JP2001041896A - Method and apparatus for detecting flaw of roll-shaped film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the flaw (especially, the flaw caused by foreign matter) generated in a roll-shaped film without erroneously detecting the same. SOLUTION: A first luminaire 2A irradiates the whole surface in the width direction of a roll with first light. The second luminaire 2B arranged on the side opposite to the first luminaire 2A so as to hold the line of sight of an image input device 3 between both luminaires irradiates the whole surface in the width direction of the roll with second light so as to suppress the generation of a dummy flaw on the surface of a roll-shaped film 1. The third luminaire 2C arranged between the first and second luminaires 2A, 2B irradiates the whole surface in the width direction of the roll with third light so as to suppress the generation of a dummy flaw in the roll-shaped film 1. The image input device 3 picks up the reflected images of the whole surface in the width direction of the roll-shaped film 1 irradiated by the luminaires 2A, 2B, 2C and an image processor 4 detects the presence of the flaw in the roll-shaped film 1 on the basis of the picked-up image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect detecting apparatus and a defect detecting method for detecting a defect caused by, for example, a foreign substance inside a roll-shaped film. The present invention relates to a defect detection method and a defect detection device for a roll film.

[0002]

2. Description of the Related Art Conventionally, attempts have been made to automate the detection of defects such as foreign matter generated when a roll-shaped film wound around a paper tube is wound up using an image processing technique. Such a technique is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-1478.
There is a technique disclosed in Japanese Patent Publication No. 68 (hereinafter, referred to as a first publication). In this technique, a solid-state imaging camera captures a reflected image from the outer peripheral surface of the sheet roll, and compares it with a reflected image having no defective portion to determine whether or not there is a defect.

In the technique disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 9-133638 (hereinafter, referred to as "second publication"), two light beams, a main light beam and a sub light beam, are radiated so that the end of a roll-shaped film is wound. The detection of a pseudo defect is suppressed so that a defect due to a foreign substance or the like on a roll-shaped film can be detected.

[0004]

However, defects caused by foreign matters that occur when a roll-shaped film is wound up are, for example, as follows.
It mainly occurs inside a roll-shaped film. For this reason, in order to detect a defect occurring inside such a roll-shaped film, for example, high-intensity light is irradiated so that irradiation light reaches the inside of the roll-shaped film, and this is irradiated with an image input device (eg, It is conceivable that the image is captured by an image sensor and subjected to image processing to detect a defect.

[0005] However, even when the light having such a high light intensity is irradiated, the light is scattered on the surface of the roll-shaped film due to, for example, the end of winding of the surface of the roll-shaped film, or a cavity in the film (bubbles, Due to multiple reflections due to gaps), the end of winding of these roll-shaped films and the cavities in the films are assumed to have the same brightness (density) (pseudo-defects) as defects due to foreign matter in the roll-shaped films (pseudo-defects). It is not easy to reliably detect defects without erroneously detecting these pseudo defects as defects due to foreign matter inside the roll film.

Therefore, for example, by adjusting the arrangement, angle and the like of an illumination device, an image input device, and the like, the difference in shading between the defective portion and the pseudo defective portion is emphasized, so that the defect can be accurately detected by the foreign matter. However, in practice, it is difficult to appropriately adjust the arrangement, the angle, and the like of the illumination device, the image input device, and the like that constitute the optical system according to the defect due to the foreign matter.

For example, the technique disclosed in the above-mentioned first publication only compares a captured image with a non-defective image, so that it may not be possible to reliably detect a defect depending on the type of defect. Also, in the technique disclosed in the above-mentioned second publication, it is difficult to suppress the detection of pseudo defects such as voids (bubbles and gaps) in the film inside the roll-shaped film. It cannot be said that it can be reliably detected.

Even if such an adjustment of the optical system can make the difference in density between a defective portion and a pseudo-defect portion to some extent, and can improve the accuracy of defect detection to some extent, this still has a limit. is there. In other words, even if the optical system is adjusted to make the difference in density between the defective portion and the pseudo defective portion stand out, both the defective portion and the pseudo defective portion are irradiated by the same optical system. It is difficult to make a difference in density between the pseudo defect portion and the pseudo defect portion, and it is difficult to improve the accuracy of defect detection only by adjusting the optical system.

Therefore, it is necessary to devise not only the adjustment of the optical system as described above, but also the process of highlighting a defect caused by a foreign matter generated inside the roll-shaped film in the image processing of the image captured through the image input device. is there.

By the way, in a general image processing technique, a process of making a characteristic portion stand out by a feature extraction process such as a differential process is performed. However, even when such a feature extraction process is performed, it is difficult to make the feature portion stand out if there is not much difference in shading between the feature portion and other portions. Similarly, when there is not much difference in shading between the defect portion of the foreign matter and the pseudo defect portion such as the end of winding of the roll film, image processing is performed so as to highlight the defect portion in the defect detection of the roll film. It is also difficult.

Further, since defects due to foreign matter include very fine ones such as hair, for example, it is difficult to perform image processing so as to highlight such a defective portion due to such foreign matter. The density (brightness) of an image input to the image processing device via the image input device according to the type of defect such as a foreign substance generated on the surface of the roll-shaped film and the manner of adjusting the optical system.
Therefore, it is difficult to determine a defect due to a foreign substance by directly using the density (luminance) of an input image in image processing. In other words, when the overall brightness of the input image is increased or decreased, the normal part is determined to be a defective part, or conversely, the defective part is determined to be a normal part. It is difficult to detect defects with high accuracy.

The present invention has been made in view of such a problem, and by optimizing the adjustment of the optical system and the image processing, a defect (particularly a defect due to foreign matter) generated inside the roll-shaped film. It is an object of the present invention to provide a method and an apparatus for detecting a defect of a roll-shaped film, which can detect a defect accurately and accurately without erroneously detecting the defect.

[0013]

According to the present invention, there is provided a method for detecting a defect in a roll-shaped film according to the present invention. One or two or more first lights are irradiated on the entire surface, and one or two or more second lights are irradiated on the entire width direction of the roll film so as to suppress detection of a pseudo defect on the surface of the roll film. Then, the first light and the second light are controlled so as to suppress detection of a pseudo defect inside the roll-shaped film.
Irradiating one or more third lights on the entire width direction of the roll-shaped film from between the light and the light, and irradiating the roll-shaped film with the first light, the second light and the third light in the width direction It is characterized in that a reflection image of the entire surface is taken, and the presence or absence of a defect inside the roll-shaped film is detected based on the taken image information.

According to a second aspect of the present invention, there is provided an apparatus for detecting a defect in a roll film according to the present invention, wherein the image input apparatus captures a reflection image of the entire width direction of the roll film irradiated by an illumination device. An image processing device that detects the presence or absence of a defect inside the roll-shaped film based on imaged image information, wherein the illumination device irradiates the defective portion inside the roll-shaped film with the roll. A first illuminating device for irradiating one or more first lights to the entire surface of the film in the width direction, and a roll disposed on a side opposite to the first illuminating device with respect to a line of sight of the image input device. A second illuminating device for irradiating one or more second lights to the entire width direction of the roll-shaped film so as to suppress detection of a pseudo defect on the surface of the roll-shaped film; a first illuminating device; Installed between lighting equipment A third lighting device configured to irradiate one or more third lights to the entire surface in the width direction of the roll-shaped film so as to suppress detection of a pseudo defect inside the roll-shaped film. It is characterized by.

According to a third aspect of the present invention, there is provided an apparatus for detecting a defect of a roll film according to the present invention, wherein the image input apparatus captures a reflection image of the entire width direction of the roll film irradiated by an illuminating device, and the image input apparatus captures an image. An image processing device for detecting the presence or absence of a defect inside the roll-shaped film based on the obtained image information, wherein the image processing device obtains a density histogram of an original image captured by the image input device. A processing unit; a base image calculation unit for obtaining a base image from the density histogram obtained by the density histogram processing unit; a correction image calculation unit for obtaining a correction image from a difference between the original image and the base image; A defect discriminating section for discriminating the presence or absence of a defect inside the roll-shaped film based on the corrected image calculated by the calculating section. It is set to.

