JP2000182046A - Defect inspecting device for printing paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inspecting device for a paper money sheet capable of detecting what small paper money area of the large sheet is defective. SOLUTION: When an image signal of the paper money sheet the image of which is picked up by a line sensor camera 13 is converted into image data in an image input part 35, changed quantity of the image data is calculated in the horizontal and vertical directions by a filter part 37 and minute defect data and defect data like irregularity defect, etc., are obtained by the inspecting device. And each piece of data from the filter part 37 is stored for a specified scan line by an inspection data storage part 38. Each piece of data from the inspection data storage part 38 is inputted, judged based on each threshold and recognized as the defect by a defect judgment processing part 45. Thus, a number of a small paper money area at a defective part and each area number like a watermark input area or a plain area, etc., in the small paper money area are specified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a defect of a sheet for arranging and printing a large number of objects, such as bills, of which dimensions are specified in advance.

[0002]

2. Description of the Related Art Generally, bills are provided at predetermined positions with identification marks according to the kind of the bill and pits for a picture such as a person image, and are further printed according to the kind of the bill. ing. Such bills are formed by printing a large number of bills of the same type on a roll of printing paper. The roll-shaped printing paper is formed as an original roll through a papermaking process in which an identification mark and a picture are inserted in each area where each banknote is to be formed before printing the details, that is, in each small banknote area. Further, a print mark that functions as a positioning at the time of printing in a subsequent process is provided to the raw roll. That is, the identification mark, the clearance, and the print mark are formed in advance on the sheet of the material roll before printing.

As shown in FIG. 12, a printing paper 3 on which a plurality of small bill areas 2 indicated by dotted lines are set is wound in a roll form on the raw roll 1. In addition, small bill area 2
Is not visible, but is divided into blocks of 5 columns and 4 rows, and each block is called a large version. Therefore, each large plate is formed with a small cut bill area that becomes 20 bills. Further, print marks 4 are provided on the side of the printing paper 3 for each large plate. In the example of FIG. 12, three large plates are arranged at predetermined intervals in the width direction of the printing paper 3, and each large plate is referred to as a large plate A, a large plate B, and a large plate C. Also, this large plate is in the longitudinal direction of the printing paper 3, ie,
They are arranged at predetermined intervals in the pull-out direction indicated by the arrow.

[0004] As described above, the printing paper 3 is divided into three large plate units, and each large plate is divided into five columns and four rows of small cut bill regions, which are bills of 1,000 yen, 5,000 yen, and 10,000 yen. ing. By the time the banknote is completed, a banknote paper inspection process that detects defects on the surface of the material roll that has passed through the above-described papermaking process, a large-size cutting process that cuts large-size units, and printing that matches the type of bill And a small-piece cutting step of cutting the bill into small pieces. In the bill paper inspection process, the presence or absence of a defect on the printing paper 3 pulled out from the raw roll 1 in FIG. 12 is inspected. When performing this defect inspection, a horizontal scanning is performed in the direction perpendicular to the pull-out direction, that is, in the width direction of the printing paper 3 using a CCD line sensor camera, and the image data of the obtained large printing area is obtained.
They inspected for defects such as dirt and pinholes.

In general, various methods for optically detecting various defects are known. For example, regarding a fine defect inspection technology and a color unevenness defect inspection technology, see Japanese Patent Application No. 5-109.
No. 280, Japanese Patent Application No. 5-26892, Japanese Patent Application No. 6-16
803 and Japanese Patent Application No. 6-39283.

[0006]

In the conventional banknote paper inspection process, a large-sized printing paper 3 is used. That is, since the inspection is not performed in the unit of the small banknote area 2 in the large plate, even if the defect of the surface in the unit of the large plate can be optically inspected and extracted, the extracted defect does not correspond to any of the small banknote areas 2. There was a problem that it could not be confirmed whether or not it existed. Therefore, even if there is a defect in the small piece banknote area at the same position in a different large plate area, since the defect position cannot be specified, the defect can be repaired in the papermaking process where the raw roll was manufactured. could not. Further, in the conventional banknote paper inspection process, the detection of paper defects is performed by a method in which data extracted based on light and dark levels is identified by a predetermined threshold, and inspection for so-called unevenness in which the boundaries between minute defects and the surroundings are unclear is performed. I didn't.

