A method for detecting the end face of an optical fiber

Abstract

The present application mainly relates to the field of automation detection, and particularly relates to a kind of optical fiber end face detection method, the image of the optical fiber end face is obtained along the axial shooting;Several point light sources, uniformly distributed around the optical fiber end face;In the projection plane, located in the virtual straight line formed by the projection of point light source and the projection of circle center, the straight line and the edge of the light reflection area generated by the corresponding point light source form two intersection points, the intersection point close to the corresponding point light source is the first intersection point, and the intersection point away from the corresponding point light source is the second intersection point;According to the position information of the first intersection point and the position information of the second intersection point in the image of the optical fiber end face, the length value between the two points is obtained, and the length value is taken as the width value of the light reflection area corresponding to the corresponding point light source;According to the ratio or difference of the maximum value and the minimum value of each width value obtained, whether the overall inclination angle of the optical fiber end face is qualified is judged.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the field of automation detection, and particularly relates to a method for detecting an optical fiber end face. BACKGROUND

[0002] The prior art such as a patent with application No. 201410713984.8 and the name of a method for detecting an optical fiber end face and an optical fiber end face polishing and detecting device discloses an optical fiber end face polishing and detecting device, which comprises a power supply device, a light source, a camera device, an image processing device, an image display device, a motor driving device, a discharge device and an optical fiber clamp device. The power supply device is connected with the light source, the camera device, the image processing device, the image display device, the motor driving device and the discharge device respectively. The image processing device is connected with the camera device, the image display device, the motor driving device and the discharge device. The discharge device is composed of an electrode group. The optical fiber clamp device is connected with the motor driving device. The optical fiber clamp device is provided with an optical fiber fixing groove. The light source is opposite to the optical fiber fixing groove. The patent is a kind of optical fiber end face fusion treatment device. The optical fiber end face is fused and treated by the discharge device, and then an image of the optical fiber end face is captured by a camera device. The patent defines some data which needs to be collected for end face detection. However, the patent does not disclose a specific end face detection method.

[0003] As the patent with application number 201910430030.9 and the name of optical fiber end face polishing detection equipment and method, it discloses "a kind of optical fiber end face polishing detection equipment, the discharge heat fusion treatment is carried out to optical fiber cutting end face, ensure the consistency of the cleanliness, damage degree and end face curvature radius of optical fiber end face, and after the discharge heat fusion treatment is carried out to optical fiber end face, real-time acquisition optical fiber end face image, the optical fiber end face image for observation is transmitted to display screen, simultaneously transmitted to image processing device and carries out black-and-white binary processing for calculating the cleanliness, damage degree and curvature radius of optical fiber end face, and according to optical reflection principle, through image processing device automatically determine the heat fusion condition of optical fiber end face, to determine whether it needs to add once discharge heat fusion to ensure that optical fiber end face attachment is cleaned, cutting damage is repaired and forms appropriate curvature radius……The detection step includes: the step of collecting optical fiber end face image, the image processing device obtains the image of optical fiber end face after foreground segmentation to the image collected by camera device;The step of binary processing, the optical fiber end face image collected by camera device is transmitted to image device and carries out black-and-white binary processing;The step of calculating comparison, the curvature radius of optical fiber end face is calculated, and compared with the standard range parameter of the curvature radius of optical fiber end face in image processing device, if the comparison result meets the predefined, then end operation;Otherwise, add once polishing step, and repeat the step of collecting optical fiber end face image, the step of binary processing, and then recalculate comparison, until the curvature radius of optical fiber end face is lower than the minimum value of preset, then end operation;Curvature radius meets the predefined, refers to the inner diameter of the bright ring is in the interval between the circle of preset radius R1 to the circle of preset radius R2."The patent discloses the detection process when ring-shaped light source is used in fusion treatment device, but does not disclose specific judgment method and detection method when point light source is used.

[0004] Before the optical fiber is processed by the above-mentioned prior art melting equipment, the optical fiber needs to be cut, and the optical fiber is usually cut by a cutting knife. The optical fiber cutting knife is disclosed in a patent with application number 202120851945.X and the name of an optical fiber cutting knife. The optical fiber cutting knife body includes a cable fixing part, an optical fiber fixing table, an inner cavity, a blade seat, and a sliding rod. The cable fixing part is used to fix the stripped optical cable and arrange the optical fiber of the stripped optical cable on the optical fiber fixing table. The bottom of the optical fiber fixing table is provided with the inner cavity, and the inner cavity is provided with the sliding rod. The sliding rod is provided with a spring. The blade seat is provided with a cutting knife. The blade seat is slidingly arranged on the sliding rod. The blade seat is provided with an extension arm. When the blade seat is close to one end of the sliding rod, the spring is compressed and the extension arm is clamped in the card hole of the optical fiber cutting knife body through the clamping point of the extension arm, so that the blade seat and the optical fiber cutting knife body are relatively fixed. The cover is also provided with a breaking device, which includes a breaking spring, an extension table, and a breaking arm. During the closing process of the cover, the extension table abuts against the surface of the blade seat and compresses the breaking spring, so that the extension table and the breaking arm are retracted. When the blade seat is pushed out by the compressed spring and moves to the other end of the sliding rod, the blade seat is separated from the extension table, and the breaking arm extends and hits and breaks the optical fiber. The optical fiber cutting knife is a commonly used tool. Its working principle is to draw a knife edge on the optical fiber by a blade, and then break the optical fiber by breaking. However, such a breaking method may cause the inclination of the optical fiber end face. After melting, the inclination angle may still exist, and the existing melting end equipment does not have a corresponding detection method when a point light source is applied. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a kind of optical fiber end face detection method, and the present application is realized by the following technical scheme:

[0006] A kind of optical fiber end face detection method, optical fiber, the optical fiber has optical fiber end face, the optical fiber end face has a center; The optical fiber end face is the optical fiber end face after melting treatment, the edge of the optical fiber end face has arc transition to the end face main body,

[0007] Obtain the image of the optical fiber end face along the axial direction;

[0008] A plurality of point light sources are uniformly distributed around the optical fiber end face. In the axial direction of the optical fiber end face, a plurality of point light sources are located in front of the optical fiber end face. When the projection direction is the axial direction of the optical fiber end face, and the projection plane is the plane where the image of the optical fiber end face is located, the projection of a plurality of point light sources is located on the concentric circle of the projection of the center.

