RU2799024C1 - Plate-making method, plate-making system and can body - Google Patents

Abstract

FIELD: manufacturing of printing plates.

SUBSTANCE: printing plate manufacturing method for manufacturing printing plates based on image data divided into each colour and representing raster dots, includes: manufacturing a printing plate based on a reverse printing method in which reverse images of raster dots in one colour are formed, and printing is performed with imposition of raster dots of a different colour on the position of the reversible images; for each of the pixels, when the sum of the area ratio of the halftone dots of one colour and the area ratio of the halftone dots of the other colour is less than 100%, a gap is formed from the reversed image in one colour around the halftone dot of the other colour; and for each of the pixels, when the sum of the dot area ratio of one colour and the dot area ratio of the other colour is greater than 100%, a cover mask is formed so that the dot of the other colour penetrates the periphery of the dot of the same colour.

EFFECT: manufacturing of printing plates capable of limiting mixing and contamination of inks and providing easy registration and high colour reproducibility.

15 cl, 12 dwg

Description

The field of technology to which the invention belongs

[0001] The present invention relates to a method for manufacturing printing plates, to the production system printing forms, and to the body of the can.

State of the art

[ 0002 ] A plate to be placed in a printing apparatus for multi-color printing is made based on image data obtained by color separation of the original image into each of the colors and dot formation (for example, see Patent Document 1).

[ 0003 ] Patent Document 1 describes a printing plate manufacturing method for creating a printing plate for each of colors based on image data subjected to image scaling, including: generating dots of graphic information based on four colors after color separation; changing the colors of the image data up to seven colors that do not overlap; applying image scaling to the seven-color altered video data to prevent ink bleeding or to limit ink mixing or contamination due to printer mechanical movement.

List of cited documents

Patent Documents

[ 0004 ] Patent Document 1 (PTL1): Japanese Examined Patent Application Publication No. H7-57543.

The essence of the invention

Technical task

[ 0005 ] According to the technology described in Patent Document 1, image scaling is applied to video data representing halftone dots, and therefore the base color tends to be revealed, and the color gamut, which is the region of reproducible colors, tends to be limited, and therefore color reproducibility may decrease. However, according to the technology described in Patent Document 1, when image scaling is not applied to provide a wide color gamut to maintain high color reproducibility, printing inks are prone to mixing and contamination. In addition, according to the technology described in Patent Document 1, when image scaling is not applied, there is a need for extremely accurate registration, which can be adjusted by mechanical displacement of the printer. Moreover, a moiré pattern tends to occur, since the halftone dots in the seven colors overlap.

[ 0006 ] The present invention has been made in the circumstances described above in order to solve the problems described above. Therefore, one aspect of the subject matter of the invention is to provide printing plates capable of limiting ink mixing and contamination, and to achieve easy registration and high color reproducibility. In addition, one aspect of the subject matter of the invention is to provide a can body printed in a manner that limits ink mixing and contamination and achieves easy registration and high color reproducibility. In addition, another aspect of the subject matter of the invention is to provide printing plates capable of providing a wide gamut of colors from primary colors only, limiting the occurrence of moiré, and limiting mixing and soiling of printing inks. Further, one aspect of the subject matter is to provide a can body printed in a manner that can provide a wide gamut of colors from primary colors only, limit moire, and limit ink mixing and soiling.

The solution of the problem

[ 0007 ] According to the invention, a printing plate manufacturing method for making a printing plate based on image data divided into each of colors and representing halftone dots includes: making a printing plate based on a reverse printing method in which halftone dot reversed images are formed in one color, and perform printing with the imposition of halftone dots of a different color on the position of reversed images; for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, a gap is formed from a reversed image in one color around the dot of the other color; and for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is greater than 100%, a cover mask is formed so that the dot of the other color penetrates the periphery of the dot of the same color.

[ 0008 ] Preferably, the printing plate is a letterpress resin plate and, for each of the pixels forming the cover mask, the sum is over 100% and is equal to or less than 125%.

[ 0009 ] Preferably, the printing plate is a waterless planar printing plate, and for each of the pixels constituting the cover mask, the sum is over 100% and is equal to or less than 150%.

[ 0010 ] It is preferable that image data representing halftone dots of the same color be created by: generating image data of a divided printing plate for one color separated by color separation of the original image data; generating inverted image data by inverting shading of one color in the generated image data of the split plate; and generating dotted dots of the generated inverted image data to a negative state such that for each of the pixels, the lower the density of one color, the higher the area ratio of one color, and the image data representing the dotted dots of a different color is generated by dotting the image data of the separated printing plate , extracted by color separation of the original image data.

[ 0011 ] Preferably, the printing plate material to be printed is a two-piece assembly can or a metal plate.

[ 0012 ] According to the invention, a printing plate making system configured to make a printing plate based on image data separated into each of colors and representing halftone dots, includes: making a printing plate based on a reverse printing method in which halftone dot reversed images are formed in one color, and perform printing with the imposition of halftone dots of a different color on the position of reversed images; for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, a gap is formed from the reversed image in one color around the dot of the other color; and for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is greater than 100%, a cover mask is formed so that the dot of the other color penetrates the periphery of the dot of the same color.

[ 0013 ] According to the invention, there is provided a can body on which an image separated into each of the colors and representing halftone dots is printed. The image is formed on the basis of a reverse printing method in which reverse images of halftone dots in one color are formed, and printing is performed by superimposing halftone dots of a different color on the positions of the reversed images. For each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, a reversed image of one color around the dot of the other color is exposed. For each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is greater than 100%, a cover mask is formed so that the dot of the other color penetrates the periphery of the dot of the same color.

[ 0014 ] According to the invention, a method for manufacturing printing plates for making printing plates capable of representing colors by overprinting dots in three colors from a plurality of compound colors includes: printing with overlaying two colors out of three colors by a reverse printing method in which reverse images are formed halftone dots in one color, and perform printing with an overlay on the position of reverse images; and printing overlaying the remaining color of the three colors on the two colors by a color overlay method in which at least a portion of the halftone dots in the remaining color are placed on the halftone dots in one color and/or the halftone dots in another color.

[ 0015 ] Preferably, one color belongs to the first color group composed of colors having color components that do not overlap with each other, and the other color belongs to the second color group composed of colors having color components that do not overlap with each other, and the colors belonging to the second group are different from the colors belonging to the first group.

[ 0016 ] Preferably, the multiple compound colors are seven colors, cyan, magenta, yellow, red, green, blue and black; the first color group was cyan, magenta and yellow; the second color group is composed of red, green and blue; and the rest of the color was black.

[ 0017 ] Preferably, the half-tone dots in the rest of the color are placed at a different half-tone angle from the half-tone dots in the two colors.

[ 0018 ] Preferably, the printing plate material to be printed is a two-piece assembly can or a metal plate.

[ 0019 ] According to the invention, a printing plate making system for making printing plates capable of representing colors by overprinting dots in three colors from a plurality of compound colors includes: printing with overlaying two colors out of three colors by a reverse printing method in which reverse images are formed halftone dots in one color, and perform printing with an overlay in a different color on the position of reverse images; and printing by overlaying the remaining color of the three colors onto the two colors by a color overlay printing method in which at least a portion of the dots in the remaining color are placed on the dots in one color and/or the dots in the other color.

[ 0020 ] According to the invention, there is provided a can body printed with these colors by a dot overprint printing method in three colors from a plurality of secondary colors. Two colors out of three colors are applied by overprint printing by a reverse printing method in which reverse images of halftone dots in one color are formed, and printing is performed by superimposing halftone dots of another color on the positions of the reversed images. The remaining color of the three colors is applied by a two-color overprint printing method by a color overlay printing method in which at least a portion of the halftone dots in the remaining color are placed on halftone dots in one color and/or halftone dots in another color.

Advantageous results of the invention

[ 0021 ] According to the invention, it is possible to create printing plates capable of limiting mixing and contamination of printing inks, and providing easy registration and high color reproducibility. In addition, according to the invention, it is possible to provide a can body printed in a way capable of limiting mixing and contamination of printing inks, and providing easy registration and high color reproducibility.

