JP2004045463A - Re-covering device for optical fiber and re-covering method for optical fiber using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a re-covering method for an optical fiber by which the generation of burr is restrained and which is reliable, and to provide a re-covering device by which the generation of the burr is restrained, whose life is prolonged and which realizes the reliable re-covering of the optical fiber. <P>SOLUTION: The re-covering device where a molding groove 102 having an inside diameter of nearly the same size as the outside diameter of the fused and spliced part of the optical fiber is formed, which is equipped with an upper mold 101B and a lower mold 101A constituted by forming an injection groove for injecting ultraviolet curing resin in the internal space of the molding groove and a light source for curing the ultraviolet curing resin, and constituted so that a re-covering layer may be formed on the bare fiber part of the fused and spliced part of the optical fiber, is equipped with a light shielding layer 110 in an area corresponding to the molding groove on the outer wall of either the upper mold or the lower mold positioned on the light source side. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recoating apparatus and an optical fiber recoating method using the same.
[0002]
[Prior art]
When the optical fibers are fusion-spliced, it is necessary to recoat and reinforce the optical fiber connection.
As one of the methods for performing the recoating in this way, a method of recoating the optical fiber connection portion using a mold has been proposed.
[0003]
As shown in FIG. 8, this device is arranged such that the bare fiber portion 1 that has been fusion-bonded is located at the center of the cavity 102 formed between the lower die 101A and the upper die 101B, and is irradiated with ultraviolet rays 103S. And harden it.
[0004]
In this apparatus, when the resin liquid flows into the mating surface of the lower mold 101A and the upper mold 101B, burrs are generated after curing. Although the ultraviolet light shielding film 104 is provided on the mating surface of the mold, it is considered that burrs occur because ultraviolet light irregularly reflected inside the arc of the groove leaks to the mating surface.
Japanese Patent No. 3118994 discloses a technique of forming a metal film as a light-shielding layer on a mating surface of an upper mold and a lower mold of a mold.
[0005]
In this recoating apparatus, as shown in FIG. 9, the mold dies 101A and 101B are made of quartz glass so that the state of resin filling can be visually checked, and the resin is cured so as to transmit ultraviolet rays. Light-shielding layers 105a and 105b are provided on the contact surface between the upper surface of the lower mold 101A and the lower surface of the upper mold 102B to prevent the resin leaking from the clearance from hardening and to suppress the generation of burrs. It is configured.
[0006]
However, the edge portions E of these molding grooves are likely to be chipped, and as a result, burrs may be generated.
[0007]
[Problems to be solved by the invention]
The burrs may cause damage when the optical fiber is wound around the bobbin, or may cause deterioration of transmission characteristics due to distortion caused by the burrs.
[0008]
In addition, there may be a problem that the burrs are stuck during handling, and when the burrs are removed, the root portion of the burrs is clogged. There is a problem in that if it is eclipsed, it is necessary to refill the eclipsed part with resin.
[0009]
For this reason, when burrs occur, it is necessary to carry out deburring promptly. However, deburring up to now has been a fine work of enlarging with a microscope and cutting with a razor or the like blade, resulting in poor workability and a decrease in productivity.
[0010]
It is also conceivable to reduce the amount of ultraviolet radiation so as not to cause burrs and re-coat, but it is not possible to sufficiently increase the degree of curing of the re-coated part, and long-term reliability such as disconnection due to deterioration in glass strength is likely to occur. It is feared that it will have an adverse effect.
[0011]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly reliable optical fiber recoating method capable of suppressing generation of burrs.
[0012]
It is another object of the present invention to provide a recoating apparatus capable of suppressing the generation of burrs, performing long-life and highly reliable recoating of an optical fiber.
[0013]
[Means for Solving the Problems]
Therefore, in the present invention, an upper mold having a molding groove having an inner diameter substantially equal to the outer diameter of the coated optical fiber and an injection groove for injecting an ultraviolet curable resin into an inner space of the molding groove is formed. And a lower mold, and a light source for curing the ultraviolet curable resin, a recoating apparatus configured to form a recoating layer on the bare fiber portion of the optical fiber fusion splicing section, wherein the upper mold or the lower mold A light shielding layer having an opening in a region corresponding to the molding groove on one of the outer walls located on the light source side of the mold is provided.
