TW202311060A - Plate-making method, plate-making system and can body - Google Patents

Abstract

To manufacture printing plate capable of restraining inks from being mixed and murky, and providing easy registration and a high color reproducibility. There is provided a plate-making method for manufacturing printing plates capable of representing a color of each pixel by overprinting halftone dots in at least three process colors including: for each of pixels, when the sum of the halftone area ratios of the process colors is equal to or smaller than 100 %, manufacturing the printing plates based on a knockout method in which halftone dots are formed in positions at which the halftone dots in the process colors do not overlap each other, and the halftone dots in the process colors are overprinted onto each other.

Description

Plate-making method, plate-making system and tank body

The invention relates to a plate-making method, a plate-making system and a tank body.

A printing plate installed in a printing machine for multi-color printing is produced in response to image data obtained by dividing an original image into each color and converting it into halftone dots (for example, Patent Document 1).

Patent Document 1 describes a plate making method, which is image erosion in a way that does not cause ink bleeding or ink turbidity caused by mechanical deviation of the printing machine, compared to the image data obtained by dividing the original image into various colors and performing halftone dots (erosion) processing, and make printing plates of various colors based on the image data subjected to the erosion processing. [Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent Publication No. 7-57543. [Outline of Invention] [Problem to be Solved by the Invention]

In the technology described in Patent Document 1, image erosion processing is performed on dotted image data, so the underlying color is easily exposed, and the color gamut of the reproducible color area is easily limited, so the color reproducibility tends to be low. On the contrary, in the technology described in Patent Document 1, if image erosion processing is not performed in order to maintain high color reproducibility, ink turbidity tends to occur. In addition, in the technique described in Patent Document 1, if image erosion processing is not performed, high-precision registration capable of adjusting the mechanical variation of the printing machine is required.

This invention was made in view of the said situation, and one example of the subject is to solve the said problem. That is, one example of the problem of the present invention is to produce a printing plate that suppresses ink turbidity, is easy to register, and has high color reproducibility. Cans printed by hand with high reproducibility.

[Means to solve the problem]

One aspect of the present invention provides a plate making method for producing a printing plate capable of expressing the color of each pixel by overprinting dots of at least three basic colors, and the total area ratio of the dots of each color of the basic colors is 100% or less In the pixel, the dots of each color are formed at positions where the dots of each color do not overlap each other, and the dots of each color of the aforementioned basic color are knocked out to make the aforementioned printing plate. [Efficacy of Invention]

According to the present invention, it is possible to produce a printing plate that suppresses ink turbidity, is easy to register, and has high color reproducibility. Also, according to the present invention, it is possible to provide a can body printed by a technique that suppresses ink turbidity, facilitates registration, and has high color reproducibility.

Embodiments of the present invention will be described below with reference to the drawings. The following descriptions of the embodiments are merely examples of the present invention, and the content of the present invention is not limited thereto. In addition, the configurations and actions described in the embodiments are not necessarily the essential configurations and actions of the present invention.

[Composition of the plate making system] Fig. 1 is a diagram showing the configuration of a plate making system 1 of the present embodiment. FIG. 2 is a diagram for explaining a hollowing out method and an overprint method.

Plate-making system 1 is used to produce printing plates installed on plate printing machines, adopt DTP (Desktop Publishing) and CTP (Computer To Plate), and produce printing plates for multi-color printing.

The printed matter of the printing plate produced by the plate making system 1 is a can with a slightly cylindrical shape (including the intermediate molded body of the can), such as a two-piece can, or a flat metal plate. Also, the plate making system 1 produces printing plates installed on an offset printing machine that transfers ink through an intermediate transfer body (such as a blanket), or a non-offset printing machine that does not use an intermediate transfer body.

