JPS6057565B2 - optical fiber guide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fiber optical system, and more particularly to a guide body for connecting the ends of two optical fibers.
U.S. Application No. 758106, January 10, 1997 "CI of Guide Connector Assembly for Optical Fiber Connection"
This corresponds to the P application.

The above-identified U.S. application discloses a guide connector assembly for providing an optical transmission connection between the ends of a pair of single-wire optical fibers, the assembly comprising three predetermined lengths of glass rods. This is a linear guide member in which the rods are arranged in parallel and connected at their peripheral portions in the longitudinal direction to form a tip-shaped gap groove between the rods. The guide member is disposed within a cavity within the connector, and the connector is comprised of a pair of mating connector members.

Each connector member has first and second ends with a longitudinally extending passageway therebetween for passing the fiber therethrough to a hollow portion proximate the second end. It's starting to grow. The connector members are connected together at their second ends and their hollow regions define guide receiving cavities.

Each passageway has an enlarged opening at a first end that tapers to a reduced cross-sectional area toward the cavity entrance. At the entrance to the cavity, the cross-sectional area of the passage is slightly larger than the cross-sectional area of the optical fiber, so that the fiber enters the guide member through the passage and is precisely positioned. Each connector member includes an alignment hole for visually viewing the interior of the cavity to determine whether each fiber extends a predetermined length within the connector member.

That is, this hole is for confirming whether or not the fiber ends are brought into contact within the guide member to obtain a good optical signal transmission joint when the connector members are coupled. It has been found that this guide connector assembly greatly facilitates the connection between the ends of a pair of optical fibers.

However, the above-mentioned U.S. Application No. 75810 Eel Guide●The alignment performance of the guide used in the connector assembly is such that the optical fiber can be precisely aligned when the diameter of the optical fiber closely matches the inner diameter of the gap groove formed between the rods of the guide member. It can be connected in line. Therefore, the present invention relates to an improvement of the linear guide body of the above-mentioned application, which allows for more precise alignment of optical fibers whose outer diameters are not the same as the inner diameter of the pointed groove formed by the rod body, and which allows for more precise alignment of optical fibers. To provide a guide body which allows guide bodies of one size to be connected even if the diameters of the guide bodies are different.

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a guide for a guide connector assembly which has the advantages of the invention of the above-mentioned U.S. application, which provides a large tolerance for optical fiber end accommodation, and which also provides high precision optical fiber end accommodation. It is an object of the present invention to provide a guide body that can be joined with.

A second object of the present invention is to provide a guide/connector assembly guide having a simple structure and capable of coupling the ends of a pair of optical fibers with low loss.

A third object of the present invention is to provide a reusable guide connector assembly that allows precise alignment of a pair of optical fibers over a variety of diameters.

A fourth object of the present invention is to provide a guide for coaxially and precisely aligned optical fiber connections, and an assembly that can be easily disposed within a connector assembly. The above objects and others are accomplished by providing a guide for use in making an optical signal transmission connection between the ends of a pair of single optical fibers.

The guide body has at least three glass rods having a predetermined length, which rods are arranged parallel to each other, and the longitudinal peripheries of the adjacent rods are brought into contact with and connected to each other, A pointed gap groove is formed between adjacent rods. The groove has an opening and an arcuate portion at the end of the rod, the arcuate portion being able to push the ends of the fiber into one of the corners of the pointed gap groove, and to guide the ends of the fiber along the corners and into each other. It is designed to match the connection. The invention will now be described with reference to the accompanying drawings, in which identical parts are designated by the same reference numerals.

In FIG. 1, reference numeral 20 denotes a guide body used in a guide connector assembly of a fiber optic system, which temporarily or permanently connects a pair of optical signal carrying fibers.

This guide member 20 is an elongated rod-shaped member and includes at least three members 22, 24, and 26 of similar shape.

These rod-shaped members 22, 24, and 26 are preferably made of a hard material (preferably glass) and have smooth surfaces. The rod-shaped members 22, 24, and 26 are arranged with their longitudinal portions facing each other (see 29 in FIG. 3).

By arranging the rod-like members in this manner, a central internal space (or groove) 27 is formed between these members, which extends over the entire length of the guide member (or guide body).

This internal space 27 is in the form of a central groove containing a plurality of pointed gaps, each pointed gap being located in the space between a pair of abutting rod-shaped members and terminating at an abutting portion 29 of the rod-like members. There is.

The pointed gap extends over the entire length of the bar member. Each rod-like member 22, 24, 26 is bent in an arc shape, and the rod-like members 22, 24 coincide at the outer end of the radius of curvature of the guide body 20.

