JPH11132717A - Decentering direction measuring device for optical fiber ferrule and method therefor using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a judgment discrepancy and a time lag and to enhance the measurement accuracy by rotating a ferrule by a specified angle, obtaining the center point from the difference between both positions, and obtaining the decentering direction of a fine hole based on it. SOLUTION: A ferrule 1 fitted with a holder 41 is mounted on the V-groove of a V-block 42, and the ferrule 1 is rotated by 180 deg. around the axis. Since the holder 41 is fitted, the rotation is easily handled, and the rotation angle of the ferrule 1 can be accurately recognized by the reference direction 41a of the holder 41. The position of a fine hole 11 on the end face of the ferrule 1 is measured before and after the rotation, and the positions are fed to an image processing device as images. When the middle point of the line segment connecting the center points of the fine hole 11' before rotation and the fine hole 11 after rotation is obtained on a screen 53, it is the outer diameter center 12 of the ferrule 1, and the decentered quantity (d) can be measured based on the outer diameter center 12 and the center of the fine hole 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the misalignment direction of a fine hole in an optical fiber ferrule for holding an end of an optical fiber, and a measuring method using the same.

[0002]

2. Description of the Related Art In the field of optical communication, an optical connector is used when optical fibers are connected to each other or between an optical fiber and various optical elements. In this optical connector, the tip of the optical fiber is held by a ferrule.

As shown in FIG. 9, a ferrule 1 is made of ceramics or the like and has a pore 11 in the center.
A resin or metal back body 2 is joined to the rear end for use. Then, the optical fiber 3 is inserted through the through hole 21 of the back body 2, and the tip of the optical fiber 3 is inserted and fixed in the fine hole 11 of the ferrule 1.

In this way, the ferrule 1 holding the tip of the optical fiber 3 is inserted from both ends of a sleeve (not shown), and the tip surfaces of the ferrule 1 are brought into contact with each other to constitute an optical connector. Can be.

The ferrule 1 is made of ceramics such as zirconia and is precisely manufactured so that the concentricity of the pores 11 with respect to the outer diameter is high. Is difficult to completely match, and it is inevitable that a misalignment of 1.4 μm or less occurs, and this misalignment causes connection loss.

Therefore, the misalignment direction of the ferrule 1 is measured in advance, the direction is marked, and when the optical connector is used for an optical connector, the marking direction of the pair of ferrules 1 is matched to be used. A decline is being made.

In this case, an apparatus shown in FIG. 10 is used to measure the misalignment direction of the ferrule 1. First, the ferrule 1 is placed on a V block 42 having a V groove, and the ferrule 1 is rotated around an axis by rotating the ferrule 1 while abutting a roller 46 thereon.

On the other hand, from one end of the ferrule 1, the light source 5
The ferrule 1 is irradiated with light, and the position of the pore 11 on the end face of the ferrule 1 is detected by an image processing device 52 such as a camera provided on the other end side. At this time, when the ferrule 1 is rotated on the V block 41 as shown in FIG. And the pores 11
The rotation of the ferrule 1 should be stopped when the top comes to the top, and the marking 13 should be applied to the surface of the top ferrule 1.

[0009]

However, the conventional method for measuring the misalignment direction as described above has a problem that the measurement accuracy in the misalignment direction is low.

[0010] The reason for this is that a deviation easily occurs in the determination that the pore 11 has reached the uppermost portion, and the deviation tends to occur depending on the time from when it is determined that the fine hole 11 has reached the uppermost portion until the rotation of the ferrule 1 is stopped. there were.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to an apparatus for measuring the direction of misalignment of a fine hole in a ferrule having a central hole for inserting and fixing an optical fiber. A V-block to be placed, a holder for holding a ferrule and displaying a reference direction,
It is characterized by comprising a rotating means for rotating the ferrule around the axis on the V-block, and an image device for measuring the position of the pore on the end face of the ferrule.

Further, according to the present invention, using the above-described apparatus, the ferrule is held on a holder and placed on a V-block, and the ferrule is rotated by 180 ° about an axis on the V-block and rotated on the end face of the ferrule. It features a method of measuring the misalignment direction of the optical fiber ferrule, comprising measuring the positions of the front and rear pores, setting the center point of both as the center of the outer diameter, and marking in the direction of the pore viewed from the center of the outer diameter. I do.

[0013]

According to the present invention, by holding the ferrule with the holder, handling during rotation is facilitated.
The rotational position can be accurately recognized. In addition, the ferrule is rotated by 180 °, the center point is obtained from the difference between the front and rear positions, and the misalignment direction of the pores is obtained based on the center point. Measurement accuracy can be improved.

[0014]

Embodiments of the present invention will be described below.

As shown in FIG. 9, the ferrule 1 is a cylindrical body having a pore 11 for inserting and fixing the optical fiber 3. Then, in order to determine the minute misalignment direction of the fine holes 11 in the ferrule 1, the measurement is performed as follows.

