JP2007248376A - Inspection method and inspection device of printed pattern on ovd foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method and an inspection device of a printed pattern printed, on at least a part of a region on an OVD (Optical Variable Device) foil. <P>SOLUTION: A domain including at least the printed pattern is irradiated from the first illumination means with visible light from the coaxial direction to the observation direction of a photographic means, and printed pattern image data of the region, including at least the printed pattern are acquired, by taking the wavelength in visible light domain as an object by the photographic means. A storage means stores, beforehand reference printed pattern image data of the printed pattern used as a reference, or the reference printed pattern image data and reference position data, showing a reference position of the printed pattern used as a reference. An image processing means compares the printed pattern image data with the reference printed pattern image data, or compares the printed pattern image data with the reference printed pattern image data and the reference position data, and determines the quality of at least one among the shape, the area and the position of the printed pattern, based on the comparison result. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, a printed pattern is formed by intaglio printing, offset printing, or the like on an OVD foil applied to a base material such as a bank note, securities, gift certificate, or card, and at least a part of the region on the OVD foil. The present invention relates to an inspection method and an inspection apparatus for a printed pattern on an OVD foil that can reliably inspect whether a printed pattern printed on the OVD is normally printed.

  OVD (Optical Variable Device) is a foil in which a metal is deposited on a relief-shaped diffraction grating, and has a unique optical change function such as the appearance of a stereoscopic image and color shift. It is called. There are a sheet type for punching and applying a sheet-like material, a patch type formed in a previously applied shape, a linear thread type, and the like. These OVD foils are applied to some or all of valuable printed materials such as banknotes, securities, gift certificates, and credit cards as one of the anti-counterfeiting technologies because of their advanced manufacturing methods. .

  Manufacture of printed matter provided with OVD foil is performed by applying a sheet-type or patch-type hologram sheet to a substrate by transfer or pressure bonding. In addition, the thread type is applied to the inside or the surface of the paper by being see-through, transferred or pressure-bonded to the base material.

  Furthermore, overprinting of printed image lines and the like on the OVD foil is intended to improve forgery prevention. For example, a thin piece is attached to a predetermined location on a valuable document, and at least one anti-counterfeit mark having a fine structure that acts diffractively on the thin piece is provided. In a document having a structure for improving the forgery safety of a valuable document in which a part of the uneven structure for preventing forgery is later stamped on the surface, the uneven structure for preventing forgery is formed by a printing method generally used for the manufacture of banknotes. The prevention uneven structure is formed by an uneven line and a gap extending in between and substantially parallel to the surface of the valuable document, and at least a part of the gap is covered with a part of the forgery prevention mark. At least part of it is extremely curved, and when light is applied to the anti-counterfeit uneven structure, the reflection of the light can be visually recognized. When it is peeled from the price document, a crease is formed in the anti-counterfeit mark and the portion of the anti-counterfeit mark covering the gap is significantly deformed, and the anti-counterfeit mark is deformed when the anti-counterfeit mark is attached to another valuable type. A document having a structure for improving the forgery safety of a valuable document characterized in that is detected is disclosed (for example, see Patent Document 1).

  Now, as an apparatus for inspecting the OVD foil and the print area, the hologram layer included in the object to be inspected is irradiated with light so as to be incident at a predetermined inclination angle (θ1), and a hologram reproduction image recorded on the hologram layer is obtained. A light source that is applied to the imaging camera, and a light source that irradiates the printing surface and the base other than the hologram layer so as to be incident at an inclination angle (θ2) different from the inclination angle, and that provides a reflected image of the printing surface and the base And a quality inspection apparatus that includes a determination unit that simultaneously determines whether the hologram layer, the printing surface, and the background are good or bad (see, for example, Patent Document 2).

  In addition, an ultraviolet ray source that emits ultraviolet rays toward the hologram when the first synchronization signal is output, a visible light source that emits visible light toward the hologram when the second synchronization signal is output, When the synchronization signal is output, the first image data is acquired by imaging a hologram irradiated with ultraviolet rays, and when the second synchronization signal is output, the hologram irradiated with visible light is imaged. A synchronization signal for outputting a second synchronization signal output simultaneously to the visible light source and the camera, a first synchronization signal output simultaneously to the ultraviolet light source and the camera, A hologram inspection apparatus and inspection method including an output unit and a display unit that displays first and second image data acquired by a camera, and a positional relationship between transparent pattern layers printed on the hologram pattern , A technique for detecting defects in transparent pattern layer is disclosed (e.g., see Patent Document 3).

Japanese Patent No. 3053209 (page 1-8, Fig. 1-6) Japanese Patent No. 3339426 (page 1-4, Fig. 1-4) JP 2004-150885 A (page 1-20, FIG. 1-10)

  Inspection techniques such as OVD foil sticking quality include a method of inspecting a hologram reproduction image recorded on a hologram layer by a plurality of different irradiation methods and a printed surface other than the hologram reproduction image, and a hologram pattern using a plurality of light sources having different wavelengths. Inspection of the position and defects of the transparent pattern layer printed on is performed.

  However, the above OVD foil inspection method is an inspection method and apparatus in which the hologram area and the print area are provided in different areas, and the print pattern is overprinted on at least a part of the area on the OVD foil. It was not a printed pattern inspection method and inspection apparatus.

  When a medium on which an OVD is pasted and a printed pattern is overprinted in at least a part of the OVD is input in the visible light region, the pattern change of the OVD foil changes remarkably, so the photographed image is a reproduction of the OVD foil. Both the image and the printed pattern were reproduced, and it was difficult to stably extract only the printed pattern, and the quality of the printed pattern could not be inspected with high accuracy. Further, as a technique for suppressing the pattern change of the OVD foil, no effective quality control technique such as a printed image line on the OVD foil was found. Furthermore, when the substrate on which the OVD foil is affixed is a flexible medium, and the medium is inspected while being conveyed at high speed, the state of conveyance of the medium becomes unstable due to the floating of the medium, and the pattern change of the OVD foil is remarkable. Because of the change, it is difficult to stably extract the printed pattern on the OVD foil.

