JPH08286079A - Fiber optic connector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an optical fiber connector which is easy to manufacture and has reduced connection loss. [Structure] This optical fiber connector A ₁ comprises an optical fiber holder 1 and an optical fiber 3 fixed to the optical fiber holder 1, and the optical fiber holder 1 is provided with an optical fiber strand 3a up to a connection end face 1d. The bare wire portion arranging hole 1a and the covering portion arranging hole 1b for arranging the covering portion 3b of the optical fiber are integrally formed so as to be continuous in the longitudinal direction, and the bare wire portion 3a has several points a ₁ , a on its outer circumference. _The optical fiber connector is fixed in a state of being in contact with the wire portion placement hole 1a at ₂ , and is closest to the connection end face 1d at the contact point between the wire portion 3a and the wire portion placement hole 1a. The wire portion 3a at the contact point a ₁ of the position
Of the wire portion 3a so that the force acting in the radial direction of the wire and the force acting in the radial direction of the wire portion 3a at the next contact point a ₂ are substantially opposite to each other. It is arranged in the arrangement hole 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connector, and more particularly to an optical fiber connector capable of reducing the connection loss when the connection end faces of the optical fiber connectors are butted against each other.

[0002]

2. Description of the Related Art When assembling an optical fiber communication circuit, an optical fiber connector is used as a component for connecting optical fibers used. FIG. 1 is a front view of a conventional optical fiber connector as viewed from its connection end face.
3 is shown.

In FIG. 13, a plurality (four in the drawing) of wire-hole arranging holes 1a are aligned in the same horizontal plane in the longitudinal direction of the holder 1 for the optical fiber (the direction of the paper surface in the drawing). It is formed in the opened state. Then, on both sides of the connection end face of the optical fiber holder 1, pin fitting holes 2a, 2b having their own centers in the same horizontal plane as the axis of the above-mentioned wire portion placement hole 1a are formed. Pin fitting hole 2
Fitting pins (not shown) are inserted in a and 2b, and connection with another optical fiber connector can be made through the fitting pins.

The optical fiber holder 1 is usually manufactured as a resin molded product by injection molding or transfer molding of, for example, epoxy resin, and at that time, the wire arranging hole 1a, the pin fitting holes 2a, 2b, etc. Are formed using cores corresponding to these holes. The bare wire portion 3a of the optical fiber, which is exposed by peeling off the covering portion, is inserted into these bare wire portion placement holes 1a. Wire portion placement hole 1a
Is larger than the diameter of the wire portion 3a, and the optical adhesive 5 is applied to the gap 4 (usually 0.5 to 1 μm) formed between the two.
The wire portion 3a to fill the wire portion placement hole 1a.
It is glued and fixed inside.

However, in the case of the optical fiber connector shown in FIG. 13, since the wire portion 3a has a smaller diameter than the wire portion arranging hole 1a, the wire portion 3a floats in the wire portion arranging hole 1a. Since it is in an easy state, the optical fiber strand 3a
14 is inserted into the wire portion placement hole 1a, or when the gap 4 is filled with the optical adhesive 5, the wire portion 3a floats, and as shown in FIG. 14, the wire portion 3a is irregular. It may be fixed in a biased state. When the optical fiber connectors in such a state are connected to each other, axial misalignment occurs between the wire portions 3a which are the light propagation paths in the mutual optical fiber connectors, and the connection loss at that time increases. The situation is caused.

To solve such a problem, Japanese Unexamined Patent Publication No. 6-148
In Japanese Patent No. 447, a linear inclined surface that inclines deeply from both ends in the longitudinal direction toward the central portion, and a central concave arc surface that is connected to the linear inclined surface and is formed by an injection molding method using a mold. And a lid member having a surface shape corresponding to the aligning member is superposed on the aligning member having a plurality of V grooves formed on the concave arc surface, and the strands of the optical fiber are inserted from both ends. An optical fiber splicer having a structure connected to each other is disclosed.

