JP2542654B2 - Optical transmission optical fiber parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to a small diameter plastic optical fiber component suitable for use in detecting a small object in a photoelectric switch or for coupling with a fiber of 0.3 mm or less such as glass fiber. Regarding

Conventional technology Only one small diameter plastic optical fiber with a cladding diameter of 0.3 mm or less is coated directly with a resin such as polyethylene or polyvinyl chloride to a diameter of 0.8 to 1.5 mm. Even if the transmission performance of the optical fiber is good, it may be difficult for light to pass through even if it is left in the room for a long time.
An optical fiber component using such a small-diameter optical fiber cord is unreliable and lacks practicality. The reason for this is that if a small diameter plastic optical fiber of 0.3 mm or less is coated with resin for the jacket with an extruder,
It was thought that the thin fibers would be easily drawn. As a countermeasure against these problems, there has been proposed a method for producing a cord in which a fibrous material made of a material having a softening temperature higher than that of an optical fiber and a coating material is bundled and coated with a polyethylene-based or polyvinyl chloride-based polymer (Japanese Patent Publication No. 51-47628). However, according to this method, for example, when a polyester fiber or poly (p-phenylene) terephthalamide fiber is coated with polyethylene together with one plastic optical fiber of 0.3 mm or less to produce a 0.8 to 1.5 mm cord, this cord is used. There is a problem that the cord becomes curled when heat is applied to. On the other hand, there is also known a method in which a large number of untwisted filament yarns are supplied around an optical filament to shield the jacket from the softening due to heat when coating the jacket (Japanese Patent Publication Sho-61). −10802 publication). This method is different from the above-mentioned method in that a large number of filaments capable of heat shielding are arranged around the optical fiber, but when such a large number of filaments are arranged, the diameter of the cord is 0.8 to 1.5. When it is about mm, there is a drawback that considerable unevenness occurs. In particular, when these cords are exposed to a high temperature, this unevenness becomes more prominent, and in some cases, the cord coating becomes torn. Therefore, the optical transmission optical fiber parts fixed to the connector or the plug at the ends of these cords are not practical for reliability.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in order to provide a plastic optical fiber having a small diameter, which is excellent in light transmission ability without curling or unevenness.

Means for Solving the Problems That is, in the present invention, there is only one optical fiber for transmitting light, and the cladding outer diameter of the optical fiber is 0.3 mm.
The outer diameter of the jacketed cord below is 0.8-
In an optical transmission optical fiber component consisting of an optical fiber cord of 1.5 mm and a light transmitting / receiving portion, in addition to one optical fiber for transmitting light, one to seven optical fibers having exactly the same structure, material and size as the optical fiber. Use a plastic optical fiber cord with the auxiliary optical fibers excessively aligned and jacketed so that the outer diameter of the cord is 0.8 to 1.5 mm or less, and use an excess fiber at least on one side of the light transmission part We provide optical transmission optical fiber parts with fixed connectors and plugs. According to the present invention, in addition to one optical fiber for transmitting light, it is necessary to arrange one to seven auxiliary fibers that are exactly the same as the optical fiber. The auxiliary fiber is for preventing the optical fiber from being stretched when the optical fiber is jacketed, and at least one auxiliary fiber is necessary, and preferably 3 to 7 fibers. If the number is 8 or more, the outer diameter of the cord becomes too large, which is not preferable. In particular, when the number of auxiliary fibers is three, the cord is composed of four fibers in total, so that the fibers are tightly covered in a parallelogram shape and the arrangement of the optical fibers is not disturbed, so that stable transmission characteristics can be maintained. Furthermore, it is preferable that the cord bends in all directions without bending even if the cord is bent. Further, when the number of the six auxiliary fibers is 7, the cord is made of seven fibers as a whole, so that the fibers are arranged neatly in a regular hexagonal shape, which is also preferable. Since these auxiliary fibers are exactly the same as the optical fibers, they are extremely preferable in terms of reinforcing the optical fibers having the same thermal property behavior. Even if the clad diameter of the optical fiber is as small as 0.3 mm or less, if 2 to 7 auxiliary fibers are lined up, the increase in loss over time of the optical fiber will be significantly reduced, and even if the cord is heated at 80 ° C, unevenness will occur. Occur,
There is no curling. When the cord thus obtained is used as an optical fiber component such as a photoelectric switch sensor, one optical fiber is bonded and fixed to a connector or a plug. In this case, the auxiliary fiber is used for fixing together with the optical fiber for optical transmission at the portion to be fixed by adhesion. There are some cases where connectors are placed at both ends of the cord, only one is fixed to the connector and the other is used by separating the cord, and when two or more cords are fixed to one connector. Correspondences are shown in FIGS. 1 to 3, respectively. Especially, when fixing an optical fiber from two or more cords to one cord as shown in FIG. 3, the light transmitted from the auxiliary fiber may cause noise. In that case, it is necessary to cover the end of the auxiliary fiber with a black resin. As these resins, use is made of epoxy resin in which carbon black or other light-shielding pigment is dispersed, or adhesive other than epoxy resin in which carbon black or other light-shielding pigment is dispersed. can do. In addition, it is also possible to wrap it with another light-tight resin tape or cap.

