JP2014038014A - Paper dust adhesion amount inspection method and paper dust adhesion amount inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper dust adhesion amount inspection method and a paper dust adhesion amount inspection device capable of precisely inspecting adhesion amount of paper dust adhered as particles on cut-planes of a flat paper of a lamination item including plural flat papers.SOLUTION: The paper dust adhesion amount inspection device takes images of flat paper cut-planes 1a-1d using imaging apparatuses 10-13 while illuminating flat paper cut-planes 1a-1d of a lamination item 1 with illumination light 24 and calculates an average brightness of the flat paper cut-planes from the images obtained by the imaging apparatuses 10-13. The paper dust adhesion amount inspection device detects a low brightness area where the brightness value is higher than the average brightness and the average brightness value is smaller than a preset threshold value and high brightness pixels neighboring at the light source-side of the illumination light from the images obtained by the imaging apparatuses. An area of paper dust adhered on the flat paper cut-plane is calculated based on the number of the detected high brightness pixels. The adhesion amount of the paper dust is inspected by comparing a value obtained by dividing the calculation value of the adhesion area by an area of the flat paper cut-plane 1a-1d with a reference value.

Description

  The present invention relates to a method for inspecting the amount of paper dust adhering to a flat paper cut section of a laminate composed of a large number of flat papers cut to a certain size, and a paper dust adhesion amount inspection device used in the method About.

In general, in a paper factory that manufactures printing paper, information paper, etc., when shipping flat paper obtained by cutting a rolled paper into a predetermined size as a product, a laminate made up of a large number of flat paper is used as a conveyor. It is then transported to a packaging machine, and the laminate transported to the packaging machine is packaged with wrapping paper or packaging film before being shipped. On the cut surface of the laminate made of this flat paper, dust generated at the time of cutting called paper dust adheres. The paper dust is divided into granular particles in which the dust of the fibers generated when the paper is cut adheres to the cut surface due to static electricity, and fluff that has been peeled off so that the paper fibers and the coating on the paper surface are peeled off. In either case, if a large amount of paper dust adheres to the flat paper cut section of the laminate, the paper dust will fall off in the printing machine or copier, adhere to the printing drum, etc., and cause defects such as printing defects. Therefore, it is necessary to inspect before the packaging of the laminate whether or not a large amount of paper dust is attached to the flat paper cut section of the laminate.
Conventionally, inspecting the amount of paper dust adhered, an inspector visually observes a flat paper cut section of the laminate to determine whether the amount of paper dust adhered is large. For this reason, the judgment criteria differ depending on the inspector, and the product may be judged as a good product despite being a defective product.

  As a method for inspecting a flat paper cut section of a laminate made up of a large number of flat papers, Patent Document 1 discloses that the flat surface of the laminate is substantially perpendicular to the lamination direction with respect to the flat paper cut section of the laminate. It was obtained by illuminating an illumination light beam from an oblique direction with respect to the paper cut section, and imaging the plane cut section of the laminate with a CCD camera from a direction substantially perpendicular to the flat paper cut section of the laminate. Image data is converted into numerical data, and by image processing, a part with a large density value that is assumed to be a grain or fluffy part and a part with a small density value that is assumed to be a shadow part of a grain or fluff are extracted and extracted. A technique for inspecting the quality of a plane paper cut section from the ratio between the number of pixels and the number of pixels in the entire image is described.

  Further, Patent Document 2 discloses a laminate from an illumination device arranged to form an angle of 60 ° to 120 ° with respect to the optical axis of an imaging device arranged to face a flat paper cut section of the laminate. A technology that evaluates the quality of a flat paper cut section by irradiating illumination light to the flat paper cut section of the paper, and capturing an image of the flat paper cut section of the laminate with an imaging device, and obtaining a contrast evaluation value of the evaluation target range Is described.

Japanese Patent No. 3531160 JP 2009-162579 A

  However, when the technique described in Patent Document 1 is applied to the paper powder adhesion amount inspection, the area of the high density value portion and the low density value area of the laminated paper cut section of the laminate is simply added up. Therefore, it is not possible to extract only paper dust by distinguishing the part where the density value has changed due to paper wrinkles (unevenness) etc. other than paper dust. There is. In addition, the area of the part where the density value of the shadow of paper dust is low changes greatly when the relationship between the angle of the illumination and the laminate of the flat paper changes. The angle relationship with the laminate must always be the same, but the flat paper laminate is large in size and heavy, so it is difficult to correct this when position fluctuations such as meandering occur. Is accompanied.

