Optical waveguides – With disengagable mechanical connector – Structure surrounding optical fiber-to-fiber connection
Reexamination Certificate
2000-05-31
2002-11-12
Patel, Tulsidas (Department: 2839)
Optical waveguides
With disengagable mechanical connector
Structure surrounding optical fiber-to-fiber connection
C385S060000, C385S066000, C385S072000
Reexamination Certificate
active
06478473
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The invention relates to a multiple-fiber optical connector, and method for assembling the multiple-fiber optical connector.
BACKGROUND OF THE INVENTION
Multiple-fiber optical fiber ribbons in which optical fibers juxtaposed in a plurality are collectively sheathed by a sheathing portion are used as optical transmissions. Further, a multiple-fiber optical connector has been used, in which the optical fibers are exposed by removing the sheathed portion at the tip end side of a multiple-fiber optical fiber ribbon, and the terminal end portion of the multiple-fiber optical fiber ribbon including the exposed optical fibers is inserted and fixed in a ferrule.
Where connecting optical fibers to each other by using an optical connector including such a multiple-fiber optical connector, accurate alignment among the respective optical fiber insertion holes is a requisite technology in order to minimize the connection loss. Further, high production efficiency assembling work with which the ratio of defective occurrence is minimized is also required for multiple-fiber optical connectors.
A prior art multiple-fiber optical connector has a ferrule
1
(multiple-fiber connector body) as shown in FIG.
6
and
FIG. 7. A
multiple-fiber optical fiber ribbon
31
and the respective optical fibers
32
are inserted and fixed in the ferrule
1
. The ferrule
1
is provided with a boot insertion hole
12
into which the terminal end of the multiple-fiber optical fiber ribbon is inserted. Also, a V-shaped groove
21
which guides optical fibers is provided subsequent to said boot insertion hole
12
. Further, a minute hole
7
for inserting an optical fiber, which has a slightly greater diameter than that of the optical fiber is provided subsequent to the V-shaped groove
21
.
An adhesive agent inserting window
11
is formed on the upper surface of the ferrule
1
, and the adhesive agent is used to cement the multiple-fiber optical fiber ribbon
31
and the respective optical fibers
32
to the ferrule
1
. The adhesive agent inserting window also functions as a monitoring window for accurately inserting the respective optical fibers
32
into the minute holes
7
for inserting optical fibers.
The assembling process of the abovementioned prior art multiple-fiber optical connectors is as described below; First, after the sheath at the tip end side of a multiple-fiber optical fiber ribbon
31
is removed and the respective optical fibers are exposed (for taking out the heads thereof), a boot
34
is placed on the multiple-fiber optical fiber ribbon. And, the multiple-fiber optical fiber ribbon
31
is inserted into the boot insertion hole
12
, and at the same time, the respective optical fibers are inserted into minute holes
7
for inserting optical fibers along the V-shaped groove
21
. Next, an adhesive agent is supplied through the adhesive agent inserting window
11
and is filled up in the minute holes for inserting optical fibers while moving the multiple-fiber optical fiber ribbon forward and backward. And, the adhesive agent is thermally hardened, whereby the assembling is completed.
In the prior art multiple-fiber optical connector described above, the position for inserting the inserted multiple-fiber optical fiber ribbon
31
is determined, as shown in FIG.
6
(
a
), at the position where the tip end portion (end face)
33
of the sheathed portion of the multiple-fiber optical fiber ribbon is brought into contact with a stepped portion
22
being the commencing position of the V-shaped groove
21
. Further, FIG.
6
(
a
) shows that the tip end portion
33
of the sheathed portion of a multiple-fiber optical fiber ribbon is accurately positioned at the stepped portion
22
.
However, there are cases where, due to a slight unbalance in the working conditions, the tip end portion
33
of the optical fiber ribbon mounts the stepped portion
22
as shown in FIG.
6
(
b
) and mounts the upper surface of the V-shaped groove
21
. In these cases, an optical fiber is subjected to a local bending, and is seated and fixed by an adhesive agent with a bending stress given thereto. Therefore, a transmission loss is produced at the bent portion, and in the worst case an optical fiber is broken or cut off.
Also, as shown in FIG.
6
and FIG.
7
(
a
), a ferrule
1
structured so that it has an adhesive agent inserting window
11
according to the prior art is asymmetrical in the vertical direction. Therefore, as the adhesive agent is hardened and contracted in an optical connector provided with the ferrule having the abovementioned structure, the surface weak in structure, where the adhesive agent inserting window
11
is provided, is deformed concave as shown in FIG.
7
(
b
).
If such a deformation is produced, in the case of a multiple-fiber optical connector having a wide width, optical fibers whose array position is close to both sides and which are arrayed at the center portion greatly slip in the Y direction in FIG.
7
(
b
) as shown at S is the same drawing. If so, the connection loss of the optical fibers using a multiple-fiber optical connector will be increased.
In addition, where it is assumed that the optical fiber array direction is the X direction, the abovementioned Y direction is orthogonal to the X direction and Z direction of the optical fiber axis. Also, a reference number
13
indicates an inserting hole for fitting pins used to connect an optical fiber to the mating optical connector.
As a countermeasure for deformation of the multiple-fiber optical connector, it is possible that a concave deformation amount of an optical connector resulting from the hardening and contraction amount of the adhesive agent is estimated in advance, and the position of the minute holes for inserting optical fibers is offset in design. However, since the amount of deformation is made uneven in line with an unbalance in the amount of inserting an adhesive agent, it was remarkably difficult to accurately assemble a highly accurate optical connector which can minimize the connection loss.
The invention solves the abovementioned shortcomings and problems, and it is therefore an object of the invention to provide a multiple-fiber optical connector which can facilitate automation of assembling work.
DISCLOSURE OF THE INVENTION
A multiple-fiber optical connector according to the first aspect of the invention is featured in that a multiple-fiber connector having a multiple-fiber optical fiber ribbon in which optical fibers juxtaposed in a plurality are collectively sheathed by a sheathing portion, and having the optical fibers exposed by removing the sheathed portion at the tip end side of the multiple-fiber optical fiber ribbon, in which the terminal portion of the multiple-fiber optical fiber ribbon including the exposed optical fibers are inserted and fixed in a ferrule; wherein the connector is provided with a ribbon insertion hole having a greater width than the width of the multiple-fiber optical fiber ribbon, a tapered portion communicating with the multiple-fiber optical ribbon, whose diameter is decreased toward the tip end side thereof, and minute holes for inserting optical fibers which communicate with the tapered portion and are juxtaposed in a plurality so that the respective exposed optical fibers are individually inserted thereinto, from one side to the other end side in the ferrule; the width at the tip end portion of the tapered portion is formed to be narrower than that of the multiple-fiber optical fiber ribbon; and the position in a width, in the course of the tapered portion, which is roughly coincident with the multiple-fiber optical fiber ribbon stops the tip end portion of the sheathed portion at the terminal portion of a multiple-fiber optical fiber ribbon inserted from the ribbon insertion hole, and is made into a stopping portion of the sheathed portion tip end which determines the tip end position.
A multiple-fiber optical connector according to the second aspect of the invention is featured in that, in addition to a multiple-fiber optical connector
Lacasse & Associates LLC
Patel Tulsidas
Prasad Chandrika
The Furukawa Electric Co. Ltd.
LandOfFree
Multiple-fiber optical connector, and method for assembling... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multiple-fiber optical connector, and method for assembling..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiple-fiber optical connector, and method for assembling... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2991596