[0009] When the point light source emits light, it can generate a reflective area at the edge of the fiber end face, and this reflective area is imaged onto the fiber end face.

[0010] In the projection plane, on the virtual straight line formed by the projection of the point light source and the projection of the center of the circle, the straight line intersects the edge of the reflective area produced by the corresponding point light source at two points. The intersection point closer to the corresponding point light source is the first intersection point, and the intersection point farther away from the corresponding point light source is the second intersection point.

[0011] The length value between the two points is obtained based on the position information of the first intersection point and the position information of the second intersection point in the image of the fiber end face, and this length value is used as the width value of the reflective area corresponding to the corresponding point light source;

[0012] The overall tilt angle of the fiber end face is judged based on the ratio or difference between the maximum and minimum values ​​of each width obtained.

[0013] Preferably, the point light sources are lit up sequentially, and the width value of the reflective area corresponding to each point light source is obtained.

[0014] Preferably, the maximum or minimum width value of each reflective region corresponding to the point light source is selected, and the width value of the reflective region formed by the other point light source is calculated based on the maximum or minimum value to obtain the ratio of the width value of each reflective region to the reference value. If the ratio of the width value of a reflective region to the reference value is greater than the set threshold, the fiber end face is determined to be unqualified.

[0015] Preferably, the maximum or minimum width value of each reflective region corresponding to the point light source is selected, and the difference between the width value of the reflective region formed by the other point light sources is calculated using the maximum or minimum value as a reference value. The difference information of the width value of each reflective region relative to the reference value is obtained, and the ratio of the difference information to the reference value is calculated. If the ratio of the difference information to the reference value is greater than a set threshold, the fiber end face is determined to be unqualified.

[0016] Preferably, the coordinates of the center of the circle on the projection plane are fixed coordinates, or the coordinates of the center of the fiber end face are obtained by obtaining the contour information of the fiber end face in the image and obtaining the aspect ratio information based on the contour information.

[0017] Preferably,

[0018] S1: Obtain image information representing the brightness and darkness pixel values ​​at the fiber end face;

[0019] S2: Perform edge detection on the image to obtain the outline information of the fiber end face and the outline information of the reflective area located in the fiber end face;

[0020] S3: obtaining the information of the aspect ratio according to the profile information of the fiber end face, thereby obtaining the coordinate of the center of the fiber end face;

[0021] S4: calculating the straight line information between the coordinate information of each said point light source with fixed relative position in the image and the coordinate information of the center of the circle;

[0022] S5: obtaining the coordinates of the first intersection point and the second intersection point according to the straight line information and the profile information of the reflection area;

[0023] S6: calculating the distance between the first intersection point and the second intersection point according to the coordinates of the two points, thereby obtaining the width value information of the reflection area.

[0024] Preferably, two of the said point light sources form a group, and in the projection plane, the two point light sources of the group are located on the two sides of the center of the circle and on the same straight line passing through the center of the circle;

[0025] The width value information of the reflection area formed by the said point light sources in the group is obtained, and whether the overall tilt angle of the fiber end face is qualified is determined according to the ratio or difference of the two values.

[0026] A fiber end face detection method, a fiber, the fiber has a fiber end face, the fiber end face has a center; the fiber end face is a fiber end face after fusion treatment, the edge of the fiber end face has an arc transition to the main body of the end face,

[0027] Obtaining an image of the fiber end face taken in the axial direction;

[0028] A plurality of point light sources are uniformly distributed around the fiber end face; in the axial direction of the fiber end face, a plurality of point light sources are located in front of the fiber end face; when the projection direction is the axial direction of the fiber end face, and the projection plane is the plane in which the image of the fiber end face is located, the projections of a plurality of point light sources are located on the concentric circle of the projection of the center of the circle; a virtual straight line in the horizontal and / or vertical direction is set with the projection of the center of the circle as the center point in the projection plane, thereby obtaining the value direction information of the horizontal and / or vertical direction with the center of the circle as the passing point on the corresponding image;

[0029] The point light source can generate a reflection area on the edge of the side corresponding to the fiber end face, and the reflection area is imaged onto the image of the fiber end face;

[0030] Rotating the image of the fiber end face, the angle of rotation is the included angle between the corresponding point light source and the virtual straight line in the horizontal and / or vertical direction with the center of the circle as the midpoint in the projection plane;

[0031] The rotated image is scanned in the image of the fiber end face in a horizontal and / or vertical direction with the center of the circle as a passing point to obtain the reflected light width information of the reflected light region in the corresponding horizontal and / or vertical direction;

[0032] The ratio or difference of the maximum value and the minimum value of each reflected light width information is used to determine whether the overall tilt angle of the fiber end face is qualified.

[0033] Preferably, the point light sources emit light in sequence to obtain the images of the fiber end face when each single point light source emits light.

[0034] Preferably, the maximum value or the minimum value of each reflected light width value corresponding to the point light source is selected, and the ratio of the maximum value or the minimum value to the reflected light width value formed by other point light sources is calculated to obtain the ratio of the reflected light width value of each reflected light region to the reference value. If the ratio of the width value of the reflected light region to the reference value is greater than a set threshold value, it is determined that the fiber end face is unqualified.

[0035] Preferably, the maximum value or the minimum value of each reflected light width value corresponding to the point light source is selected, and the difference between the maximum value or the minimum value and the reflected light width value formed by other point light sources is calculated to obtain the difference information of the width value of each reflected light region with respect to the reference value. The difference information is compared with the reference value to obtain the ratio. If the ratio of the difference information to the reference value is greater than a set threshold value, it is determined that the fiber end face is unqualified.