[0014]
Further, in the optical fiber recoating apparatus of the present invention, an intermediate light-shielding layer formed on at least one of the contact surfaces of the upper mold or the lower mold, and one of the upper mold or the lower mold located on the light source side. An outer light-shielding layer having an opening is provided in a region of the outer wall corresponding to the molding groove.
[0015]
Preferably, the width of the opening of the outer light-shielding layer is smaller than the width of the molding groove.
[0016]
Preferably, the intermediate light-shielding layer is made of a material having a hardness equal to or higher than that of glass.
[0017]
Preferably, the upper mold or the lower mold located on the light source side is formed of black quartz in which the area is formed of a light-transmitting material so that ultraviolet rays can be transmitted to an area corresponding to the molding groove. It is characterized by having.
[0018]
Preferably, the intermediate light-shielding layer is made of black quartz.
[0019]
Preferably, a bubble discharge space is provided above the molding groove so as to communicate with the molding groove.
[0020]
Further, the method of the present invention includes a step of mounting a fusion spliced portion of an optical fiber in a molding groove of the recoating apparatus of the present invention, a step of supplying an ultraviolet curable resin into the molding groove, and Irradiating ultraviolet rays through a light blocking member so as to selectively irradiate light only from a region corresponding to the molding groove from outside one of the lower molds, and curing the resin; and Removing the fusion spliced portion of the optical fiber re-coated with the resin from the coating device.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
(First Embodiment)
As shown in FIGS. 1 to 4, the apparatus according to the present embodiment has an outer diameter of a coated portion of the optical fiber so as to form a recoating layer on the bare fiber portion 1 of the optical fiber fusion splicing portion. A molding groove 102 (102A, 102B) having an inner diameter substantially the same as that of the molding groove 102 and an injection groove for injecting a resin into the internal space of the molding groove are formed. The coating apparatus is characterized in that an outer light-shielding layer 110 having an opening O is provided on an outer wall of a lower mold 101A located on the ultraviolet lamp 108 side. The outer light-shielding layer has an opening 0 having a groove width W1 slightly smaller than the groove width W0 of the molding groove in a region corresponding to the molding groove 102. Here, FIG. 1 is an exploded perspective view of a mold of the recoating apparatus. 2A is a sectional view of a mold, FIG. 2B is a sectional view taken along line AA of FIG. 2A, FIG. 3 is an overall front view of the recoating apparatus, and FIGS. 4A to 4C. FIG. 4 is a process cross-sectional view of the recoating method.
[0023]
In the recoating method using this apparatus, a mold including the upper mold 101B and the lower mold 101A is mounted on the bare fiber portion 1 of the optical fiber fusion splicing section, and the mold is filled with an ultraviolet curable resin. When irradiating ultraviolet rays to cure the ultraviolet curable resin and recoat the bare fiber portion, an opening 0 having a groove width W1 slightly smaller than the groove width W0 of the molding groove is formed in a region corresponding to the molding groove 102. Ultraviolet light is irradiated from an ultraviolet lamp 108 through an outer light-shielding layer 110 to suppress generation of burrs and form a high-quality recoating layer 113.
[0024]
Here, in order to efficiently discharge bubbles remaining in the cavity 102 formed by the molding grooves 102A and 102B, a bubble discharge space 300 extending obliquely from the molding groove 102B is provided. This makes it possible to suppress the bubbles from remaining in the recoating layer 113.
[0025]
Here, the molds 101A and 101B are made of quartz glass, and can be visually checked for a resin filling state, and are formed so that the resin is cured to transmit ultraviolet rays. Further, an intermediate light-shielding layer 105a made of black quartz is provided on the contact surface between the upper surface of the lower die 101A and the lower surface of the upper die 102B, and the resin leaked from the gap between the mating surfaces of the lower die 101A and the upper die 102B. It is configured to prevent hardening and suppress the generation of burrs.
[0026]
The intermediate light-shielding layer 105a is formed so that the edge is exposed in the molding groove. However, since the intermediate light-shielding layer 105a is made of black quartz, no cracking occurs.
[0027]
Further, since the outer light-shielding layer 110 having the opening O smaller than the width W0 of the molding groove is formed on the lower surface of the lower mold, it is assumed that the ultraviolet light does not hit around the molding groove and the resin exudes around the molding groove. Can also suppress the hardening. As described above, in addition to the outer light-shielding layer 110 formed on the outside, and the presence of the intermediate light-shielding layer 105a formed on the contact surface between the upper surface of the lower die 101A and the lower surface of the upper die 102B, extremely high reliability is achieved. The coating layer 113 can be formed. Here, 106a and 106b are clamps.
