WO1983002167A1

WO1983002167A1 - Optical coupling system

Info

Publication number: WO1983002167A1
Application number: PCT/JP1982/000465
Authority: WO
Inventors: Tanshi Kabushiki Kaisha Toyo
Original assignee: Tanaka, Toshiyasu; Ariga, Sadakazu
Priority date: 1981-12-14
Filing date: 1982-12-13
Publication date: 1983-06-23
Also published as: JPS58102201A

Abstract

Optical coupling systems are used for optical communication, measurement of light, the coupling and decoupling of optical paths, as well as being used as optical heads for optical sensors, or photoelectric switches. This kind of system has an optical fiber bundle (10) comprising a central fiber bundle (11) and a peripheral fiber bundle (12), and a focusing means including a ball lens (20). The optical fiber bundle (10) employs as the central fiber bundle (11) one of two optical fiber bundles forming optical paths independently of each other, and as the peripheral fiber bundle (12) one end of the other optical fiber bundle arranged around the periphery of the central fiber bundle (11), thereby forming a collecting terminal (15). The other ends of both of the fiber bundles are formed independently into separate ends (16). The lens (20) is provided in the vicinity of the terminal (15).

Description

Mechano-optical coupling technology

The present invention relates to an optical coupling system used in optical communication, optical measurement, and the like, for coupling and separating optical paths.

Background art

In recent years, in communication, measurement, control, etc., optical paths are formed by optical fibers, and light is used! ) Information and energy are being transmitted. Such optical transmission requires optical coupling means for performing optical path coupling, separation, and the like when light enters and exits and branches.

Fig. 1 shows a conventional optical coupling system. The input fiber 1 and the output fiber are shown in the figure.

2 and the output fiber 3 are arranged with their respective end faces orthogonal to each other, and are optically connected by an optical system consisting of a half mirror 4 and a lens 5. .

However, since this conventional optical coupling system uses a half mirror and a lens, the number of parts is increased and the assembling is troublesome and expensive.) There is a disadvantage that it is difficult to convert. Also, the optical axis shifts due to vibration. However, it has a disadvantage that it is suitable for use in places subject to high vibration.

OMPI On the other hand, there has been proposed a configuration in which a semi-reflective film is provided on a focusing π lens, but this is expensive because it is easy to manufacture.] Roller glass] has the drawback that the characteristics are so different that it is suitable for connection with a plastic fiber.

In particular, in recent years, in the case of short-distance transmission, the price structure of the entire system can be kept low, so it is conceivable to use an inexpensive plastic fiber for the transmission line. There is a demand for an optical coupling system that can be realized at a low cost with a simple structure.

Also, there is a demand for a small-sized and simple configuration for measurement and control.

The present invention has been made in view of such circumstances, and uses an optical fiber system and an optical focusing means.3) The structure is small and simple, the structure can be manufactured at low cost, and vibration and the like can be obtained. Yo

1) An object of the present invention is to provide an optical coupling system which does not cause optical axis shift and is suitable for connection with a plastic fiber.

Disclosure of the invention

According to the present invention, a center of one of a plurality of optical fiber systems that independently form an optical path, and one end of another optical fiber system is arranged around one end of the optical fiber system. And a converging means for converging the incoming and outgoing light of the optical fiber system in the vicinity of the collecting end.

The structure is small and simple.

C PI · It can be manufactured inexpensively and is not affected by vibrations. ?? The optical axis does not deviate, and it has the effect of facilitating connection with the plastic fiber.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a configuration diagram showing an example of a conventional optical coupling system, FIG. 2 is a configuration diagram showing an embodiment of the optical coupling system of the present invention, and FIG. 3 is a diagram of an optical fiber system constituting the above embodiment. FIG. 4 is an end view showing the collecting end, FIG. 4 is an end view showing the other end of the optical fiber system located around the collecting end in the above embodiment, FIG. 5, FIG. 6, FIG. Fig. 8 is an end view showing another example of the optical fiber system, and Fig. 8 shows the optical fiber system in a state in which a fixing sleeve to be attached to the case is mounted. Fig. 9 is a front view, Fig. 9 is a cross-sectional view showing the assembled end of the optical fiber system and the ball lens attached to the bracket of the case, and Fig. 10 is FIG. 11 is a front view showing an example of an optical coupler to which the optical coupling system of the present invention is applied; FIG. 11 is a front view showing a state where an optical fiber cable is connected to the optical coupler; Fig. 13, Fig. 13 and Fig. 14 are front views each showing a state in which the present invention is applied to an optical sensor, a photoelectric switch, etc., and Fig. 15 is a photoelectric switch to which the present invention is applied. FIG. 16 is a plan view showing a group of switches, and FIG. 16 is a front view showing an example in which the optical coupling system of the present invention is applied to single-wire two-way communication.