[0036] Preferably, the coordinates of the center of the circle on the projection plane are fixed coordinates, or the coordinates of the center of the circle are obtained by obtaining the contour information of the fiber end face in the image and obtaining the aspect ratio information of the fiber end face according to the contour information.

[0037] Preferably, when the coordinates of the center of the circle on the projection plane are fixed coordinates, the image information of the fiber end face is obtained by binary processing, and then the image of the fiber end face is rotated.

[0038] Preferably, the image information of the fiber end face is obtained by binary processing, the contour information of the fiber end face in the image is obtained by edge detection, the aspect ratio information of the fiber end face is obtained according to the contour information of the fiber end face, and the coordinates of the center of the circle of the fiber end face are obtained. The image of the fiber end face is rotated with the coordinates of the center of the circle of the fiber end face as the center point.

[0039] Preferably, the method for setting the virtual straight line in the horizontal and / or vertical direction with the center of the circle of the fiber end face as the center point in the projection plane is to set the straight line passing through the same row and / or the same column of pixels in the image of the fiber end face as the virtual straight line in the horizontal and / or vertical direction.

[0040] Preferably, the reflected light width information is obtained according to the number of pixels representing reflected light in the same row and / or the same column passing through the center of the circle in the image of the rotated fiber end face.

[0041] Preferably, two of the point light sources are a group, and the two point light sources of the group are located on two sides of the center of the circle and on the same straight line passing through the center of the circle on the projection plane.

[0042] The reflected light width information of the group of point light sources is obtained, and whether the overall tilt angle of the fiber end face is qualified is determined according to the ratio or difference of the two.

[0043] Preferably,

[0044] S1: Obtain image information representing bright and dark pixel values of the fiber end face.

[0045] S2: Perform edge detection on the image to obtain fiber end face contour information and contour information of the reflected light region located in the fiber end face.

[0046] S3: Obtain the horizontal / vertical ratio information according to the contour information of the fiber end face to obtain the center coordinate of the fiber end face, and obtain the horizontal and / or vertical value position direction information of the corresponding image with the center as the passing point according to the center coordinate information.

[0047] S4: Calculate the rotation angle information of each point light source according to the coordinate information of each point light source with a fixed relative position in the image and the center coordinate information, and rotate the image of the fiber end face.

[0048] S5: After each rotation, the reflected light width information of the reflected light region is obtained in the horizontal and / or vertical value direction with the center as the passing point.

[0049] The application also provides a fiber end face detection method and a fiber, wherein the fiber has a fiber end face, and the fiber end face has a center; the fiber end face is a fiber end face after fusion treatment, and the edge of the fiber end face has an arc-shaped transition to the main body of the end face,

[0050] Obtain an image of the fiber end face taken in the axial direction.

[0051] A plurality of point light sources are uniformly distributed around the fiber end face; in the axial direction of the fiber end face, a plurality of point light sources are located in front of the fiber end face; when the projection direction is the axial direction of the fiber end face and the plane in which the image of the fiber end face is located is the projection plane, the projections of a plurality of point light sources are located on a concentric circle of the projection of the center.

[0052] The point light sources can generate a reflected light region on the edge of the fiber end face when emitting light, and the reflected light region is imaged onto the image of the fiber end face.

[0053] In the projection plane, on the virtual straight line formed by the projection of the point light source and the projection of the center of the circle, the straight line intersects the edge of the reflective area produced by the corresponding point light source at two points. The intersection point closer to the corresponding point light source is the first intersection point, and the intersection point farther away from the corresponding point light source is the second intersection point.

[0054] The length value between the first or second intersection point and the center of the circle in the image of the fiber end face is obtained based on the position information of the first or second intersection point and the position information of the center of the circle in the image of the fiber end face, and this length value is used as the width value corresponding to the corresponding point light source.

[0055] The overall tilt angle of the fiber end face is judged based on the ratio or difference between the maximum and minimum values ​​of each width obtained.

[0056] This invention also provides a method for detecting the end face of an optical fiber, wherein the optical fiber has an end face with a center; the end face is a fused fiber end face, and the edge of the end face has an arc-shaped transition towards the end face body, characterized in that:

[0057] Acquire an axially captured image of the fiber end face;

[0058] A plurality of point light sources are evenly distributed around the end face of the optical fiber; in the axial direction of the end face of the optical fiber, the plurality of point light sources are located in front of the end face of the optical fiber; when the projection direction is the axial direction of the end face of the optical fiber, and the plane where the image of the end face of the optical fiber is located is the projection plane, the projection of the plurality of point light sources is located on the concentric circles of the projection of the center of the circle.

[0059] When the point light source emits light, it can generate a reflective area at the edge of the fiber end face, and this reflective area is imaged onto the fiber end face.

[0060] In the projection plane, on the virtual straight line formed by the projection of the point light source and the projection of the center of the circle, the straight line intersects the edge of the reflective area produced by the corresponding point light source at two points. The intersection point closer to the corresponding point light source is the first intersection point, and the intersection point farther away from the corresponding point light source is the second intersection point.

[0061] The length value between two points is obtained based on the position information of the first intersection point and the second intersection point in the image of the fiber end face. Alternatively, the length value between the first intersection point or the second intersection point and the center of the circle in the image of the fiber end face is obtained based on the position information of the first intersection point or the second intersection point and the position information of the center of the circle in the image of the fiber end face. The symmetry of each reflective area is determined based on the length value information, thereby determining whether the overall tilt angle of the fiber end face is qualified.

[0062] The present application provides a method for detecting the end face of an optical fiber, which can be applied to a fusion end device. The end face of the optical fiber is irradiated by a plurality of point light sources to obtain a crescent-shaped reflection image. The ratio or difference of the length values of the reflection regions between the point light sources and the center of the circle (i.e. the width of the crescent-shaped reflection region) is obtained to determine whether the tilt angle of the end face of the optical fiber is qualified. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 A schematic diagram showing the relative positions of the optical fiber, the point light source and the camera is shown.