According to a fourth aspect of the present invention, there is provided the roll-shaped film defect detecting apparatus according to the third aspect, wherein the illumination device irradiates a defective portion inside the roll-shaped film. A first illuminating device for irradiating one or more first lights to the entire surface of the film in the width direction, and a roll disposed on a side opposite to the first illuminating device with respect to a line of sight of the image input device. In order to suppress the detection of pseudo defects on the surface of the rolled film, 1
Or a second lighting device for irradiating two or more second lights,
One or more third or more third illuminating devices are disposed between the illuminating device and the second illuminating device, and are disposed on the entire width direction of the roll film so as to suppress detection of a pseudo defect inside the roll film.
And a third lighting device for irradiating light.

According to a fifth aspect of the present invention, there is provided the roll film defect detecting apparatus according to the third or fourth aspect, wherein the image processing apparatus performs an eload process on an original image captured by the image input apparatus. An eload processing unit for performing output to the density histogram processing unit and the corrected image calculation unit, performing a binarization process on the corrected image calculated by the corrected image calculation unit; A labeling processing unit that performs a labeling process on the binarized image obtained by the processing unit, wherein the defect determination unit determines whether there is a defect due to foreign matter inside the roll-shaped film based on a processing result of the labeling processing unit. Is distinguished.

According to a sixth aspect of the present invention, there is provided the roll-shaped film defect detecting apparatus according to any one of the third to fifth aspects, wherein the base image calculating section determines whether the variance of the density histogram is small. A density value of a base image is calculated from an average density value of the density histogram obtained by the density histogram processing unit, and when the variance of the density histogram is large, a minimum density of the density histogram obtained by the density histogram processing unit It is characterized in that a density value of a base image is calculated from the value.

According to a seventh aspect of the present invention, in the apparatus for detecting a defect of a roll-shaped film according to the second aspect of the present invention, the pseudo-defect on the surface of the roll-shaped film is reduced. This is caused by the end of the winding of the film, the pseudo defect inside the roll-shaped film is caused by the cavity in the film of the roll-shaped film, and the image processing apparatus is configured to It is characterized by detecting the presence or absence of a defect due to foreign matter.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. First, a roll-shaped film defect detection apparatus according to an embodiment of the present invention, FIG.
This will be described with reference to FIG. The roll film defect detecting apparatus according to the present embodiment is for detecting a defect of a roll film as an object to be inspected.

First, the roll film and the types of defects thereof will be described. As shown in FIG. 2, the roll film 1 is a transparent or translucent film (for example, a wrap film or the like) and has a cylindrical core [paper tube, for example, having an outer diameter of 90 mm.
mm (radius: 45 mm)] The film 1A is wound into a roll around 1B. Here, a 1000 m wound film roll [for example, an outer diameter of 154 mm (a radius of 77 mm)]
Will be described.

As shown in FIGS. 4 (A) to 4 (F), types of such defects of the roll-shaped film 1 are strip-shaped wrinkles 50A, winding bumps 50B, scratches 50C, vertical wrinkles 50D,
There are oblique wrinkles 50E, foreign matters 50F and the like. Here, the strip-shaped wrinkles 50A are strip-shaped wrinkles that are generated when the film has a locally thin portion, as shown in FIG.
It has a certain width α, and is characterized in that it occurs over the entire circumference of the roll surface.

As shown in FIG. 4B, the winding bump 50B is formed due to a concave portion of a rubber roll for transporting a film, and has a surface wound around the entire roll in a rolled state. The feature is that it swells and becomes bumpy. The winding bumps include a high one [winding bump (large)] 50BA and a low height [winding bump (small)] 50BB. Here, winding hump (small) 50
BB refers to a material having a height of about 50 micrometers (also called μm or micron) to about 1000 micrometers and a width of about 1 to 2 cm.

The scratch 50C is, as shown in FIG. 4C, a scratch or the like caused by a cutter for cutting the film, and is characterized by being generated over the entire circumference of the roll surface. As shown in FIG. 4D, the vertical wrinkles 50D are characterized in that unlike the above-described wrinkles, short vertical streaks enter randomly and do not extend over the entire circumference of the roll surface. As shown in FIG. 4E, the oblique wrinkles 50E are caused by defective film cutting or the like. In particular, it often occurs around winding bumps.

As shown in FIG. 4F, the foreign matter 50F
For example, burnt portions of the film, insects and hair that have entered between the films, which appear to be mainly black, and are characterized by being generated inside the roll-shaped film 1. The size of the foreign matter (also referred to as a black foreign matter) which is considered to be a defect is, for example, about 0.
4 mm or more. Although not such a defect, the end of winding 50G on the surface of the roll-shaped film 1 (see FIG. 4 (G)) and the defect detected as a defect in the defect detection (pseudo-defect), Internal cavities inside the film (eg bubbles, gaps)
50H (see FIG. 4 (F)), the inside of the roll-shaped film 1 starts to be wound, and the paper tube has a spiral.

The roll film defect detecting apparatus according to the present embodiment detects a defect due to foreign matter 50F inside the roll film 1 among these defects. The feature of the defect due to the foreign matter 50F is that it occurs inside the roll film 1 as described above. Also,
According to the defect detection by the dark defect method of recognizing a low-luminance portion as a defect, this defect also has a feature that the luminance of the defective portion protrudes to a side lower than the luminance of the normal portion (the side where the original image becomes black). is there.

Therefore, in the present embodiment, the peak value of the luminance value (minus peak value) is determined by the dark defect method, which focuses on the features of these defects and recognizes a low luminance portion (a black portion in the original image) as a defect. Is used to detect the presence or absence of a defect. For this reason, as shown in FIG.
It comprises an illumination device (light source) 2, an image input device 3, an image processing device (data processing device) 4, and a display device 5.

The optical system is composed of the illumination device 2 and the image input device 3. Further, an image processing system (data processing system, signal processing system) is configured by the image processing device 4 that processes image information (image data) captured by the image input device 3 and detects a defect. Here, the optical system is configured to satisfy the following conditions. This is so that the brightness of the normal portion other than the defective portion due to the foreign material 50F inside the roll-shaped film 1 becomes higher than the brightness of the defective portion when performing image processing and detecting the defect using the foreign material 50F as described later. (That is, to make the original image whiter), the brightness of the defective portion is made relatively lower (that is, the original image becomes blacker) to make the defective portion stand out. This is to make it possible to detect a defect by 50F.

The illuminating device 1 and the illuminating device 1 are arranged so that, of the irradiating light from the illuminating device 2, the reflected light in the range of the highest luminance among the reflected light reflected on the normal portion of the surface of the roll film 1 does not enter the image input device 3. The angle with the image input device 3 is adjusted. The illuminating device 2 uses a device having as high a light amount as possible (especially a device having high directivity (or parallelism)). This is because the irradiation light from the illumination device 2 is perpendicularly incident on the surface of the roll-shaped film 1 to reduce the reflected light on the surface of the roll-shaped film 1 as much as possible. (As deep as possible) so that the irradiation light reaches the foreign matter 50F inside the roll-shaped film 1.
This is because a defect caused by the defect can be easily detected.