EXAMPLES Next, the present invention will be described in more detail with reference to examples.

Example 1 1.0 m of four 0.265 mm optical fibers lined up and jacketed with low density polyethylene (density 0.924, M13)
I got the code of mφ. The optical fibers were arranged in a parallelogram shape. There were no irregularities on the surface of this cord. The transmission loss was 180 dB / km at 650 nm. The tip of this cord was stripped off with a wire stripper and one of them was left and the other three were cut short. This and 0.5mm
1.0m with optical fiber jacketed with polyethylene
The cord of which the tip of the mφ cord was stripped off with a wire stripper was fixed to a plug together with a black adhesive to obtain an optical fiber component. As the black adhesive, a high super 5 minute curable type (manufactured by Cemedine) in which carbon black was dispersed was used. This optical fiber component has an inner diameter of 0.8 mm
The light is reflected from the plug at 70 ℃, 1000 ℃
There was no contraction in the cord after Hr. Light from a stabilized light source (MG927A manufactured by Anritsu) was incident on a 0.265 mm optical fiber and reflected by a reflector (Gray card manufactured by Kodak Co., Ltd.) at a distance of 5 mm. The power of the light was −55 dBm, but after 1000 hours − It was 56 dBm.

Example 2 Seven 0.265 mm optical fibers were aligned and jacketed with polyethylene to obtain a 1.3 mmφ cord. The fiber at the center of this cord was used as a fiber for optical transmission. The cross section of this fiber cord was located exactly in the center of the cord, and the eccentricity of the fiber was zero.
The transmission loss of this fiber was 180 dB / km. Then, the optical fiber component was obtained by mounting the optical fiber component on the plug in the same manner as in Example 1. The power of the light reflected by a reflector (Kodak gray card) that is 5mm apart from a 0.265mm optical fiber with a stabilized light source (MG927A manufactured by Anritsu) is -55dBm.
However, it was −56 dBm after 70 ° C. and 1000 hours. In addition,
Since this fiber cord has a small knitting rate, it is easy to align the axes.

Effect of the Invention When the optical fiber component of the present invention is used for detecting a small object in a photoelectric switch or for coupling with a fiber of 0.3 mm or less such as a glass fiber, the cord is uneven even at a high temperature of 70 ° C. It is possible to obtain an excellent effect that the transmission performance is stable without the occurrence of curl and curling.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a case where connectors are arranged at both ends of a cord in an optical fiber component of the present invention, and FIG. 2 is a schematic cross-sectional view of a case where only one is fixed to a connector and the other is used by separating the cord. FIG. 3 is a schematic cross-sectional view of fixing an optical fiber from two or more cords to one connector. 1 ... Optical fiber cord, 2 ... Optical transmission fiber, 3 ... Auxiliary fiber, 4 ... Connector or plug

Claims (2)

(57) [Claims] 1. An optical fiber cord having only one optical fiber for transmitting light and having a cladding outer diameter of 0.3 mm or less and a jacketed cord having an outer diameter of 0.8 to 1.5 mm. In the optical transmission optical fiber component consisting of parts, in addition to one optical fiber for transmitting light, one to seven auxiliary optical fibers having exactly the same structure, material, and size as the optical fiber are excessively arranged, Optical transmission using a plastic optical fiber cord with an outer diameter of 0.8 to 1.5 mm or less and using excess fiber in at least one of the light transmitting and receiving parts with an adhesive to fix the cord and connector or plug. Optical fiber parts. 2. The optical transmission optical fiber component according to claim 1, wherein the end of the auxiliary optical fiber is covered with a resin that does not transmit light.