[0064] Figure 2 A schematic diagram showing the structure of the end face of the optical fiber with a tilt angle is shown.

[0065] Figure 3 A schematic diagram showing the image when one point light source is on is shown.

[0066] Figure 4 A schematic diagram showing the image line when four point light sources are on is shown. DETAILED DESCRIPTION

[0067] The present application will be further described below in conjunction with the drawings and specific embodiments.

[0068] The device used in the present method is shown in Figure 1 The optical fiber 1 has an end face, and the end face has a center. The end face is the end face of an optical fiber after being processed by the prior art fusion method. The edge of the end face has an arc-shaped transition to the main body of the end face. The end face of the optical fiber after being processed by the fusion method eliminates burrs and impurities such as dust particles caused by cutting the optical fiber. As shown in Figure 2 If the end face of the optical fiber is tilted, the tilt angle may not disappear after the fusion is completed. Here Figure 2 are side views of two situations in which the optical fiber 1 has a tilt angle. The camera 3 used in the present patent is directly opposite the end face of the optical fiber, and the forward end face of the optical fiber is photographed, so the tilted angle cannot be directly photographed.

[0069] When the fiber end face is detected, several point light sources emit light at the same time or in turn, so that the camera 3 can obtain the image of the fiber end face when the several point light sources emit light. The simultaneous emission or the sequential emission of each point light source is related to the number of point light sources. If the number of point light sources is too large, the images formed will affect each other, and the point light sources need to emit light in turn. The length value of the line between the point light source and the center of the circle is obtained, and it is judged whether the tilt angle of the fiber end face is too large. Therefore, the technical scheme provided by the present patent generally does not need the point light sources to emit light in turn. The image can be displayed on the fusion end device through the display screen. The pixels on the image and the pixels that need to be calculated in the present method can be different. The pixels displayed on the image can be compressed and processed. The processor and the memory of the fusion end device process the image, copy the pixel data obtained by the camera to a calculated area, and perform binaryzation processing on the gray value of the pixel. The gray value exceeding the set gray value is a bright spot, and the gray value below the set gray value is a black spot, so as to form a black and white image information of the fiber end face. The contour information of the image can be obtained through edge detection, so as to obtain the area information of the fiber end face. When calculating the information of the reflection area, some noise points caused by device noise, error interference or external environment are removed.

[0070] In the axial direction of the fiber or the fiber end face, several point light sources 2 are located in front of the fiber end face. In the projection of the axial direction, the several point light sources 2 are located on the concentric circle of the fiber center, and the point light sources 2 are uniformly distributed around the fiber end face.

[0071] The fiber end face is placed in a closed dark space, and the point light source 2 emits light to irradiate on the fiber end face. Here, the role of the point light source is to produce reflection on the curved edge of the fiber end face, rather than a light source that illuminates the entire fiber end face. As shown in Figure 3 Since it is a point light source and the fiber end face is a circular cross section, the camera 3 located in front of the fiber end face can only receive the reflection produced by the curved part of the edge of the fiber end face. The reflection is a crescent-shaped reflection area. The reflection produced by the fiber end face which is substantially parallel to the ccd plane of the camera 3 will not be received by the camera 3. The irradiation of the point light source 2 on the background far away from the fiber end face will form a white background in the imaged image. The imaging of the fiber end face, except the crescent-shaped reflection, the remaining part of the end face will form a dark fiber end face image.

[0072] Theoretically, two or more point light sources are sufficient, but in practice, four point light sources are generally used. Although the term "point light source" is used in this patent, it can also refer to parallel light sources facing the fiber end face. Furthermore, the fiber end face is the end face after end-fusion treatment. Even with the same equipment and the same qualified, tilt-free end face, the size of the arc at the edge of the fiber end face may differ due to external environment, discharge power, and other factors. Therefore, the overall size of the crescent-shaped reflection formed after each fusion may also differ (the reflections of the same fiber are the same, but the reflections of different fibers after fusion are different in size from the reflections of the previous fiber). However, the symmetry of each reflection is basically the same.

[0073] When the projection direction is the axis of the fiber end face, and the plane containing the image of the fiber end face is taken as the projection plane, the projections of several point light sources are located on concentric circles of the projection of the center. If the image formed by camera 3 is regarded as a projection plane, although this projection plane is a virtual image, if the imaging area of ​​camera 3 is large enough, it can still observe the relative positions of the point light sources, and these relative positions are fixed. When a point light source emits light, it can generate a reflective area at the edge of the fiber end face. This reflective area is imaged onto the image of the fiber end face. Theoretically, if the imaging area is large enough, the position of the point light source can also appear on the image. Therefore, the image of the fiber end face can also be understood as the aforementioned projected image. The description method of "projection plane" is used in this patent mainly because the image captured by the camera is mainly an image of the fiber end face. Generally speaking, point light sources do not appear in the real image. Placing the image and the point light sources on the same plane facilitates description and subsequent calculations. Therefore, the description method of "projection plane" is adopted.

[0074] Example 1:

[0075] like Figure 4 As shown, within the projection plane, a virtual straight line is formed by the projection of the point light source and the projection of the center of the circle. This straight line intersects the edge of the reflective area generated by the corresponding point light source at two points. The intersection point closer to the corresponding point light source is the first intersection point, and the intersection point farther away from the corresponding point light source is the second intersection point. Based on the position information of the first and second intersection points within the image of the fiber optic end face, the length value d between the two points is obtained, and this length value d is used as the width value of the reflective area corresponding to the corresponding point light source.

