JPH11108637A - Quality inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quality inspection device wherein inspection range is widened for versatility, and inspection precision is improved for realizing reliability in inspection. SOLUTION: A device comprises an imaging camera 2 for imaging an inspected surface of an inspected object 1, a bright field lighting source 4 for projecting a bright field light 5 for lighting the inspected surface, a dark field lighting source 6 for projecting a dark field light 7 for lighting it, and a judging means 8 for judging presence of defect on it based on the output from the imaging camera 2. Here, the bright field lighting source 4 or the dark field lighting source 6 is selected for use according to the inspected object, otherwise both are used. The light field light 5 wherein such reflection component as mirror surface, etc., is obtained with sure or the dark field light 7 wherein such component as color, irregular reflection, etc., are obtained with sure is selected for use, otherwise both are used, thus inspection precision is improved when applied to various inspection objects.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror surface, a gold or silver matte surface, an uneven surface, or a printing surface made of ink, or a printing surface made of ink, on various inspected objects such as a long object and a sheet-fed printed material. Scratches on the surface to be inspected, such as the surface and the coating layer on the printed surface, or aluminum ground, etc.
The present invention relates to a quality inspection device used for detecting various types of defects such as printing errors and stains, and more particularly, to a lighting device thereof.

[0002]

2. Description of the Related Art Conventionally, as an example of this type of quality inspection apparatus, a surface to be inspected of a running inspection object is illuminated by a light source, imaged by an imaging camera, and an image signal obtained by the imaging is differentiated to obtain an image. By detecting the density change of the inspection surface and comparing and comparing the signal pattern obtained by binarizing this differential waveform with a previously created master pattern, the presence or absence of a defect on the inspection surface is detected. A known configuration is known.

As another conventional example, a surface to be inspected of a running inspection object is illuminated by a light source and imaged by an imaging camera, and multi-gradation image data is obtained from an image signal obtained by the imaging. A configuration is known in which the presence / absence of a defect on a surface to be inspected is detected by comparing and contrasting the density level of each part of the tone image data with the density level of each part of the master image.

[0004]

By the way, for example, when the surface to be inspected is a printing surface made of color ink, if direct light is used as the illumination light, the light is reflected on the surface to be inspected and enters the imaging camera. , The illuminance is too high, it is difficult to identify the color components, it is not possible to accurately detect printing mistakes, etc.
Even when the surface to be inspected is a matte surface of gold or silver, if direct light is used, it is difficult to obtain a diffuse reflection component, and light and dark are generated. In addition, when the surface to be inspected has a convex portion, the difference in the size of the shadow due to the convex portion having a different height hardly occurs in direct light,
Height cannot be detected. On the other hand, by using dark-field illumination light as illumination light, it is easy to identify color components such as color inks, and it is easy to obtain diffuse reflection components in the case of gold or silver satin, so that defects such as scratches can be obtained. And the height of the projection can be detected.

Therefore, in any of the above-mentioned conventional examples, the light source is set so as to illuminate the surface to be inspected, so that the imaging camera has a dark field. However, in the case of the illumination light serving as a dark field, for example, when the surface to be inspected is a mirror surface, the reflected light from this mirror surface does not enter the imaging camera. Not detectable. Also, when the surface to be inspected has a transparent synthetic resin coat layer on the color ink layer,
Similarly, defects such as scratches on the coat layer cannot be reliably detected. As described above, in the conventional configuration using only the dark-field illumination light source, the inspection target is restricted,
In addition to being unable to cope with the spread of the inspection target, there are problems such as poor detection accuracy.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. The object to be inspected can be broadened and versatility can be obtained. In addition, the detection accuracy can be improved to improve the reliability of the inspection. It is an object of the present invention to provide a quality inspection device that can be improved.

[0007]

In order to solve the above-mentioned problems, a quality inspection apparatus according to the present invention comprises: an image pickup means for picking up an image of a surface to be inspected of an object to be inspected; A bright-field illumination light source that emits a bright-field illumination light serving as a bright field, and a dark-field illumination light source that illuminates the surface to be inspected and emits a dark-field illumination light that becomes a dark field in the imaging unit. Determining means for determining the presence or absence of a defect on the surface to be inspected based on an output from the imaging means, wherein the bright-field illumination light source and the dark-field illumination light source are selectively provided corresponding to an inspection object. It is configured to be used alone or in combination.

In order to solve the above-mentioned problems, another quality inspection apparatus according to the present invention, in the above-described configuration, is arranged such that bright-field illumination light emitted from a bright-field illumination light source is entirely incident in correspondence with an inspection object. Or, it can be controlled so as to be only a certain incident angle, irregularly reflected dark field illumination light emitted from the dark field illumination light source to the surface to be inspected, and from the surface to be inspected to the imaging means. It is provided with a control plate having a diffuse reflection surface that can be incident as bright-field illumination light.

