JPH11304644A - Optical fiber continuity testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform conductor core comparison operation while a connection loss and an insertion loss are reduced, to obtain a stable leakage light power even if the color of an optical fiber and the fresh air temperature change, and to perform conductor comparison operation easily. SOLUTION: An optical fiber 7 is bent to a specific diameter between a recessed part 2a of a female head 2 and a projecting part 3a of a male head 3, and a leakage light power is detected from a light reception sensor 4. A pressing member 8 that can be freely elevated in the direction of the optical fiber 7 is provided at the side of the male head 3, thus freely changing the press force using a traveling means. When the fresh air temperature and the color of the optical fiber 7 change, the amount of the descent of the pressing member 8 is varied, thus varying the leakage light power being detected by the light reception sensor 4. By varying the pressing force, both the connection loss and the insertion loss can be reduced and a stable leakage light power can be obtained without affecting the information transmission during in-line service, thus easily performing a conductor comparison operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber continuity test apparatus used for the construction and maintenance of an optical fiber line network, and which is stable even if the color of the sheath of the optical fiber to be compared with the core and the external temperature change. The present invention relates to an optical fiber continuity test apparatus capable of receiving leaked optical power and performing highly reliable optical fiber alignment.

[0002]

2. Description of the Related Art Since an optical fiber cable usually includes a large number of optical fiber cores and is long as long as several km, a single optical fiber cable is required when connecting or terminating the optical fiber cable. It is necessary to perform a core line checking operation for checking the wires one by one at the front end and the rear end to confirm that they are the same core line. At present, in response to growing demand for high-speed and broadband services,
The introduction of fiber optic cables into subscriber lines is spreading in area. In such a situation, works such as relocation of troubles of optical fiber cables and cable integration are increasing year by year, and core switching work accompanying these works is carried out at night and during long hours of line borrowing. Therefore, an optical fiber cable switching system for switching an active line to a new line at high speed has been developed for the purpose of improving workability and reducing work cost while ensuring serviceability to a user. In such a system as well, a core line checking operation for efficiently confirming the current optical fiber core line for maintenance work at two different switching points is important.

By the way, FTTH / FTTC in the 21st century
Toward (Fiber to the home / Fiber to thecurb), the sophistication of access networks and the construction of rational communication networks have become major issues. Among them, a branch optical fiber network (hereinafter referred to as PDS (Passive Doubl
e Star) is promising. As one of such PDS lines, there is a form in which one intra-station transmission device and a plurality of subscriber terminals are connected by a PDS line configuration including a passive and wavelength-independent star coupler, and this is used. Multimedia communication such as a video distribution service has been attempted.

In general, the optical fiber core contrast technique is used for constructing and maintaining an optical line network by bending an optical fiber, detecting leaked optical power and confirming the optical fiber to be compared with the optical fiber. As described above, the optical fiber cable is composed of a large number of optical fiber cores, and a single cable extends several kilometers. Therefore, when connecting and fusing these optical fiber cores, it is necessary to perform a core-contrast operation for comparing the front end and the rear end one by one to confirm that they are the same core.

[0005] As one of the optical branching lines currently under study, a plurality of test light wavelengths different from the communication wavelength are assigned to each post-branch optical fiber, and by controlling this test wavelength, each post-branch optical fiber is controlled. There is a configuration that contrasts the cords. The optical fiber control of this optical fiber is selected from a new test light wavelength range (for example, 1.615 to 1.675 μm) from the optical fiber control light source installed in the station, and the test light wavelength to be adopted is selected in the field. The bending radius of the optical fiber is regulated to a predetermined diameter at the core wire bending portion, and the optical fiber is gripped. Thus, the optical fiber contrast operation for obtaining the target optical fiber by detecting the leaked light of the test light wavelength by the light receiving unit is performed.

[0006]

However, the conventional optical fiber continuity test apparatus has a configuration in which an optical fiber to be compared with a core wire is bent along a head portion having a predetermined diameter to generate leakage light, and the angle of bending is Can not be changed and fixed, so if the color of the outer sheath of the optical fiber (for example, formed of nylon coating) or the ambient temperature changes, the leakage optical power may decrease, and the optical fiber There has been a problem that the core wire cannot be identified.

