JP3952169B2 - Tape-like optical fiber manufacturing apparatus and manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tape-shaped optical fiber core in which two or more optical fiber strands are collectively covered with an ultraviolet curable resin or the like, and in particular, a manufacturing apparatus and a manufacture of a tape-shaped optical fiber core having a wide interval between optical fiber strands. It is about the method.
[0002]
[Prior art]
The tape-shaped optical fiber core is a state in which a plurality of optical fiber strands having an outer diameter of 0.25 mm arranged in parallel by applying a protective coating to an optical fiber strand, for example, a glass fiber having an outer diameter of 0.125 mm An optical fiber core wire that is covered with a coating resin and formed into a tape shape. As the coating resin, an ultraviolet curable resin is usually used, and the optical fiber strands are collectively coated in a state of being in close contact with each other. Therefore, if the outer diameter of the optical fiber is 0.25 mm, the pitch of the optical fiber in the tape-shaped optical fiber is 0.25 mm.
[0003]
However, the pitch of the optical fiber is too small to directly connect the terminal portion of the tape-shaped optical fiber to a photoelectric conversion device or optical connector. For this reason, a tape-shaped optical fiber core wire having a large optical fiber strand pitch is known. For example, a tape-shaped optical fiber having a larger optical fiber pitch has the same dimensions as a normal four-core optical fiber, but two inner optical fibers There are no optical fiber strands where the optical fiber strands are located, and the optical fiber strands are increased so that the optical fiber strands exist only on the two outer sides.
[0004]
For example, as shown in FIG. 3A, a tape-shaped optical fiber core having an increased interval between two optical fiber strands 21 or a two-core optical fiber strand 21 as shown in FIG. An optical fiber core wire in which a tensile strength member 24 is interposed therebetween to stabilize the pitch and shape between optical fiber strands is known (Japanese Patent Laid-Open No. 11-316327). Further, the gap between the four optical fiber strands 21 as shown in FIG. 3C is set to 0.2 to 0.8 mm, and the thickness of the collective coating 22 at this portion is made thinner than that of the optical fiber strand portion. A tape-shaped optical fiber core is known (Japanese Patent Laid-Open No. 11-231183). Further, a tape-shaped optical fiber core wire having a secondary coating for making FIG. 3A flat as shown in FIG. 3D is also known (Japanese Patent Laid-Open No. 2002-48955).
[0005]
FIG. 4 is a configuration diagram showing an outline of a general tape-shaped optical fiber manufacturing apparatus. In the figure, 1 is an optical fiber feeding device, 2 is a guide roller, 3 is a concentrator, 4 is a coating die device, 5 is an ultraviolet irradiation device, 8 is a tension adjusting device, and 9 is a winding device. A plurality of optical fiber strands are first concentrated on the same plane by the concentrator 3 via the guide roller 2 from the feeding device 1. The collected optical fiber strands are drawn into the coating die device 4, the pitch between the optical fiber strands is aligned in the coating die device, and an ultraviolet curable resin is provided near the outlet. Is collectively covered. Thereafter, the coating resin is cured by the ultraviolet irradiation device 5, passed through the tension adjusting device 8, and wound by the winding device 9.
[0006]
A tape-shaped optical fiber having a large distance between the optical fiber strands must be manufactured so that the distance between the fibers is within a specified range because of the connector attachment in the apparatus. In the above-described general method for manufacturing a tape-shaped optical fiber, an elliptical die is used as a die in the coating die apparatus, and the tape-shaped optical fiber having a larger optical fiber strand pitch is used as the die. When used in the manufacture of optical fiber, there is a large amount of resin between the optical fiber strands, so the effect of resin curing shrinkage is large, and it is difficult to keep the distance between the optical fiber strands within a specified range. .
[0007]
From this point of view, the problem shown in FIG. 3B can be solved by interposing a tensile body between the optical fiber strands. However, the addition of a tensile body brings about a significant cost increase and is not a good idea.
[0008]
Therefore, simply using an ordinary tape-shaped optical fiber core without using a tensile member and having a large distance between the optical fiber strands, as described above, the effect of resin curing shrinkage is large. In the manufacturing process, when the interval is wide, the viscosity is improved, and when it is narrow, the resin temperature is adjusted so as to reduce the viscosity, or the interval between the optical fiber strands is adjusted, or the production line speed is changed. Thus, a method of adjusting the distance between the optical fiber strands has been adopted. However, even if it is adjusted once, the interval changes over time due to changes in resin viscosity, etc., and is monitored with a monitor during manufacturing.When the interval between the optical fiber strands starts to change, the equipment is stopped, It takes a lot of time to determine the conditions due to the effect of the viscosity of the ultraviolet curable resin, such as adjusting the temperature again.
