JPH04314009A - Method for inspecting terminal of multiple fiber - Google Patents

Abstract

PURPOSE:To obtain a multiple fiber terminal inspection method capable of mechanizing the terminal inspection of a multiple fiber. CONSTITUTION:In the multiple fiber terminal inspection method for inspecting the terminal of a multiple fiber 1 formed by unitedly coating plural optical fiber 1a, separating a multiple fiber 1 into individual optical fibers on its terminal and cutting the respective fibers to prescribed length, the terminals of the individual optical fibers 1a separated from the multiple fiber 1 are inspected by optical inspecting means 6, 7.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting the terminals of multicore fibers.

0002

2. Description of the Related Art A multicore fiber is, for example, a plurality of optical fibers arranged in parallel and integrally covered with a protective coating made of synthetic resin or the like. When optically connecting such a multi-core fiber to optical equipment, etc., or when optically connecting it to another multi-core fiber when measuring the loss of the multi-core fiber itself, the coating must be removed and exposed at the end of the multi-core fiber in advance. Terminal treatments such as cleaning the plurality of optical fiber strands and cutting the optical fiber strands to a predetermined length are performed.

0003

[Problem to be Solved by the Invention] By the way, in a multi-core fiber that has been subjected to such terminal treatment, if the optical fiber strands at the ends are not properly trimmed, it may cause damage to other multi-core fibers or optical equipment. During optical connection, etc., proper optical connection of each optical fiber strand may be hindered, or the other optical fiber strand may be damaged.

[0004] For this reason, in the optical connection of multi-core fibers, it is necessary to inspect the terminals to see if the optical fiber strands that have undergone terminal treatment are properly trimmed. Conventionally, such inspections have been carried out manually. This was done by visual inspection. However, since the optical fiber wire is extremely thin with a diameter of about 125 μm, there is a problem that the optical fiber wire is difficult to distinguish and the work is complicated.

[0005] Moreover, the manual inspection of the terminals of bare optical fibers has been a major obstacle to mechanizing the work from processing the terminals of multi-core fibers to optical connections. The present invention has been made in view of the above points, and an object of the present invention is to provide a multi-core fiber terminal inspection method that can mechanize the multi-core fiber terminal inspection.

[0006]

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, a plurality of optical fiber strands are integrally coated, the terminals are separated into individual optical fiber strands, and
In a multi-core fiber end inspection method for inspecting the end of a multi-core fiber cut to a predetermined length, the end of the multi-core fiber separated into individual optical fiber strands is inspected by an optical inspection means. This is a method.

[0007] Preferably, the optical inspection means has a light projector that emits test light and a light receiver that receives the test light emitted from the projector, and is formed between the light projector and the light receiver. The terminals of the individually separated optical fiber strands are inserted into the inspection optical path, and the terminals of the individual optical fiber strands in the multi-core fiber are inspected based on the inspection light detected by the light receiver. .

Preferably, the optical inspection means is an image processing device that analyzes and inspects the end of the multi-core fiber separated into individual optical fiber strands by image processing.

[0009]

[Operation] The optical inspection means optically inspects the ends of the individually separated optical fiber strands, and based on the inspection results, determines whether or not the cutting process of the plurality of end-treated optical fiber strands is good or bad. be done.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 10. The method of the present invention inspects the terminal end of a multi-core fiber 1 which has been terminal-treated in the following manner. As shown in FIG. 3, the multi-core fiber 1 consists of a plurality of optical fibers 1a arranged in parallel and integrally covered with a protective coating 1b made of synthetic resin or the like. First, the coating 1b is removed from the terminal. The optical fibers 1a are removed to expose four individually separated optical fiber strands 1a. Next, dirt, dust, silicone oil, etc. adhering to the surface of each optical fiber strand 1a are wiped off with, for example, a wiping cloth containing alcohol or the like. After that, the four optical fiber strands 1a
is cut with a jig such as a fiber cutter and trimmed as shown in FIG.

[0011] The plurality of optical fiber strands 1a cut in this manner are inspected by the inspection system 5 described below to determine whether they have been properly trimmed by the method of the present invention. As shown in FIGS. 1 and 2, the inspection system 5 includes, as an optical inspection means, a light projector 6 that emits test light and a light receiver 7 that receives the test light. 7, an inspection optical path LP of inspection light is formed. Here, the light projector 6 and the light receiver 7 use, for example, a transmission type laser sensor that emits and receives laser light consisting of a band-shaped parallel light beam. When a laser sensor is used as a light projector, there is little variation in the intensity of the emitted inspection light.
Stable test results can be obtained.