[0076] If the center of the circle is taken as a fixed point: the relative coordinates of the positions of the actual point light sources in the image of the fiber end face are known for a device, and the fiber is fixed in the device, so the coordinates of the center of the fiber end face can be taken as a fixed value in general. As the angle of the directional coordinate to be acquired based on the center of the circle has been actually known, the length value between the two points of the corresponding light reflection area can be obtained by acquiring the profile coordinates of the light reflection area according to the corresponding angle each time. If the side length of a square pixel is taken as 1, the distance between the first intersection point and the second intersection point can be calculated according to the coordinates in the corresponding fixed direction, and the distance data calculated is scaled in proportion to obtain the width value data of the light reflection area finally applied. Actually, the four point light sources can be arranged in the opposite horizontal and vertical directions for the convenience of setting and application.

[0077] If the center of the circle needs to be calculated: the image is profile-extracted, and then the information of the aspect ratio is obtained to obtain the coordinates of the center of the fiber end face. After the coordinates of the center are obtained, the coordinates of the point light sources are connected to obtain a virtual straight line formed by the projection of the point light source and the projection of the center of the circle, which can be regarded as a range of values, and the two intersection points, i.e., the first intersection point and the second intersection point, of the profile coordinates of the corresponding point light source.

[0078] The judgment mode is that the maximum value or the minimum value in the width values of the light reflection areas corresponding to the point light sources is selected, and the width values of the light reflection areas formed by the other point light sources are calculated by taking the maximum value or the minimum value as a reference to obtain the ratio of the width values of the light reflection areas to the reference value. If the ratio of the width value of the light reflection area to the reference value is greater than a set threshold value, it is determined that the fiber end face is unqualified.

[0079] Meanwhile, the distance between the first intersection point or the second intersection point and the center of the circle can also be taken as a reference value, or multiple value modes are performed at the same time.

[0080] In the present patent, four point light sources are mainly taken as examples for illustration.

[0081] When judging whether the inclination angle of the fiber end face is qualified:

[0082] For example, the width values of the four reflective regions obtained after detection are 8.90, 6.12, 7.83 and 9.26 respectively. At this time, the minimum value 6.12 is selected as the reference value, and the ratio calculation is performed with each width value (the minimum value as the denominator). The calculation results are 1.45, 1, 1.28 and 1.51 respectively. In theory, if the fiber end face is a plane, the four ratios are basically 1, and the threshold value of the maximum allowable inclination angle of the fiber end face is 1.20. As long as one of the data is greater than the threshold value, it is determined that the fiber end face has too large inclination angle, and therefore the fiber end face is unqualified. The reference value can also be replaced by the diameter value of the detected fiber end face.

[0083] The width value data described above is a virtual value, not the actual width value of the reflective region. It is mainly calculated and compressed according to the pixel number of the fiber end face, and is a virtual width value. The threshold value of the maximum allowable inclination angle can be obtained according to actual experimental data. Although the width value data described above is a virtual value, when the maximum value or the minimum value thereof is taken as a reference value and compared with other width values, it can still reflect the difference between the width values of the reflective regions in the image, so as to obtain the symmetry characteristics of the reflective regions, and to determine whether the inclination angle of the fiber end face is qualified. In other data cases in the present patent, the corresponding data is not described in detail.

[0084] Since the slope of the fiber end face must be high on one end and low on the other end, the high and low sides correspond to each other, so a plurality of point light sources can be taken as a group. In the projection plane, a group of point light sources is located on both sides of the center and on the same straight line passing through the center. The direct data of a group is calculated by difference or ratio. If one group of ratio or difference does not meet the set threshold value, the fiber end face is directly determined to be unqualified.

[0085] For example, in the above data, the minimum value 6.12 and the maximum value 9.26 must be the highest point and the lowest point respectively. The ratio calculation of the two is 1.51, which is much larger than the threshold value 1.20, so the fiber end face is determined to be unqualified.

[0086] Alternatively, when determining whether the inclination angle of the fiber end face is qualified:

[0087] The maximum value or the minimum value of the width values of the reflective regions corresponding to the point light sources is selected, and the difference value calculation is performed with the width values of the reflective regions formed by other point light sources with the maximum value or the minimum value as the reference value. The difference information of the width values of the reflective regions relative to the reference value is obtained, and the ratio calculation is performed with the difference information and the reference value. If the ratio of the difference information and the reference value is greater than the set threshold value, the fiber end face is determined to be unqualified.

[0088] The general process of the data acquisition of the above technical solution is realized in the program as follows:

[0089] S1: obtaining image information of the fiber end face through binary processing;

[0090] S2: obtaining fiber end face contour information and contour information of the reflective region located in the fiber end face through edge detection of the image;

[0091] S3: obtaining the information of the horizontal-vertical ratio according to the contour information of the fiber end face to obtain the center coordinate of the fiber end face;

[0092] S4: calculating the straight line information between the coordinates of the fixed relative position of each point light source in the image and the center coordinate information according to the straight line information;

[0093] S5: obtaining the coordinates of the first intersection point and the second intersection point according to the straight line information and the contour information of the reflective region;

[0094] S6: calculating the distance between the first intersection point and the second intersection point to obtain the width value information of the reflective region.

[0095] Embodiment 2:

[0096] Embodiment 1 is to obtain the corresponding width value data by calculating the coordinates of the first intersection point and the second intersection point, while the method of embodiment 2 is to rotate the reflective region of the image to the horizontal or vertical direction with the center as the midpoint in the plane, so as to more simply obtain the corresponding width value data, specifically:

[0097] A fiber end face detection method, a fiber, the fiber has a fiber end face, the fiber end face has a center. The fiber end face is a fiber end face after fusion treatment, the edge of the fiber end face has an arc transition to the main body of the end face, and an image of the fiber end face is obtained in the axial direction.

[0098] A plurality of point light sources are uniformly distributed around the fiber end face. In the axial direction of the fiber end face, the plurality of point light sources are located in front of the fiber end face. When the projection direction is the axial direction of the fiber end face and the projection plane is the plane where the image of the fiber end face is located, the projection of the plurality of point light sources is located on a concentric circle of the projection of the center. A virtual straight line in the horizontal and / or vertical direction is set with the projection of the center as the center point in the projection plane, so as to obtain the value direction information of the horizontal and / or vertical direction with the center as the passing point on the corresponding image.