That is, when the optical fiber is bent at the above-mentioned constant angle, the optical fiber generally becomes harder when the temperature becomes lower, and becomes in a state where a stress is applied, thereby increasing leakage light. Conversely, when the temperature rises, the material becomes softer and no stress is applied, and the leakage light decreases. Since the above-mentioned optical fiber contrast operation is performed during line borrowing (during in-line service), the light receiving unit that receives light leaked from the optical fiber minimizes coupling loss and insertion loss and does not affect information on the line. Must be done in However, if the bending angle of the optical fiber is fixed as described above, the leakage light power changes due to a change in temperature, and at the same time, the coupling loss and insertion loss fluctuate, which may affect information on the line. . Further, the optical fiber has an outer sheath of various colors, and is used for each color according to, for example, a region, a use, or a manufacturer. It has been confirmed that in such an optical fiber, even when the bending angle is fixed, the above-mentioned leaked light power differs according to the color of the outer cover. Therefore, if the bending angle of the optical fiber is fixed as described above, the leaked light power will be different depending on the color of the outer cover.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to carry out a core-contrast operation in a state where the coupling loss and the insertion loss are reduced. It is an object of the present invention to provide an optical fiber continuity test apparatus capable of obtaining stable leaked optical power even when performing the above operation and facilitating the operation of checking the optical fiber.

[0009]

In order to achieve the above object, an optical fiber continuity test apparatus according to the present invention comprises a male head for winding an optical fiber to be measured in a substantially semicircular shape. 3) and a part of each of the incident end side and the outgoing end side of the light of the optical fiber to be measured, which has a curved portion having the same diameter as the diameter of the male head, is pressed by the curved portion. Two female heads (2) for sandwiching and holding the same, a light receiving sensor (4) disposed between the two female heads, for detecting power of light leaked from the optical fiber, A pressing member that is movably disposed at a position closer to the incident end side of the incident end side of the measured fiber pressed by the head and presses the measured fiber against the female head with a pressing force corresponding to the amount of movement. (8).

The female head (2) is fixedly arranged, and the male head (3) is configured to be vertically movable with respect to the female head. May be provided with a lifting means (10) for vertically moving the pressing member (8) with respect to the female head.

In addition, as described in claim 3, a moving means (10) having an actuator (12) capable of changing the amount of vertical movement for moving the pressing member (8) toward the female head, and the cord. The control operation may be configured to include control means (20) for controlling the movement of the actuator of the moving means so that both the coupling loss and the insertion loss of the optical fiber are stabilized.

In a preferred embodiment of the present invention, the apparatus further comprises a temperature detecting means for detecting an outside air temperature at a location to be contrasted with the cord, wherein the control means includes a controller for detecting the temperature detected by the temperature detecting means. A configuration may be adopted in which a pressing force corresponding to the above is obtained and the movement of the actuator of the moving means is controlled.

According to a fifth aspect of the present invention, there is provided a storage section (22) in which a plurality of data indicating the temperature and the pressing force are stored in advance for each temperature, and the control means (20) comprises the temperature detection means. It is also possible to adopt a configuration in which the pressing force corresponding to the temperature output from (15) is obtained from the storage unit and the movement of the actuator of the moving means is controlled.

According to a sixth aspect of the present invention, the control means (20) stores a pressing force corresponding to the color of the outer cover of the optical fiber in advance, and uses the corresponding pressing force based on the setting of the outer cover color. The actuator of the moving means may be controlled to move.