[ 0022 ] Moreover, according to the invention, it is possible to create printing plates capable of providing a wide color gamut from compound colors only, limiting the occurrence of moiré, and limiting mixing and contamination of printing inks. In addition, according to the invention, it is possible to provide a can body printed in a manner that can provide a wide gamut of colors from primary colors only and limit mixing and contamination of printing inks.

Brief description of the drawings

[ 0023 ] FIG. 1 illustrates the configuration of a plate making system according to Embodiment 1;

Fig. 2A illustrates a reverse printing method;

2B illustrates a color overlay printing method;

3A illustrates a gap formed by one color and another color for the reverse printing method;

3B illustrates a cover mask formed by one color and another color for the reverse printing method;

Fig. 4 illustrates the relationship between the sum of the area ratio of halftone dots of one color and the ratio of the areas of halftone dots of another color, and the size of the gap or the size of the cover mask;

Fig. 5 is a flowchart illustrating the steps of the plate making method for making plates using the plate making system illustrated in Fig. 1;

Fig.6A-6E illustrate the progress of the method of manufacturing printing plates, illustrated in Fig.5;

Fig. 7 illustrates the configuration of the plate making system according to Embodiment 2;

Figa-8E illustrate the color separation using the color wheel;

9 illustrates a first group and a second group of color component ranges separated by color separation using a color wheel;

Fig. 10A illustrates an example of a reverse printing method for overprinting two colors separated by color separation using a color wheel;

10B illustrates an example of an overlay printing method for overprinting two colors separated by color separation using a color wheel;

11 illustrates specific examples of target color separations; And

FIG. 12 is a flow chart illustrating the steps of a printing plate making method using the plate making system illustrated in FIG. 7. FIG.

Description of embodiments of the invention

[ 0024 ] Hereinafter, embodiments of the invention will be described with reference to the drawings. The embodiments described later illustrate some examples of the invention, but do not limit the subject matter of the invention. In addition, all configurations and operations described in the embodiments do not necessarily represent the essential configurations and operations of the invention.

[ 0025 ]

Embodiment 1

<Plate Making System Configuration>

1 illustrates the configuration of the plate making system 1 according to Embodiment 1. 2A and 2B illustrate a reverse printing method and a color overlay printing method.

[ 0026 ] The plate making system 1 is a system configured to make plates to be placed in a flatbed printer. The plate making system 1 is a system adapted for DTP (Desktop Publishing) and CTP (Computer-to-Print Plate). The plate making system 1 is a system configured to make printing plates for multi-color printing.

[ 0027 ] The printable material for the plate made by the plate making system 1 is a can body, such as a two-piece can assembly having an approximately cylindrical shape, or a flat metal plate. In addition, the plate making system 1 is a system configured to make plates to be placed in an offset printer configured to transfer inks through an intermediate transfer element, or a non-offset printer not configured to use an intermediate transfer element.

[ 0028 ] FIG. 1 illustrates a plate making system 1 configured to make plates placed on an offset printer 30 for transferring inks to the outer circumferential surface of a material to be printed through an intermediate transfer element. The material to be printed is a two-piece assembly can, and the like, having an approximately cylindrical shape. Preferably, the plate produced by the plate making system 1 illustrated in FIG. 1 is a letterpress resin plate having ink image areas which are formed by a photosensitive resin layer and the like. Preferably, the printing plate making system 1 illustrated in FIG. ), in which an image is recorded on the surface of a polymer plate using a laser and developed. Alternatively, the printing plate obtained in the printing plate making system 1 illustrated in FIG. layer.

[ 0029 ] The plate making system 1 includes a data processing apparatus 10 configured to generate image data for making a plate by applying various image processing to the original image data, and a plate making apparatus 20 configured to make plates based on the image data for creating a printable.

[ 0030 ] The data processing apparatus 10 is configured to edit, for example, modify the markup and color tone of the original image data described by the page description language. Then, the data processing apparatus 10 creates image data for making a plate by performing plate separation processing such as color separation of compound colors and color fills, and performing half-dot processing to represent the shading of each of the colors by dot aggregation, and transfers the image data to the plate making device 20 . The data processing device 10 includes a processor, a memory unit, and a program for driving the data processing device 10.

[ 0031 ] The data processing apparatus 10 includes a plate separation processing section 11 configured to perform plate separation processing, a half dot generation condition setting section 12 configured to set the half dot generation processing conditions, a half dot generation processing section 13 , configured to perform processing for forming halftone dots, and a transmission processing section 14 configured to perform processing for transmitting data to the plate maker 20 .

[ 0032 ] The plate separation processing section 11 divides the colors of the edited original image data into each of the compound colors and color fills, and applies UCR (subtraction from under black) in areas where colors overlap with each other to reproduce achromatic colors . Composite colors can be, for example, four colors, cyan, magenta, yellow and black, or seven colors, with red, green and blue in addition to these four colors. The plate separation processing section 11 creates image data after the plate separation, which is image data for each of the colors obtained by color separation of the original image data.

[ 0033 ] The half dot generation condition setting section 12 sets the half dot generation conditions for generating halftone dots of the split plate image data created in the plate split processing section 11 . The half-dot forming conditions are adjusted to the image data of the separated printing plate for each of the colors. Conditions for forming the halftone dots include the shape of the halftone dots, the area ratio of the halftone dots, the number of halftone lines and the halftone angle for each of the colors, and the condition for the reverse printing method.

[ 0034 ] The plate making system 1 is capable of representing colors other than separation colors by ink overprinting in separation colors. In this case, the plate making system 1 can produce plates suitable for overprinting the colors separated by color separation by the reverse printing method. The reverse printing method is a method of creating reverse images of halftone dots in one of two overprinted colors, which is closer to the base of the printed material, and printing with overlay of halftone dots in a different color further from the base of the printed material to the positions of the reversed images. The color of the halftone dots to be masked may be far from the basis of the printed material.

[ 0035 ] Preferably, when the composite colors are four colors, cyan, magenta, yellow and black, the two reverse overprint colors are selected from cyan, magenta and yellow. Alternatively, it is preferred that when the primary colors are seven colors cyan, magenta, yellow, red, green, blue and black, the two reverse overprinted colors are one color selected from red, green and blue.

[ 0036 ] In the example illustrated in Fig. 2A, one color is magenta M tone and the other color is cyan C tone, and magenta M tone and cyan C tone are reverse printed. In Fig. 2A, reversed dot patterns are formed in magenta M tone as one color at positions which are applied with cyan C tone as another color. In other words, it is such a setting that halftone dots in cyan C tone as another color are placed in reverse image positions of halftone dots in magenta M tone as one color. Using the reverse printing method, the printing ink in one color and the printing ink in another color are superimposed on each other without contacting each other as much as possible.

[ 0037 ] In contrast, in order to represent colors other than separation colors, conventional plate making systems often produce printing plates by superposition printing of color separations, a color overlay printing method, without reverse images made for halftone dots in both of two printable colors. In the color overlay printing method, at least a portion of the dots in one of the two colors to be printed overlap with the dots in the other color, and therefore the ink in one color and the ink in the other color are in contact with each other and printed on top of each other.

[ 0038 ] The half dot formation condition setting section 12 determines the image data of the separated printing plate for each of the two colors intended for the reverse printing method as a condition for the reverse printing method, which is one of the half dot formation conditions. Then, the half dot formation condition setting section 12 adjusts the half dot area ratio of one color and the half dot area ratio of the other color for each of the pixels of the determined image data of the separated printing plate. The detailed adjusted dot area ratio values of each of one color and the other color for the reverse printing method will be described with reference to FIGS. 3A and 3B, and FIG.

[ 0039 ] The half dot generation processing section 13 generates half dot image data of the divided platen created by the plate separation processing section 11 based on the half dot generation conditions set by the half dot formation condition setting section 12 . The image data representing the halftone dots is binary data such as 1 bit TIFF (Raster Graphics Storage Format). Image data representing dots is used as plate making image data when the plate making apparatus 20 creates plates. The half dot processing section 13 can be configured as a RIP (Raster Image Processor) package.

