Optical coupling member and optical connector using the same

The present invention provides an optical coupling member and an optical connector using the optical coupling member, capable of improving the efficiency of an assembly work of the optical connector and positioning optical fibers in the optical connector with high accuracy. The optical coupling member (10) has: holding members (11) for being able to hold optical fibers (21) that are inserted from insertion holes (11a) formed at end parts; lenses housed in housing parts formed at opposite end parts of the holding members (11); and a joining member (13) for connecting the holding members (11) as aligned in parallel to each other, the joining member being formed of an elastic material.

TECHNICAL FIELD

The present invention relates to an optical coupling member for coupling a plurality of optical fibers to an optical connector and also to the optical connector using the optical coupling member.

BACKGROUND ART

In an optical fiber communication system, an optical connector with a plurality of optical fibers aligned at predetermined intervals is used to connect to another optical device or optical connector. Alignment of the optical fibers is generally performed by shaft alignment using positioning grooves such as V-shaped grooves provided at predetermined intervals.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Patent Application Publication No. 2002-72016

SUMMARY OF THE INVENTION

Technical Problem

However, in the above-described method for alignment of the optical fibers, placement of the optical fibers in the positioning grooves takes much time, which causes a problem of inefficiency of the assembly work of the optical connector.

The present invention was made in view of the foregoing and aims to provide an optical coupling member and an optical connector using the same, capable of positioning optical fibers in the optical connector with high accuracy and improving the efficiency of the assembly work of the optical connector.

Solution to Problem

The present invention provides an optical coupling member characterized by comprising: holding members for being able to hold optical fibers that are inserted from insertion holes formed at end parts of the holding members; lenses housed in housing parts formed at opposite end parts of the holding members; and a joining member for connecting the holding members as aligned, the joining member being formed of an elastic material.

According to the above-described optical coupling member, as the plural holding members capable of holding the optical fibers are connected in parallel to each other by the joining member, it is possible to position the optical fibers with high accuracy without the need to align the optical fibers one by one in positioning grooves in an optical connector. Therefore, it is possible to position the optical fibers highly accurately thereby to assemble the optical connector and also possible to improve the efficiency of the assembly work of the optical connector.

In the above-described optical coupling member, the joining member may cover the holding members around evenly. In this case, as a part of the joining member holds circumferences of the holding members evenly, it is possible to hold the holding members stably.

Besides, in the above-described optical coupling member, the joining member may cover a part of each of the holding members in a radial direction. In this case, as a radial part of each holding member is not covered by the joining member and exposed, it is possible to arrange holding members as a whole on positioning grooves in the optical connector. Therefore, the structure of the optical connector is simplified, thereby making it possible to reduce the manufacturing cost.

Further, in the above-described optical coupling member, a groove part may be formed in the joining member, between every adjacent two of the holding members.

Furthermore, in the above-described optical coupling member, a through hole may be formed in the joining member, between every adjacent two of the holding members.

Furthermore, in the above-described optical coupling member, the through hole may comprise a plurality of through holes arranged in parallel to the holding members.

In these case, as the groove part or through holes are formed thereby to improve the flexibility of the joining member between the holding members, it is possible to improve the flexibility of the optical coupling member as a whole and improve the efficiency of the assembly work of the optical connector.

Furthermore, in the above-described optical coupling member, the joining member may have an opening which makes parts of the holding members exposed when seen from the above.

In this case, as the flexibility of the joining member is improved at the position where the opening is formed, it is possible to improve the flexibility of the optical coupling member as a whole and improve the efficiency of the assembly work of the optical connector.

Further, in the above-described optical coupling member, the optical fibers and the lenses may be each positioned by being in contact with a circumferential wall surface formed by a recess that is provided in a part of an outer circumferential surface of each of the holding members. In this case, as the end surfaces of the optical fibers and the lenses are positioned in contact with the circumferential wall surfaces, it is possible to assure high positioning accuracy of the optical fibers and the lenses.

The present invention also provides an optical connector characterized by connecting the optical coupling member according to any of the above-described aspects. In this case, as the plural holding members capable of holding the optical fibers are connected in parallel to each other by the joining member, it is possible to position the optical fibers with high accuracy without the need to align the optical fibers one by one in positioning grooves in an optical connector. Therefore, it is possible to position the optical fibers highly accurately thereby to assemble the optical connector and also possible to improve the efficiency of the assembly work of the optical connector.

Technical Advantage of the Invention

According to the present invention, it is possible to improve the efficiency of the assembly work of the optical connector and also possible to make the optical connector assembled by positioning the optical fibers in the optical connector with high accuracy.

DESCRIPTION OF EMBODIMENTS

With reference to the attached drawings, embodiments of the present invention will be described in detail below.

