JP2000187008A - Inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable automatic setting of an area to be inspected and an area not to be inspected by picking up the image of illuminated hologram-processed printed matter, extracting a hologram-processed area as a bright part of image data, and setting an area not to be inspected including the hologram-processed area. SOLUTION: Illumination means 2a-2c illuminate hologram-processed printed matter 20 so that an image pickup means 1 such as an area sensor camera may receive light containing regularly reflected light. An image signal outputted by the image pickup means 1 is subjected to A/D conversion 3, inputted to a data processing part 4 as image data, and stored in a storage device as reference image data 5 or inspection object image data 6. The hologram-processed area extracting means 9 of the data processing part 4 extracts a hologram- processed area as a bright part of image data. A means 10 for setting an area not to be inspected sets an area not to be inspected including the hologram- processed area. A comparing and determining means 11 compares the reference image data 5 and the inspection object image data 6 except the area not to be inspected and inspects the presence or absence of defects in the processed printed matter 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of inspecting the quality of a printed matter. In particular, the present invention relates to an inspection apparatus for inspecting a hologram processed print having a hologram processed area and a print area.

[0002]

2. Description of the Related Art Defective printed materials include poor registration, missing colors,
Poor color, fog, water loss, paper wrinkles, dirt, hickey,
There is a defect called ink splash, oil dripping, doctor streak, and the like. The causes of these defects include those caused by printing materials such as paper, ink, and fountain solution, and those caused by printing processes such as printing presses, printing plates, and operator operations (condition setting). As an apparatus for comprehensively inspecting the appearance defect of such printed matter, for example, Japanese Patent Publication No.
A technique relating to an inspection apparatus of a method of comparing the reference image data of an image memory with image data of an inspection object obtained by imaging in a pixel unit to determine the quality of a printed matter is described.
The reference image data is image data read by the image pickup apparatus from a picture of a printed material transferred when a normal printed material is printed, and is stored in an image memory. The inspection target image data is image data read by the imaging device every time an inspection is performed from a printed material to be inspected during printing.

[0003] In addition to the inspection apparatus of the type that performs inspection by comparing with such reference image data, it is necessary to distinguish the area to be inspected from the area to be inspected in the printed matter to be inspected in other types of inspection apparatuses. is there. By distinguishing the areas in this manner, bad influences (noise) from the uninspected area on the quality determination of the inspected area are eliminated. For this reason, conventionally, in an image display monitor of an inspection apparatus that displays image data (usually, but not limited to, reference image data) read by an imaging apparatus, an operator sets a setting to distinguish an area to be inspected from an area not to be inspected. Input before the start of inspection.

[0004]

As described above, in the conventional inspection apparatus, since the operator sets the area to be inspected and the area not to be inspected, the operator needs to learn the complicated setting operation. . In addition, since it coincides with the busy time zone at the start of printing, the work load in the setting becomes extremely large, and production setting may be hindered due to incorrect setting.

Further, in the conventional inspection apparatus, it is a precondition that the setting of the area to be inspected and the area not to be inspected are the same for all the image data to be inspected. That is, the distinction between the region to be inspected and the region not to be inspected set before the start of the inspection cannot be changed until the inspection of a series of printed materials is completed (until the print item is switched). However, the operator performs setting input based on only one piece of image data captured by sampling, and there is generally no guarantee that the setting is appropriate for other image data. .

Therefore, in the case where the area to be inspected and the area not to be inspected change in the printed matter read by the image pickup apparatus at each inspection, the conventional inspection apparatus cannot be applied at all. For example, such a printed matter is found in a printed matter using a printing paper provided with a hologram that is not synchronized with the printing in advance. In particular, in securities, cash vouchers, gift certificates, vouchers, and the like, printed matter provided with a hologram to prevent forgery is used.
Such prints have strict print quality standards and require inspection.

Therefore, an object of the present invention is to automatically set an area to be inspected and an area not to be inspected.
An object of the present invention is to provide an inspection apparatus for a hologram-processed printed material that can make its settings effective even when the area of the printed material read by the imaging device changes every time the inspection is performed.