[ 0040 ] In order to generate half-dot image data of the separated printing plate for each of the two colors for the reverse printing method, the half-dot processing section 13 creates half-dots under different conditions between one color and the other color. To be more specific, in order to dot the image data of the separated printing plate in one color, the dot generation processing section 13 creates the inverted image data by reversing the shading of one color once, and dots the created inverted image data to the negative state. In the negative state for each of the pixels, the lower the color density, the higher the dot area ratio. On the other hand, in order to generate half-dot image data of a split plate image in a different color, the half-dot processing section 13 creates half-dot image data of a split plate image in a different color as in a positive state. In the positive state for each of the pixels, the higher the color density, the higher the dot area ratio.

[ 0041 ] The transmission processing section 14 performs processing for transmitting image data representing the halftone dots generated by the halftone dot generation processing section 13 to the plate making apparatus 20 as plate making image data.

[ 0042 ] The plate maker 20 generates a plate for each of the colors based on the image data transmitted from the processing section 14 to transmit the data processing apparatus 10, that is, image data representing the dots for each of the colors. Preferably, the data processing device 10 is a device configured to make printing plates by the above-described DLE method or LAMS method. The plate making apparatus 20 can form printing plates by laser engraving or lasering a resin plate to form areas with an image and areas without an image, based on image data representing dots for each of the colors.

[ 0043 ]

<Reverse Dot Forming Condition for Reverse Printing Method>

3A and 3B illustrate a lumen X and a cover mask Y formed with one color and another color for the reverse printing method. One color is magenta M tone, and a known dot image is produced in magenta M tone. The other color is cyan C tone, and a cyan C tone dot is formed at the reverse image position of the magenta M tone dot. 4 illustrates the relationship between the sum of the area ratio of halftone dots of one color and the ratio of the areas of halftone dots of another color, and the x value of the X gap or the y size of the Y cover mask.

[ 0044 ] To adjust the dot area ratio of each of one color and another color intended for the reverse printing method, the dot formation condition setting section 12 adjusts the dot area ratio based on the sum of the dot area ratio of one color and the dot area ratio of the other colors. To be more specific, for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, the dot generation condition setting section 12 adjusts the conditions so that a gap X occurs from the reverse image of the dot in one color around a halftone dot of another color. In addition, for each of the pixels, when the sum of the dot area ratio of one color dot and the dot area ratio of the other color is greater than 100%, the dot generation condition setting section 12 sets conditions so that a dot of a different color penetrates into the periphery of the dot. of the same color to form a Y covermask. A Y covermask occurs such that the center position of the halftone dot in the other color approximates the center position of the halftone dot in one color, and the size of the halftone dot in the other color is larger than the size of the halftone dot inversion in one color . For the cover mask Y, the ink in one color may be superimposed on the ink in the other color, and the ink in the other color may be superimposed on the ink in the same color. In addition, in one embodiment, the reverse image is produced in two colors, but the lumen X and the cover mask Y can be formed when the reverse image is produced in three or more colors. Moreover, the shape of the halftone dot is not limited to a circle, but may be polygonal or otherwise. Here, the dot area ratio is the ratio of the dot area to unit area, and indicates the degree of color shading.

[ 0045 ] The example illustrated in FIG. 3A shows a situation where the sum of the dot area ratio of magenta M tone as one color and the dot area ratio of cyan C tone as the other color is less than 100%. In this case, a gap X having a size x from the magenta M tone as one color is formed around the dot of the cyan C tone as the other color. Preferably, the gap X is formed along the entire circumference of the periphery of the halftone dot. Thus, even though each of the colors does not register, the inks hardly come into contact with each other, and therefore mixing and contamination of the inks can be limited. The amount x of the gap X may be a value obtained by subtracting the radius of the dot in cyan C tone as another color from the radius of the reverse image of the dot magenta M tone as one color.

[ 0046 ] The example illustrated in FIG. 3B shows a situation where the sum of the dot area ratio of magenta M tone as one color and the dot area ratio of cyan C tone as the other color is more than 100%. In this case, a cover mask Y having a size of y is formed, so that the dot in cyan C tone as another color penetrates the periphery of the dot in magenta M tone as one color with the size y. Preferably, the Y cover mask is formed along the entire circumference of the periphery of the dot. Thus, even if each of the colors does not register, the base is not easily developed. The y-value of the Y cover mask may be a value obtained by subtracting the radius of the reverse image of the dot in magenta M tone as one color from the radius of the dot in cyan C tone as the other color.

[ 0047 ] The dot forming condition setting section 12 can properly adjust the sum of the dot area ratio of one color and the dot area ratio of the other color to adjust the x size of the gap X or the y size of the cover mask Y, and adjust the shading of the color represented by overprint printing one color and another color.

[ 0048 ] In Fig. 4, the size x of the lumen X or the size y of the cover mask Y, due to the sum of the dot area ratio of one color and the dot area ratio of the other color, are listed in the boxes, which are the intersections of the dot area ratios of the same color described along the vertical axis, and the ratios of the areas of raster dots of a different color, described along the horizontal axis. In Fig. 4, black numbers on a white background show the x size of the lumen X, and white numbers on a dark background show the y size of the cover mask Y. In addition, black numbers "0" on a light gray background show a state in which the lumen X and Y cover mask are not formed, that is, one color and another color are overprinted with high register accuracy. Moreover, in Fig. 4, the word "overprint" written in black on a white background indicates that one color or another color is 100%.

[ 0049 ] Fig. 4 illustrates the relationship between the sum of the dot area ratio of one color and the dot area ratio of another color, and the x value of the gap X or the y size of the cover mask Y when the number of scan lines is 100 lpi (lines per inch). In this case, 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 a cover mask Y having a size y of "0.05 mm" is formed. When the dot area ratio of one color is "90%" and the dot area ratio of another color is "40%", their sum is "130%." In addition, when the size y of the cover mask Y increases, the contact area of one color and the other color increases, and it easily causes ink mixing and contamination. Therefore, it is preferable that the sum of the dot area ratio of one color and the dot area ratio of the other color be adjusted to form a cover mask Y of one color and another color to such an extent that the size y of the cover mask Y does not exceed a predetermined value. The ease of mixing and soiling of printing inks varies depending on the type of printing plates, and therefore the amount is adjusted depending on the type of printing plates.

[ 0050 ] For each of the pixels constituting the cover mask Y, the half dot condition setting section 12 adjusts the sum of the dot area ratio of one color and the dot area ratio of the other color to a value greater than 100% and equal to or less than 125%. when the printing plate is a resin letterpress plate, and by a value greater than 100% and equal to or less than 150% when the printing plate is a waterless planar printing plate. In this way, for the pixels forming the cover mask Y, the dot forming condition setting section 12 can adjust the state for the reverse printing method to be suitable for overprinting one color and another color while limiting mixing and contamination of printing inks.

[ 0051 ]

<Method of making printing plates using the plate making system>

FIG. 5 represents the execution steps of the printing plate making method using the printing plate making system 1 illustrated in FIG. 1. FIG. 6A-6E illustrate the progress of the plate making process illustrated in FIG.

[ 0052 ] The steps from step S501 to step S506 illustrated in FIG. 5 may be executed by the data processing device 10 based on execution commands issued by the user through the user interface provided in the data processing device 10. Step S507 illustrated in FIG. 5 may be performed by the plate making apparatus 20 .

[ 0053 ] In step S501, the plate making system 1 acquires the original image data in the data processing apparatus 10 .

[ 0054 ] FIG. 6A illustrates one example where the plate making system 1 receives raw image data 100 including colors represented by magenta M tone and cyan C tone. In the original image data 100 illustrated in Fig. 6A, the mixture colors with magenta M tone and cyan C tone gradation are presented in the right area of the page, and the white letter "F" is placed on the left area in cyan C tone with 100%.

[ 0055 ] In step S502, the plate making system 1 edits the received original image data. The plate making system 1 adjusts the markup to match the printed area of the printed material, and modifies the color tone to edit the original image data.

[ 0056 ] In step S503, the plate making system 1 applies the plate separation processing to the edited source video data. The plate making system 1 color-separates the edited original image data into each of the compound colors and color fills, and creates a separated plate image data for each of the colors.

