JP2002139656A - Structure for multiple optical fiber connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve smoothness after polishing the tip face of a ferrule. SOLUTION: In a multiple optical fiber connector, that connects multiple optical fibers by abutting ferrule tip faces 10A on each other by a prescribed pressurizing force, the tip face 10A of the ferrule is formed into a shape in the direction of the row of multiple optical fibers, such that the center area is made narrower than both end areas, namely in a recessed shape, where the proximity to the optical fiber inserting holes 12 is recessed from other parts. As a result, the tip face 10A of the ferrule is polished more in the center area where polishing area is narrower, while being polished less in both end areas where polishing area is wider, so that smoothness is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a multi-core optical fiber connector, and more particularly to a technique for improving the smoothness of a ferrule tip after polishing.

[0002]

2. Description of the Related Art Conventionally, a multi-core optical fiber connector (hereinafter referred to as "optical connector") for connecting multi-core optical fibers (hereinafter referred to as "optical fibers") by abutting ferrule tips with a predetermined pressing force. It is known. To connect an optical fiber using an optical connector, the optical fiber is inserted into the optical fiber insertion hole of the ferrule, and the tip is made to protrude from the tip surface of the ferrule. Next, the optical fiber tips protruding from the ferrule tip face are trimmed, and the ferrule tip face is polished flat by a polishing machine. At this time, since the optical fiber is harder than the ferrule tip, the tip of the optical fiber projects from the ferrule tip after polishing. Then, while positioning the optical axis of the optical fiber with the guide pin fitted to the ferrule, the tip surfaces of the ferrules are butted by the pressing force of the clamp spring to connect the optical fiber.

[0003]

However, when the tip of the ferrule is polished, both ends are polished more easily than the center thereof. Therefore, the tip of the ferrule after polishing is as shown in FIG. In addition, the central portion tends to have a convex shape protruding from both ends. For this reason, when optical connectors having such a shape are connected to each other, as shown in FIG. 9, the optical fibers at both ends in the column direction of the optical fibers may be separated from each other, and the connection may be insufficient.

In view of the above-mentioned conventional problems, the present invention employs a structure in which the smoothness after polishing of the ferrule tip surface is improved to prevent the connection of optical fibers from becoming insufficient. An object of the present invention is to provide a structure of an optical fiber connector.

[0005]

According to the first aspect of the present invention, there is provided a multi-fiber optical fiber connector for connecting multi-fiber optical fibers by abutting the ferrule tips with a predetermined pressing force. The tip surface of the ferrule is formed in a concave shape in which the central portion is narrower than both ends in the row direction of the multi-core optical fiber.

According to such a configuration, since the ferrule tip end face is formed in a concave shape in which the central portion is narrower than both ends in the row direction of the multi-core optical fiber, the central portion having a small polishing area is polished more. On the other hand, both ends having a large polishing area are polished less. For this reason, the protrusion amount of the convex shape at the center of the ferrule tip end surface is reduced, and the smoothness of the ferrule tip end surface is improved.

In the invention according to claim 2, the concave shape is:
The vicinity of the multi-core optical fiber is formed substantially linearly. According to this configuration, since the vicinity of the multi-core optical fiber is formed in a substantially linear shape, the cross-sectional area of the multi-core optical fiber is reduced while securing strength for firmly holding the multi-core optical fiber.

[0008] In the invention according to claim 3, the concave shape is:
It is characterized by being formed in a substantially arc shape. According to this configuration, since the concave shape is formed in a substantially arc shape, the amount of polishing at the tip surface of the ferrule gradually increases from both ends to the center, so that the smoothness after polishing is further improved. I do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the attached drawings. The optical connector, as shown in FIG.
A set of ferrules 10 and a substantially cylindrical metal 2
A book guide pin 20, a clamp spring 30 for abutting the ferrule tip surfaces 10A with each other with a predetermined pressing force,
It is comprised including.

As shown in FIG. 2, the ferrule 10 has a shape in which two rectangular parallelepipeds having different cross-sectional areas are connected, and the optical fiber insertion holes 12 through which the optical fibers 40 are inserted are formed in a row along the axial direction. Formed. Further, on both sides of the optical fiber insertion hole 12, there are formed guide pin holes 14 through which guide pins 20 for positioning and aligning the optical axis of the optical fiber 40 with high precision are inserted. Further, an adhesive filling window 16 into which a resin as an adhesive is poured is formed on one end face facing the optical fiber insertion hole 12 so as to fix the optical fiber 40 to the ferrule 10.

As a feature of the present invention, the ferrule tip surface 1
0A has a shape in which the center is narrower than both ends in the row direction of the optical fibers 40, that is, the optical fiber insertion hole 1
The vicinity of 2 is formed in a concave shape that is more concave than other portions. In this case, the concave shape is formed substantially linearly in the vicinity of the optical fiber 40 in view of the convenience of ferrule manufacturing and the like. In this way, the cross-sectional area can be reduced while securing the strength for firmly holding the optical fiber 40.