The rod-shaped member 26 that is in contact with the rod-shaped members 22 and 24 is aligned with the innermost radius of curvature of the arc-shaped guide member 20. Said groove 2
7 is configured to receive the ends of the optical fibers to be connected and arrange them coaxially.

The diameter of the rod-shaped member is selected such that the diameter of the central portion of the groove formed between them is larger than the diameter of the optical fiber to be connected. Since the rod-shaped members 22, 24, and 26 have an arc shape, the optical fiber inserted into the groove 27 is pressed into the gap between the tip of the groove 27 formed between the rod-shaped members 22 and 24, and the peripheral part of the optical fiber is pressed into the groove. It contacts the peripheral portions of the rod-shaped members 22 and 24 within a gap of 27.

Since the arc shape allows the optical fiber to be pushed into the gap between the rods 22 and 24, it is not necessary to strictly match the diameter of the optical fiber and the diameter of the groove 27. Therefore, even if the diameter of the optical fibers is smaller than the diameter of the groove 27, if they are inserted from opposite sides of the guide body 20, both optical fibers will be pushed equally into the gap between the rods 22 and 24, so that the light will not be transmitted. The fibers can be aligned in a single line. With such a guide member 20, the ends of a plurality of optical fibers with different diameters can be connected with one guide member, and the difference between the diameter of the groove 27 and the diameter of the end of the optical fiber is within an allowable value. Optical fibers can be connected even in larger cases.

The guide member 20 is preferably made of glass, and the glass rods are stretched while still hot to the required size and brought into contact with each other so that the longitudinal portions of the peripheries touch each other (see FIG.
29) to form contact fusion.

Glass is important not only for manufacturing reasons, but also from a functional standpoint.

That is, if glass is used, shrinkage is extremely low and dimensional stability as a guide member can be obtained. Furthermore, glass is hard and provides smooth interstitial surfaces and is therefore less abrasive or wear-resistant. These properties generally prevent optical fibers covered with softer materials, such as plastic, from burning or being damaged (
Without these characteristics, the optical fiber will be damaged when the optical fiber is inserted, or the guide itself will be damaged, and if any accident occurs, it will cause unnecessary strength loss due to the damaged surface. ). Further, if the guide body is made of glass, it is transparent and the end of the inserted optical fiber can be seen, which is convenient for connecting the optical fiber.

Further, since the groove is shaped like a beautiful end, the optical end of the fiber contacts only the innermost surface of the rod-like members 22, 24, and 26.

Therefore, when the fiber is inserted into the gap-like groove, there is virtually no friction between the fiber and the rod. Furthermore, since the fiber optical end is press-fitted into the gap between the rod-like members 22 and 24, if the diameters of the fiber optical ends are equal, the fiber ends will precisely axially coincide within the guide body. and held in proper position. Groove 27 of guide member 20
Groove 27 is provided so that a small diameter optical fiber can be easily inserted into the
The cross-sectional area of both open ends of the groove 27 is larger than the cross-sectional area of the other portion of the groove 27. That is, in order to widen the open end of the groove 27, the end of the guide member is placed in an acid bath, such as hydrofluoric acid, and the free end of the rod-shaped member is opened as indicated at 28 in FIG. The portion may be etched into a tapered shape. FIG. 2 shows a guide 20 within the connector assembly, which may be contained within a cylindrical housing 30 to facilitate use of the guide.

This housing 30 facilitates the use of the guide member within the connecting member. Housing is nylon, ABSl
Preferably, it is molded from an injection molded plastic such as styrene, NORY, or a cast plastic such as an epoxy resin.

At each end of the cylindrical housing 30 there is a tapered truncated conical opening 40 for accessing the end of the groove 27 extending into the guide body 20.

In the embodiment of FIG. 2, the connector is comprised of a pair of hermaphroditic matching connector members 32,34.

These connector members 32, 34 are identical in size and shape. The connector member 34 has a pair of fingers 36, which have an arcuate cross section as shown in FIG. 3, and are provided on opposite sides of the connector member 34 in the diametrical direction. Similarly, as shown in FIG. 3, the connector member 32 has a pair of fingers 38 having an arcuate cross section, and the fingers 38 are provided on diametrically opposite sides of the connector member 32. . The fingers 36, 38 of the connector members 34, 32 thus form an annular ring that provides a space for receiving the guide member 20 within the cylindrical housing 30. Connector member 32 is attached to cable 42 and connector 34 is connected to fiber optic cable 44.