The image input device 3 includes a roll film 1
Is arranged so that its optical axis is as perpendicular as possible to the inspection area on the surface of the. The angle between the illumination device 2 and the image input device 3 is arranged to be as narrow as possible. This is for minimizing the influence of the reflected light on the surface of the roll-shaped film 1 and making it easier to detect a defective portion due to the foreign matter 50F inside (particularly a deep portion) of the roll-shaped film 1. The roll film 1 has a length of 500 m to 1 m.
There are various types (brands) such as 000 m rolled film rolls, and the winding diameter differs depending on each type, which causes the optical axis of the image input device 3 to shift.
This is to minimize the displacement of the optical axis of the image input device 3. Further, since the optical axis of the image input device 3 is shifted as the optical axis of the image input device 3 is inclined with respect to the roll film 1, the optical axis of the image input device 3 is not shifted as much as possible. To do that. With such an arrangement, the measurement accuracy can be improved.

In this embodiment, the illumination device 2 and the image input device 3 are configured to satisfy these conditions as follows. The lighting device 2 includes a first lighting device 2A that irradiates the first light, a second lighting device 2B that irradiates the second light, and a third lighting device 2B.
A third illuminating device 2 </ b> C for irradiating light is provided, and can irradiate three lights over the entire width direction of the roll film 1. Thus, the lighting device 2
Is configured as a three-lamp optical system using three lighting devices 2A to 2C.

Then, these three lighting devices 2A to 2A
By adjusting the type, irradiation position and irradiation angle of the irradiation light of C, the winding end 50G of the surface of the roll film 1 is adjusted.
In the film of the roll or roll film 1 (bubbles, gaps)
Optical processing is performed on a pseudo defect such as 50H to lower the luminance of a defective portion due to a foreign substance 50F inside the roll-shaped film 1 (that is, to make the original image black) and to generate inside the roll-shaped film 1. This suppresses a decrease in luminance of a pseudo defect such as a cavity 50H in the film (for example, bubbles and gaps) and a winding end 50G on the surface of the roll-shaped film 1 (that is, the original image becomes black).

The first illuminating device 2A irradiates the first light on the entire surface of the roll film 1 in the width direction so as to irradiate a defective portion due to the foreign matter 50F inside the roll film 1. The first lighting device 2A mainly has a function of lowering the luminance of the foreign matter 50F inside the roll film 1 (that is, making the original image black).

Therefore, the first illuminating device 2 A is designed so that the light (first light) reaches the inside of the roll film 1.
Strength (light intensity) over the entire width of the roll film 1 in the roll width direction
It is preferable to use a device that can irradiate with high light, for example, an illumination of a large amount of light such as an aperture type fluorescent lamp (having a larger amount of light than a normal fluorescent lamp) or a transmission light. The first lighting device 2A may use, for example, a normal fluorescent lamp, LED lighting, fiber lighting, or the like.

The first illuminating device 2A is, for example, a straight tube fluorescent lamp (aperture type fluorescent lamp), a transmission light, a halogen fiber, or the like, so that a good band-like reflection image can be obtained in parallel with the roll film 1. It is preferable to use a lamp having a length such as a lamp and to dispose it above the roll film 1 so as to extend in the roll width direction of the roll film 1.

The first lighting device 2A thus configured
Is arranged as close as possible to the roll-shaped film 1 so that the reflected light inside the roll-shaped film 1 reaches an inspection area (imaging area by the image input device 3) on the surface of the roll-shaped film 1. At an appropriate angle. Since the first lighting device 2A has a large light amount and a small surface reflection, a large amount of light reaches the inside of the roll-shaped film 1.

For example, as shown in FIG. 2, the first lighting device 2A is disposed at a position separated from the outer peripheral surface of the roll film 1 by a predetermined distance (for example, about 30 mm to about 45 mm). Further, it is disposed at a position separated from the reference plane Z including the inspection point P of the roll-shaped film 1 by a predetermined distance (for example, about 20 mm to about 30 mm). The first lighting device 2A is disposed such that its outer peripheral surface is located at a position separated by a predetermined distance (for example, about 40 mm to about 60 mm) from a reference axis Y passing through the center of the cross section of the roll-shaped film 1.

As shown in FIG. 3, the first lighting device 2A connects the line of sight of the camera [the optical axis of the image input device, the cross-sectional center of the roll film 1 and the center of the image input device 3 (camera center). Line] as a reference line, and is disposed within a first predetermined angle range (for example, about 39 ° ± 15 °). In particular, it is preferable to arrange them so as to be within the first set angle range (for example, about 39 ° ± 5 °). Here, the clockwise direction is minus (-) with respect to the camera line of sight as the reference line.
And the counterclockwise direction is plus (+).

When the first illuminating device 2A irradiates a large amount of light in this manner, the light from the first illuminating device 2A is scattered by the winding end 50G on the surface of the roll-shaped film 1, and the roll-shaped film 1 Since it does not reach the inside and the brightness at the end portion of the winding is further reduced (that is, the original image becomes black), it is difficult to distinguish from the foreign matter 50F (the original image becomes black) inside the roll film 1,
It becomes difficult to reliably detect a defect due to the foreign matter 50F of the roll film 1. Therefore, a second lighting device 2B is provided.

The second illuminating device 2B is disposed on the opposite side of the first illuminating device 2A with respect to the camera line of sight of the image input device 3, and the end 50G of the surface of the roll film 1 is wound.
The second light is applied to the entire surface of the roll film 1 in the width direction so as to suppress the detection of the pseudo defect due to the above. The second illuminating device 2B mainly has a function of increasing the luminance at the end 50G of the winding of the surface of the roll-shaped film 1 (that is, whitening the original image).

For this reason, it is preferable to use a device capable of irradiating the entire surface of the roll film 1 in the roll width direction with diffused light (light having low directivity), for example, a white fluorescent lamp, as the second lighting device 2B. The second illuminating device 2B uses a long tube such as a straight tube fluorescent lamp or a halogen fiber lamp so as to obtain a good band-shaped reflection image parallel to the roll film 1, and uses a roll-like film. It is preferable to arrange above the film 1 so as to extend in the roll width direction of the roll-shaped film 1.

The second lighting device 2B thus configured
Are arranged as close as possible to the roll-shaped film 1 and are arranged at an angle such that the scattered reflected light on the surface of the roll-shaped film 1 is incident on the image input device 3 (for example, a condition where the surface reflection at the end of winding is large). Is done. For example, as shown in FIG. 2, the second lighting device 2 </ b> B is a predetermined distance (for example, about 30 m) from the reference plane Z including the inspection point P of the roll film 1.
m to about 45 mm). In addition, the second lighting device 2B has an outer peripheral surface having a predetermined distance (for example, about 40 mm) from a reference axis Y passing through the center of the cross section of the roll-shaped film 1.
mm to about 60 mm).

The second illuminating device 2B is disposed on the opposite side of the first illuminating device 2A and the third illuminating device 2C with respect to the camera line of sight of the image input device 3. For example, as shown in FIG. 3, the second lighting device 2 </ b> B is disposed so as to be within a third predetermined angle range (for example, approximately −18 ° ± 10 °) with respect to the camera line of sight. In particular, it is preferable to arrange them so as to be within the third set angle range (for example, about −18 ° ± 5 °).

As described above, the light from the second illumination device 2B is diffused as a diffused light to randomly irradiate a wide area of the surface of the roll-shaped film 1 so that the second light from the second illumination device 2B is irradiated with the roll-shaped film 1 The scattered reflected light is reflected by the image input device 3 at the winding end portion of the surface of the roll-shaped film 1 so that the brightness at the winding end portion of the roll film 1 is prevented from lowering (that is, the original image becomes black). .

Since the diffused light randomly irradiates a wide area of the surface of the roll-shaped film 1, multiple reflections occur due to bubbles, wrinkles, etc. near the surface of the roll-shaped film 1. 1 foreign matter 50
Although the SN ratio (S / N) of F may decrease, in the present embodiment, since the arrangement of the lighting device is considered, the S / N of the foreign matter 50F of the roll-shaped film 1 decreases. There is no end.