First description is made, with reference toFIGS. 1 and 2, about an optical connector to which an optical coupling member according to an embodiment of the present invention is connected.FIGS. 1 and 2are diagrams each for explaining an example of an optical connector to which the optical coupling member according to the embodiment of the present invention is connected.FIG. 1Ais a perspective view illustrating an example of the optical connector to which the optical coupling member according to the embodiment of the present invention is connected,FIG. 1Bis a perspective view illustrating the optical connector illustrated inFIG. 1Afrom which a cover member of a housing is removed, andFIG. 1Cis a perspective view illustrating the optical connector illustrated inFIG. 1Bfrom which the optical coupling member is removed.FIG. 2Ais an top view illustrating an example of the optical connector to which the optical coupling member according to the embodiment of the present invention is connected,

FIG. 2Bis a cross sectional view seen along the arrow A-A inFIG. 2A,FIG. 2Cis a cross sectional view seen along the arrow B-B inFIG. 2AandFIG. 2Dis a cross sectional view seen along the arrow C-C inFIG. 2A.

As illustrated inFIG. 1A, the optical connector1has an approximately rectangular solid shaped housing2. At an end part2aof the housing2, a plurality of optical fibers21jutting from a multi-core optical fiber cable20are inserted, and at the opposite end part2bof the housing2, an optical coupling member10mounted on the optical fibers21is partially exposed. The optical fibers21used here may be, without any limitations, publicly known glass optical fibers, plastic optical fibers or H-PCF (Hard Plastic Clad Fiber).

As illustrated inFIG. 1B, in the optical connector1, on a base2cof the housing2from which the cover member2dis removed, the optical fibers21and the optical coupling member10are arranged. In the embodiment of the present invention, four optical fibers21are jutting from the multi-core optical fiber cable20. The optical coupling member10is configured to include holders11and a joining member13for joining the holders11in parallel to each other. The number of holders11is the same as the number of the optical fibers21(four in the embodiment of the present invention). The optical coupling member10is mounted on the optical fibers21by inserting the optical fibers21into the holders11via insertion holes11aprovided at end parts of the holders11.

As illustrated inFIG. 1C, in the optical connector1, there are provided in the base2cof the housing2near the opposite end part2b, positioning grooves23and24and a recess part25for positioning and fixing the optical coupling member10. In the positioning grooves23, the holders11in the optical coupling member10are arranged. In the positioning grooves24, the optical fibers21jutting from the insertion holes11aof the holders11are arranged therein. In the recess part25, the joining member13in the optical coupling member10is arranged therein.

In the present embodiment, the number of the positioning grooves23is four as is the same with the holders11and the optical fibers21, and the positioning grooves23are arranged in parallel and equally spaced from each other. The width of each of the positioning grooves23is formed to be approximately equal to the diameter of each holder11. The positioning grooves24are provided as connected to the respective positioning grooves23and its width is approximately equal to the diameter of each optical fiber21. The recess part25is configured to have such a size that the joining member13can be housed therein and the recess part25is provided at an intermediate part of the positioning grooves23so as to divide the positioning grooves23.

As illustrated inFIG. 2A, in the optical connector1, parts of the holders11(a part of the optical coupling member10) jutting from the opposite end part2bare aligned as equally spaced from each other and the respective jutting parts are equal in length from each other.

As illustrated inFIG. 2B, the positioning grooves23in the optical connector1each have a V shaped cross section. In the positioning grooves23, the holders11in the optical coupling member10are placed therein and aligned. When the holders11are arranged on the positioning grooves23, their lower half parts are housed in the positioning grooves23and upper half parts are jutting from the positioning grooves23.

As illustrated inFIG. 2C, the recess part25in the optical connector1is formed to have a U shaped cross section and its depth is formed approximately equal to half of the thickness of a part of the optical coupling member10where the joining member13is provided. When the joining member13is arranged in the recess part25in the optical connector1, its lower half part is housed in the recess part25and its upper half part juts from the recess part25.

In the optical connector1, the cover member2dof the housing2is in contact with an upper end part of the joining member13. With this structure, the joining member13receives a downward force from the cover member2dso that the optical coupling member10as a whole is fixed as pressed toward the base2c.

As illustrated inFIG. 2D, the optical coupling member10is configured such that when the optical coupling member10is positioned by the positioning grooves23and24and the recess part25, its tip end part juts from the opposite end part2bof the housing2.

The following description is made about the structure of the optical coupling member10according the embodiment of the present invention connected to this optical connector1.

The optical coupling member10according to the first embodiment will be described based onFIG. 3.FIG. 3provides explanatory views each illustrating the optical coupling member according to the first embodiment.FIG. 3Ais a perspective view of the optical coupling member10according to the first embodiment,FIG. 3Bis a top view of the optical coupling member10,FIG. 3Cis a front view of the optical coupling member10andFIG. 3Dis a cross sectional view seen along the arrow D-D inFIG. 3B.

As illustrated inFIGS. 3A to 3D, the optical coupling member10is configured to have the holders11as holding members each having an approximately cylindrical shape, lenses12held at end parts of the respective holders11and the joining member13for joining the plural holders11in parallel to each other.