The present invention has been made to solve the above problems, and the location of an extracted defect is determined by a minimum unit set in a sheet, that is, in the above case, a large plate is used. It is an object of the present invention to provide a paper inspection apparatus capable of specifying and detecting a small-sized bill area and detecting a minute defect or an uneven defect.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided a printing paper defect inspection apparatus for inspecting a printing paper defect in which scheduled positions of a plurality of printing target areas to be arranged and printed are set in advance. Conveying means, imaging means for imaging the printing paper provided near the conveying means,
Illumination means provided in the vicinity of the imaging means, and print marks are provided on the printing paper corresponding to the position of a print target, and the print marks can be detected before the imaging means performs imaging. Print mark detecting means, means for counting the amount of movement of the printing paper by the transport means, and pulse control means for triggering count data from the counting means by output data from the print mark detecting means. An image data storage unit that stores image data obtained from the imaging unit in synchronization with an output signal of the pulse control unit; and a defect that detects a defect on the printing paper from the image data obtained from the imaging unit. Detecting means, defect data from the defect detecting means, and an image stored in the image data storing means. From over data, and summarized in that the and a defect position determining means for extracting a defect position in the print target area set in advance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram of a bill paper inspection apparatus according to one embodiment of the present invention. The bill paper inspection device 10 includes a transport mechanism 12 that transports the printing paper 3 pulled out from the material roll 1, and a printing paper 3 on the transport mechanism 12.
An imaging unit 15 including a line sensor camera 13 using a CCD for imaging the image and an illuminator 14 for illuminating an imaging location;
The printing paper 3 provided between the imaging unit 15 and the web roll 1
The video signal from the print mark detection sensor 18 for detecting the print mark 4 at the end of the image and the video signal from the camera 13 of the imaging unit 15 are converted into digital image data, and data emphasizing a defect for each predetermined number of scan lines is obtained. And a bill paper inspection control device 20 for specifying the type of the defect data and the small bill region in which the defect exists.

Further, the bill paper inspection control device 20 displays a monitor 21 for displaying an image of the printing paper 3 captured by the line sensor camera 13 and the inspection result of the bill paper inspection control device 20 in a display format described later. At the same time, a personal computer 23 for causing the printer 22 to print inspection results is connected. Further, at the rear end of the transport mechanism 12, a sorting machine 24 that sorts a large plate of a good product and a large plate of a defective product based on the inspection result from the bill paper inspection control device 20 is connected.

As shown in FIG. 1, the printing paper 3 pulled out from the material roll 1 is transported to the transport mechanism 12 by an imaging unit 15.
The inspection roller 16 is provided so as to be opposed to.
Therefore, the printing paper 3 is imaged by the imaging unit 15 at the position of the inspection roller 16. A slitter 25 and a cutting cutter 27 are provided between the inspection roller 16 and the sorting machine 24. The slitter 25 is for cutting the printing plate 3 between the large plates of the printing paper 3 shown in FIG.
Is for cutting in the direction perpendicular to the running direction of the sheet, that is, in the width direction, as shown by the two-dot chain line in the same manner.

[0012] Between the raw roll 1 and the inspection roller 16,
A print mark detection sensor 18 is provided. The print mark 4 is used for positioning at the time of printing a bill, and is provided on a side portion of the printing paper 3, that is, outside the large plate area where the bill is printed. The print mark detection sensor 18 outputs a mark detection signal each time the print mark 4 is detected.
4 is input. In addition, an encoder 33 that generates a pulse signal at fixed intervals synchronized with the rotation of the inspection roller 16 is provided near the inspection roller 16. The pulse signal from the encoder 33 is used to create information such as inspection area coordinates for capturing image data from the imaging unit 15 in correspondence with a predetermined inspection area. That is, since the print mark 4 exactly corresponds to the position of the bill printing area, the inspection area is specified by triggering the pulse signal from the encoder 33 with the mark detection signal output from the print mark detection sensor 18. can do.

The bill paper inspection control device 20 includes an imaging unit 15
In addition, an output signal from the encoder 33 is input. This control device 20 is configured as shown in FIG.
That is, the mark detection signal from the print mark detection sensor 18 is input to the pulse controller 34 and the imaging unit 1
5 are input to the image input unit 35, respectively. The video signal input to the image input unit 35 is synchronized with the pulse signal from the pulse controller 34, and is output as digital image data expressing the pixel density in 256 gradations.

The image data from the image input section 35 is input to a frame memory 36. The frame memory 36 stores image data of a predetermined number of scanning lines, for example, ten or more scanning lines. The stored image data is
The image is used to display an image on the monitor 21 and is input to an intra-slice area position determination processing unit 42 described later. The image data from the image input unit 35 is input to the filter unit 37. In the filter unit 37, a micro filter for extracting data emphasizing the contours of minute foreign matter and pinholes from the input image data, a binarization filter for binarizing large dirt and defects such as pinholes with light and dark, and It is composed of a color non-uniformity filter that extracts data that emphasizes color non-uniformity whose boundary with the surroundings is not clear.