The third lighting device 2C is provided between the first lighting device 2A and the second lighting device 2B (that is, between the first lighting device 2A and the image input device 3, or between the image input device 3 and the second lighting device). 2B), and the third light is applied to the entire surface in the width direction of the roll-shaped film 1 so as to suppress the detection of a pseudo defect due to the in-film cavity (bubbles, gap) 50H inside the roll-shaped film 1. Irradiation. This third lighting device 2
C mainly increases the amount of light incident on the inside of the roll-shaped film 1 and increases the brightness of the in-film cavity (bubbles, gaps) 50H inside the roll-shaped film 1 (that is, whitens the original image). It has a function.

For this reason, the third lighting device 2C operates so that light (third light) reaches the inside of the roll-shaped film 1.
The strength (light quantity,
It is preferable to use a large amount of illumination such as an aperture type fluorescent lamp (having a larger light amount and higher directivity than a normal fluorescent lamp), a transmission light, or the like, which can be irradiated with light having high directivity. The third illumination device 2C may use a diffuse illumination system, for example, a normal fluorescent lamp, fiber illumination, or the like.

The third illuminating device 2C includes, for example, a straight tube fluorescent lamp (aperture type fluorescent lamp or a normal fluorescent lamp) or the like so as to obtain a good strip-shaped reflection image parallel to the roll film 1. It is preferable to use a light having a length such as a transmission light or a halogen fiber lamp and to dispose it above the roll-shaped film 1 so as to extend in the roll width direction of the roll-shaped film 1.

The third illuminating device 2C thus configured
Is disposed as close to the roll film 1 as possible.
In particular, it is desirable that the distance between the roll film 1 and the third lighting device 2C be as short as possible between the roll film 1 and the first lighting device 2A. Thereby, the S / N of the foreign matter 50F of the roll-shaped film 1 can be improved.

For example, as shown in FIG. 2, the third lighting device 2C is disposed at a position separated from the outer peripheral surface of the roll film 1 by a predetermined distance (for example, about 70 mm to 80 mm). The third lighting device 2C is disposed at a position separated by a predetermined distance (for example, about 5 mm) from a reference axis Y passing through the center of the cross section of the roll-shaped film 1. As described above, by providing the third lighting device 2C in addition to the first lighting device 2A, if the amount of light incident on the inside of the roll film 1 is increased, the foreign matter 50F inside the roll film 1 can be increased.
(Ie, the original image becomes black), and the difference in density from the normal portion can be emphasized, but the brightness of the film cavity (bubbles, gaps) 50H of the roll film 1 is also low. Therefore, it is difficult to distinguish the foreign matter 50F inside the roll-shaped film 1 from the in-film cavity (bubbles, gaps) 50H of the roll-shaped film 1 or the like.

Therefore, the irradiation angle of the third lighting device 2C is
By changing the irradiation angle of the first illuminating device 2A, a cavity (bubble, gap) 50 in the film inside the roll-shaped film 1 can be obtained.
H causes multiple reflections, thereby suppressing a decrease in the luminance of the cavity (bubbles, gaps) 50H in the film (ie, the darkening of the original image). Here, the third illuminating device 2C is configured to prevent the specularly reflected light of the third light from the third illuminating device 2C on the surface of the roll-shaped film 1 from being incident on the image input device 3 while the first illuminating device 2A It is arranged at a position as close as possible to the camera line of sight between the second lighting device 2B.

For example, as shown in FIG. 3, the third lighting device 2C is disposed so as to be within a third predetermined angle range (for example, approximately ± 13 ° ± 10 °) with respect to the camera line of sight. In particular, the third set angle range (for example, about ± 13 ° ± 5
°). Also, the third
The lighting device 2C includes a third lighting device 2C as shown in FIG.
A tangent line connecting the center of the roll and the outer peripheral surface of the roll-shaped film 1;
It is preferable to arrange the roll-shaped film 1 such that the angle with respect to the reference axis Y passing through the center of the cross section of the roll-shaped film 1 is a predetermined angle (for example, about 31 °).

As described above, the lighting devices 2A, 2B, and 2C can solve the above contradictory problems, and can improve the S / N of hair, which is one of the most difficult foreign substances, It can be. That is, as viewed from the image input device 3, the three-light illumination by the illumination devices 2A, 2B, and 2C is performed by the first illumination device 2A and the third illumination device 2 having high directivity.
By using C to increase the amount of light incident on the roll-shaped film 1 and changing these irradiation angles, the film cavity (bubbles, gaps) in the roll-shaped film 1 is changed.
At 50H, multiple reflections occur, and the film cavity (bubbles,
(Gap) Prevents the luminance of 50H from lowering (the original image is darkened), and further arranges the second lighting device 2B on the opposite side of the first lighting device 2A with respect to the camera line of sight, and rolls it with diffused light. The end 50G of the winding of the film 1 is prevented from being darkened. Thus, according to the present optical system, the S / N of the hair, which is one of the most difficult foreign substances, can be improved.

The image input device (image sensor) 3 captures a reflection image of the entire surface of the roll film 1 in the roll width direction (inspection area) irradiated by the illumination device 2, and inputs this image data to the image processing device 4. For example, a CCD image sensor (CCD area sensor, CCD
A solid-state imaging camera (CCD camera, imaging device) using a line sensor) is used. Although a CCD image sensor is used here, another line sensor or area sensor may be used. Particularly, a line sensor is preferable.

As shown in FIG. 2, the image input device 3 is fixedly disposed at a position separated from the inspection point P on the outer peripheral surface of the roll film 1 by a predetermined distance (for example, about 500 mm to about 950 mm). It is desirable. The image input device 3 is arranged such that a distance from a camera center to a reference axis (actually, a reference plane) Y passing through the center of the cross section of the roll film 1 is a set distance (for example, about 70 mm to about 160 mm). desirable.

The image input device 3 is disposed on the opposite side of the first illumination device 2A with respect to the reference axis Y. For example, it is desirable that the image input device 3 be disposed at a predetermined angle (about 5 ° to about 15 °) with respect to the reference axis Y about the inspection point P. Thus, a belt-like reflection image of the inspection area of the roll-shaped film 1 is captured.
The arrangement of the optical system is not limited to this, and it is desirable that the illumination devices 2A, 2B, and 2C be as close as possible to the inspection point P of the roll-shaped film 1 and irradiate light efficiently. Will be separated by a predetermined distance so as not to enter the field of view of the image input device 3, and will be separated from the roll film 1 by a distance as in the present embodiment. In addition, it is easier to obtain a good image by bringing the image input device 3 closer to the inspection point P of the roll-shaped film 1, but since the focal length and the imaging range are also limited, in practice, an appropriate image can be obtained from the roll-shaped film 1. Distance (distance suitable for detection resolution)
Just let them go.

The image input device 3 sequentially captures the belt-shaped reflection images on the outer peripheral surface of the roll-shaped film 1 while rotating the roll-shaped film 1 so as to capture the reflection image of the entire circumference of the roll-shaped film 1. Has become. The image processing device (data processing unit) 4 processes the image data input from the image input device 3 and detects the foreign matter 50F inside the roll film 1 as a defect.

As shown in FIG. 1, the image processing device 4 includes an eroding processing unit 10, a density histogram processing unit 11, a base image calculation unit 12, a corrected image calculation unit 13, a binarization processing unit 14, Labeling processing unit 15 and defect determination unit 1
6 is provided. The image processing device 4 captures, as an original image, an image of one roll of the outer peripheral surface of the roll-shaped film 1 (the entire outer peripheral surface) which is sequentially captured by the image input device 3, and performs an eroding process on the original image. Is performed, the image data of the original image that has been subjected to the eload processing is reduced, and then image processing described later is performed.

