JP2003241021A - Optical fiber module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber module which can suppress optical connection loss through easy optical axis alignment without using any expensive optical axis aligning member unlike before to eliminate optical axis deviation between optical fibers or an optical fiber and a light emission and reception unit when the both are optically connected to each other and further protect a connection end part at the tip of an optical fiber against damage due to contacting. <P>SOLUTION: A taper ring (optical axis aligning member) 40 molded in a different single body while fitted in the inner circumference of a cylindrical optical fiber connection sleeve 30 is only set and this taper ring 40 can be replaced according to specifications. Taper beveled parts 20b having the same tilt angle with a taper hole 42 of the taper ring 40 are formed at tip circumferential edges of ferrules 20 and 21 fixed to end parts of optical fibers 10 and 11, so the taper beveled parts 20b are brought into slide contact with the taper hole 42 while guided and then the optical axes C<SB>1</SB>and C<SB>2</SB>of the optical fibers 10 can automatically be aligned with each other through the ferrule 20 to eliminate the optical axis deviation S, so that the ferrule 20 can automatically be positioned by being moved to a specified position in the taper ring 40. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber module having an optical axis aligning member which can be easily mounted at low cost.

[0002]

2. Description of the Related Art In recent years, optical communication systems have become widespread in the field of vehicles such as automobiles, and optical fibers having a small core diameter and a large transmission band have been adopted as the communication capacity increases. When optically connecting such optical fibers, there is a problem that the optical connection loss between the optical fibers increases when the core diameter is small. Generally, in the case of connecting glass fibers for communication using an optical connector, the connection end face of the optical fiber is processed into an aspherical shape or the like so as to be in contact with the optical fiber to reduce the optical connection loss. There is. It should be noted that the optical fiber described below refers to an optical fiber composed only of a core and a clad.

When such a connecting technology for glass fibers for communication is applied to an optical communication system of an automobile, the connecting end surfaces of the optical fibers cannot be contacted with each other because the connecting end surfaces of the optical fibers are easily scratched by traveling vibration or impact of the vehicle body. . Also, due to running vibration and shock of the vehicle body, wear occurs due to frictional contact between the ferrule fixed to the connecting end of the optical fiber and the sleeve on the optical connector side. Cause damage to.

As a prior art proposed to solve the above problem, for example, there is one described in JP-A-49-53849. In this case, a sleeve-shaped member called a capillary tube is gradually reduced in diameter from both ends of the tube toward the center of the tube, and one optical fiber and the other optical fiber are inserted from both ends of the tube to face each other at the center of the tube. The optical axis deviation of the optical fiber is adjusted so that the optical axis deviation is absorbed and the optical axis can be adjusted. The inner diameter of the central portion of the tube is set to be slightly larger than the outer diameter of the optical fiber.

[0005]

However, the structure disclosed in this publication has the following problems. One is
In a sleeve-shaped capillary tube that has an optical axis alignment function,
Since the one optical fiber and the other optical fiber are directly opposed to each other from both ends of the tube, that is, the bare optical fibers are aligned without using a ferrule. Therefore, when the connecting end portions of the tips of the optical fibers come into contact with the inner surface of the capillary tube, there is a concern that the connecting end portions of the optical fibers may be damaged. In addition, considering the application to automobiles, one of them is abrasion due to friction with the inner surface of the capillary tube where the optical fiber connecting end is in contact due to vehicle body vibration or impact, and the above-mentioned abrasion debris is also generated. As a result, the optical connection efficiency between the optical fibers is impaired. Further, one of the problems is that the inner diameter of the capillary tube at the tube central portion is set to be slightly larger than the outer diameter of the optical fiber. There is a problem that the connection end faces of the two scratch each other.

Therefore, in order to solve the above-mentioned problems in the case of performing optical communication between optical fibers, a highly accurate and expensive member capable of performing an optical axis alignment function is required, which causes a cost increase. Has become.

From the above, the main object of the present invention is to perform optical connection between the optical fibers or between the optical fiber and the light emitting / receiving unit, in order to align the optical axes of the optical fibers and the optical emitting / receiving unit, and it is expensive as in the prior art. (EN) Provided is an optical fiber module which can easily perform optical axis alignment without using any optical axis alignment member and can protect a connecting end portion of a tip end of an optical fiber from damage due to contact or the like.

