JP5370953B2 - Printed inspection equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device of printed matter on which printing patterns are printed by inks, having different characteristics in an infrared region. <P>SOLUTION: The inspection device of the printed matter is constituted of a pressing means comprising an elongation means for fixing and installing a material to be printed on the fixing means of an inspection stand while stretching the wrinkles, bending or flotation of the material to be printed; an illumination means having a plurality of illumination units for emitting light containing infrared rays; an image input means for acquiring infrared image data; a memory means for storing the determination data for a printing pattern becoming reference and the reference position image data showing the reference position of the printing pattern becoming reference; a comparison determining means for comparing the infrared image data with the determined data to determined the quality; and an information means for reporting the propriety of the area and/or density of the printing pattern of the material to be printed, on the basis of the comparison result. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a technique for inspecting the quality of a printed matter printed by a printing machine, a printer, or the like, and more particularly, for a printed matter printed with ink having different characteristics in the infrared region, which is used for secret information printed matter readable by infrared rays. The present invention relates to an inspection apparatus and an inspection method thereof.

  For securities such as stock certificates, bonds, checks, gift certificates, and lotteries, machine reading information is printed with inks having different characteristics in the infrared region so that they can be read by a machine. The printed machine reading information can be read in the infrared region. As the ink having different characteristics in the infrared region, an infrared transmitting ink that transmits infrared rays, an infrared absorbing ink that absorbs infrared rays, and an infrared reflecting ink that reflects infrared rays are known due to the difference in properties.

  Infrared transmitting ink includes ink having a property of transmitting infrared rays in the ink composition. Irradiation of infrared rays to printed matter printed with this infrared transmitting ink on paper causes infrared rays to be transmitted. Depending on the characteristics of the substrate of the printed matter, the amount of reflected infrared light varies, but the infrared rays are reflected again. Infrared light passes through the infrared transmitting ink, and the irradiated infrared light returns.

  Infrared absorbing ink includes ink having a property of absorbing infrared rays in the ink composition. When infrared rays are irradiated to a printed matter obtained by printing this infrared absorbing ink on paper, the infrared rays are absorbed and the irradiated infrared rays do not return.

  Infrared reflective ink includes an ink composition having a property of reflecting infrared rays. When infrared rays are irradiated to a printed matter obtained by printing this infrared reflective ink on paper, the ink reflects the infrared rays, and the irradiated infrared rays are reflected.

  Inks having different characteristics in the infrared region each have such characteristics. For example, a barcode pattern is formed on a substrate such as paper by printing, and the ink on the substrate is used. The barcode pattern is irradiated with infrared rays, the amount of reflected infrared light is detected, and the barcode pattern is reproduced by infrared characteristics such as transmission, reflection and absorption. Thus, inks having different characteristics in the infrared region are used as machine authentication means for preventing counterfeiting.

  When printing with inks having different characteristics in this infrared region, a pattern pattern or bar code pattern is formed by selecting from an offset ink, flexo ink, gravure ink, screen ink, intaglio ink, etc. The

  Furthermore, a printed matter on which machine reading information is printed using at least two types of inks among infrared transmission ink, infrared absorption ink and infrared reflection ink is disclosed.

  For example, the printing area includes a first printing area printed with a printing ink having infrared absorption characteristics, and a second printing area printed with a general printing ink. The first printing area and the second printing area It is a printed matter in which the color tone of the printing area is visually difficult to distinguish, the printing ink of the first printing area is printed with the printing ink containing the infrared absorbing pigment, and the first printing area is visualized by the absorption of infrared rays. An infrared-absorbing printed material characterized in that it has been disclosed is disclosed (for example, see Patent Document 1).

  The parts printed with ink having different characteristics in the infrared region, starting with Patent Document 1, have the same color tone in the visible light region, and are therefore difficult to identify visually, inspecting print quality and inspecting misuse of ink It was very difficult to manage the quality of printed matter.

  As such a printed matter inspection means, a printed matter inspection method printed with ink having different characteristics in the infrared region, the surface of the printed matter is irradiated from the illumination means to the surface of the printed matter, the image input means, Infrared image data obtained by imaging the printed matter in the infrared wavelength region of 750 nm or more is input, the storage means stores the input infrared image data and the infrared reference image data of the standard printed matter, and the image processing means stores the infrared image data. There is disclosed a printed matter inspection method and inspection apparatus characterized by comparing data with pre-registered infrared reference image data and inspecting the print quality of the printed matter based on the comparison result. It is also described that the position of the illumination means is installed at a position of 45 ° with respect to the camera (see, for example, Patent Document 2).

JP-A 63-307996 (first page, FIG. 2) JP 2006-226857 A (page 1-11, FIG. 1-7)

  However, when inspecting a small printed matter such as a gift certificate, the inspection device of Patent Document 1 can acquire infrared image data without causing uneven illumination when irradiating infrared light. However, when inspecting relatively large prints such as poster size, A0, A1, A2, A3 plate size, B0, B1, B2, B3 plate size, etc., uneven illumination is necessary when irradiating infrared light. Has occurred, making it difficult to obtain infrared image data to be inspected.

