JP5396660B2 - Print quality inspection system - Google Patents

Description

  The present invention relates to an inspection method and an inspection apparatus for quality inspection on a printing machine for printed matter that is required to be prevented from forgery or duplication such as banknotes, stock certificates, securities such as bonds, various certificates and valuable printed matter. It is.

  In recent years, due to the rapid development of scanners and color copiers, forgery or alteration techniques tend to be diversified. For this reason, various techniques are applied to precious printed matter such as banknotes in order to give a counterfeit prevention effect by applying a watermark to paper or applying various functional inks.

  Regarding anti-counterfeiting technology used for these valuable printed materials, inspections related to various anti-counterfeiting technologies are performed after printing, but in post-printing inspection, it will be discovered after a large number of defective products occur, Online inspection on a printing press is required.

  In recent years, since the speed of printing presses has been increased, it is necessary to suppress paper flutter in order to inspect the quality of printed matter being conveyed at high speed. Therefore, as a quality inspection method on the printing press, the printed matter is fixed to the impression cylinder of the printing press by injecting air to fix the printed matter being conveyed, and a reflection image of the printed matter is input in advance. A method of performing a quality inspection of a printed matter by comparing with a stored threshold value is disclosed (for example, see Patent Document 1).

  In addition, by providing a transparent inspection cylinder in the printing press and providing illumination or image input means in the inspection cylinder, the reflected and / or transmitted image of the printed material is input and compared with a threshold value stored in advance. A quality inspection method for making a determination is disclosed (for example, see Patent Document 2).

JP 2004-136585 A Special table 2007-534074 gazette

  However, in the quality inspection method of Patent Document 1, since only the reflected image of the printed material is input, it is not possible to inspect the watermark image or the like applied to the printed material. In addition, in order to inspect infrared reflections and absorption pair inks (hereinafter referred to as IR pair inks) applied to the front and back of printed matter, image input devices must be installed in at least two places of the printing press. Was left.

  Further, in the invention of Patent Document 2, since a transparent drum is provided as an inspection cylinder, in a printing press with high pressure, there is a problem in cylinder strength, and in order to provide a new mechanism, existing printing is performed. It cannot be easily attached to the machine. Therefore, the subject that equipment expense including maintenance cost was needed remained.

  The present invention has been considered in view of the above-described problems. Reflected and transmitted images such as functional ink and watermark images applied to printed matter can be printed on paper after printing by a printing machine without providing a new inspection cylinder or the like. By providing a transparent plate in the transport section and bringing the printed material into close contact with the transparent plate, it is possible to capture a reflected and / or transmitted image of the printed material without being affected by the flicker during paper transport, and on a reliable printing press. The present invention relates to a quality inspection method and a quality inspection apparatus for printed matter that performs a functional inspection.

  The printed matter quality inspection apparatus of the present invention includes an image input unit that captures an image of a conveyed printing paper, and a determination unit that compares and determines preset reference data and an image input by the image input unit. An inspection device that includes an air ejection unit that blows air onto printing paper that is gripped and transported by a chain gripper, and a paper contact unit that closely contacts the printing paper with air from the air ejection unit. The inspection apparatus picks up an image of the printed paper by an image input unit.

  In addition, the paper contact portion is a quality inspection device in which a plurality of air blow-off portions are formed to remove air staying between the paper contact portion and the paper by blowing air onto the printed matter.

  The air ejection part is a quality inspection device having a plurality of regularly arranged air ejection ports.

  The image input unit is a quality inspection device that captures a reflected image and / or a transmitted image of a printed material.

  Further, the inspection unit is a quality inspection apparatus that is disposed at an upper part and / or a lower part of the printed matter that is closely contacted by the paper contact part and has at least one illumination part that irradiates the printed matter with visible light. .

  Further, the sheet quality inspection unit is a quality inspection apparatus having an abnormality alarm unit and / or an abnormality display unit that issues an abnormality warning when there is an abnormality in the sheet.

  In addition, the quality inspection method for printed paper according to the present invention compares an image input unit that captures an image of a conveyed printing paper with a reference data set in advance and an image input by the image input unit. An inspection method having a determination unit that determines a chain gripper that grips and conveys printing paper, an air ejection unit that blows air onto the printing paper, and paper adhesion that causes the printing paper to adhere to the air from the air ejection unit A step of carrying the printing paper gripped by the chain gripper into the paper contact portion, and the printing paper carried into the paper contact portion as an image input unit. And a method for inspecting a printing paper comprising the step of taking out the printing paper after imaging from the paper contact portion.