  As a result of sincere research in view of such problems, the inventors of the present invention have applied OVD foil illumination light in the same direction as the observation direction, thereby observing OVD in an image taken in the visible light region. It has been found that it is possible to suppress the reproduced image of the foil and extract the printed pattern. Furthermore, the illumination light is arranged so as to oppose each other with respect to the light that irradiates the illumination light of the OVD foil in the coaxial direction with the observation direction (coaxial light) and the light that diffuses in the observation direction (diffused light: the irradiated position) ) At the same time, it was possible to suppress the reproduced image of the OVD foil in the image taken in the visible light region, and it was found that the printed pattern on the OVD foil can be extracted stably.

  An object of the present invention is to solve such a conventional problem. In the case where a printed pattern of a medium in which a printed pattern is overprinted on at least a partial area of an OVD foil is photographed in a visible light range. The OVD foil pattern did not change, and the image taken was able to stably shoot and photograph the printed pattern on the OVD foil without reproducing both the reproduced image of the OVD foil and the printed pattern. An object of the present invention is to propose an inspection method and an inspection apparatus for a printed pattern on an OVD foil that can inspect whether a printed pattern is normally printed based on image data.

  Furthermore, the substrate on which the OVD foil is affixed is a flexible medium such as paper, and when the medium is inspected while being conveyed at high speed, even if the flexible medium such as paper is lifted or undulated, the OVD foil The printed pattern on the OVD foil can be stably photographed without reproducing both the reproduced image and the printed pattern, and quality inspection is performed to check whether the printed pattern is printed correctly based on the photographed image data. It is an object of the present invention to propose an inspection method and an inspection apparatus for a printed pattern on an OVD foil.

  The present invention is a method for inspecting a printed pattern of a medium in which a printed pattern is overprinted in at least a part of an area on an OVD foil applied to a substrate, and the illumination unit includes at least a first illumination unit. The region including at least the printed pattern from the first illumination unit is irradiated with a visible light source in a direction coaxial with the observation direction of the imaging unit, and at least the printed pattern is applied to the wavelength of the visible light region by the imaging unit. Print pattern image data of the area to be included is acquired, and the reference print pattern image data of the reference print pattern or the reference print pattern image data and the reference position data indicating the reference position of the reference print pattern are stored in advance by the storage unit Storing and comparing the print pattern image data and the reference print pattern image data by the image processing means, or the print pattern image data and the reference print The image data and the reference position data are compared, and at least a part of the OVD foil is determined based on the comparison result to determine whether at least one of the shape, area, and position of the printed pattern is acceptable. This is a method for inspecting a printed pattern of a medium on which a printed pattern is overprinted.

  The illumination unit of the present invention irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit, and a first illumination unit that irradiates the visible light source from a direction coaxial with the observation direction of the imaging unit. The second illumination means includes a plurality of illuminations, and the plurality of illumination positions are arranged to face each other with respect to a position irradiated with a visible light source from the diffusion direction. A medium on which the printed pattern is overprinted on at least a part of the OVD foil, wherein a visible light source from the diffusion direction of the second illumination unit is irradiated to at least the area including the printed pattern. This is a printed pattern inspection method.

  The illumination unit of the present invention irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit, and a first illumination unit that irradiates the visible light source from a direction coaxial with the observation direction of the imaging unit. The second illumination means includes a plurality of illuminations, and the plurality of illumination positions irradiate the reflection means with visible light from at least two directions and are reflected by the reflection means. Visible light diffuses the light reflected by the diffusing means and irradiates at least a part of the area on the OVD foil with the visible light diffused by the diffusing means on at least the area including the printed pattern. This is a method for inspecting a printed pattern of a medium on which a printed pattern is overprinted.

  Further, the acquired print pattern image data of the present invention is binarized by an image processing unit, and is a medium on which a print pattern is overprinted in at least a part of an area on an OVD foil. This is a printed pattern inspection method.

  In the invention, it is preferable that the reference print pattern image data of the reference print pattern is a binarized reference print pattern image data in which at least a part of the print pattern is printed on the OVD foil. Is a method for inspecting the printed pattern of the overprinted medium.

  Further, the present invention is an inspection device for a printed pattern of a medium in which a printed pattern is overprinted in at least a part of the region on the OVD foil applied to the substrate, and at least for the region including the printed pattern, Illuminating means having at least first illumination means for irradiating a visible light source from a direction coaxial with the observation direction of the photographing means, and print pattern image data of an area including at least the printed pattern for the wavelength of the visible light area. Photographing means; reference print pattern image data of a reference print pattern; or storage means for storing reference position data indicating the reference position of the reference print pattern image data and the reference print pattern; and the print pattern image data Or the reference print pattern image data, or the print pattern image data is compared with the reference print pattern image data and the reference position data. The printed pattern is overprinted on at least a partial area on the OVD foil, comprising image processing means for determining at least one of the shape, area, and position of the printed pattern based on the comparison result. This is an inspection device for printed patterns on a medium.

  The illumination unit of the present invention irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit, and a first illumination unit that irradiates the visible light source from a direction coaxial with the observation direction of the imaging unit. The second illumination means includes a plurality of illuminations, and the plurality of illumination positions are arranged to face each other with respect to a position irradiated with a visible light source from the diffusion direction. A medium on which the printed pattern is overprinted on at least a part of the OVD foil, wherein a visible light source from the diffusion direction of the second illumination unit is irradiated to at least the area including the printed pattern. This is a printed pattern inspection device.

  The illumination unit of the present invention irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit, and a first illumination unit that irradiates the visible light source from a direction coaxial with the observation direction of the imaging unit. The second illumination means includes a plurality of illuminations, and the plurality of illumination positions irradiate the reflection means with visible light from at least two directions and are reflected by the reflection means. Visible light diffuses the light reflected by the diffusing means and irradiates at least a part of the area on the OVD foil with the visible light diffused by the diffusing means on at least the area including the printed pattern. This is an inspection device for a printed pattern of a medium on which a printed pattern is overprinted.

