JP2012068535A - Multi-core optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-core optical connector which is inexpensive and easy to assemble.SOLUTION: A multi-core optical connector comprises a ferrule body part 11 formed of a resin which is transparent to the light propagating in optical fiber ribbons 20, convex lenses 12 which are integrally formed with the body part 11 and lined up on a front face 11a of the body part 11, and fiber holes 14 which are integrally formed with the body part 11 on a rear face 11b of the body part 11, extend along the optical axes of the convex lenses 12, and have a predetermined depth for insertion of optical fibers 21 from behind. A ferrule 10 is manufactured to form a single piece by injection molding, so that an inexpensive multi-core optical connector can be provided without precision assembly work.

Description

  The present invention relates to a multi-core optical connector.

  Computers that require large amounts of data transmission between external devices or boards, such as high-performance computers (HPCs) or high-performance servers, use optical interconnection technology for data transmission between boards or between boards and backplanes. It has been proposed to use.

  In such an optical interconnection technology, a multi-core optical cable, for example, an optical fiber ribbon for holding a plurality of optical fibers in a ribbon shape or an optical flat cable formed with a plurality of waveguides is used as a transmission path for transmitting a large amount of data. It is done. Therefore, a multi-core optical connector that can connect multi-core optical cables is required for the optical connector used in these high-performance computers.

  Conventionally, as a multi-core optical connector, there is a wide range of MT (Mechanically Transferable) connectors that polish an end face of an optical fiber held by a ferrule, abut the end face, and perform optical transmission between optical fibers through opposing end faces. in use.

  However, in the MT connector, in order to reduce the coupling loss, the axial cores of the opposing optical fibers must be matched with high accuracy. For this reason, precise molding and processing of the connector and further precise attachment of the optical fiber to the connector are required, and the manufacturing cost increases.

  There is known an optical connector in which optical transmission between optical fibers is performed by parallel light rays and the axial alignment accuracy of the facing optical fibers is relaxed. In this optical connector, a collimating lens is disposed at the tip of the optical fiber facing each other. The light emitted from one optical fiber is collimated through the lens, and the collimated parallel light bundle is condensed at the tip of the other optical fiber by the lens disposed at the tip of the other optical fiber and into the other optical fiber. Is transmitted. As described above, since the light transmission between the lenses is transmitted by the parallel light flux, the tolerance for the lens interval and the deviation of the optical axis of the lens is large. For this reason, the tolerance of molding and processing of the connector is large and can be manufactured at low cost.

Japanese Patent Laid-Open No. 06-034845 JP 2007-163969 A JP 2007-178790 A

(Problems to be solved by the invention)
As described above, the conventional MT optical connector has a problem of high cost because it requires high-precision molding and processing for manufacturing connector parts such as ferrules and housing components.

  In addition, a conventional multi-core optical connector using a collimated lens is manufactured by dividing a lens and a ferrule into a plurality of parts, and then assembling and integrating them. For example, the ferrule is divided and formed into a part in which parallel grooves are formed and a part in which lenses are formed. And after inserting an optical fiber in a parallel groove and fixing an optical fiber, the components in which the lens was formed are attached and a ferrule is assembled. However, if the ferrule is divided into a plurality of parts and molded, the number of molds and the assembly process increase. Furthermore, in order to assemble the optical fiber and the lens with precise alignment, a precise mold is required. For this reason, there exists a problem that manufacturing cost is high.

  The present invention provides a multi-core optical connector in which the positional relationship between a lens and an optical fiber or an optical waveguide is precisely determined and manufactured at low cost by using a ferrule manufactured by integral molding including the lens. With the goal.

  According to one aspect of the present invention for solving the above-described problems, a ferrule main body formed from a resin that is transparent to light propagating through an optical fiber ribbon, and the main body are formed by integral molding with the main body. And a convex lens arranged in front of the main body, and a rear surface of the main body portion formed by integral molding with the main body portion, extending along the optical axis of the convex lens, and an optical fiber inserted from the rear. And a fiber hole having a depth.

  According to the present invention, since the ferrule is integrally formed including the lens, a multi-core optical connector in which the positional relationship between the lens and the optical fiber or the optical waveguide is precisely determined can be provided at low cost.

Structure explanatory drawing of the ferrule of 1st Embodiment of this invention Structure explanatory drawing of the fiber hole of the first embodiment of the present invention Sectional drawing of the fiber hole of 1st Embodiment of this invention The expanded sectional view of the fiber hole tip part of a 1st embodiment of the present invention Sectional drawing of the multi-core optical connector of 1st Embodiment of this invention Structure explanatory drawing of the multi-core optical connector of 2nd Embodiment of this invention Structure explanatory drawing of the multi-core optical connector of 3rd Embodiment of this invention Structure explanatory drawing of the ferrule of 4th Embodiment of this invention Side sectional view of the multi-core optical connector according to the fourth embodiment of the present invention. Structure explanatory drawing of the ferrule of 5th Embodiment of this invention

  1st Embodiment of this invention is related with the multi-core optical connector for couple | bonding an optical fiber ribbon mutually.