For this reason, in this embodiment, an eroding processing section 10 is provided. The eroding processing section (shrinkage processing section, erosion processing section) 10 performs an eroding process on the image data (original image) on the outer peripheral surface of the roll-shaped film 1 sequentially taken in by the image input device 3 and performs an eroding process. The corrected original image is output to the density histogram processing unit 11 and the corrected image calculation unit 13.

Here, the eroding process means that the minimum value of the density value (luminance value) within an arbitrary processing data range is determined for the image data of the outer peripheral surface of the roll film 1 sequentially taken in by the image input device 3. This is a process in which the minimum value is obtained and stored as a density value (luminance value) at a predetermined position within the processing data range, and this is output as output data. This processing is repeatedly performed for each of the processing data ranges, and is performed for all the image data on the outer peripheral surface of the roll-shaped film 1 sequentially taken in by the image input device 3. The eroding process is a kind of morphological process, and is also called a shrinking process and an eroding process.

Here, as shown in FIG. 5, the eroding processing section 10 divides an arbitrary processing data range into a plurality of small areas in a matrix, for example, by vertically and horizontally dividing the area into nine small areas (vertical 3.times. 5), the minimum value of the density values (luminance values) of these nine areas is obtained, and this minimum value is stored, for example, in a position indicated by x in FIG. The data is output to the histogram processing unit 11 and the corrected image calculation unit 13. This is also referred to as 3 × 3 eload processing.

For example, when the processing data range is 9 pixels of 3 pixels vertically and horizontally, the density value (luminance value) of these 9 pixels
Is obtained, and this minimum value is stored as the density value (luminance value) of the pixel at the center position among the nine pixels, and this is used as output data. When such image data is processed by the image processing device 4, it is necessary to reduce the image data captured by the image input device 3.
To prevent the loss of the image data of the defect portion caused by the foreign matter 50F, that is, the black defect portion appearing as a black defect (black defect) in the image captured by the image input device 3,
This is to prevent the image data from deteriorating.

The original image read into the image processing device 4 as described above has a value corresponding to the intensity of the light emitted from the illumination device 2, the sensitivity of the image input device 3, and the like.
Normally, the brightness value of a normal portion other than the defective portion does not become a constant value. For this reason, the luminance of the defective part due to the foreign matter 50F is affected by the luminance of the normal part, and it is difficult to absolutely evaluate the luminance of the defective part, and it is difficult to detect a defect based on the luminance of the defective part.

For this reason, in the present embodiment, the processing and calculation by the density histogram processing unit 11, the base image calculation unit 12, and the correction image calculation unit 13 are performed. The density histogram processing unit (density frequency distribution calculation unit) 11
An original image (e.g., 5000 width × 5000 lines, 5000 lines) which is captured by the image input device 3 and subjected to the eload processing.
The density histogram processing is performed on (pixels × 5000 pixels). Then, the obtained density histogram information is output to the base image calculation unit 12.

Here, the density histogram processing unit 11
Is designed to divide an original image subjected to the eload processing into a base density information area, and obtain a density histogram (density frequency distribution) for image data of each of the divided areas. For example, the base density information area is an area of 20 pixels in the X-axis direction and 100 pixels in the Y-axis direction. When the original image is 5000 × 5000 pixels, 250 × 5
It is divided into 0 base density information areas.

Here, the reason that the area width of the base density information area is different between the X-axis direction and the Y-axis direction is to support shading in the camera width direction. Also,
The reason why the base density information area is set to 20 pixels × 100 pixels is that the size of a defect due to the foreign matter 50F is assumed to be, for example, about 5 pixels to about 100 pixels.

The density histogram obtained by the density histogram processing section 11 is, for example, as shown in FIGS. That is, in the density histogram in the region of the normal portion (base portion) of the roll-shaped film 1, as shown in FIG. 7, only the frequency (the number of pixels) of the density value (luminance value) of the base portion of the roll-shaped film 1 is high. On the other hand, the defect caused by the foreign matter 50F inside the roll-shaped film 1 and the winding end 50 on the surface of the roll-shaped film 1
As shown in FIG. 6, the density histogram in a region where a pseudo defect exists, such as G or a cavity (bubbles, gaps) 50H in the film inside the roll-shaped film 1, shows the density value (luminance) of the base portion of the roll-shaped film 1. Value) (the number of pixels) increases, and the frequency of the density value on the side where the density value (luminance value) is higher than the density value (luminance value) of the base portion (that is, the original image becomes black) also increases. .

The base image calculating section 12 calculates a base image based on the density histogram obtained for each base density information area by the density histogram processing section 11. Then, the calculated base image information is output to the corrected image calculation unit 13. Here, the base image is considered to be an image when it is assumed that there are no defects due to the foreign matter 50F of the roll-shaped film 1 and no false defects such as the end 50G of winding of the roll-shaped film 1 and the cavities (bubbles, gaps) 50H in the film. be able to.

The base image calculating section 12 calculates the minimum value (minimum density value) of the density histogram, the maximum value (maximum density value) of the density histogram, and the average value (average density value) of the density histogram. The base image is calculated based on the value of. Here, the minimum value of the density histogram is a density value (density level) at a position where the frequency (the number of pixels) of the density histogram rapidly increases.
It is. For the minimum value of the density histogram, the density histogram is searched in ascending order, and the point where the frequency first exceeds the threshold value is calculated as the minimum value (min). The density histogram may be searched in ascending order, and the point at which the frequency greatly increases by a predetermined value or more first may be calculated as the minimum value. This minimum value is indicated by the density value A in FIGS.

The maximum value of the density histogram is a density value at a position where the frequency (the number of pixels) of the density histogram sharply decreases. For the maximum value of the density histogram, the density histogram is searched in descending order, and a point whose frequency first exceeds the threshold value is calculated as the maximum value (max). Note that the density histogram may be searched in descending order, and a point at which the frequency first increases greatly by a predetermined value or more may be calculated as the maximum value. This maximum value is indicated by the density value B in FIGS.

The average value of the density histogram is the average density value of the density histogram, which is the average density value of the original image subjected to the eload processing. This average density value (average value) is indicated by a density value C in FIGS. Next, the base image calculation unit 12 calculates the variance of the density histogram. And if the variance of this density histogram is large,
Whether the value is smaller is determined based on whether a value obtained by subtracting the average density value from the maximum value (max) of the density histogram is larger than a threshold value (th1). This is represented by the following equation (1).

Maximum value−Average density value> Threshold value (1) If the result of this determination is that the variance of the density histogram is large, the minimum value (min) of the density histogram described above is used as the density value of the base image. Is used. Here, the case where the variance of the density histogram is large means, for example, a defective portion due to foreign matter 50F inside the roll-shaped film 1, the end of winding 50G of the roll-shaped film 1, the cavity (bubbles, gaps) 50H in the film of the roll-shaped film 1. The density value of the base image in this case is calculated as a value obtained by subtracting the variance coefficient from the minimum value of the density histogram. This is represented by the following equation (2).

The density value of the base image = minimum value−dispersion coefficient (2) Here, the dispersion coefficient is a coefficient corresponding to the degree of dispersion of the density histogram, and is represented by, for example, the following equation (3). . (Maximum value−minimum value) / 2 (3) On the other hand, when the variance of the density histogram is small, the average density value of the above density histogram is used as the density value of the base image.

Here, the case where the variance of the density histogram is small is, for example, a normal portion of the roll film 1, and the density value of the base image in this case is the average density value of the density histogram. This is represented by the following equation (4). Density value of base image = average value (4) Thereby, for example, foreign matter 5 inside roll-shaped film 1
When 0F is detected, the detection signal is disturbed by the end of winding 50G of the roll-shaped film 1 to cause darkening, wrinkles in a normal portion (non-defective portion) and darkness after suction are caused, and these portions and foreign matter are removed. It is difficult to distinguish the defective part from the defective part by the 50F, and therefore, when performing image processing on the original image taken in from the image input device 3, it is possible to prevent that much processing time is required particularly for creating a base image. it can.

