JPH07181346A - Measuring method of hole or v-groove - Google Patents

Abstract

PURPOSE:To provide a measuring method of hole or V-groove which can make a highly precise measurement. CONSTITUTION:A measuring pin 2 is inserted into a measuring part l such as a hole or V-groove (guide pin insert hole of multicore ferrule, fiber insert hole, or the like), a profile form measuring machine 4 is brought into contact with the outer circumferential part of the protruding part 3 of the measuring pin 2 to multipoint-measure the profile form of the measuring pin 2, and the measured values are arithmetically processed to measure the measuring part 1. Thus, this method has no influence of the shading of the insert hole or V- groove, the sagging of the profile, and dust as in transmitted light method because of the contact type to the measuring pin 2, and can perform a highly precise measurement because the multipoint measurement can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The method of measuring holes, V-grooves, etc. according to the present invention is a guide pin insertion hole of an optical connector ferrule used for optical communication, a center position of a fiber insertion hole, and a dimension between two guide pin insertion holes. , Dimensions between multiple fiber insertion holes,
It is used to determine the dimension between the guide pin insertion hole and the fiber insertion hole, the positional deviation of the fiber insertion hole from the reference line connecting the two guide pin insertion holes, and the like.

[0002]

2. Description of the Related Art In recent years, a multi-fiber optical connector as shown in FIG. This multi-fiber optical connector is shown in Figure 4.
As shown in (b), two multi-core ferrules C each having a guide pin insertion hole A and a fiber insertion hole B are used in combination. In this case, the fiber of the optical fiber tape core wire D is inserted and fixed in the fiber insertion hole B of the multi-core ferrule C, and is guided to the guide pin insertion hole A of one of the two multi-core ferrules C to be connected. By inserting the pin E and inserting the projecting portion E of the guide pin E into the guide pin insertion hole A of the other multi-core ferrule C, the two multi-core ferrules C are abutted and connected to each other. The fibers inserted into and fixed to the core ferrule C are butted against each other. Further, the clamp spring F is pushed in from below the abutting both multi-core ferrules C, and the pressing portion G is pressed against the outer surface of each multi-core ferrule C so as to secure the connection of both multi-core ferrules C. is there.

In order to improve the coupling accuracy of the fibers in the coupling, the dimension L between the two guide pin insertion holes A of the multi-core ferrule C (FIG. 6), the dimension W between the plurality of fiber insertion holes B, and the guides. Pin insertion hole A and fiber insertion hole B
The distance between them is accurate, and the fiber insertion hole B is connected to the reference line XX connecting the centers of the two guide pin insertion holes A.
It is necessary that the is not displaced.

Since the multi-core ferrule C is coupled as described above, when the guide pin insertion hole A is displaced, the fibers inserted into the fiber insertion hole B are misaligned even if the fiber insertion hole B is correct. Resulting in. As described above, in the multi-core ferrule C, the guide pin insertion hole A serves as a reference for mechanical connection of the connector. Further, a line (XX line in FIG. 6) connecting the centers of the guide insertion holes A obtained in the dimension measurement of the multi-core ferrule C becomes one axis of the coordinate system. Therefore, in order to improve the measurement accuracy of the multi-core ferrule C, the point is how to accurately measure the center of the guide insertion hole A.

The quality of the multi-core ferrule C as described above is conventionally judged by inserting and fixing the fiber in the fiber insertion hole B of the multi-core ferrule C, and measuring the connection loss after polishing the butted end face. It was common to judge.

However, in the conventional measuring method, it is necessary to insert and fix each fiber into the fiber insertion hole B of the multi-core ferrule C, so that the work up to measuring the connection loss is troublesome.

Therefore, before the fiber is inserted and fixed in the fiber insertion hole B of the multi-fiber ferrule C, if the dimensions of the multi-fiber ferrule C itself can be measured and the quality can be determined, the trouble of the conventional measuring method is eliminated, and It is also very advantageous in terms of improving the product yield.

