Printing method of concave printing anti-counterfeiting pattern and identification method of anti-counterfeiting pattern

Abstract

The present application belongs to the technical field of printing, and particularly relates to a printing method of a concave printing anti-fake pattern and an anti-fake pattern identification method thereof, comprising the following steps: (1) printing layout, color separation and plate making; (2) screen ruling; (3) engraving of a concave printing roller; (4) overprinting; the present application realizes the production of the concave printing anti-fake pattern by combining the pre-printing color separation and screen ruling technology, the concave printing plate making technology, the overprinting printing technology and the modern mobile technology, so that a new anti-fake technology can be applied to the printing packaging, and the anti-fake function is easy to be identified by consumers, the anti-fake function breaks the traditional anti-fake concept, the printing packaging anti-fake technology is greatly improved, and the anti-fake property of the printing packaging product is improved.

Description

Technical Field

[0001] This invention belongs to the field of printing technology, specifically relating to a printing method for intaglio anti-counterfeiting patterns and a method for identifying the anti-counterfeiting patterns. Background Technology

[0002] The enormous profits from counterfeiting or fake goods have driven counterfeiters to take risks and delve into methods of breaking security codes and forging documents. Counterfeiters often focus on falsifying outer packaging, labels, and documents. In particular, the rapid development of computer graphics processing technology, color copying, high-precision scanning, high-resolution printing, and digital printing technology has made existing security measures easily compromised. Therefore, researching and developing various new and efficient anti-counterfeiting technologies is an urgent need for social and economic development.

[0003] In the printing industry, there are many existing anti-counterfeiting technologies, and the anti-counterfeiting effects of different printing technologies vary. Most printing anti-counterfeiting technologies are material-added anti-counterfeiting technologies, which require the use of special materials, such as fluorescent ink, photochromic ink, scented ink, electroplated aluminum materials, hot stamping plates, etc., to print additional anti-counterfeiting information. The implementation of these anti-counterfeiting technologies is costly and the production process is complex. For example, Chinese invention patent CN104149504A discloses a processing method for anti-counterfeiting printed materials, which includes the following steps: Step 1, printing a base pattern on a substrate using optically variable ink; Step 2, designing embossing patterns on gravure and relief printing plates, wherein the outline of the embossing pattern is smaller than the outline of the base pattern; Step 3, making gravure and relief printing plates according to the embossing patterns, wherein the working contact surface of the gravure and relief printing plates is an inclined surface, and the angle between the inclined surface and the substrate surface is 1 to 30°; Step 4, using embossing equipment to complete the embossing process within the area defined by the base pattern on the substrate. This invention utilizes embossing technology and the color-changing properties of optically variable inks to present two color patterns from the same viewing angle. The resulting anti-counterfeiting printed material presents patterns that are easy to identify and difficult to counterfeit, thus greatly increasing the product's anti-counterfeiting security level.

[0004] To address this issue, this invention proposes a method for creating anti-counterfeiting patterns using gravure printing technology. Gravure printing is a pressure-based printing process where the image areas of the printing plate are lower than the plate's surface. During printing, the entire printing roller is inked, and a doctor blade uses pressure to scrape away the ink from the blank areas, leaving only the ink in the cells of the image areas. Under pressure, the ink in the roller cells is transferred to the substrate, resulting in a printed product. Because gravure printing uses indentations carved according to the original image, the thickness of the lines and the density of the ink can be arbitrarily controlled during the engraving process, making it difficult to imitate and forge. In particular, the depth of the indentations is extremely difficult to replicate accurately from the printed image, making it very difficult for counterfeiters to reproduce the same density of ink in gravure prints, thus enhancing the effectiveness of anti-counterfeiting measures. In addition, gravure printing has the advantages of high printing efficiency, good quality, and long service life of printing plate rollers. Therefore, it can be seen that gravure printing anti-counterfeiting technology can not only improve anti-counterfeiting capabilities, but also reduce printing production costs, and has significant promotion and application value for mass printing. Summary of the Invention

[0005] To address the above problems, this invention provides a method for printing intaglio anti-counterfeiting patterns and a method for identifying the anti-counterfeiting patterns.