[ 0057 ] FIG. 6B illustrates an example where the plate making system 1 color-separates the original image data illustrated in FIG. images 112 of the divided printing plate in blue C tone. In the magenta M tone separated plate image data 111, the magenta M tone density gradually increases from the top side to the bottom side of the right area in the page, and the magenta M tone density is zero in the left area. In the cyan C split plate image data 112, the density of the cyan C tone gradually increases once, and then gradually decreases from the top side to the bottom side of the right area in the page, and a white letter "F" is placed on the left area in the cyan C tone. 100%.

[ 0058 ] In step S504, the plate making system 1 executes dot-forming condition setting processing to adjust the dot-forming conditions for generating dotted dots of the split plate image data created by the plate splitting processing. Specifically, the plate making system 1 determines the image data of the separated plate in each of one color and another color for the reverse printing method, and adjusts the dot area ratio for each of the one color and the other color for each of the pixels of the target image data. split print. In this case, the plate making system 1 adjusts the dot area ratio of one color and the dot area ratio of the other color to the proper shape of the gap X and the cover mask Y, based on the sum of the dot area ratio of one color and the dot area ratio of the other color.

[ 0059 ] In the example illustrated in FIG. 6B, the plate making system 1 determines the split plate image data in one color intended for the reverse printing method as the split plate image data 111 in magenta M tone, and the split plate image data plates in a different color intended for the reverse printing method, as the image data 112 of the divided printing plate in cyan C tone. Then, as described with reference to FIGS. 3A, 3B, and 4, the plate making system 1 adjusts the magenta M tone dot area ratio in the separated plate image data 111 and the cyan C tone dot area ratio in the separated plate image data 112. shape so as to properly form the lumen X and the cover mask Y.

[ 0060 ] In step S505, the plate making system 1 generates halftone dot image data of the divided platen formed by the platen separation processing based on the halftone dot generation conditions by processing to adjust the halftone dot formation condition. Specifically, when dot generation of single color split plate image data occurs, the plate making system 1 creates reverse image data of single color split plate image data by reversing shading of one color, and dots the created reverse image data to the negative state. . On the other hand, when dot formation of the split plate image data in a different color occurs, the plate making system 1 generates dot data of the split plate image in a different color as in a positive state.

[ 0061 ] FIG. 6C illustrates an example where the plate making system 1 creates reversed image data 121 by reversing the shading of magenta M tone as one color of the split plate image data 111 illustrated in FIG. 6B. In the reversed image data 121, the density of the magenta M tone gradually decreases from the top side of the right area to the bottom side in the page, and the magenta M tone is 100% placed in the left area. Here, the split plate image data 112 illustrated in FIG. 6C is the same as the split plate image data 112 in cyan C illustrated in FIG. 6B.

[ 0062 ] Fig. 6D illustrates an example where the plate making system 1 creates dot dots of the reverse image data 121 in magenta M tone as one color illustrated in Fig. 6C on the negative state, and creates image data 131 in magenta M tone, representing bitmap dots. The magenta M tone image data 131 representing the halftone dots is in a state where the magenta M tone shading of the inverse image data 121 illustrated in FIG. 6 is inverted. In magenta M tone image data 131 representing halftone dots, a dot reverse image H1 is created in magenta M tone based on the shading of magenta M tone in the split plate image data 111 illustrated in FIG. 6B. The reverse image H1 of the halftone dot is represented as a white halftone dot stamped from magenta M tone.

[ 0063 ] In addition, Fig. 6D illustrates an example where the plate making system 1 creates dot-dot image data of the split plate image 112 in cyan tone as another color, illustrated in Fig. 6C, on a positive state, and creates image data 132 in blue C tone, representing halftone dots. In the cyan C image data 132 representing the halftone dots, the cyan C tone dot H2 is formed based on the shading of the cyan C tone in the split plate image data 112 illustrated in FIG. 6B.

[ 0064 ] In step S506, the plate making system 1 performs transmission processing to transmit image data representing the half dots formed by the half dot processing as plate making image data from the data processing apparatus 10 to the plate making apparatus 20 forms. In the example of FIG. 6D, the plate making system 1 transmits magenta M tone image data 131 representing halftone dots and cyan C tone image data 132 representing halftone dots from the data processing apparatus 10 to the plate maker 20 .

[ 0065 ] In step S507, the plate making system 1 produces a plate for each of the colors by the plate maker 20, based on the image data transmitted by the transmission processing. In the example of FIG. 6D, the plate making system 1 drives the plate making apparatus 20 based on the dot image data 131 to make a plate for magenta M tone. Then, the plate making system 1 drives the plate making apparatus 20 based on the dot image data 132 to make a plate for cyan. At this stage, the execution of the printing plate manufacturing method illustrated in FIG. 5 is completed.

[ 0066 ] FIG. 6E illustrates an example of a print image 140 printed on a printable material using magenta M tone and cyan C tone plates that are made based on the image data 132 illustrated in FIG. 6D. In the printed image 140, the center location of the reverse image H1 formed in the magenta M tone approximately corresponds to the center location of the dot H2 in cyan C tone, and the magenta M tone and cyan C tone are applied by the reverse overprinting method.

[ 0067 ]

<Technological advantage>

As described above, the plate making system 1 according to this embodiment is a system configured for making plates based on the Reverse Printing Method. In addition, for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color for the reverse printing method is less than 100%, the plate making system 1 according to this embodiment generates a gap X from reverse image of a dot in one color around a dot in another color, and when the sum is over 100%, the plate making system 1 according to this embodiment forms a cover mask Y so that the dot in the other color penetrates into the periphery of the reverse image of the dot dots in the same color.

[ 0068 ] Therefore, by simply properly adjusting the sum of the dot area ratio of one color and the dot area ratio of another color, the plate making system 1 according to this embodiment can adjust the size x of the gap X, or the size y of the cover mask Y. To be more specific, system 1 The platemaker according to this embodiment generates a gap X when the sum of the dot area ratios is less than 100%, and forms a cover mask Y when the sum of the dot area ratios is more than 100%. Thus, the plate making system 1 according to this embodiment has a larger allowable value for misregistration than when plates are made by the conventional reverse printing method, and therefore can form plates that easily achieve register accuracy. In addition, the plate making system 1 according to this embodiment limits the contact of printing inks by using the Reverse Printing Method, and therefore can create printing plates capable of limiting mixing and contamination of printing inks. In addition, it easily covers the base color, and therefore it is possible to create printing plates capable of providing a wide reproducible color gamut, and achieving high density even with a raster background. In this way, the plate making system 1 according to this embodiment can produce plates having a higher color reproducibility than when the plates are made by the overprinting method. Therefore, the printing plate making system 1 can create printing plates that limit mixing and contamination of printing inks, and easily achieve register accuracy and high color reproducibility in a relatively simple manner.

[ 0069 ] In addition, the plate making system 1 according to this embodiment can create printing plates capable of providing a wide reproducible color gamut and achieve high density even with a screen background, and therefore can create printing plates that do not require excessive ink thickness and excessive pressure on the printing plate, and can reduce the amount of printing ink used.

[ 0070 ] In addition, compared to when the plates are made by the overlay method, the plate making system 1 according to this embodiment does not need to carefully compensate for ink misregistration (trapping), and therefore does not require strict control of the amount of tackiness of ink-based inks. overprint order. Thus, the plate making system 1 according to this embodiment can create printing plates with a small limitation due to ink properties, and therefore can create printing plates with a high degree of freedom.

[ 0071 ] In addition, in the plate making system 1 according to this embodiment, when the plate is a letterpress resin plate, the above-described sum is adjusted to a value greater than 100%, and equal to or less than 125%, for the pixels formed by the cover mask Y , and, on the other hand, when the printing plate is a waterless planar printing plate, the above-described amount is adjusted to a value of more than 100%, and equal to or less than 150%, for the pixels formed by the cover mask Y. Thereby, the plate making system 1 according to this An embodiment can create printing plates that further limit ink mixing and contamination, and provide easy registration and high color reproducibility for the pixels formed by the Y covermask.