  On the other hand, the technique described in Patent Document 2 does not extract the paper dust that adheres to the flat paper cut section of the laminate and evaluates the amount of the paper dust. The amount of adhesion is determined based on the fact that the luminance value varies. In this case, paper dust abnormalities that occur in a wide range, such as paper clearance at the time of cutting that occurs due to poor clearance of the cutting blade that cuts the winding paper or sharpness of the blade, cause a slight amount of paper dust adhesion. However, in the case where paper dust generated during cutting flies in the air and adheres to the edge of the flat paper, it adheres as a grain to the cross section of the flat paper. Since the number is small, there is a possibility that the area of the portion where the luminance varies is extremely small, and it is determined that the amount of paper dust attached is small. Also, in this method, similarly to Patent Document 1, the area of the shadow portion of the paper powder, that is, the portion having a low density value, is not maintained unless the angle relationship between the illumination and the laminate of the flat paper is always kept the same. It will change and an accurate evaluation will not be obtained.

  The present invention has been made in view of the above-described problems, and accurately inspects the amount of paper powder adhering in the form of grains on a plane paper cut section of a laminate composed of a large number of flat papers. It is an object of the present invention to provide a paper dust adhesion amount inspection method and a paper dust adhesion amount inspection device that can perform the same.

  In order to solve the above-mentioned problems, the invention of claim 1 inspects the amount of paper dust adhering to the cross section of the flat paper cut surface of a laminate formed by laminating a large number of flat paper cut to a certain size. Illuminating illumination light at a predetermined angle with respect to the plane paper cutting section, and converting the plane paper cutting section into the plane paper cutting section. On the other hand, an image is picked up by an image pickup device at a predetermined angle, the average brightness of the plane paper cut section is calculated from the image obtained by the image pickup device, and the brightness value is lower than a set threshold value compared to the average brightness. A luminance area is detected from the image, and a high-luminance pixel adjacent to the low-luminance area on the light source side of the illumination light is detected from the image, the luminance value being higher than a set threshold value compared to the average luminance. Detect and detect the amount of paper dust adhering to the flat paper cut section from the number of pixels of the high brightness pixel. After calculating the Chakumenseki, characterized in that by comparing the value obtained by dividing the area of the flat-size paper cutting plane calculated values of the adhesion area with a reference value to check the adhesion amount of the paper powder.

The invention of claim 2 is the paper dust adhesion amount inspection method according to claim 1, wherein illumination light is applied to the flat paper cutting section of the laminate at an angle of 30 ° or less with respect to the flat paper cutting section. Irradiation is performed, and the flat paper cut section is imaged at an angle of 60 ° to 120 ° with respect to the flat paper cut section.
According to a third aspect of the present invention, in the paper dust adhesion amount inspection method according to the first or second aspect, an average luminance calculation area having a width of several pixels in a height direction and a horizontal direction of the flat paper cut section is provided. The average brightness of the slab-cut section is calculated by setting the pixels above and below each pixel of the image obtained by the imaging device, and the width of several pixels in the height direction and the lateral direction of the slab-cut section Is set to the left and right of each pixel of an image obtained by the imaging device, and the shadow generated by the presence of paper dust is captured by the illumination light.

  According to a fourth aspect of the present invention, there is provided an apparatus for inspecting the amount of paper powder adhering to a flat paper cut section of a laminate formed by laminating a large number of flat papers cut to a certain size, wherein the lamination A plurality of illuminating devices for irradiating illumination light onto a flat paper cut section of a product at a predetermined illumination angle with respect to the flat paper cut section, and the flat paper cut section of the laminate into the flat paper cut section On the other hand, a plurality of imaging devices that capture images at a predetermined imaging angle, a means for calculating an average luminance of the stencil cutting section from an image obtained by the imaging device, and a luminance value equal to or less than a threshold value set by the average luminance A low-luminance area of the image, and a high-luminance pixel having a luminance value higher than a threshold set by the average luminance and adjacent to the low-luminance area on the light source side of the illumination light. And means for detecting from the surface of the paper powder adhering to the cross section of the flat paper Means for calculating from the number of pixels the high luminance pixel, characterized in that the calculated value of the adhesion area and means for comparing with a reference value divided by the area of the flat-size paper cut surface.