[0008]

The above objects are achieved by the present invention described below. That is, the inspection apparatus according to claim 1 of the present invention is an inspection apparatus that inspects a hologram processed print having a hologram processed area and a print area, and an imaging unit that images the hologram processed print and outputs an imaging signal. And an illuminating unit that illuminates the processed print so that the imaging unit receives light including specularly reflected light,
A / D conversion means for inputting the imaging signal to generate image data, hologram processing area extraction means for extracting the hologram processing area as a bright part in the image data, and a non-inspection area including the hologram processing area. And non-inspection area setting means for setting.

According to the present invention, the hologram processed printed matter is imaged by the imaging means, an imaging signal is output, and the processed printed matter is illuminated by the illumination means such that the imaging means receives light including specularly reflected light. An image signal is input by the conversion means, image data is generated, a hologram processing area is extracted as a bright part in the image data by the hologram processing area extraction means, and a non-inspection area including the hologram processing area is set by the non-inspection area setting means. You. Therefore, there is provided an inspection apparatus for a hologram processed print, which can automatically set an area to be inspected and an area not to be inspected.

[0010] The inspection apparatus according to claim 2 of the present invention comprises:
2. The inspection apparatus according to claim 1, wherein the non-inspection area setting means sets an entire predetermined range in a direction parallel or at right angles to a transfer direction of the hologram processed print as an uninspection area. ADVANTAGE OF THE INVENTION According to this invention, the hologram processing which can make the setting effective even in the case where the area | region in the direction parallel to a conveyance direction or a perpendicular direction changes with respect to the printed matter read by an imaging device at each inspection. An apparatus for inspecting printed matter is provided.

Further, the inspection apparatus according to claim 3 of the present invention comprises:
The inspection apparatus according to claim 1, wherein a reference image for image inspection obtained by imaging by the imaging unit and an inspection target image are compared with each other except for the non-inspection area to determine whether there is a defect in the web. This has a comparison / determination means for inspection. According to the present invention, the presence / absence of a defect in the web is inspected by comparing the reference image for image inspection obtained by imaging by the imaging unit and the inspection target image except for the non-inspection area by the comparison determination unit.

The inspection apparatus according to claim 4 of the present invention comprises:
4. The inspection apparatus according to claim 1, wherein the hologram is a reflection hologram having a reflection layer of a metal thin film on a two-dimensional hologram surface on which relief interference fringes are recorded. According to the present invention, the hologram provided on the hologram processed print is a reflection hologram having a reflection layer of a metal thin film on a two-dimensional hologram surface on which relief interference fringes are recorded. That is, the reflection layer of the reflection hologram strongly regularly reflects the irradiation light of the illumination means. Therefore, strong specularly reflected light is received by the imaging means, and it is easy to distinguish the hologram area from other areas, so that the inspection apparatus of the present invention can be suitably applied.

[0013] The inspection apparatus according to claim 5 of the present invention comprises:
The inspection apparatus according to any one of claims 1 to 4, wherein the imaging means is a line sensor camera, and the hologram processed print is a web, and the main scanning by the line sensor camera and the sub-scanning by transporting the web. And an image pickup signal is output by imaging the web. ADVANTAGE OF THE INVENTION According to this invention, the inspection of the hologram processed printed matter of the web conveyed by a line sensor camera can be performed.

[0014]

Next, the present invention will be described with reference to embodiments. FIG. 1 shows an example of the configuration of the inspection apparatus of the present invention. In FIG. 1, 1 is an imaging unit, 2a to 2c are illumination units, 3 is an A / D conversion unit, 4 is a data processing unit,
Is reference image data, 6 is inspection object image data, 7 is non-inspection area data, 8 is determination data, 9 is hologram processing area extraction means, 10 is non-inspection area setting means, 11 is comparison determination means, and 20 is hologram processing It is a printed matter.

The image pickup means 1 picks up an image of a hologram processed print and outputs an image pickup signal. As the imaging unit 1, for example, an area sensor camera, a line sensor camera, or the like can be used. When an area sensor camera is used, an electronic shutter is operated in synchronization with the transfer of the hologram processed print 20 to be inspected, or an illumination is instantaneously emitted to capture an image of a predetermined area. When a line sensor camera is used, imaging is performed by combining the main scanning by the line sensor camera and the sub-scanning by transferring the hologram processed print 20. That is, the main scanning by the line sensor camera is performed in synchronization with the transfer of the hologram processed printed material 20 to be inspected, and the main scanning is repeated a predetermined number of times to image a predetermined area.