The illumination light amount emitted from one or both of the bright-field illumination light source and the dark-field illumination light source, or both, to the surface to be inspected can be adjusted in accordance with the inspection object.

Further, the control plate can be configured so as to be able to change the amount of diffuse reflection on the diffuse reflection surface in accordance with an object to be inspected. As an example, a plurality of control plates having diffuse reflection surfaces with different amounts of diffuse reflection are provided. Can be used selectively.

It is preferable that the imaging means is arranged so that an optical axis incident from the surface to be inspected is inclined with respect to the surface to be inspected. It is preferable that the density level of the gradation image data is compared with the reference density level to determine whether or not there is a defect.

According to the present invention configured as described above,
It is a direct light to the imaging means, and a bright-field illumination light capable of reliably obtaining a reflection component such as a mirror surface, and a dark-field illumination light capable of reliably obtaining a component such as color and diffuse reflection. By selectively using them alone or in combination, they can be applied to various types of test objects to improve detection accuracy.

Further, the incident angle of the illuminating light emitted from the bright-field illumination light source can be controlled, and by using a control plate for irregularly reflecting the illuminating light emitted from the dark-field illumination light source, a shallow concave portion can be formed. The present invention can be applied to a necessary standard for inspection, such as non-detection and detection of a deep recess.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram showing a quality inspection apparatus according to a first embodiment of the present invention, FIG. 2 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection apparatus, and FIG. CL- of Fig. 2 by the quality inspection device
FIG. 3B is an explanatory view of an inspection principle in a CL line, and FIG. 3B is an explanatory view of an inspection principle in a comparative example.

In FIG. 1, reference numeral 1 denotes an object to be inspected, which runs in a direction indicated by an arrow by running means (not shown) such as a belt. Reference numeral 2 denotes a camera such as a CCD licensor which is a means for imaging the inspected surface 3 of the running inspected object 1 over the entire width thereof, and tilts an optical axis incident from the inspected surface 3 with respect to the inspected surface 3. It is arranged to let. 4 is the surface to be inspected 3
And a bright-field illumination light source that emits bright-field illumination light 5 that becomes a bright field in the imaging camera 2.
Alternatively, they are arranged at a plurality of locations (one location in the illustrated example). Reference numeral 6 denotes a dark-field illumination light source that illuminates the surface 3 to be inspected and emits dark-field illumination light 7 serving as a dark field in the imaging camera 2, and is arranged at one or a plurality of locations (two locations in the illustrated example). Have been. As the bright-field illumination light source 4 and the dark-field illumination light source 6, a plurality of lamps are arranged in line or a straight tube lamp is used, and the inspection surface 3 is illuminated with substantially uniform illuminance over the entire width. Is set to be able to. Reference numeral 8 denotes a determination unit that compares the density level of the multi-tone image data obtained from the output of the imaging camera 2 with the reference density level to determine whether or not the inspection surface 3 has a defect.

The operation of the above configuration will be described below. It is assumed that the inspection object 1 in the present embodiment has the inspection surface 3 which is a mirror surface and has a flaw 11 on a part of the mirror surface 3 as shown in FIG. The inspection object 1 is caused to travel, and the surface 3 to be inspected is illuminated only by the bright-field illumination light 5 emitted from the bright-field illumination light source 4 during the traveling, so that the inspection surface 3 extends over the entire length in the width direction. Images are sequentially taken by the imaging camera 2. The determination means 8 creates a multi-tone area image from the data of the 256-step multi-tone line image sequentially output from the imaging camera 2, and determines the density level of each part of the multi-tone area image by the 256 Compare the density level of each part of the multi-tone area image with
The presence or absence of a defect is determined based on the allowable value of the density level difference between the corresponding portions of the two images.

When the mirror surface, which is the surface 3 to be inspected, is illuminated by the bright-field illumination light 5, the mirror surface has a high reflectance with respect to the imaging camera 2 and a high density level. For example, as shown in FIG. The reference density level of the mirror surface to be inspected 3 is set to 200 levels, the allowable values on the “bright” side and “dark” side are each set to 10 levels, and the inspected surface 3 is set to the bright field illumination light source 4. Is illuminated only by the bright-field illumination light 5 emitted from. Then, as shown in FIG. 2, it is assumed that a defect (scratch) 11 exists on the mirror surface which is the surface 3 to be inspected.
As described above, while the reference density level of the mirror surface which is the inspection surface 3 is high, the density level of the defect 11 becomes low due to irregular reflection. If the position appears on the “dark” side as a change in pulse shape, and this changed portion is, for example, 50 levels, it exceeds the allowable value, and in this case, it is determined to be a defect.