Another object of the present invention is to apply the ferrule fixed at the connecting end portion of the end of the optical fiber to the optical connector housing side by vibrating or shocking the vehicle body, particularly when applied to optical communication of a vehicle such as an automobile. An object of the present invention is to provide an optical fiber module capable of suppressing abrasion due to contact friction with a member and maximizing optical connection loss between optical fibers due to abrasion dust and the like.

[0009]

In order to solve the above-mentioned problems, an optical fiber module according to a first aspect of the present invention comprises a cylindrical optical fiber connecting sleeve 30 which constitutes an optical connector housing, and an optical fiber connecting sleeve 30. An optical axis-aligning member that is a single-molded tubular body that fits in the inner central portion of the fiber connecting sleeve 30 and that has a tapered hole 42 whose inner diameter gradually decreases from both ends of the tubular body toward the inner central portion ( Taper ring 40).

From the above, the optical fiber module according to the first aspect of the present invention is shown in FIGS. 1 (a), 1 (b) and 2 (a),
As shown in (b), a cylindrical optical fiber connection sleeve 3
The optical axis aligning member 40, which is fitted separately to the inner circumference of 0 and is separately formed, is set, and the optical axis aligning member 40 can be exchanged according to the specifications. In addition, for example, when a member such as a ferrule fixed to the end of the optical fiber is inserted into the optical axis alignment member 40, the tapered hole 42
The insertion members are automatically aligned on the axis by being guided by, and the optical axis shift can be corrected and the alignment can be performed.

Further, in the optical fiber module according to a second aspect of the invention, the ferrule 20 fixed to the connecting end portion of the tip of the optical fiber is provided, and the taper angle of the taper hole 42 of the optical axis aligning member 40 is provided around the tip of the ferrule 20. Has a taper chamfered end portion 20b having the same inclination angle as the above, and the outer diameter of the ferrule 20 is larger than the central hole diameter d of the taper hole 42 of the optical axis aligning member 40, and is guided by the taper hole 42. Ferrule 20
Is slidably in contact with the tapered chamfered end portion 20b and is inserted, the ferrule 20 inserted to a predetermined position of the optical axis aligning member 40 can be automatically positioned on the optical axis.

From the above, in the optical fiber module according to the second aspect, as shown in FIGS. 1 (a) and 1 (b), for example, the ferrule 20 is provided at the connecting end portion of the tip of the optical fiber 10.
When the ferrule 20 is fixed and the ferrule 20 is inserted into the optical axis aligning member 40, a tapered chamfered end portion 20b having the same inclination angle as the tapered hole 42 of the optical axis aligning member 40 is formed on the peripheral edge of the tip of the ferrule 20. Therefore, if the tapered chamfered end portion 20b is slidably guided while being guided in the tapered hole 42, the optical axis C ₁ of the optical fiber 10 can be automatically aligned through the ferrule 20, and the ferrule 20 Can be moved to a predetermined position with respect to the optical axis aligning member 40 and automatically positioned.

Further, in the optical fiber module according to a third aspect of the present invention, one optical fiber 10 and the other optical fiber 11 are attached to the tapered hole 42 of the optical axis aligning member 40 from both ends thereof, respectively. It is characterized by being inserted through and facing each other.

From the above, in the optical fiber module according to the third aspect, as shown in FIGS. 1A and 1B, the optical fibers 10 and 11 are opposed to each other via the ferrules 20 and 21 thereof. Even when the optical axes C ₁ and C ₂ are aligned with each other, the ferrules 20 and 21 are attached to the optical axis aligning member 40.
If it is inserted from both ends, the optical axes C ₁ and C ₂ are automatically aligned by being guided by the tapered hole 42. At that time, the diameter d of the central portion of the tapered hole 42 is determined by the ferrules 20, 2
Since the outer diameter of the ferrule 20 is smaller than the outer diameter of the ferrule 20, the opposed end faces of the ferrules 20 and 21 are positioned at a predetermined position without contacting each other. By avoiding contact between the end faces of the ferrules 20 and 21, damage due to contact between the end faces of the optical fibers 10 and 11 can be prevented.