The plate making system 1 illustrated in Fig. 1 is used to produce printing plates. The printing plates use two-piece cans and other tanks with a slightly cylindrical shape as the objects to be printed, and are installed on the transfer through the intermediate transfer body relative to the outer peripheral surface of the tanks. Offset printing machine for printing ink 30 . The printing plate produced by the plate-making system 1 shown in FIG. 1 is preferably a resin relief plate with a photosensitive resin layer or the like forming a printing portion where ink is superimposed. The plate making system 1 shown in Fig. 1 is preferably DLE (Direct Laser Engraving) which uses laser sublimation resin to make printing plates while engraving, or LAMS (which uses lasers to write and develop images on the surface of resin plates) Laser Ablation Masking System) to make printing plates. In addition, the printing plate produced by the plate making system 1 shown in FIG. 1 can also be a non-level plate that forms a non-printing portion where ink is not superimposed with a silicone resin layer and does not use a dampening solution.

The plate making system 1 includes a data processing device 10 for performing various image processing on original document image data to create image data for plate making, and a plate making device 20 for making printing plates in response to the image data for plate making.

The data processing device 10 edits the original image data expressed in page description language such as layout and tone correction. Next, the data processing device 10 performs color separation processing such as color decomposition of basic colors and special colors, and dot conversion processing for expressing the shades of each color as a set of dots, thereby producing image data for plate making, and sending a letter to the plate making device 20 . The data processing device 10 includes a processor, a memory device, and a program for executing the functions of the data processing device 10 .

The data processing device 10 is equipped with a color separation processing unit 11, a network dot conversion condition setting unit 12, a network dot conversion processing unit 13, and a sending processing unit 14. The color separation processing unit 11 is for color separation processing, and the network dot conversion condition setting unit 12 is a Setting the conditions of the dot conversion process, the dot conversion processing unit 13 performs the dot conversion processing, and the transmission processing unit 14 performs the processing of sending the data to the plate making device 20 .

The color separation processing unit 11 decomposes the color of the edited original image data into basic colors, and performs UCR (under color removal) on the part where the achromatic color is reproduced in the part where the colors overlap each other. The basic color is the ink color used for printing. For example, it can be 4 colors of cyan, magenta, yellow and black, or 7 colors of red, green and blue, or 8 colors of white W. The color-separation processing unit 11 creates the image data of the original document and extracts the image data of each color by color decomposition, that is, the color-separation image data.

The halftone conversion condition setting unit 12 sets the halftone conversion conditions for the color separation image data created by the color separation processing unit 11 , that is, the halftone conversion condition. The dot conversion condition is set for each color-separated image data. The dot conversion conditions include the dot shape of each color, the dot area ratio, the number of screen lines, and the screen angle, and also include the relevant conditions of the hollowing method.

The plate making system 1 performs overprinting of inks of various colors extracted by color decomposition, thereby making printing plates capable of expressing colors other than those extracted by color decomposition. At this time, the plate making system 1 can produce a printing plate that can overprint each color extracted by color decomposition in a hollowed out manner.

The hollowing method is to form a blank dot in one of the two colors that is close to the base side of the printed matter, and overprint the dot of the other color that is farther away from the base side of the printed matter than the other color at the position where the blank dot is formed. The color that forms the halftone dot can also be the color that is away from the base side of the printed object.

Next, the method of hollowing out using two colors will be described. The method of hollowing out using 3 colors will be explained later. When four colors of cyan, magenta, yellow and black are used as basic colors, the two colors to be overprinted by hollowing out are preferably two colors selected from among cyan, magenta and yellow. Alternatively, when the 7 colors of cyan, magenta, yellow, red, green, blue and black are used as the basic colors, the two colors to be overprinted by hollowing out are preferably one selected from cyan, magenta and yellow color, and one color selected from red, green and blue.

In the example in Fig. 2(a), magenta M is used as one color and cyan C is used as the other color, and magenta M and cyan C are overprinted by hollowing out. In Figure 2(a), in the magenta M of one color, blank dots are formed at the superposition of cyan C of another color. In other words, the dots of cyan C of another color are set in such a way that the dots of the blank dots of one color of magenta M form part. In the hollowing out method, the printing ink of another color and the printing ink of one color are overprinted without contact as much as possible.

In contrast, in the conventional plate making system, as shown in Figure 2(b), when expressing colors other than the colors extracted by color decomposition, a printing plate in which each color extracted by color decomposition is overprinted is often produced. . The overprinting method is a method of overprinting without forming blank dots in the two overprinted colors. In the overprinting method, at least a part of the dots of one color is superimposed on the dots of the other color in the two colors of overprinting, so that the ink of one color and the ink of the other color will contact and overprint.