As shown in FIG. 3, the concave shape may be a substantially circular arc shape in which the central portion in the column direction of the optical fiber 40 is most concave. In this case, since the amount of polishing of the ferrule tip end surface 10A gradually increases from both ends toward the center, the smoothness after polishing can be further improved. In addition, the clamp spring 30 has a substantially rectangular base 30.
The claw portions 30B are integrally connected to the four corners of A, and the base end portion 10B of the ferrule 10 is sandwiched between the claw portions 30B, thereby abutting the ferrule tip end surfaces 10A with each other with a predetermined pressing force.

Next, a procedure for connecting the optical fiber 40 using the optical connector having the above configuration will be described. First, the optical fiber 40 is inserted into the optical fiber insertion hole 12 formed in the ferrule 10, and the optical fiber 40 is made to protrude from the distal end face 10A. In this state, a resin is poured from the adhesive filling window 16 of the ferrule 10 to fix the optical fiber 40 to the ferrule 10. And
The distal end portion of the optical fiber 40 protruding from the ferrule distal end surface 10A is trimmed, and the ferrule distal end surface 10A is planarly polished by a polishing machine (not shown). At this time, since the ferrule tip end surface 10A is formed in a shape in which the central portion is narrower than both ends in the row direction of the optical fibers 40, the central portion having a smaller polishing area is polished more, while the polishing area is smaller. Wide ends are less polished. Therefore, the protrusion amount of the convex shape at the center of the ferrule tip end surface 10A is reduced, and the smoothness is improved as shown in FIG.

The guide pin hole 1 of the ferrule 10
After the guide pin 20 is inserted through the ferrule 4, the ferrule tip surfaces 10 </ b> A are brought into contact with each other while the optical axis of the optical fiber 40 is accurately positioned by the guide pin 20. Then, as a result of the smoothness of the ferrule tip end surface 10A being improved, as shown in FIG. 5, both ends of the optical fibers 40 in the row direction are prevented from being separated, and the optical fibers 40 can be securely connected. .

Thereafter, a clamp spring 30 is attached to the ferrule 10 so that the ferrule tip end surface 10A
The members press each other with a predetermined pressing force, and a stable connection state is maintained. In the optical connector described above, the concave shape is formed on both sides of the optical fiber insertion hole 12, but the concave shape may be formed only on one side. In addition, in order to suppress the connection loss, as shown in FIGS.
Needless to say, the present invention can be applied to polishing to 8 °).

[0016]

As described above, according to the first aspect of the present invention, the front end surface of the ferrule is polished more at the central portion having a smaller polishing area, but less at both end portions having a larger polishing area. Therefore, the amount of protrusion of the convex shape at the central portion of the tip surface of the ferrule is reduced, and the smoothness can be improved.

According to the second aspect of the present invention, it is possible to reduce the cross-sectional area of the multi-core optical fiber while securing the strength for firmly holding the same. According to the third aspect of the present invention, the amount of polishing on the front end surface of the ferrule gradually increases from both ends to the center, so that the smoothness after polishing can be further improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an optical connector according to the present invention.

FIG. 2 shows a detailed shape of a ferrule, wherein (A) is a top view and (B) is a side view.

FIG. 3 is an explanatory view showing another shape of the tip surface of the ferrule.

FIG. 4 is an explanatory view showing a ferrule shape after polishing.

FIG. 5 is an explanatory diagram showing a connection state of an optical fiber.

6A and 6B show an example in which the present invention is applied to an optical connector in which a ferrule tip surface is polished obliquely, wherein FIG. 6A is a front view and FIG.

7A and 7B show another example in which the present invention is applied to an optical connector in which a ferrule tip surface is polished obliquely, where FIG. 7A is a front view and FIG.

FIG. 8 is an explanatory view showing a ferrule shape after polishing according to a conventional technique.

FIG. 9 is an explanatory diagram showing a connection state of an optical fiber in a conventional technique.

[Explanation of symbols]

 10 Ferrule 10A Ferrule tip 40 Optical fiber

Claims (3)

[Claims] 1. A multi-core optical fiber connector structure for connecting multi-core optical fibers by abutting ferrule end surfaces with a predetermined pressing force, wherein the ferrule end surface is arranged in a row direction of the multi-core optical fibers. 2. The structure of a multi-core optical fiber connector according to claim 1, wherein the concave portion is formed such that a central portion is narrower than both end portions. 2. The structure of a multi-core optical fiber connector according to claim 1, wherein said concave shape is formed in a substantially linear shape in the vicinity of said multi-core optical fiber. 3. The multi-core optical fiber connector according to claim 1, wherein said concave shape is formed in a substantially arc shape.