JPH05203835A - Plug for optical connector and the same - Google Patents

Abstract

PURPOSE:To provide the optical connector which consists of a small number of components and is suitably reduced in size and cost. CONSTITUTION:The plug for the optical connector consists of a housing 10 which has an internal space 14 where an optical fiber can be curved and a fiber insertion hole 16 is formed at one end side and an optical fiber 12 which is fixed to the housing 10 so that its tip project from the fiber insertion hole 16; and this plug is mounted on an adapter 22 and optical fibers are made to abut on each other in a sleeve 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector plug and an optical connector. In the field of optical communication and the like, an optical connector is used to detachably connect optical fibers to each other. Since optical connectors generally have a structure in which the end faces of optical fibers are abutted against each other, high-precision manufacturing technology is required to prevent optical loss due to axis misalignment, and low cost due to frequent use. Is required.

[0002]

2. Description of the Related Art FIG. 6 is a cutaway perspective view of a conventional optical connector plug. The optical fiber led out from the optical fiber cord 2 is inserted and fixed in the ferrule 4 such that the tip of the optical fiber coincides with the end face of the ferrule 4. The ferrule 4 is provided in the housing 6 while being biased in the longitudinal direction by the coil spring 8.

When connecting such optical connector plugs, two optical connector plugs are attached from both sides to an adapter having a sleeve in which the tip portion of the ferrule 4 is closely fitted. With this arrangement, the ferrules 4 come into coaxial contact with each other in the sleeve, and an appropriate pressure is applied to the contact portion by the coil spring 8.
Optical connection between optical fibers becomes possible.

[0004]

In the conventional optical connector, the number of constituent parts is large, and high precision manufacturing technology is required for parts such as ferrules. There was a problem of high cost.

The present invention was created in view of the above circumstances, and an object thereof is to provide an optical connector having a small number of parts and suitable for downsizing and cost reduction, and an optical connector plug as a component thereof. .

[0006]

FIG. 1 is a diagram for explaining the principle of the present invention, and shows the basic structure of an optical connector plug according to the present invention. This optical connector plug comprises a housing 10 and an optical fiber 12. Housing 10
A space 14 in which the optical fiber can be curved is defined inside, and a fiber insertion hole 16 is formed at one end of the housing 10. The optical fiber 12 is fixed to the side of the housing 10 opposite to the fiber insertion hole 16 so that the tip of the optical fiber 12 projects from the fiber insertion hole 16.

In the optical connector of the present invention, the first and second optical connector plugs each having the above-mentioned structure and the respective optical fibers of the first and second optical connector plugs are inserted from both sides. Sometimes, a sleeve that supports the optical fiber so that the end faces of the optical fiber are coaxially contacted with each other, and the state where the optical fiber is curved in the space is maintained when the optical fibers are contacted with each other. As described above, the sleeve and the adapter for supporting the first and second optical connector plugs are provided.

[0008]

According to the present invention, when the tips of the optical fibers are butted against each other in the sleeve, the curved state of the optical fiber is maintained in the space of the housing. Therefore, in this state, the optical fiber is restored. The force acts as a pressing force between the optical fibers. Therefore, it is possible to obtain the pressing force of the optical fibers required for optical coupling without separately providing a biasing means such as a coil spring. Further, since the optical fiber is inserted into the sleeve as it is, the ferrule is not necessary. As described above, according to the present invention, it is possible to realize an optical connector having a small number of parts and suitable for downsizing and cost reduction.

[0009]

EXAMPLES Examples of the present invention will be described below. 2 is a cutaway perspective view of an optical connector showing an embodiment of the present invention, and FIG. 3 is a sectional view showing a mounted state of the optical connector. This optical connector comprises a pair of optical connector plugs 18 (only one is shown in FIG. 2), a sleeve 20, and an adapter 22. The sleeve 20 is housed in the adapter 22.

The optical fiber 12 is fixed to the housing 10 by the secondary coating 24, and the portion of the optical fiber 12 accommodated in the space 14 inside the housing 10 and the portion protruding from the fiber insertion hole 16 are covered. Has the secondary coating removed. Further, the primary coating of the optical fiber 12 is removed from the portion protruding from the fiber insertion hole 16.

In this embodiment, the portion of the optical fiber 12 where the secondary coating 24 remains and the fiber insertion hole 16 are set on different axes so that the optical fiber 12 is pre-curved.

The inner diameter of the sleeve 20 is the optical fiber 12
It has a roughly cylindrical shape that is slightly larger than the outer diameter of
Both ends of the sleeve 20 are tapered so that the optical fiber can be easily inserted from both sides. The sleeve 20 is loosely fitted in the adapter 22, and the axial movement of the sleeve 20 is the protrusion 2.
It is regulated by 6. As the material of the sleeve 20, glass, resin, or ceramics, which is hard to scratch the optical fiber, is selected.

The adapter 22 has a lock mechanism 28, and when the optical connector plug 18 is inserted into the plug insertion hole 30 of the adapter 22, the tip projection 28A of the lock mechanism 28 has a side surface of the housing 10 of the optical connector plug. The optical connector plug 18 is prevented from coming off from the adapter 12 with a small force by elastically engaging with the concave portion 32 formed in.

The operation of the optical connector shown in FIGS. 2 and 3 will be described. First, one of the optical connector plugs 18 is inserted into the plug insertion hole 30 of the adapter 22. As a result of this insertion operation, the tip of the optical fiber 12 is moved to the sleeve 2
Inserted at 0.