  Since the quality inspection method and quality inspection apparatus for printed matter of the present invention can capture a transmission image of the printed matter, it is possible to input anti-counterfeiting techniques such as watermarks and infrared images applied to the front and back sides, and separate the images on the front and back sides. There is an effect that it is possible to perform quality control without inputting into the.

  In addition, since the quality inspection method and apparatus for printed matter according to the present invention can be dealt with by improving a part of the delivery unit, it can be easily installed without major modification of the apparatus, and the printed matter flickers. Therefore, it is possible to reliably perform quality inspection without requiring a large amount of remodeling cost.

It is a block diagram which shows the structure of the quality inspection apparatus of this invention. It is a flowchart figure which shows the inspection process in the quality inspection method of the printed matter of this invention. It is the schematic which shows an example of the printing machine containing the quality inspection apparatus of this invention. It is the schematic which shows an example at the time of the paper inspection in the quality inspection apparatus of this invention. It is a figure which shows an example of the air blow-off part which the air blow-off part was given to the transparent plate. It is a figure which shows the example of an air blow-off part. It is a figure which shows an example of the watermark test result in the quality inspection apparatus of this invention. It is a flowchart figure which shows the discrimination | determination result of the infrared characteristic in the quality inspection apparatus of this invention. 6 is a diagram illustrating an example of a determination image for an infrared image in Embodiment 1. FIG. FIG. 6 is a diagram illustrating a detection result of a paper defect portion in the first embodiment.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. However, the present invention is not limited to the best mode for carrying out the invention described below, and includes various other embodiments within the scope of the technical idea in the scope of the claims.

  The quality inspection method and quality inspection apparatus for printed matter of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the quality inspection apparatus of the present invention, FIG. 2 is a flowchart showing the inspection process in the quality inspection method for printed matter of the present invention, and FIG. 3 shows the quality inspection apparatus of the present invention. 4 is a schematic diagram showing an example of a sheet inspection in the quality inspection apparatus of the present invention, and FIG. 5 is a diagram showing an example of an air blow-off portion provided on a transparent plate. FIG. 6 is a diagram showing an example of the shape of the air blow-through portion, FIG. 7 is a diagram showing a watermark inspection result in the quality inspection device of the present invention, and FIG. 8 is an infrared characteristic in the quality inspection device of the present invention. The flowchart figure which shows the discrimination | determination result is shown, respectively.

First, the structure in the quality inspection method and quality inspection apparatus of the printed matter of this invention is demonstrated using FIG. First, sheets are stacked in a sheet supply unit, and the sheet is fed to the sheet transport unit by the sheet supply unit (M1). The fed sheet is conveyed to the sheet processing unit by the conveying means (M2).
Paper processing such as pattern printing is performed by the paper processing means (M3), and then the paper is conveyed to the discharge means (M10) by the paper transport means (M4). A quality inspection device is provided in the conveying means (M4), the quality of the printed matter is inspected by the measuring means (M5), and the quality of the printed matter is judged in the judging means (M6).

  At the time of quality judgment, in order to eliminate the fluttering at the time of transporting the printed matter, the transparent printed board is provided at the top of the transported printed matter and the air jetting part is provided at the bottom of the printed matter, and air is blown so that the printed matter is in close contact with the transparent plate. It is possible to make a highly accurate determination by suppressing the fluttering of the image, capturing an accurate image of the printed material, and comparing it with a threshold value input in advance. By inputting a transmission image as an image during conveyance of the printed material, an image such as a watermark or infrared characteristics applied to the printed material is input, and quality inspection is performed.

  Further, when the determination result by the determination unit (M6) shows that there is no quality abnormality, the normal sheet is continuously discharged by the transport unit (M4). When the quality is abnormal, the control means (M7) stops the paper supply means (M1) and the paper transport means (M2), thereby preventing the occurrence of a large amount of paper loss. Moreover, it is a quality inspection device which notifies the occurrence of abnormality by the alarm means (M8) and / or the display means (M9) to alert and / or warn the operator.