Cable 42 has an optical fiber 46 that is preferably connected to cable 42 by an epoxy adhesive between fiber 46 and the cable at the end of the cable. Cable 44 also includes an optical fiber 48 secured to the end of cable 44, similar to optical fiber 46 of cable 42. A cylindrical hole 50 extends fully into the body of the member from the outer end of the connector member 32. The cable 42 is inserted into this opening 50.
is secured by a suitable adhesive applied around the periphery of this cable, so that the cable is secured within the opening 50 in the connector member 3.
It is fixed to 2. Similarly, a cylindrical hole 52 extends fully into the body of the member from the outer end of the connector member 34. The opening 50 in the connector member 32 tapers 54 into the cavity formed between the fingers 36,38.
Similarly, the opening 52 of the connector member 34 also has a tapered shape 56.
and extends into the cavity formed between the fingers 36 and 38. The ends of the optical fibers 46, 48 thus extend from the cable tubes 42, 44 and into the opening 4 of the cylindrical housing 30.
0 and enters the clearance groove 27 formed in the guide member 20 within the bars 22, 24, 26. When the cables 42, 44 are attached to the connectors 32, 34, the optical fibers 46, 48
To ensure that the ends of the optical fibers abut each other, the ends of the optical fibers can be cut to a predetermined length using longitudinally aligned holes 60. There is an annular recess on the outer surface of the fingers 36, 38, so that the connector members 32, 3
An O-ring 58 is installed in the annular recess after the fingers 36 and 38 are brought into contact with the body of the opposing connector member, respectively.

Therefore, O-ring 58 holds connector members 32, 34 together. The transmission connection state of the end of the optical fiber in the guide member 20 is such that oil having a refractive index matching the refractive index of the core of the optical fiber is applied to the gap groove 2.
I was able to get it within 7, so it's an improvement. If a permanent connection is desired rather than an intermittent connection, index-matched epoxy can be placed in the gap groove to secure the fiber ends.

FIG. 4 shows another embodiment of the guide according to the invention, in which the guide consists of three similar elongated rod-like members 72, 74.
, 76.

Preferably, each rod-shaped member is made of glass. These rod-shaped members 72, 74, and 76 are disposed in parallel and are integrally fixed with their longitudinal portions facing each other. The rod-like members are put together to form the guide member, and the cylindrical rods may be heated and stretched to align the rods in parallel and fix them in one piece. After cutting the rod to a predetermined length, a high-temperature dowel is inserted into the end of the guide member (guide body) 70 to form a tapered opening 78 at the end.

Bend both ends of the guide body 70 as follows.

That is, the central portion is straight and the ends are bent approximately parallel to, but transversely from, the axis of the central portion. In other words, the ends of the guide member 70 are bent at the first radius 82 at either end of its straight central portion so that the ends extend laterally to one end of the central portion. Additionally, as the guide moves outward, the ends at 80 are bent to be approximately parallel to the straight portion of the guide. The rod-shaped members 72, 74, 76 thus define a central internal space or groove 84 between the rods that extends over the entire length of the guide.

This internal space 84 is in the form of a central groove containing apical gaps (each apical gap being between a pair of opposed bar members).

The rods 72 , 74 are aligned laterally with the ends of the rods in a direction furthest from a direction away from the central portion of the guide member 70 .

Therefore, when the optical fiber is inserted into the gap groove of the guide member 70, the optical fiber is pushed into the gap between the rod-shaped members 72 and 74.

That is, as shown in FIG. 6, the optical fibers are brought into contact with the circumferential surfaces 86, 88 of the rods 72, 74 of the guide member 70. Sufficient coupling can be obtained if the gap groove is at least twice the diameter of the optical fiber. Since the guide member 70 is composed of an arcuate end portion and a straight center portion, it is easier to align a pair of optical fibers inserted into the guide member 70 from both ends thereof. .

That is, as shown in FIG. 5, the optical fiber 90 inserted on the left side and the optical fiber 92 inserted on the right side are precisely coaxially aligned, and the ends of the optical fibers 90 and 92 are aligned. More specifically, as shown in FIG. 6, the optical fiber 92 is pushed into the gap between the rods 72 and 74, and is pushed as far inward as possible into the gap while facing the walls 86 and 88 of the rods 72 and 74. It will be done. Similarly, the fibers 90 are also pressed against the walls 86, 86, and both fibers are brought into contact with each other by the straight portion at the center of the guide member, and both ends of the fibers are in close contact with each other. Its light transmission is further improved by index-matching oil inserted into the gap. As illustrated in FIG. 6, optical fiber 72 has an optical core 94 and a cladding 96 of different refractive index, which facilitates light retention within the core of the optical fiber. . Further, the refractive index of the glass rods 72, 74, and 76 is particularly different from the refractive index of the optical fiber in order to improve light retention within the optical transmission path.

