JPH0360090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical connector used for connecting optical fibers.

In recent years, with the progress of research and development of optical fibers, optical communication is also being put into practical use. When using this optical fiber as a long-distance transmission line, current technology that can only manufacture optical fibers of a limited length employs a method of splicing multiple optical fibers together. As a means for connecting this optical fiber, a method using an optical connector that can be arbitrarily separated even after connection is often adopted.

Conventionally, an optical connector having a structure as shown in FIG. 1 has been used. The optical connector is composed of an adapter 1 and a plug 2, and the adapter 1 has a sleeve 4 fixed in a sleeve housing 3. In addition, the plug 2 is an optical fiber core wire 5.
A ferrule 6 is placed over the end of the ferrule housing 7 via a spring 6'.
It is installed inside. Then, by inserting the pair of ferrules 6 into the sleeve 4 and screwing or bionet locking the sleeve housing 3 and the ferrule housing 7, the pair of ferrules 6 are moved in the axial direction by the biasing force of the spring 6'. The optical fiber cores 5 are pressed together
is connected.

However, since the ferrule is covered with a ferrule housing and is provided with a sleeve housing that has a larger outer diameter than the ferrule housing 7, the entire optical connector is large, and when connecting several tens of optical fiber cables, the connection part becomes large. The disadvantage is that it swells to a large extent.

Therefore, in order to alleviate such drawbacks, the present invention has the following features:
The purpose is to provide an optical connector with a small outer diameter.

The structure of the present invention that achieves this object includes a pair of ferrules that are attached to the ends of optical fibers to be coupled and have a clamped pressure portion, and a pair of ferrules that are inserted into each other by moving in the direction of the coupling axis. It is formed of a metal plate of uniform thickness, which has a guide member that is fixed to align the axis of the optical fiber, a bottom portion that is a flat plate portion, and clamping pressure portions that are raised at right angles from both ends of the bottom portion. The clamping pressure part has grooves in which the pair of ferrules inserted into the guide member are respectively fitted, and when the ferrules are fitted into these grooves, the clamping pressure part and the bottom part are deformed into an arcuate shape. and a fixing housing formed independently of the guide member, which presses the clamped pressure portion with the elasticity of the clamping pressure portion so that the pair of ferrules press against each other in the axial direction of each of the ferrules. It is characterized by being

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

A plan view showing an embodiment of the optical connector according to the present invention is shown in FIG. 2, and a plan view is shown in FIG. 3. A ferrule 9 concentric with the left and right optical fibers 8 is integrally attached to the ends of the optical fibers 8. The ferrule 9 has a cylindrical shape and includes a flange portion 10 as a portion to be subjected to clamping pressure.
The left and right ferrules 9 are connected to the sleeves 11 from both sides, respectively.
It is inserted inside. This sleeve 11 aligns the axes of the optical fibers 8 by inserting the ferrule 9 therethrough, and has a cylindrical shape. Reference numeral 12 denotes a fixing housing, into which a pair of left and right ferrules 9 inserted into the sleeve 11 are fitted. Fixed housing 1
Reference numeral 2 is made of a metal plate having a uniform wall thickness, and includes a flat bottom portion 12a and a pair of scissors that are raised at right angles from both ends of the bottom portion 12a and have curved surfaces such that the opposing surfaces protrude. Pressure parts 12b, 12c
It consists of. It has clamping pressure parts 12b and 12c, and a groove 13 into which the ferrule 9 is fitted is formed in the center of the clamping pressure part 12a. Because of this shape, the left and right clamping pressure parts 12 in FIG.
When the pair of left and right ferrules 9 inserted into the sleeve 11 are fitted into the fixing housing 12 while pushing the ferrules b and 12c apart to the left and right, the bottom part 12a is deformed into an arched shape together with the clamping pressure parts 12b and 12c. A pair of left and right ferrules 9 are pressed together in a state in which the flange portions 10 are pressed against each other in the axial direction of the ferrules 9.
is fixed within the fixation housing 12. That is,
The pressing force on the ferrule 9 is determined by the fixing housing 12.
The axial alignment of the optical fiber core 8 is achieved by the overall deformation of the fixing housing 12.
This is done by means of a sleeve 11 which is independent of the . Further, a through hole 15 is provided directly below the flange portion 10 in FIG.
The pair of left and right ferrules 9 connected by the sleeve 11 can be separated from the fixing housing 12 by pushing the flange portion 10 through the rod 5 . In this example, the outer diameter of the ferrule 9 is φ2.5.
mm, outer diameter of flange part 10 is φ4.5 mm, sleeve 1
1 is 11 mm in length, and the fixing housing 12 is made of stainless steel plate with a wall thickness of 0.4 mm.

