JPH08122576A - Optical connector with coated optical fiber and its assembling method - Google Patents

Abstract

PURPOSE: To provide an optical connector with a coated optical fiber which has a short hardening time of an adhesive and eliminates a need of correction for too much or too less adhesive and is easily assembled by filling the adhesive charging hole of the optical connector with the adhesive and burying a chip there and hardening the adhesive. CONSTITUTION: After an optical fiber 17 which has the coating of the end part peeled to expose a coated optical fiber 15 is inserted to an optical fiber insertion hole 13 of an optical connector 11, an adhesive charging hole 19 is filled with an adhesive 21. A chip 29 is put on the adhesive 21, and a pressure is applied to the chip 29 from above to press the chip 29 until the upper face of the chip 29 is leveled with that of the optical connector 11. The pressurized adhesive 21 flows into the clearance to the optical fiber in the optical fiber insertion hole 13 and fills the clearance to overflow from the front end of the optical fiber insertion hole 13 and overflows from the space between the chip 29 and the adhesive charging hole 19. This overflowed adhesive 21 is wiped off, and the adhesive is hardened, and the end face of the optical connector 11 is polished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector with an optical fiber core wire and an assembling method thereof.

[0002]

2. Description of the Related Art As shown in FIGS. 8 and 9, a conventional optical connector with an optical fiber core wire is exposed by peeling off the coating of the end portion of the optical fiber core wire 15 into an optical fiber insertion hole 13 of the optical connector 11. The optical fiber 17 is inserted, and the adhesive filling port 19 of the optical connector 11 is filled with the adhesive 21 and cured. The optical fiber core wire 15 is in the form of a tape-shaped multi-core optical fiber core wire. The adhesive filling port 19 is formed in the direction orthogonal to the optical fiber insertion hole 13 and the optical fiber core wire insertion hole 23 behind the optical fiber insertion hole 13. Reference numeral 25 is a guide pin insertion hole for positioning the optical connector.

[0003]

The conventional optical connector with an optical fiber core wire has the following problems. If the amount of the adhesive is too large, the adhesive 21 rises from the surface of the optical connector 11 as shown in FIG.
When the optical connectors 11 are pressed against each other by the lever 27, the leaf spring 27 is easily removed. For this reason, excess adhesive must be removed so that the surface becomes flat. If the amount of the adhesive is too small, the adhesive strength may be insufficient, so it is necessary to refill the adhesive so that the surface becomes flat. Therefore, the assembly process is complicated and takes time. Since the adhesive filling port 19 has a large opening area and a certain depth, a large amount of the adhesive is used and it takes time to cure the adhesive.

The linear expansion coefficient of the adhesive 21 is equal to that of the optical connector 11.
Since it is larger than the linear expansion coefficient of, the optical connector 11 warps as shown in FIG. 11 at a low temperature, and the connection loss increases.

When it is used in a place of high temperature and high humidity, the optical connector absorbs moisture to change its shape and size, resulting in an increase in connection loss.

When an ultraviolet curable adhesive is used as the adhesive, the ultraviolet curable adhesive is cured from the surface, and the cured adhesive becomes less likely to transmit ultraviolet rays.
It is difficult to sufficiently cure the adhesive near the optical fiber. For this reason, the optical fiber is not completely fixed, and the end face of the optical fiber is likely to be scratched when the end face of the optical connector is polished, which also increases the connection loss.

Since the adhesive is naturally filled, the adhesive does not sufficiently flow into the clearance (about 1 μm) between the optical fiber insertion hole of the optical connector and the optical fiber inserted therein. For this reason, there is a portion where the inner peripheral surface of the optical fiber insertion hole and the outer peripheral surface of the optical fiber are not adhered to each other, and this causes a scratch on the end surface of the optical fiber during polishing of the end surface of the optical connector, which increases the connection loss.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention inserts an optical fiber, which is exposed by peeling off the coating of the end portion of the optical fiber core, into the optical fiber insertion hole of the optical connector. Then, in the adhesive filling port of the optical connector,
The adhesive is filled and the chip is embedded with the outer surface thereof exposed to cure the adhesive (claim 1).

In order to solve the above problems, in the above construction, it is desirable that the chip is made of a material having a linear expansion coefficient smaller than that of the adhesive (claim 2).

In order to solve the above-mentioned problems (1) and (2)-(3), it is desirable that the chip is made of a material having less hygroscopicity than the optical connector in each of the above-mentioned configurations (claim 3).

Further, in order to solve the above-mentioned problems (1), (2), and (3)-, in each of the above-mentioned constitutions, when an ultraviolet curable adhesive is used as the adhesive, the ultraviolet rays pass through the chip. It is desirable that it is made of a material (claim 4).

In order to solve the above-mentioned problems, in assembling an optical connector with an optical fiber core, an end of the optical fiber core is stripped and exposed in an optical fiber insertion hole of the optical connector. After inserting the optical fiber and filling the adhesive filling port of the optical connector with the adhesive, the chip placed on the adhesive is pressed from the outer surface to be embedded in the adhesive filling port, and then the adhesive is applied. It is preferable to adopt a method of curing (Claim 5).

