JP3264275B2 - Welding type used for end face treatment of plastic optical fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding type used for processing an end face of a plastic optical fiber.

[0002]

2. Description of the Related Art Conventionally, plastic optical fibers used in optical sensors and optical communications have their end faces formed as smooth as possible in order to prevent light attenuation at the end faces of the optical fibers serving as open ends and connection ends. It is preferable to put
As a forming method, other than a method of polishing an optical fiber end using a polishing device or the like, a method of cutting with a hot knife, and a method of pressing an optical fiber end against a mirror-finished hot plate, the mirror-finished hot plate is pressed. A welding method for transferring the plate surface to the optical fiber side is conceivable.

[0003] However, the method of polishing the end of the optical fiber has a problem that a large number of work steps and work time are required for the polishing operation, and the method of cutting with a hot knife requires a sufficiently smooth end face. There is a problem in that the optical fiber cannot be obtained and the precision is inferior. Therefore, it is advantageous to perform the end face treatment of the optical fiber by a welding method that can form a smooth and simple end face.

[0004]

As described above, even when the end of the optical fiber is formed smoothly, the reflection of light on the end surface causes a decrease in sensitivity and an adverse effect on the element. In the worst case, In some cases, communication failure may occur.

Therefore, a method for effectively preventing such end-face reflection has been intensively studied. Instead of forming the end face of the optical fiber at 90.degree. It has been found that the end face reflection is minimized if the end face is formed so as to have a constant inclination angle.

However, the above-mentioned welding method is a method of forming an end face by pressing an end of an optical fiber against a hot plate. Therefore, in order to form an end face so as to have a fixed inclination angle with respect to the axis, Although the optical fiber must be pressed in a state of being inclined with respect to the hot plate surface, it is difficult to always maintain the optical fiber at a predetermined inclination angle with respect to the hot plate surface, and the adjustment of the inclination angle is also difficult. There is a problem that it cannot be easily performed.

Therefore, an object of the present invention is to improve the welding method that can form a smooth end face simply and accurately as described above, thereby achieving a smooth and constant inclination angle with respect to the axis. An object of the present invention is to provide a welding die used for processing an end face of a plastic optical fiber that can easily and accurately form an end face having the same.

[0008]

Means for Solving the Problems In order to solve the above problems,
According to the first aspect of the present invention, a plastic optical fiber is inserted into a ferrule cut so that a front end surface thereof has a predetermined inclination angle with respect to an axis so that a front end portion thereof is slightly protruded. The tip is pressed against the mirror-finished hot plate surface while keeping the inclination angle by being in line with the welding die, and the mirror-finished hot plate surface along the tip surface of the ferrule is transferred to the mirror-finished end surface. The welding type used for the end face treatment of the plastic optical fiber used when forming at the tip of the plastic optical fiber, the block body placed on a mirror-finished hot plate surface,
A guide hole of a ferrule penetrating from an upper surface to a lower surface of the block body, the guide hole has a predetermined inclination angle with respect to the hot plate surface, and the upper surface and the lower surface of the block body are non-parallel. It is formed in.

According to a second aspect of the present invention, the coating material at the tip of the plastic optical fiber in which the outer periphery of the fiber core wire is coated with the coating material is slightly peeled off, and the plastic optical fiber is moved along a welding mold. While maintaining a predetermined inclination angle, the tip is pressed against the mirror-finished hot plate surface, and the mirror-finished hot plate surface having the inclination angle with respect to the axis is transferred to the tip of the plastic optical fiber. A welded type used for processing an end face of a plastic optical fiber used for forming a finished end face, a block body mounted on a mirror-finished hot plate surface, and an upper surface to a lower surface of the block body And a guide hole for the plastic optical fiber penetrating the hot plate surface. It has a tilt angle, in which upper and lower surfaces of the block body is non-parallel to.

According to a third aspect of the present invention, the tip of the plastic optical fiber whose core wire is not covered with the coating material is mirror-finished while keeping a predetermined inclination angle by following a welding mold. The end face of the plastic optical fiber used to form an end face on which the mirror-finished hot plate face having the inclination angle with respect to the axis is transferred to the tip of the plastic optical fiber by pressing against the hot plate face. The welding type used for processing, having a block body mounted on a mirror-finished hot plate surface, and a guide hole of the plastic optical fiber penetrating from the upper surface to the lower surface of the block body, The guide hole has a predetermined inclination angle with respect to the hot plate surface, and the upper surface and the lower surface of the block body are non-parallel. And it is formed.