[0009]
In contrast, in a tape-shaped optical fiber having a constricted shape between the optical fiber strands as shown in FIGS. 3A and 3C, the resin interposed between the optical fiber strands is small. The effect of curing shrinkage is reduced, and the distance between the optical fiber strands is difficult to change. In order to mold this shape, a tape-shaped optical fiber core having substantially the same shape is manufactured using a gourd-shaped die. However, in the shape having the constricted portion 23, the winding state in the winding device in the case where the tape-shaped optical fiber core is continuously manufactured in a long length is disturbed, which causes distortion in the tape-shaped optical fiber core. Sometimes this can cause breakage. Further, when the tape is unwound from the winding device, the tape-shaped optical fiber core is tangled or twisted, and therefore, the workability is lowered and the transmission loss is increased.
[0010]
Therefore, as shown in FIG. 3 (D), the secondary coating 25, which is the second layer coating, is applied on the primary coating 22, which is the first layer batch coating in a gourd shape, so that the outer shape is constricted. It has been proposed to make the shape flat as a whole.
[0011]
However, even in the constricted shape as shown in FIGS. 3A and 3B, the distance between the optical fiber strands changes before being cured in the ultraviolet irradiation furnace. Also, as shown in FIG. 3D, if the primary coating 22 has a constricted shape, the spacing between the optical fiber strands similarly changes at the stage where the primary coating is applied. Even if the next coating 25 is applied, the change in the spacing remains.
[0012]
Therefore, it has been difficult to accurately manufacture the gap between the optical fiber strands in the prior art with a tape-shaped optical fiber having a wide gap.
[0013]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described circumstances, and in a tape-shaped optical fiber in which the distance between optical fiber strands is widened, the tape-shaped optical fiber can be manufactured with high accuracy. The object is to provide a manufacturing apparatus and a manufacturing method.
[0014]
[Means for Solving the Problems]
The present invention provides a first coating means that coats a plurality of optical fiber strands at a time so as to form a constricted shape between the optical fiber strands with an ultraviolet curable resin, and the coating means. In an apparatus for manufacturing a tape-shaped optical fiber having ultraviolet irradiation means for irradiating and curing a coated ultraviolet curable resin by irradiating ultraviolet rays, the first coating means coats the ultraviolet curable resin using a die. The ultraviolet irradiation means has spot light irradiation means for irradiating spot light and flat light irradiation means for irradiating flat light, and the spot light irradiation means ranges from the exit position of the die to 50 mm. In the inner position, the spot light is irradiated so as to cure the resin between the optical fiber strands by concentrating the power between the optical fiber strands toward the constricted portion. Flat light irradiation means is characterized in that it irradiates the flat light so as to cure the entire resin coating against irradiated tape-like optical fiber by the spot light irradiating means.
[0015]
The present invention also includes a first coating step in which a plurality of optical fiber strands are spaced apart and collectively covered with an ultraviolet curable resin so as to have a constricted shape between the optical fiber strands. In the method of manufacturing a tape-shaped optical fiber having an ultraviolet irradiation process in which the ultraviolet curable resin is cured by irradiating with ultraviolet light, the first coating process is to coat the ultraviolet curable resin with a die. And the ultraviolet irradiation step includes a spot light irradiation step of irradiating spot light and a flat light irradiation step of irradiating flat light, and the spot light irradiation step is within a range of 50 mm from the exit position of the die. In the position, spot power is irradiated so as to cure the resin between the optical fiber strands by concentrating the power between the optical fiber strands toward the constricted portion. DOO light irradiation step is characterized in that by the spot light irradiating step is to irradiate the flat light so as to cure the entire resin coating against irradiated tape-shaped optical fiber.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration diagram for explaining an example of an embodiment of an apparatus for manufacturing a tape-shaped optical fiber according to the present invention. In the figure, 1 is an optical fiber feeding device, 2 is a guide roller, 3 is a concentrator, 4 is a primary coating die device, 5 is a primary ultraviolet irradiation device, 6 is a secondary coating die device, and 7 is 2 A secondary ultraviolet irradiation device, 8 is a tension adjusting device, and 9 is a winding device.