Considering the pressing force of a pair of ferrules,
In order to have the same performance as conventional optical connectors, it is necessary to suppress optical loss to about 0.5 dB or less when a tensile force of 1 kg is applied to the optical fiber.
For this purpose, the pressure applied to the ferrule should be 1Kg or more, but even if the pressure is 2Kg or more, the breaking force between the bare optical fiber and the ferrule fixed with adhesive is approximately 1.5Kg, and 1.5Kg If more tensile force is applied, it will break between the bare optical fiber and the ferrule, so it is meaningless.

Since the connector according to the present invention has such a structure, it is easy to separate and assemble, and the outer diameter of the entire optical connector can be reduced to 8 mm or less, whereas conventionally it was about 16 mm. In addition to coupling loss, optical loss includes loss due to tension in the optical fiber (occurred when ferrules are pulled apart from each other). Coupling losses due to ferrule bonding are generally approximately
Since it is 0.48 dB, by keeping the pressure applied to the ferrule from the clamping portion and the bottom at 1 kg or more, the loss due to stretching the optical fiber can be suppressed to 0.5 dB or less. Normally, the loss due to optical connector coupling is required to be 1.0 dB or less, and the optical connector according to the present invention
0.48dB+0.5dB=0.98dB, which satisfies this requirement. Furthermore, normally such tensile force does not act all the time, and the optical connector according to the present invention recovers from the initial loss state after the load is removed in response to temporary tensile force caused by handling, etc., so there is no problem. do not have.

In addition, in this embodiment, a flange portion is provided on the ferrule to form a portion to be subjected to clamping pressure, but the portion to be subjected to clamping pressure is provided by forming a portion with a smaller outer diameter on the side opposite to the tip of the ferrule. Good too. Also,
The ferrule or sleeve may be metal or plastic. The sleeve may have a structure in which it is split in the axial direction, and there is no problem even if the housing is provided outside the sleeve as long as the outer diameter is not large. Sometimes, a lid may be placed over the top of FIG. 3 to prevent the pair of ferrules from coming off the fixing housing or to reinforce the fixing housing.

As described above in conjunction with the drawings, according to the present invention, the optical fibers can be pressed against each other in the axial direction by simply fitting a pair of ferrules inserted into the sleeve into the fixing housing. Because of the coupling structure, the optical connector can be miniaturized and furthermore, the optical connector can be easily assembled and disassembled. At this time, since the sleeve and the fixing housing are independent, the axis alignment of the optical fiber core wire by the sleeve can be performed satisfactorily without being affected by other external forces. Furthermore, although the present invention has been described with respect to a single-fiber optical connector, it can also be applied to a multi-fiber optical connector with a similar configuration.

[Brief explanation of drawings]

Figure 1 is a structural diagram of a conventional optical connector, Figure 2,
FIG. 3 is a plan view and a front view, respectively, showing an embodiment of the optical connector according to the present invention. 8 is an optical fiber core, 9 is a ferrule, 10 is a flange portion, 11 is a sleeve, 12 is a fixing housing, 12a is a bottom portion, and 12b and 12c are clamping pressure portions.

Claims (1)

[Scope of Claims] 1. A pair of ferrules that are attached to the ends of optical fibers to be coupled and have a clamped pressure portion, and a pair of phenols that are inserted and fixed by moving them in the direction of the coupling axis. The guide member is made of a metal plate with a uniform wall thickness, which has a guide member for aligning the axis of the optical fiber, and a flat bottom part and clamping pressure parts raised at right angles from both ends of the bottom part. The clamping pressure part has grooves into which the pair of ferrules inserted into the member are respectively fitted, and when the ferrules are fitted into these grooves, the clamping pressure part and the bottom part deform into an arch shape, and the elasticity at this time causes the clamping pressure to be applied. The fixing housing is formed independently of the guide member and presses the pressurized part through the guide member so that the pair of ferrules press against each other in the axial direction of each of the ferrules. optical connector.