JPH0926306A - Method and apparatus for measurement of tip shape of optical fiber assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the radius of curvature and the decentering amount of the tip of an optical fiber assembly bringing the tip of the optical fiber assembly into contact with a screen plate, irradiating the tip with light, to generate interference rings N with reflected light from the plate and that from the tip, making a circular marker agree with the rings and the order of the rings, and measuring the diameter of the marker. SOLUTION: Interference rings, an optical fiber (a) and circular markers E1, E2 are displayed on the image of a monitor. An operator brings the marker E1 into contact with the rings N of a prescribed order. Then, a CPU computes the radius of curvature of the tip on the basis of the diameter and the order of the marker E1. The central coordinates of the marker E1 are set as the coordinates of the curvature center (h) on the screen G. Then, the operator makes the marker E2 agree with the image of the fiber (a). The CPU sets the central coordinates of the marker E2 as the coordinates of the center (i) of the image of the fiber (a). A decentering amount is computed is computed on the basis of the coordinates of the center (i) and those of the curvature center (h). Thereby, the radius of curvature of the tip of an optical fiber assembly and a decentering amount with reference to the fiber (a) can be measured without putting a burden on the operator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber assembly tip shape measuring method and a tip shape measuring apparatus.
More specifically, an optical fiber assembly tip shape measuring method and tip shape measuring apparatus capable of measuring the radius of curvature of the tip of the optical fiber assembly processed into a substantially spherical surface, and the tip of the optical fiber assembly processed into a substantially spherical surface. The present invention relates to a method for measuring the tip shape of an optical fiber assembly and a tip shape measuring apparatus capable of measuring the center of curvature of the core and the eccentricity of the optical fiber.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing an example of a conventional optical fiber assembly tip shape measuring apparatus. This optical fiber assembly tip shape measuring apparatus 200 has a holding portion 1 for holding an optical fiber assembly K in which an optical fiber a is inserted into a ferrule d and a tip KT is processed into a substantially spherical surface, and the optical fiber assembly K. A glass plate 2 which is provided perpendicularly to the axial direction and which is abutted by the tip KT of the optical fiber assembly K held by the holding portion 1, and a monochromatic light is radiated to the tip KT through the glass plate 2 and the glass plate The light source unit 3 that causes an interference ring (N in FIG. 6) due to the reflected light at 2 and the reflected light at the tip KT, and an enlarged image of the interference ring N and the tip K (G in FIG. 7). An optical system 4 and a CCD camera 5 for picking up images, a linear marker generator 206 for generating linear markers (LH1, LH2, LV1, LV2 in FIG. 7) on the image, and a linear marker on the image. Operating section 2 for performing the operator an operation to move the
08, a monitor 9 for displaying the image and the linear marker, and a CPU 207 for calculating the radius of curvature of the tip KT, the center of curvature of the tip KT, and the eccentric amount of the optical fiber a from the position of the linear marker. Composed.

The light source unit 3 includes a white light lamp 31 and a bandpass filter 32 for generating a monochromatic light, a lens system 33 for collimating the monochromatic light and irradiating the glass plate 2 vertically to the glass plate 2. The monochromatic light from the glass plate 2
The half mirror 34 that transmits light to the optical system 4 side and reflects the light reflected from the glass plate 2 side to the optical system 4 side.

As shown in FIG. 6, on the glass plate 2, an interference ring N produced by interference between the light reflected by the glass plate 2 and the light reflected by the tip KT can be seen. The optical fiber a can be seen through the glass plate 2.

As shown in FIG. 7, an image G on the monitor 9 has an interference ring N, an optical fiber a, and a linear marker L.
H1, LH2, LV1 and LV2 are shown. Therefore, the operator operates the operation unit 208 to move the linear markers LH1, LH2, L as shown in FIG.
V1 and LV2 are brought into contact with the interference ring N of a predetermined order.
Then, the CPU 207 causes the linear markers LH1, L
From the positions of H2, LV1, and LV2 and the order, the tip K
Calculate the radius of curvature of T. Further, the coordinates of the center of curvature h on the screen G are calculated. Next, the operator operates the operation unit 2
By operating 08, the linear markers LH1, LH2, LV1 and LV2 are brought into contact with the image of the optical fiber a as shown in FIG. 7B. Then, the CPU 207 displays the screen G from the positions of the linear markers LH1, LH2, LV1, LV2.
The coordinates of the center i of the image of the optical fiber a at are calculated.
Then, the amount of eccentricity is calculated from the coordinates of the center i and the coordinates of the center of curvature h.