[0006] The specific technical solution is: a printing method for intaglio anti-counterfeiting patterns, including the following steps: (1) Print and type the anti-counterfeiting graphic information content, and then color-separate the typed graphic information to make yellow, red, blue and black plates. (2) The graphic information of the yellow, red and blue plates are screened separately. Starting from different dot levels, dot shapes, dot angles and dot line counts, the graphics of the yellow, red and blue plates are screened at different levels. The solid areas outside the yellow, red and blue plates are screened to obtain yellow screen, red screen, blue screen and black screen, thus making a printing file and black plate file from yellow to red to blue. (3) Engraving the gravure roller according to the file prepared in step (2); (4) Use an intaglio roller with different shades of engraved text and images to overprint. The first print is yellow, the second is red, the third is blue, and the fourth is black. In this way, the four sets of ink colors are overprinted on the printed matter in a regular manner. The blue mesh cutout text on the front of the overprinted printed matter has a hidden anti-counterfeiting effect.

[0007] Furthermore, in step (2), the color ratio of the screen is 20% yellow, 40% red, 80% blue, and 100% black, or 30% yellow, 60% red, 90% blue, and 100% black.

[0008] Furthermore, in step (3), the engraving of the gravure roller adopts the electro-engraving process.

[0009] Furthermore, the engraving process parameters of the gravure roller in step (3) are as follows: yellow group 60L / 38° / 110° / KM01 / 5.0.6.0, red group 80L / 40° / 120° / KM02 / 5.0.7.0, blue group 100L / 42° / 130° / KM03 / 5.0.8.0, and black group 120L / 44° / 140° / KM04 / 5.0.7.0.

[0010] Furthermore, in step (3), the engraving depths of the gravure rollers are 30U for the yellow group, 40U for the red group, 50U for the blue group, and 80U for the black group.

[0011] The present invention also provides a method for identifying anti-counterfeiting patterns printed by the above-mentioned intaglio anti-counterfeiting pattern printing method, wherein when light is shone from the back of the printed product, hidden blue mesh text can be displayed at the light source point on the front.

[0012] The beneficial effects of this invention are as follows: This invention combines pre-press color separation and plate making and halftone screen technology, gravure printing plate making technology, overprinting printing technology and modern mobile technology to realize the production of gravure printing anti-counterfeiting patterns, enabling the application of a new anti-counterfeiting technology in printing and packaging, and providing anti-counterfeiting functions that are easy for consumers to identify. Moreover, the anti-counterfeiting function breaks the traditional concept of anti-counterfeiting, greatly improves the anti-counterfeiting technology of printing and packaging, and enhances the anti-counterfeiting properties of printed packaging products. Attached Figure Description

[0013] Figure 1 This is a rendering of the yellow version of the invention; Figure 2 This is a rendering of the red version of the invention; Figure 3 This is a rendering of the blue plate of the present invention; Figure 4 This is an image showing the effect of the fourth printing of the black plate in this invention; Figure 5 These are renderings of Schemes 1 through 9 with different color ratios; Figure 6 This is a diagram illustrating the recognition effect of the anti-counterfeiting pattern of this invention. Detailed Implementation

[0014] To make the technical problems and solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0015] The present invention provides a printing method for intaglio anti-counterfeiting patterns, which utilizes pre-press color separation and plate making and halftone technology, as well as the dot color rendering principle and dot color expression method, to make the graphic information on the printing substrate have a latent shadow hiding effect.

[0016] There are generally two methods for representing halftone dots: one is to change the color entirely by varying the dot area ratio; the other is to change the color by varying the ink layer thickness, meaning the color becomes darker as the ink layer deepens. This invention uses the method of changing the color by varying the ink layer thickness. Furthermore, there are two other methods for representing halftone dot color: one is to represent color by dot overlay, and the other is to represent color by dot juxtaposition. This invention uses the method of representing color by dot overlay.