  Next, the inspection process in the printed matter quality inspection method of the present invention will be described with reference to FIG. First, the paper is supplied to the paper supply unit (S1), and the paper is sent to the transport unit (S2). The paper transported in the transport unit is transported to the paper processing unit, where the processing unit (S3) processes the paper such as printing, and the paper is then transported by the paper contact transport unit (S4). At that time, quality inspection (S5) is performed on the paper transport, and if it is determined that there is no abnormality in the print quality (S6), the printed matter is continuously transported by the transport section (S4) and the finished product is discharged (S7). Do. When a quality abnormality occurs, it is determined that there is an abnormality (S8), an alarm (S9) and / or an abnormality display (S10) is notified to the worker, and the control mechanism provides a paper supply unit and / or This is a step of stopping the machine (S11) of the paper transport unit.

  If it is determined that there is an abnormality by the above-described steps, the abnormal printed matter is removed and the apparatus is operated again. By repeating these steps, it is possible to minimize the number of lost paper sheets.

  Next, an example of a schematic diagram of a printing press including the quality inspection apparatus of the present invention will be described with reference to FIG. The paper (1) loaded on the paper supply unit is conveyed onto the conveyance board by the paper supply unit (2). On the transport board, the transport belt (3) transports the paper to the paper processing unit at regular intervals, and sends the paper one by one to the paper processing unit (4). The sheet that has been subjected to processing such as printing is continuously conveyed by the conveyance guide (9) and stacked on the discharge unit (10).

  For normal printing machines that do not perform online quality inspection, if an abnormal product occurs, it will not be possible to stop the machine unless sampling is inspected by delivery and the abnormality is found directly. It will occur in large quantities. For this reason, a printing machine using the quality inspection apparatus of the present invention is provided with an inspection unit in the paper transport section after printing.

  The inspection unit (11) of the present invention comprises an image input unit (5), a transparent plate (6), an air ejection unit (8), and an illumination unit (7) such as LED lighting, and the upper part of the conveyance sheet in the middle of the conveyance guide. In addition, the quality of the processed product can be checked online by providing a CCD camera (5) as an image input unit at the bottom and an illuminating unit (7) at a position where the conveyance paper is sandwiched.

  A feature of the paper quality inspection apparatus of the present invention is that it has a function of suppressing paper flutter during conveyance. A normal printing machine is in a state in which the paper is fixed only by the gripping part, so the printed product has a large flutter due to conveyance, and an accurate image of the printed product cannot be input, making it difficult to perform a quality inspection. It is. Therefore, by providing a transparent plate (6) and an air jetting portion (8) at the upper part and / or lower part of the measuring device, air is blown against the paper so as to be in close contact with the transparent plate (6) to eliminate fluttering. This makes it possible to perform an accurate quality inspection.

  When an abnormality is found in the paper quality in the measuring device, the control device is notified of a determination NG, and the delivery device (2) and the conveyor belt (3) are stopped to prevent the generation of a large amount of abnormal products.

Next, the paper conveyance state in the quality inspection apparatus of this invention is demonstrated using FIG.
FIG. 4A is an enlarged view of the state of paper conveyance as viewed from the side, when the paper (1) picked up and conveyed by the paper holder (12) is conveyed to the inspection unit (11). It can be seen that the air is in close contact with the transparent plate (6) by the air from the air ejection portion (8) provided at the lower part of the transport paper. At this time, the transparent plate (6) is provided with a plurality of air blow-off portions (13) in order to reduce paper fluttering due to air accumulation, and the transported paper is securely adhered to the transparent plate (6). . In FIG. 4A, two air ejection portions (8) are provided, but it is preferable to provide them at a position where the image input portion (5) is sandwiched. The sheet that is in close contact with the transparent plate (6) is irradiated with specific light by the illumination unit (7) installed at the top and / or bottom of the sheet, and a transmission and / or reflection image of the sheet is input.

  FIG.4 (b) is the schematic which looked at the quality inspection apparatus of this invention from diagonally upward direction. In FIG. 4B, five image input units (5) are provided in order to show inspection in a multi-row printed matter having a five-row configuration, but the number of installed units can be changed in accordance with the inspection location. The paper conveyed to the inspection unit (11) is subjected to pass / fail judgment by inputting an image of a functionally imparted portion such as a watermark and comparing it with a preset threshold value.