In the assembling method of the fifth aspect, the configurations of the second to fourth aspects can be adopted.

[0015]

According to the first aspect of the invention, the amount of the adhesive used can be reduced by the amount corresponding to the volume of the chip, and the curing time of the adhesive can be shortened. Also, when the chip is embedded, excess adhesive will squeeze out, so by wiping off the squeezed-out adhesive, you can remove the excess adhesive after the adhesive has hardened, or add the adhesive that was insufficient. This saves time and effort and simplifies the assembly process.

According to the second aspect of the invention, since the linear expansion coefficient of the composite of the adhesive and the chip approaches the linear expansion coefficient of the optical connector, the optical connector is less likely to warp even at low temperatures. Therefore, increase in connection loss is unlikely to occur.

According to the third aspect of the invention, since the optical connector is less likely to absorb moisture, the shape and dimensions of the optical connector are less likely to change even when used in high temperature and high humidity locations, and therefore the connection is made. Loss increase is unlikely to occur.

Further, according to the invention of claim 4, the thickness of the ultraviolet curable adhesive is reduced by the thickness of the chip, and the ultraviolet light passing through the chip hits the thin adhesive, so that the adhesive near the optical fiber is adhered. The agent can be sufficiently cured.

According to the invention of claim 5, the adhesive is pressed by the pressure of the chip, and the adhesive is sufficiently filled in the clearance between the optical fiber insertion hole of the optical connector and the optical fiber inserted therein. Pour in. Therefore, the inner peripheral surface of the optical fiber insertion hole and the outer peripheral surface of the optical fiber are well adhered to each other over the entire circumference, and the end surface of the optical fiber is not scratched when the end surface of the optical connector is polished.

[0020]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2 show an embodiment of the present invention. A feature of this optical connector with an optical fiber core is that the chip 29 is embedded in the adhesive filling port 19 of the optical connector 11 together with the adhesive 21 with its outer surface exposed. Other configurations are the same as those of the conventional optical connector with optical fiber core wire shown in FIGS. 8 and 9,
The same parts are designated by the same reference numerals.

The tip 29 has an outer peripheral dimension of an adhesive filling port.
It is a plate-shaped member that is slightly smaller than the inner peripheral size of 19. Therefore, a gap is formed between the outer peripheral surface of the chip 29 and the inner peripheral surface of the adhesive filling port 19, and this gap is also filled with the adhesive 21. The outer surface of the chip 29 is preferably flush with the surface of the optical connector 11 on which the adhesive filling port 19 is formed.

Next, a method of assembling the optical connector with the optical fiber core wire shown in FIG. 1 will be described. First, as shown in FIG. 3, an optical connector 11, a tape-shaped multi-core optical fiber core wire 15 in which an optical fiber 17 is exposed by stripping an end coating, an adhesive 21, and a chip 29 are prepared. Although the adhesive 21 is shown as a lump, it is actually liquid. Next, as shown in FIG. 4, the optical fiber 17 at the end of the optical fiber 15 is inserted into the optical fiber insertion hole 13 of the optical connector 11, and then the adhesive filling port 19 is filled with the adhesive 21. The adhesive 21 is not filled so that the adhesive filling port 19 is full as in the past, but the adhesive 21
It is filled to such an extent that the depth to the upper surface of is smaller than the thickness of the tip 29.

Next, the chip 29 is placed on the adhesive 21, and the chip 29 is pressed from the upper surface so that the upper surface of the chip 29 is an optical connector.
Push in the tip 29 until it is level with the top surface of 11. Then, the pressurized adhesive 21 flows into the clearance between the optical fiber insertion hole 13 and the optical fiber 17, fills the clearance, and overflows from the tip of the optical fiber insertion hole 13 as shown in FIG. Together with the tip 29 and the adhesive filling port 19
The adhesive 21 also overflows from the gap. Next, the adhesive 21 that has overflowed is wiped off to cure the adhesive, and the optical connector 11
By polishing the end face of the optical fiber, an optical connector with an optical fiber core wire as shown in FIGS. 1 and 2 can be obtained.

As the chip 29, the adhesive 21 after curing is used.
It is desirable to use one having a smaller linear expansion coefficient. The adhesive is, for example, an epoxy adhesive (coefficient of linear expansion 1.2
^{X10 -5} / ° C), the material of the tip 29 is, for example, iron (coefficient of linear expansion 1.1 × 10 ^-5 / ° C). Then, the linear expansion coefficient of the composite of the adhesive and the chip approaches the linear expansion coefficient of the optical connector, so that the warp of the optical connector at low temperature can be reduced.

Further, it is desirable that the material of the chip 29 is one that has less hygroscopicity than the optical connector (for example, metal or ceramic). In this way, even if the optical connector is used in a place of high temperature and high humidity, the change in the shape and size of the optical connector is small, and the increase in connection loss is small.