[0006]

In the above-mentioned conventional optical fiber assembly tip shape measuring apparatus 200, four linear markers LH1, LH2, LV1 and LV2 are placed so as to be in contact with the images of the interference ring N and the optical fiber a. Operation to move is necessary. However, circles (images of the interference ring N and the optical fiber a) and straight lines (straight line markers LH1, LH2, LV1, L
It is a very minute work to visually check whether or not V2) is in contact, because it is necessary to stare at one point (contact point).
On top of that, this has to be repeated many times (twice just by measuring the radius of curvature). Therefore, there is a problem that the burden on the operator is very large. Therefore, an object of the present invention is to measure the radius of curvature of the tip of the optical fiber assembly and the amount of eccentricity with respect to the optical fiber without burdening the operator, and a method for measuring the tip shape of the optical fiber assembly. It is to provide a measuring device.

[0007]

According to a first aspect of the present invention, an optical fiber assembly in which an optical fiber is inserted into a ferrule and whose tip is processed into a substantially spherical surface is abutted against a screen plate and the screen is also attached. By irradiating the tip through the plate with light, an interference ring is generated by the reflected light from the screen plate and the reflected light from the tip,
A measurement of the tip shape of an optical fiber assembly, characterized in that a substantially circular marker is fitted to one of the interference rings, and the radius of curvature of the tip is obtained from the order of the fitted interference ring and the diameter of the substantially circular marker. Provide a way.
Conventionally, a very detailed work of staring at one point was required, but in the present invention, it is sufficient to visually check whether or not the circle (interference ring) and the circle (substantially circular marker) match each other. No need to gaze and work is easy. That is,
Whether the circles coincide with each other or deviate from each other can be easily visually recognized from the overall shape. In addition, in order to measure the radius of curvature, it has conventionally been necessary to move two linear markers, but in the present invention, it is sufficient to move the substantially circular marker only once. Therefore, the burden on the operator can be reduced. As a result, the productivity and reliability of measurement can be improved.

According to a second aspect of the present invention, in the above-mentioned optical fiber assembly tip shape measuring method, the center of the substantially circular marker when the substantially circular marker is matched with the interference ring is obtained. Measurement of the tip shape of an optical fiber assembly, wherein the center of the substantially circular marker when the substantially circular marker or another substantially circular marker is fitted to the optical fiber is obtained, and the eccentricity amount is obtained from the two centers. Provide a way. Similar to the first aspect, the work is easy because it is sufficient to visually confirm whether the circle (interference ring, optical fiber) and the circle (substantially circular marker) match. Further, conventionally, it was necessary to move the linear marker 8 times in total, but in the present invention, the substantially circular marker may be moved only 2 times. Therefore, the burden on the operator can be reduced. As a result, the productivity and reliability of measurement can be improved.

According to a third aspect of the present invention, a holding portion for holding an optical fiber assembly in which an optical fiber is inserted into a ferrule and the tip of which is processed into a substantially spherical surface, and a tip of the optical fiber held in the holding portion are provided. An abutting screen plate, a light source unit that irradiates the tip through the screen plate with light to generate an interference ring due to the reflected light at the screen plate and the reflected light at the end, and an imaging unit for imaging the interference ring. A display unit for displaying an image by the image pickup unit, a marker generation unit for generating one or more substantially circular markers that can be moved and enlarged or reduced on the image by the image pickup unit, and movement or enlargement / reduction of the substantially circular marker. When an operator operates the operation unit and a substantially circular marker for any of the interference rings, the order of the matched interference ring and the substantially circular shape The radius of curvature of the tip is calculated from the diameter of the marker, and the center of the substantially circular marker at that time and the center of the substantially circular marker when the substantially circular marker or another substantially circular marker is fitted to the optical fiber A tip shape measuring apparatus comprising: a calculation unit that obtains an eccentric amount from one center. According to the tip shape measuring apparatus of the third aspect, the method for measuring the tip shape of the optical fiber assembly of the first aspect and the second aspect can be suitably implemented.