The illuminating means 2a to 2c illuminate the processed print so that the imaging means 1 receives light including specularly reflected light. Among the light beams that the illuminating means 2a and 2b irradiate the hologram processed print 20, the light beam received by the imaging device 1 is diffused light. Also, of the light beams emitted from the illumination unit 2c to the hologram processed print 20 via the half mirror, the light beams received by the imaging unit 1 are specularly reflected light. In the example shown in FIG. 1, illumination is performed from three different positions, but is not limited to this configuration. In the present invention, the image pickup unit 1 including the image pickup unit 1 and the illumination units 2a to 2c is configured so that the image pickup unit 1 receives specularly reflected light from a hologram as a non-inspection area.

A / D conversion means (analog-to-digital conv
erter) 3 inputs an image pickup signal output from the image pickup means 1;
An analog signal is converted into digital data to generate image data. The data processing unit 4 is a data processing device such as a microcomputer or a personal computer, and can include a dedicated high-speed image processing unit or the like in its configuration. The image data generated by the A / D converter 3 is input by the data processing unit 4 and stored in the storage device of the data processing unit 4 as the reference image data 5 or the inspection target image data 6. This image data is image data obtained by imaging with one cycle of the plate cylinder as a cycle. Normally, printed matter (regular paper) that becomes a product in a printing press
Are printed, the reference image data is stored immediately before the start of the inspection, and the inspection target image data is stored during the inspection. The data processing unit 4 also stores non-inspection area data 7 which is data relating to a non-inspection area set by the non-inspection area setting means 10, judgment data 8 which is data relating to good / bad judgments performed by the comparison judgment means 11, and the like. Store it in the device.

The hologram processing area extracting means 9, the non-inspection area setting means 10, and the comparison judging means 11 can be realized by hardware and software of the data processing section 4. The hologram processing area extracting means 9 extracts the hologram processing area as a bright part in the image data. Normally, reference image data 5 is used as the image data. The non-inspection area setting means 10 sets a non-inspection area including the hologram processing area. The data relating to the non-inspection area is the non-inspection area data 7. The process of setting the non-inspection area will be described later in detail (see FIG. 3). The comparison determination unit 11 compares, for example, the reference image data and the inspection target image data except for the non-inspection area,
The presence or absence of a defect in the hologram processed print 20 is inspected.

Here, the hologram processed printed material 20 to be inspected will be described. As already explained,
In particular, in securities, cash vouchers, gift certificates, vouchers, and the like, printed matter provided with a hologram to prevent forgery is used. Such prints have strict print quality standards and require inspection. As a hologram provided on printing paper, a reflection hologram having a reflection layer of a metal thin film on a two-dimensional hologram surface on which relief interference fringes are recorded is widely used. The thickness of the recording layer substantially required as a hologram is 1
About 0 to 20 μm is sufficient. Therefore, the thickness of the portion of the printing paper provided with the hologram does not particularly increase.

Since the material for the reflection type hologram is inexpensive and suitable for mass production, for example,
Hot press replication is applied. By the hot press duplication method, a transfer foil hologram, which is a material for transferring a hologram to printing paper, is manufactured. In the transfer foil hologram, a polyester film (P
ET film) is used as the base film. The PE
A thermoplastic resin layer is formed on the surface of the T film that has been subjected to the release treatment, following the protective film. In a state where the thermoplastic resin layer is semi-molten, hot pressing is performed by a press stamper on which relief-shaped interference fringes are formed to copy the relief-shaped interference fringes. Then, a vapor-deposited film of aluminum (Al) is formed on the surface of the hot-pressed thermoplastic resin layer, and a heat-sensitive adhesive layer is formed on the surface of the vapor-deposited film by coating. By this hot press duplication method, a transfer foil hologram is obtained.

