JP3525760B2 - Surface profile measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates defects such as fine irregularities of the object surface to the surface shape measurement equipment for detecting fast and accurate.

[0002]

2. Description of the Related Art Conventionally, as a surface profile measuring apparatus, there is one described in Japanese Patent Application Laid-Open No. 10-9838. In this surface shape measuring apparatus, an illuminating means for illuminating the target object, a moving means for moving the target object so that the illumination incident angle at each position on the target object surface continuously changes, and the target object are continuously operated. An image pickup means for capturing a plurality of images having different illumination incident angles at respective positions on the object surface, and the same for all points of the object surface for the plurality of images having different illumination incident angles. The image processing means for obtaining the distribution of the regular reflection illumination incident angles when the lightness at the point is maximum and obtaining the angle distribution image showing the distribution of the regular reflection illumination incident angles of all the points on the object surface.

Further, since the positional relationship between the image pickup means and the object changes, it is necessary to associate the same point of the object between the images. In this case, the moving speed of the object and the configuration of the optical system. And the same points on the object are associated with each other.

In such a surface shape measuring apparatus, the inclination of the surface at every position on the surface of the object is measured with a simple apparatus configuration, and the minute unevenness defect of the planar object is detected at high speed and with high accuracy.

[0005]

However, in the above-mentioned conventional surface shape measuring apparatus, since the same point on the object is associated between the images based on the moving speed of the object,
When an object is placed on the manufacturing line and moved, the line speed of the manufacturing line changes due to troubles, etc., making it difficult to accurately associate the same point on the object between images, and surface shape measurement accuracy There is a problem that it may decrease.

The present invention has been made in view of the above circumstances, and an object thereof is to accurately correspond to the same point on an object between images without being influenced by a change in the moving speed of the object. association is possible, the surface shape of the object at high speed and high accuracy and to provide a surface shape measurement equipment that can be measured.

[0007]

In order to achieve the above object, the invention according to claim 1 is such that the illumination means 2 for illuminating the object 1 and the illumination incident angle at each position on the surface of the object 1 are different. Moving means 3 for moving the object 1 so as to change continuously
And an imaging unit 4 that continuously captures the object 1 to obtain a plurality of images with different illumination incident angles at each position on the surface of the object 1, and for these images with different illumination incident angles. Then, for all the points on the surface of the object 1, an angle distribution image showing the distribution of the angles of the regular reflection illumination on all the points on the surface of the object 1 is obtained when the brightness at the same point is maximum. In the surface shape measuring apparatus including the image processing unit 5 for obtaining the object, a movement detecting unit 6 for detecting that the object 1 has moved by a predetermined moving amount is provided, and an image is captured corresponding to the detection by the moving detecting unit 6. The feature is that the means 4 is operated.

In such a surface shape measuring apparatus, it is detected that the object 1 has moved by a predetermined amount of movement, and the image pickup means 4 is operated in response to this detection, whereby a plurality of images having different illumination incident angles are displayed. Since the information is acquired, it is possible to accurately associate the same point on the object 1 between the images regardless of the change in the moving speed of the object 1.

[0009]

[0010]

Further, in the invention described in claim 1 , in the above , the movement detecting means 6 is provided on the surface of the object 1 along the movement direction, and the mark 8 whose position is known is arranged. It is configured to detect the position of.

In such a surface shape measuring apparatus, the position of the mark 8 whose arrangement position is known is detected and the moving amount of the mark 8 is used as the moving amount of the object 1. The movement of the amount can be detected.

The invention according to claim 2 is characterized in that, in the invention according to claim 1 , the mark 8 is a plurality of dots.

In such a surface shape measuring apparatus, since the mark 8 has a plurality of dot shapes, the position of each mark 8 can be easily detected.

Further, in the invention described in claim 1 , in the above-mentioned, the correction means for detecting the lateral deviation of the position of the mark 8 by the movement detecting means 6 and correcting the deviation as the lateral deviation of the object 1. 9 is provided.