  FIG. 1 is an explanatory view of the structure of a ferrule according to a first embodiment of the present invention. FIG. 1 (a) is a cross-sectional view and FIG. 1 (b) is a right front view. FIG. 1A shows a cross section taken along the line AA ′ in FIG.

  Referring to FIG. 1, a ferrule 10 used in the multicore optical connector 40 (see FIG. 5) of the first embodiment includes a ferrule main body portion 11 provided with a fiber hole 14 into which an optical fiber 21 is inserted, a lens, 12 and a positioning block 13 are manufactured as a resin molded product in which these are integrally molded. In the first embodiment, as the optical fiber ribbon to be coupled, for example, the optical fiber ribbon 20 in which the core wires 22 covering the periphery of the optical fiber 21 are arranged in 12 rows and 2 columns and laminated is used. As this optical fiber 21, for example, a GI 50 fiber (core diameter 50 μm, cladding layer diameter 125 μm) can be used. The optical fiber 21 is fixed to the ferrule body 11 using an adhesive 15.

  As the resin used as the material of the ferrule 10, a resin used for injection molding and transparent to light transmitted through an optical fiber is used. Here, an olefin resin such as polyolefin was used.

  The main body 11 is formed as a substantially rectangular parallelepiped having a width of about 2000 μm, a height of about 8000 μm, and a depth of about 6000 μm, for example. A convex lens 12 is formed on the front surface 11 a of the main body 11. The convex lens 12 is formed by molding so that a part of the front surface 11a of the main body 11 protrudes into a semi-convex lens shape. For example, the convex lens 12 has a high height according to the arrangement of the optical fibers 21 of the optical fiber ribbon 20. They are arranged in a matrix of 12 in the vertical direction with a pitch of 500 μm and 2 in the horizontal direction with a pitch of 500 μm, that is, in a matrix of 12 rows and 2 columns. In this specification, the traveling direction of light traveling toward the lens 12 in the optical fiber 21 in the optical fiber ribbon 20 is referred to as the front or front surface (front surface direction), and the reverse direction is the rear or rear surface (rear surface direction). That's it.

  A fiber hole 14 is provided on the rear surface 11 b of the main body 11. The fiber holes 14 have a blind hole structure with the optical axis of the lens 12 as the central axis and open in the rear surface 11b of the main body 11 and are arranged in, for example, 12 rows and 2 columns in accordance with the arrangement of the lenses 12.

  The depth of the fiber hole 14 is designed so that the bottom surface is located at the focal position of the lens 12, for example, the bottom surface is located at a position 1250 μm away from the tip of the lens 12 having a radius of curvature of 430 μm.

  FIG. 2 is an explanatory view of the structure of the fiber hole according to the first embodiment of the present invention. FIG. 2 (a) is a partial cross section of the main body 11, and FIGS. The AA 'cross section of is shown.

  Referring to FIG. 2 (a), the fiber hole 14 constitutes a fitting portion 14a in which the tip portion (front portion) is fitted to the optical fiber 21, and the rear end portion is expanded rearward (toward the opening). A tapered portion 14b having a tapered shape is formed.

  The fitting portion 14a is formed as a hole having a depth of, for example, 2000 μm extending along the central axis with the optical axis of the lens 12 as the central axis. The fitting portion 14 a supports the optical fiber 21 by fitting to the outer periphery of the optical fiber 21 so that the central axis of the optical fiber 21 fitted into the fitting portion 14 a coincides with the central axis of the lens 12. 2B to 2C, a groove 14c extending in the central axis direction is formed on the side wall of the fitting portion 14a. The groove 14c serves as a passage through which the adhesive 15 escapes when the optical fiber 21 with the adhesive 15 attached to the tip is inserted. By providing the groove 14c, the optical fiber 21 to which the adhesive 15 is attached can be easily inserted into the fitting portion 14a.

  Referring to FIG. 2B, the shape of the fitting portion 14 a is, for example, a cylinder having a diameter of 125 μm that fits on the outer periphery of the optical fiber 21, and a groove that extends parallel to the cylinder axis formed on the outer periphery of the cylinder. 14c. The cylindrical portion is separated into, for example, three ridges 14 d by the groove 14 c, and the tip of the ridge 14 d is fitted to the outer periphery of the optical fiber 21 to support the optical fiber 21.

