Color block and printing system

Abstract

The color block is provided with a plurality of white parts (102) arranged in a color block area (101) formed by a specified color to be reproduced on the printed matter. The plurality of color portions (103) are arranged on a patch region (101) having the plurality of white portions (102). The white portions (102) are arranged between adjacent color portions (103) among the plurality of arranged color portions (103).

Description

Technical Field

[0001] The invention relates to a color block and a printing system. Background Art

[0002] Regarding color tone management in multi-color printing such as offset printing, there is an adjustment method that makes the printed color closer to the target color by measuring the solid area density to obtain the difference from the target density. In order to obtain the solid area density, a color bar (control bar) is provided on a part of the printed matter, and a solid color block (color block with a 100% area ratio of the color block to the halftone dot) is printed on the color bar.

[0003] Figure 7 A printed product printed by a printing press is shown. A band-shaped color strip 2-2 is printed in a blank portion outside a pattern area 2-1 on a printed product 2. For example, in the case of four-color printing of cyan (C), magenta (M), yellow (Y), and black (K), the color strip 2-2 is composed of regions S1-Sn, which include solid patches 2a1, 2a2, 2a3, and 2a4 prepared for measuring the solid area density of the four colors. The regions S1-Sn correspond to the number of ink fountain keys in the printing unit of each color in the printing press. The width of each region S1, S2, ..., Sn corresponds to the width of the ink fountain key. Therefore, the total width of the color strip is determined by the number and width of the ink fountain key.

[0004] Reference List

[0005] Patent Literature

[0006] Patent document 1: JP 5022682 B. Summary of the invention

[0007] Technical issues

[0008] For example, in color printing in offset printing (lithography), intermediate colors are reproduced by appropriately mixing dots of the four colors of CMYK. Therefore, in this type of color printing, when the size of the dots on the printed matter changes relative to the dots on the plate, the color seen by the human eye also changes. These changes in the dots on the printed matter are not reflected in the color patches and the colors do not change in the color patches, so the dot status cannot be checked in color management using color patches.

[0009] Therefore, conventionally, when the color tone changes due to the size change of the dots on the printed product as described above, the printing operator visually checks the color tone difference relative to the sample printed product and adjusts the density. This visual color adjustment depends on the skills of the operator, so the time and number of times required for adjustment and the number of wasted sheets of paper may increase more than necessary.

[0010] The present invention has been achieved to solve these problems and aims to allow color management using color patches even if the size of dots on a printed product has changed.

[0011] Means of solving the problem

[0012] The color patch according to the present invention is a color patch for color adjustment printed on a blank portion of a printed product printed by a printing press, and includes a non-colored portion in a patch area consisting of a designated color to be reproduced on the printed product.

[0013] A printing system according to the present invention includes: a printing press capable of printing on a supplied sheet; a measuring device configured to measure the color of a color block printed on a blank portion of a printed product printed by the printing press to obtain color adjustment data; and a controller configured to adjust the supply amount of ink of each color supplied to the printing press for printing the printed product based on the color adjustment data obtained by the measuring device, wherein the color block includes a non-colored portion in a color block area consisting of a specified color intended to be reproduced on the printed product.

[0014] Effects of the Invention

[0015] As described above, the non-colored portion is included in the color patch area according to the present invention, so color management can be performed using the color patch even if the size of dots on the printed product has changed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [ Figure 1 ] Figure 1 A configuration diagram illustrating the configuration of color patches according to an embodiment of the present invention is shown.

[0017] [ Figure 2 ] Figure 2 A configuration diagram illustrating another configuration of a color block according to an embodiment of the present invention is shown.

[0018] [ Figure 3 ] Figure 3 A configuration diagram illustrating the configuration of another color patch according to an embodiment of the present invention is shown.

[0019] [ Figure 4 ] Figure 4 A configuration diagram illustrating the configuration of another color patch according to an embodiment of the present invention is shown.

[0020] [ Figure 5 ] Figure 5 A configuration diagram illustrating the configuration of another color patch according to an embodiment of the present invention is shown.

[0021] [ Figure 6 ] Figure 6 A configuration diagram illustrating a configuration of a printing system according to an embodiment of the present invention is shown.

[0022] [ Figure 7 ] Figure 7 A plan view schematically illustrating a printed product printed by a printing press is shown. DETAILED DESCRIPTION

[0023] Now refer to Figure 1 A color patch according to an embodiment of the present invention is described. The color patch is a color patch for color adjustment, which is included in a plate for printing a printed matter and is printed on a blank portion of a printed matter printed by a printing press. The above-mentioned printing press is provided with a measuring device to measure the color of the color patch to obtain color adjustment data, and the data of the color patch is used to adjust the color to be reproduced on the printed matter based on the measurement result of the measuring device. The color patch constitutes a color bar provided on a planographic plate and printed by a planographic printing press for managing the color tone of a four-color ink printing press, and the colors are, for example, cyan, magenta, yellow, and black.

