WO2009154160A1

WO2009154160A1 - Optical connector

Info

Publication number: WO2009154160A1
Application number: PCT/JP2009/060829
Authority: WO
Inventors: 崇松井
Original assignee: アルプス電気株式会社
Priority date: 2008-06-20
Filing date: 2009-06-15
Publication date: 2009-12-23

Abstract

Disclosed is an optical connector with which there is reduced loss and increased light transmission efficiency. Taking a divergence angle between an axial centerline (O-O) and a straight line (P) connecting a base portion (P1) of a flange portion (22c) that projects sidewards from a side of a light conducting path (22A) formed as a sleeve (22) and a maximum outer dimension portion (P2) of a lens (22B) as (O), then when the divergence angle (O) is set at no less than 30º and less than 90º, light emitted from the lens (22B) can be detected by a photoreceptor (21) without leak therefrom even in proximity of the maximum outer dimension of the lens (22B) away from the axial centerline (O-O). Accordingly, the loss of the optical connector as a whole can be reduced and the transmission efficiency thereof can be increased.

Description

Optical connector

The present invention relates to an optical connector for optical communication, and more particularly to an optical connector having an improved light transmission efficiency between an optical element such as a photodiode and an optical fiber.

As an optical connector in which the light transmission efficiency between an optical element such as a photodiode and an optical fiber is improved, there is a prior art described in, for example, Patent Document 1 below.

In the optical connector described in Patent Document 1, an optical element for light reception or light emission is disposed opposite to the end face on the smaller diameter side of the conical light guide, and the diameter dimension facing the end face of the optical fiber is A lens is integrally formed on the large side.

In addition, the diameter of the end face (light emitting surface side) of the light guide is formed smaller than the light receiving surface of the light receiving optical element (FIG. 7 of Patent Document 1). Alternatively, the diameter of the end face (light receiving surface side) on the light guide side is formed to be larger than the light emitting surface of the light emitting optical element (FIG. 8 of Patent Document 1).
Patent 3958891 Specification

The optical connector shown in Patent Document 1 has the following problems.
In the mode shown in FIG. 7 of Patent Document 1, that is, in the optical connector for optically connecting between the light receiving optical element and the fiber, the end surface of the light guide on which the light propagated while totally reflecting in the light guide is Out of the air into the outside air, and then enter the light receiving optical element. Also, the refractive index is generally larger in the light guide than in air in such a configuration. For this reason, when the angle of light passing through the end face on the exit side of the light guide into the air is larger than the critical angle at the interface between the end face on the exit side of the light guide and the air, the light is said interface And may be returned to the inside of the light guide, and there is a problem that it is difficult to improve the transmission efficiency of the entire optical connector.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an optical connector which can reduce the loss more than the conventional one and can improve the light transmission efficiency.

The present invention relates to an optical connector provided with an optical fiber for propagating light, an optical element for emitting or receiving light, and a sleeve for performing optical connection between the optical fiber and the optical element.
The sleeve is provided with a substantially frusto-conical light guide gradually expanding toward the optical element from one small diameter end, and the side of the light guide has a laterally projecting flange portion, and A convex lens is integrally formed on an end face of the sleeve facing the optical element;
When viewed in cross section passing through the axial center line of the sleeve, the opening angle between the axial center line and the straight line connecting the base of the flange and the maximum outer diameter of the lens is 30 degrees. The above is characterized by being less than 90 degrees.

In the present invention, light leakage can be prevented particularly when a sleeve is adopted on the light receiving module side, so that an optical connector with high light transmission efficiency can be obtained.

In the above, it is preferable that the inclination angle of the side surface of the light guide path be 0.5 degrees or more and 1 degree or less.

The loss in the entire optical connector can be reduced, and the sleeve can be formed with high precision.

In the above, it is preferable that a substantially annular guide continuous with the flange portion be integrally formed.
In the above means, it is not necessary to provide a special mounting structure in the housing for the light guide.