  With reference to FIG. 2C, the shape of the fitting portion 14 a may be a square column having a square cross section that fits on the outer periphery of the optical fiber 21, for example, a quadrangular column. The fitting portion 14a supports the outer periphery of the optical fiber 21 in close contact with the four sides. On the other hand, the corners of the square do not come into contact with the optical fiber 21 and become grooves 14c that allow the adhesive 15 to escape.

  Furthermore, referring to FIG. 2 (d), the fitting portion 14 a may be a cylindrical shape into which the optical fiber 21 is fitted, and a groove 21 c may be formed on the outer periphery of the optical fiber 21. The groove 21c is formed on the outer periphery of the cladding layer 21b so as not to increase the loss of light propagating through the core 21a of the optical fiber 21. The cylindrical fitting portion 14a is easy to manufacture a mold and remove the mold, which will be described later.

  Referring to FIG. 2A again, the tapered portion 14b is formed as a taper having a length of, for example, 2750 μm and having the optical axis of the lens 12 as a central axis and the diameter of the tapered portion 14b expanding rearward along the central axis. The taper angle is 2 ° to 3 °, for example.

  The optical fiber 21 is inserted into the fiber hole 14 from the rear surface 11b of the main body 11 with the adhesive 15 attached to the tip thereof or in a state where the adhesive 15 has been injected into the fiber hole 14 in advance. The optical fiber 21 inserted into the tapered portion 14b is guided to the fitting portion 14a along the taper, and is easily fitted into the fitting portion 14a. When the fitting portion 14a is fitted, the adhesive 15 adhering to the tip of the optical fiber 21 fills the fitting portion 14a and then escapes to the tapered portion 14b through the groove 14c, thereby avoiding an increase in fitting pressure. Easy to insert.

  FIG. 3 is a cross-sectional view of the fiber hole of the first embodiment of the present invention, showing the fiber hole 14 into which the optical fibers 21 having different lengths are inserted.

  Referring to FIG. 3, the optical fiber 21 inserted into the plurality of fiber holes 14 is drawn from one end of the optical fiber ribbon 20 and is cut with its tip aligned to a predetermined length. However, it is difficult to cut the tips of all the optical fibers 21 so as to be aligned at right angles to the extending direction of the optical fiber ribbon 20. For this reason, the length of the tip portion of the optical fiber 21 inserted into the fiber hole may vary.

  If there is such a variation in the length of the optical fiber 21, the position of the tip of the optical fiber 21 varies, the tip of the optical fiber 21 cannot be precisely matched with the focal point of the lens 12, and the coupling loss increases.

  In the first embodiment, the fiber hole 14 is expanded in diameter by the tapered portion 14b. For this reason, when the long optical fiber 21 is inserted from the rear after the tip abuts against the bottom of the fiber hole 14, the long optical fiber 21 is bent in the enlarged diameter tapered portion 14 b to absorb the variation in length. Therefore, even if the length of the tip portion of the optical fiber 21 varies, the variation is absorbed, and the tips of all the optical fibers 21 are fixed by the adhesive in a state where the tips of the optical fibers 21 are in contact with the bottom (tip) of the fiber hole 14. The For this reason, since the multi-core optical connector 40 with small loss is realized even if the cutting accuracy of the optical fiber 21 is low, the multi-core optical connector can be manufactured at low cost.

  FIG. 4 is an enlarged cross-sectional view of the front end of the fiber hole according to the first embodiment of the present invention, showing the fiber hole 14 into which the optical fiber 21 is inserted.

  Referring to FIG. 4, the optical fiber 21 fitted into the fitting portion 14 a is fixed by the adhesive 15 with the tip abutting against the bottom surface of the fitting portion 14 a. That is, the gap between the tip of the optical fiber 21 and the bottom surface of the fitting portion 14 a is filled with the adhesive 15. As the adhesive 15, an adhesive having a refractive index between the refractive index of the main body 11 and the refractive index of the core 21 a of the optical fiber 21, preferably having a refractive index close to the core 21 a is used.

  Undesigned irregularities 19 and 25 may be formed on the tip of the optical fiber 21 or the bottom surface of the fitting portion 14a. For example, the unevenness 25 on the cut surface of the unpolished optical fiber 21 or the unevenness 19 on the surface of the injection molded product. Thus, by using the adhesive 15 having a refractive index close to that of the core 21a, light scattering on the surfaces of the irregularities 25 and 19 is suppressed, and light loss due to scattering can be reduced. Therefore, since the end of the optical fiber 21 can be used without subjecting the end surface to the cut surface, the multi-core optical connector can be manufactured at a low cost by omitting the polishing step.

  As the adhesive 15, for example, an ultraviolet curable epoxy can be used. In the ultraviolet curing type, since there is no heat curing of the adhesive, deformation due to heating can be avoided. Instead of the adhesive 15, a resin having a refractive index close to that of the core 21a may be used, and the opening of the tapered portion 14b may be sealed with a curable adhesive.