First, the ferrule 1 is held by the holder 41 as shown in FIG. This holding tool 41 has a reference direction 41a.
And an insertion hole 41 b for inserting and fixing the ferrule 1. 2A, the ferrule 1 is fixed to the insertion hole 41b by utilizing the elasticity of the holder 41 itself, or as shown in FIG. As shown in FIG. 3), a pressing member 41 such as a spring is provided beside the insertion hole 41b.
With c provided, the ferrule 1 can be pressed and fixed.

The holder 41 is used to clarify the rotational position of the ferrule 1 which is rotationally symmetric, and can also facilitate handling during rotation, which will be described later.

Next, as shown in FIG. 3, the ferrule 1 to which the holder 41 is attached is placed on the V block 42.
The V-block 42 has two V-grooves 42a and a concave portion 42b between the V-grooves 42a. The cylindrical side surface of the ferrule 1 is placed in both the V-grooves 42a, and the holder 41 comes to the position of the concave portion 42b. Place on. Thus, the V groove 42
By mounting the ferrule 1 on the “a”, the cylindrical side surface of the ferrule 1 can be reliably and accurately supported.

Next, on the V block 41, the ferrule 1
Is rotated 180 ° around the axis. Specifically, for example, as shown in FIG.
4A, the holding tool 41 is first brought into contact with one of the stoppers 43 as shown in FIG. 4A, and the ferrule 1 and the holding tool 41 are rotated in the direction of the arrow as shown in FIG.
As shown in (b), the holding tool 41 is connected to the other stopper 43.
Rotate until it touches. At this time, the stopper 43 may be accurately arranged in advance so that the rotation angle of the ferrule 1 becomes 180 °.

At this time, for accurate measurement, it is important to rotate the ferrule 1 while pressing it on the V-groove 42a of the V-block 42. For this purpose, as shown in FIG. 5A, for example, the ferrule 1 is pressed in the direction of the V-block 42 by an elastic body 44 such as a spring, and in this state, the holding tool 41 is rotated with the hand 45 or the like. You can do it.
Alternatively, as shown in FIG. 5B, a roller 46 is disposed above the ferrule 1 and the ferrule 1 is rotated by simultaneously rotating the ferrule 1 while pressing the ferrule 1 in the direction of the V block 42 with the roller 46. Can also.

In this rotation step, the holding of the holder 41 facilitates the handling of the rotation, and the ferrule 1 is set by the reference direction 41a of the holder 41.
Can be accurately recognized.

Next, before and after the rotation, the position of the pore 11 on the end face of the ferrule 1 is measured. Specifically, as shown in FIG. 6, light is emitted from a light source 51 disposed on one end of the ferrule 1 placed on the V block 42, and a lens, a camera,
Image processing device 52 including a binarization device, a monitor television, and the like
Place. Then, the position of the pore 11 on the end face of the ferrule 1 is captured as an image by the image processing device 52.

That is, the end face of the ferrule 1 before the rotation and the end face after the 180 ° rotation are captured as images. At this time, as shown in FIG. 7A, the pores 11 ′ before rotation and the pores 11 after rotation are displayed on the same screen 53, and both the pores 11 and 11 ′ are displayed on this screen 53. When the midpoint of a line segment connecting the center points of the ferrules 1 is obtained, this becomes the outer diameter center 12 of the ferrule 1.

Therefore, the outer diameter center 12 and the pore 11
By calculating the distance to the center of, the amount of misalignment d can be measured. Further, as shown in FIG. 7B, when the angle θ formed by the direction of the hole 11 after rotation with respect to the reference direction 41a displayed on the holder 41 is measured counterclockwise, the misalignment direction with respect to the reference direction 41a is obtained. Angle θ can be determined.

The angle θ in the misalignment direction and the misalignment amount d can be automatically measured by the image processing device 52.

Finally, the ferrule 1 is marked in the misalignment direction based on the above measurement results. Specifically, the ferrule 1 to which the holder 41 is attached is removed from the V-block 42 and set in the center hole of the angle display plate 54 as shown in FIG. On the angle display plate 54, an angle of 0 to 360 ° is displayed clockwise around the center hole, and the reference direction 41a of the holder 41 is adjusted to the position of the misalignment angle θ measured in the previous step. . At this time, since the misalignment direction of the ferrule 1 is the direction of 0 ° of the angle display plate 54, the marking 13 may be provided on the surface of the ferrule 1 in this direction.

The marking 13 can be formed by various means such as applying a paint such as oil-based ink, irradiating a laser beam, attaching a seal, and the like. Is formed on the surface of the ferrule 1.

Also, according to the misalignment amount d measured earlier,
If you change the shape and color of the marking 13,
The misalignment amount can be displayed simultaneously with the misalignment direction.