In the above, it is preferable that a convex lens be integrally formed on the end face of the sleeve facing the optical fiber.

In the above means, the light transmission efficiency between the sleeve and the optical fiber can be enhanced, and it is particularly effective when applied to the light emitting module side.

It is preferable that a convex lens is provided on the light emitting surface or the light receiving surface of the optical element.
In the above means, the light transmission efficiency between the optical element and the optical fiber can be enhanced.

In the present invention, light transmission efficiency can be enhanced in an optical connector provided with an optical fiber for propagating light and a sleeve for performing optical connection between an optical element for emitting or receiving light.

FIG. 1 is a cross-sectional view of an optical connector showing a first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing the relationship between an optical module, a sleeve and an optical fiber provided in the optical connector of FIG. FIG. 3A is a cross-sectional view showing the sleeve on the light receiving module side, and FIG. 3B is a graph showing the range of the optimum inclination angle of the light guide path of the light receiving module side sleeve.

The optical connector according to the present invention is employed, for example, in an automobile employing the Media Oriented Systems Transport (MOST), which is an in-vehicle network of an information system. MOST is a network based on a ring topology using plastic optical fibers (POF).

As shown in FIG. 1, the optical connector 1 for MOST has a pair of optical modules (a light emitting module 10 and a light receiving module 20) for light reception (for reception) and light emission (for transmission), These are comprised in the state accommodated in one housing 40. FIG.

As shown in FIG. 1, an open end 40A to which a plug (not shown) provided at an end of an optical fiber is attached is formed at an end of the housing 40 on the X2 side. At the end on the X1 side of the housing 40, the light emitting module 10,

fixing regions

41 and 42 for attaching the light receiving module 20,

positioning recesses

43 and 44 for fixing the sleeve, and individual optical fibers in the

plug Insertion recesses

45 and 46 and the like are provided for inserting ferrules (not shown) provided on the periphery of the connector.

Through

holes

47 and 48 into which

light guide paths

12A and 22A of

sleeves

12 and 22 described later are inserted between the positioning recess 43 and the insertion recess 45 and between the positioning recess 44 and the insertion recess 46, respectively. Is formed.

As shown in FIG. 1, the light emitting module 10 has a light emitting element (optical element) 11 and a sleeve 12, and the light receiving module 20 has a light receiving element (optical element) 21 and a sleeve 22. The light emitting element 11 in the present embodiment is formed of an LED, and the light receiving element 21 is formed of a photodiode.

The light emitting element 11 and the light receiving element 21 are fixed in a state in which a transparent resin is coated on a semiconductor bare chip (not shown) on the upper surfaces (surfaces on the X2 side of FIG. 1) of the

bases

11A and 21A formed of resin. It is done. Alternatively, the

convex lenses

13 and 23 may be fixed to face the

sleeves

12 and 22 on the front surface of the semiconductor bare chip, respectively.

The outer shapes of the light emitting element 11 and the light receiving element 21 are formed in substantially the same shape, and only the types of semiconductor bare chips provided inside the

bases

11A and 21A are different. Frame-

shaped ribs

11a and 21a for positioning are provided around the outer edge portions of the

bases

11A and 21A, respectively.

A reflective film is laminated on the upper surfaces of the

bases

11A and 21A, and the light emitting element 11 reflects light emitted from the semiconductor bare chip for light emission to the outside in the X2 direction in the figure, and the light receiving element 21 enters the base 21A. Can be focused on a semiconductor bare chip for light reception.

Since the configurations of the sleeve 12 and the sleeve 22 in the present invention are the same, the following description will be made mainly using one sleeve 12. In addition, although each code | symbol is added and demonstrated to a 12th number about each site | part of the sleeve 12, the code | symbol corresponding to a 22nd number shall be added about the sleeve 22. FIG.