  Referring again to FIG. 1, positioning blocks 13 having a substantially rectangular parallelepiped shape having, for example, a width of 6000 μm, a height of 2000 μm, and a depth of 3000 μm are provided at the upper and lower ends of the main body 11. As described above, the positioning block 13 is formed as an integrally molded product together with the main body 11, the lens 12 and the fiber hole 14.

  A positioning surface 13 b is formed on the front surface of the positioning block 13. The positioning surface 13b is formed to protrude forward from the front surface 11a of the main body 11 on which the lens 12 is formed. And the positioning surface 13b of the positioning block 13 provided above and below the main body 11 forms a reference plane parallel to the front surface 11a of the main body 11. Therefore, the front surface 11a of the main body portion 11 is made to come into contact with the positioning reference surface of other parts (for example, other ferrules or parts such as housings combined with the ferrule 10 of the first embodiment) by contacting the positioning surface 13b. Can be supported in parallel to the alignment reference plane of the parts.

  Further, the positioning block 13 is provided with guide holes 13a of, for example, 1000 μm parallel to the optical axis of the lens, that is, parallel to the central axis of the fiber hole 14, at both end portions of the positioning block 13 (near both ends in the width direction). Yes. When assembling together with other parts, this guide hole 13a is fitted with a guide pin provided in the other part or a guide pin 16 to be inserted into the guide hole of the other part. And used for positioning the main body 11. The guide hole 13a and the guide pin 16 are inserted with a tolerance of 50 μm, for example.

  The guide hole 13a is used to determine the rotation direction in which the front surface 11a of the main body 11 rotates about the vertical axis of the reference surface determined by the positioning surface 13b. Thereby, it is possible to easily match the arrangement direction of the lenses 12 formed on the front surface 11a with the arrangement direction of the lenses formed on other components.

  This shift in the alignment direction of the lenses 12 causes a positional shift of the optical axes between the lenses 12, but the front surface 11a on which the lenses 12 are formed is always held parallel to the positioning surface 13b. Since the optical axis of the lens 12 is formed perpendicular to the front surface 11a, the optical axis of the facing lens 12 is always kept parallel. Therefore, the coupling loss caused by the inclination of the optical axis between the lenses 12 is suppressed. On the other hand, the coupling loss due to the optical axis misalignment (the positional misalignment of the optical axes in the parallel direction) is smaller than the coupling loss due to the optical axis tilt deviation. For this reason, the allowable dimensional error in forming the guide hole 13a is larger than that of the MT connector, and the guide hole 13a can be formed with sufficient accuracy by injection molding.

  The ferrule 10 described above is manufactured as an integrally molded product by a well-known injection molding method usually used for resin molding. With reference to FIG. 1, a mold used for injection molding is divided into, for example, a ferrule 10 in two parts from the rear end of the alignment block 13 to the front and rear, and the part for molding the rear part from the divided surface is the upper mold, and the front part is The part to be molded is manufactured as a lower mold.

  The upper mold includes a rectangular parallelepiped cavity that forms the rear part of the main body 11 and a needle that is suspended from the bottom surface of the cavity. This needle has the shape of the fiber hole 14, and is provided in a matrix of 12 rows and 2 columns like the fiber hole 14. It is also possible to manufacture the needle as a core and insert it into a hole provided in the bottom surface of the cavity to constitute the upper mold. By using the needle as the core, after the upper mold is removed from the main body 11 after molding, the needle can be pulled out from the fiber hole 14 alone, so that it can be easily removed from the mold. In addition, since the damaged needle can be replaced during injection molding, the mold can be easily repaired. Of course, the needle may be manufactured as a mold integrated with the lower mold.

  The lower mold includes a rectangular parallelepiped cavity that forms the rear portion of the main body 11 and a rectangular parallelepiped cavity that forms the positioning blocks 13 at both ends of the cavity. On the bottom surface of the cavity that forms the main body 11, a half-lens-shaped depression that molds the lens 12 is formed in 12 rows and 2 columns, similar to the lens 12. Further, a cylinder that forms the guide hole 13 a is suspended from the bottom surface of the cavity that forms the positioning block 13. In addition, you may manufacture this cylinder as a core.

  The ferrule 10 of the first embodiment is manufactured as an integrally molded product by resin injection molding using the upper and lower molds as molds.

  The ferrule 10 of the first embodiment described above can be assembled as a multi-core optical connector that connects two ferrules 10 to connect optical fiber ribbons to each other.

  FIG. 5 is a cross-sectional view of the multicore optical connector according to the first embodiment of the present invention, showing a multicore optical connector 40 assembled by butting two ferrules 10 together.