On the other hand, as a comparative example, when the inspection surface 3 is illuminated using only the dark-field illumination light 7, the inspection surface 3
Since the reflectance of the mirror surface with respect to the imaging camera 2 is low and the density level is low, as shown in FIG. 3B, for example, the reference density level of the mirror surface as the inspection surface 3 is set to 10 levels, Allowable values of “bright” side and “dark” side are 1 each
It is assumed that the level is set to 0 level. Then, in this case, the reflectance from the defect 11 increases compared to the reflectance of the mirror surface due to irregular reflection, and the reference density level of the mirror surface, which is the surface to be inspected, has a pulse shape on the “bright” side at the position of the defect 11. Appear as change. However, since the reflectance from only the edge portions on both sides of the defect 11 is high, the actual size of the defect 11 is not reflected, the pulse shape is narrow, and the reflectance is low. May not exceed an allowable value (for example, 10 levels), and may be erroneously recognized as not a defect.

Therefore, when the surface 3 to be inspected is a mirror surface, a diffuse reflection component is not required for the detection, so that the dark-field illumination light source 6 is not required, and the defect can be detected only by the bright-field illumination light source 4. Can be done.

Next, a second embodiment of the present invention will be described. FIG. 4 is a schematic configuration diagram showing a quality inspection apparatus according to a second embodiment of the present invention, FIG. 5 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection apparatus, and FIG.
FIG. 6 is an explanatory view of the inspection principle at the line CL-CL in FIG. 5 by the quality inspection apparatus, and FIG. 6B is an explanatory view of the inspection principle of a comparative example.

In FIG. 4, reference numeral 1 denotes an inspection object. 2 is a camera such as a CCD licensor, 4 is a bright-field illumination light source,
Reference numeral 6 denotes a dark-field illumination light source, and reference numeral 8 denotes a determination unit. These components are the same as those in the first embodiment.

The operation of the above configuration will be described below. It is assumed that the inspection object 1 in the present embodiment has a surface 3 to be inspected which is a gold or silver matte surface, and has a light defect 12 and a dark defect 13 partially as shown in FIG. The inspected object 1 is caused to travel, and during the traveling, the inspected surface 3 is illuminated only by the dark-field illumination light 7 emitted from the dark-field illumination light source 6 so that the inspected surface 3 extends over the entire length in the width direction. Images are sequentially taken by the imaging camera 2. In the determination means 8, 25 sequentially output from the imaging camera 2.
The presence / absence of a defect is determined in the same manner as in the first embodiment from the data of the six-stage multi-tone line image.

As shown in FIG. 6A, for example, the reference density level is set to 120 levels, the allowable values on the "bright" side and the "dark" side are set to 10 levels, and the surface 3 to be inspected is set. It is assumed that the illumination is performed only by the dark-field illumination light 7 emitted from the dark-field illumination light source 6. Then, as shown in FIG. 5, the bright defect 12 and the dark defect 1
3 is present, the density level of the gold or silver matte surface as the surface to be inspected is “bright” side and “dark” side at the positions of the light defect 12 and the dark defect 13 with respect to the reference density level. Appears as a change in the pulse shape, and this changed part is, for example,
If the levels are 230 levels and 30 levels, respectively, the above-mentioned allowable values are exceeded, and in this case, each is determined to be defective.

On the other hand, as in the comparative example, the bright-field illumination light source 4
6B, when the surface 3 to be inspected is illuminated using only the bright-field illumination light 5 as shown in FIG. For example, the defect 13 is determined to be a defect because the defect 13 has a level of 100 and exceeds the allowable value.
In the case of No. 2, for example, the level is 235, the change in the pulse shape is small, and there is a case where the change does not exceed the allowable value, making the determination difficult.

From now on, when the surface 3 to be inspected is a gold or silver matte surface, a diffuse reflection component is required for its detection, so that the bright-field illumination light 5 which is direct light with high illuminance is emitted. Obviously, the visual field illumination light source 6 becomes unnecessary, and the defect can be detected only with the dark field illumination light source 6 that emits the dark field illumination light 7 capable of obtaining diffuse reflection components.

Next, a third embodiment of the present invention will be described. FIG. 7 is a schematic configuration diagram showing a quality inspection apparatus according to a third embodiment of the present invention, FIG. 8 is a plan view for explaining an example of an inspection object inspected by the quality inspection apparatus, and FIG.
FIG. 9B is an explanatory view of the inspection principle of the same quality inspection apparatus at the line CL-CL in FIG. 8, and FIG. 9B is an explanatory view of the inspection principle of a comparative example.

In FIG. 7, reference numeral 1 denotes an inspection object. 2 is a camera such as a CCD licensor, 4 is a bright-field illumination light source,
Reference numeral 6 denotes a dark-field illumination light source, and reference numeral 8 denotes a determination unit. These components are the same as those in the first embodiment.

