrule assembly 301 as mentioned above, since the optical fiber 304 and the ferrule 305 are separated components and there is a clearance between these components (indicated with the reference sign G in
In order to solve the above-mentioned problem, an objective of the present invention is to provide an optical fiber ferrule assembly, an optical connector including the optical fiber ferrule assembly, and a method for producing an optical fiber ferrule assembly which enable preventing the optical fiber from tilting and misalignment with regard to the ferrule.
An optical fiber ferrule assembly according to the present invention includes an optical fiber, and a ferrule made of resin, wherein the optical fiber is integrated with the ferrule by embedding an end of the optical fiber into the ferrule via insert molding.
An optical connector according to the present invention includes the optical fiber ferrule assembly, a housing for accommodating an end of the optical fiber ferrule assembly, and a holder incorporated in the housing, the holder being configured to prevent the optical fiber ferrule assembly from removal.
A method for producing an optical fiber ferrule assembly according to the present invention includes disposing an end of an optical fiber within a mold for a ferrule, and filling the mold with resin to form the ferrule via insert molding and simultaneously integrate the ferrule with the optical fiber.
The present invention can enable preventing the optical fiber from tilting and misalignment with regard to the ferrule, since there is no clearance between the optical fiber and the ferrule. This can enable preventing a reduction of the telecommunication reliability between an optical connector equipped with the optical fiber ferrule assembly and a partner connector.
An “optical fiber ferrule assembly”, an “optical connector” and a “method for producing an optical fiber ferrule assembly” according to particular embodiments of the present invention shall be described with reference to
An optical connector 10 as shown in
Each of the optical fiber ferrule assemblies 1 includes an optical fiber 4 and a ferrule 5 made of resin.
As shown in
The ferrule 5 is molded in an outer circumference of the optical fiber 4 without clearances except for a region of holes 57 described later, wherein the ferrule 5 has a small diameter section 51 with a cylindrical shape located closer to an end face of the optical fiber 4, a large diameter section 52 with a cylindrical shape having a larger diameter than the small diameter section 51, and annular overhangs 54, 55, 56 in an integrated manner, the overhangs 54, 55, 56 overhanging from an outer circumferential surface of the large diameter section 52.
A step 53 is formed at a transition between the small diameter section 51 and the large diameter section 52. Further, a plurality of holes 57 are formed in the small diameter section 51, wherein the holes 57 extend from an outer surface of the small diameter section 51 to an outer circumferential surface of the optical fiber 4 (an outer circumferential surface of the primary coating 41). These holes 57 are formed by disposing a plurality of pins 7 for positioning the optical fiber into a mold 6 for the ferrule 5.
The housing 2 consists of resin. The housing 2 is configured to be fitted to a housing for a partner connector which is not shown. In the fitting process, the step 53 comes into contact with the housing for the partner connector which is not shown.
The holder 3 consists of resin. The holder 3 includes ribs 31 to be positioned between the overhangs 54 and 55, ribs 32 to be positioned between the overhangs 55 and 56, and engagement ribs 33 to engage with the overhangs 56, wherein the engagement ribs 33 allow preventing that the optical fiber ferrule assemblies 1 is removed out of the housing 2.
Next, a method for producing the optical fiber ferrule assembly 1 as described above shall be described with reference to
First, the secondary coating 42 is removed at an end of the optical fiber 4. Then, the end of the optical fiber 4 is disposed into the mold 6. At this time, the end of the optical fiber 4 is positioned accurately with the plurality of pins 7 by closing the separated molds 6a and 6b together. Next, the closed mold 6 is filled with a molten resin, which is cooled to be cured. In this manner, the ferrule 5 is molded via insert molding, and simultaneously, the ferrule 5 and the optical fiber 4 are integrated with each other. Finally, the mold 6 is opened to remove a molded product. Through the above-described steps, the optical fiber ferrule assembly 1 is obtained.
The optical fiber ferrule assembly 1 produced with the above-described method has no clearance between the optical fiber 4 and the ferrule 5, which can enable preventing the optical fiber 4 from tilting and misalignment with regard to the ferrule 5. Furthermore, for the optical fiber ferrule assembly 1 according to the present example, accurate positioning is achieved with the plurality of pins 7 during insert molding, so that the optical fiber 4 is positioned relative to the ferrule 5 with high precision. This can enable preventing a reduction of the telecommunication reliability between the optical connector 10 equipped with the optical fiber ferrule assembly 1 and a partner connector.
Additionally, for the optical fiber ferrule assembly 1 as described above, the optical fiber 4 is integrated with the ferrule 5 by embedding an end of the optical fiber 4 into the ferrule 5 during the insert molding, which can enable firm fixture with higher certainty than laser welding and adhesion with an adhesive according to conventional examples. Moreover, the optical fiber ferrule assembly 1 as described above does not requires any clearances between the optical fiber 4 and the ferrule 5, which enables a more compact design.
It is to be noted that the embodiments as described above merely illustrate representative examples for the present invention, and the present invention is not limited to these embodiments. I.e., various modifications may be performed without departing from the core of the present invention. It is obvious that such modifications are included in the scope of the present invention as far as the modifications comprise the features of the present invention.
1 Optical fiber ferrule assembly
2 Housing
3 Holder
4 Optical fiber
5 Ferrule
6 Mold
7 Pin
10 Optical connector
57 Hole
Number | Date | Country | Kind |
---|---|---|---|
2019-129087 | Jul 2019 | JP | national |