Corrugated board sheet defect detecting device, corrugated board sheet defect removing device and corrugated board sheet manufacturing device

Patent metadata

Field	Value
Publication number	US-11002686-B2
Application number	US-201616070985-A
Country	US
Kind code	B2
Filing date	Dec 28, 2016
Priority date	Jan 29, 2016
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A corrugated board sheet defect detecting device detects a defect in a single-faced cardboard sheet guided by a guide member with corrugated core paper facing outwards. The device includes a radiating device, an image capturing device, an image processing device, and an assessing device. The radiating device is configured to radiate light toward the core paper at a radiation angle relative to the single-faced cardboard sheet. The image capturing device is configured to capture an image of a portion of the core paper irradiated with the light. The image processing device is configured to a light portion and a dark portion in a direction in which the single-faced cardboard sheet is transported based on the captured image. The assessing device is configured to assess a quality by comparing a length of the light portion and a length of the dark portion.

First claim

The invention claimed is:

1. A corrugated board sheet defect detecting device that detects a defect in a single-faced cardboard sheet guided by a guide member with corrugated core paper facing outwards, the device comprising:
a radiating device configured to radiate light toward the core paper at a radiation angle which is inclined through a predetermined angle set in advance relative to the single-faced cardboard sheet, and to form a shadow of a flute of the core paper;
an image capturing device configured to capture an image of a portion of the core paper, the portion being irradiated with the light;
an image processing device configured to define a light portion and a dark portion in a direction in which the single-faced cardboard sheet is transported based on a shadow image of the flute of the core paper captured by the image capturing device; and
an assessing device configured to:
compare a length of the light portion and a length of the dark portion in one flute of the core paper defined by the image processing device with assessment values set in advance; and

when the one flute of the core paper is determined to be defective, identify a position of the one defective flute on the core paper and assess the core paper including the one defective flute as defective,
wherein the radiating device radiates parallel light toward the core paper.

2. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the guide member has a curved surface.

3. The corrugated board sheet defect detecting device according to claim 2 , wherein the guide member is a guide roller.

4. The corrugated board sheet defect detecting device according to claim 2 , wherein the guide member is a columnar body or a cylindrical body.

5. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the guide member is a plate-shaped body.

6. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the guide member is provided with a suction unit on a guiding surface thereof that guides the single-faced cardboard sheet.

7. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the assessing device assesses the quality by comparing the length of the light portion with a first assessment value and assesses the quality by comparing the length of the dark portion with a second assessment value.

8. The corrugated board sheet defect detecting device according to claim 7 ,
wherein the first assessment value and the second assessment value are a value calculated by averaging out lengths of a plurality of the light portions, on which quality assessment is already completed, and a value calculated by averaging out lengths of a plurality of the dark portions, on which quality assessment is already completed, respectively.

9. The corrugated board sheet defect detecting device according to claim 7 ,
wherein the first assessment value and the second assessment value are set as a first assessment range and a second assessment range which are obtained by adding predetermined margins to prescribed reference values of the lengths of the light portion and the dark portion.

10. The corrugated board sheet defect detecting device according to claim 9 ,
wherein the first assessment value and the second assessment value are set for each type of the single-faced cardboard sheet, and are stored in a memory device.

11. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the assessing device assesses the quality by comparing a ratio between the length of the light portion and the length of the dark portion with an assessment value.

12. The corrugated board sheet defect detecting device according to claim 11 ,
wherein the assessing device assesses the quality by comparing an average value of ratios between lengths of a plurality of the light portions and lengths of a plurality of the dark portions with the assessment value.

13. The corrugated board sheet defect detecting device according to claim 12 ,
wherein the assessment value is a ratio between a total value of the lengths of the plurality of the light portions, on which quality assessment is already completed, and a total value of the lengths of the plurality of the dark portions, on which quality assessment is already completed.

14. The corrugated board sheet defect detecting device according to claim 13 ,
wherein the assessment value is a ratio between an average value of the lengths of the plurality of the light portions, on which quality assessment is already completed, and an average value of the lengths of the plurality of the dark portions, on which quality assessment is already completed.

15. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the assessing device assesses the quality by comparing a light portion average value, which is calculated by averaging out lengths of a plurality of the light portions, with a first assessment value and assesses the quality by comparing a dark portion average value, which is calculated by averaging out lengths of a plurality of the dark portions, with a second assessment value.

16. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the radiation angle of the radiating device is an angle relative to a perpendicular line, which is perpendicular to the single-faced cardboard sheet and passes through a flute top portion of the core paper, and is set to an angle larger than an angle between the perpendicular line and an inclined line along an inclined surface of a flute of the core paper.

17. The corrugated board sheet defect detecting device according to claim 16 ,
wherein the image processing device defines the light portion and the dark portion by adding up image capturing data pieces in a predetermined pixel unit in a width direction of the single-faced cardboard sheet based on the images captured by the image capturing device.

18. The corrugated board sheet defect detecting device according to claim 1 , further comprising:
a radiation angle changing device configured to change the radiation angle of the radiating device.

19. The corrugated board sheet defect detecting device according to claim 18 ,
wherein the image processing device defines the light portion and the dark portion by adding up image capturing data pieces in a predetermined pixel unit in a width direction of the single-faced cardboard sheet based on the images captured by the image capturing device.

20. The corrugated board sheet defect detecting device according to claim 1 ,
wherein the image processing device defines the light portion and the dark portion by adding up a part of image capturing data pieces in a width direction of the single-faced cardboard sheet on the basis of the images captured by the image capturing device.

Assignees

• Mitsubishi Heavy Ind Mach Systems Ltd

Inventors

• Yamada Masahiro
• Toyohara Takashi
• Ishibuchi Hiroshi
• Mizutani Hideki
• Ogino Akira
• Takemoto Shuichi
• Fukushige Naoyuki

Classifications

• G01N2021/8924

  Dents; Relief flaws · CPC title

• G01N2021/8917

  Paper, also ondulated · CPC title

• G01N2021/8887

  based on image processing techniques · CPC title

• G01N21/8914

  characterised by the material examined · CPC title

• B31F1/2831 Primary

  Control · CPC title