In such a surface shape measuring apparatus, since the lateral deviation of the object 1 is corrected, even if the lateral deviation of the object 1 occurs, the same point on the object 1 is accurately associated between the images. You can

The invention according to claim 3 is the same as claim 1.
In the inventions described in Item 1 to 2, the edge 1 in the width direction of the object 1
The edge detecting means 10 for detecting 5 is provided, and the correcting means 9 is provided.
However, the lateral deviation of the object 1 is corrected by both the edge 15 detected by the edge detecting means 10 and the mark 8 detected by the movement detecting means 6.

In such a surface shape measuring apparatus, since the lateral displacement of the object 1 is corrected by both the edge 15 in the width direction of the object 1 and the mark 8, the similar mark 8 is the width of the object 1. When it is difficult to identify the same mark 8 among pixels that are scattered in the direction, the same mark 8 can be easily identified by the relative positional relationship with the edge 15.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the correcting means 9 corrects the lateral deviation of the object 1 by using pattern matching. Is configured as a feature.

With such a surface shape measuring apparatus, even if the shape of the mark 8 is complicated, the deviation of the mark 8 can be easily measured by pattern matching.

Further, in the invention described in claim 5, in the invention described in claims 1 to 3 , the correction means 9 corrects the lateral displacement of the object 1 by using Hough transform. It is characterized by that.

In such a surface shape measuring apparatus, even if the same mark 8 is imaged differently between images, it can be recognized as the same mark 8 by the Hough transform and the distance between the marks can be accurately estimated.

[0023]

[0024]

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION A surface shape measuring apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an explanatory view showing a surface profile measuring apparatus according to an embodiment of the present invention.

This surface shape measuring apparatus comprises an illumination means 2 for illuminating the object 1 and a moving means for moving the object 1 so that the illumination incident angle at each position on the surface of the object 1 continuously changes. 3, an image pickup means 4 for continuously capturing images of the object 1 to obtain a plurality of images having different illumination incident angles at respective positions on the surface of the object 1, and a plurality of images having different illumination incident angles. On the other hand, for all points on the surface of the object 1, the distribution of the incident angle of specular reflection illumination when the brightness at the same point is maximized is obtained, and the angle distribution showing the distribution of the incident angle of specular reflection illumination on all points of the surface of the object 1 is obtained. And an image processing means 5 for obtaining an image. Then, a movement detecting means 6 for detecting that the object 1 has moved a predetermined movement amount is provided, and the image pickup means 4 is operated in response to the detection by the movement detecting means 6.

As the object 1, a rolled copper-clad laminate is used. The moving means 3 utilizes the rotation of the rotating roller 7 arranged in front of and behind the object 1. The copper-clad laminate, which is the object 1, is wound like a roll on the feed-side rotating roller 7a of the two rotating rollers 7 of the moving means 3, and is wound by the rotation of the winding-side rotating roller 7b. Move by being affected. Further, a linear light source that is long in the width direction of the object 1 that illuminates the surface of the flat part 11 between the rotating rollers 7 of the object 1 from above is used as the illumination means 2, and the flat part of the object 1 is used as the imaging means 4. 11 A TV camera is used to shoot the surface from above. Lighting means 2
Is a rotary roller 7a on the delivery side with respect to the center of the flat portion 11.
The image pickup means 4 is arranged on the side closer to the winding roller 7b than the center of the flat portion 11.

The illumination means 2 and the image pickup means 4 are fixed, and the object 1 is moved by the movement means 3 while the illumination means 2 is being moved.
The component of the light emitted from the device that is specularly reflected on the surface of the object 1 is observed.

FIGS. 2 to 4 are explanatory views for explaining how an image looks at different illumination incident angles in this observation. 2A to 2D show the reflected light reflected from the surface of the object 1 when the position of the defect portion A having the unevenness on the surface of the object 1 is moved from L1 to L4. A locus is shown, a solid line LA shows the reflected light at the defect portion A, and a dotted line LB shows the reflected light at the flat surface portion B located to the side of the defect portion A. The dotted line LC indicates the reflected light at the position where the reflected light that is specularly reflected on the surface of the planar object 1 is incident on the imaging unit 4. In addition, FIGS. 3A to 3D are imaging means 4 corresponding to FIGS. 2A to 2D.
The captured image of is shown. In addition, FIG. 4 is a graph showing the change in brightness at each position of the defect portion A and the plane portion B of FIG.

