JP2000081538A - Cleaner for connection end of optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily remove dust and an oil film sticking to the connection end of an optical fiber by forming a porous body of a specified synthetic resin as a cleaning part brought into contact with the exposed end of the optical fiber. SOLUTION: A cleaning part 2 is fixed with an adhesive on the top of a grasping member 1 made of wood or paper caked with an adhesive or of a synthetic resin. The cleaning part 2 brought into contact with the exposed end of an optical fiber is a porous body of a synthetic resin containing >=12 methylene units in the repeating units. The synthetic resin is, e.g. a polyester urethane resin or a polyether urethane type thermoplastic elastomer. In the case of a thermoplastic polyurethane resin, a powdery inorganic compound such as calcium carbonate is dispersed in the resin and mixed, the mixture is molded and the calcium carbonate is dissolved with chemicals to form open pores.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connection for removing a contaminant attached to an end of an exposed optical fiber of a connector for connecting an optical fiber cable to another optical fiber cable or other connection equipment. The present invention relates to an end cleaner.

[0002]

2. Description of the Related Art An optical connector for connecting optical fibers, which are glass fibers used in an optical cable, includes an optical fiber in a hollow cylinder made of a tough ceramic material such as zirconia called ferrule or glass. The optical fiber that is inserted and fixed with an adhesive is disposed in the sleeve cylinder of the connection holder, and the end of the optical fiber is polished together with the end of the ferrule that is the joined outer skin member.

In this optical connector, it is essential to connect optical fibers efficiently with low optical loss, low reflection, and it is required that the connecting portions of the optical fibers have a precision of a micro unit. Adhering of dust and hand oil is a serious problem.

Conventionally, as a cleaning unit for removing dust and oil film adhered to the end of the optical fiber,
Japanese Utility Model Laid-Open Publication No. 3-117208 and Japanese Utility Model Laid-Open Publication No. 3-117209 disclose the use of cloth woven from ultrafine fibers of 0.1 denier or less. Also, JP-A-9-10
Japanese Patent No. 5835 discloses a cleaning unit using a metal, a conductive plastic material, or a conductive rubber material.

[0005]

The above-mentioned prior art cleaners have not been satisfactory in the performance of removing dust and oil films. Even if the dust and oil film on the target part can be temporarily removed by the wiper effect of the cleaning unit,
If the dust or oil film is not caught by the cleaning unit, the dust or oil film may return to the relevant portion again. There is a problem in that, for example, there is a possibility of adhesion due to static electricity or the like.

[0006]

That is, the present invention is to provide a connector for connecting an optical fiber cable to another optical fiber cable or other connecting device, and to contact the exposed end of the optical fiber to remove contaminant deposits on the end. In the optical fiber connection end cleaner to be removed, at least the cleaning portion in contact with the exposed end of the optical fiber is made of a synthetic resin porous body in which at least 12 or more methylenes are present in the repeating unit. The gist is an optical fiber connection end cleaner.

As the synthetic resin having 12 or more methylenes in the repeating unit, polyester urethane resin,
Examples thereof include a polyether urethane resin, a polyester urethane-based thermoplastic elastomer, and a polyether urethane-based thermoplastic elastomer. The polyether urethane resin can be formed by adding a glycol component to 1,4-butanediol and isocyanate, and the glycol component is polyoxyethylene glycol, polyoxypropylene-polyoxyethylene glycol, polyoxybutylene glycol, polyoxytetramethylene. Glycol and the like.

In the case where the resin is a thermoplastic polyurethane resin, an inorganic compound powder such as calcium carbonate is dispersed and mixed in the thermoplastic polyurethane resin, followed by molding, followed by dissolving calcium carbonate with a chemical to form communicating pores. Can be. As a specific example, a mixture obtained by uniformly mixing polyurethane, calcium carbonate, dimethylformamide, and ethylene glycol at 140 ° C. is cooled, and then pulverized into fine particles to obtain a molded product having a desired shape by injection molding. Then, it is immersed in an aqueous hydrochloric acid solution (or a mixed solution with nitric acid) to extract calcium carbonate as calcium chloride to obtain a molded article of a polyurethane resin having communicating pores.

