Micro-character printing method

Abstract

To provide a printing method with which it is possible to inexpensively print a micro-character with good quality.SOLUTION: According to an embodiment, a printing method includes: a first step of designating a micro-character from original data; a second step of adjusting a character width of the micro-character designated in the first step; and a third step of printing the micro-character by printing using a plate on which the character width is already adjusted in the second step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for printing microcharacters on printed matter that has been subjected to anti-counterfeiting technology, such as security labels, booklets, and printed securities. [Background technology]

[0002] Conventionally, printed materials that incorporate anti-counterfeiting technology, such as security labels such as anti-counterfeit labels, booklets such as passports, and printed securities such as stock certificates, bonds, checks, gift certificates, lottery tickets, and commuter passes, have been printed with tiny characters of 100 μm or less, also known as microcharacters, as an effective means of preventing counterfeiting, alteration, falsification, and the like.

[0003] This type of microtext is too large to be reproduced by a regular home printer, so when a printed matter with microtext is copied using a home printer, some of the characters are printed in a blurred manner. Therefore, printed matter produced using this method can easily be identified as a counterfeit by magnifying it.

[0004] As one type of authenticity determination technology using microtext, Patent Document 1 discloses a technology for determining authenticity by mechanically reading an image of a printed matter bearing microtext, identifying the microtext portion of the read image, and checking whether the microtext is printed at the correct size.

[0005] Furthermore, in order to accurately determine the authenticity of microtext, high-quality microtext printing without bleeding or smearing is required. In this regard, Patent Document 2 discloses a technology for providing a receiving layer on the substrate as a measure against bleeding in printing.

[0006] Furthermore, a coating technique is also known to prevent bleeding onto paper. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2023-073847 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-276323 Summary of the Invention [Problem to be solved by the invention]

[0008] However, applying a coating to prevent bleeding into the paper increases printing costs, and coating also makes it difficult to use anti-counterfeit ink that penetrates the paper, which limits the methods of preventing counterfeiting of printed securities and may reduce security.

[0009] One way to address this issue is to increase the amount of pigment in the ink, increasing the ink's viscosity and improving bleeding. However, too much pigment can reduce paper adhesion, potentially causing blurring and unevenness in solid areas. These factors reduce the quality of the micro-text.

[0010] The present invention has been made in view of the above circumstances, and has as its object to provide a printing method that is capable of printing high-quality microcharacters at low cost. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention takes the following measures.

[0012] The first aspect of the invention includes a first step of specifying micro characters from original data, a second step of adjusting the character width of the micro characters specified in the first step, and a third step of printing the micro characters by printing using a plate whose character width has been adjusted in the second step.

[0013] A second aspect of the invention is the printing method of the first aspect, wherein in the first step, the micro characters are printed in any one of black characters, solid characters, and white characters.

[0014] The third aspect of the invention is the printing method of the second aspect, in which, if in the first step the printed micro-characters are ink characters or solid single color characters and blurring due to bleeding is confirmed, in the second step the character width of the plate is reduced by 10% or more and 30% or less.

[0015] The fourth aspect of the invention is the printing method of the second aspect, in which, if the micro-characters are printed in white in the first step and the printed micro-characters are found to be blurred, the character width of the plate is increased by 10% or more and 30% or less in the second step.

[0016] A fifth aspect of the invention is the printing method according to any one of the first to third aspects, wherein the microcharacters printed in the third step have a height of 100 μm or less and a line width of 40 μm or more.

[0017] A sixth aspect of the invention is the printing method of the fifth aspect, in which the micro characters printed in the third step are in a font other than serif font.

[0018] A seventh aspect of the invention is the printing method of the first aspect, wherein the ink used in the offset printing is an ink for offset printing.

[0019] An eighth aspect of the invention is a printing method of the first aspect, in which the ink used in printing is a security ink containing any of ultraviolet fluorescent ink, infrared fluorescent ink, infrared transparent ink, and infrared absorbing ink. [Effects of the Invention]

[0020] According to the present invention, a printing method can be realized that can print high-quality microcharacters at low cost. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a flowchart showing the flow of a printing method according to an embodiment of the present invention. [Figure 2]FIG. 2 is a plan view showing an example of a printed matter printed by the printing method according to this embodiment. [Figure 3] FIG. 3 is an enlarged plan view showing an example of micro characters printed in toned solid (solid black) by offset printing without adjusting the line width. [Figure 4] FIG. 4 is an enlarged plan view showing an example of microcharacters offset printed in white without adjusting the line width. [Figure 5] FIG. 5 is an enlarged plan view showing an example of micro characters (solid black) printed without bleeding by the plate adjusted in the second step. [Figure 6] FIG. 6 is an enlarged plan view showing an example of microcharacters (white-out characters) printed without bleeding by the plate adjusted in the second step. [Figure 7] FIG. 7 is an enlarged plan view showing an example of a micro character (solid black) having an assumed character width. [Figure 8] FIG. 8 is an enlarged plan view showing an example of a micro character (white outline) having an assumed character width. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc., are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed and redundant explanations will be omitted as appropriate.