  In particular, a multi-faceted large-format printed material having a plurality of gift certificates or the like that are cut into small pieces has a problem that it becomes difficult to obtain infrared image data in a predetermined area, resulting in an inspection error. For example, the infrared image data that should be actually acquired is shown in FIG. 1A, whereas the infrared image data that is actually acquired is the infrared image data in a predetermined area as shown in FIG. In some cases, it was not acquired properly. Further, if the printed material is inspected as it is on the inspection table, it is difficult to obtain infrared image data to be inspected due to problems such as wrinkles, curvature or lifting, and there is a problem that an inspection error occurs. There is an electrostatic adsorption device as one of the methods for pressing the printed material, but this method rubs the surface of the printed material with hands or brushes to make it wrinkle-free and adsorbs it by static electricity. Since the configuration is necessary, there has been a problem of fouling undried printed matter and a problem that it takes time to install it on the inspection table.

  An object of the present invention is to solve such a conventional problem. Even when a large printed matter such as a poster size, A3 plate size, A4 plate size, etc. is inspected, uneven illumination is obtained. Infrared image data to be inspected can be acquired without occurrence of rusting, and the surface of the printed material can be obtained by pressing means for correcting wrinkles, bending or lifting when the printed material is placed on the inspection table. An object of the present invention is to propose a printed matter inspection apparatus and an inspection method for preventing occurrence of wrinkling, curving, or lifting of the printed material without rubbing, and causing no inspection error.

  The present invention is an inspection apparatus for printed matter in which a printed pattern is printed with inks having different characteristics in the infrared region, and a fixed portion for fixing and installing one side of the printed matter on an inspection table with at least one contact jig, and the printed matter In order to extend wrinkles, bends or lifts, hold the other side of the printed material opposite to one side with at least one contact jig, and extend and fix the printed material to the opposite side. A plurality of illumination units each composed of pressing means comprising an extending portion and n illuminations (n is an integer of 2 or more) provided symmetrically with respect to the substrate to be irradiated with infrared rays or light including infrared rays on the surface of the substrate. An illuminating unit, an image input unit that captures an image of a printed material irradiated with infrared rays by the illuminating unit, and acquires infrared image data; The storage means for storing the reference position image data indicating the reference position of the quasi-printed pattern in advance and the obtained infrared image data and the reference position image data are compared to generate the position-corrected infrared image data. Comparison determination means for comparing the infrared image data and the determination data to determine the quality of the printed pattern area and / or shading, and a notification means for notifying the quality of the printed pattern area and / or shading based on the determination result An inspection apparatus for printed matter, comprising:

  The illumination means of the present invention has at least three illumination units, the first illumination unit is disposed closest to the examination table, and the second illumination unit and the third illumination unit are sequentially separated from the examination table. An illumination unit, an (m-1) th illumination unit, and an mth illumination unit (m is an integer of 4 or more), and the first illumination unit is a substrate to be printed from each illumination constituting the first illumination unit. The second illumination unit irradiates a region on the diagonal side from the respective illuminations constituting the second illumination unit with the approximate center of the substrate as a boundary. Irradiation is performed, and the third illumination unit and the m-th illumination unit irradiate the entire printed material widely.

  The printed matter inspection apparatus of the present invention is characterized in that each of the illuminations constituting the illumination unit has a plurality of infrared LEDs arranged in a grid or at random.

  The printed matter inspection apparatus of the present invention is characterized in that each of the illuminations constituting the illumination unit is provided with diffusing means on the entire surface or a part thereof.

  The printed matter inspection apparatus according to the present invention includes an illumination adjustment unit that enables an illumination unit to adjust an irradiation angle and / or an illumination position of infrared light or light including infrared light, and an irradiation light amount adjustment unit that enables adjustment of the irradiation light amount. It is characterized by having.

  Further, the image input means in the printed matter inspection apparatus of the present invention removes a wavelength region of less than 870 nm from the wavelength acquired from the printed material irradiated with infrared rays by the illumination means, and transmits the infrared wavelength range of 870 nm or more. And a visible light cut infrared transmission filter that obtains infrared image data.

  Further, the image input means in the printed matter inspection apparatus of the present invention is characterized in that it uses a CCD area sensor camera to input infrared image data, previously stored infrared image reference data and reference position image data.

  In addition, the notification means in the printed matter inspection apparatus of the present invention displays infrared image data on the display unit, and displays the area where the infrared image data is rejected in a different color from the other areas.

  In addition, the ink having different characteristics in the infrared region, which is the object of the inspection device for printed matter of the present invention, is one of infrared transmitting ink, infrared absorbing ink, and infrared reflecting ink, and the printing material uses those inks. It is a printed matter printed by combining one or more.