[0009]

The cleaning unit is made of a single-piece porous synthetic resin, so that there is no detachment of the cleaning unit itself such as lint, and dust and oil can be captured in the holes. Since the synthetic resin has at least 12 or more methylenes in the repeating unit, the synthetic resin has a high affinity with those having a linear structure composed of methylene, such as hand oil, so that the oil can be trapped (adsorbed). It will be easy. In addition, a proper space area is opened in the surface of the cleaning portion that comes into contact with the target portion to be cleaned. The dirt is captured by the hole portion and the dirt removal effect by the portion other than the hole that substantially contacts the target portion (wiper effect). And can work efficiently. Furthermore, by adopting a material containing a large amount of methylene in the cleaning part, the frictional resistance of the member is relatively high due to a three-dimensionally and strongly interacting molecular structure in which the displacement between molecules is small with respect to external force. It is possible to contact the dirt substantially in contact with the target portion and finely vibrate the dirt-removing portion, thereby facilitating the dirt removal and the incorporation into the holes.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 shown in an external perspective view is one in which wood or paper is solidified with an adhesive, or a cleaning unit 2 is fixed to the tip of a gripping member 1 which is a bar made of synthetic resin with an adhesive. is there. As shown in FIG. 2 which is a vertical cross-sectional view of FIG. 1, an adhesive layer 3 is formed between the gripping member 1 and the cleaning unit 2. The adhesive can be used without particular limitation as long as it does not invade other members, but has a relatively high viscosity of several tens cps or more so that the adhesive does not penetrate and seal the porosity of the cleaning portion. It is preferred to use

FIG. 3 shows another example. Cleaning unit 2
6 is an example of a position of a fixing method for the holding member 1 of FIG. That is,
A concave portion 2a having a diameter smaller than the outer diameter of the gripping member 1 is formed in a portion of the cleaning unit 2 where the gripping member 1 contacts, and the end of the gripping member 1 is pressed into the concave portion 2a. An adhesive layer may be appropriately formed in the recess 2a serving as the press-fitting portion in the same manner as in the above example.

FIG. 4 shows still another example. Gripping member 1 '
Is a synthetic resin cylindrical body, and a long rod-shaped cleaning portion 2 'is inserted into its inner hole. In this embodiment, a clean and clean end face that comes into contact with the optical fiber can be formed by cutting the dirty tip of the cleaning section 2 'after the cleaning operation.

FIG. 5 is a sectional view of a main part for explaining a cleaning operation. The cleaning operation is performed in the example shown in FIG. A cleaning member 2 of a cleaner is inserted into a sleeve tube 7 of an optical connector 8 in which an optical fiber 5 is inserted into a ferrule 4 which is a cylindrical outer shell member made of zirconia and arranged inside a sleeve tube 7 of a connection holder 6. The gripping member 1 held in hand by being brought into contact with the polished end surfaces of the ferrule 4 and the optical fiber 5
The cleaning unit 2 is rotated by the
Of the ferrule 4 and the end face of the optical fiber 5 are rubbed. At the same time, the side of the cleaning unit 2 is
To remove contaminants (not shown) such as dust and hand oil adhering to the end surfaces of the ferrule 4 and the optical fiber 5 and the peripheral portion thereof. Further, if the entire length of the cleaning portion 2 is formed so as to contact the entire length of the inside of the sleeve 7, the ferrule 4, the end surface of the optical fiber 5, and the inner surface of the sleeve 7 can be cleaned by a single cleaning operation. Removal can also be performed.

FIG. 6 shows still another example. It is a modified example of the shape of the cleaning unit 2. A projection 2b having the same diameter as or slightly smaller than the outer diameter of the optical fiber 5 is provided at the center of the distal end surface of the cylindrical cleaning portion 2. By doing so, at the time of cleaning, the force for bringing the optical fiber 5 into close contact with the end face of the optical fiber 5 located at the center of the ferrule 4 can be concentrated, and the attached contaminants can be more reliably removed. Similar effects can be obtained by forming the tip surface of the cleaning portion 2 into a convex tapered shape as in the projection 2b shown in FIG. 7, and in this case, the cleaning portion 2 can be easily shaped only by polishing. This is advantageous because it is possible.

