JP3222595B2 - Glass fiber length measuring method and measuring apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the length of a glass fiber.

[0002]

2. Description of the Related Art When manufacturing an optical fiber bundle, a glass member is melted and drawn into a glass fiber having a predetermined wire diameter, and the glass fiber is cut into a predetermined length to obtain a single fiber. The thus obtained single fibers are bundled in units of tens of thousands by aligning their end faces, and the bundled single fibers are again heated and drawn to form an optical fiber bundle having a desired diameter. .

By the way, in order to obtain a high quality optical fiber bundle,
It is required that a large number of single fibers are regularly and orderly arranged and bundled. Therefore, conventionally, an inspection of whether or not these many single fibers are regularly and orderly arranged is performed by visually observing whether or not an image guided by the bundled single fibers has distortion. . In this inspection, when the image is distorted, it is determined that many single fibers are not regularly and orderly arranged.

[0004]

However, if the lengths of the single fibers are not uniform, irregularities are formed on the end face of the single fiber bundle obtained by bundling the single fibers, and the irregularities cause an image guided by the single fiber bundle. If the image is distorted in the inspection, the distortion is caused by the fact that many single fibers are not regularly aligned and bundled, or the length of each single fiber. And it is not possible to specify whether the end faces of the single fiber bundle in which many of them are bundled are not aligned or not.

[0005] Therefore, in order to reliably determine the quality of the alignment of the single fibers by the inspection, it is desirable to keep the length of the single fibers with high precision and uniformity when manufacturing the single fibers. It is convenient if the length of the manufactured single fiber can be measured with high precision in response to the above, and the single fiber having a length outside the predetermined standard can be removed.

Incidentally, not only the single fiber constituting the optical fiber bundle, but also a glass fiber which is a completed product by itself,
It is, of course, convenient if the length can be measured with high accuracy.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to measure the length of various glass fibers such as glass fibers constituting an optical fiber bundle with high accuracy. It is an object of the present invention to provide a method and apparatus for measuring the length of a glass fiber that can be used.

[0008]

According to a first aspect of the present invention, there is provided a method for measuring the length of a glass fiber having both ends, the method comprising illuminating each end face of the glass fiber, Each end face of the glass fiber was photographed by a separate television camera, and the signal of an image photographed by each television camera was subjected to image processing to detect the coordinates of the end face of the glass fiber in each photographed image, The length of the glass fiber is measured based on the coordinates of each detected end face of the glass fiber in the photographed image and the interval between the television cameras.

The invention according to claim 2 relates to an apparatus for measuring the length of a glass fiber having both ends and extending linearly, and is capable of moving in a direction parallel to the extending direction of the glass fiber. A pair of television cameras are provided, each end face of which is directed in a direction intersecting with the extending direction of the glass fiber, and a pair of television cameras whose optical axis directions of the photographing lens systems are parallel to each other, and illuminate both end faces of the glass fiber. Illuminating means, image processing means for performing image processing of a signal of a captured image of each television camera which has captured an image of each end face of the glass fiber illuminated by the illuminating means, and an image processing result by the image processing means. Coordinate detecting means for detecting the coordinates of each end face of the glass fiber in the image taken by each of the television cameras, And coordinates in the in the taken image of the end faces of the Sufaiba, based on said interval of the television camera in a direction along the extending direction of the glass fiber,
Calculating means for calculating the length of the glass fiber.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for measuring the length of a glass fiber according to the present invention will be described below. FIG. 1 is an explanatory view showing a schematic configuration of a mechanical portion of a glass fiber length measuring apparatus to which the method of the present invention is applied.

In FIG. 1, reference numeral 1 denotes a glass fiber length measuring device, and 3 denotes a transparent and linear glass fiber.
It is manufactured by stretching and drawing a glass member having a triple structure of a clad and an acid-soluble glass, and is cut into a predetermined length L. A conveyor 5 conveys the glass fibers 3 from a glass fiber manufacturing apparatus (not shown) to an optical fiber bundle manufacturing apparatus (not shown) in a direction orthogonal to the direction of the paper of FIG. The glass fiber 3 is placed on the conveying surface 51 of the conveyor 5 so as to extend horizontally in a direction perpendicular to the conveying direction of the conveyor 5.

