JP4012473B2 - Optical coupler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical coupler that does not require precise alignment.
[0002]
[Background]
An optical connector for connecting optical fibers or the like includes a cylindrical ferrule and a pair of plugs that are detachably fitted to the ferrule, and the plugs are connected to optical fiber or other connection ends. The parts are fixed integrally with each other.
[0003]
[Problems to be solved by the invention]
Although conventional optical connectors made of ceramics etc. need to match the relative positions of the connecting end faces of the optical fibers connected to each other accurately with micrometer accuracy, extremely high dimensional accuracy is required. The processing is difficult and the manufacturing cost increases.
[0004]
OBJECT OF THE INVENTION
An object of the present invention is to provide an optical coupler capable of transmitting and receiving light even if there is some positional deviation or inclination.
[0005]
[Means for Solving the Problems]
An optical coupler according to the present invention is an optical coupler formed of an optically transparent material, and has an annular first optical connection end surface on which light is incident and / or emitted, and an opposite side of the first optical connection end surface. An inclined end surface that is located on the side and continuously changes along the circumferential direction of the first optical connection end surface, and between the inclined end surface and the first optical connection end surface extends a cylindrical portion having an inner and outer circumferential surfaces, the inclined end surface is formed on the stepped portion of the cylindrical portion is discontinuous, the second optical connection end face light you exit and / or entrance and It is characterized by comprising.
[0006]
In the present invention, when the light from the light source enters the cylindrical portion from the second optical connection end face, the light is propagated in the circumferential direction of the cylindrical portion by repeating total reflection on the inner peripheral surface and the outer peripheral surface. Further, due to the presence of the inclined end surface inclined with respect to the first connection end surface, a part of the light reflected by the inclined end surface is emitted from the first connection end surface, and finally from an almost entire area of the first connection end surface. Light is emitted to On the other hand, if the light is incident into the cylindrical portion from a first connection end face, the inclined end face which is inclined with respect to the first connecting end face, the circumferential direction of the cylindrical portion while repeating total reflection at the inner circumferential surface and outer circumferential surface of the cylindrical portion And finally light is emitted from the second connection end face.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the optical coupler according to the present invention, the first optical connection end face may be formed of at least one prism body having a top portion extending along a circumferential direction thereof.
[0008]
Alternatively, the first optical connection end surface may be formed of a plurality of prism bodies whose top portions extend radially with respect to the cylindrical portion. In this case, the height of the top portion may be lower toward the inner peripheral surface side of the cylindrical portion, or the height of the top portion may be constant.
[0009]
The inclined end surface may be formed of a plurality of prism bodies whose top portions extend radially with respect to the cylindrical portion.
[0010]
A light reflecting film covering the inclined end face and the inner and outer peripheral surfaces of the cylindrical portion can be further provided.
[0011]
A light source and / or a light detection sensor can be arranged on the second optical connection end face.
[0012]
Alternatively, it is also possible to integrally form a transparent light guide part that projects from the second optical connection end face in the tangential direction of the inner peripheral surface and the outer peripheral surface of the cylindrical part and is connected to the light source and / or the light detection sensor. It is.
[0013]
The second optical connection end surface may be constituted by a part of a plane perpendicular to the first optical connection end surface and including the axis of the cylindrical portion.
[0014]
【Example】
Embodiments of the optical coupler according to the present invention will be described in detail with reference to FIGS. 1 to 5. However, the present invention is not limited to these embodiments, and further combinations thereof may be made. All changes and modifications encompassed within the scope of the inventive concept described in the scope are possible, and of course can be applied to any other technique belonging to the spirit of the invention.
[0015]
The appearance of an embodiment in which the optical coupler according to the present invention is applied as a plug of an optical connector is shown in an exploded state in FIG. 1, and the coupling state is shown in FIG. In other words, the optical connector 10 includes a cylindrical ferrule 11, a pair of plugs 12i and 12o that are detachably fitted to the ferrule 11, and a second optical connection (described later) of the one plug 12i. A light source 14 joined to the end face 13 and a light detection sensor 15 joined to the second optical connection end face 13 of the other plug 12o are provided. A power source (not shown) is connected to the light source 14 via a cable, and an optical signal detected by the light detection sensor 15 is output to a signal processing device (not shown) via the cable.