[0017] The present invention provides a method for printing intaglio anti-counterfeiting patterns, comprising the following steps: The anti-counterfeiting graphic and text information is printed and typed, and the typed graphic and text information is then separated into colors to create a yellow plate (such as...). Figure 1 As shown), red version (as shown) Figure 2 As shown), blue version (as shown) Figure 3 As shown), black version (as shown) Figure 4 (as shown) (2) The graphic information of the yellow, red and blue plates are screened separately. Starting from different dot levels, dot shapes, dot angles and dot line counts, the graphics of the yellow, red and blue plates are screened at different levels. The solid areas outside the yellow, red and blue plates are screened to obtain yellow screen, red screen, blue screen and black screen, thus making a printing file and black plate file from yellow to red to blue. (3) Engraving the gravure roller according to the file prepared in step (2); Currently, there are two methods for engraving gravure rollers: laser engraving and electro-engraving. This invention uses electro-engraving technology to engrave four sets of graphic information—yellow, red, blue, and black—on the same gravure roller. During the roller engraving process, the four sets of graphic information are engraved with different numbers of engraving lines. Because the anti-counterfeiting graphics of this invention require a transitional layer, and the printed product needs to have hidden anti-counterfeiting features, after multiple experiments, it was determined that the engraving line counts for the four sets of yellow, red, blue, and black should be 60L, 80L, 100L, and 120L, respectively. This engraving method is beneficial for achieving a smooth transition and concealment of the text on the printed product.

[0018] Meanwhile, the amount of ink transferred is related to the depth of the gravure engraving, commonly known as the cell, which is an important factor in the amount of ink applied. Therefore, it is also necessary to determine the engraving depth of the gravure roller. After multiple experiments, the engraving depths of the four groups of yellow, red, blue, and black were determined to be 30U, 40U, 50U, and 80U, respectively.

[0019] Furthermore, the hidden anti-counterfeiting text of this invention is also affected by the engraving screen lines, screen angles, needle angles, engraving curves, and text edge enhancement. The influence of screen lines, screen angles, and needle angles on depth under normal printing conditions is generally as follows: 1. With the same screen lines and screen angles, the smaller the needle angle, the deeper the depth; 2. With the same screen lines and needle angles, the smaller the screen angle, the deeper the depth; 3. With the same screen angles and needle angles, the smaller the screen line, the deeper the depth. Taking into account the relationship between these influencing factors, the final engraving process parameters are determined as follows: Yellow group 60L / 38° / 110° / KM01 / 5.0.6.0, Red group 80L / 40° / 120° / KM02 / 5.0.7.0, Blue group 100L / 42° / 130° / KM03 / 5.0.8.0, Black group 120L / 44° / 140° / KM04 / 5.0.7.0. (Taking the yellow group as an example, 60L refers to the screen ruling, 38° refers to the screen angle, 110° refers to the pointer angle, KM01 refers to the engraving curve, and 5.0.6.0 refers to edge enhancement.) Screen ruling, also known as engraving line count, refers to the number of cells per unit length (commonly L / cm or LPI), directly determining the level of detail in an image. A higher line count results in finer cells and richer image detail.

[0020] The halftone angle, also known as the screen angle, refers to the angle between the direction of the cells arranged in halftone and the horizontal direction. In multicolor printing, different color plates must use different halftone angles so that after the color plates are overprinted, the direction of the cells is inconsistent and there is no repetitive regularity, thus avoiding moiré patterns that interfere with visual perception.

[0021] The needle angle, also known as the engraving needle angle, refers to the cone angle (tip angle) of the diamond engraving needle used for electro-engraving. It directly determines the inverted cone shape and depth of the cells. The engraving needle cuts into the printing plate roller at a certain angle. The smaller the needle angle, the sharper the needle tip, and the smaller the engraved cell opening, but the greater the engraving depth; conversely, the larger the angle, the shallower the engraving depth.