[0017]
In this embodiment, the secondary coating 25 as the second layer coating is applied on the primary coating 22 as the first layer batch coating in the gourd shape as described in FIG. Thus, it is possible to manufacture a tape-shaped optical fiber core whose outer shape is entirely flat so that there is no constriction. A tape-shaped optical fiber manufactured by this manufacturing apparatus will be described. FIG. 3D shows a two-core optical fiber core. A secondary coating 25 is applied to a primary coating that collectively covers two optical fiber strands 21 having a nominal outer diameter of 0.25 mm coated with an ultraviolet curable resin.
[0018]
In this example, there are two cores, but as a practical tape-shaped optical fiber core, 2 to 16 cores are normal, and the gap between the optical fiber strands 21 is in the range of about 0.1 to 1.0 mm. It is. Therefore, when an optical fiber having an outer diameter of 0.25 mm is used, the pitch of the optical fiber is about 0.35 to 1.25 mm. An ultraviolet curable resin is used as the coating material, and an ultraviolet curable resin having a Young's modulus of 637 to 1127 MPa (temperature: 25 ° C., JIS K7113) is used for the primary coating 22. For the secondary coating 25, the same ultraviolet curable resin as that of the primary coating 22 may be used, but one having a Young's modulus of 147 to 285 MPa (temperature 25 ° C., JIS K7113) smaller than the primary coating may be used. . By reducing the Young's modulus of the secondary coating 25, it is possible to easily remove the coating of only the secondary coating 25. Thereby, only the secondary coating 25 is removed when the optical fiber ribbon is separated and branched into an optical fiber to form a connection with various devices, optical connectors, etc., so that the primary coating is thin. By separating at the constricted portion 23, the terminal processing can be easily performed. The secondary coating 25 may be formed so as to fill the recess 23, but the primary coating 22 may be entirely covered from the viewpoint of forming a batch coating. In addition, the surface of the secondary coating 25 should be as flat as possible so that it can be smoothly wound during manufacturing. If the flatness S (difference between the lowest and highest portions of the surface irregularities) is 0.02 mm or less, it is possible to satisfactorily wind up an optical fiber ribbon of 30 km or more with aligned winding.
[0019]
A plurality of optical fiber strands are collected on the same plane by the concentrator 3 through the guide roller 2 from the feeding device 1. Then, the collected optical fiber strands are introduced into the primary coating die device 4 so that the pitch between the optical fiber strands is uniformed in the coating die and is collectively covered with an ultraviolet curable resin. Is done. Next, the coating resin is cured by the primary ultraviolet irradiation device 5. Since the die shape in the primary coating die apparatus 4 is a constricted shape, the tape-shaped optical fiber core coated with the primary coating is an optical fiber strand as in the example described with reference to FIG. The covering between them is thinner than the outer diameter of the optical fiber. In a specific example of this example, the coating thickness in the vicinity of the optical fiber is 5 to 50 μm, and the thickness of the constricted portion of the gourd is in the range of 5 to 200 μm.
[0020]
This tape-shaped optical fiber core wire is introduced into the secondary coating die device 6 to perform secondary coating, and the secondary ultraviolet irradiation device 7 cures the coating resin. Thereafter, the film is wound up by the winding device 9 through the tension adjusting device 8.
[0021]
The present invention is characterized by the primary ultraviolet irradiation device 5. FIG. 2 is a schematic configuration diagram for explaining an example of an ultraviolet irradiation device used in the present invention. In the figure, the same parts as those in FIG. Reference numeral 10 denotes an optical fiber, 11 denotes a tape-shaped optical fiber, 12 denotes a spot light irradiation part, 12a denotes an ultraviolet lamp part, 12b denotes an optical fiber, 12c denotes an emission end, and 13 denotes a flat light irradiation part. A case where the tape-shaped optical fiber core manufacturing apparatus of FIG. 1 is used will be described as an example.