According to the above configuration, by sandwiching the optical fiber 7 between the female head 2 and the male head 3, the optical fiber 7 is bent to a predetermined diameter, and the light receiving sensor 4 detects leaked light. Can be. The pressing members 8 provided on the sides of the male and female heads 2 and 3 correspond to the optical fibers 7 in accordance with the color of the optical fibers 7 and the change in the outside temperature.
The light receiving sensor 4 can receive stable leakage light power in a state in which the coupling loss and the insertion loss are reduced by changing the pressing force to the light. As a result, it is possible to smoothly perform the core wire contrast operation without affecting information transmission during the inline service.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the optical fiber continuity test apparatus according to the present invention will be described below. FIG. 1 is a front view showing a light receiving head of the optical fiber continuity test apparatus. The light receiving head 1 has a fixed female head 2 and a vertically movable male head 3. The female head 2 has a substantially semicircular concave surface 2a having a predetermined radius of bending radius. This female head 2
In the vicinity of the bottom of the concave surface 2a, there is provided a light receiving sensor 4, such as a PD, whose light receiving surface 4a faces the concave surface 2a side, and the light receiving sensor 4 detects light leaking from the optical fiber 7 as described later. The light receiving sensor 4 is disposed at an angle such that the normal direction of the light receiving surface 4a is substantially perpendicular to the tangent of the optical fiber 7. The male head 3 is configured to be vertically movable with respect to the female head 2 by moving means (not shown). A convex surface 3 corresponding to the bending radius of the concave surface 2a of the female head 2 is provided below the male head 3.
a is formed.

Between the female head 2 and the male head 3, an optical fiber 7 for centering the cord is temporarily inserted.
The optical fiber 7 is bent by the pair of concave surface 2a and convex surface 3a at the bending radius having the predetermined diameter as shown in the figure. A groove 3b for guiding the position of the optical fiber 7 is formed on the concave surface 3a of the male head 3.

On the concave surface 2a of the female head 2 and on the optical path front side of the optical fiber 7, an introduction bending portion 2aa for introducing the optical fiber 7 drawn from the outside into the concave surface 2a.
Are formed. The introduction bent portion 2aa is formed with a concave surface 2a.
This is an arc surface having a predetermined diameter that is bent in a direction opposite to the bending direction of the optical fiber 7, and the introduction angle of the optical fiber 7 (the tangential direction of the concave surface 2a and the convex surface 3a) can be changed at the introduction portion of the optical fiber 7. The illustrated female head 2 is divided into two parts from the center, but each is fixedly arranged on a base (not shown) with the light receiving sensor 4 interposed therebetween. Alternatively, the female head 2 may be formed of one block body, and the light receiving sensor 4 may be provided in the hole formed.

A holding member 8 is provided at a position above the introduction bending portion 2aa of the female head 2. The holding member 8 is formed of a substantially rectangular parallelepiped block in which at least a portion of the contact surface 8a that comes into contact with the optical fiber 7 from a position above the introduction bending portion 2aa is formed in an arc shape having a predetermined diameter. The pressing member 8 is vertically movable by a lifting means (not shown). The elevating means in this embodiment forms a screw hole 3c on the side of the male head 3, and the holding member 8 has a long hole 8b of a predetermined length in the vertical direction.
Is formed, and the holding member 8 is fixed to the male head 3 with the screw 11. The holding member 8 is fixed to the male head 3 so as to be finely movable by a predetermined amount in the height direction within the range of the elongated hole 8b. The pressing member 8 is simultaneously moved by the vertical movement of the male head 3.

A description will be given of the operation of contrasting the cords according to the above configuration.
Before executing the optical fiber contrast operation during the line borrowing (during the inline service), before the execution, the change of the leaked light power due to the change of the pressing force by the pressing unit 8 against the optical fiber 7 and the change on the optical fiber 7 The effect on the propagated information is measured in advance. For this reason, the light receiving head 1 is previously inserted into another optical fiber 7 (not in-line service) on a trial basis, and a power meter (not shown) is connected to a stage subsequent to the light receiving head 1 to measure insertion loss and coupling loss. After determining the optimum pressing force and obtaining various data, the light receiving head 1 is inserted into the optical fiber 7 of the inline service.

The measurement of the insertion loss and the coupling loss will be described. First, with the optical fiber 7 interposed between the female head 2 and the male head 3, the male head 3 is lowered as shown in FIG. 1 and sandwiched between the female head 2, and the optical fiber 7 is It is curved at a predetermined diameter along the convex surface 3a. Thus, the test light leaks from the optical fiber 7, and the light receiving sensor 4 detects the leaked light power.
At the same time, the optical fiber 7 is externally pressed by the pressing member 8 at the entrance of the light receiving head 1, that is, immediately before the female head 2 and the male head 3, so that the light receiving sensor corresponds to the pressing force of the pressing member 8. 4, the leakage light power is varied.