  Next, an example of the air blow-off portion (13) applied to the transparent plate (6) will be described with reference to FIGS. FIG. 5 is an enlarged view of a part of the inspection unit (11). When a multi-sided printed material is conveyed as the printed material (1) to be conveyed, each row has an image input unit (5), but in the middle of the conveyed printed material (1) and the transparent plate (6). Since air is present, an air blow-off portion (13) for escaping air from the air blowing portion (8) is provided. The shape of the air blow-off portion (13) is not particularly limited, and may be a triangle, pentagon, ellipse, or the like as shown in FIG. 6, and a plurality of air blow-offs in the same direction. It is also possible to give parts.

  Further, when the printed product (1) to be conveyed is in close contact with the transparent plate (6), the air blow-off portion (13) of the transparent plate (6) and the printed product (1) are in contact with each other. Ink that has not been completely dried may be scraped off. Therefore, it is preferable that the corner portion of the air blow-off portion (13) in contact with the printed matter (1) is chamfered. Furthermore, it is preferable that the air blow-off portion is installed before the image input unit (5) is installed. This is because the printed matter (1) that is in close contact with the transparent plate (6) by the air is pushed out to the air blow-off portion (13) portion, so that a slight wave is generated in the printed matter (1).

  FIG. 5 exemplifies the inspection method for the sheet (1) on which the multi-sided printing is performed. As the position of the air blow-off portion (13) of the transparent plate (6), the multi-sided sheet ( It is preferable to install in the margin of 1).

  Next, watermark inspection in the quality inspection apparatus of the present invention will be described with reference to FIG. FIG. 7 shows the time of inspection of the watermark portion (14) of the printed matter (1). The illumination portion (7) irradiates light from below the printed matter, thereby enabling the input of a watermark image. . The watermark portion is imaged by the image input unit (5) to obtain an input image. The obtained input image is subjected to a pass / fail judgment by performing a comparison calculation process with a threshold value input in advance.

  Regarding the watermark inspection, the image captured by the image input unit (5) is divided, and the pass / fail determination is performed by checking the contrast ratio between the image in each region and the image input in advance. The defective portion (15) is detected for each divided area.

  Next, infrared characteristic inspection in the quality inspection apparatus of the present invention will be described with reference to the flowchart of FIG. The inspection unit can be input by providing a sharp cut filter for inputting an infrared region image in the image input unit (5), and the other configuration is the same as in FIG. .

  First, an inspection process is started (S5-3) by a timing signal (S5-2) when the printed (S5-1) paper (1) is conveyed to the inspection unit (11). The conveyed paper (1) is in close contact with the transparent plate (6), and an image in the infrared region is captured by the image input unit (5) (S5-4). The captured image is binarized (S5-5), and the number of pixels is determined (S5-6). The determined number of pixels of the input image is compared with the number of reference pixels inputted in advance (S5-7), and if it is within the range of the number of reference pixels, the infrared characteristic ink is appropriately printed. Therefore, it is determined as regular paper (S5-8), and the printing process is continued (S5-9). However, if it is outside the range of the number of reference pixels, the infrared characteristic ink is erroneously printed, so it is determined as waste paper (S5-10). When the waste paper is generated, the control device is operated and the machine is stopped (S5-11).

  The above-described inspection process is not particularly limited as long as it is a configuration that can perform pass / fail determination such as a watermark or an infrared characteristic image, and various known techniques can be used.

  Next, an embodiment in which an infrared characteristic is actually inspected using the quality inspection apparatus of the present invention will be described with reference to FIGS. In the printed matter, after paper processing such as printing is performed, delivery is discharged through inspection by the inspection unit, and FIG. 9 shows the result of inspection by the inspection unit.

  When there is no abnormality in the normal printed matter, when the captured image is binarized, an image equivalent to the comparison region (18) of the reference printed matter (16) is obtained, and it is determined that there is no abnormality in the detection region. Then, the conveyance of the sheet is continued.

  On the other hand, in the abnormal area (19) of the inspection printed matter (17), when an abnormality of a foreign matter or the like (20) that should not exist originally is observed, when the captured image is binarized, the comparison area (18 of the reference printed matter) ) Is obtained, and an abnormality is detected.

  When the above-described image is detected, it is determined that there is an abnormality in the detected area in the inspected printed matter, and is excluded as an abnormal printed matter. Further, when an abnormality is detected, there is a possibility that there are factors in printing materials and the machine itself. In this case, since a large amount of abnormal printed matter is concerned, a function to stop the paper supply unit is provided.