  Referring to FIG. 5, in the multi-core optical connector 40 of the first embodiment, two ferrules 10 in which an optical fiber 21 is inserted into a fiber hole 14 and fixed using an adhesive 15 are positioned on each other's positioning surface 13b. Are assembled together by bringing them into close contact with each other and using guide pins 16. The guide pins 16 are closely fitted in guide holes 13 a formed in both ferrules 10 to fix both ferrules 10. It is also possible to insert the guide pin 16 into the guide hole 13a so as to be insertable / removable, and to fix both ferrules using a housing having a latch mechanism as in a second embodiment described later.

  In the multi-core optical connector 40 of the first embodiment, the front surfaces 11a of the two ferrules 10 that are abutted with each other are arranged in parallel to the positioning surface 13b by bringing the positioning surfaces 13b into close contact with each other. Accordingly, the lenses 12 formed on the front surfaces 11a of both ferrules 10 are arranged in parallel to each other, and as a result, the optical axes of the lenses 12 perpendicular to the front surface 11a are parallel to each other.

  On the other hand, positioning errors caused by the guide pins 16 cause the lenses 12 arranged in a row to rotate in a plane perpendicular to the optical axis. This positional shift causes a positional shift in which the central axis (optical axis) of the lens 12 is shifted in parallel while keeping the optical axis parallel. However, since the optical axes of the opposing lenses 12 are held in parallel, the coupling loss is small, and even when the guide pin 16 is loosely inserted, practically sufficient alignment accuracy is realized.

  As described above, in the multi-core optical connector according to the first embodiment, the ferrule 10 having the lens 12 and the fiber hole 14 is manufactured as an integrally molded product, so that the lens 12 and the fiber 21 are precisely aligned. A multi-core optical connector can be manufactured at low cost.

  Furthermore, by integrally forming the positioning block 13 including the positioning surface 13b and the guide hole 13a, the multi-core optical connector 40 with the optical axis held in parallel and with little coupling loss can be easily assembled.

  The second embodiment of the present invention relates to a multi-core optical connector 41 (backplane connector) for attaching a board to a backplane.

  FIG. 6 is an explanatory view of the structure of the multi-core optical connector according to the second embodiment of the present invention. FIG. 6 (a) is a side sectional view of the pin insert 50A and the socket insert 50B, and FIG. 6 (b) and FIG. c) represents front views of the pin insert 50A and the socket insert 50B, respectively. 6B and 6C are views of the pin insert 50A and the socket insert 50B as seen from the lens 12 forming surface side in the direction of the optical fiber 21. FIG.

  With reference to FIG. 6A, the multi-core optical connector 41 of the second embodiment is connected to the pin insert 50A fixed to one end of the board 61 and the main surface of the backplane and coupled to the pin insert 50A. Socket insert 50B.

  With reference to FIG. 6A and FIG. 6B, the pin insert 50A includes a pin-side housing 51A fixed to one end of the board 61 by, for example, fastening. The pin-side housing 51 </ b> A has a recess into which the main body 11 and the positioning block 13 of the ferrule 10 are loosely inserted at the front end, and a guide pin 16 that fits into a guide hole 13 a formed in the positioning block 13. A slit-like through-hole through which the optical fiber ribbon 20 or the core wire 22 passes is provided at the bottom of the recess into which the main body 11 is loosely inserted. Further, an elastic mechanism 55, for example, a spring or rubber is provided at the bottom of the recess into which the positioning block 13 is loosely inserted.

  The ferrule 10 to which the optical fiber 21 is fixed is loosely inserted through the main body 11 and the positioning block 13 into the above-mentioned recess, and is further held by the pin-side housing 51A through the guide pin 16 through the guide hole 13a. At this time, the positioning block 13 is swingably held by the elastic mechanism 55 with respect to the pin-side housing 51A.

  The pin-side housing 51A is further formed with engaging portions 52a constituting one of the latch 52 mechanisms at the upper and lower ends. The engaging portion 52a engages with a latch claw 52b formed on the socket side housing 51B described below, and constitutes a latch 52 that couples the pin insert 50A to the socket insert 50B.

  6 (a) and 6 (c), the socket insert 50B is fixed to the main surface of the computer backplane 62 by, for example, snapping, and held by the socket side housing 51B. And the ferrule 10 to be used.

  The socket-side housing 51B includes a recess having the same structure as the pin-side housing 51A. The ferrule 10 is fitted into the recess and is held by the socket-side housing 51B. At this time, the ferrule 10 is held so as to be swingable via the elastic mechanism 55. Note that the guide pin 16 is not provided in the socket-side housing 51B. The optical fiber ribbon 20 coupled and fixed to the ferrule 10 passes through the socket-side housing 51B and extends on the main surface of the backplane 62. Alternatively, it is pulled out through the backplane 62.