[0099] The point light source can generate a reflective region on the edge corresponding to the side of the fiber end face, and the reflective region is imaged onto the image of the fiber end face.

[0100] The image of the fiber end face is rotated, and the angle of rotation is the angle between the corresponding point light source and the virtual straight line in the horizontal and / or vertical direction in the projection plane with the center of the circle as the midpoint.

[0101] The rotated image is scanned in the horizontal and / or vertical direction in the image of the fiber end face with the center of the circle as the passing point, and the reflected light width information of the reflected light region in the corresponding horizontal and / or vertical direction is obtained.

[0102] The ratio or difference between the maximum and minimum of each reflected light width information obtained is used to determine whether the overall tilt angle of the fiber end face is qualified.

[0103] The relative positions of the point light sources in the projection of the fiber end face in the axial direction are fixed, and the horizontal and vertical directions are set in the projection plane with the center of the circle. Since the position of the camera 3 on the device is fixed, the position coordinates of each point light source in the image captured by the camera 3 are also known and fixed, and generally the fixed position of the fiber is also known, so the center of the fiber end face is also fixed and known. Of course, to reduce the deviation, the center point coordinates of the fiber end face in the image can also be the coordinates of the center of the fiber end face calculated by the system, and the image of the fiber end face is equivalent to the projection of the fiber end face itself in the axial direction, with the center of the circle as the center point having a virtual straight line in the horizontal and vertical direction.

[0104] The optical fiber is fixed in the fusion end equipment each time, and its position has deviation each time, but the deviation is very small, especially in proportion to the distance of the optical fiber to the point light source, so the point light source and the center of the circle can be regarded as fixed points when calculating the rotation angle. If the center of the circle is regarded as a fixed point, each point light source also has a corresponding fixed position coordinate in the image, and the relative position of each point light source to the virtual straight line in the vertical or horizontal direction relative to the known center coordinate has an included angle α, and the value of α is 0 to 180 degrees. Because the relative position of the center and each point light source is fixed, the included angle α of the point light source is also fixed, and each time the image is rotated, it can be rotated according to the pre-known included angle α of the point light source to the horizontal or vertical direction of the center coordinate system. If four point light sources are used, the four point light sources can be directly arranged above the virtual straight line in the vertical or horizontal direction of the center, and if they are all normalized to the upper side of the vertical direction, the included angles α are 0 degrees, 90 degrees, 180 degrees and 90 degrees respectively, and at this time, the length of the virtual straight line in the reflecting area can be calculated respectively, and if it is normalized to the horizontal direction, it is the maximum horizontal width. In fact, this case does not need to rotate the image, because the position of the point light source in the horizontal or vertical direction is known, so it only needs to calculate the length of the virtual straight line in the reflecting area in the horizontal direction and the vertical direction respectively when one point light source is on.

[0105] If the images are all rotated and normalized to the upper side of the vertical direction in the image, the optical fiber end surface coordinate in the longitudinal direction passing through the center is obtained, and in fact, only the longitudinal coordinate information needs to be obtained, and the same longitudinal coordinate information is searched in the outline coordinate information of the reflecting area, and two coordinate values can be certainly found, and the difference between the two horizontal coordinates can be calculated to obtain the corresponding reflecting width value information.

[0106] Because the image is rotated according to the vertical or horizontal direction of the center, the reflecting width value information can be obtained according to the difference between the vertical width coordinates or the horizontal width coordinates of the same column or the same row of the reflecting area of the rotated image.

[0107] For example, after rotating the image four times, the reflecting width values obtained each time are 8.90, 6.12, 7.83 and 9.26 respectively. At this time, the minimum value 6.12 is selected as the reference value, and the ratio calculation is performed on each reflecting width (the minimum value as the denominator), and the calculation results are 1.45, 1, 1.28 and 1.51 respectively. In theory, if the optical fiber end surface is a plane, the four ratios are basically 1, and the threshold value of the maximum inclination angle of the optical fiber end surface is 1.20, so as long as one of the data is greater than the threshold value, it is determined that the inclination angle of the optical fiber end surface is too large, and therefore the optical fiber end surface is unqualified.

[0108] Since the slope of the fiber end face must be one end high and the other end low, high and low two sides corresponding, so can be a number of point light source two for a group, in the projection plane, a group of point light source is located in the center of the two sides and located through the center of the same straight line. The two direct data of a group are calculated by difference or ratio, and one group ratio or difference does not meet the set threshold value, then directly can determine that the fiber end face is unqualified.

[0109] For example, if the actual corresponding data is the minimum value 6.12 and the maximum value 9.26, the two must be the highest point and the lowest point, and the ratio is 1.51, which is much larger than the threshold value 1.20, so the fiber end face is judged to be unqualified.

[0110] Alternatively, when judging whether the inclination angle of the fiber end face is qualified:

[0111] Select the maximum or minimum value of each corresponding to the point light source to form the reflected light width, and calculate the difference value of the maximum or minimum value as the reference value and the reflected light width value formed by other point light sources, to obtain the difference information of the width value of each reflected light area relative to the reference, and calculate the ratio of the difference information and the reference value, if the ratio of the difference information and the reference value is greater than the set threshold value, the fiber end face is determined to be unqualified.

[0112] The general process of data acquisition of the above technical solution is realized in the program:

[0113] S1: Obtain the image information of the fiber end face by binary processing;

[0114] S2: Edge detection is performed on the image to obtain the profile information of the fiber end face and the profile information of the reflected light area located in the fiber end face;

[0115] S3: Obtain the information of the aspect ratio according to the profile information of the fiber end face to obtain the center coordinates of the fiber end face, and obtain the value position direction information of the horizontal and / or vertical direction passing through the center according to the center coordinate information;

[0116] S4: Calculate the rotation angle information of each point light source according to the coordinate information of each point light source with fixed relative position in the image and the center coordinate information, and rotate the image of the fiber end face;

[0117] S5: After each rotation, the reflected light width information of the reflected light area is obtained according to the value position direction of the horizontal and / or vertical direction passing through the center.