Since the end portion of the sleeve 20 is tapered, even if the sleeve 20 or the optical fiber 12 is misaligned in a direction perpendicular to the fiber axis direction, the optical fiber 12 is accurately attached to the sleeve 20. Is inserted. Therefore, as long as the inner diameter accuracy of the sleeve 20 is ensured, high shape accuracy is not required for the housing 10 of the optical connector plug and the insertion hole 30 of the adapter 22.

Next, the other optical connector plug 18 is inserted into the plug insertion hole 30 of the adapter 22. With this insertion operation, the optical fiber 12 is inserted into the sleeve 20, and the end faces of the optical fiber 12 are brought into contact with each other inside the sleeve 20.

The length of the portion of the optical fiber 12 projecting from the housing 10 is such that when the optical fibers 12 come into contact with each other in the sleeve 20, the optical fiber 12 is slightly curved in the space 14 of the housing 10. It is set to change. Therefore, the elastic force associated with the change in the curved state acts on the optical fibers 12 in the sleeve 20 in the axial direction, so that an appropriate contact force between the optical fibers 12 is secured and optical coupling is achieved.

The end face of the optical fiber 12 may be flatly polished or may be slightly spherically polished. By polishing the end surface of the optical fiber 12 into a spherical shape, it is possible to improve the adhesion between the cores of the optical fiber 12 and obtain high optical coupling efficiency.

In this embodiment, the housing space 14
The optical fiber 12 positioned inside is pre-curved so that a large force is not required at the initial stage of deformation of the optical fiber 12 in the space 14.

That is, when the optical fiber 12 is not pre-curved, a relatively large force is required when the optical fiber is buckled by an axial force applied to the optical fiber to start deformation. By bending the optical fiber in advance as in the present embodiment, the initial stress for buckling the optical fiber is not required. Therefore, when the optical fibers 12 are butted against each other in the sleeve 20, the optical fibers are not curved only in one of the plugs, and the optical fibers are evenly curved in both plugs, so that the required contact is achieved. The contact stress can be obtained.

FIG. 4 is a sectional view of an optical connector plug showing another embodiment of the present invention. The difference between this embodiment and the previous embodiment is that the fixed part and the free end of the optical fiber 12 are not arranged on different axes in order to bend the optical fiber 12 in advance, but the fixed part of the optical fiber 12 is arranged. The free end is coaxially arranged, and the optical fiber 12 is pre-curved by the curving portion 34 of the housing 10. With this configuration, the same effect as that of the previous embodiment can be obtained.

By the way, when the optical fiber 12 is used as it is, the surface of the optical fiber 12 is damaged by the friction with the sleeve 20 or the fiber insertion hole 16 of the housing, and the optical fiber is damaged. There is a risk of

Therefore, in such a case, a carbon coating is formed on at least a portion of the optical fiber 12 protruding from the fiber insertion hole 16 and a portion in contact with the housing. By doing so, the optical fiber is less likely to be damaged, and the life of the optical connector can be extended. The carbon coating can be formed on the optical fiber by a method well known in the manufacturing process of the optical fiber.

FIG. 5 is a cutaway perspective view of an optical connector showing still another embodiment of the present invention. In this embodiment, the optical connector plug 18 is provided with a plurality of optical fibers 12 in the housing 10 as in the previous embodiments, and the adapter 22 has a number of sleeves corresponding to the number of fibers on the plug side. 20 are provided at substantially the same pitch as the fiber pitch.

With this structure, a plurality of optical fibers can be attached / detached at the same time by a single attaching / detaching operation. In this case, the sleeve 20 as described with reference to FIG.
By loosely fitting the optical fiber into the housing 22, it is possible to eliminate the accumulation of manufacturing errors in the arrangement direction of the optical fiber 12 and the sleeve 20, and thus it is possible to easily achieve the multi-core optical connector.

[0026]

As described above, according to the present invention,
It is possible to provide an optical connector plug and an optical connector suitable for downsizing and cost reduction with a small number of parts.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a cutaway perspective view of an optical connector showing an embodiment of the present invention.

FIG. 3 is a sectional view of an optical connector showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view of an optical connector plug showing another embodiment of the present invention.

FIG. 5 is a cutaway perspective view of an optical connector according to still another embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 10 Housing 12 Optical Fiber 16 Fiber Insertion Hole 18 Optical Connector Plug 20 Sleeve 22 Adapter

Claims (4)

[Claims] 1. A housing (10) in which a space (14) is formed so that an optical fiber can be curved, and a fiber insertion hole (16) is formed at one end side thereof, and a tip of the housing (10). An optical connector comprising an optical fiber (12) fixed to the housing (10) on the side opposite to the fiber insertion hole (16) so as to project from the fiber insertion hole (16). plug. 2. The first and second optical connector plugs (18) each having the structure according to claim 1, and the respective optical fibers of the first and second optical connector plugs are inserted from both sides. When the optical fiber (1
The optical fiber so that the end faces of 2) come into contact with each other on the same axis.
The sleeve (20) for supporting (12), and the optical fiber (12) so that the curved state in the space (14) is maintained when the optical fiber (12) is in contact with each other. An optical connector comprising a sleeve (20) and an adapter (22) for supporting the first and second optical connector plugs (18). 3. The optical fiber (12) is provided in the housing (1).
The optical connector plug according to claim 1 or the optical connector according to claim 2, wherein the optical connector plug is housed in the space (14) along the curved portion of (0). 4. The housing and at least a portion of the optical fiber (12) protruding from the fiber insertion hole (16).
The plug for optical connector according to claim 1 or 3, or the optical connector according to claim 2 or 3, characterized in that a carbon coating is formed on a portion in contact with (10).