BEST MODE FOR CARRYING OUT THE INVENTION

First, the embodiment shown in FIGS. 2 to 4 will be described.

― CV.FI I do. Here, FIG. 2 is a configuration diagram showing an embodiment of the optical coupling system of the present invention, FIG. 3 is an end view showing an assembly end of an optical fiber system constituting the above embodiment, FIG. FIG. 9 is an end view showing the other end of the optical fiber system located around the collecting end in the above embodiment.

In these figures, the optical coupling system of the present invention comprises an optical fiber system 10 composed of a central fiber system 11 and a peripheral fiber system 12, and a ball lens. And 20 focusing means.

In the optical fiber system 10, one of two optical fiber systems that independently form an optical path is defined as a central fiber system 11, and a peripheral fiber system 12 is formed around one end of the optical fiber system. Then, one end of another optical fiber system is disposed to form a collective end 15. The other ends of the two fiber systems are independently provided with separated ends 16. The central fiber system 11 and the peripheral fiber system 12 are not limited to one each, but can be composed of multiple independent optical fiber systems. You. For example, the one shown in Fig. 7 is composed of one central fiber system 11 and six peripheral fiber systems 12.

In the optical fiber system 10 shown in FIG. 2, the central fiber system 11 is a single-core fiber 13, for example, a single core made of plastic having a diameter of about 1 leak. On the other hand, the peripheral fiber system 12 is a fine fiber 14, for example, a direct fiber. It is composed of several hundred glass fibers with a diameter of about 50 μτη. The collecting end 15 is, for example, the end

Insert the end of the single-fiber fiber 13 as the center fiber system 11 into a cylindrical jig with an inner diameter that approximately matches the outer diameter of the fiber 15. Insert a large number of fine fibers 14 as the peripheral fiber system 12 between the outer circumference and the inner circumference of the jig, fix them with adhesive, and remove the jig to form Is done. In addition, although not shown in this embodiment, as shown in FIG. 7, which will be described later, it is also possible to form a collecting end using a coating. This is achieved by inserting a single-core fiber 13 into a resin tube, which is a coating, and then placing a fine fiber between the fiber 13 <outer circumference and the inner circumference of the tube. A large number of bars 14 are inserted and D-fixed by heat-shrinking the adhesive or the tube. Furthermore, the collecting end 15 is a fine fiber.

14 is formed into a ribbon shape by means of welding, bonding, etc. in advance, and is used as a peripheral fiber system 12 as a single core fiber.

It can also be formed by winding a cylindrical shape around the center fiber system 11 consisting of 13. Of course, the present invention is not limited to these forming methods, and other methods may be used. On the other hand, the other end of the peripheral fiber system 12 is separated from the central fiber system 11 and bundled in a circular shape.

The optical fiber system 10 is not limited to the one shown in FIG. 2 described above, but may be any of various materials, shapes, structures, and the like. 5 to 7 show other embodiments.

Ολ-ίΡΙ

The IFO Here is an example.

The optical fiber system 10 shown in FIG. 5 is provided with a support projection 18a on the inner periphery and uses a sleeve 18 to form an assembly end. A single fiber 13 is inserted into the center of the sleeve 18 with the support projection 18a, and the outer periphery of the single fiber 13 and the sleeve 1 are held together. A large number of fine fibers 14 pass through between the inner circumference and the inner circumference. In the optical fiber system 10 shown in FIG. 6, both the central fiber system 11 and the peripheral fiber system 12 are composed of fine fibers 14. The optical fiber system 10 shown in FIG. 7 is composed of a single fiber 13 on the outer periphery of the central fiber 11 from a single fiber 1: 3. Six peripheral fiber systems 12 are provided and fixed with a covering 17 and an adhesive 17a. Alternatively, a sleeve 18 may be used instead of the coating 17.

The ball lens 20 has a substantially spherical shape, is provided near the collecting end 15, and focuses the input / output light of the optical fiber system 10. The ball lens 20 is formed of glass, plastic, or the like, and has a size such that the light emitted from the peripheral fiber system 12 can be focused in the optical axis direction. The size is determined in consideration of the fact that it is installed in the optical connector. The ball lens was used as the focusing means because of its wide angle and short focal length. That is, the focal length is shortened.]), The focusing means and the optical fiber system are combined. This is because they can be close to each other and can be downsized as a whole, and because of the wide angle.], Because the emitted light of the peripheral fiber system 12 can be used effectively. It is. This ball lens 20 may be coated with an anti-reflection film, whereby the reflection loss on the lens surface can be reduced and the noise due to the reflected light is reduced. Can be reduced