The holder11is formed, for example, by molding with a metal material, a resin material and a ceramics material. The metal material for forming the holder11may be, for example, stainless steel, a copper material or the like. The resin material for forming the holder11may be, for example, polypropylene (PP), acrylonitrile-butadiene-styrene copolymer (ABS), polyacetal (POM), polycarbonate (PC), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polybutylene naphthalate (PEN), polyethersulfone (PES), polyphenylene ether (PPE), Polyamide imide (PAI), Polyether imide (PEI) or the like. The holder11is formed by performing various molding works such as injection molding, extrusion molding and press molding on these resin materials.

The ceramics material for forming the holders11may be, for example, zirconia, alumina, silicon nitride, silicon carbide or the like. The holder11is formed by performing various molding works such as injection molding, extrusion molding and press molding on these ceramics materials. Further, the material for forming the holder11may be glass or crystallized glass.

As illustrated inFIG. 3D, at an end part of the holder11at the lens12side, there is formed an opening11b. Inside this opening11b, a housing part11cis formed for housing the lens12. This housing part11cis formed to have a size slightly smaller than the diameter of the lens12so that the lens12can be pressure-inserted therein.

Inside the holder11, a through hole11dis formed to have an approximately same diameter as the outer diameter of the optical fiber21. This through hole11dis provided to be connected to the insertion hole11aand the housing part11c.

In each holder11, a plurality of positioning recesses11eare formed. These positioning recesses11eare provided on the outer circumference of the holder11, between the housing part11cand the through hole11d, for positioning the lens12and the optical fiber21(seeFIG. 4). These positioning recesses11eare formed by performing a pressure work on the holder11using a machine tool.

Further, in the holder11, there are provided a plurality of recesses11f. These recesses11fare formed, after the optical fiber21is inserted into the holder11, by performing a pressure work on the outer circumferential surface of the holder11using a machine tool. These recesses11fare provided for fixing the optical fiber21by sandwiching the optical fiber21between the bottom wall surfaces. InFIGS. 3A to 3D, the recesses11fare already formed. The optical fiber21inserted into the holder11may be fixed by an adhesive agent.

The lens12is a ball lens having a spherical shape formed by molding with a glass material or a plastic material. As illustrated inFIG. 3D, the lens12is housed in the housing part11cof the holder11. InFIGS. 3A to 3D, the lens12is arranged as wholly housed in the holder11, however, a part of the lens12may be exposed from the opening11d.

The joining member13is formed of an elastic material (stretchable material) such as elastomer and is provided to cover the holders11around evenly. The joining member13has an approximately rectangular solid shape and is arranged at the position to connect the center positions of the holders. The length of a side of the joining member13along the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member13is formed to be larger than the diameter of the holder11(seeFIG. 3C). With these configurations, the joining member13is able to hold the holders11with stable balance reliably.

The joining member13is formed to be integral with the holders11by insertion molding or by inserting the holders11into the joining member13.

In the joining member13, there are provided groove parts13aeach having a V-shaped cross section and being formed between every adjacent holders11, in parallel to the holders11. The groove parts13aare configured in pairs such that two groove parts13are depressed from the respective opposite surfaces of the joining member13toward the center. With these groove parts13a, it is possible to improve flexibility between the holders11in the joining member13, thereby improving the flexibility of the optical coupling member10as a whole and also improving the efficiency of the assembly work of the optical connector1.

Here, the groove parts13ahave been described as each having a V shaped cross section. However, the shape of each groove part13ais not limited to this, and may be modified appropriately. For example, the groove part may have an arc shaped cross section or square cross section.

Next description is made about a method for positioning the optical fiber21and the lens12using the positioning recess11e, with reference toFIG. 4.FIG. 4is an enlarged view of a part around the positioning recess11ewhen the optical fiber21is inserted into the holder11.

As illustrated inFIG. 4, the positioning recess11eis configured such that the angle of a part facing the lens12and the angle of a part facing the optical fiber21become different with respect to the plane orthogonal to the insertion direction of the optical fiber21illustrated by the arrow E (for example, the plane F that is arranged in parallel with the end surface of the optical fiber21illustrated inFIG. 4and passes through the center of the positioning recess11e). This positioning recess11eis formed by performing a pressure work using machine tools with different-shaped tip ends.

The positioning recesses11eare provided on the same circumference of the holder11as equally spaced from each other (three positioning recesses in this embodiment). In the optical coupling member10, the plural positioning recesses11eare formed by performing a pressure work on the outer circumference sides of the holders11using the above-mentioned machine tools simultaneously. The lens12and the optical fiber21are in contact, at plural points, with the plural positioning recesses11eformed on the same circumference and therefore, it is possible to position the lens12and the optical fiber21with high accuracy.

In accordance with the shape of each positioning recess11e, a circumferential wall surface formed by the positioning recess11eis also configured such that the angle of a part facing the lens12and the angle of a part facing the optical fiber21become different with respect to the plane orthogonal to the insertion direction of the optical fiber21as illustrated by the arrow E (for example, the plane F that is arranged in parallel with the end surface of the optical fiber21illustrated inFIG. 4and passes through the center of the positioning recess11e). Of this circumferential wall surface, the part facing the lens12is called a circumferential wall surface11e1and the part facing the optical fiber21is called a circumferential wall surface11e2.