FIG. 8 shows another modification of the shape of the cleaning section 2. The tip of the cleaning section 2 is formed in a wavy surface. Examples of the forming method include cutting, polishing, and injection molding using a mold. By doing so, the strength of the contact between the ferrule 4 and the end face of the optical fiber 5 can be increased during cleaning, so that the strongly contacted part moves on the optical fiber 5 like a wiper, and the weakly contacted or non-contacted part is moved. It is possible to mainly perform dirt trapping and to efficiently operate the dirt removing function.

As the cleaning section 2 of the cleaner having the structure shown in FIGS. 1, 6, 7 and 8, various materials were used, and the degree of removal of adhering contaminants was tested. .

Example 1 Royalsen R390 was prepared using Royalsen R390PNAT (manufactured by Nippon Milactran Co., Ltd.), which is a polyether urethane resin comprising 1,4-butanediol, isocyanate and polyoxytetramethylene glycol.
After cooling 15 parts of PNAT, 73 parts of calcium carbonate, 1 part of dimethylformamide and 11 parts of ethylene glycol uniformly at 140 ° C., the mixture was cooled to obtain pellets which were pulverized into fine particles.
% Of aqueous solution of hydrochloric acid to extract calcium carbonate as calcium chloride to obtain a columnar polyurethane resin long molded article having communicating pores. The obtained polyurethane resin long molded product was cut into an appropriate size, the surface was polished, and shaped into a columnar shape as shown in FIG. 1 to obtain a cleaning portion. The cleaning portion was adhered to a paper bar as a gripping member to obtain a cleaner of Example 1. The opening area of the cleaning section is 80%, and the Shore A hardness is 45.
The coefficient of friction of the optical connector with respect to the ferrule and the optical fiber of the cleaning section was 0.9.

Example 2 The polyurethane resin long molded product described in Example 1 was cut into an appropriate size and the surface was polished, so that the cylindrical cleaning portion 2 shown in FIG. A cleaning portion was obtained by shaping the optical fiber 5 into a shape provided with a projection 2b having the same diameter as or slightly smaller than the outer diameter of the optical fiber 5, and a cleaner of Example 2 was obtained in the same manner as in Example 1 except for the above.

EXAMPLE 3 The polyurethane resin long molded article described in Example 1 was cut into a suitable size and the surface was polished, whereby the tip end face shown in FIG. The same procedures as in Example 1 were carried out to obtain a cleaner of Example 3.

Example 4 The polyurethane resin long molded product described in Example 1 was cut into an appropriate size, and the surface was cut with a corrugated blade to shape the tip end surface shown in FIG. 8 into a wavy shape. A cleaning unit was obtained, and the other conditions were the same as in Example 1 to obtain a cleaner of Example 4.

Embodiment 5 In obtaining a cleaning unit, Royalsen R390
A cleaner of Example 5 was obtained in the same manner as in Example 1, except that 4 parts of PNAT and 84 parts of calcium carbonate were used. The opening area of the cleaning section is 95%, the Shore A hardness is 30 degrees,
The coefficient of friction of the cleaning section with respect to the ferrule and the optical fiber of the optical connector was 0.8.

Embodiment 6 In obtaining the cleaning unit, Royalsen R390
A cleaner of Example 6 was obtained in the same manner as in Example 1, except that PNAT was 32 parts and calcium carbonate was 56 parts. The opening area of the cleaning section is 75% and the Shore A hardness is 60
The coefficient of friction of the optical connector with respect to the ferrule and the optical fiber of the cleaning section was 2.0.

Comparative Example 1 A laminate of Toraysee Miracle Cloth (manufactured by Toray Industries, Inc.), which is a cloth material of polyester fiber (2 to 3 μm), was wound around a paper rod as a gripping member, and the cleaner of Comparative Example 1 was used. Obtained. The coefficient of friction of the cleaning unit with respect to the ferrule of the optical connector and the optical fiber was 0.9.