  Further, the present invention provides a printing pattern using ink having different characteristics in the infrared region using an inspection device including a pressing unit, an illumination unit, an image input unit, a storage unit, a comparison determination unit, and a notification unit. A method for inspecting a printed material printed with the above-mentioned method, in which one side of the printed material is fixed to the inspection table by at least one first contact jig provided as a pressing means, and the printed material is stretched to be wrinkled, bent or lifted. The other side opposite to the one side of the printed material is held by at least one second contact jig provided as a pressing means, and is extended and fixed to the opposite side of the first contact jig, and the illumination means As described above, a plurality of illumination units composed of n illuminations (n is an integer of 2 or more) provided symmetrically with respect to the printed matter are arranged in the vertical direction from the printed matter, and the surface of the printed matter is infrared. Or, the infrared ray image data of the printed matter irradiated with infrared rays from the illumination means is obtained by irradiating light including infrared rays, and the reference print pattern judgment data and the reference print pattern reference are obtained by the storage means. Reference position image data indicating the position is stored in advance, and the position is corrected by comparing the infrared image data acquired by the image input unit with the reference position image data stored in advance in the storage unit by the comparison determination unit. Infrared image data is generated and the position-corrected infrared image data is compared with determination data stored in advance in the storage means to determine the quality of the printed pattern area and / or shading. The quality of the printed matter determined by the comparison determination unit is notified.

  In the printed matter inspection method of the present invention, the illumination unit has at least three illumination units, the first illumination unit is disposed closest to the inspection table, and the second illumination is sequentially separated from the inspection table. Each having a unit, a third lighting unit, and an m-th lighting unit (m is an integer of 4 or more), and each of the lights constituting the first lighting unit is an area on the near side with respect to the approximate center of the printed matter. The respective illuminations constituting the second illumination unit irradiate the diagonally regions with the approximate center of the printed product as a boundary, and the third illumination unit and the mth illumination unit irradiate the entire printed product. It is characterized by wide irradiation.

  Further, the printed matter inspection method of the present invention is characterized in that the display unit provided in the notifying means displays the area where the infrared image data is rejected in a different color from the other areas.

  In the printed matter inspection method of the present invention, the ink having different characteristics in the infrared region is one of infrared transmitting ink, infrared absorbing ink, and infrared reflecting ink, and the printed matter is a combination of one or more of these inks. It is the printed matter printed by this.

  The present invention is not limited by the size of the paper from a small-size printed material such as a gift certificate to A3 size, poster size, multi-sided large-sized printed material, and without uneven illumination, It is possible to acquire infrared image data to be inspected.

  In addition, the printed matter inspection apparatus of the present invention is provided with pressing means for correcting wrinkles, curvature, or lifting when the printed matter is placed on the inspection table, so that the printed matter is wrinkled, curved, or lifted. Etc., and inspection errors do not occur.

  Furthermore, the pressing means has a fixing part and an extension part, the fixing part has at least one contact jig for fixing one side of the printed material, and the extending part is a part of the printed material fixed by the fixing part. It is a mechanism that has at least one contact jig that stretches while fixing the other side opposite to the one side, and since there is no rubbing mechanism, the undried printed matter is not soiled and the time to install it on the inspection table The inspection time is shortened by shortening.

  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 various other embodiments are included within the scope of the technical idea described in the scope of claims.

(Printed product inspection device)
The printed matter inspection device of the present invention is a printed matter inspection device in which a printed pattern is printed with ink having different characteristics in the infrared region.

  FIG. 2 shows a schematic diagram of a printed matter inspection apparatus 1 according to the present invention. As shown in FIG. 2, the printed matter inspection apparatus 1 includes a pressing unit 2, an illumination unit 3, an image input unit 4, a storage unit 5, a comparison determination unit 6, and a notification unit 7.

  The pressing means 2 is composed of an extending portion that fixes and installs the printing material on the fixing portion of the inspection table and fixes the printing material while extending the wrinkles, curvature, or lifting. As shown in FIG. 3, the substrate A is placed on the inspection table 8 by the pressing means 2. The fixing portion 9 of the pressing means 2 has at least one first contact jig 9 a that fixes one side of the printing material A, and the extending portion 10 faces one side of the printing material A fixed by the fixing portion 9. And at least one second contact jig 10a that extends while sandwiching the other side. In FIG. 3, three first contact jigs 9a and two second contact jigs 10a are formed. The number of the first contact jig 9a and the second contact jig 10a is not particularly limited. For example, an electrostatic chucking device, which is a known sheet pressing unit, is a system in which the surface of a printed material is rubbed with a hand or a brush to make it wrinkle-free and attracted by electrostatic attraction. However, there is a problem that an undried printed material is soiled for rubbing and a time is required for inspection. On the other hand, since the pressing means 2 of the present invention can remove the wrinkle, curve or lift of the printing material without rubbing the surface of the printing material, it is possible to acquire infrared image data to be inspected, and there is an inspection error. It does not occur. Further, the ink does not stain the undried printed material.

  Further, as shown in FIG. 3, the pressing means 2 has one or more abutting pins 11 for abutting and setting the substrate A to the photographing reference position. Thereby, the substrate A can be easily set at a predetermined position at the photographing reference position.