In the circumferential wall surface11e1formed at the part facing the lens12in the positioning recess11e, the angle θ1of the circumferential wall surface11e1with respect to the plane orthogonal to the insertion direction of the optical fiber21as illustrated by the arrow E (for example, plane G that is arranged in parallel with the end surface of the optical fiber21illustrated inFIG. 4and passes through a base end part of the positioning recess11e) is 0 to 45 degrees, inclusive. As the circumferential wall surface11eiformed by the positioning recess11eis used, it is possible to position the lens12while supporting a part of the lens21at the optical fiber21side, thereby enhancing the positioning accuracy of the lens12.

On the other hand, in the circumferential wall surface11e2formed at the part facing the optical fiber21in the positioning recess11e, the angle θ2of the circumferential wall surface11e2with respect to the plane orthogonal to the insertion direction of the optical fiber21illustrated by the arrow E (for example, the plane H that is arranged in parallel with the end surface of the optical fiber21illustrated inFIG. 4) is 0 to 20 degrees, inclusive. As the circumferential wall surface11e2formed by the positioning recess11eis used, for example, when the end surface of the optical fibers21is arranged at grade, it is possible to position the optical fibers21in contact with the circumferential wall surface11e2, thereby assuring the positioning accuracy of the optical fiber21.

Here, in the above description, the plural positioning recesses11eare provided by way of example. However, this is not intended to limit the present invention. A positioning recess11emay be provided as an annular recess part formed over the whole circumferential surface of the holder11, between the housing part11cand the through hole11d.

Next description is made about the assembly process of the optical connector1using the optical coupling member10according to the first embodiment. The assembly process of the optical connector1includes a step (a) of mounting the optical coupling member10on the optical connector1and a step (b) of inserting optical fibers21into the optical coupling member10. Each of the steps will be described in detail below.

First, the optical coupling member10is arranged as being positioned using the positioning grooves23and24and the recess part25of the optical connector1(seeFIGS. 1B and 1C). The pitch of the positioning grooves13and the pitch of the holders11connected by the joining member13are set to be equal to each other, and by arranging the joining member13on the recess25and arranging the holders11on the positioning grooves23, it is possible to mount the holders11on the optical connector1, in parallel to each other.

Further, as the joining member13is formed of an elastic material such as elastomer and has groove parts13a, thereby improving the flexibility of the joining member13. Accordingly, even if the pitch of the positioning grooves23and the pitch of the holders11connected by the joining member13are slightly different, it is possible to arrange the holders11on the positioning groove23and position them accurately.

Next, each optical fiber21is inserted via the insertion hole11aof the holder11into the through hole11d. The optical fiber21is guided by the inner wall that defines the through hole11dand reaches the positioning recess11e. Once the optical fiber21gets in contact with the circumferential wall surface11e2formed by the positioning recess11e, the insertion work is finished.

After the optical fiber21is positioned by the positioning recess11e, a plurality of recesses11fare formed in a part of the holder11by performing a pressure work using a machine tool thereby to fix the optical fiber21.

Once these steps (a) and (b) are finished, the optical connector1as illustrated inFIGS. 1 and 2is obtained. Here, in the assembly process of the optical connector1, the order of the steps (a) and (b) is not limited to this, but may be reversed like the order of the steps (b) and (a).

As described above, as the plural holders11capable of supporting the optical fibers21are connected in parallel with each other by the joining member13in the optical coupling member10, it is possible to position the optical fibers21with high accuracy without the need to align the optical fibers21one by one in the positioning grooves23in the optical connector1. Accordingly, it is possible to improve the efficiency of the assembly work of the optical connector1and allow highly accurate positioning of the optical fibers21in the optical connector1.

The optical coupling member10according to the first embodiment has been described such that the groove parts13aare formed at parts of the joining member13. An optical coupling member according to the second embodiment is different from the optical coupling member10according to the first embodiment in that such groove parts are not formed in the second embodiment. In the following description, the following description is made about the structure of the optical coupling member according to the second embodiment, focusing on the difference from the optical coupling member10according to the first embodiment.

FIG. 5provides diagrams each for explaining an optical coupling member30according to the second embodiment.FIG. 5Ais a perspective view of the optical coupling member30according to the second embodiment,FIG. 5Bis a top view of the optical coupling member30,FIG. 5Cis a front view of the optical coupling member30andFIG. 5Dis a side view of the optical coupling member30. In the second embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member30ais formed by molding with an elastic material such as elastomer and is provided to cover the holders11around evenly. The joining member30ais formed to have an approximately rectangular solid shape and is arranged at the position to connect the centers of the holders11. The length of a side of the joining member30aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member30ais formed to be larger than the diameter of the holders11(seeFIG. 5C).

Thus, according to the optical coupling member30of the second embodiment, the structure of the joining member30ais able to be simplified and therefore, it is possible to reduce the manufacturing cost of the joining member30aand finally reduce the manufacturing cost of the optical coupling member30.