As shown in FIGS. 2 to 3, in (a),
No specular reflection component can be observed in both the defect portion A and the plane portion B.
In (b), the specular reflection component on the plane portion B can be observed,
The specular reflection component cannot be observed in the defect portion A whose surface direction is locally different. In (c), the specular reflection component cannot be observed at the flat surface portion B, but the specular reflection component can be observed at the defect portion A.
In (d), the specular reflection component cannot be observed in both the defect portion A and the plane portion B.

As shown in FIG. 4, it is understood that the plane incident portion B and the defect portion A having a different inclination from each other have different illumination incident angles (corresponding to the positions Pa and Pb) showing the maximum brightness. In this way, by continuously measuring the lightness while changing the light incident angle, the light incident angle at which the lightness is maximized at each measurement point of the object 1, that is, the specular reflected light incident angle is obtained. By obtaining the illumination incident angle at all points on the surface of the inspection object 1, an image (angle distribution image) showing the distribution of the regular reflection illumination incident angle can be obtained.

Next, the processing operation of the surface profile measuring apparatus will be described below. First, the movement detection unit 6 detects that the object 1 has moved by a predetermined movement amount, and the imaging trigger generation device 12 generates an imaging trigger. Next, the image pickup means 4 is operated by this image pickup trigger, and a plurality of images with different illumination incident angles at each position on the surface of the object 1 are acquired. Next, the captured image is stored in the image memory in the image processing means 5. In this case, the positions of the same points between consecutive images are displaced by a predetermined amount of movement, so that the same points are associated with each other between a plurality of captured images. next,
With respect to all the captured images, the distribution of the incident angle of specular reflection illumination when the brightness at the same point is maximum is obtained for all the points on the surface of the object 1. Next, an angle distribution image showing the distribution of the regular reflection illumination incident angles of all points on the surface of the object 1 is obtained. Then, by using the inclination information of the surface stored in the angle distribution image, it is possible to detect minute dents, bulges, scratches and the like existing on the plane of the object 1.

The movement detecting means 6 is, for example, an encoder 13.
A device that outputs one pulse at a predetermined rotation angle θ1 while the rotating roller 7 makes one rotation, such as
It is provided on the axial side of the winding roller 7b. The output of the encoder 13 is input to the movement amount calculation unit 14, and the movement amount calculation unit 14 calculates the movement amount of the object 1. The movement amount of the object 1 is given by the equation (1).

[0035]   Moving amount of object = number of pulses x moving amount per pulse ... (1)

In equation (1), the amount of movement per pulse is given by equation (2).

[0037]   Moving amount per pulse = 2 x π x (radius of rotating roller 7 + total rotation of rotating roller) Number x thickness of object 1 x (predetermined rotation angle θ1 / 360 °) (2)

In the equation (2), the cumulative number of rotations of the rotary roller means that the object 1 is wound around the circumference of the rotary roller 7 by this number. From the equation (2), when the rotary roller 7 rotates at a constant rotational speed, the greater the total number of rotations of the rotary roller, that is, the more the portion of the target 1 that is wound around the rotary roller 7, the more flat the target 1. Since the portion 11 moves away from the center of the rotation axis of the rotating roller 7, the moving speed of the flat portion 11 is high. Then, when the movement amount of the object 1 calculated by the movement amount calculation unit 14 reaches a predetermined movement amount, a signal is sent to the image pickup trigger generation device 12, and the image pickup trigger generation device 12 causes the image pickup means 4 to take an image pickup trigger. Is output. In addition, when the target object 1 is not a scroll-shaped object but moves on a belt conveyor,
Since the moving speed of the belt conveyor is constant, the moving amount per pulse is constant. If the moving amount per pulse is set to a predetermined moving amount, the encoder 13
It is also possible to operate the imaging trigger generator 12 by the output pulse of.