The glass fiber length measuring device 1 measures the length L of the glass fiber 3 and is disposed above the conveyor 5 and includes a guide rail 11 and a horizontal moving frame 1 shown in FIG.
2, the vertical moving frame 13, the CCD camera 14, the support frame 15, and the illumination unit 16, and the monitor television 1 shown in FIG.
7, an image processing unit 18 and a fiber length measuring unit 19.

As shown in FIG. 1, the guide rail 11 extends in a horizontal direction which is parallel to the transfer surface 51 of the conveyor 5 and is orthogonal to the transfer direction. A pair of horizontal moving frames 12 are provided as shown in FIG.
1 is movably supported in the horizontal direction.

As shown in FIG. 1, a pair of vertical moving frames 13 are provided, each of which is provided with a screw 132 inserted in a long hole 131 whose longitudinal direction is the vertical direction.
It is attached to 2. That is, each vertical moving frame 13 is supported by each horizontal moving frame 12 so as to be movable in the vertical direction.

[0015] CCD camera 14 (corresponding to a television camera)
As shown in FIG. 1, a pair is provided, each of which is held by each vertical moving frame 13, and its photographing lens system 141 is directed to the portion of the conveyor 5 below in the vertical direction. That is, each C
The photographing lens system 141 of the CD camera 14 points the conveyor 5 in a direction intersecting with the extending direction of the glass fiber 3 on the conveyor 5, and the optical axis directions of the photographing lens systems 141 are parallel to each other. In this embodiment, each of the C
The angle of view of the CD camera 14 is set to 3 ° to 5 °.

As shown in FIG. 1, a pair of support frames 15 are provided, and each of the support frames 15 is attached to a side of each vertical moving frame 13. Each support frame 15 extends vertically downward from the side of each vertical moving frame 13 and has a substantially L-shape with its tip bent inward. A support portion 151 is formed at the tip of each bent support frame 15.

As shown in FIG. 1, the illumination section 16 (corresponding to illumination means) includes a light source 161 and a pair of light guides 162 connected to the light source 161. As shown in FIG. 1, the light guides 162 are mounted on the support portions 151 of the support frames 15 so as to face each other and to be located on the same straight line. Each light guide 1
62 guides the light from the light source 161,
3 out.

An image signal photographed by each of the CCD cameras 14 is input to the monitor television 17, where the photographed images are displayed by the CCD cameras 14.
In FIG. 2, for simplicity, the images captured by the two CCD cameras 14 are shown as being synthesized on one monitor television 17, but actually the images captured by each CCD camera 14 are individually displayed. It is displayed on the monitor TV 17. An image signal captured by each of the CCD cameras 14 is input to the image processing unit 18, where the image signals from the CCD cameras 14 are subjected to image processing, and a high-contrast pixel portion in the image is extracted. Will be

The fiber length measuring section 19 is connected to the image processing section 18 as shown in FIG. The fiber length measuring unit 19 is composed of, for example, a CPU or the like. The fiber length measuring unit 19 includes the CCD cameras 14 determined by the horizontal distance L1 between the horizontal moving frames 12 shown in FIG. L2 between the photographing lens systems 141 (FIG. 1)
And two-dimensional coordinate data of each pixel in the image captured by each CCD camera 14. In addition, each of the above C
The distance L2 between the photographing lens systems 141 of the CD camera 14 is
After positioning each horizontal moving frame 12 with respect to the guide rail 11 and fixing the position of each CCD camera 14 in the horizontal direction, measurement is performed by any means, for example, operation of a keyboard connected to the fiber length measuring unit 19, etc. Is input to the fiber length measuring unit 19.