The guide member 70 is preferably mounted within a cylindrical housing 98 made of injection molded thermoplastic or cast plastic. This housing 98 is formed in the same manner as the housing 30 of the guide member 20. Further, the guide member 70 inside the housing 98
is used in the manner shown in FIG. 2 with respect to the guide member 20. As described above, the guide connector assembly according to the present invention quickly and effectively connects the ends of a pair of single optical fibers;
This can be easily released by removing the O-ring 58 from the peripheral recess around the finger and loosening the connector members 32, 34.

That is, in this case, the connector members 32, 34 are separated and the fiber end within the guide member 20 (or 70) is removed. When the fiber ends are to be recombined, they can be inserted into the cylindrical housing 30 (or 98) of the guide member and brought into alignment by the guide member. Since the guide member according to the invention is provided with an arcuate portion, optical fibers of various diameters can be connected in unison with this guide member of one size.

Furthermore, the tolerance regarding the outer diameter of the optical fiber relative to the inner diameter of the clearance groove within the guide member may be low. Additionally, the arcuate portion of the guide member allows the optical fiber to be offset from the axis of the connector, causing the optical fiber to flexibly deflect if the optical fiber contacts the connector members 32, 34 prior to closing. This has the effect of preventing unnecessary damage to the fiber due to excessive pressure being applied to the fiber end face. This feature allows for loose tolerances on the length of the fiber. These advantages are obtained together with all the advantages of the parent application. The cylindrical housing formed around the guide members 20 and 70 is such that the entrance opening to the guide member is centered in the connector member when the housing is inserted into the cavity formed between the fingers of the connector. Fiber ends can be quickly connected.

Furthermore, since the open end of the cylindrical housing is coaxial within the connector member, the guide member can be inserted without being angularly aligned with the connector member.

Additionally, the opening of the cylindrical housing is sufficiently wide to allow easy insertion of the fiber end into the end of the guide member.

The present invention is not limited to the content described above, and any improvements or modifications within the scope that do not change the gist of the invention shall fall within the scope of the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a guide body for connecting optical fibers according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of a guide connector assembly according to the present invention, showing a state in which a pair of optical fiber ends are connected. 3 is a sectional view taken along the line 3-3 in FIG. 2, FIG. 4 is a perspective view of another example of the optical fiber connection guide according to the present invention, and FIG. 5 is a longitudinal section of the guide shown in FIG. 4. So, a pair of 20... guide bodies, 22, 24, 26...
... Rod-shaped member, 27 ... Point-shaped gap groove, 29 ... Contact portion, 30 ... Cylindrical housing, 32, 34 ...・Connector member, 3
6, 38... Finger portion of connector member, 40...
...Aperture, 46, 48...Optical fiber,
50, 52... Cylindrical hole, 54, 56...
...Taper, 58...0 ring, 70...
...Guiding body, 72, 74, 76... Rod-shaped member,
78... Taper opening, 80... Bent part, 84... Internal groove, 86, 88...
Wall surface of rod-shaped member, 90, 92... optical fiber, 98... cylindrical housing.

Claims (1)

[Scope of Claims] 1. An optical fiber guide for making an optical signal transmission connection between a pair of optical fibers, comprising at least three glass rods having a predetermined length, the rods being parallel to each other. the longitudinal peripheries of the proximal rods are arranged in contact with and connected to each other, forming a pointed gap groove between the proximal rods, the groove forming an open end at the end of the rod; an arcuate portion, the arcuate portion forcing the ends of the fiber into one of the corners of the pointed gap groove, and causing the ends of the fiber to align and connect with each other along the corner; Optical fiber guide. 2. The optical fiber guide according to claim 1, wherein a central portion of the optical fiber guide along its length is substantially straight. 3. The central portion is connected to an arcuate portion at each end thereof, the arcuate portion extending laterally to one side of the central portion, and the ends of the guide body are substantially parallel to the central portion. The optical fiber guide according to claim 2, wherein the optical fiber guide is connected to an arcuate portion that is bent back so as to extend. 4. The optical fiber according to claim 3, wherein two of the rods are arranged horizontally with respect to the one side, and an end of the guide body extends from the one corner. Guide body. 5. The optical fiber guide according to claim 1, wherein the rod has an arc shape over the entire length of the guide. 6. The guide body is disposed within a cylindrical housing, the housing having a pair of openings at opposite ends thereof, the openings being tapered inwardly to provide a wide opening for each end of the guide body. 2. The optical fiber guide according to claim 1, wherein the optical fiber guide has a shape that makes it easy to insert the optical fiber end into the guide. 7. The optical fiber guide according to claim 1, wherein the arcuate portion of the guide bends the fiber and gives the fiber concomitant flexibility in fiber accommodation length.