However, in the case of this optical fiber splicer, the V-grooves for arranging the strands of the optical fiber must be formed on the concave arc surface by the injection molding method, and therefore the alignment member is manufactured. It will be quite difficult. Further, in this component, an optical fiber whose bare wire portion is exposed is inserted from both ends of the component to fix them, and then the optical fiber connector is cut in the thickness direction. However, high precision is required for the selection of the cutting position and the cutting width at that time, and the resulting optical fiber connector becomes very expensive.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the conventional optical fiber connector, and despite having a very simple structure, the wire portion of the optical fiber is positioned with high accuracy. Therefore, it is an object of the present invention to provide an optical fiber connector having a novel structure in which connection loss is reduced.

[0009]

In order to solve the above-mentioned problems, the present invention comprises an optical fiber holder and an optical fiber fixed to the optical fiber holder. The element wire portion arranging hole for arranging the element wire portion of the optical fiber to the connection end surface and the covering portion arranging hole for arranging the covering portion of the optical fiber are integrally formed in a continuous manner in the longitudinal direction. The line portion is an optical fiber connector fixed in a state of being in contact with the wire portion placement hole at some points on the outer periphery thereof, and the contact point between the wire portion and the wire portion placement hole. Among them, the force acting in the radial direction of the wire portion at the contact point at the position closest to the connection end surface and the force acting in the radial direction of the wire portion at the contact point located next are substantially mutually. The wire portion is the wire portion so that the force is in the opposite direction. Optical fiber connector, characterized in that arranged on 置孔 is provided.

[0010]

In the optical fiber connector of the present invention, the coating on the connection end face side is peeled off and exposed at each of the wire arranging hole and the covering portion arranging hole that are integrally formed so as to be continuous in the longitudinal direction of the optical fiber holder. The optical fiber is fixed to the optical fiber holder by arranging the bare wire portion of the optical fiber and the unpeeled coating portion.

At this time, there is a vertical step between the outlet on the connection end face side of the wire arranging hole and the inlet located on the opposite side, such that the inlet has a higher central position than the outlet. By providing the wire portion, the wire portion inserted and arranged in the wire portion arrangement hole is curved and extends from the inlet to the outlet, and the outer circumference thereof is at least 2 from the wall surface of the wire portion arrangement hole. It has a point of contact.

At this time, at the contact point located on the inlet side of the wire portion placement hole, the wire portion receives, for example, a downward force from the wall surface of the wire portion placement hole, and at the contact point located on the outlet side. The wire portion receives an upward force from the wall surface of the wire portion arrangement hole. That is, at the contact point closest to the connection end face (contact point on the outlet side) and the contact point located next (contact point on the inlet side), the forces acting in the radial direction of the wire are substantially opposite to each other. It will be generated as a force of direction.

Further, since the wire portion has elasticity, it is pressed against the contact point on the outlet side by the downward force received at the contact point on the inlet side. Therefore, at the contact point of the wire portion located near the connection end face (contact point on the outlet side), the force that presses the wire portion toward the contact point always acts from one direction. Is always pressed in one direction of the wire portion arrangement hole and does not float.

That is, the wire portion located on the connection end face is positioned in a state corresponding to the form of the designed wire portion arranging hole.

[0015]

【Example】

Example 1 Hereinafter, the optical fiber connector of the present invention will be described in detail with reference to the drawings. Figure 1 is a partially cutaway front view showing a state viewed optical fiber connector A ₁ of the present invention from the connection end face side, FIG. 2 is a sectional view taken along the line II-II of Figure 1.

In FIGS. 1 and 2, the optical fiber holder 1 is integrally formed with an element wire arrangement hole 1a and a covering portion arrangement hole 1b in a continuous state in the longitudinal direction of the optical fiber holder 1. . Then, here, the coating of the optical fiber 3 is peeled off by a desired length, and its peripheral surface is exposed.
a and the covering portion 3b are arranged. Here, the hole diameter of the wire portion placement hole 1a is 0.5 to 1 μm larger than the diameter of the wire portion 3a.
The diameter is about the same, and the inlet 1c of the wire portion 3a and the wire portion 3
A straight hole having a desired height difference in the vertical direction is formed between the outlet of a, that is, the connection end face 1d of the optical fiber holder. That is, the center point of the entrance 1c is closer to the exit 1d
It is located higher than the center point of.