The inspection data accumulating section 38 includes a defect judging section 4
The defect determination processing unit 45 determines various types of defects. Further, the defect determination processing unit 45 is connected to the small cut position determination processing unit 43 and
6 are connected to the in-break area position determination processing units 42, respectively. The small piece area memory 40 is connected to the small piece area position determination processing unit 42, and the large size area memory 41 is connected to the small piece area position determination processing unit 43 and the small piece position determination processing unit 43.

FIG. 2 is an enlarged view of one small bill area 2. That is, although both are indicated by dotted lines,
An identification mark 5 is formed at the upper left, and a clearance area 6 is formed at the center. The plain area 7 surrounds the identification mark and the clearance area. FIG. 3 shows one large plate A taken out, and the large plate A includes 20 small-sized bill areas in 5 columns and 4 rows. Each small bill area has the structure shown in FIG.

In FIG. 1, the coordinates of the target portion being processed by the filter unit 37 and the defect determination processing unit 45, that is, the position coordinates of the processed portion on the printing paper 3 are completely synchronized. . The same image data from the image input unit 35 is provided to the filter unit 37 and the frame memory 36, and information on a large plate of a target for which a defect is to be determined, for example, information of a large plate A is stored in the large plate area memory 41. The information about the small pieces of the object for which the defect determination is performed is held in the small piece area memory 40. The small piece area memory 40 holds small piece information of a target for which a defect is to be determined in the large version held in the large area memory. Further, the small piece area memory 40 stores not only the target small piece information but also the area within the small piece banknote area, that is, the identification mark 5, the insertion area 6, and the plain area 7 shown in FIG. Is stored.

As shown in FIG. 4, the small area memory 40 stores the coordinate data in the X and Y directions of the small area currently undergoing the defect determination processing. The X direction indicates the scanning direction of the line sensor camera 13, and the Y direction indicates the transport direction. Each grid represents one pixel, Wa
, Wa are inspection window numbers, and m1, m2,..., And mi represent small-cut banknote area numbers currently undergoing defect determination processing. 2, an identification mark 5, a clearance area 6, and a plain area 7 are designated.

As shown in FIG. 5, the large-size area memory 41 stores the coordinate data of the large-size A in the X and Y directions which is currently undergoing the defect determination processing. X direction is line sensor camera 1
3 indicates the scanning direction, and the Y direction indicates the transport direction. Each lattice represents the small bill area 2. W
, Wbi are inspection window numbers, and h1, h2, ..., hi represent small cut bill area numbers currently undergoing defect determination processing.

Next, the operation of this embodiment will be described. FIG.
Paper 3 containing large plate A divided into 4 rows and 5 columns as shown in
Is captured by the line sensor camera 13 shown in FIG. 1, and when the print mark detection sensor 18 detects the print mark 4, the image input unit 35 converts the color video signal from the camera 13 into a digital signal, and then, based on the optical error. The corrected image data is output to the frame memory 36 and the filter unit 37. The filter unit 37 performs a micro-filter process on the image data from the image input unit 35 to emphasize the contour of the fine defect, a data obtained by performing a binarization filter process on the image data from the image input unit 35, and a color unevenness. Output the highlighted data. In particular, in the bill insertion area 6 (FIG. 2), the clearance area 6 is formed by forming a portion having a small density according to the pattern or picture to be inserted with respect to the thickness of the plain area 7 of the paper. It is formed. Therefore, the inspection of unevenness is also important.

The data after the binarization filter processing is, for example, data (bright) after the binarization filter processing when the defect is a pinhole, and the data after the binarization filter processing when the defect is dirty. Output as data (dark). Also,
First unevenness data that emphasizes vertical color unevenness of high-frequency components of image data, second unevenness image data that emphasizes horizontal color unevenness of high-frequency components of image data, and vertical unevenness of low-frequency components of image data. The third data in which the color unevenness is enhanced and the fourth unevenness data in which the horizontal color unevenness of the low frequency component of the image data is enhanced are output.

On the other hand, the in-slice area position determination processing unit 42 specifies an area mi which is an inspection target area stored in the in-slice area memory 40. In the small cut position determination processing unit 43, hi indicating the small cut position of the inspection target stored in the large plate area memory 41 is specified. In this way, the target small piece banknote area in the large plate area and the identification mark 5, the insertion area 6, and the plain area 7 in the small piece banknote area, which are synchronized with the area where the filter process is being executed, are specified. The presence / absence of a defect obtained by the defect determination process following the filter process can be output by specifying the corresponding small cut banknote area. In this manner, the position coordinates of the large plate area of the sheet and the small bill area in each large plate area can be grasped in advance in synchronization with the position where the filter processing and the defect determination processing are being performed. As a result, even in a plain state where neither the large plate area nor the small cut bill area is visible in the paper, the specific large plate area where the detected defect exists, and the specific large plate area within the large plate area The position can be confirmed up to the small bill region and a specific region within the small bill region, that is, a clearance region and a plain region.