According to a fourth aspect of the present invention, a plurality of the guide holes are formed in the block body.

[0012]

[0013]

According to a fifth aspect of the present invention, the plurality of guide holes have the same inclination angle.

According to a sixth aspect of the present invention, the plurality of guide holes have different inclination angles.

According to a seventh aspect of the present invention, in the block body, a lower peripheral portion of the formed guide hole is formed of a material having high thermal conductivity.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Principle) Prior to the description of a preferred embodiment of the present invention, the principle will be described.
The welding mold 10 in FIG. 1 is a first proposal example for explaining the principle of the present invention, and is a rectangular parallelepiped metal block 1.
1 is provided with a guide hole 12 penetrating from its upper surface 11a to its lower surface 11b, and is used by being placed on an upper surface 20a of a hot plate 20, as shown in FIG.

The through hole 12 is formed with the block body 11 mounted on the upper surface 20a of the hot plate 20 and having an inclination angle α with respect to the upper surface 20a. The ferrule is set slightly larger than the outer diameter of the ferrule so that a ferrule attached to the end of the fiber can be inserted.

Note that the inclination angle α may be set to an angle that minimizes end face reflection based on the NA (numerical aperture) of the plastic optical fiber whose end face is to be processed.

Hereinafter, a method for treating an end face of a plastic optical fiber using the welding mold 10 will be described.

As shown in FIG. 2 (a), the plastic optical fiber F projects slightly from the ferrule 40 whose tip surface 41 is cut so as to have a predetermined inclination angle β with respect to the axis. Insert as follows. Note that the inclination angle β of the distal end surface of the ferrule 40 and the inclination angle α of the guide hole 12 of the welding mold 10 are the same.

Then, the welding mold 10 is set on the upper surface 20a of the hot plate 20, and as shown in FIG.
Ferrule 40 with plastic optical fiber F inserted
Is inserted into the guide hole 12 of the welding die 10 and the ferrule 40 is inserted.
Is pressed against the upper surface 20a of the hot plate 20.

At this time, since the ferrule 40 and the plastic optical fiber F are maintained at a tilt angle α with respect to the upper surface 20a of the hot plate 20 by the guide holes 12, the upper surface 20 of the hot plate 20 is maintained.
An end face having an inclination angle α with respect to the axis, that is, an end face parallel to the end face 41 of the ferrule 40 is formed at the tip of the plastic optical fiber F pressed against a. Since the upper surface 20a of the hot plate 20 is mirror-finished, the end surface of the plastic optical fiber F is
The mirror-finished upper surface 20a is transferred as it is,
The state becomes extremely smooth.

At the end of the ferrule 40 thus treated, the end of the plastic optical fiber F crushed by the hot plate 20 spreads out of the fiber insertion hole 40a of the ferrule 40. 3 functions as a stopper for the plastic optical fiber F with respect to the ferrule 40.
A ferrule 40 having a tapered large diameter portion 40b whose inner diameter increases toward the distal end at the distal end of the fiber insertion hole 40a is used as in the second proposal example shown in FIGS. Then, the distal end of the plastic optical fiber F crushed by the hot plate 20 is housed in the large diameter portion 40b, and functions to prevent the plastic optical fiber F from being pulled out of the ferrule 40 and the distal end of the plastic optical fiber F is connected to the ferrule 40. Tip surface 4
A terminal portion whose end face is along the front end face 41 of the ferrule 40 without protruding from 1 is formed.

FIG. 4 shows an end face processing method (third proposed example) when a ferrule is not used. In this end face processing method, first, as shown in FIG. 4A, the coating material c at the tip end of the plastic optical fiber F in which the outer periphery of the fiber core wire f is coated with the coating material c is slightly peeled off.

Then, the plastic optical fiber F from which the coating material c at the distal end has been peeled is inserted into the guide hole 12 of the welding mold 10 as shown in FIG. Hot fiber 20
Pressed on the upper surface 20a of the. The welding die 10 used at this time needs to have a guide hole 12 whose diameter is set to be slightly larger than the outer diameter of the plastic optical fiber F so that the plastic optical fiber F can be inserted. .

