JP3435070B2 - Optical fiber connector and optical wiring board - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical fiber connector, an optical wiring board, and an optical fiber.

[0002]

2. Description of the Related Art FIG. 1 shows an example of a conventional optical fiber connector, here, an eight-core type optical fiber connector for simultaneously connecting eight optical fibers. FIG. 1 (a) is an exploded perspective view before assembly. FIG. 1B is a partial sectional view after assembly.
In FIG. 1, 1 and 2 are plugs, 3 is an adapter, 4 is a clip, and a plurality of optical fibers, here eight optical fibers 5,
The 5'are connected to each other as described below.

First, the end faces of the optical fibers 5 and 5'are shaped by cleavage or polishing, and then tapered (5a). The fixing holes 1 provided in the plugs 1 and 2 with the optical fibers 5 and 5 ′ being slightly larger than the outer diameter of the optical fiber.
Pass through a and 2a and fix with an adhesive or the like. Optical fiber 5,
When the plugs 1 and 2 to which 5'is attached are fitted to the adapter 3, the optical fibers 5 and 5'are provided in the adapter 3,
It is simultaneously inserted into the through hole 3a which is slightly larger than the outer diameter of the optical fiber.

Here, the optical fiber 5 is fixed (6) by protruding from the tip of the plug 1 in advance, and when the two plugs 1 and 2 hit each other and the fitting is completed, the two optical fibers 5 and 5 ' The tip hits, and the optical fiber 5 buckles and bends in the space 1b provided in the plug 1. It should be noted that the deflectable optical fiber may be one as shown, or may be both.

The buckling force at this time becomes a pressing force, and the end faces of the optical fibers 5 and 5'are brought into close contact with each other. The buckling force can be controlled by the length of deflection, and if the length is 7 mm, the outer diameter is 1
In the case of 25 μm glass optical fiber, about 0.7 N (70
gf). With such a force, the optical fibers are brought into close contact with each other. Further, the amount of deflection can be controlled by the length of the protruding optical fiber. With a protrusion length of about 50 μm, the optical fiber bends about 0.3 mm. With such an amount, it is possible to suppress the probability of optical fiber breakage and radiation loss due to bending of propagating light to such an extent that there is no practical problem. The fitting between the plugs 1 and 2 and the adapter 3 is held by the clip 4.

As for the optical characteristics, when an optical fiber having an outer diameter of 125 μm is connected through a through hole having an inner diameter of 126 μm, a connection loss of 0.3 dB or less is realized when a single-mode optical fiber having a long wavelength band for communication is used. A return loss of 60 dB is achieved when the end faces are cleaved, and a return loss of about 50 dB is achieved when the end faces are polished. Since a ferrule and a spring member are not used, it is possible to realize a small-sized optical fiber connector that can be used for a plurality of optical fibers. Moreover, the plug and the adapter can be manufactured by injection molding suitable for mass production, and a low price can be realized. This is because the taper of the entrance portion of the through hole of the adapter and the taper of the end surface portion of the optical fiber relax the molding precision required for inserting the optical fiber into the through hole of the adapter.

[0007]

However, in the above-mentioned conventional optical fiber connector, the number of optical fibers that can be connected by one connector is determined by the number that allows the inner diameter accuracy of the through holes of the adapter to be uniform. However, in the case of injection molding, if the number is 10 or more, the yield is reduced, and it is difficult to increase the number that can be handled.

Further, in the conventional connector, it is necessary to pass the optical fiber through the through hole of the plug from the tip to a predetermined position for about 10 mm in the connector assembling process. It is not easy to pass the optical fiber through the thin hole, and the optical fiber may be rubbed against the inner wall of the through hole to be scratched, which may reduce the reliability of breakage of the bent portion of the optical fiber. Further, an adhesive is required to fix the optical fiber, and if this is not required, the assembling work becomes efficient.