As a result of the inspection as described above, for example, the plain region 7 of the small-sized banknote region 2 in row A and column 2 of the large plate A shown in FIG.
6 is recognized as the second unevenness data, and the watermark region 6 on the B row and 4th column of the large version A is recognized as the fourth unevenness data. The test results shown are obtained.

In the first embodiment, the method for detecting a defect of only the large plate A has been described. However, the raw roll 1 is composed of the large plate A, the large plate B, and the large plate C as shown in FIG. Have been. When such three rows of large plates are to be inspected at the same time, three line sensor cameras 13 are provided, and three types of defect type determination means 51 are also provided. Accordingly, when the three types of defect type determination means 51 are provided, the display on the personal computer 23 displays the defects in the small-sized bill area for each of the large plates A, B, and C as shown in FIG. In the example of the figure, the large plates A and B indicate that the defect is 0 and the single small bill region of C has a defect.

FIG. 8 is a schematic configuration diagram of a bill paper inspection apparatus according to the second embodiment. The bill paper inspection device 60 of FIG.
A slitter position detection sensor 61 for detecting the position of the slitter 25 is provided. As shown in FIG. 9, the position of the slitter 25 for cutting the sheet is movable, and when the slitter 25 deviates from an appropriate cutting position during a continuous process, the operator can, for example, set an appropriate reference position indicated by a dotted line in FIG. It operates to correct to. The slitter position detection sensor 61 outputs the displacement amount and the displacement direction by correcting the position of the slitter 25.

Information on the displacement of the slitter position is input to the banknote inspection controller 65 as position information. After that, the in-slice segment position determination processing unit 66 and the small slice position determination processing unit 67 determine the amount of change between the previous slitter position detection signal before the current displacement from the slitter position detection sensor 61 and the current slitter position detection signal. Then, each inspection window is corrected. That is, the slitter position detection signal is fed back to the image input unit 35, and the input image position in the X direction is corrected based on the displacement between the reference slitter position and the current detected slitter position detection signal. As a result, the positions of the small-cut area number and the small-cut position number during the conveyance of the sheet are corrected, and more accurate defect inspection can be performed.

As described above, the clearance area in the small bill area is formed by inserting a predetermined pattern by changing the density of the paper. Is distinguished from a plain area, and thus, a pit area may be recognized as a non-uniform defect by a defect inspection even though it is originally normal.
Therefore, by intentionally assuming that the indented area is the same as the surrounding plain area, for example, a white background, it is possible to prevent the area from being erroneously identified as an uneven defect. That is, by making the surface of the inspection roller 16 in FIG. 1 the same color as the paper, for example, white, and irradiating the paper passing through the surface of the inspection roller 16 with illumination for inspection, the reflected light from the clearance area becomes Since it is dominated by the reflected light from the surface of the inspection roller 16, it is possible to avoid erroneous recognition as an unevenness defect. The color of the inspection surface will be selected according to the color of the plain area of the paper to be inspected.

Further, as a cause of erroneously recognizing a non-uniformity defect in spite of an originally normal clearance area, there is a positional relationship between illumination and a camera. As shown in FIGS. 10 and 11, the inspection target area is originally irradiated from the illuminator 14 so as to have the maximum illuminance, and the position of the camera 13 is arranged toward the position of the maximum illuminance. That is, the normal camera 1
3 is arranged at the position indicated by the solid line in FIG.
Is required to be directed to the position of the maximum illuminance portion a. However, as a result, a normal penetration pattern formed in the penetration area of the sheet may be identified as an uneven defect. This has been found to occur even when the surface of the above-described inspection roller 16 is white, although it differs depending on the type of the clearance area.

Such erroneous recognition can be improved by moving the position of the camera 13 in parallel as indicated by a dotted line in FIG. The parallel movement of the camera 13 is achieved by moving the optical axis of the camera from the position of the maximum illuminance to a position where the illuminance is slightly reduced, as indicated by a dotted line in FIG. That is, by moving the optical axis of the camera from the position of the maximum illuminance a in FIG. 11 to the position b where the illuminance is slightly lowered, the normal penetration area is not identified as a non-uniform defect, and the surface of the inspection roller under the paper is inspected. Recognition as a uniform white color can avoid erroneous recognition as a defect. This phenomenon is that even when the surface of the inspection roller is whitened by specular reflection at the position of the maximum illuminance, the pattern in the penetrating area is optically detected, but by moving to a position where the illuminance is slightly lowered, the camera It is considered that the diffused light area is imaged, and the color of the surface of the inspection roller can be imaged without being affected by the clearance area.