[0028]
That is, first, as shown in FIG. 4A, a bare fiber portion 1 having an outer diameter of about 125 microns, which is fusion-spliced, is formed at the center of a cavity 102 formed between the lower die 101 and the upper die 101B. Then, urethane acrylate resin 950Y200 manufactured by JSR Corporation is filled into the molding groove 102 forming a columnar cavity having an inner diameter of 260 μm through the injection groove 104.
[0029]
In this state, irradiation is performed for 45 seconds from the outside of the mold using an ultraviolet lamp 108. The irradiation time can be adjusted according to the irradiation lamp power.
Thus, the recoating layer 113 made of urethane acrylate is formed.
[0030]
Then, as shown in FIG. 4B, the upper mold and the lower mold are removed, and the recoating layer 113 without burrs can be obtained.
[0031]
In this way, it is possible to obtain a recoated optical fiber. This recoating length L was about 38 mm.
[0032]
The optical fiber thus formed has a very good recoating area without the presence of burrs.
[0033]
Even if the resin seeps into the contact area between the upper mold and the lower mold, the presence of the outer light-shielding layer 110 and the intermediate light-shielding layer 105a can prevent the reception of ultraviolet rays and suppress the curing. Almost no burrs occur.
[0034]
In the above-described embodiment, the bubble discharging space is formed, but the bubble discharging space is formed obliquely upward from the inner wall of the molding groove to the front molding groove, upward along the longitudinal direction of the molding groove. Since the space is formed so as to penetrate the groove, the residual air in the molding groove can be discharged very efficiently.
[0035]
Further, the intermediate light-shielding layer 105a is not limited to black quartz, but is effective for curing the mold resin, such as a chromium, tungsten, aluminum, or carbon film, or a two-layer film in which a titanium layer is formed on a tungsten layer. What is necessary is just to form so that the light of a wavelength range may be shielded. Further, it is also possible to suppress peeling due to a difference in thermal expansion coefficient by forming a multilayer film.
[0036]
Further, in the first embodiment, since the intermediate light-shielding layer is made of black quartz which is a material having high hardness, the deterioration of the edge E of the forming grooves 102A and 102B forming the cavity 102 is prevented.
[0037]
(Second embodiment)
Next, a second embodiment of the present invention will be described. In the first embodiment, the light-shielding layer is provided on the outside of the lower mold 101A and on the contact surface between the lower mold 101A and the upper mold 101B, as shown in FIGS. 5A and 5B. As described above, it is also effective to form the outer light-shielding layer 110 having the opening O only on the outside of the lower mold 101A.
[0038]
Other parts are the same as in the first embodiment. The same parts are denoted by the same reference numerals, and description thereof will be omitted.
In the first embodiment, the bubble discharge space 300 is formed continuously over the entire length of the molding groove, but is not provided in this example.
[0039]
Furthermore, when the opening O is smaller than the width WO of the molding groove, the light incident from the opening O does not reach the periphery of the molding groove, so that the hardening of the resin oozing around the molding groove can be suppressed.
Further, the width of the opening O of the outer light-shielding layer may be slightly larger by increasing the degree of light collection of the light source for curing, such as by using a laser.
[0040]
(Third embodiment)
Next, a third embodiment of the present invention will be described. In the first embodiment, the light-shielding layer is formed. However, in this example, the other area except for the molding groove is made of light-shielding black quartz.
That is, as shown in FIGS. 6 and 7, the bare fiber portion is re-coated using a lower mold 301A composed of a light-transmitting region 301R made of quartz and a light-shielding region made of black quartz. The other parts are the same as in the first and second embodiments.
[0041]
According to this configuration, since there is no light wraparound, it is possible to reliably suppress the occurrence of burrs. In addition, the possibility that the edge of the molding groove is applied is small.
[0042]
In the above embodiment, the upper mold 301B is also made of black quartz, but the mold on the side opposite to the light source may not use a light-shielding material.
[0043]
As is well known, black quartz is formed by adding a blackening element such as V, Mo, or Nb or a compound thereof as a blackening agent to silica powder and melting by heating. In this example, the lower mold 301A partially includes the translucent region 301R, but the following method is used for manufacturing the lower mold.