Further, in the conventional connector, the optical fiber is smoothly inserted into the through hole due to the taper of the entrance portion of the through hole of the adapter and the end surface portion of the optical fiber, but if the molding accuracy can be further relaxed. The manufacturing cost of the mold used for molding can be reduced. Further, if the taper of the end face portion of the optical fiber becomes unnecessary, the work of the end face treatment of the optical fiber can be simplified.

Further, in order to smoothly insert the optical fiber into the through hole for abutting, a clearance is required between the optical fiber and the through hole, and this clearance is the largest factor of the connection loss. If unnecessary, the connection loss can be greatly improved.

[0011]

Further, in an optical wiring board for connecting optical components and optical modules on a printed circuit board with optical fibers, it is necessary to attach a connector to the terminal. However, if even one optical fiber fails to process, the whole is defective. Become. Therefore,
With the increase in the number, the yield at the time of assembly and the ease of assembly become very important problems.

An object of the present invention is that the connection work is easy and the loss is small, and a large number of optical fibers can be connected together, and various optical components and optical modules can be efficiently connected by optical fibers on a printed circuit board. An optical fiber connector and an optical wiring board that can be connected to the optical fiber .

[0014]

In order to solve the above-mentioned problems, according to claim 1 of the present invention, a first optical fiber bundle consisting of at least one optical fiber is fixedly held near the end thereof. One optical fiber holding section, a second optical fiber holding section that fixedly holds the vicinity of an end of a second optical fiber bundle including at least one optical fiber, and first and second optical fiber bundles A third optical fiber holding portion that holds the end portion of the optical fiber in a state where the end surfaces of the optical fiber are abutted to each other.
And at least one of the first optical fiber bundle between the third optical fiber holding portions or the second optical fiber bundle between the second and third optical fiber holding portions is in a bent state,
In an optical fiber connector in which first to third optical fiber holding portions are arranged and fixed to each other, each of the first to third optical fiber holding portions holds at least one optical fiber on one surface. has a block having an optical fiber holding structure, the first to third blocks constituting the optical fiber holding unit I plurality der respectively, first
Place the block that constitutes the optical fiber holder on one surface.
First housing which is fixed so as to cover except the other side facing
And the block that constitutes the second optical fiber holding unit.
Fix it so that it covers it except for the other side facing the one side.
A second housing and a third optical fiber holding part
The block to be placed on the other side opposite to the one side.
Delivered and fixed, and holding the fixed third optical fiber
The first optical fiber holder is provided on both sides of the block that constitutes the holding section.
The first housing and the block that fixes the holding part are fixed.
And the blocks that make up the second optical fiber holder are fixed
The second housing through the other exposed side
A third housing for storing and fixing is provided .

According to the first aspect of the present invention, by forming a block for holding optical fibers in units of the number of optical fibers whose yield does not extremely decrease, and connecting them, it is possible to realize a connector that can handle a large number of fibers. From the top
Housing assembly provides a structure suitable for automated assembly.
Can be revealed.

[0016]

[0017]

According to a second aspect of the present invention , the blocks forming the first and second optical fiber holding portions are made of an elastic body, and the optical fiber holding structure has an opening slightly smaller than the outer diameter of the optical fiber and an inner portion The groove is about the size of the optical fiber cross section. In the third aspect , the cross-sectional shape of the groove is a shape obtained by cutting an upper portion of a circle or an ellipse. Further, in claim 4 , the cross-sectional shape of the groove is a shape obtained by cutting an upper portion of a polygon.

According to the second aspect, the third aspect, and the fourth aspect , the optical fiber can be fitted from above, and the optical fiber can be mounted without passing through the hole.

According to a fifth aspect of the present invention , the optical fiber holding structure of the block constituting the third optical fiber holding portion is provided with a through hole whose diameter is about the cross section of the optical fiber, and the through hole is continuously provided. And a groove whose upper part is open.