The corrected image calculating section 13 calculates the difference between the original image and the base image which have been taken in by the image input device 3 and have been subjected to the eroding process, and uses the difference as a corrected image. That is, the corrected image calculation unit 13 subtracts the density value of the corresponding pixel of the base image from the density value of each pixel of the original image subjected to the eload processing (subtraction processing), and corrects the density value obtained as a result of the subtraction. This is the density value of each pixel of the image. Then, the calculated correction image information is output to the binarization processing unit 14.

In this case, the density value of the base image is calculated as described above, and the corrected image is calculated based on the density value. This is because the base line for the X-axis density profile of the original image is calculated. This means that a corrected density profile is calculated. That is, the above-described calculation of the density value of the base image can be considered to be the calculation of the baseline with respect to the X-axis density profile of the original image, and the calculation of the above-described density value of the corrected image is considered to be the calculation of the corrected density profile. be able to.

In this case, first, for the original image (for example, 5000 width × 5000 lines) which is taken in by the image input device 3 and subjected to the eload processing, the origin O is set to the upper left corner of the original image.
Then, a density profile (original density profile) of the X axis taken in the right direction is calculated. This function is called an original density profile calculation unit. Note that the X-axis concentration profile includes a portion including a defect portion due to the foreign substance 50F.

Note that the X-axis density profile of the original image is
In FIG. 8, it becomes as shown by the solid line A. In FIG. 8, a portion indicated by a symbol X is, for example, a foreign material 5 inside the roll-shaped film 1.
This is a defective portion due to OF. Further, the baseline of the X-axis density profile of the original image is calculated as the X-axis density profile of the base image calculated as described above. This function is called a baseline calculation unit. The method of calculating the X-axis density profile of the base image is the same as that described above. The base line of the X-axis density profile of the original image, that is, the X-axis density profile of the base image is as shown by a broken line B in FIG.

Then, the corrected density profile is calculated by subtracting the base line (broken line B in FIG. 8) from the original density profile (solid line A in FIG. 8) thus calculated. This function is called a correction density profile calculation unit. This corrected density profile is as shown by the one-dot chain line C in FIG. The binarization processing unit 14 binarizes the corrected image by comparing the density value of each pixel of the corrected image calculated by the corrected image calculation unit 13 with a threshold value. Then, the binarized image information obtained by this processing is output to the labeling processing unit 15.

For example, the binarization processing unit 14 sets the density value to 1 (hereinafter referred to as a defect candidate point and a defect) when the density value of a pixel constituting the corrected image is equal to or larger than the threshold value, If it is smaller than 0, the density value is set to 0. The labeling processing unit 15 assigns one label to the same connected component of the binarized image subjected to the binarization processing by the binarization processing unit 14, and aggregates adjacent defect candidate points to form an aggregate. This is to perform a labeling process. In addition, since an aggregate is obtained by converting defect candidate points into particles, these are referred to as defect particles. Then, the labeling processing section 15 outputs the label image subjected to the labeling processing to the defect determination section 16.

The defect discriminating section 16 includes a labeling processing section 15
Is to determine whether there is a defect due to the foreign matter 50F inside the roll-shaped film 1 for each defective particle based on the label image subjected to the labeling process. That is, the defect determining unit 16 first calculates the area (number of pixels) and the density value (luminance value) of the defective particles in the label image subjected to the labeling processing by the labeling processing unit 15, and calculates the area and density of these defective particles. Based on the value, it is determined whether or not there is a defect due to the foreign matter 50F inside the roll-shaped film 1.

Here, the area of the defective particle is calculated by integrating the number of pixels of the defective particle to which the same label is assigned in the label image. In addition, the density value of the defective particle is defined as the density value of the pixel of the original image (or the corrected image) corresponding to these pixels, which is the largest among the pixels constituting the defective particle, as the representative density value of the defective particle. It is to be calculated. The area and the density value of the defective particle calculated in this way are stored in a storage device.

Then, the defect judgment based on the area and the density value of the defective particle is judged as acceptable or unacceptable by using a judgment table associating the area, the density value (brightness value) and the judgment value as shown in FIG.
Hold, reject judgment. In addition, when there is a defect due to the foreign matter 50F inside the roll-shaped film 1, it is rejected. Here, as shown in FIG. 9, the determination table has an area (number of pixels) on the horizontal axis and a density value (luminance value) on the vertical axis.
The judgment value 0 is output when the area and the density value of the defective particles fall into the acceptable region, the judgment value 1 is outputted when the defect particle enters the reserved region, and the judgment value 2 when the defect particle enters the rejected region.
Is output.

Further, in this embodiment, even if it is determined that there is no defect due to the foreign matter 50F inside the roll-shaped film 1, as shown in FIG. By using the number table in which the judgment value indicating the pass or hold and the count number are associated with each other, the number of defective particles passed or held in the above-described judgment table is counted, and the pass or fail of the roll film 1 is determined. The determination of suspension or rejection is made.

Here, as shown in FIG. 10, in the number table, the horizontal axis represents the judgment value indicating pass / hold (pass 0, hold 1), and the vertical axis represents the count number. And, when the number of the pass judgment value 0 is within the count number 10 and the number of the hold judgment value 1 is the count number 9 or less, it is judged as pass,
The number of pass judgment values 0 is larger than the count number 10 and 15
In the following cases, the determination is suspended, and when the number of pass determination values 0 is greater than the count number 15 and when the number of suspension determination values 1 is greater than the count number 9, it is determined to be rejected.

In this case, the defect is determined based on the area and the density value of the defect particle. However, as shown in FIG. 11, the area of the defect particle, the density value (luminance value) and the number of the defect particles (luminance value) are determined. The presence / absence of a defect in the roll-shaped film 1 and the degree of the defect may be determined by using a three-dimensional determination table in which the number of defects is associated, and evaluation such as pass, reject, and suspension may be performed.

The image processing device 4 creates display data for displaying the result of the determination on the display device 5. That is, the image processing apparatus 4 displays data (for example, 500 width × 50 lines) of reduced data (for example, 2500 width × 2500 lines) of the original image indicating the result of the determination by the defect determination unit 16.
0 line). And
The display data is output to the display device 5. The image processing device 4 stores the result of the determination by the defect determining unit 16 as data in a storage device.

The display device 5 displays display data in accordance with the above-described determination result. For example, when a defect is detected by the image processing device 4, the presence or absence, position, degree, etc. of the defect are monitored. Is displayed on the screen. For example, an original image is displayed on the display device 5, and a defect position in the original image is indicated by an arrow. Since the roll-shaped film defect detection device according to an embodiment of the present invention is configured as described above, a defect detection method using this device is as follows.

That is, as shown in FIG.
At 10, first, while rotating the roll-shaped film 1,
The image input device 3 sequentially takes in the reflection image (image data) of the roll-shaped film 1 and reads it as an image (original image) of the entire outer peripheral surface of the roll-shaped film 1, and a black defect (black defect) in the original image. In order to prevent the black defect data of the defective portion from deteriorating due to the foreign matter 50F appearing as the above, an eroding process (3 × 3 eroding process) is performed. In step S20,
In order to increase the data processing speed, the read image data is reduced (for example, reduced from 5000 width × 5000 lines to 2500 width × 2500 lines), and the process proceeds to step S30.

In step S30, the density histogram processing section 11 divides the read original image into base density information areas (for example, 20 pixels × 100 pixels). Here, since the original image is 2500 pixels × 2500 pixels, a 125 × 25 area is created. Then, the density histogram processing is performed on the entire area of the original image for each base density information area to obtain a density histogram.