[0022]
A plurality of optical fiber strands concentrated on the same plane by the concentrator of FIG. 1 are introduced into the primary coating die apparatus 4. The resin coated in a constricted shape with the primary coating die apparatus 4 is irradiated with ultraviolet rays and cured. In this embodiment, the ultraviolet light irradiation is performed by the spot light irradiation unit 12 and the flat light irradiation unit 13. The spot light irradiation unit 12 includes an ultraviolet lamp unit 12a, an optical fiber 12b, and an emission end 12c. The spot light irradiation unit 12 transmits light from a light source such as an ultraviolet lamp provided in the ultraviolet lamp unit 12a through the optical fiber 12b, and the emission end. The spot light is irradiated from 12c toward the exit of the die of the primary coating die device 4. The direction of irradiating the spot light is the direction toward the constricted portion, and the irradiation is mainly performed so that the power is concentrated between the optical fiber strands. In FIG. 2, as shown in a partially enlarged view surrounded by a circle, even when the ultraviolet rays emitted from the emission end 12 c of the optical fiber 12 b spread at an opening angle, the ultraviolet rays are irradiated in a spot shape, and the amount of light at the center is the largest. The light intensity distribution. In the example shown in the partially enlarged view, the distance L from the end of the optical fiber 12b is 10 mm, the spot diameter D is 5 to 6 mm, and 5.6 W / cm ² in the center portion where the dots are marked, The present invention is not limited to this value. Further, a condensing lens can be provided at the exit end 12c to obtain an appropriate spot diameter, and the irradiation efficiency can be increased by the condensing action.
[0023]
The tape-shaped optical fiber core irradiated by the spot light irradiation unit 12 is introduced into the flat light irradiation unit 13 and subjected to ultraviolet irradiation, and the entire resin coating is cured. The flat light irradiation unit 13 does not irradiate flat light in a complete sense, but can irradiate irradiation light to a degree that is not condensed as compared with the spot light irradiation unit 12, and directly with an ultraviolet lamp. What is irradiated may be sufficient. In addition, if the resin coating is sufficiently cured by the spot light irradiation unit 12, the flat light irradiation unit 13 may not be provided.
[0024]
Thus, in the present invention, the ultraviolet curable resin coated in the shape having the constricted portion is irradiated with the spot light between the optical fiber strands at the exit of the coating means. That is, the optical fiber strands are irradiated with the spot light immediately after the optical fiber strands are covered. The outlet of the coating means means the position where the coating is completed, in the case of a die, the range from the outlet position of the die to 50 mm, and the term “immediately after” means the time when the coating is completed and the die in the case of the die. It means the range of time from the time of exiting the outlet to 500 msec, and within these ranges, the resin between the optical fiber strands is cured so as to ensure the spacing between the optical fiber strands. Can do.
[0025]
FIG. 5 shows the experimental results of measuring the variation in the spacing between the optical fiber wires due to the presence or absence of spot light irradiation. In the figure, the vertical line indicates the range of variation in the distance between the optical fiber strands. When spot light is not irradiated, it is not only reduced to 650 to 730 μm, but also has a wide change range and can be said to be unstable. On the other hand, when spot light is irradiated, in one example, 730 to 760 μm, and in another example, 720 to 770 μm, the reduction amount is small and the change range is narrow. Since the change range is narrow, it is possible to anticipate the reduction amount in advance.
[0026]
In addition, it is not always necessary to use a die for coating the ultraviolet curable resin, and an appropriate coating means such as a coating apparatus can be used. Even when a coating apparatus is used, the resin can be coated in a constricted shape by the surface tension of the applied resin by making the viscosity appropriate.
[0027]
In the above-described embodiment, since the ultraviolet curable resin between the optical fiber strands is coated so as to be thin, it is difficult to receive a change in the distance between the optical fiber strands due to the viscosity of the resin and the linear velocity. Since the resin is cured into a gourd type by the ultraviolet light irradiated to the outlet of the coating means, the ultraviolet curable resin can be cured in a state in which the distance between the optical fiber strands does not fluctuate due to the rigidity of the optical fiber strands. Furthermore, when the second layer UV curable resin is coated, since the first layer coating resin is cured, the passage resistance with the jig in the process of coating the second layer UV curable resin is reduced. Can be reduced.
[0028]
However, in the present invention, the second resin coating for covering the constricted portion with the resin so as to fill the constricted portion and covering the constricted portion with the resin is not necessarily provided. do not need. In the manufacturing apparatus described with reference to FIG. 4, as described with reference to FIGS. 1 and 2, the ultraviolet irradiation apparatus 5 performs spot light irradiation with ultraviolet light. In other words, in FIG. By omitting the device 6 and the secondary ultraviolet irradiation device 7, a tape-shaped optical fiber having a constricted portion is also included in the present invention. Depending on the application, even if the second layer of resin coating for flattening is not required, it is sufficient, which is advantageous from the viewpoint of cost.