Therefore, the wire portion 3a extends straight from the inlet 1c of the wire portion arranging hole so that its upper peripheral surface contacts at a point a ₂ where the wire portion arranging hole 1a is located, and from the contact point a ₂ downward. It is arranged in the wire portion arranging hole 1a in a state in which the lower peripheral surface is curved at a point a ₁ near the connecting end surface 1d and is in contact with the lower end surface. At this time, at the contact point a ₂ , a downward force is applied from the wall surface of the wire portion placement hole 1a in the radial direction of the wire portion 3a. The wire portion 3a made of quartz glass exerts its restoring force, and at the contact point a ₁ , the lower peripheral surface of the wire portion 3a is pressed against the wall surface of the wire portion arranging hole 1a, and an upward reaction force is exerted. Is added.

Thus, all the wire portions 3a arranged in the plurality of wire portion arrangement holes 1a are pressed against the wall surface of the wire portion arrangement hole 1a from above in the vicinity of the connection end face 1d. Therefore, the axial center of each strand 3a is fixed at the same height. When each wire portion 3a is fixed in the above-mentioned state, its axis is positioned at the same height as the center point of the pin fitting holes 2a (2b) formed on both sides of the connection end face 1d. In addition, it is necessary to determine the positional relationship between the bare wire portion arranging hole 1a and the pin fitting hole 2a (2b) at the time of manufacturing an optical fiber connector described later. If this positional relationship is not established, when the optical fiber connectors A ₁ are pin-fitted to each other and connected, an axial misalignment occurs between the wire portions, resulting in an increase in connection loss.

The optical fiber connector A ₁ is manufactured as follows. It will be described with reference to FIG. 3 and FIG. 4 which is a sectional view taken along the line IV-IV of FIG. First, a mold having two halves is prepared, which is composed of an upper mold 6a and a lower mold 6b, the central part of which is a recess and the periphery of which is surrounded by a jetty-shaped wall. Then, when the upper mold 6a and the lower mold 6b are combined, a cavity 1'having the same shape as the optical fiber holder to be manufactured is formed by the recesses of each other.

On the surface of the wall portion on one side of the lower die 6b, there are as many V-shaped grooves 7a as the number of strands of the optical fiber to be arranged.
And V-shaped grooves 8a (8b) for forming pin fitting holes are formed on both sides of the V-shaped grooves 7a. In addition, a rectangular groove 7b (7c) that encloses the coating portion of the optical fiber to be arranged is formed on the surface of the wall portion on the other side of the lower die 6b and the surface of the wall portion of the upper die 6a corresponding thereto. Has been done.

The core 9 is set in the cavity 1'of the mold including the upper mold 6a and the lower mold 6b. Here, the core 9 has a molding pin gripping portion 9a having substantially the same shape as that of the coating portion of the optical fiber, and a diameter 0 of a diameter of the wire arranging hole which is attached to the molding pin gripping portion 9a and is to be formed. The molding pin 9b has a large diameter of about 0.5 to 1 μm. The tip of the molding pin 9b is inserted into a V-shaped groove 7a formed in one wall of the upper die 6a and the lower die 6b, and the molding pin gripping portion 9a is the other of the upper die 6a and the lower die 6b. The rectangular grooves 7b and 7c formed in the wall portion of the above are encapsulated from the up and down direction and fixed there.

At this time, the molding pin 9b is located at the position b ₂ where the molding pin 9b is attached to the molding pin grip portion 9a.
When manufacturing the upper mold 6a and the lower mold 6b, the shaft center of b is formed on one wall of the lower mold 6b so that the shaft center is higher than the shaft center at the insertion position b ₁ into the V-shaped groove 7a. V-shaped groove 7
The positional relationship in the height direction between the groove a and the grooves 7b and 7c formed on the other wall is determined.