  According to the first and fourth aspects of the present invention, the average brightness of the plane paper cut section is calculated from the image obtained by the imaging device, the brightness value is higher than the threshold value set by the average brightness, and the brightness value is higher than the average brightness. By detecting from the image the low-brightness area below the set threshold and the high-brightness pixels adjacent on the light source side of the illumination light, only the paper dust that adheres as particles to the flat paper cut section of the laminate It becomes possible to extract. Furthermore, the influence of the angle between the illumination and the laminate of the flat paper can be reduced by calculating the adhesion area of the paper dust adhering to the flat paper cutting section from the number of pixels of the high luminance pixels. Therefore, it is possible to accurately inspect the amount of paper powder adhering in the form of grains on the flat paper cut section of the laminate.

According to the invention of claim 2, it is possible to obtain an image having a large contrast between the portion where the paper dust is adhered and the portion where the paper dust is not adhered, and thereby to the flat paper cut section of the laminate. It is possible to more accurately inspect the amount of paper powder adhering as particles.
According to the invention of claim 3, it becomes possible to reduce the influence of uneven brightness of lighting and horizontal stripes (laminated stripes of flat paper) appearing on the plane paper cut section. It is possible to more accurately inspect the amount of paper powder adhering in the form of grains on the paper cutting section.

It is a top view which shows an example of the paper dust adhesion amount inspection apparatus used when implementing this invention. It is a figure which shows an example of the usage method of the paper dust adhesion amount inspection apparatus shown in FIG. It is a flowchart which shows an example in the case of test | inspecting by this invention whether the adhesion amount of the paper dust adhering as a grain to the flat paper cutting cross section of a laminated body exceeds a reference value. It is a figure which shows the average luminance calculation area set with respect to each pixel of the image obtained by the imaging device shown in FIG. It is a figure which shows the reflection direction of the illumination light irradiated to the paper powder of a flat paper cutting cross section. It is a figure which shows the reflection direction of the illumination light irradiated to the paper pain of a flat paper laminated body. It is a figure which shows the case where the illumination light is irradiated to the flat paper cutting cross section of the laminate at an angle larger than 30 ° with respect to the flat paper cutting cross section and the case where it is irradiated at an angle of 30 ° or less. It is a figure which shows the case where the flat paper cutting section of a laminated body is imaged with an angle smaller than 60 degrees with respect to a flat paper cutting section, and the case where it images with an angle larger than 120 degrees.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, an example of the paper dust adhesion amount inspection apparatus used when implementing this invention is shown. The paper dust adhesion amount inspection apparatus shown in FIG. 1 is a paper dust adhering in the form of grains on the flat paper cutting sections 1a to 1d of a laminate 1 made of a large number of flat papers obtained by cutting a web. The transfer table 3 and 4, the laminate delivery mechanism 5, the illumination devices 6 to 9, the imaging devices 10 to 13, the elevating mechanisms 14 to 17, and the width direction drive mechanisms 18 to 21 are provided. ing.
In addition, the flat paper cut sections 1a and 1b of the laminate 1 are flat paper cut sections (slit surfaces) cut by a slitter (not shown), and the flat paper cut sections 1c and 1d of the laminate 1 are cross sections (not shown). A flat paper cut section (cross knife surface) cut with a knife is shown.

When the flat paper cut section of the laminate 1 is a slit surface, a part of the flat paper cut section is inspected in the entire height direction. Moreover, when the flat paper cut section of the laminate 1 is a cross knife surface, the entire width direction is inspected at a certain height.
The conveyance table 3 conveys the laminate 1 placed on the conveyance pallet 2 and includes a number of conveyance rolls.
The laminate delivery mechanism 5 delivers the laminate 1 placed on the transport pallet 2 from the transport table 3 to the transport table 4, and the laminate 1 placed on the transport pallet 2 is indicated by an arrow in the figure. It is composed of a plurality of chain conveyors and the like that convey in the direction.

The transport table 4 transports the stack 1 placed on the transport pallet 2 transported by the stack delivery mechanism 5 and is disposed at right angles to the transport table 3.
The laminate delivery mechanism 5 delivers the laminate 1 from the transport table 3 to the transport table 4, and is composed of a plurality of belt conveyors or the like that transport the laminate 1 in the direction of the arrow in the figure.
The illuminating devices 6 and 7 irradiate the flat paper cutting sections 1a and 1b of the laminate 1 with illumination light from the lateral direction of the laminate 1, and are applied to the flat paper cutting sections 1a and 1b of the laminate 1. Thus, the illumination light is arranged on both sides of the transport table 3 so that the illumination light is irradiated at an angle of 30 ° or less.