The halftone dot condition setting unit 12 designates individual color separation image data of one of the two colors to be subjected to the cutout method and the other color as a condition related to the cutout method as one of the halftone dot formation conditions. Next, the dot conversion condition setting unit 12 sets the dot area ratios of one color and another color for each pixel of the designated color separation image data. The details of setting the dot area ratios of the one color and the other color to be the target of the knockout method will be described later.

The halftone processing unit 13 converts the color separation image data created by the color separation processing unit 11 into halftone dots according to the dot conversion conditions set by the halftone conversion condition setting unit 12 . The dotted image data is, for example, binary data such as 1bit TIFF (Tagged Image File Format). This dotted image data is used as image data for plate making when the plate making device 20 makes a printing plate. The dot conversion processing unit 13 can be configured by software RIP (Raster Image Processor) or the like.

The halftone dot processing unit 13, when dot halftone individual color-separated image data of one of the two colors to be targeted by the knockout method and the other color, halftone the one color and the other color under different conditions. Specifically, when the halftone dot processing unit 13 halftones the one-color color-separated image data, it temporarily creates reversed image data in which the shades of one color are reversed in the one-color color-separated image data, and reverses the created image data. Image data is dotted with a negative condition. The negative condition is a condition that the lower the pixel density, the higher the halftone dot area ratio. In this regard, when the halftone conversion processing unit 13 converts the color separation image data of another color into halftone dots, it directly converts the color separation image data of another color into halftone dots under positive conditions. The positive condition is a condition that pixels with higher color density have higher halftone dot area ratio.

The transmission processing unit 14 performs a process of transmitting the image data converted into a dot by the halftone processing unit 13 to the plate making apparatus 20 as image data for plate making.

The plate production device 20 produces printing plates of each color in response to the video data transmitted from the transmission processing unit 14 of the data processing device 10 , that is, the video data to be dotted for each color. The plate making device 20 preferably makes printing plates by the above-mentioned DLE method or LAMS method. The plate making device 20 performs laser engraving or exposure on the resin plate based on the image data of the dots of each color to form a printing part and a non-printing part, thereby making a printing plate.

[Conditions for dot conversion related to the hollowing out method] FIG. 3 is a diagram for explaining a gap A and a biting portion B formed in one color and another color to be subjected to the hollowing method. One color is magenta M with white dots formed. The other color is cyan C and forms a cyan C dot in the blank dot position of magenta M. Fig. 4 is a graph showing the relationship between the total value of the dot area ratio of one color and the dot area ratio of another color, and the size a of the gap A or the size b of the bite portion B.

The halftone dot conversion condition setting unit 12 sets the halftone dot area ratios of the one color and the other color that are subject to the knockout method based on the total value of the halftone dot area ratio of one color and the halftone dot area ratio of the other color. Specifically, the dot conversion condition setting unit 12 is set in such a manner that, among pixels whose total value of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, a dot of the same color is formed around a dot of the other color. Leave the gap A between the white dots. Also, the dot conversion condition setting section 12 is set in such a manner that the dot area ratio of one color and the dot area ratio of the other color exceed 100% in total, so that the dots of the other color are bitten around the blank dots of the same color. The bite part B.

The biting portion B is formed in such a way that the center position of the dots of the other color is slightly consistent with the center position of the dots of the same color, and the size of the dots of the other color is larger than the size of the dots of the same color. In the nip portion B, the upper and lower relationship of the overlapping of the ink of one color and the other color may be arbitrary. Also, in this embodiment, the hollow formed by two colors is formed, but the gap A and the biting part B may be formed in the hollow of three or more colors. The dot shape is not limited to a circle, and may be a polygon or other shapes. Also, the dot area ratio is the ratio of the area occupied by the dots per unit area, which expresses the shade of the color.