  Since there are cases where a plurality of detection areas are provided in the inspection sample excluded as described above, an abnormality occurrence portion is displayed on the operation panel as to which detection area is abnormal. The operator can confirm the area where the abnormality of the excluded inspection sample is indicated, and can take quick measures such as replacement of printed materials and machine adjustment.

  Note that the size and concentration of foreign matter such as foreign matter that can be determined in this quality inspection apparatus are not limited to large and dark ones as shown by 20 in FIG. 9, and it is possible to detect abnormalities of various sizes and concentrations. It is. Moreover, the quality inspection apparatus of this invention can also evaluate the infrared characteristics given to the front and back by inputting a transmission image.

Next, the measurement result regarding the infrared characteristic obtained by the Example using the test | inspection unit (11) of this invention and the comparative example which does not use the test | inspection unit (11) is demonstrated using FIG. FIG. 10A shows that the paper is classified into 14 levels according to the defective area (mm ² ) and the density (%) of the defective portion of each defective paper. FIG. 10B is a detection result when the air ejection part (8) and the transparent plate (6) are not used in the inspection unit (11) of the present invention. The column printed on the sheet (1) is shown. As a result of FIG. 10B, since it is difficult to input an image due to fluttering of the conveyed multi-sided printing sheet (1), the missing paper cannot be detected with high accuracy.

  FIG.10 (c) is a detection result when the test | inspection unit (11) of this invention is used, but the air blow-off part (13) is not given to the transparent plate (6). Since the case where the area and density of the defective part in the infrared region are low is not detected, the image of the printed matter (1) is accurately captured by the air interposed between the printed matter (1) and the transparent plate (6). It can be seen that the defective paper cannot be detected.

  FIG. 10 (d) shows the result of inspecting the printed matter by the inspection unit (11) of the present invention. Since air interposed between the transparent plate (6) and the printed matter (1) can be reliably removed by the air blow-off portion (13) of the transparent plate (6), the fluttering of the printed matter (1) is completely suppressed, Since the image can be accurately captured, it can be seen that the defective paper is reliably detected even if the area and density of the defective portion are low.

  In the above-described embodiment, the defect detection related to the infrared characteristic is performed. However, it is possible to inspect a visible image or a luminescent image by comparing with a threshold value input in advance, and the inspection unit (11 of the present invention). It goes without saying that reliable online inspections for various functionalities can be realized by changing the image input unit in FIG.

  In addition, the inspection unit of the present invention can be installed in a processing machine other than a printing machine such as an OVD pasting machine, and can correspond to various apparatuses as an inspection unit for inspecting a conveyed sheet. .

DESCRIPTION OF SYMBOLS 1 Paper 2 Paper supply part 3 Conveyor belt 4 Processing part 5 Image input part 6 Transparent board 7 Illumination part 8 Air ejection part 9 Conveyance guide 10 Discharge part 11 Inspection unit 12 Paper grip part 13 Air blow-off part 14 Measurement part 15 Missing area 16 Reference Printed Material 17 Inspection Printed Product 18 Reference Printed Product Comparison Area 19 Inspection Printed Product Abnormal Area 20 Inspection Printed Product Abnormality Detection Unit

Claims (3)

An air ejection part that blows air onto the printing paper that is gripped and conveyed by the chain gripper, a paper contact part that closely contacts the printing paper by the air from the air ejection part, and the printing paper that is contacted by the paper contact part At least one illumination unit that irradiates the printing paper disposed above and / or below, an image input unit that captures an image of the conveyed printing paper, preset reference data, and the image An inspection apparatus having a determination unit that compares and determines the image input by the input unit,
The paper contact portion is formed by a transparent member having at least one air blow-through portion,
The air injection unit, a plurality of formed to write no position sandwiching at least the image input unit,
Each of the plurality of formed air ejection portions has a plurality of air ejection ports formed along the width direction of the printing paper perpendicular to the conveyance direction of the printing paper ,
A quality inspection apparatus for printed matter, wherein the image input unit captures a reflection and / or transmission image on the printing paper that is in close contact with the paper contact portion.
The surface of at least one air blow-off portion formed in the paper contact portion is chamfered. The quality inspection apparatus for printed matter according to claim 1, wherein the quality inspection device is provided. 3. The quality inspection of printed matter according to claim 1, wherein the determination unit includes an abnormality alarm unit and / or an abnormality display unit that issues an abnormality warning to an operator when there is an abnormality in the printing paper. apparatus.

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