The optical coupling member10according to the first embodiment has been described such that the groove parts13aare formed at parts of the joining member13. An optical coupling member according to the third embodiment is different from the optical coupling member10according to the first embodiment in that an opening is formed instead of such groove parts. The following description is made about the structure of the optical coupling member according to the third embodiment, focusing on the difference from the optical coupling member10according to the first embodiment.

FIG. 6provides diagrams each for explaining an optical coupling member31according to the third embodiment.FIG. 6Ais a perspective view of the optical coupling member31according to the third embodiment,FIG. 6Bis a top view of the optical coupling member31,FIG. 6Cis a front view of the optical coupling member31, andFIG. 6Dis a side view of the optical coupling member31.

In the third embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member31ais formed by molding with an elastic material such as elastomer and is provided to cover the holders11around evenly. In the joining member31a, an opening31bis formed which makes parts of the holders11seen from the above. The joining member31ais arranged at the position to connect the centers of the holders11. The length of a side of the joining member31aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member31ais formed to be larger than the diameter of the holder11(seeFIG. 6C).

Thus, according to the optical coupling member31of the third embodiment, as the joining member31ahas the opening31bformed to make parts of the holders11exposed, it is possible to improve the flexibility of the joining member31aat the position where the opening31bis formed, thereby improving the flexibility of the optical coupling member31as a whole and also improving the efficiency of the assembly work.

The optical coupling member10according to the first embodiment has been described such as the groove parts13aare formed at parts of the joining member13. An optical coupling member according to the fourth embodiment is different from the optical coupling member10according to the first embodiment in that through holes are formed instead of such groove parts. The following description is made about the structure of the optical coupling member according to the fourth embodiment, focusing on the difference from the optical coupling member10according to the first embodiment.

FIG. 7provides diagrams each for explaining an optical coupling member32according to the fourth embodiment.FIG. 7Ais a perspective view of the optical coupling member32according to the fourth embodiment,FIG. 7Bis a top view of the optical coupling member32,FIG. 7Cis a front view of the optical coupling member32, andFIG. 7Dis a side view of the optical coupling member32. In the fourth embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member32ais formed by molding with an elastic material such as elastomer and is provided to cover the holders11around evenly. The joining member32ahas an approximately rectangular solid shape and is arranged at the position to connect the centers of the holders11. The length of a side of the joining member32aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member32ais formed to be larger than the diameter of the holder11(seeFIG. 7C).

In the joining member32a, through holes32bare formed each between every adjacent holders11, and each through hole32bhas a rectangular shape and its long side is provided in parallel with the holders11. According to the optical coupling member32of the fourth embodiment, as the joining member32ahas the rectangular through holes32b, it is possible to improve the flexibility of the joining member32abetween the holders11, thereby improving the flexibility of the optical joining member32as a whole and also improving the efficiency of the assembly work.

The optical coupling member32according to the fourth embodiment has been described such as the rectangular through holes32bare formed at parts of the joining member32a. An optical coupling member according to the fifth embodiment is different from the optical coupling member32according to the fourth embodiment in that a plurality of through holes are arranged instead of the rectangular through holes. The following description is made about the structure of the optical coupling member according to the fifth embodiment, focusing on the difference from the optical coupling member32according to the fourth embodiment.

FIG. 8provides diagrams each for explaining an optical coupling member33according to the fifth embodiment.FIG. 8Ais a perspective view of the optical coupling member33according to the fifth embodiment,FIG. 8Bis a top view of the optical coupling member33,FIG. 8Cis a front view of the optical coupling member33andFIG. 8Dis a side view of the optical coupling member33. In the fifth embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member33ais formed by molding with an elastic material such as elastomer and is provided to cover the holders11around evenly. The joining member33ahas an approximately rectangular solid shape and is arranged at the position to connect the centers of the holders11. The length of a side of the joining member33aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member33ais formed to be larger than the diameter of the holder11(seeFIG. 8C).

In the joining member33a, a plurality of through holes33bare formed between every adjacent holders11in parallel with the holders11. According to the optical coupling member33of the fifth embodiment, as the joining member33ahas the through holes33b, it is possible to improve the flexibility of the joining member33abetween the holders11, thereby improving the flexibility of the optical coupling member32as a whole and also improving the efficiency of the assembly work.

The optical coupling member30according to the second embodiment has been described such that the joining member30acovers the holders11around evenly. An optical coupling member according to the sixth embodiment is different from the optical coupling member30according to the second embodiment in that a joining member covers parts of the holders11along the radial direction. The following description is made about the structure of the optical coupling member according to the sixth embodiment, focusing on the different from the optical coupling member30according to the second embodiment.

FIG. 9provides diagrams each for explaining an optical coupling member34according to the sixth embodiment.FIG. 9Ais a perspective view of the optical coupling member34according to the sixth embodiment,FIG. 9Bis a bottom view of the optical coupling member34,FIG. 9Cis a front view of the optical coupling member34arranged in the optical connector1, andFIG. 9Dis a side view of the optical coupling member34. In the sixth embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member34ais formed by molding with an elastic material such as elastomer. The joining member34ahas an approximately rectangular solid shape and is arranged at the positions to connect the centers of the holders11. The length of a side of the joining member34aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member34ais formed to be slightly larger than the radius of the holder11(seeFIG. 9D). With this structure, a radial part of each of the holders (a part of the holder11in the radial direction) is covered by the joining member34aand the other part juts from the joining member34a. The joining member34acovers the holders11by half in the radial direction (seeFIG. 9C).