  Further, the acquired print pattern image data of the present invention is binarized by an image processing unit, and is a medium on which a print pattern is overprinted in at least a part of an area on an OVD foil. This is a printed pattern inspection device.

  In the invention, it is preferable that the reference print pattern image data of the reference print pattern is a binarized reference print pattern image data in which at least a part of the print pattern is printed on the OVD foil. Is an inspection device for printed patterns on overprinted media.

  In the present invention, when a printed pattern of a medium in which a printed pattern is overprinted on at least a partial area of the OVD foil is photographed in the visible light region, the pattern of the OVD foil is not changed, Since the OVD reproduction image is not captured, only the printed pattern of the image is captured, so the printed pattern on the OVD foil is stably captured, and the printed pattern is printed normally based on the captured image data. Can be inspected.

  Further, when the substrate on which the OVD is attached is a flexible medium such as paper, and the medium is inspected while being conveyed at a high speed, even if the flexible medium is lifted or swelled, the captured image has an OVD. Since only the printed pattern is photographed without photographing the reproduction image of the foil, the printed pattern on the OVD foil is stably photographed, and the printed pattern is normally printed based on the photographed image data. Quality inspection. Therefore, all (on-machine) inspection is possible. Further, since a stable image is input and quality inspection is possible even in a stationary state, the quality of printing on the OVD foil can be confirmed and the quality inspection of printing can be performed with higher accuracy in the printing process.

  Furthermore, since the input method is in the visible light region, the quality of the printed pattern on the OVD foil can be inspected without being affected by the characteristics of the printing ink.

  The best mode for carrying out the present invention will be described 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 described in the scope of claims.

  Embodiments of the present invention will be described. The method and apparatus for inspecting a printed pattern on an OVD foil according to the present embodiment is printed on a patch-type OVD foil 2a applied on a substrate 1, for example, as shown in FIG. Printed product 4a of printed pattern 3a, printed product 4b of printed pattern 3b printed on thread type OVD foil 2b as shown in FIG. 1 (b), window opening as shown in FIG. 1 (c) A printed pattern such as a printed material 4c of the printed pattern 3c printed on the thread type OVD foil 2c can be an inspection target. Examples of the printed pattern include, but are not limited to, letters, numbers, symbols, designs, patterns, and the like. Moreover, the ink which prints a printing pattern will not be specifically limited if it is the ink which can be visually recognized in visible region. Further, the brightness of the color of the printed pattern is not particularly limited. In addition, the type of ink is preferably UV-OX ink or UV ink which has quick drying properties for printing on the OVD foil. The printing method is not particularly limited, such as an offset printing method or an intaglio printing method. Moreover, the lightness of the color of the base material 1 is not specifically limited.

  The printed pattern inspection device on the OVD foil according to the present embodiment is for inspecting the printed pattern 3 on the OVD foil 2 applied to the printed material 4 as shown in FIG. The illumination unit 12 includes an image input unit 15 including an imaging unit 13 and an input unit 14, a storage unit 16, and an image processing unit 17.

  The illumination unit 12 irradiates the visible light source 18 a from the direction coaxial with the observation direction of the photographing unit 13 to the region including the printed pattern applied to the base material 1. By irradiating the region including the printed pattern applied to the base material 1 with the visible light source 18a from the observation direction of the imaging unit 13 and the coaxial direction, the pattern of the OVD foil is not changed and the captured image is displayed. Since the reproduction image of the OVD foil is not photographed but only the printed pattern is photographed, the printed pattern on the OVD foil can be photographed stably. What is necessary is just to select suitably as what the light source of the illumination means 12 irradiates light, such as an incandescent bulb, a light emitting diode, a halogen lamp, and an HID lamp.

  Furthermore, the inspection apparatus for the printed pattern on the OVD foil according to the present embodiment is an inspection apparatus 11 for inspecting the printed pattern 3 on the OVD foil 2 applied to the printed material 4 as shown in FIG. Includes a first illumination unit 12a, a second illumination unit 12b, an image input unit 15 including an imaging unit 13 and an input unit 14, a storage unit 16, and an image processing unit 17.

  The first illumination unit 12a irradiates the visible light source 18a from the direction coaxial with the observation direction of the imaging unit 13 onto the region including the printed pattern applied to the substrate 1, and the second illumination unit 12b captures the image. The means 13 is irradiated with a visible light source 18b from the diffusion direction with respect to the observation direction. The first illuminating means 12a and the second illuminating means 12b are preferably shadowless illumination capable of uniformly irradiating the photographing means 13 with the same axis and diffused irradiation simultaneously. A visible light source 18a from the direction coaxial with the observation direction of the photographing means 13 and a visible light source 18b from the diffusion direction with respect to the observation direction of the photographing means 13 are irradiated to the region including the printed pattern imparted to the substrate 1. Thus, since the pattern of the OVD foil does not change and the reproduced image of the OVD foil is not photographed in the photographed image, but only the printed pattern is photographed. Therefore, the printed pattern on the OVD foil is stably photographed. can do. What is necessary is just to select suitably as what the light source of the illumination means 12 irradiates light, such as an incandescent bulb, a light emitting diode, a halogen lamp, and an HID lamp.

  The second illumination means 12b has at least two illuminations. For example, when there are two illuminations, it is necessary to face each other so that the illumination can be performed from two directions as shown in FIG. The number of irradiation directions of the second illumination means 12b is not limited to two directions, and can be selected as appropriate, such as four directions and six directions.

  In image data acquisition when the substrate printed on the OVD foil is a card, print pattern image data can be obtained by setting the angle and installation position of strict illumination means and photographing means, but it is a flexible medium. In the case of paper, even if the light source in the visible light region is irradiated from the same position, the pattern of the OVD foil is reproduced due to the slight difference in the paper state that occurs during conveyance, so the printed pattern on the OVD foil is stabilized. It cannot be extracted. Even in such a case, the printed pattern can be stably extracted by the illumination means described below.