[0016]
The inner diameter of the ferrule 11 that defines the facing position of the pair of plugs 12i, 12o is set so as to correspond to the outer diameter of the pair of plugs 12i, 12o so that they are in a clearance fit relationship. It is not necessary to define the relative position of the first optical connection end face 16 (described later) of the plugs 12i and 12o so accurately, and it is not necessary to completely contact them.
[0017]
The external appearance of the plugs 12i and 12o in the present embodiment is shown in an enlarged manner in FIG. 3, and the external appearance cut at the stepped portion and developed linearly is schematically shown in FIG. In other words, the plug 12 corresponding to the optical coupler of the present invention is located on the opposite side of the annular first optical connection end surface 16 and the first optical connection end surface 16, and the distance between the first optical connection end surface 16 is the first. An inclined end surface 17 that continuously changes along the circumferential direction of the one optical connection end surface 16, and extends between the inclined end surface 17 and the first optical connection end surface 16, and includes an inner peripheral surface 18 i and an outer peripheral surface 18 o. And a second optical connection end surface 13 formed on a step portion 19 of the cylindrical portion 18 where the inclined end surface 17 is discontinuous. The first optical connection end face 16 is formed by a plurality of concentric prism bodies 20 each having a top portion 20t extending along the circumferential direction, and the light emitted from the first optical connection end face 16 is cylindrical. While suppressing the diffusion to the inside and outside in the radial direction of the portion 18, incident light from a wider angle along the radial direction of the cylindrical portion 18 is allowed to enter the plug 12 from the first optical connection end face 16. it can. The inclined end surface 17 is formed in a sawtooth shape by a plurality of prism bodies 21 having apexes 21t extending radially with respect to the cylindrical portion 18, and the first inclined surface portion 21s inclined more strongly with respect to the inclined end surface 17; The second inclined surface portion 21v perpendicular to the first optical connection end surface 16, and the light incident on the plug 12 from the second optical connection end surface 13 is more efficiently generated by the presence of the first inclined surface portion 21s. While the light is totally reflected on the first optical connection end face 16 side, the light incident into the plug 12 from the first optical connection end face 16 is more efficiently totally reflected on the second optical connection end face 13 side.
[0018]
The surfaces of the plugs 12 other than the first optical connection end face 16 and the second optical connection end face 13 are all covered with a light reflection layer (not shown) formed of a metal thin film such as aluminum, and the first optical connection end face 16 and the second optical connection end face 16. Consideration is given so that light does not enter and exit from other than the optical connection end face 13. The outer diameter of the cylindrical portion 18 is set so as to have a clearance fit with respect to the inner diameter of the ferrule 11.
[0019]
When the dimensions of the main part of the plug 12 in this embodiment are shown as an example, the inner diameter and the outer diameter of the cylindrical portion 18 are 8 mm and 10 mm, respectively, and the height of the cylindrical portion 18 varies linearly in the range of 1.5 to 3 mm. Therefore, the height of the second optical connection end face 13 located at the step portion 19 is 1.5 mm.
[0020]
Light emitted from the light source 14 connected to the second optical connection end face 13 of one plug 12i enters the one plug 12i from the second optical connection end face 13 of one plug 12i, and It propagates in the circumferential direction of the cylindrical portion 18 by repeating total reflection on the inner peripheral surface 18i and the outer peripheral surface 18o. Further, due to the presence of the inclined end surface 17 inclined with respect to the first optical connection end surface 16, a part of the light reflected by the inclined end surface 17 is emitted from the first optical connection end surface 16, and finally the first optical connection end. The light is emitted in an annular shape from almost the entire end face 16. Thus, the light emitted from the first optical connection end face 16 of one plug 12i enters the cylindrical portion 18 of the other plug 12o from the first optical connection end face 16 of the other plug 12o, and the first light. The inclined end surface 17 inclined with respect to the connection end surface 16 propagates in the circumferential direction of the cylindrical portion 18 while repeating total reflection on the inner peripheral surface 18i and the outer peripheral surface 18o of the cylindrical portion 18, and finally the second optical connection end surface. 13 and is detected by the light detection sensor 15 mounted on the second optical connection end face 13. In this case, the annular first optical connection end face 16 has a large area even if there is a slight misalignment or misalignment between these two plugs 12i, 12o. The light can be reliably guided from one optical plug 12i to the other optical plug 12o.