Next, in step S40, the base image calculation unit 12 calculates the average density value of the density histogram based on the density histogram obtained for each base density information area for the entire area of the original image. Minimum value (the density value at the point where the frequency of the density histogram suddenly increases),
The maximum value (the density value at the point where the frequency of the density histogram sharply decreases) is obtained. Further, the base image calculation unit 12 calculates the density variance of the density histogram for each base density information area. When the density variance is small, the average density value is used as the density value of the base image, and when the density variance is large, the density value of the base image is calculated by using the minimum value as the density value of the base image. Calculate a base image for the original image.

Next, in step S50, the corrected image calculating section 13 calculates a corrected image by taking the difference between the read original image and the base image. That is, the corrected image calculation unit 13
Subtracts the density value of the corresponding pixel of the base image from the density value of each pixel of the read original image, calculates a corrected image as a density value of the corrected image as a density value of the corrected image, and Proceed to S60.

In step S60, the binarization processing section 14
Performs a binarization process by comparing the density value of each pixel of the corrected image with a threshold value. That is, the binarization processing unit 14 sets the density value of the pixel constituting the corrected image to 1 if the density value is equal to or higher than the threshold value (a defect candidate point), and if the density value is smaller than the threshold value. The binarization processing is performed by setting the density value of the pixel to 0, and further, in step S70, the labeling processing unit 15 aggregates the defect candidate points of the binarized image into an aggregate to form an aggregate. 1 for the same connected component
One label is assigned, and a labeling process is performed in which adjacent defect candidate points are aggregated to form an aggregate (defect particle), and the process proceeds to step S80.

In step S80, first, the defect determining section 16
Calculates the area and density value of the defective particles based on the label image subjected to the labeling process, and calculates the area and the density of these defective particles.
Based on the density values, a pass, hold, or reject judgment is made using a judgment table in which areas, density values (luminance values), and judgment values are associated as shown in FIG. The presence or absence of a defect due to the foreign matter 50F is determined. Further, by using the number table in which the determination values indicating pass / hold and the count number as shown in FIG. 10 are associated with each other, the number of defective particles passed / held in the above-described determination table is counted. Pass, hold, roll film 1
Make a rejection decision. Note that the defect determination unit 16 stores the determination result as data in a storage device.

Next, in step S90, display data for displaying the result of this determination on the display device 5 is created. That is, the defect determination unit 16 compresses and converts the reduced data (for example, 2500 width × 2500 lines) of the original image indicating the determination result into data (for example, 500 width × 500 lines) of a size that can be displayed by the display device 5. Then, in step S100, the defect determination unit 16 outputs the display data thus created to the display device 5.
Thus, when the roll-shaped film 1 has a defect due to the foreign matter 50 </ b> F, the determination result is displayed on the display device 5.

Therefore, according to the defect detecting device and the defect detecting method for the rolled film according to the embodiment of the present invention, the rolls are controlled by the arrangement of the illuminating devices 2A, 2B, 2C and the image input device 3 constituting the optical system. Detection of a pseudo defect on the surface of the roll film 1 and a pseudo defect inside the roll film 1 can be suppressed, the defects inside the roll film 1 can be made more prominent, and the defect can be captured by the image input device 3. The base image of the original image that has been subjected to the eroding process is calculated, and based on the calculated base image, a corrected image in which the defect inside the roll-shaped film 1 is emphasized is calculated. There is an advantage that the defect can be accurately and accurately detected without erroneously detecting a defect inside the film-shaped film 1.

In particular, the first illumination device 2 constituting the optical system
A, the arrangement and the irradiation angle of the second lighting device 2B and the third lighting device 2C are adjusted to optimal ones (that is, the irradiation light from the optical system is adjusted), and the first lighting device 2A and the second lighting device are adjusted. 2
B, by optimizing the arrangement of the image input device 3 with respect to the third lighting device 2C, the winding end 50G of the roll-shaped film 1 as a pseudo defect on the surface of the roll-shaped film 1 and the inside of the roll-shaped film 1 The detection of the void 50H in the film of the roll-shaped film 1 as a pseudo-defect can be suppressed, and the defect caused by the foreign matter 50F inside the roll-shaped film 1 can be emphasized. Another advantage is that a defect due to foreign matter 50F inside the roll-shaped film 1 can be accurately and accurately detected without erroneously detecting a defect caused by the 50F and a pseudo-defect on the surface or inside of the roll-shaped film 1. is there.

Further, the base image calculating section 12 calculates a base image based on the density histogram of the original image which has been taken in by the image input device 3 and has been subjected to the eroding processing. Since the corrected image in which the defect caused by the foreign matter 50F of the film 1 is emphasized is calculated, and the defect determination unit 16 detects the defect of the roll-shaped film 1 based on the corrected image, the defect caused by the foreign matter 50F of the roll-shaped film 1 is detected. There is also an advantage that defect detection can be performed accurately and accurately without erroneous detection.

Since the defect discriminating section 16 discriminates the presence or absence of a defect due to the foreign matter 50F inside the roll-shaped film 1 based on the processing result of the labeling processing section 15, the defect due to the foreign matter inside the roll-shaped film 1 is determined. There is also an advantage that defect detection can be performed more accurately and more accurately without erroneous detection. Further, when the variance of the density histogram is small, the base image calculation unit 12 calculates the density value of the base image based on the average density value of the density histogram obtained by the density histogram processing unit 11, and when the variance of the density histogram is large, Since the density value of the base image is calculated based on the minimum density value of the density histogram obtained by the density histogram processing unit 11, there is an advantage that the calculation of the density value of the base image by the base image calculation unit 12 becomes easy.

In the above embodiment, each of the first lighting device 2A, the second lighting device 2B, and the third lighting device 2C is constituted by one lighting device. However, the present invention is not limited to this. The first lighting device 2A, the second lighting device 2B, and the third lighting device 2C may be configured by two or more lighting devices. Further, in the above-described embodiment, both the adjustment of the optical system and the image processing are optimized to detect a defect due to a foreign substance generated inside the roll-shaped film 1. Only one of the optimal adjustment of the optical system and the optimal image processing among the modes may be performed.

[0101]

As described above in detail, according to the method for detecting a defect on a roll-shaped film according to the first aspect of the present invention, the pseudo-defect on the surface of the roll-shaped film is adjusted by adjusting the irradiation light by the optical system. And the detection of pseudo defects inside the roll-shaped film can be suppressed, and the defects inside the roll-shaped film can be emphasized. There is an advantage that a defect inside the roll film can be detected accurately and accurately without erroneously detecting a defect.

According to the roll defect film detecting apparatus of the present invention, the arrangement and the irradiation angle of the first illuminating device, the second illuminating device and the third illuminating device constituting the optical system, and the first and second illuminating devices, By arranging the image input device with respect to the first lighting device, the second lighting device, and the third lighting device, etc., it is possible to suppress detection of a pseudo defect on the surface of the roll film or a pseudo defect inside the roll film, and Since defects inside the film can be emphasized, the defects in the roll film can be accurately and accurately detected without erroneously detecting the defects inside the roll film and the pseudo defects inside or outside the roll film. There is an advantage that an internal defect can be detected.

According to the roll film defect detecting apparatus of the present invention, the base image is calculated based on the density histogram of the original image captured by the image input device, and the roll film is calculated based on the base image. Compensation image that emphasizes the defect of is calculated, and the defect of the roll-shaped film is detected based on the corrected image, so that the defect generated on the surface of the roll-shaped film is not erroneously detected, accurately, and accurately. There is an advantage that defect detection can be performed.

According to the roll film defect detecting apparatus of the present invention, the internal defects of the roll film can be highlighted by the arrangement of the illumination devices and image input devices constituting the optical system. The base image of the original image captured by the image input device is calculated, and a corrected image in which defects inside the roll film are emphasized is calculated based on the calculated base image. Therefore, there is an advantage that the defect can be detected more accurately and more accurately without erroneously detecting a defect inside the roll-shaped film.