The sleeve 12 is integrally formed of, for example, a synthetic resin material of, for example, a polyolefin type which is excellent in transparency or light transmittance. It is preferable that the side surfaces of the sleeve 12 excluding the both end surfaces be covered with a cladding layer having a lower refractive index. However, when used in contact with air having a refractive index lower than that of a synthetic resin material, air is used as a clad layer (air clad) without being covered with a clad layer made of another material. Good.

As shown in FIGS. 2A and 2B, the sleeve 12 has a light guide 12A whose longitudinal direction is the X direction shown in the drawing. The light guide 12A is formed in a substantially frusto-conical shape in which the diameter dimension thereof becomes smaller toward the X2 side and expands toward the X1 side. A convex lens 12B is integrally formed on one end face 12a on the side of the large diameter X1 in the drawing. The other end face 12b on the side of the small diameter X2 in the drawing forms a plane perpendicular to the axial center line OO. The end face 51 a of the optical fiber 51 is disposed opposite to the other end face 12 b of the light guide 12 A of the sleeve 12. In the light receiving module 20 side, the end face 52a of the optical fiber 52 is disposed opposite to the other end face 22b of the light guide 22A of the sleeve 22.

On the light emitting element side (X1 side) on the side portion of the light guide 12A, a flange portion 12c that protrudes toward the side (Y direction) which is a direction orthogonal to the axial center line OO is formed. A substantially annular guide portion 12C having a concentric axis with the axial center line OO is integrally formed. The substantially annular guide portion 12C is formed as an annular or cylindrical portion, a positioning convex portion 12C1 is provided circumferentially at one end on the X1 side, and the other end 12C2 is extended in the X2 direction. The substantially annular guide portion 12C is formed to have a constant diameter with respect to the axial center line OO. Furthermore, as shown in FIG. 1, a plurality of positioning ribs 12D having a convex shape extending in the longitudinal direction are integrally formed on the outer circumferential surface of the substantially annular guide portion 12C at predetermined intervals in the circumferential direction (FIG. 2) Omitted). The sleeve 12 is generally formed with high dimensional accuracy by using an injection molding method.

Here, FIG. 3B is a graph showing the optimum range of the inclination angle δ of the side surface of the light guide 22A formed in a substantially frusto-conical shape when the sleeve 22 is adopted on the light receiving module 20 side. . As shown in FIG. 3A, when the dimension in the longitudinal direction (X direction) of the light guide path 22A is L1, and the width dimension (X direction) of the flange portion 22c is L2, the optical connector 1 for L2: L1 Change [dB] of the loss of the light guide 22A is shown for each inclination angle .delta. Of the side surface of the light guide 22A.

As shown in FIG. 3B, in the sleeve 22 constituting the light receiving module 20, the inclination angle δ of the side surface of the light guide path 22A is better at 1 degree than 1.5 degrees, and further 1 degree It can be seen that 0.5 degrees is better than that.

However, when the inclination angle δ is less than 0.5 degrees, the sleeve 22 is placed in a mold and injection molded, and then the portion of the light guide 22A is made of metal when the mold is pulled out from the sleeve 22 after curing. It becomes difficult to get out of the mold and it is easy to cause burrs and the like. Therefore, a preferable range of the inclination angle δ of the side surface of the light guide path 22A is 0.5 degrees or more and 1 degree or less.

Further, as shown in FIG. 2B, in the light receiving module 20, the root portion P1 on the X2 side of the flange portion 22c protruding sideward from the side surface of the light guide 22A and the maximum outer diameter portion P2 of the lens 22B The opening angle between the connecting straight line P and the axial center line OO is assumed to be θ.

Although the radiation angle φ when light is emitted from the end face of the optical fiber is approximately 30 degrees although it varies depending on the type of optical fiber, the opening angle θ is preferably 30 degrees or more. Further, since the opening angle θ does not exceed 90 degrees, the opening angle θ is preferably less than 90 degrees.