Thus, in the core 9 set in the cavity 1'of the mold, the molding pin 9b is hollowly supported in the cavity 1'with a predetermined inclination. Then, a molten resin made of epoxy resin or the like is injected into the cavity 1 ', and after curing it, the upper mold 6a and the lower mold 6b are demolded,
Further, the core 9 is removed. As a result, it is 0.5 to 0.5 mm larger than the large hole and the wire part having the same shape as the covering part of the optical fiber to be arranged.
It is possible to obtain a resin molded product in which a through hole in which small holes having a large diameter of about 1 μm are connected is formed in the longitudinal direction.

The outer shape of the obtained resin molding is the same as the outer shape of the optical fiber connector (holding tool) for the purpose of manufacturing, and the small holes described above are inclined at a predetermined angle from the point b ₂ to the point b _1. It has a straight hole. By inserting, adhering and fixing the fiber 3 in the through hole of the resin molded body, the optical fiber connector A ₁ as shown in FIG. 2 is obtained.

Embodiment 2 FIG. 5 is a sectional view showing another optical fiber connector A ₂ of the present invention. In the optical fiber connector A _2, strand portions disposed hole 1a is in a straight hole which is not inclined in the longitudinal direction of the optical fiber holder 1. However, the center point position of the wire portion arrangement hole 1a and the center point position of the covering portion arrangement hole 1b are eccentric about several μm in the vertical direction.

Therefore, as shown in FIG. 5, the wire portion 3a of the optical fiber having the covering portion 3b arranged in the covering portion arranging hole 1b is, as shown in FIG. 5, from the inlet 1c to the outlet (connecting end face). ) It extends in a curved state between 1d and comes into contact with the wall surface of the bare wire portion arranging hole 1a at the contact points a ₁ and a ₂ and, as in the case of the optical fiber connector A ₁ , the connection end face 1d.
Positioning is realized by pressing downward in the vicinity of.

FIG. 6 is a sectional view showing the relationship between the mold and the core set in the cavity when the optical fiber holder for the optical fiber connector A ₂ shown in FIG. 5 is manufactured by resin molding. is there. In the core 9 used here, the molding pin grip portion 9a and the molding pin 9b are eccentric. Specifically, the axial center position of the molding pin grip portion 9a is about several μm higher than the axial center position of the molding pin 9b, and at the same time, on the tip end portion of the molding pin 9b inserted into the V-shaped groove 7a. The peripheral surface is in contact with the surface of one wall of the upper mold 6a.
Further, regarding the grooves 7b and 7c formed on the other wall portions of the upper mold 6a and the lower mold 6b, the groove 7c is deeper than the groove 7b. However, it does not change that both grooves 7b and 7c form a shape capable of enclosing the coating portion of the optical fiber as a whole.

In this state, a molten resin such as an epoxy resin is injected and cured in the cavity 1 ', the mold is removed, and the core 9 is removed. Then, the optical fiber holder as shown in FIG. 1 is obtained. Example 3 FIG. 7 is a sectional view showing still another optical fiber connector A ₃ of the present invention.

In this optical fiber connector A ₃ ,
The center points of the element wire placement hole 1a and the covering portion placement hole 1b of the optical fiber holder 1 are not eccentric. However, the covering portion arranging hole 1b is larger than the covering portion 3b of the optical fiber by about several μm, and when the covering portion 3b is arranged there, a strip having a thickness of about several μm is formed below the covering portion 3b. By inserting 10, the covering portion 3b is pushed upward.

As a result, the center point of the inlet 1c of the wire arranging hole 1a is moved upward by several μm from the outlet (connection end face) 1d. The wire portion 3a inserted from the inlet 1c extends in a curved state up to the outlet 1d and contacts the wall surface of the wire portion arranging hole 1a at the contact points a ₂ and a ₁ to form a connection end surface. In the vicinity of 1d, it is pressed downward and the positioning is realized there.