[ 0072 ] In addition, with the plate making system 1 according to this embodiment, image data representing halftone dots in one color is created by reversing the shading of one color in the divided platen image data separated by color separation of the original image data, and generating halftone dots of the inverted data images on the negative state. Meanwhile, the plate making system 1 according to this embodiment creates image data representing dots in one color by generating dots of image data of a divided plate in another color separated by color separation of the original image data. Therefore, the plate making system 1 according to this embodiment is capable of superimposing one color having a reverse image onto another color in a relatively simple manner. Thus, the plate making system 1 according to this embodiment can create plates more easily and achieves easy registration and high color reproducibility.

[ 0073 ] In addition, the plate making system 1 according to this embodiment creates plates for printing on a two-piece assembly can or a metal plate as a printing material. The printing surface of a two-piece jar assembly or a metal plate does not show ink permeability and therefore provides ease of registration, while limiting ink mixing and contamination is a greater problem for conventional printing plates than when the printed material is paper and the like. Even if the material to be printed is a two-piece assembly can or a metal plate, the plate making system 1 according to this embodiment can create plates based on the Reverse Printing Method, and control the size x of the gap X, or the size y of the cover mask Y. Accordingly, , even if the printed material is a two-piece assembly can or a metal plate, the plate making system 1 according to this embodiment can produce plates capable of limiting ink mixing and contamination, and provide easy registration and high color reproducibility.

[ 0074 ] In addition, the base color of the can body printed using the plate making system 1 according to this embodiment can be easily covered by the reverse printing method, and therefore the can body is printed by a method suitable for producing a wide gamut of reproducible colors and presenting a high density. even a raster background. This makes it possible to provide a can body printed using the plate making system 1 according to this embodiment to achieve high color reproducibility in a relatively simple way than an overlay printed can body.

[ 0075 ]

Embodiment 2

<Plate Making System Configuration>

7 illustrates the configuration of the plate making system 1 according to Embodiment 2.

[ 0076 ] The plate making system 1 is a system configured to make plates to be placed in a flatbed printer. The plate making system 1 is a system adapted for DTP (Desktop Publishing) and CTP (Computer-to-Print Plate). The plate making system 1 is a system configured to make printing plates for multi-color printing.

[ 0077 ] The printable material for the plate made by the plate making system 1 is a can body such as a two-piece can assembly having an approximately cylindrical shape or a flat metal plate. In addition, the plate making system 1 is a system configured to make plates to be placed in an offset printer configured to transfer inks through an intermediate transfer element, or a non-offset printer not configured to use an intermediate transfer element.

[ 0078 ] FIG. 7 illustrates a plate making system 1 configured to make plates placed on an offset printer 30 for transferring inks to the outer circumferential surface of a material to be printed via an intermediate transfer element. The material to be printed is a two-piece assembly can, and the like, having an approximately cylindrical shape. It is preferable that the plate produced by the plate making system 1 illustrated in Fig. 7 is a waterless planar printing plate without the use of an aqueous dampening solution, and having non-image, ink-free areas which are formed by the silicone resin layer and thus similar. In addition, the printing plate obtained in the printing plate making system 1 illustrated in FIG. 7 may be a letterpress resin plate having ink image areas which are formed by a photosensitive resin layer and the like.

[ 0079 ] The plate making system 1 includes a data processing apparatus 10 configured to create image data for making a plate by applying various image processing on the original image data, and a plate making apparatus 20 configured to make plates based on the image data for creating a printable.

[ 0080 ] The data processing apparatus 10 is configured to edit, for example, modify the markup and color tone of the original image data described by the page description language. Then, the data processing apparatus 10 creates image data for making a plate by performing plate separation processing such as color separation and performing half-dot processing for representing the shading of each of the colors by dot aggregation, and transfers the image data to the plate-maker 20 forms. The data processing device 10 includes a processor, a memory unit, and a program for driving the data processing device 10.

[ 0081 ] The data processing apparatus 10 includes a plate separation processing section 11 configured to perform plate separation processing, a half dot generation condition setting section 12 configured to set the half dot generation processing conditions, a half dot generation processing section 13 , configured to perform processing for forming half-tone dots, and a transmission processing section 14 configured to perform processing for transmitting data to the plate maker 20 .

[ 0082 ] The plate separation processing section 11 divides the colors of the edited original image data into each of the compound colors, and creates the separated plate image data that is the image data for each of the separation colors. The secondary colors of this embodiment are seven colors, such as cyan C, magenta M, yellow Y, red R, green G, blue B, and black K. Color separation details will be described later with reference to FIGS. 8A to FIGS. eleven.

[ 0083 ] The half dot generation condition setting section 12 sets the half dot generation conditions for generating halftone dots of the split plate image data created in the print plate split processing section 11 . The conditions for generating halftone dots are set to the image data of the separated printing plate for each of the colors, as well as the conditions for the reverse printing method and the overlay printing method.

[ 0084 ] The plate making system 1 creates printing plates capable of representing other colors than the separated secondary colors by overprinting the separated secondary colors. In this case, by performing color separation in the manner described later with reference to FIGS. 8A to FIG. color separation.

[ 0085 ] When the target color is represented by a two-colour overlay printing from the secondary colors separated by color separations, the plate making system 1 creates printing plates capable of two-color overlay printing by reverse printing. Meanwhile, when the target color is represented by overprinting three colors from the secondary colors separated by color separation, the plate making system 1 creates plates capable of overprinting two of the three colors by the reverse printing method, and performing overprinting of the remaining one color by the reverse printing method. overlay printing.

[ 0086 ] The reverse printing method is a method of creating reverse images of half dots in one of two overprinted colors, and printing with superimposed half dots in the other color on the positions of the reverse images. With the reverse printing method, ink in one color and ink in another color are superimposed on each other without contacting each other as much as possible.

[ 0087 ] In the overlay method for halftone dots in both of the two overprinted colors, reverse images are not made. In the overlay method, at least a portion of the dots in one of the two colors to be printed are superimposed on the dots in the other color, and therefore the ink in one color and the ink in the other color are in contact with each other and superimposed.

[ 0088 ] The dot forming condition setting section 12 determines two-color separated plate image data for the reverse printing method and color separated plate image data for the overlay printing method. Then, the half dot condition setting section 12 adjusts the half dot area ratios for each of the pixels of the determined image data of the split plate. Detailed dot-forming conditions for the reverse printing method and the overlay printing method will be described later with reference to FIGS. 8A to FIG. 11 .

[ 0089 ] The half dot generation processing section 13 generates half dot image data of the divided platen created by the plate separation processing section 11 based on the half dot generation conditions set by the half dot formation condition setting section 12 . The image data representing the halftone dots is binary data such as 1 bit TIFF (Raster Graphics Storage Format). Image data representing dots is used as plate making image data when the plate making apparatus 20 creates plates. The half dot processing section 13 can be configured as a RIP (Raster Image Processor) package.

[ 0090 ] The half-dot generating processing section 13 creates half-dot image data of the separated printing plate for each of the two colors intended for the reverse printing method on a different state between one and the other of the two colors. More specifically, in order to dot the image data of the separated printing plate in one of the two colors, the dot forming processing section 13 creates the reversed image data by reversing the shading of one color once, and dots the created reversed image data to the negative state. In the negative state for each of the pixels, the lower the color density, the higher the dot area ratio. On the other hand, in order to generate half-dot image data of the split plate image in the other of the two colors, the half-dot processing section 13 creates half-dot image data of the split plate image in the other color as in the positive state. In the positive state for each of the pixels, the higher the color density, the higher the dot area ratio.

[ 0091 ] The transmission processing section 14 performs processing for transmitting image data representing the halftone dots generated by the halftone dot generation processing section 13 to the plate making apparatus 20 as plate making image data.

[ 0092 ] The plate maker 20 generates a plate for each of the colors based on the image data transmitted from the processing section 14 to transmit the data processing apparatus 10, that is, image data representing the dots for each of the colors. Preferably, the printing plate making apparatus 20 is an apparatus configured to manufacture the above-described waterless planar printing form. The printing plate maker 20 can create a printing plate by exposing the silicone resin layer with a laser based on image data representing the dots for each of the colors, peeling off the cured silicone resin layer, and developing the mold to form areas with an image and areas without an image.