Further, since the multi-fiber ferrule C is usually molded by plastic, if the multi-fiber ferrule C itself can be used to judge the quality of the multi-fiber ferrule C before the fiber is inserted and fixed, the fact can be measured when a defect occurs. It is possible to speedily feed back to the previous step (molding step) and stop the generation of defective products at that time.

Therefore, conventionally, the hole position of the multi-core ferrule before inserting and fixing the fiber has been measured by using the measuring system shown in FIG. 5 (a). In the measurement by this measuring system, the multi-core ferrule C to be measured is vertically oriented at a predetermined position on a translucent stage H such as a glass plate (the guide pin insertion hole A and the fiber insertion hole B in FIG. The light from the light source J below the stage H is projected onto the stage H, and the light is guided to one end of the guide pin insertion hole A and the fiber insertion hole B of the ferrule I on the stage H. Is incident on the other end and transmitted (transmitted) to the other end, the state of the transmitted light at the output end is photographed by the CCD camera L through the microscope K installed on the emission side, and the image from the CCD camera L is imaged by the image processing device M. After processing, the edges of the guide pin insertion hole A and the fiber insertion hole B are detected, and based on the detected edges, several coordinate points P ₁ , P ₂ and P ₃ of the edge are calculated, and the coordinate points P ₁ , P ₂ and P ₃ are calculated. Guide pin insertion hole A based on measurement coordinates The diameter of the fiber insertion hole B, and which was to calculate the center.

[0010]

In the measuring method using the measuring system shown in FIG. 5 (a), since the displacement of the stage H is read by the laser scale N, its accuracy (resolution 0.005 μm) is too high. Even with a glass scale, the resolution is 0.1 μm, which is not unacceptable accuracy. However, since the edge of the multi-core ferrule C is detected by the transmitted light method based on the transmitted light, there are the following problems.

1. The contours of the guide pin insertion hole A and the fiber insertion hole B may be out of focus due to a mismatch of light amounts (too bright or too dark). 2. If the edge portions of the guide pin insertion hole A and the fiber insertion hole B are sagged or chipped, the captured image becomes unclear. 3. If dust or the like adheres to the guide pin insertion hole A and the fiber insertion hole B, it becomes an obstacle and the captured images of those holes become unclear. 4. When the multi-core ferrule is plastic, the holes may be distorted and deformed into a non-perfect circle due to the deformation after molding. Therefore, the measurement of the center of the guide hole that serves as a mechanical reference varies. Moreover, the variation width is as large as about 2 μm. Naturally, the pitch dimensions of the guide pin insertion hole A and the fiber insertion hole B were too large, σ = about 1 μm, during repeated measurement, which was insufficient.

An object of the present invention is to provide a method for measuring holes, V-grooves, etc., which enables highly accurate measurement.

[0013]

As shown in FIGS. 1 and 3, the method of measuring holes, V-grooves, etc. according to the present invention is, as shown in FIGS. 1 and 3, a guide pin insertion hole or a V-groove, a fiber insertion hole or a multi-core connector ferrule 1. Inserts the measuring pin 2 into the measuring portion 1 such as a V-groove, and brings the contour measuring device 4 into contact with the outer peripheral portion of the protruding portion 3 of the measuring pin 2 protruding outside the measuring portion 1 to make the measuring pin 2 The contour shape is measured at multiple points and the measured values are arithmetically processed to measure the measuring unit 1.

[0014]

In the method of measuring holes, V-grooves, etc. of the present invention, the measuring unit 1
Since the contour measuring device 4 is brought into contact with the outer peripheral portion of the protruding portion 3 of the measuring pin 2 inserted in the multi-point measurement and the measured values are arithmetically processed, for example, the center position of the measuring portion 1 can be obtained. . Therefore, the light transmitted through the guide pin insertion hole, the fiber insertion hole, or the V groove of the multi-core ferrule can be measured more accurately than the case where the image is taken and measured.