  The reflecting means 20 and the diffusing means 21 have at least two or more reflecting means and diffusing means 21, and in the illuminating means, the imaging means 13 observes the region including the printed pattern applied to the substrate 1. The visible light 18a from the direction coaxial with the direction and the visible light 18b from the diffusing direction are irradiated to the photographing means 13, but when there are two second illumination means 12b as shown in FIG. And two diffusion means 21 are provided. The illumination unit 12b directly irradiates the reflection unit 20 with visible light and reflects the visible light. The reflected visible light is applied to the diffusing means 21 to diffuse the visible light. The first illumination means 12a emits visible light from the same direction as the photographing means. The visible light 18a from the coaxial direction and the diffused visible light become the visible light 18b from the diffusing direction to the photographing means 13 and irradiate at least a region including the printed pattern 3 by the photographing means 13. Print pattern photographing data of an area including at least the print pattern 3 is acquired for the wavelength of the visible light area. The material of the reflecting means 20 is formed of a metal layer such as nickel or chrome, and is a plate shape in FIG. 4, but may be a curved shape, a dome shape, or the like. The surface shape of the reflecting means is not limited to a mirror body, and may be an uneven shape or a non-uniform shape. Further, the number of the reflection means 20 is not necessarily the same as the number of illuminations, and a plurality of reflection means may be arranged for one illumination. The diffusing unit 21 is formed of diffusing glass, a diffusing optical filter, or the like, and has a plate shape in FIG. 4, but may have a curved shape, a dome shape, or the like. As described above, even in such a form, it is preferable that the illuminating unit 12 is a shadowless illumination that can uniformly irradiate the photographing unit 13 with coaxial and diffuse irradiation simultaneously.

  For example, FIG. 5A shows a printed matter 4 having a printed pattern 3 on the OVD foil 2 applied to the substrate. FIG. 5B shows a pattern in which the pattern in the OVD foil is changed by changing the angle of the same OVD foil 2 region. The printed pattern photographing data 5 of the printed matter 4 is the printed pattern photographing data only for the printed pattern without the reproduced image of the OVD foil being photographed in the photographed image without changing the pattern of the OVD foil as shown in FIG. 5 is photographed. Print pattern image data 6 shown in FIG. 6B is obtained from the print pattern photographing data 5. At this time, the print pattern photographing data 5 as an analog signal is converted into print pattern image data 6 as digital data by an analog / digital conversion circuit.

  However, in the illumination position where the imaging unit 13 is irradiated only with the visible light source 18b from the diffusing direction with respect to the observation direction, the region including the printed pattern applied to the substrate 1 as shown in FIG. When an attempt is made to acquire the print pattern image data 5 and the print pattern image data 6 of the print pattern 3 on the OVD foil 2 attached to the print 4 of FIG. 5, the OVD image is reproduced as shown in FIG. The pattern cannot be extracted. Further, with respect to the region including the printed pattern applied to the base material 1 as shown in FIG. 7B, the visible light source 18a and the imaging unit 13 are unidirectional from the observation direction of the imaging unit 13. When trying to acquire the print pattern image data 5 and the print pattern image data 6 of the print pattern 3 on the OVD foil 2 applied to the printed matter 4 in FIG. 5 at the illumination position where the visible light source 18b from the diffusion direction is irradiated. As shown in FIG. 8, the OVD image is reproduced, and the printed pattern cannot be extracted.

  The photographing means acquires photographing data under the visible light region, and the type thereof is not particularly limited, and examples thereof include a CCD line sensor camera and a CCD area sensor camera. The CCD line sensor camera is suitable for acquiring photographing data of the printed pattern 3 while the printed matter 4 is being conveyed by the inspection cylinder as shown in FIG. 9, and is used as an imaging means of the inspection apparatus 11a. On the other hand, the CCD area sensor camera is suitable for acquiring photographing data of the printed pattern 3 in a state where the printed matter 4 is stationary as shown in FIG. 10, and is used as an imaging means of the inspection apparatus 11b.

  It is desirable to arrange the camera of the photographing means in a direction orthogonal to the transport direction of the printed matter 4 so that the reproduced image of the OVD foil is not reproduced.

  In the storage unit 16, as shown in FIG. 11, the reference print pattern image data 31 of the reference print pattern or the reference print pattern image data 31 of the reference print pattern and the reference position of the reference print pattern are provided by a hard disk of a computer or the like. Is stored in advance. The reference print pattern image data 31 of the reference print pattern may be used as the reference print pattern image data 32 obtained by the binarization process. In this case, the calculation speed is improved at the stage of comparison.

  The input print pattern image data 6 is temporarily stored in the storage unit 16.

  The image processing means 17 can perform binarization processing on the print pattern image data 6. FIG. 12 shows print pattern image data 7 obtained by binarizing the print pattern image data 6 of FIG. Binarization is a method in which an object is cut out from an image in order to analyze the characteristics of the image and a background and a figure are separated. An image represented by two values of 0 and 1 from a grayscale image having a density value. Is to convert to With this binarization processing, when the bright part is white and the dark part is black, the result is as shown in FIG. Even if the image of the OVD foil and the image of the contour portion of the OVD foil remain somewhat in the printed pattern image data 6 as shown in FIG. 13A, a certain threshold value is set and binarization processing is performed to perform the OVD foil image, OVD. The image of the outline portion of the foil can be removed, and the image of the OVD foil as shown in FIG. 13B and the binarized printed pattern image data 7 in which the outline portion of the OVD foil is not reproduced are obtained.

  Further, the print pattern image data 6 input by the calculation unit of the image processing unit 17 and the reference print pattern image data 31 are compared. Alternatively, the print pattern image data 6 is compared with the reference print pattern image data 31 and the reference position data 33. Alternatively, the printing pattern image data 6 is compared with the printing pattern image data 7 obtained by binarization processing by the image processing means and the reference printing pattern image data 32 obtained by binarization processing. Alternatively, the print pattern image data 7 obtained by binarizing the print pattern image data 6 by the image processing means is compared with the reference print pattern image data 32 and the reference position data 33 obtained by binarization processing. . Based on the comparison result, the quality of at least one of the shape, area and position of the printed pattern of the medium on which the printed pattern is overprinted in at least a part of the OVD foil is determined.