  As shown in FIG. 4, the illumination means 3 includes a plurality of illumination units 12 in which illumination 12a and illumination 12b for irradiating infrared rays or light containing infrared rays are symmetrically installed on the surface of the printing material A fixed to the inspection table 8. Have one. As shown in FIG. 5A, the illumination 12a and the illumination 12b are installed in parallel, and the illumination 12a and the illumination 12b are installed in parallel to one side of the inspection table 8 or the printing material A. Here, the illumination 12a and the illumination 12b are symmetric, as shown in FIG. 5A, where the positional relationship between the illumination 12a and the illumination 12b in the X direction (for example, the long side direction) is the center of the examination table 8. Alternatively, the left and right positional relationship with respect to the center P of the substrate A is the same or substantially the same, and the positional relationship between the illumination 12a and the illumination 12b in the Y direction (for example, the short side direction) This means that the position in the Y direction with respect to the printed material A is the same or substantially the same. The above description is the best mode of the positions of the illumination 12a and the illumination 12b, and the positional relationship in the X direction (for example, the long side direction) is a left-right position with respect to the center of the inspection table 8 or the center P of the substrate A. The relationship is the same or substantially the same, and the positional relationship in the Y direction (for example, the short side direction) of the illumination 12a and the illumination 12b is the same or substantially the same in the Y direction with respect to the inspection table 8 or the substrate A. Although it is the same, the present invention is not limited to this. Further, as shown in FIG. 5 (b), the positional relationship in the Z direction (height direction) of the illumination 12a and the illumination 12b illumination is the same or substantially the same in the vertical height from the inspection table 8 or the substrate A. is there. FIG. 5B is a cross-sectional view taken along the line XX ′ in FIG. Note that the number of lights provided in one lighting unit 12 is not particularly limited as long as it is two or more. In FIG. 4, the case where the illumination unit 12 has three is shown. The number of the lighting units 12 is not particularly limited, but it is preferable to have three or more lighting units 12 in the case where the printed material is a relatively large size, such as A3 size, poster size, multi-sided large-sized printed material.

  Moreover, in order to prevent generation | occurrence | production of illumination nonuniformity, it is preferable that the width | variety of illumination 12a, 12b is wider than the width | variety of the to-be-printed object A. FIG. For example, as shown in FIG. 5C, when the width h1 of the printing material is the width h2 of the illumination, it is preferable to have a relationship of h2 ≧ h1.

  The irradiation position of the illumination means 3 will be described. FIG. 6 is an explanatory diagram when there are three illumination units 12 in which the illumination 12a and the illumination 12b are installed symmetrically. The first illumination unit is arranged closest to the examination table 8, and the second illumination unit and the third illumination unit are arranged so as to be sequentially away from the examination table. As shown in FIG. 6A, each of the illuminations constituting the first illumination unit irradiates an area on the near side with the approximate center of the printed material as a boundary. As shown in FIG. 6B, the second illumination unit irradiates a diagonal region from the respective illuminations constituting the second illumination unit, with the approximate center of the printed material as a boundary. As shown in FIG. 6C, the third illumination unit irradiates the entire printed material widely. FIG. 6 (d) is a combination of FIGS. 6 (a) to 6 (c). The irradiation positions of the first illumination unit, the second illumination unit, and the third illumination unit are changed. In addition, by irradiating the printed material with infrared light, the printed material is irradiated with uniform infrared light, and infrared image data without uneven irradiation is obtained.

  Next, an example of changing the irradiation position of the illumination unit 3 will be described. FIG. 7 is an explanatory diagram in the case where there are three lighting units 12 in which the lighting 12a and the lighting 12b are installed symmetrically and the lighting 12c and the lighting 12d are installed symmetrically. In this case, one lighting unit has four lights. The first illumination unit is disposed closest to the examination table 8, and the second illumination unit and the third illumination unit are provided so as to be sequentially away from the examination table. As shown in FIG. 7A, each of the illuminations constituting the first illumination unit irradiates an area on the near side with the approximate center of the printed material as a boundary. As shown in FIG. 7B, the second illumination unit irradiates a diagonal region from the respective illuminations constituting the second illumination unit, with the approximate center of the printed material as a boundary. As shown in FIG. 7C, the third illumination unit irradiates the entire printing material widely. FIG. 7 (d) is a combination of FIGS. 7 (a) to 7 (c). The irradiation positions of the first illumination unit, the second illumination unit, and the third illumination unit are changed to match. By irradiating the printed material with infrared light, the printed material is irradiated with uniform infrared light, and infrared image data without uneven irradiation can be obtained. The illumination unit 12 shown in FIGS. 4 and 6 has the illumination 12a and the illumination 12b symmetrically formed, the illumination unit 12 shown in FIG. 7 has the illumination 12a and the illumination 12b symmetrically formed, and the illumination 12c and the illumination 12d It is formed symmetrically. That is, the illumination in FIGS. 4, 6 and 7 is installed from two directions, but the present invention is not limited to this, and for example, the illumination is installed symmetrically in three directions or four directions. To form a lighting unit (not shown).