FIGS. 2 and 3 are schematic diagrams showing the bent state of the optical fiber. FIG. 2 shows a bent state of the optical fiber having a configuration in which the holding member 8 is not provided, and FIG. 3 shows a bending state of the optical fiber when the holding member 8 is provided. Table 1 is a list showing insertion loss and coupling loss measured when the pressing force by the pressing member 8 is changed. The measurements in Table 1 indicate that the outside air temperature is normal temperature (25 degrees).
The color of the outer sheath of the optical fiber 7 was changed to blue. The optical fiber 7 is an SM fiber having an outer diameter of 0.9 of the outer skin and a core diameter of 10 μm.

[0023]

[Table 1]

The insertion loss is obtained by calculating the received light power detected by the power meter. That is, the light receiving power (P1) when the optical fiber 7 is in a linear state without passing through the light receiving head 1.
It is calculated and output based on a difference between the optical fiber 7 and the light receiving power (P2) when the optical fiber 7 is bent by the light receiving head 1. This insertion loss is caused when the optical fiber 7 is bent by the light receiving head 1.
, Which corresponds to the loss of the test light propagating through the line.
Desirably, it is not more than dB. The coupling loss is obtained by calculating the leakage light power at the light receiving sensor 4. That is, the output is calculated based on the difference between the leakage light power (p1) when the optical fiber 7 is in a straight line state without passing through the light receiving head 1 and the leakage light power (p2) when the optical fiber 7 is bent by the light receiving head 1. This coupling loss corresponds to the efficiency for detecting the test light when the bending is performed by the light receiving head 1, and it is desirable that this value be, for example, 50 dB or less in order to obtain stable leaked light.

As shown in FIGS. 2 and 3, the optical fiber 7
The light receiving head 1 is curved into an arc of a predetermined diameter by the female head 2 and the male head 3. For this reason, the male head 3 is equivalently described in a circular shape. In addition, the introduction bending portion 2 of the female head 2
aa equivalently bends the optical fiber 7 into an arc shape having a predetermined diameter. Further, as shown in FIG. 3, the holding member 8 is also equivalently described as a circular member because the contact surface 8a makes point contact with the optical fiber 7.

Then, as shown in FIG.
In the case where there is no (conventional), the coupling loss becomes a high value exceeding 50 dB, as shown in the bending “absent” in Table 1, and
The leaked light power of the test light propagating through the optical fiber 7 cannot be detected, and the cores cannot be compared with the test light as it is. However, by providing the pressing member 8 and applying a predetermined pressing force, the coupling loss can be reduced to about 50 dB in any of the bending “weak” and “strong” in Table 1, and the leakage light power can be reduced. As a result, the detection can be performed stably, and the operation of comparing the cords can be smoothly performed.

Here, "weak" and "strong" indicate the pressing force against the optical fiber 7 by the contact surface 8a of the holding member 8, and the bending by the holding member 8 is "weak" and "strong". In any case, the insertion loss can be set to 2 dB or less, and there is no possibility of affecting information propagating through the optical fiber 7 during in-line service. The term "weak" means that the state in which the contact surface 8a of the pressing member 8 is in contact with the outer cover of the optical fiber 7 is the origin position (0), and the distance between the optical fiber 7 and the introduction bending portion 2aa is slightly narrowed and slightly crushed. The state in which the optical fiber 7 is pressed as described above, and "strong" indicates a state in which a larger pressing force is applied from "weak".

The pressing force of the pressing member 8 can be changed by changing the mounting position of the pressing member 8 with respect to the male head 3 by the moving means 10. In this preparatory stage, the pressing force of the pressing member 8 is changed. The pressing force is set so that both the insertion loss and the coupling loss are reduced within the range of “weak” and “strong”. That is, it can be said that the pressing force when the pressing member 8 is used is a “standard pressing force” near the middle position between “weak” and “strong”. As described above, by applying the pressing force of the pressing member 8 to the optical fiber 7, it is possible to stably receive the leakage light power as compared with a state in which the pressing member 8 is not provided.