[0029]
When the manufacturing linear speed changes, the light receiving energy per unit time changes and the curing speed changes. Therefore, if the manufacturing linear speed is increased, the curing speed decreases and the distance between the optical fiber strands becomes narrow. Become. In order to compensate for this, the power of the ultraviolet light is controlled according to the linear velocity. The value of the detected linear velocity or the set value of the linear velocity is used to increase the power of ultraviolet light when the linear velocity is high, and decrease the power of ultraviolet light when the linear velocity is low. Regardless of the speed, maintaining the curing speed can increase the accuracy of the spacing between the optical fiber strands.
[0030]
【The invention's effect】
As is apparent from the above description, according to the present invention, there is an effect that the interval between the optical fiber strands can be accurately achieved in the tape-shaped optical fiber core in which the interval between the optical fiber strands is widened.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram for explaining an example of an embodiment of an apparatus for manufacturing a tape-shaped optical fiber of the present invention.
FIG. 2 is a schematic configuration diagram for explaining an example of an ultraviolet irradiation device used in the present invention.
FIG. 3 is an explanatory diagram of a tape-shaped optical fiber core wire.
FIG. 4 is a configuration diagram showing an outline of a general tape-shaped optical fiber manufacturing apparatus.
FIG. 5 is a result of an experiment in which a variation in an interval between optical fiber strands due to the presence or absence of spot light irradiation is measured.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical fiber delivery apparatus, 2 ... Guide roller, 3 ... Concentrator, 4 ... Primary coating die apparatus, 5 ... Primary ultraviolet irradiation apparatus, 6 ... Secondary coating dice apparatus, 7 ... Secondary ultraviolet irradiation DESCRIPTION OF SYMBOLS 8 ... Tension adjusting device, 9 ... Winding device, 10 ... Optical fiber strand, 11 ... Tape-shaped optical fiber core wire, 12 ... Spot light irradiation part, 12a ... Ultraviolet lamp part, 12b ... Optical fiber, 12c ... Output end, 13... Flat light irradiation unit.

Claims (6)

A first coating means that coats a plurality of optical fiber strands at a time so that the gap between the optical fiber strands is constricted with an ultraviolet curable resin; and an ultraviolet ray that is coated with the coating means. In an apparatus for manufacturing a tape-shaped optical fiber having ultraviolet irradiation means for irradiating and curing a curable resin with ultraviolet rays,
The first coating means is for coating the ultraviolet curable resin with a die,
The ultraviolet irradiation means has spot light irradiation means for irradiating spot light and flat light irradiation means for irradiating flat light,
The spot light irradiation means concentrates the power between the optical fiber strands toward the constricted portion at a position within a range of 50 mm from the exit position of the die so as to cure the resin between the optical fiber strands. Irradiates with spot light,
The flat light irradiation means irradiates the tape-shaped optical fiber core wire irradiated by the spot light irradiation means with flat light so as to cure the entire resin coating. Fiber core manufacturing equipment.   A tape-shaped optical fiber core whose coating resin is cured by the ultraviolet irradiation means has a second coating means for covering the constricted portion with a resin so as to form a flat shape. The manufacturing apparatus of the tape-shaped optical fiber core wire of Claim 1.   3. The production of a tape-shaped optical fiber according to claim 1, further comprising control means for controlling the power of the ultraviolet light of the spot light irradiation means in accordance with the linear velocity of the optical fiber. apparatus. A first coating step in which a plurality of optical fiber strands are spaced apart and collectively covered with an ultraviolet curable resin so as to form a constriction between the optical fiber strands; and the coated ultraviolet curable resin In the method of manufacturing a tape-shaped optical fiber having an ultraviolet irradiation step of curing by irradiating with ultraviolet rays,
The first coating step is to coat the ultraviolet curable resin using a die,
The ultraviolet irradiation step has a spot light irradiation step of irradiating spot light and a flat light irradiation step of irradiating flat light,
In the spot light irradiation step, power is concentrated between the optical fiber strands toward the constricted portion at a position within a range of 50 mm from the exit position of the die so as to cure the resin between the optical fiber strands. Irradiates with spot light,
The flat light irradiation step irradiates the tape-shaped optical fiber core wire irradiated in the spot light irradiation step with flat light so as to cure the entire resin coating. Manufacturing method of fiber core wire.   It has a second resin coating step of covering the constricted portion with a resin so as to fill the constricted portion with respect to the tape-shaped optical fiber core in which the coating resin is cured by the ultraviolet irradiation step. The manufacturing method of the tape-shaped optical fiber core wire of Claim 4.   6. The method of manufacturing a tape-shaped optical fiber according to claim 4, wherein the power of the spot light is controlled according to a linear velocity of the optical fiber.

Images