  The illumination means of the present invention has at least three illumination units, the first illumination unit is arranged closest to the examination table, and the second illumination unit and the third illumination unit are sequentially separated from the examination table. The lighting unit includes an illumination unit and an mth illumination unit (m is an integer of 4 or more). The second illumination unit irradiates the diagonal area from the respective illuminations constituting the second illumination unit, with the approximate center of the substrate being printed as a boundary, and the third illumination unit. The m-th lighting unit can irradiate the entire printed material widely, and even if the printed material is a relatively large A3 size, poster size, multi-sided large format printed material, etc., uneven illumination does not occur.

  As shown in FIG. 8 (a), each of the lights constituting the illumination unit 12 of the illumination means 3 has a plurality of infrared LEDs 13a and 13b arranged in a lattice pattern or randomly arranged as shown in FIG. 8 (b). . Although the infrared LED is described in FIG. 8, other usable light sources include incandescent bulbs containing infrared rays, those that emit only infrared rays such as infrared lamps, halogen lamps, sunlight, HID lamps (High What is necessary is just to select suitably from what irradiates the light containing infrared rays, such as Discharge Lamp.

  Further, as shown in FIG. 9A, diffusion means 14a and 14b are provided in a part of the illumination unit 12 of the illumination means 3, and as shown in FIG. 9B, the entire surface of the illumination unit 12 of the illumination means 3 is provided. By providing the diffusing means 14a and 14b, the light from the infrared LED is diffused, and the printed material is irradiated with uniform infrared light. The diffusing means 14a and 14b can be appropriately provided on the entire surface or a part of the illumination unit 12 in accordance with the illumination state. As the diffusion means, a diffusion plate capable of diffusing general light can be used. Note that the diffusing means is preferably provided in the first lighting unit.

  As shown in FIG. 10 (a), the illumination units 12a and 12b of the illumination means 3 include an illumination adjustment unit 15a for an irradiation angle of light that includes infrared rays or infrared rays, an illumination adjustment unit 15b for an illumination position, and an illumination adjustment for an irradiation height By providing the illumination adjustment unit for the irradiation angle and the illumination position and the irradiation light amount adjustment unit for the irradiation light amount so that at least one of the units 15c can be adjusted, it is possible to irradiate the printed material with uniform infrared light. The lighting units 12 a and 12 b and the housing 16 are fixed by a connection frame 17. The illumination adjustment unit 15a for the irradiation angle is provided at a position where the illumination units 12a and 12b and the connection frame 17 are installed, and further at a position where the housing 16 and the connection frame 17 are installed. The illumination adjustment unit 15c having the irradiation height is provided also as a mechanism in which the connection frame 17 and the casing 16 are installed, and can be fixed by moving the height up and down. FIG. 10B is a diagram illustrating a state in which the connection frame 17 that is the illumination adjustment unit 15b at the illumination position is expanded and contracted. The illumination position can be adjusted by extending and contracting in this way. Moreover, the illumination adjustment unit can easily adjust the irradiation angle, the irradiation height, and / or the illumination position by providing an irradiation angle adjustment scale, an irradiation height adjustment scale, and / or an illumination position adjustment scale.

  In addition, it is preferable that the nonuniformity of the density value in the entire area of the printing material irradiated by the illumination unit 3 is within ± 6% as measured by the optical power meter. Moreover, it is preferable that the irradiation light quantity of the whole area of a to-be-printed material is 120 microwatts or more. Furthermore, it is preferable that the illumination means 3 has a density monitoring means on a reference plate for illumination monitoring in order to monitor the lack of illuminance of infrared rays or light including infrared rays. Thereby, even when the amount of infrared light of the illumination unit 12 decreases, the amount of infrared light can be adjusted instantaneously.

  As shown in FIG. 4, the illuminating means 3 is preferably provided with a visible light source unit 19 of 0.4 mW or more in a housing that does not affect the measurement so that the substrate can be easily set at a predetermined position. The visible light source unit 19 is preferably lit only when a shielding door described later is opened.

  Next, infrared image data captured from the printing material A irradiated with infrared rays is obtained by the illumination means 3 by the image input means 4. The camera used for the image input means 4 is not particularly limited as long as it has spectral sensitivity in the infrared region, and examples thereof include a CCD area sensor camera or a CMOS sensor camera having spectral sensitivity in the infrared region. However, since the inspection apparatus of the present invention acquires a still image by offline inspection, a CCD area sensor camera or a CMOS sensor camera having spectral sensitivity in the infrared region is preferable. More preferably, a large-sized large-sized printed material having a size of 440 × 680 mm or more is imaged by a combination of a CCD area sensor camera or a CMOS sensor camera and a lens, and distortion is within 0.2% in the entire region of the obtained infrared image. .

  The light reflected from the printing material contains visible light and ultraviolet light that are unnecessary for inspection due to the influence of ambient light. Therefore, it is necessary for a camera that captures an optical filter that cuts visible light and transmits more than infrared light. By attaching to the lens unit, only the infrared region can be extracted. For example, by removing a wavelength region of less than 870 nm from the wavelength acquired from the printing material A irradiated with infrared rays and providing a visible light cut infrared transmission filter that transmits the infrared wavelength region of 870 nm or more, infrared rays are provided. Only the region can be extracted, high-accuracy infrared image data can be acquired, and an infrared transmittance waveform as shown in FIG. 11 is obtained. Furthermore, a high-accuracy infrared image can be obtained against disturbance noise by providing a bandpass filter that removes the wavelength band shorter than the wavelength irradiated with infrared light and removes the wavelength band other than the wavelength band irradiated by the irradiation means. Data can be acquired. Thus, it is possible to obtain stable infrared image data by cutting off reflected light in unnecessary areas and receiving only light in the infrared area necessary for image processing of the printing material.