According to claim 5, since it is possible to expand an invitation amount for inserting the optical fiber into the through hole to the fiber pitch, the positional accuracy of the optical fiber tip is reduced, reduction of injection molding precision realizable.

According to a sixth aspect of the invention , the block forming the third optical fiber holding portion is made of an elastic body, and the optical fiber holding structure is a through hole having a diameter slightly smaller than the cross section of the optical fiber. To do. Further, in claim 7 , the block forming the third optical fiber holding portion is made of an elastic body, and the optical fiber holding structure of the block has a through hole having a diameter slightly smaller than an optical fiber cross section and the through hole. It is characterized by comprising a slit provided.

According to the sixth and seventh aspects , since the through hole can be elastically deformed according to the optical fiber and the clearance can be made zero, the connection loss can be reduced.

Further, in an eighth aspect of the present invention, in an optical wiring board for connecting a predetermined two points by at least one optical fiber, the terminal is equipped with the optical fiber connector according to any one of the first to fifth aspects. Is characterized by.

According to the eighth aspect , since the optical fiber can be mounted on the optical fiber connector portion from above, it is possible to realize an optical wiring board with an optical fiber connector which can be efficiently assembled.

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to embodiments.

FIG. 2 shows an example of the embodiment of the optical fiber connector of the present invention, in this case, a 36-fiber optical fiber connector in which three sets of 12 optical fibers are simultaneously connected. Is an exploded perspective view, and FIG. 6B is a partial cross-sectional view after assembly. In FIG. 2, 11 and 12 are plugs and 13
Is an adapter, and 14 is a clip.

The plug 11 is an optical fiber holding structure for holding 12 optical fibers on one surface, as shown in FIG.
Here, the plug block 20 is provided with a groove 21 having a circular cross-section whose upper part is cut, and a predetermined number of plug blocks 20, three in this case, fixed so as to cover one surface of the plug block 20 except for the other surface side. It is composed of a plug housing 15.

The plug 12 is the plug block 2 described above.
0, a predetermined number of plug blocks 20, three in this case, and a plug housing 16 for fixing the plug blocks 20 so as to cover the one surface except the other surface side.

As shown in FIG. 4, the adapter 13 is an optical fiber holding structure for holding 12 optical fibers on one surface, here, an adapter block 30 having a through hole 31.
And a predetermined number of adapter blocks 30, three in this case, are housed and fixed through the other surface facing one surface, and the plug blocks 20 are fixed on both sides of the fixed adapter block 30. Plug housing 1
5 and a plug housing 16 to which the plug block 20 is fixed, and an adapter housing 17 that accommodates and fixes the other side through the exposed side.

In the present embodiment, three blocks having an optical fiber holding structure for holding twelve optical fibers are connected in series to form a 36-core type optical fiber. It is difficult to make the inner diameters of the holding structure, especially the through holes uniform, but if there are about 12
It can be manufactured with a certain yield, and it becomes easy to increase the number of optical fibers. In addition, 36
The optical fibers 18, 18 'of the book are formed into grooves 21 as described later.
The plug block 20 fixedly held by the
Install so that housings 15 and 16 can be covered from above
Then, the plugs 11 and 12 are completed. In this way
As shown in FIG. 2 (a), the formed plugs 11 and 12 are
The adapter fixed in the center of the adapter housing 17
The optical fiber
The ends of the ribs 18, 18 'have their end faces butted against each other.
As will be described later, the through hole 31 of the adapter block 30
The optical fibers 18, 18 'are connected to each other and completed
Therefore, it is possible to create a connector in a plane mounting.
The connector assembly process is suitable for automation. The above is claim 1.
Involved in.

[0038]

The state at this time is as shown in FIG. 2 (b), but the optical fibers 18 and 18 'are inserted into the through hole 31 of the adapter block 30 from both sides, and one optical fiber, here 18 is bent. The tip of the optical fiber is pressed by the flexure and the buckling force in the space 19 so as to be in close contact with each other and optically connected. This connected state is held by a clip 14 made of a metal having a spring property, such as stainless steel or phosphor bronze.