  Further, as shown in FIG. 11, the storage means 16 stores in advance reference outline data 34 indicating the outline of the reference print pattern, and the image processing means 17 performs binarization processing on the input print pattern image data 6. The print pattern contour data 8 is extracted from the binarized print pattern image data 7, the print pattern contour data 8 is compared with the reference contour data 34, and at least the OVD foil is compared based on the comparison result. It is also possible to determine whether or not the shape of the printed pattern of the medium in which the printed pattern is overprinted in a part of the region is good.

  Further, as shown in FIG. 11, the storage means 16 stores reference area data 35 indicating the area value of the reference print pattern in advance, and the image processing means 17 binarizes the input print pattern image data 6. To calculate the print pattern area value 9 from the binarized print pattern image data 7, compare the print pattern area value 9 with the reference area data 35, and based on the comparison result, It is also possible to determine whether or not the print state of the print pattern of the medium on which the print pattern is overprinted in at least a part of the region is good.

  Further, in the storage unit 16, as shown in FIG. 11, the coordinates 36 representing the position of the printed pattern serving as a reference when the printed pattern is printed on the substrate and the reference for detecting the position of the printed pattern serving as the reference. Coordinates 37 indicating the positions are stored in advance, and the image processing means performs binarization processing on the input print pattern image data 6 and prints printed on the base material from the binarized print pattern image data 7 The coordinates 10 representing the pattern position and the coordinates 10a representing the reference position for detecting the position of the printed pattern are calculated, and the coordinates 10 representing the position of the printed pattern printed on the substrate and the position of the printed pattern are detected. The coordinate 10a indicating the reference position of the image is compared with the coordinates 36 representing the position of the reference printed pattern and the coordinate 37 indicating the reference position for detecting the position of the reference printed pattern. It is also possible to determine the quality of the position of the printed pattern in which at least a part of the region is printed pattern overprinted medium OVD foil Zui.

  The coordinates 37 indicating the reference position for detecting the position of the printed pattern serving as a reference is a coordinate representative of the reference mark and the base material, and the reference mark is formed by printing, cleaning, etc., and represents the base material. As for the coordinate, the coordinate of the edge part of a base material is mentioned. Therefore, in this case, it is necessary to photograph at least the area including the printed pattern and the reference mark by the photographing means. In addition, it is necessary to photograph at least the region including the printed pattern and the end portion of the substrate with the photographing means.

  The calculation unit of the image processing unit 17 compares the print pattern image data with the reference print pattern image data, etc. by a comparison determination method represented by pattern matching and image processing, a feature point extraction method, and the like.

  According to the inspection of the printed pattern, if it is within the allowable value range, it is determined to be normal and treated as a normal product, and if it is outside the allowable value range, it is determined to be defective and disposed of as an abnormal product. Further, the comparison result can be notified by display means, voice, and printing. The display can be displayed on a display, a liquid crystal screen or the like, and the output may be printed with a symbol or the like on the abnormal product.

  The flow of the method for inspecting the printed pattern of the medium in which the printed pattern is overprinted in at least a part of the region on the OVD foil applied to the base material of the present invention is as follows. A visible light source from a direction coaxial with the observation direction of the imaging means is irradiated to the area including the image.

  The region including the printed pattern irradiated with the visible light source in the second step is imaged with respect to the wavelength of the visible light region with respect to the region including the printed pattern applied to the substrate by the image input unit including the imaging unit. Then, the photographed print pattern image data is converted into print pattern image data and input.

  In the third step, the reference print pattern image data stored in advance in the storage means of the computer is read out by the arithmetic unit of the image processing means, and the input print pattern image data is compared with the read reference print pattern image data. . Alternatively, the print pattern image data is compared with the reference print pattern image data and the reference position data. Alternatively, the print pattern image data obtained by binarizing the print pattern image data by the image processing unit is compared with the reference print pattern image data obtained by the binarization process. Alternatively, the print pattern image data obtained by binarizing the print pattern image data by the image processing unit is compared with the reference print pattern image data and the reference position data obtained by the binarization process. Based on the comparison result, the quality of at least one of the shape, area and position of the printed pattern of the medium on which the printed pattern is overprinted in at least a part of the OVD foil is determined.

  Further, in the third step, the storage means stores in advance reference contour data indicating the contour of the reference print pattern, and the image processing means performs binarization processing on the input print pattern image data 6 to obtain binary data. Print pattern contour data is extracted from the value-processed print pattern image data, the print pattern contour data is compared with the reference contour data, and based on the comparison result, the print pattern is present in at least a part of the OVD foil. It is also possible to determine the quality of the printed pattern of the overprinted medium.

  In the third step, the storage means stores in advance reference area data indicating the area value of the reference print pattern, and the image processing means performs binarization processing on the input print pattern image data, The area value of the printed pattern is calculated from the printed pattern image data subjected to the value processing, the area value of the printed pattern is compared with the reference area data, and the printed pattern is formed in at least a part of the OVD foil based on the comparison result. It is also possible to determine whether or not the printing state of the printed pattern of the overprinted medium is good.

  Further, in the third step, the storage means sets coordinates representing the position of the printed pattern as a reference when the printed pattern is printed on the substrate and a reference position for detecting the position of the printed pattern as a reference. In the image processing means, the input print pattern image data is binarized, and the position of the print pattern printed on the base material from the binarized print pattern image data is represented. And coordinates indicating the reference position for detecting the position of the printed pattern, coordinates representing the position of the printed pattern printed on the substrate, and coordinates indicating the reference position for detecting the position of the printed pattern; The coordinates representing the position of the printed pattern serving as a reference and the coordinates indicating the reference position for detecting the position of the printed pattern serving as a reference are compared, and at least a partial region of the OVD foil based on the comparison result It is also possible to determine the quality of the position of the printed pattern of the printed pattern is overprinted medium.