[0118] Other feature points can also be used as reference points in this patent, such as the two end points of the crescent-shaped reflected light area, or the centroid of the crescent as a reference point for taking value.

Claims

1. A method for detecting a fiber end face, the fiber having a fiber end face, the fiber end face having a center; the fiber end face being a fiber end face after fusion treatment, the edge of the fiber end face having an arc transition to the main body of the fiber end face, the method comprising: obtaining an image of the fiber end face taken along an axial direction; a plurality of point light sources being uniformly distributed around the fiber end face; in the axial direction of the fiber end face, a plurality of the point light sources being located in front of the fiber end face; when the projection direction is the axial direction of the fiber end face and the projection plane is the plane in which the image of the fiber end face is located, the projections of the plurality of point light sources being located on a concentric circle of the projection of the center; the point light sources being capable of generating a reflection area on the edge of the fiber end face when emitting light, the reflection area being imaged onto the image of the fiber end face; in the projection plane, a virtual straight line being formed by the projection of the center and the projection of the point light source, the straight line and the edge of the reflection area generated by the corresponding point light source forming two intersection points, the intersection point closer to the corresponding point light source being a first intersection point, the intersection point farther from the corresponding point light source being a second intersection point; obtaining a length value between the first intersection point and the second intersection point according to the position information of the first intersection point and the position information of the second intersection point in the image of the fiber end face, and taking the length value as a width value of the reflection area corresponding to the corresponding point light source; determining whether the overall tilt angle of the fiber end face is qualified according to the ratio or difference between the maximum value and the minimum value of the obtained width values. 2.The method of claim 1, wherein: the point light sources are lit in sequence and the width values of the reflection areas corresponding to the corresponding point light sources are obtained. 3.The method of claim 1, wherein: the maximum value or the minimum value of the width values of the reflection areas corresponding to the point light sources is selected, and the width values of the reflection areas formed by other point light sources are calculated by taking the maximum value or the minimum value as a reference value, to obtain the ratio of the width values of the reflection areas to the reference value, and if there is a ratio of the width value of the reflection area to the reference value greater than a set threshold value, the fiber end face is determined to be unqualified. 4.The method of claim 1, wherein: the maximum value or the minimum value of the width values of the reflection areas corresponding to the point light sources is selected, and the width values of the reflection areas formed by other point light sources are calculated by taking the maximum value or the minimum value as a reference value, to obtain the difference information of the width values of the reflection areas to the reference value, and the difference information and the reference value are calculated by taking the ratio, and if there is a ratio of the difference information to the reference value greater than a set threshold value, the fiber end face is determined to be unqualified. 5.The method of claim 1, wherein: the coordinates of the center in the projection plane are fixed coordinates, or the coordinates of the center of the fiber end face are obtained by obtaining the contour information of the fiber end face in the image and obtaining the aspect ratio information according to the contour information. 6.The method of any one of claims 1 to 5, wherein: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ S1: obtaining image information of the fiber end face representing bright and dark pixel values; S2: performing edge detection on the image to obtain profile information of the fiber end face and profile information of the light reflection area located in the fiber end face; S3: obtaining information of the horizontal and vertical ratio according to the profile information of the fiber end face to obtain the center coordinate of the fiber end face; S4: calculating the straight line information between the coordinate information of each said point light source with a fixed relative position in the image and the center coordinate information according to the straight line information; S5: obtaining the coordinates of the first intersection point and the second intersection point according to the straight line information and the profile information of the light reflection area; S6: calculating the distance between the first intersection point and the second intersection point according to the coordinates of the first intersection point and the second intersection point to obtain the width value information of the light reflection area.

7. The fiber end face detection method according to any one of claims 1 to 5, wherein: two of the point light sources are a group, and on the projection plane, the two point light sources of the group are located on the same straight line passing through the center of the circle and on both sides of the center of the circle; the width value information of the light reflection area formed by the point light sources in the group is obtained, and whether the overall tilt angle of the fiber end face is qualified is determined according to the ratio or difference of the two.

8. A fiber end face detection method, a fiber, the fiber having a fiber end face, the fiber end face having a center; the fiber end face being a fiber end face after fusion treatment, the edge of the fiber end face having an arc-shaped transition to the main body of the end face, characterized in that: obtaining an image of the fiber end face taken along the axial direction; a plurality of point light sources are uniformly distributed around the fiber end face; in the axial direction of the fiber end face, a plurality of the point light sources are located in front of the fiber end face; when the projection direction is the axial direction of the fiber end face, and the plane in which the image of the fiber end face is located is the projection plane, the projections of a plurality of the point light sources are located on the concentric circle of the projection of the center of the circle; a virtual straight line in the horizontal and / or vertical direction is set with the projection of the center of the circle as the center point in the projection plane, thereby obtaining the value direction information of the horizontal and / or vertical direction with the center of the circle as the passing point on the corresponding image; the point light source can generate a light reflection area on the edge of the side corresponding to the fiber end face, and the light reflection area is imaged onto the image of the fiber end face; the image of the fiber end face is rotated, and the angle of rotation is the included angle between the corresponding point light source and the virtual straight line in the horizontal and / or vertical direction with the center of the circle as the midpoint in the projection plane; the rotated image is scanned in the horizontal and / or vertical direction in the image of the fiber end face with the center of the circle as the passing point, and the light reflection width information of the light reflection area in the corresponding horizontal and / or vertical direction is obtained; whether the overall tilt angle of the fiber end face is qualified is determined according to the ratio or difference of the maximum value and the minimum value of each light reflection width information obtained.

9. The fiber end face detection method according to claim 8, wherein: a plurality of the point light sources emit light in sequence, and the images of the fiber end face when a plurality of single point light sources emit light are obtained.