In such a surface shape measuring apparatus, it is detected that the object 1 has moved by a predetermined amount of movement, and the image pickup means 4 is operated in response to this detection, whereby a plurality of images with different illumination incident angles are displayed. Since the information is acquired, it is possible to accurately associate the same point on the object 1 between the images regardless of the change in the moving speed of the object 1. In addition, the rotating roller 7
Since the number of rotations is measured to detect the movement of the object 1 by a predetermined movement amount, a rotation detecting device having a simple structure like the encoder 13 can be used as the movement detecting means 6.

FIG. 5 is an explanatory view showing an example of the movement detecting means 6 different from the above in the surface profile measuring apparatus and the operation thereof.

As shown in FIG. 5, this movement detecting means 6
Is for detecting the position of the mark 8 which is provided on the surface of the object 1 in the moving direction and whose arrangement position is known. As the object 1, a rolled copper-clad laminate which is wound and moved by the moving means 3 used in the above surface shape measuring apparatus is used. The object 1 is provided with a plurality of dot-shaped marks 8 on the surface of the object 1 substantially in parallel with the movement direction and at substantially constant intervals, and the position of the mark 8 in the width direction is set. And the distance between the adjacent marks 8 is known. This mark 8 may have been already installed at the manufacturing stage on the rolled copper-clad laminate. In this case, this mark 8 should be used, and if it is not already installed, it should be attached somewhere during the manufacturing stage. To do. As the movement detecting means 6,
A TV camera is used and it arrange | positions above the flat part 11 of the target object 1. First, the flat portion 11 of the object 1 including the mark 8 is continuously imaged by the TV camera. Next, the movement amount calculation unit 1
Reference numeral 4 captures a plurality of images in which the positions of the marks 8 continuously move, and the amount of movement of the marks 8 is calculated from the positional deviation of the marks 8 between the images. Then, when the movement amount of the object 1 calculated by the movement amount calculation unit 14 reaches a predetermined movement amount, a signal is sent to the image pickup trigger generation device 12, and the image pickup trigger generation device 12 causes the image pickup means 4 to take an image pickup trigger. Is output.

In such a surface shape measuring apparatus, the position of the mark 8 whose arrangement position is known is detected and the movement amount of the mark 8 is used as the movement amount of the object 1. The movement of the amount can be detected. Further, since the mark 8 has a plurality of dot shapes, the position of each mark 8 can be easily detected.

FIG. 6 is an explanatory view showing an example of the movement detecting means 6 different from the above in the surface profile measuring apparatus of the above. Further, FIG. 7 is an explanatory diagram for explaining the operation of the movement detecting means 6 of the above. In addition, the description from here will be referred to as the present invention.
The main part of the embodiment will be described.

As shown in FIG. 6, this surface profile measuring apparatus is provided with a correction means 9 for detecting the lateral deviation of the position of the mark 8 and correcting the deviation as the lateral deviation of the object 1.
As shown in FIG. 7, in the rotating roller 7, when the object 1 is wound and moves, lateral displacement may occur in the width direction,
Due to the lateral displacement of the object 1, lateral displacement of the same point may occur between captured images of the image capturing means 4, and the same point may not be associated. The correction means 9 detects the lateral shift amount X of the object 1 and corrects the lateral shift at the same point between the images picked up by the image pickup means 4 to facilitate the correspondence of the same points. The correction unit 9 captures a plurality of images in which the positions of the marks 8 are continuously captured by the TV camera, calculates the lateral shift amount of the marks 8 between the images, and in the image processing unit 5, the correction unit 9 detects When the same points are associated between the captured images, the lateral shift of the object 1 is corrected at the same time.

Since the lateral deviation of the object 1 is corrected, even if the lateral deviation of the object 1 occurs, it is possible to accurately associate the same point on the object 1 between the images.

FIG. 8 is an explanatory view for explaining the operation of the movement detecting means 6 different from the above in the surface shape measuring apparatus of the above.