When an ultraviolet curable adhesive is used as the adhesive 21, it is advisable to use an adhesive having a property of transmitting ultraviolet rays (for example, glass) as the chip 29. By doing so, the ultraviolet ray passing through the chip hits the ultraviolet ray-curable adhesive which is thinned by the thickness of the chip, so that the adhesive agent in the vicinity of the optical fiber can be sufficiently cured. Therefore, the optical fiber is securely fixed, and the end face of the optical fiber is not scratched during polishing.

FIG. 6 shows another example of a method of assembling the optical connector with an optical fiber core according to the present invention. In this method, after the chip 29 is put in the adhesive filling port 19, the adhesive 21 is filled through the gap between the chip 29 and the inner surface of the adhesive filling port 19. In this case, the tip 29 and the adhesive filling port 19
It is necessary to make the gap with the inner surface large enough to fill the adhesive 21.

FIG. 7 shows still another example of a method for assembling the optical connector with an optical fiber core according to the present invention. In this method, an adhesive injection hole 31 is formed in the chip 29, the chip 29 is placed in the adhesive filling port 19, and then the adhesive 21 is filled from the adhesive injection hole 31. Is.

[0029]

According to the first aspect of the present invention, it is possible to obtain an optical connector with an optical fiber core wire which has a short curing time of the adhesive and does not require correction due to an excess or an excessive amount of the adhesive. .

According to the second aspect of the invention, the optical connector is less likely to warp even at a low temperature, and the increase in connection loss can be suppressed.

According to the third aspect of the present invention, even when the optical connector is used in a high temperature and high humidity place, the shape and dimensions of the optical connector are less likely to change, and an increase in connection loss can be suppressed.

According to the fourth aspect of the present invention, when the ultraviolet curable adhesive is used, the ultraviolet curable adhesive can be sufficiently cured and the optical fiber can be fixed securely.

According to the invention of claim 5, the adhesive can be surely poured into the clearance between the inner peripheral surface of the optical fiber insertion hole and the outer peripheral surface of the optical fiber of the optical connector, so that the optical fiber is inserted in the optical fiber insertion hole. The fiber can be securely fixed. Therefore, the end face of the optical fiber is not damaged when the end face of the optical connector is polished.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an optical connector with an optical fiber core wire according to the present invention.

FIG. 2 is a vertical cross-sectional view of the optical connector with an optical fiber core wire of FIG.

FIG. 3 is a perspective view showing a first stage of an assembling method of the optical connector with an optical fiber core according to the present invention.

FIG. 4 is a perspective view showing the next stage of FIG.

5 is a perspective view showing the next stage of FIG. 4. FIG.

FIG. 6 is a perspective view showing another example of a method for assembling the optical connector with an optical fiber core wire according to the present invention.

FIG. 7 is a perspective view showing still another example of a method of assembling the optical connector with an optical fiber core wire according to the present invention.

FIG. 8 is a perspective view showing a conventional optical connector with an optical fiber core wire.

9 is a vertical cross-sectional view of the optical connector with an optical fiber core wire of FIG.

FIG. 10 is an explanatory diagram showing a problem of a conventional optical connector with an optical fiber core wire.

FIG. 11 is an explanatory view showing another problem of the conventional optical connector with an optical fiber core wire.

[Explanation of symbols]

 11: Optical connector 13: Optical fiber insertion hole 15: Tape-shaped multi-core optical fiber core wire 17: Optical fiber 19: Adhesive filling port 21: Adhesive 23: Optical fiber core wire insertion hole 25: Guide pin insertion hole 29: Tip

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroyuki Yanase, 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Naoko Shimoji 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Shinji Nagasawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (5)

[Claims] 1. An optical fiber, which is exposed by peeling off a coating on an end of an optical fiber core, is inserted into an optical fiber insertion hole of an optical connector, and an adhesive is filled in an adhesive filling port of the optical connector. At the same time, an optical connector with an optical fiber core wire is characterized in that the chip is embedded with its outer surface exposed and the adhesive is cured. 2. The chip is made of a material having a linear expansion coefficient smaller than that of a cured adhesive.
An optical connector with the optical fiber core wire described. 3. The chip according to claim 1, wherein the chip is made of a material having less hygroscopicity than the optical connector.
An optical connector with the optical fiber core wire described. 4. The optical connector with an optical fiber core wire according to claim 1, wherein the adhesive is made of an ultraviolet curable adhesive, and the chip is made of a material that transmits ultraviolet rays. 5. An optical fiber, which is exposed by peeling off the coating of the end portion of the optical fiber core, is inserted into the optical fiber insertion hole of the optical connector, and after filling the adhesive filling port of the optical connector with the adhesive, A method for assembling an optical connector with an optical fiber core, characterized in that a chip placed on an adhesive is pressed from the outer surface thereof to be embedded in an adhesive filling port, and then the adhesive is cured.