10. The fiber end face detection method according to claim 8, wherein: ​ ​ ​ ​ ​ ​ ​ ​ ​ The maximum value or minimum value of the reflection width values corresponding to the point light sources is selected, and the reflection width values of other point light sources are calculated based on the maximum value or minimum value as a reference value to obtain the ratio of the reflection width values of each reflection area to the reference value. If the ratio of the width value of the reflection area to the reference value is greater than a set threshold value, it is determined that the fiber end face is unqualified.

11. The fiber end face detection method of claim 8, wherein: The maximum value or minimum value of the reflection width values corresponding to the point light sources is selected, and the reflection width values of other point light sources are calculated based on the maximum value or minimum value as a reference value to obtain the ratio of the reflection width values of each reflection area to the reference value. If the ratio of the width value of the reflection area to the reference value is greater than a set threshold value, it is determined that the fiber end face is unqualified.

12. The fiber end face detection method of claim 8, wherein: The coordinates of the center of the circle on the projection plane are fixed coordinates, or the center coordinates of the fiber end face are obtained by obtaining the contour information of the fiber end face in the image and obtaining the aspect ratio information based on the contour information.

13. The fiber end face detection method of claim 8, wherein: When the coordinates of the center of the circle on the projection plane are fixed coordinates, the image information of the fiber end face is obtained by binary processing, and the image of the fiber end face is rotated.

14. The fiber end face detection method of claim 8, wherein: The image information of the fiber end face is obtained by binary processing, the contour information of the fiber end face in the image is obtained by edge detection, the aspect ratio information of the fiber end face is obtained based on the contour information, and the center coordinates of the fiber end face are obtained, and the image of the fiber end face is rotated with the center coordinates as the center point.

15. The fiber end face detection method of claim 8, wherein: The method for setting a virtual straight line in the horizontal and / or vertical direction with the center of the fiber end face as the center point in the projection plane is that the straight line passing through the same row and / or the same column of pixels in the image of the fiber end face is taken as the virtual straight line in the horizontal and / or vertical direction.

16. The fiber end face detection method of claim 15, wherein: The reflection width information is obtained based on the number of pixels representing reflection in the same row and / or the same column passing through the center of the rotated image of the fiber end face.

17. The fiber end face detection method of claim 8, wherein: Two of the point light sources are a group, and on the projection plane, the two point light sources of the group are located on both sides of the center of the circle and on the same straight line passing through the center of the circle; The reflection width information of the group of point light sources is obtained, and whether the overall inclination angle of the fiber end face is qualified is determined based on the ratio or difference of the two.

18. The fiber end face detection method of any one of claims 8 to 17, wherein: S1: Obtain the image information of the fiber end face representing the bright and dark pixel values; S2: edge detection is performed on the image to obtain the profile information of the fiber end face and the profile information of the reflection region on the fiber end face; S3: the information of the aspect ratio is obtained according to the profile information of the fiber end face to obtain the center coordinate of the fiber end face, and the information of the position direction of the horizontal and / or vertical passing through the center is obtained according to the center coordinate information; S4: the rotation angle information of each point light source is calculated according to the coordinate information of each point light source with fixed relative position in the image and the center coordinate information, and the image of the fiber end face is rotated; S5: after each rotation, the reflection width information of the reflection region is obtained in the direction of the horizontal and / or vertical passing through the center.

19. A fiber end face detection method, a fiber having a fiber end face, the fiber end face having a center; the fiber end face being a fiber end face after fusion treatment, the edge of the fiber end face having an arc transition to the main body of the end face, characterized in that: an image of the fiber end face is obtained along the axial direction; a plurality of point light sources are uniformly distributed around the fiber end face; in the axial direction of the fiber end face, a plurality of the point light sources are located in front of the fiber end face; when the projection direction is the axial direction of the fiber end face and the projection plane is the plane where the image of the fiber end face is located, the projections of the plurality of point light sources are located on the concentric circle of the projection of the center; the point light sources can generate a reflection region on the edge of the fiber end face when emitting light, and the reflection region is imaged onto the image of the fiber end face; in the projection plane, a virtual straight line is formed by the projection of the point light source and the projection of the center, and the straight line forms two intersection points with the edge of the reflection region generated by the corresponding point light source, the intersection point close to the corresponding point light source being the first intersection point, and the intersection point far from the corresponding point light source being the second intersection point; the length value between the first intersection point or the second intersection point and the center is obtained according to the position information of the first intersection point or the second intersection point and the position information of the center of the fiber end face in the image of the fiber end face, and the length value is taken as the width value corresponding to the corresponding point light source; whether the overall tilt angle of the fiber end face is qualified is judged according to the ratio or difference of the maximum value and the minimum value of each width value.

20. A fiber end face detection method, a fiber having a fiber end face, the fiber end face having a center; the fiber end face being a fiber end face after fusion treatment, the edge of the fiber end face having an arc transition to the main body of the end face, characterized in that: an image of the fiber end face is obtained along the axial direction; a plurality of point light sources are uniformly distributed around the fiber end face; in the axial direction of the fiber end face, a plurality of the point light sources are located in front of the fiber end face; when the projection direction is the axial direction of the fiber end face and the projection plane is the plane where the image of the fiber end face is located, the projections of the plurality of point light sources are located on the concentric circle of the projection of the center; the point light sources can generate a reflection region on the edge of the fiber end face when emitting light, and the reflection region is imaged onto the image of the fiber end face; In the projection plane, on the virtual straight line formed by the projection of the point light source and the projection of the circle center, the straight line forms two intersection points with the edge of the reflection area generated by the corresponding point light source, the intersection point close to the corresponding point light source is the first intersection point, and the intersection point far from the corresponding point light source is the second intersection point; According to the position information of the first intersection point and the position information of the second intersection point in the image of the fiber end face, the length value between the two points is obtained, or according to the position information of the first intersection point or the position information of the second intersection point and the position information of the circle center of the fiber end face in the image, the length value between the first intersection point or the second intersection point and the circle center is obtained, and the symmetry of each reflection area is judged according to the length value information, so as to judge whether the overall inclination angle of the fiber end face is qualified.

Images