As shown in FIG. 8, this surface shape measuring apparatus is provided with edge detecting means 10 for detecting the edge 15 in the width direction of the object 1, and the correcting means 9 is detected by this edge detecting means 10. Edge 15 and movement detection means 6
The lateral shift of the object 1 is corrected based on both the mark 8 detected by. The TV camera used in the above surface shape measuring apparatus is used as the edge detecting means 10,
A plurality of images in which the positions of the edge 15 and the mark 8 are continuously moved are captured, and the lateral deviation of the object 1 is corrected by using the same correction means 9 as above. In this case, the movement detection means 6
The distance (Y1 and Y2) between the edge 15 and the mark 8 is measured for each image captured by the TV camera of, and the mark 8 having the same distance between the edge 15 and the mark 8 is used as the same mark between a plurality of images. 8 and the same correction means 9 as above
Is used to detect and correct the lateral shift amount X of the object 1.

In such a surface shape measuring apparatus, since the lateral displacement of the object 1 is corrected by both the edge 15 in the width direction of the object 1 and the mark 8, the same mark 8 has the same width as the object 1. When it is difficult to identify the same mark 8 among pixels that are scattered in the direction, the same mark 8 can be easily identified by the relative positional relationship with the edge 15.

FIG. 9 is an explanatory view for explaining the correction method by the correction means 9 in the above surface shape measuring apparatus.

As shown in FIG. 9, the correction means 9 corrects the lateral displacement of the object 1 using pattern matching. Pattern matching is an operation in which a template representing a known target is moved within an image, the degree of similarity at each point in the image is calculated, and the point at which the calculated degree of similarity is maximum is detected. That is, finding the best match in the image with the template. For example, in the image 1, a certain mark 8 is selected as a template, and the mark 8 that best matches this template is selected as the image 2
Detect from inside. The most matching marks 8 in the different images 1 and 2 are regarded as the same mark 8 on the object 1, and the distance between the two marks 8 is calculated to obtain the movement amount of the marks 8.

In such a surface shape measuring apparatus, even if the shape of the mark 8 is complicated, the deviation of the mark 8 can be easily measured by pattern matching.

FIG. 10 is an explanatory view for explaining a correction method by the correction means 9 in the above surface shape measuring apparatus.

As shown in FIG. 10, this correction means 9
The Hough transform is used to correct the lateral shift of the object 1. When the target object 1 is rolled while moving laterally and moves, the straight line representing the edge 15 in the image is tilted at an angle θ2, and the mark 8 may be rotated at the same angle θ2 as the tilt of this straight line. In such a case, the Hough transform is used so that the two images can be recognized as the same mark 8 having different inclinations. The Hough transform is used for detecting a pattern involving rotation. In this case, the mark 8 is detected by using the Hough transform in each image, and the same mark 8 is detected between the images.
The rotation angle of is calculated and corrected.

In such a surface shape measuring apparatus, even if the same mark 8 has different shapes in the images, it can be recognized as the same mark 8 by the Hough transform and the distance between the marks 8 can be accurately estimated.

[0055]

According to the first aspect of the present invention, it is detected that the object has moved a predetermined amount of movement, and the image pickup means is operated in response to the detection to acquire a plurality of images having different illumination incident angles. Therefore, the same point on the object can be accurately associated between the images without being affected by the change in the moving speed of the object.

[0056]

Further, according to the first aspect of the invention, since the position of the mark whose arrangement position is known is detected and the movement amount of the mark is set as the movement amount of the object, the movement of the object by the predetermined predetermined movement amount is accurate. Can be detected.

According to the second aspect of the invention, since the mark has a plurality of dot shapes, the position of each mark can be easily detected.

Further, according to the first aspect of the present invention, since the lateral displacement of the object is corrected, even if the lateral displacement of the object occurs, it is possible to accurately associate the same point on the object between the images. .

According to the third aspect of the invention, since the lateral deviation of the object is corrected by both the edge of the object in the width direction and the mark, similar marks are scattered in the width direction of the object. However, if it is difficult to identify the same mark between pixels,
The relative position relationship with the edge facilitates the identification of the same mark.