  The coordinates indicating the reference position for detecting the position of the printed pattern serving as a reference are coordinates representative of the reference mark and the base material, and the reference mark is formed by printing, cleaning, etc., and represents the base material. Is the coordinates of the end of the substrate. Therefore, in this case, it is necessary to photograph at least the area including the printed pattern and the reference mark by the photographing means. In addition, it is necessary to photograph at least the region including the printed pattern and the end portion of the substrate with the photographing means.

  The calculation unit of the image processing means compares the print pattern image data with the reference print pattern image data, etc. by a comparison determination method represented by pattern matching and image processing, a feature point extraction method, and the like.

  Hereinafter, although the Example of the inspection method and inspection apparatus of the printed pattern on OVD foil of this invention is described in detail using drawing, the content of this invention is not limited to these Examples.

Example 1
As shown in FIG. 15, a printed pattern in which the OVD foil 2 is pasted on the white paper of the base material 1 and is printed with UV-OX intaglio ink (color: black) or the like on at least a part of the OVD foil 2 and its peripheral part. 3 was overprinted, and the reference mark 10b was printed near the printed pattern 3 with UV-OX intaglio ink (color: black) or the like to obtain a printed matter 4d.

  FIG. 14 shows the quality inspection of the printed pattern off-line when the printed pattern of the printed matter 4d is stationary. The inspection device 11c for inspecting the printed pattern 3 on the OVD foil 2 applied to the printed matter 4d includes a surface emitting flat dome illumination (LFX100SW: manufactured by CCS Co., Ltd.) as the illumination means 12, an imaging means 13 and an input unit. 14 is an inspection apparatus 11 c including an image input unit 15 including 14, a storage unit 16, an image processing unit 17 including a calculation unit, and a notification unit 22.

  The visible light source from the illuminating means 12 includes a visible light source 18a from a direction coaxial with the observation direction of the photographing means 13, and a reference mark 10b provided to the substrate 1 with a visible light source 18b from the diffusing direction to the photographing means 13. Irradiation was applied to the area of the printed pattern 3 contained. In the image input unit 15, the image capturing unit 13 acquires the print pattern image data 5 including the reference mark for the wavelength of the visible light region, and includes the print pattern 3 applied to the base material from the print pattern image data 5. On the other hand, the input unit 14 acquired the printed pattern image data 6 including the reference mark of the two-dimensional image for the wavelength in the visible light region.

  The printed pattern image data 6 including the input reference mark is binarized by the image processing means 17 to the input print pattern image data, and the printed pattern image data including the binarized reference mark is displayed. Data 7 was generated.

  The binarized print pattern image data 7 was compared with the binarized reference print pattern image data stored in the storage unit of the computer in advance by the calculation unit of the image processing unit.

  This comparison process is performed by dividing two image data of the reference print pattern image data and the binarized print pattern image data 7 to be inspected into n × m pixels (n and m are integers of 1 or more). The shape was inspected by comparison and pattern matching. A determination was made for each target pixel, and a match rate of 90% or more was determined to be acceptable. The matching rate and the area per pixel unit may be determined as appropriate.

  Further, the print pattern image data 7 including the binarized reference mark is converted into coordinates representing the reference mark 10b and coordinates of the center of gravity O of the print pattern by the calculation unit of the image processing means. Asked. The coordinates representing the reference mark 10b and the coordinates of the barycentric point O of the printed pattern with respect to the reference mark 10b are the coordinates and the reference representing the position of the reference printed pattern stored in advance in the storage means of the computer. Comparison was made with the coordinates representing the reference mark for detecting the position of the printed pattern.

  For the measurement of the position of the print pattern, coordinates t representing the reference mark 10b with respect to the reference mark 10b are obtained from the print pattern image data 7 including the binarized reference mark shown in FIG. Here, the coordinates representing the reference mark 10b are not particularly limited as long as the coordinates can identify the reference mark 10b, and may be the center of gravity. In FIG. 16, it is the specific coordinate t. Subsequently, the print pattern 3 is determined from the image data extracted above, and the center of gravity O is similarly calculated and obtained. Using the coordinates t (X0, Y0) representing the reference mark 10b obtained by this calculation as a base point, and extracting the center of gravity O (X1, Y1) of the printed pattern calculated by the same calculation, the reference mark 10b is represented. X1-X0 and Y1-Y0 are obtained from the coordinate t of the coordinates to be performed and the coordinate value of the center of gravity O of the printed pattern, are calculated, and the position is measured from the numerical values. For the presence / absence measurement of the printed pattern, the center of gravity is calculated from the image data obtained by extracting the printed pattern, the area of the target printed pattern is calculated, and the presence / absence of the printed pattern is measured. Thus, the inspection of the printed pattern is performed for the quality and position of the printing state. The shape and size of the reference mark are not particularly limited. In addition to printing, the corners of the substrate may be used as a reference.

  In this way, quality inspection such as shape inspection and position inspection of the printed pattern is performed by pattern matching, and the pass / fail is determined by the image processing unit according to the result. If the result of the shape inspection is negative based on these two determination results, the result is displayed on the liquid crystal monitor of the notification means 22 so that a warning by a speaker sounds. Furthermore, characters of “defective” (reason for rejection: misalignment, etc.) may be printed on the printed material for rejection.

(Example 2)
FIG. 17 shows the quality inspection of the printed pattern of the printed matter 4e on-line in the transport state of the printed matter, which is an inspection on the production line. The printed material 4e is conveyed by the inspection cylinder. At this time, as a conveyance type of the inspection cylinder, a known type such as a gripper or a suction type may be appropriately used. In the present embodiment, the printing paper is held by a gripper, and the rear portion of the paper (relative to the conveyance direction) is fixed by a suction method. Further, when not using the inspection cylinder, the printed pattern 3 of the inspection object can be inspected online during the conveyance on the production line by using a sheet conveyance method such as a belt conveyance or a chain gripper. In this case, it is desirable to suppress the lifting of the paper as much as possible.

  As shown in FIG. 17, an OVD foil 2 is pasted on the white paper of the substrate 1, and a printing pattern is printed with UV-OX intaglio ink (color: black) or the like on at least a part of the OVD foil 2 and its peripheral part. No. 3 is overprinted, and the reference mark 10c is printed near the printed pattern 3 with UV-OX intaglio ink (color: black) or the like to obtain a printed matter 4e.