[ 0093 ]

<Color Separation, Reverse Printing Method and Overlay Printing Method>

Figa and 8B illustrate the color separation using the color wheel. Fig.9 illustrates the ranges of color components separated by color using the color wheel, which are grouped into the first color group and the second color group. 10A and 10B illustrate an example where two colors separated by color separation using a color wheel are overprinted by a reverse printing method and an overlay printing method.

[ 0094 ] For color separation of the original image data, the plate separation processing section 11 performs color separation separately between the lightness components and the color components. To be more specific, the plate separation processing section 11 extracts the lightness component as black K by GCR (grey component replacement), and extracts the color components as cyan C, magenta M, yellow Y, red R, green G, or blue B by color separation. using the color wheel.

[ 0095 ] Color wheel separation is a method of separating the color components of a target color into cyan C, magenta M, yellow Y, red R, green G, and blue B, in a balanced state, based on the color wheel, and extracting them. In color wheel separations, the color components of the target color are cyan C, magenta M, and yellow Y, and the mixture of magenta M and yellow Y is replaced by red R, the mixture of yellow Y and cyan C is replaced by green G, and the mixture of cyan C and magenta M colors are replaced by blue B.

[ 0096 ] In color wheel separation, the color components of the target color are separated in a balanced state using cyan C, magenta M, and yellow Y tones, which are the three primary colors of the subtractive color mixture, and red R, green G, and blue B tones, which are the three primary colors of the additive mixture of colors, and therefore it is possible to reproduce all the colors represented by the color wheel in principle and provide a wide color gamut. Therefore, according to this embodiment, the secondary colors are seven colors including black K in addition to six colors, cyan C, magenta M, yellow Y, red R, green G, and blue B, and they are overprinted to represent other lights. than the composite colors.

[ 0097 ] FIG. 8A illustrates the range of each of the Cyan C, Magenta M, Yellow Y, Red R, Green G, and Blue B components separated by color wheel separation. 8B illustrates the range of each of the cyan C, magenta M, and yellow Y components separated by color separation using a color wheel divided into only cyan C, magenta M, and yellow Y tones.

[ 0098 ] Comparing between Fig. 8A and Fig. 8B, it can be seen that the range of each of the components separated by color separation using the color wheel is narrower than when the color wheel is only divided into cyan C, magenta M, and yellow Y tones. Thereby, the color components are separated using a color wheel, and in this way, when two colors other than black K are overprinted in an overprinting manner, the area of the overlapping portion of one and the other of the two colors can be reduced. Thus, by separating the color components using the color wheel, a wide color gamut can be achieved and mixing and contamination of colors other than black K can be limited.

[ 0099 ] Here, in this embodiment, among the six colors separated by color component separation using the color wheel, the color group of cyan C, magenta M, and yellow Y, which are the three primary colors of the subtractive color mixture, is determined as the first color a group, and a color group of red R, green G, and blue B, which are complementary colors to the first color group, and the three primary colors of the additive color mixture, are defined as the second group.

[ 0100 ] The ranges of each of the cyan C, magenta M, and yellow Y tones constituting the first color group are spaced apart from each other and do not overlap with others, as illustrated in FIG. In the same way, the ranges of each of the components, red R, green G and blue B tones constituting the second color group, are spaced apart from each other and do not overlap with others, as illustrated in Fig.9. That is, the first color group is composed of cyan C, magenta M, and yellow Y tones, having color components that do not overlap with each other, and the second color group is composed of red R, green G, and blue B tones, having color components that do not overlap with each other. .

[ 0101 ] As described above, when two colors other than black K, which are separated by color separation using a color wheel, are overprinted in an overprinting manner, it is possible to reduce the area of the color overlap area. However, in order to provide a color gamut, overlapping of colors is unavoidable to some extent, and inks can be mixed and soiled by overprinting. On the other hand, when two colors are reverse printed, the inks in the two colors do not come into contact with each other as much as possible. In addition, when one color from the first color group and one color from the second color group are reverse overprinted, two colors with closer tones are reverse overprinted than when the two colors of cyan C, magenta M, and yellow Y, which are the three primary colors of the subtractive color mixture are applied by overlay printing by the reverse printing method, and therefore the ink mixing and soiling does not occur easily even if the two colors are in contact with each other.

[ 0102 ] Therefore, when the plate making system 1 represents the color components of the original image data by overprinting two colors other than black K separated by color separation using the color wheel, the dot forming condition setting section 12 adjusts the state so that the two colors are applied reverse overlay printing. Specifically, when one of the two colors belongs to the first group and the other belongs to the second group, the dot formation condition setting section 12 sets the state so that one color belonging to the first group and the other belonging to the second group are applied by printing. with reverse printing overlay. Thereby, the plate making system 1 can produce plates capable of providing a wide color gamut and limiting ink mixing and contamination as much as possible.

[ 0103 ] Fig. 10A illustrates an example where cyan C and green G tones separated by color wheel separation are overprinted by reverse printing. In the example of FIG. 10A, it can be seen that reverse images are formed at positions where one of cyan C and green G is superimposed on another color, and dots in one color are placed at positions of reverse images in the other color.

[ 0104 ] FIG. 10B illustrates an example where cyan C and green G tones separated by color wheel separation are overprinted with an overlay method. Here, the dot area ratio is the same as in Fig. 10A. In the example of FIG. 10B, at least a portion of the halftone dots in one of the cyan C and green G tones overlap with halftone dots in the other color. Moreover, in the example of Fig. 10B, it can be seen that a white W tone is opened as the base color.

[ 0105 ] When comparing between Fig. 10A and Fig. 10B, when applying the reverse printing method, it is possible to limit ink contact and easily cover the base color, and therefore provide a wide color gamut and achieve a high density even with a raster background than when using the overlay printing method .

[ 0106 ] In addition, in the plate making system 1, the plate separation processing section 11 extracts the lightness components of the original image data as black K by GCR. The plate making system 1 manufactures plates capable of representing the lightness components of the original image data by overprinting the extracted black K with colors other than black K that represent the color components. By using the plate making system 1 to represent the lightness components of the original image data, the dot forming condition setting section 12 adjusts the state such that black K is superimposed on colors other than black K, which represent color components, by the superposition printing method. By applying the overlay printing method, the screen angle and the number of screen lines of screen dots in black K tone do not need to be consistent with these parameters of the two colors other than black K tone, and can be set freely. In this case, the screen dot condition setting section 12 adjusts the screen angle and the number of screen lines of the screen dots in black K to values that can limit the occurrence of moiré. In order to limit the occurrence of moiré, it is preferable that the screen angle of the screen dots in black K is different from the screen angles of the screen dots in two colors other than black K, which are overprinted by reverse printing.

[ 0107 ] When inks other than K black ink are overlaid on K black ink, the wet K black ink is transferred to non-K black printing plates and can then be blended into cells with ink for colors other than black K, from printing plates through a foam roller, and the like. Then paints in other colors than the black K tone paint mix with the black K tone paint and become contaminated, reducing the color tones, and therefore can immediately become useless.

[ 0108 ] In contrast, when ink in black K tone is applied to inks in colors other than ink in black K tone, even if wet inks in colors other than ink in black K tone are transferred to the printing plate for black K tone and mixed in a cell with paint, the color tone of the paint in black K does not change much, and therefore cannot immediately become useless. Therefore, the case where the ink in the black K tone is superimposed on the ink in other colors than the ink in the black K tone can more limit the contamination of the inks than in the first case.

[ 0109 ] Therefore, in the plate making system 1 for representing the lightness components of the original image data, the dot forming condition setting section 12 adjusts the state so that black K tone is overprinted with colors other than black K tone that represent the color components of the method overlay printing. Thus, the plate making system 1 can create plates capable of limiting the occurrence of moiré and also limit the conditions under which inks in colors other than K black mix with K black and become soiled.

[ 0110 ] Thus, in the plate making system 1, the plate separation processing section 11 separates the color components of the original image data into cyan C, magenta M, yellow Y, red R, green G, and blue B using a color wheel. Then, in the plate making system 1 for representing the color components of the original image data by overprinting two compound colors other than black K, the dot forming condition setting section 12 adjusts the state so that the two compound colors are applied by overlay printing by reverse printing. Moreover, in the plate making system 1 for representing the lightness components of the original image data, the dot forming condition setting section 12 adjusts the state so that the black K tone is superimposed on the composite colors other than the black K that represent the color components, overlay printing method.