According to a fourth aspect of the present invention, the present invention provides a holding portion for holding an object to be measured whose tip is processed into a substantially spherical surface, a screen plate against which the tip of the object to be held held by the holding portion abuts, and this screen plate. A light source unit that irradiates the tip with light through the light source to generate an interference ring due to the light reflected by the screen plate and the light reflected by the tip, an imaging unit that images the interference ring, and an image by the imaging unit is displayed. A display unit, a marker generation unit that generates a substantially circular marker that can be moved and enlarged / reduced on the image by the image pickup unit, an operation unit that allows an operator to move and enlarge / reduce the substantially circular marker, and Calculation for calculating the radius of curvature of the tip from the order of the matched interference ring and the diameter of the substantially circular marker when the substantially circular marker is matched to any of the interference rings Providing tip shape measuring apparatus characterized by comprising and. According to the tip shape measuring apparatus of the fourth aspect, the method for measuring the tip shape of the optical fiber assembly of the first aspect can be suitably implemented.

According to a fifth aspect of the present invention, an image pickup means for picking up an image of a tip of an object to be measured, a display section for displaying an image by the image pickup means, and a movable and enlarging / reducing on the image by the image pickup means. When a substantially circular marker is aligned with a circular object in the image, a marker generation unit that generates one or more substantially circular markers, an operation unit that an operator operates to move and scale the substantially circular marker, And a calculation unit for calculating the diameter of the circular object from the diameter of the substantially circular marker. According to the tip shape measuring apparatus of the fifth aspect, it is sufficient to visually check whether or not the circle (circular object) and the circle (substantially circular marker) match each other, and therefore the work is easy. Further, conventionally, it was necessary to move the linear marker twice, but in the present invention, the substantially circular marker may be moved only once.
Therefore, the burden on the operator can be reduced. As a result, the productivity and reliability of measurement can be improved.

According to a sixth aspect of the present invention, the present invention provides an image pickup means for picking up the tip of an object to be measured, a display section for displaying an image by the image pickup means, and a movable and scaled image on the image by the image pickup means. A marker generation unit for generating one or more substantially circular markers, an operation unit for an operator to move and enlarge or reduce the substantially circular marker, and a substantially circular marker for the first circular object in the image. The center of the substantially circular marker when the second circular object is matched with the second circular object is calculated, and the center of the substantially circular marker when the second circular object is matched with the second circular object is calculated. Provided is a tip shape measuring device comprising a calculation unit for calculating. According to the tip shape measuring apparatus of the sixth aspect, the method of measuring the tip shape of the optical fiber assembly of the second aspect can be preferably implemented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the embodiments of the invention shown in the drawings. Note that the present invention is not limited by this. FIG. 1 is a configuration diagram showing an optical fiber assembly tip shape measuring apparatus according to an embodiment of the present invention. This optical fiber assembly tip shape measuring device 1
Reference numeral 00 designates a holding portion 1 for holding an optical fiber assembly K in which the optical fiber a is inserted into the ferrule d and the tip KT is processed into a substantially spherical surface, and is provided perpendicularly to the axial direction of the optical fiber assembly K. Further, the glass plate 2 with which the tip KT of the optical fiber assembly K held in the holding portion 1 abuts, and the tip KT is irradiated with monochromatic light through the glass plate 2, and the reflected light from the glass plate 2 and the tip KT. Light source unit 3 that causes an interference ring (N in FIG. 2) due to reflected light from
And an optical system 4 and a CCD camera 5 for picking up an enlarged image (G in FIG. 3) of the interference ring N and the tip K.
And a circular marker generator 6 for generating circular markers (E1, E2 in FIG. 3) on the image, and an operation unit 8 for the operator to move and enlarge or reduce the circular marker on the image. A monitor 9 for displaying the image and the circular marker, and a CPU 7 for calculating the radius of curvature of the tip KT, the center of curvature of the tip KT, and the eccentricity of the optical fiber a from the position and diameter of the circular marker. Composed.