The example in Fig. 3(a) shows the case where the total value of the dot area ratio of one color of magenta M and the dot area ratio of another color of cyan C does not reach 100%. At this time, a gap A with the one-color magenta M is formed with a size a around the halftone dots of the other-color cyan C. The gap A is preferably formed around the entire circumference of the mesh dot. This makes it difficult for the ink to touch even if the scale of each color is shifted, and clouding can be suppressed. The size a of the gap A can be the subtraction value obtained by subtracting the radius of the dots of the other color cyan C from the radius of the space forming part of the magenta M of one color.

The example in Fig. 3(b) shows the case where the total value of the dot area ratio of one color of magenta M and the dot area ratio of another color of cyan C exceeds 100%. At this time, a biting portion B is formed in which halftone dots of another color of cyan C are bitten into the periphery of halftone dots of one color of magenta M at a size b. The biting portion B is preferably formed on the entire circumference around the dot. Thereby, even if the scales of each color are shifted from the base, it is not easy to be exposed. The size b of the biting portion B can be the subtraction value obtained by subtracting the radius of the blank forming part of one color of magenta M from the radius of the dots of another color of cyan C.

The dot conversion condition setting unit 12 can appropriately set the total value of the dot area ratio of one color and the dot area ratio of another color, thereby controlling the size a of the gap A or the size b of the bite portion B, and controlling the overprinting of one color and the other. The shade of color expressed by a color.

In Fig. 4, the vertical axis is the dot area ratio of one color, and the horizontal axis is the dot area ratio of the other color, and the intersection of these is the size a of the gap A or the size b of the biting part B formed in these total values . In Figure 4, the numbers in black on a white background indicate the size a of the gap A, and the numbers in white on a dark gray background indicate the size b of the biting portion B. Also, in Fig. 4, the number "0" in black on a light gray background indicates the state where the gap A and the biting portion B are not formed, that is, it indicates that overprinting is performed in a state where one color slightly overlaps another color. Also, in Fig. 4, "fill" in black characters on a white background means that one color or another color is filled.

Figure 4 shows the relationship between the total value of the dot area ratio of one color and the dot area ratio of the other color, and the size a of the gap A or the size b of the bite part B when the screen line number is 100 lpi (line per inch). At this time, when the dot area ratio of one color is "90%" and the dot area ratio of the other color is "40%", it can be seen that the biting portion B with a size b of "0.05mm" is formed. When the dot area ratio of one color is "90%" and the dot area ratio of the other color is "40%", the total value of these is "130%". Also, if the size b of the biting portion B becomes larger, the contact area between one color and another color will increase, and the ink will easily become cloudy. Therefore, it is preferable to form one color within the range where the size b of the biting portion B does not exceed a specific value. In the same way as the bite portion B of another color, set the total value of the dot area ratio of one color and the dot area ratio of the other color. The degree of turbidity of ink varies with the type of printing plate, so the total value is set according to the type of printing plate.

The dot conversion condition setting unit 12 sets the total value of the dot area ratio of one color and the dot area ratio of the other color in the pixels forming the biting portion B, and when the printing plate is a resin letterpress, it is set to a range of more than 100% and less than 125%. The value within is set to a value within the range of more than 100% and less than 150% when the printing plate is a non-level plate. In this way, the halftone dot conversion condition setting unit 12 can set conditions related to the knockout method in a method of suppressing ink turbidity and overprinting one color and another color in the pixels forming the bite portion B.

Next, the method of hollowing out using three colors will be explained. The three colors to be overprinted by hollowing out are preferably the colors expressing the hue of the color of the pixel, and it is preferable to select other than black K or white W among the basic colors. When four colors of cyan C, magenta M, yellow Y and black K are used as basic colors, three colors of cyan C, magenta M and yellow Y are preferred. Alternatively, when the seven basic colors of cyan C, magenta M, yellow Y, red R, green G, blue B, and black K are used as the basic colors, it is preferable to contain a color selected from cyan C, magenta M, and yellow Y. At least one color, and at least one color selected from red R, green G, and blue B. In addition, if the basic colors are cyan C, magenta M, yellow Y, red R, green G, and blue B, the combination of fluorescent colors and gold inks that cannot be expressed can expand the expressable color gamut. In addition, eight colors of cyan C, magenta M, yellow Y, red R, green G, blue B, black K, and white W may be used as the basic colors. Also, the number of colors to be hollowed out is not limited to three colors, and more than three colors may be hollowed out.