Further, in the optical fiber module according to the fourth aspect, the optical fiber 10 is inserted into the tapered hole 42 of the optical axis aligning member 40 from the one end side through the ferrule 20, and from the other end side. It is characterized in that the light receiving element 50 or the light emitting element 51 constituting the light receiving and emitting unit is inserted and faced each other.

From the above, the optical fiber module according to the fourth aspect of the present invention, as shown in FIG.
The optical fiber 10 is inserted from one end side to the other end side, and the light receiving element 50 or the light emitting element 5 of the light receiving and emitting unit is inserted from the other end side.
In the case where either of the optical axes C ₁ and C ₃ is aligned by inserting any one of them, even if the dimensional accuracy or the positioning accuracy on the light emitting and receiving unit side is extremely rough, the optical axis C ₁ and the optical axis C ₁ of the optical fiber 10 It is possible to adjust the axis automatically by absorbing the deviation of the optical axis between them. Also,
As shown in FIG. 4, even in the case of a bidirectional optical communication system using the light receiving element 50 and the light emitting element 51 of the light emitting and receiving unit,
The optical axes C ₃ of the light emitting / receiving elements 50 and 51 and the optical fiber 1
The optical axis shift from the optical axis C _{1 of} 0 can be automatically and efficiently absorbed and aligned.

Therefore, in each of the first to fourth aspects of the invention, by providing a simple member called the optical axis aligning member 40, a highly accurate and expensive member for optical axis aligning as in the prior art. It is no longer necessary to use, and it is effective for maximizing the optical connection loss between optical fibers or between the optical fiber and the light emitting and receiving unit by automatically and easily absorbing the optical axis deviation and aligning. is there.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an optical fiber module according to the present invention will be described below in detail with reference to the drawings. As shown in FIGS. 1 (a) and 1 (b), a cylindrical synthetic resin optical fiber connection sleeve 30 that constitutes an optical connector housing is provided, and the optical fiber connection sleeve 30 is separately molded in a central portion. Further, the taper ring 40 of the optical axis aligning member according to the present invention is fitted and incorporated.

As is apparent from FIGS. 1 (a) and 1 (b) shown as a single body, the taper ring 40 is a synthetic resin cylinder in this example, and a taper hole 42 is formed inside a ring body 41 of the cylinder. Has been formed. Both ends of the cylinder of the tapered hole 42 are large diameter portions 43 and 44 at the inlet end, and the inner diameter is gradually reduced toward the inner central portion. Such an inner center is formed as a central small-diameter portion 45 having a dimension d having the smallest inner diameter. The taper ring 40 as described above can be formed as a single piece with an outer diameter and a length that can be freely adjusted in accordance with the dimensional specifications of the optical fiber connection sleeve 30 and the like that form the optical connector housing.

The material of the taper ring 40 includes the material of the optical fiber connecting sleeve 30 and the ferrules 20 and 2 shown below.
A polymer resin that is more flexible than the first material is used,
A material with excellent wear resistance and impact resistance that can withstand the in-vehicle environment is selected. Examples of such materials include polyurethane elastomers (flexibility: JIS hardness 72A, wear resistance: N
20 times the BR), polyester elastomer (flexibility:
JIS hardness 71A, wear resistance: 8 times that of NBR).

1A and 1B, one and the other optical fibers 10 and 11 are opposed to each other through an optical fiber connecting sleeve 30 and the assembled optical fiber 40, and the optical fibers 10 and 11 are opposed to each other. The example of the structure when connecting to is shown. Signal light is emitted from one of the optical fibers 10 and 11 as transmitted light, and received light is incident on the other.

Ferrules 20 and 21 are fixed to the ends of the optical fibers 10 and 11 facing each other, and the end faces of the ferrules 20 and 21 are polished to obtain the optical fiber 1.
It is flush with the end faces of 0 and 11. The outer diameter D of each of the ferrules 20 and 21 is larger than the inner diameter d of the central small-diameter portion 45 of the taper hole 42 in the taper ring 40, and is set to D> d. Therefore, ferrule 2
When 0 and 21 are inserted into the tapered hole 42, the ferrules 20 and 21 do not go over the central small diameter portion 45 of the tapered hole 42 toward each other. Further, a tapered chamfered end portion 20b having the same inclination angle as that of the tapered hole 42 of the tapered ring 40 is provided on the peripheral edges of the ends of the ferrules 20 and 21.