In the inspection system 5, the inspection light emitted from the light emitter 6 is shielded at a constant speed by a shielding plate (not shown) provided on the emitter 6 side or the light receiver 7 side, and is detected by the light receiver 7. The amount of received laser light is set to vary linearly from all light to zero, or vice versa, from zero to all light. Then, the multi-core fiber 1 is held by a positioning device (not shown) such as an X-Y table, and as shown in FIGS.
The end of the optical fiber strand 1a is inserted into the inspection optical path LP.

Then, the strip-shaped parallel inspection light emitted from the projector 6 is blocked at a constant speed by, for example, the shielding plate provided on the projector 6 side, and the amount of light received by the receiver 7 is equal to the total amount of light. decreases from to zero. In the following description, a case where the inspection light is not blocked by the shielding plate will be referred to as a full-light state. When the shielding of the inspection light by the shielding plate is completed, the four optical fiber strands 1a inserted into the inspection optical path LP are moved back by the positioning device, and the terminal inspection of the multi-core fiber 1 is completed.

At this time, the relationship between the amount of light received by the light receiver 7 (Q) and the moving distance (L) due to the shielding of the test light by the shielding plate is determined by inserting the optical fiber 1a into the test optical path LP. Figure 5 shows the case where 4 pieces are cut to the same length.
FIG. 6 shows a case where a real optical fiber 1a is inserted. Here, as shown in FIG. 7, when four optical fiber strands 1a cut to the same length are inserted into the inspection optical path LP, the inspection system 5 detects the amount of light received by the light receiver 7 (Q )
As shown in FIG. 6, the amount decreases linearly through step portions S1 to S4, which are formed by blocking the transmission of the inspection light by each optical fiber strand 1a. From this, in the multi-core fiber 1 to be inspected, the optical fiber strand 1
It is also possible to specify the number of a. In addition, in FIGS. 5 and 6, QMAX and QG are the light received by the light receiver 7 when the ends of the four optical fibers 1a are not inserted into the inspection optical path LP in the above-mentioned full light state, respectively. (QMAX) and the amount of light received by the light receiver 7 (QG) when four optical fibers 1a, all of which are properly trimmed, are inserted.

From the above relationship, if the four optical fibers 1a inserted into the inspection optical path LP are not cut to the same length, for example, as shown in FIG.
If the length of the third optical fiber strand 1a is shorter than the others, or as shown in FIG. 9, the length of the third optical fiber strand 1a from the top is longer than the others and protrudes In this case, the detection pattern of the amount of light (Q) received by the light receiver 7 shown in FIG. 6 changes variously.

Therefore, in the method of the present invention, it is possible to determine and specify which optical fiber strand 1a is in a state of defective cutting from this detection pattern. For example, in the case of the multicore fiber 1 shown in FIG. 8, the number of optical fiber strands 1a inserted into the inspection optical path LP is three. Therefore, the amount of light received by the light receiver 7 in the full light state Q2
Since the amount of light corresponding to one optical fiber 1a increases, the amount of light becomes between the amount of received light QMAX and the amount of received light QG (QG < Q2 < QMAX ). Furthermore, in the case of the multicore fiber 1 shown in FIG. 8, in the inspection system 5,
When the above-mentioned shielding plate blocks the inspection light at a constant speed, the amount of received light (Q) detected by the light receiver 7 is as shown in FIG. This results in a detection pattern without a step corresponding to the optical fiber strand 1a. In addition, according to this method, as is clear from the detection pattern shown in FIG. 6, the number of optical fiber strands in the multicore fiber to be inspected can also be specified from the number of step portions S.

Therefore, if the method of the present invention is combined with a system in which the detection pattern of the amount of light (Q) detected by the light receiver 7 is compared and processed by an arithmetic processing unit (ECU), the end of the multi-core fiber 1 can be To mechanically and automatically inspect and determine whether or not the four optical fiber strands 1a in a section are properly cut, including the defective state of cutting of a specific optical fiber strand 1a. Can be done.

In addition, in the full light state, the amount of light received by the light receiver 7 is Q
By measuring I, it is possible to easily check only the quality of the cut state of the optical fiber 1a without blocking the inspection light with a shielding plate and checking the detection pattern of the amount of light (Q) detected by the light receiver 7. can be determined.