Figs. 5 and 6 show examples of hollowing out in three colors of cyan C, magenta, and yellow Y. As shown in Fig. 5 and Fig. 6, it is the situation of the knockout method of overprinting the dots of three colors. Set by the total value of dot area ratio. That is, the halftone dot formation condition setting unit 12 sets a halftone dot at a position where the halftone dots of each color do not overlap each other among pixels whose total halftone dot area ratio of each color is 100% or less. In particular, the dot area ratio is set so that a gap is formed around at least one dot of each color in pixels whose dot area ratios of each color total less than 100%. Also, the dot conversion condition setting section 12 is set in such a manner that, among the pixels whose dot area ratios of the respective colors exceed 100%, at least one of the colors forms a halftone dot biting into the surrounding halftone dots of the other two colors. The formation of gaps or bites is the same as the two-color hollows in Figure 3, and the two-color hollows in Figure 3 are formed at the border of individual colors.

Fig. 5(a) and Fig. 5(b) show examples in which the total value of the dot area ratio of each color is less than 100%. Fig. 5(a) shows an example in which the dot area ratio of each color in each pixel is 10% for yellow Y, 30% for magenta M and cyan C, and the total dot area ratio is 70%. At this time, gaps are respectively formed between cyan C and magenta M, and between magenta M and yellow Y.

FIG. 5(b) shows an example in which the dot area ratio of each color in each pixel is 10% for yellow Y, 40% for magenta M, and 30% for cyan C, and the total dot area ratio is 80%. At this time, a gap is formed between the cyan C and the magenta M.

Fig. 5(c) shows an example in which the total value of the dot area ratio of each color exceeds 100%. Figure 5(c) shows an example in which yellow Y is 15%, magenta M is 40%, cyan C is 60%, and the total dot area ratio is 115%. At this time, biting portions are respectively formed between the cyan C and the magenta M, and between the magenta M and the yellow Y.

In the example of Fig. 5(a) to Fig. 5(c), the dots of each color are circular, and the dots of each color are arranged in such a way that pixels of one color contain other colors. In addition, halftone dots of each color are concentrically arranged in the pixels.

Also, the dots of each color do not need to be in the same shape. For example, as shown in Figure 6(a) and Figure 6(b), the cyan C dots can be formed into a rectangular shape with a circular space, and the yellow Y can be formed In order to form a circle (ring shape) with a circular space, magenta M is formed into a circle shape.

Fig. 6(a) shows an example in which the dot area ratio of each color in each pixel is 30% for cyan C, 35% for yellow Y, and 35% for magenta M, and the total value of the dot area ratio is 100%. Therefore, cyan C, yellow Y, and magenta M are respectively overprinted without gaps.

FIG. 6(b) shows an example in which the dot area ratio of each color in each pixel is 30% for cyan C, 30% for yellow Y, and 30% for magenta M, and the total dot area ratio is 90%. Therefore, gaps are formed between cyan C and yellow Y, and between yellow Y and magenta M, respectively.

In addition, as shown in Fig. 7(a) to Fig. 7(c), for example, the dots of each color may be in the shape of squares with different sizes and each color may be concentrically arranged in the pixel (Fig. 7(a)) , it is also possible to form the dots of one color (such as cyan C) into a square shape and make the other two colors (such as yellow Y and magenta M) into a rectangular shape arranged in a square shape (Fig. 7(b), Figure 7(c)).

It is possible to overprint white W or black K, or white W and black K on pixels that can be overprinted in the above-mentioned at least 3 colors in a hollowed-out manner. That is, only white W, only black K, or white W and black K can be overprinted by hollowing out the pixel obtained by hollowing out the three colors. Also, at this time, it is preferable to arrange the halftone dots of white W or black K, or white W and black K at different screen angles from the halftone dots of the other three colors. As described above, only white W, only black K, or white W and black K are superimposed on the pixel obtained by hollowing out the three colors, thereby improving the brightness reproducibility of the pixel. In addition, when the base is a mirror surface such as metal, a transparent color can be reproduced without white W superimposing, and an opaque color can be reproduced when white W is superimposed, so the color reproduction range can be expanded.