As described above, when the opening angle θ is 30 degrees or more and less than 90 degrees, light emitted from the lens 22B is less leaked in the light receiving element 21 even in the vicinity of the maximum outer shape of the lens 22B separated from the axial center line OO. It becomes possible to detect in the state. For this reason, the fall of the transmission efficiency as the optical connector 1 whole can be prevented.

As shown in FIGS. 1 and 2, the

sleeves

12 and 22 are attached to the inside of the housing 40 from the side of the illustration X1. At this time, the

sleeves

12 and 22 are mounted through the fixing

regions

41 and 42 with the

other end face

12b or 22b of the

light guide path

12A or 22A facing in the X2 direction. The

other end face

12b, 22b side of the

light guide path

12A, 22A is inserted into the through

hole

47, 48 through the

positioning recess

43, 44. At this time, the substantially annular guide portion 12C is also inserted into the positioning recesses 43 and 44 simultaneously. When the other end 12C2 of the substantially annular guide portion 12C abuts on the bottom surface of the

positioning recess

43, 44, the insertion of the

sleeves

12, 22 is completed.

Since the plurality of positioning ribs 12D abut the inner surfaces of the positioning recesses 43 and 44 in each direction, it is possible to position the

sleeves

12 and 22 with high accuracy in the X direction and the Z direction orthogonal thereto. Further, the other ends 12C2 and 22C2 of the substantially

annular guide portions

12C and 22C abut on the bottom surfaces of the positioning recesses 43 and 44, whereby the

sleeves

12 and 22 can be positioned with high accuracy in the Y direction. Therefore, the other end faces 12b and 22b of the

light guide paths

12A and 22A can be set at a fixed position in the housing 40, and the other end faces 12b and 22b and the end faces of the

optical fibers

51 and 52 on the plug side can be constantly used. It can be attached so as to provide the opposite spacing as designed between 51a and 52a. Therefore, an optical connector with high light transmission efficiency can be obtained.

Next, the light emitting module 10 and the light receiving module 20 fix the fixing

regions

41 and 42 in the housing 40. At this time, the light emitting module 10 and the light receiving module 20 are attached with the frame shaped

ribs

11a and 21a for positioning directed in the Y1 direction in the drawing. That is, as shown in FIG. 1, when the light emitting module 10 and the light receiving module 20 are attached, they are formed inside the frame shaped

ribs

11a and 21a and on the surface of the

bases

11A and 21A at one end of the

sleeves

12 and 22 on the Y2 side. The positioning convex portions 12C1 and 22C1 abut. The light emitting module 10 and the light receiving module 20 are fixed in the fixing

regions

41 and 42 in such a state of being in contact with each other. Therefore, the facing distance between the light emitting element 11 and the light receiving element 21 provided in the light emitting module 10 and the light receiving module 20 and the

lenses

12B and 22B on the

sleeve

12 and 22 side, or the case where the

convex lenses

13 and 23 are provided. Can be mounted so that the facing distance between the

convex lenses

13 and 23 and the

lenses

12B and 22B on the

sleeve

12 and 22 side is always constant. Therefore, an optical connector with high light transmission efficiency can be obtained.

As described above, according to the present invention, since the attachment accuracy of the

sleeves

12 and 22, the light emitting module 10, the light receiving module 20 and the

optical fibers

51 and 52 can be enhanced in the X axis direction, an optical connector with high light transmission efficiency is provided. be able to.

In addition, since the said

sleeves

12 and 22 can be shared to the light emission module 10 and the light reception module 20 with the same shape, it is also possible to reduce the manufacturing cost of an optical connector.