The operation of the above configuration will be described below. It is assumed that the inspected object 1 in the present embodiment has a surface 3 to be inspected which has an uneven surface, and has a light defect 14 and a dark defect 15 in a part as shown in FIG. The inspection object 1 is caused to travel, and during the traveling, the bright-field illumination light source 4
The surface 3 to be inspected is illuminated only by the bright-field illumination light 5 emitted from the camera, and the surface 3 to be inspected is sequentially imaged by the imaging camera 2 over the entire length in the width direction. In the determination means 8,
The presence / absence of a defect is determined in the same manner as in the first embodiment from the data of the 256-level multi-gradation line image sequentially output from the imaging camera 2.

As shown in FIG. 9A, for example, the reference density level is set to 120 levels, and the "bright" side and the "dark" side are set.
The tolerances on the sides are set to 10 levels, and the inspection surface 3
Is illuminated only by the bright-field illumination light 5 emitted from the bright-field illumination light source 4. Then, as shown in FIG.
Assuming that the light defect 14 and the dark defect 15 exist on the surface 3 to be inspected, the density level of the uneven surface, which is the surface to be inspected, is “bright” at the positions of the light defect 14 and the dark defect 15 with respect to the reference density level.
The pulse shape changes on the side and the “dark” side. If the changed portions are, for example, at the 230th level and the 30th level, the allowable values are exceeded, and in this case, the defect is determined. When the surface 3 to be inspected is an uneven surface, the influence of the shadow behind the convex portion 30 is minimized by using the bright-field illumination light 5, that is, the pulse shape appearing on the “dark” side is an allowable value. It is possible to prevent the detection of the defect 15 on the “dark” side by preventing it from being detected as a defect by making it smaller within the range.

On the other hand, as a comparative example, when only the dark-field illumination light 7 is used, as shown in FIG. 9B, the bright defect 14 and the dark defect 15 can be determined as defects. However, the shadow behind the protrusion 30, that is, the pulse shape appearing on the “dark” side may become so large as to exceed an allowable value, and may be erroneously recognized as the pulse shape of the defect 15 on the “dark” side.

Therefore, as in the present embodiment, the inspection surface 3
In the case where the light source has irregularities, the dark-field illumination light source 6 becomes unnecessary, and the defect can be detected only by the bright-field illumination light source 4.

Next, a fourth embodiment of the present invention will be described. FIG. 10 is a schematic configuration diagram showing a quality inspection device according to a fourth embodiment of the present invention, FIG. 11 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection device, and FIG.
FIG. 12A is an explanatory view of the inspection principle by the same quality inspection apparatus at the line CL-CL in FIG. 11, and FIG. 12B is an explanatory view of the inspection principle of a comparative example.

In FIG. 10, reference numeral 1 denotes an inspection object. 2
Is a camera such as a CCD licensor, 4 is a bright-field illumination light source, 6 is a dark-field illumination light source, and 8 is a determination means, and their configurations are the same as those in the first embodiment.

The operation of the above configuration will be described below. In the inspection object 1 in the present embodiment, the inspection surface 3 is a printing surface of the color ink 17 on the paper 16 and has a light defect 18 and a dark defect 19 in a part as shown in FIG. And Run this inspection object 1,
During the traveling, the inspection surface 3 is illuminated only by the dark-field illumination light 7 emitted from the dark-field illumination light source 6, and the inspection surface 3 is sequentially imaged by the imaging camera 2 over the entire length in the width direction. The determination means 8 determines the presence or absence of a defect from the data of the 256-level multi-gradation line image sequentially output from the imaging camera 2 in the same manner as in the first embodiment.

As shown in FIG. 12A, for example, paper 1
6 is set to 180 levels, the reference density level of the color ink 17 is set to a desired level corresponding to each color, and the allowable values on the “bright” side and “dark” side are set to 10 levels, respectively. It is assumed that the surface 3 to be inspected is illuminated only by the dark-field illumination light 7 emitted from the dark-field illumination light source 6. Then, as shown in FIG. 11, assuming that a light defect 18 and a dark defect 19 exist on the inspection surface 3, the density level of the paper 16 surface of the inspection target surface is higher than the reference density level. "Bright" at position 18 and dark defect 19
A change in pulse shape appears on the side and the “dark” side, and since this changed portion exceeds the allowable value, in this case, it is determined to be a defect. When the surface to be inspected 3 is a printing surface, the dark color illumination light 7 is used, so that the printed color ink 17 is used.
And only the light necessary to detect the color of the ink is guided to the imaging camera 2, and the difference in the pulse shape between the characters A and B of the ink 17 having different colors is increased, so that the difference between the inks is determined. Erroneous recognition of a defect such as a printing error can be prevented.

On the other hand, when only the bright-field illumination light 5 is used as in the comparative example, the illuminance of the reflected light on the surface 3 to be inspected is too high, and as shown in FIG. The level is increased to, for example, 230 levels, and the defect 19 on the “dark” side exceeds the allowable value.
As for the defect 18 on the “bright” side, the change in the pulse shape is small and does not exceed the allowable value, which may cause erroneous recognition.