Therefore, as shown in FIG. 1A, when the optical fibers 10 and 11 are inserted from both ends of the taper ring 40 for optical connection, both ferrules 20 and 11 are connected.
Insert 21 facing each other. At that time, even if the optical axis shift occurs and the optical axis shift S exists between the optical axes C ₁ and C ₂ , the tapered chamfered ends 20b of the ferrules 20 and 21 are guided by the ring side tapered hole 42 and slidably contact each other. While moving, the optical axis shift S is absorbed and the center axis is automatically aligned so as to align the central axes with the optical axes C ₁ and C ₂ .

Subsequently, as shown in FIG. 1 (b), the ferrules 20 and 21 move in opposition to each other at a predetermined position where the ferrules 20 and 21 cannot move any further, that is, due to the inner diameter d of the tapered hole 42. The central narrow portion 45 is positioned at the scissors position. In this positioning state, the taper tilt angle is set so that a gap is created between the end faces of the ferrules 20 and 21, and the end faces 10 of the optical fibers 10 and 11 are set.
The a and 11a never come into contact with or come into contact with each other, and are protected from damage such as scratches. Taper hole 42 of taper ring 40
By adjusting the hole diameter and inclination angle of the optical fiber 1
The amount of gap between the end surfaces 10a and 11a of 0 and 11 can be adjusted.

Further, since the taper ring 40 is formed of a resin material having excellent flexibility, abrasion resistance and impact resistance as described above, the optical fibers 10, 11 due to vibration or impact are used.
Damage to the ferrules 20 and 21 and wear due to friction at the portions where the ferrules 20 and 21 contact at the tapered chamfered ends 20b can be reduced. Therefore, it is possible to eliminate the fear that abrasion dust is generated and the optical connection efficiency between the optical fibers 10 and 11 is impaired.

On the other hand, FIG. 3 shows the optical fiber 10 on one side.
And the light receiving element 50 on the other side in this case with the taper ring 4
It is sectional drawing which shows the example of a structure which carries out self-alignment at 0 and is optically connected. In aligning the optical axes C ₁ and C ₃ of both, even when the dimensional accuracy of the light receiving element 50 is extremely rough,
When guided along the taper hole 42 of the taper ring 40, the optical axis shift between the optical fiber 10 and the optical axis C ₁ can be absorbed and the centering can be performed automatically.

Further, FIG. 4 shows a light receiving element 50 and a light emitting element 5.
1 is a perspective view of a practical structural example showing a bidirectional optical communication system using a light emitting / receiving unit consisting of 1; The optical connector shown here is an optical plug 31 and an optical receptacle 3.
2 and the like, and two taper rings 40 are respectively arranged on the transmitting side and the receiving side on these optical paths. Two transmission / reception optical fibers 10, 10 are inserted from one side of the tapered hole 42 of the tapered ring 40 through a ferrule. The optical plug 31 has such optical fibers 10, 1
0 is connected via a ferrule, and the optical receptacle 32
Be combined with. A light emitting / receiving unit including the light emitting / receiving elements 50 and 51 is mounted on the optical receptacle 32 via a taper ring 40. Also in this case, the optical axis shift between the optical axes C ₃ of the light emitting / receiving elements 50 and 51 and the optical axis C ₁ of the optical fiber 10 can be automatically and efficiently absorbed and aligned.

As can be understood from the above, by providing a simple member such as a taper ring 40 whose dimensional size can be adjusted separately from the optical fiber connection sleeve 30 on the optical connector housing side, the optical axis can be adjusted as in the conventional case. It is not necessary to use a highly accurate and expensive member for alignment, and the alignment of the optical axis is automatically and easily absorbed by aligning. This is effective in maximizing the optical connection loss between the optical fibers 10 and 11 or between the optical fiber and the light emitting / receiving unit.

[0029]

As described above, in the optical fiber module according to the first aspect of the present invention, the optical axis alignment is separately formed by fitting into the inner circumference of the cylindrical optical fiber connecting sleeve. Only by setting the member (taper ring), there is a degree of freedom that this optical axis aligning member can be replaced according to the specifications. Further, for example, when a member such as a ferrule fixed to the end of the optical fiber is inserted into the optical axis aligning member, such an inserting member is automatically aligned on the axis by being guided by the tapered hole to correct the optical axis deviation. While being able to align.