The plug housings 15 and 16 have different fixing positions for the plug block 20 to form a flexible optical plug and an inflexible optical fiber. However, the plug block 20 is fixed to one plug housing. If two places are provided and selected at the time of use, only one die for manufacturing the member is required, which leads to cost reduction.

As shown in FIG. 3, the groove 21 of the plug block 20 has an opening slightly smaller than the outer diameter of the optical fiber and an inner portion having a size approximately equal to that of the optical fiber. The shape is circular, elliptical in cross section, or polygonal in cross section. If the plug block 20 is manufactured by molding a resin or the like, it has appropriate elasticity and the optical fiber can be pushed in and fixed from above.

At this time, if the inner size is made slightly larger than the outer diameter of the optical fiber, the position of the optical fiber can be adjusted after the mounting. On the contrary, if the inner dimension is made slightly smaller than the outer diameter of the optical fiber, the optical fiber can be fixed after mounting without an adhesive. If the semicircular portion 22 is provided, it is possible to insert the optical fiber from the rear end, which is necessary in some cases. Further, the provision of the semicircular portion 23 serves as a portion for receiving the coating portion of the optical fiber. The above relates to claims 2 , 3, and 4 .

Further, as shown in FIG. 4, the adapter block 30 has a fiber receiver 32 opened at the top at the entrance of the through hole 31. With an optical fiber pitch of 250 microns, the amount of picking up the optical fiber can be increased to 250 microns in diameter. An optical fiber is smoothly inserted by making the cross-sectional shape a semicircle and smoothly connecting the fiber receiver 32 and the through hole 31 with a tapered shape.

FIG. 5 shows another example of the adapter block, here an example of the adapter block 40 in which the fiber receiver has a V-shaped cross section. FIG. 5A is an exploded perspective view before assembly, and FIG. b) is a perspective view after assembly. That is, the body 41
14 V-grooves 42 having an opening of 250 microns are provided on one surface, a part of the V-grooves 42 is counterbored (43), and two cylinders (for example, an optical fiber) 44 having a slightly larger outer diameter than the optical fiber to be used are provided. , Installed in the V-grooves 42 at both ends, and the lid 45
It is easily made by mounting.

Such an adapter block 30 or 4
With the structure of 0, it is possible to reduce the required amount of positional accuracy of the tip of the optical fiber, which has the effect of reducing the required accuracy of all members, and to absorb the positional error that occurs when the blocks are connected. Is possible. Further, the insertion can be performed without the taper of the tip of the optical fiber. Further, at the time of fitting, the plugs 11 and 12 are inserted into the adapter 13 from above, and the plug 1 is formed by the length of the through hole 31 or the through hole formed between the V groove 42 and the lid 45.
The connection is completed by moving 1 and 12 in the axial direction of the optical fiber, so that the connection can be made in a form close to planar mounting. The above relates to claim 5 .

If the adapter block 30 shown in FIG. 4 is molded from resin to be an elastic body, and the inner diameter of the through hole 31 is slightly smaller than the outer diameter of the optical fibers 18 and 18 ', the optical fibers 18 and 18' will be connected at the time of connection. It is inserted while pushing through the through hole 31. Thereby, the through hole 31 and the optical fiber 18, 1
The 8'clearance is gone. The above relates to claim 6 .

FIG. 6 shows still another example of the adapter block, here, an example of the adapter block 50 having slits in the through holes. That is, the adapter block 50 is an elastic body formed of resin and has a through hole 51.
The inner diameter is smaller than the outer diameter of the optical fiber, and the slit 52 is provided. When the optical fiber is inserted into the through hole 51 at the time of connection, the slit 52 expands according to the outer diameter, and there is no clearance between the through hole 51 and the optical fiber.
With the above two structures, it is possible to minimize the axial deviation of the two optical fibers and realize a low connection loss. In addition, 53
Is a fiber receiver similar to that of FIG. The above relates to claim 7 .