The illuminating devices 8 and 9 irradiate the flat paper cutting sections 1 c and 1 d of the laminate 1 with illumination light from the lateral direction of the laminate 1, and are applied to the flat paper cutting sections 1 c and 1 d of the laminate 1. Thus, the illumination light is arranged on both sides of the transport table 4 so that the illumination light is irradiated at an angle of 30 ° or less.
The imaging devices 10 and 11 image the flat paper cut sections 1a and 1b of the laminate 1, and the flat paper cut sections 1a and 1b of the laminate 1 are imaged at an angle of 60 ° to 120 °. As shown in FIG.
The imaging devices 12 and 13 image the flat paper cut sections 1c and 1d of the laminate 1, and the flat paper cut sections 1c and 1d of the laminate 1 are imaged at an angle of 60 ° to 120 °. As shown in FIG.

The elevating mechanisms 14 and 15 drive the illuminating devices 6 and 7 and the imaging devices 10 and 11 up and down in the height direction of the laminate 1, and are arranged on both sides of the transport table 3.
The elevating mechanisms 16 and 17 are used when the slit surface and the cross knife surface of the laminate 1 are interchanged, and drive the illumination devices 8 and 9 and the imaging devices 12 and 13 up and down in the height direction of the laminate 1. Are arranged on both sides of the transfer table 4.

  The width direction drive mechanisms 18 and 19 adjust the positions of the illumination devices 6 and 7 and the imaging devices 10 and 11 by moving the illumination devices 6 and 7, the imaging devices 10 and 11 and the elevating mechanisms 14 and 15 in the width direction of the transport table 3. Are arranged on both sides of the transport table 3. The width direction driving mechanisms 18 and 19 measure the position of the flat paper cutting sections 1a and 1b with a distance meter (not shown) to make the distance between the imaging devices 10 and 11 and the flat paper cutting sections 1a and 1b constant. This is so that the camera is always in focus with the cut surfaces of the flat paper laminates of various sizes, and the imaging size of one pixel is made constant.

  The width direction drive mechanisms 20 and 21 adjust the positions of the illumination devices 8 and 9 and the imaging devices 12 and 13 by moving the illumination devices 8 and 9, the imaging devices 12 and 13 and the lifting mechanisms 16 and 17 in the width direction of the transport table 4. And is arranged on both sides of the transfer table 4. The width direction driving mechanisms 20 and 21 measure the positions of the flat paper cutting sections 1c and 1d with a distance meter (not shown) to make the interval between the imaging devices 12 and 13 and the flat paper cutting sections 1c and 1d constant. The camera is always in focus with the cut surfaces of the flat paper laminates of various sizes, and the imaging size of one pixel is made constant.

The paper dust adhesion amount inspection apparatus shown in FIG. 1 further includes an image memory 22 for storing images of the flat paper cutting sections 1 a to 1 d imaged by the imaging devices 10 to 13, and stored in the image memory 22. By processing the image with the image processing device 23, it is configured to inspect the adhesion amount of the paper powder adhering in the form of grains on the flat paper cut sections 1 a to 1 d of the laminate 1.
FIG. 2 shows an example of how to use the paper dust adhesion amount inspection apparatus shown in FIG. 1. When inspecting the adhesion amount of paper dust adhering to the flat paper cut sections 1 a to 1 d of the laminate 1, first, the conveyance is performed. The tables 3 and 4 and the laminate delivery mechanism 5 are operated to transport the laminate 1 to the position shown in FIG. And the width direction drive mechanisms 18-21 are operated, the illuminating devices 6-9, the imaging devices 10-13, and the raising / lowering mechanisms 14-17 are moved to the width direction of the conveyance tables 3 and 4, and the illuminating devices 6-9 and an imaging device are moved. Adjust the position of 10-13.

After that, in the inspection of the flat paper cutting sections 1a and 1b, the illumination light 24 is irradiated from the lighting devices 6 and 7 to the flat paper cutting sections 1a and 1b of the laminate 1, and the lighting devices 6 and 15 are used by the lifting devices 14 and 15. 7 and the imaging devices 10 and 11 are moved from the upper end portion to the lower end portion of the laminate 1, and the flat paper cutting sections 1 a and 1 b are imaged by the imaging devices 10 and 11 in a vertical row.
In the inspection of the flat paper cut sections 1c and 1d, the illumination devices 24 and 9 irradiate the flat paper cut sections 1c and 1d of the laminate 1 with illumination light 24, and the transport table 4 is moved to the front end of the laminate 1. To the rear end, and the plane cutting sections 1c and 1d are imaged by the imaging devices 12 and 13 in rows.
The inspection of the flat paper cutting sections 1a and 1b and the inspection of the flat paper cutting sections 1c and 1d are not limited to one time, and the inspection place can be arbitrarily changed as required.