According to the roll-orientation film defect detecting device of the present invention, the original image picked up by the image input device is subjected to an eroding process, and further, the defect discriminating unit is provided with a processing result by the labeling processing unit. Is used to determine the presence or absence of a defect inside the roll-shaped film based on the above, so that the defect can be detected more accurately and more accurately without erroneously detecting a defect due to a foreign substance inside the roll-shaped film. There is.

According to the roll film defect detecting apparatus of the present invention, when the variance of the density histogram is small, the base image calculation section determines the average density value of the density histogram obtained by the density histogram processing section. To calculate the density value of the base image, and when the variance of the density histogram is large, the density value of the base image is calculated from the minimum density value of the density histogram obtained by the density histogram processing unit. There is an advantage that the calculation of the density value becomes easy.

According to the roll film defect detecting apparatus of the present invention, the end of winding of the roll film as a pseudo defect on the surface of the roll film and the roll as a pseudo defect inside the roll film are provided. There is an advantage that a defect due to a foreign substance inside the roll-shaped film can be accurately and accurately detected without erroneously detecting a cavity in the film of the roll-shaped film as a defect.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an image processing apparatus provided in a roll film defect detecting apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an overall configuration of a roll-shaped film defect detection apparatus according to an embodiment of the present invention, and is a diagram illustrating the roll-shaped film in a side view.

FIG. 3 is a schematic diagram for explaining an arrangement of an illumination device and an image input device of the roll-shaped film defect detection device according to one embodiment of the present invention, and is a diagram showing the roll-shaped film in a side view.

FIG. 4 is a schematic diagram for explaining a defect (or a pseudo defect) detected by the roll film defect detection device according to one embodiment of the present invention, wherein (A) is a band-shaped wrinkle,
(B) is a winding bump, (C) is a wound, (D) is a vertical wrinkle,
(E) is an oblique wrinkle, (F) is a foreign substance, a cavity in a film,
(G) indicates the end of winding (pseudo defect), and (A), (C),
(F) is a schematic sectional view, (B), (D), (E), (G) is a schematic front view.

FIG. 5 is a diagram for explaining an eroding process in the roll film defect detecting apparatus according to the embodiment of the present invention.

FIG. 6 is a diagram showing a density histogram obtained by the roll film defect detection apparatus according to one embodiment of the present invention, showing a density histogram when there is a defect due to foreign matter or a pseudo defect such as end of winding. It is.

FIG. 7 is a diagram showing a density histogram obtained by the roll film defect detection apparatus according to the embodiment of the present invention, and shows a density histogram of a normal portion.

FIG. 8 is a diagram showing a density profile, a baseline, and a corrected density profile of an original image calculated by the roll film defect detection apparatus according to one embodiment of the present invention.

FIG. 9 is a diagram for explaining a determination table used for defect determination by the roll film defect detection apparatus according to one embodiment of the present invention.

FIG. 10 is a diagram for explaining a number table used for defect determination by the roll film defect detection apparatus according to one embodiment of the present invention.

FIG. 11 is a view for explaining a three-dimensional determination table used for defect determination by the roll film defect detection apparatus according to one embodiment of the present invention.

FIG. 12 is a flowchart illustrating a defect detection method by the roll film defect detection apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 roll film (object to be inspected) 2 lighting device 2A first lighting device 2B second lighting device 2C third lighting device 3 image input device (imaging device, CCD camera) 4 image processing device (data processing device) 5 display Apparatus 10 Eload processing unit 11 Density histogram processing unit 12 Base image calculation unit 13 Correction image calculation unit 14 Binarization processing unit 15 Labeling processing unit 16 Defect determination unit 50F Foreign matter 50G End of winding 50H In-film cavity (bubbles, gaps)

Claims (7)

[Claims] 1. A method of irradiating one or two or more first lights on the entire width direction of a roll-shaped film so as to irradiate a defect portion inside the roll-shaped film. One or two or more second lights are applied to the entire width direction of the roll-shaped film so as to suppress the detection, and the first light and the second light are irradiated so as to suppress the detection of a pseudo defect inside the roll-shaped film. Irradiating one or more third lights to the entire width direction of the roll film from between the second light and the roll film irradiated by the first light, the second light and the third light A method for detecting a defect in a roll-shaped film, the method comprising: capturing a reflection image of the entire surface in the width direction of the roll-shaped film; and detecting presence or absence of a defect inside the roll-shaped film based on the captured image information. 2. An image input device that captures a reflection image of the entire width direction of the roll film illuminated by an illumination device, and an internal portion of the roll film based on image information captured by the image input device. An image processing device for detecting the presence or absence of a defect, wherein the illuminating device irradiates a defective portion inside the roll-shaped film with one or more first light beams across the entire width direction of the roll-shaped film. A first illuminating device that irradiates the image input device with the first illuminating device opposite to the first illuminating device with respect to the line of sight of the image input device, so that detection of a pseudo defect on the surface of the roll film can be suppressed. A second illuminator for irradiating one or more second lights to the entire width direction of the roll-shaped film; and a second illuminator disposed between the first illuminator and the second illuminator; Suppress detection of internal pseudo defects Characterized in that it is constituted by a third illumination device for irradiating the one or more third optical widthwise entire surface of the roll film in so that the defect detection apparatus of the rolled film. 3. An image input device for capturing a reflection image of the entire width direction of the roll film irradiated by the illumination device, and a defect inside the roll film based on image information captured by the image input device. An image processing device for detecting the presence or absence of the image, wherein the image processing device obtains a density histogram of an original image captured by the image input device, and a density histogram obtained by the density histogram processing unit. A base image calculation unit that obtains a base image from the base image; a corrected image calculation unit that obtains a corrected image from the difference between the original image and the base image; and a roll shape based on the corrected image calculated by the corrected image calculation unit. A defect detecting device for a roll-shaped film, comprising: a defect determining unit that determines whether or not there is a defect inside the film. 4. A first illuminating device for irradiating one or two or more first lights to an entire surface in a width direction of the roll-shaped film so that the illuminating device can illuminate a defective portion inside the roll-shaped film; The roll-type film is disposed on the opposite side of the first illuminating device with respect to the line of sight of the image input device, and is capable of suppressing detection of pseudo defects on the surface of the roll-like film in the width direction of the roll-like film. A second illuminating device for irradiating one or more second lights to the first and second illuminating devices; and a second illuminating device disposed between the first illuminating device and the second illuminating device to suppress detection of a pseudo defect inside the roll film. 4. The roll-shaped film according to claim 3, further comprising a third lighting device that irradiates one or more third lights to the entire width direction of the roll-shaped film so as to be able to perform the operation. Defect detection device. 5. An image processing apparatus comprising: an image processing device that performs an eload process on an original image captured by the image input device and outputs the processed image to the density histogram processing unit and the corrected image calculation unit; A binarization processing unit that binarizes the corrected image calculated by the unit; and a labeling processing unit that labels the binarized image obtained by the binarization processing unit. 5. The roll film defect detecting device according to claim 3, wherein the unit determines the presence or absence of a defect due to a foreign substance inside the roll film based on a processing result of the labeling processing unit. 6. When the variance of the density histogram is small, the base image calculation unit calculates a density value of the base image from an average density value of the density histogram obtained by the density histogram processing unit. 6. The method according to claim 3, wherein when the variance is large, a density value of the base image is calculated from a minimum density value of the density histogram obtained by the density histogram processing unit. Roll film defect detection device. 7. The pseudo defect on the surface of the roll film is caused by the end of winding of the roll film, and the pseudo defect inside the roll film is caused by a cavity in the film of the roll film. The roll-shaped image processing apparatus according to claim 2, wherein the image processing apparatus detects the presence or absence of a defect due to a foreign substance inside the roll-shaped film. Film defect detector.