Thus, according to the optical coupling member34of the sixth embodiment, as each of the holders11has a part not covered by the joining member34aand jutting therefrom, it is possible to arrange all the holders11in the positioning grooves23without forming the recess part25in the optical connector1(seeFIG. 9C). Therefore, it is possible to simplify the structure of the optical connector1and to reduce its manufacturing cost.

The optical coupling member34according to the sixth embodiment has been described such that the joining member34acovers the holders11by half in the radial direction. An optical coupling member according to the seventh embodiment is different from the optical coupling member34according to the sixth embodiment in the covering range where the joining member covers the holders11in the radial direction. The following description is made about the structure of the optical coupling member according to the seventh embodiment, focusing on the difference from the optical coupling member34according to the sixth embodiment.

FIG. 10provides diagrams each for explaining an optical coupling member35according to the seventh embodiment.FIG. 10Ais a perspective view of the optical coupling member35according to the seventh embodiment,FIG. 10Bis a bottom view of the optical coupling member35,FIG. 10Cis a front view of the optical coupling member35arranged in the optical connector1, andFIG. 10Dis a side view of the optical coupling member35. In the seventh embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member35ais formed by molding with an elastic material such as elastomer. The joining member35ahas an approximately rectangular solid shape and is arranged at the position to connect the centers of the holders11. The length of a side of the joining member35aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member35ais larger than the radius of the holder11and smaller than the diameter of the holder11(seeFIG. 10D). With this structure, a radial part of each holder11is covered by the joining member35aand the other part juts from the joining member35a. The joining member35acovers each holder11by three fourths in the radial direction (seeFIG. 10C).

Thus, according to the optical coupling member35of the seventh embodiment, as the holders11have parts not covered by the joining member35abut exposed, it is possible to arrange the holders11as a whole on the positioning grooves23without forming the recess part25in the optical connector1(seeFIG. 10C). Therefore, the structure of the optical connector1is simplified, thereby making it possible to reduce the manufacturing cost.

Further, in the optical coupling member35, as the joining member35acovers the holders11by three fourths in the radial direction, it is possible to hold the holders11more stably as compared with the optical coupling member34according to the sixth embodiment.

The optical coupling member31according to the third embodiment has been described such that the joining member31ahaving the opening31bcovers the holders11around evenly. An optical coupling member according to the eighth embodiment is different from the optical coupling member31according to the third embodiment in that a joining member having an opening covers a part of each holder11in the radial direction. The following description is made about the structure of the optical coupling member according to the eighth embodiment, focusing on the difference from the optical coupling member31according to the third embodiment.

FIG. 11provides diagrams each for explaining an optical coupling member36according to the eighth embodiment.FIG. 11Ais a perspective view of the optical coupling member36according to the eighth embodiment,FIG. 11Bis a bottom view of the optical coupling member36,FIG. 11Cis a front view of the optical coupling member36arranged in the optical connector1, andFIG. 11Dis a side view of the optical coupling member36. In the eighth embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

The joining member36ais formed by molding with an elastic material such as elastomer. In the joining member36a, an opening36ais formed which makes a part of each holder11exposed when seen from the above. The joining member36ais arranged at the position to connect the centers of the holders11. The length of a side of the joining member36aalong the longitudinal direction of each holder11is approximately half of the length of the holder11. The thickness of the joining member36ais formed to be slightly larger than the radius of the holder11(seeFIG. 11D). With this structure, a radial part of each holder11is covered by the joining member36aand the other part juts from the joining member36a. The joining member36acovers each holder11by half in the radial direction (seeFIG. 11C).

Thus, according to the optical coupling member36of the eighth embodiment, as the holders11have parts not covered by the joining member36aand exposed, it is possible to arrange all the holders11on the positioning grooves23without forming the recess part25in the optical connector1(seeFIG. 11C). Therefore, the structure of the optical connector1is simplified, thereby making it possible to reduce the manufacturing cost.

Besides, according to the optical coupling member36of the eighth embodiment, as the joining member36ahas the opening36bwhich makes a part of each holder11exposed, the flexibility of the joining member36ais improved at the position where the opening36bis formed, thereby making it possible to improve the flexibility of the optical coupling member36as a whole and also improve the efficiency of the assembly work.

The optical coupling member10according to the first embodiment has been described such that the joining member13is arranged at the position to connect the centers of the holders11. An optical coupling member according to the ninth embodiment is different from the optical coupling member10according to the first embodiment in that a joining member connects parts of the holders11near respective insertion holes11a. The following description is made about the structure of the optical coupling member according to the ninth embodiment, focusing on the difference from the optical coupling member10according to the first embodiment.