  A flowchart for inspecting the flat paper cut sections 1a to 1d of the laminate 1 is shown in FIG. 3, and an average luminance calculation area 26 set for each pixel of the image obtained by the imaging devices 10 to 13, FIG. 4 shows the low luminance calculation area 28 and the inspection target pixel 27. The average brightness calculation area is determined not to be the average brightness of the entire planes 1a, 1b, 1c, 1d, but to be obtained in a narrow area near the pixel to be inspected. This is because the brightness can be considered to be constant in a minute region even if there is unevenness in brightness caused by undulation in the laminate 1 and the manner in which the illumination light strikes. Accordingly, each area has a size of about 5 mm in the horizontal direction and about 3 mm in the vertical direction. Also, the reason why the areas are separated from the inspection target pixel 27 without being set immediately is to prevent the areas from containing grains when the paper powder grains are large. Therefore, a distance of about 0.5 mm to 1.5 mm is set in both the vertical and horizontal directions.

  The paper dust adhesion amount inspection apparatus shown in FIG. 1 stores the laminate 1 according to the flowchart shown in FIG. 3 when the images of the flat paper cutting sections 1a to 1d imaged by the imaging devices 10 to 13 are stored in the image memory 22. The flat paper cutting sections 1a to 1d are inspected. Specifically, when the images of the flat paper cut sections 1a to 1d are stored in the image memory 22, the average luminance calculation area 26 is moved up and down with respect to the inspection target pixel 27 as shown in FIG. The calculation area 28 is set to the left and right (step S1). Next, the average brightness of the set average brightness calculation area 26 is calculated as the average brightness of the flat paper cut sections 1a to 1d (step S2). Note that the upper and lower directions described here refer to the paper stacking direction, and the left and right refer to a direction perpendicular to the paper stacking direction.

  Here, the average luminance calculation area 26 has an area width of several pixels (for example, 3 to 6 pixels) in the height direction of the flat paper cut section, and the average luminance calculation area 26 is set to each inspection target pixel 27. By setting above and below (refer to FIG. 4), the effect of horizontal stripes appearing on the cross section of the flat paper (lightness and darkness caused by different lighting methods depending on entering and exiting each flat paper) is averaged. Can be reduced. Moreover, since it is installed on both the upper and lower sides, it is possible to cope with the case where the grain of the paper powder is just at the level difference and the average brightness is different between the upper and lower sides of the paper powder.

When the average luminance of the average luminance calculation area 26 is calculated in step S2, the paper dust adhesion amount inspection device in FIG. 1 calculates the average luminance in the low luminance calculation area 28 set on the left and right of each pixel (step S2). S3).
Here, the reason for using the low luminance calculation areas 28 set to the left and right of the inspection target pixel 27 instead of the average luminance of the average luminance calculation area 26 set above and below each pixel when calculating the low luminance is that illumination The reason why the shadow is generated in the grain is set in both the left and right directions in order to determine which side the shadow is generated. Further, the reason why the width in the height direction is set in the setting of the low luminance calculation area is to reduce the influence of the horizontal stripes appearing on the plane paper cut section.

  When the low luminance value is calculated in step S3, the paper dust adhesion amount inspection apparatus in FIG. 1 calculates the average luminance of the average luminance calculation area 26 set above and below each pixel and the luminance value of the inspection target pixel 27 as follows. (1) and (2) are compared, and the pixel 27 to be inspected in which one or both of the expressions (1) and (2) is established is recognized as a bright point that is particularly brighter than the surroundings. A low luminance calculation area 28 that has a high luminance point and is set to the left and right and an average luminance calculation area 26 that is set to the top and bottom are expressed by the following equations (3), (4), (5), and (6). When one or both of the expressions (3) and (4) are satisfied, it is recognized that a low-luminance area that is particularly darker than the surroundings exists on the right side of the inspection target pixel 27, and (5), (6 ) If either or both of the expressions hold, the pixel to be inspected 27 It is recognized that a low-luminance area that is particularly darker than the surroundings exists on the left side, and the inspection target pixel 27 that is adjacent in the order of the high-luminance point (inspection pixel 27) and the low-luminance area from the light source side of the illumination light is stored in the image memory. It detects from the image stored in 22 (step S4).