Of course, depending on the type of the insertion area, the material of the paper, etc., it is not necessary to image the position where the illuminance is lowered. It is not preferable to set the illuminance lowering position so as to hinder other defect inspections.

[0031]

As described above, according to the present invention, in the defect inspection process of the printing paper, the defective portion of the paper before the printing process can be accurately specified, and the clearance provided in the bill or the like can be obtained. Defect inspection of a sheet on which a pattern or the like having a different density of the sheet, such as an area, is formed in advance is also possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a bill to be inspected according to the present invention.

FIG. 3 is a configuration diagram of a large plate in which small cut bill areas to be inspected according to the present invention are gathered.

FIG. 4 is an explanatory view of an inspection window of a small cut bill area to be inspected according to the present invention.

FIG. 5 is an explanatory diagram of a large-size inspection window to be inspected according to the present invention.

FIG. 6 is an explanatory diagram of an inspection result in the present invention.

FIG. 7 is a diagram showing an example of an inspection result display according to the present invention.

FIG. 8 is a schematic configuration diagram of another embodiment of the present invention.

FIG. 9 is an explanatory diagram of the operation of the slitter of the present invention.

FIG. 10 is a partially enlarged schematic view of still another embodiment of the present invention.

FIG. 11 is an operation explanatory diagram of FIG. 10;

FIG. 12 is a configuration diagram of a banknote printing material roll to be inspected according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw material roll 2 Small cut banknote area 3 Printing paper 4 Print mark 5 Identification mark 6 Penetration area 7 Plain area 10 Banknote paper inspection device 12 Transport mechanism 13 Line sensor camera 14 Illuminator 15 Imaging part 16 Inspection roller 18 Print mark detection Sensor 20 Bill paper inspection control device 21 Monitor 22 Printer 23 Personal computer 24 Separator 25 Slitter 27 Cutting cutter 33 Encoder 34 Pulse controller 35 Image input unit 36 Frame memory 37 Filter unit 38 Inspection data storage unit 40 Small cut area memory 41 Large print area Memory 42 Small piece position determination processing section 43 Small piece position determination processing section 45 Defect determination processing section 60 Bill paper inspection device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriyuki Arai 66-2 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside Toshiba Engineering Corporation (72) Inventor Norijun Sugiyama No.66, Horikawa-cho, Sachi-ku, Kawasaki-shi, Kanagawa 2 Toshiba Engineering Co., Ltd. F term (reference) 5B057 AA04 BA19 CA08 CA12 CA16 CB06 CB12 CB16 CE06 CE12 CH09 DA03 DA08 DB02 DB09

Claims (6)

[Claims] 1. A printing paper defect inspection apparatus for inspecting a defect of a printing paper in which scheduled positions of a plurality of printing target areas to be array-printed are set in advance, and means for transporting the printing paper; Image pickup means for picking up the print sheet provided in the printer; illuminating means provided near the image pickup means; print marks provided on the print sheet corresponding to the position of the print target area; A print mark detecting means provided so as to be able to detect a print mark before the image is taken by the image taking means; a means for counting the amount of movement of the printing paper by the carrying means; and A pulse control unit that is triggered by output data from a print mark detection unit; and image data obtained from the imaging unit. An image data storage unit that stores the image data in synchronization with an output signal of the trawl unit; a defect detection unit that detects a defect of the printing paper from the image data obtained from the imaging unit; A defect detection unit for extracting a defect position in the preset print target area from the image data stored in the image data storage unit. 2. The printing paper defect inspection apparatus according to claim 1, wherein the printing paper is a bill printing paper. 3. The printing target area is a small piece banknote area corresponding to a bill type, and within this small piece banknote area,
3. The printing paper defect inspection apparatus according to claim 2, wherein at least a penetration area and a plain area are set. 4. The apparatus according to claim 1, wherein a roller is provided in the conveying means near the image pickup means.
The printing paper defect inspection apparatus according to the above. 5. The printing paper defect inspection apparatus according to claim 4, wherein a surface color of the roller is set to a color similar to a color of the plain area of the printing paper. 6. The image forming apparatus according to claim 4, wherein said image pickup means is set so as to pick up an image on a printing paper at a position shifted from a maximum illuminance position of illumination light emitted from said illumination means. Printing paper defect inspection device.