[0023] Best modes for carrying out the present invention will be described below with reference to the drawings.

[0024] FIG. 1 is a flowchart showing the flow of a printing method according to an embodiment of the present invention.

[0025] That is, the printing method according to this embodiment includes a first step of specifying the character width of micro characters from the original data; a second step (S2) of adjusting the character width of the plate by narrowing the line width of the specified micro characters in the original image data for printing for black or solid characters and widening the line width for white characters; and a third step (S3) of printing the micro characters on paper such as high-quality paper, coated paper, or synthetic paper using a plate whose character width has been adjusted in the second step. In other words, when printing micro characters using offset printing, the printing method according to this embodiment reduces bleeding by printing using a plate made by adjusting the character width in anticipation of bleeding. Note that the paper may also be provided with other security features, such as watermarking, fiber weaving, or hologram transfer.

[0026] In the first step (S1), the micro characters to be printed are specified as black characters, toned solid characters, or white characters. The ink tack used to print these micro characters is an ink meter with a radius of 7 to 12 mm measured at 400 rpm, a temperature of 30°C, and a 1-minute measurement, and the flow is a spread meter with a radius of 14 to 20 mm measured at 25°C.

[0027] For example, if offset printing is performed under conditions where the tack and flow are lower than those mentioned above, the ink viscosity will be too high, which may result in blurring of the micro-characters in the solid black and toned solid, resulting in a decrease in quality. Similar printing can also be achieved with intaglio printing and inkjet printing by adjusting the tack and flow.

[0028] Therefore, if the microtext is printed exactly as specified in the original, and if it is printed in black or solid, the printed microtext may be blurred due to bleeding. In this case, in the second step (S2), the line width of the characters on the plate is reduced by 10% to 30%. In other words, a font (character face) with outlines that are 10% to 30% inside the outline of the registered font is used as the platemaking data. In printing, the original is received as vector data, for example, and then converted into raster data for platemaking using software called a RIP. During this RIP process, the characters can be converted exactly as in the original, or the line width can be made thicker or narrower.

[0029] On the other hand, when printing white microtext, unevenness or blurring may occur in solid areas, potentially reducing print quality. If the tack and flow are higher than the conditions described below, the ink viscosity may become too soft, resulting in increased bleeding and making it impossible to print accurate microtext. Specifically, the corners of the microtext may be rendered rounded, and if microtext in a font with sharp corners, such as Mincho or Gothic, is used, the corners may be rounded, potentially reducing the quality of the microtext.

[0030] Therefore, if white micro characters are specified in the first step (S1), the specified micro characters may be blurred due to bleeding. In this case, in the second step (S2), the character width of the plate is increased by 10% or more and 30% or less.

[0031] The micro characters printed in the third step (S3) have a height of 100 μm or less and a line width of 40 μm or more. Preferably, the font of the micro characters does not include serif characters.

[0032] In the third step (S3), printing is performed. If this printing is offset printing, the ink used in the offset printing can be a color ink or medium for offset printing. The ink for offset printing can also be a UV-drying ink. In addition, to enhance counterfeit prevention, security ink containing any of ultraviolet fluorescent ink, infrared fluorescent ink, infrared transmitting ink, and infrared absorbing ink can also be used in the offset printing.

[0033] Next, a printed matter printed by the printing method according to this embodiment will be described.

[0034] FIG. 2 is a plan view showing an example of a printed matter printed by the printing method according to this embodiment.

[0035] This printed matter 10 is an anti-counterfeit printed matter with microtext printed on it. The paper for the printed matter 10 can be high-quality paper. However, instead of high-quality paper, coated paper, synthetic paper, etc. can also be used. In addition, the paper may be provided with other security features such as watermarking, fiber incorporation, or hologram transfer.

[0036] In addition to the microtext printed in areas M1 and M2, the printed matter 10 also has a pattern A printed thereon. The pattern A can also be printed by offset printing. However, the pattern A is not limited to being printed by offset printing alone, and may be printed using a different printing method, such as partially using intaglio printing or screen printing.

[0037] In printing plates, the line width of black characters is narrow and the line width of white characters is wide, but printed matter printed with this plate has approximately the same line width between the toned solid and white characters. More specifically, the difference in line width can be kept to ±10% or less, and more preferably ±5% or less. Forming such micro characters improves the visibility of the characters when observed under magnification. Furthermore, printing micro characters with uniform line widths requires high-precision printing technology, making them difficult to counterfeit and highly resistant to counterfeiting.