When the heat-sensitive adhesive layer of the transfer foil hologram and the printing paper are overlapped and hot-pressed, the heat-sensitive adhesive layer and the printing paper adhere to each other. Since the protective film is formed on the surface of the PET film that has been subjected to the peeling treatment, the PET film and the protective film can be peeled off, and all the layers below the protective film are transferred to printing paper. You. That is, a layer of the relief interference fringes whose reflectance is increased by the Al vapor deposition film is transferred to the printing paper. When the relief interference fringes are observed at a position at a predetermined (relatively narrow) angle with respect to the incident light, an image can be observed by holographic interference. In general, the hologram has an Al vapor-deposited film formed thereon, so that the hologram specularly reflects incident light.

Printing is performed on the printing paper provided with the hologram, and a hologram processed print is obtained. FIG. 2 shows an example of the printed hologram. In FIG. 2, 1
Is a printing paper, 2a to 2d are printed character patterns, and 3a to 3g are holograms. The printed character patterns 2a to 2d are printed with one cycle of the plate cylinder as a cycle. Also, the holograms 3a ~
3g is transferred at a cycle set in a transfer foil hologram transfer device. As shown in FIG. 2, the arrangement intervals of the printed character patterns 2a to 2d and the arrangement intervals of the holograms 3a to 3g are different and are not synchronized. That is, the printing process of the printed character patterns 2a to 2d and the transfer process of the holograms 3a to 3g are different processes. In this example, the printing character patterns 2a to 2d are printed on the printing paper 1 on which the holograms 3a to 3g have been transferred in advance.

As described above, when inspecting the quality of the printing process using the inspection apparatus of the present invention, the inspection is performed based on image data obtained by imaging with one cycle of the plate cylinder as a cycle. In the image data, inspection is performed using the character patterns 2a to 2d of the hologram processed printed material 20 as an inspection region and the holograms 3a to 3g as non-inspection regions.

Next, a process for setting a non-inspection area in the inspection apparatus of the present invention will be described. FIG. 3 is a flowchart showing a process of setting a non-inspection area in the inspection apparatus of the present invention. In FIG. 3, the flow from step S1 to step S5 shows the process of processing. 3 (A) is step S2, FIG. 3 (B) is step S3, FIG. 3 (C)
FIG. 4 is a schematic diagram for explaining processing in each step S4 using image data.

First, in step S1, printing on a printing paper on which hologram processing has been performed is started. Next, in step S2, when a good hologram processed print 20 that can be used as a product is obtained, the imaging signal output by the imaging unit 1 is converted to the reference image data 5
Is stored in the data processing unit 4 of the inspection apparatus. The reference image data 5 is, as schematically shown in FIG.
The part of the hologram where the regular reflection light is imaged by the imaging means is an image that is extremely bright relative to the surrounding parts.

Next, in step S3, the hologram processing area extraction means 9 extracts the hologram processing area as an extremely bright part in the reference image data 5. For example, the reference image data 5 can be binarized and extracted as its bright part. As the threshold value for binarization, an appropriate fixed value, a pixel value that becomes a valley in a histogram of pixel values, a threshold value determined by a discriminant analysis method, or the like can be used. Further, the hologram processing area extraction means 9 determines the position of the boundary between the extracted hologram processing area and the other area. For example, hologram processed printed matter 2
The position of the boundary of the hologram processing area in the direction parallel to or perpendicular to the zero transfer direction is determined.

As to which of the parallel direction and the perpendicular direction, the direction perpendicular to the direction in which the hologram processing is performed on the printing paper is usually selected. In other words, the hologram exists continuously or discontinuously (interrupted) in the direction in which the hologram processing was performed. Therefore, by determining the position of the boundary in the perpendicular direction, the hologram is located inside the boundary. Exists, and no hologram exists outside the boundary. The position of the boundary of the hologram processing region can be determined as the position of a pixel that changes from a bright part to a dark part in the above-described binary image data, or the position between pixels where the change occurs. FIG. 3B schematically shows the position (X _i , X _{i + m} ) in the reference image data 5. X
_{i to} X _{i + m} are hologram processing areas. i is the position, m
Corresponds to the width of the hologram processing area.

Next, in step S4, the non-inspection area setting means 10 sets a non-inspection area including the hologram processing area. For example, the above-mentioned hologram processed printed matter 20
The entirety of a predetermined range in a direction parallel to or perpendicular to the transfer direction is set as a non-inspection area. The predetermined range in the reference image data 5 is schematically shown in FIG. X _{in to} X _{i + m + n} are non-inspection areas. n corresponds to an allowable range for a position error in hologram processing and printing.