To the fiber length measuring section 19, data of a pixel portion having a high contrast in an image taken by each CCD camera 14 extracted by the image processing section 18 is inputted.
The center of gravity of each pixel portion is detected based on the data of each pixel portion, and the CC of each pixel serving as the center of gravity is detected.
Two-dimensional coordinates in an image captured by the D camera 14 are detected.

Further, the two-dimensional coordinates of each pixel serving as the detected center of gravity in each photographed image and the distance L between the held photographing lens system 141 of each CCD camera 14 are shown.
2, the actual length between each pixel that is the center of gravity of the high-contrast pixel portion is calculated. In this embodiment, the fiber length measuring unit 19 corresponds to a coordinate detecting unit and a calculating unit.

Next, a description will be given of a case where the length L of the glass fiber 3 is measured by the glass fiber length measuring apparatus 1 of the present embodiment having the above-described configuration. First, the pair of horizontal moving frames 12 are moved along the guide rails 11, and the support portions 151 of the support frames 15 attached to the sides of each horizontal moving frame 12 face both sides of the transport surface 51 of the conveyor 5, Tip 1 of light guide 162 attached to each support 151
63 is both end surfaces 31 of the glass fiber 3 on the transport surface 51
1 and the horizontal moving frames 12 are positioned so that both end faces 31 of the glass fiber 3 are located substantially at the centers of the photographing areas of the CCD cameras 14 held by the pair of vertical moving frames 13. I do.

Subsequently, the screws 132 are loosened to move the respective vertical moving frames 13 along the elongated holes 131, and the CCD camera 14 held in each of the vertical moving frames 13 uses the CCD camera 14 to move both end faces 31 of the glass fiber 3. In taking a picture, each vertical moving frame 13 is positioned so that the focus is aligned with the both end faces 31, and the screw 132 is tightened again. The positioning of the horizontal moving frame 12 and the vertical moving frame 13 is completed, and each C
If the CD camera 14 is fixed, each CCD camera 1
The distance L2 between the four photographing lens systems 141 is measured by an arbitrary means and input to the fiber length measuring unit 19.

After the completion of the above-mentioned operation, when the conveyance of the glass fiber 3 by the conveyor 5 from the glass fiber manufacturing apparatus (not shown) to the optical fiber bundle manufacturing apparatus is started, both end faces 31 of the glass fiber 3 being conveyed are started. The conveyor 5 is temporarily stopped at a position facing each light guide 162.
While the conveyor 5 is stopped, both ends 31 of the glass fiber 3 are illuminated by light from the light source 161 that is guided by each light guide 162 and emitted from the tip 163 thereof.

When both ends 31 of the glass fiber 3 are illuminated with the light from the light source 161, both ends 31 of the glass fiber 3 are photographed by the CCD cameras 14. In this case, since the glass fiber 3 is transparent, the glass fiber 3 is not actually photographed, and only the thin line light of each of the end faces 31 illuminated with the light from the light source 161 and irregularly reflected is transmitted to each CCD camera. 14.

An image signal from each CCD camera 14 that has taken a fine line of light irregularly reflected on both end faces 31 of the glass fiber 3 is subjected to image processing in an image processing section 18, and the contrast in the image taken by each CCD camera 14 is high. Only the pixel portion is extracted. The extracted data of each pixel portion is input to the fiber length measuring unit 19, where the pixel serving as the center of gravity of each extracted pixel portion and the two-dimensional coordinates of each pixel serving as the center of gravity in each of the captured images Are detected. That is, the fiber length measuring unit 19 detects two-dimensional coordinates of each end face 31 of the glass fiber 3 in an image captured by each CCD camera 14.

The fiber length measuring section 19 further inputs the two-dimensional coordinates of each end face 31 of the detected glass fiber 3, the two-dimensional coordinates of the center pixel in the image captured by each CCD camera 14, The distance between both end faces 31 of the glass fiber 3, that is, the length L of the glass fiber 3, is calculated based on the held distance L2 between the photographing lens systems 141 of the CCD cameras 14.
As a specific calculation method, for example, since the distance between the center pixels in the image captured by each CCD camera 14 is equal to the distance L2, the two-dimensional coordinates of each center pixel and each end face 31 of the glass fiber 3 are used. The length L of the glass fiber 3 is calculated by increasing or decreasing the value of the distance according to the deviation from the distance L2.