[0022] The engraving curve, also known as the electro-engraving level curve, is a level curve used to control the correspondence between the tonal values ​​of the original artwork and the cell depth (or aperture). It is used to compensate for the non-linear loss of tonal values ​​during the printing process and to ensure the correct reproduction of the image tonal values.

[0023] Edge enhancement, also known as edge sharpening, is an image processing capability in electro-engraving systems used to improve the clarity of the edges of engraved images (especially text and lines). It uses image algorithms to identify changes in grayscale values ​​within the image and selectively adjusts the size and depth of the cells on the inner and outer sides of the image, thereby counteracting the jaggedness caused by the discrete arrangement of the cells and making the edges visually clearer and sharper.

[0024] (4) Using the intaglio rollers with different shades of text and images engraved in step (3), overprinting is performed. The first print is yellow, the second is red, the third is blue, and the fourth is black. In this way, the four sets of ink colors are overprinted on the printed matter in a regular manner. The blue mesh cutout text on the front of the overprinted printed matter has a hidden anti-counterfeiting effect (such as...). Figure 5 , Figure 6 (As shown).

[0025] To determine the optimal CMYK color scheme, yellow, magenta, cyan, and black were sequentially printed onto the substrate using an intaglio overlay printing method, with different color ratios. The effect of the printed anti-counterfeiting pattern was then observed. The specific implementation details are as follows: When using CMYK halftone printing in prepress, if we calculate based on the white area of ​​the printing paper as 1, then the first color, yellow (Y), can be calculated as 1-Y; the second color, magenta, is M(1-Y)(1-M)YM; the third color, cyan (c), is (1-Y)(1-M)(1-C)CYM; and the fourth color, black (K), is (1-Y)(1-M)(1-C)(1-K)CMYK. Based on this, nine four-color mixing schemes are determined, as shown in the table below. (Note: The printing plates for each scheme are from the same gravure printing roller.) Option 1 Yellow webpage: 10%; Red webpage: 20%; Blue webpage: 60%; Black webpage: 70%. Because the net screen values ​​of the blue and black net screens are similar, the printed images and text information have no hidden anti-counterfeiting effect. like Figure 5 As shown in Scheme 1 Option 2 Yellow webpage: 10%; Red webpage: 20%; Blue webpage: 60%; Black webpage: 100%. Because yellow and red screens have low screen values, while black screens have high screen values, the printed images and text are blurry. like Figure 5 As shown in Scheme 2 Option 3 Yellow webpage: 10%; Red webpage: 30%; Blue webpage: 70%; Black webpage: 80%. Because the difference between yellow and red screens is minimal, while blue screens have a higher screen value, the printed images and text lack transitional layers and conceal anti-counterfeiting features. like Figure 5 Scheme 3 is shown Option 4 Yellow webpage: 10%; Red webpage: 30%; Blue webpage: 70%; Black webpage: 100%. Because the difference in screen ruling between yellow and red screens is minimal, while the screen rulings for blue and black screens are significantly higher, the printed images and text are blurry and lack any hidden anti-counterfeiting features. like Figure 5 As shown in Scheme 4 Option 5 Yellow webpage: 20%; Red webpage: 40%; Blue webpage: 80%; Black webpage: 80%. Because the screen rulings for blue and black mesh are the same, the blue mesh images on the printed product lack transitional layers and do not have any hidden anti-counterfeiting effects. like Figure 5 Scheme 5 is shown Option Six Yellow webpage: 20%; Red webpage: 40%; Blue webpage: 80%; Black webpage: 100%. Because the halftone values ​​of yellow, red, blue, and black exhibit an increasing relationship, and are influenced by the gravure roller engraving process and printing technology, the printing tonal transitions are obvious, resulting in good image and text concealment in the printed product. like Figure 5 Scheme 6 is shown Option 7 Yellow webpage: 20%; Red webpage: 50%; Blue webpage: 90%; Black webpage: 90%. Because the red screen has a higher halftone value, while the blue and black screens have the same halftone value, the printed images are blurry and there is color bleeding. like Figure 5 Scheme 7 is shown Option 8 Yellow webpages account for 30%, red webpages for 60%, blue webpages for 90%, and black webpages for 90%. Because the red netting value is relatively high, while the blue and black netting values ​​are the same, the text is blurry and the colors are mixed. like Figure 5 As shown in Scheme 8 Option Nine Yellow webpage: 30%; Red webpage: 60%; Blue webpage: 90%; Black webpage: 100%. Because the halftone values ​​of yellow, red, and blue increase progressively, and due to the influence of the roller engraving process of the black plate and the depth of the cells, the printing tonal transitions are obvious, and the image and text concealment effect is good. like Figure 5 Scheme 9 is shown After printing experiments with nine different proportions, it can be seen that Scheme 6 (20% yellow screen, 40% red screen, 80% blue screen, and 100% black screen) and Scheme 9 (30% yellow screen, 60% red screen, 90% blue screen, and 100% black screen) produce printed products with better anti-counterfeiting effects.