(Top) Average luminance value of average luminance calculation area 26a + threshold value I <
Luminance value of inspection target pixel 27 (1)
(Bottom) Average luminance value in the average luminance calculation area 26b + threshold I <
Luminance value of inspection target pixel 27 (2)
(Upper) Average luminance value of average luminance calculation area 26a−threshold II>
(Right) Low brightness calculation area 28a (3)
(Bottom) Average luminance value of average luminance calculation area 26b−threshold II>
(Right) Low brightness calculation area 28a (4)
(Upper) Average luminance value of average luminance calculation area 26a−threshold II>
(Left) Low brightness calculation area 28b (5)
(Bottom) Average luminance value of average luminance calculation area 26b−threshold II>
(Left) Low brightness calculation area 28b (6)

Further, for example, even when it is determined that both sides of the inspection target pixel 27 are particularly darker than the surroundings such that the expressions (3) and (5) are established, the high luminance point minus the low luminance from the light source side of the illumination light. Since the arrangement of the areas is established, the high luminance point, that is, the inspection target pixel 27 is detected.
Note that the thresholds set in the average luminance calculation area 26 and the low luminance calculation area 28 are calculated from a large amount of paper dust image data. The threshold II is set from 10 to 15.

  As shown in Fig. 5, there is a bright part (high-intensity part) on the illumination side, opposite to the lighting just next to the high-intensity part. There is a dark part (low luminance part) generated by grains on the side. Therefore, if the coordinates of the low-luminance area are within a certain range in the lateral direction opposite to the illumination with respect to the coordinates of the detected high-luminance pixel, it can be determined that the high-luminance pixel is due to the paper powder particles 25. Thus, the luminance change due to the paper dust is a luminance change in which the high luminance portion is adjacent to the low luminance portion in the horizontal direction with respect to the direction of the illumination light 24.

Paper pain (a dent generated when a part of the flat paper comes into contact with a part of the laminating apparatus) is one that causes a light and dark state on the laminated surface of the flat paper. When the illumination light hits the paper pain, the illumination light 24 is reflected by the paper pain 29 as shown in FIG. And since it becomes a pair of the brightness | luminance change which becomes a high-intensity part next to a low-intensity part in the horizontal direction with respect to the direction of illumination, discrimination | determination is possible.
When a high-luminance pixel is detected in step S4, the paper dust adhesion amount inspection device in FIG. 1 detects the paper dust adhering to the flat paper cutting sections 1a to 1d of the laminate 1 based on the detected number of pixels of the high-luminance pixel. The adhesion area is calculated (step S5).

If the number of detected high-luminance pixels is N and the area per pixel of the high-luminance pixels is S ₁ , the paper dust adhesion area S ₂ can be obtained from S ₂ = 2N × S ₁ . This is because the laminate 1 may be inclined in the middle of conveyance, and the angle between the illumination and the side surface of the flat paper laminate is not necessarily constant, and is a measure for reducing this effect. When the flat paper laminate is conveyed obliquely, the angle of illumination relatively changes, so the length of the dark part (shadow part) shown in FIG. 5 changes. In particular, since the illumination angle in this embodiment is 30 degrees or less, the length of the shadow portion is larger than the diameter of the grain. In this state, for example, when the flat paper laminate is inclined in a direction in which the angle of illumination becomes relatively small, the length of the shadow portion becomes very large. On the other hand, the high luminance portion has an area about half the diameter of the grain and does not change much even if the illumination angle changes. Therefore, it is possible to obtain a highly accurate area value by obtaining the area of the paper dust only with the area of the high-luminance portion that hardly changes due to the angle of illumination.

  When the adhesion area of the paper dust is calculated in step S5, the paper dust adhesion amount inspection apparatus in FIG. 1 divides the calculated adhesion area of the paper dust by the area of the flat paper cutting sections 1a to 1d (hereinafter referred to as the paper dust adhesion area inspection apparatus). The area ratio of the paper dust to the flat paper cutting sections 1a to 1d) is calculated in step S6. When the paper powder area ratio with respect to the flat paper cutting sections 1a to 1d is calculated in step S6, the paper powder adhesion amount inspection device in FIG. 1 compares the calculated paper powder area ratio with the pass / fail reference value. (Step S7). Then, the pass / fail reference value and the comparison result are output to a display device (not shown) or the like in step S8.