[0038] In particular, offset printing requires adjusting printing conditions such as ink viscosity and plate pressure to prevent ink smearing and bleeding, which requires skill, making it difficult to create counterfeit products that reproduce the genuine article.In addition, when printing microtext using inkjet printing, individual character strings can be created for tickets, lotteries, coupons, etc., and the regularity of the character strings can be used to determine authenticity.

[0039] As such a regular string, a unique string may be generated for each ticket or lottery, and this string may be paired with a hash value generated by a cryptographic hash function. The cryptographic hash function may use either or both symmetric cryptography and asymmetric cryptography. By using asymmetric cryptography, authenticity can be determined using a public key, and the public key can be pre-installed in a verification device, enabling offline verification.

[0040] The micro characters may be alphabetic characters, Arabic numerals, or both micro characters and Arabic numerals.

[0041] From the viewpoint of printability and visibility, the micro characters may be a string of letters, Arabic numerals, or both. Micro characters are also called microtext.

[0042] The toned solid and white characters can be the same character string. This makes it easier to compare them. The toned solid and white MyMic characters can also be formed in the same character size. They can also be different character sizes. If the character size is the same, printing is easy. If the character size is different, it requires high skill to print, making it more difficult to counterfeit.

[0043] Furthermore, the character size of each of the toned solid and white microcharacters may be the same or different. The same font can be used, which is less likely to create a sense of incongruity. The toned solid and white microcharacters may be formed in the same color or in different colors.

[0044] Furthermore, the toned solid and white micro characters can be formed in a single color or a mixture of colors. If the color is light, it is easier to form high-resolution micro characters. If the color is mixed, it is necessary to match the colors of the plates, making counterfeiting more difficult.

[0045] Next, the micro characters printed in the areas M1 and M2 will be explained in the following Examples 1 to 3.

[0046] Example 1 In Example 1, to print the micro-characters, micro-characters ("SECURE") with a specified character width of 50 μm were printed on fine paper using UV-curable offset ink with a tack of 9.1 and a flow of 16.5.

[0047] FIG. 3 is an enlarged plan view showing an example of micro characters printed in toned solid (solid black) by offset printing without adjusting the line width.

[0048] FIG. 4 is an enlarged plan view showing an example of microcharacters offset printed in white without adjusting the line width.

[0049] FIG. 5 is an enlarged plan view showing an example of micro characters (solid black) printed without bleeding by the plate adjusted in the second step.

[0050] FIG. 6 is an enlarged plan view showing an example of microcharacters (white-out characters) printed without bleeding by the plate adjusted in the second step.

[0051] FIG. 7 is an enlarged plan view showing an example of a micro character (solid black) having an assumed character width.

[0052] FIG. 8 is an enlarged plan view showing an example of a micro character (white outline) having an assumed character width.

[0053] In the case of solid black printing, as shown in Figure 3, bleeding caused the solid black to spread, resulting in thicker than expected micro characters ("SECURE") b1, confirming a decrease in quality. On the other hand, in the case of outline printing, as shown in Figure 4, bleeding of the solid black into the outline caused thinner than expected micro characters ("SECURE") w1, confirming a decrease in quality.

[0054] Therefore, in the second step, the character width of the plate was adjusted. Specifically, the character width was adjusted to be 10 μm narrower for the original data of solid black microcharacter b1. When printing using this plate, if there is no bleeding, the microcharacter b2 shown in Figure 5 will be obtained. On the other hand, for the plate that printed the white microcharacter w1 shown in Figure 4, the character width was adjusted to be 10 μm wider. When printing using this plate, if there is no bleeding, the microcharacter w2 shown in Figure 6 will be obtained.

[0055] Next, in the third step, microcharacters were printed by offset printing using UV-curable offset ink, using a plate with the character width adjusted in this way. As a result, in the case of solid black printing, microcharacters b3 were obtained by solid black printing with a width of 50 μm, as expected, as shown in Figure 7. In addition, in the case of white printing, microcharacters w3 were obtained by white printing with a width of 50 μm, as expected, as shown in Figure 8.

[0056] Example 2 In Example 2, microcharacters were printed under the same conditions as in Example 1, except that only the assumed character width of the microcharacters was changed. In Example 1, the assumed character width of the microcharacters was 50 μm, but in Example 2, it was set to 150 μm.

[0057] In Example 2, in the case of solid black printing, the black spread due to bleeding, resulting in thicker than expected micro characters ("SECURE") b1, and a decrease in quality was confirmed, as shown in Figure 3. In the case of outline printing, the black spread into the outline, resulting in thinner than expected micro characters ("SECURE") w1, and a decrease in quality was confirmed, as shown in Figure 4.