Therefore, when the surface to be inspected is a surface to be printed with the color ink 17 as in the present embodiment, the bright-field illumination light source 4 becomes unnecessary, and the defect can be accurately detected only by the dark-field illumination light source 6. Will be able to do that.

Next, a fifth embodiment of the present invention will be described. FIG. 13 is a schematic configuration diagram showing a quality inspection device according to a fifth embodiment of the present invention, FIG. 14 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection device, and FIG.
(A) is an explanatory view of the inspection principle by the same quality inspection apparatus at the line CL-CL in FIG. 14, and (b) and (c) are explanatory views of the inspection principle of a comparative example, respectively.

In FIG. 13, reference numeral 1 denotes an inspection object. 2
Is a camera such as a CCD licensor, 4 is a bright-field illumination light source, 6 is a dark-field illumination light source, and 8 is a determination means. These components are the same as those in the first embodiment.

The operation of the above configuration will be described below. In the inspection object 1 in the present embodiment, the inspection surface 3 is a printing surface of the color ink 17 on the paper 16 and a coat layer 20 provided on the printing surface.
As shown in FIG. 4, a defect (scratch) 21
And the paper 16 has a dark defect 19 on a part thereof. The inspection object 1 is caused to travel, and in the course of the traveling, the inspection surface 3 is irradiated with the bright-field illumination light 5 emitted from the bright-field illumination light source 4 and the dark-field illumination light 7 emitted from the dark-field illumination light source 6. , And the imaging surface 2 is sequentially imaged by the imaging camera 2 over the entire length in the width direction. Judgment means 8
In, the presence or absence of a defect is determined in the same manner as in the first embodiment from the data of the 256-level multi-tone line image sequentially output from the imaging camera 2.

As shown in FIG. 15A, for example, the reference density level of a portion other than the color ink 17 is set to 180 levels, and the reference density level of the color ink 17 is set to a desired level corresponding to each color. Set,
The allowable values on the “bright” side and the “dark” side are set to 10 levels, respectively, and the inspection surface 3 is emitted from the bright field illumination light 5 and the dark field illumination light 6 emitted from the bright field illumination light source 4. It is assumed that illumination is performed using both the dark-field illumination light 7. And FIG.
As shown in FIG. 4, assuming that a defect (scratch) 21 and a dark defect 19 exist on the coat layer 20 of the surface 3 to be inspected and on the surface of the paper 16, the portion of the defect 21 is irregularly reflected with respect to the reference density level. Since the density level is low, a change in pulse shape appears on the “dark” side at the position of the defect 21 of the coat layer 20 on the surface to be inspected, and on the “dark” side at the position of the dark defect 19 on the paper 16 surface. It appears as a change in the pulse shape, and since these changed portions exceed the allowable value, in this case, it is determined as a defect. When the surface 3 to be inspected is the printing surface and the coating layer 20 thereon, by using the bright-field illumination light 5,
As in the case of the first embodiment, the light is reflected by the coat layer 20, and the defect 2 is reflected in the same manner as in the case of the mirror surface of the first embodiment.
1 can be accurately detected, and by using the dark field illumination light 7, as in the fourth embodiment, it is scattered by the printed color ink 17, and is necessary for detecting the color of the ink. Guide light to the imaging camera 2 to increase the difference in pulse shape between the characters A and B of the inks 17 of different colors to prevent erroneous recognition of defects such as printing errors due to differences in ink. can do.

On the other hand, as a comparative example, when only the bright-field illumination light 5 is used, the reflectance from the coat layer 20 increases, and therefore, as shown in FIG. Is set to 230 levels, and the allowable values on the “bright” side and “dark” side are each set to 10 levels.
In this case, since the density level of the portion of the defect 21 becomes low due to irregular reflection, the reference density level of the surface to be inspected 3 has a pulse shape on the “dark” side at the position of the defect 21 on the coat layer 20. Appear as a change, and this part, for example,
If the level is 150, it is determined that the defect exceeds the allowable value, and the defect is determined. However, the defect 19 on the paper surface 16 has an illuminance of the reflected light that is too high and does not exceed the allowable value. There is a risk of misrecognition.

On the other hand, as another comparative example, when only the dark-field illumination light 7 is used, the reflectance from the coat layer 20 is low, so that, for example, as shown in FIG. It is assumed that the density level is set to 150 levels, and the allowable values on the “bright” side and “dark” side are set to 10 levels, respectively. In this case, the dark defect 19 appears as a change in the pulse shape on the “dark” side with respect to the reference density level, and since the changed portion exceeds the allowable value, it is determined to be a defect. On the other hand, the reflectivity from the defect 21 increases compared to the reflectivity of the coat layer 20 due to irregular reflection, and the reference density level appears as a change in pulse shape on the “bright” side at the position of the defect 21. However, since the reflectance decreases,
In some cases, the pulse shape that appears with respect to the reference density level does not exceed the allowable value, and there is a possibility that the pulse shape is erroneously recognized as not a defect.