  The image input means 4 can input the infrared image reference data and the reference position image data stored in advance in the storage unit for comparison with the infrared image data of the substrate, and the infrared image data of the substrate. Furthermore, it is possible to input data of four end areas in a predetermined range of the printing material used in the installation position monitoring means described later. The infrared image data, the infrared image reference data and the reference position image data stored in the storage unit in advance are preferably in a pit map format of 256 pixels × 2672 pixels and 256 colors in consideration of inspection processing time and inspection accuracy. However, it is not limited to a pit map format of 256 pixels of 4000 pixels × 2672 pixels.

  The storage unit 5 stores reference position image data and determination data for comparison with infrared image data of the printing material. Further, infrared image reference data for obtaining a difference image, which will be described later, upper limit and lower limit data of dispersion values as determination data, upper limit and lower limit data of average values as determination data, and installation position monitoring means Data of the four end regions in a predetermined range of the reference printed material to be used is stored. Although different depending on the comparison inspection method, the infrared image reference data and the reference position image data are stored in a pit map format of 256 colors of, for example, 4000 pixels × 2672 pixels. The reference position image data, the determination data, and the infrared image reference data can be set as a region of interest. A plurality of reference position image data, a plurality of determination data, and a plurality of infrared image reference data can be set. The region of interest here is an image region to be subjected to statistical processing. The number of regions of interest is not particularly limited, but it is preferable to provide about 1 to 600 locations. The region of interest can be set and changed in advance by using the mouse pointer in the display-only window. The shape of the region of interest is not particularly limited, and a polygon can be set and the shape can be changed. In the inspection of the printed matter of this apparatus, it is assumed that a maximum of about 600 areas can be handled, and in the case of multi-sided large format printed matter, the region of interest is duplicated.

  The storage means 5 can store inspection results described later. In this way, it is possible to easily follow up by storing the inspection results. As the inspection result, date and time, lot number, frequency distribution ratio, average value, variance value, and the like can be stored in the storage unit 4 in text format or CSV format.

  The comparison determination unit 6 compares the infrared image data of the printed material with the reference position image data stored in the storage unit in advance, generates position-corrected infrared image data, and obtains the position-corrected infrared image data obtained. And the determination data are compared, and the quality of the printed pattern area and / or shading is determined.

  Comparison between the infrared image data of the substrate to be printed and the infrared image reference data stored in the storage unit in advance is performed by a method using a difference image. In this process, in order to inspect the infrared image data of the printing material, accurate affine transformation is performed, and position correction and / or rotation correction of the infrared image data precision is performed. Actually, the shift (position and rotation) between the infrared image data and the infrared image reference data is measured, and the coordinates are converted. In rotation correction, all pixels are stored by the bilinear method. For example, the coordinate points (99, 99) and (2599, 2599) of the infrared image reference data are set to density value = 0, the density values of other pixels are set to 255, and the coordinate points (100, 97) and (2600, 2597) is set to density value = 0, and other pixels are set to density value = 255.

  Next, the comparison / determination means 6 compares the obtained position-corrected infrared image data with the determination data. The comparison between the position-corrected infrared image data and the determination data is performed by a general comparison inspection method. For example, pattern matching, comparison and comparison from a threshold value, calculation of a feature value from a histogram, and determination of a threshold value from a difference image The calculation of the position and area is not particularly limited. In addition to the above-described method using the difference image, the comparison determination unit 6 can take various methods according to the purpose.

  The comparison determination unit 6 can also perform position correction processing, rotation correction processing, and difference image processing on infrared image data. Furthermore, the comparison / determination means 6 can also perform a shading correction process, a floating density area deletion process, a masking process, a threshold value removal process, a minimum area removal process, and the like as general image processing. For example, by performing shading correction processing on infrared image data, it is possible to correct uneven density in infrared image data on image processing.

  When there is a difference in the amount of light passing due to vignetting or the passing angle between the central part and the peripheral part of the lens, or shading correction processing, if there is a difference in light conversion characteristics due to non-uniformity of CCD elements, a wide range of brightness in the image Since non-uniform distribution exists, this is applied in such a case. Various correction methods can be used. For example, an image obtained by photographing a blank sheet without printing can be smoothed, a high-pass filter, or the like to obtain a position-independent gray value.

  In the floating density area deletion process, a known mode method is applied to obtain a density histogram of an image, detect a valley of the histogram, and use this as a threshold value. By this method, it is possible to separate a light / dark target to be extracted from light / dark images from the background and extract a light / light image. Furthermore, when the density level is different for each printing substrate, it is possible to cut out a gray-scale image of ink printed following the density level.