Using the core detector provided with the light-receiving head 1 prepared in advance as described above, a core-core checking operation is performed on site. Incidentally, the same light receiving head 1 as that prepared beforehand is used.
It is not always necessary to use the other light receiving head 1 if the pressing force of the pressing member 8 of the light receiving head 1 is set to an appropriate pressing force based on the result obtained in the preliminary preparation.
May be used. Further, in the core wire contrast operation, a part of the optical fiber 7 is inserted into the light receiving head 1 and is bent at the predetermined diameter without using the power meter used in the preparation. The optical fiber 7 corresponds to one of the N-divided fibers on the 1-to-N optical distribution type line, and is laid at the work site of the optical fiber contrast.
Next, test light having a wavelength within the above-described predetermined range is incident from the far end (station side) of the optical fiber 7. This test light propagates through the optical fiber 7 and passes through the light receiving head 1 of the fiber optic comparator.

When the optical fiber 7 is sandwiched between the female head 2 and the male head 3, the light receiving side of the light receiving head 1 is simultaneously pressed by the pressing member 8 with a predetermined pressing force. As a result, as described above, a stable leakage light power can be obtained from the light receiving sensor 4 in a state where the insertion loss and the coupling loss are small, and the test light can be received stably. Can be performed smoothly.

Next, Tables 2 to 4 are a list of measurement data showing the coupling loss and the insertion loss for each color of the outer cover of the optical fiber 7 and each wavelength of the test light. In each of these data, a measured value at an optimal pressing force when the pressing force of the pressing member 8 is changed is described. Data is measured 20 times for each color and each wavelength. The test light was 1.61 as described above.
Since it is 5 to 1.675 μm, 1.626
μm (1626 nm), 1.639 μm, 1.654 μm
m were measured for three wavelengths. The outside temperature was set to normal temperature (25 degrees).

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

Table 2 shows that the color of the outer sheath of the optical fiber 7 is yellow, Table 3 shows blue, and Table 4 shows white. Among them, the coupling loss is generally the smallest in the blue outer sheath of the optical fiber 7, and the leakage is large. The result that the optical power can be easily obtained is obtained. In addition, by providing the pressing member 8 and applying an appropriate pressing force, the coupling loss and the insertion loss can be set to values that do not hinder the operation of controlling the core wire during the in-line service in each color over the entire wavelength band of the test light. It is shown.

Next, Tables 5 to 7 show that the optical fiber 7
3 is a list of measurement data on coupling loss and insertion loss when the temperature changes. Table 5 shows that the color of the outer sheath of the optical fiber 7 is yellow, Table 6 shows blue, and Table 7 shows white. In any of the measurements, the holding member 8 was designed to minimize the coupling loss and the insertion loss at room temperature (25 ° C.). The measurement is performed with the pressing force adjusted. The measurement at each temperature was performed five times, and the average value and the maximum value (worst value) were also described.

[0037]

[Table 5]

[0038]

[Table 6]

[0039]

[Table 7]

As shown in the figure, when the temperature of the optical fiber 7 is yellow or blue, the coupling loss tends to decrease and the leakage light tends to increase. For white, the measurement data fluctuated for each measurement location. At least in all colors, a change in coupling loss and insertion loss was observed with a change in temperature. Thus, it can be said that by changing the pressing force of the pressing portion 8 in accordance with the outside air temperature of the work site to be compared with the core wire, the coupling loss and the insertion loss can be changed to appropriate values. Therefore, by measuring in advance the pressing force at which the coupling loss and the insertion loss for each outside temperature can be reduced at the preparation stage, the pressing force corresponding to the obtained outside temperature can be obtained at the site of the core wire contrast work. By generating the force by the pressing unit 8, it is possible to stably obtain the leaked optical power without affecting the inline service.

In the embodiment described above, the pressing to the optical fiber is performed manually, but if the color of the optical fiber and the characteristics of the optical fiber due to the change of the outside temperature are stored in advance, a certain color can be obtained. It is also possible to make it possible to receive a stable leakage light power by varying the pressing force against the optical fiber when the temperature is low or when the temperature is low. In a second embodiment described below, a configuration for performing such automatic setting of the pressing force will be described. FIG. 4 is a configuration diagram showing the optical fiber continuity test device of the second embodiment.