As described above, in the present embodiment, both end faces 31 of the glass fiber 3 are illuminated with the light emitted from the tip 163 of the light guide 162, and the illuminated end faces 31 of the glass fiber 3 are respectively CCD. In addition to photographing with the camera 14, the image processing unit 18 performs image processing on a signal of an image photographed by each CCD camera 14, and extracts high-contrast pixel portions in each photographed image, which becomes the center of gravity of each pixel portion. The pixels and the two-dimensional coordinates of each pixel serving as the center of gravity in the captured image are detected by the fiber length measuring unit 19, and the detected two-dimensional coordinates of each pixel of the center of gravity and the imaging lens system of each CCD camera 14 are detected. 141 based on the distance L2 between
The length L of the glass fiber 3 is measured by a fiber length measuring unit 19.
, The length L of the glass fiber 3
Can be measured with high accuracy.

Further, since each CCD camera 14 has to photograph only one end face 31 of the glass fiber 3 and not the entire glass fiber 3, the angle of view of the photographing lens system 141 is set to 3 ° to 5 ° which is narrower than usual. Therefore, an image with little distortion at the periphery of the photographing area can be obtained by each CCD camera 1.
4, the two-dimensional coordinates of both end faces 31 of the glass fiber 3 can be detected with high accuracy, and the measurement accuracy of the length L of the glass fiber 3 can be further improved. Furthermore, since the measurement accuracy can be freely changed by changing the lens magnification of the taking lens system 141, it is possible to easily perform the length measurement with desired accuracy.

Further, according to the glass fiber length measuring apparatus 1 of this embodiment, the length L of the glass fiber 3 can be measured in a non-contact manner. This is suitable for measuring the length L of the glass fiber 3 conveyed to the apparatus on the conveyance path. Then, by doing so, the glass fiber 3 having a length outside the standard is discarded on the transport path based on the measurement result, thereby eliminating the irregularity of the glass fiber 3 with respect to the length, and having the length conforming to the standard. Only the glass fibers 3 can be supplied to the optical fiber bundle manufacturing apparatus (not shown). When a large number of the glass fibers 3 are bundled in order to obtain an optical fiber bundle, unevenness occurs on the end face of the glass fiber bundle. Can not be.

Thus, when an image is guided by the glass fiber bundle in order to inspect the alignment state of the glass fibers 3 bundled in a large number, image distortion due to unevenness of the end face of the glass fiber bundle occurs. Therefore, by inspecting the guided image for the presence or absence of distortion, it is possible to reliably determine the alignment of the many bundled glass fibers 3. That is, the method and apparatus of the present invention are also suitable for performing the above-described inspection and the like when manufacturing an optical fiber bundle.

Further, according to the glass fiber length measuring apparatus 1 of the present embodiment, the guide rail 11 is extended in parallel with the extending direction of the glass fiber 3, and a pair of horizontal rails movable along the guide rail 11 is provided. The moving frame 12 has a vertical moving frame 13
, Each CCD camera 14 is held through the guide rail 11 based on the position of each horizontal moving frame 12 on the guide rail 11.
The distance between the CD cameras 14, that is, the distance L 2 between the photographing lens systems 141 of each CCD camera 14 can be easily detected, and each CCD camera 14 is set to glass according to the width of the conveyor 5 and the length of the glass fiber 3. The fiber 3 can be easily moved along the extending direction.