[0058] In contrast, in Example 2, in the second step, the character width was adjusted to be 30 μm narrower for the plate on which solid black microcharacters b1 as shown in FIG. 3 were printed. When printing was performed using this plate, if there was no bleeding, microcharacters b2 as shown in FIG. 5 would be obtained. On the other hand, the character width was adjusted to be 30 μm wider for the plate on which white microcharacters w1 as shown in FIG. 4 were printed. When printing was performed using this plate, if there was no bleeding, microcharacters w2 as shown in FIG. 6 would be obtained. In other words, since the character width in Example 2 is three times that of Example 1, the adjustment width was also three times wider.

[0059] Next, in the third step, microcharacters were printed by offset printing using UV-curable offset ink using a plate with the character width adjusted in this way. As a result, in the case of solid black printing, microcharacters b3 were obtained by solid black printing with a width of 150 μm as expected, as shown in Figure 7. In addition, in the case of white printing, microcharacters w3 were obtained by white printing with a width of 150 μm as expected, as shown in Figure 8.

[0060] As can be seen from the results of Examples 1 and 2, even if the character width of the micro characters is different, by adjusting the plate using the same adjustment width ratio, it is possible to print similarly high-quality micro characters.

[0061] Example 3 In Example 3, the same type of ink as in Example 1 was used, but the pigment ratio in the ink was changed to print the micro-characters. Specifically, in Example 1, a UV-drying offset ink with a tack of 9.1 and a flow of 16.5 was used, whereas in Example 3, a UV-drying offset ink with a tack of 6.5 and a flow of 14 was used to print the micro-characters. The other conditions were the same as in Example 1.

[0062] In Example 3, in the case of solid black printing, the black spread due to bleeding, resulting in thicker than expected micro characters ("SECURE") b1, and a decrease in quality was confirmed, as shown in Figure 3. In the case of outline printing, the black spread into the outline, resulting in thinner than expected micro characters ("SECURE") w1, and a decrease in quality was confirmed, as shown in Figure 4.

[0063] In response to this, as in Example 1, in the second process, the character width was adjusted to be 30 μm narrower for the plate on which solid black microcharacters b1 as shown in Figure 3 were printed, and the character width was adjusted to be 30 μm wider for the plate on which white microcharacters w1 as shown in Figure 4 were printed.

[0064] Next, in the third step, microcharacters were printed by offset printing using UV-curable offset ink using a plate with the character width adjusted in this way. As a result, in the case of solid black printing, microcharacters b3 were obtained by solid black printing with a width of 150 μm as expected, as shown in Figure 7. In addition, in the case of white printing, microcharacters w3 were obtained by white printing with a width of 150 μm as expected, as shown in Figure 8.

[0065] As can be seen from the results of Examples 1 and 3, even when micro-characters are printed using inks with different pigment ratios, high-quality micro-characters can be printed by printing using a plate that has been adjusted by approximately 10% to 30% relative to the expected character width of the micro-characters.

[0066] As described above, the printing method according to this embodiment makes it possible to print high-quality microcharacters at low cost.

[0067] Although the best mode for carrying out the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to such a configuration. Those skilled in the art may conceive of various modifications and alterations within the scope of the technical ideas of the invention as defined in the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention. [Explanation of symbols]

[0068] 10 Printed matter A Picture M1, M2 area b1, b2, b3 Micro text (solid black) w1, w2, w3 micro letters (white)

Claims

1. A first step of specifying micro characters from original data; a second step of adjusting the character width of the microcharacters specified in the first step; a third step of printing the microcharacters by printing using the plate whose character width has been adjusted in the second step.

2. 2. The printing method according to claim 1, wherein in the first step, the micro characters are printed in one of black characters, solid characters, and white characters.

3. 3. The printing method according to claim 2, wherein in the first step, if the micro characters are black characters or solid monochrome characters, and if blurring due to bleeding is confirmed in the printed micro characters, in the second step, the character width of the plate is reduced by 10% or more and 30% or less.

4. 3. The printing method according to claim 2, wherein, in the first step, when the micro characters are printed in white, if the printed micro characters are found to be blurred due to bleeding, the character width of the plate is increased by 10% or more and 30% or less in the second step.

5. The printing method according to claim 1 , wherein the microcharacters printed in the third step have a height of 100 μm or less and a line width of 40 μm or more.

6. 6. The printing method according to claim 5, wherein the micro characters printed in the third step are in a font other than serif font.

7. 2. The printing method according to claim 1, wherein the ink used in the offset printing is an ink for offset printing.

8. 2. The printing method according to claim 1, wherein the ink used in the printing is a security ink containing any one of ultraviolet fluorescent ink, infrared fluorescent ink, infrared transmitting ink, and infrared absorbing ink.

Images