The optical fiber contrast device of this embodiment includes the light receiving head 1 described in the first embodiment and the temperature detecting means 15.
And control means 20. Temperature detection means 15
Outputs a detection signal corresponding to the outside air temperature at the site to the control means 20. The control means 20
A processing unit 21 such as a PU and a storage unit 22 for obtaining a pressing amount based on the input detection signal,
Output to 0.

The lifting means 10 in this embodiment is different from the first embodiment in that the male head 3
The actuator 12 is fixed to the
The lifting member 8 is configured to move up and down by the operation of (1).

The storage unit 22 stores the relationship between the temperature and the pressing amount for each color of the optical fiber 7. Explaining how to set the stored contents, for example, in the yellow optical fiber 7 shown in Table 5, when the outside air temperature is 25 degrees, the optimum coupling loss and insertion loss can be obtained by the "reference pressing force". Based on this, when the outside air temperature is 0 degrees and 40 degrees, the pressing force is variably set so that the coupling loss and the insertion loss shown in Table 5 are both low. That is, when the outside air temperature is 0 degrees, a point where the coupling loss and the insertion loss are reduced by moving in a direction in which the pressing force is weakened as compared with the reference pressing force at 25 degrees is searched. On the other hand, when the outside air temperature is 40 degrees, a point where the coupling loss and the insertion loss are reduced by moving in the direction of increasing the pressing force as compared with the reference pressing force at 25 degrees is searched. As described above, for a plurality of temperatures within the range of 0 to 40 degrees with respect to the normal temperature (25 degrees), the lowering amount of the pressing member 8 is reduced for a lower temperature, and the lowering amount of the pressing member 8 is reduced for a higher temperature. Search for a point where both are increased and both coupling loss and insertion loss are reduced. The obtained pressing amount is stored in the storage unit 22 in a table format so as to be paired with the temperature. still,
The temperature-pressing force table data for each color of the optical fiber 7 is stored in the storage unit 22.

The control operation of the above configuration will be described. When performing the optical fiber contrast, the optical fiber 7 is connected to the female head 2 and the male head 3.
And bend at a specified diameter. Further, the color of the optical fiber 7 to be compared with the cord is selected and input to the control means 20 by the color setting means 16 including a switch or the like. And the control means 20
Sets the table data corresponding to this color to be readable, obtains the corresponding pressing force from the table data in the storage unit 22 based on the outside air temperature obtained from the temperature detection unit 15, and obtains the actuator 12 of the elevation unit 10. Output to The pressing member 8 presses the optical fiber 7 with the pressing force varied by an amount corresponding to the temperature difference with the reference pressing force as a center. For example, when the outside air temperature is lower than 25 degrees, the pressing force is smaller than the reference pressing force, and when it is higher, the pressing force is increased.

The pressing member 8 is pressed by the actuator 12 with a pressing force corresponding to the temperature.
, The optimum coupling loss and insertion loss can be obtained at this external temperature. In this way, even if the outside temperature of the work site to be compared with the core wire changes, the optimum coupling loss and insertion loss can be automatically obtained even if the operator does not perform the setting according to the change of the outside temperature. In addition, it is possible to smoothly perform the operation of comparing the cords. Note that the control means 20 is configured to interpolate the table data in the storage unit 22 and corresponds to the input temperature data even if the temperature input from the temperature detection means 15 does not match the stored temperature. The pressing force can be obtained. Further, even if the outside air temperature changes during the core wire contrast work, the pressing force of the pressing member 8 is changed in accordance with the change in the temperature, so that the core wire contrast work can always be stably performed. Become.

In the second embodiment, the pressing force is varied in accordance with the measured outside temperature. However, as shown by the dashed line in FIG. A configuration in which a feedback loop FB that feeds back a signal to the control unit 20 may be provided. In such a configuration, arithmetic processing can be performed by adding the state of the coupling loss based on the detection signal of the light receiving sensor 4. That is, referring to the value of the coupling loss when the pressing force of the pressing member 8 is changed in accordance with the change in the outside air temperature as described above, whether the coupling loss is equal to or less than a predetermined value necessary for the core wire contrast operation is determined. Can be monitored. In addition, the best point can be automatically searched by making a slight change in the ± direction based on the pressing force generated by the actuator 12 so that the coupling loss can be reduced as well as the monitoring.