  As shown in FIG. 16, the quality of the printed pattern on-line in the transport state of the printed pattern 4e is such that the inspection device 11d for inspecting the printed pattern 3 on the OVD foil 2 applied to the printed article 4e Surface emitting flat dome illumination (LFX100SW: manufactured by CCS Co., Ltd.) as the illumination means 12, image input means 15 including the imaging means 13 and the input unit 14, storage means 16, image processing means 17 including the calculation unit, and notification means 22 It is an inspection apparatus 11d provided with.

  The visible light source from the illuminating means 12 includes a visible light source 18a from a direction coaxial with the observation direction of the photographing means 13, and a reference mark 10c provided to the base material 1 with a visible light source 18b from the diffusion direction to the photographing means 13. Irradiation was applied to the area of the printed pattern 3 contained. In the image input unit 15, the image capturing unit 13 acquires the print pattern image data 5 including the reference mark for the wavelength of the visible light region, and includes the print pattern 3 applied to the base material from the print pattern image data 5. On the other hand, the input unit 14 acquired the printed pattern image data 6 including the reference mark of the two-dimensional image for the wavelength in the visible light region.

  The input print pattern image data 6 including the reference marks is binarized by the image processing means 17 to generate the print pattern image data 7 including the reference marks.

  The binarized print pattern image data 7 was compared with the binarized reference print pattern image data stored in the storage unit of the computer in advance by the calculation unit of the image processing unit.

  In this comparison processing, the two image data of the reference print pattern image data and the binarized print pattern image data 7 to be inspected are divided into n × m pixels (n and m are integers of 1 or more), respectively. In comparison, the shape confirmation was inspected by pattern matching, and determination was made for each target pixel. The matching rate and the area per pixel unit may be determined as appropriate.

  For the measurement of the position of the printed pattern, coordinates t representing the reference mark 10c with respect to the reference mark 10c are obtained from the printed pattern image data 7 including the binarized reference mark shown in FIG. Here, the coordinates representing the reference mark 10c are not particularly limited as long as the coordinates can identify the reference mark 10c. In FIG. 18, the coordinates are the center of gravity t coordinates. Subsequently, the print pattern 3 is determined from the image data extracted above, and the center of gravity O is similarly calculated and obtained. Using the coordinates t (X0, Y0) representing the reference mark 10c obtained by this calculation as a base point, and extracting the center of gravity O (X1, Y1) of the printed pattern calculated by the same calculation, the reference mark 10c is represented. X1-X0 and Y1-Y0 are obtained from the coordinate t of the coordinates to be performed and the coordinate value of the center of gravity O of the printed pattern, are calculated, and the position is measured from the numerical values. For the presence / absence measurement of the printed pattern, the center of gravity is calculated from the image data obtained by extracting the printed pattern, the area of the target printed pattern is calculated, and the presence / absence of the printed pattern is measured. Thus, the inspection of the printed pattern is performed for the quality and position of the printing state. The shape and size of the reference mark are not particularly limited. In addition to printing, the corners of the substrate may be used as a reference.

  In this way, quality inspection such as shape inspection and position inspection of the printed pattern is performed by pattern matching, and the pass / fail is determined by the image processing unit according to the result. If the result of the shape inspection is negative based on these two determination results, the result is displayed on the liquid crystal monitor of the notification means 22 so that a warning by a speaker sounds. Furthermore, characters of “defective” (reason for rejection: misalignment, etc.) may be printed on the printed material for rejection.

  Further, the printed matter 4e attached with the OVD foil conveyed in the inspection cylinder in the on-line inspection may be slightly lifted from the inspection cylinder or the paper may be swelled. Can always capture and input stable print pattern image data, and can accurately inspect the print pattern quality of a medium in which the print pattern is overprinted in at least a part of the OVD foil and its peripheral part.

It is a figure which shows the printed matter by which the printing pattern was overprinted in the at least one part area | region of OVD foil provided to the base material 1. FIG. It is explanatory drawing of the inspection apparatus of the printed pattern 3 on the OVD foil 2 by this Embodiment. It is explanatory drawing of the inspection apparatus of the printed pattern 3 on the OVD foil 2 by this Embodiment. It is explanatory drawing of the inspection apparatus of the printed pattern 3 on the OVD foil 2 by this Embodiment. It is a figure which shows the printed matter 4 which has the printed pattern 3 on the OVD foil 2 provided to the base material 1. FIG. It is explanatory drawing of the printing pattern imaging | photography data 5 and the printing pattern image data 6. FIG. For a region including a printed pattern applied to the base material 1, or a region including a printed pattern applied to the base material 1 when the imaging means 13 is irradiated with only the visible light source 18 b from the diffusion direction. FIG. 5 is a diagram in the case where the visible light source 18a is irradiated from the observation direction and the coaxial direction of the imaging unit 13 and the visible light source 18b from one diffusion direction is irradiated to the imaging unit 13. It is the printing pattern imaging | photography data 5 and the printing pattern image data 6 which were obtained with the illumination means of FIG. It is explanatory drawing of the test | inspection apparatus which test | inspects the printed pattern 3 while the printed matter 4 is conveyed by the test | inspection cylinder. This is an inspection device that inspects the printed pattern 3 while the printed matter 4 is stationary. It is explanatory drawing of a memory | storage means. It is explanatory drawing of the printing pattern image data 7 by which the binarization process was carried out. It is explanatory drawing of the printing pattern image data 7 obtained by binarizing the printing pattern image data 6. FIG. It is printed matter 4d. It is explanatory drawing of the inspection apparatus 11c. It is explanatory drawing which detects the position of a printing pattern from the specific coordinate of a reference mark. It is explanatory drawing of the inspection apparatus 11d. It is explanatory drawing which detects the position of a printing pattern from the gravity center coordinate of a reference mark.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2, 2a, 2b, 2c OVD foil 3, 3a, 3b, 3c Print pattern 4, 4a, 4b, 4c, 4d, 4e Printed matter 5 Print pattern photographing data 6 Print pattern image data 7 Binarized processing Print pattern image data 8 Print pattern outline data 9 Print pattern area value 10 Coordinates representative of print pattern position printed on substrate 10a Coordinates indicating reference position for print pattern position detection 10b, 10c standard Mark 11, 11a, 11b, 11c, 11d Inspection apparatus 12 Illuminating means 12a First illuminating means 12b Second illuminating means 13 Imaging means 14 Input unit 15 Image input means 16 Storage means 17 Image processing means 18, 18a, 18b Visible Light source 19 Transparent substrate 20 Reflecting means 21 Diffusing means 22 Notifying means 31 Reference print pattern image data of a reference print pattern 32 2 Reference print pattern image data obtained by the digitization process 33 Reference position data indicating the reference position of the reference print pattern
34 Reference outline data indicating the outline of the reference print pattern 35 Reference area data indicating the area value of the reference print pattern 36 Coordinates representative of the position of the reference print pattern 37 Reference position of the reference print pattern Coordinates indicating the reference position for detection
P standard t coordinate