Further, an aspect shown in FIG. 8 of Patent Document 1, that is, an optical connector for optically connecting a light emitting optical element and a fiber, and a diameter of the conical light guide path facing the end face of the optical fiber In the case where the lens is integrally formed on the large size side, light is efficiently transmitted from the lens to the end face of the fiber in the vicinity of the central optical axis (central axis of the light guide), but larger than the core diameter of the optical fiber In the vicinity of the maximum diameter of the lens, that is, the light emitted from the lens does not enter the end face of the fiber and becomes leaked light, which tends to reduce the transmission efficiency as a whole. Means for solving the above problems are shown in the following second embodiment.

FIG. 4 shows a second embodiment of the present invention, and is an enlarged sectional view showing the relationship between an optical module, a sleeve and an optical fiber provided in an optical connector.

The configuration in the optical connector shown in FIG. 4 is the same as that of the first embodiment except for a part, and the diameter dimension of the

light guide paths

12A and 22A forming the

sleeves

12 and 22 is opposite to the end face of the optical fiber The only difference is that

convex lenses

12E and 22E are provided on the small end faces 12b and 22b. Further, the diameters of the

convex lenses

12E and 22E are formed substantially the same as the core diameter of the optical fiber.

Thus, when the

convex lenses

12E and 22E are provided on the end faces of the

light guide paths

12A and 22A facing the end faces 51a and 51a of the

optical fibers

51 and 52, in the case of the light emitting module 10, in particular, the convex lenses 12E. Since it becomes easy to condense the light radiate | emitted from these in the end surface 51a of the optical fiber 51, it becomes possible to improve light transmission efficiency further.

In the optical connector according to the above-described embodiment, the configuration in which both the light emitting module 10 and the light receiving module 20 are included in one housing 40 has been described. However, the present invention is not limited thereto. Alternatively, only one light emitting module 10 or only the other light receiving module 20 may be provided.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the optical connector which shows the 1st Embodiment of this invention. FIG. 2 is an enlarged sectional view showing the relationship between an optical module, a sleeve and an optical fiber provided in the optical connector of FIG. 1. (A) is a cross-sectional view showing a sleeve on the light receiving module side, and (B) is a graph showing the range of the optimum inclination angle of the light guide of the light receiving module side sleeve. The expanded sectional view which shows the 2nd Embodiment of this invention, and shows the relationship of the optical module provided in an optical connector, a sleeve, and an optical fiber.

1 Optical connector 10 Light emitting module (optical module)
11 Light emitting element (optical element)
12 sleeve 12A light guide path 12B lens 12C guide portion 12D positioning rib 12E convex lens 12c flange portion 13 convex lens 20 light receiving module (optical module)
21 light receiving element (optical element)
Reference Signs List 22 sleeve 22A light guide 22B lens 22C guide 22D guide rib 22E convex lens 22c flange 23 convex lens 40

housing

41, 42 fixed

area

43, 44

positioning recess

45, 46

insertion recess

47, 48 through

hole

51, 52

light Fiber

51a, 52a Optical fiber end face

Claims

In an optical connector provided with an optical fiber for propagating light, an optical element for emitting or receiving light, and a sleeve for optical connection between the optical fiber and the optical element,
The sleeve is provided with a substantially frusto-conical light guide gradually expanding toward the optical element from one small diameter end, and the side of the light guide has a laterally projecting flange portion, and A convex lens is integrally formed on an end face of the sleeve facing the optical element;
When viewed in cross section passing through the axial center line of the sleeve, the opening angle between the axial center line and the straight line connecting the base of the flange and the maximum outer diameter of the lens is 30 degrees. An optical connector characterized by the above and less than 90 degrees.
The optical connector according to claim 1, wherein an inclination angle of a side surface of the light guide path is 0.5 degrees or more and 1 degree or less.
The optical connector according to claim 1 or 2, wherein a substantially annular guide continuous to the flange portion is formed.
The optical connector according to any one of claims 1 to 3, wherein a convex lens is integrally formed on an end face of the sleeve facing the optical fiber.
The optical connector according to any one of claims 1 to 4, wherein a convex lens is provided on a light emitting surface or a light receiving surface of the optical element.