[0048]

[0049]

[0050]

FIG. 7 shows an example of an embodiment of an optical wiring board using the optical fiber connector described so far.
FIG. 1A is a perspective view of the whole, and FIG. 1B is an explanatory view at the time of manufacturing.

The substrate 71 of the optical wiring board is, for example, an adhesive sheet, on which the optical fiber 72 is connected between predetermined two points, and the curvature is taken into consideration in the breakage and bending loss of the optical fiber. Minimum radius of curvature (generally 20m radius
It is wired and fixed so that it does not fall below m). As shown in FIG. 2B, a height adjusting plate 73 is used so that the wiring board 71 and the optical fiber holding structure portion of the plug block 20 of the optical fiber connector described above have the same height. If 72 is installed from above, the optical fiber 7 is attached to the optical fiber holding structure portion of the plug block 20.
Since 2 can be fitted from above, it is possible to assemble efficiently, it is possible to automate by machine, and it is possible to manufacture an optical wiring board with an optical connector (plug) in which the optical fiber does not bend. After mounting the optical fiber, cover the plug housing 15 (or 16) from above,
The plug 11 (or 12) is completed. The above is claim 8.
Involved in.

[0053]

As shown in FIG. 8 , the optical waveguide circuit 8 is provided with a fiber guide 81 having a structure in which the adapter block 30 or 40 or 50 is divided into two at the center thereof.
The optical waveguide circuit 82 is installed at the center of the guide hole.
If it is aligned with the core center of the optical waveguide 83, the optical fiber connector can easily connect the optical fiber and the optical waveguide circuit, and the optical wiring board described above can be used to install the optical fiber on the printed circuit board. Connection between waveguide modules can be easily performed.

FIG. 8 shows an example of a 1 × 8 splitter, and shows an example in which a total of 9 optical waveguides for input and output are collectively connected by a 12-core connector.

When the plug block, the adapter block, the plug housing, the adapter housing, etc. are injection-molded with a liquid crystal polymer, a high molding accuracy is obtained and the thermal expansion of the housing is suppressed, and the deflection amount of the optical fiber at the time of connection fluctuates. It is possible to realize a member that does not require stable optical connection.

[0057]

As described above, according to the optical fiber connector of the present invention, the number of connectable optical fibers can be easily expanded by connecting the optical fiber holding blocks in units of a predetermined number. It is possible to provide an optical fiber connector in which optical fiber mounting and connector assembly are easy.

Further, according to the optical wiring board of the present invention, it is possible to provide an optical wiring board with an optical fiber connector which can be easily assembled.

[0059]

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a conventional optical fiber connector.

FIG. 2 is a configuration diagram showing an example of an embodiment of an optical fiber connector of the present invention.

FIG. 3 is a configuration diagram showing details of a plug block.

FIG. 4 is a configuration diagram showing details of an adapter block.

FIG. 5 is a configuration diagram showing another example of an adapter block.

FIG. 6 is a configuration diagram showing still another example of the adapter block.

FIG. 7 is a configuration diagram showing an example of an embodiment of an optical wiring board of the present invention.

FIG. 8 is a configuration diagram showing an example of an optical waveguide circuit with an adapter.

[Explanation of symbols]

11, 12: Plug, 13: Adapter, 14: Clip, 15, 16: Plug housing, 17: Adapter housing, 18, 18 ', 72: Optical fiber, 19: Deflection space of optical fiber, 20: Plug block, 21 :
Grooves, 22 and 23: Semicircle part, 30, 40 and 50: Adapter block, 31, 51: Through hole, 32, 53: Fiber receiver, 41: Main body, 42: V groove, 43: Counterbore, 44:
Height adjusting cylinder, 45: lid, 52: slit, 71:
Substrate, 73: Height adjusting plate, 81: Fiber guide, 8
2: optical waveguide circuit, 83: optical waveguide.