Next, FIG. 11 shows a CC as an optical inspection means.
D (charge coupled device)
Another embodiment of the present invention using a camera is shown. In this embodiment, a plurality of optical fiber strands 1a, which are the targets of inspection of the multi-core fiber 1, are photographed with a CCD camera 10,
Based on this, the terminal of the multi-core fiber 1 is inspected.

The CCD camera 10 connects images of a plurality of optical fibers 1a onto an imaging device such as a CCD, and obtains images by capturing the reflected light from the optical fibers 1a as electronic changes. . Then, by image processing the images of the plurality of optical fiber strands 1a captured by the CCD camera 10, it is possible to check whether or not there is a cutting defect in the optical fiber strand 1a described in the above embodiment, and to identify the defective cut optical fiber strands 1a. In addition to identification, it is also possible to determine the cleanliness of the plurality of photographed optical fiber strands 1a, the presence or absence of diagonal cutting in the cutting process, etc.

[0021]

As is clear from the above explanation, according to the multi-core fiber terminal inspection method of the present invention, the terminals separated into individual optical fiber strands are inspected by optical inspection means. The terminals of multi-core fibers can be easily inspected without the need for manpower, and the terminal inspection of terminal-treated multi-core fibers can be mechanized and automatically processed. Therefore, it is possible to mechanize the work of processing the terminals of multi-core fibers, inspecting the processed terminals, and making optical connections.

Further, the optical inspection means includes a light projector that emits test light and a light receiver that receives the test light emitted from the light projector, and an inspection optical path formed between the light projector and the light receiver. The inspection system can be easily constructed by inserting the ends of the individual separated optical fibers and inspecting the ends of the individual optical fibers based on the inspection light detected by the receiver. can do.

On the other hand, if an image processing device is used as an optical inspection means, which analyzes and inspects the terminals separated into individual optical fiber strands by image processing, more detailed information such as the shape of each optical fiber strand can be obtained. Information can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an inspection system for explaining the multi-core fiber terminal inspection method of the present invention.

FIG. 2 is a front view of the inspection system shown in FIG. 1.

FIG. 3 is a perspective view of the terminal of the multicore fiber before terminal processing.

FIG. 4 is a perspective view of the terminal end of a multi-core fiber from which a coating has been removed and a terminal treatment such as trimming a plurality of optical fiber strands has been performed.

FIG. 5 is a light reception characteristic diagram showing a detection pattern of the amount of light received by the light receiver when no optical fiber is inserted into the inspection optical path.

FIG. 6 is a light reception characteristic diagram showing a detection pattern of the amount of light received by the light receiver when an appropriately trimmed optical fiber wire is inserted into the inspection optical path.

FIG. 7 is a view taken along the line VII-VII in FIG. 1;

8 is a side view of a case where an optical fiber strand, one of which is short due to poor cutting processing, is inserted into the inspection optical path in FIG. 7; FIG.

9 is a side view of FIG. 7 when a long optical fiber is inserted into the inspection optical path due to a poor cutting process; FIG.

10 is a light reception characteristic diagram showing a detection pattern of the amount of light detected by the light receiver in the case of FIG. 8; FIG.

FIG. 11 is a perspective view showing another embodiment of the present invention.

[Explanation of symbols]

1 Multi-core fiber 1a Optical fiber strand 5 Inspection system 6 Emitter (optical inspection means) 7 Light receiver (optical inspection means) 10 CCD camera (image processing device) LP Inspection optical path

Claims (3)

[Claims] Claim 1: A plurality of optical fiber strands are integrally coated, the terminals are separated into individual optical fiber strands, and
In a multi-core fiber end inspection method for inspecting the end of a multi-core fiber cut to a predetermined length, the end of the multi-core fiber separated into individual optical fiber strands is inspected by an optical inspection means. A multi-core fiber terminal inspection method characterized by the following. 2. The optical inspection means includes a light projector that emits test light, and a light receiver that receives the test light emitted from the light projector, and is formed between the light projector and the light receiver. 2. The method of claim 1, wherein the ends of the individually separated optical fibers are inserted into the inspection optical path, and the ends of the individual optical fibers in the multi-core fiber are inspected based on the inspection light detected by a light receiver. 1. The multi-core fiber terminal inspection method according to 1. 3. The multi-core fiber according to claim 1, wherein the optical inspection means is an image processing device that analyzes and inspects the end of the multi-core fiber separated into individual optical fiber strands by image processing. Fiber terminal inspection method.