In the present embodiment, the ball lens 20 is used. However, the focusing means is not limited to this, and another means may be used. 'For example, a lens having a' link 'shape can be used for the peripheral fiber system 12. In addition, the lens is provided for both the central fiber system 11 and the peripheral fiber system 12, but may be provided for only one of them, for example, for the peripheral fiber system. The above-mentioned ring-shaped lens may be attached to only the lens 12. Further, in this embodiment, the collecting end face 15 of the optical fiber system 10 is provided uniformly, but, for example, the peripheral fiber corresponding to the spherical surface of the ball lens 20 is provided. It is also possible to have a structure that protrudes the i-system 12 from the central fiber system 11. In this case, it is preferable to use a mushroom-shaped lens as a focusing means.

In the optical coupling system of the present invention, the central fiber system 11 and the peripheral fiber system 12 are used as transmission lines, respectively, and the other optical fibers are provided at the collecting end 1.5 and the separating end 16. Cable and 'ίΡΙ It is for connecting a connector! ? An optical transmission system can be constructed, but the optical fiber system 10 is formed short, and together with the ball lens 20, the optical coupling system is accommodated in an appropriate case. It is considered to be common to construct The housing of the optical fiber system 10 in the case is performed, for example, as shown in FIGS.

In other words, the housing in the case should be fixed to each of the collecting end 15 and the separating end 16 of the optical fiber system 10.

19 is attached, and this is inserted into the through hole 23 of the socket portion 22 of the case 21 from the inside of the case 21. The sleeve 19 is made of a metal cylinder having a flange 19a for locking ¾2), and the collecting end of the optical fiber system 10

After applying a coating 17 of a synthetic resin, for example, a heat-shrinkable resin tube, to the 15 and the separation end 16, insert this into a cylinder and fix it by means such as crimping or bonding. Then, as shown in Fig. 7, the coating 17 was used to fix the ends.

If necessary, further coating may be applied. In addition, as described above, when the sleeve 18 is used to form the collecting end 15, it can be used as it is.

On the other hand, the ball lens 20 is fitted by being fitted into a concave portion 24 provided in a through hole 23 of the socket portion 22. The position of the ball lens 20 is such that the collection end 15 of the optical fiber system 10 is located near the outside of the focal position, and the position is 0?

0 Is set to For example, if the focus is ball lens

When the spherical surface of the ball lens 20 is very close to the spherical surface 20, the spherical surface of the ball lens 20 is located at a position close to the collecting end 15 inserted into the through hole 23 (including the case where the spherical surface of the ball lens 20 is in contact therewith. ) Is set to. '

Next, the operation of the optical coupling system of the present invention will be described together with the application examples shown in FIGS. 10 to 16.

FIG. 10 shows an example of an optical coupler in which the optical fiber system and the ball lens are mounted and accommodated as described above. The optical coupler shown in FIG. , Case 31 and socket portions 32a, 32b, 32c provided at both ends thereof. .

In this optical coupler, as shown in FIG. 11, an optical fiber cable 34 having a plug 33 is connected to the socket sections 32a, 32b, and 32c. ), It is possible to drop and insert optical signals in an optical communication system. That is, the light from the optical fiber cables 34b and 34c is focused by the optical fiber system 10 and the ball lens 20 (see FIG. 2), and the optical fiber cables 34a and 34c are focused. And the light from the optical fiber cable 34a is sent to the central fiber system 11 and the peripheral fiber system 12 of the optical fiber system 10 described above. The light is split (distributed) into the optical fiber cables 34b and 34c, respectively. In this case, the branching ratio is determined by the central fiber system 11 and the peripheral fibers. It is possible to change J by changing the opening area ratio of the system 12.

As is clear from this example, according to the optical coupling system of the present invention, the optical fiber system 10 branches (distributes) and aggregates light, so that the structure is small and simple. Therefore, it is easy to assemble and can be manufactured at low cost, and the optical axis may not be shifted due to vibration or the like.

The optical coupling method of the present invention can also be applied to optical heads such as optical sensors and photoelectric switches. FIG. 12 to FIG. 15 show various embodiments thereof. In other words, this head connects the optical fiber system 10 and the ball lens 20 shown in FIG. 2 with the collecting end 15 and the ball lens 20 of the socket. 32a, the separated end 16 of the central fiber system 11 corresponds to the socket part 32b, and the separated end 16 of the peripheral fiber system 12 corresponds to the socket part 32c. And housed in case 31.