In this embodiment, the case where the optical axis directions of the photographing lens systems 141 of the respective CCD cameras 14 are parallel to each other has been described. However, each CCD camera 14 is tilted to direct both end surfaces 31 of the glass fiber 3. In that case, the glass fiber 3 is taken into consideration by taking into account the inclination of each CCD camera 14 and the distance between each end face 31 of the glass fiber 3 and the taking lens system 141 of each CCD camera 14. Can be calculated by the fiber length measuring unit 19. In this embodiment, both end faces 31 of the glass fiber 3 are photographed by the CCD camera 14.
Both end faces 31 of the glass fiber 3 may be photographed by a normal television camera other than the CD camera.

Further, the measuring device for carrying out the method of the present invention is not limited to the structure shown in the present embodiment, and the method and the device of the present invention are applicable to a glass as a single fiber constituting an optical fiber bundle. It is needless to say that the present invention can be applied not only to the measurement of the length of the fiber but also to the measurement of the length of a glass fiber which is a completed product by itself.

[0035]

As described above, according to the present invention, there is provided a method for measuring the length of a glass fiber having both ends,
Each end face of the glass fiber is illuminated, each end face of the illuminated glass fiber is photographed by a separate television camera, an image photographed by each television camera is processed, and the glass in the image is processed. The coordinates of the end face of the fiber are detected, and the length of the glass fiber is measured based on the coordinates of the detected end face of the glass fiber in the image and the interval between the television cameras. For this reason, it is possible to measure the length of various glass fibers such as the glass fibers constituting the optical fiber bundle with high accuracy.

According to the present invention, since the length of the glass fiber can be measured in a non-contact manner, for example, the length of the glass fiber supplied to the optical fiber bundle manufacturing apparatus is measured in the supply path. Further, when manufacturing an optical fiber bundle, when inspecting the alignment state of a large number of glass fibers bundled, the quality of the alignment state based on the presence or absence of distortion of the image guided by the glass fiber bundle is determined. This is preferable for ensuring the operation.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a schematic configuration of a mechanical portion of a glass fiber length measuring apparatus to which the method of the present invention is applied.

FIG. 2 is an explanatory diagram showing a configuration of a signal processing portion in the glass fiber length measuring device of FIG.

[Explanation of symbols]

 Reference Signs List 1 glass fiber length measuring device 14 CCD camera (television camera) 141 photographing lens system 16 illumination unit (illumination unit) 18 image processing unit (image processing unit) 19 fiber length measurement unit (coordinate detection unit, calculation unit) 3 glass fiber 31 Glass fiber end face L Glass fiber length L2 Distance between taking lens systems (TV camera spacing)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-42407 (JP, A) JP-A-58-191918 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 102 G01M 11/00-11/08

Claims (2)

(57) [Claims] 1. A method for measuring the length of the glass fibers with both ends, each end face illuminated City of said glass fiber, it said the illuminated each end face of the glass fiber taken with each individual television camera, Image processing is performed on a signal of an image taken by each of the television cameras to detect the coordinates of the end face of the glass fiber in each of the taken images, and the respective shot images of the end faces of the detected glass fiber are detected. A method for measuring the length of a glass fiber, wherein the length of the glass fiber is measured based on coordinates inside and the interval between the television cameras. 2. An apparatus for measuring the length of a linearly extending glass fiber having both ends, wherein the glass fiber is disposed so as to be movable in a direction parallel to the extending direction of the glass fiber. the extension in the extending direction and the direction intersecting the respective end faces directed respectively, with each other of the imaging lens system pair of television cameras the optical axis direction is parallel to an illumination means for illuminating both end faces of the glass fiber, the lighting Each of said glass fibers illuminated by means
An image processing unit that performs image processing on a signal of an image captured by each of the television cameras that has captured an image of the end face ; and, based on an image processing result obtained by the image processing unit, each of the glass fibers in the image captured by each of the television cameras. Coordinate detecting means for detecting the coordinates of the end face , and each of the glass fibers detected by the coordinate detecting means
Calculating means for calculating a length of the glass fiber based on coordinates of the end face in the captured images and an interval between the television cameras in a direction along an extending direction of the glass fiber. Characteristic glass fiber length measuring device.