Here, when the area ratio of the paper dust to the flat paper cutting sections 1a to 1d exceeds the reference value, the amount of the paper powder adhering to the flat paper cutting sections 1a to 1d of the laminate 1 is the reference value. A message notifying that the number is exceeded is output to a display device or the like. Moreover, when the area ratio of the paper dust to the flat paper cutting sections 1a to 1d is equal to or less than the reference value, the amount of the paper powder adhering to the flat paper cutting sections 1a to 1d of the laminate 1 is equal to or less than the reference value. A message informing this is output to a display device or the like.
In addition, the area ratio of paper dust can be calculated | required from the following Formula.
Area ratio = area of paper dust part ÷ camera field of view = (number of pixels of paper dust grains x pixel unit area) ÷ (number of pixels of camera field of view x pixel unit area)
= (Number of pixels of paper dust grains) ÷ (number of pixels of camera field of view)

  As described above, illumination light is irradiated from the illumination devices 6 to 9 to the flat paper cutting sections 1a to 1d of the laminate 1, and the flat paper cutting sections 1a to 1d of the laminate 1 are irradiated by the imaging devices 10 to 13. By taking an image and calculating the average luminance of the flat cut sections 1a to 1d from the images obtained by the imaging devices 10 to 13, low luminance pixels having a luminance value higher than the average luminance and lower than the average luminance It becomes possible to detect the high brightness pixels adjacent on the light source side of the illumination light from the images obtained by the imaging devices 10 to 13. Further, the adhesion area of paper dust is calculated from the number of high-luminance pixels to the flat paper cutting sections 1a to 1d, and the calculated value of the adhesion area is divided by the area of the flat paper cutting sections 1a to 1d as a reference value. It is possible to determine whether or not the amount of paper powder adhering in the form of grains on the flat paper cut sections 1a to 1d is below the reference value. It is possible to accurately inspect the amount of paper powder adhering as grains on the paper cutting sections 1a to 1d.

  Moreover, when calculating the average luminance of the flat paper cut sections 1a to 1d as in the present embodiment described above, the area width of several pixels in the height direction and the horizontal direction of the flat paper cut sections 1a to 1d. By setting the average luminance calculation area 26 having the above and below, right and left of each pixel of the image obtained by the imaging devices 10 to 13 to calculate the average luminance of the flat paper cutting sections 1a to 1d, More precisely the amount of paper dust adhering in the form of grains on the flat paper cut sections 1a to 1d of the laminate 1 without being greatly affected by the influence of horizontal stripes appearing on the surfaces 1a to 1d and uneven brightness of illumination light. Can be inspected.

  FIG. 7 shows the case where the illumination light 24 is irradiated on the flat paper cutting sections 1a to 1d of the laminate 1 at an angle larger than 30 ° and an angle of 30 ° or less with respect to the flat paper cutting sections 1a to 1d. When the illumination light 24 is irradiated to the flat paper cut sections 1a to 1d of the laminate 1 at an angle larger than 30 ° with respect to the flat paper cut sections 1a to 1d, as shown in FIG. Of the illumination light 24 irradiated to the flat paper cut sections 1a to 1d, the illumination light 24 irradiated to the paper powder particles 25 has a higher probability of being reflected light that does not enter the imaging devices 10 to 13.

On the other hand, when the illumination light 24 is irradiated to the flat paper cut sections 1a to 1d of the laminate 1 at an angle of 30 ° or less with respect to the flat paper cut sections 1a to 1d, as shown in FIG. The probability that the illumination light 24 reflected by the paper powder particles 25 enters the imaging devices 10 to 13 increases. Further, as the illumination angle of the illumination light 24 with respect to the flat paper cut sections 1a to 1d becomes smaller, the length of the shadow generated by the paper powder particles 25 becomes longer.
Therefore, as in the present embodiment described above, the paper powder is irradiated by irradiating the illuminating light 24 to the flat paper cut sections 1a to 1d of the laminate 1 at an angle of 30 ° or less with respect to the flat paper cut section 1a. An image with a large contrast (contrast) between the part to which the film is attached and the part to which the film is not attached can be obtained, whereby the paper adhered to the flat paper cut sections 1a to 1d of the laminate 1 as particles. The amount of powder adhering can be inspected more accurately.