Therefore, when the surface 3 to be inspected is the printing surface and the coat layer 20 as in this embodiment, the defect can be accurately detected by using both the bright-field illumination light source 4 and the dark-field illumination light source 6. It can be detected.

In this embodiment, only the coat layer 20 is detected, only the print surface is detected, or a black background is printed with gold foil, and the coat layer 20 is further printed on the test object with the coat layer 20 provided thereon. Optimal conditions can be determined by a combination of lighting of the bright-field illumination light source 4 and dark-field illumination light source 6 and setting of the dimming value in response to a change in the inspection target, that is, the inspection condition, such as the detection of a surface. . As an example, one of the bright-field illumination light source 4 and the dark-field illumination light source 6 can be turned on and the other can be turned off, or both can be turned on. It can be selected in the range of 120%.

Next, a sixth embodiment of the present invention will be described. FIG. 16 is a schematic configuration diagram showing a quality inspection apparatus according to a sixth embodiment of the present invention, and FIGS. 17A and 17B are a plan view and a cross-sectional view of an inspection object inspected by the quality inspection apparatus. FIGS. 18 (a), 18 (b), and (c) are explanatory diagrams of use examples of the quality inspection apparatus, and FIGS.
(B) is the CL-C of FIG.
FIG. 19C is an explanatory diagram of the inspection principle at the L line, and FIG.

In FIG. 16, reference numeral 1 denotes an inspection object, which runs on the inspection roll 26 in the direction of the arrow. Reference numeral 2 denotes a camera such as a CCD licensor, 4 denotes a bright-field illumination light source, 6 denotes a dark-field illumination light source, and 8 denotes a determination unit. These components are the same as those in the first embodiment. In the present embodiment, further, the bright-field illumination light 5 emitted from the bright-field illumination light source 4 is entirely incident on the surface 3 to be inspected corresponding to the inspection object, or only at a certain incident angle. The dark-field illumination light 7 emitted from the dark-field illumination light source 6 is irregularly reflected on the surface to be inspected, and the bright-field illumination from the surface 3 to the imaging camera 2 is performed. A control plate 27 having a diffuse reflection surface 27a that can be incident as light is provided. This control plate 27 is, for example,
One in which the irregular reflection surface 27a on the imaging camera 2 side is set to have a high reflectance on a matte surface such as white, and another in which the irregular reflection surface 27a
Is set to have a low reflectance on a matte surface such as black, and is used as a replacement. The control plate 27 is finely adjusted in the vertical direction by a fine adjustment mechanism (not shown) so that the incident angle of the bright-field illumination light 5 with respect to the inspection surface 3 is adjusted.

The operation of the above configuration will be described below. As shown in FIGS. 17A and 17B, the inspected object 1 in the present embodiment is a surface of the aluminum foil 28 and a printed surface printed with the color ink 17 on the surface, as shown in FIGS. It is assumed that a portion of the aluminum foil 28 has a shallow recess 29 and a portion of the aluminum foil 28 has a deep recess 30. When a transparent synthetic resin coat layer is laminated on such an aluminum foil 28 from the printed surface by extrusion, a shallow recess 29 formed in the aluminum foil 28 is formed.
Is repaired into a flat shape by the heat given at the time of lamination, so when inspecting before laminating the coat layer,
The shallow recess 29 must not be detected as a defect, but only the deep recess 30 needs to be detected as a defect.

Then, the inspection object 1 is caused to travel, and in the course of the traveling, the dark-field illumination light 7 emitted from the dark-field illumination light source 6 and the reflected light of the dark-field illumination light 7 by the irregular reflection surface 27a are generated. Illuminating the inspection target surface 3 with a combination with the bright-field illumination light 5 emitted from the bright-field illumination light source 4 and limited to a certain incident angle by the control plate 27 as necessary;
The imaging camera 2 extends over the inspected surface 3 over its entire length in the width direction.
To sequentially capture images. The determination means 8 determines the presence or absence of a defect from the data of the 256-level multi-gradation line image sequentially output from the imaging camera 2 in the same manner as in the first embodiment. At this time, as a result of inspecting a part of the inspection object 1 in advance, if there is no concave portion in the inspection object 1, the bright-field illumination light 5 emitted from the bright-field illumination light source 4 Since the light does not enter the imaging camera 2 at the surface 3 to be inspected,
As shown in FIG. 18A, the control plate 27 is raised so that the bright-field illumination light 5 is hardly restricted (the bright-field illumination light 5 is partially controlled by the lowering of the control plate 27 and cut off. The dark-field illumination light 7 emitted from the dark-field illumination light source 6 is irregularly reflected by the irregular reflection surface 27a of the control plate 27, and reflected by the surface 3 to be inspected as bright-field illumination light. 2 is set to be incident. When a shallow concave portion 29 is present in the inspection object 1, as shown in FIG. 18B, the control plate 27 is slightly lowered, and the light reflected by the irregular reflection surface 27a of the dark-field illumination light 7 becomes a shallow concave portion. 29
Is set so that the reflected light is incident on the imaging camera 2 as bright-field illumination light. When the deep concave portion 30 exists in the inspection object 1, as shown in FIG. 18C, the control plate 27 is slightly lowered, and a part of the bright field emitted from the lower side of the bright field illumination light source 4. The deep recess 30 is illuminated by the illumination light 5 for use, and the reflected light is set so as to enter the imaging camera 2.