  The mask processing does not match the shape of the inspection object in the normal processing region shape, and when irregular image information such as the background becomes an obstacle to the inspection, the shape of the inspection object is obtained by binarization processing, etc. The inspection object is the processing content. Performing inspection such as damage determination using this area is called mask processing, and an arbitrary shape at that time or a reference image in which it is stored is called a mask.

  In the threshold removal processing, an image composed of pixels having a density equal to or higher than the boundary reference value can be created by adding the original grayscale image to the binarized image obtained by binarizing the grayscale image using the boundary reference value.

  In the minimum area removal processing, one or two density threshold values are set and binarized, label processing is performed on the extracted image, and a portion having a larger area than a preset area threshold value is extracted. By this method, the minimum area can be removed.

  The notifying unit 7 notifies the quality of the printed pattern area and / or the gradation of light and shade of the printed material based on the comparison result of the comparison determining unit 6. The notification means 7 can notify that the multi-faced large-format printed material is abnormal, and further notify an abnormal portion (small cut portion) in the multi-faced large-format printed material. The notification means 7 notifies the authenticity by using large and small display screens such as liquid crystal, vibration, sound, print media, electronic recording media, and the like. When displaying on the display screen, text display, image display, and the like are possible, and it is preferable that the error part is displayed in a different color from the normal part. Further, the notification means 7 can display graphs such as a frequency distribution display and a density cross-section graph in addition to notifying that the multi-faced large-format printed matter is abnormal and notifying the abnormal portion. The frequency distribution display numerically analyzes the distribution state of the concentration within the specified range from the inspection object data. The density cross-sectional graph display numerically analyzes the density value within the specified range from the inspection object data. It is preferable that the display can display a line graph of the concentration section in a display-only window. Note that the medium is not limited as long as the notification unit is a unit that can easily notify the surroundings. Furthermore, it is preferable that infrared image data is displayed by the display unit, and the region where the infrared image data is not displayed is displayed in a different color from the other regions.

  The printed matter inspection apparatus 1 of the present invention is preferably capable of inputting and setting photographing conditions in the illumination unit 3 and the image input unit 4 through a dedicated photographing condition input screen. Furthermore, it is preferable that the printed matter inspection apparatus 1 further includes an installation position monitoring unit for the printed material for monitoring whether the printed material is installed at a predetermined position. The installation position monitoring means monitors the installation position when fixing the printed material on the inspection table. The image input means inputs the data of the four end regions in the predetermined range of the printed material, The data is stored in the storage unit 4 in advance and compared with the data that is the reference of each of the four ends, and if it is within the allowable range, the inspection is executed as good. To do.

  As shown in FIG. 12, the printed matter inspection apparatus 1 according to the present invention is preferably installed in a housing 16 in which an illumination unit, a pressing unit, and an image input unit are shielded from light. The casing preferably has a shielding door 18 through which a substrate can be taken in and out of the casing. FIG. 12 shows a state where the shielding door 18 is shielded and an opened state. The shapes of the housing 16 and the shielding door 18 are not particularly limited. FIG. 13 shows the inspection device 1 for printed matter contained in the housing 16. The pressing unit 2 has the configuration mechanism shown in FIG. 3 installed in the housing 16, and the illuminating unit is configured such that the illumination 12a and the illumination 12b irradiate the surface of the substrate A with infrared rays or light including infrared rays are symmetrical. The illumination unit 12c and the illumination unit 12d have three illumination units installed symmetrically. Moreover, about the visible light source unit, one visible illumination 19a and one visible illumination 19b are installed symmetrically. The number of visible light source units is not particularly limited. (Do not draw the shielding door.)

  The ink having different characteristics in the infrared region of the printing material is one of infrared transmission ink, infrared absorption ink, and infrared reflection ink, and the printed material contains one or more of infrared transmission ink, infrared absorption ink, and infrared reflection ink. Printed matter printed in combination.

  Further, the printed material can be inspected even if it is a multifaceted large format printed material in which the same specific image printed with ink having different characteristics in the infrared region is printed in each of the specific regions divided into a plurality.

(Inspection method for printed matter)
Inspection of printed matter in which a printed pattern is printed with ink having different characteristics in the infrared region by using an inspection apparatus including a pressing unit, an illumination unit, an image input unit, a storage unit, a comparison determination unit, and a notification unit A flow chart of the method is shown in FIG.

  As shown in FIG. 14, as a first step, one side of the printed material is fixed to the inspection table by at least one first contact jig provided as a pressing means, and the wrinkle, bend or lift of the printed material is extended. For this purpose, the other side opposite to one side of the printed material is held by at least one second contact jig provided as a pressing unit, and is extended and fixed to the side opposite to the first contact jig.

  As a second step, a plurality of illumination units composed of illumination provided symmetrically with respect to the printed matter are arranged on the surface of the fixed printed matter as illumination means in the vertical direction from the printed matter. Irradiate light containing. The illumination means includes at least three illumination units, and the first illumination unit is disposed closest to the examination table, and the second illumination unit, the third illumination unit, and the m-th image unit are sequentially separated from the examination table. Illumination unit (m is an integer of 4 or more), and each illumination that constitutes the first illumination unit irradiates the area on the near side with respect to the approximate center of the printed matter, and the second illumination unit It is preferable to irradiate a diagonal region with the respective illuminations constituting the border about the center of the printed material as a boundary, and to irradiate the entire printed material widely with the third illumination unit and the mth illumination unit.