According to the above-described method for measuring the misalignment direction, by attaching the holder 41 to the ferrule 1, not only the handling during rotation is facilitated but also the rotational position of the ferrule 1 can be accurately recognized. Can be. Further, since it is sufficient to compare the images of the end face before and after rotating the ferrule 1 by 180 °, the ferrule 1 is always in a stationary state when confirming the image. Therefore, accurate measurement can be performed without occurrence of a deviation in judgment and a deviation in time as in the conventional example.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The measurement accuracy when the misalignment direction of the ferrule 1 was measured by the present invention and the conventional measuring method was obtained by calculation.

The ferrule 1 is made of zirconia ceramics, having an outer diameter of 2.5 mm, a length of 10.5 mm, and pores 11
Having an inner diameter of 0.125 mm and a concentricity of the pores 11 with respect to the outer diameter of 1 μm was used.

First, in the conventional method, a deviation of about 0.05 μm at the maximum occurs when the ferrule 1 is rotated to determine that the fine hole 11 has reached the uppermost part. Therefore, when converted into an angle in the misalignment direction, a misalignment of cos ⁻¹ (1-2 × 0.05 / 1) = 25.8 ° occurs.

Further, the ferrule 1 is rotated at a rate of 3 seconds / rotation, and there is a time lag of about 0.1 second before the rotation is stopped based on the above judgment. Then, a shift of 0.1 × 360/3 = 12 ° occurs, and when they are combined, an angle shift of 25.8 + 12 = 37.8 ° in the misalignment direction occurs.

On the other hand, in the measuring method of the present invention, only one error in the image analyzer 52 is considered, and when one unit at the time of image analysis is 0.015 μm, a maximum deviation of three units is considered.
In this case, the angle deviation in the misalignment direction is tan ^-1 (0.015 × 3 / (1/2)) = 5.1 °.

As described above, in the conventional method, a maximum of 37.000 is required between the direction in which the marking 13 is provided and the true misalignment direction.
While an error of 8 ° occurs, in the present invention, at most 5.
It can be seen that there is only an error of 1 ° and the measurement accuracy can be increased.

[0036]

As described above, according to the present invention, there is provided a method for measuring the direction of misalignment of a fine hole in a ferrule having a fine hole for inserting and fixing an optical fiber in the center, comprising: Is held on a V-block while being held by a holder, and the ferrule is rotated 180 ° around the axis on the V-block.
° rotation, by measuring the position of the pores before and after rotation on the ferrule end face, the center point of both as the center of the outer diameter, by marking in the direction of the pores viewed from the center of the outer diameter, The misalignment direction can be measured with extremely high accuracy. Therefore, the joining loss when this ferrule is used as an optical connector can be reduced, and a high-performance optical connector can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are views showing a process of attaching a holder to a ferrule in a method of measuring a misalignment direction of an optical fiber ferrule according to the present invention.

FIGS. 2A and 2B are diagrams showing another embodiment of the holder of FIG. 1;

FIGS. 3 (a) and 3 (b) are views showing a step of placing a ferrule on a V-block in the measurement method of the present invention.

FIGS. 4A and 4B are diagrams showing a step of rotating a ferrule in the measuring method of the present invention.

5 (a) and 5 (b) show various embodiments in the process of FIG.

FIG. 6 is a diagram showing a device for measuring a ferrule end face in a measuring method of the present invention.

FIGS. 7A and 7B are images showing ferrule end faces measured by the apparatus of FIG. 6;

FIG. 8 is a view showing a step of determining a marking position of a ferrule in the measuring method of the present invention.

9A is a side view of a general optical fiber ferrule, and FIG. 9B is a longitudinal sectional view of the same.

FIG. 10 is a view showing a conventional optical fiber ferrule misalignment direction measuring apparatus.

11 (a) and (b) are diagrams showing a measuring method using the apparatus of FIG.

[Explanation of symbols]

 1: Ferrule 11: Pores 13: Marking 2: Back body 21: Through hole 3: Optical fiber 41: Holder 42: V block 43: Stopper 44: Elastic body 45: Hand 46: Roller 51: Light source 52: Image processing Device 53: Screen 54: Angle display board

Claims (2)

[Claims] An apparatus for measuring the misalignment direction of a fine hole in a ferrule having a fine hole for inserting and fixing an optical fiber in the center, comprising: a V-block on which a ferrule is mounted; A holder for displaying the reference direction by using a rotating means for rotating the ferrule around the axis on the V-block, and an image processing device for measuring the position of the fine hole at the end face of the ferrule. Direction measuring device. 2. A method for measuring a misalignment direction of a fine hole of a ferrule having a fine hole for inserting and fixing an optical fiber in the center, the ferrule being held by a holder and mounted on a V-block. The ferrule is rotated 180 ° around the axis on the V-block, the positions of the pores before and after rotation are measured at the end face of the ferrule, and the center point of both is defined as the center of the outer diameter, and the fineness viewed from the center of the outer diameter is determined. A method for measuring a misalignment direction of an optical fiber ferrule, comprising a step of marking in the direction of a hole.