The light source unit 3 includes a white light lamp 31 and a bandpass filter 32 for generating monochromatic light, a lens system 33 for collimating the monochromatic light and irradiating the glass plate 2 vertically to the glass plate 2. The half mirror 34 transmits the monochromatic light to the glass plate 2 side and reflects the reflected light from the glass plate 2 side to the optical system 4 side.

As shown in FIG. 2, on the glass plate 2, an interference ring N generated by the interference between the light reflected by the glass plate 2 and the light reflected by the tip KT can be seen. The optical fiber a can be seen through the glass plate 2.

As shown in FIG. 3, the image G on the monitor 9 has an interference ring N, an optical fiber a, and a circular marker E.
1 and E2 are shown. Therefore, the operator operates the operation unit 8 to bring the circular marker E1 into contact with the interference ring N of a predetermined order as shown in FIG. Then, the CPU 7 calculates the radius of curvature of the tip KT from the diameter of the circular marker E1 and the order. The diameter of the circular marker E1 is D, the order is m, the wavelength of monochromatic light is λ,
When the radius of curvature is R, R = (D × D) / (4 · m · λ). In addition, the center coordinates of the circular marker E1 are displayed on the screen G.
The coordinates of the center of curvature h at. Next, the operator operates the operation unit 8 to match the circular marker E2 with the image of the optical fiber a as shown in FIG. Then, the CPU 7 sets the center coordinates of the circular marker E2 to
The coordinates of the center i of the image of the optical fiber a on the screen G are set. Then, the amount of eccentricity is calculated from the coordinates of the center i and the coordinates of the center of curvature h.

As described above, the radius of curvature of the tip KT of the optical fiber assembly K and the optical fiber a can be achieved without imposing a burden on the operator.
The amount of eccentricity with respect to can be measured. As a result, the productivity and reliability of measurement can be improved.

FIG. 4 shows a modification of the circular marker E1. The circular marker E1 shown in (a) is a double line, and an interference ring is inserted between the double lines. It is possible to match the interference ring more accurately than in the case of a single line. The circular marker E1 shown in (b) has a divided shape, and can be easily distinguished from the interference ring.
Further, the center display x may be provided.

It should be noted that only one circular marker E1 is generated, and this circular marker E1 is fitted to the interference ring N,
Then, it may be matched with the optical fiber a. When the circular marker E1 is matched with the outer circumference of the cladding of the optical fiber a and the circular marker E2 is matched with the outer circumference of the core of the optical fiber a, the diameter of the core of the optical fiber a can be measured from the diameter of the circular marker E2. The amount of eccentricity can be measured from the difference between the center positions of the circular markers E1 and E2. In addition, the circular marker E1 is fitted to the outer circumference of the ferrule d, and the circular marker E2 is attached to the optical fiber a.
The outer diameter of the ferrule d can be measured from the diameter of the circular marker E1 by matching with the outer circumference of the core of the circular marker E.
The amount of eccentricity can be measured from the difference between the center positions of 1 and E2.

[0020]

According to the method of measuring the tip shape of the optical fiber assembly and the tip shape measuring apparatus of the present invention, the circle (interference ring, optical fiber, ferrule, circular object) and the circle (substantially circular marker) are matched. Since it is only necessary to visually check whether or not there is
Work becomes easier. In addition, the number of operations by the operator can be reduced. Therefore, the burden on the operator can be reduced, and as a result, the productivity and reliability of measurement can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an optical fiber assembly tip shape measuring apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an interference ring.

FIG. 3 is an explanatory view of an operation according to the present invention for measuring a radius of curvature and an eccentricity amount.

FIG. 4 is an explanatory diagram showing a modified example of a circular marker.

FIG. 5 is a configuration diagram showing an example of a conventional optical fiber assembly tip shape measuring apparatus.

FIG. 6 is an explanatory diagram of an interference ring.

FIG. 7 is an explanatory diagram of a conventional operation for measuring a radius of curvature and an eccentricity amount.