COMPARATIVE EXAMPLE 2 In obtaining a cleaning unit, Royalsen R390
A cleaner of Comparative Example 2 was obtained in the same manner as in Example 1, except that 38 parts of PNAT and 50 parts of calcium carbonate were used. The opening area of the cleaning section is 70%, and the Shore A hardness is 65.
The coefficient of friction of the cleaning unit with respect to the ferrule and the optical fiber of the optical connector was 2.3.

COMPARATIVE EXAMPLE 3 When obtaining a cleaning unit, use Royal Sen R390
A cleaner of Comparative Example 3 was obtained in the same manner as in Example 1, except that 2 parts of PNAT and 86 parts of calcium carbonate were used. The opening area of the cleaning section is 98%, the Shore A hardness is 25 degrees,
The coefficient of friction of the cleaning section with respect to the ferrule of the optical connector and the optical fiber was 0.7.

[0026]

<Test 1> SC connector (HSC) which is an optical connector manufactured by NTT International Corporation
1 μl of silicone oil KF96-50 (manufactured by Shin-Etsu Chemical Co., Ltd.) on the end face of the ferrule and optical fiber
Place the dropping material in place of the dirt in the coupling holder, insert the cleaning part of each example and comparative example into the sleeve cylinder of the coupling holder, and rotate five times while pressing against the end face of the ferrule and the optical fiber. Then, the cleaning operation was performed, and the degree of removal of the silicon oil was visually checked with an optical microscope (400 times). The results are shown in Evaluation 1 of Table 1. ：: Silicon oil was completely removed. X: Silicon oil remains.

<Test 2> 1 μl of KF96-50 (manufactured by Shin-Etsu Chemical Co., Ltd.), a silicone oil, was dropped on the ferrule of the SC connector (HSC), an optical connector manufactured by NTT International Corporation, and the end face of the optical fiber. A substitute for dirt is placed in the connection holder, the cleaning section of each of the examples and the comparative example is inserted into the sleeve cylinder of the connection holder, and rotated five times while pressing against the end surfaces of the ferrule and the optical fiber. After performing the cleaning work, it is connected to a connector whose optical signal loss is known, and the optical fiber solution kit TS6 is used.
The loss amount of the optical connector portion was measured using 50A (manufactured by Black Box Japan K.K.). Table 1 shows the results
Is shown in Evaluation 2. The smaller the loss amount, the more the dirt was removed. For reference, the loss amount of an uncleaned optical connector and the loss amount of an unused optical connector to which no dirt is attached are also shown.

[0028]

[Table 1]

As described above, the optical fiber connecting end cleaner of the present invention can sufficiently remove dust and oil film adhering to the connecting end of the end face of the optical fiber.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an example.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is a longitudinal sectional view showing another example.

FIG. 4 is a longitudinal sectional view showing still another example.

FIG. 5 is a sectional view of a main part showing a working state.

FIG. 6 is a vertical sectional view of a main part showing a modification.

FIG. 7 is a vertical sectional view of a main part showing another modification.

FIG. 8 is a vertical cross-sectional view of a main part showing a further modified example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 'gripping member 2, 2' cleaning part 2a concave part 2b projection part 3 adhesive layer 4 ferrule 5 optical fiber 6 connection holder 7 sleeve cylinder 8 optical connector

Claims (5)

[Claims] 1. An optical fiber coupling end cleaner for contacting an exposed end of an optical fiber of a connector for connecting an optical fiber cable to another optical fiber cable or other connection device to remove contaminants attached to the end. An optical fiber connection end cleaner, wherein at least the cleaning portion that comes into contact with the exposed end of the optical fiber is a synthetic resin porous body having at least 12 or more methylenes in a repeating unit. 2. The cleaner for an optical fiber connection end according to claim 1, wherein the synthetic resin is a thermoplastic polyurethane resin. 3. The cleaner for an optical fiber connection end according to claim 1, wherein an opening area of holes per unit surface area of the porous body of the synthetic resin is in a range of 75% to 95%. . 4. The optical fiber connection end cleaner according to claim 1, wherein a coefficient of friction of the synthetic resin with the end surface of the optical fiber and its outer cover member is 0.8 to 2.0. 5. The synthetic resin porous body has a Shore A hardness of 30 to 60 degrees.
The optical fiber connection end cleaner according to any one of the above.