  The socket insert 50B includes latch claws 52b at the upper and lower ends. The latch claw 52b is engaged with an engaging portion 52a formed on the pin-side housing 51A to constitute the latch 52. The board 61 is attached to the backplane 52 by inserting guide pins formed on the pin-side housing 52A into the guide holes 13a of the ferrule 10 held by the socket-side housing 51B and provided on the front surfaces of the positioning blocks 13 of each other. This is done by bringing the positioning surface 13b into close contact. The pin-side housing 51A and the socket-side housing 51B are pressed against each other by the latch 52 and urged by the latch 52 so that the positioning surfaces 13b are in close contact with each other.

  Both the pin side housing 51A and the socket side housing 51B described above can be manufactured as an integrally molded product.

  The third embodiment of the present invention relates to a multi-core optical connector provided with a shutter mechanism that prevents light leakage from an optical fiber.

  FIG. 7 is an explanatory view of the structure of the multi-core optical connector according to the third embodiment of the present invention. FIG. 7 (a) is a side sectional view of the pin insert 50A and the socket insert 50B, and FIG. 7 (b) and FIG. c) represents front views of the pin insert 50A and the socket insert 50B, respectively. 7B and 7C are views of the pin insert 50A and the socket insert 50B as viewed from the lens 12 forming surface side in the direction of the optical fiber 21. FIG.

  The multi-core optical connector 42 of the third embodiment is provided with a double door shutter 54 that opens inward in front of the socket insert 50B, that is, in front of the lens 12 of the ferrule 10 held in the socket side housing 51B. Other structures are the same as those of the multi-core optical connector 41 of the second embodiment.

  Referring to FIG. 7, when the pin insert 50 </ b> A is removed from the socket insert 50 </ b> B, the double door shutter 54 is biased to close. Accordingly, at this time, the shutter 54 is automatically closed.

  When the pin insert 50A is coupled to the socket insert 50B, the guide pin 16 first contacts the shutter 54, and the shutter 54 opens from the center to the inside. Thereafter, as in the second embodiment, the pin insert 50A and the socket insert 50B are coupled.

  In the third embodiment, when the pin insert 50A is removed from the socket insert 50B, the light from the optical fiber 21 on the socket insert 50B side is shielded by the shutter 54 and does not leak outside. For this reason, it is possible to prevent the leaked light from entering the eyes of the worker, and the safety of the work is enhanced.

  The fourth embodiment of the present invention relates to an L-type multi-core optical connector 50 that bends light emitted from an optical fiber and couples it in a right angle direction.

  FIG. 8 is an explanatory view of the structure of a ferrule according to a fourth embodiment of the present invention. FIG. 8 (a) is a plan view, FIG. 8 (b) is a side view, and FIG. 8 (c) is a front view.

  Referring to FIG. 8, the ferrule 10A of the fourth embodiment has a substantially rectangular parallelepiped main body 11 having a positioning surface 11f formed on a front surface 11a. On one side surface 11c of the main body part 11, semi-convex lens-like lenses 12 formed by integral molding with the main body part 11 are arranged in a matrix of 12 rows and 2 columns, for example. Note that one side surface 11c of the main body 11 is formed perpendicular to the positioning surface 11f, and therefore the optical axis of the lens 12 is parallel to the positioning surface 11f.

  A fiber hole 14 that extends along a circular arc from the focal position of the lens 12 and opens to the rear surface 11 b of the main body 11 is formed integrally with the main body 11 in the main body 11. The fiber hole 14 constitutes a fitting portion 14a whose tip is fitted to the optical fiber 21, and constitutes a tapered portion 14b whose opening portion expands toward the opening. The fitting portion 14a and the tapered portion 14b are the same as the fitting portion 14a and the tapered portion 14b of the first embodiment except that the central axis is an arc. In the fiber hole 14, the optical fiber 21 exposed by peeling off the coating of the core wire 22 of the optical fiber ribbon 20 shown in FIG. 6 is fitted and fixed with the adhesive 15. These are made in the same manner as in the first embodiment, including the materials.

  Furthermore, a substantially rectangular parallelepiped positioning block 13 is integrally formed with the main body on the upper and lower surfaces of the main body 11. The positioning block 13 is provided with a guide hole 13a penetrating perpendicularly to the positioning surface 11f. As will be described later, the guide hole 13a is used to position the side surface 11c (lens 12 forming surface) of the main body 11 perpendicularly to the optical axis of the opposing lens.

  The ferrule 10A of the fourth embodiment described above can be manufactured by injection molding similar to the ferrule 10 of the first embodiment. However, the needle extending on the arc for forming the fiber hole 14 constituting the upper mold of the mold is manufactured as a core. By using the core, the needle can be extracted along the arc after removing the upper mold.

  FIG. 9 is a side sectional view of the multi-core optical connector according to the fourth embodiment of the present invention, and shows the structure of an L-type multi-core optical connector 50 using the ferrule 10A shown in FIG.