[0021]
In the above-described embodiment, the plurality of prism bodies 20 with the top portions 20t extending annularly are formed on the first optical connection end face 16, but the plurality of prism bodies with the top portions extending radially with respect to the cylindrical portion 18 are formed in the first. One optical connection end face 16 may be formed.
[0022]
The appearance of another embodiment of the optical coupler according to the present invention is shown in FIG. 5, but the same reference numerals are given to elements having the same functions as those of the previous embodiment, and the duplicate description is omitted. To do. That is, the first optical connection end face 16 in the present embodiment is formed by a plurality of prism bodies 20 having apexes 20t extending radially with respect to the cylindrical portion 18, and the height of each apex 20t is the cylindrical portion 18. The inner peripheral surface 18i of the cylindrical portion 18 is lowered so that it converges at one point on the central axis of the cylindrical portion 18 when the top portion 20t is extended to the central side of the cylindrical portion 18.
[0023]
In the present embodiment, the height of the top portion 20t of the prism body 20 is set to be lower toward the inner peripheral surface 18i side of the cylindrical portion 18, but it is also possible to set all of them to a constant height. In addition, although the inclined end face 17 is formed as a smooth plane, the same prism body 21 as in the previous embodiment may be formed.
[0024]
The second optical connection end face 13 projects from here to the tangential direction of the inner peripheral face 18 i and the outer peripheral face 18 o of the cylindrical portion 18, and forms a rectangular bar shape having the same cross-sectional shape as the second optical connection end face 13 The light guide 22 is integrally formed, and the light source 14 and the light detection sensor 15 that are in parallel are connected to the tip of the light guide 22. As described above, when the light source 14 and the light detection sensor 15 are arranged side by side and attached to the tip of the light guide unit 22, the light emitted from the light source 14 is prevented so that the light detection sensor 15 does not erroneously detect the light from the light source 14. It is necessary to set the wavelength and the wavelength of light detected by the photodetector to be different.
[0025]
Therefore, the light from the light source 14 attached to the light guide unit 22 enters the cylindrical part 18 of the optical coupler 23 from the light guide unit 22 through the second optical connection end face 13, and finally the first optical connection. The light is emitted in an annular shape from almost the entire end face 16. On the other hand, light incident on the cylindrical portion 18 from the first optical connection end face 16 of the optical coupler 23 is finally emitted from the light guide portion 22 via the second optical connection end face 13, and enters the light guide portion 22. Detected by the mounted light detection sensor 15. In this case, since the wavelength of the light detected by the light detection sensor 15 and the wavelength of the light emitted from the light source 14 are different, the light detection sensor 15 may detect light emitted from the light source 14 by mistake. There is no problem.
[0026]
In the embodiment shown in FIGS. 1 and 2, the pair of plugs 12i and 12o are integrally connected via the ferrule 11, but the other plug 12o is connected to one plug, for example, 12i. It is also possible to set so that can be rotated. In this case, a slight gap is formed between the first optical connection end faces 16 of the pair of plugs 12i and 12o so that the opposing first optical connection end faces 16 do not rub against each other as the other plug 12o rotates. It is preferable to consider the above. When such a configuration is employed, a large-capacity signal can be easily exchanged using light between the rotating body and the stationary body.
[0027]
【The invention's effect】
According to the optical coupler of the present invention, the annular first optical connection end surface on which light is incident and / or emitted is located on the opposite side of the first optical connection end surface, and the distance between the first optical connection end surface is first. An inclined end surface that continuously changes along the circumferential direction of the optical connection end surface, a cylindrical portion that extends between the inclined end surface and the first optical connection end surface, and has an inner peripheral surface and an outer peripheral surface, and an inclined end surface allowed There is formed a step portion of the cylindrical portion is discontinuous, because the light is comprises an exit and / or second optical connection end face you incident, mutually opposed first optical connection end face of the two optical couplers When transmitting and receiving light, the annular first optical connection end surface has a large area even if there is a slight misalignment or inclination between these two optical couplers. Therefore, light can be reliably guided from one optical coupler to the other optical coupler.
[0028]
When the first optical connection end surface is formed by at least one prism body having a top portion extending along the circumferential direction of the first optical connection end surface, the radially inner side and the outer side of the cylindrical portion from the first optical connection end surface The light can be emitted in a condensed state by suppressing diffusion of the emitted light to the light, or the light can be incident in a condensed state from the first optical connection end face.