When it is necessary to detect a defect such as a foreign matter which is a dark defect on the aluminum foil 28, the irregular reflection surface 27 is required.
a is white and the surface of the aluminum foil 28 is illuminated brightly,
When it is not necessary to detect a defect, the irregular reflection surface 27a is set to black, and the surface of the aluminum foil 28 is irradiated with lower illuminance than the above case. By irradiating the surface of the aluminum foil 28 brightly, the pulse shape can be changed from the reference density level to a value higher than the allowable value at the defect portion and detected as a defect. By irradiating with the illuminance, it is possible to detect that the defect is not a defect by changing the pulse shape from the reference density level to a low value within an allowable value at the defect.

When a white control plate 27 is used for the irregular reflection surface 27a, as shown in FIG. 19A, for example, the reference density level is set to 200 levels, and the "bright" side and the "dark" side are set.
Side is set to 10 levels each, and diffuse reflection surface 2
When the black control plate 27 is used in FIG.
As shown in (b), for example, the reference density level is set to 40 levels, and the reference density level of the color ink 17 is set to a desired level corresponding to each color.
It is assumed that the allowable values on the “bright” side and the “dark” side are set to 10 levels, respectively. Then, for example, FIGS.
Assuming that a shallow concave portion 29 exists in the surface 3 to be inspected as shown in FIG. The light incident on the imaging camera 2 after being reflected by the surface 3 to be inspected is irregularly reflected by the concave portion 29 than the light reflected on the surface of the other aluminum foil 28 and entering the imaging camera 2. It will be slightly brighter. Therefore, as shown in FIGS. 19 (a) and (b), a slight pulse on the "bright" side at the position of the concave portion 29 where the density level of the surface of the aluminum foil 28 which is the inspection surface is shallower than the reference density level. It appears as a change in shape, and since this changed portion does not exceed the allowable value, it is determined that it is not a defect. Also, the deep recess 3
By setting 0 to the state of FIG. 18C as described above, the illumination with the bright-field illumination light 5 causes the light to enter the imaging camera 2 with higher illuminance.
As shown in (a) and (b), when the changed portion has a high density level and exceeds the permissible value, it is determined as a defect.

On the other hand, when the control plate 27 is not used, for example, as shown in FIG.
If the level is set to 0 level and the allowable values on the “bright” side and “dark” side are each set to 10 levels, the bright-field illumination light 5
And shallow recesses 30 due to dark field illumination light 7
As described above, the light is incident on the imaging camera 2, and not only the deep concave portion 30 but also the shallow concave portion 29 appear as a change in the pulse shape exceeding the allowable value from the reference density level, so that it is determined as a defect. Will be.

Therefore, by using the control plate 27 as in the embodiment of the present invention, it is possible to judge that the shallow concave portion 29 of the aluminum foil 28 repaired at the time of laminating the coat layer is not a defect and prevent erroneous detection. it can.

In this embodiment, the scratches on the surface 3 to be inspected have the state shown in FIG. 18A when there is no concave part, the state shown in FIG. 18C, the state is set to the state shown in FIG. 18C, and the light diffusely reflected by the irregular reflection surface 27a of the control plate 27 is used, whereby the detection can be performed according to the inspection principle described in the first embodiment. .

[0055]

As described above, according to the present invention, illumination light for a bright field, which can reliably obtain a reflection component such as a mirror surface, and color, diffuse reflection, etc. By selectively using the illumination light for dark field, which can reliably obtain the above component, alone or in combination, it is possible to improve the detection accuracy by applying it to various inspection targets. Therefore, versatility can be obtained, and the reliability of inspection can be improved.

Further, the incident angle of the illumination light emitted from the bright-field illumination light source can be controlled, and the use of a control plate for irregularly reflecting the illumination light emitted from the dark-field illumination light source allows the shallow concave portion to be formed. The present invention can be applied to a necessary standard for inspection, such as non-detection and detection of a deep recess.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a quality inspection device according to a first embodiment of the present invention.

FIG. 2 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection apparatus.

FIG. 3 (a) is the CL-C of FIG. 2 by the same quality inspection device.
FIG. 7B is an explanatory view of the inspection principle at the L line, and FIG. 8B is an explanatory view of the inspection principle of the comparative example.