FIG. 12provides diagrams each for explaining an optical coupling member37according to the ninth embodiment.FIG. 12Ais a perspective view of the optical coupling member37according to the ninth embodiment,FIG. 12Bis a top view of the optical coupling member37,FIG. 12Cis a front view of the optical coupling member37andFIG. 12Dis a side view of the optical coupling member37. In the ninth embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

A joining member37ais formed by molding with an elastic material such as elastomer and covers the holders11around evenly. The joining member37ais arranged at the position to connect parts of the holders11near the respective insertion holes11aand covers end parts of the holders11where the insertion holes11aare formed. The joining member37ahas an approximately rectangular solid shape and the length of a side of the joining member37aalong the longitudinal direction of each holder11is approximately one fifth of the length of the holder11. The thickness of the joining member37ais larger than the diameter of the holder11(seeFIG. 12C).

Thus, according to the optical coupling member37according to the ninth embodiment, as the joining member37ais provided at the position to connect the parts of the holders11near the respective insertion holes11a, it is possible to arrange all the holders11on the positioning grooves23without forming the recess part15to cut across the positioning grooves23in the optical connector1. Therefore, the structure of the optical connector1is simplified, thereby making it possible to reduce the manufacturing cost.

Further, according to the optical coupling member37of the ninth embodiment, as the structure of the joining member37ais simplified, thereby making it possible to reduce the manufacturing cost of the joining member37aand consequently to reduce the manufacturing cost of the optical coupling member37.

The optical coupling member37according to the ninth embodiment has been described such that the joining member37ais arranged covering the insertion holes11aof the holders11. An optical coupling member according to the tenth embodiment is different from the optical coupling member37according to the ninth embodiment in that a joining member does not cover the insertion holes11aof the holders11. The following description is made about the structure of the optical coupling member according to the tenth embodiment, focusing on the difference from the optical coupling member37according to the ninth embodiment.

FIG. 13provides diagrams each for explaining an optical coupling member38according to the tenth embodiment.FIG. 13Ais a perspective view of the optical coupling member38according to the tenth embodiment,FIG. 13Bis a top view of the optical coupling member38,FIG. 13Cis a front view of the optical coupling member38andFIG. 13Dis a side view of the optical coupling member38. In the tenth embodiment, common structural parts with the optical coupling member10according to the first embodiment are denoted by like reference numerals and their explanation is omitted here.

The joining member38ais formed by molding with an elastic material such as elastomer and covers the holders11around evenly. The joining member38ais arranged at the position to connect parts of the holders11near the respective insertion holes11ain such a manner as to make the insertion holes11aexposed. The joining member38ahas an approximately rectangular solid shape and the length of a side of the joining member38aalong the longitudinal direction of each holder11is shorter than that of the joining member37aof the optical coupling member37according to the ninth embodiment. The thickness of the joining member38ais larger than the diameter of the holder (seeFIG. 13C).

Thus, according to the optical coupling member38of the tenth embodiment, as the joining member38ais provided near end parts of the holders11, it is possible to arrange all the holders11on the positioning grooves23without forming the recess part25to cut across the positioning grooves23in the optical connector1. Consequently, the structure of the optical connector1is simplified, thereby making it possible to reduce the manufacturing cost.

Further, according to the optical coupling member38of the tenth embodiment, as the structure of the joining member38ais simplified, it is possible to reduce the manufacturing cost of the joining member38aand consequently reduce the manufacturing cost of the optical coupling member38.

Furthermore, according to the optical coupling member38of the tenth embodiment, as the insertion holes11aof the holders11are exposed as compared with the optical coupling member37according to the ninth embodiment, it is possible to facilitate insertion of the optical fibers21.

The optical coupling member10according to the first embodiment has been described such that the holders11are placed on the positioning grooves23of the optical connector1thereby to assemble the optical connector1. An optical coupling member according to the eleventh embodiment is different from the optical coupling member according to the first embodiment in that an optical connector is assembled by inserting holders into insertion holes of the optical connector. The following description is made about the structure of the optical coupling member according to the eleventh embodiment and the structure of the optical connector to which the optical coupling member is connected, focusing on the differences from the optical coupling member10according to the first embodiment and the optical connector1to which the optical coupling member10is connected.

FIGS. 14 and 15are diagrams each for explaining an example of an optical connector to which an optical coupling member according to the eleventh embodiment is connected.FIG. 14Ais a perspective view illustrating an example of the optical connector to which the optical coupling member according to the eleventh embodiment is connected,FIG. 14Bis a perspective view illustrating the optical connector illustrated inFIG. 14Afrom which a cover member of a housing is removed,FIG. 14Cis a perspective view illustrating the optical connector illustrated inFIG. 14Bfrom which the optical coupling member is removed,FIG. 15Ais a top view illustrating an example of the optical connector to which the optical coupling member according to the eleventh embodiment is connected,FIG. 15Bis a cross sectional view taken along the arrow A-A inFIG. 15A, andFIG. 15Cis a cross sectional view taken along the arrow C-C inFIG. 15A. In the eleventh embodiment, common structural parts with the optical coupling member according to the first embodiment and the optical connector1to which the optical coupling member10is connected are denoted by like reference numerals and their explanation is omitted here.