Similar to the case of two-color cutouts, the dot conversion condition setting unit 12 sets the total value of the dot area ratios of at least three colors cut out in the pixels forming the bite portion B, and sets it to more than 100 when the printing plate is a resin relief plate. % and a value within a range of 125% or less, and a value within a range of more than 100% and a value of 150% or less when the printing plate is a non-level plate. In this way, the halftone dot conversion condition setting unit 12 can set conditions related to the knockout method in a method of suppressing ink turbidity and overprinting three colors in the pixels forming the bite portion B. Also, when overprinting white W or black K, or white W and black K in at least three colors, if the dot area ratio of at least three colors is the same as that of white W or black K, or white W and black K When the total area ratio falls within the range of 160% or less, ink turbidity can be suppressed.

[Plate making method using a plate making system] Fig. 8 is a diagram showing the flow of a plate making method for making a printing plate using the plate making system 1 shown in Fig. 1 .

Steps S501 to S506 shown in FIG. 8 are executed by the data processing device 10 according to the operation command input by the user through the user interface of the data processing device 10 . Step S507 shown in FIG. 8 can be implemented by the plate making device 20 .

In step S501 , the plate making system 1 loads the original image data into the data processing device 10 .

In step S502, the plate making system 1 edits the image data of the incoming manuscript. The plate making system 1 is to edit the original image data by correcting the layout or color tone in accordance with the printing area of the printed matter.

In step S503, the plate making system 1 performs color separation processing on the edited original image data. The plate making system 1 decomposes the color of the edited original image data into each basic color, and produces color-separated image data of each color.

In step S504 , the plate making system 1 performs a setting process of dot conversion conditions, which is to set the dot conversion conditions when the color separation image data produced by the color separation process is converted into dots. In particular, the plate making system 1 designates individual color separation image data of three colors to be targeted by the knockout method, and sets dot area ratios of the three colors for each pixel of the designated color separation image data. At this time, the plate making system 1 sets the halftone dot area ratios of the three colors so that the gap A and the bite portion B are appropriately formed based on the total value of the halftone dot area ratios of the three colors.

In step S505 , the plate making system 1 converts the color separation image data produced by the color separation process into dots in response to the dot conversion conditions set in the dot conversion setting process.

In step S506, the plate making system 1 performs a sending process, which is to send the image data obtained by halftone dot conversion from the data processing device 10 to the plate making device 20 as the image data for plate making.

In step S507 , the plate making system 1 produces printing plates of various colors in the plate making device 20 in response to the transmitted image data.

[Effect] As mentioned above, the plate making system 1 of this embodiment produces printing plates according to the hollowing method. Next, the plate making system 1 of this embodiment is a plate making method for making a printing plate that can express the color of each pixel by overprinting dots of at least three basic colors. The total dot area ratio of each color of the basic colors is Among the pixels below 100%, dots are formed at positions where the dots of each color do not overlap each other.

Therefore, the plate making system 1 of this embodiment has high color reproducibility and can suppress inks of dots of each color from contacting each other, so it is possible to manufacture a printing plate in which ink turbidity can be suppressed.

In addition, the plate making system 1 of this embodiment is to form a dot of the same color around the dots of the other color in the pixels where the total value of the dot area ratio of one color and the dot area ratio of the other color is less than 100%. The gap A between the blank screen dots, in the pixels whose total value exceeds 100%, forms the biting part B where the screen dots of another color bite into the surrounding blank screen dots of the same color.

Therefore, the plate making system 1 of this embodiment can control the size a of the gap A or the size b of the bite portion B by appropriately setting the total value of the dot area ratio of one color and the dot area ratio of the other color. Specifically, the plate making system 1 of this embodiment forms the gap A when the total dot area ratio is less than 100%, and forms the bite portion B when the total dot area ratio exceeds 100%. Thereby, compared with the printing plate of the conventional hollowing method, the plate making system 1 of this embodiment has a larger allowable value for the deviation of the scale, and can produce a printing plate that is easy to register. In addition, the plate making system 1 of this embodiment prevents the ink from contacting each other by hollowing out, so it can produce a printing plate that can suppress ink turbidity, and the color of the base is easily concealed, so the reproduction color gamut can be expanded, and the printing plate can be produced. Printing plates with high density can be obtained even on flat screens. Accordingly, the plate making system 1 of this embodiment can produce printing plates with high color reproducibility compared to the production of printing plates of the superimposed printing method. Therefore, the plate making system 1 of this embodiment can produce printing plates with less ink turbidity, easy registration, and high color reproducibility in a relatively simple way.