[0029]
Similarly, even when the first optical connection end surface is formed by a plurality of prism bodies whose tops extend radially with respect to the cylindrical portion, the diffusion of emitted light from the first optical connection end surface is suppressed and the light is condensed. The light can be emitted in the state, or conversely, the light can be incident from the first optical connection end face in the condensed state. In particular, when the height of the top portion is set to be lower toward the inner peripheral surface side of the cylindrical portion, the emitted light can be deflected radially inward of the cylindrical portion.
[0030]
When the inclined end surface is formed by a plurality of prisms whose tops extend radially with respect to the cylindrical portion, out of the light propagating in the cylindrical portion, the light totally reflected by the inclined end surface is used as the first optical connection end surface. On the other hand, it can be deflected to have a larger inclination angle.
[0031]
When a transparent light guide part that projects from the second optical connection end face in the tangential direction of the inner and outer peripheral surfaces of the cylindrical part and is connected to the light source and / or the light detection sensor is formed integrally with the cylindrical part, Since the propagation direction of the light incident from the light part into the cylindrical part can be aligned to some extent, the intensity distribution of the light emitted from the first optical connection end face can be controlled relatively easily. Similarly, since only the light that has entered the light guide portion from the first optical connection end surface through the cylindrical portion is detected by the light detection sensor, it is possible to more reliably avoid false detection of stray light by the photodetector.
[0032]
When the light source and / or the light detection sensor are arranged on the second optical connection end face, the optical coupler and the light source and / or the light detection sensor can be unitized extremely compactly.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the appearance of an embodiment of an optical connector using an optical coupler according to the present invention in an exploded state.
2 is a partially broken side view of the optical connector in the embodiment shown in FIG. 1; FIG.
FIG. 3 is an enlarged perspective view of one plug in the embodiment shown in FIG. 1;
4 is a perspective view schematically showing the plug shown in FIG. 3 cut at a stepped portion and developed linearly. FIG.
FIG. 5 is a perspective view showing the appearance of another embodiment of the optical coupler according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Optical connector 11 Ferrule 12, 12i, 12o Plug 13 2nd optical connection end surface 14 Light source 15 Photodetection sensor 16 1st optical connection end surface 17 Inclined end surface 18 Cylindrical part 18i Inner peripheral surface 18o Outer peripheral surface 19 Step part 20 Prism body 20t, 21t Top part 21 Prism body 21s First slope part 21v Second slope part 22 Light guide part 23 Optical coupler

Claims (8)

An optical coupler formed of an optically transparent material,
An annular first optical connection end surface on which light is incident and / or emitted ;
An inclined end surface that is located on the opposite side of the first optical connection end surface, and whose interval with the first optical connection end surface continuously changes along the circumferential direction of the first optical connection end surface;
A cylindrical portion extending between the inclined end face and the first optical connection end face, and having an inner peripheral face and an outer peripheral face;
The inclined end surface is formed on the stepped portion of the cylindrical portion is discontinuous, the optical coupler, wherein the light is comprising a second optical connection end face you exit and / or entrance.   2. The optical coupler according to claim 1, wherein the first optical connection end face is formed by at least one prism body having a top portion extending along a circumferential direction thereof.   2. The optical coupler according to claim 1, wherein the first optical connection end surface is formed of a plurality of prism bodies whose top portions extend radially with respect to the cylindrical portion.   4. The optical coupler according to claim 3, wherein a height of the top portion is lowered toward the inner peripheral surface side of the cylindrical portion.   The optical coupler according to claim 3, wherein the height of the top is constant.   6. The optical coupler according to claim 1, wherein the inclined end surface is formed by a plurality of prism bodies whose tops extend radially with respect to the cylindrical portion.   The light guide further includes a transparent light guide that projects from the second optical connection end surface in a tangential direction of the inner peripheral surface and the outer peripheral surface of the cylindrical portion, and to which a light source and / or a light detection sensor is connected. The optical coupler according to any one of claims 1 to 6, wherein the optical coupler is formed integrally with the cylindrical portion.   The optical coupler according to claim 1, wherein a light source and / or a light detection sensor is disposed on the second optical connection end face.

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