Claims (10)

A method for inspecting a printed pattern of a medium in which a printed pattern is overprinted in at least a part of an area on an OVD foil applied to a substrate,
The illuminating means has at least a first illuminating means, and irradiates a visible light source from the first illuminating means to a region including at least the printed pattern with a visible light source in a direction coaxial with an observation direction of the photographic means. Obtaining print pattern image data of an area including at least the print pattern for the wavelength of the light area;
The storage means stores in advance reference print pattern image data of a reference print pattern or reference position data indicating the reference print pattern image data and a reference position of the reference print pattern,
By the image processing means, the print pattern image data is compared with the reference print pattern image data, or the print pattern image data is compared with the reference print pattern image data and the reference position data,
Inspecting the printed pattern of the medium on which the printed pattern is overprinted in at least a part of the area on the OVD foil, wherein at least one of the shape, area and position of the printed pattern is determined based on the comparison result Method. The illumination unit includes a first illumination unit that irradiates a visible light source from a direction coaxial with an observation direction of the imaging unit, and a second illumination unit that irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit. Consists of
The second illumination means has a plurality of illuminations,
The plurality of illumination positions are arranged to face each other with respect to a position irradiated with a visible light source from the diffusion direction,
The printed pattern is overprinted on at least a part of the OVD foil according to claim 1, wherein a visible light source from the diffusion direction of the second illuminating unit is irradiated to at least a region including the printed pattern. Inspection method for printed patterns on printed media. The illumination unit includes a first illumination unit that irradiates a visible light source from a direction coaxial with an observation direction of the imaging unit, and a second illumination unit that irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit. Consists of
The second illumination means has a plurality of illuminations,
The plurality of illumination positions irradiate the reflecting means with visible light from at least two directions,
The visible light reflected by the reflecting means diffuses the light reflected by the diffusing means,
3. The medium in which a printed pattern is overprinted on at least a part of an area on an OVD foil according to claim 1, wherein visible light diffused by the diffusing unit is irradiated to at least a region including the printed pattern. Inspection method for printed patterns.   4. The acquired printed pattern image data is binarized by an image processing means, and the printed pattern is overprinted in at least a part of the area on the OVD foil according to claim 1, 2 or 3. For inspecting printed pattern of printed media.   5. The at least part of the region on the OVD foil according to claim 1, wherein the reference print pattern image data of the reference print pattern is binarized reference print pattern image data. A method for inspecting a printed pattern on a medium on which a printed pattern is overprinted. An inspection device for a printed pattern of a medium in which a printed pattern is overprinted in at least a part of an area on an OVD foil applied to a substrate,
An illuminating unit having at least a first illuminating unit that irradiates at least a region including the printed pattern with a visible light source from a direction coaxial with an observation direction of the photographing unit;
Photographing means for acquiring printed pattern image data of a region including at least the printed pattern for a wavelength of a visible light region;
Storage means for preliminarily storing reference print pattern image data of a reference print pattern or reference position data indicating the reference print pattern image data and a reference position of the reference print pattern;
The print pattern image data is compared with the reference print pattern image data, or the print pattern image data is compared with the reference print pattern image data and the reference position data, and the shape of the print pattern is determined based on the comparison result. An apparatus for inspecting a printed pattern of a medium in which a printed pattern is overprinted on at least a part of an area on an OVD foil, comprising image processing means for determining at least one of area and position. The illumination unit includes a first illumination unit that irradiates a visible light source from a direction coaxial with an observation direction of the imaging unit, and a second illumination unit that irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit. Consists of
The second illumination means has a plurality of illuminations,
The plurality of illumination positions are arranged to face each other with respect to a position irradiated with a visible light source from the diffusion direction,
The printed pattern is overprinted on at least a part of the OVD foil according to claim 6, wherein a visible light source from the diffusion direction of the second illuminating means is irradiated to at least a region including the printed pattern. Inspection device for printed pattern of printed media. The illumination unit includes a first illumination unit that irradiates a visible light source from a direction coaxial with an observation direction of the imaging unit, and a second illumination unit that irradiates a visible light source from a diffusion direction with respect to the observation direction of the imaging unit. Consists of
The second illumination means has a plurality of illuminations,
The plurality of illumination positions irradiate the reflecting means with visible light from at least two directions,
The visible light reflected by the reflecting means diffuses the light reflected by the diffusing means,
8. The medium in which a printed pattern is overprinted on at least a part of the OVD foil according to claim 6 or 7, wherein visible light diffused by the diffusing unit is irradiated to at least a region including the printed pattern. Printing pattern inspection equipment.   9. The acquired printed pattern image data is binarized by an image processing means, and the printed pattern is overprinted in at least a part of the area on the OVD foil according to claim 6, 7 or 8. Inspection device for printed pattern of printed media.   10. The at least partial region on the OVD foil according to claim 6, wherein the reference print pattern image data of the reference print pattern is binarized reference print pattern image data. Inspection device for printed patterns on media with printed patterns printed on top.

Images