[ 0111 ] That is, the plate making system 1 creates plates for representing predetermined colors by overprinting three colors from the above-described seven composite colors. That is, two colors other than black K, which represent the color components of the original image data, and black K, which represents the lightness components of the original image data, are overprinted. Then, in the plate making system 1, among the imprinted three colors, two colors representing color components are overprinted by reverse printing, and black K tone as the rest of the three colors, and two colors representing color components are overprinted by overprinting. In addition, in the plate making system 1, two colors other than black K, which represent color components of the original image data, are one of cyan C, magenta M, and yellow Y belonging to the first color group, and one of red R , green G and blue B, belonging to the second color group. Through this, the plate making system 1 can create printing plates capable of producing a wide color gamut from compound colors only, limiting the occurrence of moiré, and limiting ink mixing and soiling.

[ 0112 ] Fig. 11 illustrates specific examples of target color separations.

[ 0113 ] Fig. 11 illustrates an example where the target color is composed of cyan C having a density of 80%, magenta M having a density of 70%, and yellow Y having a density of 50%. The sum of the color densities is 200%.

[ 0114 ] When the target color is separated, the plate making system 1 first extracts a color mixture of three colors, cyan C, magenta M, and yellow Y as black K, by GCR. In this way, the target color is replaced with a color composed of black K having a density of 50%, cyan C having a density of 30%, and magenta M having a density of 20%. The sum of the color densities is reduced to 100%.

[ 0115 ] Then, the plate making system 1 extracts the color mixture of the two colors cyan C and magenta M as cyan B by color separation using a color wheel. In this way, the target color is replaced by a color composed of black K having a density of 50%, blue B having a density of 20% and cyan C having a density of 10%. The sum of the color densities is reduced to 80%.

[ 0116 ] Thus, by color separation using GCR and the color wheel, the plate making system 1 can produce plates capable of producing a wide color gamut from the compound colors only, limit the occurrence of moiré, and limit ink mixing and contamination, and reduce the amount of ink used.

[ 0117 ]

<Method of making printing plates using the plate making system>

FIG. 12 is a flowchart illustrating the execution steps of the printing plate making method for making printing plates using the plate making system 1 illustrated in FIG. 7. FIG.

[ 0118 ] Steps S601 to S606 illustrated in FIG. 12 may be executed by the data processing device 10 based on execution commands issued by the user through the user interface provided in the data processing device 10. Step S607 illustrated in Fig. 12 may be performed by the plate making apparatus 20 .

[ 0119 ] In step S601, the plate making system 1 acquires the original image data in the data processing apparatus 10 .

[ 0120 ] In step S602, the plate making system 1 edits the received original image data. The plate making system 1 adjusts the markup to match the printed area of the printed material, and modifies the color tone to edit the original image data.

[ 0121 ] In step S603, the plate making system 1 applies the plate separation processing to the edited source video data. The plate making system 1 color-separates the edited original image data into each of the composite colors, and creates a separated plate image data for each of the colors.

[ 0122 ] In step S604, the plate making system 1 performs dot-forming condition setting processing to set dot-forming conditions for generating dotted dots of the split plate image data created by the plate splitting processing. Specifically, the plate making system 1 determines the image data of the separated plate in each of one color and another color for the reverse printing method, and adjusts the dot area ratio for each of the one color and the other color for each of the pixels of the target image data. split print. One color for the reverse printing method is one of cyan C, magenta M and yellow Y belonging to the first color group, and the other is one of red R, green G and blue B belonging to the second color group. In addition, the plate making system 1 determines the image data of the divided plate in the color for the overlay printing method, and adjusts the dot area ratio of the same color and the dot area ratio, the number of dot lines, the dot angle, and the like. The color intended for the overlay printing method is black K color.

[ 0123 ] In step S605, the plate making system 1 generates halftone dot image data of the divided platen formed by the platen separation processing based on the halftone dot generation conditions of the processing adjusted by the halftone dot forming condition setting processing. Specifically, when dot-dotting of single-color separated plate image data for the reverse printing method occurs, the plate making system 1 creates inverted image data by reversing shading of one color, and dots the created inverted image data to a negative state. Meanwhile, when dot formation of the split plate image data in a different color for the reverse printing method occurs, the plate making system 1 generates dot data of the split plate image in a different color as in a positive state. In addition, when the dot formation of the split plate image data in the color for the overlay printing method occurs, the plate making system 1 dots the split plate image data as in a positive state.

[ 0124 ] In step S606, the plate making system 1 performs transmission processing to transmit image data representing the half dots generated by the half dot forming processing as plate making image data from the data processing apparatus 10 to the plate making apparatus 20 forms.

[ 0125 ] In step S607, the plate making system 1 produces a plate for each of the colors by the plate maker 20, based on the image data transmitted by the transmission processing. At this stage, the execution of the printing plate manufacturing method illustrated in FIG. 12 is completed.

[ 0126 ]

<Technological advantage>

As described above, the printing plate making system 1 according to this embodiment is a system configured to make printing plates capable of representing colors by dot overprint printing in three colors from a plurality of composite colors. Then, in the plate making system 1 according to this embodiment, two of the three colors are reverse printed, and the remaining one of the three colors and the two reverse printed colors are overprinted by the overlay printing. Thereby, the plate making system 1 can produce plates capable of producing a wide color gamut from compound colors only, limiting the occurrence of moiré, and limiting ink mixing and soiling.

[ 0127 ] In addition, in the plate making system 1 according to this embodiment, one of the colors intended for the reverse printing method belongs to the first color group composed of colors having color components that do not overlap with each other, and the other intended for the reverse printing method, belongs to the second color group composed of colors having color components that do not overlap with each other. That is, one color and another color belong to different color groups, and the component ranges may overlap. However, even if the ranges of the components overlap with each other, the plate making system 1 according to this embodiment can overprint inks without ink contact as far as possible by the reverse printing method. Therefore, the plate making system 1 according to this embodiment can produce plates capable of producing a wide color gamut from compound colors only, limiting the occurrence of moiré, and limiting ink mixing and soiling.

[ 0128 ] Furthermore, in the plate making system 1 according to this embodiment, the multiple secondary colors are seven colors, cyan C, magenta M, yellow Y, red R, green G, blue B, and black K. Then, in the plate making system 1 of the printing plates according to this embodiment, the first color group is composed of cyan C, magenta M, and yellow Y tones, the second color group is composed of red R, green G, blue B tones, and the above-described remaining one of the three colors is black K. That is, the first color group the group is composed of the three primary colors of the subtractive color mixture, and the second color group is composed of the three primary colors of the additive color mixture, and therefore the plate making system 1 according to this embodiment can create printing plates capable of expanding the available color gamut from only the composite colors. In addition, the color intended for the overlay printing method is black K tone, and therefore, the plate making system 1 according to this embodiment can produce plates capable of limiting the mixing of inks other than black K with black K, and become contaminated. Therefore, the plate making system 1 according to this embodiment can produce plates capable of limiting the occurrence of moiré, extending the available color gamut from only compound colors, and limiting ink mixing and contamination.

[ 0129 ] In addition, in the plate making system 1 according to this embodiment, dots in the remaining one of the three colors described above are placed at a dot angle different from that of the dots in two colors for the reverse printing method. Therefore, even if dots in the remaining one of the three colors described above are overprinted by the overlay printing method, the plate making system 1 according to this embodiment can limit the occurrence of moiré. Thus, the plate making system 1 according to this embodiment can produce plates capable of producing a wide color gamut from compound colors only, limit ink mixing and fouling, and limit the occurrence of moiré.

[ 0130 ] Moreover, the printing plate making system 1 according to the embodiments creates printing plates for printing on a two-piece assembly can or a metal plate as a printing material. The printing surface of a two-piece can or metal plate assembly does not exhibit ink permeability, and therefore limits ink mixing and contamination, while providing a color gamut only from compound colors is a significant problem for traditional printing plates, especially when the printed material is paper and the like. . Even if the material to be printed is a two-piece assembly can or a metal plate, the plate making system 1 according to embodiments can produce plates capable of representing colors by dot overprinting of multiple composite colors. Accordingly, even if the material to be printed is a two-piece assembly can or a metal plate, the plate making system 1 according to the embodiments can produce plates capable of producing a wide color gamut from compound colors only, limit the occurrence of moiré, and limit blending and contamination. colors.