  Referring to FIG. 9, the multi-core optical connector 50 of the fourth embodiment includes a socket insert 50B fixed to the back plane 62 and a pin insert 50A that holds the ferrule 10A.

  The pin insert 50A includes an engaging portion 52a that constitutes a lock mechanism and a recess into which the ferrule 10A is loosely inserted. An elastic mechanism 55 for holding the ferrule 10A in a swingable manner, for example, an elastic body is provided on the bottom surface of the recess. The pin insert 50A is fixed to one end of the board 61.

  The socket insert 50 </ b> B is fixed to the back plane 62 using, for example, a hook 63. A ferrule 10 </ b> B that holds the optical fiber 21 in parallel with the back plane 62 is fixed to one end of the socket insert 50 </ b> B. This ferrule 10B has the same structure as the main body part 11 of the ferrule 10 of the first embodiment, and the lenses 12 arranged in 12 rows and 2 columns on the front surface and the fiber holes 14 corresponding to the lenses 12 on the rear surface. It is integrally molded. The positioning block 13 is not provided.

  The socket insert 50 </ b> B is formed as a reference surface 64 whose main surface facing the pin insert 50 </ b> A is substantially parallel to the backplane 62. The ferrule 10 </ b> B is fixed with the lens 12 formation surface perpendicular to the reference surface 54.

  Further, the socket insert 50B has a set of guide pins 16 suspended from the reference surface 64 and a set of latch claws 52b. The guide pin 16 is inserted into the guide hole 13a of the ferrule 10A and positioned so that the optical axis of the lens 12 formed on the side surface 11c of the ferrule 10A is parallel to the optical axis of the lens 12 formed on the ferrule 10B. The latch claw 52b engages with an engaging portion 52a formed on the pin insert 50A, and constitutes a latch 52 mechanism that couples and fixes the pin insert 50A to the socket insert 50B.

  When the pin insert 50A is coupled to the socket insert 50B, the ferrule 10A held in a swingable manner is supported with the positioning surface 11f in close contact with the reference surface 64. Therefore, the optical axis of the lens 12 formed on the side surface 11 c perpendicular to the positioning surface 11 f is parallel to the reference surface 64. The guide pin 16 is inserted into the guide hole 13a and restricts rotation around the vertical axis to the reference surface 64 of the ferrule 10A. The optical axis of the lens 12 formed on the ferrule 10A is parallel to the optical axis of the lens 12 formed on the ferrule 10B, that is, the side surface 11c of the ferrule 10A is parallel to the front surface (lens forming surface) of the ferrule 10B. In addition, the rotation angle of the ferrule 10A is determined. The accuracy of the rotation angle depends on the accuracy of the formation position of the guide hole 13a. However, since the guide holes 13a are arranged outside the both ends of the row of the lenses 12 arranged in a row and have a sufficiently large interval, the necessary accuracy can be usually obtained easily. If necessary, a mechanism for positioning the lens forming surfaces of the ferrules 10A and 10B in parallel, for example, a block having surfaces parallel to both surfaces, may be provided on the reference surface 64.

  The fifth embodiment of the present invention relates to a multi-core optical connector for coupling an optical flat cable 30 provided with a plurality of optical waveguides.

  10A and 10B are explanatory views of the structure of a ferrule according to a fifth embodiment of the present invention. FIG. 10A is a side cross-sectional view, FIG. 10B is a cross-sectional view along AA ′ in FIG. c) represents a BB ′ cross section in FIG.

  Referring to FIG. 10, in the fifth embodiment, an optical flat cable 30 (referred to as a flexible optical waveguide) obtained by laminating a plurality of optical waveguides 31 extending in parallel and processed into a tape shape is used. The optical flat cable 30 has, for example, an arrangement similar to the arrangement of the optical fibers 21 of the optical fiber ribbon 20 of the first embodiment. For example, optical waveguides 31 having 12 rows in the width direction and 2 rows in the thickness direction are formed. Yes.

  The ferrule 10C used in the fifth embodiment includes a slot 18 into which the optical flat cable 30 is inserted from the rear surface. Others are the same as the ferrule 10 of 1st Embodiment. The slot 18 is formed by integral molding together with the main body 11 and the positioning block 13 of the ferrule 10C.

  As for the slot 18, the front-end part comprises the fitting part 18a, and the rear-end part comprises the taper part 18b. The fitting portion 18 a is a slot having a bottom surface (tip) positioned at the focal point of the lens 12 and having a narrow rectangular cross section that fits into the optical flat cable 30, and a side wall (a wall surface facing the main surface of the optical flat cable 30. ), A groove 18c extending in the optical axis direction of the lens 12 is formed. A ridge 18d is formed between the grooves 18c. The ridge 18d has a side wall surface in contact with the main surface of the optical flat cable 30 to be sandwiched therebetween.