FIG. 4 is a schematic configuration diagram showing a quality inspection device according to a second embodiment of the present invention.

FIG. 5 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection apparatus.

FIG. 6 (a) is the CL-C of FIG. 5 by the same quality inspection device.
FIG. 7B is an explanatory view of the inspection principle at the L line, and FIG. 8B is an explanatory view of the inspection principle of the comparative example.

FIG. 7 is a schematic configuration diagram showing a quality inspection device according to a third embodiment of the present invention.

FIG. 8 is an explanatory plan view showing an example of an inspection object to be inspected by the quality inspection apparatus.

9 (a) is the CL-C of FIG. 8 by the same quality inspection device.
FIG. 7B is an explanatory view of the inspection principle at the L line, and FIG. 8B is an explanatory view of the inspection principle of the comparative example.

FIG. 10 is a schematic configuration diagram showing a quality inspection device according to a fourth embodiment of the present invention.

FIG. 11 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection apparatus.

FIG. 12 (a) shows the CL of FIG. 11 by the same quality inspection apparatus.
FIG. 7B is an explanatory view of an inspection principle at a CL line, and FIG. 8B is an explanatory view of an inspection principle of a comparative example.

FIG. 13 is a schematic configuration diagram showing a quality inspection device according to a fifth embodiment of the present invention.

FIG. 14 is an explanatory plan view showing an example of an inspection object inspected by the quality inspection apparatus.

FIG. 15A shows the CL of FIG. 14 by the same quality inspection apparatus.
(B) and (c) are inspection principle explanatory diagrams of a comparative example, respectively.

FIG. 16 is a schematic configuration diagram showing a quality inspection device according to a sixth embodiment of the present invention.

FIGS. 17A and 17B are an explanatory plan view and an explanatory cross-sectional view illustrating an example of an inspection object inspected by the quality inspection apparatus.

FIGS. 18 (a), (b), and (c) are explanatory diagrams each showing an example of use of the quality inspection apparatus.

19 (a) and (b) show FIG. 1 by the same quality inspection apparatus.
FIG. 7A is an explanatory view of the inspection principle on the CL-CL line,
(C) is an explanatory view of the inspection principle of the comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inspection object 2 Imaging camera 3 Inspection surface 4 Bright-field illumination light source 5 Bright-field illumination light 6 Dark-field illumination light source 7 Dark-field illumination light 8 Judgment means 22 Cover 27 Control plate 27a Diffuse reflection surface

Continuing from the front page (72) Inventor Hiromi Okamoto 1-5 Kagamiba Oyanagicho, Minami-ku, Kyoto Duck Engineering Co., Ltd. (72) Inventor Takayuki Shibahara 1-5 Kagamiba Oyanagicho, Minami-ku, Kyoto Duck Engineering Stock Inside the company (72) Inventor Yoshitaka Hikami 1-5 Kagamiba Oyanagicho, Minami-ku, Kyoto Duck Engineering Co., Ltd.

Claims (6)

[Claims] 1. An imaging means for imaging a surface to be inspected of an object to be inspected, a bright-field illumination light source for illuminating the surface to be inspected and emitting bright-field illumination light to be a bright field in the imaging means. A dark-field illumination light source that illuminates the surface to be inspected and emits dark-field illumination light that becomes a dark field in the imaging unit, and determines whether there is a defect in the surface to be inspected based on an output from the imaging unit. A quality inspection apparatus comprising: a determination unit for determining, wherein the bright-field illumination light source and the dark-field illumination light source are selectively used alone or in combination in accordance with an inspection target. 2. The method according to claim 1, wherein the bright-field illumination light emitted from the bright-field illumination light source is controlled so that the whole is incident or only at a certain incident angle corresponding to the inspection object. A control plate having a diffuse reflection surface capable of irregularly reflecting dark-field illumination light emitted from the illumination light source on the surface to be inspected and allowing the dark-field illumination light to enter the imaging means as bright-field illumination light from the surface to be inspected; The quality inspection device according to claim 1. 3. The apparatus according to claim 1, wherein the amount of illumination light emitted from one or both of the bright-field illumination light source and the dark-field illumination light source to the surface to be inspected is adjusted in accordance with the inspection object. Quality inspection device as described. 4. The quality inspection apparatus according to claim 2, wherein the control plate is configured to be capable of changing the amount of diffused reflection on the irregular reflection surface in accordance with an inspection target. 5. The quality inspection apparatus according to claim 1, wherein the imaging unit is arranged so that an optical axis incident from the inspection surface is inclined with respect to the inspection surface. 6. The quality according to claim 1, wherein said judging means judges the presence or absence of a defect by comparing the density level of the multi-tone image data obtained from the output of the imaging means with a reference density level. Inspection equipment.