[0026] This invention also provides a method for identifying anti-counterfeiting patterns printed using the above-mentioned intaglio printing method. When light is shone from the back of the printed material, hidden blue-and-white perforated text can be displayed at the light source point on the front, such as... Figure 6 As shown.

[0027] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for printing an intaglio anti-counterfeiting pattern, characterized in that, Includes the following steps: (1) Print and type the anti-counterfeiting graphic information content, and then color-separate the typed graphic information to make yellow, red, blue and black plates. (2) The graphic information of the yellow, red and blue plates are screened separately. Starting from different dot levels, dot shapes, dot angles and dot line counts, the graphics of the yellow, red and blue plates are screened at different levels. The solid areas outside the yellow, red and blue plates are screened to obtain yellow screen, red screen, blue screen and black screen, thus making a printing file and black plate file from yellow to red to blue. (3) Engraving the gravure roller according to the file prepared in step (2); (4) Use an intaglio roller with different shades of engraved text to overprint. Print yellow for the first time, red for the second time, blue for the third time, and black for the fourth time. In this way, the four sets of ink colors are overprinted on the printed matter in a regular manner. The blue mesh hollow text on the front of the overprinted printed matter has a hidden anti-counterfeiting effect. In step (2), the color ratio of the screen is 20% yellow, 40% red, 80% blue, and 100% black, or 30% yellow, 60% red, 90% blue, and 100% black. In step (3), the engraving depths of the gravure rollers are 30U for the yellow group, 40U for the red group, 50U for the blue group, and 80U for the black group.

2. The printing method of an intaglio anti-counterfeiting pattern according to claim 1, characterized in that, In step (3), the engraving of the gravure roller is carried out using an electro-engraving process.

3. The printing method of an intaglio anti-counterfeiting pattern according to claim 1, characterized in that, The engraving process parameters of the gravure roller in step (3) are as follows: yellow group 60L / 38° / 110° / KM01 / 5.0.6.0, red group 80L / 40° / 120° / KM02 / 5.0.7.0, blue group 100L / 42° / 130° / KM03 / 5.0.8.0, black group 120L / 44° / 140° / KM04 / 5.0.7.0; taking the yellow group as an example, 60L refers to the screen line, 38° refers to the screen angle, 110° refers to the pointer angle, KM01 refers to the engraving curve, and 5.0.6.0 refers to the edge enhancement.

4. The anti-counterfeiting pattern identification method printed by the intaglio printing anti-counterfeiting pattern printing method as described in claim 1, characterized in that, When a light is shone from the back of the print, the hidden blue-and-white stencil text will be revealed at the light source point on the front.

Images