Embodiment 4 FIG. 9 which is a sectional view taken along the line IX-IX of FIG. 8 and FIG.
₃ shows an optical fiber connector A ₄ of the present invention. In the case of this optical fiber connector A ₄ , the optical fiber holder is composed of the wire portion 3
a is arranged and the surface 11a is a surface parallel to the bottom surface 11b, the end surface 11c of the horizontal surface member 11 and its own end surface 12c are in contact, and the horizontal surface member 1
The surface 12a located on the first side is superposed on the inclined surface member 12 which forms an inclined surface inclined at a predetermined angle with respect to the bottom surface 12b, the horizontal surface member 11 and the inclined surface 12a of the inclined surface member 12, The surface 13a corresponding to the surface 11a is a horizontal surface similar to the surface 11a, and the surface 13b corresponding to the inclined surface 12a of the inclined surface member 12 is the inclined surface 12.
and a lid member 13 having an inclined surface similar to that of a. Then, concave portions 14a and 14b are formed in the surface portion connected to the inclined surface 12a of the inclined surface member 12 and the surface portion connected to the inclined surface 13b of the lid member 13, respectively,
When these members are assembled, their concave grooves 14a,
Arrangement hole 1 in which the covering portion 3b of the optical fiber is arranged at 14b
4 are formed.

FIG. 10 is an exploded perspective view showing the above-mentioned optical fiber holder. In FIG. 10, the horizontal surface member 11
A plurality of (4 in the figure) V-shaped grooves 15 are provided on the surface 11a of the
And two V-shaped grooves 1 that function as pin fitting holes on both sides
Both 6a and 16b are engraved in parallel with the bottom surface 11b. Further, a V-shaped groove 17 having the same cross-sectional shape as the V-shaped groove 15 of the horizontal surface member 11 is engraved on the inclined surface 12a of the inclined surface member 12 so as to be inclined with respect to the bottom surface 12b at a predetermined angle. The surface portion continuous with 17 is cut to a predetermined depth to form a groove 14a.

Further, in the case of the lid member 13, the horizontal surface member 1
A horizontal surface 13a which is compatible with the surface 11a of No. 1 is formed, and shallow concave grooves are formed on both sides of the horizontal surface 13a at positions corresponding to the pin fitting holes 16a and 16b up to the boundary with the inclined surface 13b. Then, the inclined surface 13 having the same inclination angle as the inclined surface 12a of the inclined surface member 12 is continuous with the horizontal surface 11a.
b is formed, and the surface portion connected to the inclined surface 13b is cut to a predetermined depth to form a groove 14b.

Each of these members is molded by a molding method using, for example, a mold manufactured into a predetermined shape. The optical fiber connector A ₄ is manufactured as follows. That is, first, the end surface 11c of the horizontal surface member 11 and the end surface 12c of the inclined surface member 12 are bonded and fixed with an adhesive. As a result, the V-shaped groove 15 and the V-shaped groove 17 are continuous in the longitudinal direction.

Then, as shown in FIG. 9, the fiber portion 3a of the optical fiber is arranged in the V-shaped grooves 15 and 17, and the covering portion 3b is arranged in the concave groove 14a. 13 is mounted and the surface of each member is fixed by adhesion. As a result, the covering portion 3b of the optical fiber is arranged in the covering portion arranging hole 14 formed by the concave grooves 14a and 14b, and the bare wire portion 3a is formed.
Passes through the wire portion arrangement hole formed by the V-shaped groove 17 of the inclined surface 12a and the V-shaped groove 15 of the horizontal surface 11a and reaches the connection end surface 11d.

The wire portion 3a has an inclined surface 13b of the lid member 13.
At a certain point a ₂ on its upper peripheral surface to be curved, and at a certain point a ₁ on the horizontal plane of the horizontal surface member 11 to contact its lower peripheral surface to the V-shaped groove 15 toward the outlet (connection end surface) 11 d. Extend to. At this time, in the vicinity of the connection end surface 11d, as shown in FIG.
As shown in FIG. 5, the wire portion 3a contacts the surface of the V-shaped groove 15 at two points, and the restoring force of the wire portion 3a is divided into two parts f ₁ and f ₁ in the direction orthogonal to the contact surface. . However, the resultant force f ₂ of the two divided resiliency f _1, f ₁ acts downwards, the wire portion 3a by its pressed downward of the V-grooves 15, wherein the positioning is realized.

In the optical fiber connector A ₄ , the cross section of the wire arranging hole is V-shaped, but this cross section is not limited to this, and, for example, as shown in FIG. A slope 1 that is symmetrical with respect to the axis of the wire portion 3a
It may be a hole having a sectional shape having 8a and 18b.