[0024] The color patch includes a white non-colored portion 102 in a color patch area 101 composed of a designated color to be reproduced on a printed product. In this example, a plurality of non-colored portions 102 are arranged in the color patch area 101. A plurality of color portions 103 are arranged in the color patch area 101 including the plurality of non-colored portions 102. Surrounded by the arranged plurality of color portions 103, the non-colored portions 102 are arranged between adjacent color portions 103. In this example, the plurality of non-colored portions 102 have a stripe pattern in a direction parallel to the conveying direction of the printed product, and are arranged in a direction perpendicular to the conveying direction.

[0025] For example, a color block may be provided for each of four designated colors, cyan, magenta, yellow, and black. For example, in a cyan color block, the color portion 103 is cyan. For example, in a magenta color block, the color portion 103 is magenta. For example, in a yellow color block, the color portion 103 is yellow. For example, in a black color block, the color portion 103 is black.

[0026] In addition to the above four colors, in multicolor printing in which the designated colors orange, green and violet are added, color patches can be provided for each of orange, green and violet in addition to cyan, magenta, yellow and black. It should be noted that it is not necessary for all color patches to have non-colored portions.

[0027] In addition, in the color block, such as Figure 2 As shown, the non-colored portion 102a may be in a lattice shape in the region 101a. In this example, there are a plurality of arranged non-colored portions 102a and a plurality of color portions 103a are arranged in the color block region 101a including the plurality of non-colored portions 102a. Each of the plurality of color portions 103a is arranged squarely in a rectangular shape (or square).

[0028] like Figure 3 As shown, each non-colored portion 102b may have a ring shape in the area 101b in the color block. In this example, there are multiple non-colored portions 102b and the multiple non-colored portions 102b are arranged in a ring shape and concentrically. There is a colored portion 103b between adjacent non-colored portions 102b. Also in this example, there are multiple color portions 103b in the area 101b.

[0029] like Figure 4 As shown, the non-colored portion 102c may have a spiral shape in the area 101c in the color block. In this example, one spiral non-colored portion 102c may be formed in a continuous integral form. The area sandwiched between the spiral non-colored portion 102c and the four corner areas outside the spiral non-colored portion 102c constitutes the colored portion 103c. In this example, there is a single integral color portion 103c in the area 101c.

[0030] In addition, if Figure 5 As shown, the non-colored portion 102d may have a meandering shape in the region 101d in the color block. The non-colored portion 102d having a meandering shape may be formed in a continuous integral form. The region outside the non-colored portion 102d having a meandering shape constitutes a color portion 103d. In this example, the region 101d includes a single integral color portion 103d.

[0031] Next, we will refer to Figure 6 A printing system according to an embodiment of the present invention is described. The printing system includes: a printer 151 capable of printing on a supplied sheet (e.g., paper); and a measuring device 152 for measuring the color of a color patch printed on a blank portion of a printed product printed by the printer 151 to obtain color adjustment data.

[0032] The printing system also includes a controller 153 that adjusts the ink supply amount of each color supplied to the printer 151 for printing a printed product based on the color adjustment data obtained by the measuring device 152. As described above, the color block includes a non-colored portion in a color block area consisting of a specified color intended to be reproduced on the printed product. For example, the color block may include a plurality of non-colored portions arranged in the color block area. For example, the controller 153 includes a normal printing result of the color block according to the above-mentioned embodiment as a reference by measuring the color with the measuring device 152. The controller 153 performs control by comparing the result obtained by the measuring device 152 in an actual printing operation with the stored reference (see Patent Document 1).

[0033] As described above, there are non-colored portions in patch areas composed of designated colors intended to be reproduced on printed products, and therefore, changes in dot size on printed products are reflected in the color portions, thereby allowing color management using patches.

[0034] Hereinafter, the difference between the case of using a solid color patch and the case of using a color patch including a plurality of non-colored portions 102 having a stripe pattern according to the embodiment is examined using the case of dot enlargement as an example.

[0035] When using a solid color patch, the density is adjusted to a reference value (the same as the sample print) by measuring the solid color patch. The ink density is the same as the sample, and the color should be the same in theory in the print. However, when checking the pattern on the print, the color tone may be different due to other factors. For example, when the dots on the print become larger, the colored area increases. In addition, when the dots on the print appear larger, the color density on the pattern appears higher to the human eye.