[0015]

EXAMPLE A method for measuring holes, V-grooves, etc. according to the present invention is shown in FIGS.
It will be described in detail based on. The measurement unit 1 is shown in FIG.
Shows the case of the guide pin insertion hole 6 and the fiber insertion hole 7 of the multi-core ferrule 8, and the case shown in FIG.

As the multi-core ferrule 8 shown in FIG. 1, for example, there are 4 cores, 8 cores, etc. in which the arrangement pitch of the guide pin insertion holes 6 is 8 mm in design value and the arrangement pitch of the fiber insertion holes 7 is 0.25 mm. The material of the multi-core ferrule 8 may be plastic.

In FIG. 1, the measuring pin 2 is inserted into the guide pin insertion hole 6 of the multi-core ferrule 8. In this case, the measuring pin 2 may have any length, but at least 3 mm or more can be inserted, and the protruding portion 3 having a length necessary for measurement protrudes outside the ferrule 8.
The measuring pin 2 has an outer diameter accuracy of 0.1 μ, for example.
m, roundness of 0.1 μm or less, cylindricity of 0.3 μm or less,
A tool that can be inserted into the guide pin insertion hole 6 with a clearance of 0.1 μm or less is prepared.

Next, of the measuring pin 2 of FIG. 1, the contour of the protruding portion 3 protruding from the ferrule 8 is measured. In this case, the measurement of the measuring pin 2 is performed by using a contour shape measuring machine 4 such as a contact type length measuring machine or a roundness measuring machine, and the tip end of these is measured as shown in FIG. Trace along the surface.
In this case, the ferrule 8 in which the measuring pin 2 is inserted is fixed with a vise or a dedicated jig so as not to move. It is desirable to perform this contour measurement in a constant temperature and humidity chamber (for example, 22 ° C. 60%) in order to eliminate dimensional variations due to temperature changes.

As the contour shape measuring instrument 4, it is desirable to use one having a minimum resolution of about 0.1 μm. The tip shape of the contactor 9 of the contour shape measuring machine 4 may be a cone, a semi-cone, or the like. As for the number of measurement points, if a sample ring of 1 micron pitch is used and the range of ± 60 ° from the apex of the pin is set as the measurement region, a pin of φ2 mm has about 2000 points, and a very large number of points can be captured as data.

The center position of the measuring pin 2, that is, the center position of the guide pin insertion hole 6 is calculated by arithmetically processing the value of the circular arc obtained by the contour measurement. Further, based on this center position, the dimension between the center positions, that is, the measured pitch dimension of the guide pin insertion hole 6 (L in FIG. 6) can be obtained. An example of the measurement result (the number of measurements n = 15) is shown below.

(1) 8.0000 mm (6) 8.0002 mm (11) 8.0001 mm (2) 8.0000 mm (7) 8.0000 mm (12) 8.0002 mm (3) 7.9997 mm (8) 8. 0002mm (13) 8.0002mm (4) 8.0003mm (9) 8.0002mm (14) 8.0005mm (5) 8.0005mm (10) 8.0000mm (15) 8.0003mm

From the above, the average was 8.0016 and the standard deviation was 0.000206, and the standard deviation was ⅕ of the value obtained by the conventional method, and the significant difference was clarified.

According to the method for measuring holes, V-grooves, etc. of the present invention,
Since the center position of the guide pin insertion hole 6 can be obtained as described above, the guide pin insertion hole 6 can be calculated based on the center position.
, The reference line XX connecting the center positions of the two guide pin insertion holes 6, the positional deviation of the fiber insertion hole 7 with respect to the reference line XX, and the like can be measured.