[0044]
First, a mixed powder obtained by mixing a blackening agent containing a blackening metal element with silica powder is vitrified, and silica powder not containing a blackening agent is vitrified to form a quartz glass molded body for a black part and quartz for a transparent part. Form a glass molding. These are filled in respective regions of the heat-resistant mold, and heated and melted at about 1900 ° C. in a vacuum atmosphere to form a light-shielding lower mold 301A having a light-transmitting region 301R.
[0045]
Although the urethane acrylate resin is used in the first to third embodiments, it is needless to say that another ultraviolet curable resin may be used.
[0046]
【The invention's effect】
As described above, according to the apparatus of the present invention, it is possible to provide a long-life and highly reliable recoating apparatus without generating burrs.
According to the method of the present invention, recoating with high reliability can be performed without generation of burrs.
[Brief description of the drawings]
FIG. 1 is an exploded view of a mold of an optical fiber recoating apparatus according to a first embodiment of the present invention.
FIG. 2 is a sectional view of a mold of the recoating apparatus according to the first embodiment of the present invention.
FIG. 3 is a diagram showing a recoating apparatus according to the first embodiment of the present invention.
FIG. 4 is a diagram showing a step of recoating the optical fiber according to the first embodiment of the present invention.
FIG. 5 is a diagram showing an optical fiber recoating apparatus according to a second embodiment of the present invention.
FIG. 6 is an exploded view of a mold of an optical fiber recoating apparatus according to a third embodiment of the present invention.
FIG. 7 is a sectional view of a mold of a recoating apparatus according to a third embodiment of the present invention.
FIG. 8 is a diagram showing a conventional optical fiber recoating apparatus.
FIG. 9 is a diagram showing a conventional optical fiber recoating apparatus.
[Explanation of symbols]
Reference Signs List 1 bare fiber portion 1S fiber fusion portion 100 bubble discharge groove 101A lower mold 101B upper mold 102A molding groove 102B molding groove B flash 105a intermediate light shielding layer 105b intermediate light shielding layer 110 outer light shielding layer 111 coating resin 113S semi-cured resin 113 recoating layer

Claims (7)

An upper die and a lower die, which form a molding groove having an inner diameter substantially equal to the outer diameter of the coated optical fiber, and form an injection groove for injecting an ultraviolet curable resin into an inner space of the molding groove, A light source for curing the ultraviolet curable resin, a recoating device configured to form a recoating layer on the bare fiber portion of the optical fiber fusion spliced portion,
An optical fiber re-coating device, comprising: a light-shielding layer having an opening in a region corresponding to the molding groove on one of outer walls located on a light source side of the upper mold or the lower mold. An upper die and a lower die, which form a molding groove having an inner diameter substantially equal to the outer diameter of the coated optical fiber, and form an injection groove for injecting an ultraviolet curable resin into an inner space of the molding groove, A light source for curing the ultraviolet curable resin, a recoating device configured to form a recoating layer on the bare fiber portion of the optical fiber fusion spliced portion,
An intermediate light-shielding layer formed on at least one of the upper and lower mold contact surfaces,
An optical fiber re-coating device, comprising: an outer light-shielding layer having an opening in a region corresponding to the molding groove on one of outer walls of the upper mold and the lower mold located on the light source side. The optical fiber re-coating apparatus according to claim 1, wherein an opening of the outer light-shielding layer is narrower than the molding groove. One of the upper mold and the lower mold, which is located on the light source side, can transmit ultraviolet rays to a region corresponding to the molding groove, so that the region is made of black quartz made of a translucent material. The optical fiber recoating device according to claim 1, wherein 3. The optical fiber recoating device according to claim 2, wherein the intermediate light-shielding layer is made of black quartz. The optical fiber re-coating device according to any one of claims 1 to 5, further comprising a bubble discharging space configured to communicate with the molding groove above the molding groove. A step of placing a fusion spliced portion of an optical fiber in a molding groove of the recoating device according to any one of claims 1 to 5,
Supplying an ultraviolet curable resin into the molding groove;
A step of irradiating ultraviolet rays through a light-shielding member so that light is selectively applied only to a region corresponding to the molding groove from outside one of the upper mold and the lower mold, thereby curing the resin. When,
Removing the fusion spliced portion of the optical fiber recoated with the resin from the recoating device.

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