As illustrated inFIG. 14A, the optical connector100has an approximately rectangular solid shaped housing2. At an end part2aof the housing2, a plurality of optical fibers21are inserted which are jutting from a multi-core optical fiber cable20. At the opposite end part2bof the housing2, parts of the optical coupling member39mounted on the optical fibers21are jutting therefrom.

As illustrated inFIG. 14B, in the optical connector100, the optical fibers21and the optical coupling member39are arranged on the base2cfrom which a cover member2dof the housing2is removed. In the present embodiment, four optical fibers21are jutting from the multi-core optical fiber cable20. The optical coupling member39is configured to have holders11that are equal in number to the optical fibers21(four in this embodiment) and the joining member39afor connecting the holders11in parallel to each other. The optical coupling member39is fixed to the optical fibers21by inserting the optical fibers21into the holders11.

As illustrated inFIG. 14C, the joining member39ain the optical coupling member39is arranged at the position to connect the parts of the holders11near their respective insertion holes11aand covers the end parts of the holders11where the insertion holes11aare formed. The joining member39ais formed by molding with an elastic material such as elastomer and covers the holders11around evenly. The joining member39amay be configured to have a groove part with a V shaped cross section formed between every adjacent holders11and in parallel to the holders11.

In the optical connector100, insertion holes101are formed on the base2cof the housing2, near the opposite end part2b, for positioning and fixing the optical coupling member39. In the insertion holes101, the holders11of the optical coupling member39are inserted thereinto from one end part2aside. The optical coupling member39inserted into the insertion holes101is positioned once a part of the joining member39areaches the insertion holes101.

In the present embodiment, the number of insertion holes101is four in accordance with the number of the holders11or optical fibers21, and the insertion holes101are provided in parallel and equally spaced. Each of the insertion holes101is configured to have a diameter approximately equal to the diameter of the holder11.

As illustrated inFIG. 15A, in the optical connector100, parts of the optical coupling member39jutting from the opposite end part2bare aligned at even intervals and the lengths of the jutting parts are equal to each other.

As illustrated inFIG. 15B, the holders11of the optical coupling member39are inserted into the insertion holes101in the optical connector100and aligned.

As illustrated inFIG. 15C, the optical coupling member39is configured such that when the optical coupling member39is positioned by bringing a part of the joining member39ainto contact with the insertion holes101in the optical connector100, the tip end parts of the optical coupling member39jut from the opposite end part2bof the housing2by a predetermined length.

As described above, as the plural holders11capable of supporting the optical fibers21are connected in parallel to each other by the joining member39ain the optical coupling member39, it is possible to position the optical fibers21with high accuracy without need to insert the optical fibers21into the insertion holes101in the optical connector100one by one and align them. Therefore, it is possible to improve the efficiency of the assembly work of the optical connector100and also possible to assemble the optical connector100by positioning the optical fibers21in the optical connector100with high accuracy.

Here, the present invention is not limited to the above-described embodiments, but may be embodied in various forms. In the above-described embodiments, the size and shape are not limited to the sizes and shapes illustrated in the attached drawings and may be modified appropriately as far as they fall within the scope where the effect of the present invention is produced. Other modifications may be also made appropriately without departing from the scope of the purpose of the present invention.

In the above-described embodiments, each holder11has an approximately cylindrical shape, however the shape of the holder11is not limited to this and may be modified appropriately. The holder11may take any shape as far as a housing part11cfor housing a lens12is formed at an end part and an insertion hole11afor inserting an optical fiber21is formed at the opposite end part. For example, the holder may take a square-tube shape (that is, tube body of which a cross section orthogonal to the insertion direction of the optical fiber21is a square shape).

Further, in the above-described embodiments, each positioning groove23of the optical connector1has been described as having a V-shaped cross section. However, the shape of the positioning groove23is not limited to this and may be modified appropriately. The positioning groove23may take any shape in accordance with the shape of the holder11. For example, the cross section of the positioning groove23may have a circular arc shape or a square shape.

In the above-described embodiments, the lens12and the optical fibers21have been described as being positioned while a part of each lens12and a part of each optical fiber21are in contact with the circumferential wall surfaces formed by the positioning recess11eformed in each holder11. However, the method for positioning the lens12and the optical fibers21is not limited to this and may be modified appropriately. For example, each lens12and each optical fiber21may be positioned by bringing only one of the lens12and the optical fiber21into contact with the circumferential surface formed by the positioning recess11eand the other may be positioned by a part other than the positioning recess11ein the holders11. Note that in this case, the part for positioning the other needs to be designed to have a fixed positional relationship with the positioning recess11e. That is, as for the holders11, the present invention includes such an idea that each lens12and each optical fiber21are positioned by brining one of the lens12and the optical fiber21into contact with the positioning recess11e.

The disclosure of Japanese Patent Application No. 2012-210995, filed on Sep. 25, 2012, including the specification, drawings, and abstract, is incorporated herein by reference in its entirety.