At this time, as in the case of the first proposed example,
Hot tip 2 of plastic optical fiber F
When the plastic optical fiber F is pressed to zero, the plastic optical fiber F itself is maintained at a predetermined inclination angle, so that an end face having a predetermined inclination angle with respect to the axis is formed at the tip of the plastic optical fiber F. Is done.

In the third proposed example, the plastic optical fiber F in which the outer periphery of the fiber core wire f is covered with the coating material c is used.
However, for example, it is also possible to use a plastic optical fiber consisting of only a bare fiber core wire having no covering material. However, in the welding type used in this case, the diameter of the guide hole needs to correspond to a plastic optical fiber consisting of only a fiber core wire.

( Reference Technology ) FIGS. 5 and 6 show a welding type according to a reference technology of the present invention. The welding type shown in FIGS. 5 and 6 has the block body 11 provided with a plurality of guide holes 12 having different inclination angles α. By providing a plurality of guide holes 12 having different inclination angles α in this manner, it is possible to simultaneously perform end face processing on a plurality of types of plastic optical fibers. Although not shown, if a plurality of guide holes 12 having the same inclination angle α are provided, a plurality of plastic optical fibers of the same type can be simultaneously end-face treated.

(Embodiment) FIG. 7 shows a welding type according to an embodiment of the present invention.
ing. In the welding type shown in FIG. 7, a plurality of guide holes 12 having different inclination angles α are provided in the block body 11, and the upper surface 11a and the lower surface 11b of the block body 11 are formed non-parallel. Therefore, when this welding type is used, two types of end face treatments with different inclination angles α can be performed in one guide hole 12 by exchanging the upper and lower sides.

The above-mentioned welding mold 10 has a metal block 11, which is
The hot plate 20 is not necessarily required to be made of metal.
, For example, a heat-resistant resin or the like.

However, if the entire block 11 is made of a heat-resistant resin or the like, the thermal conductivity of the heat-resistant resin itself is generally low, so that the tip of the plastic optical fiber F is heated mainly from the end face side. Therefore, the plastic optical fiber F is not easily melted. In particular, when the ferrule 40 having the large diameter portion 40b is used, the entire large diameter portion 40b is not filled with the plastic optical fiber F.
There is a problem that a gap is formed between the plastic optical fiber F and the ferrule 40.

Therefore, as shown in FIGS. 8A and 8B, the lower part of the block body 11, that is, the guide hole 12
A height d portion corresponding to the large diameter portion 40b of the ferrule 40 inserted into the ferrule 40 is formed by a metal element 11c having a high thermal conductivity, and an upper portion of the block body 11 is formed of a heat-resistant resin element having a low thermal conductivity. When the ferrule 40 is heated by the large diameter portion 40b of the ferrule 40 from the peripheral surface side as well, the plastic optical fiber F The tip portion is easily melted, and the entire large-diameter portion 40b of the ferrule 40 is filled with the plastic optical fiber F.

In this example, the entire lower portion of the block body 11 is formed of a metal element. However, only the peripheral portion of the guide hole 12 may be formed of a metal element. In addition, as shown in FIG. 7, when the upper and lower parts are used interchangeably, the upper part, the middle part, and the lower part are divided into three parts, the upper part and the lower part are made of a metal element, and the intermediate part is made of a heat-resistant resin element. Need to be formed.

[0035]

According to the first to third aspects of the present invention, the upper surface and the lower surface of the block body are formed non-parallel when the end face of the plastic optical fiber is processed. The guide hole enables two types of end face treatments with different inclination angles, which is reasonable.

According to the invention described in claims 4 to 6 , when performing the end face treatment of the plastic optical fiber,
Since a plurality of guide holes are formed in the block body, the end faces of a plurality of plastic optical fibers can be processed at the same time, thereby improving workability. In this case, a plurality of guide holes may have the same inclination angle as in claim 5 , or may have different inclination angles, respectively, as in claim 6 .