[Explanation of symbols]

100 optical fiber assembly tip shape measuring device 1 holding part 2 glass plate 3 light source part 4 optical system 5 CCD camera 6 circular marker generator 7 CPU 8 operation part 9 monitor E1, E2 circular marker

Claims (6)

[Claims] 1. A screen plate in which an optical fiber is inserted into a ferrule and the end of an optical fiber assembly in which the end is processed into a substantially spherical surface is abutted against a screen plate and the tip is irradiated with light through the screen plate. An interference ring is generated by the reflected light from the reflected light from the tip and the reflected light from the tip, and a substantially circular marker is matched to any one of the interference rings, and the order of the matched interference ring and the diameter of the substantially circular marker are used to A method for measuring the tip shape of an optical fiber assembly, characterized in that the radius of curvature of the tip is obtained. 2. The method for measuring the tip shape of an optical fiber assembly according to claim 1, wherein the center of the substantially circular marker when the substantially circular marker is matched with the interference ring is determined, and further the substantially circular marker is obtained. A method for measuring the tip shape of an optical fiber assembly, wherein the center of a substantially circular marker when a marker or another substantially circular marker is fitted to the optical fiber is obtained, and the amount of eccentricity is obtained from the two centers. 3. A holding part for holding an optical fiber assembly in which an optical fiber is inserted into a ferrule and whose tip is processed into a substantially spherical surface, a screen plate against which the tip of the optical fiber held by the holding part abuts, and this screen plate. A light source unit that irradiates light through the tip through the light and causes an interference ring due to the reflected light at the screen plate and the reflected light at the tip,
An image pickup means for picking up the image of the interference ring; a display section for displaying an image by the image pickup means; and a marker generation section for generating one or more substantially circular markers that are movable and expandable / reducible on the image by the image pickup means. An operation part for the operator to move and enlarge / reduce the substantially circular marker, the order of the matched interference ring and the diameter of the substantially circular marker when the substantially circular marker is matched with any of the interference rings. The radius of curvature of the tip is calculated from the center and the center of the substantially circular marker at that time and the center of the substantially circular marker when the substantially circular marker or another substantially circular marker is fitted to the optical fiber are eccentric from two centers. A tip shape measuring apparatus, comprising: a calculation unit for obtaining a quantity. 4. A holder for holding an object to be measured whose tip is processed into a substantially spherical surface, a screen plate against which the tip of the object to be held held by the holder abuts, and light is radiated to the tip through the screen plate. A light source unit that causes an interference ring due to the light reflected by the screen plate and the light reflected by the tip, an image pickup unit that images the interference ring, a display unit that displays an image by the image pickup unit, and the image pickup unit. A marker generation unit that generates a substantially circular marker that is movable and expandable / reducible on an image, an operation unit that is operated by an operator to move and enlarge / reduce the substantially circular marker, and the interference ring. It is characterized by further comprising an arithmetic unit for calculating the radius of curvature of the tip from the order of the interference ring and the diameter of the substantially circular marker when the circular markers are matched. Tip shape measuring device. 5. An image pickup means for picking up an image of a tip of an object to be measured,
A display unit for displaying an image by the image pickup unit, a marker generation unit for generating one or more substantially circular markers that can be moved and enlarged / reduced on the image by the image pickup unit, and movement / enlargement / reduction of the substantially circular marker. An operation unit operated by an operator, and an arithmetic unit that calculates the diameter of the circular object from the diameter of the substantially circular marker when the circular object in the image is matched with the substantially circular marker. And a tip shape measuring device. 6. An image pickup means for picking up an image of a tip of an object to be measured,
A display unit for displaying an image by the image pickup unit, a marker generation unit for generating one or more substantially circular markers that can be moved and enlarged / reduced on the image by the image pickup unit, and movement / enlargement / reduction of the substantially circular marker. The operation unit operated by the operator and the center of the substantially circular marker when the substantially circular marker is matched with the first circular object in the image are obtained, and the substantially circular marker or another substantially circular marker is used as the second marker.
The tip shape measuring apparatus, further comprising: an arithmetic unit that finds the centers of the substantially circular markers when they are matched with the circular object and calculates the center-to-center distance from these two centers.