  As a third step, infrared image data of a printed material irradiated with infrared rays from the illumination unit is acquired by the image input unit.

  As a fourth step, the infrared image data obtained by performing the position correction by comparing the infrared image data acquired by the image input unit with the reference position image data stored in advance in the storage unit is generated by the comparison determination unit. Then, the infrared image data subjected to the position correction and the determination data stored in advance in the storage unit are compared to determine whether the print pattern area and / or shading is acceptable.

  As a fifth step, the notification means notifies the quality of the printed matter determined by the comparison determination means. It is preferable that the notification means displays infrared image data on the display unit, and can display the area where the infrared image data is rejected in a color different from other areas.

  As a fourth step, the comparison between the infrared image data and the reference position image data stored in the storage means and the comparison between the position-corrected infrared image data and the determination data can be performed by a general method, and are particularly limited. There is nothing.

  The ink having different characteristics in the infrared region of the printing material is one of infrared transmission ink, infrared absorption ink, and infrared reflection ink, and the printed material contains one or more of infrared transmission ink, infrared absorption ink, and infrared reflection ink. Printed matter printed in combination.

  Further, the printed material can be inspected even if it is a multifaceted large format printed material in which the same specific image printed with ink having different characteristics in the infrared region is printed in each of the specific regions divided into a plurality.

It is a figure which shows the problem of the conventional infrared image data. It is a figure which shows the schematic diagram of the inspection apparatus 1 of the printed matter in this invention. It is explanatory drawing of the holding means. It is explanatory drawing of the illumination means. It is explanatory drawing of the illumination means. It is a figure which shows the irradiation position of the illumination means. It is a figure which shows the irradiation position of the illumination means. It is explanatory drawing of infrared LED13a, 13b of the illumination means 3. FIG. It is explanatory drawing of the spreading | diffusion means 14a, 14b of the illumination means 3. FIG. It is explanatory drawing of the irradiation angle 15a of the illumination means 3, and the illumination position 15b. It is the waveform of the infrared transmittance obtained by the image input means provided with the visible light cut infrared transmission filter. It is a figure which shows the housing | casing 16 and the shielding door 18. FIG. FIG. 2 is a diagram illustrating an inspection apparatus 1 for printed matter that enters a housing 16. It is a figure which shows the flowchart of the inspection method of the printed matter which printed the printing pattern with the ink which has a different characteristic in an infrared region.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed product inspection apparatus 2 Pressing means 3 Illuminating means 4 Image input means 5 Storage means 6 Comparison determination means 7 Notification means 8 Inspection table 9 Fixing part 9a First contact jig 10 Extension part 10a Second contact jig 11 Contact pin 12 Illumination unit 11a, 11b, 11c, 11d Illumination 13a, 13b Infrared LED
14a, 14b Diffusing means 15a Illumination angle illumination adjustment unit 15b Illumination position illumination adjustment unit 15c Illumination height illumination adjustment unit 16 Housing 17 Connection frame 18 Shielding door 19 Visible light source unit 19a, 19b Visible illumination A Printed material P Center

Claims (1)

An inspection apparatus for printed matter in which a printed pattern is printed with ink having different characteristics in the infrared region,
A fixing portion that fixes and installs one side of the printed material on the inspection table with at least one contact jig, and at least one other side that faces the one side of the printed material in order to extend wrinkles, bends, or lift of the printed material. A holding means comprising an extending portion that extends and fixes to the opposite side of the contact jig that fixes the substrate to be printed while gripping by two contact jigs;
An illumination unit comprising n (n is an integer of 2 or more) illuminations that irradiate the surface of the printed material with the same or substantially the same positional relationship on the left and right with respect to the center of the printed material. At least three, the first lighting unit is arranged closest to the examination table, the second lighting unit and the third lighting unit are arranged so as to be sequentially away from the examination table,
The first illumination unit irradiates an area on the near side of each of the illuminations constituting the first illumination unit, with the substantial center of the printed material as a boundary, and the second illumination unit includes the first illumination unit The illumination unit irradiates the opposite areas from the respective illuminations constituting the second illumination unit with the substantial center of the substrate as a boundary, and the third illumination unit illuminates the entire substrate widely. ,
Image input means for capturing infrared image data by imaging the printed material irradiated with infrared rays by the illumination means;
Storage means for preliminarily storing reference print pattern determination data and reference position image data indicating a reference position of the reference print pattern;
The acquired infrared image data and the reference position image data are compared to generate position-corrected infrared image data, the position-corrected infrared image data and the determination data are compared, and the printed pattern area and / or Or a comparison determination means for determining the quality of the shade,
An inspecting apparatus for printed matter, comprising: a notifying unit for notifying the quality of the area and / or shading of the printed pattern based on the determination result.

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