According to the seventh aspect of the present invention, since the lower peripheral portion of the guide hole has the block body formed of a material having high thermal conductivity, the tip portion of the plastic optical fiber is located on the end face side. Since the plastic optical fiber is heated not only from the side but also from the peripheral surface side, the plastic optical fiber is easily melted, and there is an effect that the end surface can be properly processed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first proposed example of a welding type.

FIG. 2 is a process chart showing a first proposed example of a method for treating an end face of a plastic optical fiber.

FIG. 3 is a process chart showing a second proposed example of the above.

FIG. 4 is a process chart showing a third proposal example of the above.

FIG. 5 is a sectional view showing a welding-type reference technique .

FIG. 6 is a sectional view showing a welding type reference technique .

FIG. 7 is a sectional view showing one embodiment of a welding type.

FIG. 8 is a cross-sectional view showing still another embodiment of the welding type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Welding type 11 Block body 11a Upper surface 11b Lower surface 12 Guide hole 20 Hot plate 20a Upper surface

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 6/36 G02B 6/00 G02B 6/10 G02B 6/24

Claims (7)

(57) [Claims] 1. A plastic optical fiber is inserted into a ferrule cut so that a front end surface thereof has a predetermined inclination angle with respect to an axis, so that a front end portion thereof slightly protrudes,
By keeping the inclination angle by aligning the ferrule with the welding mold, the tip is pressed against the mirror-finished hot plate surface, and the mirror-finished hot plate surface is transferred along the tip surface of the ferrule. A block body mounted on a mirror-finished hot plate surface, which is used for processing the end surface of the plastic optical fiber used when forming the end surface at the tip of the plastic optical fiber; A guide hole of a ferrule penetrating from an upper surface to a lower surface of the block body, wherein the guide hole has a predetermined inclination angle with respect to the hot plate surface, and the upper surface and the lower surface of the block body are non-parallel. A welded type used for processing an end face of a plastic optical fiber, characterized in that it is formed. 2. A coating material at the tip end of a plastic optical fiber whose outer periphery is covered with a coating material is slightly peeled off, and the plastic optical fiber is kept along a welding mold to maintain a predetermined inclination angle. While pressing the tip of the hot plate surface onto the mirror-finished hot plate surface to form the end surface of the plastic optical fiber on which the mirror-finished hot plate surface having the inclination angle with respect to the axis is transferred is formed. The welding type used for processing the end face of the plastic optical fiber used in the above, wherein the block is placed on a mirror-finished hot plate surface, and the plastic optical fiber penetrates from the upper surface to the lower surface of the block. The guide hole has a predetermined inclination angle with respect to the hot plate surface, Serial block body upper surface and the end face welding type used for processing a plastic optical fiber lower surface and is characterized by being non-parallel to the. 3. A plastic optical fiber whose fiber core is not covered with a covering material is pressed along a welding mold while pressing a tip of the plastic optical fiber against a mirror-finished hot plate surface while maintaining a predetermined inclination angle. The welding type used for processing an end face of a plastic optical fiber used for forming an end face on which a hot plate surface having the above-mentioned inclination angle with respect to the axis and having been mirror-finished is transferred to the tip of the plastic optical fiber. A block body mounted on a mirror-finished hot plate surface, and a guide hole for the plastic optical fiber penetrating from an upper surface to a lower surface of the block body, wherein the guide hole is It has a predetermined inclination angle with respect to the surface, and the upper surface and the lower surface of the block body are formed non-parallel. Welding type used in the end face treatment of the plastic optical fiber to. 4. A welding type used for treating an end face of a plastic optical fiber according to claim 1, wherein a plurality of said guide holes are formed in said block body. Welding type used for end face treatment of plastic optical fibers. 5. The plastic optical fiber according to claim 4,
A welding type used for fiber end face treatment, wherein a plurality of the guide holes have the same inclination angle.
Used for the end face treatment of plastic optical fiber
Welding type. 6. A plastic optical fiber according to claim 4.
A welding type used for treating an end face of a fiber, wherein a plurality of the guide holes have different inclination angles.
End treatment of plastic optical fiber
Welding type used for 7. The method according to claim 1, wherein:
Used for end face treatment of mounted plastic optical fiber
The block body has a lower peripheral portion of the formed guide hole.
Characterized by a material with high thermal conductivity
Used for end face treatment of plastic optical fiber
Welding type.