  The tapered portion 18b opens on the rear surface 11b of the main body 11 with a taper angle of 2 ° to 3 °, for example. This taper is formed in the width direction of the optical flat cable 30 (the vertical direction on the paper surface in FIG. 10A) and in the thickness direction of the optical flat cable 30 (the vertical direction on the paper surface in FIG. 10C). The optical flat cable 30 inserted into the tapered portion 18b from the rear is guided into the fitting portion 18a along the taper and inserted until the tip comes into contact with the bottom surface of the fitting portion 18a. In addition, it is the same as that of 1st Embodiment that an adhesive agent is made to adhere to the front-end | tip of the optical flat cable 30, and is inserted, or an adhesive agent is inject | poured near the bottom face of the fitting part 18a previously.

  In the fifth embodiment, there is no effect of aligning the tips of the optical fibers 21 having irregular lengths as in the first embodiment. Therefore, when the optical flat cable 30 is cut, the tips of the optical waveguides 31 must be aligned and cut. However, in the optical flat cable 30, the optical waveguide 31 is not separated separately, so that it is easy to cut with the tips aligned, and there is no particular problem.

  The ferrule 10C of the fifth embodiment described above can also be applied to an L-type multi-core optical connector similarly to the multi-core optical connector of the fourth embodiment. That is, the slot 18 of the fifth embodiment is formed in an arc shape like the fiber hole 14 shown in FIG. At this time, the length of the optical waveguide inside the arc must be cut shorter than the outer optical waveguide. This troublesome cutting can be avoided by using, for example, two optical flat cables in which optical waveguides are formed in one row (one layer).

  In the fifth embodiment, since an optical flat cable with an integrated optical waveguide is used, it is easy to cut the optical waveguide with the tips aligned. In addition, since the optical waveguide is integrated, the optical flat cable can be easily attached and fixed because it can be inserted into the slot at a time.

  By applying the present invention to data transmission between computer boards or externally, a large amount of data transmission can be realized at low cost.

10, 10A to 10C Ferrule 11 Body 11a Front 11b Rear 11c Side 12 Lens 13 Positioning block 13a Guide hole 13b, 11f Positioning surface 14 Fiber hole 14a, 18a Fitting 14b, 18b Taper 14c, 18c Groove 14d, 18d Ridge DESCRIPTION OF SYMBOLS 15 Adhesive 16 Guide pin 18 Slot 19, 25 Concavity and convexity 20 Optical fiber ribbon 21 Optical fiber 21a Core 21b Clad layer 21c Groove 22 Core wire 23 Light 30 Optical flat cable 31 Optical waveguide 40, 41, 42, 50 Multi-core optical connector 50A Pin Insert 50B Socket insert 51A Pin side housing 51B Socket side housing 52 Latch 52a Engagement part 52b Latch claw 54 Shutter 55 Elastic mechanism 61 Board 62 Backplane 6 Caulking 64 reference plane

Claims (5)

A ferrule body formed from a resin transparent to light propagating through the optical fiber ribbon;
Convex lenses formed by integral molding with the main body and arranged in front of the main body,
A fiber hole having a predetermined depth that is formed on the rear surface of the main body portion by integral molding with the main body portion, extends along the optical axis of the convex lens, and into which an optical fiber is inserted from behind.
A multi-core optical connector. A positioning block formed by integral molding with the main body, and formed with a positioning surface parallel to the front of the main body on the front end surface protruding forward from the front of the main body;
A guide hole provided in the positioning block and into which a guide pin is inserted along the optical axis of the convex lens;
The multi-core optical connector according to claim 1. In the multi-core optical fiber connector that is mounted in close contact with the reference plane of the housing,
A ferrule body formed of a resin transparent to light propagating through the optical fiber ribbon and having a positioning surface in close contact with the reference surface formed on the front surface;
Convex lenses formed by integral molding with the main body, and arranged in a direction parallel to the positioning surface on the side of the main body,
A fiber hole into which an optical fiber is inserted, which is formed by integral molding with the main body and extends along a circular arc from the rear surface of the main body to the focal position of the convex lens;
A multi-core optical connector. The fiber hole has a fitting portion formed in the front and a tapered portion formed in the rear,
The fitting portion includes a groove extending in an extending direction of the hole on an outer periphery of the hole fitting into the optical fiber,
The tapered portion has a tapered shape that extends rearward.
The multi-core optical connector according to claim 1, 2, or 3. Instead of the resin, using a resin transparent to the light propagating through the optical flat cable formed with a plurality of waveguides,
Instead of the fiber hole into which the optical fiber is inserted, the slot has a depth equal to the fiber hole and into which the optical flat cable is inserted,
The multi-core optical connector according to claim 1, wherein the optical fiber connector is a multi-core optical connector.