According to the method for measuring holes, V-grooves, etc. of the present invention,
Center position, contour of the fiber insertion hole 7 of the multi-core ferrule,
It is also possible to find the pitch and the like. In this case, the outer diameter of a commonly used optical fiber is about φ0.125 mm,
When the measuring pin 2 having the same diameter as that is inserted into the fiber insertion hole 7 and the contactor 9 of the contour shape measuring machine 4 is brought into contact with the measuring pin 2 in the same manner as in Example 1, the measuring pin is measured. 2 may lose contact pressure (measurement pressure: usually several gf) and bend or break, making measurement impossible.

In order to solve such a problem, the diameter of the portion 10 of the multi-core ferrule 8 to be inserted into the fiber insertion hole 7 (measuring portion 1) as the measuring pin 2 is made thin as shown in FIG. 2 (a). However, it is desirable to use the stepped measuring pin 2 in which the protruding portion 3 protruding to the outside of the multi-core ferrule 8 is thickened. This makes it possible to perform high-precision measurement that is exactly the same as in Example 1. However, in this case, it is assumed that the concentricity of the stepped measuring pin 2 is sufficiently high (ideally 0.1 μm or less). If the concentricity is not obtained, the measuring pin 2 is rotated to measure in any direction, and the center of the fiber insertion hole 7 is calculated by calculation.

The method of measuring the holes, V-grooves, etc. of the present invention is not limited to the measurement of the guide pin insertion hole 6, the fiber insertion hole 7 etc. of the multi-core ferrule, but as shown in FIG. It can also be applied to the measurement of the pitch, the depth, etc. of a groove or a V groove formed by etching a silicon substrate.

[0027]

The method of measuring holes, V-grooves, etc. according to the present invention has the following effects because the measuring pin 2 is inserted to perform contact-type measurement. 1. Since there is no blurring of the measuring pin 2 unlike the conventional transmitted light method, highly accurate measurement is possible. 2. Since the contour of the measuring pin 2 is measured by the contact method, highly accurate measurement is possible even if the contour of the hole or the V groove is sagging. 3. Since the contour of the measuring pin 2 is measured, the measuring pin 2
It is easy to remove the dust adhering to, and is relatively unaffected by the dust. 4. Since the measuring pin 2 having a roundness is used, the problem when the hole or the V groove is a non-roundness can be eliminated. 5. Due to the time required for measurement in the transmitted light method, many edges could not be detected for one hole (maximum 10 to 20 points), but in the measurement method of the present invention, a maximum of several hundreds due to the adjustment of the sampling interval. Since multiple points or more can be measured, highly accurate measurement is possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method for measuring holes, V-grooves, etc. according to the present invention.

FIG. 2 (a) is an explanatory view of a stepped measuring pin used in the method for measuring holes, V-grooves, etc. of the present invention, and FIG. 2 (b) is a diagram showing the measuring pin of (a) inserted into a multi-core ferrule. FIG.

FIG. 3 is an explanatory diagram for measuring a V groove by the measuring method of the present invention.

FIG. 4 (a) is an explanatory view of coupling of multi-core ferrules, (b).
Is a perspective view of a multi-core ferrule.

5A is an explanatory view of a method for measuring a guide pin insertion hole and a fiber insertion hole of a conventional multi-core ferrule, FIG.
FIG. 6A is an explanatory diagram of a center position calculation method based on the measurement data in (a).

FIG. 6 is an explanatory view of a guide pin insertion hole and a fiber insertion hole in the multi-core ferrule.

[Explanation of symbols]

 1 Measuring part 2 Measuring pin 3 Protruding part 4 Contour shape measuring machine

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Yanase 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Ken Kanai 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Shinji Nagasawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. A contour measuring machine is inserted into a measuring portion 1 such as a hole or a V-groove so that an end portion of the measuring pin 2 protrudes to the outside, and the measuring pin 2 has an outer peripheral portion of a protruding portion 3 of the measuring pin 2. 4, a multi-point contour shape of the measuring pin 2 is measured, and the measured values are arithmetically processed to measure the measuring unit 1.
Measuring method of V groove.