[0038]

As is apparent from the above description, claim 1
In the optical fiber connector of the above, since the force of pressing the wire portion always in one direction acts on the wire portion arranged in the wire portion placement hole in the vicinity of the connection end face, the wire portion is Positioned in the placement hole with high accuracy. Therefore, when the connection end faces of this optical fiber connector are butted,
Since there is no axial misalignment between the strands of each other, the connection loss is reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of an optical fiber connector A ₁ of the present invention as viewed from a connection end face side.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a partially cutaway front view showing a mold used when manufacturing the holder for the optical fiber connector A ₁ .

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view showing an optical fiber connector A ₂ of the present invention.

FIG. 6 is a cross-sectional view showing a mold used when manufacturing the holder for the optical fiber connector A ₂ .

FIG. 7 is a sectional view showing an optical fiber connector A ₃ of the present invention.

FIG. 8 is a front view of the optical fiber connector A ₄ of the present invention when viewed from the connection end face side.

FIG. 9 is a sectional view taken along line IX-IX in FIG. 8;

FIG. 10 is an exploded perspective view showing an optical fiber holder of the optical fiber connector A ₄ .

FIG. 11 is a cross-sectional view showing the vicinity of the connection end face of the optical fiber connector A ₄ .

FIG. 12 is a cross-sectional view showing a cross-sectional shape of another wire-wire-position disposing hole.

FIG. 13 is a front view of a conventional optical fiber connector as viewed from the connection end face side.

FIG. 14 is a front view showing a conventional optical fiber connector in which a wire portion has an axis deviation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber holder 1a Element wire part arrangement hole 1b Covering part arrangement hole 1c Entrance of wire part arrangement hole 1d Connection end face (exit of element wire part arrangement hole) 2a, 2b Pin fitting hole 3 Optical fiber 3a Optical fiber 3 Wire portion 3b Coating portion 4 of optical fiber 3 Gap 5 Optical adhesive 6a Upper mold 6b Lower mold 7a V-shaped groove 7b, 7c Arc-shaped groove 8a, 8b V-shaped groove 9 Core 9a Molded pin gripping portion 9b Molded Pin 10 Strip 11 Horizontal surface member 11a Surface of horizontal surface member 11b Bottom surface of horizontal surface member 11 11c End surface of horizontal surface member 11 11d Connection end surface (exit of wire portion arrangement hole) 12 Inclined surface member 12a Inclined surface of inclined surface member 12b Bottom surface of the inclined surface member 12c End surface of the inclined surface member 12 Lid member 13a Horizontal surface of the lid member 13b Inclined surface of the lid member 14 Cover portion arrangement holes 14a, 14b Concave Groove 15 V-shaped groove 16a, 16b V-shaped groove 17 V-shaped groove 18a, 18b Slope

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Takashi Shigematsu 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Shinji Nagasawa 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (3)

[Claims] 1. An optical fiber holder comprising an optical fiber holder and an optical fiber fixed to the optical fiber holder, wherein the optical fiber holder has a wire portion for arranging the wire portion of the optical fiber to a connection end face. The arrangement hole and the covering portion arrangement hole for arranging the covering portion of the optical fiber are integrally formed so as to be continuous in the longitudinal direction, and the wire portion of the optical fiber is arranged at some points on the outer periphery thereof. An optical fiber connector fixed in contact with a hole, of the contact points of the wire portion and the wire portion disposing hole, the wire rod at a contact point closest to the connection end face. Of the wire portion such that the force acting in the radial direction of the portion and the force acting in the radial direction of the wire portion at the contact point located next are approximately opposite to each other. An optical fiber connector, which is arranged in an arrangement hole. 2. The optical fiber connector according to claim 1, wherein the wire portion arrangement hole is a straight hole, and the center position on the covering portion arrangement hole side is higher than the center position on the connection end face side. 3. The optical fiber connector according to claim 1, wherein the axis of the wire portion arrangement hole and the axis of the covering portion arrangement hole are eccentric.