[0036] As described above, even if the dots on the printed product are enlarged, the state of the dots in the solid color patch cannot be confirmed (measured), so it is unclear to what extent the density should be reduced using the measurement results. Therefore, the operator adjusts the color tone (such as reducing the density) while checking the color of the sample pattern.

[0037] In addition, in the case of using color patches including multiple stripe-shaped non-colored parts (stripe patches), when the dots on the printed matter become larger, this is also reflected on the color patches so that the dots in the color parts become larger, and thus the area of ​​the multiple non-colored parts decreases. This is also reflected in the color patch measurement results.

[0038] For example, in the test printing, the L of the stripe color block on the printed product is measured by the measuring device. a b When the dot size increases, the area of ​​the non-colored part of the stripe color block decreases, and the area of ​​the colored part increases relatively, so the L value in the measurement result a b The color difference can be obtained using the measurement result, so the obtained value can be fed back and the color tone adjustment (density reduction) can be automatically performed. It should be noted that L a b The value is related to the commonly used colorimetric system, in which "L " indicates brightness, "a b " indicates chromaticity. "a " indicates the red direction, "-a " indicates the green direction, "b " indicates the yellow direction, "-b " indicates the blue direction. In addition, the color difference is the difference between colors, which is L a b The distance value between the reference color and the point where the color is measured in the color space.

[0039] As a result of the actual test printing, the best evaluation result was obtained when the color tone was automatically adjusted using a stripe patch with a color portion area ratio of 85%. In this test printing, the plan view shape of the color patch was 4.375 mm wide and 3.5 mm high. In this case, it is considered that more accurate color management can be performed by adjusting the color tone using a stripe patch with a color portion area ratio of 85%.

[0040] For example, in a rotary printing press, the ink contained in the ink fountain is supplied to the ink fountain roller via a plurality of ink fountain keys, and the ink supplied to the ink fountain roller is supplied to the printing plate via a group of ink rollers. Figure 7 The width of each area of ​​the color bar shown is determined by the width of the ink fountain key, so when a printing press with a 35 mm wide ink fountain key is used, the width of one color bar area is 35 mm. Therefore, the width of the above-mentioned color block has a value obtained by dividing one color bar area (35 mm) by eight color blocks (the sum of seven color blocks and one color block without color). In addition, the height of the above-mentioned color block can be a value determined by the performance of the color tone management mechanism composed of the measuring device 152 and the controller 153, for example, it can be a value between 3.0 and 5.0 mm.

[0041] Furthermore, it has been found that the use of color patches including non-colored portions having stripes parallel to the direction of transport of the printed product makes it less susceptible to print obstructions such as double feeds and unclean prints that occur during printing.

[0042] As described above, since the non-colored portion is included in the color patch area according to the present invention, color management can be performed using the color patch even if the dot size on the printed matter varies.

[0043] It should be noted that the present invention is not limited to the above-mentioned embodiments, and it is obvious that within the technical concept of the present invention, those skilled in the art can realize many variations and combinations. For example, although lithography is used as an example above, the present invention is not limited thereto and can be similarly applied to other color printing.

[0044] Label list

[0045] 101…area, 102…non-colored portion, 103…colored portion, 151…printing machine, 152…measuring device, 153…controller, 2…printed matter, 2-1…pattern area, 2-2…color stripe, 2a1-2a4…solid color blocks, S1-Sn…color stripe area.

Claims

1. A color patch for color adjustment printed on a blank portion of a printed product printed by a printing press, the color patch including a non-colored portion in a color patch area consisting of a designated color intended to be reproduced on the printed product.

2. The color block according to claim 1, comprising a plurality of non-colored portions arranged in a color block area.

3. The color block according to claim 1 or 2, wherein The printing press is provided with a measuring device configured to measure the color of the color patch to obtain color adjustment data, and The color adjustment data of the color patch is used to adjust the color to be reproduced on the printed product based on the measurement result of the measuring device.

4. A printing system comprising: a printing press capable of printing on supplied sheets; a measuring device configured to measure the color of a color patch printed on a blank portion of a printed product printed by a printing press to obtain color adjustment data; as well as A controller configured to adjust a supply amount of each color of ink supplied to a printing press for printing a printed product based on the color adjustment data obtained by the measuring device, wherein The color patch includes a non-colored portion in a color patch area composed of a designated color intended to be reproduced on a printed product.

5. The printing system according to claim 4, wherein The color block includes a plurality of non-colored portions arranged in the color block area.

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