[0048]

According to the optical fiber continuity test apparatus of the present invention, the optical fiber is bent to a predetermined diameter at the male and female heads, and the leak light is detected by the light receiving sensor. Is a structure provided with a pressing member that can be moved up and down by the elevating means and that can change the pressing force against the optical fiber, so that the coupling loss and insertion loss can be changed so that the optical fiber core contrast operation can be performed. Therefore, the insertion loss can be reduced and the cores can be compared without affecting the information transmission during the in-line service. At the same time, the coupling loss is reduced and the leakage light power at the light receiving sensor is increased to stabilize the core alignment work. You can do it. Even if the outside air temperature at the site to be compared with the core wire is unknown or fluctuates, if the control means is configured to variably control the pressing force corresponding to this temperature, it is possible to obtain stable leaked light power. Thus, it is possible to constantly and stably perform the core wire contrast operation. In addition, the optical fiber exists in each color, and the leakage light power is different for each color, but by setting the color of the optical fiber at the time of the core wire contrast, the pressing force is changed corresponding to this color, It is possible to stably perform the cord contrast operation.

[Brief description of the drawings]

FIG. 1 is a front view showing a light receiving head of an optical fiber continuity test device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a bent state of an optical fiber.

FIG. 3 is a schematic diagram showing a bent state of an optical fiber when a holding member is provided.

FIG. 4 is a configuration diagram showing a second embodiment of the optical fiber continuity test device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light receiving head, 2 ... Female head, 2a ... Concave part, 3 ... Male head, 3a ... Convex part, 4 ... Light receiving sensor, 7 ... Optical fiber,
8 pressing member, 8a contact surface, 10 elevating means, 1
DESCRIPTION OF SYMBOLS 1 ... screw, 12 ... actuator, 15 ... temperature detection means,
16 color setting means, 20 control means, 21 processing unit, 2
2. Storage unit.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ikuaki Tanaka 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (6)

[Claims] 1. A male head (3) for winding an optical fiber to be measured in a substantially semicircular shape, and an optical fiber to be measured having a curved portion having the same diameter as the male head and wound around the male head. Two female heads (2) for pressing and holding a part of each of the light incident end side and the light emitting end side of the light with a curved portion, and disposed between the two female heads; Light receiving sensor (4) for detecting the power of light leaked from the fiber
And a pressing force corresponding to the amount of movement of the measured fiber to the female head, which is movably disposed at a position closer to the incident end than the part of the measured fiber pressed by the female head. An optical fiber continuity test device, comprising: a pressing member (8) for pressing in (1). 2. The female head (2) is fixedly arranged, the male head (3) is configured to be vertically movable with respect to the female head, and the pressing member (8) is provided on the male head side. The optical fiber continuity test apparatus according to claim 1, further comprising a lifting means (10) for raising and lowering the head vertically with respect to the female head. 3. A moving means (10) having an actuator (12) capable of moving the pressing member (8) toward the female head with a variable amount of up and down movement; The optical fiber continuity test apparatus according to claim 1, further comprising: a control means (20) for controlling the movement of the actuator of the moving means so that both the insertion loss and the insertion loss are stabilized. 4. A temperature detecting means (15) for detecting an outside air temperature at a location to be compared with a cord, wherein said control means (20) obtains a pressing force corresponding to the temperature detected by said temperature detecting means. 4. The optical fiber continuity test apparatus according to claim 3, wherein the movement of the actuator of the moving means is controlled. 5. A storage unit (22) in which a plurality of data indicating the temperature and the pressing force are stored in advance for each temperature, wherein the control unit (20) controls the temperature output from the temperature detection unit (15). 5. The optical fiber continuity test apparatus according to claim 4, wherein the pressing force corresponding to the above is obtained from the storage unit to control the movement of the actuator of the moving means. 6. The control means (20) stores in advance a pressing force corresponding to the color of the sheath of the optical fiber, and controls the movement of the actuator of the moving means with the corresponding pressing force based on the setting of the color of the sheath. The optical fiber continuity test device according to claim 3, wherein