In FIG. 12, an optical fiber cable 34 forming an optical path up to a detection target 35 is connected to a socket section 32a via a plug 33. The optical sensor head. This is because, when illumination light is made to enter from the socket part 32c, the illumination light is guided to the peripheral fiber system 12 and reaches the ball lens 20. The light is focused and enters the optical fiber cable 34, which is emitted from the tip of the cable 34 and irradiates the detection target 35. And the The reflected light from the detection target 35 is guided to the optical fiber cable 34 to reach the ball lens 20 where it is focused and has a predetermined branching ratio. The light enters the fiber systems 11 and 12. Light incident on the center fiber system 11 is emitted from the socket 32b and used for measurement and the like.

In the above case, if the branching ratio is small, that is, the amount of light incident on the central fiber system 11 is larger than the amount of light incident on the peripheral fiber system 12]? 'Target

Most of the information light from 35 can be made to enter the central fiber system 11 and the SN ratio can be improved.

13 and 14 show the case where the detection circuit 36 is connected to the socket section (32b, 32c :) by the Braggin method, and the former is the socket. The point 32a is made to directly face the detection target 35, and the latter is made to face via the optical fiber cable 34. The detection circuit 36 includes a light source such as a light emitting diode and a driving circuit therefor, and a light receiving circuit including a light receiving element (both are not shown). To exchange power and signals with external circuits.

In addition, the detection circuit 36 may be provided with a switch function], so that a photoelectric switch can be configured. FIG. 15 shows a remote photoelectric switch group in which a large number of such photoelectric switches are provided, which can be used for automatic control and the like.

ΟΜΡΙ Further, the optical coupling system of the present invention can be applied to single-wire bidirectional optical communication. FIG. 16 shows an example of this, in which an optical coupler 30 according to the present invention is connected to both ends of an optical fiber cable 34 forming a single optical path, and the optical coupler 3 is connected to the optical fiber cable 34. The transmission / reception circuit 38 is connected to each of the 0s.

The transmission / reception circuit 38 has a light source such as a light emitting diode forming a transmission unit and a driving circuit thereof, and a light receiving circuit including a light receiving element forming a reception unit (neither is shown). A signal and electric power are exchanged with an external device through the input / output terminal 39.

The optical coupler 30 is a central fiber system of the peripheral fiber system 12 .The branching ratio with respect to 11 is set to be small, and the peripheral fiber system 12 is connected to the transmission unit. The central fiber system 11 corresponds to each of the above receivers. Most of the optical signal transmitted from the other end of the optical fiber cable 34 can be made to enter the central fiber system 11. Therefore, according to this optical coupler, bidirectional communication can be efficiently performed with reduced branch loss.

The optical fiber cable 34 is connected to the optical fiber system 10 of the optical coupler 30 via the ball lens 20, so that the diameter can be selected as appropriate. Large diameter, inexpensive plastic fiber can be used.

-Industrial applicability The optical coupling system according to the present invention can branch and aggregate optical signals by being connected to another optical fiber cable, and can perform optical fiber link, optical communication, etc. It is useful for realizing an optical transmission system. In addition, if a part for performing optical coupling is accommodated in a case, it can be used as an optical coupler of an individual component. Furthermore, it can be used as an optical head such as an optical sensor and a photoelectric switch.

Claims

The scope of the claims

1. With one of a plurality of optical fiber systems that form optical paths independently of each other as a center, one end of another optical fiber system is arranged around one end to form an aggregate end. And an optical coupling system comprising: a converging means for converging the input / output light of the optical fiber system in the vicinity of the collecting end.

2. The optical coupling system according to claim 1, wherein the central fiber system is constituted by a single-core fiber, and the peripheral fiber system is constituted by a large number of fine fibers. .

3. In a sleeve with a support protrusion on the inner circumference, a single-core

The fiber is inserted and held at the center of the sleeve by the support projection, and a fine fiber is inserted between the single fiber and the inner circumference of the sleeve. 2. The optical coupling system according to claim 1, wherein said optical system comprises said collecting end.

4. The optical coupling system according to claim 1, wherein the focusing means is constituted by a ball lens.

5. The light according to claim 1, wherein the focusing means comprises a ball lens, and the ball lens is coated with an antireflection film. Combination method.

6. Place the end of the above assembly and optical fiber

A socket having a through hole into which the other end of the paper system is fitted is provided, and a base for attaching the above-mentioned gathering end is provided.

O PI

, \ IrO -15-Install a ball lens in the through hole of the socket, and fix the fixing fiber to each of the collecting end and the other end of the optical fiber system. The sleeve is mounted, and each end where the sleeve is mounted is mounted in the through hole of the socket section, and the optical fiber system is accommodated in the case. The optical coupling method described in Paragraph 1, 2 or 3