In addition, the plate making system 1 of this embodiment can produce a printing plate that expands the reproduction color gamut and can obtain a high-density feeling even with a flat screen, so it does not require excessive ink application and excess plate pressure, and can produce a printing plate that can reduce ink printing. Printed version of usage.

In addition, compared with the production of overprint printing plates, there is no problem with the ink trapping in the plate making system 1 of this embodiment, so it is not necessary to strictly manage the viscosity value of the ink according to the overprinting sequence. Thereby, the plate making system 1 of this embodiment can produce printing plates without being limited by ink characteristics, so printing plates can be produced with a high degree of freedom.

Also, in the plate making system 1 of the present embodiment, when the printing plate is a resin relief plate, the above-mentioned total value in the pixels forming the bite portion B is set to a value within the range of more than 100% and 125% or less, and the printing plate is set to no In the case of a horizontal plate, the above-mentioned total value in the pixels forming the bite portion B is set to a value within a range of more than 100% and 150% or less. Thereby, the plate making system 1 of this embodiment can form a printing plate with further suppressed ink turbidity, easy registration, and high color reproducibility in the pixels forming the bite portion B.

In addition, in the plate making system 1 of this embodiment, in the color-separated image data of one color extracted by color decomposition of the original image data, the intensity of one color is reversed to form reversed image data, and the reversed image data is converted into Negative conditions are used to perform dot conversion, thereby producing one-color dot conversion image data. In contrast, in the plate making system 1 of the present embodiment, the original image data is converted into a halftone image data of another color extracted by color decomposition, thereby creating halftone dotted image data of another color. Therefore, in the plate making system 1 of this embodiment, a printing plate that forms a blank in one color and overprints another color can be produced by a relatively simple method. Thereby, the plate making system 1 of this embodiment can more easily produce printing plates that suppress ink turbidity, are easy to register, and have high color reproducibility.

Also, the plate making system 1 of the present embodiment is for producing printing plates using two cans or metal plates as printed objects. Compared with the situation where paper is used as the printed object of the previous printing plate, the printed surface of the two-piece can or metal plate is non-ink-permeable, so it is a more serious problem to suppress ink turbidity and facilitate registration. In the plate making system 1 of this embodiment, even if the printed matter is two cans or metal plates, the printing plate can be produced by hollowing out, and the size a of the gap A or the size b of the bite part B can be controlled. Therefore, the plate making system 1 of the present embodiment can produce a printing plate with suppressed ink turbidity, easy registration, and high color reproducibility even if the printed object is a two-piece can or a metal plate.

In addition, in the tank body printed using the plate making system 1 of this embodiment, the color of the base is easily concealed by hollowing out, so the color gamut of reproduction can be expanded, and a high-density feeling can be obtained even with a flat screen. Manual printing. Therefore, compared with the cans printed by overprinting, the cans printed by the plate making system 1 of this embodiment can obtain the cans with higher color reproducibility in a simpler way.

[Other implementation types] In the above-mentioned embodiment, the plate-making system 1 is to produce a printing plate with can bodies such as two-piece cans or metal plates as printed objects. However, the plate-making system 1 is not limited thereto, and a printing plate may be produced in which a three-dimensional object having a substantially cylindrical shape such as a bottle, a cup, or the like is used as an object to be printed. In addition, the plate making system 1 can also produce printing plates that use planar objects such as paper, labels, films, or sheets as printed objects. In addition, the plate making system 1 can also produce printing plates that use non-metallic materials such as plastics and glass with low ink permeability as printed objects.

[other] The technologies of the above-mentioned implementation forms and modification examples can be exchanged and applied in each implementation form. The content of the present invention is not limited to the above-mentioned implementation forms, and changes can be made without exceeding the scope of the patent application.