Next, in step S4, the inspection is started. The imaging unit 1 performs imaging in synchronization with the transfer of the hologram-processed printed material 20, using one round of the plate cylinder as one unit of the inspection target image. The inspection target image data 6 is sequentially input to the data processing unit 4 and updated in synchronization with the transfer of the hologram processed print 20. Each time the inspection target image data 6 is updated, the comparison determination unit 11 compares the reference image data 5 with the inspection target image data 6 except for the non-inspection area described above.
Thus, the presence or absence of a defect in the hologram processed print 20 is inspected.

Although the present invention has been described with reference to the embodiment, the present invention is not limited to this, and can be implemented in various forms based on the technical idea of the present invention. It goes without saying that it is included. For example, the hologram processing region is not limited to a hologram as long as it is a region that performs strong regular reflection. It may be a metal foil processed region having no hologram, or a surface layer of optically smooth plastic or the like. That is, in the present invention, the hologram processing region is a representative example for convenience of explanation. The hologram processing region in the present invention means a region showing strong regular reflection.

[0031]

As described above, according to the inspection apparatus according to the first aspect of the present invention, there is provided an inspection apparatus for a hologram processed print, which can automatically set an area to be inspected and an area not to be inspected. According to the inspection apparatus of the second aspect of the present invention, even in a case where the area in the direction parallel to or perpendicular to the transport direction changes in the printed matter read by the imaging device at each inspection, the setting can be performed. A hologram-processed printed matter inspection apparatus capable of making the above effective is provided. Further, according to the inspection apparatus according to claim 3 of the present invention, the comparison and determination unit compares the reference image for image inspection obtained by imaging by the imaging unit and the inspection target image except for the non-inspection region, thereby reducing Inspect for defects. According to the inspection apparatus of the fourth aspect of the present invention, strong specularly reflected light is received by the imaging means, and it becomes easy to distinguish the hologram area from other areas. Therefore, the inspection apparatus of the present invention is preferably applied. can do. Further, according to the inspection device of the fifth aspect of the present invention, it is possible to inspect the hologram processed printed material of the web transferred by the line sensor camera.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a configuration of an inspection device of the present invention.

FIG. 2 is a diagram showing an example of a hologram processed print.

FIG. 3 is a flowchart showing a process for setting a non-inspection area in the inspection apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Imaging means 2a-2c Illumination means 3 A / D conversion means 4 Data processing unit 5 Reference image data 6 Inspection object image data 7 Non-inspection area data 8 Judgment data 9 Hologram processing area extraction means 10 Non-inspection area setting means 11 Comparison judgment Means 20 Hologram processed printed matter

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G07D 7/00 G06F 15/62 410A

Claims (5)

[Claims] 1. An inspection apparatus for inspecting a hologram processed printed matter having a hologram processed area and a printed area, wherein the imaging means outputs an image signal by imaging the hologram processed printed matter; Illuminating means for illuminating the processed print so as to receive light including: A / D conversion means for inputting the imaging signal to generate image data; and extracting the hologram processing area as a bright part in the image data An inspection apparatus comprising: a hologram processing region extracting unit that performs the operation; and a non-inspection region setting unit that sets a non-inspection region including the hologram processing region. 2. The inspection apparatus according to claim 1, wherein the non-inspection area setting means sets the entirety of a predetermined range in a direction parallel or perpendicular to a transfer direction of the hologram processed print as a non-inspection area. Inspection equipment characterized. 3. The inspection apparatus according to claim 1, wherein a reference image for image inspection obtained by imaging by the imaging means and an inspection target image are compared except for the non-inspection area, thereby obtaining the web. An inspection apparatus comprising a comparison / determination means for inspecting the presence or absence of a defect in the apparatus. 4. The inspection apparatus according to claim 1, wherein the hologram is a reflection hologram having a metal thin film reflection layer on a two-dimensional hologram surface on which relief interference fringes are recorded. Inspection equipment. 5. An inspection apparatus according to claim 1, wherein said imaging means is a line sensor camera, and said hologram processed print is a web, and said main scanning and said web are performed by said line sensor camera. An inspection apparatus for capturing an image of the web and outputting an image signal in combination with sub-scanning by transport of the web.