Front page continuation (72) Inventor Shinichi Iwano 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Koichi Arishima 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corp. (72) Inventor Mamoru Hirayama 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corp. (72) Inventor Ryuji Honda 3-19 Nishishinjuku, Shinjuku-ku, Tokyo No. 2 Nihon Telegraph and Telephone Corp. (72) Inventor Makoto Sumita 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corp. (56) References JP-A-6-94948 (JP, A) Japanese Unexamined Patent Publication No. 7-13033 (JP, A) Japanese Unexamined Patent Publication No. 8-304658 (JP, A) Japanese Unexamined Patent Publication No. 9-159859 (JP, A) Actual Development No. 5-20004 (JP, U) (58) Survey Fields (Int.Cl. ⁷ , DB name) G02B 6/24

Claims (8)

(57) [Claims] 1. A first optical fiber holding portion for fixedly holding the vicinity of an end portion of a first optical fiber bundle formed of at least one optical fiber, and a second light formed of at least one optical fiber. A second optical fiber holding portion that fixedly holds the vicinity of the end portion of the fiber bundle, and a third optical fiber holding portion that holds the end portions of the first and second optical fiber bundles with their end faces abutting each other. And a state in which at least one of the first optical fiber bundle between the first and third optical fiber holding portions or the second optical fiber bundle between the second and third optical fiber holding portions is bent. As described above, in the optical fiber connector in which the first to third optical fiber holding portions are arranged and fixed to each other, each of the first to third optical fiber holding portions has at least one optical fiber on one surface. Fiber optic holding fiber Has a block with lifting structures, the I first to third blocks a plurality der each constituting the optical fiber holding unit, the scratch blocks constituting the first optical fiber holding portion of
First fixed to cover so as to cover except for the other surface side facing the surface
The housing and the block constituting the second optical fiber holding part are
The second fixing to cover so as to cover the other surface side opposite to the surface
The housing and the block constituting the third optical fiber holding part are
While storing and fixing via the other surface facing the surface,
Block that constitutes the fixed third optical fiber holding unit
Blocks forming first optical fiber holding parts on both sides of the
Holding first housing and second optical fiber holding
The second housing to which the blocks that make up the
The third hook that stores and fixes the other side of the other side through the exposed side.
An optical fiber connector having a housing . 2. A block constituting the first and second optical fiber holding portions is made of an elastic body, and the optical fiber holding structure has an opening having a diameter slightly smaller than the outer diameter of the optical fiber and an inner portion having an optical fiber sectional structure. The optical fiber connector according to claim 1 , wherein the optical fiber connector is a groove having a size. 3. The optical fiber connector according to claim 2 , wherein the cross-sectional shape of the groove is a shape obtained by cutting an upper portion of a circle or an ellipse. 4. The optical fiber connector according to claim 2 , wherein the cross-sectional shape of the groove is a shape obtained by cutting an upper portion of a polygon. 5. An optical fiber holding structure of a block which constitutes a third optical fiber holding portion, has a through hole having a diameter of about the size of an optical fiber cross section, and a through hole continuously provided in the through hole and having an upper opening. 2. A groove formed by forming a groove.
5. The optical fiber connector according to any one of 4 to 4 . 6. The block constituting the third optical fiber holding portion is made of an elastic body, and the optical fiber holding structure is a through hole having a diameter slightly smaller than the cross section of the optical fiber. 4. The optical fiber connector according to any one of 4 above. 7. The block forming the third optical fiber holding portion is made of an elastic body, and the optical fiber holding structure of the block is provided with a through hole having a diameter slightly smaller than the cross section of the optical fiber and the through hole. optical fiber connector of claims 1 to 4, wherein any one, characterized in that it consists of a slit. 8. An optical wiring board for connecting a predetermined two points by at least one optical fiber, characterized in that the terminal is equipped with the optical fiber connector according to any one of claims 1 to 4. Wiring board.