The terms used in the above-mentioned implementation forms and patent claims are not limited terms. For example, "contains" should be interpreted as "contains but not limited to". "Possess" should be interpreted as "possess but not limited to". "Have" should be interpreted as "has but not limited to".

1: Plate making system 10: Data processing device 11: Color separation processing department 12: Network condition setting department 13: Network processing department 14: Letter processing department 20: Plate making device 30:Offset printing machine A: Clearance a: the size of the gap B: Biting part b: The size of the biting part C: Blue M: Magenta

Fig. 1 is a diagram showing the configuration of the plate making system of this embodiment. Figures 2(a) and 2(b) are diagrams for explaining the hollowing out method and the overprinting method. Figures 3(a) and 3(b) are diagrams for explaining the gaps and biting portions formed in one color and another color which are the object of the hollowing method. Fig. 4 is a diagram showing the relationship between the total value of the dot area ratio of one color and the dot area ratio of the other color, and the size of the gap or the size of the biting portion. Figures 5(a)~5(c) are diagrams used to illustrate the hollowing out method of three colors. Figures 6(a) and 6(b) are diagrams for explaining the three-color hollowing method. Figs. 7(a) to 7(c) are diagrams for explaining other examples of dot shapes in the three-color hollowing out method. Fig. 8 is a diagram showing the flow of a plate making method for making printing plates using the plate making system shown in Fig. 1 .

1: Plate making system

10: Data processing device

11: Color separation processing department

12: Network condition setting department

13: Network processing department

14: Letter processing department

20: Plate making device

30:Offset printing machine

Claims (12)

A plate-making method, which is to produce a printing plate that can express the color of each pixel by overprinting dots of at least three basic colors, and the plate-making method includes: In pixels where the total dot area ratio of each color of the aforementioned basic colors is 100% or less, dots are formed at positions where the dots of each color do not overlap with each other, and the dots of each color of the aforementioned basic colors are overprinted by hollowing out to produce the aforementioned printing Version. The plate-making method according to claim 1, wherein, in pixels whose dot area ratios of the respective colors of the basic colors are less than 100%, a gap is formed around at least one dot of each of the basic colors, and when the total value exceeds 100%. In % of the pixels, at least one mesh dot of each of the above-mentioned basic colors is bitten into the biting part around the individual mesh dot. The plate making method according to claim 2, wherein the printing plate is a resin relief plate, and the range of the total value in the pixels forming the bite portion is more than 100% and 125% or less. The plate making method according to claim 2, wherein the printing plate is a non-level plate, and the range of the total value in the pixels forming the bite portion is more than 100% and 150% or less. The plate making method according to any one of claims 1 to 4, wherein dots of each color are arranged in such a way that pixels of one color contain other colors. The plate making method according to any one of Claims 1 to 5, wherein dots of each color are concentrically arranged in the aforementioned pixels. The plate making method according to any one of Claims 1 to 6, wherein the object to be printed on the aforementioned printing plate is a substantially cylindrical can body or a metal plate. The plate making method according to any one of claims 1 to 7, wherein only black, only white, or black and white are further superimposed on the aforementioned pixels. The plate making method as described in Claim 8, wherein the aforementioned black and white are hollowed out by the aforementioned hollowing out method. The plate making method as described in claim 8 or 9, wherein the dots of black only, white only, or black and white are arranged at different screen angles from the dots of at least three colors. A plate-making system for producing a printing plate capable of expressing the color of each pixel by overprinting dots of at least three basic colors, the plate-making system comprising: the total area ratio of the dots of each color of the above-mentioned basic colors is 100% or less In the pixel, dots of each color are formed at positions where the dots of each color do not overlap each other, and the dots of each color of the aforementioned basic color are hollowed out to make the aforementioned printing plate. A can body, which is printed to express the color of each pixel by overprinting dots of at least three basic colors, in which the dot area ratio of each color of the above-mentioned basic colors is 100% or less, in the dots of each color Dots are formed at positions that do not overlap with each other, and printing is carried out by hollowing out the dots of the aforementioned basic colors and various colors for overprinting.

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