Further, in the optical fiber module according to the second aspect, for example, when a ferrule is fixed to the connecting end portion of the tip of the optical fiber and the ferrule is inserted into the optical axis aligning member, the tip of the ferrule is inserted. Since a taper chamfered end with the same inclination angle as the taper hole of the optical axis aligning member is formed on the peripheral edge, if the taper chamfered end is guided and slidably contacted with the taper hole, the light is transmitted through the ferrule. The optical axis of the fiber can be automatically aligned, and further, the ferrule can be moved to a predetermined position with respect to the optical axis alignment member and automatically positioned.

Further, according to the optical fiber module of the third aspect, even when the optical fibers are faced to each other via their ferrules to align the optical axes, both ferrules are inserted from both ends of the optical axis aligning member. If so, both optical axes are automatically aligned by being guided by the tapered hole. At this time, since the diameter of the central portion of the taper hole having the smallest diameter is smaller than the outer diameter of the ferrule, the facing end surfaces of the ferrule are positioned at a predetermined position without contacting each other. By avoiding contact between the end faces of the ferrule, damage due to contact between the end faces of the optical fiber can be prevented.

Further, in the optical fiber module according to a fourth aspect of the invention, the optical fiber is inserted into the optical axis aligning member from one end side thereof, and from the other end side thereof, either the light receiving element or the light emitting element of the light emitting and receiving unit. When aligning both optical axes by inserting, even if the dimensional accuracy and positioning accuracy on the light emitting and receiving unit side is extremely rough, the optical axis deviation from the optical axis of the optical fiber is absorbed to automatically It can be aligned. Further, even in the case of a bidirectional optical communication system using the light receiving element and the light emitting element of the light emitting and receiving unit, the optical axis shift between the optical axis of the light receiving and emitting element and the optical axis of the optical fiber is automatically and efficiently performed. Can be absorbed and aligned.

[Brief description of drawings]

1A and 1B are views of an optical fiber module according to an embodiment of the present invention before and after an optical axis shift is aligned by inserting one and the other optical fibers into a taper ring. It is a side surface sectional view showing a mode.

2A and 2B are a perspective view and a sectional view of a taper ring alone.

FIG. 3 is a side sectional view showing a mode in which an optical axis shift between an optical fiber and a light receiving element is aligned by a taper ring.

FIG. 4 is an exploded perspective view showing an example of a bidirectional optical communication system of a light receiving element and a light emitting element and a transmitting / receiving optical fiber.

[Explanation of symbols]

10, 11 Optical fibers 20, 21 Ferrules 20b, 21b Tapered chamfered end 30 Optical fiber connection sleeve (optical connector housing) 40 Tapered ring 41 Ring body 42 Tapered hole 43, 44 Inlet large diameter portion 45 Central small diameter portion 50 Light receiving element (Light emitting / receiving unit) 51 Light emitting element (light emitting / receiving unit) S Optical axis shift

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H036 QA45                 2H037 AA01 BA02 BA11 DA03 DA04                       DA15

Claims (4)

[Claims] 1. A tubular optical fiber connecting sleeve that constitutes an optical connector housing, and a single-piece tubular body that fits into the inner central portion of the optical fiber connecting sleeve. And an optical axis aligning member having a taper hole whose inner diameter is gradually reduced toward the optical fiber module. 2. A ferrule fixed to a connecting end portion of a tip of an optical fiber has a tapered chamfered end portion having a same inclination angle as a taper angle of a taper hole of the optical axis aligning member on a peripheral edge of the ferrule. The outer diameter of the ferrule is larger than the center hole diameter of the taper hole of the optical axis aligning member, and the ferrule is guided by the taper hole and slidably inserted at the tapered chamfered end to insert the optical axis. The optical fiber module according to claim 1, wherein the ferrule inserted to a predetermined position of the member can be automatically positioned on the optical axis. 3. An optical fiber, wherein one optical fiber and the other optical fiber are inserted into the tapered hole of the optical axis aligning member from both ends through the ferrules and face each other. 2. The optical fiber module described in 2. 4. An optical fiber is inserted into the tapered hole of the optical axis aligning member from the one end side through the ferrule,
The optical fiber module according to claim 2, wherein a light receiving element or a light emitting element that constitutes a light emitting and receiving unit is inserted from the other end side to face each other.