[ 0131 ] In addition, in the plate making system 1 according to the embodiments, the can body is printed such that two of the three colors are reverse-printed, and the remaining one of the three colors and the two reverse-printed colors are printed. by overlay printing by overlay printing method. Thus, in the plate making system 1 according to embodiments, the body of the can can be printed such that a wide color gamut is provided only by the secondary colors, mixing and contamination of inks is limited, and moiré is limited.

[ 0132 ]

<Another variant>

In the above embodiments, the plate making system 1 is a system configured to make plates for printing on a can body, such as a two-piece assembly can, or a metal plate as a printing material. However, this is by no means a limitation. The plate making system 1 may be a system configured to make plates for printing on a three-dimensional object made of a non-metallic material, such as a mug or a bottle. Moreover, the plate making system 1 may be a system configured to make plates for printing on a flat object such as paper, label, film, and sheet.

[ 0133 ]

<Other indications>

The embodiments described above, including the modification, may use their features among themselves. The above-described embodiments are not intended to be limiting, but may be modified to the extent that they do not go beyond the scope of the claims.

[ 0134 ] The terms used in the above embodiments and in the claims are to be construed as non-exclusive terms. For example, the term "comprising" should be construed without limitation to the subject matter described as being included. The term "comprising" should be construed without limitation to the subject matter described as being contained. The term "including" should be construed without limitation to the subject matter described as being included. The term "having" is to be construed without limitation to the subject matter as having.

List of reference positions

[ 0135 ]

1 plate making system

10 data processing device

11 processing section for plate separation

12 section for setting the conditions for the formation of halftone dots

13 dot processing section

14 processing section for transmission

20 plate maker

30 offset printer

100 original image data

111 split plate image data

112 split plate image data

121 reversed image data

131 image data

132 image data

140 printed image

X clearance

X lumen size

Y cover mask

Y size of cover mask

H1 reverse image

H2 half dot

b blue

C blue

G green

K black

M purple

R red

Y yellow

W white.

Claims (51)

1. A printing plate making method for making printing plates based on image data divided into each of colors and representing halftone dots, the printing plate making method comprising: manufacturing a printing plate based on a reverse printing method in which reverse images of halftone dots in one color are formed, and printing is performed by overlaying halftone dots of a different color on the positions of the reversed images; for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, forming a gap from the reverse image in one color around the dot of the other color; And for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is greater than 100%, forming a cover mask so that the dot of the other color penetrates the periphery of the dot of the same color. 2. The method of manufacturing printing plates according to claim 1, in which: the printing plate is a polymer letterpress plate; And for each of the pixels constituting the cover mask, said sum is greater than 100% and is equal to or less than 125%. 3. The method of manufacturing printing plates according to claim 1, in which: the printing plate is a form of waterless flat printing; And for each of the pixels constituting the cover mask, said sum is greater than 100% and is equal to or less than 150%. 4. The printing plate manufacturing method according to one of claims 1 to 3, wherein image data representing half-tone dots in one color is generated by: creating separate plate image data in one color separated by color separation of the original image data; generating reverse image data by reversing the shading of one color in the generated individual plate image data; And dotting the created reverse image data into a negative state such that for each of the pixels, the lower the density of one color, the higher the area ratio of said one color, and wherein image data representing halftone dots of a different color is generated by generating halftone dots of individual plate image data separated by color separation of the original image data. 5. The printing plate manufacturing method according to one of claims 1 to 4, wherein the printing material for the printing plate is a two-piece assembly can or a metal plate. 6. A plate making system (1) configured to make printing plates based on image data separated into each of the colors and representing halftone dots, the plate making system comprising: manufacturing a printing plate based on a reverse printing method in which reverse images of halftone dots in one color are formed, and printing is performed by overlaying halftone dots of a different color on the positions of the reversed images; for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, forming a gap from the reverse image in one color around the dot of the other color; And for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is greater than 100%, forming a cover mask so that the dot of the other color penetrates the periphery of the dot of the same color. 7. The body of the can, on which an image is printed, divided into each of the colors and representing the halftone dots, in which: an image is formed based on a reverse printing method in which reverse images of halftone dots in one color are formed, and printing is performed by overlaying halftone dots of a different color on the positions of the reversed images; for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is less than 100%, a gap is formed from the reversed image in one color around the dot of the other color; And for each of the pixels, when the sum of the dot area ratio of one color and the dot area ratio of the other color is greater than 100%, a cover mask is formed so that the dot of the other color penetrates into the periphery of the dot of the same color. 8. A printing plate manufacturing method for manufacturing printing plates capable of representing the colors of overprinted screen dots in three colors from a plurality of secondary colors, the printing plate manufacturing method comprising: two-color superposition printing out of three colors by a reverse printing method in which reverse dot images in one color are formed, and dot dot printing of a different color is printed on the positions of the reverse images; And printing by overlaying the remaining color of three colors on two colors by an overlay printing method in which at least a portion of the halftone dots in the remaining color are superimposed on halftone dots in one color and/or halftone dots in another color, wherein: one color belongs to the first color group, composed of colors having color components that do not overlap with each other; And the other color belongs to a second color group composed of colors having color components that do not overlap with each other, and the colors belonging to the second group are different from the colors belonging to the first group. 9. The method of manufacturing printing plates according to claim 9, in which: the numerous secondary colors are the seven colors cyan, magenta, yellow, red, green, indigo, and black; the first color group is cyan, magenta and yellow; the second color group is composed of red, green and blue; And the rest of the color is black. 10. A method for making printing plates according to one of claims 8 and 9, wherein the dots in the rest of the color are placed at a dot angle different from the dots in the two colors. 11. A printing plate manufacturing method for manufacturing printing plates capable of representing the colors of overprinted screen dots in three colors from a plurality of secondary colors, the printing plate manufacturing method comprising: two-color superposition printing out of three colors by a reverse printing method in which reverse dot images in one color are formed, and dot dot printing of a different color is printed on the positions of the reverse images; And printing by overlaying the remaining color of the three colors on two colors by an overlay printing method in which at least a portion of the halftone dots in the remaining color are superimposed on halftone dots in one color and/or halftone dots in another color, while the halftone dots in the rest of the color are placed at a halftone angle different from the halftone angles of the halftone dots in the two colors. 12. The printing plate manufacturing method according to one of claims 8 to 11, wherein the printing plate material is a two-piece assembly can or a metal plate. 13. A printing plate manufacturing method for manufacturing printing plates capable of representing the colors of overprinted screen dots in three colors from a plurality of composite colors, the printing plate manufacturing method comprising: two-color superposition printing out of three colors by a reverse printing method in which reverse dot images in one color are formed, and dot dot printing of a different color is printed on the positions of the reverse images; And printing by overlaying the remaining color of the three colors on two colors by an overlay printing method in which at least a portion of the halftone dots in the remaining color are superimposed on halftone dots in one color and/or halftone dots in another color, wherein the printing material for the printing plates is a two-piece assembly can or a metal plate. 14. A plate making system (1) for making printing plates capable of representing colors by dot overprinting in three colors from a plurality of secondary colors, the plate making system comprising: two-color superposition printing out of three colors by a reverse printing method in which reverse dot images in one color are formed, and dot dot printing of a different color is printed on the positions of the reverse images; And printing by overlaying the remaining color of three colors on two colors by an overlay printing method in which at least a portion of the halftone dots in the remaining color are superimposed on halftone dots in one color and/or halftone dots in another color , wherein the printing material for the printing plates is a two-piece assembly can or a metal plate. 15. A can body printed to represent colors by dot overprint printing in three colors from a plurality of secondary colors, wherein: two colors out of the three colors are overprinted by a reverse printing method in which halftone dot images in one color are reversed and the halftone dot images in another color are overprinted on the positions of the reverse images; And performing printing by overlaying the remaining color of the three colors on the two colors by an overlay printing method in which at least a portion of the dots in the remaining color are superimposed on the dots in one color and/or the dots.

Images