  FIG. 8 shows a case in which the flat paper cut sections 1a to 1d of the laminate 1 are imaged at an angle smaller than 60 ° and an angle larger than 120 ° with respect to the flat paper cut sections 1a to 1d. When the flat paper cut sections 1a to 1d of the article 1 are imaged at an angle smaller than 60 ° or larger than 120 ° with respect to the flat paper cut sections 1a to 1d, as shown in FIG. It becomes difficult for the illumination light 24 reflected by the light to enter the imaging devices 10 to 13.

On the other hand, when images of the flat paper cut sections 1a to 1d of the laminate 1 are taken at an angle of 60 ° to 120 ° with respect to the flat paper cut sections 1a to 1d, as shown in FIG. The illumination light 24 reflected by the powder particles 25 is likely to enter the imaging devices 10 to 13.
Accordingly, as in the above-described embodiment, the flat paper cutting sections 1a to 1d of the laminate 1 are imaged by the imaging devices 10 to 13 at an angle of 60 ° to 120 ° with respect to the flat paper cutting sections 1a to 1d. By doing so, it is possible to obtain an image with a large contrast (contrast) between the portion where the paper dust is adhered and the portion where the paper powder is not adhered, and thereby the grains are formed on the flat paper cut sections 1 a to 1 d of the laminate 1. Thus, it is possible to more accurately inspect the amount of paper powder adhering.

DESCRIPTION OF SYMBOLS 1 ... Laminate 1a-1d ... Flat paper cutting section 2 ... Conveying pallet 3, 4 ... Conveying table 5 ... Laminate delivery mechanism 6-9 ... Illuminating device 10-13 ... Imaging device 14-17 ... Lifting mechanism 18-21 Width direction drive mechanism 22 Image memory 23 Image processing device 24 Illumination light 25 Paper grain

Claims (4)

  A method for inspecting the amount of paper dust adhering to a flat paper cut section of a laminate formed by laminating a large number of flat paper cut to a certain size, the plan paper cut section of the laminate The illumination light is irradiated at a predetermined angle with respect to the plane paper cutting section, and the plane paper cutting section is imaged with a predetermined angle with respect to the plane paper cutting section, and the imaging apparatus The average brightness of the stencil cut section is calculated from the image obtained by the above, and a low-brightness area having a brightness value equal to or lower than a set threshold value compared to the average brightness is detected from the image, and the average brightness and In comparison, the high-luminance pixels that are higher than the set threshold value and are adjacent to the low-luminance area on the light source side of the illumination light are detected from the image, and the flat paper is calculated from the number of pixels of the high-luminance pixels. After calculating the adhesion area of the paper dust adhering to the cut surface, the calculated value of the adhesion area is Adhesion amount testing method of paper powder, wherein a value obtained by dividing the area of Kitaira-size paper cut surface is compared with a reference value to check the adhesion amount of the paper powder.   Illumination light is irradiated to the flat paper cut section of the laminate at an angle of 30 ° or less with respect to the flat paper cut section, and the flat paper cut section is 60 ° with respect to the flat paper cut section. The paper dust adhesion amount inspection method according to claim 1, wherein imaging is performed at an angle of ˜120 °.   An average luminance calculation area having a width of several pixels in the height direction and the horizontal direction of the flat paper cut section is set above and below each pixel of the image obtained by the imaging device, and While calculating the average brightness, set a low brightness calculation area having a width of several pixels in the height direction and the horizontal direction of the flat paper cut section on the left and right of each pixel of the image obtained by the imaging device, The paper dust adhesion amount inspection method according to claim 1, wherein a shadow generated by the presence of the paper dust by the illumination light is captured.   An apparatus for inspecting the amount of paper dust adhering to a flat paper cut section of a laminate formed by laminating a large number of flat papers cut to a certain size, the flat paper cut section of the laminate A plurality of illuminating devices that irradiate illumination light at a predetermined illumination angle with respect to the flat paper cutting section, and a flat paper cutting section of the laminate at a predetermined imaging angle with respect to the flat paper cutting section. A plurality of image pickup devices for picking up images, a means for calculating an average luminance of the slab-cut section from an image obtained by the image pickup device, and a low-brightness area whose luminance value is less than or equal to a threshold value set by the average luminance. Means for detecting from among the image, a means for detecting a high-luminance pixel that has a luminance value higher than a threshold value set from the average luminance and is adjacent to the low-luminance area on the light source side of the illumination light; The area of paper dust adhering to the cross-section of flat paper is the high brightness pixel. Means for calculating from the number of pixels, adhesion of paper dust amount inspection apparatus characterized by comprising a means for comparing with a reference value divided by the area of the flat-size paper cutting plane calculated values of the adhesion area.

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