According to the fourth aspect of the invention, even if the mark shape is complicated, the mark deviation can be easily measured by pattern matching.

According to the fifth aspect of the present invention, even if the same mark is imaged differently between images, it can be recognized as the same mark by the Hough transform, and an accurate distance between marks can be estimated.

[0063]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a surface shape measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a locus of reflected light in which light from a light source is reflected on the surface of an object when the position of a defect portion A having irregularities on the surface of the object is moved from L1 to L4 in the above surface shape measuring apparatus. And the solid line shows the reflected light at the defect A,
The dotted line indicates the reflected light at the flat surface portion B located on the side of the defect portion A.

FIG. 3 shows a picked-up image of an image pickup unit corresponding to FIGS. 2 (a) to 2 (d).

FIG. 4 is a graph showing the change in brightness at each position of the defect portion A and the plane portion B of FIG.

FIG. 5 is an explanatory diagram showing an example of movement detecting means different from the above in the surface shape measuring apparatus of the above and an operation thereof.

FIG. 6 is an explanatory diagram showing an embodiment of the present invention in the surface profile measuring apparatus according to the above with a movement detecting means different from the above.

FIG. 7 is an explanatory diagram for explaining the operation of the above movement detection means.

FIG. 8 is an explanatory diagram for explaining the operation of the movement detection means different from the above in the surface profile measuring apparatus of the above.

FIG. 9 is an explanatory diagram illustrating a correction method by a correction unit in the above surface shape measuring apparatus.

FIG. 10 is an explanatory diagram illustrating a correction method by a correction unit in the surface profile measuring apparatus of the above.

[Explanation of symbols]

A defective part B flat surface 1 object 2 lighting means 3 means of transportation 4 Imaging means 5 Image processing means 6 Movement detection means 7 rotating roller 7a Feeding side rotating roller 7b Roller on the winding side 8 mark 9 Correction means 10 Edge detection means 11 Flat part 12 Imaging trigger generator 13 encoder 14 Moving amount calculation unit 15 Edge 16 templates

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-6-281593 (JP, A) JP-A-10-9838 (JP, A) JP-A-3-26547 (JP, A) JP-A-6- 235624 (JP, A) JP 8-152416 (JP, A) JP 5-149890 (JP, A) JP 9-5058 (JP, A) JP 62-111860 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01B 11/30 G01N 21/89

Claims (5)

(57) [Claims] 1. An illuminating means for illuminating an object, a moving means for moving the object such that an illumination incident angle at each position on the object surface changes continuously, and an image of the object continuously captured. Then, the image pickup means for acquiring a plurality of images having different illumination incident angles at respective positions on the object surface, and the same point for all points on the object surface for the plurality of images having different illumination incident angles. Surface shape measuring apparatus comprising: an image processing unit that obtains a distribution of specular reflection illumination incident angles when the lightness at the maximum is obtained, and obtains an angle distribution image that shows a distribution of specular reflection illumination incident angles of all points on the object surface. In the above, a movement detecting means for detecting that the object has moved a predetermined movement amount is provided, and the image pickup means is operated in response to the detection by the movement detecting means. Over the moving direction All SANYO which provided a position detects the position of the mark is known to detect the lateral displacement of the position of the mark by the movement detection unit, and a correcting means for correcting the deviation as lateral object front surface shape measuring apparatus you wherein a. 2. A surface shape measuring apparatus according to claim 1, wherein the mark is intended that the form of a plurality of points. 3. An edge detecting means for detecting an edge in the width direction of the object, wherein the correcting means detects the object from both the edge detected by the edge detecting means and the mark detected by the movement detecting means. 3. The surface profile measuring device according to claim 1, wherein the lateral profile deviation is corrected. Wherein correction means, the surface shape measuring apparatus of claims 1 to 3, wherein the corrects the lateral deviation of the object using the pattern matching. Wherein correction means, according to claim 1, characterized in that to correct the lateral deviation of the object using the Hough transform
3. The surface shape measuring device according to 3 above.